WO2022019200A1 - Transparent display device and manufacturing method therefor - Google Patents

Transparent display device and manufacturing method therefor Download PDF

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Publication number
WO2022019200A1
WO2022019200A1 PCT/JP2021/026551 JP2021026551W WO2022019200A1 WO 2022019200 A1 WO2022019200 A1 WO 2022019200A1 JP 2021026551 W JP2021026551 W JP 2021026551W WO 2022019200 A1 WO2022019200 A1 WO 2022019200A1
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WO
WIPO (PCT)
Prior art keywords
semiconductor element
display device
elastomer stamp
wafer
transparent display
Prior art date
Application number
PCT/JP2021/026551
Other languages
French (fr)
Japanese (ja)
Inventor
諒 江口
将英 古賀
幸宏 垰
Original Assignee
Ａｇｃ株式会社
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Filing date
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Publication of WO2022019200A1 publication Critical patent/WO2022019200A1/en

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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G09F9/33—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being semiconductor devices, e.g. diodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
    • H01L21/52—Mounting semiconductor bodies in containers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages

Definitions

  • the present invention relates to a transparent display device and a method for manufacturing the same.
  • Patent Document 1 discloses, among such display devices, a transparent display device in which the size of the LED element is fine and the back side can be visually recognized via the display device.
  • a method of arranging a semiconductor element such as an LED element on a transparent substrate by using a micro transfer printing technique is known. Specifically, after the elastomer stamp is pressed against the LED element patterned on the wafer, the LED element attached to the elastomer stamp is pulled up and pulled away from the wafer. Then, after the LED element is conveyed while being attached to the elastomer stamp, it is pressed against the transparent substrate to transfer the LED element onto the transparent substrate.
  • Patent Documents 2 and 3 disclose a micro transfer printing technique.
  • the inventors have found the following problems with respect to a method for manufacturing such a transparent display device.
  • the elastomer stamp When the elastomer stamp is pressed against the LED element, the inventors have aligned the center of the portion of the elastomer stamp that protrudes most toward the LED element and the center of the portion of the LED element that protrudes most toward the elastomer stamp. .. Then, after the elastomer stamp was pressed against the LED element, the LED element attached to the elastomer stamp was simply pulled up in a direction perpendicular to the substrate surface of the wafer.
  • the present invention has been made in view of such circumstances, and provides a method for manufacturing a transparent display device having excellent productivity.
  • the present invention provides a method for manufacturing a transparent display device having the following configuration [1].
  • [1] It is a manufacturing method of a transparent display device. After the elastomer stamp is pressed against the semiconductor element having an area of 100,000 ⁇ m 2 or less patterned on the wafer, the semiconductor element attached to the elastomer stamp is pulled up and pulled away from the wafer. Including that the semiconductor element is conveyed while being attached to the elastomer stamp, and then the semiconductor element is pressed against a transparent substrate and arranged.
  • the present invention provides a method for manufacturing a transparent display device having the following configuration [3].
  • [3] It is a manufacturing method of a transparent display device. After the elastomer stamp is pressed against the semiconductor element having an area of 100,000 ⁇ m 2 or less patterned on the wafer, the semiconductor element attached to the elastomer stamp is pulled up and pulled away from the wafer. After transporting the semiconductor element while being attached to the elastoma stamp, the semiconductor element is pressed against a transparent substrate and arranged, and after the elastoma stamp is pressed against the semiconductor element, the semiconductor element is pressed. Before pulling away from the wafer At least one of the semiconductor element and the elastomer stamp in contact with each other is moved in a first direction parallel to the substrate surface of the wafer. Manufacturing method of transparent display device.
  • the semiconductor element formed on the wafer includes a rectangular region having a rectangular shape in a plan view, and the semiconductor element is fixed to the wafer via a fixing portion formed on one side of the rectangular region.
  • the present invention provides a method for manufacturing a transparent display device having the following configuration [14].
  • a transparent base material A semiconductor device, each of which is arranged on the transparent substrate for each pixel and has an area of 10,000 ⁇ m 2 or less, is provided.
  • the semiconductor element is A rectangular semiconductor layer in plan view and A protrusion extending from one side of the semiconductor layer toward the outside of the semiconductor element in a plan view is provided. The end portion of the protruding portion is formed so as to be inclined obliquely with respect to one side of the semiconductor layer in a plan view.
  • Transparent display device is
  • FIG. 3 is a cross-sectional view taken along the line II-II in FIG. It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment.
  • the "transparent display device” refers to a display device that can visually recognize visual information such as a person and a background located on the back side of the display device under a desired usage environment. It should be noted that “visible” is determined at least in a non-display state, that is, a state in which the display device is not energized.
  • transparent means that the transmittance of visible light is 40% or more, preferably 60% or more, and more preferably 70% or more. It may also indicate that the transmittance is 5% or more and the haze value is 10 or less. When the transmittance is 5% or more, when the outside is viewed from the room during the daytime, the outside can be seen with the same or higher brightness as the room, and sufficient visibility can be ensured.
  • the transmittance when the transmittance is 40% or more, the back side of the transparent display device can be visually recognized without any problem even if the brightness of the front side and the back side of the transparent display device is about the same. Further, when the haze value is 10 or less, sufficient background contrast can be secured.
  • transparent means whether or not a color is applied, that is, it may be colorless and transparent, or it may be colored and transparent.
  • the transmittance refers to a value (%) measured by a method conforming to ISO9050.
  • the haze value refers to a value measured by a method conforming to ISO 14782.
  • FIG. 1 is a schematic partial plan view showing an example of a transparent display device according to the first embodiment.
  • FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
  • the right-handed xyz orthogonal coordinates shown in FIGS. 1 and 2 are for convenience in explaining the positional relationship of the components. Normally, the z-axis positive direction is vertically upward, and the xy plane is a horizontal plane.
  • the transparent display device includes a transparent base material 10, a light emitting unit 20, an IC chip 30, wiring 40, and a protective layer 50.
  • the display area 101 in the transparent display device is an area composed of a plurality of pixels and in which an image is displayed.
  • the image includes characters.
  • the display area 101 is composed of a plurality of pixels arranged in the row direction (x-axis direction) and the column direction (y-axis direction).
  • FIG. 1 shows a part of the display area 101, and shows a total of 4 pixels, 2 pixels each in the row direction and the column direction.
  • one pixel PIX is shown surrounded by an alternate long and short dash line.
  • the transparent base material 10 and the protective layer 50 shown in FIG. 2 are omitted.
  • FIG. 1 is a plan view, the light emitting unit 20 and the IC chip 30 are displayed in dots for easy understanding.
  • each pixel PIX includes a light emitting unit 20 and an IC chip 30.
  • the light emitting unit 20 and the IC chip 30 are arranged in a matrix with a pixel pitch Px in the row direction (x-axis direction) and a pixel pitch Py in the column direction (y-axis direction). If the pixels are arranged in a predetermined direction at a predetermined pixel pitch, the arrangement format of the pixels PIX, that is, the light emitting unit 20 is not limited to the matrix shape.
  • the light emitting unit 20 in each pixel PIX includes at least one light emitting diode element (hereinafter, LED element). That is, the transparent display device according to the present embodiment is a display device that uses an LED element for each pixel PIX, and is called an LED display or the like.
  • LED element light emitting diode element
  • each light emitting unit 20 includes a red LED element 21, a green LED element 22, and a blue LED element 23.
  • the LED elements 21 to 23 correspond to sub-pixels (sub-pixels) constituting one pixel.
  • each light emitting unit 20 has LED elements 21 to 23 that emit red, green, and blue, which are the three primary colors of light, the transparent display device according to the present embodiment can display a full-color image.
  • each light emitting unit 20 may include two or more LED elements of similar colors. This makes it possible to expand the dynamics range of the image.
  • the LED elements 21 to 23 have a minute size and are so-called micro LED elements. Specifically, the width (length in the x-axis direction) and the length (length in the y-axis direction) of the LED element 21 on the transparent substrate 10 are, for example, 100 ⁇ m or less, preferably 50 ⁇ m or less, more preferably 50 ⁇ m or less, respectively. It is 20 ⁇ m or less. The same applies to the LED elements 22 and 23. The lower limit of the width and length of the LED element is, for example, 3 ⁇ m or more due to various manufacturing conditions and the like. Although the dimensions, that is, the width and the length of the LED elements 21 to 23 in FIG. 1 are the same, they may be different from each other.
  • the area occupied by each of the LED elements 21 to 23 on the transparent substrate 10 is, for example, 10,000 ⁇ m 2 or less, preferably 3,000 ⁇ m 2 or less, and more preferably 500 ⁇ m 2 or less.
  • the lower limit of the area occupied by one LED element is, for example, 10 ⁇ m 2 or more due to various manufacturing conditions and the like.
  • the area occupied by the constituent members such as the LED element and the wiring refers to the area in the xy plan view in FIG.
  • the shape of the LED elements 21 to 23 shown in FIG. 1 is rectangular (including a square), but is not particularly limited.
  • the LED elements 21 to 23 have, for example, a mirror structure for efficiently extracting light to the visual recognition side. Therefore, the transmittance of the LED elements 21 to 23 is as low as, for example, about 10% or less.
  • the LED elements 21 to 23 having a minute size having an area of 10,000 ⁇ m 2 or less are used. Therefore, for example, even when observing the transparent display device from a short distance of about several tens of centimeters to 2 m, the LED elements 21 to 23 are almost invisible.
  • the area where the transmittance is low is narrow in the display area 101, and the visibility on the back side is excellent.
  • the degree of freedom in arranging the wiring 40 and the like is large.
  • the “region having a low transmittance in the display region 101” is, for example, a region having a transmittance of 20% or less. The same applies hereinafter.
  • the transparent display device according to the present embodiment can be used by being attached to a curved transparent plate such as a window glass for an automobile, or by being enclosed between two curved transparent plates.
  • the transparent display device according to the present embodiment can be curved.
  • the LED elements 21 to 23 are not particularly limited, but are, for example, inorganic materials.
  • the red LED element 21 is, for example, AlGaAs, GaAsP, GaP, or the like.
  • the green LED element 22 is, for example, InGaN, GaN, AlGaN, GaP, AlGaInP, ZnSe, or the like.
  • the blue LED element 23 is, for example, InGaN, GaN, AlGaN, ZnSe, or the like.
  • the luminous efficiency that is, the energy conversion efficiency of the LED elements 21 to 23 is, for example, 1% or more, preferably 5% or more, and more preferably 15% or more.
  • the luminous efficiency of the LED elements 21 to 23 is 1% or more, sufficient brightness can be obtained even with the small size LED elements 21 to 23 as described above, and the LED elements 21 to 23 can be used as a display device during the daytime. Further, when the luminous efficiency of the LED element is 15% or more, heat generation is suppressed, and encapsulation inside the laminated glass using the resin adhesive layer becomes easy.
  • the pixel pitches Px and Py are, for example, 100 to 3000 ⁇ m, preferably 180 to 1000 ⁇ m, and more preferably 250 to 400 ⁇ m, respectively.
  • the pixel pitches Px and Py are, for example, 100 to 3000 ⁇ m, preferably 180 to 1000 ⁇ m, and more preferably 250 to 400 ⁇ m, respectively.
  • the pixel pitches Px and Py are, for example, 100 to 3000 ⁇ m, preferably 180 to 1000 ⁇ m, and more preferably 250 to 400 ⁇ m, respectively.
  • the pixel pitches Px and Py are, for example, 100 to 3000 ⁇ m, preferably 180 to 1000 ⁇ m, and more preferably 250 to 400 ⁇ m, respectively.
  • the area of one pixel PIX is Px ⁇ Py.
  • the area of one pixel is, for example, 1 ⁇ 10 4 ⁇ m 2 to 9 ⁇ 10 6 ⁇ m 2 , preferably 3 ⁇ 10 4 to 1 ⁇ 10 6 ⁇ m 2 , and more preferably 6 ⁇ 10 4 to 2 ⁇ 10 5 ⁇ m 2 . be.
  • the area of one pixel may be appropriately selected depending on the size of the display area 101, the application, the viewing distance, and the like.
  • the ratio of the area occupied by the LED elements 21 to 23 to the area of one pixel is, for example, 30% or less, preferably 10% or less, more preferably 5% or less, and further preferably 1% or less.
  • three LED elements 21 to 23 are arranged in a row in the positive direction of the x-axis in this order in each pixel, but the present invention is not limited to this.
  • the arrangement order of the three LED elements 21 to 23 may be changed.
  • the three LED elements 21 to 23 may be arranged in the y-axis direction.
  • the three LED elements 21 to 23 may be arranged at the vertices of the triangle.
  • each light emitting unit 20 includes a plurality of LED elements 21 to 23
  • the distance between the LED elements 21 to 23 in the light emitting unit 20 is, for example, 100 ⁇ m or less, preferably 10 ⁇ m or less. be.
  • the LED elements 21 to 23 may be arranged so as to be in contact with each other. This makes it easier to standardize the first power supply branch line 41a and improve the aperture ratio.
  • each light emitting unit 20 includes three LED elements that emit light having different wavelengths, in some light emitting units 20, the LED elements are arranged side by side in the x-axis direction or the y-axis direction, and in the other light emitting unit 20, the LED elements are arranged side by side. , LED elements of each color may be arranged at the apex of the triangle.
  • the IC chip 30 is arranged for each pixel PIX and drives the light emitting unit 20. Specifically, the IC chip 30 is connected to each of the LED elements 21 to 23 via a drive line 45, and the LED elements 21 to 23 can be individually driven.
  • the IC chip 30 is, for example, a hybrid IC including an analog region and a logic region.
  • the analog region includes, for example, a current control circuit, a transformer circuit, and the like.
  • the IC chip 30 may be arranged for each of a plurality of pixels, and a plurality of pixels to which each IC chip 30 is connected may be driven. For example, if one IC chip 30 is arranged for every four pixels, the number of IC chips 30 can be reduced to 1/4 of the example of FIG. 1, and the area occupied by the IC chip 30 can be reduced. Moreover, the IC chip 30 is not indispensable.
  • Area of the IC chip 30 is, for example 100,000Myuemu 2 or less, preferably 10,000 2 or less, more preferably 5,000 .mu.m 2 or less.
  • the transmittance of the IC chip 30 is as low as about 20% or less, but by using the IC chip 30 of the above size, the region of the display region 101 where the transmittance is low is narrowed, and the visibility on the back surface side is improved.
  • the wiring 40 includes a power supply line 41, a ground line 42, a row data line 43, a column data line 44, and a plurality of drive lines 45.
  • the power supply line 41, the ground line 42, and the column data line 44 extend in the y-axis direction.
  • the row data line 43 extends in the x-axis direction.
  • the power supply line 41 and the column data line 44 are provided on the x-axis negative direction side of the light emitting unit 20 and the IC chip 30, and the ground line 42 is provided from the light emitting unit 20 and the IC chip 30. Is also provided on the positive side of the x-axis.
  • the power supply line 41 is provided on the side in the negative direction of the x-axis with respect to the column data line 44.
  • the row data line 43 is provided on the y-axis negative direction side with respect to the light emitting unit 20 and the IC chip 30.
  • the power supply line 41 includes a first power supply branch line 41a and a second power supply branch line 41b.
  • the ground line 42 includes a ground branch line 42a.
  • the row data line 43 includes a row data branch line 43a.
  • the column data line 44 includes a column data branch line 44a. Each of these branch lines is included in the wiring 40.
  • each power supply line 41 extending in the y-axis direction is connected to a light emitting unit 20 and an IC chip 30 of each pixel PIX arranged side by side in the y-axis direction. More specifically, in each pixel PIX, the LED elements 21 to 23 are arranged side by side in the x-axis positive direction in this order on the x-axis positive direction side of the power line 41. Therefore, the first power supply branch line 41a branched from the power supply line 41 in the positive direction of the x-axis is connected to the end of the LED elements 21 to 23 in the positive direction of the y-axis.
  • the IC chip 30 is arranged on the y-axis negative direction side of the LED elements 21 to 23. Therefore, between the LED element 21 and the column data line 44, the second power supply branch line 41b branched in the y-axis negative direction from the first power supply branch line 41a is extended in a straight line, and the y-axis of the IC chip 30 is extended. It is connected to the negative side of the x-axis of the end on the positive side.
  • each ground wire 42 extending in the y-axis direction is connected to an IC chip 30 of each pixel PIX arranged side by side in the y-axis direction.
  • the ground branch line 42a branched from the ground line 42 in the negative direction on the x-axis is linearly extended and connected to the end on the positive side of the x-axis of the IC chip 30.
  • the ground line 42 is connected to the LED elements 21 to 23 via the ground branch line 42a, the IC chip 30, and the drive line 45.
  • each row data line 43 extending in the x-axis direction is connected to an IC chip 30 of each pixel PIX arranged side by side in the x-axis direction (row direction).
  • the row data branch line 43a branched from the row data line 43 in the positive direction of the y-axis is linearly extended and connected to the end of the IC chip 30 in the negative direction of the y-axis.
  • the row data line 43 is connected to the LED elements 21 to 23 via the row data branch line 43a, the IC chip 30, and the drive line 45.
  • each column data line 44 extending in the y-axis direction is connected to an IC chip 30 of each pixel PIX arranged side by side in the y-axis direction (column direction).
  • the column data branch line 44a branched from the column data line 44 in the positive direction on the x-axis is linearly extended and connected to the end on the negative side of the x-axis of the IC chip 30.
  • the column data line 44 is connected to the LED elements 21 to 23 via the column data branch line 44a, the IC chip 30, and the drive line 45.
  • the drive line 45 connects the LED elements 21 to 23 and the IC chip 30 in each pixel PIX. Specifically, in each pixel PIX, three drive lines 45 are extended in the y-axis direction, and each of them is the y-axis negative side end of the LED elements 21 to 23 and the y-axis positive side of the IC chip 30. It is connected to the end.
  • the arrangement of the power supply line 41, the ground line 42, the row data line 43, the column data line 44, their branch lines, and the drive line 45 shown in FIG. 1 is merely an example and can be changed as appropriate.
  • at least one of the power line 41 and the ground line 42 may extend in the x-axis direction instead of the y-axis direction.
  • the power line 41 and the column data line 44 may be interchanged.
  • the entire configuration shown in FIG. 1 may be upside down, left-right inverted, or the like. Further, the row data line 43, the column data line 44, their branch lines, and the drive line 45 are not essential.
  • the wiring 40 is a metal such as copper (Cu), aluminum (Al), silver (Ag), and gold (Au). Of these, a metal containing copper or aluminum as a main component is preferable from the viewpoint of low resistivity and cost. Further, the wiring 40 may be covered with a material such as titanium (Ti), molybdenum (Mo), copper oxide, carbon, etc. for the purpose of reducing the reflectance. Further, the surface of the coated material may have irregularities.
  • the width of the wiring 40 in the display area 101 shown in FIG. 1 is, for example, 1 to 100 ⁇ m, preferably 3 to 20 ⁇ m. Since the width of the wiring 40 is 100 ⁇ m or less, the wiring 40 is almost invisible even when observing the transparent display device from a short distance of about several tens of centimeters to 2 m, and the visibility on the back side is excellent. .. On the other hand, in the case of the thickness range described later, if the width of the wiring 40 is 1 ⁇ m or more, it is possible to suppress an excessive increase in the resistance of the wiring 40, and suppress a voltage drop and a decrease in signal strength. In addition, it is possible to suppress a decrease in heat conduction due to the wiring 40.
  • the wiring 40 when the wiring 40 extends mainly in the x-axis direction and the y-axis direction, a cross extending in the x-axis direction and the y-axis direction by the light emitted from the outside of the transparent display device. A diffraction image may be generated and the visibility on the back side of the transparent display device may be reduced. By reducing the width of each wiring, this diffraction can be suppressed and the visibility on the back side can be further improved. From the viewpoint of suppressing diffraction, the width of the wiring 40 may be 50 ⁇ m or less, preferably 10 ⁇ m or less, and more preferably 5 ⁇ m or less.
  • the electrical resistivity of the wiring 40 is, for example, 1.0 ⁇ 10 -6 ⁇ m or less, preferably 2.0 ⁇ 10 -8 ⁇ m or less.
  • the thermal conductivity of the wiring 40 is, for example, 150 to 5,500 W / (m ⁇ K), preferably 350 to 450 W / (m ⁇ K).
  • the distance between adjacent wirings 40 in the display area 101 shown in FIG. 1 is, for example, 3 to 100 ⁇ m, preferably 5 to 30 ⁇ m. If there is an area where the wiring 40 is dense, the visibility on the back side may be hindered. By setting the distance between adjacent wirings 40 to 3 ⁇ m or more, such obstruction of visual recognition can be suppressed. On the other hand, by setting the distance between adjacent wirings 40 to 100 ⁇ m or less, sufficient display capability can be ensured. When the distance between the wirings 40 is not constant due to the curved wiring or the like, the above-mentioned distance between the adjacent wirings 40 indicates the minimum value.
  • the ratio of the area occupied by the wiring 40 to the area of one pixel is, for example, 30% or less, preferably 10% or less, more preferably 5% or less, still more preferably 3% or less.
  • the transmittance of the wiring 40 is as low as 20% or less, or 10% or less, for example.
  • the total area occupied by the light emitting unit 20, the IC chip 30, and the wiring 40 with respect to the area of one pixel is, for example, 30% or less, preferably 20% or less, and more preferably 10% or less.
  • the transparent base material 10 is a transparent material having an insulating property.
  • the transparent base material 10 has a two-layer structure of the main substrate 11 and the adhesive layer 12.
  • the main substrate 11 is, for example, a transparent resin, as will be described in detail later.
  • the adhesive layer 12 is, for example, an epoxy-based, acrylic-based, olefin-based, polyimide-based, or novolak-based transparent resin adhesive.
  • the main substrate 11 may be a thin glass plate having a thickness of, for example, 200 ⁇ m or less, preferably 100 ⁇ m or less. Further, the adhesive layer 12 is not essential.
  • polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN)
  • olefin resins such as cycloolefin polymer (COP) and cycloolefin copolymer (COC)
  • cellulose and acetyl Cellulose cellulose-based resin such as triacetyl cellulose (TAC), imide-based resin such as polyimide (PI), amide-based resin such as polyamide (PA), amide-based resin such as polyamideimide (PAI), polycarbonate (PC), etc.
  • Carbonate-based resin sulfone-based resin such as polyether sulfone (PES), paraxylene-based resin such as polyparaxylene, polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAc). ), Vinyl resin such as polyvinyl alcohol (PVA) and polyvinyl butyral (PVB), acrylic resin such as polymethyl methacrylate (PMMA), ethylene / vinyl acetate copolymer resin (EVA), thermoplastic polyurethane (TPU), etc. Examples thereof include urethane-based resins and epoxy-based resins.
  • PES polyether sulfone
  • paraxylene-based resin such as polyparaxylene
  • PE polyethylene
  • PVC polyvinyl chloride
  • PS polystyrene
  • PVAc polyvinyl acetate
  • Vinyl resin such as polyvinyl alcohol (PVA) and polyvinyl butyral (PVB
  • polyethylene naphthalate (PEN) and polyimide (PI) are preferable from the viewpoint of improving heat resistance.
  • cycloolefin polymer (COP), cycloolefin copolymer (COC), polyvinyl butyral (PVB) and the like are preferable in that the double refractive index is low and distortion and bleeding of the image seen through the transparent substrate can be reduced.
  • the above materials may be used alone, or two or more kinds of materials may be mixed and used.
  • the main substrate 11 may be formed by laminating flat plates made of different materials.
  • the total thickness of the transparent substrate 10 is, for example, 3 to 1000 ⁇ m, preferably 5 to 200 ⁇ m.
  • the internal transmittance of visible light of the transparent substrate 10 is, for example, 50% or more, preferably 70% or more, and more preferably 90% or more.
  • the transparent base material 10 may have flexibility. Thereby, for example, the transparent display device can be attached to a curved transparent plate, or can be used by being sandwiched between two curved transparent plates. Further, it may be a material that shrinks when heated to 100 ° C. or higher.
  • the LED elements 21 to 23 and the IC chip 30 are provided on the transparent base material 10, that is, the adhesive layer 12, and are connected to the wiring 40 arranged on the transparent base material 10. .
  • the wiring 40 is composed of a first metal layer M1 formed on the main substrate 11 and a second metal layer M2 formed on the adhesive layer 12.
  • the total thickness of the wiring 40 that is, the thickness of the first metal layer M1 and the thickness of the second metal layer M2 is, for example, 0.1 to 10 ⁇ m, preferably 0.5 to 5 ⁇ m.
  • the thickness of the first metal layer M1 is, for example, about 0.5 ⁇ m
  • the thickness of the second metal layer M2 is, for example, about 3 ⁇ m.
  • the ground wire 42 extending in the y-axis direction since the ground wire 42 extending in the y-axis direction has a large amount of current, it has a two-layer structure including the first metal layer M1 and the second metal layer M2. There is. That is, at the portion where the ground wire 42 is provided, the adhesive layer 12 is removed, and the second metal layer M2 is formed on the first metal layer M1.
  • the power line 41, the row data line 43, and the column data line 44 shown in FIG. 1 also have a two-layer structure including the first metal layer M1 and the second metal layer M2. have.
  • the power supply line 41, the ground line 42, and the column data line 44 extending in the y-axis direction intersect with the row data line 43 extending in the x-axis direction.
  • the row data line 43 is composed of only the first metal layer M1
  • the power line 41, the ground line 42, and the column data line 44 are composed of only the second metal layer M2. It is composed of.
  • an adhesive layer 12 is provided between the first metal layer M1 and the second metal layer M2, and the first metal layer M1 and the second metal layer M2 are insulated from each other.
  • the first power supply branch line 41a is composed of only the first metal layer M1
  • the column data line 44 is the second metal. It is composed of only the layer M2.
  • the ground branch line 42a, the drive line 45, and the first power supply branch line 41a are composed of only the second metal layer M2 and cover the end portions of the LED elements 21 to 23 and the IC chip 30. Is formed in.
  • the second power supply branch line 41b, the row data branch line 43a, and the column data branch line 44a are similarly composed of only the second metal layer M2.
  • the first power supply branch line 41a is composed of only the first metal layer M1 at the intersection with the column data line 44, and is composed of only the second metal layer M2 at other portions. Further, even if a metal pad made of copper, silver, gold or the like is arranged on the wiring 40 formed on the transparent base material 10, and at least one of the LED elements 21 to 23 and the IC chip 30 is arranged on the metal pad. good.
  • the protective layer 50 is a transparent resin formed on substantially the entire surface of the transparent base material 10 so as to cover and protect the light emitting portion 20, the IC chip 30, and the wiring 40.
  • the thickness of the protective layer 50 is, for example, 3 to 1000 ⁇ m, preferably 5 to 200 ⁇ m.
  • the elastic modulus of the protective layer 50 is, for example, 10 GPa or less. When the elastic modulus is low, the impact at the time of peeling can be absorbed and the damage of the protective layer 50 can be suppressed.
  • the internal transmittance of visible light of the protective layer 50 is, for example, 50% or more, preferably 70% or more, and more preferably 90% or more.
  • vinyl-based resins such as polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB) , Olefin resin such as cycloolefin polymer (COP), cycloolefin copolymer (COC), urethane resin such as thermoplastic polyurethane (TPU), polyester resin such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Examples thereof include acrylic resins such as polymethyl methacrylate (PMMA) and thermoplastic resins such as ethylene / vinyl acetate copolymer resin (EVA).
  • PE polyethylene
  • PVC polyvinyl chloride
  • PS polystyrene
  • PVAc polyvinyl acetate
  • PVA polyvinyl alcohol
  • PVB polyvinyl butyral
  • Olefin resin such as cycloole
  • FIGS. 2 to 10 are cross-sectional views showing an example of a method for manufacturing a transparent display device according to the first embodiment.
  • 3 to 10 are cross-sectional views corresponding to FIG. 2.
  • a first metal layer M1 is formed on substantially the entire surface of the main substrate 11, and then the first metal layer M1 is patterned by photolithography to form a lower layer wiring.
  • the lower layer wiring is formed by the first metal layer M1 at the position where the power supply line 41, the ground line 42, the row data line 43, the column data line 44, and the like shown in FIG. 1 are formed. No lower layer wiring is formed at the intersection of the power line 41, the ground line 42, and the column data line 44 with the row data line 43.
  • the LED element is placed on the tacky adhesive layer 12 (that is, on the transparent substrate 10). 21 to 23 and the IC chip 30 are mounted.
  • the LED elements 21 to 23 are patterned after growing crystals on the wafer by using, for example, a liquid phase growth method, an HVPE (Hydride Vapor Phase Epitaxy) method, a MOCVD (Metal Organic Chemical Vapor Deposition) method, or the like. Obtained by doing.
  • the LED elements 21 to 23 patterned on the wafer are transferred onto the transparent substrate 10 by using a micro transfer printing technique. Details of the micro transfer printing technique according to this embodiment will be described later.
  • the method of mounting the IC chip 30 on the transparent base material 10 is not particularly limited.
  • the IC chip 30 patterned on the Si wafer may be transferred onto the transparent substrate 10 by using the micro transfer printing technique according to the present embodiment in the same manner as the LED elements 21 to 23. That is, the micro transfer printing technique according to the present embodiment can be applied to semiconductor elements such as LED elements 21 to 23 and IC chips 30 patterned on a wafer.
  • the photoresist FR1 is formed on substantially the entire surface of the transparent substrate 10 including the main substrate 11 and the adhesive layer 12, and then the photoresist FR1 on the first metal layer M1 is patterned. Remove by.
  • the photoresist FR1 at the intersection of the power line 41, the ground line 42, and the column data line 44 in the row data line 43 shown in FIG. 1 is not removed.
  • the adhesive layer 12 at the portion where the photoresist FR1 has been removed is removed by dry etching to expose the first metal layer M1, that is, the lower layer wiring.
  • all the photoresist FR1 on the transparent substrate 10 is removed.
  • a seed layer for plating (not shown) is formed on substantially the entire surface of the transparent substrate 10.
  • the photoresist FR2 at the portion where the upper layer wiring is formed is removed by patterning to expose the seed layer.
  • a second metal layer M2 is formed by plating on the site where the photoresist FR2 has been removed, that is, the seed layer.
  • the upper layer wiring is formed by the second metal layer M2.
  • a transparent display device is obtained by forming the protective layer 50 on substantially the entire surface of the transparent substrate 10.
  • FIG. 11 is a plan view of the LED element 23 patterned on the wafer.
  • 12 to 14 are cross-sectional views showing an example of a micro transfer printing technique in the method for manufacturing a transparent display device according to the first embodiment.
  • FIG. 12 is a cross-sectional view taken along the line XII-XII of FIG.
  • FIGS. 11 to 14 are for convenience in explaining the positional relationship of the components. Normally, the z-axis positive direction is vertically upward, and the xy plane is a horizontal plane, which is common between drawings. Further, although the blue LED element 23 will be described below, the same applies to the red LED element 21 and the green LED element 22. Further, FIG. 11 shows a specific size of the LED element 23 in the embodiment described later.
  • each LED element 23 is fixed to the column via a fixing portion.
  • a plurality of LED elements 23 are regularly patterned on the wafer WF in the x-axis direction and the y-axis direction.
  • a plurality of LED elements 23 are arranged in a matrix on the wafer WF.
  • the wafer WF in the case of the blue LED element 23 and the green LED element 22, for example, a Si wafer, a sapphire wafer, or the like is used. In the case of the red LED element 21, a GaAs wafer or the like is used.
  • the LED element 23 includes a buffer layer BL, an N-type semiconductor layer NL, a P-type semiconductor layer PL, an insulating layer IL, a contact CT, an N electrode NE, and a P electrode PE. ..
  • a manufacturing method will be described together with the configuration of the LED element 23.
  • the buffer layer BL, the N-type semiconductor layer NL, and the P-type semiconductor layer PL are formed in this order on substantially the entire surface of the wafer WF.
  • the P-type semiconductor layer PL is patterned to form a mesa structure as shown in FIG.
  • the buffer layer BL and the N-type semiconductor layer NL are patterned into the shapes shown in FIGS. 11 and 12. At this time, as shown in FIG. 12, the buffer layer BL and the N-type semiconductor layer NL constituting the LED element 23 and the support column are left on the wafer WF. In other words, as shown in FIG. 12, the buffer layer BL and the N-type semiconductor layer NL between the LED element 23 and the support column are removed, and a groove is formed.
  • the insulating layer IL is formed so as to cover the surfaces of the N-type semiconductor layer NL and the P-type semiconductor layer PL.
  • the insulating layer IL is formed so as to cover the support column through the groove between the LED element 23 and the support column.
  • the insulating layer IL is not formed on the contact CT and on the region where the N electrode NE is formed in the N-type semiconductor layer NL.
  • the N electrode NE is formed on the N-type semiconductor layer NL
  • the P electrode PE is formed on the contact CT.
  • the P-type semiconductor layer PL is connected to the P electrode PE via the contact CT.
  • the wafer WF on the lower side of the LED element 23 (specifically, directly under the buffer layer BL in the LED element 23) is removed by anisotropic etching or the like.
  • the LED element 23 is formed so as to float from the substrate surface of the wafer WF.
  • the LED element 23 is fixed to the support column only through the fixing portion protruding in the positive direction of the y-axis.
  • the fixing portion according to the present embodiment is composed of an insulating layer IL.
  • the insulating layer IL is not particularly limited, but is composed of , for example, silicon nitride (Si 3 N 4).
  • the N-type semiconductor layer NL and the P-type semiconductor layer PL have a rectangular shape in a plan view.
  • the planar shape of the buffer layer BL not shown in FIG. 11 is the same as that of the N-type semiconductor layer NL.
  • the insulating layer IL covering the N-type semiconductor layer NL and the P-type semiconductor layer PL also has a rectangular shape in a plan view. That is, the LED element 23 formed on the wafer WF has a rectangular region having a rectangular shape in a plan view, and is fixed to the wafer WF only on one side of the rectangular region. In the example of FIG. 11, the LED element 23 is fixed to the support of the wafer WF via the fixing portion with only one short side of the N-type semiconductor layer NL (that is, the buffer layer BL) which is a rectangular region.
  • the LED element 23 may be fixed to the wafer WF in any way.
  • the LED element 23 may be fixed to the wafer WF with two or more sides of the N-type semiconductor layer NL (that is, the buffer layer BL) which is a rectangular region.
  • the LED element 23 may not be formed so as to float from the substrate surface of the wafer WF, but may be formed so that the bottom surface of the LED element 23 is in contact with the substrate surface of the wafer WF.
  • the width of the P-type semiconductor layer PL in the y-axis direction is smaller than the width of the N-type semiconductor layer NL in the y-axis direction, as shown in FIG.
  • the width of the P-type semiconductor layer PL in the x-axis direction is about the same as the width of the N-type semiconductor layer NL in the x-axis direction.
  • the P electrode PE has a rectangular shape in a plan view and is formed in the center of the P-type semiconductor layer PL.
  • the N electrode NE has a rectangular shape in a plan view, and is formed at the center of the N-type semiconductor layer NL on the negative side in the y-axis direction in the x-axis direction.
  • the elastomer stamp 80 for picking up the LED element 23 includes a flat plate-shaped substrate 81 and a protrusion 82 projecting from the main surface of the substrate 81 in the vertical direction (negative direction on the z-axis). ing.
  • the hatching of the elastomer stamp 80 is omitted for ease of understanding.
  • the protrusion 82 is provided for arranging the LED element 23 on each pixel in the transparent display device shown in FIG. Therefore, the distance between the protrusions 82 corresponds to the pixel pitches Px and Py shown in FIG.
  • the protrusion 82 may be a multi-step protrusion having two or more steps.
  • the elastomer stamp 80 may be supported on a hard substrate such as a glass substrate, a metal substrate, or a ceramic substrate in order to secure the overall rigidity. That is, the substrate may be provided on the main surface on the upper side (the z-axis positive direction side) of the elastomer stamp 80 shown in FIG.
  • the elastomer stamp 80 is lowered, and the elastomer stamp 80 is pressed against the LED element 23 patterned on the wafer WF. Further, as shown in FIG. 13, the elastomer stamp 80 is pushed in until the LED element 23 approaches the substrate surface of the wafer WF.
  • the larger the pushing amount the easier it is for the fixed portion to break, which is preferable, but the pushing amount is limited by the height of the protrusion 82.
  • the pushing amount is set to 20 to 95% of the height of the protrusion 82.
  • the pushing amount is preferably 40 to 95% of the height of the protrusion 82, and more preferably 60 to 95% of the height of the protrusion 82.
  • the LED element 23 attached to the protrusion 82 of the elastomer stamp 80 is pulled up and pulled away from the wafer WF.
  • the fixed portion is broken and the LED element 23 is pulled away from the wafer WF by the pushing operation of the LED element 23 by the elastomer stamp 80 shown in FIG. 13 and the pulling operation of the LED element 23 by the elastomer stamp 80 shown in FIG. ..
  • the holding time is preferably 0 to 600 seconds.
  • the holding time is more preferably 0 to 300 seconds, still more preferably 1 to 180 seconds.
  • the center O2 of the protrusion 82 of the elastomer stamp 80 and the P electrode PE of the LED element 23 are used.
  • the center O1 of the above is shifted in a predetermined direction. That is, the center of the portion of the elastomer stamp 80 that protrudes most toward the LED element 23 side and the center of the portion of the LED element 23 that protrudes most toward the elastomer stamp 80 side are shifted in a predetermined direction.
  • the protrusion 82 in the elastomer stamp 80 is a multi-stage protrusion
  • the center of the most protruding portion on the LED element 23 side is the center of the most advanced protrusion in the protrusion 82.
  • the center O2 of the protrusion 82 of the elastomer stamp 80 is shifted from the center O1 of the P electrode PE of the LED element 23 toward the negative y-axis direction. That is, the position of the LED element 23 pressed by the projection 82 of the elastomer stamp 80 is moved in the direction away from the fixed portion of the LED element 23. Therefore, it is considered that the bending moment acting on the fixed portion of the LED element 23 becomes large and the fixed portion is easily broken.
  • the center O2 of the protrusion 82 of the elastomer stamp 80 may be shifted from the center O1 of the P electrode PE of the LED element 23 in the x-axis direction. In this case, it is considered that a shear stress due to twisting can be applied to the fixed portion of the LED element 23 in addition to the bending moment, and the fixed portion is likely to break.
  • the shift amount is, for example, 5 to 50% of the width of the LED element 23 in a predetermined direction (for example, the x-axis direction when shifting in the x-axis direction and the y-axis direction when shifting in the y-axis direction). ..
  • the amount of shift is preferably 10 to 40% of the width of the LED element 23 in a predetermined direction, and more preferably 10 to 30% of the width of the LED element 23 in a predetermined direction.
  • the size of the LED element 23 is defined by the region occupied by the semiconductor layer (N-type semiconductor layer NL and P-type semiconductor layer PL) in a plan view.
  • the elastoma stamp 80 is pressed against the LED element 23, at least one of the LED element 23 and the elastoma stamp 80, which are in contact with each other in the pressed state, is x parallel to the wafer WF. Move in the axial direction or the y-axis direction. Of course, it may be moved in the x-axis direction (first direction) and the y-axis direction (second direction). Alternatively, when the LED element 23 attached to the elastomer stamp 80 is pulled up after the elastomer stamp 80 is pushed in, at least one of the LED element 23 and the elastomer stamp 80 that are in contact with each other may be moved in the same manner.
  • a force for moving the LED element 23 in the positive direction of the x-axis acts. That is, it is considered that a bending moment due to a force for moving the LED element 23 in the positive direction on the x-axis is applied to the fixed portion in addition to the bending moment due to pushing (a force for moving the LED element 23 in the negative direction on the z-axis).
  • tensile stress acts on the x-axis negative side end of the fixed portion of the LED element 23, and compressive stress acts on the x-axis positive side end of the fixed portion. That is, it is considered that a force that tears the fixed portion of the LED element 23 from the end on the negative side in the x-axis direction acts, and the fixed portion is easily broken.
  • the movement amount is, for example, 5 to 50% of the width of the LED element 23 in a predetermined direction (for example, the x-axis direction when moving in the x-axis direction and the y-axis direction when moving in the y-axis direction). And.
  • the amount of movement is preferably 10 to 40% of the width of the LED element 23 in a predetermined direction, and more preferably 10 to 30% of the width of the LED element 23 in a predetermined direction.
  • the center O2 of the protrusion 82 of the elastomer stamp 80 and the P electrode PE of the LED element 23 are used.
  • the center O1 is shifted in a predetermined direction.
  • the elastoma stamp 80 in contact with the LED element 23 is moved relative to the wafer WF in a predetermined direction parallel to the wafer WF.
  • the fixed portion of the LED element 23 is likely to break.
  • the pickup yield of the LED element 23 by the elastomer stamp 80 is increased, and the productivity of the transparent display device is improved.
  • the fixed portion becomes more stable. It is more likely to break. As a result, the pickup yield of the LED element 23 by the elastomer stamp 80 is increased, and the productivity of the transparent display device is dramatically improved.
  • FIG. 15 is a plan view of the LED element 23 separated from the wafer WF by the manufacturing method of the transparent display device according to the first embodiment. That is, FIG. 15 is a plan view of the LED element 23 mounted on the transparent base material 10 in the transparent display device.
  • the fixed portion protrudes from one short side of the rectangular N-type semiconductor layer NL in a plan view toward the outside of the LED element 23. That is, the fixed portion is a protruding portion in the LED element 23.
  • the end portion (broken portion) of the fixed portion is formed so as to be inclined obliquely with respect to the short side of the N-type semiconductor layer NL in a plan view.
  • the end portion (broken portion) of the fixed portion is formed in parallel with the short side of the N-type semiconductor layer NL in a plan view.
  • Example 1 is a comparative example.
  • a micro-sized LED element 23 patterned on the wafer WF was manufactured by using a photolithography technique.
  • a Si wafer was used as the wafer WF, and a GaN layer was used as the N-type semiconductor layer NL and the P-type semiconductor layer PL.
  • the width (short side width) in the x-axis direction of each LED element 23 is 10 ⁇ m, and the width in the y-axis direction (long side). The width) was 15 ⁇ m.
  • FIG. 11 the width in the x-axis direction of each LED element 23 (the region occupied by the N-type semiconductor layer NL and the P-type semiconductor layer PL) is 10 ⁇ m, and the width in the y-axis direction (long side). The width) was 15 ⁇ m.
  • the width of the LED element 23 in the x-axis direction is 13 ⁇ m, and the width in the y-axis direction is 17 ⁇ m.
  • the width of the fixed portion in the x-axis direction was 8 ⁇ m.
  • the width (short side width) in the x-axis direction of each protrusion 82 on the LED element 23 side is 10 ⁇ m
  • the width in the y-axis direction (long side width) is 11 ⁇ m
  • the width (height) in the z-axis direction is. It was set to 22 ⁇ m.
  • Table 1 summarizes the experimental conditions and results of Examples 1 to 9.
  • Table 1 as experimental conditions, the amount of deviation (projection center position) between the xy plane center O2 of the protrusion 82 and the xy plane center O1 of the P electrode PE shown in FIG. 11 when the elastomer stamp 80 is pressed against the LED element 23. The amount of deviation) is shown. Further, the amount of movement of the LED element 23 in the state where the elastomer stamp 80 is pushed in (the amount of movement of the LED when pushed in) and the amount of movement of the LED element 23 when the elastomer stamp 80 is pulled up (the amount of movement of the LED when pulled up) are shown. Further, Table 1 also shows the pickup yield of the LED element 23 by the elastomer stamp 80 as an experimental result.
  • Example 1 The xy plane center O2 of the protrusion 82 of the elastomer stamp 80 shown in FIG. 11 and the xy plane center O1 of the P electrode PE of the LED element 23 were aligned with each other. As shown in FIG. 13, after the protrusion 82 of the elastomer stamp 80 was brought into contact with the LED element 23, the elastomer stamp 80 was pushed in by 17 ⁇ m and held for 3 minutes after being pushed in. After that, the elastomer stamp 80 was accelerated to a target speed of 140 mm / s by gravitational acceleration (9.8 m / s 2 ), pulled up by 5 mm, and the LED element 23 was picked up. The pickup yield of the LED element 23 was 9%.
  • Example 2 As shown in Table 1, an example except that the xy plane center O2 of the projection 82 of the elastomer stamp 80 shown in FIG. 11 is displaced by 3 ⁇ m in the negative direction of the y axis from the xy plane center O1 of the P electrode PE of the LED element 23. The conditions were the same as in 1. The pickup yield of the LED element 23 was 15%, which was higher than that of Example 1.
  • Example 3 As shown in Table 1, an example except that the xy plane center O2 of the projection 82 of the elastomer stamp 80 shown in FIG. 11 is displaced by 2 ⁇ m in the positive direction of the x axis from the xy plane center O1 of the P electrode PE of the LED element 23. The conditions were the same as in 1. The pickup yield of the LED element 23 was 22%, which was higher than that of Example 1.
  • Example 4 As shown in Table 1, the conditions were the same as in Example 1 except that the projection 82 of the elastomer stamp 80 was brought into contact with the LED element 23 and pushed in, and the LED element 23 was displaced by 3 ⁇ m in the negative direction of the y-axis. Shifting the LED element 23 by 3 ⁇ m in the negative direction of the y-axis is the same as shifting the elastomer stamp 80 by 3 ⁇ m in the opposite direction (positive direction of the y-axis) (the same applies hereinafter). The pickup yield of the LED element 23 was 24%, which was higher than that of Example 1.
  • Example 5 As shown in Table 1, the conditions were the same as in Example 1 except that the projection 82 of the elastomer stamp 80 was brought into contact with the LED element 23 and pushed in, and the LED element 23 was displaced by 2 ⁇ m in the positive direction of the x-axis. The pickup yield of the LED element 23 was 23%, which was higher than that of Example 1.
  • Example 6> As shown in Table 1, the conditions were the same as in Example 1 except that the projection 82 of the elastomer stamp 80 was brought into contact with the LED element 23 and pushed in, and the LED element 23 was displaced by 2 ⁇ m in the negative direction of the x-axis. The pickup yield of the LED element 23 was 29%, which was higher than that of Example 1.
  • Example 7 As shown in Table 1, the conditions were the same as in Example 2 except that the projection 82 of the elastomer stamp 80 was brought into contact with the LED element 23 and pushed in, and the LED element 23 was displaced by 2 ⁇ m in the negative direction of the x-axis. The pickup yield of the LED element 23 was 90%, and the pickup yield was dramatically improved as compared with Example 2.
  • Example 8> As shown in Table 1, with the protrusion 82 of the elastoma stamp 80 in contact with the LED element 23 and pushed in, the LED element 23 is displaced by 2 ⁇ m in the negative direction of the x-axis, and then the LED element 23 is further moved in the negative direction of the y-axis.
  • the conditions were the same as in Example 7 except that the displacement was 3 ⁇ m.
  • the pickup yield of the LED element 23 was 91%, which was equivalent to that of Example 7 and was extremely good.
  • Example 9 As shown in Table 1, with the protrusion 82 of the elastoma stamp 80 in contact with the LED element 23 and pushed in, the LED element 23 is displaced by 3 ⁇ m in the negative direction of the x-axis, and then the LED element 23 is further moved in the negative direction of the y-axis. It was shifted by 3 ⁇ m. In addition, when pulling up the elastomer stamp 80, the LED element 23 in contact with the elastomer stamp 80 was displaced by 3 ⁇ m in the negative direction of the x-axis, and then the LED element 23 was further displaced by 3 ⁇ m in the negative direction of the y-axis. Further, the pushing amount was set to 20 ⁇ m. Other than that, the conditions were the same as in Example 8. The pickup yield of the LED element 23 was 93%, which was equivalent to that of Examples 7 and 8 and was extremely good.

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Abstract

A transparent display device manufacturing method according to one embodiment of the present invention comprises: pressing an elastomer stamp (80) against semiconductor elements (23) that each have an area of 100,000 μm2 or less and that is patterned on a wafer (WF), and then pulling up the semiconductor elements (23), which are being stuck to the elastomer stamp (80), so as to separate same from the wafer (WF); and conveying the semiconductor elements (23) while being stuck to the elastomer stamp (80), and then pressing and disposing the semiconductor elements (23) on to a transparent substrate (10). When the semiconductor elements (23) are pressed against the elastomer stamp (80), the center of portions of the elastomer stamp (80) that protrude most prominently toward the semiconductor elements (23) and the center of portions of the semiconductor element (23) that protrude most prominently toward the elastomer stamp (80) are displaced from each other in a prescribed direction.

Description

透明表示装置及びその製造方法Transparent display device and its manufacturing method
　本発明は、透明表示装置及びその製造方法に関する。 The present invention relates to a transparent display device and a method for manufacturing the same.
　発光ダイオード（ＬＥＤ：Light Emitting Diode）素子を画素に用いた表示装置が知られている。特許文献１には、このような表示装置のうち、ＬＥＤ素子のサイズが微細であって、当該表示装置を介して背面側を視認可能な透明表示装置が開示されている。 A display device using a light emitting diode (LED: Light Emitting Diode) element as a pixel is known. Patent Document 1 discloses, among such display devices, a transparent display device in which the size of the LED element is fine and the back side can be visually recognized via the display device.
　このような透明表示装置の製造方法において、マイクロトランスファープリンティング技術を用いて、透明基材上にＬＥＤ素子等の半導体素子を配置する手法が知られている。具体的には、ウェハ上にパターニングされたＬＥＤ素子にエラストマスタンプを押し当てた後、エラストマスタンプに貼り付けたＬＥＤ素子を引き上げてウェハから引き離す。そして、ＬＥＤ素子をエラストマスタンプに貼り付けたまま搬送した後、透明基材に押し当て、当該透明基材上にＬＥＤ素子を転写する。
　特許文献２、３には、マイクロトランスファープリンティング技術について開示されている。 In a method for manufacturing such a transparent display device, a method of arranging a semiconductor element such as an LED element on a transparent substrate by using a micro transfer printing technique is known. Specifically, after the elastomer stamp is pressed against the LED element patterned on the wafer, the LED element attached to the elastomer stamp is pulled up and pulled away from the wafer. Then, after the LED element is conveyed while being attached to the elastomer stamp, it is pressed against the transparent substrate to transfer the LED element onto the transparent substrate.
Patent Documents 2 and 3 disclose a micro transfer printing technique.
特開２００６－３０１６５０号公報Japanese Unexamined Patent Publication No. 2006-301650 特開２００７－０２７６９３号公報Japanese Unexamined Patent Publication No. 2007-027693 米国特許出願公開第２０１０／０１２３２６８号U.S. Patent Application Publication No. 2010/01232268
　発明者らは、このような透明表示装置の製造方法に関し、以下の問題点を見出した。
　発明者らは、ＬＥＤ素子にエラストマスタンプを押し当てる際、エラストマスタンプにおいてＬＥＤ素子側に最も突出した部位の中心と、ＬＥＤ素子においてエラストマスタンプ側に最も突出した部位の中心とを位置合わせしていた。そして、ＬＥＤ素子にエラストマスタンプを押し当てた後、エラストマスタンプに貼り付けたＬＥＤ素子を、単純にウェハの基板面と垂直な方向に引き上げていた。 The inventors have found the following problems with respect to a method for manufacturing such a transparent display device.
When the elastomer stamp is pressed against the LED element, the inventors have aligned the center of the portion of the elastomer stamp that protrudes most toward the LED element and the center of the portion of the LED element that protrudes most toward the elastomer stamp. .. Then, after the elastomer stamp was pressed against the LED element, the LED element attached to the elastomer stamp was simply pulled up in a direction perpendicular to the substrate surface of the wafer.
　しかしながら、このような手法では、エラストマスタンプによってＬＥＤ素子をウェハから引き離してピックアップできる確率（以下、「ピックアップ収率」という）が低く、透明表示装置の生産性に劣るという問題があった。
　なお、透明表示装置に用いるＬＥＤ素子以外の微細な半導体素子についてもマイクロトランスファープリンティング技術を適用可能であり、同様の問題が生じ得る。 However, such a method has a problem that the probability that the LED element can be separated from the wafer and picked up by the elastoma stamp (hereinafter referred to as “pickup yield”) is low, and the productivity of the transparent display device is inferior.
It should be noted that the micro transfer printing technique can be applied to a fine semiconductor element other than the LED element used in the transparent display device, and the same problem may occur.
　本発明は、このような事情に鑑みなされたものであって、生産性に優れた透明表示装置の製造方法を提供するものである。 The present invention has been made in view of such circumstances, and provides a method for manufacturing a transparent display device having excellent productivity.
　本発明は、以下［１］の構成を有する透明表示装置の製造方法を提供する。
［１］
　透明表示装置の製造方法であって、
　ウェハ上にパターニングされた１００，０００μｍ２以下の面積を有する半導体素子にエラストマスタンプを押し当てた後、前記エラストマスタンプに貼り付けた前記半導体素子を引き上げて前記ウェハから引き離すことと、
　前記半導体素子を前記エラストマスタンプに貼り付けたまま搬送した後、前記半導体素子を透明基材上に押し当てて配置ことと、を含み、
　前記半導体素子に前記エラストマスタンプを押し当てる際、
　前記エラストマスタンプにおいて前記半導体素子側に最も突出した部位の中心と、前記半導体素子において前記エラストマスタンプ側に最も突出した部位の中心とを、所定の方向にずらす、
透明表示装置の製造方法。 The present invention provides a method for manufacturing a transparent display device having the following configuration [1].
[1]
It is a manufacturing method of a transparent display device.
After the elastomer stamp is pressed against the semiconductor element having an area of 100,000 μm 2 or less patterned on the wafer, the semiconductor element attached to the elastomer stamp is pulled up and pulled away from the wafer.
Including that the semiconductor element is conveyed while being attached to the elastomer stamp, and then the semiconductor element is pressed against a transparent substrate and arranged.
When the elastomer stamp is pressed against the semiconductor element,
The center of the portion of the semiconductor element most protruding toward the semiconductor element side and the center of the portion of the semiconductor element most protruding toward the elastomer stamp side are displaced in a predetermined direction.
Manufacturing method of transparent display device.
　本発明の一態様においては、
［２］前記半導体素子に前記エラストマスタンプを押し当てた後、前記半導体素子を前記ウェハから引き離す前に、互いに接触している前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を、前記ウェハの基板面と平行な第１の方向に移動させる、［１］に記載の透明表示装置の製造方法。 In one aspect of the invention
[2] After pressing the elastoma stamp against the semiconductor element and before pulling the semiconductor element away from the wafer, at least one of the semiconductor element and the elastoma stamp in contact with each other is attached to the substrate of the wafer. The method for manufacturing a transparent display device according to [1], wherein the transparent display device is moved in a first direction parallel to a surface.
　本発明は、以下［３］の構成を有する透明表示装置の製造方法を提供する。
［３］
　透明表示装置の製造方法であって、
　ウェハ上にパターニングされた１００，０００μｍ２以下の面積を有する半導体素子にエラストマスタンプを押し当てた後、前記エラストマスタンプに貼り付けた前記半導体素子を引き上げて前記ウェハから引き離すことと、
　前記半導体素子を前記エラストマスタンプに貼り付けたまま搬送した後、前記半導体素子を透明基材上に押し当てて配置ことと、を含み
　前記半導体素子に前記エラストマスタンプを押し当てた後、前記半導体素子を前記ウェハから引き離す前に、
　互いに接触している前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を、前記ウェハの基板面と平行な第１の方向に移動させる、
透明表示装置の製造方法。 The present invention provides a method for manufacturing a transparent display device having the following configuration [3].
[3]
It is a manufacturing method of a transparent display device.
After the elastomer stamp is pressed against the semiconductor element having an area of 100,000 μm 2 or less patterned on the wafer, the semiconductor element attached to the elastomer stamp is pulled up and pulled away from the wafer.
After transporting the semiconductor element while being attached to the elastoma stamp, the semiconductor element is pressed against a transparent substrate and arranged, and after the elastoma stamp is pressed against the semiconductor element, the semiconductor element is pressed. Before pulling away from the wafer
At least one of the semiconductor element and the elastomer stamp in contact with each other is moved in a first direction parallel to the substrate surface of the wafer.
Manufacturing method of transparent display device.
　本発明の一態様においては、
［４］前記半導体素子に前記エラストマスタンプを押し当てた後、押し込んだ状態で、前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を、前記第１の方向に移動させる、［２］又は［３］に記載の透明表示装置の製造方法。 In one aspect of the invention
[4] After the elastomer stamp is pressed against the semiconductor element, at least one of the semiconductor element and the elastomer stamp is moved in the first direction in the pressed state, [2] or [3]. ] The method for manufacturing the transparent display device described in the above.
［５］前記半導体素子に前記エラストマスタンプを押し当てた後、押し込んだ状態で、前記ウェハの基板面に平行かつ前記第１の方向と交差する第２の方向に、前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を移動させる、［４］に記載の透明表示装置の製造方法。 [5] After the elastoma stamp is pressed against the semiconductor element, the semiconductor element and the elastoma stamp are pressed in a second direction parallel to the substrate surface of the wafer and intersecting the first direction. The method for manufacturing a transparent display device according to [4], wherein at least one of the above is moved.
［６］前記半導体素子に前記エラストマスタンプを押し当てた後、前記エラストマスタンプに貼り付けた前記半導体素子を引き上げる際、互いに接触している前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を、前記第１の方向に移動させる、［２］～［５］のいずれか一項に記載の透明表示装置の製造方法。 [6] When the semiconductor element attached to the elastomer stamp is pulled up after the elastomer stamp is pressed against the semiconductor element, at least one of the semiconductor element and the elastomer stamp in contact with each other is pressed. The method for manufacturing a transparent display device according to any one of [2] to [5], which is moved in the first direction.
［７］前記半導体素子に前記エラストマスタンプを押し当てた後、前記エラストマスタンプに貼り付けた前記半導体素子を引き上げる際、互いに接触している前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を、前記ウェハの基板面に平行かつ前記第１の方向と交差する第２の方向に移動させる、［６］に記載の透明表示装置の製造方法。 [7] When the semiconductor element attached to the elastoma stamp is pulled up after the elastoma stamp is pressed against the semiconductor element, at least one of the semiconductor element and the elastoma stamp in contact with each other is subjected to the above. The method for manufacturing a transparent display device according to [6], wherein the transparent display device is moved in a second direction parallel to the substrate surface of the wafer and intersecting the first direction.
［８］前記ウェハ上に形成された前記半導体素子は、平面視矩形状の矩形領域を備え、前記半導体素子は、前記矩形領域の一辺に形成された固定部を介して前記ウェハに固定されていると共に、前記ウェハの基板面から浮遊するように形成されている、［１］～［７］のいずれか一項に記載の透明表示装置の製造方法。 [8] The semiconductor element formed on the wafer includes a rectangular region having a rectangular shape in a plan view, and the semiconductor element is fixed to the wafer via a fixing portion formed on one side of the rectangular region. The method for manufacturing a transparent display device according to any one of [1] to [7], which is formed so as to float from the substrate surface of the wafer.
［９］前記エラストマスタンプに貼り付けた前記半導体素子を引き上げて前記ウェハから引き離す際、前記固定部が破断する、［８］に記載の透明表示装置の製造方法。 [9] The method for manufacturing a transparent display device according to [8], wherein the fixed portion breaks when the semiconductor element attached to the elastomer stamp is pulled up and separated from the wafer.
［１０］前記固定部が、絶縁層である、［８］又は［９］に記載の透明表示装置の製造方法。 [10] The method for manufacturing a transparent display device according to [8] or [9], wherein the fixing portion is an insulating layer.
［１１］前記エラストマスタンプに貼り付けた前記半導体素子を引き上げて前記ウェハから引き離す際、前記固定部の破断部が、前記矩形領域の一辺に対して斜めに傾斜する、［８］～［１０］のいずれか一項に記載の透明表示装置の製造方法。 [11] When the semiconductor element attached to the elastomer stamp is pulled up and pulled away from the wafer, the broken portion of the fixed portion is inclined diagonally with respect to one side of the rectangular region [8] to [10]. The method for manufacturing a transparent display device according to any one of the above items.
［１２］前記半導体素子に前記エラストマスタンプを押し当てる際、前記半導体素子が、前記ウェハの基板面に近付くまで、前記エラストマスタンプを押し込む、［８］～［１１］のいずれか一項に記載の透明表示装置の製造方法。 [12] The item according to any one of [8] to [11], wherein when the elastomer stamp is pressed against the semiconductor element, the elastomer stamp is pressed until the semiconductor element approaches the substrate surface of the wafer. Manufacturing method of transparent display device.
［１３］前記半導体素子は、１０，０００μｍ２以下の面積を有する発光ダイオード素子である、［１］～［１２］のいずれか一項に記載の透明表示装置の製造方法。 [13] The method for manufacturing a transparent display device according to any one of [1] to [12], wherein the semiconductor element is a light emitting diode element having an area of 10,000 μm 2 or less.
　本発明は、以下［１４］の構成を有する透明表示装置の製造方法を提供する。
［１４］
　透明基材と、
　前記透明基材上において画素ごとに少なくとも１つ配置されると共に、それぞれが１０，０００μｍ２以下の面積を有する半導体素子と、を備え、
　前記半導体素子が、
　平面視矩形状の半導体層と、
　平面視において前記半導体層の一辺から当該半導体素子の外側に向かって突出した突出部と、を備え、
　前記突出部の端部が、平面視において前記半導体層の一辺に対して斜めに傾斜するように形成されている、
透明表示装置。 The present invention provides a method for manufacturing a transparent display device having the following configuration [14].
[14]
With a transparent base material
A semiconductor device, each of which is arranged on the transparent substrate for each pixel and has an area of 10,000 μm 2 or less, is provided.
The semiconductor element is
A rectangular semiconductor layer in plan view and
A protrusion extending from one side of the semiconductor layer toward the outside of the semiconductor element in a plan view is provided.
The end portion of the protruding portion is formed so as to be inclined obliquely with respect to one side of the semiconductor layer in a plan view.
Transparent display device.
　本発明によれば、生産性に優れた透明表示装置の製造方法を提供できる。 According to the present invention, it is possible to provide a method for manufacturing a transparent display device having excellent productivity.
第１の実施形態に係る透明表示装置の一例を示す模式的な部分平面図である。It is a schematic partial plan view which shows an example of the transparent display device which concerns on 1st Embodiment. 図１におけるＩＩ－ＩＩ切断線による断面図である。FIG. 3 is a cross-sectional view taken along the line II-II in FIG. 第１の実施形態に係る透明表示装置の製造方法の一例を示す断面図である。It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. 第１の実施形態に係る透明表示装置の製造方法の一例を示す断面図である。It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. 第１の実施形態に係る透明表示装置の製造方法の一例を示す断面図である。It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. 第１の実施形態に係る透明表示装置の製造方法の一例を示す断面図である。It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. 第１の実施形態に係る透明表示装置の製造方法の一例を示す断面図である。It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. 第１の実施形態に係る透明表示装置の製造方法の一例を示す断面図である。It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. 第１の実施形態に係る透明表示装置の製造方法の一例を示す断面図である。It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. 第１の実施形態に係る透明表示装置の製造方法の一例を示す断面図である。It is sectional drawing which shows an example of the manufacturing method of the transparent display device which concerns on 1st Embodiment. ウェハ上にパターニングされたＬＥＤ素子２３の平面図である。It is a top view of the LED element 23 patterned on a wafer. 第１の実施形態に係る透明表示装置の製造方法におけるマイクロトランスファープリンティング技術の一例を示す断面図である。It is sectional drawing which shows an example of the microtransfer printing technique in the manufacturing method of the transparent display device which concerns on 1st Embodiment. 第１の実施形態に係る透明表示装置の製造方法におけるマイクロトランスファープリンティング技術の一例を示す断面図である。It is sectional drawing which shows an example of the microtransfer printing technique in the manufacturing method of the transparent display device which concerns on 1st Embodiment. 第１の実施形態に係る透明表示装置の製造方法におけるマイクロトランスファープリンティング技術の一例を示す断面図である。It is sectional drawing which shows an example of the microtransfer printing technique in the manufacturing method of the transparent display device which concerns on 1st Embodiment. 第１の実施形態に係る透明表示装置の製造方法によって、ウェハＷＦから切り離されたＬＥＤ素子２３の平面図である。It is a top view of the LED element 23 separated from the wafer WF by the manufacturing method of the transparent display device which concerns on 1st Embodiment.
　以下、本発明を適用した具体的な実施形態について、図面を参照しながら詳細に説明する。但し、本発明が以下の実施形態に限定される訳ではない。また、説明を明確にするため、以下の記載及び図面は、適宜、簡略化されている。 Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. Further, in order to clarify the explanation, the following description and drawings are appropriately simplified.
　本明細書において「透明表示装置」とは、表示装置の背面側に位置する人物や背景等の視覚情報を、所望の使用環境下で視認可能な表示装置を指す。なお、視認可能とは、少なくとも表示装置が非表示状態、すなわち通電されていない状態で判定される。 In the present specification, the "transparent display device" refers to a display device that can visually recognize visual information such as a person and a background located on the back side of the display device under a desired usage environment. It should be noted that "visible" is determined at least in a non-display state, that is, a state in which the display device is not energized.
　本明細書において、「透明」とは、可視光の透過率が４０％以上、好ましくは６０％以上、より好ましくは７０％以上であることを指す。また、透過率５％以上かつヘイズ値が１０以下であることを指していてもよい。透過率が５％以上であれば、室内から日中の屋外を見た際に、室内と同程度以上の明るさで屋外を見られ、充分な視認性を確保できる。 In the present specification, "transparent" means that the transmittance of visible light is 40% or more, preferably 60% or more, and more preferably 70% or more. It may also indicate that the transmittance is 5% or more and the haze value is 10 or less. When the transmittance is 5% or more, when the outside is viewed from the room during the daytime, the outside can be seen with the same or higher brightness as the room, and sufficient visibility can be ensured.
　また、透過率が４０％以上であれば、透明表示装置の前面側と背面側との明るさが同程度であっても、透明表示装置の背面側を実質的に問題なく視認できる。また、ヘイズ値が１０以下であれば、背景のコントラストを充分に確保できる。
　「透明」とは、色が付与されているか否かは問わず、つまり無色透明であってもよく、有色透明であってもよい。
　なお、透過率は、ＩＳＯ９０５０に準拠する方法により測定された値（％）を指す。ヘイズ値は、ＩＳＯ１４７８２に準拠する方法により測定された値を指す。 Further, when the transmittance is 40% or more, the back side of the transparent display device can be visually recognized without any problem even if the brightness of the front side and the back side of the transparent display device is about the same. Further, when the haze value is 10 or less, sufficient background contrast can be secured.
The term "transparent" means whether or not a color is applied, that is, it may be colorless and transparent, or it may be colored and transparent.
The transmittance refers to a value (%) measured by a method conforming to ISO9050. The haze value refers to a value measured by a method conforming to ISO 14782.
（第１の実施形態）
＜透明表示装置の構成＞
　まず、図１及び図２を参照して、第１の実施形態に係る透明表示装置の構成について説明する。図１は、第１の実施形態に係る透明表示装置の一例を示す模式的な部分平面図である。図２は、図１におけるＩＩ－ＩＩ切断線による断面図である。
　なお、当然のことながら、図１及び図２に示した右手系ｘｙｚ直交座標は、構成要素の位置関係を説明するための便宜的なものである。通常、ｚ軸正向きが鉛直上向き、ｘｙ平面が水平面である。 (First Embodiment)
<Configuration of transparent display device>
First, the configuration of the transparent display device according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic partial plan view showing an example of a transparent display device according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
As a matter of course, the right-handed xyz orthogonal coordinates shown in FIGS. 1 and 2 are for convenience in explaining the positional relationship of the components. Normally, the z-axis positive direction is vertically upward, and the xy plane is a horizontal plane.
　図１及び図２に示すように、本実施形態に係る透明表示装置は、透明基材１０、発光部２０、ＩＣチップ３０、配線４０、保護層５０を備えている。透明表示装置における表示領域１０１は、複数の画素から構成され、画像が表示される領域である。なお、画像は文字を含む。図１に示すように、表示領域１０１は、行方向（ｘ軸方向）及び列方向（ｙ軸方向）に並んだ複数の画素から構成されている。図１には、表示領域１０１の一部が示されており、行方向及び列方向に２画素ずつ計４画素が示されている。ここで、１つの画素ＰＩＸが一点鎖線によって囲んで示されている。また、図１では、図２に示した透明基材１０及び保護層５０が省略されている。さらに、図１は平面図だが、理解を容易にするため、発光部２０及びＩＣチップ３０がドット表示されている。 As shown in FIGS. 1 and 2, the transparent display device according to the present embodiment includes a transparent base material 10, a light emitting unit 20, an IC chip 30, wiring 40, and a protective layer 50. The display area 101 in the transparent display device is an area composed of a plurality of pixels and in which an image is displayed. The image includes characters. As shown in FIG. 1, the display area 101 is composed of a plurality of pixels arranged in the row direction (x-axis direction) and the column direction (y-axis direction). FIG. 1 shows a part of the display area 101, and shows a total of 4 pixels, 2 pixels each in the row direction and the column direction. Here, one pixel PIX is shown surrounded by an alternate long and short dash line. Further, in FIG. 1, the transparent base material 10 and the protective layer 50 shown in FIG. 2 are omitted. Further, although FIG. 1 is a plan view, the light emitting unit 20 and the IC chip 30 are displayed in dots for easy understanding.
＜発光部２０、ＩＣチップ３０、及び配線４０の平面配置＞
　まず、図１を参照して、発光部２０、ＩＣ（Integrated Circuit）チップ３０、及び配線４０の平面配置について説明する。
　図１に示すように、一点鎖線によって囲まれた画素ＰＩＸが、行方向（ｘ軸方向）に画素ピッチＰｘで、列方向（ｙ軸方向）に画素ピッチＰｙで、マトリクス状に配置されている。ここで、図１に示すように、各画素ＰＩＸは、発光部２０及びＩＣチップ３０を備えている。すなわち、発光部２０及びＩＣチップ３０は、行方向（ｘ軸方向）に画素ピッチＰｘで、列方向（ｙ軸方向）に画素ピッチＰｙで、マトリクス状に配置されている。
　なお、所定の方向に所定の画素ピッチで配置されれば、画素ＰＩＸすなわち発光部２０の配置形式はマトリクス状に限らない。 <Plane arrangement of light emitting unit 20, IC chip 30, and wiring 40>
First, with reference to FIG. 1, the planar arrangement of the light emitting unit 20, the IC (Integrated Circuit) chip 30, and the wiring 40 will be described.
As shown in FIG. 1, the pixel PIX surrounded by the alternate long and short dash line is arranged in a matrix with a pixel pitch Px in the row direction (x-axis direction) and a pixel pitch Py in the column direction (y-axis direction). .. Here, as shown in FIG. 1, each pixel PIX includes a light emitting unit 20 and an IC chip 30. That is, the light emitting unit 20 and the IC chip 30 are arranged in a matrix with a pixel pitch Px in the row direction (x-axis direction) and a pixel pitch Py in the column direction (y-axis direction).
If the pixels are arranged in a predetermined direction at a predetermined pixel pitch, the arrangement format of the pixels PIX, that is, the light emitting unit 20 is not limited to the matrix shape.
　図１に示すように、各画素ＰＩＸにおける発光部２０は、少なくとも１つの発光ダイオード素子（以下、ＬＥＤ素子）を含む。すなわち、本実施形態による透明表示装置は、各画素ＰＩＸにＬＥＤ素子を用いる表示装置であり、ＬＥＤディスプレイ等と呼ばれる。 As shown in FIG. 1, the light emitting unit 20 in each pixel PIX includes at least one light emitting diode element (hereinafter, LED element). That is, the transparent display device according to the present embodiment is a display device that uses an LED element for each pixel PIX, and is called an LED display or the like.
　図１の例では、各発光部２０が、赤色系のＬＥＤ素子２１、緑色系のＬＥＤ素子２２、及び青色系のＬＥＤ素子２３を含んでいる。ＬＥＤ素子２１～２３は、１つの画素を構成する副画素（サブピクセル）に対応する。このように、各発光部２０が、光の三原色である赤、緑、青を発光するＬＥＤ素子２１～２３を有するため、本実施形態に係る透明表示装置は、フルカラー画像を表示できる。
　なお、各発光部２０は同系色のＬＥＤ素子を２つ以上含んでいてもよい。これにより、画像のダイナミクスレンジを拡大できる。 In the example of FIG. 1, each light emitting unit 20 includes a red LED element 21, a green LED element 22, and a blue LED element 23. The LED elements 21 to 23 correspond to sub-pixels (sub-pixels) constituting one pixel. As described above, since each light emitting unit 20 has LED elements 21 to 23 that emit red, green, and blue, which are the three primary colors of light, the transparent display device according to the present embodiment can display a full-color image.
In addition, each light emitting unit 20 may include two or more LED elements of similar colors. This makes it possible to expand the dynamics range of the image.
　ＬＥＤ素子２１～２３は、微小サイズを有し、いわゆるマイクロＬＥＤ素子である。具体的には、透明基材１０上におけるＬＥＤ素子２１の幅（ｘ軸方向の長さ）及び長さ（ｙ軸方向の長さ）はそれぞれ、例えば１００μｍ以下、好ましくは５０μｍ以下、より好ましくは２０μｍ以下である。ＬＥＤ素子２２、２３についても同様である。ＬＥＤ素子の幅及び長さの下限は、製造上の諸条件等から例えば３μｍ以上である。
　なお、図１におけるＬＥＤ素子２１～２３の寸法すなわち幅及び長さは同一であるが、互いに異なっていてもよい。 The LED elements 21 to 23 have a minute size and are so-called micro LED elements. Specifically, the width (length in the x-axis direction) and the length (length in the y-axis direction) of the LED element 21 on the transparent substrate 10 are, for example, 100 μm or less, preferably 50 μm or less, more preferably 50 μm or less, respectively. It is 20 μm or less. The same applies to the LED elements 22 and 23. The lower limit of the width and length of the LED element is, for example, 3 μm or more due to various manufacturing conditions and the like.
Although the dimensions, that is, the width and the length of the LED elements 21 to 23 in FIG. 1 are the same, they may be different from each other.
　また、透明基材１０上においてＬＥＤ素子２１～２３のそれぞれが占める面積は、例えば１０，０００μｍ２以下、好ましくは３，０００μｍ２以下、より好ましくは５００μｍ２以下である。なお、１つのＬＥＤ素子が占める面積の下限は、製造上の諸条件等から例えば１０μｍ２以上である。ここで、本明細書において、ＬＥＤ素子や配線等の構成部材が占める面積は、図１におけるｘｙ平面視での面積を指す。
　なお、図１に示したＬＥＤ素子２１～２３の形状は、矩形状（正方形を含む）であるが、特に限定されない。 The area occupied by each of the LED elements 21 to 23 on the transparent substrate 10 is, for example, 10,000 μm 2 or less, preferably 3,000 μm 2 or less, and more preferably 500 μm 2 or less. The lower limit of the area occupied by one LED element is, for example, 10 μm 2 or more due to various manufacturing conditions and the like. Here, in the present specification, the area occupied by the constituent members such as the LED element and the wiring refers to the area in the xy plan view in FIG.
The shape of the LED elements 21 to 23 shown in FIG. 1 is rectangular (including a square), but is not particularly limited.
　ここで、ＬＥＤ素子２１～２３は、例えば、光を視認側に効率よく取り出すためのミラー構造を有している。そのため、ＬＥＤ素子２１～２３の透過率は、例えば１０％以下程度と低い。しかしながら、本実施形態に係る透明表示装置では、上述の通り、面積１０，０００μｍ２以下の微小サイズのＬＥＤ素子２１～２３を用いている。そのため、例えば数１０ｃｍ～２ｍ程度の近距離から、透明表示装置を観察するような場合でも、ＬＥＤ素子２１～２３はほとんど視認できない。また、表示領域１０１において透過率が低い領域が狭く、背面側の視認性に優れている。その上、配線４０等の配置の自由度も大きい。
　なお、「表示領域１０１において透過率が低い領域」とは、例えば、透過率が２０％以下の領域である。以下同様である。 Here, the LED elements 21 to 23 have, for example, a mirror structure for efficiently extracting light to the visual recognition side. Therefore, the transmittance of the LED elements 21 to 23 is as low as, for example, about 10% or less. However, in the transparent display device according to the present embodiment, as described above, the LED elements 21 to 23 having a minute size having an area of 10,000 μm 2 or less are used. Therefore, for example, even when observing the transparent display device from a short distance of about several tens of centimeters to 2 m, the LED elements 21 to 23 are almost invisible. Further, the area where the transmittance is low is narrow in the display area 101, and the visibility on the back side is excellent. Moreover, the degree of freedom in arranging the wiring 40 and the like is large.
The “region having a low transmittance in the display region 101” is, for example, a region having a transmittance of 20% or less. The same applies hereinafter.
　また、微小サイズのＬＥＤ素子２１～２３を用いているため、透明表示装置を湾曲させても、ＬＥＤ素子が損傷し難い。そのため、本実施形態に係る透明表示装置は、自動車用のウインドウガラスのような湾曲した透明板に装着したり、湾曲した２枚の透明板の間に封入したりして使用できる。ここで、透明基材１０として可撓性を有する材料を用いれば、本実施形態に係る透明表示装置を湾曲させられる。 Further, since the LED elements 21 to 23 of a minute size are used, the LED element is not easily damaged even if the transparent display device is curved. Therefore, the transparent display device according to the present embodiment can be used by being attached to a curved transparent plate such as a window glass for an automobile, or by being enclosed between two curved transparent plates. Here, if a flexible material is used as the transparent base material 10, the transparent display device according to the present embodiment can be curved.
　ＬＥＤ素子２１～２３は、特に限定されないが、例えば無機材料である。赤色系のＬＥＤ素子２１は、例えばＡｌＧａＡｓ、ＧａＡｓＰ、ＧａＰ等である。緑色系のＬＥＤ素子２２は、例えばＩｎＧａＮ、ＧａＮ、ＡｌＧａＮ、ＧａＰ、ＡｌＧａＩｎＰ、ＺｎＳｅ等である。青色系のＬＥＤ素子２３は、例えばＩｎＧａＮ、ＧａＮ、ＡｌＧａＮ、ＺｎＳｅ等である。 The LED elements 21 to 23 are not particularly limited, but are, for example, inorganic materials. The red LED element 21 is, for example, AlGaAs, GaAsP, GaP, or the like. The green LED element 22 is, for example, InGaN, GaN, AlGaN, GaP, AlGaInP, ZnSe, or the like. The blue LED element 23 is, for example, InGaN, GaN, AlGaN, ZnSe, or the like.
　ＬＥＤ素子２１～２３の発光効率すなわちエネルギー変換効率は、例えば１％以上、好ましくは５％以上、より好ましくは１５％以上である。ＬＥＤ素子２１～２３の発光効率が１％以上であると、上述のように微小サイズのＬＥＤ素子２１～２３でも充分な輝度が得られ、表示装置として日中にも利用できる。また、ＬＥＤ素子の発光効率が１５％以上であると、発熱が抑制され、樹脂接着層を用いた合わせガラス内部への封入が容易になる。 The luminous efficiency, that is, the energy conversion efficiency of the LED elements 21 to 23 is, for example, 1% or more, preferably 5% or more, and more preferably 15% or more. When the luminous efficiency of the LED elements 21 to 23 is 1% or more, sufficient brightness can be obtained even with the small size LED elements 21 to 23 as described above, and the LED elements 21 to 23 can be used as a display device during the daytime. Further, when the luminous efficiency of the LED element is 15% or more, heat generation is suppressed, and encapsulation inside the laminated glass using the resin adhesive layer becomes easy.
　画素ピッチＰｘ、Ｐｙはそれぞれ、例えば１００～３０００μｍ、好ましくは１８０～１０００μｍ、より好ましくは２５０～４００μｍである。画素ピッチＰｘ、Ｐｙを上記範囲とすることによって、充分な表示能を確保しつつ、高い透明性を実現できる。また、透明表示装置の背面側からの光によって生じ得る回折現象を抑制できる。
　また、本実施形態に係る透明表示装置の表示領域１０１における画素密度は、例えば１０ｐｐｉ以上、好ましくは３０ｐｐｉ以上、より好ましくは６０ｐｐｉ以上である。 The pixel pitches Px and Py are, for example, 100 to 3000 μm, preferably 180 to 1000 μm, and more preferably 250 to 400 μm, respectively. By setting the pixel pitches Px and Py in the above range, high transparency can be realized while ensuring sufficient display capability. In addition, it is possible to suppress a diffraction phenomenon that may occur due to light from the back surface side of the transparent display device.
Further, the pixel density in the display area 101 of the transparent display device according to the present embodiment is, for example, 10 ppi or more, preferably 30 ppi or more, and more preferably 60 ppi or more.
　また、１画素ＰＩＸの面積はＰｘ×Ｐｙである。１画素の面積は、例えば１×１０４μｍ２～９×１０６μｍ２、好ましくは３×１０４～１×１０６μｍ２、より好ましくは６×１０４～２×１０５μｍ２である。１画素の面積を１×１０４μｍ２～９×１０６μｍ２とすることで、適切な表示能を確保しつつ、表示装置の透明性を向上させられる。１画素の面積は、表示領域１０１のサイズ、用途、視認距離等によって適宜選択すればよい。 The area of one pixel PIX is Px × Py. The area of one pixel is, for example, 1 × 10 4 μm 2 to 9 × 10 6 μm 2 , preferably 3 × 10 4 to 1 × 10 6 μm 2 , and more preferably 6 × 10 4 to 2 × 10 5 μm 2 . be. By setting the area of one pixel to 1 × 10 4 μm 2 to 9 × 10 6 μm 2 , the transparency of the display device can be improved while ensuring an appropriate display capability. The area of one pixel may be appropriately selected depending on the size of the display area 101, the application, the viewing distance, and the like.
　１画素の面積に対してＬＥＤ素子２１～２３が占める面積の割合は、例えば３０％以下、好ましくは１０％以下、より好ましくは５％以下、さらに好ましくは１％以下である。１画素の面積に対してＬＥＤ素子２１～２３が占める面積の割合を３０％以下とすることで、透明性及び背面側の視認性が向上する。 The ratio of the area occupied by the LED elements 21 to 23 to the area of one pixel is, for example, 30% or less, preferably 10% or less, more preferably 5% or less, and further preferably 1% or less. By setting the ratio of the area occupied by the LED elements 21 to 23 to the area of one pixel to 30% or less, the transparency and the visibility on the back side are improved.
　図１では、各画素において、３つのＬＥＤ素子２１～２３が、この順にｘ軸正方向に一列に並べて配置されているが、これに限定されない。例えば、３つのＬＥＤ素子２１～２３の配置順を変更してもよい。また、３つのＬＥＤ素子２１～２３を、ｙ軸方向に並べてもよい。あるいは、３つのＬＥＤ素子２１～２３を三角形の頂点に配置してもよい。 In FIG. 1, three LED elements 21 to 23 are arranged in a row in the positive direction of the x-axis in this order in each pixel, but the present invention is not limited to this. For example, the arrangement order of the three LED elements 21 to 23 may be changed. Further, the three LED elements 21 to 23 may be arranged in the y-axis direction. Alternatively, the three LED elements 21 to 23 may be arranged at the vertices of the triangle.
　また、図１に示すように、各発光部２０が複数のＬＥＤ素子２１～２３を備えている場合、発光部２０におけるＬＥＤ素子２１～２３同士の間隔は、例えば１００μｍ以下、好ましくは１０μｍ以下である。また、ＬＥＤ素子２１～２３同士は、互いに接するように配置されていてもよい。これにより、第１電源分岐線４１ａを共通化し易くなり、開口率を向上させられる。 Further, as shown in FIG. 1, when each light emitting unit 20 includes a plurality of LED elements 21 to 23, the distance between the LED elements 21 to 23 in the light emitting unit 20 is, for example, 100 μm or less, preferably 10 μm or less. be. Further, the LED elements 21 to 23 may be arranged so as to be in contact with each other. This makes it easier to standardize the first power supply branch line 41a and improve the aperture ratio.
　なお、図１の例では、各発光部２０における複数のＬＥＤ素子の配置順、配置方向等は互いに同じだが、異なっていてもよい。また、各発光部２０が波長の異なる光を発する３つのＬＥＤ素子を含む場合、一部の発光部２０では、ＬＥＤ素子をｘ軸方向又はｙ軸方向に並べて配置し、他の発光部２０では、各色のＬＥＤ素子を三角形の頂点に配置してもよい。 In the example of FIG. 1, the arrangement order, arrangement direction, etc. of the plurality of LED elements in each light emitting unit 20 are the same as each other, but may be different. Further, when each light emitting unit 20 includes three LED elements that emit light having different wavelengths, in some light emitting units 20, the LED elements are arranged side by side in the x-axis direction or the y-axis direction, and in the other light emitting unit 20, the LED elements are arranged side by side. , LED elements of each color may be arranged at the apex of the triangle.
　図１の例では、ＩＣチップ３０は、画素ＰＩＸごとに配置され、発光部２０を駆動する。具体的には、ＩＣチップ３０は、ＬＥＤ素子２１～２３のそれぞれに駆動線４５を介して接続されており、ＬＥＤ素子２１～２３を個別に駆動できる。ＩＣチップ３０は、例えば、アナログ領域と論理領域とを備えたハイブリッドＩＣである。アナログ領域は、例えば、電流制御回路及び変圧回路等を含んでいる。 In the example of FIG. 1, the IC chip 30 is arranged for each pixel PIX and drives the light emitting unit 20. Specifically, the IC chip 30 is connected to each of the LED elements 21 to 23 via a drive line 45, and the LED elements 21 to 23 can be individually driven. The IC chip 30 is, for example, a hybrid IC including an analog region and a logic region. The analog region includes, for example, a current control circuit, a transformer circuit, and the like.
　なお、ＩＣチップ３０を複数の画素ごとに配置し、各ＩＣチップ３０が接続された複数の画素を駆動してもよい。例えば、ＩＣチップ３０を４画素ごとに１個配置すれば、ＩＣチップ３０の個数を図１の例の１／４に削減し、ＩＣチップ３０が占める面積を削減できる。また、ＩＣチップ３０は必須ではない。 Note that the IC chip 30 may be arranged for each of a plurality of pixels, and a plurality of pixels to which each IC chip 30 is connected may be driven. For example, if one IC chip 30 is arranged for every four pixels, the number of IC chips 30 can be reduced to 1/4 of the example of FIG. 1, and the area occupied by the IC chip 30 can be reduced. Moreover, the IC chip 30 is not indispensable.
　ＩＣチップ３０の面積は、例えば１００，０００μｍ２以下、好ましくは１０，０００μｍ２以下、より好ましくは５，０００μｍ２以下である。ＩＣチップ３０の透過率は２０％以下程度と低いが、上記のサイズのＩＣチップ３０を用いることによって、表示領域１０１において透過率が低い領域が狭くなり、背面側の視認性が向上する。 Area of the IC chip 30 is, for example 100,000Myuemu 2 or less, preferably 10,000 2 or less, more preferably 5,000 .mu.m 2 or less. The transmittance of the IC chip 30 is as low as about 20% or less, but by using the IC chip 30 of the above size, the region of the display region 101 where the transmittance is low is narrowed, and the visibility on the back surface side is improved.
　図１に示すように、配線４０は、電源線４１、グランド線４２、行データ線４３、列データ線４４、及び駆動線４５を複数ずつ備えている。
　図１の例では、電源線４１、グランド線４２、及び列データ線４４はｙ軸方向に延設されている。他方、行データ線４３は、ｘ軸方向に延設されている。 As shown in FIG. 1, the wiring 40 includes a power supply line 41, a ground line 42, a row data line 43, a column data line 44, and a plurality of drive lines 45.
In the example of FIG. 1, the power supply line 41, the ground line 42, and the column data line 44 extend in the y-axis direction. On the other hand, the row data line 43 extends in the x-axis direction.
　また、各画素ＰＩＸにおいて、電源線４１及び列データ線４４は、発光部２０及びＩＣチップ３０よりもｘ軸負方向側に設けられており、グランド線４２は、発光部２０及びＩＣチップ３０よりもｘ軸正方向側に設けられている。ここで、電源線４１は、列データ線４４よりもｘ軸負方向側に設けられている。また、各画素ＰＩＸにおいて、行データ線４３は、発光部２０及びＩＣチップ３０よりもｙ軸負方向側に設けられている。 Further, in each pixel PIX, the power supply line 41 and the column data line 44 are provided on the x-axis negative direction side of the light emitting unit 20 and the IC chip 30, and the ground line 42 is provided from the light emitting unit 20 and the IC chip 30. Is also provided on the positive side of the x-axis. Here, the power supply line 41 is provided on the side in the negative direction of the x-axis with respect to the column data line 44. Further, in each pixel PIX, the row data line 43 is provided on the y-axis negative direction side with respect to the light emitting unit 20 and the IC chip 30.
　さらに、詳細には後述するが、図１に示すように、電源線４１は、第１電源分岐線４１ａ及び第２電源分岐線４１ｂを備えている。グランド線４２は、グランド分岐線４２ａを備えている。行データ線４３は、行データ分岐線４３ａを備えている。列データ線４４は、列データ分岐線４４ａを備えている。これら各分岐線は、配線４０に含まれる。 Further, as will be described in detail later, as shown in FIG. 1, the power supply line 41 includes a first power supply branch line 41a and a second power supply branch line 41b. The ground line 42 includes a ground branch line 42a. The row data line 43 includes a row data branch line 43a. The column data line 44 includes a column data branch line 44a. Each of these branch lines is included in the wiring 40.
　図１に示すように、ｙ軸方向に延設された各電源線４１は、ｙ軸方向に並設された各画素ＰＩＸの発光部２０及びＩＣチップ３０に接続されている。より詳細には、各画素ＰＩＸにおいて、電源線４１よりもｘ軸正方向側において、ＬＥＤ素子２１～２３がこの順にｘ軸正方向に並設されている。そのため、電源線４１からｘ軸正方向に分岐した第１電源分岐線４１ａが、ＬＥＤ素子２１～２３のｙ軸正方向側端部に接続されている。 As shown in FIG. 1, each power supply line 41 extending in the y-axis direction is connected to a light emitting unit 20 and an IC chip 30 of each pixel PIX arranged side by side in the y-axis direction. More specifically, in each pixel PIX, the LED elements 21 to 23 are arranged side by side in the x-axis positive direction in this order on the x-axis positive direction side of the power line 41. Therefore, the first power supply branch line 41a branched from the power supply line 41 in the positive direction of the x-axis is connected to the end of the LED elements 21 to 23 in the positive direction of the y-axis.
　また、各画素ＰＩＸにおいて、ＩＣチップ３０は、ＬＥＤ素子２１～２３のｙ軸負方向側に配置されている。そのため、ＬＥＤ素子２１と列データ線４４との間において、第１電源分岐線４１ａからｙ軸負方向に分岐した第２電源分岐線４１ｂが、直線状に延設され、ＩＣチップ３０のｙ軸正方向側端部のｘ軸負方向側に接続されている。 Further, in each pixel PIX, the IC chip 30 is arranged on the y-axis negative direction side of the LED elements 21 to 23. Therefore, between the LED element 21 and the column data line 44, the second power supply branch line 41b branched in the y-axis negative direction from the first power supply branch line 41a is extended in a straight line, and the y-axis of the IC chip 30 is extended. It is connected to the negative side of the x-axis of the end on the positive side.
　図１に示すように、ｙ軸方向に延設された各グランド線４２は、ｙ軸方向に並設された各画素ＰＩＸのＩＣチップ３０に接続されている。具体的には、グランド線４２からｘ軸負方向に分岐したグランド分岐線４２ａが、直線状に延設され、ＩＣチップ３０のｘ軸正方向側端部に接続されている。
　ここで、グランド線４２は、グランド分岐線４２ａ、ＩＣチップ３０、及び駆動線４５を介して、ＬＥＤ素子２１～２３に接続されている。 As shown in FIG. 1, each ground wire 42 extending in the y-axis direction is connected to an IC chip 30 of each pixel PIX arranged side by side in the y-axis direction. Specifically, the ground branch line 42a branched from the ground line 42 in the negative direction on the x-axis is linearly extended and connected to the end on the positive side of the x-axis of the IC chip 30.
Here, the ground line 42 is connected to the LED elements 21 to 23 via the ground branch line 42a, the IC chip 30, and the drive line 45.
　図１に示すように、ｘ軸方向に延設された各行データ線４３は、ｘ軸方向（行方向）に並設された各画素ＰＩＸのＩＣチップ３０に接続されている。具体的には、行データ線４３からｙ軸正方向に分岐した行データ分岐線４３ａが、直線状に延設され、ＩＣチップ３０のｙ軸負方向側端部に接続されている。
　ここで、行データ線４３は、行データ分岐線４３ａ、ＩＣチップ３０、及び駆動線４５を介して、ＬＥＤ素子２１～２３に接続されている。 As shown in FIG. 1, each row data line 43 extending in the x-axis direction is connected to an IC chip 30 of each pixel PIX arranged side by side in the x-axis direction (row direction). Specifically, the row data branch line 43a branched from the row data line 43 in the positive direction of the y-axis is linearly extended and connected to the end of the IC chip 30 in the negative direction of the y-axis.
Here, the row data line 43 is connected to the LED elements 21 to 23 via the row data branch line 43a, the IC chip 30, and the drive line 45.
　図１に示すように、ｙ軸方向に延設された各列データ線４４は、ｙ軸方向（列方向）に並設された各画素ＰＩＸのＩＣチップ３０に接続されている。具体的には、列データ線４４からｘ軸正方向に分岐した列データ分岐線４４ａが、直線状に延設され、ＩＣチップ３０のｘ軸負方向側端部に接続されている。
　ここで、列データ線４４は、列データ分岐線４４ａ、ＩＣチップ３０、及び駆動線４５を介して、ＬＥＤ素子２１～２３に接続されている。 As shown in FIG. 1, each column data line 44 extending in the y-axis direction is connected to an IC chip 30 of each pixel PIX arranged side by side in the y-axis direction (column direction). Specifically, the column data branch line 44a branched from the column data line 44 in the positive direction on the x-axis is linearly extended and connected to the end on the negative side of the x-axis of the IC chip 30.
Here, the column data line 44 is connected to the LED elements 21 to 23 via the column data branch line 44a, the IC chip 30, and the drive line 45.
　駆動線４５は、各画素ＰＩＸにおいて、ＬＥＤ素子２１～２３とＩＣチップ３０とを接続している。具体的には、各画素ＰＩＸにおいて、３本の駆動線４５がｙ軸方向に延設され、それぞれがＬＥＤ素子２１～２３のｙ軸負方向側端部とＩＣチップ３０のｙ軸正方向側端部とを接続している。 The drive line 45 connects the LED elements 21 to 23 and the IC chip 30 in each pixel PIX. Specifically, in each pixel PIX, three drive lines 45 are extended in the y-axis direction, and each of them is the y-axis negative side end of the LED elements 21 to 23 and the y-axis positive side of the IC chip 30. It is connected to the end.
　なお、図１に示した電源線４１、グランド線４２、行データ線４３、列データ線４４、及びそれらの分岐線、並びに駆動線４５の配置はあくまでも一例であり、適宜変更可能である。例えば、電源線４１及びグランド線４２の少なくとも一方が、ｙ軸方向でなくｘ軸方向に延設されていてもよい。また、電源線４１と列データ線４４とを入れ換えた構成でもよい。 The arrangement of the power supply line 41, the ground line 42, the row data line 43, the column data line 44, their branch lines, and the drive line 45 shown in FIG. 1 is merely an example and can be changed as appropriate. For example, at least one of the power line 41 and the ground line 42 may extend in the x-axis direction instead of the y-axis direction. Further, the power line 41 and the column data line 44 may be interchanged.
　また、図１に示した構成全体を、上下反転させた構成あるいは左右反転させた構成等でもよい。
　さらに、行データ線４３、列データ線４４、及びそれらの分岐線、並びに駆動線４５は必須ではない。 Further, the entire configuration shown in FIG. 1 may be upside down, left-right inverted, or the like.
Further, the row data line 43, the column data line 44, their branch lines, and the drive line 45 are not essential.
　配線４０は、例えば銅（Ｃｕ）、アルミニウム（Ａｌ）、銀（Ａｇ）、金（Ａｕ）等の金属である。このうち、低抵抗率であることやコスト的な観点から銅又はアルミニウムを主成分とする金属であることが好ましい。また、配線４０は、反射率を低減することを目的として、チタン（Ｔｉ）、モリブデン（Ｍｏ）、酸化銅、カーボン等の材料で被覆されていてもよい。また、被覆した材料の表面に凹凸が形成されていてもよい。 The wiring 40 is a metal such as copper (Cu), aluminum (Al), silver (Ag), and gold (Au). Of these, a metal containing copper or aluminum as a main component is preferable from the viewpoint of low resistivity and cost. Further, the wiring 40 may be covered with a material such as titanium (Ti), molybdenum (Mo), copper oxide, carbon, etc. for the purpose of reducing the reflectance. Further, the surface of the coated material may have irregularities.
　図１に示した表示領域１０１における配線４０の幅は、いずれも例えば１～１００μｍ、好ましくは３～２０μｍである。配線４０の幅が１００μｍ以下であるため、例えば数１０ｃｍ～２ｍ程度の近距離から、透明表示装置を観察するような場合でも、配線４０はほとんど視認できず、背面側の視認性に優れている。他方、後述する厚さの範囲の場合、配線４０の幅を１μｍ以上であれば、配線４０の抵抗の過度な上昇を抑制し、電圧降下や信号強度の低下を抑制できる。また、配線４０による熱伝導の低下も抑制できる。 The width of the wiring 40 in the display area 101 shown in FIG. 1 is, for example, 1 to 100 μm, preferably 3 to 20 μm. Since the width of the wiring 40 is 100 μm or less, the wiring 40 is almost invisible even when observing the transparent display device from a short distance of about several tens of centimeters to 2 m, and the visibility on the back side is excellent. .. On the other hand, in the case of the thickness range described later, if the width of the wiring 40 is 1 μm or more, it is possible to suppress an excessive increase in the resistance of the wiring 40, and suppress a voltage drop and a decrease in signal strength. In addition, it is possible to suppress a decrease in heat conduction due to the wiring 40.
　ここで、図１に示すように、配線４０が主にｘ軸方向及びｙ軸方向に延びている場合、透明表示装置の外部から照射された光によってｘ軸方向及びｙ軸方向に延びた十字回折像が発生し、透明表示装置の背面側の視認性が低下する場合がある。各配線の幅を小さくすることによって、この回折を抑制し、背面側の視認性をさらに向上させられる。回折を抑制する観点から、配線４０の幅を５０μｍ以下、好ましくは１０μｍ以下、より好ましくは５μｍ以下としてもよい。 Here, as shown in FIG. 1, when the wiring 40 extends mainly in the x-axis direction and the y-axis direction, a cross extending in the x-axis direction and the y-axis direction by the light emitted from the outside of the transparent display device. A diffraction image may be generated and the visibility on the back side of the transparent display device may be reduced. By reducing the width of each wiring, this diffraction can be suppressed and the visibility on the back side can be further improved. From the viewpoint of suppressing diffraction, the width of the wiring 40 may be 50 μm or less, preferably 10 μm or less, and more preferably 5 μm or less.
　配線４０の電気抵抗率は、例えば１．０×１０－６Ωｍ以下、好ましくは２．０×１０－８Ωｍ以下である。また、配線４０の熱伝導率は、例えば１５０～５，５００Ｗ／（ｍ・Ｋ）、好ましくは３５０～４５０Ｗ／（ｍ・Ｋ）である。 The electrical resistivity of the wiring 40 is, for example, 1.0 × 10 -6 Ωm or less, preferably 2.0 × 10 -8 Ωm or less. The thermal conductivity of the wiring 40 is, for example, 150 to 5,500 W / (m · K), preferably 350 to 450 W / (m · K).
　図１に示した表示領域１０１における隣接する配線４０同士の間隔は、例えば３～１００μｍ、好ましくは５～３０μｍである。配線４０が密になっている領域があると、背面側の視認を妨げる場合がある。隣接する配線４０同士の間隔を３μｍ以上とすることによって、そのような視認の妨げを抑制できる。他方、隣接する配線４０同士の間隔を１００μｍ以下とすることによって、充分な表示能を確保できる。
　なお、配線４０が湾曲していること等によって配線４０同士の間隔が一定でない場合、上述の隣接する配線４０同士の間隔は、その最小値を指す。 The distance between adjacent wirings 40 in the display area 101 shown in FIG. 1 is, for example, 3 to 100 μm, preferably 5 to 30 μm. If there is an area where the wiring 40 is dense, the visibility on the back side may be hindered. By setting the distance between adjacent wirings 40 to 3 μm or more, such obstruction of visual recognition can be suppressed. On the other hand, by setting the distance between adjacent wirings 40 to 100 μm or less, sufficient display capability can be ensured.
When the distance between the wirings 40 is not constant due to the curved wiring or the like, the above-mentioned distance between the adjacent wirings 40 indicates the minimum value.
　１画素の面積に対して配線４０が占める面積の割合は、例えば３０％以下、好ましくは１０％以下、より好ましくは５％以下、さらに好ましくは３％以下である。配線４０の透過率は、例えば２０％以下、あるいは１０％以下と低い。しかしながら、１画素において配線４０が占める面積の割合を３０％以下とすることによって、表示領域１０１において透過率の低い領域が狭くなり、背面側の視認性が向上する。
　さらに、１画素の面積に対して発光部２０、ＩＣチップ３０、及び配線４０が占める面積の合計は、例えば３０％以下、好ましくは２０％以下、より好ましくは１０％以下である。 The ratio of the area occupied by the wiring 40 to the area of one pixel is, for example, 30% or less, preferably 10% or less, more preferably 5% or less, still more preferably 3% or less. The transmittance of the wiring 40 is as low as 20% or less, or 10% or less, for example. However, by setting the ratio of the area occupied by the wiring 40 in one pixel to 30% or less, the region with low transmittance is narrowed in the display region 101, and the visibility on the back surface side is improved.
Further, the total area occupied by the light emitting unit 20, the IC chip 30, and the wiring 40 with respect to the area of one pixel is, for example, 30% or less, preferably 20% or less, and more preferably 10% or less.
＜透明表示装置の断面構成＞
　次に、図２を参照して、本実施形態に係る透明表示装置の断面構成について説明する。
　透明基材１０は、絶縁性を有する透明な材料である。図２の例では、透明基材１０は、主基板１１及び接着剤層１２である２層構造を有している。
　主基板１１は、詳細には後述するように、例えば透明樹脂である。
　接着剤層１２は、例えばエポキシ系、アクリル系、オレフィン系、ポリイミド系、ノボラック系等の透明樹脂接着剤である。
　なお、主基板１１は、厚さが例えば２００μｍ以下、好ましくは１００μｍ以下等の薄いガラス板でもよい。また、接着剤層１２は、必須ではない。 <Cross-sectional configuration of transparent display device>
Next, with reference to FIG. 2, the cross-sectional configuration of the transparent display device according to the present embodiment will be described.
The transparent base material 10 is a transparent material having an insulating property. In the example of FIG. 2, the transparent base material 10 has a two-layer structure of the main substrate 11 and the adhesive layer 12.
The main substrate 11 is, for example, a transparent resin, as will be described in detail later.
The adhesive layer 12 is, for example, an epoxy-based, acrylic-based, olefin-based, polyimide-based, or novolak-based transparent resin adhesive.
The main substrate 11 may be a thin glass plate having a thickness of, for example, 200 μm or less, preferably 100 μm or less. Further, the adhesive layer 12 is not essential.
　主基板１１を構成する透明樹脂として、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）等のポリエステル系樹脂、シクロオレフィンポリマー（ＣＯＰ）、シクロオレフィンコポリマー（ＣＯＣ）等のオレフィン系樹脂、セルロース、アセチルセルロース、トリアセチルセルロース（ＴＡＣ）等のセルロース系樹脂、ポリイミド（ＰＩ）等のイミド系樹脂、ポリアミド（ＰＡ）等のアミド系樹脂、ポリアミドイミド（ＰＡＩ）等のアミドイミド系樹脂、ポリカーボネート（ＰＣ）等のカーボネート系樹脂、ポリエーテルスルホン（ＰＥＳ）等のスルホン系樹脂、ポリパラキシレン等のパラキシレンケイ系樹脂、ポリエチレン（ＰＥ）、ポリ塩化ビニル（ＰＶＣ）、ポリスチレン（ＰＳ）、ポリ酢酸ビニル（ＰＶＡｃ）、ポリビニルアルコール（ＰＶＡ）、ポリビニルブチラール（ＰＶＢ）等のビニル系樹脂、ポリメタクリル酸メチル（ＰＭＭＡ）等のアクリル系樹脂、エチレン・酢酸ビニル共重合樹脂（ＥＶＡ）、熱可塑性ポリウレタン（ＴＰＵ）等のウレタン系樹脂、エポキシ系樹脂等を例示できる。 As the transparent resin constituting the main substrate 11, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), olefin resins such as cycloolefin polymer (COP) and cycloolefin copolymer (COC), cellulose and acetyl Cellulose, cellulose-based resin such as triacetyl cellulose (TAC), imide-based resin such as polyimide (PI), amide-based resin such as polyamide (PA), amide-based resin such as polyamideimide (PAI), polycarbonate (PC), etc. Carbonate-based resin, sulfone-based resin such as polyether sulfone (PES), paraxylene-based resin such as polyparaxylene, polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAc). ), Vinyl resin such as polyvinyl alcohol (PVA) and polyvinyl butyral (PVB), acrylic resin such as polymethyl methacrylate (PMMA), ethylene / vinyl acetate copolymer resin (EVA), thermoplastic polyurethane (TPU), etc. Examples thereof include urethane-based resins and epoxy-based resins.
　上記の主基板１１に用いられる材料のうち、耐熱性向上の観点からはポリエチレンナフタレート（ＰＥＮ）、ポリイミド（ＰＩ）が好ましい。また、複屈折率が低く、透明基材を通して見た像の歪みや滲みを低減できる点では、シクロオレフィンポリマー（ＣＯＰ）、シクロオレフィンコポリマー（ＣＯＣ）、ポリビニルブチラール（ＰＶＢ）等が好ましい。
　上記材料を単一で用いても、２種以上の材料を混合して用いてもよい。さらに、異なる材料の平板を積層させて主基板１１を構成してもよい。 Of the materials used for the main substrate 11, polyethylene naphthalate (PEN) and polyimide (PI) are preferable from the viewpoint of improving heat resistance. Further, cycloolefin polymer (COP), cycloolefin copolymer (COC), polyvinyl butyral (PVB) and the like are preferable in that the double refractive index is low and distortion and bleeding of the image seen through the transparent substrate can be reduced.
The above materials may be used alone, or two or more kinds of materials may be mixed and used. Further, the main substrate 11 may be formed by laminating flat plates made of different materials.
　透明基材１０全体の厚さは、例えば３～１０００μｍ、好ましくは５～２００μｍである。透明基材１０の可視光の内部透過率は、例えば５０％以上、好ましくは７０％以上、より好ましくは９０％以上である。
　また、透明基材１０は可撓性を有していてもよい。これにより、例えば透明表示装置を湾曲した透明板に装着したり、湾曲した２枚の透明板の間に挟んで使用したりできる。また、１００℃以上に加熱した際に収縮する材料であってもよい。 The total thickness of the transparent substrate 10 is, for example, 3 to 1000 μm, preferably 5 to 200 μm. The internal transmittance of visible light of the transparent substrate 10 is, for example, 50% or more, preferably 70% or more, and more preferably 90% or more.
Further, the transparent base material 10 may have flexibility. Thereby, for example, the transparent display device can be attached to a curved transparent plate, or can be used by being sandwiched between two curved transparent plates. Further, it may be a material that shrinks when heated to 100 ° C. or higher.
　図２に示すように、ＬＥＤ素子２１～２３及びＩＣチップ３０は、透明基材１０すなわち接着剤層１２上に設けられており、透明基材１０上に配置された配線４０と接続されている。図２の例では、配線４０は、主基板１１上に形成された第１メタル層Ｍ１、及び接着剤層１２上に形成された第２メタル層Ｍ２から構成されている。 As shown in FIG. 2, the LED elements 21 to 23 and the IC chip 30 are provided on the transparent base material 10, that is, the adhesive layer 12, and are connected to the wiring 40 arranged on the transparent base material 10. .. In the example of FIG. 2, the wiring 40 is composed of a first metal layer M1 formed on the main substrate 11 and a second metal layer M2 formed on the adhesive layer 12.
　配線４０の厚さすなわち第１メタル層Ｍ１の厚さと第２メタル層Ｍ２の厚さとの合計は、例えば０．１～１０μｍ、好ましくは０．５～５μｍである。第１メタル層Ｍ１の厚さは、例えば０．５μｍ程度、第２メタル層Ｍ２の厚さは、例えば３μｍ程度である。 The total thickness of the wiring 40, that is, the thickness of the first metal layer M1 and the thickness of the second metal layer M2 is, for example, 0.1 to 10 μm, preferably 0.5 to 5 μm. The thickness of the first metal layer M1 is, for example, about 0.5 μm, and the thickness of the second metal layer M2 is, for example, about 3 μm.
　詳細には、図２に示すように、ｙ軸方向に延設されたグランド線４２は、電流量が多いため、第１メタル層Ｍ１及び第２メタル層Ｍ２を含む２層構造を有している。すなわち、グランド線４２が設けられた部位では、接着剤層１２が除去され、第１メタル層Ｍ１上に第２メタル層Ｍ２が形成されている。図２には示されていないが、図１に示した電源線４１、行データ線４３、及び列データ線４４も、同様に、第１メタル層Ｍ１及び第２メタル層Ｍ２を含む２層構造を有している。 Specifically, as shown in FIG. 2, since the ground wire 42 extending in the y-axis direction has a large amount of current, it has a two-layer structure including the first metal layer M1 and the second metal layer M2. There is. That is, at the portion where the ground wire 42 is provided, the adhesive layer 12 is removed, and the second metal layer M2 is formed on the first metal layer M1. Although not shown in FIG. 2, the power line 41, the row data line 43, and the column data line 44 shown in FIG. 1 also have a two-layer structure including the first metal layer M1 and the second metal layer M2. have.
　ここで、図１に示すように、ｙ軸方向に延設された電源線４１、グランド線４２、及び列データ線４４と、ｘ軸方向に延設された行データ線４３とは、交差している。図２には図示されていないが、この交差部では、行データ線４３は第１メタル層Ｍ１のみから構成され、電源線４１、グランド線４２、及び列データ線４４は第２メタル層Ｍ２のみから構成されている。そして、この交差部では、第１メタル層Ｍ１と第２メタル層Ｍ２との間に接着剤層１２が設けられ、第１メタル層Ｍ１と第２メタル層Ｍ２とが絶縁されている。
　同様に、図１に示した列データ線４４と第１電源分岐線４１ａとの交差部では、第１電源分岐線４１ａが第１メタル層Ｍ１のみから構成され、列データ線４４が第２メタル層Ｍ２のみから構成されている。 Here, as shown in FIG. 1, the power supply line 41, the ground line 42, and the column data line 44 extending in the y-axis direction intersect with the row data line 43 extending in the x-axis direction. ing. Although not shown in FIG. 2, at this intersection, the row data line 43 is composed of only the first metal layer M1, and the power line 41, the ground line 42, and the column data line 44 are composed of only the second metal layer M2. It is composed of. At this intersection, an adhesive layer 12 is provided between the first metal layer M1 and the second metal layer M2, and the first metal layer M1 and the second metal layer M2 are insulated from each other.
Similarly, at the intersection of the column data line 44 and the first power supply branch line 41a shown in FIG. 1, the first power supply branch line 41a is composed of only the first metal layer M1, and the column data line 44 is the second metal. It is composed of only the layer M2.
　また、図２の例では、グランド分岐線４２ａ、駆動線４５、及び第１電源分岐線４１ａは第２メタル層Ｍ２のみから構成され、ＬＥＤ素子２１～２３及びＩＣチップ３０の端部を覆うように形成されている。図２には示されていないが、第２電源分岐線４１ｂ、行データ分岐線４３ａ、及び列データ分岐線４４ａも、同様に、第２メタル層Ｍ２のみから構成されている。 Further, in the example of FIG. 2, the ground branch line 42a, the drive line 45, and the first power supply branch line 41a are composed of only the second metal layer M2 and cover the end portions of the LED elements 21 to 23 and the IC chip 30. Is formed in. Although not shown in FIG. 2, the second power supply branch line 41b, the row data branch line 43a, and the column data branch line 44a are similarly composed of only the second metal layer M2.
　なお、第１電源分岐線４１ａは、上述の通り、列データ線４４との交差部では第１メタル層Ｍ１のみから構成され、それ以外の部位では第２メタル層Ｍ２のみから構成されている。また、透明基材１０上に形成された配線４０上に、銅、銀、金製等の金属パッドを配置し、その上にＬＥＤ素子２１～２３及びＩＣチップ３０の少なくとも一方を配置してもよい。 As described above, the first power supply branch line 41a is composed of only the first metal layer M1 at the intersection with the column data line 44, and is composed of only the second metal layer M2 at other portions. Further, even if a metal pad made of copper, silver, gold or the like is arranged on the wiring 40 formed on the transparent base material 10, and at least one of the LED elements 21 to 23 and the IC chip 30 is arranged on the metal pad. good.
　保護層５０は、発光部２０、ＩＣチップ３０、及び配線４０を覆って保護するように、透明基材１０上の略全面に形成された透明樹脂である。
　保護層５０の厚さは、例えば３～１０００μｍ、好ましくは５～２００μｍである。
　保護層５０の弾性率は、例えば１０ＧＰａ以下である。弾性率が低い方が、剥離時の衝撃を吸収でき、保護層５０の破損を抑制できる。
　保護層５０の可視光の内部透過率は、例えば５０％以上、好ましくは７０％以上、より好ましくは９０％以上である。 The protective layer 50 is a transparent resin formed on substantially the entire surface of the transparent base material 10 so as to cover and protect the light emitting portion 20, the IC chip 30, and the wiring 40.
The thickness of the protective layer 50 is, for example, 3 to 1000 μm, preferably 5 to 200 μm.
The elastic modulus of the protective layer 50 is, for example, 10 GPa or less. When the elastic modulus is low, the impact at the time of peeling can be absorbed and the damage of the protective layer 50 can be suppressed.
The internal transmittance of visible light of the protective layer 50 is, for example, 50% or more, preferably 70% or more, and more preferably 90% or more.
　保護層５０を構成する透明樹脂として、ポリエチレン（ＰＥ）、ポリ塩化ビニル（ＰＶＣ）、ポリスチレン（ＰＳ）、ポリ酢酸ビニル（ＰＶＡｃ）、ポリビニルアルコール（ＰＶＡ）、ポリビニルブチラール（ＰＶＢ）等のビニル系樹脂、シクロオレフィンポリマー（ＣＯＰ）、シクロオレフィンコポリマー（ＣＯＣ）等のオレフィン系樹脂、熱可塑性ポリウレタン（ＴＰＵ）等のウレタン系樹脂、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）等のポリエステル系樹脂、ポリメタクリル酸メチル（ＰＭＭＡ）等のアクリル系樹脂、エチレン・酢酸ビニル共重合樹脂（ＥＶＡ）等の熱可塑性樹脂を例示できる。 As the transparent resin constituting the protective layer 50, vinyl-based resins such as polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB) , Olefin resin such as cycloolefin polymer (COP), cycloolefin copolymer (COC), urethane resin such as thermoplastic polyurethane (TPU), polyester resin such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Examples thereof include acrylic resins such as polymethyl methacrylate (PMMA) and thermoplastic resins such as ethylene / vinyl acetate copolymer resin (EVA).
＜透明表示装置の製造方法＞
　次に、図２～図１０を参照して、第１の実施形態に係る透明表示装置の製造方法の一例について説明する。図３～図１０は、第１の実施形態に係る透明表示装置の製造方法の一例を示す断面図である。図３～図１０は、図２に対応した断面図である。 <Manufacturing method of transparent display device>
Next, an example of a method for manufacturing the transparent display device according to the first embodiment will be described with reference to FIGS. 2 to 10. 3 to 10 are cross-sectional views showing an example of a method for manufacturing a transparent display device according to the first embodiment. 3 to 10 are cross-sectional views corresponding to FIG. 2.
　まず、図３に示すように、主基板１１上の略全面に第１メタル層Ｍ１を成膜した後、第１メタル層Ｍ１をフォトリソグラフィによってパターニングし、下層配線を形成する。具体的には、図１に示した電源線４１、グランド線４２、行データ線４３、及び列データ線４４等が形成される位置に、第１メタル層Ｍ１によって下層配線を形成する。
　なお、電源線４１、グランド線４２、及び列データ線４４における行データ線４３との交差部には下層配線を形成しない。 First, as shown in FIG. 3, a first metal layer M1 is formed on substantially the entire surface of the main substrate 11, and then the first metal layer M1 is patterned by photolithography to form a lower layer wiring. Specifically, the lower layer wiring is formed by the first metal layer M1 at the position where the power supply line 41, the ground line 42, the row data line 43, the column data line 44, and the like shown in FIG. 1 are formed.
No lower layer wiring is formed at the intersection of the power line 41, the ground line 42, and the column data line 44 with the row data line 43.
　次に、図４に示すように、主基板１１上の略全面に接着剤層１２を成膜した後、タック性を有する接着剤層１２上に（すなわち透明基材１０上に）、ＬＥＤ素子２１～２３及びＩＣチップ３０を実装する。 Next, as shown in FIG. 4, after the adhesive layer 12 is formed on substantially the entire surface of the main substrate 11, the LED element is placed on the tacky adhesive layer 12 (that is, on the transparent substrate 10). 21 to 23 and the IC chip 30 are mounted.
　ここで、ＬＥＤ素子２１～２３は、例えば液相成長法、ＨＶＰＥ（Hydride Vapor Phase Epitaxy）法、ＭＯＣＶＤ（Metal Organic Chemical Vapor Deposition）法等を用いて、ウェハ上に結晶を成長させた後、パターニングすることによって得られる。ウェハ上にパターニングされたＬＥＤ素子２１～２３を、マイクロトランスファープリンティング技術を用いて、透明基材１０上に転写する。本実施形態に係るマイクロトランスファープリンティング技術の詳細については後述する。 Here, the LED elements 21 to 23 are patterned after growing crystals on the wafer by using, for example, a liquid phase growth method, an HVPE (Hydride Vapor Phase Epitaxy) method, a MOCVD (Metal Organic Chemical Vapor Deposition) method, or the like. Obtained by doing. The LED elements 21 to 23 patterned on the wafer are transferred onto the transparent substrate 10 by using a micro transfer printing technique. Details of the micro transfer printing technique according to this embodiment will be described later.
　ＩＣチップ３０の透明基材１０上への実装方法は特に限定されない。例えばＳｉウェハ上にパターニングされたＩＣチップ３０を、ＬＥＤ素子２１～２３と同様に、本実施形態に係るマイクロトランスファープリンティング技術を用いて、透明基材１０上に転写してもよい。すなわち、本実施形態に係るマイクロトランスファープリンティング技術は、ウェハ上にパターニングされたＬＥＤ素子２１～２３やＩＣチップ３０等の半導体素子に適用できる。 The method of mounting the IC chip 30 on the transparent base material 10 is not particularly limited. For example, the IC chip 30 patterned on the Si wafer may be transferred onto the transparent substrate 10 by using the micro transfer printing technique according to the present embodiment in the same manner as the LED elements 21 to 23. That is, the micro transfer printing technique according to the present embodiment can be applied to semiconductor elements such as LED elements 21 to 23 and IC chips 30 patterned on a wafer.
　次に、図５に示すように、主基板１１及び接着剤層１２を含む透明基材１０上の略全面にフォトレジストＦＲ１を成膜した後、第１メタル層Ｍ１上のフォトレジストＦＲ１をパターニングによって除去する。ここで、図１に示した行データ線４３における電源線４１、グランド線４２、及び列データ線４４との交差部のフォトレジストＦＲ１は除去されない。 Next, as shown in FIG. 5, the photoresist FR1 is formed on substantially the entire surface of the transparent substrate 10 including the main substrate 11 and the adhesive layer 12, and then the photoresist FR1 on the first metal layer M1 is patterned. Remove by. Here, the photoresist FR1 at the intersection of the power line 41, the ground line 42, and the column data line 44 in the row data line 43 shown in FIG. 1 is not removed.
　次に、図６に示すように、フォトレジストＦＲ１が除去された部位の接着剤層１２をドライエッチングによって除去し、第１メタル層Ｍ１すなわち下層配線を露出させる。
　次に、図７に示すように、透明基材１０上のフォトレジストＦＲ１を全て除去する。その後、透明基材１０上の略全面に図示しないめっき用シード層を形成する。 Next, as shown in FIG. 6, the adhesive layer 12 at the portion where the photoresist FR1 has been removed is removed by dry etching to expose the first metal layer M1, that is, the lower layer wiring.
Next, as shown in FIG. 7, all the photoresist FR1 on the transparent substrate 10 is removed. After that, a seed layer for plating (not shown) is formed on substantially the entire surface of the transparent substrate 10.
　次に、図８に示すように、透明基材１０上の略全面にフォトレジストＦＲ２を成膜した後、上層配線を形成する部位のフォトレジストＦＲ２をパターニングによって除去し、シード層を露出させる。
　次に、図９に示すように、フォトレジストＦＲ２が除去された部位すなわちシード層上に、めっきによって第２メタル層Ｍ２を形成する。これによって、第２メタル層Ｍ２によって上層配線が形成される。 Next, as shown in FIG. 8, after the photoresist FR2 is formed on substantially the entire surface of the transparent substrate 10, the photoresist FR2 at the portion where the upper layer wiring is formed is removed by patterning to expose the seed layer.
Next, as shown in FIG. 9, a second metal layer M2 is formed by plating on the site where the photoresist FR2 has been removed, that is, the seed layer. As a result, the upper layer wiring is formed by the second metal layer M2.
　次に、図１０に示すように、フォトレジストＦＲ２を除去する。さらに、フォトレジストＦＲ２の除去によって露出したシード層を、エッチングによって除去する。
　最後に、図２に示すように、透明基材１０上の略全面に保護層５０を形成することによって、透明表示装置が得られる。 Next, as shown in FIG. 10, the photoresist FR2 is removed. Further, the seed layer exposed by the removal of the photoresist FR2 is removed by etching.
Finally, as shown in FIG. 2, a transparent display device is obtained by forming the protective layer 50 on substantially the entire surface of the transparent substrate 10.
＜マイクロトランスファープリンティング技術＞
　次に、図１１～図１４を参照して、本実施形態に係る透明表示装置の製造方法におけるマイクロトランスファープリンティング技術について説明する。図１１は、ウェハ上にパターニングされたＬＥＤ素子２３の平面図である。図１２～図１４は、第１の実施形態に係る透明表示装置の製造方法におけるマイクロトランスファープリンティング技術の一例を示す断面図である。ここで、図１２は、図１１のＸＩＩ－ＸＩＩ切断線による断面図である。 <Micro transfer printing technology>
Next, with reference to FIGS. 11 to 14, the micro transfer printing technique in the method for manufacturing the transparent display device according to the present embodiment will be described. FIG. 11 is a plan view of the LED element 23 patterned on the wafer. 12 to 14 are cross-sectional views showing an example of a micro transfer printing technique in the method for manufacturing a transparent display device according to the first embodiment. Here, FIG. 12 is a cross-sectional view taken along the line XII-XII of FIG.
　なお、当然のことながら、図１１～図１４に示した右手系ｘｙｚ直交座標は、構成要素の位置関係を説明するための便宜的なものである。通常、ｚ軸正向きが鉛直上向き、ｘｙ平面が水平面であり、図面間で共通である。また、以下では、青色系のＬＥＤ素子２３について説明するが、赤色系のＬＥＤ素子２１、緑色系のＬＥＤ素子２２についても同様である。また、図１１には、後述する実施例におけるＬＥＤ素子２３の具体的なサイズが記載されている。 As a matter of course, the right-handed xyz orthogonal coordinates shown in FIGS. 11 to 14 are for convenience in explaining the positional relationship of the components. Normally, the z-axis positive direction is vertically upward, and the xy plane is a horizontal plane, which is common between drawings. Further, although the blue LED element 23 will be described below, the same applies to the red LED element 21 and the green LED element 22. Further, FIG. 11 shows a specific size of the LED element 23 in the embodiment described later.
　まず、図１１及び図１２を参照して、ＬＥＤ素子２３の構成及び製造方法について説明する。
　図１１に示すように、ウェハＷＦ上には、ｘ軸方向に延設された支柱がｙ軸方向に平行に並んでパターニングされており、各ＬＥＤ素子２３は、固定部を介して支柱に固定されている。すなわち、ウェハＷＦ上に複数のＬＥＤ素子２３がｘ軸方向及びｙ軸方向に規則的に並ぶようにパターニングされている。特に、図１１の例では、ウェハＷＦ上に複数のＬＥＤ素子２３がマトリクス状に配置されている。
　ウェハＷＦとして、青色系のＬＥＤ素子２３や緑色系のＬＥＤ素子２２の場合、例えばＳｉウェハやサファイアウェハ等を用いる。赤色系のＬＥＤ素子２１の場合、ＧａＡｓウェハ等を用いる。 First, the configuration and manufacturing method of the LED element 23 will be described with reference to FIGS. 11 and 12.
As shown in FIG. 11, on the wafer WF, columns extending in the x-axis direction are patterned side by side in parallel in the y-axis direction, and each LED element 23 is fixed to the column via a fixing portion. Has been done. That is, a plurality of LED elements 23 are regularly patterned on the wafer WF in the x-axis direction and the y-axis direction. In particular, in the example of FIG. 11, a plurality of LED elements 23 are arranged in a matrix on the wafer WF.
As the wafer WF, in the case of the blue LED element 23 and the green LED element 22, for example, a Si wafer, a sapphire wafer, or the like is used. In the case of the red LED element 21, a GaAs wafer or the like is used.
　図１１、図１２に示すように、ＬＥＤ素子２３は、バッファ層ＢＬ、Ｎ型半導体層ＮＬ、Ｐ型半導体層ＰＬ、絶縁層ＩＬ、コンタクトＣＴ、Ｎ電極ＮＥ、及びＰ電極ＰＥを備えている。ここで、図１２を参照して、ＬＥＤ素子２３の構成と共に製造方法についても説明する。
　まず、ウェハＷＦ上の略全面に、バッファ層ＢＬ、Ｎ型半導体層ＮＬ、Ｐ型半導体層ＰＬの順に形成する。Ｐ型半導体層ＰＬ上にコンタクトＣＴを形成した後、Ｐ型半導体層ＰＬをパターニングし、図１２に示すようなメサ構造を形成する。 As shown in FIGS. 11 and 12, the LED element 23 includes a buffer layer BL, an N-type semiconductor layer NL, a P-type semiconductor layer PL, an insulating layer IL, a contact CT, an N electrode NE, and a P electrode PE. .. Here, with reference to FIG. 12, a manufacturing method will be described together with the configuration of the LED element 23.
First, the buffer layer BL, the N-type semiconductor layer NL, and the P-type semiconductor layer PL are formed in this order on substantially the entire surface of the wafer WF. After forming the contact CT on the P-type semiconductor layer PL, the P-type semiconductor layer PL is patterned to form a mesa structure as shown in FIG.
　さらに、バッファ層ＢＬ及びＮ型半導体層ＮＬを図１１、図１２に示すような形状にパターニングする。この際、図１２に示すように、ＬＥＤ素子２３及び支柱を構成するバッファ層ＢＬ及びＮ型半導体層ＮＬを、ウェハＷＦ上に残留させる。換言すると、図１２に示すように、ＬＥＤ素子２３と支柱との間のバッファ層ＢＬ及びＮ型半導体層ＮＬは除去され、溝が形成される。 Further, the buffer layer BL and the N-type semiconductor layer NL are patterned into the shapes shown in FIGS. 11 and 12. At this time, as shown in FIG. 12, the buffer layer BL and the N-type semiconductor layer NL constituting the LED element 23 and the support column are left on the wafer WF. In other words, as shown in FIG. 12, the buffer layer BL and the N-type semiconductor layer NL between the LED element 23 and the support column are removed, and a groove is formed.
　次に、Ｎ型半導体層ＮＬ及びＰ型半導体層ＰＬの表面を覆うように絶縁層ＩＬを形成する。この際、図１２に示すように、絶縁層ＩＬは、ＬＥＤ素子２３と支柱との間の溝を介して、支柱も覆うように形成される。他方、コンタクトＣＴ上、及びＮ型半導体層ＮＬにおいてＮ電極ＮＥを形成する領域上には、絶縁層ＩＬを形成しない。
　次に、図１２に示すように、Ｎ型半導体層ＮＬ上にＮ電極ＮＥを形成すると共に、コンタクトＣＴ上にＰ電極ＰＥを形成する。Ｐ型半導体層ＰＬは、コンタクトＣＴを介してＰ電極ＰＥに接続される。 Next, the insulating layer IL is formed so as to cover the surfaces of the N-type semiconductor layer NL and the P-type semiconductor layer PL. At this time, as shown in FIG. 12, the insulating layer IL is formed so as to cover the support column through the groove between the LED element 23 and the support column. On the other hand, the insulating layer IL is not formed on the contact CT and on the region where the N electrode NE is formed in the N-type semiconductor layer NL.
Next, as shown in FIG. 12, the N electrode NE is formed on the N-type semiconductor layer NL, and the P electrode PE is formed on the contact CT. The P-type semiconductor layer PL is connected to the P electrode PE via the contact CT.
　最後に、図１２に示すように、ＬＥＤ素子２３の下側（具体的には、ＬＥＤ素子２３におけるバッファ層ＢＬ直下）のウェハＷＦを異方性エッチング等によって除去する。これにより、図１２に示すように、ＬＥＤ素子２３がウェハＷＦの基板面から浮遊するように形成される。ＬＥＤ素子２３は、ｙ軸正方向に張り出した固定部のみを介して支柱に固定されている。図１２に示すように、本実施形態に係る固定部は、絶縁層ＩＬから構成されている。絶縁層ＩＬは、特に限定されないが、例えば窒化シリコン（Ｓｉ３Ｎ４）から構成される。 Finally, as shown in FIG. 12, the wafer WF on the lower side of the LED element 23 (specifically, directly under the buffer layer BL in the LED element 23) is removed by anisotropic etching or the like. As a result, as shown in FIG. 12, the LED element 23 is formed so as to float from the substrate surface of the wafer WF. The LED element 23 is fixed to the support column only through the fixing portion protruding in the positive direction of the y-axis. As shown in FIG. 12, the fixing portion according to the present embodiment is composed of an insulating layer IL. The insulating layer IL is not particularly limited, but is composed of , for example, silicon nitride (Si 3 N 4).
　図１１に示すように、Ｎ型半導体層ＮＬ及びＰ型半導体層ＰＬは、平面視矩形状の形状を有している。図１１に示されていないバッファ層ＢＬの平面形状はＮ型半導体層ＮＬと同様である。そして、Ｎ型半導体層ＮＬ及びＰ型半導体層ＰＬを覆う絶縁層ＩＬも平面視矩形状の形状を有している。すなわち、ウェハＷＦ上に形成されたＬＥＤ素子２３は、平面視矩形状の矩形領域を備え、矩形領域の一辺のみにおいてウェハＷＦに固定されている。図１１の例では、ＬＥＤ素子２３は、矩形領域であるＮ型半導体層ＮＬ（すなわちバッファ層ＢＬ）の一方の短辺のみおいて固定部を介してウェハＷＦの支柱に固定されている。 As shown in FIG. 11, the N-type semiconductor layer NL and the P-type semiconductor layer PL have a rectangular shape in a plan view. The planar shape of the buffer layer BL not shown in FIG. 11 is the same as that of the N-type semiconductor layer NL. The insulating layer IL covering the N-type semiconductor layer NL and the P-type semiconductor layer PL also has a rectangular shape in a plan view. That is, the LED element 23 formed on the wafer WF has a rectangular region having a rectangular shape in a plan view, and is fixed to the wafer WF only on one side of the rectangular region. In the example of FIG. 11, the LED element 23 is fixed to the support of the wafer WF via the fixing portion with only one short side of the N-type semiconductor layer NL (that is, the buffer layer BL) which is a rectangular region.
　なお、ＬＥＤ素子２３は、ウェハＷＦにどのように固定されていてもよい。例えば、ＬＥＤ素子２３は、矩形領域であるＮ型半導体層ＮＬ（すなわちバッファ層ＢＬ）の２辺以上おいてウェハＷＦに固定されていてもよい。さらに、ＬＥＤ素子２３が、ウェハＷＦの基板面から浮遊するように形成されておらず、ＬＥＤ素子２３の底面がウェハＷＦの基板面に接するように形成されていてもよい。 The LED element 23 may be fixed to the wafer WF in any way. For example, the LED element 23 may be fixed to the wafer WF with two or more sides of the N-type semiconductor layer NL (that is, the buffer layer BL) which is a rectangular region. Further, the LED element 23 may not be formed so as to float from the substrate surface of the wafer WF, but may be formed so that the bottom surface of the LED element 23 is in contact with the substrate surface of the wafer WF.
　ＬＥＤ素子２３はメサ構造を有しているため、図１１に示すように、Ｐ型半導体層ＰＬのｙ軸方向の幅が、Ｎ型半導体層ＮＬのｙ軸方向の幅よりも小さい。他方、図１１に示すように、Ｐ型半導体層ＰＬのｘ軸方向の幅は、Ｎ型半導体層ＮＬのｘ軸方向の幅と同程度である。
　図１１の例では、Ｐ電極ＰＥは、平面視矩形状の形状を有しており、Ｐ型半導体層ＰＬの中心部に形成されている。Ｎ電極ＮＥは、平面視矩形状の形状を有しており、Ｎ型半導体層ＮＬにおけるｙ軸負方向側端部のｘ軸方向中央部に形成されている。 Since the LED element 23 has a mesa structure, the width of the P-type semiconductor layer PL in the y-axis direction is smaller than the width of the N-type semiconductor layer NL in the y-axis direction, as shown in FIG. On the other hand, as shown in FIG. 11, the width of the P-type semiconductor layer PL in the x-axis direction is about the same as the width of the N-type semiconductor layer NL in the x-axis direction.
In the example of FIG. 11, the P electrode PE has a rectangular shape in a plan view and is formed in the center of the P-type semiconductor layer PL. The N electrode NE has a rectangular shape in a plan view, and is formed at the center of the N-type semiconductor layer NL on the negative side in the y-axis direction in the x-axis direction.
　次に、マイクロトランスファープリンティング技術について説明する。
　図１２に示すように、ＬＥＤ素子２３をピックアップするためのエラストマスタンプ８０は、平板状の基体８１と、基体８１の主面から垂直方向（ｚ軸負方向側）に突出した突起８２とを備えている。なお、理解を容易にするため、エラストマスタンプ８０のハッチングは省略した。 Next, the micro transfer printing technique will be described.
As shown in FIG. 12, the elastomer stamp 80 for picking up the LED element 23 includes a flat plate-shaped substrate 81 and a protrusion 82 projecting from the main surface of the substrate 81 in the vertical direction (negative direction on the z-axis). ing. The hatching of the elastomer stamp 80 is omitted for ease of understanding.
　突起８２は、図１に示した透明表示装置における各画素にＬＥＤ素子２３を配置するために設けられている。そのため、突起８２の間隔は、図１に示した画素ピッチＰｘ、Ｐｙに対応している。突起８２は、２段階以上の多段階の突起であってもよい。また、エラストマスタンプ８０は、全体の剛性を担保するため、例えばガラス基板、金属基板、セラミック基板等の硬質な基板上に担持されていてもよい。すなわち、図１２に示したエラストマスタンプ８０の上側（ｚ軸正方向側）の主面に基板が設けられていてもよい。 The protrusion 82 is provided for arranging the LED element 23 on each pixel in the transparent display device shown in FIG. Therefore, the distance between the protrusions 82 corresponds to the pixel pitches Px and Py shown in FIG. The protrusion 82 may be a multi-step protrusion having two or more steps. Further, the elastomer stamp 80 may be supported on a hard substrate such as a glass substrate, a metal substrate, or a ceramic substrate in order to secure the overall rigidity. That is, the substrate may be provided on the main surface on the upper side (the z-axis positive direction side) of the elastomer stamp 80 shown in FIG.
　まず、図１２、図１３に示すように、エラストマスタンプ８０を降下させ、ウェハＷＦ上にパターニングされたＬＥＤ素子２３にエラストマスタンプ８０を押し当てる。さらに、図１３に示すように、ＬＥＤ素子２３がウェハＷＦの基板面に近付くまで、エラストマスタンプ８０を押し込む。
　ここで、押し込み量が大きい程、固定部が破断し易くなり、好ましいが、押し込み量は、突起８２の高さによって制限される。例えば、押し込み量を突起８２の高さの２０～９５％とする。押し込み量は、好ましくは、突起８２の高さの４０～９５％、さらに好ましくは、突起８２の高さの６０～９５％である。 First, as shown in FIGS. 12 and 13, the elastomer stamp 80 is lowered, and the elastomer stamp 80 is pressed against the LED element 23 patterned on the wafer WF. Further, as shown in FIG. 13, the elastomer stamp 80 is pushed in until the LED element 23 approaches the substrate surface of the wafer WF.
Here, the larger the pushing amount, the easier it is for the fixed portion to break, which is preferable, but the pushing amount is limited by the height of the protrusion 82. For example, the pushing amount is set to 20 to 95% of the height of the protrusion 82. The pushing amount is preferably 40 to 95% of the height of the protrusion 82, and more preferably 60 to 95% of the height of the protrusion 82.
　次に、図１４に示すように、エラストマスタンプ８０の突起８２に貼り付けたＬＥＤ素子２３を引き上げてウェハＷＦから引き離す。図１３に示したエラストマスタンプ８０によるＬＥＤ素子２３の押し込み動作と、図１４に示したエラストマスタンプ８０によるＬＥＤ素子２３の引き上げ動作とによって、固定部が破断し、ＬＥＤ素子２３がウェハＷＦから引き離される。
　ここで、エラストマスタンプ８０を所定の位置まで押し込んだ後、ウェハＷＦから引き離すまでの保持時間が長い程、固定部が破断し易くなるが、保持時間が長いと、サイクルタイムも長くなり、生産性が低下する。例えば、保持時間は、０～６００秒が好ましい。保持時間は、０～３００秒がより好ましく、１～１８０秒がさらに好ましい。
　その後、ＬＥＤ素子２３を、エラストマスタンプ８０に貼り付けたまま搬送し、透明基材１０に押し当てることによって、図４に示すように、透明基材１０上にＬＥＤ素子２３を配置する。 Next, as shown in FIG. 14, the LED element 23 attached to the protrusion 82 of the elastomer stamp 80 is pulled up and pulled away from the wafer WF. The fixed portion is broken and the LED element 23 is pulled away from the wafer WF by the pushing operation of the LED element 23 by the elastomer stamp 80 shown in FIG. 13 and the pulling operation of the LED element 23 by the elastomer stamp 80 shown in FIG. ..
Here, the longer the holding time from pushing the elastomer stamp 80 to a predetermined position until it is separated from the wafer WF, the easier it is for the fixed portion to break, but the longer the holding time, the longer the cycle time and productivity. Decreases. For example, the holding time is preferably 0 to 600 seconds. The holding time is more preferably 0 to 300 seconds, still more preferably 1 to 180 seconds.
After that, the LED element 23 is conveyed while being attached to the elastomer stamp 80 and pressed against the transparent base material 10, so that the LED element 23 is arranged on the transparent base material 10 as shown in FIG.
　図１３、図１４に示すように、押し込み動作によって固定部に作用する曲げモーメントと、引き上げ動作によって固定部に作用する反対方向への曲げモーメントとによって、固定部が破断すると考えられる。
　なお、本明細書に記載した固定部が破断するメカニズムは、あくまでも現時点において推察されるものである。 As shown in FIGS. 13 and 14, it is considered that the fixed portion is broken by the bending moment acting on the fixed portion by the pushing operation and the bending moment acting on the fixed portion by the pulling operation in the opposite direction.
The mechanism by which the fixed portion described in the present specification breaks is only inferred at this time.
　発明者らは、これまで、ＬＥＤ素子２３にエラストマスタンプ８０を押し当てる際、図１１に示すエラストマスタンプ８０の突起８２のｘｙ平面中心Ｏ２と、ＬＥＤ素子２３のＰ電極ＰＥのｘｙ平面中心Ｏ１とを位置合わせしていた。すなわち、エラストマスタンプ８０においてＬＥＤ素子２３側に最も突出した部位の中心と、ＬＥＤ素子２３においてエラストマスタンプ８０側に最も突出した部位の中心とを位置合わせしていた。 So far, when the elastomer stamp 80 is pressed against the LED element 23, the inventors have described the xy plane center O2 of the protrusion 82 of the elastomer stamp 80 shown in FIG. 11 and the xy plane center O1 of the P electrode PE of the LED element 23. Was aligned. That is, the center of the portion of the elastomer stamp 80 most protruding toward the LED element 23 side and the center of the portion of the LED element 23 most protruding toward the elastomer stamp 80 side were aligned.
　そして、ＬＥＤ素子２３にエラストマスタンプ８０を押し当てた後、エラストマスタンプ８０に貼り付けたＬＥＤ素子を、単純にウェハＷＦの基板面と垂直な方向（ｚ軸正方向）に引き上げていた。
　しかしながら、このような手法では、エラストマスタンプ８０によるＬＥＤ素子２３のピックアップ収率が低く、透明表示装置の生産性に劣るという問題があった。 Then, after the elastomer stamp 80 was pressed against the LED element 23, the LED element attached to the elastomer stamp 80 was simply pulled up in the direction perpendicular to the substrate surface of the wafer WF (the z-axis positive direction).
However, such a method has a problem that the pickup yield of the LED element 23 by the elastomer stamp 80 is low and the productivity of the transparent display device is inferior.
　図１１に示すように、本実施形態に係る透明表示装置の製造方法では、ＬＥＤ素子２３にエラストマスタンプ８０を押し当てる際、エラストマスタンプ８０の突起８２の中心Ｏ２と、ＬＥＤ素子２３のＰ電極ＰＥの中心Ｏ１とを所定の方向にずらす。すなわち、エラストマスタンプ８０においてＬＥＤ素子２３側に最も突出した部位の中心と、ＬＥＤ素子２３においてエラストマスタンプ８０側に最も突出した部位の中心とを、所定の方向にずらす。エラストマスタンプ８０における突起８２が多段階の突起の場合、ＬＥＤ素子２３側に最も突出した部位の中心は、突起８２における最先端に位置する突起の中心である。 As shown in FIG. 11, in the method for manufacturing a transparent display device according to the present embodiment, when the elastomer stamp 80 is pressed against the LED element 23, the center O2 of the protrusion 82 of the elastomer stamp 80 and the P electrode PE of the LED element 23 are used. The center O1 of the above is shifted in a predetermined direction. That is, the center of the portion of the elastomer stamp 80 that protrudes most toward the LED element 23 side and the center of the portion of the LED element 23 that protrudes most toward the elastomer stamp 80 side are shifted in a predetermined direction. When the protrusion 82 in the elastomer stamp 80 is a multi-stage protrusion, the center of the most protruding portion on the LED element 23 side is the center of the most advanced protrusion in the protrusion 82.
　図１１の例では、エラストマスタンプ８０の突起８２の中心Ｏ２をＬＥＤ素子２３のＰ電極ＰＥの中心Ｏ１からｙ軸負方向側にずらしている。すなわち、エラストマスタンプ８０の突起８２によって押圧するＬＥＤ素子２３における位置を、ＬＥＤ素子２３の固定部から遠ざかる方向に移動させている。そのため、ＬＥＤ素子２３の固定部に作用する曲げモーメントが大きくなり、固定部が破断し易くなると考えられる。 In the example of FIG. 11, the center O2 of the protrusion 82 of the elastomer stamp 80 is shifted from the center O1 of the P electrode PE of the LED element 23 toward the negative y-axis direction. That is, the position of the LED element 23 pressed by the projection 82 of the elastomer stamp 80 is moved in the direction away from the fixed portion of the LED element 23. Therefore, it is considered that the bending moment acting on the fixed portion of the LED element 23 becomes large and the fixed portion is easily broken.
　また、エラストマスタンプ８０の突起８２の中心Ｏ２をＬＥＤ素子２３のＰ電極ＰＥの中心Ｏ１からｘ軸方向にずらしてもよい。この場合には、ＬＥＤ素子２３の固定部に対し、曲げモーメントに加え、ねじりによる剪断応力を付与でき、固定部が破断し易くなると考えられる。 Further, the center O2 of the protrusion 82 of the elastomer stamp 80 may be shifted from the center O1 of the P electrode PE of the LED element 23 in the x-axis direction. In this case, it is considered that a shear stress due to twisting can be applied to the fixed portion of the LED element 23 in addition to the bending moment, and the fixed portion is likely to break.
　このように、エラストマスタンプ８０の突起８２の中心Ｏ２をＬＥＤ素子２３のＰ電極ＰＥの中心Ｏ１からずらすと、ＬＥＤ素子２３の固定部が破断し易くなる。その結果、エラストマスタンプ８０によるＬＥＤ素子２３のピックアップ収率が高くなり、透明表示装置の生産性が向上する。 In this way, if the center O2 of the protrusion 82 of the elastomer stamp 80 is displaced from the center O1 of the P electrode PE of the LED element 23, the fixed portion of the LED element 23 is likely to break. As a result, the pickup yield of the LED element 23 by the elastomer stamp 80 is increased, and the productivity of the transparent display device is improved.
　ここで、ずらし量は、例えば、所定の方向（例えば、ｘ軸方向にずらす場合はｘ軸方向、ｙ軸方向にずらす場合はｙ軸方向）におけるＬＥＤ素子２３の幅の５～５０％とする。ずらし量は、好ましくは、所定の方向におけるＬＥＤ素子２３の幅の１０～４０％、さらに好ましくは、所定の方向におけるＬＥＤ素子２３の幅の１０～３０％である。本明細書において、ＬＥＤ素子２３のサイズは、平面視において半導体層（Ｎ型半導体層ＮＬ及びＰ型半導体層ＰＬ）が占める領域によって規定される。 Here, the shift amount is, for example, 5 to 50% of the width of the LED element 23 in a predetermined direction (for example, the x-axis direction when shifting in the x-axis direction and the y-axis direction when shifting in the y-axis direction). .. The amount of shift is preferably 10 to 40% of the width of the LED element 23 in a predetermined direction, and more preferably 10 to 30% of the width of the LED element 23 in a predetermined direction. In the present specification, the size of the LED element 23 is defined by the region occupied by the semiconductor layer (N-type semiconductor layer NL and P-type semiconductor layer PL) in a plan view.
　さらに、図１３に示すように、ＬＥＤ素子２３にエラストマスタンプ８０を押し当てた後、押し込んだ状態で、互いに接触しているＬＥＤ素子２３及びエラストマスタンプ８０の少なくとも一方を、ウェハＷＦと平行なｘ軸方向又はｙ軸方向に移動させる。勿論、ｘ軸方向（第１の方向）及びｙ軸方向（第２の方向）に移動させてもよい。
　あるいは、エラストマスタンプ８０を押し込んだ後、エラストマスタンプ８０に貼り付けたＬＥＤ素子２３を引き上げる際、互いに接触しているＬＥＤ素子２３及びエラストマスタンプ８０の少なくとも一方を、同様に移動させてもよい。 Further, as shown in FIG. 13, after the elastoma stamp 80 is pressed against the LED element 23, at least one of the LED element 23 and the elastoma stamp 80, which are in contact with each other in the pressed state, is x parallel to the wafer WF. Move in the axial direction or the y-axis direction. Of course, it may be moved in the x-axis direction (first direction) and the y-axis direction (second direction).
Alternatively, when the LED element 23 attached to the elastomer stamp 80 is pulled up after the elastomer stamp 80 is pushed in, at least one of the LED element 23 and the elastomer stamp 80 that are in contact with each other may be moved in the same manner.
　すなわち、ＬＥＤ素子２３にエラストマスタンプ８０を押し当てた後、ＬＥＤ素子２３をウェハＷＦから切り離す前に、互いに接触しているＬＥＤ素子２３及びエラストマスタンプ８０の少なくとも一方を、ウェハＷＦと平行な所定方向に移動させる。この際、ＬＥＤ素子２３と突起８２との接触位置は移動しない。 That is, after pressing the elastoma stamp 80 against the LED element 23 and before separating the LED element 23 from the wafer WF, at least one of the LED element 23 and the elastoma stamp 80 in contact with each other is placed in a predetermined direction parallel to the wafer WF. Move to. At this time, the contact position between the LED element 23 and the protrusion 82 does not move.
　このような動作により、ＬＥＤ素子２３の固定部に対し、押し込み動作や引き上げ動作による曲げモーメントを作用させつつ、さらに引張応力、圧縮応力等を負荷でき、固定部が破断し易くなると考えられる。その結果、エラストマスタンプ８０によるＬＥＤ素子２３のピックアップ収率が高くなり、透明表示装置の生産性が向上する。
　以下に詳細に説明する。 It is considered that such an operation allows a bending moment due to a pushing operation or a pulling operation to be applied to the fixed portion of the LED element 23, and further a tensile stress, a compressive stress, or the like can be applied, so that the fixed portion is easily broken. As a result, the pickup yield of the LED element 23 by the elastomer stamp 80 is increased, and the productivity of the transparent display device is improved.
This will be described in detail below.
　例えば、図１１において、エラストマスタンプ８０をｘ軸正方向に移動させると、ＬＥＤ素子２３をｘ軸正方向に移動させようとする力が作用する。すなわち、固定部には、押し込み（ＬＥＤ素子２３をｚ軸負方向へ移動させようとする力）による曲げモーメントに加えて、ｘ軸正方向へ移動させる力による曲げモーメントが加わると考えられる。その場合、ＬＥＤ素子２３の固定部のｘ軸負方向側端部に引張応力が作用し、固定部のｘ軸正方向側端部に圧縮応力が作用する。すなわち、ＬＥＤ素子２３の固定部をｘ軸負方向側端部から引き裂く力が作用し、固定部が破断し易くなると考えられる。 For example, in FIG. 11, when the elastomer stamp 80 is moved in the positive direction of the x-axis, a force for moving the LED element 23 in the positive direction of the x-axis acts. That is, it is considered that a bending moment due to a force for moving the LED element 23 in the positive direction on the x-axis is applied to the fixed portion in addition to the bending moment due to pushing (a force for moving the LED element 23 in the negative direction on the z-axis). In that case, tensile stress acts on the x-axis negative side end of the fixed portion of the LED element 23, and compressive stress acts on the x-axis positive side end of the fixed portion. That is, it is considered that a force that tears the fixed portion of the LED element 23 from the end on the negative side in the x-axis direction acts, and the fixed portion is easily broken.
　反対に、図１１において、エラストマスタンプ８０をｘ軸負方向に移動させると、ＬＥＤ素子２３をｘ軸負方向に移動させようとする力が作用する。すなわち、固定部には、押し込み動作（ＬＥＤ素子２３をｚ軸負方向へ移動させる力）による曲げモーメントに加えて、ｘ軸負方向へ移動させる力による曲げモーメントが加わると考えられる。その場合、ＬＥＤ素子２３の固定部のｘ軸正方向側端部に引張応力が作用し、固定部のｘ軸負方向側端部に圧縮応力が作用する。すなわち、ＬＥＤ素子２３の固定部をｘ軸正方向側端部から引き裂く力が作用し、固定部が破断し易くなると考えられる。 On the contrary, in FIG. 11, when the elastomer stamp 80 is moved in the negative direction on the x-axis, a force for moving the LED element 23 in the negative direction on the x-axis acts. That is, it is considered that the bending moment due to the force for moving the LED element 23 in the negative direction on the x-axis is applied to the fixed portion in addition to the bending moment due to the pushing operation (the force for moving the LED element 23 in the negative direction on the z-axis). In that case, tensile stress acts on the x-axis positive side end of the fixed portion of the LED element 23, and compressive stress acts on the x-axis negative side end of the fixed portion. That is, it is considered that a force that tears the fixed portion of the LED element 23 from the end portion on the positive direction side of the x-axis acts, and the fixed portion is easily broken.
　また、図１１において、エラストマスタンプ８０をｙ軸正方向に移動させると、ＬＥＤ素子２３をｙ軸正方向に移動させようとする力が作用する。そのため、固定部には、押し込み動作による曲げモーメントに加えて、ＬＥＤ素子２３の固定部全体に圧縮応力が作用し、固定部が破断し易くなると考えられる。
　反対に、図１１において、エラストマスタンプ８０をｙ軸負方向に移動させると、ＬＥＤ素子２３をｙ軸負方向に移動させようとする力が作用する。そのため、固定部には、押し込み動作による曲げモーメントに加えて、ＬＥＤ素子２３の固定部全体に引張応力が作用し、固定部が破断し易くなると考えられる。 Further, in FIG. 11, when the elastomer stamp 80 is moved in the positive direction of the y-axis, a force for moving the LED element 23 in the positive direction of the y-axis acts. Therefore, in addition to the bending moment due to the pushing operation, compressive stress acts on the entire fixed portion of the LED element 23 on the fixed portion, and it is considered that the fixed portion is likely to break.
On the contrary, in FIG. 11, when the elastomer stamp 80 is moved in the negative direction on the y-axis, a force for moving the LED element 23 in the negative direction on the y-axis acts. Therefore, in addition to the bending moment due to the pushing operation, tensile stress acts on the entire fixed portion of the LED element 23 on the fixed portion, and it is considered that the fixed portion is likely to break.
　ここで、移動量は、例えば、所定の方向（例えば、ｘ軸方向に移動する場合はｘ軸方向、ｙ軸方向に移動する場合はｙ軸方向）におけるＬＥＤ素子２３の幅の５～５０％とする。移動量は、好ましくは、所定の方向におけるＬＥＤ素子２３の幅の１０～４０％、さらに好ましくは、所定の方向におけるＬＥＤ素子２３の幅の１０～３０％である。 Here, the movement amount is, for example, 5 to 50% of the width of the LED element 23 in a predetermined direction (for example, the x-axis direction when moving in the x-axis direction and the y-axis direction when moving in the y-axis direction). And. The amount of movement is preferably 10 to 40% of the width of the LED element 23 in a predetermined direction, and more preferably 10 to 30% of the width of the LED element 23 in a predetermined direction.
　以上に説明した通り、本実施形態に係る透明表示装置の製造方法では、ＬＥＤ素子２３にエラストマスタンプ８０を押し当てる際、エラストマスタンプ８０の突起８２の中心Ｏ２と、ＬＥＤ素子２３のＰ電極ＰＥの中心Ｏ１とを所定の方向にずらす。このような構成によって、ＬＥＤ素子２３の固定部が破断し易くなる。その結果、エラストマスタンプ８０によるＬＥＤ素子２３のピックアップ収率が高くなり、透明表示装置の生産性が向上する。 As described above, in the method for manufacturing the transparent display device according to the present embodiment, when the elastomer stamp 80 is pressed against the LED element 23, the center O2 of the protrusion 82 of the elastomer stamp 80 and the P electrode PE of the LED element 23 are used. The center O1 is shifted in a predetermined direction. With such a configuration, the fixed portion of the LED element 23 is likely to break. As a result, the pickup yield of the LED element 23 by the elastomer stamp 80 is increased, and the productivity of the transparent display device is improved.
　また、本実施形態に係る透明表示装置の製造方法では、ＬＥＤ素子２３に接触しているエラストマスタンプ８０を、ウェハＷＦと平行な所定の方向に、ウェハＷＦに対して相対的に移動させる。このような構成によって、ＬＥＤ素子２３の固定部が破断し易くなる。その結果、エラストマスタンプ８０によるＬＥＤ素子２３のピックアップ収率が高くなり、透明表示装置の生産性が向上する。 Further, in the method for manufacturing a transparent display device according to the present embodiment, the elastoma stamp 80 in contact with the LED element 23 is moved relative to the wafer WF in a predetermined direction parallel to the wafer WF. With such a configuration, the fixed portion of the LED element 23 is likely to break. As a result, the pickup yield of the LED element 23 by the elastomer stamp 80 is increased, and the productivity of the transparent display device is improved.
　さらに、エラストマスタンプ８０の突起８２の中心Ｏ２とＬＥＤ素子２３のＰ電極ＰＥの中心Ｏ１とのずらしと、ＬＥＤ素子２３に接触しているエラストマスタンプ８０の移動と、を組み合わせると、固定部がより一層破断し易くなる。その結果、エラストマスタンプ８０によるＬＥＤ素子２３のピックアップ収率が高くなり、透明表示装置の生産性が劇的に向上する。 Further, when the shift between the center O2 of the protrusion 82 of the elastomer stamp 80 and the center O1 of the P electrode PE of the LED element 23 and the movement of the elastomer stamp 80 in contact with the LED element 23 are combined, the fixed portion becomes more stable. It is more likely to break. As a result, the pickup yield of the LED element 23 by the elastomer stamp 80 is increased, and the productivity of the transparent display device is dramatically improved.
　ここで、図１５は、第１の実施形態に係る透明表示装置の製造方法によって、ウェハＷＦから切り離されたＬＥＤ素子２３の平面図である。すなわち、図１５は、透明表示装置において透明基材１０に搭載されるＬＥＤ素子２３の平面図である。図１５に示すように、平面視矩形状のＮ型半導体層ＮＬの一方の短辺からＬＥＤ素子２３の外側に向かって固定部が突出している。すなわち、固定部はＬＥＤ素子２３における突出部である。そして、固定部の端部（破断部）が、平面視においてＮ型半導体層ＮＬの短辺に対して斜めに傾斜するように形成されている。これまでの製造方法によってウェハＷＦから切り離されたＬＥＤ素子では、固定部の端部（破断部）が、平面視においてＮ型半導体層ＮＬの短辺と平行に形成されていた。 Here, FIG. 15 is a plan view of the LED element 23 separated from the wafer WF by the manufacturing method of the transparent display device according to the first embodiment. That is, FIG. 15 is a plan view of the LED element 23 mounted on the transparent base material 10 in the transparent display device. As shown in FIG. 15, the fixed portion protrudes from one short side of the rectangular N-type semiconductor layer NL in a plan view toward the outside of the LED element 23. That is, the fixed portion is a protruding portion in the LED element 23. The end portion (broken portion) of the fixed portion is formed so as to be inclined obliquely with respect to the short side of the N-type semiconductor layer NL in a plan view. In the LED element separated from the wafer WF by the conventional manufacturing method, the end portion (broken portion) of the fixed portion is formed in parallel with the short side of the N-type semiconductor layer NL in a plan view.
　以下に、本発明に係る例を示すが、本発明は、以下の例に限定して解釈されるものではない。例２～９が、本発明の実施例である。例１は、比較例である。 The following are examples of the present invention, but the present invention is not construed as being limited to the following examples. Examples 2 to 9 are examples of the present invention. Example 1 is a comparative example.
［ＬＥＤ素子の作製］
　図１１、図１２に示したように、フォトリソグラフィ技術を用いて、ウェハＷＦ上にパターニングされた微小サイズのＬＥＤ素子２３を作製した。ウェハＷＦとしてはＳｉウェハを用い、Ｎ型半導体層ＮＬ及びＰ型半導体層ＰＬとしてはＧａＮ層を用いた。図１１に示したように、各ＬＥＤ素子２３（Ｎ型半導体層ＮＬ及びＰ型半導体層ＰＬが占める領域）のｘ軸方向の幅（短辺幅）は１０μｍ、ｙ軸方向の幅（長辺幅）は１５μｍとした。図１１に示したように、絶縁層ＩＬを含めると、ＬＥＤ素子２３のｘ軸方向の幅は１３μｍ、ｙ軸方向の幅は１７μｍである。また、固定部のｘ軸方向の幅は８μｍとした。 [Manufacturing of LED element]
As shown in FIGS. 11 and 12, a micro-sized LED element 23 patterned on the wafer WF was manufactured by using a photolithography technique. A Si wafer was used as the wafer WF, and a GaN layer was used as the N-type semiconductor layer NL and the P-type semiconductor layer PL. As shown in FIG. 11, the width (short side width) in the x-axis direction of each LED element 23 (the region occupied by the N-type semiconductor layer NL and the P-type semiconductor layer PL) is 10 μm, and the width in the y-axis direction (long side). The width) was 15 μm. As shown in FIG. 11, when the insulating layer IL is included, the width of the LED element 23 in the x-axis direction is 13 μm, and the width in the y-axis direction is 17 μm. The width of the fixed portion in the x-axis direction was 8 μm.
［エラストマスタンプの作製］
　図１２に示したエラストマスタンプ８０のエラストマとしては、シリコーンゴム（東レ・ダウコーニング社のシルガード１８４Ｗ／Ｃ）を用いた。フォトリソグラフィ技術を用いて、Ｓｉ基板上に突起８２を形成するための凹部をパターニングして成形型を作製した。この成形型とガラス基板とを対向配置させ、両者の間にシリコーンゴムを注入し、硬化させることによって、突起８２を有するエラストマスタンプ８０を作製した。エラストマスタンプ８０全体の剛性を確保するため、エラストマスタンプ８０は上記ガラス基板に担持させた。各突起８２のＬＥＤ素子２３側に最も突出した部位のｘ軸方向の幅（短辺幅）は１０μｍ、ｙ軸方向の幅（長辺幅）は１１μｍ、ｚ軸方向の幅（高さ）は２２μｍとした。 [Making an elastomer stamp]
As the elastomer of the elastomer stamp 80 shown in FIG. 12, silicone rubber (Silgard 184W / C manufactured by Toray Dow Corning Co., Ltd.) was used. Using a photolithography technique, a molding mold was produced by patterning a recess for forming a protrusion 82 on a Si substrate. The molding mold and the glass substrate were placed facing each other, and silicone rubber was injected between them and cured to produce an elastomer stamp 80 having protrusions 82. In order to secure the rigidity of the entire elastomer stamp 80, the elastomer stamp 80 was supported on the glass substrate. The width (short side width) in the x-axis direction of each protrusion 82 on the LED element 23 side is 10 μm, the width in the y-axis direction (long side width) is 11 μm, and the width (height) in the z-axis direction is. It was set to 22 μm.
　表１に例１～９の実験条件及び結果をまとめて示す。
Figure JPOXMLDOC01-appb-T000001
 Table 1 summarizes the experimental conditions and results of Examples 1 to 9.
Figure JPOXMLDOC01-appb-T000001
　表１には、実験条件として、エラストマスタンプ８０をＬＥＤ素子２３に押し当てる際の図１１に示した突起８２のｘｙ平面中心Ｏ２とＰ電極ＰＥのｘｙ平面中心Ｏ１とのずれ量（突起中心位置ずれ量）を示した。また、エラストマスタンプ８０を押し込んだ状態でのＬＥＤ素子２３の移動量（押し込み時ＬＥＤ移動量）及びエラストマスタンプ８０を引き上げる際のＬＥＤ素子２３の移動量（引き上げ時ＬＥＤ移動量）を示した。
　さらに、表１には、実験結果として、エラストマスタンプ８０によるＬＥＤ素子２３のピックアップ収率も示した。 In Table 1, as experimental conditions, the amount of deviation (projection center position) between the xy plane center O2 of the protrusion 82 and the xy plane center O1 of the P electrode PE shown in FIG. 11 when the elastomer stamp 80 is pressed against the LED element 23. The amount of deviation) is shown. Further, the amount of movement of the LED element 23 in the state where the elastomer stamp 80 is pushed in (the amount of movement of the LED when pushed in) and the amount of movement of the LED element 23 when the elastomer stamp 80 is pulled up (the amount of movement of the LED when pulled up) are shown.
Further, Table 1 also shows the pickup yield of the LED element 23 by the elastomer stamp 80 as an experimental result.
＜例１＞
　図１１に示したエラストマスタンプ８０の突起８２のｘｙ平面中心Ｏ２と、ＬＥＤ素子２３のＰ電極ＰＥのｘｙ平面中心Ｏ１とが一致するように位置合わせした。
　図１３に示すように、エラストマスタンプ８０の突起８２をＬＥＤ素子２３に接触させた後、エラストマスタンプ８０を１７μｍ押し込み、押し込み後に３分間保持した。その後、エラストマスタンプ８０を目標速度１４０ｍｍ／ｓまで重力加速度（９．８ｍ／ｓ２）で加速させつつ、５ｍｍ引き上げ、ＬＥＤ素子２３をピックアップした。
　ＬＥＤ素子２３のピックアップ収率は９％であった。 <Example 1>
The xy plane center O2 of the protrusion 82 of the elastomer stamp 80 shown in FIG. 11 and the xy plane center O1 of the P electrode PE of the LED element 23 were aligned with each other.
As shown in FIG. 13, after the protrusion 82 of the elastomer stamp 80 was brought into contact with the LED element 23, the elastomer stamp 80 was pushed in by 17 μm and held for 3 minutes after being pushed in. After that, the elastomer stamp 80 was accelerated to a target speed of 140 mm / s by gravitational acceleration (9.8 m / s 2 ), pulled up by 5 mm, and the LED element 23 was picked up.
The pickup yield of the LED element 23 was 9%.
＜例２＞
　表１に示すように、図１１に示したエラストマスタンプ８０の突起８２のｘｙ平面中心Ｏ２を、ＬＥＤ素子２３のＰ電極ＰＥのｘｙ平面中心Ｏ１からｙ軸負方向に３μｍずらした以外は、例１と同様の条件とした。
　ＬＥＤ素子２３のピックアップ収率は１５％であり、例１よりもピックアップ収率が向上した。 <Example 2>
As shown in Table 1, an example except that the xy plane center O2 of the projection 82 of the elastomer stamp 80 shown in FIG. 11 is displaced by 3 μm in the negative direction of the y axis from the xy plane center O1 of the P electrode PE of the LED element 23. The conditions were the same as in 1.
The pickup yield of the LED element 23 was 15%, which was higher than that of Example 1.
＜例３＞
　表１に示すように、図１１に示したエラストマスタンプ８０の突起８２のｘｙ平面中心Ｏ２を、ＬＥＤ素子２３のＰ電極ＰＥのｘｙ平面中心Ｏ１からｘ軸正方向に２μｍずらした以外は、例１と同様の条件とした。
　ＬＥＤ素子２３のピックアップ収率は２２％であり、例１よりもピックアップ収率が向上した。 <Example 3>
As shown in Table 1, an example except that the xy plane center O2 of the projection 82 of the elastomer stamp 80 shown in FIG. 11 is displaced by 2 μm in the positive direction of the x axis from the xy plane center O1 of the P electrode PE of the LED element 23. The conditions were the same as in 1.
The pickup yield of the LED element 23 was 22%, which was higher than that of Example 1.
＜例４＞
　表１に示すように、エラストマスタンプ８０の突起８２をＬＥＤ素子２３に接触させて押し込んだ状態で、ＬＥＤ素子２３をｙ軸負方向に３μｍずらした以外は、例１と同様の条件とした。ＬＥＤ素子２３をｙ軸負方向に３μｍずらすことは、エラストマスタンプ８０を反対方向（ｙ軸正方向）に３μｍずらすことと同じである（以下同様）。
　ＬＥＤ素子２３のピックアップ収率は２４％であり、例１よりもピックアップ収率が向上した。 <Example 4>
As shown in Table 1, the conditions were the same as in Example 1 except that the projection 82 of the elastomer stamp 80 was brought into contact with the LED element 23 and pushed in, and the LED element 23 was displaced by 3 μm in the negative direction of the y-axis. Shifting the LED element 23 by 3 μm in the negative direction of the y-axis is the same as shifting the elastomer stamp 80 by 3 μm in the opposite direction (positive direction of the y-axis) (the same applies hereinafter).
The pickup yield of the LED element 23 was 24%, which was higher than that of Example 1.
＜例５＞
　表１に示すように、エラストマスタンプ８０の突起８２をＬＥＤ素子２３に接触させて押し込んだ状態で、ＬＥＤ素子２３をｘ軸正方向に２μｍずらした以外は、例１と同様の条件とした。
　ＬＥＤ素子２３のピックアップ収率は２３％であり、例１よりもピックアップ収率が向上した。 <Example 5>
As shown in Table 1, the conditions were the same as in Example 1 except that the projection 82 of the elastomer stamp 80 was brought into contact with the LED element 23 and pushed in, and the LED element 23 was displaced by 2 μm in the positive direction of the x-axis.
The pickup yield of the LED element 23 was 23%, which was higher than that of Example 1.
＜例６＞
　表１に示すように、エラストマスタンプ８０の突起８２をＬＥＤ素子２３に接触させて押し込んだ状態で、ＬＥＤ素子２３をｘ軸負方向に２μｍずらした以外は、例１と同様の条件とした。
　ＬＥＤ素子２３のピックアップ収率は２９％であり、例１よりもピックアップ収率が向上した。 <Example 6>
As shown in Table 1, the conditions were the same as in Example 1 except that the projection 82 of the elastomer stamp 80 was brought into contact with the LED element 23 and pushed in, and the LED element 23 was displaced by 2 μm in the negative direction of the x-axis.
The pickup yield of the LED element 23 was 29%, which was higher than that of Example 1.
＜例７＞
　表１に示すように、エラストマスタンプ８０の突起８２をＬＥＤ素子２３に接触させて押し込んだ状態で、ＬＥＤ素子２３をｘ軸負方向に２μｍずらした以外は、例２と同様の条件とした。
　ＬＥＤ素子２３のピックアップ収率は９０％であり、例２よりもピックアップ収率が劇的に向上した。 <Example 7>
As shown in Table 1, the conditions were the same as in Example 2 except that the projection 82 of the elastomer stamp 80 was brought into contact with the LED element 23 and pushed in, and the LED element 23 was displaced by 2 μm in the negative direction of the x-axis.
The pickup yield of the LED element 23 was 90%, and the pickup yield was dramatically improved as compared with Example 2.
＜例８＞
　表１に示すように、エラストマスタンプ８０の突起８２をＬＥＤ素子２３に接触させて押し込んだ状態で、ＬＥＤ素子２３をｘ軸負方向に２μｍずらした後、さらにＬＥＤ素子２３をｙ軸負方向に３μｍずらした以外は、例７と同様の条件とした。
　ＬＥＤ素子２３のピックアップ収率は９１％であって、例７と同等で極めて良好であった。 <Example 8>
As shown in Table 1, with the protrusion 82 of the elastoma stamp 80 in contact with the LED element 23 and pushed in, the LED element 23 is displaced by 2 μm in the negative direction of the x-axis, and then the LED element 23 is further moved in the negative direction of the y-axis. The conditions were the same as in Example 7 except that the displacement was 3 μm.
The pickup yield of the LED element 23 was 91%, which was equivalent to that of Example 7 and was extremely good.
＜例９＞
　表１に示すように、エラストマスタンプ８０の突起８２をＬＥＤ素子２３に接触させて押し込んだ状態で、ＬＥＤ素子２３をｘ軸負方向に３μｍずらした後、さらにＬＥＤ素子２３をｙ軸負方向に３μｍずらした。加えて、エラストマスタンプ８０を引き上げる際にも、エラストマスタンプ８０に接触しているＬＥＤ素子２３をｘ軸負方向に３μｍずらした後、さらにＬＥＤ素子２３をｙ軸負方向に３μｍずらした。さらに、押し込み量を２０μｍとした。それ以外は、例８と同様の条件とした。
　ＬＥＤ素子２３のピックアップ収率は９３％であって、例７、例８と同等で極めて良好であった。 <Example 9>
As shown in Table 1, with the protrusion 82 of the elastoma stamp 80 in contact with the LED element 23 and pushed in, the LED element 23 is displaced by 3 μm in the negative direction of the x-axis, and then the LED element 23 is further moved in the negative direction of the y-axis. It was shifted by 3 μm. In addition, when pulling up the elastomer stamp 80, the LED element 23 in contact with the elastomer stamp 80 was displaced by 3 μm in the negative direction of the x-axis, and then the LED element 23 was further displaced by 3 μm in the negative direction of the y-axis. Further, the pushing amount was set to 20 μm. Other than that, the conditions were the same as in Example 8.
The pickup yield of the LED element 23 was 93%, which was equivalent to that of Examples 7 and 8 and was extremely good.
　なお、本発明は上記実施形態に限られたものではなく、趣旨を逸脱しない範囲で適宜変更できる。 The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit.
　この出願は、２０２０年７月２０日に出願された日本出願特願２０２０－１２３９４１を基礎とする優先権を主張し、その開示の全てをここに取り込む。 This application claims priority based on Japanese application Japanese Patent Application No. 2020-123941 filed on July 20, 2020, and incorporates all of its disclosures herein.
１０　透明基材
１１　主基板
１２　接着剤層
２０　発光部
２１～２３　ＬＥＤ素子
３０　ＩＣチップ
４０　配線
４１　電源線
４１ａ　第１電源分岐線
４１ｂ　第２電源分岐線
４２　グランド線
４２ａ　グランド分岐線
４３　行データ線
４３ａ　行データ分岐線
４４　列データ線
４４ａ　列データ分岐線
４５　駆動線
５０　保護層
８０　エラストマスタンプ
８１　基体
８２　突起
１０１　表示領域
ＢＬ　バッファ層
ＣＴ　コンタクト
ＦＲ１、ＦＲ２　フォトレジスト
ＩＬ　絶縁層
Ｍ１　第１メタル層
Ｍ２　第２メタル層
ＮＥ　Ｎ電極
ＮＬ　Ｎ型半導体層
ＰＥ　Ｐ電極
ＰＩＸ　画素
ＰＬ　Ｐ型半導体層
ＷＦ　ウェハ 10 Transparent base material 11 Main substrate 12 Adhesive layer 20 Light emitting part 21-23 LED element 30 IC chip 40 Wiring 41 Power supply line 41a First power supply branch line 41b Second power supply branch line 42 Ground line 42a Ground branch line 43 line Data line 43a row data branch line 44 column data line 44a column data branch line 45 drive line 50 protective layer 80 elastoma stamp 81 substrate 82 protrusion 101 display area BL buffer layer CT contact FR1, FR2 photoresist IL insulating layer M1 first metal layer M2 first 2 Metal layer NE N electrode NL N type semiconductor layer PE P electrode PIX pixel PL P type semiconductor layer WF wafer

Claims (14)

  1. 　透明表示装置の製造方法であって、
    　ウェハ上にパターニングされた１００，０００μｍ２以下の面積を有する半導体素子にエラストマスタンプを押し当てた後、前記エラストマスタンプに貼り付けた前記半導体素子を引き上げて前記ウェハから引き離すことと、
    　前記半導体素子を前記エラストマスタンプに貼り付けたまま搬送した後、前記半導体素子を透明基材上に押し当てて配置することと、を含み、
    　前記半導体素子に前記エラストマスタンプを押し当てる際、
    　前記エラストマスタンプにおいて前記半導体素子側に最も突出した部位の中心と、前記半導体素子において前記エラストマスタンプ側に最も突出した部位の中心とを、所定の方向にずらす、
    透明表示装置の製造方法。     It is a manufacturing method of a transparent display device.
    After the elastomer stamp is pressed against the semiconductor element having an area of 100,000 μm 2 or less patterned on the wafer, the semiconductor element attached to the elastomer stamp is pulled up and pulled away from the wafer.
    The present invention includes the process of transporting the semiconductor element while being attached to the elastomer stamp, and then pressing the semiconductor element onto a transparent substrate for arranging the semiconductor element.
    When the elastomer stamp is pressed against the semiconductor element,
    The center of the portion of the semiconductor element most protruding toward the semiconductor element side and the center of the portion of the semiconductor element most protruding toward the elastomer stamp side are displaced in a predetermined direction.
    Manufacturing method of transparent display device.
  2. 　前記半導体素子に前記エラストマスタンプを押し当てた後、前記半導体素子を前記ウェハから引き離す前に、
    　互いに接触している前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を、前記ウェハの基板面と平行な第１の方向に移動させる、
    請求項１に記載の透明表示装置の製造方法。     After pressing the elastomer stamp against the semiconductor device and before pulling the semiconductor device away from the wafer,
    At least one of the semiconductor element and the elastomer stamp in contact with each other is moved in a first direction parallel to the substrate surface of the wafer.
    The method for manufacturing a transparent display device according to claim 1.
  3. 　透明表示装置の製造方法であって、
    　ウェハ上にパターニングされた１００，０００μｍ２以下の面積を有する半導体素子にエラストマスタンプを押し当てた後、前記エラストマスタンプに貼り付けた前記半導体素子を引き上げて前記ウェハから引き離すことと、
    　前記半導体素子を前記エラストマスタンプに貼り付けたまま搬送した後、前記半導体素子を透明基材上に押し当てて配置することと、を含み、
    　前記半導体素子に前記エラストマスタンプを押し当てた後、前記半導体素子を前記ウェハから引き離す前に、
    　互いに接触している前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を、前記ウェハの基板面と平行な第１の方向に移動させる、
    透明表示装置の製造方法。     It is a manufacturing method of a transparent display device.
    After the elastomer stamp is pressed against the semiconductor element having an area of 100,000 μm 2 or less patterned on the wafer, the semiconductor element attached to the elastomer stamp is pulled up and pulled away from the wafer.
    The present invention includes the process of transporting the semiconductor element while being attached to the elastomer stamp, and then pressing the semiconductor element onto a transparent substrate for arranging the semiconductor element.
    After pressing the elastomer stamp against the semiconductor device and before pulling the semiconductor device away from the wafer,
    At least one of the semiconductor element and the elastomer stamp in contact with each other is moved in a first direction parallel to the substrate surface of the wafer.
    Manufacturing method of transparent display device.
  4. 　前記半導体素子に前記エラストマスタンプを押し当てた後、押し込んだ状態で、
    　前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を、前記第１の方向に移動させる、
    請求項２又は３に記載の透明表示装置の製造方法。     After pressing the elastomer stamp against the semiconductor element, in the pressed state,
    At least one of the semiconductor element and the elastomer stamp is moved in the first direction.
    The method for manufacturing a transparent display device according to claim 2 or 3.
  5. 　前記半導体素子に前記エラストマスタンプを押し当てた後、押し込んだ状態で、
    　前記ウェハの基板面に平行かつ前記第１の方向と交差する第２の方向に、前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を移動させる、
    請求項４に記載の透明表示装置の製造方法。     After pressing the elastomer stamp against the semiconductor element, in the pressed state,
    At least one of the semiconductor element and the elastomer stamp is moved in a second direction parallel to the substrate surface of the wafer and intersecting the first direction.
    The method for manufacturing a transparent display device according to claim 4.
  6. 　前記半導体素子に前記エラストマスタンプを押し当てた後、前記エラストマスタンプに貼り付けた前記半導体素子を引き上げる際、
    　互いに接触している前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を、前記第１の方向に移動させる、
    請求項２～５のいずれか一項に記載の透明表示装置の製造方法。     When the semiconductor element attached to the elastomer stamp is pulled up after the elastomer stamp is pressed against the semiconductor element.
    At least one of the semiconductor element and the elastomer stamp in contact with each other is moved in the first direction.
    The method for manufacturing a transparent display device according to any one of claims 2 to 5.
  7. 　前記半導体素子に前記エラストマスタンプを押し当てた後、前記エラストマスタンプに貼り付けた前記半導体素子を引き上げる際、
    　互いに接触している前記半導体素子及び前記エラストマスタンプの少なくともいずれか一方を、前記ウェハの基板面に平行かつ前記第１の方向と交差する第２の方向に移動させる、
    請求項６に記載の透明表示装置の製造方法。     When the semiconductor element attached to the elastomer stamp is pulled up after the elastomer stamp is pressed against the semiconductor element.
    At least one of the semiconductor element and the elastomer stamp in contact with each other is moved in a second direction parallel to the substrate surface of the wafer and intersecting the first direction.
    The method for manufacturing a transparent display device according to claim 6.
  8. 　前記ウェハ上に形成された前記半導体素子は、平面視矩形状の矩形領域を備え、
    　前記半導体素子は、前記矩形領域の一辺に形成された固定部を介して前記ウェハに固定されていると共に、前記ウェハの基板面から浮遊するように形成されている、
    請求項１～７のいずれか一項に記載の透明表示装置の製造方法。     The semiconductor element formed on the wafer includes a rectangular region having a rectangular shape in a plan view.
    The semiconductor element is fixed to the wafer via a fixing portion formed on one side of the rectangular region, and is formed so as to float from the substrate surface of the wafer.
    The method for manufacturing a transparent display device according to any one of claims 1 to 7.
  9. 　前記エラストマスタンプに貼り付けた前記半導体素子を引き上げて前記ウェハから引き離す際、
    　前記固定部が破断する、
    請求項８に記載の透明表示装置の製造方法。     When pulling up the semiconductor element attached to the elastomer stamp and pulling it away from the wafer,
    The fixed part breaks,
    The method for manufacturing a transparent display device according to claim 8.
  10. 　前記固定部が、絶縁層である、
    請求項８又は９に記載の透明表示装置の製造方法。     The fixing portion is an insulating layer.
    The method for manufacturing a transparent display device according to claim 8 or 9.
  11. 　前記エラストマスタンプに貼り付けた前記半導体素子を引き上げて前記ウェハから引き離す際、
    　前記固定部の破断部が、前記矩形領域の一辺に対して斜めに傾斜する、
    請求項８～１０のいずれか一項に記載の透明表示装置の製造方法。     When pulling up the semiconductor element attached to the elastomer stamp and pulling it away from the wafer,
    The broken portion of the fixed portion is inclined diagonally with respect to one side of the rectangular region.
    The method for manufacturing a transparent display device according to any one of claims 8 to 10.
  12. 　前記半導体素子に前記エラストマスタンプを押し当てる際、
    　前記半導体素子が、前記ウェハの基板面に近付くまで、前記エラストマスタンプを押し込む、
    請求項８～１１のいずれか一項に記載の透明表示装置の製造方法。     When the elastomer stamp is pressed against the semiconductor element,
    Push the elastomer stamp until the semiconductor element approaches the substrate surface of the wafer.
    The method for manufacturing a transparent display device according to any one of claims 8 to 11.
  13. 　前記半導体素子は、１０，０００μｍ２以下の面積を有する発光ダイオード素子である、
    請求項１～１２のいずれか一項に記載の透明表示装置の製造方法。     The semiconductor element is a light emitting diode element having an area of 10,000 μm 2 or less.
    The method for manufacturing a transparent display device according to any one of claims 1 to 12.
  14. 　透明基材と、
    　前記透明基材上において画素ごとに少なくとも１つ配置されると共に、それぞれが１０，０００μｍ２以下の面積を有する半導体素子と、を備え、
    　前記半導体素子が、
    　平面視矩形状の半導体層と、
    　平面視において前記半導体層の一辺から当該半導体素子の外側に向かって突出した突出部と、を備え、
    　前記突出部の端部が、平面視において前記半導体層の一辺に対して斜めに傾斜するように形成されている、
    透明表示装置。     With a transparent base material
    A semiconductor device, each of which is arranged on the transparent substrate for each pixel and has an area of 10,000 μm 2 or less, is provided.
    The semiconductor element is
    A rectangular semiconductor layer in plan view and
    A protrusion extending from one side of the semiconductor layer toward the outside of the semiconductor element in a plan view is provided.
    The end portion of the protruding portion is formed so as to be inclined obliquely with respect to one side of the semiconductor layer in a plan view.
    Transparent display device.
PCT/JP2021/026551 2020-07-20 2021-07-15 Transparent display device and manufacturing method therefor WO2022019200A1 (en)

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