CN117393688B - Display module, preparation method and display device - Google Patents
Display module, preparation method and display device Download PDFInfo
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- CN117393688B CN117393688B CN202311685819.1A CN202311685819A CN117393688B CN 117393688 B CN117393688 B CN 117393688B CN 202311685819 A CN202311685819 A CN 202311685819A CN 117393688 B CN117393688 B CN 117393688B
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Classifications
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- 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
- H01L33/62—Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
-
- 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
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/48—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
- H01L23/50—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor for integrated circuit devices, e.g. power bus, number of leads
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/18—Printed circuits structurally associated with non-printed electric components
- H05K1/181—Printed circuits structurally associated with non-printed electric components associated with surface mounted components
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2933/00—Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
- H01L2933/0008—Processes
- H01L2933/0033—Processes relating to semiconductor body packages
- H01L2933/0066—Processes relating to semiconductor body packages relating to arrangements for conducting electric current to or from the semiconductor body
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- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Computer Hardware Design (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Theoretical Computer Science (AREA)
- Led Device Packages (AREA)
Abstract
The invention relates to the technical field of LED display devices, in particular to a display module, a preparation method and a display device, wherein a chip adapter plate comprises a substrate for bearing a film chip, a first connecting part, a conducting hole formed in the substrate and a second connecting part, the film chip is connected with a circuit in a PCB (printed circuit board) through the first connecting part, the conducting hole and the second connecting part in the chip adapter plate, and in addition, the application also provides the display device taking the film chip as a pixel unit, and the arrangement of the chip adapter plate facilitates the electric connection of the film chip and the PCB in the display module.
Description
Technical Field
The invention relates to the technical field of LED display devices, in particular to a display module, a preparation method and a display device.
Background
The LED display device is composed of micro LED chips forming each pixel, has the advantages of high brightness, high luminous efficiency, small power and the like, and can be applied to multiple fields of cross-type wearable equipment, televisions, AR/VR and the like.
In the current stage, in the oversized LED display product (more than 100 inches), the adopted pixel unit mainly consists of Mini LED chips, and the circuit structure in the PCB is generally matched with the Mini LED chip structure, however, with the development of electronic technology and the further reduction of the LED chip size, film chips such as Micro LED chips and the like are widely applied, but at present, the processing precision of the PCB preparation process cannot reach the precision requirement of the film chip size, and the film chips cannot be directly connected with the PCB of the industrial mass production process level.
Disclosure of Invention
Aiming at the technical problems in the prior art, the invention provides a display module and a preparation method, and aims at: the display module using the thin film chip as the pixel unit can realize the electric connection between the thin film chip and the PCB in the display module.
In order to achieve the above purpose, the invention adopts the following technical scheme:
the utility model provides a display module assembly, this display module assembly includes PCB board, pixel unit, sets up in the positive third connecting portion of PCB board, sets up in the drive unit at PCB board back, drive unit's driving method is the PM drive, third connecting portion with circuit electricity in the PCB board is connected, a serial communication port, the display module assembly includes the chip keysets, the chip keysets is used for with pixel unit with circuit connection in the PCB board, the chip keysets includes:
the pixel unit comprises at least one thin film chip, wherein the thin film chip is a Micro LED chip;
the first connecting part is positioned on the front surface of the substrate, and the size of the first connecting part is matched with the electrode size of the thin film chip: the first connecting part comprises a first positive electrode connecting part and a first negative electrode connecting part, the first positive electrode connecting part and the first negative electrode connecting part are respectively connected with a positive electrode and a negative electrode of the same film chip, and the distance between the first positive electrode connecting part and the first negative electrode connecting part is matched with the distance between the positive electrode and the negative electrode of the same film chip;
the conductive hole is arranged on the substrate and is used for electrically connecting the first connecting part and the second connecting part;
the second connecting part is positioned on the back surface of the substrate, and the size of the second connecting part is matched with that of the third connecting part: the second connecting part comprises a second positive electrode connecting part and a second negative electrode connecting part, the third connecting part comprises a third positive electrode connecting part and a third negative electrode connecting part, the second positive electrode connecting part is connected with the corresponding third positive electrode connecting part, the second negative electrode connecting part is connected with the corresponding third negative electrode connecting part, and the interval between the second positive electrode connecting part and the second negative electrode connecting part is matched with the interval between the corresponding third positive electrode connecting part and the corresponding third negative electrode connecting part;
the thin film chip is electrically connected with the third connecting part, a circuit in the PCB and the driving unit through the first connecting part, the conductive hole and the second connecting part in the chip adapter plate;
the thin film chip is positioned on one side of the substrate far away from the PCB;
the driving unit transmits a current control signal to the thin film chip through the third connecting part, a circuit in the PCB, the second connecting part, the first connecting part and the conducting hole, and controls the thin film chip to be turned on or turned off.
It is further characterized in that,
the primary color of the surface of the thin film chip in the substrate is black, the substrate is made of BT plate, glass, ceramic or PET, and the thickness of the substrate is 0.05 mm-0.5 mm.
Further, the length and width dimensions of the film chip are 10 micrometers to 100 micrometers, and the thickness range is 2 micrometers to 6 micrometers.
The preparation method of the display module is used for preparing the display module and is characterized by comprising the following steps:
providing a PCB, wherein the front surface of the PCB is provided with a third connecting part, the back surface of the PCB is provided with a driving unit, and the driving mode of the driving unit is PM driving;
providing a substrate, wherein a conductive hole is formed in the substrate;
preparing a first connecting part on the front surface of the substrate, and enabling the first connecting part to be electrically connected with the corresponding conductive hole, wherein the size of the first connecting part is matched with the electrode size of the thin film chip: the first connecting part comprises a first positive electrode connecting part and a first negative electrode connecting part, the first positive electrode connecting part and the first negative electrode connecting part are respectively connected with a positive electrode and a negative electrode of the same film chip, and the distance between the first positive electrode connecting part and the first negative electrode connecting part is matched with the distance between the positive electrode and the negative electrode of the same film chip;
preparing a second connecting part on the back of the substrate, wherein one end of the second connecting part is electrically connected with the corresponding conductive hole, and the size of the second connecting part is matched with that of the third connecting part: the second connecting part comprises a second positive electrode connecting part and a second negative electrode connecting part, the third connecting part comprises a third positive electrode connecting part and a third negative electrode connecting part, the second positive electrode connecting part is connected with the corresponding third positive electrode connecting part, the second negative electrode connecting part is connected with the corresponding third negative electrode connecting part, and the interval between the second positive electrode connecting part and the second negative electrode connecting part is matched with the interval between the corresponding third positive electrode connecting part and the corresponding third negative electrode connecting part;
providing a plurality of thin film chips, wherein the thin film chips are Micro LED chips, and the thin film chips are arranged on the substrate in an array structure in a mass transfer mode, and electrodes of the thin film chips are electrically connected with the corresponding first connecting parts;
bonding the back surface of a substrate in the chip adapter plate with the PCB, wherein the second connecting part on the back surface of the substrate is correspondingly connected with the third connecting part;
the thin film chip is positioned on one side of the substrate far away from the PCB;
the driving unit transmits a current control signal to the thin film chip through the third connecting part, a circuit in the PCB, the second connecting part, the first connecting part and the conducting hole, and controls the thin film chip to be turned on or turned off.
It is further characterized in that,
forming a through hole penetrating through the substrate in the substrate by adopting a laser perforating or mechanical drilling mode;
filling a first conductive metal material in the through hole to form a conductive hole;
preparing a first connecting part on the front surface of the substrate by adopting a photoetching process or a stripping process;
and coating conductive welding materials on the surface of the first connecting part.
Further, the method further comprises the step of preparing the second connecting portion comprising: a magnetron sputtering coating process is adopted to grow seed materials on the back surface of the substrate to form a seed layer;
and preparing the second connecting part on the surface of the seed layer by adopting a photoetching process or a stripping process.
Further, a bottom glue filling process is adopted, a connecting layer is arranged between the substrate and the PCB, the substrate and the PCB are correspondingly connected through the connecting layer, and the method comprises the following steps:
filling a first solution in the gap between the second connecting parts;
heating and curing the first solution to form a semi-cured layer of the first solution;
filling a second solution in the gap between the third connecting parts;
correspondingly connecting the other end of the second connecting part with the third connecting part, and attaching the upper surface of the second solution to the lower surface of the semi-solidified layer;
and heating and curing the semi-cured layer and the second solution, and bonding the back surface of the substrate with the PCB.
The display device is formed by splicing a plurality of display modules, and is characterized in that the display modules are the display modules.
The structure and the method can achieve the following beneficial effects:
in this application display module assembly, be provided with the chip keysets, be provided with base plate, conductive aperture, first connecting portion, second connecting portion in the chip keysets, the film chip passes through first connecting portion, conductive aperture, second connecting portion and third connecting portion, circuit in the PCB board, drive unit electricity is connected, the film chip passes through the chip keysets promptly, realize being connected with the PCB board electricity, the positive first connecting portion's of chip keysets size and film chip's electrode size match, have characteristics of little linewidth, high accuracy, can satisfy miniature film chip's high accuracy installation requirement. The size of the second connecting part on the back of the chip transfer board is matched with the size of the third connecting part on the surface of the PCB, so that the chip transfer board is favorably and firmly connected with the PCB.
Drawings
FIG. 1 is a schematic diagram of a front view of a conventional display module;
FIG. 2 is a schematic cross-sectional view of a connection portion connecting a thin film chip to a conventional display module;
FIG. 3 is a schematic cross-sectional structure of a thin film chip;
FIG. 4 is a schematic cross-sectional view of a chip interposer of the present invention;
FIG. 5 is a schematic cross-sectional view of a display module according to the present invention;
FIG. 6 is a schematic top view of the display module of the present invention;
fig. 7 is a schematic top view of the display device of the present invention.
Reference numerals: a PCB board 1, a third positive electrode connection part 31, a third negative electrode connection part 32;
a thin film chip 4, a pixel unit 40, a first type semiconductor layer 41, a light emitting layer 42, a second type semiconductor layer 43, a current spreading layer 44, an insulating layer 45, a reflective layer 46, a first electrode 471, a second electrode 472, an ohmic contact layer 48;
the substrate 5, the conductive hole 6, the first positive electrode connection portion 71, the first negative electrode connection portion 72, the second positive electrode connection portion 81, the second negative electrode connection portion 82, the encapsulation film 9, the Mini-LED chip 10, and the pitch L.
Detailed Description
In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It is noted that the terms "comprises" and "comprising," and any variations thereof, in the description and claims of the present invention and in the foregoing figures, are intended to cover a non-exclusive inclusion, such that a process, method, apparatus, article, or device that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or device.
Fig. 1 provides a conventional display module, which includes a PCB board 1, a circuit (not shown in the figure) distributed in the PCB board 1, a driving unit disposed on the back of the PCB board 1, a third connection portion disposed on the front of the PCB board 1, and a pixel unit 40, wherein the third connection portion is electrically connected to the circuit in the PCB board, and the driving unit is used for controlling the pixel unit 40 to be turned on or off, and in the prior art, the pixel unit 40 is formed by a Mini-LED chip 10.
The thin film chip is used as the pixel unit 40 in the display module, wherein the thin film chip 4 comprises an epitaxial wafer, a current expansion layer 44, an insulating layer 45, a reflecting layer 46 and an electrode, the electrode comprises a first electrode 471 and a second electrode 472, the epitaxial wafer comprises a first type semiconductor layer 41, a light emitting layer 42 and a second type semiconductor layer 43, the first type semiconductor layer 41, the light emitting layer 42, the second type semiconductor layer 43, the current expansion layer 44, the insulating layer 45, the reflecting layer 46 and the electrode are distributed from top to bottom in sequence, the upper surface of the first type semiconductor layer 41 is a light emitting surface, one end of the first electrode is electrically connected with the first type semiconductor layer through an ohmic contact layer 48, one end of the second electrode 472 is electrically connected with the second type semiconductor layer 43 through the current expansion layer 44, the reflecting layer 46 is used for reflecting light, and the first electrode 471 and the second electrode 472 are used for being electrically connected with a circuit in the PCB.
The thin film chip 4 is a blue light chip or a green light chip, the first type semiconductor layer 41 is an N type GaN layer, the second type semiconductor layer 43 is a P type GaN layer, and the light emitting layer 42 is a quantum well layer.
In the present embodiment, the materials of the current spreading layer 44, the insulating layer 45, the reflecting layer 46, and the electrode are not particularly limited, the current spreading layer 44 is preferably ITO, and the insulating layer 45 is preferably Al 2 O 3 、SiO 2 The reflective layer 46 is preferably made of a metal such as Ni or Ag, and the first electrode 471 and the second electrode 472 are preferably made of copper.
If the thin film chip 4 is a red light chip or a yellow light chip, the first type semiconductor layer is an N type AlGaInP layer, and the second type semiconductor layer is a P type AlGaInP layer.
Referring to fig. 2, the size of the thin film chip is smaller (for example, the length of the thin film chip is 40 μm, the width of the thin film chip is 60 μm, or 50 μm, the electrode spacing is 10 μm to 20 μm), but in the PCB board of the conventional display module, the size of the third connecting portion is larger (for example, the length of the third connecting portion is 110 μm, the width of the third connecting portion is 120 μm, the distance between the two third connecting portions is about 50 μm to 70 μm), and the size difference between the electrode of the thin film chip and the bonding pad (i.e., the third connecting portion) on the PCB board is larger, so that the thin film chip cannot be precisely and firmly connected with the third connecting portion in the PCB board directly.
For the technical problem that a thin film chip in the prior art cannot be accurately and firmly connected with a third connecting part in a PCB, the following provides a preparation method of a display module, which comprises the following steps of:
s1, providing a substrate, wherein the primary color of the outer surface of the substrate is black, and conducting holes are formed in the substrate, and the specific steps comprise:
s11, a mechanical drilling mode is adopted, and a through hole penetrating through the substrate is formed in the substrate;
s12, electroplating a first conductive metal material in the through hole to form a conductive hole, wherein the first conductive metal material is preferably copper in the embodiment;
s2, preparing a first connecting part on the front surface of the substrate, wherein the first connecting part is electrically connected with a corresponding conductive hole, the size of the first connecting part is matched with the electrode size of the thin film chip, and the specific steps comprise:
s21, preparing a first connecting part on the front surface of the substrate by adopting a photoetching process, wherein the method comprises the following steps:
s2111, depositing a second conductive metal material on the front surface of the substrate by adopting an electron beam evaporation method or a magnetron sputtering coating process, wherein the thickness range is 3-5 mu m, and the preferred thickness range is 4 mu m in the embodiment, and the second conductive metal material is copper;
s2112, coating a first photoresist on the surface of the second conductive metal material;
s2113, based on the first mask, exposing and developing the first photoresist to expose the area to be etched of the second conductive metal material;
s2114, etching the area to be etched of the second conductive metal material by adopting a plasma dry etching or chemical liquid wet etching mode based on the development pattern;
s2115, cleaning and removing the first photoresist, thereby forming a first connection portion.
In another embodiment, the first connection portion may be formed by a lift-off process, and the specific preparation steps include:
s2121, coating a second photoresist on the front surface of the substrate;
s2122, exposing and developing the second photoresist based on the second mask;
s2123, electroplating a second conductive metal material on the front surface of the substrate by adopting an electron gun, wherein the thickness range is 3-5 mu m, the preferred thickness range is 4 mu m, and the second conductive metal material is copper;
s2124, stripping the second conductive metal material based on the developed pattern to form a first connection part;
s2125, cleaning and removing the residual second photoresist.
S22, coating tin or silver on the upper surface of the first connecting part.
S3, preparing a second connecting part on the back surface of the substrate, wherein the specific steps comprise:
s31, growing a seed material on the back surface of the substrate by adopting a magnetron sputtering coating process to form a seed layer, wherein the seed material is titanium or titanium tungsten alloy;
s32, preparing and forming a second connecting part on the surface of the seed layer by adopting a photoetching process, wherein the second connecting part is used for being electrically connected with a third connecting part in the PCB, and the preparing steps of the second connecting part comprise:
s3211, electroplating a second conductive metal material on the surface of the seed layer, wherein the thickness range is 30-50 mu m, and the preferred thickness range is 40 mu m, and the second conductive metal material is copper;
s3212, covering a dry film on the surface of the second conductive metal material;
s3213, exposing and developing the dry film based on the second mask plate to expose the area to be etched of the second conductive metal material;
s3214, etching the area to be etched of the second conductive metal material by adopting a dry etching or wet etching mode based on the development pattern;
and S3215, cleaning to remove the residual dry film, thereby forming a second connecting part.
In another embodiment, the second connection portion may be formed by a lift-off process, which specifically includes the following steps:
s3221, covering a dry film on the surface of the seed layer;
s3222, exposing and developing the dry film based on the second mask;
s3223, electroplating a second conductive metal material on the whole surface of the developed dry film, wherein the thickness range is 30-50 mu m, the preferred thickness range is 40 mu m, and the second conductive metal material is copper;
s3224, peeling the second conductive metal material based on the developed pattern to form a second connection portion.
When the second connecting part and the third connecting part are correspondingly connected, tin or silver is coated on the surface of the second connecting part, and the tin or silver is a conductive welding material, so that the second connecting part and the third connecting part are connected quickly and firmly.
In the step S2, the photoresist is solution and the thickness is controllable, so that the high-precision first connection portion with smaller cross-sectional area and smaller space (i.e., the first connection portion with small line width and high precision, the space between the first positive connection portion and the second positive connection portion with small line width is 5 micrometers-20 micrometers) can be prepared, and the size of the first connection portion is matched with the size of the electrode of the thin film chip, thereby being beneficial to the accurate installation of the micro thin film chip. In the step S3, the second connection portion is realized based on dry film lithography, and the dry film thickness is fixed and is generally greater than the thickness of the liquid photoresist, so that the second connection portion with larger cross-sectional area and larger space or the third connection portion on the PCB board can be prepared.
And S4, correspondingly mounting the thin film chip on the first connecting part in a mass transfer mode, and correspondingly connecting the electrode of the thin film chip with the corresponding first connecting part, so as to obtain the thin film chip adapter plate. In this embodiment, the bulk transfer mode refers to that firstly, a laser stripping mode is adopted to strip a wafer substrate, micro LED chips on the wafer are transferred onto a temporary substrate, then, a laser transfer, needling transfer or PDMS stamp adsorption transfer process mode is adopted to transfer Micro LED chips on the temporary substrate onto a chip transfer board, when laser transfer is adopted, the temporary substrate is made of transparent materials, such as glass, and when needling transfer is adopted, the temporary substrate is made of flexible substrates, such as a blue film provided with a glue layer.
The laser transfer refers to transferring Micro LED chips on a wafer substrate to a temporary substrate (such as a glass substrate) by adopting a laser stripping mode (namely stripping the wafer substrate through laser irradiation), so that the Micro LED chips are arrayed on the temporary substrate, and when in laser transfer, the temporary substrate is turned over, so that the Micro LED chips are correspondingly connected with a first connecting part, and laser irradiates again for de-colloid, so that the temporary substrate is separated from the Micro LED chips, and the Micro LED chips are transferred to a chip adapter plate.
The needling transfer refers to firstly peeling a wafer substrate by adopting a laser peeling mode, transferring Micro LED chips on the wafer to a blue film, then enabling the Micro LED chips to correspond to the first connecting portions, enabling a puncture needle to penetrate through the blue film to push the Micro LED chips, enabling the Micro LED chips to be adhered to the corresponding first connecting portions, and transferring the Micro LED chips to a chip adapter plate.
The PDMS seal adsorption transfer means that a wafer substrate is firstly stripped by adopting a laser stripping mode, micro LED chips on the wafer are transferred to a temporary substrate, then the Micro LED chips are adsorbed by adopting a PDMS seal, the Micro LED chips are separated from the temporary substrate, the PDMS seal moves, the Micro LED chips are transferred to the corresponding positions of a chip adapter plate, and the PDMS seal is stripped, so that the PDMS seal adsorption transfer of the Micro LED chips is realized.
In another embodiment, the LED chip is a blue light chip or a green light chip, and the non-red light chip is used for mass transfer, and then the Micro LED chip on the wafer can be directly transferred to the chip transfer board by adopting a laser transfer mode.
In the preparation method, the first connecting part with smaller cross section area is prepared on the front surface of the substrate, and the thin film chip with smaller electrode size is connected through the first connecting part so as to meet the miniaturization requirement of the thin film chip.
In the preparation process of the chip adapter plate, a circuit is not required to be prepared, a first connecting part (the thickness range of the first connecting part is 1-5 mu m), a second connecting part (the thickness range of the second connecting part and the third connecting part is 5-50 mu m) and a conductive hole are prepared on the surface of a substrate, the preparation process is simple, and compared with the method of redesigning, preparing a PCB and adjusting a circuit distribution structure in the PCB, the chip adapter plate provided by the application has the advantages that the problem that the cost is obviously increased due to complex process design of the PCB is avoided, and the cost is saved.
The chip transfer board structure prepared by the method is shown in fig. 4, and the chip transfer board comprises: the substrate 5, the first connection portion, the second connection portion, and the conductive hole 6, wherein the substrate 5 is used for carrying the pixel units 40, the pixel units 40 are distributed on the front surface of the substrate 5 in an array structure, the size of the substrate 5 is 150mm x 180mm, the range of the distance L between two adjacent pixel units 40 is 0.6mm to 1.5mm, and in this embodiment, 0.9mm is preferred. Each pixel unit 40 includes at least one thin film chip 4, and in this embodiment, each pixel unit 40 is formed by three thin film chips 4, respectively: the LED lamp comprises a red LED chip, a green LED chip and a blue LED chip, wherein the red LED chip, the green LED chip and the blue LED chip are sequentially arranged from left to right and light color mixing is performed.
In this embodiment, the arrangement mode of the three thin film chips 4 is not specifically limited, and the red LED chips, the green LED chips, and the blue LED chips may be arranged in a "delta" structure.
The first connecting portion is located on the front side of the substrate 5 and is used for electrically connecting the thin film chip 4 with the conductive hole 6, the second connecting portion is located on the back side of the substrate 5 and is used for electrically connecting with the third connecting portion, the first connecting portion, the second connecting portion and the third connecting portion are all made of second conductive metal materials, copper is preferred to be used as the second conductive metal materials, and tin is arranged on the surface of the copper.
In this case, the first connection portion includes a first positive connection portion 71 and a first negative connection portion 72, the second connection portion includes a second positive connection portion 81 and a second negative connection portion 82, the third connection portion includes a third positive connection portion 31 and a third negative connection portion 32, the cross-sectional area of the second positive connection portion 81 is larger than the cross-sectional area of the first positive connection portion 71 and smaller than or equal to the cross-sectional area of the third positive connection portion 31, the cross-sectional area of the second negative connection portion 82 is larger than the cross-sectional area of the first negative connection portion 72 and smaller than or equal to the cross-sectional area of the third negative connection portion 32.
The first positive electrode connection portion 71 and the first negative electrode connection portion 72 have smaller dimensions, in this embodiment, the cross-sectional areas of the first positive electrode connection portion 71 and the first negative electrode connection portion 72 are 50 μm by 70 μm, the pitches are 15 μm to 20 μm, the cross-sectional areas of the second positive electrode connection portion 81 and the second negative electrode connection portion 82 are larger than the first electrode 471 and the second electrode 472 of the thin film chip 4, respectively, the cross-sectional areas of the second positive electrode connection portion 81 and the second negative electrode connection portion 82 are 80 μm by 100 μm, the pitches are 60 μm, and the dimensions and the pitches of the third positive electrode connection portion and the third negative electrode connection portion are matched.
The first connecting part and the second connecting part structure not only meet the installation requirement of the miniature film chip 4, but also are beneficial to the firm connection of the film chip 4 and the third connecting part in the PCB.
The conductive hole 6 is a through hole penetrating through the substrate, and the through hole is filled with a first conductive metal: copper, the first connecting portion is connected to the one end of this conductive aperture, and the second connecting portion is connected to the other end, has made things convenient for miniature film chip 4 to be connected with the third connecting portion in the PCB board 1 through first connecting portion, conductive aperture, second connecting portion.
In addition, the chip adapter also comprises a packaging film 9, wherein the packaging film 9 is a light-transmitting dodging film, a diffusion film or an antireflection film, and the packaging film 9 is pressed on the front surface of the substrate 5 and the light-emitting surface of the film chip 4 through a film press, or is attached on the front surface of the substrate 5 and the light-emitting surface of the film chip 4 through a film attaching machine, so that the chip adapter not only has the functions of protecting the film chip 4 and preventing the film chip 4 from being worn or knocked and damaged, but also has the dodging or light diffusion function, and the light emitted by the film chip 4 is more uniform.
The substrate 5 used by the chip adapter plate is a BT plate, the size of the first connection portion on the front side of the BT plate is smaller, and in the present application, the overall primary color of the BT plate is black, which is favorable for improving the display contrast. In addition, in the COB module of Mini-LED chip, be provided with circuit wiring in the PCB board, circuit wiring is yellow, and the surface is usually exposed in PCB board surface, need adopt the thick black glue of some glue process coating just can reduce circuit wiring to show the influence of contrast, and in this application, the chip keysets connects in PCB board openly, the film chip distributes in the base plate openly of chip keysets (namely the film chip is located the one side of keeping away from the PCB board in the chip keysets), there is not circuit wiring in the base plate, circuit wiring's influence to showing the contrast has been avoided, consequently, the setting of chip keysets in this application has satisfied the connection requirement of circuit in film chip and the conventional PCB board, and is favorable to simplifying the technology, promote and show the contrast.
In the chip adapter plate, the proportion of the total area of the first connecting part to the total area of the substrate 5 is smaller than the proportion of the total area of the third connecting part to the total area of the PCB, so that the influence of the connecting part (the color of the connecting part is usually yellow or silver) on the display contrast is reduced, and the further improvement of the display contrast is facilitated.
S5, a bottom glue filling process is adopted, a connecting layer is arranged between the substrate and the PCB, the substrate and the PCB are correspondingly connected through the connecting layer, and the method specifically comprises the following steps:
s51, enabling a second connecting part on the back surface of the substrate to face upwards;
s52, coating a first solution in gaps between the second connecting parts by using a first dispenser, wherein the first solution is made of epoxy resin;
s53, heating and curing the first solution by adopting a first curing furnace to form a semi-cured layer, so as to prevent the first solution from flowing to pollute a film chip or influence subsequent bonding operation when the subsequent substrate is correspondingly connected with the PCB, wherein the thickness of the semi-cured layer is equal to that of the second connecting part;
s54, filling a second solution in gaps between the third connecting parts by adopting a second dispensing machine, wherein the second solution is the same as the first solution in material;
s55, rotating the substrate by 180 degrees to enable the second connecting part to face downwards, wherein one end of the second connecting part corresponds to the corresponding conductive hole, and the other end corresponds to the third connecting part;
s56, heating and curing the semi-cured layer and the second solution by adopting a second curing furnace. The semi-cured layer and the second glue solution have viscosity, and the substrate and the PCB can be firmly bonded after curing, so that the connection firmness of the chip adapter plate and the PCB is further enhanced, and the mechanical strength of the chip adapter plate and the PCB is enhanced. In addition, the connecting layer has viscosity, fills in the gaps of the third connecting parts and the second connecting parts, plays an insulating role, and further prevents conduction between two adjacent third connecting parts and between the second connecting parts.
The display module prepared by the method is shown in fig. 5 and 6, in the display module, a driving unit (not shown in the figure) is sequentially connected with a corresponding third connecting part, a corresponding second connecting part, a corresponding conductive hole, a corresponding first connecting part and a corresponding thin film chip through a circuit (not shown in the figure), and in the application, the driving mode of the driving unit is PM driving and mainly comprises electronic elements such as a driving IC, a capacitor, a resistor and the like.
The display module with the chip adapter is applied to a display device, and a plurality of display modules distributed in array are spliced to form the display device, referring to fig. 7, when the display device displays, the driving IC transmits control current signals to the first electrode and the second electrode of the corresponding thin film chip through the circuit, the third connecting part, the second connecting part, the conducting hole and the first connecting part, the first electrode transmits current to the current expansion layer, the current expansion layer transmits the current to the second type semiconductor layer (such as a P-type GaN layer) after expanding the current, the second electrode transmits the current to the first type semiconductor layer (such as an N-type GaN layer) through the ohmic contact layer, so that the light is generated by the light-emitting layer, and the light generated by the light-emitting layer is reflected by the reflecting layer and then emitted through the light-emitting surface.
It is to be understood that the foregoing detailed description of the invention is merely illustrative of the invention and is not limited to the embodiments of the invention. It will be understood by those of ordinary skill in the art that the present invention may be modified or substituted for elements thereof to achieve the same technical effects; as long as the use requirement is met, the invention is within the protection scope of the invention.
Claims (8)
1. The display module comprises a PCB, a pixel unit, a third connecting part arranged on the front surface of the PCB, and a driving unit arranged on the back surface of the PCB, wherein the driving mode of the driving unit is PM driving, the third connecting part is electrically connected with a circuit in the PCB, the display module is characterized in that the display module comprises a chip adapter plate,
the chip patch panel is used for connecting the pixel unit with a circuit in the PCB, and comprises:
the pixel unit comprises at least one thin film chip, wherein the thin film chip is a Micro LED chip;
the first connecting part is positioned on the front surface of the substrate, and the size of the first connecting part is matched with the electrode size of the thin film chip: the first connecting part comprises a first positive electrode connecting part and a first negative electrode connecting part, the first positive electrode connecting part and the first negative electrode connecting part are respectively connected with a positive electrode and a negative electrode of the same film chip, and the distance between the first positive electrode connecting part and the first negative electrode connecting part is matched with the distance between the positive electrode and the negative electrode of the same film chip;
the conductive hole is arranged on the substrate and is used for electrically connecting the first connecting part and the second connecting part;
the second connecting part is positioned on the back surface of the substrate, and the size of the second connecting part is matched with that of the third connecting part: the second connecting part comprises a second positive electrode connecting part and a second negative electrode connecting part, the third connecting part comprises a third positive electrode connecting part and a third negative electrode connecting part, the second positive electrode connecting part is connected with the corresponding third positive electrode connecting part, the second negative electrode connecting part is connected with the corresponding third negative electrode connecting part, and the interval between the second positive electrode connecting part and the second negative electrode connecting part is matched with the interval between the corresponding third positive electrode connecting part and the corresponding third negative electrode connecting part;
the substrate covers the whole surface including the front surface of the PCB, the proportion of the total area of the first connecting part to the total area of the substrate is smaller than the proportion of the total area of the third connecting part to the total area of the PCB, and the primary color of the surface of the thin film chip in the substrate is black;
the thin film chip is electrically connected with the third connecting part, a circuit in the PCB and the driving unit through the first connecting part, the conductive hole and the second connecting part in the chip adapter plate;
the thin film chip is positioned on one side of the substrate far away from the PCB;
the driving unit transmits a current control signal to the thin film chip through the third connecting part, a circuit in the PCB, the second connecting part, the first connecting part and the conducting hole, and controls the thin film chip to be turned on or turned off.
2. The display module of claim 1, wherein the substrate is made of BT plate, glass, ceramic or PET, and the thickness of the substrate is 0.05mm to 0.5mm.
3. The display module of claim 1, wherein the thin film chip has a length and width dimension ranging from 10 microns to 100 microns and a thickness ranging from 2 microns to 6 microns.
4. A method for manufacturing a display module according to claim 1, comprising:
providing a PCB, wherein the front surface of the PCB is provided with a third connecting part, the back surface of the PCB is provided with a driving unit, and the driving mode of the driving unit is PM driving;
providing a substrate, wherein a conductive hole is formed in the substrate;
preparing a first connecting part on the front surface of the substrate, and enabling the first connecting part to be electrically connected with the corresponding conductive hole, wherein the size of the first connecting part is matched with the electrode size of the thin film chip: the first connecting part comprises a first positive electrode connecting part and a first negative electrode connecting part, the first positive electrode connecting part and the first negative electrode connecting part are respectively connected with a positive electrode and a negative electrode of the same film chip, and the distance between the first positive electrode connecting part and the first negative electrode connecting part is matched with the distance between the positive electrode and the negative electrode of the same film chip;
preparing a second connecting part on the back of the substrate, wherein one end of the second connecting part is electrically connected with the corresponding conductive hole, and the size of the second connecting part is matched with that of the third connecting part: the second connecting part comprises a second positive electrode connecting part and a second negative electrode connecting part, the third connecting part comprises a third positive electrode connecting part and a third negative electrode connecting part, the second positive electrode connecting part is connected with the corresponding third positive electrode connecting part, the second negative electrode connecting part is connected with the corresponding third negative electrode connecting part, and the interval between the second positive electrode connecting part and the second negative electrode connecting part is matched with the interval between the corresponding third positive electrode connecting part and the corresponding third negative electrode connecting part;
providing a plurality of thin film chips, wherein the thin film chips are Micro LED chips, and the thin film chips are arranged on the substrate in an array structure in a mass transfer mode, and electrodes of the thin film chips are electrically connected with the corresponding first connecting parts;
bonding the back surface of a substrate in the chip adapter plate with the PCB, wherein the second connecting part on the back surface of the substrate is correspondingly connected with the third connecting part;
the substrate covers the whole surface including the front surface of the PCB, the proportion of the total area of the first connecting part to the total area of the substrate is smaller than the proportion of the total area of the third connecting part to the total area of the PCB, and the primary color of the surface of the thin film chip in the substrate is black;
the thin film chip is positioned on one side of the substrate far away from the PCB;
the driving unit transmits a current control signal to the thin film chip through the third connecting part, a circuit in the PCB, the second connecting part, the first connecting part and the conducting hole, and controls the thin film chip to be turned on or turned off.
5. The method for manufacturing a display module according to claim 4, wherein a through hole penetrating through the substrate is formed in the substrate by means of laser drilling or mechanical drilling;
filling a first conductive metal material in the through hole to form a conductive hole;
preparing a first connecting part on the front surface of the substrate by adopting a photoetching process or a stripping process;
and coating conductive welding materials on the surface of the first connecting part.
6. The method of claim 5, further comprising the step of preparing the second connection portion comprising: a magnetron sputtering coating process is adopted to grow seed materials on the back surface of the substrate to form a seed layer; and preparing the second connecting part on the surface of the seed layer by adopting a photoetching process or a stripping process.
7. The method for manufacturing a display module according to claim 6, wherein a bottom filling process is adopted to provide a connection layer between the substrate and the PCB, and the substrate and the PCB are correspondingly connected through the connection layer, comprising:
filling a first solution in the gap between the second connecting parts;
heating and curing the first solution to form a semi-cured layer of the first solution;
filling a second solution in the gap between the third connecting parts;
correspondingly connecting the other end of the second connecting part with the third connecting part, and attaching the upper surface of the second solution to the lower surface of the semi-solidified layer;
and heating and curing the semi-cured layer and the second solution, and bonding the back surface of the substrate with the PCB.
8. A display device, which is formed by splicing a plurality of display modules, wherein the display modules are the display modules according to claim 1.
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CN114122221A (en) * | 2021-11-23 | 2022-03-01 | 利亚德光电股份有限公司 | LED display module and manufacturing method thereof |
CN114843254A (en) * | 2022-04-27 | 2022-08-02 | 惠州视维新技术有限公司 | Mini LED backlight module and manufacturing method thereof |
CN115692457A (en) * | 2022-06-29 | 2023-02-03 | 上海闻泰电子科技有限公司 | Display screen, preparation method thereof and display device |
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CN114122221A (en) * | 2021-11-23 | 2022-03-01 | 利亚德光电股份有限公司 | LED display module and manufacturing method thereof |
CN114843254A (en) * | 2022-04-27 | 2022-08-02 | 惠州视维新技术有限公司 | Mini LED backlight module and manufacturing method thereof |
CN115692457A (en) * | 2022-06-29 | 2023-02-03 | 上海闻泰电子科技有限公司 | Display screen, preparation method thereof and display device |
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