KR101622399B1

KR101622399B1 - Led device

Info

Publication number: KR101622399B1
Application number: KR1020090076192A
Authority: KR
Inventors: 박칠근; 박주도; 최문구
Original assignee: 엘지전자 주식회사
Priority date: 2009-08-18
Filing date: 2009-08-18
Publication date: 2016-05-18
Also published as: KR20110018630A

Abstract

The present invention provides an LED device capable of mounting an LED device without using wire bonding. According to an embodiment of the present invention, there is provided a plasma display panel comprising: a submount substrate having a first upper electrode in a first region of a top surface and a second upper electrode in a second region; A vertical LED element having first and second device electrodes on the upper and lower sides, respectively, and a lower second device electrode bonded to the first upper electrode; And a conductive film disposed in contact with the shape of the vertical LED element and electrically connecting the first device electrode on the LED device and the second upper electrode on the submount substrate do.

LED, Package, Diode, Conductive Film, Transparent Plate.

Description

LED DEVICE {LED DEVICE}

The present invention relates to an LED (Light Emitting Diode) device, and more particularly, to a package of an LED device.

LED devices have advantages such as high efficiency, high speed response, long life, small size, light weight and energy saving by low power consumption, and they have excellent features such as an environment friendly light source that does not generate carbon monoxide and is anhydrous light source, . In addition, it is possible to freely design line, surface and space with point light source and ultra-small optical device, and it is predicted that sustainable growth will be very broad in the fields of applications such as display, signal, display, lighting, bio, telecommunication, do.

A common method for attaching an LED element to a required device is to connect the electrode of the LED element with the electrode of the device by wire. However, since the size of the LED element is very small, expensive bonding equipment is required for precise wire bonding of the LED element. In addition, when a single device is implemented using a plurality of LED elements, wire bonding must be performed on all the LED elements, which requires a long process time.

The present invention provides an LED device capable of mounting an LED device without using wire bonding.

According to an embodiment of the present invention, there is provided a plasma display panel comprising: a submount substrate having a first upper electrode in a first region of a top surface and a second upper electrode in a second region; A vertical LED element having first and second device electrodes on the upper and lower sides, respectively, and a lower second device electrode bonded to the first upper electrode; And a conductive film disposed in contact with the shape of the vertical LED element and electrically connecting the first device electrode on the LED device and the second upper electrode on the submount substrate do.

According to another embodiment of the present invention, there is provided a plasma display panel comprising: a submount substrate having a first upper electrode in a first region of a top surface and a second upper electrode in a second region; A vertical LED element having first and second device electrodes on the upper and lower sides, respectively, and a lower second device electrode bonded to the first upper electrode; A first solder having a bottom surface in contact with the second upper electrode and having substantially the same height as the vertical LED element; And a conductive film for electrically connecting the first device electrode and the solder.

The present invention allows the LED element to be electrically connected to the device by using a transparent plate having a conductive film, without using a wire bonding process and a silicon filling process when the vertical LED device is to be built in the device. Therefore, expensive wire bonding equipment is not required in the process of manufacturing the LED device. In the previous method, a plurality of LED elements are successively subjected to a wire bonding process, which requires a lot of processing time. However, according to the present invention, a plurality of LED elements are electrically connected to a device in a single wafer level unit . Therefore, the manufacturing process time of the LED device can be reduced, thereby greatly reducing the manufacturing cost.

In addition, since wires are not used in the process of connecting or attaching the LED device to the device, it is possible to improve the illuminance unevenness of the LED device caused by the light emitted from the LED device reflected by the wire or absorbed by the wire.

In addition, in the case of using a phosphor sheet for realizing white light, it is possible to solve the difficult problem of joining caused by the wire when the phosphor sheet is bonded to the LED element.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in order to facilitate a person skilled in the art to easily carry out the technical idea of the present invention. do.

1 is a sectional view showing an LED element for explaining the present invention. Particularly, Fig. 1 shows a vertical LED device for high output which is widely used for display and illumination.

1, the LED device comprises a wafer substrate region 1, a P-GaN layer 2, an MQW (active multiple active) layer 3, an N-GaN layer 4, a negative electrode 5 , A positive electrode (6), and a reflective layer (7).

As shown in Fig. 1, a negative electrode 5 and a positive electrode 6 for electrically connecting the LED element to the LED element are formed on the upper and lower sides of the LED element, respectively.

Fig. 2 is a process sectional view showing an LED device including the LED device shown in Fig. 1. Fig.

1 and 2, the LED device includes connection portions 13a and 13b formed through a ceramic or semiconductor substrate 10 used as a submount substrate. The LED device 20 has connection portions 13a and 13b for electrical connection with the LED device 20. [ The upper electrodes 17a and 17b and the lower electrodes 18a and 18b are connected to each other through the connection portions 13a and 13b. The connection portions 13a and 13b form through holes passing through the substrate 10 and are formed by embedding conductive material. The lower electrodes 18a and 18b are for electrical connection with the metal wiring of the PCB substrate to which the LED device will be later mounted.

The upper electrodes 17a and 17b are electrically connected to the positive electrode 6 and the negative electrode 5, respectively. The positive electrode 6 is connected to the upper electrode 17a via the solder 70. The negative electrode 5 and the upper electrode 17b of the submount substrate are electrically connected to each other by a wire bonding method using Au or Al wire 60. In order to realize white light, a phosphor layer 30 is formed on the LED element 20 to protect the LED element and the phosphor layer 30 and the wire 60, A transparent silicone resin 50 is formed by a molding method to control the distribution of light.

As described above, the wire bonding process is used to electrically connect the LED device to the vertical LED device package. Therefore, expensive wire bonding equipment is required to manufacture LED devices. In addition, the wire bonding process can not simultaneously perform wire bonding to all the LED devices at the wafer level in a single process, and the wire bonding process can not be performed sequentially for individual LED devices.

Therefore, it takes a long time to process by wire bonding, and the manufacturing cost of the LED device is greatly increased. In addition, light emitted from the LED element 20 by the wire 60 may be reflected or absorbed, resulting in nonuniform luminance uniformity as well as lowering the luminous efficiency. In the subsequent process, when a white light is realized by using a phosphor layer or a phosphor sheet, a phosphor sheet must be bonded to the LED. However, it is difficult to bond the phosphor sheet to the wire 60.

In the present invention, an LED element is bonded to an upper electrode on a submount substrate, a phosphor is formed to realize white light, and a transparent plate having a conductive film such as ITO film or CNT (Carbon Nano tube) is bonded to a conductive film , And an externally applied voltage can be transmitted to the LED element through the conductive film. The submount substrate has an upper electrode and a lower electrode on upper and lower sides, respectively, and electrically connects the upper electrode electrically connected to the pliable electrode of the LED element through the through hole and the lower electrode for electrical connection to the PCB.

3 and 4 are cross-sectional views illustrating an LED device according to a preferred embodiment of the present invention. A manufacturing process of the LED device according to the present embodiment will be described with reference to FIGS. 3 and 4. FIG.

The LED device according to the present embodiment is characterized in that the negative electrode 27 and the positive electrode 28 are bonded to both sides of the LED element 21 and the connection portions 14a and 14b passing through the submount substrate 11 are disposed The upper electrodes 16a and 16b for electrical connection with the LED element 21 and the lower electrodes 19a and 19b for electrical connection with the metal wiring of the PCB substrate are electrically connected to each other through the connection portions 14a and 14b .

The first upper electrode 16a is electrically connected to the negative electrode 27 which is the device electrode of the LED element 21 through the solder 70a. The conductive film 41 is disposed along the shape of the LED element 21 and a part of the conductive film 41 is electrically connected to the positive electrode 28 which is the element electrode of the LED element 21, And the solder 70b. The insulating layer 71 allows the first upper electrode 16a and the conductive film 41 to be insulated from each other.

As the submount substrate 11, not only a ceramic substrate such as an aluminum nitride (AlN) film, an aluminum oxide (AlOx) film, an Al ₂ O ₃ film, a BeO film, A metal substrate such as copper, aluminum, or silver, a photo sensitive glass (PSG), or an insulating substrate such as a PCB may be used. The submount substrate may also be made by mixing materials having excellent thermal conductivity properties to improve the thermal conductivity.

The connection portions 14a and 14b are formed by making a through hole penetrating the submount substrate 11 and filling the through hole with a conductive material. As a method for forming the through hole, a wet etching method, a dry etching method, a laser drilling method, or the like can be used, and it can be formed using a bulk micromachining technique.

Methods for electrically connecting the upper electrodes 16a and 16b and the lower electrodes 19a and 19b through the through holes include a method by electroplating, a method by lift-off, A patterning technique of a semiconductor process technology such as a mixing method in which a lift-off and an electroplating are mixed is used.

After the electrode metal is embedded in the upper and lower surfaces of the submount substrate and the through holes are formed on the lower surface of the submount substrate, the electrode metal of a certain portion is removed by a laser or the like so that the connection portions 14a, 14b and the upper electrodes 16a, And the lower electrodes 19a and 19b may be formed at one time. Alternatively, the connection portions 14a and 14b may be formed by screen printing or ink jetting.

In addition, when the submount substrate 11 is a semiconductor substrate such as silicon or a metal substrate such as copper or aluminum, an insulating layer (not shown) for electrical insulation is formed on the front surface of the substrate and the front surface of the substrate. The insulating layer 71 may be formed using a silicon oxide film having excellent insulation characteristics by a thermal oxidation method and may be a silicon nitride film formed by low pressure chemical vapor deposition (LPCVD) or plasma enhanced chemical vapor deposition (PECVD) Can be used. In the case of using an insulating substrate, formation of the insulating layer 71 may be omitted.

Continuing on, the upper electrode 16a is electrically connected to the positive electrode 28 of the LED element by using the solder 70a. The solder 70a is formed on the upper electrode 16a by a dispensing method using cream solder or conductive epoxy or the like and the upper electrode 16a and the flexible electrode 28 of the LED element The LED element 21 is placed on the solder 70a, and heat is applied to the LED element 21 to join the LED element 21 by a reflow process. Alternatively, a pattering process may be performed to distinguish a portion to be protected from a portion to be soldered by using a semiconductor process, and an e-beam evaporation process may be performed to remove the gold (AuSn) The solder 70a may be formed using red tin (PbSn), silver tin (AgSn), or the like. It is more preferable that the solder 70a used herein is not only conductive but also has a higher reflow temperature than that of the solder used when bonding the submount substrate on the PCB in the packaging process of a subsequent LED element, .

Continuing on, the phosphor layer 30a is provided on the LED element 21. The phosphor layer 30a is formed by mixing and defoaming a phosphor powder with a silicon solution and by using dispensing, screen printing, or ink jetting. As another method of using the phosphor layer 30a, a phosphor sheet may be used for bonding by using an adhesive such as a silicon solution or by a lamination process in a wafer level unit . The phosphor layer 30a should not be formed on the negative electrode 27 of the LED element 21 so that the conductive film 41 and the negative electrode 27 of the LED element 21 can be electrically connected.

The insulating layer 71 is formed of a material that can act as an adhesive for electrically bonding the transparent plate 42 with the conductive film, as well as electrically insulating the upper portion of the submount substrate. The insulating layer 71 is formed on the upper portion of the upper electrode 16a for the purpose of electrically connecting the conductive film 41 on the portion where the flexible electrode 26 of the LED element 21 is to be joined and on the upper electrode 16b for negative, Except for the portion to be connected. The insulating layer 71 serves to electrically insulate the upper electrode 16a for the positive and the conductive film 41 from each other.

When the submount substrate 10 is used as a conductive substrate or a semiconductor substrate, the insulating layer 71 must be formed so that the conductive film 41 is also insulated from the submount substrate 10. [ This insulating layer can be formed using an insulating adhesive in a process for bonding the transparent plate 42 to which the conductive film 41 is attached, without additional process for forming a separate insulating layer.

In addition, if the size of the upper electrode 16a for the application of the LED element 21 is equal to or smaller than the size of the flexible electrode 28 of the LED element, the step of the insulating layer 71 is omitted .

In addition, in the electrode connecting step of the LED element 21, the upper electrode for power supply 16a may not be exposed to the outside, so that the upper electrode 16a may be isolated so as not to be in contact with the conductive film 41. In this case, there is no need to dispose the insulating layer 71, but a separate method for bonding the transparent plate 42 to which the conductive film is attached is needed.

5 is a cross-sectional view showing the conductive film and the transparent plate shown in Fig.

A method of attaching the transparent plate 42 with the conductive film 41 to the LED device will be described with reference to FIG.

The transparent plate 42 to which the conductive film 41 according to the present embodiment is attached may be formed by molding using a molding method using silicon, polycarbonate, acryl, PMMA, or the like, ) Substrate or the like may be used. The conductive film 41 is uniformly bonded to the lower surface where the transparent plate 42 is bonded to the submount substrate.

A cavity is formed in a portion of the submount substrate on which the LED element 21 is bonded on the upper electrode 16a of the submount substrate so that the conductive film 41 Is electrically connected to the negative electrode 27 of the LED element 21 and is electrically connected to the negative upper electrode 16b of the submount substrate 11 at the same time.

5, the width W of the cavity may be sufficiently wide in consideration of an alignment error for joining the transparent plate 42, and the height H may be set to be large enough for the LED element 21, Substantially the same as the overall height of the < / RTI > In order to facilitate the electrical contact of the conductive film 41, a conductive film 41 is formed on the upper surface of the negative electrode 27 of the LED element 21 and the upper electrode 16b for negative, An adhesive layer may be further formed.

The conductive film 41 may be formed using an ITO film used for an LCD module or a carbon nano tube, and may be bonded to the transparent plate 42 using an adhesive transparent film. The transparent plate 42 with the conductive film 41 should not be deformed or deteriorated by heat generated when driving the LED element 21 as well as being excellent in transparency of light emitted from the LED element 21, And the refractive index of GaN, which is an electrode material of the device, is not greatly different.

6 is a cross-sectional view illustrating an LED device according to a second preferred embodiment of the present invention. The same reference numerals are used for the layers serving as those shown in Figs. 4 and 5.

6, the LED device according to the second embodiment is manufactured in a flat manner without forming a cavity in the transparent plate 42a, and after the conductive film 41a is attached, the insulating layer 71b and the solder The height of the LED element 21 is increased by the height of the LED element 21. The conductive film 41a is electrically connected to the negative electrode 27 of the LED element 21 through the solder 70c and electrically connected to the negative upper electrode 16b through the solder 70d .

The negative electrode 27 is electrically connected to the conductive film 41a through the solder 70c and the phosphor layer 30a is formed on the upper surface of the LED element 21. [ The phosphor layer 30a is formed on the upper surface of the LED element 21 other than the solder 70c so that the negative electrode 27 can be electrically formed with the conductive film 41a through the solder 70c. In this embodiment, it is advantageous that the transparent plate 42a is made excellent and the conductive film 41a is easily formed on the transparent plate 42a.

7 is a cross-sectional view illustrating an LED device according to a third preferred embodiment of the present invention. The layers serving as those shown in Figs. 4 to 6 have the same reference numerals.

7, the LED device according to the present embodiment is manufactured by bonding a transparent plate 42 with a conductive film 41 to a submount substrate 11 to which an LED element 21 is bonded, The lower electrode 41 is electrically connected to the negative electrode 27 of the LED element 21 and at the same time is electrically connected to the negative upper electrode 16b of the submount substrate 11. [ At this time, the conductive film 41 is electrically connected to the negative electrode 27 of the LED element 21 through the solder 70c, and the solder 70b is electrically connected to the negative upper electrode 16b of the sub- ). &Lt; / RTI >

A feature of the LED device according to the present embodiment is that the phosphor layer 30b is formed on the transparent plate 42 in the upper region of the LED element 21. [ The phosphor layer 30b is arranged in alignment with the center portion of the LED element 21. The width of the phosphor layer 30b may be formed as the width of the LED element 21, or may be formed smaller or larger. In some cases, the phosphor layer 30b may be formed in the entire region above the transparent plate 42. [

As described above, the LED device according to the present embodiment does not use the previously used wire bonding process by bonding the transparent plate with the conductive film on the submount substrate to which the LED device is bonded. Therefore, expensive wire bonding equipment is not required in the process of manufacturing the LED device. In the previous method, a plurality of LED elements are successively subjected to a wire bonding process, which requires a lot of processing time. However, according to the present embodiment, electrodes of a plurality of LED elements can be electrically connected in a single wafer level unit . Therefore, the processing time of the LED device can be reduced, thereby greatly reducing the manufacturing cost.

In addition, since wires are not used in the process of connecting or attaching the LED device to the device, it is possible to improve the illuminance unevenness of the LED device caused by the light emitted from the LED device reflected by the wire or absorbed by the wire. Further, in the case of using a phosphor sheet to realize white light, it is possible to solve the difficult problem of joining caused by the wire when bonding the phosphor sheet to the LED element.

In order to control the distribution of light emitted from the LED device, the LED device according to the present embodiment may further include a lens disposed above the transparent plate. The lens may be manufactured separately from the transparent plate and attached to the transparent plate, or may be formed by simultaneously forming the lens during the production of the transparent plate. The LED device can be manufactured by collectively processing the submount substrate as well as the transparent plate process with the conductive film in a wafer level and thereafter separating into individual package units. The LED device can be manufactured efficiently.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, I will understand. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims, as well as the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view showing an LED element for explaining the present invention. Fig.

2 is a cross-sectional view showing a package of the LED element shown in Fig.

3 and 4 are cross-sectional views illustrating an LED device according to a preferred embodiment of the present invention.

6 is a sectional view showing an LED device according to a second preferred embodiment of the present invention.

7 is a sectional view showing an LED device according to a third preferred embodiment of the present invention.

Description of the Related Art [0002]

41: conductive film 42: transparent plate

25: LED N electrode 26: LED P electrode

70a, 70b: solder 71: adhesive layer

17a, 17b: first electrodes 18a, 18b: second electrodes

13a: connection for the positive electrode

13b Connection for negative electrode

10: Sub-mount substrate

30a, 30b: phosphor layer 20: LED element

Claims

A sub-mount substrate having a first upper electrode in a first region of an upper surface and a second upper electrode in a second region;

A vertical LED element having first and second device electrodes on the upper and lower sides, respectively, and a lower second device electrode bonded to the first upper electrode;

A conductive film disposed to be in contact with the shape of the vertical LED element and electrically connecting the first device electrode on the LED device to the second upper electrode on the submount substrate;

A transparent plate provided on the conductive film; And

And a fluorescent layer disposed on the transparent plate in an upper region of the LED element.

delete

The method according to claim 1,

The submount substrate has a first lower electrode in a first region of a lower surface and a second lower electrode in a second region of a lower surface, And a second connection unit electrically connecting the first upper electrode and the second lower electrode to each other.

The method according to claim 1,

And a solder for bonding between the second device electrode of the LED element and the first upper electrode.

The method according to claim 1,

And an insulation layer for insulation between the conductive film and the first upper electrode.

The method according to claim 1,

And a fluorescent layer disposed on a top surface of the LED element in a remaining region where the first device electrode is not disposed.

delete

The method according to claim 1,

The conductive film

An ITO film or CNT is used.

A first solder having a bottom surface in contact with the second upper electrode and having substantially the same height as the vertical LED element;

A conductive film for electrically connecting the first device electrode and the solder;

A transparent plate provided on the conductive film; And

delete

10. The method of claim 9,

And a second solder for bonding between the second device electrode of the LED element and the first upper electrode.

10. The method of claim 9,

14. The method of claim 13,

Wherein the height of the insulating layer is substantially equal to the height of the LED device and is arranged to expose an upper surface of the first solder and a top surface of the first device electrode of the LED device.

10. The method of claim 9,

delete