CN116417553A

CN116417553A - Light-emitting module and display device

Info

Publication number: CN116417553A
Application number: CN202111658790.9A
Authority: CN
Inventors: 王杰凌; 陈清河; 邱亚新; 时军朋; 韩梦超; 林振端; 余长治; 徐宸科
Original assignee: Hubei San'an Photoelectric Co ltd
Current assignee: Hubei San'an Photoelectric Co ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2023-07-11

Abstract

The application discloses a light emitting module and a display device, wherein the light emitting module comprises a plurality of light emitting elements which are arranged at intervals; the wiring layer is formed on the plurality of light-emitting elements and is used for being electrically connected with the light-emitting elements; the conductive pad is formed on one side of the wiring layer far away from the light-emitting element and is electrically connected with the wiring layer; the packaging layer is positioned at the periphery of the conductive bonding pad; the protection pad is formed on one side of the packaging layer far away from the light-emitting element and is positioned in the thimble operation area of the light-emitting module. According to the protection pad, the protection pad is additionally arranged in the thimble operation area of the light-emitting module, when the thimble acts on the area, the thimble can be effectively prevented from piercing or bursting the packaging layer, the packaging layer still has a good protection effect on the light-emitting element, the damage to the light-emitting element is avoided, and the failure of the light-emitting module is avoided.

Description

Light-emitting module and display device

Technical Field

The present disclosure relates to the field of semiconductor technologies, and more particularly, to a light emitting module and a display device.

Background

Light emitting diodes are widely used in various fields such as display devices, lamps for vehicles, general illumination lamps, etc. due to their characteristics of high reliability, long life span, and low power consumption, for example, they can be used as backlight sources for various display devices. In order to perform effective mechanical protection on the light emitting diode, the light emitting diode is often packaged and formed into a light emitting module, which can enhance heat dissipation, improve light extraction efficiency, and optimize light beam distribution. However, the reliability of the light emitting module obtained by the existing method is poor, and how to obtain a light emitting module with high reliability is still a difficult problem.

Disclosure of Invention

A light emitting module according to an embodiment of the present disclosure may include: a plurality of light emitting elements arranged at intervals, each light emitting element having a thickness of 15 μm or less; the filling layer is filled between the adjacent light-emitting elements; the wiring layer is formed on the plurality of light-emitting elements and is used for being electrically connected with the light-emitting elements; the conductive pad is formed on one side of the wiring layer far away from the light-emitting element and is electrically connected with the wiring layer; wherein the filling layer contains a black filling component, and the particle size of the black filling component is less than or equal to 1/10 of the thickness of the light-emitting element, or the particle size of the black filling component is less than or equal to 1 mu m.

A light emitting module according to still another embodiment of the present disclosure may include: a plurality of light emitting elements arranged at intervals; the wiring layer is formed on the plurality of light-emitting elements and is used for being electrically connected with the light-emitting elements; the conductive pad is formed on one side of the wiring layer far away from the light-emitting element and is electrically connected with the wiring layer, and the thickness of the conductive pad is larger than 5 mu m; wherein the wiring layer and the conductive pad are in direct contact.

A light emitting module according to still another embodiment of the present disclosure may include: a plurality of light emitting elements are arranged at intervals; the wiring layer is formed on the plurality of light-emitting elements and is used for being electrically connected with the light-emitting elements; the conductive pad is formed on one side of the wiring layer far away from the light-emitting element and is electrically connected with the wiring layer; the wiring layer has a first region and a second region, the first region is a region overlapping the conductive pad in a vertical direction, the second region is a region connecting the first region and the light emitting element, a connection position of the first region and the second region is provided between the first region and the second region, a length of the connection position of the first region and the second region is greater than 20 [ mu ] m, or a length of the connection position of the first region and the second region is 40% or more of a length of any side of the conductive pad.

A light emitting module according to still another embodiment of the present disclosure may include: a plurality of light emitting elements arranged at intervals; the filling layer is filled between the adjacent light-emitting elements; the wiring layer is formed on the plurality of light-emitting elements and is used for being electrically connected with the light-emitting elements; the conductive pad is formed on one side of the wiring layer far away from the light-emitting element and is electrically connected with the wiring layer; the adhesive layer is located between the light emitting element and the filler layer.

A light emitting module according to still another embodiment of the present disclosure may include: a plurality of light emitting elements arranged at intervals; the wiring layer is formed on the plurality of light-emitting elements and is used for being electrically connected with the light-emitting elements; the conductive pad is formed on one side of the wiring layer far away from the light-emitting element and is electrically connected with the wiring layer; the packaging layer is positioned at the periphery of the conductive bonding pad; the protection pad is formed on one side of the packaging layer far away from the light-emitting element and is positioned in the thimble operation area of the light-emitting module.

A light emitting module according to still another embodiment of the present disclosure may include: a plurality of light emitting elements are arranged at intervals; the wiring layer is formed on the plurality of light-emitting elements and is used for being electrically connected with the light-emitting elements; the conductive pad is formed on one side of the wiring layer far away from the light-emitting element and is electrically connected with the wiring layer; the conductive protection layer is positioned between the conductive pad and the wiring layer.

The method for manufacturing the light emitting module according to the further embodiment of the present disclosure may include the steps of: providing a first transparent layer; a plurality of light emitting elements fixedly arranged at intervals on a surface of the first transparent layer; forming a filling layer around the light emitting element; manufacturing a wiring layer on the filling layer; forming a conductive pad on the wiring layer, wherein the thickness of the conductive pad is more than or equal to 5 mu m, and the conductive pad is in direct contact with the wiring layer; an encapsulation layer is formed around the conductive pads.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a plan view of a light emitting module according to a first embodiment of the present application;

FIG. 2 is a cross-sectional view taken along line A-A' of FIG. 1;

FIG. 3 is a cross-sectional view of a light emitting module according to a second embodiment of the present application;

FIG. 4 is a cross-sectional view of a light emitting module according to a second embodiment of the present application;

FIG. 5 is a cross-sectional view of a light emitting module according to a third embodiment of the present disclosure;

fig. 6 is a flowchart of a method for manufacturing a light emitting module according to a fourth embodiment of the present application;

fig. 7a to 15 are cross-sectional views and plan views of part of corresponding manufacturing processes of the light emitting module according to the fourth embodiment of the present application;

fig. 16 is a plan view of a light emitting module according to a fifth embodiment of the present application;

FIG. 17 is a plan view of FIG. 16 omitting conductive pads to facilitate labeling of wiring layers;

fig. 18 is a cross-sectional view of a light emitting module according to a sixth embodiment of the present application;

fig. 19 is a cross-sectional view of a light emitting module according to a sixth embodiment of the present application;

fig. 20 is a plan view of a light emitting module according to a seventh embodiment of the present application;

fig. 21 is a plan view of a light emitting module according to a seventh embodiment of the present application.

Illustration of:

a 100 transparent layer; 1001 a first transparent layer; 1002 a second transparent layer; 200 light emitting elements; 201 a first light emitting element; 202 a second light emitting element; 203 a third light emitting element; 210 a fill layer; 300 wiring layers; 3000 total wiring layers; 3001 a first region; 3002 a second region; 3003 a third region; 3004 the connection location of the first region and the second region; 301 a first sub-wiring; 302 a second sub-wiring; 303 a third sub-wiring; 304 a fourth sub-wiring; 310 a first layer; 320 a second layer; 330 an insulating layer; 400 conductive protective layer; 500 conductive pads; 501 a first bonding pad; 502 a second bond pad; 503 a third bond pad; 504 fourth bond pads; 510 a conductive layer; 520 an adhesive layer; 530 a protective layer; 540 eutectic layer; 600 packaging layers; 700 seed layer; 800 guard pads.

Detailed Description

Other advantages and effects of the present application will become apparent to those skilled in the art from the present disclosure, when the following description of the present application is taken in conjunction with the accompanying drawings. The present application may be carried out or operated in different embodiments, and various modifications or changes may be made in the details of the application based on different points of view and applications without departing from the spirit of the application.

In the description of the present application, it should be noted that, the azimuth or positional relationship indicated by the terms "upper" and "lower" and the like are based on the azimuth or positional relationship shown in the drawings, or the azimuth or positional relationship that is commonly put when the product of the application is used, only for convenience of description of the present application and simplification of the description, and are not to indicate or imply that the apparatus or element referred to must have a specific azimuth, be configured and operated in a specific azimuth, and therefore should not be construed as limiting the present application. Furthermore, the terms "first" and "second," etc. are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

Example 1

Fig. 1 is a schematic plan view for explaining a light emitting module of a first embodiment of the present application, and fig. 2 is a schematic sectional view taken along a line A-A' of fig. 1.

Referring to fig. 1 and 2, the light emitting module includes a plurality of light emitting elements 200 arranged at intervals and having different wavelength ranges, and gaps between adjacent light emitting elements 200 are filled with a filling layer 210 to electrically isolate the adjacent light emitting elements 200. The wiring layer 300 is formed on the plurality of light emitting elements 200 and is used for electrical connection with the light emitting elements 200. The conductive pad 500 is formed at a side of the wiring layer 300 remote from the light emitting element 200 and is electrically connected to the light emitting element 200 through the wiring layer 300.

In one embodiment, the light emitting element 200 mainly refers to a light emitting diode of a micrometer scale, and has a width and a length ranging from 2 to 5 μm, 5 to 10 μm, 10 to 20 μm, 20 to 50 μm, or 50 to 100 μm, and a thickness ranging from 2 to 15 μm, preferably 5 to 10 μm. In this embodiment, the light emitting module includes a first light emitting element 201, a second light emitting element 202, and a third light emitting element 203.

Specifically, each light emitting element 200 includes a semiconductor stacked layer, which may include a first semiconductor layer, a second semiconductor layer, and an active layer disposed therebetween, which are sequentially arranged, wherein the first semiconductor layer is an N-type semiconductor layer, the second semiconductor layer is a P-type semiconductor layer, and the active layer is a multi-layered quantum well layer, which may provide radiation of red light or green light or blue light. The N-type semiconductor layer, the multi-layer quantum well layer, and the P-type semiconductor layer are only basic constituent units of the light emitting element 200, and the light emitting element 200 may further include other functional structure layers having an optimization effect on the performance of the light emitting element 200.

The first light emitting element 201, the second light emitting element 202, and the third light emitting element 203 respectively radiate light of different wavelength ranges, for example, the first light emitting element 201 radiates blue light, the second light emitting element 202 radiates green light, and the third light emitting element 203 radiates red light. In an embodiment, the different light emitting elements 200 may have different semiconductor stacked layers so as to directly radiate light in different wavelength ranges, and specific materials of the semiconductor stacked layers are selected according to the wavelength of the radiated light, which includes but is not limited to aluminum gallium arsenide, gallium arsenide phosphide, aluminum gallium indium phosphide, gallium nitride, indium gallium nitride, zinc selenide, or gallium phosphide. In another embodiment, the different light emitting elements 200 may have the same semiconductor stacked layers, for example, the semiconductor stacked layers in the first light emitting element 201, the second light emitting element 202, and the third light emitting element 203 all radiate blue light, and a wavelength conversion layer is disposed on the light emitting surface of the second light emitting element 202 to convert the radiated blue light into green light, and a wavelength conversion layer is disposed on the light emitting surface of the third light emitting element 203 to convert the radiated blue light into red light.

Each light emitting element 200 further includes a first electrode and a second electrode. The semiconductor stack layer has a mesa exposing the first semiconductor layer, a first electrode formed on the mesa and electrically connected to the first semiconductor layer, and a second electrode formed on the second semiconductor layer and electrically connected to the second semiconductor layer.

Preferably, the thickness difference between the light emitting elements 200 is less than or equal to 5 μm, so that the transfer yield of the light emitting module transferred onto the transparent layer 100 described later can be effectively improved, and the light emitting effect of the light emitting module can be improved.

In one embodiment, referring to fig. 1 and 2, the light emitting module further includes a transparent layer 100, the light emitting element 200 is disposed on the transparent layer 100, and a surface of the transparent layer 100 away from the light emitting element 200 is a light emitting surface of the light emitting module, that is, light emitted by the light emitting element 200 is emitted to the outside through the transparent layer 100. The transparent layer 100 has a light transmittance of 60% or more in the visible light range.

In one embodiment, referring to fig. 2, the transparent layer 100 includes a first transparent layer 1001 and a second transparent layer 1002, the second transparent layer 1002 being located between the first transparent layer 1001 and the light emitting element 200.

The first transparent layer 1001 may be selected from inorganic light transmissive materials such as glass, transparent ceramics, sapphire, and the like. Preferably, the light emitting module needs to have a certain thickness for the client to use, so the thickness of the first transparent layer 1001 is preferably greater than 10 μm, particularly preferably 30 μm to 50 μm, 50 μm to 100 μm or 100 μm to 300 μm.

The second transparent layer 1002 is positioned between the first transparent layer 1001 and the light emitting element 200 so that the light emitting element 200 can be adhered to the first transparent layer 1001 through the second transparent layer 1002. The second transparent layer 1002 may entirely cover the entire surface of the first transparent layer 1001, but is not limited thereto, and may be located only under the light emitting element 200 so that the light emitting element 200 can be adhered to the transparent layer 1001 through the second transparent layer 1002.

The different light emitting elements 200 generally have different thicknesses, and by providing the second transparent layer 1002 between the first transparent layer 1001 and the light emitting elements 200, the height difference of the light emitting surfaces of the respective light emitting elements 200 is reduced, so that the light emitted from the side surfaces of the light emitting elements 200 is absorbed by the filling layer 210 described below as much as possible, and the contrast of the light emitting module can be improved. The thickness of the second transparent layer 1002 is preferably 1 μm to 15 μm or 3 μm to 10 μm. If the thickness of the second transparent layer 1002 is greater than 15 μm, the alignment accuracy of the light emitting element 200 may be affected.

As an alternative embodiment, because of the high cost of the inorganic light-transmitting material such as sapphire and the complex manufacturing process, the first transparent layer 1001 may also be selected from thermosetting organic materials such as epoxy, silica gel, polyimide and the like, which are low in cost. In an embodiment, the first transparent layer 1001 may be a member formed by dispersing nanoparticles of zirconium dioxide, silicon oxide, aluminum oxide, boron nitride, etc. in a light-transmitting organic material of epoxy, silica gel, polyimide, etc., wherein the nanoparticles of zirconium dioxide, silicon oxide, aluminum oxide, boron nitride, etc. may increase the strength of the first transparent layer 1001. In addition, the contrast of the light-emitting module can be adjusted by adjusting the content of nano particles such as zirconium dioxide, silicon oxide, aluminum oxide, boron nitride and the like. In an embodiment, when the first transparent layer 1001 is a thermosetting organic material, the second transparent layer 1002 is negligible.

In one embodiment, referring to fig. 1 and 2, the light emitting module further includes a filling layer 210, and the filling layer 210 is filled between the adjacent light emitting elements 200 or around the sidewalls of the light emitting elements 200, to prevent color mixing or light interference between the adjacent light emitting elements 200, so as to improve the contrast ratio of the light emitting module. The filling layer 210 is provided as a black glue layer absorbing light.

The thickness of the light emitting element 200 is preferably in the range of 2 to 15 μm and the interval between adjacent light emitting elements 200 is less than 50 μm, and thus, it is preferable to cure with a material having good fluidity when forming the filling layer 210. The particle size of the black filling component filled in the filling layer 210 is preferably not more than 1/10 of the thickness of the light emitting element 200, which can avoid the problem that the coating effect of the filling layer 210 on the light emitting element 200 is poor due to the overlarge particle size of the black filling component, and thus the contrast of the light emitting module is affected. The filling layer 210 may be specifically a member formed by dispersing a black filling component having a particle size of not more than 1 μm in a transparent or semitransparent material such as silica gel, epoxy resin, polyimide, low temperature glass, polysiloxane, polysilazane, etc., and the black filling component in the filling layer 210 includes, but is not limited to, carbon black, titanium nitride, iron oxide, ferroferric oxide, iron powder, etc. The particle size of the black filler is preferably in the range of 10 to 100nm, alternatively 100 to 200nm, alternatively 200 to 300nm, alternatively 300 to 500nm. Black dye may also be used for the fill layer 210.

The filling layer 210 covers at least 50% of the sidewalls of the light emitting elements 200 near the light emitting surface, preferably covers all the sidewalls of the light emitting elements 200, so as to prevent color mixing or light interference between adjacent light emitting elements 200 and improve the contrast of the light emitting module. Alternatively, the thickness of the filling layer 210 may be greater than that of the light emitting element 200, and light interference caused by light leakage at the bottom of the light emitting element 200 may be prevented. The thickness of the filler layer 210 is preferably less than 15 μm.

In one embodiment, referring to fig. 1 and 2, a wiring layer 300 is formed over a plurality of light emitting elements 200 and is used to electrically connect with the light emitting elements 200. The wiring layer 300 includes a plurality of wirings, and the periphery of the wiring layer is filled with an insulating layer 330 to electrically isolate adjacent wirings.

The wiring layer 300 includes a first sub-wiring 301, a second sub-wiring 302, a third sub-wiring 303, and a fourth sub-wiring 304, wherein the first sub-wiring 301 serves as a common wiring, first electrodes in the first light emitting element 201, the second light emitting element 202, and the third light emitting element 203 are commonly connected to the first sub-wiring 301, second electrodes in the first light emitting element 201 are connected to the second sub-wiring 302, second electrodes in the second light emitting element 202 are connected to the third sub-wiring 303, and second electrodes in the third light emitting element 203 are connected to the fourth sub-wiring 304. The wiring layer 300 may be formed together on the filling layer 210.

Alternatively, the first sub-wiring 301 serves as a common wiring, the second electrodes of the first light emitting element 201, the second light emitting element 202, and the third light emitting element 203 are commonly connected to the first sub-wiring 301, the first electrode of the first light emitting element 201 is connected to the second sub-wiring 302, the first electrode of the second light emitting element 202 is connected to the third sub-wiring 303, and the first electrode of the third light emitting element 203 is connected to the fourth sub-wiring 304. The wiring layer 300 may be formed together on the filling layer 210.

The wiring layer 300 has opposite upper and lower surfaces, wherein the lower surface of the wiring layer 300 is in contact with the filling layer 210 and the light emitting element 200, and the upper surface of the wiring layer 300 is used to form the insulating layer 330.

The wiring layer 300 may be a single layer or a plurality of layers made of at least one material of titanium, copper, chromium, nickel, gold, platinum, aluminum, titanium nitride, tantalum, or the like. In this embodiment, the wiring layer 300 may include a first layer 310 and a second layer 320, the first layer 310 being in direct contact with the light emitting element 200, the second layer 320 being formed over the first layer 310. The first layer 310 serves to adhere the second layer 320 to the light emitting element 200 and the filling layer 210, and the second layer 320 mainly plays a conductive role. The material of the first layer 310 includes, but is not limited to, one or more of titanium, nickel, titanium nitride, tantalum nitride, or tantalum, and the material of the second layer 320 includes, but is not limited to, one or more of copper, aluminum, or gold. The wiring layer 300 may be prepared by sputtering, evaporation, or the like.

Preferably, the thickness of the wiring layer 300 is preferably 50nm to 1000nm, wherein the thickness of the first layer 310 is preferably 10nm to 200nm, the thickness of the second layer 320 is preferably 200nm to 800nm, and the thickness of the first layer 310 is smaller than the thickness of the second layer 320.

In one embodiment, referring to fig. 1 and 2, a conductive pad 500 is formed at a side of the wiring layer 300 remote from the light emitting element 200 and is electrically connected to the light emitting element 200 through the wiring layer 300.

The conductive pad 500 includes a first pad 501, a second pad 502, a third pad 503, and a fourth pad 504, the first pad 501 serving as a common pad to which first electrodes of the first light emitting element 201, the second light emitting element 202, and the third light emitting element 203 are commonly connected through a first sub-wiring 301, the second electrode of the first light emitting element 201 is connected to the second pad 502 through a second sub-wiring 302, the second electrode of the second light emitting element 202 is connected to the third pad 503 through a third sub-wiring 303, and the second electrode of the third light emitting element 203 is connected to the fourth pad 504 through a fourth sub-wiring 304.

Alternatively, the first pad 501 serves as a common pad, the second electrodes in the first light emitting element 201, the second light emitting element 202, and the third light emitting element 203 are commonly connected to the first pad 501 through the first sub-wiring 301, the first electrode of the first light emitting element 201 is connected to the second pad 502 through the second sub-wiring 302, the first electrode in the second light emitting element 202 is connected to the third pad 503 through the third sub-wiring 303, and the first electrode in the third light emitting element 203 is connected to the fourth pad 504 through the fourth sub-wiring 304.

In one embodiment, the conductive pad 500 includes a conductive layer 510, and the conductive layer 510 may be a single layer or a plurality of layers made of at least one material of titanium, copper, gold, platinum, etc., and preferably has a thickness of 10 to 50 μm, for example, 20 μm, 30 μm, 40 μm.

As an alternative embodiment, the conductive pad 500 includes a conductive layer 510 and a protective layer 530 sequentially formed over the wiring layer 300. Before the light emitting module is mounted on the display device, the protective layer 530 completely covers the upper surface of the conductive layer 510, so that the conductive layer 510 can be effectively prevented from being oxidized, and the stability of the light emitting module can be improved; when the light emitting module is mounted on a display device, the protective layer 530 is damaged or removed. The protective layer 530 does not affect the bondability and conductivity of the conductive pad 500, and its thickness is preferably 25 to 50nm.

The protective layer 530 may be made of metal materials such as gold and platinum, and the conductive pad 500 is soldered to the circuit board at a predetermined temperature during the mounting of the light emitting module to the display device by using a soldering material, which flows and deforms during the soldering process, so that the deformation of the soldering material may damage the integrity of the protective layer 530 made of metal materials such as gold and platinum.

Alternatively, the protective layer 530 may be an organic material such as OSP, which is dissolved and removed by soldering the conductive pad 500 and the circuit board with a soldering material at a predetermined temperature during the mounting of the light emitting module to the display device.

Preferably, an adhesive layer 520 is further disposed between the conductive layer 510 and the protective layer 530. The adhesive layer 520 may be a single layer or a plurality of layers made of at least one material of chromium, titanium, nickel, tantalum nitride, tantalum, etc. The thickness of the adhesive layer 520 is preferably 3 to 5 μm.

In one embodiment, referring to fig. 2, the encapsulation layer 600 fills the perimeter of the conductive pads 500 to electrically isolate adjacent sub-pads from each other. The encapsulation layer 600 is provided as a glue layer absorbing light, and particularly preferably is a member formed by dispersing a black filling component including, but not limited to, carbon black, titanium nitride, iron oxide, ferroferric oxide, iron powder, and the like in a transparent or translucent material such as silica gel, epoxy, polyimide, low temperature glass, polysiloxane, polysilazane, and the like.

Since the thickness of the light emitting element 200 and the wiring layer 300 is thin, the encapsulation layer 600 preferably has a thickness to protect the light emitting element 200 and the wiring layer 300 from external factors, and the thickness of the encapsulation layer 600 is preferably more than 20 μm, and at this time, the thickness of the conductive pad 500 is also more than 20 μm. The encapsulation layer 600 is doped with doped particles having a particle diameter of more than 1 μm, such as silicon dioxide, which can enhance the mechanical properties of the encapsulation layer 600, thereby better protecting the light emitting element 200 and the wiring layer 300.

Preferably, the surface of the encapsulation layer 600 remote from the wiring layer 300 is flush with the surface of the conductive layer 510 in the conductive pad 500 remote from the wiring layer 300.

Preferably, the thickness of the conductive pad 500 is preferably 5 μm or more, which may be formed by electroplating.

In one embodiment, referring to fig. 2, an insulating layer 330 is located on the upper surface of the wiring layer 300 and fills the periphery of the wiring in the wiring layer 300. The insulating layer 330 is opened with a via hole above the wiring layer 300 for forming the conductive pad 500. The number of the through holes is the same as that of the conductive pads 500, that is, one through hole corresponds to one conductive pad 500.

The insulating layer 330 may be a member formed of epoxy, polysiloxane, or photoresist, so as to prevent the wiring layer 300 from being oxidized, and electrically isolate different wirings, thereby avoiding leakage failure of the light emitting module.

The upper surface of the wiring layer 300 is provided with a seed layer 700, and the seed layer 700 conducts electricity to prepare the conductive pad 500 by electroplating. The seed layer 700 may be a single layer or a plurality of layers made of at least one material of titanium, copper, gold, platinum. In this embodiment, the seed layer 700 is preferably a Ti/Cu stack, and the thickness thereof is preferably 100 to 2000nm.

Example two

Fig. 3 is a schematic cross-sectional view for explaining a light emitting module of a second embodiment of the present application. Unlike the first embodiment, the following is: the conductive pad 500 includes a conductive layer 510, an adhesive layer 520, and a eutectic layer 540 sequentially formed over the wiring layer 300.

The conductive layer 510 may be a single layer or a plurality of layers made of at least one material of titanium, copper, gold, platinum, etc., and has a thickness of preferably 10 to 50 μm, for example, 20 μm, 30 μm, 40 μm.

The adhesive layer 520 is located between the conductive layer 510 and the protective layer 530, and may be a single layer or a plurality of layers made of at least one material of chromium, titanium, nickel, tantalum nitride, tantalum, and the like. The thickness of the adhesive layer 520 is preferably 3 to 5 μm.

The eutectic layer 540 may be a single layer or a plurality of layers made of at least one material of Sn, snAg, auSn and the like, and has a thickness of 10 to 50nm. The eutectic layer 540 can effectively increase the binding force of the light emitting module when being applied to a circuit board, and the convenience of the client is improved because solder paste is not required to be printed again or only a small amount of solder paste is required to be brushed during application.

Preferably, the surface of the encapsulation layer 600 away from the wiring layer 300 is flush with the surface of the eutectic layer 540 in the conductive pad 500 away from the wiring layer 300, so that the surface of the light emitting module is flat, which is beneficial for the use of clients.

Preferably, as shown in fig. 4, the conductive pad 500 further includes a protective layer 530 disposed on the eutectic layer 540. Before the light-emitting module is mounted on the display device, the protective layer 530 completely covers the upper surfaces of the eutectic layer 540 and the conductive layer 510, so that the eutectic layer 540 and the conductive layer 510 can be effectively prevented from being oxidized, and the stability of the light-emitting module is improved; when the light emitting module is mounted on a display device, the protective layer 530 is damaged or removed. The protective layer 530 does not affect the bondability and conductivity of the conductive pad 500, and its thickness is preferably 25 to 50nm.

Example III

Fig. 5 is a schematic cross-sectional view for explaining a light emitting module of a third embodiment of the present application.

The difference from the first or second embodiment is that: the wiring layer 300 is provided with a conductive protective layer 400, and the conductive protective layer 400 is located between the wiring layer 300 and the conductive pad 500, particularly preferably between the wiring layer 300 and the seed layer 700. Since the wiring layer 300 is always exposed and easily oxidized by air before the seed layer 700 or the conductive pad 500 is formed, the conductive protective layer 400 is provided between the conductive pad 500 and the wiring layer 300, and the wiring layer 300 is protected in advance by the conductive protective layer 400 to prevent the portion of the wiring layer 300 for connection with the seed layer 700 or the conductive pad 500 from being oxidized due to exposure to air, thereby providing the conductive pad 500 with good bonding property and conductivity.

As shown in fig. 5, a portion of the wiring layer 300 for connection with the conductive pad 500 is formed with a conductive protective layer 400. The conductive protection layer 400 is disposed in the through hole in the insulating layer 330, but not limited thereto, and in another embodiment, the conductive protection layer 400 may completely cover the wiring layer 300.

The conductive protective layer 400 may be a single layer or a plurality of layers made of at least one material of nickel, gold, platinum, titanium, etc. In this embodiment, the conductive protection layer 400 is preferably a Ni/Au stack. The thickness of the conductive protective layer 400 is preferably 1 to 10nm, alternatively 10 to 100nm, alternatively 100 to 2000nm. The conductive protection layer 400 may be prepared by sputtering, evaporation, or the like.

Preferably, the projected area of the conductive protection layer 400 in the vertical direction is greater than or equal to the projected area of the lower surface of the conductive pad 500 in the vertical direction, so that the entire lower surface of the conductive pad 500 is in contact with the wiring layer 300 through the conductive protection layer 400, and the wiring layer 300 connected to the conductive pad 500 can be prevented from being oxidized, thereby effectively improving the bondability and conductivity of the conductive pad 500. If the projected area of the conductive protection layer 400 in the vertical direction is smaller than the projected area of the lower surface of the conductive pad 500 in the vertical direction, the wiring layer 300 that is not covered by the conductive protection layer 400 and needs to be connected to the conductive pad 500 is oxidized, and the conductive pad 500 is still easy to fall off or has poor contact with the wiring layer 300, so that the effect of improving the bonding property and conductivity of the conductive pad 500 is not achieved.

Example IV

The embodiment discloses a manufacturing method of a light-emitting module. Fig. 6 is a schematic flowchart for explaining a method of manufacturing a light emitting module of the fourth embodiment of the present application.

The manufacturing method comprises the following steps:

providing a first transparent layer 1001;

a plurality of light emitting elements 200 arranged at fixed intervals on the surface of the first transparent layer 1001;

forming a filling layer 210 around the light emitting element 200;

Fabricating a wiring layer 300 on the filling layer 210;

forming a conductive pad 500 on the wiring layer 300, the conductive pad 500 having a thickness of 5 μm or more and directly contacting the wiring layer 300;

filling the encapsulation layer 600 around the conductive pad 500;

and performing singulation treatment to form a single light emitting module.

The following detailed description refers to the accompanying drawings.

S1, a first transparent layer 1001 is provided, and the first transparent layer 1001 may be set with reference to embodiment 1. The first transparent layer 1001 includes a first surface and a second surface, where the first surface is a light-emitting surface.

S2, as shown in fig. 7a and 7B, fig. 7B is a cross-sectional view taken along line B-B' of fig. 7a, and a series of arrays of light emitting elements 200 are fixed on the second surface of the first transparent layer 1001. The array comprises a series of light emitting cells, each corresponding to a pixel, comprising at least three light emitting elements 200 radiating light of different wavelength ranges. In a preferred embodiment, the first transparent layer 1001 is a sapphire substrate, and the light emitting device 200 is combined with the first transparent layer 1001 through a second transparent layer 1002. The second transparent layer 1002 can be provided with reference to embodiment 1. The second transparent layer 1002 covers the second surface of the first transparent layer 1001.

S3, as shown in fig. 8, a filling layer 210 is formed around the light emitting elements 200, and the filling layer 210 is filled between adjacent light emitting elements 200 or around the sidewalls of the light emitting elements 200.

S4, as shown in fig. 9a and 9B, fig. 9B is a cross-sectional view of line B-B' of fig. 9a, and a total wiring layer 3000 is formed on the filler layer 210. The total wiring layer 3000 may include a plurality of unitized wiring layers 300, the unitized wiring layers 300 being arranged in columns in a first direction X and in rows in a second direction Y, the first direction being perpendicular to the second direction. Referring to fig. 9c, fig. 9c is an enlarged schematic view of a portion I of fig. 9b, and the unitized wiring layer 300 includes a first sub-wiring 301, a second sub-wiring 302, a third sub-wiring 303, and a fourth sub-wiring 304, the first light emitting element 201 is electrically connected to the first sub-wiring 301 and the second sub-wiring 302, the second light emitting element 202 is electrically connected to the first sub-wiring 301 and the third sub-wiring 303, and the third light emitting element 203 is electrically connected to the first sub-wiring 301 and the fourth sub-wiring 304. Each of the sub-wirings 301 to 304 has a first region 3001, a second region 3002, and a third region 3003, respectively, wherein the first region 3001 is a region overlapping the conductive pad 500 in the vertical direction, the second region 3002 connects the light emitting element 200 and the first region 3001, and the third region 3003 extends from the first region 3001 to an edge of the light emitting module.

Taking the wiring layer (D22) 300 of the second row of the second column as an example, the connection relationship between the individual wiring layers will be described. Here, for example, the unitized wiring layer of the first row and the first column is abbreviated as D11, the unitized wiring layer of the second row and the third column is abbreviated as D23, the unitized wiring layer of the third row and the fifth column is abbreviated as D35, and so on. First sub-wiring 301 of D22 _D22 Fourth sub-wiring 304 with D12 _D12 Second sub-wiring 302 of D21 _D21 Third sub-wiring 303 of D21 _D21 Connecting; second sub-wiring 302 of D22 _D22 Third sub-wiring 303 with D12 _D12 Fourth sub-wiring 304 of D12 _D12 First sub-wiring 301 of D23 _D23 Connecting; third sub-wiring 303 of D22 _D22 Second sub-wiring 302 with D32 _D32 First sub-wiring 301 of D23 _D23 Fourth sub-wiring 304 of D23 _D23 Connecting; fourth sub-wiring 303 of D22 _D22 Third sub-wiring 304 with D21 _D21 First sub-wiring 301 of D32 _D32 Second sub-wiring 302 of D32 _D32 And (5) connection. Other unitized wiring layers 300 and so on. The individual unitized wiring levels 300 are connected in such a manner that the overall wiring level 3000 is in an interconnect state.

S5, as shown in fig. 10a and 10B, fig. 10B is a cross-sectional view of line B-B' of fig. 10a, and a conductive pad 500 is formed on the wiring layer 300. The conductive pad 500 is formed in the first region 3001 of the wiring layer 300 by electroplating, and the conductive pad 500 has a thickness of 5 μm or more and directly contacts the wiring layer 300.

S6, as shown in fig. 11, the encapsulation layer 600 is filled around the conductive pad 500, and the encapsulation layer 600 may be provided with reference to embodiment 1.

S7, performing singulation treatment to form a single light-emitting module.

Fig. 12 shows a schematic plan view of a light emitting module formed by the method, and a corresponding cross-sectional view is shown with reference to fig. 13. The light emitting module includes: the light emitting device includes a first transparent layer 1001, a light emitting element 200, a filling layer 210, a wiring layer 300, a conductive pad 500, and a package layer 600, wherein the wiring layer 300 includes a first sub-wiring 301, a second sub-wiring 302, a third sub-wiring 303, and a fourth sub-wiring 304. The first light emitting element 201 is electrically connected to the first sub-wiring 301 and the second sub-wiring 302, the second light emitting element 202 is electrically connected to the first sub-wiring 301 and the third sub-wiring 303, and the third light emitting element 203 is electrically connected to the first sub-wiring 301 and the fourth sub-wiring 304. Each of the sub-wirings 301 to 304 has a first region 3001, a second region 3002, and a third region 3003, respectively, wherein the first region 3001 is a region overlapping the conductive pad 500 in the vertical direction, the second region 3002 connects the light emitting element 200 and the first region 3001, and the third region 3003 extends from the first region 3001 to an edge of the light emitting module. Preferably, the third area 3003 includes at least 3 pins 305 extending from the first area 3001 to the edge of the light emitting module, but not limited thereto, and the third area 3003 may have enough area extending to the edge of the light emitting module to connect with the adjacent three light emitting modules. And the sides of the pins 305 of the third region 3003 are preferably flush with the sides of the package layer 600.

The first transparent layer 1001, the light emitting element 200, the filling layer 210, the conductive pad 500, and the encapsulation layer 600 can be designed with reference to embodiment 1.

In the manufacturing method of the present embodiment, the wiring layers 300 are designed such that before the singulation process, the individual singulated wiring layers 300 are interconnected, so that the conductive pads 500 can be formed at the corresponding positions in the individual singulated wiring layers 300 by electroplating or the like without providing a seed layer, thereby simplifying the manufacturing process. Further, in the process of preparing the conductive pad 500 by electroplating, the surface of the wiring layer 300 may be etched by a wet method, and the oxide layer on the surface of the wiring layer 300 may be removed, so that the wiring layer 300 is in direct contact with the conductive pad 500, and poor electrical bonding caused by oxidation of the wiring layer 300 is avoided.

As an alternative embodiment, as shown in fig. 14, the package layer 600 covers the sidewalls of the wiring layer 300, so that the electrical defect caused by oxidation of the wiring layer 300 exposed at the edge of the light emitting module can be avoided.

As an alternative embodiment, as shown in fig. 15, the pins 305 extending from the wiring layer 300 to the edge may be partially etched to avoid the electrical defect caused by oxidation of the wiring layer 300 exposed at the edge of the light emitting module.

Example five

Fig. 16 shows a schematic plan view of a light emitting module according to a fifth embodiment of the present application, corresponding cross-sectional views are shown with reference to fig. 13. Fig. 17 is a schematic plan view of fig. 16 in which the conductive pad 500 is omitted to facilitate labeling of the wiring layer 300. The light emitting module includes: the first transparent layer 1001, the light emitting element 200, the filling layer 210, the wiring layer 300, the conductive pad 500, and the encapsulation layer 600. Wherein the first transparent layer 1001, the light emitting element 200, the filling layer 210, the conductive pad 500, and the encapsulation layer 600 may be designed according to the requirements with reference to the foregoing embodiments.

Referring to fig. 16 and 17, the wiring layer 300 may include a first region 3001 and a second region 3002. The first region 3001 is a region overlapping the conductive pad 500 in the vertical direction, and the second region 3002 is a region connecting between the first region 3001 and the light emitting element 200, and a connection position 3004 of the first region and the second region exists between the first region 3001 and the second region 3002. Since the difference between the thermal expansion coefficients of the encapsulation layer 600 and the conductive pad 500 is large, the interface between the encapsulation layer 600 and the conductive pad 500 has residual stress, and if the length H1 of the connection location 3004 of the first region and the second region is too small, the connection location 3004 of the first region and the second region is easily broken due to the residual stress, so that the connection between the first region 3001 and the second region 3002 is easily broken, and the electrical connection between the conductive pad 500 and the light emitting element 200 is failed. In this embodiment, the length H1 of the connection location 3004 between the first area and the second area is preferably greater than or equal to 20 μm, so as to ensure that even if the wiring layer at the second area 3002 is cracked, a complete section of the second area 3002 can be electrically connected to the light emitting element 200.

In one embodiment, the length H1 of the connection location 304 between the first area and the second area is more than 40% of the length H2 of either side of the conductive pad 500, so that even if the wiring layer at the second area 3002 is cracked, a complete electrical connection between the second area 3002 and the light emitting element 200 is ensured. Preferably, the distance between the first area 3001 and the edge of the wiring layer 300 near the light emitting module is less than or equal to 20 μm.

For convenience of client use, the shape of the first pad 501 is not consistent with the shape of the second pad 502, the third pad 503, and the fourth pad 504, which may serve as a logo. It is specifically noted that the ratio of H1 to H2 may be a ratio of the total length H1 of the connection position between the first area 3001 and the second area 3002 in the first pad 501 to the total length H2 of the corresponding two sides of the first pad 501.

Example six

Fig. 18 is a schematic cross-sectional view for explaining a light emitting module of a sixth embodiment of the present application.

The differences from the first to fifth embodiments are: the light emitting module further includes an insulating adhesive layer 220, and the adhesive layer 220 is disposed between the light emitting element 200 and the filling layer 210. Due to poor bonding between the filling layer 210 and the light emitting element 200, the light emitting element 200 may be separated from the filling layer 210 during use of the client, thereby causing luminance degradation of the light emitting module. Therefore, the adhesion layer 220 is provided between the light-emitting element 200 and the filler layer 210, and the thickness thereof is 1 μm or less, preferably 5nm to 100nm, 100nm to 300nm, or 300nm to 600nm. The thickness of the adhesion layer 220 is smaller, which does not affect the structure of the light emitting module, and can improve the bonding force between the light emitting element 200 and the filling layer 210, thereby avoiding the separation between the light emitting element 200 and the filling layer 210.

Preferably, as shown in fig. 18, the adhesive layer 220 is a continuous layer, and the adhesive layer 220 covers the upper surface and the sidewalls of the light emitting element 200 and the gaps between adjacent light emitting elements 200 and exposes the first and second electrodes in the light emitting element 200.

As an alternative embodiment, as shown in fig. 19, the adhesive layer 220 is a discontinuous layer, and the adhesive layer 220 covers part of the upper surface and the sidewall of the light emitting element 200 and the gap between adjacent light emitting elements 200 and exposes the first electrode and the second electrode in the light emitting element 200.

It should be noted that, in the light emitting element 200, the adhesion layer 220 may remain on the first electrode and the second electrode, and the remaining adhesion layer 220 does not affect the conductivity of the light emitting module.

Example seven

Fig. 20 is a schematic plan view for explaining a light emitting module of a seventh embodiment of the present application.

The differences from the first to sixth embodiments are: the light emitting module further includes a protection pad 800, and the protection pad 800 is formed on a side of the encapsulation layer 600 away from the light emitting element 200.

The protection pad 800 is located in the thimble operation area of the light emitting module. The above-mentioned thimble operation region is a region covered by a range error when the thimble is operated on a surface of the package layer 600 away from the light emitting element 200, for example, a circular region having a radius of not more than 300 μm, preferably a circular region having a radius of not more than 150 μm. When the light emitting module is attached to or die-bonded to the display panel, the ejector pins risk to puncture the ejector pin operation area, thereby damaging the light emitting element 200 below the encapsulation layer 600, and causing the light emitting module to fail.

Through add the protection pad 800 in the thimble operation area of light emitting module, when the thimble effect is in above-mentioned region, can effectively avoid the thimble to puncture or break up encapsulation layer 600, make encapsulation layer 600 still have good protection effect to light emitting element 200 to avoid light emitting element 200 to cause the damage, and avoid light emitting module to become invalid.

Preferably, the protection pad 800 is not electrically connected with the wiring layer 300. The guard pad 800 is formed together with the conductive pad 500 in the same process, and the material of the guard pad 800 is the same as that of the conductive pad 500. The protection pad 800 has good structural strength, and various ejector pins can be selected to act on the protection pad in the subsequent chip mounting or die bonding process, so that the chip mounting or die bonding speed is improved.

In one embodiment, referring to fig. 20, the conductive pad 500 is looped around the periphery of the protection pad 800, the side of the conductive pad 500 facing the protection pad 800 is configured in an arc shape, and the arc opening faces the protection pad 800. By arranging the conductive pad 500 in the above structure, the distance between the conductive pad 500 and the guard pad 800 can be increased, so that the shorting phenomenon caused by the contact between the conductive pad 500 and the guard pad 800 can be avoided. In the present embodiment, the sides of the first pad 501, the second pad 502, the third pad 503, and the fourth pad 504 facing the protection pad 800 are each configured in an arc shape, and the arc-shaped openings are each facing the protection pad 800.

Preferably, the first pad 501, the second pad 502, the third pad 503 and the fourth pad 504 are different in shape or size, so as to facilitate identification of the type of the conductive pad 500, and to facilitate subsequent determination of the cutting position. The total area of the conductive pads 500 is preferably 20% to 70% of the area of the light emitting module.

Preferably, referring to fig. 20, the distance D between the conductive pad 500 and the edge of the light emitting module ₁ Greater than 20 μm. Distance D between protective pad 800 and edge of light emitting module ₂ Greater than 20 μm.

Preferably, the protection pad 800 is spaced apart from each of the first pad 501, the second pad 502, the third pad 503, and the fourth pad 504.

Preferably, the plurality of light emitting elements includes three of the first light emitting element 201, the second light emitting element 202, and the third light emitting element 203, and the protection pad 800 shields at least a partial area of the second light emitting element 202 thereunder, or the protection pad 800 shields at least the plurality of light emitting elements 202 thereunder.

As an alternative embodiment, as shown in fig. 21, the protection pad 800 may be a part of the first pad 501, the second pad 502, the third pad 503, or the fourth pad 504, and a part of the corresponding pad extending toward the central area of the light emitting module is formed as the protection pad 800 to protect the thimble operation area of the light emitting module, so as to effectively avoid the thimble from piercing or bursting the package layer 600.

As can be seen from the above technical solution, the filling layer 210 is formed between the adjacent light emitting elements 200, and is made by curing a material with good fluidity, and the particle size of the black filling component in the filling layer 210 is not greater than 1/10 of the thickness of the light emitting element 200, so as to improve the coating effect of the filling layer 210 on the light emitting element 200 and improve the contrast of the light emitting module. The encapsulation layer 600 is formed at the periphery of the conductive pad 500, has a large thickness and strength, and protects the light emitting element 200 and the wiring layer 300 from external factors. Therefore, different insulating structures can be arranged at different positions of the light-emitting module to meet the requirements of different positions of the light-emitting module at the same time, so that the light-emitting module has high contrast and mechanical properties at the same time.

Further, the conductive pad 500 includes a protective layer 530, and before the light emitting module is mounted on the display device, the protective layer 530 completely covers the upper surface of the conductive layer 510, so that the conductive layer 510 can be effectively prevented from being oxidized, and the stability of the light emitting module can be improved; when the light emitting module is mounted on the display device, the protective layer 530 is damaged or removed, and the bonding property and conductivity of the conductive pad 500 are not affected.

Further, the conductive pad 500 further includes a eutectic layer 540, which can effectively increase the bonding property of the light emitting module during application, and does not need to print solder paste again during application, thereby improving the convenience of use of the client.

Further, by adding the conductive protection layer 400 between the wiring layer 300 and the conductive pad 500, the portion of the wiring layer 300 for connection with the conductive pad 500 can be effectively prevented from being oxidized, and the phenomenon that the conductive pad 500 is easily detached or easily has poor contact due to the oxidation of the wiring layer 300 can be improved, and the bonding property and conductivity of the conductive pad 500 are improved.

Further, by adding the protection pad 800 in the thimble operation area of the light emitting module, when the thimble acts in the area, the puncture of the thimble or the bursting of the encapsulation layer 600 can be effectively avoided, so that the encapsulation layer 600 still has a good protection effect on the light emitting element 200, thereby avoiding the damage to the light emitting element 200 and avoiding the failure of the light emitting module. Wherein the guard pad 800 is formed together with the conductive pad 500 in the same process, and the material of the guard pad 800 is the same as that of the conductive pad 500. The protection pad 800 has good structural strength, and various ejector pins can be selected to act on the protection pad in the subsequent chip mounting or die bonding process, so that the chip mounting or die bonding speed is improved.

The foregoing is merely a preferred embodiment of the present application, and it should be noted that modifications and substitutions can be made by those skilled in the art without departing from the technical principles of the present application, and these modifications and substitutions should also be considered as being within the scope of the present application.

Claims

1. A light emitting module, comprising:

a plurality of light emitting elements arranged at intervals;

a wiring layer formed on the plurality of light emitting elements and electrically connected to the light emitting elements;

a conductive pad formed on a side of the wiring layer away from the light emitting element and electrically connected to the wiring layer;

the packaging layer is positioned at the periphery of the conductive bonding pad;

and the protection pad is formed on one side of the packaging layer far away from the light-emitting element and is positioned in the thimble operation area of the light-emitting module.

2. The lighting module of claim 1, wherein the conductive pad is looped around the periphery of the protection pad, wherein a side of the conductive pad facing the protection pad is configured as an arc, and wherein an arc opening faces the protection pad.

3. The lighting module of claim 1, wherein the total area of the conductive pads is 20% to 70% of the area of the lighting module.

4. The lighting module of claim 1, wherein the guard pad is spaced from the lighting module edge by more than 20 μm and the conductive pad is spaced from the lighting module edge by more than 20 μm.

5. The lighting module of claim 1, wherein the guard pad is spaced apart from the conductive pad.

6. The lighting module of claim 1, wherein the guard pad is disposed in connection with the conductive pad, the guard pad being a portion of the conductive pad.

7. The lighting module of claim 1, wherein the material of the guard pad is the same as the material of the conductive pad.

8. The light emitting module of claim 1, wherein the guard pad shields at least a portion of the light emitting element below the guard pad.

9. The light-emitting module according to claim 1, further comprising a filler layer filled between adjacent light-emitting elements, wherein the filler layer contains a black filler component having a particle diameter of 1/10 or less than 1 μm of the thickness of the light-emitting elements.

10. The light emitting module of claim 1 wherein the conductive pad has a thickness greater than 20 μm and the encapsulation layer has a thickness greater than 20 μm.

11. The light emitting module of claim 1, wherein the wiring layer has a thickness of 50 to 1000nm.

12. The light emitting module of claim 1, wherein the conductive pad comprises a conductive layer, an adhesive layer, and a protective layer, the conductive layer has a thickness of greater than 20 μm, the adhesive layer has a thickness of 3 to 5 μm, and the protective layer has a thickness of 25 to 50nm.

13. A display device comprising a plurality of light emitting modules according to any one of claims 1 to 12.