CN208271943U

CN208271943U - A kind of flip LED chips

Info

Publication number: CN208271943U
Application number: CN201820667669.XU
Authority: CN
Inventors: 王兵
Original assignee: Foshan Nationstar Semiconductor Co Ltd
Current assignee: Foshan Nationstar Semiconductor Co Ltd
Priority date: 2018-05-04
Filing date: 2018-05-04
Publication date: 2018-12-21
Anticipated expiration: 2028-05-04

Abstract

The utility model discloses a kind of flip LED chips, including substrate, epitaxial layer on substrate, the epitaxial layer includes the first semiconductor layer, active layer and the second semiconductor layer, through the second semiconductor layer and active layer, and it is set to the first electrode on the first semiconductor layer, transparency conducting layer on the second semiconductor layer, second electrode and insulating layer on transparency conducting layer, reflecting layer on insulating layer, the first alloy pad in first electrode, the second alloy pad in second electrode, first electrode and second electrode mutually insulated.By the way that alloy pad is arranged on the surface of electrode, the metal migration in electrode is reduced, the reliability of flip LED chips is effectively increased.

Description

A kind of flip LED chips

Technical field

The utility model relates to LED technology field more particularly to a kind of flip LED chips.

Background technique

LED (Light Emitting Diode, light emitting diode) be it is a kind of using Carrier recombination when release energy shape At luminous semiconductor devices, LED chip is with power consumption is low, coloration is pure, the service life is long, small in size, the response time is fast, energy conservation and environmental protection Equal many advantages.

Currently, display applications field, RGB Mini LED chip overcomes the welding of positive cartridge chip and lacking for reliability It falls into, in combination with the advantage of COB encapsulation, further reduces display screen point spacing, the visual effect of corresponding end product is big Width is promoted, while sighting distance can substantially reduce, and indoor display screen is enabled to be further substituted with original market LCD.

On the other hand, the use of RGB Mini LED chip collocation flexible base board, the high image quality that also can be realized curved surface are aobvious Show effect, in addition its self luminous characteristic, has extremely wide market in terms of some special formed demands (such as automobile is shown).

In order to meet the size requirement of RGB Mini LED chip, convenient for encapsulation, the general LED chip for using inverted structure To make, but big bonding pad area is larger used in existing flip LED chips etc., can not carry out resistant to hydrolysis migration process, by The influence of use environment and packaging body leakproofness often makes electrode migrate metal due to heated, hydrolytic dissociation.Cause This, the hydrolysis resistance problem for the big pad such as how promoting is badly in need of solving.

Summary of the invention

Technical problem to be solved by the utility model is to provide a kind of flip LED chips, by the surface of electrode Alloy pad is set, reduces the metal migration in electrode, effectively increases the reliability of flip LED chips.

In order to solve the above-mentioned technical problem, the utility model provides a kind of flip LED chips, comprising:

Substrate；

Epitaxial layer on substrate, the epitaxial layer include the first semiconductor layer, active layer and the second semiconductor layer；

Through the second semiconductor layer and active layer, and the first electrode being set on the first semiconductor layer；

Transparency conducting layer on the second semiconductor layer；

Second electrode and insulating layer on transparency conducting layer；

Reflecting layer on insulating layer；

The first alloy pad in first electrode, the second alloy pad in second electrode, first electrode and Second electrode mutually insulated.

As an improvement of the above scheme, the first alloy pad and the second alloy pad are made of AuSi.

As an improvement of the above scheme, first electrode and second electrode are made of metal layer, wherein metal layer includes Cr Layer, Al layers, Ti layers and Pt layers.

As an improvement of the above scheme, described Cr layers with a thickness of 10-30 angstroms, Al layers with a thickness of 1000-1500 angstroms, Ti layers with a thickness of 500-1000 angstroms, Pt layers with a thickness of 500-1000 angstroms.

As an improvement of the above scheme, described Cr layers with a thickness of 15-20 angstroms, Al layers with a thickness of 1200-1400 angstroms, Ti layers with a thickness of 650-850 angstroms, Pt layers with a thickness of 650-850 angstroms.

As an improvement of the above scheme, the material of the transparency conducting layer is indium tin oxide.

As an improvement of the above scheme, insulating layer is by SiO₂、Si₃N₄、Al₂O₃、TiO₂And Ta₂O₃One of be made.

As an improvement of the above scheme, reflecting layer is by SiO₂、Si₃N₄、TiO₂、ZnO、MgF₂、CaF₂、 SrF₂、BaF₂、 ZnSe、ZnS、ZrO₂And Al₂O₃One of be made.

Implement the utility model, has the following beneficial effects:

1, the utility model provides a kind of flip LED chips, a kind of flip LED chips, comprising: substrate is set to substrate On epitaxial layer, the epitaxial layer includes the first semiconductor layer, active layer and the second semiconductor layer, through the second semiconductor layer and Active layer, and the first electrode being set on the first semiconductor layer, the transparency conducting layer on the second semiconductor layer are set to transparent Second electrode and insulating layer on conductive layer, the reflecting layer on insulating layer, the first alloy pad in first electrode, The second alloy pad in second electrode, first electrode and second electrode mutually insulated.By being arranged on the surface of electrode Alloy pad reduces the metal migration in electrode, effectively increases the reliability of flip LED chips.

2. the utility model provides a kind of flip LED chips, the first alloy pad and the second alloy pad are by AuSi It is made.The hardness of Au Si is preferable, can effectively resist pad in welding to the active force of electrode, so that guard electrode, prevents It is chipping and fall off.Due to when welding, needing to electrode into strike in pad, therefore a work can be generated to electrode Firmly, so that electrode is easy to fall off and fragmentation.

3. electrode, when being powered, hydrolysis, migration can occur for the metal in electrode, the utility model passes through on the surface of electrode The alloy pad made of AuSi is formed, can effectively slow down the metal in electrode and hydrolysis, migration occurs.In addition, alloy pad In AuSi can carry out thermal diffusion with metal in blocking electrode, so that slowing down metal in electrode occurs hydrolysis, migration.

4. the AuSi in alloy pad is exposed, exposed after hydrolysis, migration occur for the metal in electrode AuSi hair oxidation further slows down the metal in electrode and continues to migrate, have to form oxide film layer on the surface of electrode The reliability for increasing flip LED chips of effect.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of the utility model flip LED chips；

Fig. 2 is the electrode structure schematic diagram of the utility model flip LED chips.

Specific embodiment

It is practical new to this below in conjunction with attached drawing to keep the purpose of this utility model, technical solution and advantage clearer Type is described in further detail.

Referring to Fig. 1, the utility model provides a kind of flip LED chips, including substrate 10, outer on substrate 10 Prolong layer 20, the epitaxial layer 20 includes the first semiconductor layer 21, active layer 22 and the second semiconductor layer 23, runs through the second semiconductor Layer 23 and active layer 22 and the first electrode 31 being set on the first semiconductor layer 21, transparent on the second semiconductor layer 23 are led Electric layer 40, second electrode 32 and insulating layer 50 on transparency conducting layer 40, the reflecting layer 60 on insulating layer 50 is set to The first alloy pad 71 in first electrode 31, the second alloy pad 72 in second electrode 32, first electrode 31 and Two electrodes, 32 mutually insulated.

The material of substrate 10 can be sapphire, silicon carbide or silicon, or other semiconductor materials, in the present embodiment Substrate 10 be preferably Sapphire Substrate 10.

First semiconductor layer 21 provided by the embodiments of the present application and the second semiconductor layer 23 are gallium nitride-based semiconductor, Active layer 22 is gallium nitride base active layer 22；In addition, the first semiconductor layer 21 provided by the embodiments of the present application, the second semiconductor layer 23 and active layer 22 material can also be other materials, this application is not particularly limited.

Wherein, the first semiconductor layer 21 can be n type semiconductor layer, then the second semiconductor layer 23 is p type semiconductor layer；Or Person, the first semiconductor layer 21 is p type semiconductor layer, and the second semiconductor layer 23 is N type semiconductor layer, for the first semiconductor The conduction type of layer 21 and the second semiconductor layer 23, needs to be designed according to practical application, does not do specific limit to this application System.

It should be noted that being equipped between the substrate 10 and the epitaxial layer 20 in the other embodiments of the application Caching rushes layer (not shown).

The material of the transparency conducting layer 40 is indium tin oxide, but not limited to this.

Referring to fig. 2, first electrode 31 and second electrode 32 are made of metal layer 30, wherein metal layer 30 includes Cr layers 301, Al layer 302, Ti layer 303 and Pt layer 304.

It should be noted that the utility model uses Cr layer 301 as bottom, since Cr has good conductive property, And Cr metal can carry out good Ohmic contact with transparency conducting layer 40, therefore can be effectively reduced contact resistance；Secondly Cr metal and 40 adhesion strength of transparency conducting layer are preferable, can avoid metal layer 30 and fall off.Then, Al successively is formed on Cr layer 301 Layer 302, Ti layer 303 and Pt layer 304.Wherein, the reflectivity of the Al layer 302 is high compared with Cr layer 301, to improve going out for chip Light efficiency.Further, since the stability of Ti and Pt are preferable, Ti layer 303 and Pt layers are formed on Al layer 302 304, the Al that can effectively prevent in Al layer 302 occur dissolution, migration, on alter.Due to flip LED chips when packaged, envelope Colloid used in filling and technique cannot prevent completely steam entrance and colloid in air that need to pass through high-temperature baking, so that Al layers Dissolution, migration occur for the Al in 302.Ti layer 303 and Pt layer 304 in the utility model can prevent steam to Al layer 302 Corrosion.

The Cr layer 301 with a thickness of 10-30 angstroms, Al layer 302 with a thickness of 1000-1500 angstroms, the thickness of Ti layer 303 Be 500-1000 angstroms, Pt layer 304 with a thickness of 500-1000 angstroms.

Preferably, the Cr layer 301 with a thickness of 15-20 angstroms, Al layer 302 with a thickness of 1200-1400 angstroms, Ti layer 303 With a thickness of 650-850 angstroms, Pt layer 304 with a thickness of 650-850 angstroms.

Since Cr layer 301 is used as bottom adhesion layer, thickness cannot be too thick, otherwise will affect LED chip light emitting It absorbs, i.e. Al layer 302 does not have reflex.301 thickness of Cr layer corresponds to reflectivity (450nm wavelength), and 301 thickness of Cr layer exists There is preferable reflectivity, adhesion strength is poor when being lower than 10 angstroms and control difficulty is big at 10-30 angstroms.Wherein, when the Al layer 302 Thickness less than 1000 angstroms when, cannot preferably play the reflecting properties of Al layer 302, chip brightness is lower；When the Al layer 302 Thickness when being greater than 2000 angstroms, because Al metal itself is relatively active easy to migrate, the protection difficulty increase of Al layer 302.When Pt layer 304 Thickness when being respectively less than 500 angstroms, 304 thickness of Pt layer is too thin can not to be played the role of protecting Al layer 302, when the thickness of Pt layer 304 is equal When greater than 1000 angstroms, cost of manufacture is excessively high.

In order to guarantee that 32 mutually insulated of first electrode 31 and second electrode, insulating layer 50 are additionally arranged at the first semiconductor layer 21 Surface.Preferably, insulating layer 50 is by SiO₂、Si₃N₄、Al₂O₃、TiO₂And Ta₂O₃One of be made.

Reflecting layer 60 is by SiO₂、Si₃N₄、TiO₂、ZnO、MgF₂、CaF₂、SrF₂、BaF₂、ZnSe、 ZnS、ZrO₂And Al₂O₃In One kind be made.In this application, reflecting layer 60 is for reflect by what active layer 22 issued.The effect of insulating layer 50 be by Reflecting layer 60 preferably adheres to 40 surface of transparency conducting layer, prevents reflecting layer 60 from falling off and fragmentation.Due to reflecting layer 60 with Stress between transparency conducting layer 40 is larger, directly reflecting layer 60 is arranged on 40 surface of transparency conducting layer, reflecting layer 60 is easy It falls off and fragmentation.

Preferably, the first alloy pad and the second alloy pad are made of AuSi.

It should be noted that the hardness of Au Si is preferable, pad can be effectively resisted in welding to the active force of electrode, To guard electrode, prevents fragmentation and fall off.Due to when welding, being needed to electrode into strike, therefore in pad An active force can be generated to electrode, so that electrode is easy to fall off and fragmentation.

When being powered, hydrolysis, migration can occur electrode for the metal in electrode, and the utility model passes through the surface shape in electrode At the alloy pad made of AuSi, it can effectively slow down the metal in electrode and hydrolysis, migration occurs.In addition, in alloy pad AuSi can carry out thermal diffusion with metal in blocking electrode, so that slowing down metal in electrode occurs hydrolysis, migration.

Further, after hydrolysis, migration occur for the metal in electrode, the AuSi in alloy pad is exposed, exposed AuSi out sends out oxidation, to form oxide film layer on the surface of electrode, the metal further slowed down in electrode continues Migration, is effectively increased the reliability of flip LED chips.

Above disclosed is only a kind of preferred embodiment of the utility model, certainly cannot be practical to limit with this Novel interest field, therefore equivalent variations made according to the claim of the utility model still belong to what the utility model was covered Range.

Claims

1. a kind of flip LED chips characterized by comprising

Substrate；

Transparency conducting layer on the second semiconductor layer；

Second electrode and insulating layer on transparency conducting layer；

Reflecting layer on insulating layer；

2. flip LED chips according to claim 1, which is characterized in that the first alloy pad and the weldering of the second alloy Disk is made of AuSi.

3. flip LED chips according to claim 1, which is characterized in that first electrode and second electrode are by metal layer It is made, wherein metal layer includes Cr layers, Al layers, Ti layers and Pt layers.

4. flip LED chips according to claim 3, which is characterized in that described Cr layers with a thickness of 10-30 angstroms, Al layers With a thickness of 1000-1500 angstroms, Ti layers with a thickness of 500-1000 angstroms, Pt layers with a thickness of 500-1000 angstroms.

5. flip LED chips according to claim 4, which is characterized in that described Cr layers with a thickness of 15-20 angstroms, Al layers With a thickness of 1200-1400 angstroms, Ti layers with a thickness of 650-850 angstroms, Pt layers with a thickness of 650-850 angstroms.

6. flip LED chips according to claim 1, which is characterized in that the material of the transparency conducting layer is indium tin oxygen Compound.

7. flip LED chips according to claim 1, which is characterized in that insulating layer is by SiO₂、Si₃N₄、Al₂O₃、TiO₂With Ta₂O₃One of be made.

8. flip LED chips according to claim 1, which is characterized in that reflecting layer is by SiO₂、Si₃N₄、TiO₂、ZnO、 MgF₂、CaF₂、SrF₂、BaF₂、ZnSe、ZnS、ZrO₂And Al₂O₃One of be made.