Light emitting device with buffer pads

• US 10,170,455 B2
• Filed: 07/25/2017
• Issued: 01/01/2019
• Est. Priority Date: 09/04/2015
• Status: Active Grant

• Current Assignee: PlayNitride Display Co., Ltd.
• Original Assignee: PlayNitride Inc.
• Inventors: Lin, Tzu-Yang, Lai, Yu-Hung, Lo, Yu-Yun
• Primary Examiner(s): Muse, Ismail A
• Application Number:
  US15/658,422
• Publication Number:
  US 20170323873A1
• Time in Patent Office: 525 Days
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05639 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05655 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05664 Palladium [Pd] as principal constituent
• CPC Class Codes: H01L 2224/05666 Titanium [Ti] as principal constituent
• CPC Class Codes: H01L 2224/05669 Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/05671 Chromium [Cr] as principal constituent
• CPC Class Codes: H01L 2224/05681 Tantalum [Ta] as principal constituent
• CPC Class Codes: H01L 2224/05684 Tungsten [W] as principal constituent
• CPC Class Codes: H01L 2224/05686 with a principal constituent of the material being a non metallic, non metalloid inorganic material
• CPC Class Codes: H01L 2224/05693 with a principal constituent of the material being a solid not provided for in groups H01L2224/056 - H01L2224/05691, e.g. allotropes of carbon, fullerene, graphite, carbon-nanotubes, diamond
• CPC Class Codes: H01L 2224/0579 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/058 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/08225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/80001 by connecting a bonding area directly to another bonding area, i.e. connectorless bonding, e.g. bumpless bonding
• CPC Class Codes: H01L 2224/81001 involving a temporary auxiliary member not forming part of the bonding apparatus
• CPC Class Codes: H01L 2224/95 at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
• CPC Class Codes: H01L 2224/95001 : involving a temporary auxiliary member not forming part of the bonding apparatus, e.g. removable or sacrificial coating, film or substrate
• CPC Class Codes: H01L 2224/95136 : involving guiding structures, e.g. shape matching, spacers or supporting members
• CPC Class Codes: H01L 24/00 : Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 24/06 : of a plurality of bonding areas
• CPC Class Codes: H01L 24/08 : of an individual bonding area
• CPC Class Codes: H01L 24/95 : at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
• CPC Class Codes: H01L 25/0753 : the devices being arranged next to each other
• CPC Class Codes: H01L 25/167 : comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/1214 : comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/013 : Alloys
• CPC Class Codes: H01L 2924/053 : Oxides composed of metals from groups of the periodic table
• CPC Class Codes: H01L 2924/0542 : 12th Group
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/0675 : Polyester
• CPC Class Codes: H01L 2924/069 : Polyurethane
• CPC Class Codes: H01L 2924/07025 : Polyimide
• CPC Class Codes: H01L 2924/10155 : being other than a cuboid
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/1304 : Transistor
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2933/0033 : relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0066 : relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/0093 : Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/20 : with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/382 : the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/44 : characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/486 : adapted for surface mounting
• CPC Class Codes: H01L 33/58 : Optical field-shaping elements
• CPC Class Codes: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light emitting device includes a carrier, a plurality of light emitting diode chips and a plurality of buffer pads. Each light emitting diode chip includes a first type semiconductor layer, an active layer, a second type semiconductor layer, a via hole and a plurality of bonding pads. The via hole sequentially penetrates through the first type semiconductor layer, the active layer and a portion of the second type semiconductor layer. The first type semiconductor layer, the active layer, the second type semiconductor layer and the via hole define a epitaxial structure. The buffer pads are disposed between the carrier and the second type semiconductor layer, wherein the buffer pads is with Young'"'"'s modulus of 2˜10 GPa, the second bonding pad is disposed within the via hole to contact the second type semiconductor layer, and the epitaxial structure is electrically bonded to the receiving substrate through the bonding pads.

Claims

1. A light emitting device, comprising:

a carrier;

a plurality of light emitting diode chips, disposed on the carrier, wherein each light emitting diode chip comprises;

a first type semiconductor layer;

an active layer, disposed on the first type semiconductor layer;

a second type semiconductor layer, disposed on the active layer;

a via hole, sequentially penetrating through the first type semiconductor layer, the active layer and a portion of the second type semiconductor layer, wherein the first type semiconductor layer, the active layer, the second type semiconductor layer and the via hole define an epitaxial structure; and

a plurality of bonding pads, disposed between the epitaxial structure and a receiving substrate and comprising a first bonding pad electrically connected to the first type semiconductor layer and a second bonding pad electrically connected to the second type semiconductor layer; and

a plurality of buffer pads, located on the carrier and disposed between the carrier and the second type semiconductor layers of the epitaxial structures, wherein the buffer pads are with Young'"'"'s modulus of 2˜

10 GPa, the second bonding pad is disposed within the via hole to contact the second type semiconductor layer, and the epitaxial structures are electrically bonded to the receiving substrate through the bonding pads,

wherein an area of an orthogonal projection of each of the buffer pads on the carrier is 0.6 times to 1.2 times of an area of an orthogonal projection of the epitaxial structure on the carrier.

2. The light emitting device as claimed in claim 1, wherein a material of the buffer pads is organic with Young'"'"'s modulus of 2.9˜

3.6 GPa.

3. The light emitting device as claimed in claim 2, wherein the material of the buffer pads is organic with break elongation 5˜

10% and residual stress 30˜

40 MPa.

4. The light emitting device as claimed in claim 1, wherein the receiving substrate comprises a plurality of circuit electrodes, and the bonding pads are electrically connected to the circuit electrodes.

5. The light emitting device as claimed in claim 1, wherein each light emitting diode chip further comprises:

an insulating layer, disposed on the first type semiconductor layer and a sidewall of the via hole, wherein the insulating layer forms a contact opening to expose the first type semiconductor layer and forms another opening in the via hole to expose the second type semiconductor layer, and the first bonding pad is disposed in the contact opening, the second bonding pad is disposed in another opening, and a portion of the insulating layer is located between a side wall of the via hole and the second bonding pad.

6. The light emitting device as claimed in claim 1, wherein the receiving substrate comprises a plurality of sub-pixels, each of the epitaxial structures corresponds to one of the sub-pixels.

7. The light emitting device as claimed in claim 1, wherein the receiving substrate comprises a plurality of light-obstructed structures, and the light-obstructed structures and the light emitting diode chips are arranged alternately.

8. The light emitting device as claimed in claim 7, wherein a height of each light-obstructed structure is higher than a position of the active layer of the adjacent epitaxial structure.

9. The light emitting device as claimed in claim 1, wherein the thickness of the second type semiconductor layer is 3 times to 15 times of a thickness of the active layer, and the thickness of the second type semiconductor layer is 10 times to 20 times of the thickness of the first type semiconductor layer.

10. The light emitting device as claimed in claim 1, wherein in a vertical direction with respect to the carrier, each of the buffer pads and the epitaxial structure are conformal patterns.

11. The light emitting device as claimed in claim 1, wherein the receiving substrate comprises a thin film transistor substrate, a complementary metal oxide semiconductor substrate, a printed circuit board substrate or a flexible substrate.

12. The light emitting device as claimed in claim 1, wherein an orthogonal projection area of the first bonding pad on the receiving substrate is the same as an orthogonal projection area of the second bonding pad on the receiving substrate.

13. The light emitting device as claimed in claim 1, wherein an orthogonal projection area of the first bonding pad on the receiving substrate is different from an orthogonal projection area of the second bonding pad on the receiving substrate.