GALLIUM ARSENIDE DEVICES WITH COPPER BACKSIDE FOR DIRECT DIE SOLDER ATTACH

• US 20150364411A1
• Filed: 03/10/2015
• Published: 12/17/2015
• Est. Priority Date: 06/13/2014
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: Shen, Hong
• Granted Patent: US 9,530,719 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/561 Batch processing
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 21/6836 Wafer tapes, e.g. grinding or dicing support tapes adhesive tapes in general C09J7/20
• CPC Class Codes: H01L 21/76898 formed through a semiconductor substrate
• CPC Class Codes: H01L 2221/68327 used during dicing or grinding
• CPC Class Codes: H01L 2221/68331 of passive members, e.g. die mounting substrate
• CPC Class Codes: H01L 2221/6834 used to protect an active side of a device or wafer
• CPC Class Codes: H01L 2224/02313 Subtractive methods
• CPC Class Codes: H01L 2224/02331 Multilayer structure
• CPC Class Codes: H01L 2224/02371 connecting the bonding area on a surface of the semiconductor or solid-state body with another surface of the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/0239 Material of the redistribution layers
• CPC Class Codes: H01L 2224/03 Manufacturing methods
• CPC Class Codes: H01L 2224/03424 Immersion coating, e.g. in a solder bath immersion processes C23C2/00
• CPC Class Codes: H01L 2224/03464 Electroless plating
• CPC Class Codes: H01L 2224/04026 Bonding areas specifically adapted for layer connectors
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05008 Bonding area integrally formed with a redistribution layer on the semiconductor or solid-state body, e.g.
• CPC Class Codes: H01L 2224/05147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05155 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05548 Bonding area integrally formed with a redistribution layer on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/05569 : the external layer being disposed on a redistribution layer on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/05647 : Copper [Cu] 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 2224/131 : 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 2224/16227 : the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/27312 : Continuous flow, e.g. using a microsyringe, a pump, a nozzle or extrusion
• CPC Class Codes: H01L 2224/2732 : Screen printing, i.e. using a stencil
• CPC Class Codes: H01L 2224/291 : 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 2224/29111 : Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/2929 : with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29294 : with a principal constituent of the material being a liquid not provided for in groups H01L2224/292 - H01L2224/29291
• CPC Class Codes: H01L 2224/293 : 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 2224/32012 : relative to the bonding area, e.g. bond pad
• CPC Class Codes: H01L 2224/32225 : the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32245 : the item being metallic
• CPC Class Codes: H01L 2224/45124 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 : Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 : Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48091 : Arched
• CPC Class Codes: H01L 2224/48227 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48247 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2224/81 : using a bump connector
• CPC Class Codes: H01L 2224/81815 : Reflow soldering
• CPC Class Codes: H01L 2224/83 : using a layer connector
• CPC Class Codes: H01L 2224/83143 : Passive alignment, i.e. self alignment, e.g. using surface energy, chemical reactions, thermal equilibrium
• CPC Class Codes: H01L 2224/83192 : wherein the layer connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/83411 : Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/83439 : Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/83444 : Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/83455 : Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/83464 : Palladium [Pd] as principal constituent
• CPC Class Codes: H01L 2224/83815 : Reflow soldering
• CPC Class Codes: H01L 2224/83851 : being an anisotropic conductive adhesive
• CPC Class Codes: H01L 2224/85 : using a wire connector
• CPC Class Codes: H01L 2224/85201 : Compression bonding
• CPC Class Codes: H01L 2224/85203 : Thermocompression bonding
• CPC Class Codes: H01L 2224/85205 : Ultrasonic bonding
• CPC Class Codes: H01L 2224/85207 : Thermosonic bonding
• CPC Class Codes: H01L 2224/92147 : the second connecting process involving a wire connector
• CPC Class Codes: H01L 2224/92247 : the second connecting process involving a wire connector
• CPC Class Codes: H01L 2224/94 : at wafer-level, i.e. with connecting carried out on a wafer comprising a plurality of undiced individual devices
• CPC Class Codes: H01L 2224/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 23/3128 : the substrate having spherical bumps for external connection
• CPC Class Codes: H01L 23/481 : Internal lead connections, e.g. via connections, feedthrough structures
• CPC Class Codes: H01L 23/49541 : Geometry of the lead-frame
• CPC Class Codes: H01L 23/49548 : Cross section geometry H01L23/49562 takes precedence
• CPC Class Codes: H01L 23/49551 : characterised by bent parts
• CPC Class Codes: H01L 24/02 : Bonding areas on insulating substrates, e.g. chip carriers, H01L23/49816, H01L23/49838, H01L23/5389; Manufacturing methods related thereto
• CPC Class Codes: H01L 24/03 : Manufacturing methods
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 24/13 : of an individual bump connector
• CPC Class Codes: H01L 24/16 : of an individual bump connector
• CPC Class Codes: H01L 24/27 : Manufacturing methods
• CPC Class Codes: H01L 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/45 : of an individual wire connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/81 : using a bump connector
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/85 : using a wire connector wire bonding in general B23K20/004
• CPC Class Codes: H01L 24/92 : Specific sequence of method steps
• CPC Class Codes: H01L 24/94 : at wafer-level, i.e. with connecting carried out on a wafer comprising a plurality of undiced individual devices
• CPC Class Codes: H01L 24/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/10156 : at the periphery
• CPC Class Codes: H01L 2924/10157 : at the active surface
• CPC Class Codes: H01L 2924/10329 : Gallium arsenide [GaAs]
• CPC Class Codes: H01L 2924/142 : HF devices
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/15313 : being a land array, e.g. LGA
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/3511 : Warping
• CPC Class Codes: H01L 2924/3651 : Formation of intermetallics

Abstract

Electronic devices, and methods of manufacturing the electronic devices, utilizing direct die soldering of GaAs integrated circuit dies. In some embodiments, the GaAs integrated circuit die can have a footprint approximately the same size as a die attach pad. Further, the GaAs integrated circuit die can self-align with the die attach pad after reflow of any solder layer used to attach the die.

Claims

1. An electronic circuit device comprising:

a substrate;

a die attach pad located on the substrate; and

a GaAs integrated circuit die having a copper backside contact pad and having a footprint of approximately the same size as the die attach pad, the GaAs integrated circuit die being connected to the die attach pad by a solder layer, the solder layer being disposed between the copper backside contact pad and the die attach pad on the substrate in a manner such that the GaAs integrated circuit die self-aligns with the die attach pad after reflow of the solder layer.

2. The electronic circuit device of claim 1 further comprising a barrier layer, said barrier layer being disposed between said copper backside contact pad and said solder layer.

3. The electronic circuit device of claim 1 wherein said substrate is a printed circuit board.

4. The electronic circuit device of claim 2 wherein said solder barrier layer comprises nickel.

5. The electronic circuit device of claim 4 wherein said solder barrier layer further comprises a palladium flash layer.

6. The electronic circuit device of claim 1 wherein thermal resistance of the solder layer is at least 40% lower than thermal resistance of an epoxy layer.

7. The electronic circuit device of claim 1 wherein the copper backside contact pad has a thermal conductivity of approximately 4 W/cmK.

8. A GaAs integrated circuit incorporating the electronic circuit device of claim 1.

9. A method for manufacturing a GaAs wafer assembly, said method comprising:

fabricating a GaAs wafer having a copper layer over a backside of the wafer;

electroless plating a barrier layer over said copper layer;

forming at least one singulated die from said GaAs wafer; and

direct die soldering said at least one singulated die to a die attach pad on a substrate such that a solder layer is formed between the at least one singulated die and the die attach pad, the soldering performed in a manner such that the at least one singulated die self-aligns with the die attach pad after reflow of the solder layer.

10. The method of claim 9 further comprising forming a palladium flash layer over the copper layer.

11. The method of claim 9 wherein said substrate is a printed circuit board.

12. The method of claim 9 wherein a surface area of said singulated die is substantially equivalent to a surface area of said die attach pad.

13. A GaAs integrated circuit made in accordance with the method of claim 9.

14. The GaAs integrated circuit of claim 13 wherein said GaAs integrated circuit comprises a through-wafer via at least partially filled with copper.

15. The GaAs integrated circuit of claim 14 wherein the electroless plating covers more than 40% of the through-wafer via.

16. An electronic circuit module comprising:

a singulated GaAs integrated circuit die having a copper contact pad;

a printed circuit board having a die attach pad, said die attach pad sized to receive the singulated GaAs integrated circuit die and having a footprint of approximately the same size as the singulated GaAs integrated circuit die; and

a solder layer disposed between said copper contact pad of the die and said die attach pad of the printed circuit board, said copper contact pad of the singulated GaAs integrated circuit die attached to said die attach pad of the printed circuit board in a manner such that the singulated GaAs integrated circuit die self-aligns with the die attach pad after reflow of the solder layer.

17. The electronic circuit module of claim 16 further comprising a nickel layer, said nickel layer formed between said copper contact pad and said solder layer.

18. The electronic circuit module of claim 16 further comprising a flash palladium layer, said flash palladium layer formed between said nickel layer and said copper contact pad and configured to act as a wetting layer for the solder layer.

19. The electronic circuit module of claim 16 wherein the size of said die attach pad does not exceed the size of said singulated GaAs integrated circuit die by more than 150 microns in at least one direction.

20. The electronic circuit module of claim 16 wherein said singulated GaAs integrated circuit die is a radio frequency integrated circuit die.