Patent EP0119691A2 successfully refreshed from Google Patents.
EP0119691A2
Expired / Lapsed
EP
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Bonding semiconductive bodies
Assignee: STC PLC
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Filing: 1984-01-25
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Granted: —
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Expires: 2004-01-25
Abstract
Abstract Reproduceability and reliability problems associated with using a solder preform to bond a semiconductor laser chip (1) to a heat sink (2) are avoided by a diffusion assisted bonding method. Both surfaces to be bonded are coated with relatively thick layers of gold (3,7), one of which is then coated with a submicron thickness tin layer (5) whose surface is protected from oxidation with a further coating (6) of gold. The two components are assembled and heated to bond them together by causing a molten gold-tin eutectic layer to be formed which then diffuses into the gold layers without penetrating right through them.
Inventors
- 👤 Ralph Barton Dean
- 👤 Adrian Perrin Janessen
- 👤 Jennifer Karen Stone
- 👤 Arthur Walker
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 04:01
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/20; H10W70/24; B; B23; B23K; B23K35/00; B23K35/001; H10W72/00; H10W72/30; H01; H01S; H01S5/00; H01S5/02; H01S5/022; H01S5/0235; H01S5/02355; H01S5/0237; H10H; H10H20/00; H10H20/80; H10H20/85; H10H20/857; H10W72/071; H10W72/073; H10W72/07331; H10W72/07336; H10W72/351; H10W72/352; H10W72/50; H10W72/59
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
190 words
A method of bonding a surface of a semiconductor body (1) to a surface of a thermally and electrically conductive substrate (2), characterised in that the surface of the semiconductive body is coated with a diffusion barrier layer (4) which is itself coated with a layer (3) of gold, wherein the surface of the substrate is coated with a layer (7) of gold, wherein either or both of said layers (3, 7) of gold are coated with a submicron thickness diffusion layer (5) of metal or alloy that will form or is a metal-gold eutectic with a melting point at a temperature sustainable by the semiconductor body, which diffusion layer, in the case of a material that oxidises, is protected from oxidation by a protective gold coating (6), wherein the two coated surfaces are held together while the assembly is heated to a temperature to cause the formation of a continuous molten metal-gold eutectic layer covering the area of the bond which layer diffuses entirely into the gold of said gold layers without penetrating right through these layers, whereby a diffusion assisted metallic bond is formed between the two surfaces.
Claim 2
Independent Claim
190 words
A method of bonding a surface of a semiconductor body (1) to a surface of a thermally and electrically conductive substrate (2), characterised in that the surface of the semiconductive body is coated with a diffusion barrier layer (4) which is itself coated with a layer (3) of gold, wherein the surface of the substrate is coated with a layer (7) of gold, wherein either or both of said layers (3, 7) of gold are coated with a submicron thickness diffusion layer (5) of metal or alloy that will form or is a metal-gold eutectic with a melting point at a temperature sustainable by the semiconductor body, which diffusion layer, in the case of a material that oxidises, is protected from oxidation by a protective gold coating (6), wherein the two coated surfaces are held together while the assembly is heated to a temperature to cause the formation of a continuous molten metal-gold eutectic layer covering the area of the bond which layer diffuses entirely into the gold of said gold layers without penetrating right through these layers, whereby a diffusion assisted metallic bond is formed between the two surfaces.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1, wherein the diffusion layer is made of tin or includes tin as a constituent.
Claim 4
Dependent Claim
21 words
A method as claimed in claim 1, wherein the diffusion layer is made of germanium or includes germanium as a constituent.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 1, 2 or 3, wherein the diffusion layer is made of elemental metal.
Claim 6
Dependent Claim
18 words
A method as claimed in claim 1, 2, 3 or 4, wherein the semiconductive body is a laser.
Claim 7
Dependent Claim
20 words
A method as claimed in claim 1, 2, 3, 4 or 5, wherein the semiconductive body is made of GaAlAs.
Claim 8
Dependent Claim
23 words
A method as claimed in claim 1, 2, 3, 4 or 5, wherein the semiconductive body is made of (Ga In As P).
Claim 9
Dependent Claim
18 words
A semiconductor body which has been bonded to a substrate by the method claimed in any preceding claim.
References Cited (Backward Citations)
No citation records indexed.
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