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US3680198A
Expired / Lapsed
US
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Assembly method for attaching semiconductor devices
Assignee: Fairchild Semiconductor Corp
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Filing: 1970-10-07
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Granted: 1972-08-01
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Expires: 1990-10-07
Abstract
Abstract A method of attaching a semiconductor die having an interconnecting pattern on one side of it, and having a given liquidus temperature, to a substrate which also has a metal pattern upon it corresponding with the metal pattern on the die, the substrate metal pattern having a melting point at least 10* C. less than the liquidus temperature of the die metal pattern, including the steps of: (1) picking up the die from its backside with a heated pickup tool: (2) transferring the heat from the tool to the die pattern through the backside, the amount of heat being insufficient to totally melt the die metal pattern; (3) placing the die adjacent the substrate so the heated die metal pattern is in registration with the substrate metal pattern, causing the substrate metal pattern to melt: (4) cooling the substrate and the die with their registered metal patterns in contact, thereby resolidifying the metal and forming a rigid mechanical and metallurgical joint between the two metal patterns.
Inventors
- 👤 John R Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:05
CPC Classifications
B; B23; B23K; B23K1/00; B23K1/20; B23K2101/00; B23K2101/36; B23K2101/40; H; H10; H10W; H10W72/00; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/07251; H10W72/20; H10W72/251; H10W72/252
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
223 words
The method of attaching a semiconductor die having an interconnecting metal pattern on one side of it, said die metal pattern having a given liquidus temperature, to a substrate which also has a substrate metal pattern upon it laterally corresponding at bonding locations with said metal pattern on the die, said substrate metal pattern having a liquidus temperature at least 10* C below the liquidus temperature of said die metal pattern, comprising: 1. picking up the die from its backside with a heated pickup tool; 2. transferring heat from said tool to said die metal pattern through said backside of said die, the amount of such transferred heat being sufficient to bring said die metal pattern above its solidus temperature but below its liquidus temperature; 3. placing said heated die metal patteRn adjacent to, in mechanical contact with, and in registration with the corresponding substrate metal pattern in such a manner that sufficient heat from said heated die metal pattern is transferred at the bonding locations to said substrate metal pattern to cause said substrate metal pattern to melt, to rise, to form fillets with and to soften said die metal pattern; and 4. cooling said substrate and die with their registered metal patterns in contact, thereby resolidifying the metal and forming a rigid mechanical and metallurgical joint between the two metal patterns.
Claim 2
Independent Claim
223 words
The method of attaching a semiconductor die having an interconnecting metal pattern on one side of it, said die metal pattern having a given liquidus temperature, to a substrate which also has a substrate metal pattern upon it laterally corresponding at bonding locations with said metal pattern on the die, said substrate metal pattern having a liquidus temperature at least 10* C below the liquidus temperature of said die metal pattern, comprising: 1. picking up the die from its backside with a heated pickup tool; 2. transferring heat from said tool to said die metal pattern through said backside of said die, the amount of such transferred heat being sufficient to bring said die metal pattern above its solidus temperature but below its liquidus temperature; 3. placing said heated die metal patteRn adjacent to, in mechanical contact with, and in registration with the corresponding substrate metal pattern in such a manner that sufficient heat from said heated die metal pattern is transferred at the bonding locations to said substrate metal pattern to cause said substrate metal pattern to melt, to rise, to form fillets with and to soften said die metal pattern; and 4. cooling said substrate and die with their registered metal patterns in contact, thereby resolidifying the metal and forming a rigid mechanical and metallurgical joint between the two metal patterns.
Claim 3
Dependent Claim
39 words
transferring heat from said tool to said die metal pattern through said backside of said die, the amount of such transferred heat being sufficient to bring said die metal pattern above its solidus temperature but below its liquidus temperature;
Claim 4
Dependent Claim
39 words
transferring heat from said tool to said die metal pattern through said backside of said die, the amount of such transferred heat being sufficient to bring said die metal pattern above its solidus temperature but below its liquidus temperature;
Claim 5
Dependent Claim
47 words
The method of claim 1 wherein the temperature to which the die is heated is selected so that heat transferred from said die metal pattern to said substrate metal pattern is sufficient to form an alloy between the two metal patterns upon their coming into mechanical contact.
Claim 6
Dependent Claim
67 words
placing said heated die metal patteRn adjacent to, in mechanical contact with, and in registration with the corresponding substrate metal pattern in such a manner that sufficient heat from said heated die metal pattern is transferred at the bonding locations to said substrate metal pattern to cause said substrate metal pattern to melt, to rise, to form fillets with and to soften said die metal pattern; and
Claim 7
Dependent Claim
67 words
placing said heated die metal patteRn adjacent to, in mechanical contact with, and in registration with the corresponding substrate metal pattern in such a manner that sufficient heat from said heated die metal pattern is transferred at the bonding locations to said substrate metal pattern to cause said substrate metal pattern to melt, to rise, to form fillets with and to soften said die metal pattern; and
Claim 8
Dependent Claim
29 words
cooling said substrate and die with their registered metal patterns in contact, thereby resolidifying the metal and forming a rigid mechanical and metallurgical joint between the two metal patterns.
Claim 9
Dependent Claim
29 words
cooling said substrate and die with their registered metal patterns in contact, thereby resolidifying the metal and forming a rigid mechanical and metallurgical joint between the two metal patterns.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |