US3876461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor process
Assignee: Motorola Solutions Inc
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Filing: 1973-09-04
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Granted: 1975-04-08
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Expires: 1993-09-04
Abstract
Abstract A process for improving the reliability and solderability characteristics of plastic encapsulated semiconductor devices which includes the step of immersing the devices in N-methyl-2pyrollidone.
Inventors
- 👤 Dervin L Flowers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:29
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/01; C; C08; C08G; C08G59/00; C08G59/18; C08G59/40; C08G59/44; C08G59/448; Y; Y10; Y10S; Y10S156/00; Y10S156/918; Y10S156/93; Y10T; Y10T156/00; Y10T156/11; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
48 words
IN A PROCESS OF MANUFACTURING A SEMICONDUCTOR DEVICE WHEREIN A SEMICONDUCTOR CHIP IS MOUNTED ON A LEAD FRAME AND A PLASTIC ENCAPSULATION IS MOLDED THEREAROUND, THE IMPROVEMENT COMPRISING THE STEP OF: IMMERSING THE DEVICE IN A SOLUTION OF N-METHYL-2PYROLLIDONE HEATED TO 70*-110*C FOR A PERIOD OF 1-20 MINUTES.
Claim 2
Dependent Claim
48 words
IN A PROCESS OF MANUFACTURING A SEMICONDUCTOR DEVICE WHEREIN A SEMICONDUCTOR CHIP IS MOUNTED ON A LEAD FRAME AND A PLASTIC ENCAPSULATION IS MOLDED THEREAROUND, THE IMPROVEMENT COMPRISING THE STEP OF: IMMERSING THE DEVICE IN A SOLUTION OF N-METHYL-2PYROLLIDONE HEATED TO 70*-110*C FOR A PERIOD OF 1-20 MINUTES.
Claim 3
Dependent Claim
14 words
A process as recited in claim 1 wherein the plastic is selected from the
Claim 4
Dependent Claim
14 words
A process as recited in claim 2 wherein the immersion time is 5 minutes.
Claim 5
Dependent Claim
14 words
A process as recited in claim 1 wherein said solution also contains a surfactant.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |