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US4661771A
Expired / Lapsed
US
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Method of screening resin-sealed semiconductor devices
Assignee: Fujitsu Ltd
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Filing: 1983-09-23
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Granted: 1987-04-28
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Expires: 2003-09-23
Abstract
Abstract A method of screening resin-sealed semiconductor devices having a resin body for sealing and a semiconductor chip is mounted on a die stage having a first and second bars, said first and second bars extending from said die stage to opposite side surfaces of the body and having a first and second ends exposed to said side surfaces, which method comprises the steps of applying electric voltage between said first and second ends to heat the semiconductor chip, and subjecting the device to screening test.
Inventors
- 👤 Kazuo Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:31
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/90; G; G01; G01R; G01R31/00; G01R31/28; G01R31/316; H10P74/00; H10P74/27; H10P74/277; H10P74/20; H10P74/203; H10W; H10W72/00; H10W72/50; H10W72/541; H10W72/5449; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
123 words
A method of screening a resin-sealed semiconductor device, said semiconductor device comprising a semiconductor chip, a resin body for sealing said semiconductor chip, a die stage wherein said semiconductor chip is mounted on said die stage, and first and second bars connected to said die stage extending from said die stage to opposite side surfaces of the body, said first and second bars having first and second exposed ends, said method comprising the steps of applying an electric voltage between said first and second ends of said first and second bars wherein said die stage is heated and thereby said semiconductor chip is heated, and subjecting the device to a screening test by inspecting the rate of temperature rise of said semiconductor chip.
Claim 2
Independent Claim
123 words
A method of screening a resin-sealed semiconductor device, said semiconductor device comprising a semiconductor chip, a resin body for sealing said semiconductor chip, a die stage wherein said semiconductor chip is mounted on said die stage, and first and second bars connected to said die stage extending from said die stage to opposite side surfaces of the body, said first and second bars having first and second exposed ends, said method comprising the steps of applying an electric voltage between said first and second ends of said first and second bars wherein said die stage is heated and thereby said semiconductor chip is heated, and subjecting the device to a screening test by inspecting the rate of temperature rise of said semiconductor chip.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1, including performing a functional test of the semiconductor chip during the screening test step.
Claim 4
Dependent Claim
57 words
A method as claimed in claim 1, including removing devices exhibiting an electric voltage in the forward direction of the PN junction outside a prescribed range when an electric current is passed through the PN junction of the semiconductor chip and the semiconductor chip is heated for a prescribed period of time during the screening test step.
Claim 5
Dependent Claim
52 words
A method as claimed in claim 1, including controlling the electric voltage applied between said first and second ends such that an electric voltage in the forward direction of the PN junction becomes equal to a prescribed value when an electric current is passed through the PN junction of the semiconductor chip.
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) | 1990-04-27 | 1990-10-27 | 1991-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-27 | 1994-10-27 | 1995-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-27 | 1998-10-27 | 1999-04-28 | $7700.00 | Window Closed / Lapsed |