US4431967A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of mounting a semiconductor element for analyzing failures thereon
Assignee: Mitsubishi Electric Corp
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Filing: 1980-08-21
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Granted: 1984-02-14
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Expires: 2000-08-21
Abstract
Abstract A semiconductor chip having its main face coated with an electrically insulating film is encapsulated in a plastic, electrically conducting member disposed on a metallic plate so that the surface of the insulating member is exposed and parallel to the metallic plate. The surface of the insulating film is observed by an optical microscope through a nematic liquid crystal film and a glass slide with a transparent, electrically conducting coating successively disposed on the chip with a DC voltage applied between the conducting coating and the metallic plate.
Inventors
- 👤 Tadashi Nishioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:15
CPC Classifications
H; H10; H10P; H10P74/00; G; G01; G01R; G01R31/00; G01R31/28; G01R31/302; G01R31/308; G01R31/316
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
210 words
A method which comprises the steps of: inserting a semiconductor chip including a semiconductor element disposed on a main surface of the semiconductor chip into an electrically conducting member from an upper surface thereof so as to leave said main surface of said semiconductor chip exposed while at least one portion of a surface which is opposite to the main surface and lateral surfaces of said semiconductor chip are in intimate contact with said electrically conducting member; disposing an electrically insulating spacer including an opening on the upper surface of said electrically conducting member so as to cause said opening to be opposite to the main surface of said semiconductor chip; forming a film of a nematic liquid crystal in said opening so as to be intimate contact with the main surface of said semiconductor chip; placing a transparent plate having a transparent electrically conducting film disposed on at least one surface thereof on said electrically insulating spacer so that said transparent electrically conducting film is in contact with said nematic liquid crystal film; and applying a DC voltage across said electrically conducting member and said transparent electrically conducting film, wherein failures on said semiconductor chip are analyzed by using a dynamic scattering effect of said nematic liquid crystal film.
Claim 2
Independent Claim
210 words
A method which comprises the steps of: inserting a semiconductor chip including a semiconductor element disposed on a main surface of the semiconductor chip into an electrically conducting member from an upper surface thereof so as to leave said main surface of said semiconductor chip exposed while at least one portion of a surface which is opposite to the main surface and lateral surfaces of said semiconductor chip are in intimate contact with said electrically conducting member; disposing an electrically insulating spacer including an opening on the upper surface of said electrically conducting member so as to cause said opening to be opposite to the main surface of said semiconductor chip; forming a film of a nematic liquid crystal in said opening so as to be intimate contact with the main surface of said semiconductor chip; placing a transparent plate having a transparent electrically conducting film disposed on at least one surface thereof on said electrically insulating spacer so that said transparent electrically conducting film is in contact with said nematic liquid crystal film; and applying a DC voltage across said electrically conducting member and said transparent electrically conducting film, wherein failures on said semiconductor chip are analyzed by using a dynamic scattering effect of said nematic liquid crystal film.
References Cited (Backward Citations)
US13798A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-13 | 1987-08-15 | 1988-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-13 | 1991-08-15 | 1992-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-13 | 1995-08-15 | 1996-02-14 | $7700.00 | Window Closed / Lapsed |