US3946427A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor device
Assignee: Hitachi Ltd
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Filing: 1974-10-15
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Granted: 1976-03-23
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Expires: 1994-10-15
Abstract
Abstract In a semiconductor device, the surface of a semiconductor element is covered with a silicone varnish in which the side chain radical ratio between methyl radicals and phenyl radicals is 20:1 or greater, whereby the element is effectively shielded from the external moisture.
Inventors
- 👤 Hideo Iwasawa
- 👤 Yoshiaki Wakashima
- 👤 Hideo Inayoshi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:48
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6921; H10P14/6922; H10P14/63; H10P14/6326; H10P14/6342
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
62 words
A semiconductor device comprising a semiconductor element having at least one P--N junction therein and a covering of a silicone varnish on a surface, of said semiconductor element, said silicone varnish containing methyl radicals and phenyl radicals as side chain radicals and having in the side chain radicals a ratio between said methyl radicals and said phenyl radicals of at least 20:1.
Claim 2
Dependent Claim
62 words
A semiconductor device comprising a semiconductor element having at least one P--N junction therein and a covering of a silicone varnish on a surface, of said semiconductor element, said silicone varnish containing methyl radicals and phenyl radicals as side chain radicals and having in the side chain radicals a ratio between said methyl radicals and said phenyl radicals of at least 20:1.
Claim 3
Dependent Claim
26 words
The semiconductor device of claim 1, wherein the ratio between the side chain methyl radicals and the side chain phenyl radicals is from 20:1 to 100:1.
Claim 4
Dependent Claim
19 words
The semiconductor device of claim 1, wherein the silicone varnish is applied to a thickness of 20 to 30μ.
Claim 5
Dependent Claim
16 words
The semiconductor device of claim 1, wherein the silicone varnish is covered with an epoxy resin.
Claim 6
Independent Claim
70 words
A method for producing a semiconductor device comprising applying a silicone varnish onto a surface of a semiconductor element having at least one P--N junction therein, said silicone varnish containing methyl radicals and phenyl radicals as side chain radicals and having in the side chain radicals, a ratio between said methyl radicals and said phenyl radicals of at least 20:1, and curing the applied silicone varnish at an elevated temperature.
Claim 7
Independent Claim
70 words
A method for producing a semiconductor device comprising applying a silicone varnish onto a surface of a semiconductor element having at least one P--N junction therein, said silicone varnish containing methyl radicals and phenyl radicals as side chain radicals and having in the side chain radicals, a ratio between said methyl radicals and said phenyl radicals of at least 20:1, and curing the applied silicone varnish at an elevated temperature.
Claim 8
Dependent Claim
17 words
The method of claim 5, wherein the silicone varnish comprises a silicone resin having a three-dimensional structure.
Claim 9
Dependent Claim
23 words
The method of claim 5, wherein said silicone varnish is heated to a temperature of from 150° to 200°C to effect curing thereof.
Claim 10
Dependent Claim
31 words
The method of claim 5, further comprising applying an additional coating of epoxy resin to the cured layer of silicone varnish and thereafter curing the epoxy resin at an elevated temperature.
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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) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |