Patent US4225702A successfully refreshed from Google Patents.
US4225702A
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Method of preparing polyamide acid type intermediates for processing of semiconductors
Assignee: Resonac Corp
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Filing: 1979-02-01
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Granted: 1980-09-30
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Expires: 1999-02-01
Abstract
Abstract A method of preparing a polyamide acid type intermediate is provided, by using a purified inert solvent and monomer compounds, or diamine and/or diaminoamide compounds and a tetracarboxylic acid dianhydride, whose ionic impurities and free acid contents were reduced by recrystallization purification. The polyamide acid type intermediate may improve electrical properties and heat resistance of semiconductors when it is applied to, for instance, a surface-protecting film of semiconductors or an interlayer-insulating film of semiconductors having a multiple layer wiring structure.
Inventors
- 👤 Daisuke Makino
- 👤 Yasuo Miyadera
- 👤 Seiki Harada
- 👤 Atsushi Saiki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:58
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1007; C08G73/1028; C08G73/1032; H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/303
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
92 words
A method of preparing a polyamide acid type intermediate for processing of semiconductors by reacting at least one compound selected from the group consisting of diamine and diaminoamide compounds, and a tetracarboxylic acid dianhydride, as monomer compounds, the improvement comprises using (A) an inert solvent purified by distillation or ion-exchange, and (B) said monomer compounds having been purified to have reduced contents of ionic impurities and free acid by recrystallization comprising dissolving each monomer being purified in a solvent which is heated, then filtering and cooling the filtrate to precipitate purified monomer.
Claim 2
Independent Claim
92 words
A method of preparing a polyamide acid type intermediate for processing of semiconductors by reacting at least one compound selected from the group consisting of diamine and diaminoamide compounds, and a tetracarboxylic acid dianhydride, as monomer compounds, the improvement comprises using (A) an inert solvent purified by distillation or ion-exchange, and (B) said monomer compounds having been purified to have reduced contents of ionic impurities and free acid by recrystallization comprising dissolving each monomer being purified in a solvent which is heated, then filtering and cooling the filtrate to precipitate purified monomer.
Claim 3
Dependent Claim
30 words
The method as claimed in claim 1, wherein the tetracarboxylic acid dianhydride is used in essentially equimolar amount less than ±0.5 mole % excess to the diamine and/or diaminodiamide compounds.
References Cited (Backward Citations)
US3179614A
Cited
US3678005A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-30 | 1984-03-31 | 1984-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-30 | 1988-03-31 | 1988-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-30 | 1992-03-31 | 1992-09-30 | $7700.00 | Window Closed / Lapsed |