Method for manufacturing double-sided flexible printed board
US6705007B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 1999 |
| Grant date | Mar 16, 2004 |
| Priority date | — |
| Expiry date | Dec 14, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31721
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A double-sided flexible printed circuit board is manufactured by the following steps of: (a) forming a polyimide precursor layer on a first metal layer; (b) forming a second metal layer on the polyimide precursor layer; (c) patterning the second metal layer to form a second circuit layer or (c′) patterning the first metal layer to form a first circuit layer; and (d) imidating the polyimide precursor layer to form a polyimide insulating layer. The polyimide precursor layer is obtained by dissolving a polyamic acid or other polyimide precursor in N-methyl-2-pyrrolidone or the like and applying the resultant varnish to the first metal layer. The polyimide layer is then dried. The imidation ratio of the dried polyimide precursor layer is prevented from exceeding 50%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.