Process for making a two-layer film carrier
US5217849A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1992 |
| Grant date | Jun 8, 1993 |
| Priority date | — |
| Expiry date | Feb 18, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2201/0166
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A two-layer film carrier for TAB is made from a substrate prepared by forming a copper layer on a polyimide film by additive plating. A photoresist layer is formed on the copper layer, and another photoresist layer on the polyimide film. Both of the photoresist layers are simultaneously exposed to light through a mask applied to each of them to define a desired pattern. The exposed portions of the photoresist layer on the copper layer are subjected to development and postbaking, whereby selected portions of the copper layer are exposed. The exposed portions of the copper layer are additive plated with copper, whereby leads are formed. The exposed portions of the photoresist layer on the polyimide film are subjected to development and postbaking, whereby selected portions of the polyimide film are exposed. The remaining portions of the photoresist layer are removed from the copper layer and the underlying copper layer is etched. The exposed portions of the polyimide film are etched, and the remaining portions of the photoresist layer are removed from the polyimide film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.