Patent · US Expired

Wet etching of cured polyimide

US4857143A · kind A · utility

17Cited by
4References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 16, 1988
Grant dateAug 15, 1989
Priority date
Expiry dateDec 16, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH05K3/0017
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A fully cured or substantially fully cured polyimide is etched by contacting the imide with an aqueous solution of a metal hydroxide such as an alkali metal or alkali earth hydroxide and a metallic compound selected from metal carbonates, sulfates and phosphates. The presence of the carbonate, sulfate or phosphare reduces the undercutting of a resist pattern on the polyimide.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.