Method and apparatus for removing resist particles from stripping solutions for printed wireboards
US5531889A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 1994 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Mar 8, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/422
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for removing polymer particles from the stripping solution used in the treatment of printed wireboards comprises passing a solution having resist particles dispersed therein over a screen having openings of 100 microns, where the screen is maintained at an angle of from 40 to 70.degree. to the horizontal. The apparatus comprises a curtain tube consisting of an inner concentric tube with a plurality of holes and an outer concentric tube with a slot wherein the position of the slot is adjustable, filter means comprising a screen, and a pump for circulating the solution. In one embodiment, the filter means comprises a cylindrical screen. The stripping solution comprises an aqueous solution of an organoamine, ionic nitrogen compound or alkali or alkaline-earth hydroxide, or mixtures thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.