Method of converting a positive photoresist layer to a negative photoresist image
CA 1075523 A · Owner: International Business Machines Corporation · Inventors: Moritz, Holger; Paal, Gabor
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure A normally positive acting photoresist material is made operable as a negative acting material by the additional steps following image-wise exposure, of heating the layer and subsequently blanket exposing it to light prior to developing it with an alkaline solvent.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted April 15, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 15, 1997.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.