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Product Positive. UK. C. Novolak Resin. No. 2

PATENT ASSIGNEE'S COUNTRY UK
UPDATE 07.99
PATENT ASSIGNEE This data is not available for free
PATENT CLAIMS Claim No. 1:
Method for prodg film forming novolak resin
- Condensing formol with phenols in presence of acid cata
lyst
- Then incorporating a presynthesized polymer of multihydro
xylated benzene with ketone & thereby prodg novolak re
sin block copolymer with the multi-hydroxybenzene/ketone
moiety incorporated as part of block copolymer
- Isolating novolak block copolymer by removing unreacted
formol or phenols
- Adding to copolymer water soluble organic polar solvent
(15 - 40 % solids)
- Adding deionized water; thereby precipitating novolak
block copolymer & soln of remaining unreacted phenols,
oligomers & useless monomers
- Removing soln
- Adding water soluble organic polar solvent to precipitated
copolymer & thereby providing soln (15 - 40 % solids)
- Adding deionized water, thereby again precipitating novo
lak copolymer & removing remaining soln
- Dissolving novolak block copolymer ppcc in photoresist
solvent, then removing any remaining water & polar solvent
by distn under vacuum & low T & thereby prodg soln of film
forming fractionated novolak resin block copolymer in said
photoresist solvent
Claim 6:
Method for prodg a positive photoresist compn having supe
rior lithographic performance
- All steps of Claim 1
- Last additional step. Providing an admixt.:
-- Photosensitive comp.
-- Film forming fractionated novolak resin block copolymer
-- Additional photoresist solvent
PATENT PHOTOCOPY Available on request

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