Claims
- 1. A positive photosensitive composition containing a curable cyanate ester or a prepolymer thereof and a cationic photoinitiator that generates a Bronsted acid upon exposure to actinic light wherein said cyanate ester is a polyaromatic cyanate ester containing cycloaliphatic bridging group between aromatic rings.
- 2. The photosensitive composition of claim 1 wherein said photoinitiator is an onium salt of a Group VIA or a Group VIIA element.
- 3. The photosensitive composition of claim 1 wherein said photoinitiator is a sulfonium salt.
- 4. The photosensitive composition of claim 1 wherein said photoinitiator is present in an amount of about 0.5% to about 10% by weight based upon the solid resin weight.
- 5. The photosensitive composition of claim 1 wherein said photoinitiator is present in an amount of about 3% to about 5% by weight based upon the solid resin weight.
- 6. The photosensitive composition of claim 1 which further contains up to about 5% by weight based upon the solid resin weight of a free radical initiator.
- 7. The photosensitive composition of claim 1 wherein said cyanate ester is a prepolymer.
- 8. The photosensitive composition of claim 1 which further includes a photosensitizer.
- 9. The photosensitive composition of claim 1 which further includes an organic monomer or organic polymer, or both.
- 10. The photosensitive composition of claim 9 wherein said organic polymer is an epoxy polymer.
- 11. The photosensitive composition of claim 9 wherein said organic monomer is a maleimide.
- 12. The photosensitive composition of claim 11 wherein said maleimide is represented by the following formula: ##STR18## wherein R is a divalent alkylene radical or a divalent arylene group.
- 13. The photosensitive composition of claim 12 wherein said maleimide is methylene dianiline bismaleimide.
- 14. The photosensitive composition of claim 12 which further includes a free radical initiator.
- 15. The photosensitive composition of claim 11 which further includes an inorganic filler.
Parent Case Info
This is a divisional application of U.S. Ser. No. 08/348,944, filed Nov. 25, 1994, which matured into U.S. Pat. No. 5,464,726 on Nov. 7, 1995, which is a divisional of application of U.S. Ser. No. 07/382,311, filed Jul. 20 1989, now abandoned.
US Referenced Citations (7)
Non-Patent Literature Citations (3)
Entry |
Bogan et al, 110:174276, abstracts from Chemical Abstracts of "Unique polyaromatic cyanate ester fro low dielectric printed circuit boards", Sample Journal, (1988), vol. 24, No. 6, pp. 19-25. 1985. |
Meier et al, "Photo initiated Cationic Pholymerization of Epoxides with Iron-Arene Complexes", Journal of Radiation curing Oct. 1986. pp. 27-31. 1986. |
Jerry March, Advanced Organic Chemistry: Reactions, Mechanisms and Structure, second edition, McGraw-Hill Boo Company, New York, NY 1977, pp. 225-245. 1977. |
Divisions (2)
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Number |
Date |
Country |
Parent |
348944 |
Nov 1994 |
|
Parent |
382311 |
Jul 1989 |
|