US5278010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composition for photo imaging
Assignee: International Business Machines Corp
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Filing: 1992-10-05
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Granted: 1994-01-11
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Expires: 2012-10-05
Abstract
Abstract An improved photoimagable cationically polymerizable epoxy based coating material is provided. The material includes an epoxy resin system consisting essentially of between about 10% and about 80% by weight of a polyol resin which is a condensation product of epichlorohydrin and bisphenol A having a molecular weight of between about 40,000 and 130,000; between about 20% and about 90% by weight of an epoxidized octafunctional bisphenol A formaldehyde novolak resin having a molecular weight of 4,000 to 10,000; and if flame retardancy is required between about 35% and 50% by weight of an epoxidized glycidyl ether of tetrabromo bisphenol A having a softening point of between about 60° C. and about 110° C. and a molecular weight of between about 600 and 2,500. To this resin system is added about 0.1 to about 15 parts by weight per 100 parts of resin of a cationic photoinitiator capable of initiating polymerization of said epoxidized resin system upon exposure to actinic radiation; the system being further characterized by having an absorbance of light in the 330 to 700 nm region of less than 0.1 for a 2.0 mil thick film. Optionally a photosensitizer such as perylene and its derivatives or anthracene and its derivatives may be added.
Inventors
- 👤 Richard A. Day
- 👤 Jeffrey D. Gelorme
- 👤 David J. Russell
- 👤 Steven Jo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:00
CPC Classifications
G; G03; G03C; G03C3/00; C; C08; C08G; C08G59/00; C08G59/18; C08G59/20; C08G59/32; C08G59/38; C08L; C08L63/00; G03F; G03F7/00; G03F7/004; G03F7/038; G03F7/0385; H; H05; H05K; H05K3/00; H05K3/22; H05K3/28; H05K3/285; H05K3/287
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
185 words
A printed circuit board comprising: a printed circuit substrate, a photosensitive cationically polymerizable epoxy based imaging system disposed on said substrate and imaged, developed and cured to form a solder mask; said imaging system comprising: an epoxy resin system having solids consisting essentially of between about 10% and about 80% by weight of a polyol resin having epoxy functionality and said polyol resin having a molecular weight of from about 40,000 to about 130,000; between about 20% and about 90% by weight of an epoxidized novolak resin having a molecular weight of from about 4,000 to about 10,000; an effective amount up to about 50% by weight of an epoxidized bromonated bisphenol A resin having a molecular weight of from about 600 to about 2,500 to impart flame resistance; from about 0.1 to about 15 parts by weight of a cationic photoinitiator capable of initiating polymerization in said epoxidized resin system upon exposure to actinic radiation; said resin system being further characterized by having an absorbance of light in the 330 to 700 nm region of less than 0.1 for a 2 mil thick film.
Claim 2
Dependent Claim
185 words
A printed circuit board comprising: a printed circuit substrate, a photosensitive cationically polymerizable epoxy based imaging system disposed on said substrate and imaged, developed and cured to form a solder mask; said imaging system comprising: an epoxy resin system having solids consisting essentially of between about 10% and about 80% by weight of a polyol resin having epoxy functionality and said polyol resin having a molecular weight of from about 40,000 to about 130,000; between about 20% and about 90% by weight of an epoxidized novolak resin having a molecular weight of from about 4,000 to about 10,000; an effective amount up to about 50% by weight of an epoxidized bromonated bisphenol A resin having a molecular weight of from about 600 to about 2,500 to impart flame resistance; from about 0.1 to about 15 parts by weight of a cationic photoinitiator capable of initiating polymerization in said epoxidized resin system upon exposure to actinic radiation; said resin system being further characterized by having an absorbance of light in the 330 to 700 nm region of less than 0.1 for a 2 mil thick film.
Claim 3
Dependent Claim
36 words
The invention as defined in claim 1 wherein the molecular weight of the polyol resin is between about 40,000 and 130,000 and the molecular weight of the polyepoxy resin is between about 4,000 and about 10,000.
Claim 4
Dependent Claim
14 words
The invention as defined in claim 1 wherein the photoinitiator is a sulfonium salt.
Claim 5
Dependent Claim
20 words
The invention as defined in claim 1, wherein the polyol resin is a condensation product of epichlorohydrin and bisphenol A.
Claim 6
Dependent Claim
21 words
The invention as defined in claim 1, wherein the epoxidized novolak resin is an epoxidized octafunctional bisphenol A formaldehyde novolak resin.
Claim 7
Dependent Claim
23 words
The invention as defined in claim 1, wherein the epoxidized bromonated bisphenol A resin is an epoxidized glycidyl ether of tetrabromo bisphenol A.
Claim 8
Dependent Claim
149 words
A printed circuit board comprising a printed circuit substrate, a photosensitive cationically polymerizable epoxy based imaging system disposed on said substrate and imaged, developed and cured to form a solder mask; said imaging system comprising an epoxy resin system having solids consisting essentially of between about 10% and about 80% by weight of a polyol resin having epoxy functionality and a molecular weight of between about 40,000 and about 130,000; between about 20% and about 90% by weight of an epoxidized novolak resin having a molecular weight between about 4,000 and about 10,000; from about 0.1 to about 15 parts by weight of a cationic photoinitiator capable of initiating polymerization in said epoxidized resin system upon exposure to actinic radiation; said resin system being further characterized by having an absorbance of light in the 330 to 700 nm region of less than 0.1 for a 2 mil thick film.
Claim 9
Dependent Claim
149 words
A printed circuit board comprising a printed circuit substrate, a photosensitive cationically polymerizable epoxy based imaging system disposed on said substrate and imaged, developed and cured to form a solder mask; said imaging system comprising an epoxy resin system having solids consisting essentially of between about 10% and about 80% by weight of a polyol resin having epoxy functionality and a molecular weight of between about 40,000 and about 130,000; between about 20% and about 90% by weight of an epoxidized novolak resin having a molecular weight between about 4,000 and about 10,000; from about 0.1 to about 15 parts by weight of a cationic photoinitiator capable of initiating polymerization in said epoxidized resin system upon exposure to actinic radiation; said resin system being further characterized by having an absorbance of light in the 330 to 700 nm region of less than 0.1 for a 2 mil thick film.
Claim 10
Dependent Claim
20 words
The invention as defined in claim 7, wherein the polyol resin is a condensation product of epichlorohydrin and bisphenol A.
Claim 11
Dependent Claim
21 words
The invention as defined in claim 7, wherein the epoxidized novolak resin is an epoxidized octafunctional bisphenol A formaldehyde novolak resin.
Claim 12
Dependent Claim
205 words
A printed circuit board comprising, a printed circuit substrate, a photosensitive cationically polymerizable epoxy based imaging system disposed on said substrate and imaged, developed and cured to form a solder mask; said imaging system comprising an epoxy resin system having solids consisting essentially of: between about 10% and about 80% by weight of a polyol resin having epoxy functionality wherein said polyol resin is a condensation product of epichlorohydrin and bisphenol A and said polyol resin having a molecular weight of from about 40,000 to about 130,000; between about 20% and about 90% by weight of an epoxidized octafunctional bisphenol A formaldehyde novolak resin having a molecular weight of from about 4,000 to about 10,000; an effective amount up to about 50% by weight of an epoxidized glycidyl ether of tetrabromo bisphenol A resin having a molecular weight of from about 600 to about 2,500 to impart flame resistance; from about 0.1 to about 15 parts by weight of a cationic photoinitiator capable of initiating polymerization in said epoxidized resin system upon exposure to actinic radiation; said resin system being further characterized by having an absorbance of light in the 330 to 700 nm region of less than 0.1 for a 2 mil thick film.
Claim 13
Dependent Claim
205 words
A printed circuit board comprising, a printed circuit substrate, a photosensitive cationically polymerizable epoxy based imaging system disposed on said substrate and imaged, developed and cured to form a solder mask; said imaging system comprising an epoxy resin system having solids consisting essentially of: between about 10% and about 80% by weight of a polyol resin having epoxy functionality wherein said polyol resin is a condensation product of epichlorohydrin and bisphenol A and said polyol resin having a molecular weight of from about 40,000 to about 130,000; between about 20% and about 90% by weight of an epoxidized octafunctional bisphenol A formaldehyde novolak resin having a molecular weight of from about 4,000 to about 10,000; an effective amount up to about 50% by weight of an epoxidized glycidyl ether of tetrabromo bisphenol A resin having a molecular weight of from about 600 to about 2,500 to impart flame resistance; from about 0.1 to about 15 parts by weight of a cationic photoinitiator capable of initiating polymerization in said epoxidized resin system upon exposure to actinic radiation; said resin system being further characterized by having an absorbance of light in the 330 to 700 nm region of less than 0.1 for a 2 mil thick film.
Claim 14
Dependent Claim
166 words
A printed circuit board comprising a printed circuit substrate, a photosensitive cationically polymerizable epoxy based imaging system disposed on said substrate and imaged, developed and cured to form a solder mask; said imaging system comprising an epoxy resin system having solids consisting essentially of: between about 10% and about 80% by weight of a polyol resin having epoxy functionality wherein said polyol resin is a condensation product of epichlorohydrin and bisphenol A and a molecular weight of between about 40,000 and about 130,000; between about 20% and about 90% by weight of an epoxidized octafunctional bisphenol A formaldehyde novolak resin having a molecular weight between about 4,000 and about 10,000; from about 0.1 to about 15 parts by weight of a cationic photoinitiator capable of initiating polymerization in said epoxidized resin system upon exposure to actinic radiation; said resin system being further characterized by having an absorbance of light in the 330 to 700 nm region of less than 0.1 for a 2 mil thick film.
Claim 15
Dependent Claim
166 words
A printed circuit board comprising a printed circuit substrate, a photosensitive cationically polymerizable epoxy based imaging system disposed on said substrate and imaged, developed and cured to form a solder mask; said imaging system comprising an epoxy resin system having solids consisting essentially of: between about 10% and about 80% by weight of a polyol resin having epoxy functionality wherein said polyol resin is a condensation product of epichlorohydrin and bisphenol A and a molecular weight of between about 40,000 and about 130,000; between about 20% and about 90% by weight of an epoxidized octafunctional bisphenol A formaldehyde novolak resin having a molecular weight between about 4,000 and about 10,000; from about 0.1 to about 15 parts by weight of a cationic photoinitiator capable of initiating polymerization in said epoxidized resin system upon exposure to actinic radiation; said resin system being further characterized by having an absorbance of light in the 330 to 700 nm region of less than 0.1 for a 2 mil thick film.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-10 | 1997-07-12 | 1998-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-10 | 2001-07-12 | 2002-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-10 | 2005-07-12 | 2006-01-11 | $7700.00 | Window Closed / Lapsed |