International Business Machines Corporation

Endicott Interconnect Technologies, Inc.

Richard Allen Day

David John Russell

Donald Herman Glatzel

John R Mertz

Jeffrey Donald Gelorme

Robert David Allen

Gregory Michael Wallraff

Norman A Card

John Joseph Konrad

William Dinan Hinsberg

Kevin Taylor Knadle

Kristen Ann Stauffer

Konstantinos I Papathomas

Ramesh R Kodnani

Stephen Joseph Fuerniss

Timothy Leroy Wells

Jeffrey McKeveny

William D Hinsberg, Iii

Logan L Simpson

Lawrence Robert Blumberg

Steven J Wih

Stephen J Witt

Steven Jo

Joel L Roth

A method of making a circuitized substrate in which the substrate includes circuit elements having exposed surfaces defined by two thin layers of permanent photoimaged solder mask material which are applied through fine mesh screens. The use of two thin layers assures effective coverage of the material to precisely expose the desired surfaces in high-density circuit patterns. A circuitized substrate assembly and an information handling system adapted for having one or more such assemblies therein are also provided.

Circuitized substrate assembly

A printed wiring board is formed from two or more layers, one of which has circuit lines formed thereon, and wherein the surfaces of the circuit lines are roughened only in areas that require good copper to laminate adhesion. The remainder of the circuit line surfaces are smooth. Thus, those areas for propagation of the signal on signal lines have the circuit lines smooth to maximize the signal propagation effect, while those areas where the signal propagation is not critical are rough, which improves the adhesion of one layer to another. On the voltage planes, the surface in those regions opposite the smooth surfaces of the signal planes is smooth. Thus, these areas of the voltage planes can be maintained smooth while the other areas of the surface of the voltage planes can be roughened, providing good adhesion to the adjoining dielectric material.

Selectively roughening conductors for high frequency printed wiring boards

An improved photoimagable cationically polymerizable epoxy based solder mask is provided that contains a non-brominated epoxy resin system and from about 0.1 to about 15 parts, by weight per 100 parts of resin system, of a cationic photoinitiator. The non-brominated epoxy-resin system has solids that are comprised of from about 10% to about 80% by weight, of a polyol resin having epoxy functionality; from about 0% to about 90% by weight of a polyepoxy resin; and from about 25% to about 85% by weight of a difunctional epoxy resin. The photosensitive cationically polymerizable epoxy based system is especially useful as a solder mask and does not contain bromine.

Composition for photoimaging

Through-holes in a substrate are masked during plating of the substrate by substantially filling the through-holes with a liquid material, followed by applying a photoimageable material to an external surface of the substrate, forming a predetermined pattern in the photoimageable material, circuitizing the predetermined pattern and then removing both the photoimageable material and the liquid material from the through-holes.

Method for masking a hole in a substrate during plating

Plates that are especially suitable for use in liquid crystal display structures comprising a transparent substrate; a dark mesh material on the substrate having a thickness of about 1 to about 30 microns; wherein the dark mesh material comprises a photocured photoimageable organic polymeric composition and a coloring agent; and wherein the dark mesh material has an optical density of about 0.5 to about 3 in the visible light range; and a polarizing layer are provided along with methods for their fabrication.

Plate for liquid crystal display, method and polymeric compositions

According to the present invention, an improved photoimagable cationically polymerizable epoxy based solder mask is provided that contains a non-brominated epoxy resin system and from about 0.1 to about 15 parts, by weight per 100 parts of resin system, of a cationic photoinitiator. The non-brominated epoxy-resin system has solids that are comprised of from about 10% to about 80% by weight, of a polyol resin having epoxy functionality; from about 0% to about 90% by weight of a polyepoxy resin; and from about 25% to about 85% by weight of an difunctional epoxy resin. Since the photosensitive cationically polymerizable epoxy based solder mask does not contain bromine, it is particularly advantageous halogens in waste processing chemicals or in incinerated scrap circuit boards are regulated by environmental concerns. The photosensitive cationically polymerizable non-brominated epoxy based solder mask has a glass transition temperature greater than about 100&deg; C., preferably greater than about 110&deg; C. The solder mask dries to a tack-free film; thus, artwork used in the photoimaging process will not stick to the dried soldermask film. The polyol resin which is a condensation product of epichlorohydrin and bisphenol A, has a weight average molecular weight of between about 40,000 and 130,000. The polyepoxy resin is an epoxidized multi-functional bisphenol A formaldehyde novolak resin having a weight average molecular weight of 4,000 to 10,000. The epoxidized diglycidyl ether of bisphenol A has two epoxide groups per molecule, a melting point of between about 80&deg; C. and about 110&deg; C. and a weight average molecular weight of between about 600 and 2,500. The invention also relates to a cationically polymerized solder mask.

An improved photoimagable cationically polymerizable epoxy based coating material is provided, that is suitable for use on a variety of substrates including epoxy-glass laminate boards cured with dicyandiamide. 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; and between about 35% and 72% by weight of an epoxidized glycidyl ether of a brominated bisphenol A having a softening point of between about 60&deg; C. and about 110&deg; C. and a molecular weight of between about 600 and 2,500. Optionally, a third resin may be added to the resin system. 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.

An improved photoimagable cationically polymerizable epoxy based coating material is provided, that is suitable for use on a variety of substrates including epoxy-glass laminate boards cured with dicyandiamide. 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; and between about 35% and 72% by weight of an epoxidized glycidyl ether of a brominated bisphenol A having a softening point of between about 60.degree. C. and about 110.degree. C. and a molecular weight of between about 600 and 2,500. Optionally, a third resin may be added to the resin system. 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.

The present invention provides a photoimageable soldermask that may be applied using aqueous solvents, thereby reducing the emission of organic solvents. The soldermask contains an epoxy based resin system comprised of at least one epoxy resin, a coating agent, and preferably a cationic photoinitiator and a dye.

Aqueous soldermask

According to the present invention, good image resolution of a cationically polymerized epoxy based coating, such as a solder mask or dielectric or etch resist, is provided by combining a cationically polymerized epoxy based coating with conventional epoxy glass substrates cured with a curing agent that does not produce basic reaction products. Preferably, the coating is photoimagable. The method for making the same is also provided. The coating material includes an epoxy resin system comprising between from about 10% to about 90%, preferably about 28% to about 57% by weight of a polyol epoxy resin, and from about 10% to about 90%, preferably about 43% to 72% by weight, of a brominated epoxy resin. Optionally, a polyepoxy resin or an epoxy creosol novolak resin is added to the resin system. The polyepoxy resin may be added from an effective amount up to less than 90% of the resin system; the epoxy creosol novolak may be added from an effective amount up to about 80 pph.

Composition for photo imaging

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.degree. C. and about 110.degree. 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.

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, and an effective amount of thixatropic agent. Optionally a photosensitizer such as perylene and its derivatives or anthracene and its derivatives may be added.

An improved photoimagable cationically polymerizable epoxy based coating material is provided, that is suitable for use on a variety of substrates. The material includes an epoxy resin system consisting essentially of between about 10% and about 80% by weight of a polyol resin which preferably is a condensation product of epichlorohydrin and bisphenol A having a molecular weight of between about 40,000 and 130,000; and between about 35% and 72% by weight of an epoxidized glycidyl ether of a brominated bisphenol A having a softening point of between about 60.degree. C. and about 110.degree. C. and a molecular weight of between about 600 and 2,500. A third resin, either an epoxy cresol novolak or a polyepoxy resin, is also added to the resin system. 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.

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Whitney Point, NY, United States of America

Richard Allen Day