Stock material or miscellaneous articles – Web or sheet containing structurally defined element or... – Including a second component containing structurally defined...
Reexamination Certificate
2002-10-02
2004-08-24
Chen, Vivian (Department: 1773)
Stock material or miscellaneous articles
Web or sheet containing structurally defined element or...
Including a second component containing structurally defined...
C428S323000, C428S480000, C428S482000, C428S413000, C525S107000, C525S112000, C525S165000, C525S168000, C525S170000, C525S171000, C525S172000
Reexamination Certificate
active
06780502
ABSTRACT:
FIELD OF TECHNOLOGY
This invention relates to an insulating resin composition which is suited for a solder resist or a plating resist in the fabrication of circuit boards and for an insulating film and a photosensitive adhesive for the build-up of multilayer wiring boards for mounting semiconductor devices, to a laminate obtained from said composition and to a cured product of said composition.
BACKGROUND TECHNOLOGY
Following the trend of electronic instruments towards advanced miniaturization and higher performance in recent years, there is a trend toward higher circuit density in the printed circuit boards which are used in electronic instruments and insulating resin materials to be used in printed circuit boards are required to show finer processibility. Patterning by exposure to light and development has been known as an effective technique for fine processing of insulating resin materials; this technique has relied on the use of photosensitive resin compositions and there are presently a number of performance requirements for them, for example, photosensitivity, adhesiveness to the substrate and reliability represented by impact resistance and resistance to plating.
Some insulating materials for printed wiring boards aim at preventing an occurrence of cracking and letting impact resistance and heat resistance coexist with electrical insulation reliability and a technique of incorporating fine particles of crosslinked elastic polymer with an average diameter of 5 &mgr;m or less in an insulating resin composition is disclosed in JP10-147685 A. However, the technique disclosed here yielded dispersed particles still too large in diameter and was unable to realize the coexistence of impact resistance and adhesiveness to the substrate at a sufficiently high level.
On the other hand, a resin composition containing finer particles with a diameter on the order of 70 nm is disclosed in JP8-139457 A. As pointed out later by JP10-182758 A, however, this resin composition cannot provide a sufficiently high peel strength against a plating metal because of insufficient anchor depth and surface roughness when used for insulation. JP10-182758 A discloses a composition formulated by the simultaneous use of a crosslinked elastic polymer with a particle diameter of less than 1 &mgr;m and a matter with a particle diameter of 1-10 &mgr;m. However, the technique disclosed here requires the crosslinked elastic polymer in a relatively large amount and, in the case where a base resin of high heat resistance is used, the incorporation of the crosslinked elastic polymer in question undesirably deteriorates the heat resistance of the insulating resin layer containing such base resin.
SUMMARY OF THE INVENTION
An object of this invention is to provide an insulating resin composition which exhibits excellent adhesiveness to plating metals, heat resistance, resolution characteristics and impact resistance, comprises a crosslinked elastic polymer amenable to selective etching by a permanganate salt that is used in an ordinary plating operation and is suited for an insulating resin layer in a multilayer printed wiring board and to provide a laminate such as dry film formed from said composition.
The insulating resin composition of this invention comprises a crosslinked elastic polymer in a photo-polymerizable or thermally polymerizable resin composition at the rate of 3-10 parts by weight of said crosslinked elastic polymer per 100 parts by weight of a resin component (excluding said crosslinked elastic polymer and including monomers) and said crosslinked elastic polymer has carboxyl groups and is dispersed with an average secondary particle diameter in the range of 0.5-2 &mgr;m. This insulating resin composition can be laminated to a separable support. Furthermore, this invention relates to a polymer or a cured product of the aforementioned insulating resin composition.
DETAILED DESCRIPTION OF THE INVENTION
This invention will be described in detail below.
The insulating resin composition of this invention comprises a crosslinked elastic polymer and a resin component comprising a photo-polymerizable or thermally polymerizable resin or monomer as main ingredients. The resin component here is adequate if it comprises one kind or more of photo-polymerizable or thermally polymerizable resins, oligomers and monomers and is subject to no other restriction. The resin component may be heat-curable or photo-curable or both. Moreover, the resin component may be photosensitive and preferably comprises a carboxyl-containing copolymer which can be developed by an aqueous alkaline solution. Since the resin, oligomer or monomer in the insulating resin composition with the exception of the crosslinked elastic polymer forms a matrix resin phase after polymerization or curing, it is occasionally referred to as resin component or matrix resin component in the following description.
The resin component comprises, as main ingredients, (A) a carboxyl-containing copolymer resulting from the reaction of a diol with a polyvalent carboxylic acid and having a weight average molecular weight of 3,000-40,000 and an acid value of 50-200 mgKOH/g, (B) an unsaturated compound containing one or more photo-polymerizable ethylenic unsaturated linkages in the molecule, (C) an epoxy resin and (D) a photopolymerization initiator and, preferably, the resin component comprises 100 parts by weight of the sum of components (A) and (B), 10-30 parts by weight of component (C) and 0.1-15 parts by weight of component (D).
Diols useful for the preparation of the aforementioned carboxyl-containing copolymer (A) preferably possess a symmetrical molecular structure from the viewpoint of increasing the molecular weight during polymerization because the symmetrical structure renders two hydroxyl groups in a diol molecule equally reactive with two carboxyl groups in a polyvalent carboxylic acid, preferably with two acid anhydride groups in an acid dianhydride.
Concrete examples of diols are ethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, hydrogenated bisphenol A, bis(4-hydroxyphenyl) ketone, bis(4-hydroxyphenyl) sulfone, 2,2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl) ether, bis(4-hydroxyphenyl)hexafluoropropane, 9,9-bis(4-hydroxyphenyl)fluorene, bis(4-hydroxyphenyl)dimethylsilane and 4,4′-biphenol. Examples also include addition compounds of various diglycidyl ethers of the aforementioned diols and (meth)acrylic acid, addition products of alicyclic epoxy compounds and (meth)acrylic acid and addition products of the aforementioned bisphenols and ethylene oxide or propylene oxide. Particularly preferred from the viewpoint of improved sensitivity to light exposure and enhanced resolution are the addition products of (meth)acrylic acid because they possess polymerizable unsaturated linkages and alkali-soluble carboxyl groups in the same molecule after the reaction with a polyvalent carboxylic acid.
Among carboxyl-containing copolymers, resins containing a fluorene skeleton in their unit structure (hereinafter referred to as fluorene skeleton-containing resin) are desirable for manifestation of excellent heat resistance and the use of the carboxyl-containing copolymer in which the fluorene skeleton-containing resin accounts for 30 wt % or more, preferably 50 wt % or more, is effective for manifesting heat resistance of the insulating resin composition.
Particularly preferred fluorene skeleton-containing resins are those which possess a fluorene skeleton and are obtained by the reaction of a fluorene epoxy(meth)acrylate represented by the following general formula (1)
(wherein R
1
and R
2
are hydrogen or methyl group and different from or identical with each other and R
3
-R
10
are hydrogen, an alkyl group with 1-5 carbon atoms or halogen and different from or identical with one another) with a polyvalent carboxylic acid or its acid anhydride. The reaction of a fluorenebisphenol type epoxy(meth)acrylate represented by general formula (1) with a polyvalent carboxylic acid or its acid anhydride yields an alkali-solubl
Fujishiro Koichi
Inaba Shinji
Mizuuchi Kazuhiko
Nakamura Koji
Chen Vivian
Nippon Steel Chemical Co. Ltd.
Rader & Fishman & Grauer, PLLC
LandOfFree
Insulating resin composition and laminate obtained therefrom does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Insulating resin composition and laminate obtained therefrom, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Insulating resin composition and laminate obtained therefrom will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3342027