Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2000-02-23
2001-03-27
Truong, Duc (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S087000, C528S104000, C528S129000, C528S137000, C528S154000, C528S155000, C528S403000, C528S425000, C525S480000, C525S481000, C525S482000, C525S534000, C523S423000, C523S424000
Reexamination Certificate
active
06207789
ABSTRACT:
TECHNICAL FIELD
This invention relates to a resin compound suited for encapsulation molding materials, laminating materials or adhesive materials; a resin composition, an encapsulation molding material, a laminating material and an adhesive material which make use of the compound; and an electronic component device whose elements are encapsulated with the encapsulation molding material.
BACKGROUND ART
Molding epoxy resin materials are conventionally in wide use for the encapsulation of device elements in electronic component parts such as transistors and ICs (integrated circuits). This is because the epoxy resin has properties such as molding properties, electrical properties, moisture resistance, heat resistance, mechanical properties and adhesion to component inserts which are all well balanced. In particular, a combination of o-cresol novolak epoxy resin with a phenolic novolak resin is superior in view of the balance of these properties, and is widely used as base resins of encapsulation molding materials.
In recent years, with progress of high-density packaging on printed circuit boards of electronic component parts, conventional through-hole mount packages such as DIP (dual in-line package) have become less used, and small-sized thin surface mount packages such as QFP (quad flat package), SOP (small out-line package), TQFP (thin quad flat package) and TSOP (thin small out-line package) have become more used. The surface mount packages are different in the manner of packaging from the conventional through-hole mount packages. Device elements are provisionally fastened to the wiring board surface and thereafter soldered using a solder bath or a reflowing tool, and hence the whole package is inevitably exposed to soldering heat. Thus, in the case of the surface mount packages, when packages stand moisture-absorbed, the absorbed moisture vaporizes and expands abruptly upon heating at the time of soldering, bringing about the problem of separation at adhesion interface or package cracking.
Accordingly, in order to solve such a problem, the improvement of molding materials has been made energetically. In order to avoid the package cracking during the reflowing process, the epoxy resin, and curing agents of a resin component of molding materials have been reconsidered. As a result, various molding materials compounded with a biphenyl skeleton epoxy resin having a lower hygroscopicity and better adhesive properties than the conventional o-cresol novolak epoxy resin are proposed (e.g., Japanese Patent Applications Laid-open (KOKAI) No. 64-65116 and No. 3-207714). At present, molding materials compounded with this biphenyl skeleton epoxy resin have begun to be put into practical use as materials for the encapsulation of surface mount packages, and have greatly contributed to the improvement in reflow resistance of the surface mount packages.
The molding materials compounded with the biphenyl skeleton epoxy resin have a reflow resistance remarkably superior to that of molding materials compounded with the conventional o-cresol novolak epoxy resin, but have a problem that the resin has a low glass transition point (Tg). Thus, there is a limit in application. Accordingly, a resin having much lower moisture absorption and higher adhesion has been sought.
DISCLOSURE OF THE INVENTION
The present invention was made taking account of the problems discussed above. A first object of the present invention is to provide a novel phenolic resin having a high flexibility in use, a high Tg, a low moisture absorption, high flow properties and superior adhesive properties, which is suited for encapsulation molding materials, laminating materials or adhesive materials, and a resin composition containing such a phenolic resin.
A second object of the present invention is to provide a molding material that may cause no reflow cracking even when soldering is carried out without taking any measure against moisture absorption, such as special pretreatment or wrapping, and an electronic component device whose elements are encapsulated with such a molding material.
The present inventors have found that a phenolic resin containing a specific polycyclic aromatic group is effective for solving the above problems, and have accomplished the present invention on the basis of this finding.
To achieve the first object, the present invention provides a phenolic resin (A) containing in the backbone chain a structural unit represented by the following Formula (I) or (II).
Of the resins having the structural unit of Formula (I) or (II), the phenolic resin (A) of the present invention may preferably be those represented by the following Formula (III) or (IV).
In these formulas, letter symbols m and n indicating the number of repeating units each represent a positive number. In order to achieve the above requirements in a well balanced state, the total of m and n may preferably be not more than 10 on the number average.
Ar represents at least one of divalent organic groups represented by
In the foregoing, R
1
to R
3
are groups each independently selected from a hydrogen atom and an alkyl group having 1 to 9 carbon atoms. In particular, they may each preferably be at least one of a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group and a t-butyl group. Also, the Ar's in one molecule may be the same or different, or may contain two or more types of atomic groups.
Such a phenolic resin (A) may include those containing in the resin backbone chain at least one of the following moieties (1) to (3). Incidentally, the phenolic resin (A) of the present invention may be either random copolymers or block copolymers, without regard to the manner of arrangement of the repeating units.
(1) A moiety in which the following component (V), the following component(s) (VIa) and/or (VIb) and the following component(s) (VII) and/or (VIII) combine at random, regularly or in blocks.
(2) A moiety in which the component (V) and the component(s) (VII) and/or (VIII) combine at random, alternately or in blocks.
(3) A moiety in which the component(s) (VIa) and/or (VIb) and the component(s) (VII) and/or (VIII) combine at random, alternately or in blocks.
The phenolic resins (A) of the present invention may be a mixture of two or more of the resins described above.
Of these phenolic resins (A) of the present invention, a resin composed chiefly of a copolymer in which the component (V), the component(s) (VIa) and/or (VIb) and the component(s) (VII) and/or (VIII) combine at random is particularly preferred.
The total of the components (VII) and (VIII) contained in the phenolic resin (A) may preferably be in an amount of from 2 to 50 mole %, and more preferably from 5 to 40 mole %, of the whole phenolic resin (A). Also, the total of the components (VIa) and (VIb) contained in the phenolic resin (A) may preferably be in an amount of from 10 to 80 mole %, and more preferably from 20 to 60 mole %, of the whole phenolic resin (A).
The phenolic resin (A) may also be used in such a state that it contains an oligomer comprising a random combination of the component (V) and the component(s) (VIa) and/or (VIb) or oligomers each constituted of the component (V), (VIa), (VIb), (VII) or (VIII) alone.
The resin composition containing the phenolic resin (A) have a high flexibility in use, and may widely be used as encapsulation molding materials, laminating materials or adhesive materials. For example, an epoxy resin composition making use of the phenolic resin (A) as a curing agent of epoxy resin has a low molding shrinkage, a high Tg, a low moisture absorption and high flow properties and has a superior adhesion, and hence is suited for encapsulation molding materials, laminating materials and adhesive materials. Besides, it may be used in a vast range of fields such as anisotropic conductive film materials and insulating materials.
In particular, a molding material making use of the phenolic resin (A) of the present invention as a curing agent of epoxy resin and compounded with a filler and so forth is suited for its use as
Akagi Seiichi
Furusawa Fumio
Hagiwara Shinsuke
Sue Haruaki
Tendo Kazuyoshi
Hitachi Chemical Co. Ltd.
Pennie & Edmonds LLP
Truong Duc
LandOfFree
Phenolic resin, resin composition, molding material for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Phenolic resin, resin composition, molding material for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phenolic resin, resin composition, molding material for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2438011