Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From carboxylic acid or derivative thereof
Reexamination Certificate
1999-09-27
2001-03-20
Hampton-Hightower, P. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From carboxylic acid or derivative thereof
C528S183000, C528S171000, C528S172000, C528S173000, C528S174000, C528S176000, C528S185000, C528S332000, C528S345000, C528S348000, C528S360000, C528S372000, C525S434000
Reexamination Certificate
active
06204356
ABSTRACT:
TECHNICAL FIELD
The present invention relates to polybenzoxazole resins which are excellent in thermal characteristics, electrical characteristics, mechanical characteristics, and physical characteristics, and which are usable as layer insulation films and protective films for semiconductors, layer insulation films of multilayer circuits, cover coats of flexible copper-clad sheets, solder resist films, liquid crystal-aligned films, etc.
BACKGROUND ART
Hitherto, inorganic insulation films of silicon dioxide or the like prepared by chemical vapor deposition method or the like have been used as layer insulation films for semiconductors. However, inorganic insulation films of silicon dioxide or the like are high in dielectric constant, and use of organic materials is being investigated as insulation films for the purposes of speeding up and higher performance. As organic materials for semiconductors, there are used polyimide resins which are superior in heat resistance, electrical characteristics and mechanical characteristics. With recent enhancement in function and performance of semiconductors, further remarkable improvement in heat resistance, electrical characteristics, moisture-absorption characteristics, and thermal expansion coefficient is demanded, and thus, resins of further higher performances are needed.
Under the circumstances, it has been attempted to use polybenzoxazole resins which are superior to polyimide resins in water absorption and electrical characteristics, as insulation materials for semiconductors. It is easy for polybenzoxazole resins to satisfy only one of thermal characteristics, electrical characteristics, mechanical characteristics and physical characteristics. For example, a polybenzoxazole resin comprising 4,4′-diamino-3,3′-dihydroxybiphenyl and terephthalic acid has much superior heat resistance such as high heat decomposition resistance or high Tg, but is not so good in electrical characteristics such as dielectric constant and dielectric loss tangent. A polybenzoxazole resin comprising 2,2′-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and terephthalic acid shows good electrical characteristics such as low dielectric constant, but is not so good in heat resistance and physical characteristics. Thus, at present, there are obtained no resins which are excellent in all of thermal characteristics, electrical characteristics, mechanical characteristics and physical characteristics.
DISCLOSURE OF THE INVENTION
The object of the present invention is to provide heat resistant resins excellent in all of thermal characteristics, electrical characteristics, physical characteristics and mechanical characteristics in use for semiconductors.
As a result of intensive research conducted in an attempt to solve the above problems, the inventors have found a polybenzoxazole precursor represented by the following general formula (A) and a polybenzoxazole resin represented by the following general formula (D), and have accomplished the present invention.
In the above formulas (A) and (D), n denotes an integer of 2-1000 and X denotes a structure selected from those represented by the following formulas (B):
In the above formulas (B), Y denotes a structure selected from those represented by the following formulas (C), and the hydrogen atom(s) on the benzene ring in these structures may be substituted with at least one group selected from the group consisting of methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, fluorine atom and trifluoromethyl group:
DETAILED DESCRIPTION OF THE INVENTION
The polybenzoxazole precursor of the present invention can be obtained from a bisaminophenol compound having one of the structures represented by the above formulas (B) and 2,2′-bis(trifluoromethyl)-4,4′-biphenylenedicarboxylic acid by conventional methods such as acid chloride method, activated ester method, and condensation reaction in the presence of a dehydration condensation agent such as polyphosphoric acid or dicyclohexylcarbodiimide.
Typical examples of the bisaminophenol compound having one of the structures represented by the formulas (B) which is used in the present invention, are 2,4-diaminoresorcinol, 4,6-diaminoresorcinol, 2,2′-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 2,2′-bis(4-amino-3-hydroxyphenyl)hexafluoropropane, 2,2′-bis(3-amino-4-hydroxyphenyl)propane, 2,2′-bis(4-amino-3-hydroxyphenyl)propane, 3,3′-diamino-4,4′-dihydroxydiphenyl sulfone, 4,4′-diamino-3,3′-dihydroxydiphenyl sulfone, 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3′-dihydroxybiphenyl, 3,3′-diamino-4,4′-dihydroxydiphenyl ether, 4,4′-diamino-3,3′-dihydroxydiphenyl ether, 2,2′-bis(3-amino-4-hydroxy-2-trifluoromethyl)propane, 2,2′-bis(4-amino-3-hydroxy-2-trifluoromethyl)propane, 2,2′-bis(3-amino-4-hydroxy-5-trifluoromethyl)propane, 2,2′-bis(4-amino-3-hydroxy-5-trifluoromethyl)propane, 2,2′-bis(3-amino-4-hydroxy-6-trifluoromethyl)propane, 2,2′-bis(4-amino-3-hydroxy-6-trifluoromethyl)propane, 2,2′-bis(3-amino-4-hydroxy-2-trifluoromethyl)hexafluoropropane, 2,2′-bis(4-amino-3-hydroxy-2-trifluoromethyl)hexafluoropropane, 2,2′-bis(3-amino-4-hydroxy-5-trifluoromethyl)hexafluoropropane, 2,2′-bis(4-amino-3-hydroxy-5-trifluoromethyl)hexafluoropropane, 2,2′-bis(3-amino-4-hydroxy-6-trifluoromethyl)hexafluoropropane, 2,2′-bis(4-amino-3-hydroxy-6-trifluoromethyl)hexafluoropropane, 3,3′-diamino-4,4′-dihydroxy-2,2′-trifluoromethylbiphenyl, 4,4′-diamino-3,3′-dihydroxy-2,2′-trifluoromethylbiphenyl, 3,3′-diamino-4,4′-dihydroxy-5,5′-trifluoromethylbiphenyl, 4,4′-diamino-3,3′-dihydroxy-5,5′-trifluoromethylbiphenyl, 3,3′-diamino-4,4′-dihydroxy-6,6′-trifluoromethylbiphenyl, and 4,4′-diamino-3,3′-dihydroxy-6,6′-trifluoromethylbiphenyl.
Among the methods for producing polybenzoxazole precursors of the present invention, for example, according to the acid chloride method, first, 2,2′-bis(trifluoromethyl)-4,4′-biphenylenedicarboxylic acid chloride which is an acid chloride used, can be obtained by reacting 2,2′-bis(trifluoromethyl)-4,4′-biphenylenedicarboxylic acid, in the presence of a catalyst such as N,N-dimethylformamide, with thionyl chloride in an excess amount at a temperature of room temperature to 75° C., distilling off excess thionyl chloride by heating under reduced pressure, and then recrystallizing the resulting residue by use of a solvent such as hexane. Then, the polybenzoxazole precursor can be obtained by dissolving a bisaminophenol compound usually in a polar solvent such as N-methyl-2-pyrrolidone or N,N-dimethylacetamide, followed by reacting with the 2,2′-bis(trifluoromethyl)-4,4′-biphenylenedicarboxylic acid chloride at a temperature of room temperature to −30° C. in the presence of an acid-acceptor such as pyridine.
The polybenzoxazole resin of the present invention can be obtained by subjecting the resulting polybenzoxazole precursor to condensation reaction by heating or treating with a dehydrating agent in the conventional manner. If necessary, various additives such as surface active agents and coupling agents are added to the resulting resin, and this can be used as layer insulation films and protective films for semiconductors, layer insulation film of multilayer circuits, cover coats of flexible copper-clad sheets, solder resist films, liquid crystal-aligned films, etc.
Furthermore, the precursor of the polybenzoxazole resin in the present invention can be used together with a naphthoquinonediazide compound as a photosensitive agent to provide a photosensitive resin composition.
The polybenzoxazole precursor of the present invention is preferably used in the state of varnish usually by dissolving it in a solvent. Examples of the solvent are N-methyl-2-pyrrolidone, &ggr;-butyrolactone, N,N-dime
Nakajima Michio
Saito Hidenori
Tokuhiro Maki
Watanabe Tsuyoshi
Hampton-Hightower P.
Smith , Gambrell & Russell, LLP
Sumitomo Bakelite Company Limited
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