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US 7,410,673 B2Granted
Smooth board and process for preparing a smooth board
AssigneeSan-Ei Kagaku Co., Ltd.
InventorsKiyoshi Sato, Kazunori Kitamura
Life of this patent
Estimating the term…
Abstract
The thermosetting resin composition which is valuable for an undercoat of a printed wiring board, and does not leave an air bubble in a cured film, and makes the surface polishing easy and can form a smooth printed wiring board comprises (I) an adduct of epoxy resin with unsaturated aliphatic acid, (II) a (meth) acrylate, (III) a radical polymerization initiator, (IV) a crystallizable epoxy resin, and (V) a latent curing agent.
Claims16
A process for preparing a smooth board comprising:
- applying a thermosetting resin composition to a recess on the surface of a substrate;
- carrying out primary curing of said thermosetting resin composition at a primary curing reaction starting temperature;
- polishing the surface of said thermosetting resin composition;
- and
- carrying out secondary curing of said thermosetting resin composition at a temperature of 150 to 200° C.;
- wherein said thermosetting resin composition comprises (I) 100 parts by weight of an adduct of an epoxy resin with an unsaturated aliphatic acid, the unsaturated aliphatic acid being added to 20%-80% of epoxy groups in the epoxy resin, (II) 50 to 300 parts by weight of a (meth) acrylate, (III) 5 to 20 parts by weight of a radical polymerization initiator, (IV) 50 to 200 parts by weight of a crystallizable epoxy resin, and (V) 5 to 30 parts by weight of a latent curing agent, capable of a primary curing reaction at the primary curing reaction starting temperature, and a secondary curing reaction at the temperature of 150 to 200° C., wherein the melting point of component (IV) is in a range of 80 to 110° C. which is lower than the primary curing reaction starting temperature and the viscosity of component (IV) when above its melting point is below 50 (mPa·s).
3 more elements
A process for preparing a smooth printed wiring board comprising:
- applying a thermosetting resin composition to a recess on the surface of a printed wiring board;
- carrying out primary curing of said thermosetting resin composition at a primary curing reaction starting temperature;
- polishing the surface of said thermosetting resin composition;
- and
- carrying out secondary curing of said thermosetting resin composition at a temperature of 150 to 200° C.;
- wherein said thermosetting resin composition comprises (I) 100 parts by weight of an adduct of an epoxy resin with an unsaturated aliphatic acid, the unsaturated aliphatic acid being added to 20%-80% of epoxy groups in the epoxy resin, (II) 50 to 300 parts by weight of a (meth) acrylate, (III) 5 to 20 parts by weight of a radical polymerization initiator, (IV) 50 to 200 parts by weight of a crystallizable epoxy resin, and (V) 5 to 30 parts by weight of a latent curing agent, capable of a primary curing reaction at the primary curing reaction starting temperature, and a secondary curing reaction at the temperature of 150 to 200° C., wherein the melting point of component (IV) is in a range of 80 to 110° C. which is lower than the primary curing reaction starting temperature and the viscosity of component (IV) when above its melting point is below 50 (mPa·s).
3 more elements
Dependencies are inferred from the claim text.