Low temperature flexible die attach adhesive and articles using same
AssigneeJohnson Matthey PLC
InventorsMy N. Nguyen, Yuan Y. Chien
Life of this patent
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Abstract
Described is a flexible adhesive formulation for bonding a semiconductor device to a flexible substrate and a flexible card containing a semiconductor device which can be processed in a computer.
Claims20
A method of making a cyanate ester flexible which comprises reacting the cyanate ester with at least one flexibilizer having a glass transition temperature less than about 25.degree. C., and comprising at least one member from the group consisting of compounds containing hydroxyl groups having a molecular weight of about 200 to 5000, compounds containing amine and compounds containing epoxide reactive functional groups, or mixtures thereof, to produce a formulation having a viscosity of about 5 to 50 poise and a radius of curvature of about 1 meter or more.
A method of making a cyanate ester flexible which comprises reacting the cyanate ester with at least one flexibilizer having a glass transition temperature less than about 25.degree. C. comprising at least one polyhydroxyl polymer compound having a molecular weight of about 200 to about 5000 from the group of polyhydroxyl polymer compounds within at least one of the following formulas:
- HO--(CH.sub.2).sub.m --CO--O--(CH.sub.2).sub.n OH,
- and
- HO--(CH.sub.2).sub.m --O--C--O--R--C--O--(CH.sub.2).sub.n --OH
- to produce a formulation having a viscosity of about 5 to 50 poise and a radius of curvature of about 1 meter or more.
A method of rendering a cyanate ester flexible which comprises adding to the cyanate ester at least one polyhydroxyl polymer compound having a glass transition temperature less than about 25.degree. C. and a molecular weight range of about 200 to about 5000 within at least one of the following formulas:
- HO--(CH.sub.2).sub.m --CO--O--(CH.sub.2).sub.n --OH
- and
- HO--(CH.sub.2).sub.m --O--C--O--R--C--O--(CH.sub.2).sub.m --OH
- or mixtures thereof, and grafting such polymer to the cyanate ester molecular structure.
A method of making a cyanate ester flexible which comprises reacting 4 to 16 wt. % cyanate ester with 6 to 24 wt. % of at least one flexibilizer having a glass transition temperature less than about 25.degree. C. containing one reactive functional group from the group of hydroxyl, amine and epoxide reactive functional groups, or mixtures thereof, wherein flexibilizers containing hydroxyl reactive functional groups have a molecular weight in the range of about 200 to about 5000.
Dependencies are inferred from the claim text.