Thermoplastic film die attach adhesives

Claim 1

Electrically conductive adhesive film comprising a mixture of: (A) a normally solid thermoplastic polyimide polymeric binder having a weight average molecular weight of about 100,000 to about 150,000 synthesized from: (1) a dianhydride having the structure: ##STR10## wherein A is a tetravalent residue of benzene, benzophenone, or an aromatic dietherdianhydride having the formula: ##STR11## where K is a substituted or unsubstituted group of the formula: ##STR12## where W is --O--, --S--, --SO 2 , linear or branched alkylene or alkenylene having 1 to 8 carbons or --(R)C(L)--where R and L can be the same or different lower alkyls having 1 to 8 carbons or aryl groups having 6 to 24 carbon atoms and m is 0 or 1; (2) a meta disubstituted benzene diamine having the structure: ##STR13## wherein Y is a divalent unsubstituted meta-phenylene radical or a meta-phenylene radical substutited with at least one lower alkyl group containing 1 to about 8 carbon atoms and T is selected from the group consisting of --O--, --S--, --SO--, --SO 2 --, --CO-- and lower alkylene having 1 to about 8 carbon atoms; and (3) a polysiloxanediamine having the structure: ##STR14## wherein Q is arylene, Z is a divalent oxygen, sulfide, sulfone, sulfoxide or carboxylic ester or amide group, D is a hydrocarbylene group, R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are the same or different alkyls having 1 to 8 carbons, and x, y and z are integers having values of 0 to 100; and (B) sufficient flake to provide a conducting medium, with the proviso that about 20 to about 50 mole percent of the total diamine content is a diamine having the structure of (2)