Die attach adhesive composition
AssigneeE. I. Du Pont de Nemours and Company
InventorsSara T. Joslin, Christine M. Rosell, Jerome D. Smith
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Abstract
A composition which is useful for bonding integrated circuits to inorganic dielectric substrates comprising an admixture of finely divided particles of a thermally conductive metal or metal-containing compound, non-aqueously milled amorphous glass frit and fatty acid-based surfactant dispersed, in a solution of primary organic solvent selected from ethylene glycol monobutyl ether acetate, dimethyl adipate and mixtures thereof and optionally minor amounts of certain secondary solvents and an acrylic polymer which is free of polar functional groups.
Claims15
A composition which is useful for bonding integrated circuits to inorganic dielectric substrates comprising an admixture of
- a. finely divided particles of metal and/or metal containing compound having a thermal conductivity of at least 0.2 Wcm.sup.-1 K.sup.-1 at 298 K at least 90% of the metal particles having a maximum dimension of less than 15 .mu.m;
- b. finely divided particles of a non-aqueously milled crystallizable amorphous glass frit which (1) has a DTA softening point of 300.degree.-400.degree. C., (2) has a contact angle with gold of no more than 60.degree. when measured at a peak temperature of 400.degree. C., and (3) is substantially free of alkali metal and halogen ions, the volume ratio of a. to b. being from 0.75 to 5.0;
- c. 0.2-2% weight of a surfactant selected from long chain carboxylic acids, alkyl esters of long chain carboxylic acids, and mixtures thereof, a., b., and c. being dispersed in
- d. organic medium comprising a solution of
- (1) acrylic polymer free of polar functional groups dissolved in
- (2) a solvent consisting essentially of (a) 60-100% wt. of a primary solvent selected from ethylene glycol monobutyl ether acetate, dimethyl adipate and mixtures thereof and (b) 40-0% wt. of a secondary solvent selected from glycol monoethers, terpineol, 2,2,4-trimethyl-1,2-pentanediol monoisobutyrate, tridecyl acetate and mixtures thereof, the total composition containing 0.5--5% wt. acrylic polymer, the composition having a yield stress of at least 200 dynes/cm.
Dependencies are inferred from the claim text.