High density interconnect thermoplastic die attach material and

Details High density interconnect thermoplastic die attach material and High density interconnect thermoplastic die attach material and

1991-08-05

1993-07-06

Gallagher, John J.

Adhesive bonding and miscellaneous chemical manufacture

Methods

Surface bonding and/or assembly therefor

156 83, 156155, 156182, 156281, 156305, 1563093, 1563244, 156344, 437209, 437211, B32B 3100

Patent

active

052250237

ABSTRACT:
A mixture for affixing dice to a substrate includes a thermoplastic polyimide, a solvent for the polyimide, and a solvent which does not dissolve the polyimide but adds thixotropicity to the mixture. The mixture is applied to the substrate, the dice are placed thereon, and the solvents are evaporated to bond the dice to the substrate. The bond is radiation hard and exhibits high shear pull strength. A poor solvent for the polyimide, sprayed over the dice and exposed portions of die attach material, causes some polyimide to precipitate out of solution in the exposed portions of die attach material to form a grid that extends between the dice and prevents the dice from "swimming together" during high temperature processing. In a solvent die-attachment method, the substrate is first coated with a mixture of die attach material, and the mixture is dried. Spraying a solvent over the die attach material causes the material to soften so that the dice applied thereto may adhere. The die attach material is then dried to form the bond.

REFERENCES:
patent: 3600246 (1971-08-01), Breen
patent: 3649418 (1972-03-01), James
patent: 3681139 (1972-08-01), Jannett et al.
patent: 4652398 (1987-03-01), Goswami et al.
patent: 4783695 (1988-11-01), Eichelberger et al.
L. Ying, "A Novel Approach--Thermoplastic Die Attach Adhesive", IEEE 36th Electronic Components Conference, Seattle, Wash. May 5-7, 1986, pp. 285-295.

Affiliated with

Also associated with

Rating

High density interconnect thermoplastic die attach material and does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with High density interconnect thermoplastic die attach material and , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High density interconnect thermoplastic die attach material and will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1687068