The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 11, 1996
Filed:
Dec. 30, 1994
William K Shu, Sunnyvale, CA (US);
VLSI Technology, Inc., San Jose, CA (US);
Abstract
A process for forming a stress relief layer on a semiconductor die and the resulting structure of the process is described. The stress relief layer is formed on a surface of a die which has already been attached to a die attach pad of a lead frame by a cured epoxy. The purpose of the layer is to act as a stress relief buffer by relieving the die surface from contraction forces created by a plastic material used for encapsulating the die and die attach pad portion of the lead frame, as the plastic material cools following hot injection molding of the material to form the encapsulation. Prior to application of the stress relief material onto the surface of the die, the surface is cleaned to restore its high surface energy. The stress relief material is formed by diluting a silicone compound with a non-reactive diluent such as a silicone oil so that both the surface energy and viscosity of the silicone compound is reduced. Following application of the stress relief material onto the surface of the semiconductor die, the applied layer is cured and as a consequence, the non-reactive diluent evaporates out of the applied stress relief layer.