Patent · US Expired

Molding process for encapsulating semiconductor devices using a thixotropic compound

US4996170A · kind A · utility

15Cited by
8References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 30, 1990
Grant dateFeb 26, 1991
Priority date
Expiry dateJul 30, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L2924/0002
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

An improved molding process utilizes a thixotropic compound. The thixotropic compound is transferred from a feed pot to a manifold having at least one outlet. The manifold is held at a temperature in which the thixotropic compound is not cured. The manifold is engaged with a mold that has an inlet opening that runs to a mold cavity, such that the outlet of the manifold and the inlet of the mold communicate with each other. The thixotropic compound is transferred from the manifold into the mold cavity, which is held at a temperature at which the thixotropic compound is cured. The manifold and the mold are then separated, drawing the thixotropic compound near the exit of the feed runners into the manifold, thus making a clean separation.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.