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:
Jan. 14, 1997
Filed:
May. 02, 1995
Michael D Rostoker, San Jose, CA (US);
Chok J Chia, Campbell, CA (US);
Seng-Sooi Lim, San Jose, CA (US);
LSI Logic Corporation, Milpitas, CA (US);
Abstract
A dambar-less leadframe is sandwiched between two printed circuit boards (PCBs). The PCBs form a major portion of the package body, and isolate the leadframe leads from plastic molding compound. In one embodiment, an upper PCB (substrate) is formed as a ring, having an opening containing a heat sink element. A lower PCB is also formed as a ring, and has a smaller opening for receiving a die. The back face of the die is mounted to the heat sink. The exposed front face of the die is wire bonded to inner ends of conductive traces on the exposed face of the lower PCB. The outer ends of the traces are electrically connected to the leadframe leads by plated-through vias extending through the two PCBs. The plated-through vias additionally secure the sandwich structure together. Plastic molding compound is injection/transfer molded over the front face of the die and the bond wires, forming a partially-molded package. In another embodiment, the upper PCB is a solid planar element. The back face of the die is mounted to the inside surface of the upper PCB. The die, die-receiving area, and/or package body shape have a 'certain non-square' shape (i.e., triangle, trapezoid, parallelogram, greatly-elongated rectangle, etc.).