Patent · US Expired

Semiconductor lead frame having connection bar and guide rings

US5723899A · kind A · utility

220Cited by
8References
16Claims
0Family size

Assignees

Inventor

Key dates

Filing dateAug 29, 1995
Grant dateMar 3, 1998
Priority date
Expiry dateAug 29, 2015

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L2924/351
  • WIPO fieldSemiconductors
  • WIPO sectorElectrical engineering

Abstract

A lead frame for semiconductor packages is disclosed. In the lead frame, some of the inner leads in the four sides are extended and provided with connection bars on their inside ends. Alternatively, diagonally arranged tie bars of the lead frame are extended and provided with a rectangular guide ring on their inside ends. The connection bar or guide ring functions as a dam for restricting possible overflow of adhesive, which adhesive is applied on the heat sink for bonding a semiconductor chip to the heat sink. The lead frame of the invention also prevents waste of expensive tape by letting the adhesive tape adhere only to the connection bars or to a given portion of the guide ring when mounting the lead frame to the heat sink and makes it possible higher integration of semiconductor chip by making connection bar and guide ring from the lead or the tie bar.

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