Patent · US Expired

Method for forming a flip chip on leadframe semiconductor package

US6550666B2 · kind B2 · utility

210Cited by
24References
23Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 21, 2001
Grant dateApr 22, 2003
Priority date
Expiry dateAug 21, 2021

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L2924/181
  • WIPO fieldSemiconductors
  • WIPO sectorElectrical engineering

Abstract

A predetermined amount of solder (315) is deposited on the free ends of copper posts (310) extending from die pads of a semiconductor die (305). The solder (315) is coated with flux (320) and the semiconductor die (305) is placed on a leadframe (100) with the solder deposits (315) abutting interconnect locations (335) on inner lead portions (101). When reflowed, the solder deposits (315) melt and with the assistance of the flux (320) forms solder interconnects between the free ends of the copper posts (310) and the interconnect locations (335). Due to the predetermined amount of solder (315) deposited on the free ends of the copper posts (310), the molten solder (315) tends not to flow away from the interconnect location (335). Thus, advantageously allowing a substantial portion of the solder deposit (315) to remain at the interconnect locations (335) to form solder interconnects.

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