Patent · US Expired

Method and apparatus for forming solder bumps

US6056191A · kind A · utility

49Cited by
7References
21Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 30, 1998
Grant dateMay 2, 2000
Priority date
Expiry dateApr 30, 2018

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH05K2203/0113
  • WIPO fieldMachine tools
  • WIPO sectorMechanical engineering

Abstract

The present invention discloses a method and apparatus for forming solder bumps by a molten solder screening technique in which a flexible die head constructed of a metal sheet is utilized for maintaining an intimate contact between the die head and a solder receiving mold surface. The flexible die head, when used in combination with a pressure means, is capable of conforming to any curved mold surface as long as the curvature is not more than 2.5 .mu.m per inch of die length. The present invention further provides a method and apparatus for filling a multiplicity of cavities in a mold surface by providing a stream of molten solder and then intimately contacting the surface of the molten solder with a multiplicity of cavities such that the molten solder readily fills the cavities. The apparatus further provides means for removing excess molten solder from the surface of the mold without disturbing the molten solder already filled in the cavities. The present invention further discloses a flexible die for dispensing molten solder consisting of a die body that is constructed of a metal sheet capable of flexing of not less than 1.5 .mu.m per inch of die length, a gate opening for rece…

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