Patent · US Active

Uniform solder reflow fixture

US8444043B1 · kind B1 · utility

6Cited by
17References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 31, 2012
Grant dateMay 21, 2013
Priority date
Expiry dateJan 31, 2032

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L2924/3511
  • WIPO fieldSemiconductors
  • WIPO sectorElectrical engineering

Abstract

An array of solder balls is attached to solder pads of one of a first substrate and a second substrate. After aligning the array of solder balls relative to solder pads of the other of the first substrate and the second substrate, a thermal-mass-increasing fixture is placed on a surface of the second substrate to form an assembly of the first substrate, the second substrate, and the array of the solder balls therebetween, and the thermal-mass-increasing fixture. The thermal-mass-increasing fixture is in physical contact with at least a surface of a periphery of the second substrate. The thermal-mass-increasing fixture reduces the cool-down rate of peripheral solder balls after a reflow step, thereby increasing time for deformation of peripheral solder balls during the cool-down and reducing the mechanical stress on the solder balls after the cool-down.

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