skip to main content
DOE Patents title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Method and apparatus for jetting, manufacturing and attaching uniform solder balls

Abstract

An apparatus and process are disclosed for jetting molten solder in the form of balls directly onto all the metallized interconnects lands for a ball grid array package in one step with no solder paste required. Molten solder is jetted out of a grid of holes using a piston attached to a piezoelectric crystal. When voltage is applied to the crystal it expands forcing the piston to extrude a desired volume of solder through holes in the aperture plate. When the voltage is decreased the piston reverses motion creating an instability in the molten solder at the aperture plate surface and thereby forming spherical solder balls that fall onto a metallized substrate. The molten solder balls land on the substrate and form a metallurgical bond with the metallized lands. The size of the solder balls is determined by a combination of the size of the holes in the aperture plate, the duration of the piston pulse, and the displacement of the piston. The layout of the balls is dictated by the location of the hooks in the grid. Changes in ball size and layout can be easily accomplished by changing the grid plate. This invention also allows simple preparation ofmore » uniform balls for subsequent supply to BGA users. 7 figs.« less

Inventors:
; ;
Issue Date:
Research Org.:
AT&T
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
321318
Patent Number(s):
5855323
Application Number:
PAN: 8-746,602
Assignee:
Sandia Corp., Albuquerque, NM (United States)
DOE Contract Number:  
AC04-76DP00789
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 5 Jan 1999
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; ELECTRONIC CIRCUITS; LIQUID METALS; SOLDERING; METALLURGICAL FLUX; SIZE; WELDING MACHINES; DESIGN

Citation Formats

Yost, F G, Frear, D R, and Schmale, D T. Method and apparatus for jetting, manufacturing and attaching uniform solder balls. United States: N. p., 1999. Web.
Yost, F G, Frear, D R, & Schmale, D T. Method and apparatus for jetting, manufacturing and attaching uniform solder balls. United States.
Yost, F G, Frear, D R, and Schmale, D T. Tue . "Method and apparatus for jetting, manufacturing and attaching uniform solder balls". United States.
@article{osti_321318,
title = {Method and apparatus for jetting, manufacturing and attaching uniform solder balls},
author = {Yost, F G and Frear, D R and Schmale, D T},
abstractNote = {An apparatus and process are disclosed for jetting molten solder in the form of balls directly onto all the metallized interconnects lands for a ball grid array package in one step with no solder paste required. Molten solder is jetted out of a grid of holes using a piston attached to a piezoelectric crystal. When voltage is applied to the crystal it expands forcing the piston to extrude a desired volume of solder through holes in the aperture plate. When the voltage is decreased the piston reverses motion creating an instability in the molten solder at the aperture plate surface and thereby forming spherical solder balls that fall onto a metallized substrate. The molten solder balls land on the substrate and form a metallurgical bond with the metallized lands. The size of the solder balls is determined by a combination of the size of the holes in the aperture plate, the duration of the piston pulse, and the displacement of the piston. The layout of the balls is dictated by the location of the hooks in the grid. Changes in ball size and layout can be easily accomplished by changing the grid plate. This invention also allows simple preparation of uniform balls for subsequent supply to BGA users. 7 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1999},
month = {1}
}