Solder glass with refractory filler
First Claim
Patent Images
1. In a physical blend of particulate lead-borate solder glass and particulate low expansion refractory filler said filler having a coefficient of thermal expansion of less than about 65 ×
- 10.sup.-7 /°
C (0-300°
C), for use in thermal fusion sealing to a workpiece having a lower coefficient of thermal expansion than said solder glass, the improvement wherein said refractory filler has a particle size diameter in excess of about 37 microns and not substantially in excess of 150 microns whereby the flow is increased and the coefficient of thermal contraction is decreased upon fusion sealing when compared to the flow and thermal contraction properties of a blend of the same composition which has a refractory filler particle size substantially less than 37 microns in diameter.
1 Assignment
0 Petitions
Accused Products
Abstract
Disclosed is a physical blend of particulate lead borate sealing glass and particulate refractory filler for use in forming thermal fusion seals for workpieces having a lower coefficient of thermal expansion than the sealing glass. The particulate refractory filler has a particle size diameter in excess of about 37 microns (i.e. plus 400 U.S. Sieve) to lower the expansion while maintaining adequate flow during fusion. The blend is especially useful as a package sealant for electronic components.
-
Citations
9 Claims
-
1. In a physical blend of particulate lead-borate solder glass and particulate low expansion refractory filler said filler having a coefficient of thermal expansion of less than about 65 ×
- 10.sup.-7 /°
C (0-300°
C), for use in thermal fusion sealing to a workpiece having a lower coefficient of thermal expansion than said solder glass, the improvement wherein said refractory filler has a particle size diameter in excess of about 37 microns and not substantially in excess of 150 microns whereby the flow is increased and the coefficient of thermal contraction is decreased upon fusion sealing when compared to the flow and thermal contraction properties of a blend of the same composition which has a refractory filler particle size substantially less than 37 microns in diameter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- 10.sup.-7 /°
Specification