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US 11,440,142 B2Granted
Alternative compositions for high temperature soldering applications
AssigneeOrmet Circuits, Inc.
InventorCatherine A Shearer
Life of this patent
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Abstract
Invention compositions are a replacement for high melting temperature solder pastes and preforms in high operating temperature and step-soldering applications. In the use of the invention, a mixture of metallic powders reacts below 350 degrees C. to form a dense metallic joint that does not remelt at the original process temperature.
Claims18
A transient liquid phase sintering (TLPS) composition comprising:
- a) 30-70 percent by weight (wt %) of a low melting point (LMP) particle composition, wherein the particles are selected from the group consisting of particles of at least one LMP metal (Y), at least one alloy of the at least one LMP metal (X/Y), and combinations thereof;
- b) 25-65 wt % of a high melting point (HMP) particle composition, comprising at least one metallic element (M) that is reactive with the at least one LMP metal Y of the (LMP) particle composition at a process temperature T1
- wherein the HMP particle composition has an average particle size that is less than 0.5 times the average particle size of LMP particle composition;
- c) 1-15 wt % of a fluxing vehicle, and d) 10-35 wt % of a metal powder additive A, wherein the metal powder additive A has an average particle size about 0.5 to about 1.75 times the average particle size of the LMP particle composition.
1 more element
Dependencies are inferred from the claim text.