Di- or poly-functional electron deficient olefins coated metal powders for solder paste
View Patent ↗The present invention relates to cured products of di- or poly-functional electron deficient olefins coated onto at least a portion of a surface of metal powders, such as metal powders used as appropriate in the formation of solder alloys, spheres and pastes.
1. A metal particle having di- or poly-functional electron deficient olefin coated on at least a portion of a surface thereof, wherein the di- or poly-functional electron deficient olefin is embraced by the following structure
wherein R 1 is C 1 -C 40 alkyl, C 2 -C 40 alkenyl, or C 3 -C 40 cycloalkyl group, with hydroxyl or alkoxy functionality and/or ether linkages being optional, and n is 2-4.
2. A metal particle according to claim 1 wherein the di- or poly-functional electron deficient olefin has a ceiling temperature below or equal to a melting point of the metal particle.
3. A metal particle according to claim 1 wherein the di- or poly-functional electron deficient olefin further comprises cyanoacrylate monomers embraced by the following structure:
wherein R 1 is C 1 -C 40 alkyl, C 2 -C 40 alkenyl, or C 3 -C 40 cycloalkyl group, with hydroxyl or alkoxy functionality and/or ether linkages being optional, and n is 1.
4. A metal particle according to claim 1 wherein the cyanoacrylate is selected from the group consisting of 1,5-pentanediol bis-cyanoacrylate, 1,6-hexanediol bis-cyanoacrylate, 1,8-octanediol bis-cyanoacrylate, 1,9-nonanediol bis-cyanoacrylate, 1,10-decanediol bis-cyanoacrylate and 1,12-dodecanediol bis-cyanoacrylate.
5. A metal particle according to claim 1 wherein the metal particle is solder.
6. A metal particle according to claim 1 wherein the metal particle is made from elemental metals.
7. A metal particle according to claim 1 wherein the metal particle is made from an alloy.
8. A metal particle according to claim 1 wherein the metal particle is made from an elemental metal selected from the group consisting of tin, silver, copper, lead, zinc, indium, bismuth, and rare earth metals.
9. A metal particle according to claim 1 wherein the metal particle is made from an alloy selected from the group consisting of tin/silver/copper, tin/bismuth, tin/lead, tin/zinc and tin/indium/bismuth alloys.
10. A metal particle according to claim 1 wherein the polymer coating on the metal particle is less than about 5 μm in thickness.
11. A metal particle according to claim 1 wherein the polymer coating on the metal particle is in the range from about 0.0001 to about 3.0 μm in thickness.
12. A metal particle according to claim 1 wherein the polymer coating on the metal particle is in the range from about from 0.001 to about 1 μm in thickness.
13. A solder paste composition comprising the coated metal particle according to claim 1 .
14. A solder paste composition claim 13 wherein the coated metal particles are present in amount of from about 5 to about 98% by weight with respect to the total component.
15. A method of forming a polymer coated metal particle according to claim 1 which includes the steps of:
a) providing a plurality of metal particles;
b) applying a di- or poly-functional electron deficient olefin to substantially coat at least a portion of the surface of the metal particles; and
c) permitting di- or poly-functional electron deficient olefin to cure as a polymer coating on the metal particles.
16. A method of forming a solder paste composition according to claim 13 which includes the steps of:
a) providing solder powder comprising the coated metal particle;
b) providing solder paste components; and
c) blending the polymer coated solder powder with the solder paste components to form a solder paste.