Sintering paste
A sintering powder comprising: a particulate having a mean longest diameter of less than 10 microns, wherein at least some of the particles forming the particulate comprise a metal at least partially coated with a capping agent. A sintering paste and sintering film comprising the sintering powder. A method for making a sintered joint by sintering the sintering powder, paste, or film in the vicinity of two or more workpieces.
1. A sintering paste comprising:
a sintering powder, wherein the sintering powder comprises,
a particulate comprising particles having a mean longest diameter of less than 10 microns, wherein at least some of the particles forming the particulate comprise a metal at least partially coated with a capping agent,
wherein the particulate comprises a first type of particles having a longest diameter of from 1 to 100 nm and a second type of particles having a longest diameter of from greater than 100 nm to 50 microns,
wherein the particulate comprises from 81 to 99 wt % of the first type of particles and from 1 to 19 wt % of the second type of particles;
an organosilver compound in a concentration of 1-25 wt %; and
a solvent.
2. The sintering paste of claim 1 , wherein the organosilver compound comprises one or more of silver oxalate, silver lactate, silver succinate, silver neodecanoate, silver citrate and silver stearate.
3. The sintering paste of claim 1 , further comprising a fatty acid.
4. The sintering paste of claim 1 , further comprising a peroxide.
5. The sintering paste of claim 1 , wherein the paste is resin free.
6. The sintering paste of claim 1 , wherein the paste is pin transferable and/or exhibits a thermal conductivity of greater than 200 W/mK and/or is capable of providing a die shear strength of from 25 to 45 MPa.
7. The sintering paste of claim 1 , wherein the sintering paste is applied in a sintering film.
8. The sintering paste of claim 1 , further comprising at least one of an activator, a rheology modifier, and a surfactant.
9. The sintering paste of claim 1 , wherein the first type of particles and the second type of particles are at least partially coated with the same capping agent.
10. The sintering paste of claim 1 , wherein the particulate of particles comprises 0.1 to 3 wt % capping agent.
11. The sintering paste of claim 10 , wherein the second type of particles does not contain capping agent.
12. The sintering paste of claim 10 , wherein the capping agent is octylamine.
13. The sintering paste of claim 1 comprising 2-10 wt % of the organosilver compound.
14. The sintering paste of claim 1 , further comprising a binder.
15. The sintering paste of claim 14 , wherein the binder comprises an epoxy-based resin.
16. The sintering paste of claim 1 , wherein the solvent comprises at least one of a monoterpene alcohol, a glycol, and glycol ether.
17. The sintering paste of claim 1 comprising at least one of:
i. from 1 to 15 wt % binder;
ii. from 1 to 15 wt % solvent;
iii. up to 1 wt % rheology modifier;
iv. up to 1 wt % activator; and
v. up to 6 wt % surfactant.
18. The sintering paste of claim 1 , wherein the organosilver compound comprises silver oxalate.
19. The sintering paste of claim 1 , wherein the organosilver compound comprises silver lactate.
20. The sintering paste of claim 13 , wherein the organosilver compound comprises silver oxalate.