Monodisperse spherical metal particles and manufacturing method therefor

1. A method of manufacturing monodisperse spherical metal particles, comprising passing liquid metal through a porous membrane and dispersing the resulting liquid metal particles directly in a continuous liquid phase.

2. The method according to claim 1 , wherein the porous membrane is a porous glass membrane.

3. The method of claim 2 , wherein the monodisperse spherical metal particles have a mean particle diameter in the range of 0.1-160 μm.

4. The method according to claim 1 , wherein the liquid metal is a metal having a melting point of at most 250° C. which has been melted.

5. The method according to claim 1 , wherein the continuous liquid phase further contains a dispersant.

6. The method according to claim 5 , wherein the dispersant is a metallic soap.

7. The method of claim 1 , wherein the monodisperse spherical metal particles have a mean particle diameter (particle diameter corresponding to 50 vol % in the cumulative volume distribution) in the range of 0.1-1000 μm.

8. The method of claim 1 , wherein the monodisperse spherical metal particles have a cumulative volume distribution in which:

(a) a particle diameter corresponding to 10 vol % in the distribution is at least 60% of the particle diameter corresponding to 50 vol % in the distribution; and

(b) a particle diameter corresponding to 90 vol % in the distribution is at most 125% of the particle diameter corresponding to 50 vol % in the distribution.

9. The method of claim 8 , wherein a particle diameter corresponding to 50 vol % in the distribution is 10 μm or smaller.

10. The method of manufacturing monodisperse spherical metal particles as claimed in claim 1 as solder balls for BGA/CSP type packages.