| Title |
Investigation of Process Parameters on Lead-free Solder Balls Fabricated by Droplet-Based Manufacturing Process |
| Authors |
엄호천(Ho Chun Eom); 조경목(Kyung Mox Cho); 송인혁(In Hyuck Song); 한유동(Yoo Dong Hahn) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
DBM(Droplet-Based Manufacturing); BGA(Ball Grid Array); Lead-free solder ball; Sn-Ag; Sn-Ag-Zn; Orifice size; Pressure difference; Frequency; Size and size distribution |
| Abstract |
Uniform droplet of lead-free solder balls was produced by using the Droplet-Based Manufacturing(DBM) process. Compositions of solder were Sn, Sn-3.6 wt.% Ag, and Sn-3.8 wt.%Ag-0.6 wt.% Zn. Effect of parameters such as orifice size, pressure difference, and frequency on the solder ball production was also investigated. Mean size, size distribution, and surface defect of solder balls were analyzed with variations of the parameters. Droplet spacing decreased with increasing frequency and decreasing pressure difference. Thus the size of solder ball decreased with increasing frequency and decreasing pressure difference. Size distribution fell within the narrow range of ±5% from the mean diameter of solder balls. The experimentally measured diameter of the solder balls fabricated by DBM process coincided quite well with the theoretically anticipated value of d_d=A d_o^2/3. |