There are many ways to form solder deposits on wafers. Printing solder paste and reflowing into an array of bumps is both quick and easy. Approximately six percent of the total market is formed this way; however, 70 percent of the short runs and prototypes are candidates for stenciling solder paste to form the array of bumps. S3X-BF70M and S3X-BF200N series wafer bumping paste is the standard in wafer bumping processes throughout most companies in Asia.
For ordinary 250 μm bump sizes, the S3X-BF70M series is ideal. The paste offers superior cleaning performance in a SAC305 powder with a 20~38 μm diameter. For super fine 100 μm bump sizes, Christopher offers the S3X-BF200M series with a SAC305 powder and 5~20 μm diameter.
For further information, visit http://www.christopherweb.com