1. Field of the Invention
The present invention relates to a solder ball loading method for loading a solder ball onto a printed wiring board. The solder ball is to be made into a solder bump.
2. Background Art
Solder bumps are used for electrical connection between a printed wiring board and an IC chip. The solder bumps are formed through a process of printing a flux on a connection pad formed on a printed wiring board, a process of loading a solder ball on the connection pad with the flux printed thereon, or a process of forming a solder bump from the solder ball by performing reflow.
In the aforementioned process of loading the solder ball on the printed wiring board, a mask having openings for dropping the solder ball on the printed wiring board is used. The mask includes a spacer, formed from a plurality of protrusions, such that when the solder balls are loaded on the printed wiring board, the mask is aligned with the printed wiring board the protrusions are disposed between adjacent electrode portions. Japanese Patent Application Publication No. 2006-324618, the entire contents of which are incorporated herein by reference, is an example of this process.