摘要 |
A system and process for forming a ball grid array on a substrate includes defining a plurality of openings in a resist layer on the substrate, and forming a plurality of openings in the resist layer, each positioned over a contact pad of the substrate. Flux is then deposited in the openings, and solder balls are positioned in each opening with the flux. Solder bumps are formed by reflowing the solder balls in the respective openings. The resist layer is then removed, leaving an array of solder bumps on the substrate. The flux can be deposited by depositing a layer of flux, then removing the flux, except a portion that remains in each opening. Solder balls can be positioned by moving a ball feeder across the resist layer and dropping a solder ball each time an aperture in the ball feeder aligns with an opening in the resist layer.
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