EZReball™ preform technique used for reballing area array devices is one of the methods used at BEST for the attachment of solder balls. This patented process was developed primarily with the speed of attachment and simplicity in mind. The key to this method is the engineered polyamide and other polymer-based carrier ("preform") which holds the solder balls in place. After applying flux to the bottom of the part, the balls and part land patterns are aligned and “squared up” with the device. This aligns the land patterns of the device to the preforms' ball locations. The assembly is then reflowed. After being cooled the reballing preform is simply peeled away. Finally, the part is cleaned and inspected.The solder
The major advantage of this technique is in its convenience as the solder balls are packaged inside of the preform. Each unique solder alloy, ball size and grid pattern requires a new preform. which can be engineered and fabricated in a few days at BEST Inc.
After being cooled the EZReball™ preform can be pulled off of the package. Using the right cleaning solution and soft brush the flux and adhesive residue can be clean off the package and reflowed thereby attaching the solder balls.
The package can be air dried using either a static neutralizing gun or with nitrogen.