Most Semiconductor suppliers have converted to lead free packaging creating compatibility and reliability dilemmas for Military, Aerospace and Hi-Rel applications. ISI’s process of removing lead-free (RoHS) solder spheres then attaching leaded Sn63Pb37 eutectic spheres, has been qualified by leading Commercial, Industrial, Military and Aerospace companies.
ISI has advanced their reballing process to the extent they can now certify that the silicon is protected to specific parameters throughout the process as follows: 1) ISI certifies that the parts are protected through the process to IPC/JEDEC J-STD MSL Classification as required by the semiconductor supplier. 2) ISI certifies that the process used for ball removal will protect the silicon, never subjecting it to a time temperature cycle above 50% of the supplier’s recommended cycle. 3) ISI certifies that the ball attach process will be performed in a nitrogen environment in a conduction convection oven and will never exceed 90% of the time temperature recommended by the supplier. 4) ISI certifies the parts have been 100% optically inspected to ensure the device meets the original suppliers specifications for flatness and coplanarity. The ISI process has proven reliable and affordable. ISI tailors dimensional specifications and processes to each part. Specific control parameters for each phase of handling, production and controls for temperature, humidity, ESD protection, ball size/position tolerance specifications, automation, cleanliness, 100% optical inspection and repackaging are rigorously maintained.