This instructable will use the solder preform process to teach you how to reball a plastic BGA in about 10 minutes or less. You will need:
1. Reflow source (reflow oven, hot air system, IR system)
2. Paste flux (water soluable is preferred)
3. Soldering iron w/blade tip
5. Kim wipes
6. Water and soft brush for cleaning
7. Inspection source
8. The correct preform based on the mechanical datasheet of the part being reballed
9. Device to be reballed
10. ESD wrist strap
Step 1: Deball the Device
Apply water soluable paste flux using a syringe and smear with a gloved finger on the balls of the device. Using the proper blade tip and or temperature setting based on the alloy of the solder balls, remove solder balls. Use solder wick to remove remnant solder making sure pads are flat.Make sure to move the braid up and down not sweeping the base of the part which may scratch the mask or lift pads on the part.
Step 2: Clean the Deballed Part
Using isopropyl alcohol and non static inducing wipes clean off the flux residue from the bottom of the deballed part.
Step 3: Apply Paste Flux
Inspect the device to make sure that there is not scratched mask not lifted pads on the bottom of the device. Apply water soluable paste flux to the bottom of the part. Spread with a soft brush until uniform thickness is on the bottom of the part.
Step 4: Put Preform Ball Side Up
Place preform ball side up onto flat heat resistant surface like a flat ceramic plate. Make sure the preform lines up to the patterns on the device. Make sure you are attached the proper solder alloy solder balls on to the device.
Step 5: Carefully Place Device on Top of Preform
Carefully place the device on top of the BGA reballing preform making sure the pattern orientation is correct.
Step 6: Square Up Preform to Device
Using angle brackets or other meas "square up" the preform to the BGA.
Step 7: Reflow
Place "sandwich" construction of the preform and device in to reflow oven or other heat source. Make sure the proper temperature settings are in place.
Step 8: Remove Preform
While still slightly warm remove the preform from the device. Inspect to make sure all of the balls have transferred to the device. Clean with water and a soft brush. Re-inspect for scratches on the mask or lifted pads.
Step 9: Inspect the Reballed Device
Inspect the reballed device under magnification to the standards you have in mind. If you want to have someone perform the reballing service then contact BEST Inc .