So here is my story. I decided I wanted to play around with some BGA re-balling and bought myself a "BGA re-balling kit" that came with the following:
I am trying to re-ball an ATMEL Cyclone III chip and I can't get the balls to stay put when heating with my hot air SMD wand (minimum air flow). My process is as follows:
My problem starts when I pour the balls onto the stencil. The balls do not roll and flow like they do on demonstration videos I have seen on youtube. They seem to clump together and need quite a bit of force to make roll around, enough force to knock out the balls that are already sitting in the holes. Note that the stencil is clean. Once the holes are filled and I lift the stencil off the chip a good dozen balls are left holding onto the stencil holes. I replace the missing balls by hand. Once I begin to heat the chip most balls stay put and attach properly but three or four groups seem to static cling together once the flux begins to liquefy from the heat.
I can't seem to get the process to work as smoothly as I see it done on YouTube. Anybody have any advice?
- Re-balling station (the blue one with spring loaded base and black handles)
- AMTECH RMA-223 flux
- assorted stencils
- assorted balls
- solder wick
- brushes
- scraper
- kapton tape
I am trying to re-ball an ATMEL Cyclone III chip and I can't get the balls to stay put when heating with my hot air SMD wand (minimum air flow). My process is as follows:
- Mount BGA chip to re-balling station
- Clean old solder from the BGA chip.
- clean BGA chip with 99% isopropyl alcohol
- apply a small amount of RMA-223 to the chip and spread to a thin film
- mount 0.55mm stencil on re-balling station
- pour on 0.55 balls onto stencil
- once all stencil holes are filled pour out excess balls
- remove stencil
- apply heat to melt solder balls
My problem starts when I pour the balls onto the stencil. The balls do not roll and flow like they do on demonstration videos I have seen on youtube. They seem to clump together and need quite a bit of force to make roll around, enough force to knock out the balls that are already sitting in the holes. Note that the stencil is clean. Once the holes are filled and I lift the stencil off the chip a good dozen balls are left holding onto the stencil holes. I replace the missing balls by hand. Once I begin to heat the chip most balls stay put and attach properly but three or four groups seem to static cling together once the flux begins to liquefy from the heat.
I can't seem to get the process to work as smoothly as I see it done on YouTube. Anybody have any advice?
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