USE JEDEC Specification EIA/JESD22-B102-C
Procedure:
1. Stencil print BGA solder paste pattern onto ceramic substrates
2. Carefully and accurately P&P BGA devices onto the dispensed solder paste pattern to avoid smearing the solder paste.
3. Reflow in oven with BGA profile
4. After reflow, remove the substrate and devices and allow them to cool down. After the devices cooled to room temperature, remove the the components from the ceramic substrate using tweezers.
5. Remove BGA device from ceramic plate and inspect solder BGA balls at 10X - 100X for solder coverage.
From JEDEC specification the accept/reject criteria for visual inspection of leads is as follows:
All terminations shall exhibit a continuous solder coating free from defects for a minimum of 95% of the critical surface area of any individual termination. Anomalies other than dewetting, nonwetting, and pinholes are not cause for rejection.
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