Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


BGA

Views: 2649

#73265

BGA | 22 December, 2014

What could be the possible solution for shorted BGA but only appears on the component corners. The BGA is 18mm x 18mm in size.The component solder balls are within specs and the pad design for the BGA is with standard. How can I solve this problem

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#73266

BGA | 23 December, 2014

the most common reason can be popcorning of the device or warpage of the packages during reflow. the distacnce from the boatom of the device is decreased hence the solder shorts. Trying doing some measurements on the package during simulated reflow.

There are many types of process defects on area array packages which are covered in the first SMTNet webinar I will be running which should be anounced shortly. Its devoted to BGA and area array process issues.

Many thanks Bob Willis

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#73272

BGA | 23 December, 2014

The peak temp. during reflow is 285 degree, at this temperature, would popcorning already occur?Thanks

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#73273

BGA | 24 December, 2014

Assuming its 285 Celsius as measured at the solder joint, you are overheating the die. If 285 C is your ovens setting then you need to measure the BGA package peak temperature as well as the joint temperature.

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#73274

BGA | 24 December, 2014

285 is way too high a temperature for a measured part or ball temperature. It's also high for a modern convection oven set point even at reflow.

If you have imagages of the problem we may be able to assist you further even on Chritmas Eve??

Bob Willis Bob@bobwillis.co.uk

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#73281

BGA | 28 December, 2014

thanks for all the information. i will check on it.

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