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BGA Solder Short

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Hello, Im currently having BGA solder short issue which hap... - Jul 17, 2023 by Hazira

Things I would check: - solder paste - reflow profile - st... - Jul 17, 2023 by MagyarT

Fresh production run? As in starting with BGAs opened from ... - Jul 17, 2023 by Stephen

Yes. i do check all the parameter all seams good. I did comp... - Jul 18, 2023 by Hazira

Is a fresh lot. This bga is old date code 2010. we had recei... - Jul 18, 2023 by Hazira

Those photos also look like delamination. The balls are sma... - Jul 18, 2023 by Stephen

Out of 8 pcs reject (solder short) found 1 pcs have bulging.... - Jul 18, 2023 by Hazira

You don't have people that are fanatics about vacuum sealing... - Jul 18, 2023 by Stephen

Hardly can say, possible also. As in store the packaging all... - Jul 18, 2023 by Hazira

Use T5 solder paste Make sure you dont have too much paste, ... - Aug 02, 2023 by Kirillka

May I share regarding this issue. Initially, please define t... - Aug 07, 2023 by Suradi

Good afternoon. If you provide more data, I think you can fi... - Aug 08, 2023 by serge_pirog

I think this part has terrible thermal balance. I assume in ... - Aug 15, 2023 by Evtimov

Measure the temperature of the central and edge balls. There... - Aug 17, 2023 by Denys

Reduce the aperture size, ... - Sep 20, 2023 by Linux

The actual root cause not yet define. But i do check all tha... - Sep 22, 2023 by Hazira

Here the picture after printing. ... - Sep 22, 2023 by Hazira

I see you're having trouble with the offset. Is it always li... - Sep 26, 2023 by serge_pirog

There appears to be plenty of alignment issues going on here... - Sep 26, 2023 by Carl_P

Hazira

#89713

BGA Solder Short | 17 July, 2023

Hello,

Im currently having BGA solder short issue which happen only at the center of the BGA during fresh production run.

During rework using SRT also i did encounter the same solder short issue.

Kindly provide your thoughts on this as how to approach to resolve this issue.

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MagyarT

#89714

BGA Solder Short | 17 July, 2023

Things I would check: - solder paste - reflow profile - stencil printing parameters including support, stencil itself and squeegee - MSL procedures - inspection between pick and place and reflow to check paste printing (ideally SPI) Hope this helps.

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Stephen

#89715

BGA Solder Short | 17 July, 2023

Fresh production run? As in starting with BGAs opened from the previous run? And then using BGAs that have been never opened?

Look at the balls where the shorts are. They are smaller. You have delamination. I suspect that you have moisture in your BGAs and have popcorning going on.

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Hazira

#89718

BGA Solder Short | 18 July, 2023

Yes. i do check all the parameter all seams good. I did compare my solder paste printing and profile with previous lot that did not have any BGA solder short issue which we run at the same line did not have any much difference.

During rework also i facing the same issue solder solder short at the center (rework using flux only )

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Hazira

#89720

BGA Solder Short | 18 July, 2023

Is a fresh lot. This bga is old date code 2010. we had received this BGA 2021 and the baking process is done during receiving time. Production received with vacuum seal , its very hard to tell how the BGA handling and stuff and the BGA already EOL. I did suspect the same things possible the moisture. But during rework i do bake the BGA before SRT yet i still having the same issue. Here more picture fresh lot and rework board. Beside baking the BGA, any suggestions maybe i need to do fine tuning at the reflow profile?

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Stephen

#89721

BGA Solder Short | 18 July, 2023

Those photos also look like delamination. The balls are smaller where the bridging is. There isn't more solder. It's that the solder is somehow squeezed together. Check the BGAs after removing to see if they do have a bulge. Maybe the pcb is flexing the oven?

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Hazira

#89722

BGA Solder Short | 18 July, 2023

Out of 8 pcs reject (solder short) found 1 pcs have bulging.

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Stephen

#89723

BGA Solder Short | 18 July, 2023

You don't have people that are fanatics about vacuum sealing do you? There air should be only lightly evacuated. If done like frozen food is done that can isolate parts in pockets. And actually draw moisture into the bag. And cause holes in corners.

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Hazira

#89724

BGA Solder Short | 18 July, 2023

Hardly can say, possible also. As in store the packaging all good yet i do plan to do baking before run on next production on coming oct. while optimize my profile. Any better suggestions? really appreciate

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Kirillka

#89816

BGA Solder Short | 2 August, 2023

Use T5 solder paste Make sure you dont have too much paste, usually 1 time printing instead of 2. Make sure the component is baked before production. Re-check your profile on the reflow.

Could be also a bad pcb edit, nothing you can do there.

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Suradi

#89832

BGA Solder Short | 7 August, 2023

May I share regarding this issue. Initially, please define the root cause clearly, is it from materials or process. Refer to the picture, if the short location is not randomly meaning there is the process issue. It could be stencil design or paste printer set-up. Especially for the BGA parts, the stencil design is very critical and it could create a soldering issue if it has improperly designed. For the process, ensure strongly the paste printer set-up...there is a specific parameter so called snap-off, ensure all parameters : PCB supports, squeegee angle and speed, PCB transverse after print ( print table down ) speed and delays, etc. For placement process, take a look clearly the placement parameters including the over travel speed & delays

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serge_pirog

#89838

BGA Solder Short | 8 August, 2023

Good afternoon. If you provide more data, I think you can find the problem. Could you provide: part of the Gerber file, namely the stencil and BGA pad and photo of solder paste on the board after print.

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Evtimov

#89883

BGA Solder Short | 15 August, 2023

I think this part has terrible thermal balance. I assume in reflow process the part is bending so much that it will cause the shorts you see. I would suggest you get one of these beautiful hi temp cameras and record the reflow process. This video should give you all the answers.

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Denys

#89893

BGA Solder Short | 17 August, 2023

Measure the temperature of the central and edge balls. There should be minimal difference in peak temperature and TAL offset. If not, correct reflow profile. For correct reflow profile your BGA mus be backed befor use.

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Linux

#89984

BGA Solder Short | 20 September, 2023

Reduce the aperture size,

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Hazira

#89987

BGA Solder Short | 22 September, 2023

The actual root cause not yet define. But i do check all that you stated all good setting parameter. 1 week before run the problematic batch, i had run another batch which all the BGA were good no solder short. Just recently i run another batch 21 pcs which i bake the BGA for 48 hours the result were good without changing any of my process and parameters. Will do another new batch of 100pcs to validate if moisture really the issue

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Hazira

#89988

BGA Solder Short | 22 September, 2023

Here the picture after printing.

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