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One part or two part shield

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#80655

One part or two part shield | 11 July, 2018

Hello,

we are currently designing one device that needs shielding. Under the shield, there is one BGA chip and 0402 components. Now we have a dilemma whether we should go for a one-part shield or two-part shield.

We talked with several EMS companies and they have divided opinions.

Basically, if we have one part shield we are not sure if it is going to be soldered well and boards cannot go through AOI. If we go with the two-part shield there is obvious price issue but also I am not sure that it is easier for AOI and rework as the shield is only 8mmx12mm and has a frame that has a cross on top of it for PnP machine to pick it up.

What are your experiences with something like this?

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#80656

One part or two part shield | 11 July, 2018

First depends on the volume. If its small qtys 2 part may be better. However It comes down to how much you trust your process not to have you parts under the shield Checked if you processes is good do not worry about about it.

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Rob

#80657

One part or two part shield | 12 July, 2018

We had the same issue recently, we swapped to a 2 part shield to allow AOI and SPC xray. We also tested using silver epoxy and putting a one piece can down after inspection. That worked too.

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#80658

One part or two part shield | 12 July, 2018

Have you tried with one part shield? If you did, how many units?

Also, was the reason for changing to two-part shield quality of soldering or something else?

Thanks for the help

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Rob

#80659

One part or two part shield | 12 July, 2018

Started with a 1 part shield and we had an 0201 tombstone due to the pad design. We changed the pad design but the customer wanted to be 100% sure, so we moved to a 2 part, adding the lid after verification.

We also trialled the original 1 part can using conductive expoxy after AOI which worked, but was more expensive in labour and epoxy.

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#80660

One part or two part shield | 12 July, 2018

One more question, how can AOI detect if the frame of two two-part shield has the cross on top of it for Pick'n'place?

I mean has two part shield helped you in term of inspection or in term of better soldering? Or did you put it for the satisfaction of the customer :D?

Thank you for the help!

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#80668

One part or two part shield | 13 July, 2018

The right way in your case is to use shield with cover. Place, reflow, remove shield pick up rails/tabs, AOI, close cover.

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