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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


BGA rework clearance

Views: 1400

#82414

BGA rework clearance | 23 April, 2019

I would like to setup a guideline for BGA to components around it minimum distance. To allow for rework possibilities of the BGA. What are people using as a minimum clearance out there ?

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#82429

BGA rework clearance | 24 April, 2019

Let me preface this just by saying we don't have a spec. for this ourselves since we're an EMS. We just deal with whatever the customer provides.

That said, I would think that it would depend on your specific rework machine, the nozzle designs you're working with, etc., so that not everyone would be able to use the same clearance specs.

We're looking at an IR rework station to minimize the peripheral damage and make this process a little less operator dependent.

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#82430

BGA rework clearance | 24 April, 2019

Thanks Steve for the candid reply. We would probably end up dealing with the rework in house so that is why I want to make it easy from the get go instead of jumping through hoops like I know a lot of EMS vendors like yourselves have to do for their customer. Any BGA rework vendors out there that can chime in on this question ?

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#82439

BGA rework clearance | 25 April, 2019

Hello All,

Using IR will mean that there is no minimum distance to the adjacent components as there is not hot air flow. If components are heat sensitive around the BGA you can also tape them off with a reflective tape. The IR heat will bounce straight off the tape and the adjacent components will not be affected. Using PDR's Focused IR heating system you have the added benefit of a visible heating area so you can accurately see what you are heating up. Please see this in action here (Skip to 1.13 to see our adjustable Iris) - https://www.pdr-rework.com/ir-e3-evolution-video

Hope this helped.

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#82445

BGA rework clearance | 25 April, 2019

Interesting. Makes it easier on design.

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#82449

BGA rework clearance | 25 April, 2019

Years ago it was common to see 2-3mm keep out areas around BGAs. Now with boards being so densely populated there are no clearance minimums. Regardless if the machine is using convection or IR heating, parts can be reworked without affecting adjacent components even if they are a fraction of a mm away.

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#82452

BGA rework clearance | 26 April, 2019

We just apply tacky flux to the surrounding components and to the bottom side components under the BGA. This will prevent cold solder if any solder joints reach reflow temperature the surface tension will keep them aligned and in place.

If you need to outsource your rework, please consider Precision PCB Services, Inc. We have provided rework services and operator training since 1991.

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#82455

BGA rework clearance | 26 April, 2019

Thanks for all the replies. It has been helpful.

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