J Leaded PLCC On The Bottom Of A Mixed Board

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We have a job that has through hole components on the top, a... - Sep 04, 2007 by floydf

You probably could SMT it (standard Process)first, do your P... - Sep 04, 2007 by Doug Philbrick

We agree with Doug. Your board needs to be designed with th... - Sep 05, 2007 by davef

Thanks for the advice, It was better than anything I could c... - Sep 05, 2007 by floydf

floydf

#51648

J Leaded PLCC On The Bottom Of A Mixed Board | 4 September, 2007

We have a job that has through hole components on the top, and one 44 pin j leaded PLCC on the bottom. Presently we put the through hole parts in, run it throught the wave, dispense paste on the PLCC pads, and then apply hot air. Someone suggested we glue dot the PLCC on aqnd run it through the wave. The j leads hold the bottom of the part .077mm above the board. So if we wanted to glue dot it, then I think it would take a huge splotch. Also, I'm not sure this part would solder well in a wave solder. I'm hoping someone ran into a similar problem and has a better solution to suggest.

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Doug Philbrick

#51649

J Leaded PLCC On The Bottom Of A Mixed Board | 4 September, 2007

You probably could SMT it (standard Process)first, do your PTH and then wave solder using selective solder pallets. If you stick with your current method I would consider a mini stencil such as the ones used for BGA replacement to apply paste. This way you will get fast consistent pasting.

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davef

#51654

J Leaded PLCC On The Bottom Of A Mixed Board | 5 September, 2007

We agree with Doug. Your board needs to be designed with the QFP at a 45* to the wave with scavanger pads in order to wave solder it. Otherwise if you wave solder it, you will need to hire an additional rework person.

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floydf

#51661

J Leaded PLCC On The Bottom Of A Mixed Board | 5 September, 2007

Thanks for the advice, It was better than anything I could come up with.

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