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Pin headers

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1 1 I work for a small company as an apprentice. We build ... - Oct 20, 2021 by korb23

Why not do the other side first. And paste the pins from the... - Oct 20, 2021 by Stephen

as its a customer product we cant change much of the process... - Oct 21, 2021 by korb23

Could you provide us with more informations about this issue... - Oct 21, 2021 by Djo

Why is your customer controlling your process? You should b... - Oct 21, 2021 by jdengler

I'm not clear on your current process. You run FIRST SIDE. ... - Oct 27, 2021 by ProcEng1

Down-size or stagger the pin holes to "grab" the p... - Oct 28, 2021 by Tom

Or press fit. But he said he can't change the pins or the bo... - Oct 28, 2021 by Stephen

Then adhesive or a pallet to support the header are the only... - Oct 29, 2021 by Tom

Use Loctite Chipbonder. https://www.jensentools.com/loctite... - Dec 27, 2021 by Dennis O'Donnell

korb23

#87203

Pin headers | 20 October, 2021

1 I work for a small company as an apprentice. We build mostly mass produce double sided PCBs. We are having trouble keeping the pin headers flat to the PCB through the reflow oven process.

The first side is pasted through a printer and populated by two machines (smaller parts.) The board is reflowed and put ready for the second side. We then print the second side and populate it through one or two machines. (job dependant) The PCB is then taken and flipped upside down, before reflow, and the pin headers are placed through hole by hand (not soldered) into the first side so that the legs will solder from the second side paste. As you could imagine, flipping the board back over to reflow would then would cause the pin headers to drop out. We have tried using a type of glue that dries fairly quickly and will hold the headers down while the PCB is in the oven but we haven't had much success and are still getting headers raising in the process causing us a lot of time and money on rework. Pin headers are 90 degree

If anyone has a similar problem or has a solution I'd love to hear what you have to offer.

Update: we build these for a customer who will not change the pins or the board as they will not spend any money. we are happy to spend some money our end though to improve our process.

I think we are now looking at some type of adhesive or something to support the pins through the oven.

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Stephen

#87204

Pin headers | 20 October, 2021

Why not do the other side first. And paste the pins from the connector side? Or maybe using solder preforms on the leads might work if you are afraid of the connector squishing the paste. I'm guessing the headers are raising because of the outgassing from the paste. Maybe you can paste less than 360 degrees so that the outgassing has somewhere to go other than up through the hole?

Or maybe you can make a carrier that is open on the bottom and has some kind of hold down arm on the top?

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korb23

#87205

Pin headers | 21 October, 2021

as its a customer product we cant change much of the process. the pins have gaps on them to allow for out gassing. its purely gravity when the solder is liquidous i believe. need a carrier as you say or a type of adhesive to hold them down. do you know of any smt glue

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Djo

#87211

Pin headers | 21 October, 2021

Could you provide us with more informations about this issue ( Picture of the board with components , the deffect component , DATAsheet ..) it may help us to more understand your problem and look forward to a solution ..

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jdengler

#87213

Pin headers | 21 October, 2021

Why is your customer controlling your process? You should be the expert on your processes. As long as the components that are on your second side would stay if they were processed as the first side this would be an acceptable solution to your issue.

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ProcEng1

#87241

Pin headers | 27 October, 2021

I'm not clear on your current process. You run FIRST SIDE. Then paste and build SECOND SIDE. Then you insert a header from the FIRST SIDE so the pins solder with paste on the SECOND side. And you run the board with the unsoldered header on the bottom, hanging down through the oven.

Is that correct?

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Tom

#87243

Pin headers | 28 October, 2021

Down-size or stagger the pin holes to "grab" the pins and hold them in place.

reply »

Stephen

#87244

Pin headers | 28 October, 2021

Or press fit. But he said he can't change the pins or the board.

reply »