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Paste-in-Hole reflow soldering

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#43236

Paste-in-Hole reflow soldering | 9 August, 2006

OK i have a question: I have a prototype BOM and i suggested the customer that we use Paste-in-hole for the 1 connector that they want to use, but its quite high component and not very wide: http://www.molex.com/pdm_docs/sd/022272051_sd.pdf If i use curled legs so the component wedges itself into the pcb board before Reflow, will the Paste-in-hole process still work?

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Rob

#43238

Paste-in-Hole reflow soldering | 9 August, 2006

If you kink the leads will you be able to insert it without flexing the board/moving any of the other components? Also these pin headers aren't always designed for this process so have you checked that it will take the elevated temperatures?

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mumtaz

#43239

Paste-in-Hole reflow soldering | 9 August, 2006

The curled legs may push the paste out of the hole, making things messy. This also will decrease your volume of paste which means your solder joints are not as robust as you would like. Also with this process, voiding can be a big issue depending on the paste you use. You may want to run some scrap boards and cross section them to check the quality of your joints. Rob brings up very good points as well.

Can you switch to a surface mount equivalent or is it too late? It still is in prototype, so now may be the time to switch.

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#43240

Paste-in-Hole reflow soldering | 9 August, 2006

i dont even have the gerber files yet and i have just asked the customer to change the BOM, any suggestions for Paste in hole connectors...?

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#43244

Paste-in-Hole reflow soldering | 9 August, 2006

Good afternoon,

Take my word, bent THT leads will surely cause problems with manual/automatic component insertion, and surely will create voids in solder joints. As a rule, PIH components are placed by hand and good PIH THT manual component placement practice is: one hand movement equals to one inserted component (doing this minimizes or eliminates voiding issue). You will never insert component with bend leads from first attempt.

Paste volume is another thing to consider. Paste volume required for proper intrusive reflow equals to volume of �gap� between PTH wall and component�s lead multiplied by two. Most probably you will have to design step stencil and overprint solder paste. But all this is PCB design dependent.

Have a closer look at the PCB first.

BR, Pavel

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#43245

Paste-in-Hole reflow soldering | 9 August, 2006

I agree with verifing this part is even high temp reflow compatible. The age of the original dwg release, 1986, and as there is no mention of high temp reflow compatibility, only a mat'l call out of nylon, leads me to think it is not.

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PR

#43250

Paste-in-Hole reflow soldering | 9 August, 2006

pin and paste works. don't use gel flex at screen printer.

Good luck PR

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Rob

#43253

Paste-in-Hole reflow soldering | 9 August, 2006

You are going to struggle with that sort of connector - the only pin headers that seem to have widespread sucess are the dual inline ones with bent over j leads that sit on the board. They come with a plastic hat that allows vacuum pick up. However... they are not polarised, have no friction locks, and carry a price premium that will have you reaching for your soldering iron. They also take up more board space.

Sorry!

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