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I have PCBs with SMT nuts (SMTSO2060MTJ) which has been assembled onto a PCB - the nut has kapton tape on top to allow easy pickup for assembly. image of nuts

However, removing the kapton post reflow is proving very time consuming. We have a few thousand to remove. Currently, we are using a pointy edge of a needlenose tweezer, and a kind of angled stabbing motion to spear the tape - when this works, it allows perhaps 20 to be removed before needing to remove the tapes from the tweezers. However, it's not fast. We have also tried a modified "fishhook" barb but this ripped the kapton and it wouldn't come off in one piece.

How can we do this faster/what's a better method? I have wondered if we might be able to blow them off with compressed air from the back side but the tape is quite sticky.

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    \$\begingroup\$ I bet the solder is stickier. If it's an option, can you put them back through the pick+place machine and see if that can pull them off? Or just stick a rod through the nut from the other side. \$\endgroup\$
    – Hearth
    Commented Apr 27, 2019 at 16:02
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    \$\begingroup\$ Have you tried pulling them off with a very aggressive adhesive tape? \$\endgroup\$
    – Spehro 'speff' Pefhany
    Commented Apr 27, 2019 at 16:06
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    \$\begingroup\$ @SpehroPefhany Duct tape solves all problems. \$\endgroup\$
    – Hearth
    Commented Apr 27, 2019 at 16:07
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    \$\begingroup\$ Kapton typical use silicon based glue afaik. Did you try to disolve it with ethanol or similiar? Because we frequently use it to remove kapton tape. It would be very volume consuming to setup a bath of ethanol but maybe its worth it in your case. \$\endgroup\$
    – Christian B.
    Commented Apr 27, 2019 at 16:12
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    \$\begingroup\$ I suggest you try asking at smtnet.com. There are a lot of folks there who do high volume assembly work. The Kapton adhesive is typically either acrylic or silicone-based and it doesn't come off easily. As to really sticky tape- I think we bought some from McMaster-Carr but I don't have access to the details. High grade industrial duct tape as Hearth suggests might be worth a try. \$\endgroup\$
    – Spehro 'speff' Pefhany
    Commented Apr 27, 2019 at 18:55

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After much trial and error the fastest method we have found involves poking the kapton with a rod from the back (which loosens it but doens't remove it completely), and then using tape to remove - either of these in isolation doesn't work but combined the method is pretty quick and can remove several thousand per hour when using a jig.

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