Hi Scott,
Thanks for the feedback. These will be connectors, I don't know what
manufacturer is so I can't dig into a datasheet to learn what PCB sort of
spec's will be required. I'm doing a budgetary quote for some boards that
haven't been designed yet. The customer is asking for some very rough labor
numbers based on a general description of the PCBA like: 150 single-sided
SMT components, 5 through hole connectors, 4 press fit connectors, 6-layer,
5" X 8", .031" thick PCB. When I saw the press-fit and .031" thick PCB is
what got my attention. I've never pressed any connectors into a board that
wasn't at least .062" thick...
Steve
On Thu, Aug 22, 2019 at 3:37 PM Decker, Scott Collins <
[log in to unmask]> wrote:
> Steve,
> I think the answer is, "it depends". We have a rigid-flex board that is
> .093" thick and had issues with press fit nuts, but ended up increasing the
> hole size a tiny bit to lessen the force required to press the nuts in. We
> had a supplier using a 5 ton hydraulic baring press to do the pressing and
> they promptly delaminated the boards. (That was not needed to press them
> either, you could do it with a pair of pliers almost.) Ouch!
> Anyway, I have done .031" boards in the past and used Pem nuts in them
> just fine. Just take note that they recommend different hole sizes for PCB
> versus sheet metal, etc. That said, in our case, increasing the hole size
> slightly, prevented the board from getting damaged during the press
> operation. The key to watch is the press section of the nut/spacer, and
> that it's not any longer than the board thickness.
> I've done both plated and non-plated holes and had good results in both
> cases so plating wasn't an issue in my cases at least. I would suggest that
> if you do plate the holes, don't use HASL for the finish, that will cause
> issues sometimes. In all cases too, the compression mode was to pull the
> nut into the PCB and not push it away/out. In the case of the .093" board,
> the press was just enough to hold the nut in during assembly and a few on
> off cycles so we've not had any issues with the larger hole size. Don't
> know if this helps or not, but...
> Later...
>
> Scott Decker | Senior Engineer, PCB Design Services CID+ | Electronic
> Systems Center
> COLLINS AEROSPACE
> 3445 S. 5th Street, Suite 170, Phoenix, AZ 85040 U.S.A.
> Tel: 602 308 5957 FAX: 602 243 2347
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>
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> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
> Sent: Thursday, August 22, 2019 1:05 PM
> To: [log in to unmask]
> Subject: [External] [TN] Minimum PCB thickness for press-fit technology?
>
> Hi all!
>
> I thought I'd throw the question out there while I'm google-ing for it, is
> there a minimum PCB thickness that you would want to use press-fit
> technology? I'm thinking it's .062", I think I read that somewhere, now I'm
> trying to find it. But a .031" thick PCB seems too thin. Thoughts?
>
> Steve
>
> --
> Steve Gregory
> Kimco Design and Manufacturing
> Process Engineer
> (208) 322-0500 Ext. -3133
>
> --
>
>
>
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--
Steve Gregory
Kimco Design and Manufacturing
Process Engineer
(208) 322-0500 Ext. -3133
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