# Bottomless SIP Socket/Machine Pin Header?

I'm working on a personal PCB design project where I need to be able to remove a component easily (to swap out, etc). The component has two rows of 8 pins (standard 0.1" pitch).

At first, I designed the board where the pads were slightly staggered so that the component would "lock" in. However, I quickly realized upon receiving the fabbed PCB that the component stays in, but does not make a reliable connection. I temporarily soldered in a couple 8-pin headers and that fixed the connection issue while keeping the component non-permanent. However, the header is too tall for my needs. I would prefer the component be as flush as possible with the board.

Are there such things as bottomless SIP sockets/female machine pin headers? The component has rather long pins that I cannot cut and the typical SIP socket depth seems too shallow.

An alternative might be to make the pad holes smaller on the PCB... Would this result in a reliable connection without solder?

Thanks for any help and advice!

• Yes: Google pin receptacles pcb (or mill-max pin receptacles) -- these are just the metal parts of a machined pin socket, without the plastic frame. So they can be mounted very low-profile. Downside is most of them require slightly larger pcb holes. – MarkU May 27 '15 at 6:47
• Larger PCB holes is not an issue because I plan to have to re-design a bit from my original board. One could only hope there would be no kinks to work out ;) Thanks! I'll look into this. – menehune23 May 27 '15 at 15:57

## For a next design:

If the pins on your device are long, sometimes a through board socket might work, like this one:

http://katalog.we-online.de/en/em/613_0xx_157_21?sid=1be59820d4

You can mount that at the bottom and stick the pins through the board into that socket. If you wonder whether it'll work, you can contact your local Wurth office and ask them for a couple of samples, they supply them for free to all natural persons, pro's and hobbyists alike.

Or these are SMT dual entry, that you can put on the bottom of the board, but they will stick out a bit more, as they are also for top-entry:

http://katalog.we-online.de/en/em/610_0xx_119_21?sid=1be59820d4

Many suppliers have components like that as well. If your chip's pins are average diameter it'll most likely work.

However, I have seen people make an ENIG finish board with holes that are tuned to the chip's pin size and staggered by about the hole radius. But it's usually not a production-spec kind of thing.

• Thanks! I'll check this out. It sounds like what I might need. Once I investigate it, I'll mark a response as the answer if it does indeed solve my problem. Also, are there any PTH versions of this? I'm hoping to avoid SMD as I'm trying to create a kit out of it. – menehune23 May 27 '15 at 15:58
• @andrewm1100 It's hard to see in the small image, but the first link is to a staggered THT part. One hole bends left, the next right, next left, etc. But they exist in many types from many vendors, I just use Wurth a lot because of decent prices and great service in their direct-sales World wide. (Though the THT may then stick out beneath your chip, so do ask for samples before you choose!) – Asmyldof May 27 '15 at 16:34
• Thank you! I did see shortly after asking you that it is a through-hole part. Their sample request process is extremely simple! Thanks again – menehune23 May 27 '15 at 17:06
• Do you know if there exist bottom entry sockets where the pins are not alternating, but only on one side? I think I could accommodate the pins sticking through on one side of the header, but probably not both... – menehune23 May 27 '15 at 17:21
• Actually, what would be most useful/easy is a SIP socket with no tail, so that the component can go through the board/socket while making a good connection. Does something like that exist? – menehune23 May 27 '15 at 17:48

Check out Mill-Max for a large variety of pin receptacles. Really really suggest downloading the catalog on the site and browsing through that for the parts you need - for some reason their 'product finder' interface on their website doesn't turn up all the parts that are actually available. Had a recent project that required low-profile thru-board sockets and that was the case.