'riser' DIP socket for adding a piggyback PCB? - Page 1
Forum section: electronics / projects

author: TERRA Operative
author_rank: Super Contributor
timestamp: July 07, 2018, 07:13:33 am
content: I got a bit of a project I am toying with and I am looking for a particular part that seems a bit hard to find (Or my Google-fu is weak..)I have a chip on a PCB that I have removed and put a socket in it's place.I want to install a kind of piggyback daughter board with something like a wirewrap DIP socket to lift the daughter board up to clear other components on the main board but then also put the IC into the wirewrap style socket on the daughter board. (The attached picture will make that all make sense)The problem is that wire wrap pins are too large to insert into a DIP socket, and the headers I used are too large to make contact with thin DIP chip pins.Does anyone know where I can find what I am looking for? I need it to suit a 28 pin (2x14) chip with 0.510" (12.95mm) lead width.

author: Benta
author_rank: Super Contributor
timestamp: July 07, 2018, 08:05:28 am
content: http://www.precidip.com/AppHost/9698,1/Scripts/Modules/Catalog/Default.aspx?c=15

author: Ian.M
author_rank: Super Contributor
timestamp: July 07, 2018, 08:06:50 am
content: I've done that before with turned pin sockets - take two and crop any pins you need to intercept on the top one and file flat enough that they wont touch the bottom socket, then solder Kynar wirewrapping wire into the bottom socket, using them as solder cups, and round the base of the shoulder of the pin for connections to the top socket, then take the wires to a daughterboard mounted nearby on 3M VHB foam tape.If you put solder paste in each individual socket of a 28 pin turned pin DIP socket, you could reflow it SMD style onto the protruding pins of another one, already soldered through your PCB leaving its pins free to plug into the main board. If you need more height, you could reflow it onto the ends of the pins of a wirewrap socket, previously soldered through your PCB. A fillet of epoxy to mechanically reinforce the joint may be a good idea.However as Blueskull has pointed out, as m-m turned pin headers are readily commercially available, if you can tolerate as little as 0.1" lateral offset, its best to put footprints for the socket and the header, separate, but overlapping.Hint: if its ever going to be removed, put a sacrificial 28 pin turned pin socket between it and the main board. If any pins get damaged, you've then got the chance to gently pry off the sacrificial socket and press it into a new one.

author: TERRA Operative
author_rank: Super Contributor
timestamp: July 07, 2018, 09:26:31 am
content: Quote from: blueskull on July 07, 2018, 07:17:13 amNah no reason for no offset except for my OCD and having to respin boards.Quote from: Benta on July 07, 2018, 08:05:28 amCool, thanks for the link, I'll have a look and see what they have.Quote from: Ian.M on July 07, 2018, 08:06:50 amNice technique, I might steal that idea... I want to try to keep the board as 'Plug-in' as possible so there's a minimum of flappy bits around though.

author: tooki
author_rank: Super Contributor
timestamp: July 07, 2018, 01:16:07 pm
content: Take a look at Mill-Max, for example their Series 116 DIP sockets. (Catalog page 111:https://www.mill-max.com/catalog)But also you could just use two single-row sockets, which come in far more options from Mill-Max. I also bet they can custom make something for you if it's absolutely unavoidable.

author: TERRA Operative
author_rank: Super Contributor
timestamp: July 08, 2018, 03:50:15 am
content: Bingo! Mill-Max has the part.https://www.mill-max.com/products/socket/126-XX-XXX-41-003000Thanks!