Low profile board-board connectors/headers/sockets - Page 1
Forum section: electronics / projects

author: Buriedcode
author_rank: Super Contributor
timestamp: September 29, 2016, 10:40:28 pm
content: Whilst I shouldn't get into the habit of firing off a post every time I'm slightly stuck on something, I just wondered what others have done.I am making a quick and dirty (read: cheap) wearable device, and rather than go through several iterations of boards for testing different sensors, just for testing out which ones are 'best' (as in, easy to work with, accurate, low power etc..) I decided to mount a few sensors on small module boards, preferably with pin headers or sockets so they can be placed on cheap protoboard for development, and also plugged into various incarnations of a watch. It also means I don't have to buy several of each sensor. Each one would only need 6-8 pins, and preferably provide some degree of mechanical stability.Of course standard 0.1" headers are too long, although I was thinking using SMT versions of these (standard 5-6mm pin length) but using 'bottom entry' sockets on the main board. This would allow the sensor board (20x30mm) to be plugged into a standard socket for testing, and plugged into the underside of the main board with only ~4mm distance between boards. - all this and keeping the 0.1" spacing for quick and dirty development on standard protoboard. 1.27mm would be much better of course, but then everything it plugs into will have to be 1.27mm so either an adapter, or a custom PCB.A spacing of 3-5mm ideally.An example of bottom entry:http://upload.ecvv.com/upload/Product/201110/China_2_0mm_Female_Header_Single_Row_Bottom_Entry201110271702568.jpgAre there any better options? For the later versions I'll scan over Farnell/RS for much neater low profile 0.8-1.27mm pitch connectors, but for 'low profile prototyping' there has to be a better way than either soldering pin headers permanently, botching with ribbon cable or just living with a stack of 2-3 boards with 10mm between them. Has anyone else managed this?

author: andyturk
author_rank: Frequent Contributor
timestamp: September 30, 2016, 04:23:53 am
content: I used these on a wearable prototype a couple of years ago:http://www.mouser.com/search/Refine.aspx?Ntt=FCI%20Conan%201.0mm%20ConnectorsThe board clearance is about 5mm and they have very good mechanical stability. The female connectors are bottom-left and top-right in the attached photo.

author: ebclr
author_rank: Super Contributor
timestamp: September 30, 2016, 06:48:33 am
content: https://world.taobao.com/item/37438355182.htm?fromSite=main&ali_refid=a3_430620_1006:1108833188:N:1.27mm:8a838a54ee354a0fdf8386dca27f0711&ali_trackid=1_8a838a54ee354a0fdf8386dca27f0711&spm=a312a.7700714.0.0.vJIMiY

author: Buriedcode
author_rank: Super Contributor
timestamp: September 30, 2016, 11:28:23 am
content: Andy,Interesting parts! 1mm pitch might be pushing it for now, although the sensor board and carrier board will be custom (DIY etching for now) they do seem to require a 4-5mm gap between boards.eblr: those appeared to be sockets of standard height, top entry. With a header pin length of 6mm, minus the 1.6mm for PCB, that gives 4.4mm. So I guess the 4.3mm is perfect! I might make an order from Toby Electronics (in the UK) as I believe they do some.So my options are...SMT low profile bottom entry sockets on the topside of the main board - with the sensor boards plugged into the bottom, the TH sockets can be modified for SMT providing they have holes all the way through. Or...TH bottom entry (much harder to find) that have the pins bent out for a 0.3" pitch. For single row that's 0.2".The gap, using SMT headers is 4mm, so about those achievable for the other connectors Andy linked. Whilst I have the spare time, I think I'll try and find the cheapest place to get the connectors and make up some test board stacks. For a 'watch', 3 boards would be ideal - sensor on the underside of the bottom, battery sandwiched between that and the middle board, and a top board for the display.total high (1.6 * 3) + (4 * 2) = 4.8 + 8 = 12.8. Not 'thin', but not bad for a prototype.