Miniature SMD connector for power - Page 1
Forum section: electronics / projects

author: msr
author_rank: Regular Contributor
timestamp: September 24, 2014, 12:34:26 pm
content: Hi,I have a project where I stack two boards and the power connector is supposed to be placed in the middle (a right angle connector on the edge of one of the boards).The distance between boards is 3mm so the height of that connector must be less than that,I was considering to use DF57 from Hirose but the problem is the cable assembly. The tool sold by Hirose costs 1000+ EUR/USD (actually the currency is irrelevant, it's still to much money just for cable assembly).Maximum current rating from 500mA ~ 1A is OK.Can you suggest me an alternative?

author: StefanHamminga
author_rank: Contributor
timestamp: September 24, 2014, 12:48:30 pm
content: What about the other side of the cable and the production amount? For that $1000 you can buy a lot of connector/wire assemblies in China.

author: msr
author_rank: Regular Contributor
timestamp: September 24, 2014, 12:55:55 pm
content: Quote from: StefanHamminga on September 24, 2014, 12:48:30 pmThe other side of the cable would be soldered in the battery protection circuit, so no problem. Production amount, in the initial phase, maybe a a few hundreds (100~200).Yes 1000$ can buy a lot of stuffBut can you point me to a right angle smd power connector with less than 3mm height?

author: veryevil
author_rank: Unknown
timestamp: September 24, 2014, 02:10:40 pm
content: Micro USB is 2.51mm high and can handle 1A also surface mount.

author: msr
author_rank: Regular Contributor
timestamp: September 24, 2014, 02:14:33 pm
content: Quote from: veryevil on September 24, 2014, 02:10:40 pmRight, but the USB cable is not that tiny. I need something simpler, just to connect the two wires of a small LiPo battery.Thanks for the suggestion anyway!

author: 8086
author_rank: Super Contributor
timestamp: September 24, 2014, 02:15:38 pm
content: Just use a regular R/A header?

author: msr
author_rank: Regular Contributor
timestamp: September 24, 2014, 05:37:21 pm
content: Quote from: 8086 on September 24, 2014, 02:15:38 pmDo you know any regular R/A header with profile height of <3mm and that's easy/cheap to assemble the corresponding cables?I will consider to increase the distance between the boards to 4mm so maybe its easier to find a suitable battery connector. But maintaining the 3mm would be nice.

author: 8086
author_rank: Super Contributor
timestamp: September 24, 2014, 05:53:32 pm
content: Quote from: msr on September 24, 2014, 05:37:21 pmWell a R/A header is only less than 2mm, and you can get crimp female cable connectors for standard headers...so the height won't be an issue, might take up quite a bit of board area though.If you can go to 4mm this connector is alright:http://uk.farnell.com/molex/53261-0371/connector-header-smt-ra-1-25mm/dp/1125359?Ntt=112-5359It's actually 3.4mm in height, I'm using it for a project and it seems pretty nice. I don't know about the mating connector though since the batteries I'm using already have the mating connector attached:http://uk.farnell.com/bak/lp-402025-is-3/battery-lithium-pol-3-7v-165-mah/dp/2077885

author: msr
author_rank: Regular Contributor
timestamp: September 25, 2014, 12:46:44 am
content: Even if I use 4mm between boards the connector's height must be less that that because there may be some 0402 resistors underneath.These from FCI seemed OK:http://pt.mouser.com/ProductDetail/FCI/10114830-10102LF/?qs=sGAEpiMZZMs%252bGHln7q6pm4MyMgg%2f0bv3lgMeJ%252b5xzMg%3dBut look at this crimping tool's price:http://pt.mouser.com/ProductDetail/FCI/10118656-1000/?qs=QjFvEcVG8GTpRC%252b3mHVKPA==(seems that something bad happened during the copy-paste, but the price was ~1900€)I'm wondering if there is an universal crimping tool for such tiny connectors or if we are left with these custom and very expensive crimping tools, sold by their own manufacturers.

author: ovnr
author_rank: Frequent Contributor
timestamp: September 25, 2014, 01:09:01 am
content: ConsiderMolex's Pico Ezmate- 1.65mm mated height, decent current handling ability, generally pleasant to deal with - I quite like them. Famously featured on Bridgelux's Vero LED modules.I've also crimped the connectors with a cheapish universal crimper ($30-ish). IIRC it worked fairly well - if you want, I can dig out some and give it a try again, as well as look up the exact crimper I used.

author: msr
author_rank: Regular Contributor
timestamp: September 25, 2014, 01:21:28 am
content: ovnr, that looks exactly what Im looking for! Tiny and cheap.Can you please share the exact crimper you have used? And some bricolage pro-tips or "how to crimp really small connectors using an universal crimper"

author: sacherjj
author_rank: Frequent Contributor
timestamp: September 25, 2014, 02:08:18 am
content: Quote from: ovnr on September 25, 2014, 01:09:01 amThose are the best we have found as well for thin thickness power connections.

author: ovnr
author_rank: Frequent Contributor
timestamp: September 25, 2014, 01:35:44 pm
content: Quote from: msr on September 25, 2014, 01:21:28 amJust tried it again, and it works. Due to the ridiculously small connector size, I ended up having to crimp both the conductor and the insulation in one go. I used anEngineer PA-09crimper. I'd probably suggest trying to find aPAD-11instead - it has thinner and smaller dies, and would likely work much better. TMEhas it for $75.As for how to do it: It's really not very different to larger connectors. It is, however, very fiddly (I ended up having to position the contact with tweezers to get it at the correct depth in the die) - be sure to buy plenty of contacts, because youwillscrew up a fair bit.I'd also like to point out that there are pre-made wire assemblies (2 wires in a 4-pin connector) -15 cm,30 cmand45 cm(around $1/pop). If you can use these, I strongly suggest doing it so you won't have to deal with crimping your own connectors. There are also some with thicker wires (... kinda improvised, IMO) - here's thewhole assortment.Good luck!

author: msr
author_rank: Regular Contributor
timestamp: September 26, 2014, 01:17:16 am
content: ovnr, thank you very much for your help!I was about to buy an Engineer PA-09 but I'll get PAD-11 instead.So we have a winner: Molex Pico Ezmate