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Ask HN: Who can solder tiny wires to tiny devices?

8 points by DonGateley ↗ HN
I need to find a person or service or whatever that can solder a very fine two-conductor-plus-shield cable I have to the three pads of a batch of ten very tiny MEMS microphones and I don't know where to begin. Can anyone here advise me? Even to tell me an appropriate place to ask if Ask HN isn't.

The dimensions of the MEMs microphones are 2.75mm L x 1.85mm W x 1.00mm H. It can be seen here: http://www.digikey.com/product-detail/en/SPV0840LR5H-B/423-1214-1-ND/4376286

I don't have a picture of the coax cable but it is flattened and isn't as wide as is the MEMS.

I'm an independent inventor in retirement and don't have deep pockets.

P.S. Why the hell do I get the ubiquitous "link unknown or expired" trying to submit this.

11 comments

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redtexture
Google "maker groups", and see if there are opportunities to ask those communities of people that "make" new electronics and robotic stuff as a hobby and community of friendly collaborators.

(Report back if you're successful.)

(The expired error message is a time-out message on this particular forum. It annoys everyone.)

DonGateley
Good idea. That's long been a search that I felt would open a Pandora's box I might never again climb out of. :-)

I found the Instructables which has a lot of excellent craftsmen and asked in their forum. Fingers crossed.

FWIW I really would like to know why my question was voted down to help me understand the ethic (esthetic) here?

dang
I can't see any place that a question of yours was downvoted. Perhaps it just seemed so? If you have a more specific question please send it to us at hn@ycombinator.com.
[deleted]
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cromulent
I would suggest looking into clamping it and using hot air soldering. There are some videos on YouTube.
DonGateley
I just ordered a hot air soldering station and some Gold Kapton polyamide high temp tape to hold everything in place for it and avoid my tremor problem (not particularly bad but too bad for this.) I've got a feeling I can make this work.

I had never thought of adding this device to my bag of tricks and now that I have I'm thinking of many uses that have been more than difficult in the past. Many thanks.

jdietrich
That's not an outrageously difficult part to solder by modern standards. Anyone with a modicum of soldering experience should be able to tackle the job with the right technique and a little practice.

The preferred approach is simply to use a wide chisel tip soldering iron and plenty of flux to make all the joints in one pass, and if necessary clean up the area with desoldering wick. That's the traditional method for soldering fine-pitch SMD ICs and works remarkably well, as it relies on the wetting behaviour of the solder rather than any particular dexterity or skill. The solder won't wet to the body of the package, only to the pads, so any bridges between the pads will naturally be drawn away by capillary action. As long as the wires are neatly tinned it should all go quite smoothly. A search for "drag soldering" should yield lots more information, including a number of demonstrations on YouTube.

If necessary, a basic jig to hold the part and wires could be easily constructed using a small piece of dense hardwood and a scalpel. I'd probably just hold the cable and part in place with Blu Tack and align the wires with fine tweezers.

DonGateley
I should have mentioned that I'm 70 and my hands have long been too unsteady to attempt this myself (if in fact they ever were.)
nutter
Check out the list of hack/maker spaces here to see if there's one close to you - most will have people who can help you: http://hackspaces.org/wiki/List_of_Hack_Spaces
DonGateley
Thanks. There are a couple within 50 miles of me that I've looked into but they require rather expensive memberships in order to get in and find out if anyone inside might be able to do it.

If I come up empty I will go on over and see if there are any old fashioned bulletin boards on which I could post a help note without paying for a membership.