Re-insulating fine wire connections

[alansimpson]

I am doing some research work on that involves soldering insulated fine wire (above 30 AWG) to fine pitch SMD and othre components so that I have small sensor with flying leads. The reason for this is so that I can put component on end of thin tube to make a probe type instrument.

After soldering I need to re insulate connections with a conformal coating that would be thin and tough enough to allow some flexing and not increase volume of probe end.

Can you recommend compound easy to apply and quick drying.

Working environment normal room temp. no harsh chemicals, dry.

Voltages: less than 24V

 

[itsmoked]

I have used 5 minute epoxy for that many times.

Polyurethane is also good.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Comcokid]

Humidseal 1B31 in a spray can might work. Carefully spray it from several directions with a short burst to keep the coating thin.

 

[MacGyverS2000]

I use HumiSeal 1B15H, though I don't know if that allows flexing...

Dan - Owner

http://www.Hi-TecDesigns.com

 

[ScottyUK]

Electrolube's SCC3 silicone conformal coating is pretty good and available in either an aerosol or as a liquid. Silicone conformals are generally troublesome if you need to do any rework - removing them is tricky and usually involves the kind of chemicals you don't want to be using too often.



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If we learn from our mistakes I'm getting a great education!

 

[biff44]

I always keep a bottle of Red-X Corona Dope handy (GC Electronics 10-5002) and Insulating Coating (GC Electronics 10-1762).

In your case, though I would be tempted to do the following:
1) use heat stripable insulated wire
2) after the solder connections are done, either pot the local area with 5 minute epoxy, or use the above Insulating Coating. This is to protect the solder joint (weak point) from failing.
3) If there are any long lead lengths, I would use a small dab of non-acetic acid cure RTV (the type they use in fish tanks) every 0.5" along the wire(s) length, to bond it to whatever "housing" you have. This will keep the wires from flexing under vibration and breaking due to mechanical resonance.

After that, you should be able to handle 20G of vibration without trouble.

http://www.MaguffinMicrowave.com

Maguffin Microwave wireless design consulting