solder for UHV

I am working on a system under UHV at very low temperature. Now I need to solder thermocouple wires to feedthrough (i.e. two copper pins sticking inside from one fo the vacuum port.

I want to solder thermocouple wires of extremely low temperature (~10K) for UHV applications. It appears that lead-free solder (e.g.

95%tin5%silver) works but I have no experience so far. So I want to know the answers for the following questions. If you know, please let me know!

1) what shuold I need to consider for soldering?

1) what materials should I use? Lead-free solder (tin-silver)? 2) where can I buy it?

Thank you for your support in advance!!

Nanoworld

Reply to
Nanoworld
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Is there an electron microscope lab in your department? If so, how would they do it?

(Maybe they'll do it for you.)

Reply to
Mark Thorson

Lakeshore have some application notes regarding use and installation

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of thermocouples:
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Reply to
Danny at Chrastina dot net

Don't use copper feedthroughs! You're actually going to have 6 junctions in series instead of only 2, if you do that. You can get UHV thermocouple feedthroughs specially made for this. Your best bet for connections in UHV is spot welding rather than soldering, if you can do it.

Cheers,

Phil Hobbs

Reply to
Phil Hobbs

I've had another thought: are you really going to be trying to measure temperatures of 10K with a thermocouple? Wouldn't a thermistor with a negative temperature coefficient be better for that?

Reply to
Danny at Chrastina dot net

According to my experienc we welld thous two wites with arc or spark. without any additional oxide preventing materials. We just path through the wires a spark directly on the contact between them. The spark was generatad in open aire using potential of severals KV.

Reply to
Shay

According to my experienc we welld thous two wites with arc or spark. without any additional oxide preventing materials. We just path through the wires a spark directly on the contact between them. The spark was generatad in open aire using potential of severals KV.

Reply to
Shay

According to my experienc we welld thous two wites with arc or spark. without any additional oxide preventing materials. We just path through the wires a spark directly on the contact between them. The spark was generatad in open aire using potential of severals KV.

Reply to
Shay

replying to Nanoworld, PHYSIKE wrote: please see followed URL

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Reply to
PHYSIKE

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