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Fritz
12-07-2006, 02:39 PM
Not quite sure how to express this question, but can anyone tell me how much larger a 1 micron feature on a pure nickel substrate at 20C will be when the substate temp is raised to 55C?

Can this be expressed as a percentage - that is, expect features to change by X% when substrate is raised in temp from 20 to 55C?

Santo Rugger
12-07-2006, 02:55 PM
Not quite sure how to express this question, but can anyone tell me how much larger a 1 micron feature on a pure nickel substrate at 20C will be when the substate temp is raised to 55C?

Can this be expressed as a percentage - that is, expect features to change by X% when substrate is raised in temp from 20 to 55C?

According to www.matweb.com, the linear thermal expansion coefficient of pure nickel is 13.1 µm/m-°C. With a delta T of 35C, that gives 458.5 µm/m, or .0459%. The 1 micron feature would expand to 1.0459 microns.

scr4
12-07-2006, 02:57 PM
Wikipedia (http://en.wikipedia.org/wiki/Thermal_expansion_coefficient) says linear thermal expansion coefficient of nickel is 13 x 10-6 /K at 20oC. That means raising the temperature by 35K will expand it by 35 x (13x10-6)=4.6x10-4=0.046%.

scr4
12-07-2006, 02:59 PM
... .0459%. The 1 micron feature would expand to 1.0459 microns.
I think you mean 1.000459 microns.

Fritz
12-07-2006, 03:04 PM
According to www.matweb.com, the linear thermal expansion coefficient of pure nickel is 13.1 µm/m-°C. With a delta T of 35C, that gives 458.5 µm/m, or .0459%. The 1 micron feature would expand to 1.0459 microns.
Wow, that's great - thanks!

That's my problem, I found the CTE of pure nickel on the web, but I had no idea how to use the value.

Santo Rugger
12-07-2006, 04:34 PM
I think you mean 1.000459 microns.

No, I meant 1.000459 microns. ;)

Napier
12-07-2006, 08:24 PM
You are asking about a tiny feature, only a micrometer. Everything scales linearly so if you weren't going to worry about whether a 3" bolt at room temperature is still a 3" bolt sitting on a hot car dashboard, you also can neglect whether the feature has changed size. Its being small doesn't make it more sensitive to thermal expansion.

Of course I am trying to guess why you are asking.

What are you doing, anyway? Calibrating an SEM or something?

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