Longevity of copper shielding tape adhesive

Other Hardware General Electronics
1

Does anyone know how long the acrylic adhesive typically used on copper shielding tape lasts before loosing it stickiness?

I was thinking of using it to make a fibreglass/epoxy backed capacitive sensor sensor with a life expectancy of at least 10 years.
It will be subject to temperatures between 5 and 60 deg C and high humidity.

Having it slowly come adrift after several years would be the worst case scenario.

2

We had used it in a lab shielding a Barnes IR microscope for a few decades - though it did not go through any temperature extremes.

3

Have a look at the aluminium tape used fo glass break detection thats very sticky.

4

Thanks for the info.

From doing more research it would appear that acrylic type adhesives used for long-life tapes are essentially high viscosity non-evaporating liquids that stick using van de waals forces.

The bond strength inceases over time as the adhesive flows into the surface irregularities.

Getting rid of the trapped air under vacuum will proably speed up the wetting process thus stabilising the capacitance.

5

Acrylic adhesives ?

My experience of tapes indicates that pressure sensitive silicone is more often used, dont know much about that though , but it lasts well.

6

I've seen that stuff stick to fibreglass fuel tanks in aircraft for 20 years. If it can last that long in the presence of decades of spilled avgas then it will hold together for your design life.

Obviously I didn't peel it back to check if it was acrylic or silicone under the copper but it was probably one of those two.

7

https://www.homedepot.ca/en/home/p.air-duct-aluminum-foil-tape.1000117112.html
This aluminum tape lasts for years through large temperature extremes.
.

8

The 3M copper tape I've used has a conductive acrylic adhesive and sticks very well for a long time provided the substrate is clean. Not tried it at 60 C though.

I would contact the 3M technical department with details of your application for further advice.

Russell.

9

russellz:
I would contact the 3M technical department with details of your application for further advice.

Russell.

I would agree with that, i had some copper tape from Rs about 25 years ago (make unknown), and that peeled readiliy after a year or so.
That was on fibreglass board used for finger resistance switch.

The ally tape used for break glass worked much better, the old lead break glass tape peeled like the copper stuff.