Questions about fixing a flex sensor

Hy all!

One of my flex sensor, previously ordered from Sparkfun has broken. https://www.sparkfun.com/products/8606 I have a Loctite 3880, but my engineer friend said it needs 120 °C to be able to working. But we're afraid about the flex sensor would die in 120°C. We could try that out, but we don't want to use the full tube now, so it would dry up soon after opening. We are curious if the flex sensors can work after baking in 120°C or not. Do you have any experience in fixing this?

Thanks a lot.

The Kapton-substrate in the sensor can easily cope with 120 deg. C - but i don't know with the resistive coating.

Try it - they are not /that/ expensive.

// Per.

And what about this? http://www.conrad.hu/conrad.php?name=Products&pid=530042 On the #electronics freenode IRC channel people told me to use a conductive silver glue, and this is like that. There's a datasheet of that on that page: http://www.produktinfo.conrad.com/datenblaetter/525000-549999/530042-si-01-de-Leitsilber_Inhalt_3Gramm.pdf but this is german.

Can this repair my flex sensor?

gregtom6:

Can this repair my flex sensor?

No.

And why not? And why that Loctite 3880 is better? Next time pls write wider answers. It’s a bit expensive to order always new flex sensors if one is broken, so that’s why I try to find the best solution for fixing that.

And how can I find out if all of the sensor parts will survive the baking? I don’t really know which part is the Kapton-substrate and which is the resistive coating. What is the attributes of the coating? That’s the brown plastic on the bottom of the sensor?

You can not repair your sensor's resistive coating with conductive glue. You will "short" out the resistive properties, rendering it non-working.

Simple as that.

// Per.

The sensor has broken on that red line. Can you tell me what is the brown part of the sensor and what is the grey one? Because I don't know which one is the resistive coating and which one is the kapton-substrate.

With showing this to you, can you help me better about how to fix that?

The brown is the insulating substrate, the grey is the conductive paint and the black is the resistive element.

If you have a crack in the grey conductive paint, you might be able to repair it with conductive paint.

The alternative is to place a small loop of fine tinned copper wire over the break and secure it by putting a sliver of solid silicone over both this and the adjacent grey track and carefully crimping a metal ferrule flat over the combination to apply sufficient pressure to the silicone to ensure the fine TCW makes solid contact with the grey track. A pressure crimp is after all how the main connections are made to the strip.

Paul:
And what conductive paint? Read my previous posts. The Loctite 3880, what needs 120°C and people said in here that maybe it can harm the resistive part, or

And what about this?
http://www.conrad.hu/conrad.php?name=Products&pid=530042
On the #electronics freenode IRC channel people told me to use a conductive silver glue, and this is like that. There’s a datasheet of that on that page:
http://www.produktinfo.conrad.com/datenblaetter/525000-549999/530042-si-01-de-Leitsilber_Inhalt_3Gramm.pdf
but this is german.

this? I can order this from Hungary, so it would be a cheap solution one…if it would be a solution. Or do you have a better idea?