Conductive epoxy

I plan to use some polystyrene capacitors in an upgrade. Understanding the difficulty of soldering these, would a silver bearing conductive epoxy be a reasonable alternative. I have some of the Chemtronics TW2400. Thanks for your input. I am concerned that the epoxy might add to the the caps ESR, thus negating use of the low ESR in the first place.
 
ditto... solder with confidence don't be afraid and use a good soldering iron and good solder(don't use silver has to high a melting point).I use .050" dia 63/37 rosin core for most stuff. I'm sure this will elicit a flood of opinions.

El

Exactly!

If soldered just reasonably right, only once, with 63/37 rosin core solder, and reasonably fast, you have no problem.

So instead of trying to get around to learn how to solder, just like others above I would suggest you learn to solder with confidence.
Learning to solder just reasonably well, will pay back soooo many times in the future.


Magura :D
 
No need for anything so exotic as indium. Standard 60/40 is fine if used properly.

Good soldering starts with the board design. An issue with the old axial polystyrenes was that they had unusually fine leads. Far too any pcbs had oversize holes. Also never take fragile components directly to a copper plane, even thermal relief around the pad is not really enough. A short track of a few mm is better to avoid the pad need too much heat.
 
Another possibility is to use Teflon caps. These are radial leads, however, and would require bending leads and using teflon tubing. This would increase lead length. Since these are being used as PS bypasses on high speed dac chips, would the length present a problem? Or am I looking at the same lead length in the styrene box caps, just internal . Any advice is always appreciated. Thanks
 
After some additional research(which I should have done before now) I have decided to retain the ceramic caps. I may switch out to NPO/COG. If they are good enough for Deane Jensen, they are good enough for me. I will just be replacing electrolytics with higher quality in the analog sections and oscons in the digital. Thanks for all the help. I may need to solder some styrenes at some point and your advice is greatly appreciated.
 
just a thought... box caps usually are sealed in the box with epoxy with the leads protruding through the epoxy so the leads are in contact with the epoxy and some heat absorbed by epoxy during soldering. the spec sheet on the caps will give soldering guidelines as to heat and duration that can be tolerated . I have some styrene caps that are axial leaded and in my mind that is what I envisioned , but what you described is a box cap like an X or Y cap, n'estpa(sp)...

E
 
I've used the silver bearing epoxy; it's not particularly hard to work with and it indeed conducts electricity.

In my case I repaired an RF transmitter used in an OEM automotive power door lock key fob. The transmitter had been dropped, abused, and basically destroyed to the point where it no longer worked, the PCB was physically broken, there was no solderable repair possible, and was headed for the trash.

Now, apparently Ford Motor Company wanted $160 for a new one, which, to a DIY'er who can examine the thing sans case, is like asking $25 for a drinking straw.

The repair went well, the whole thing was put back together inside some large diameter clear heat shrink tubing so the buttons could be pressed, and away we went.

Unfortunately, the woman who dropped, stepped on, lost, found, poured drinks over, and generally abused the key fob managed to destroy it a second time, in this case, she managed to rectify her previous feeble attempt at destruction and effectively turned it into something no longer recognizable, and the silver epoxy was no use this time.

But it did work for months after the initial repair, and I have no doubt that it would still be working if not for the owner's peculiar talents as a waking, talking one-woman wrecking crew. If you gave her an anvil, expect to see a huge crack through it a week later, even if during those seven days all she had done was stare at it furiously.

I would not use it on any solderable project, I have no idea of it's electrical properties, but for the unrepairable, it works.
 
Last edited: