20 years ago when I built my electronics, We use electrically conductive adhesive for securing the components to the body. But those are really delicate items not meant for hard use on mechanical force. Has anybody used electric conductive Epoxy for joining a driver to the pill or body? I’m having a really hard time getting solder to stick to the copper and we know it won’t stick to the aluminum. I’m considering investigating some good electrical epoxy and then potting over the top of that. Any thoughts?
I’d thoroughly clean the copper and then “tin” that area with solder prior to fitting the driver and LED in the pill- so you don’t have to worry about cooking the driver and LED. Then it will be easier to solder the driver edge.
I looked into conductive epoxy type compounds a few years back and didn’t find much. Any I found actually weren’t very conductive compared to solder, so you’d be introducing resistance.
1 Thank
Forget the driver and only worry about the pill. You gotta hit it with heat hard and fast, because the problem when using a dinky little soldering iron is that it wicks away heat just about as fast as you’re putting it in.
If you got an actual soldering gun like those 100W/140W jobbies, or better yet one of those old-timey copper bricks on a handle that you heat with actual fire, that would let you get the pill up to temp to melt solder, fast, then just stab at it with the solder to wet between pill and driver. Once it’s melted, withdraw the heat and let it cool.
It’s just like trying to solder thick cables… which is why they’re usually clamped vs soldered.
3 Thanks
I wouldn’t bother with conductive epoxy. My recollection is it’s not suitable for high current applications like main power in a flashlight. Too much resistance. Though it can be used for low current applications like connecting an e-switch.
For attaching a driver to a pill I solder a small piece of copper solder braid to the bottom edge of the driver, bend it over the edge of the driver and solder the other end to the adjacent edge on the top side of the driver.
Repeat three or four times around the edge of the driver then wedge the driver into the pill. Friction keeps it in place.
2 Thanks
Think you’re right. I’m using a good quality iron for fine work. But it doesn’t have enough watts for this. Even soldering to the mcpcb is difficult.
Thanks. I’ve read about that technique. I’m trying to find a method that is a bit quicker for production.
All the conductive epoxies I know of are essentially metal powder in suspension that needs to be cured or sintered, you’re probably better off using solder and a very large tip.
Aluminium pills generally use a threaded retaining ring to hold drivers down.
This will be a custom application. Resistance I’m seeing is in the mili-ohm range. Combined with tight fit and peening, it might be an acceptable solution
I’d recommend a T12 soldering station and use a broad tip.
If that’s not doable, I’d recommend preheating the Pill with a hair dryer.
For soldering wires to the MCPCB put a thermal insulator like a pop cycle stick under the MCPCB so your not heating the whole pill.
Is that an induction iron? I’m thinking of getting a metcal for that purpose.
1 Thank
