I’m pulling my teeth out here. No matter how well mated the circuit board is inside the pill, I can’t get the solder to bridge from the pill to the outer ring on the board. Can I expect the solder to flow from the two pieces to form a solid connection or do I heat it up and just splatter a blob onto the pill? Please give me a little insight! Thank you.
Aluminium just does not solder at all (well, not with normal solder at normal temperatures, supposedly there are ways not in reach of us mere mortals). The quickest you can do is what you said: splatter that blob and do not move the board again after that. But what I do nowadays is solder a thin piece of copper wire starting in a via, bend along the outside of the driver board to the outer ring on the other side of the driver, then file that a bit down to shape. then the driver can be press-fit into the pill against the protruding blob. A bit of artwork but it works well for me.
Also try taking a dremel or sandpaper and lightly scuff the area where you are going to solder, then place a good amount of solder paste on the scuffed area, heat and see if the solder bonds
Aluminum doesn't like solder, especially if it has had time to develop a thin layer of oxidation
1. Put the driver inside the pill, prepare a powerful (50W+) soldering iron with wide (at least 2 mm) soldering tip.
2. Tin your soldering tip just a bit and heat up your pill at the place where you want the blob to be. Don’t touch the driver with the tip at the moment.
3. When solder from the tip starts to stick to a pill, add a normal amount of solder directly to the soldering point. Don’t remove the tip from the pill, it should be as hot as possible.
4. Quickly (within 1-2 seconds) slide your soldering tip to the driver’s outer ring - now the tip should touch both the pill and the driver. When the solder starts melting on the driver (another 1 second), remove the tip. If you’ve done everything right, now you have a nice solder bridge.
It isn’t really hard, just requires some practice.
If all else fails...Pre-tin the pill before you add all the components. This way you can heat up the pill all you want without running the risk of damaging the driver or LED. Once you add the driver, just bridge the solder joints.
Like others have said, a clean surface, a little flux, a hot enough solder iron will go a long way. Good luck.
I drill a 1/16" hole in the pill wall just under the driver seat. I solder a copper wire ( about the size of the hole), to the driver ground ring and then I feed it through as I put in the driver. I then cut the wire to where it sticks out about 1/8" and I flatten it against the pill. Then I solder that wire, till it fills the hole and has a little blob outside. Then I file it smooth. After playing with it a few times, I have found that it works very well. I cannot solder to an aluminum pill. I have tired the "right solder" and all the tricks. It does not work for me and I gave up on that a long time back.
Now, if it's a brass pill, I clean where I want to solder with steel wool and flux it and solder it before ever putting the driver in. Then, once the driver is in, I bridge the solder from the driver over to the solder I already have on the pill. Brass solders easily, if it is clean and fluxed.
Thanks for the tip OL. With the hole filled up with solder and wire in it (ally pill) could you not give it a gentle tap to squash the solder into the pill for a good contact or is that not necessary?
As others have mentioned, pre-tinning the pill and the driver really helps. Pre-tinning the driver is easy, but pre-tinning the pill will take a lot of heat. Once you get both sides pre-tinned, wipe off any excess flux with alcohol. Excess flux can make it harder to bridge the gap.
Once you have both pieces tinned, install the driver, line up the tinned spots, heat both spots just until the solder starts to melt, and then drag the hot solder from one spot to the other. I think going from driver to the pill is easier, but going from pill to the driver results in a cleaner finish.
Make sure your solder and iron are clean. Impurities in the solder can make it harder to bridge the gap.
If you still cannot get the solder to bridge the gap, drop a tiny piece of wire between the solder spots. That always works.
Edit: I assume the OP is using a brass pill. P60 pills are brass, aren’t they?
Thanks for the replies. Yes, I use brass pills only. I’ve tried several techniques listed here and my skills have doubled just from the suggestions. Thanks guys!
Flux helps big time - be sure contact points are well covered - first put the iron tip on the pill side for a couple of secs, then drag to the board. Also, don't use a pointy tip on the iron, use a small wedge shape - more contact surface, more heat, better solder weld. Always pre-tin the iron - actually I apply the solder to the iron, hold on the pill edge for a couple of secs, then drag to the driver - the driver edge is copper, so it's easy - pill side is the tough part. I use a Hakko though - good qual, about 700 degrees.
I
just learned this tonight. I have a 45W iron that I thought would be too much so I went and bought a cheapie 25w. which seemed like it wasn’t working—- I felt like I had never soldered before. I heated up the 45w and boom I had to “drag”
some to the edge. very frustrating when it’s
your first time
If you only have a low wattage iron you can pre-heat the pill with a micro butane torch, then proceed. Be very careful not to scorch the LED, though.