Is soldering necessary?

laze_doctor:

Yes, solder has flux, but it burns off immediately after you've applied it. If you're new to soldering, you're probably using the ol' apply-and-dab method of applying solder to a connection from a blob on the end of your soldering iron. Sometimes, that's the only way to really do it. Well the flux can help you with that, especially on surface-mount devices.

I often don't use the extra flux, but it does work pretty well. After you're done soldering on a board it's easy to clean up with some rubbing alcohol and a Q-tip.

maybe solder the pins in the socket ta...da.

From my own personal experience, the new "lead free" solder is garbage, AND harder for a novice to get a good solder joint.

I think radio shack still sells good old fashioned 60/40 lead & tin based solder.

I have 3 huge rolls I bought at a flea market a few years ago...

A nice LOW WATTAGE iron made for intricate work on small IC components is ideal, I love those.

Laserbee was dead on about the flux, AVOID the stuff that is sold in the plumbing section of hardware stores or the tool section at Wal mart.

As much as I hate plugging the place, radio shack will have the right flux.

Ah the good old days, anyone else remember when Radio Shack had chips, caps and resistors for sale?

Or how about the old "engineers notebooks" by Forrest Mimms?? I still have mine, the pages are turning yellow!

Don't think your still trying to decide what to do laze_doctor but if you have a heat gun, using conductive heat shrinking could be an option. It has an electrically conductive inner side, just insert the wires and shrink. I think it is somewhat harder to find than regular heat shrink tubing though. Also, it only works if you are trying to connect to wires to each other. Obviously it wouldn't replace soldering a wire to your driver but it would work perfect for wire to wire or maybe even wire to diode pins. Here is one website, it was the first link on google:

Heat Shrink, Heat Shrink Butt Connectors, Heat Shrink Wire Connectors, Heat Shrink Electrical Connectors

What about SUPER GLUE ????

While you are at it, get some copper plated perf board and some scrap components, practice attaching caps and resistors to the perf board.

In no time you will solder things like a pro, and maybe even get addicted to building projects!

It's fun, rewarding and an inexpensive way to get trinkets for yourself.

Super glue??? - a great big NOT! non conductive, not a great adhesive either and just plain not a choice.

Yes leaded solder is the best for hobbiests, and I'd go so far to say it's best for electronics in general barring whatever ill thought-out ecologic standards your country might have on its use.

For the alloy, get the eutectic solder (63% tin, 37% lead) instead of 60/40 because it goes directly from solid to liquid without the pasty intermediate states, which can produce a bad joint.

I think he was being sarcastic about the super glue

I personally don't bother with flux and my solder joints are fine, though for beginners it is a very good idea like others have mentioned. But the best way is practice. Grab some wire, and practice until you feel you could handle the diode. Once you get the hang of it, the iron really doesn't even need to be on the diode for over 2 seconds.

The tip is tinning however. Grab the wire or whatever you want to solder to the diode, and put a little block of solder on it. Then do the same for the diode leads. Then all you have to do is hold them both together, touch the iron for a few seconds and you will get a nice strong joint.

Also yes, lead-free solder is crap, you tend to get many more crappy joints using it. I don't think my electronics store is even bothering to sell it ...

I would advise against sanding the tips of your soldering irons. The tip is typically copper with an iron plating, and you don't want to sand through the iron. It acts as a barrier between the copper and the solder, because the solder would slowly dissolve the copper if in direct contact.

This page has lots of good information on successful soldering, and if you scroll down a bit there are diagrams showing typical tip construction. Further down they do mention using emery cloth to clean excessively oxidized tips, but I'd still not recommend it. They do mention not to use files to clean the tips, due to the possibility of breaking the iron barrier. I will admit to using sand paper on the tip once, but that was when I left my iron on for a few days (the auto-off feature is broken) and a really thick layer of oxide built up on the tip. It wouldn't tin no matter what and I had an urgent job to finish, so I sanded the tip until solder would wet it, then I bought a new tip for the next job.

I've soldered 10s of thousands of joints, both surface mount and through hole, over the past couple years and I don't even own flux. I have my soldering iron, some rosin cored solder, and a tip cleaner that consists of a mass of brass wool that you just poke the tip into a couple times to clean. This is the one.

If I end up with a blob of solder on the tip that doesn't have any more flux in it keeping me from making a good joint, I just clean the tip and start over with fresh solder. I don't have time to mess with flux. We're talking well under a second per joint. One of the boards I make has 163 joints on it and I'd be miserable if it took much longer per joint.

Regarding power: I see no reason not to use the most powerful soldering iron you can. The goal is to bring the joint up to temperature as rapidly as possible, apply solder, then remove the iron. Most irons have temperature controlled tips, so imagine a scenario where you have two joints and two irons set to the same temperature but one powerful and one weak. You touch the weak one to its joint and immediately the temperature of the tip drops as heat is transfered to the joint. The control system of the iron kicks in to bring the temperature back up to the set point, but it's not that powerful so it takes some time. Meanwhile heat is flowing away from the joint and towards your precious laser diode or other component.

With the more powerful iron, the tip stays closer to its set temperature, allowing you to bring the solder joint up to temperature more rapidly. This results in less total heat going into your joint and less chance of overheating components. It's kind of like grilling a steak. If your grill is nice and hot, you can get a good char on the outside while leaving the inside medium rare, but if it's not hot enough, the inside will be browned and the outside may not be seared at all. If you have your valuable components inside of the steak, which fire do you want to use?

I use a metcal soldering station with plenty of power and RF energy transfer to the tip. It takes maybe 6 or 7 seconds from turning it on til it's ready for soldering. I also use the sharpest/smallest tip I could find (.015" radius) and it works great for everything but soldering battery terminals on my truck. Here's the one I have: Metcal PS2E-01 Soldering Station I got a good deal on mine at $50 something on ebay, though they usually go for more than that.

I personally don't use flux, but I can see where it would help a novice.

Yes the tips pit faster when sanded, so unless I have extra money to buy tips, I just sand away as often as needed.

The lower wattage iron recommendation again would apply to a novice, they will take longer to get the joint right, and a 30+ watt iron will certainly cook components while a rook is trying to get a nice solder joint.

I carry a 25 watt in my tool box on service calls, it heats up faster and solders faster, and on a call time is everything.

I still have my 400 watt pistol, and when I have to attach large items (Like fuse blocks for high power car stereos) the big gun is preferred.

I've never needed to replace my soldering tips, nor sand them down. They'll treat you right if you treat them right.

If you're going to leave your soldering iron in the holder for more than a minute (or powering it down), put a blob of solder on it (feed it). The flux in the solder will clean the tip, while the solder itself will prevent oxidization. Then when you're ready to solder again, wipe it off on the sponge and you're ready to go.

A soldering tip is not just a copper "nail" (unless it's a Radio Shack variety); it's specially made to hold solder and ease the task of soldering. You don't want to sand your soldering tip because then it won't "take" to the solder as well as the original. It'll also degrade faster over time as the protective alloys aren't there.

Invest in a decent iron. You'll reap the rewards. Think about how much it would cost to buy the parts for your laser again because they were poorly soldered up. That money could've been saved and invested into the iron. It doesn't have to be pricey, but just get a nice one you don't have to worry about. Even the $17 25W Weller Marksman that Radio Shack sells is going to last you much longer than the crappy $11 black-handled one they've always sold.

And remember to load your tip up with solder when you get it!

Bionic-Badger said:

If you're going to leave your soldering iron in the holder for more than a minute (or powering it down), put a blob of solder on it (feed it). The flux in the solder will clean the tip, while the solder itself will prevent oxidization. Then when you're ready to solder again, wipe it off on the sponge and you're ready to go.

Click to expand...

This is really good advice.. Always wipe your iron *before* soldering something, not after. A hot iron exposed to air will corrode, though a blob of solder on the tip will protect it.

While on the subject of diode sockets, they sound interesting for me. I can mount a diode test block, and run many diodes through the test block quickly to test and plot each diode, without needing to solder every diode being tested.

I'm ordering a mounting block and diode sockets from Thor, but I have a question. There is a tool listed there which pulls the sockets off of the diodes. Now, is there also a tool which presses the sockets onto the diodes? If these are a tight fit, it seems risky without a proper tool to push them on...

Exerd said:

I'm ordering a mounting block and diode sockets from Thor, but I have a question. There is a tool listed there which pulls the sockets off of the diodes. Now, is there also a tool which presses the sockets onto the diodes? If these are a tight fit, it seems risky without a proper tool to push them on...

Click to expand...

If they're anything like the pin headers, it'll be as easy as pushing the diode pins straight into the socket. They're not made to be hard to push in, and the sockets have a nice plastic grip as well. They probably only sell a removal tool because the diode may be hard to grip to pull out, or may be inset slightly into the holder. A set of needle-nose pliers should be good enough for either task.

I can only assume the sockets are meant for virgin diodes with long pins and no solder blobs on the pins... Might want to check into that first, I'm not sure they'll work well with typical harvested diodes with their 2mm leads coated in lumpy blobs of solder.