Hello,
I only have this type of flux in my local store. The owner says it's for electronics but the official website says it's for copper piping. It contains zinc chloride and ammonium chloride, which as far as I know, are acidic and should not be used for electronics?
[QUOTE]Solder grease
Flux based on zinc chloride and ammonium chloride with pasty consistency for soft soldering of copper and copper alloys for copper pipe installations, radiator construction, plumbing, dip soldering, fitting manufacturing and other solder works.
Delivery form
Content: 0,100 kg
Packaging unit: Karton à 50 Dosen[/QUOTE]
Please let me know. This flux won't create good solder joins, and when soldering two wires together, the solder won't travel smoothly around the wires and I had to feed the tip in order to get the joint.
You're not supposed to use "acid flux" on electronics.
There are 3 categories of flux for electronic soldering. (I don't know exactly what chemicals are in them).
Rosin is "traditional" and it works well. It leaves an ugly brown residue but it's not harmful if you don't clean it. "At home" for occasional hand-soldering I clean the board with alcohol but I think there are "better" solvents.
At work, we used to use liquid (cooled) freon for cleaning but that's toxic waste so it's not used anymore. I don't see rosin flux used much in industry anymore either, and I don't know if that's because alcohol doesn't work well, or because the alcohol with dissolved rosin is hazardous.
Now where I work we mostly use water soluble flux. It doesn't seem to be as "effective" as rosin for hand-soldering but it works fine in the surface-mount and wave solder machinery. It's corrosive if it's not cleaned. We use DI water for cleaning but at a previous job we just used tap water in a sink. Some components can't be submerged (some switches or buzzers, etc.) but it's OK with most parts as long as the board is dried.
For parts that can't be cleaned in water we use no-clean flux (after the main soldering & cleaning). It leaves a clear harmless residue and it's only slightly-ugly. I don't have much experience with no-clean so I don't know how "effective" it is. It seems like you can clean it with alcohol but I'm not sure if alcohol completely dissolves it and there might be some remaining residue.
We did basically the same in my ex-company. Rosin flux cannot be used in a wave solder, so that flux went away. We used regular drug store IPA, isopropal alcohol which was mostly water, for cleaning hand soldering flux.
The last board washing system used de-ionized hot water for board washing. Originally we use a regular dish washer and hot tap water. Kept that as a spare!
No clean flux was used on hand-add parts after the board was washed and IPA to clean after. It does leave a bit of white residue that some customers complained about.
All the flux used in solder paste is water soluble.
All boards were dried after wash using deionized compressed air.
And now you know a tiny bit about solder flux used in the industry. No one knows the whole story, I am sure.
Curious, why do you need separate solder flux? Electronic "wire" solder has flux in its core. The only time I use flux is when repairing something where the surface had oxidized and I can't clean it mechanically.
Yes. I have a solder wire with flux in its core, but I used it on a circuit board and it got all messy and solder joints be swimming around the board from the amount of flux. besides, it is lead-free which made it difficult to create solder joints, really. Not to mention when I try to solder two wires together with it, it just won't melt on the wire no matter how much heat I put from my iron.
The owner just wants a sale, this stuff destroys electronics, never use it. Flux for electronics is rosin based, not acid. ZnCl2 and AlCl3 are strong acids designed to etch into metal surfaces and strip off the top layer. Rosin (and other electronics fluxes) reduce metal oxides back to the metal without etching away any metal.
Many electronic components have extremely thin tin plating on the surface so strong acids are going to remove that plating leaving the underlying metal (which may be un-wettable by solders).
Brace yourself for some brutal honesty. It really sounds like, you simply haven't learned to solder very well. I've done all kinds of work with the in-core flux solder, and this kind of thing really doesn't happen to me.
There are two things I use additional flux from the tube for - desoldering operations, and occasionally when soldering tiny SMD parts.
If solder will not melt/stick to your wires, the wires are either dirty or have oxide on them. Clean copper and molten solder go together like butter on hot bread!
Added after thought. The rosin flux is there to keep the OXYGEN away from the solder and the bare hot copper.
probably because it don't have flux (checmical required to de-oxidize surfaces, increase surface tension and enable solder to "join" them.
Copper is extremely easy to be "joined" by tin and this isn't much a problem. However iron (and other metals found on PCBs and electrical components) are more difficult to handle.
Yes. If you clean them well the result is extremely handsome. They require higher temperatures and the fumes can be nasty, but I take that.
Lead-free have worse surface tension, but it shouldn't make it impossible to work with.
Ok. Let's try that again.
details
Find a joint (or spot) that you want to solder together. Grab the soldering iron on one hand, the solder tin (rosin core) in the other.
Touch the side of the joint with the iron, while also touching solder tin to that same side. the solder should melt and onto the joint. If it doesn't immediately do so, don't hurry and keep feeding in solder. Try to "wiggle" the iron round a little bit to help the molten tin grab onto the two parts.
Here. Have a youtube video.
For soldering wires, it's best practice to coat them with solder first, before trying to solder them together.
And yes, it's best to have a station or a temperature-controlled setup, but they are expensive. If you are a bit more experienced you can switch a regular iron on and off manually (a really bad PWM) to make sure it won't get too hot and burn everything up. If your solder iron's tip have gone blue-ish purple or your solder seem to be oxidizing very quickly, let it cool down a bit by unplugging, It usually have enough thermal mass to do at least a few more joints.
