Hello, I used to solder with Pb, but I changed to Sn 99% 0.7% Cu solder. I use a Soldering Iron Ceramic ZD-200N 30W. When I solder with this solder (Sn/Cu) and I then try to add solder to a neighbor pad, and try to connect them, the solder does not melt, although the Soldering Iron is heated. With Pb I have never had such type of problems. How can I fix this? I mean is counter productive, I cannot solder like this...
Use a little bridge of copper wire. Bend like the letter "L", hold it from the long shaft and solder the short part. Then cut the "handle" off.
Try a hotter iron and use liquid/paste flux.
Use a tinned jumper wire between the pads.
For 50+ years I have used 63/37 and 60/40 with flux core, never had problems; will never change to lead free versions. 
Or go back to Pb solder. It's not illegal to buy or sell it to hobbyists. The restrictions were to stop it being used on industrial scales. There will be supplies of Pb solder around for years, manufactured before the "ban" and only the hobbyists want or can use it.
Does this work for what I need to solder?
Power supply: 230V AC / 50Hz
Voltage: 24 V
Power: 48 W (max. 60 W)
Temperature range: 160 - 480°C
That is a good station. I agree with PaulRB and Larryd, use 60/40. That has worked well for me during 50 years.
Flux and/or clean surfaces is a must.
What is the purpose of flux?
When flux is hot, it removes oxidization from surfaces thus allows the solder to wet the surfaces being soldered.
Hot flux on a previously soldered component allows that connection to re-wet and flow nicely around the joint.
A joint that has hot flux on it, prevents re-oxidation during the soldering process.
63/37 solder melts at 183 degrees C. It's called eutectic solder and the alloy "magically" melts at a lower temperature than tin or lead alone.
Your lead-free solder melts at 227 degrees C, so you need a hotter soldering iron.
Flux cleans and deoxidizes, although you generally still need to start with clean surfaces. It also helps with heat transfer and I think it does something with the surface tension to help the solder "flow & stick" when it's liquid/molten.
It's difficult to solder without it flux. Most wire solder meant for electronics has a flux-core (or, if you are using solder paste, it's mixed-into the paste). But, it often helps to have a little bottle of flux in case you need more.
There are (at least) 3 types/categories of flux.
Traditional rosin flux is only active when hot so it's generally safe if you don't clean it off after soldering. But, it leaves an ugly brown residue and it requires chemicals to clean (alcohol will work but I'm not sure if alcohol actually dissolves it).
No-clean flux is inert at room temperature and it leaves a clear residue. (It also requires "chemicals" if you want to remove the residue.)
Water soluble flux can be cleaned with water and it has to be cleaned-off because it remains active (and I think conductive) at room temperature. In "the industry" they use de-ionized water but tap water is OK as long as you dry the circuit board. You can use compressed air to blow-off the water, or a blow-drier, etc. Water doesn't hurt most components, but it can sometimes damage transformers or piezo buzzers, pots, etc., so you may have to check the datasheet to see if water cleaning is OK.
At work, we mostly use water soluble flux (and lead free solder). Then components that can't be submerged are soldered later with no-clean flux.
At home, I'm still using tin-lead solder and rosin flux. I have no plans to go lead-free, but I may switch to water soluble flux.
Yes, I just used flux, nothing works... I need more heat... The Iron solder I found says among other characteristics:
"Sleep function version and non-sleep function version are both available"
Any idea what this is? I mean it has on/off button already.
Flux will not help to build bridges from one copper strip to another. Something else is the issue, temperature or likely, the solder.
I prefer cored leaded solder, but use the cored lead free stuff often, it works, not a lot of difference really.
Please post a close up image of the join.
alex5678:
Yes, I just used flux, nothing works... I need more heat... The Iron solder I found says among other characteristics:
"Sleep function version and non-sleep function version are both available"
Any idea what this is? I mean it has on/off button already.
Please be specific about the flux. Brand name and product name. Just any "flux" will not work with lead-free solder.
Paul
alex5678:
Yes, I just used flux, nothing works... I need more heat... The Iron solder I found says among other characteristics:
"Sleep function version and non-sleep function version are both available"
Any idea what this is? I mean it has on/off button already.
Hi,
What make and model of soldering iron are you looking to buy?
Sleep function basically shuts the iron down, the temperature is reduced when the iron is not in use, mainly to preserve the tip and some power.
Usually when you put the iron in its cradle, either instantly or after some time inactive it is put in sleep mode.
This means when you lift the iron out of the cradle, you have to wait for the temperature to come back up to set point, most irons with this facility take 5 to 10 Seconds.
Does your iron have a temperature readout or light to show what mode it is in?
In the long term, Lead solder reins supreme for home use, and even commercial/industrial repair. Saves time. money and quality of job.
Tom...
That is a good station. I agree with PaulRB and Larryd, use 60/40. That has worked well for me during 50 years.
Flux and/or clean surfaces is a must
Yes, I bought this one:
I do not use Pb... But the Sn is unbelievably difficult to solder....even with the flux...Ι have changed nib/point to something more thick so that I achieve something...
Hi
Ops purchase;
Tom...
Ok thicker nib works! How to I clean this flux: flux
?? Or I don't?