Lead free equipment, any good?

Thread Starter

tarts

Joined May 27, 2009
20
I just bought a soldering station which is for lead free soldering. Is there any difference in soldering station compared to "leaded tools".

I also want to buy some spare tips. I don't do lead free soldering, but can a lead free tip be used with leaded solder? Silver and tin should be even more corrosive so then lead free tips should be only better, no downsides right?
 

Wendy

Joined Mar 24, 2008
23,408
If it is a temperature controlled iron, there should be no difference. It will have to be set significantly hotter for lead free solder, since the solder needs more heat. To the old hands tin/silver solder is a major pain. The military tends to agree with this assessment, since there are significant problems (such as dendrites) with the newer stuff.
 

marshallf3

Joined Jul 26, 2010
2,358
Howeer adding some silver to common tin/lead is actually a good thing, that's what Tektronix used exclussively in their equipment for years. Doesn't raise the melting point of the alloy much at all yet produces far stronger joints.
 

jpanhalt

Joined Jan 18, 2008
11,087
I just bought a soldering station which is for lead free soldering. Is there any difference in soldering station compared to "leaded tools".
Yes. The lead-free soldering tips are different.

I also want to buy some spare tips. I don't do lead free soldering, but can a lead free tip be used with leaded solder?
Yes. See Hakko attachment below.

Silver and tin should be even more corrosive so then lead free tips should be only better, no downsides right?
I don't see that logic. No one said that lead-free tips used for lead-free solder lasted as long as tips intended for lead. See Hakko.

http://www.emsco-usa.com/pdf/hakko_pbfree_tips.pdf

Hakko and Pb-Free Soldering Tips
Starting in May of 2004, all soldering tips and desoldering nozzles manufactured by Hakko Corporation were tinned with a lead-free (Pb-Free) coating. This change was implemented to enable our customers to meet the growing demand for Pb-Free processes. The Pb-Free coating is 100% tin (Sn).
Customers that continue to use Pb based solders may use these tips with little to no change in the process. However, be sure to immediately re-tin these tips with your Sn/Pb solder as soon as the tip reaches soldering temperatures. The Sn coating will oxidize much faster than typical Sn/Pb coatings. By flooding the tip with solder the operator will prevent oxides from forming on the tinned tip surface. Heavy oxidation will affect the heat transfer ability of the tip by preventing solder from wetting to the tip. By tinning new tips with Sn/Pb solder four to five times, wiping the tip on a
damp sponge or 599 tip cleaner between solder applications, the tip will perform the same as tips tinned with Sn/Pb solder. Operators must be sure to feed solder over the entire tinned surface of the tip. Customers using Pb-Free solders will need to pay particular attention to tip maintenance. The
spread characteristics (wetting) of lead-free solders are very poor in comparison with Sn/Pb solders.
Pb-free solders wet slower that Sn/Pb solders. Poor spreading is characteristic of all leadfree solders as the absence of lead reduces the flowability of the solder. This poor spreading occurs not only with respect to boards and components but also with respect to the soldering iron tip. The melting point of lead-free solders is 20°C to 45°C (35ºF – 70ºF) higher than that of conventional Sn-Pb solders. For more information on Pb-Free soldering, please refer to the Hakko web site at www.hakkousa.com and click on the “Lead Free” button on the sidebar tower. In many applications this may mean an increase in the soldering tip temperature. Raising the tip temperature should always be done cautiously. Tips wear out rapidly at high temperatures and the flux is activated faster than the solder can wet. Solder tips are made of copper (Cu) due to its superior thermal conductivity. Since Cu will quickly go into dissolution with Sn (forming Cu/Sn intermetallic) and it will oxidize/corrode when exposed
to high temperatures, its surface is covered with iron (Fe) plating to extend the life of the tip. Fe will form intermetallics with Sn but at a slower rate than Cu/Sn. The rate of intermetallic formation becomes faster at higher tip temperatures and this tendency is particularly marked at
temperatures above 400°C (750ºF).
Tips soldered with Pb-Free solder have higher susceptibility to non-wetting caused by oxidation (see figure 1). The tip surface will appear black or dark blue and solder will not wet to the surface.
Note: Bolding is mine.

John
 
Top