What is the best solder for electronics and circuit boards

If you are looking for best solder for electronics and circuit boards, you come to the right place. Here, we will guide through a few important decisions you will make when you look for the solder for your electronics work.

Solder wire or its diameter

Solder wire comes in many different diameters such as 0.031 inch(0.8 mm), 0.02 inch(0.5 mm), 0.015 inch(0.3 mm), 0.05 inch (1.2 mm), and 0.062” (1.5 mm). Generally, .032″ thick solder suits for through hole soldering and some of the surface mount soldering. For surface mount devices with finer pitch, use .02″ or .015″. For soldering larger stranded wires, the 0.062″ thick solder wire is very helpful.

Kester 6040 Solder

Click Here to Buy highly reviewed Kester 60/40 leaded soldering wire at Amazon

Solder wire or solder paste

Solder usually come in two very common forms, soldering wire or solder paste. For electronic soldering, most of time you will need soldering wire for electronics instead of solder paste. Solder paste is often used in reflow process to solder SMD devices with very fine pitch. Here is a solder paste from MG Chemicals(product ink) at Amazon.

Lead vs lead freemudder lead free solder

Staring a decade ago, the European Union requires commercial electronics to use lead-free solder because of the health hazards. Most popular lead-free alloy often consists of Tin, Silver and Copper. It melts at a higher temperature in general, which obviously requires more heat, the common enemy of electronic components and circuit boards. If you plan to sell the devices you solder to customers in the EU, you should use lead-free solder. Otherwise, you can just use regular leaded solder with your soldering station or soldering iron. Solder with lead is usually less expensive than the lead-free solder. Lots of technicians we know of at semiconductor industry actually prefer regular leaded solder in the lab since it is easy to work with.

60/40 vs 63/37 solder

Most common lead-based solder you’ll find at the store will be 60/40 solder, 60% tin and 40% lead (60n/40Pb). There is one minor variation you may see though like 63Sn/37Pb. Compared with 60/40, 63/37 solder flows slightly better and freezes a bit faster. So, the solder joints will be less likely disturbed during solidification. Having said that, we have been using regular 60/40 for years with no issue.

Kester 63/37 solder

Click Here to Check Out 63/37 Kester Solder

Rosin-cored or acid cored:

If you use solder to solder electronic component and PCB, stick with the rosin core and stay away from acid core(usually for plumbing). Rosin core is basically a weak acid that removes oxidation and help solder spread out. This is an essential step to the soldering process.

Take a look at this thick plumbing solder and make sure that you do not buy it for your electronics work.

Solder for plumbing

Click Here to take a closer look at the plumbing solder

Extra stuff:

Kester Flux PenAs mentioned, this rosin, also called the flux, has an essential role in the soldering process. It melts at slightly lower temperature than the regular solder. It will prepare the surface of the metals to be joined. You may want to use the flux pen if the flux in the solder core is not enough for your application.


Most of the time “no-clean” solder may be not very necessary. But, here is one if you really need it.

Kester no clean solder

Click Here to Check Out Kester No Clean Core Solder


Too expensive?Kester pocket pack

Here are two alternatives that cost less. One is from Kester pocket pack solder shown on the right. The other one is from Miniatronics 60/40 rosin core solder. Here is the product link.


In Summary:

According to our past experience, the Kester solder is the best solder for electronics and circuit boards. If you have any questions, please do not hesitate to contact us. Thank you.