Know More about Low Melting Point Solder

Posted by Alphaassembly on October 24th, 2016

As the name itself explains, low melting point solder is a solder metal which has a low melting point, typically below 200o C. Low melting point solders are extensively used in the electronics industries, typically in applications where high temperatures are likely to damage the materials of the electronic components. Their uses and importance in the electronics manufacture industry is truly unmatched. In this article, we will help you know more about low melting point solders and how they are done.

Low temperature soldering
Some special manufacturing requirements may necessitate the use of low melting point solders. Components that have a likelihood of getting compromised at high temperatures require low melting point solder metals in order to achieve a joint with other surfaces. Between 50o and 183o C, there are a wide range of alloys that can be made from tin, indium, lead and bismuth. These form the most commonly used group of low temperature solders in the industry.

Important factors to consider
Low melting point solder begins with acquiring a solder alloy which contains low melting point metals which will be suitable for your job. The most important facts to consider while selecting your low melting point solder are as follows:
•    Wettability (formation of a strong metallurgical bond between both the surfaces to be soldered)
•    Mechanical reliability (the bond created should be sound enough to withstand what it was made for)
•    Interaction with soldering surfaces
•    Feasibility (should not be very expensive)
Rest of the process is more or less the same, however, since heating to a very high temperature is not required, a soldering iron may not be used. A hot plate may work fine for this job.

Benefits of low temperature solders
There are many advantages of a low melting point solder technique. The first benefit is that it reduces the cost of the surface mount assembly process. This can be achieved by using substrate and components which are comparatively low cost when seen against high-temperature soldering options. Sometimes, when a circuit board has certain sensitive components, the manufacturing process incorporates one more step which uses low temperature soldering to join these sensitive components. The most important advantage of low temperature soldering, however, is that it makes it possible to employ multiple reflow processes. Another major advantage is that most low temperature alloys are lead-free, which means there will be no toxicity issues while the process is ongoing.

Selection of fluxes for the process
Low temperature soldering involves application of a separate category of fluxes meant exclusively for low temperature applications. This is because conventional fluxes (water clean and no clean types) activate at 150o C, by which time the low temperature solder metal already melts. Fluxes should be subjected to two tests before finally making the selection for your low temperature solder. The first is the spreading test, which helps you determine the strength of fluxes. The second is the wetting balance test, which helps you to determine the activation temperature of the flux.

The information above is meant to give insights about low temperature soldering to the readers. Low temperature soldering has made it possible to create electronics with highly efficient materials and high safety standards.

About The Author:

Alpha Assembly Solutions is a premier company engaged in the development and manufacture of high quality electronics assembly materials. Since the year of its inception, way back in 1872, the company has played its role on the frontline of innovation, bringing many first-to-market products to the fore thereby, creating a premier niche for itself in the market.