Soldering is one of the oldest technologies developed by humankind, perhaps as long as 6,000 years ago. Early uses were in the making of jewelry, cookware, utensils, and weapons. Metals such as gold, silver, and of course, copper, were soldered in such applications.
From this early time until now, soldering was accomplished by using a solder, flux, and heat to bond metals together. The most common example in our industry today is bonding copper PWB pads to the leads of components with lead-free solder. So, until today, little has changed in the basics of this ancient technology.
The high reflow oven temperatures required to melt lead-free solder, about 240°C, can wreak havoc with the polymer materials in the PWB and components. In addition, this high temperature reflow process can result in defects such as voiding, graping, head-in-pillow, and others.
If there was a way to solder SAC305 at temperatures well below 200°C, it would be a game changer. There would be little concern for PWB or component thermal damage and many of the aforementioned process-related defects would vanish. So, soldering SAC305 at low temperatures is like the Holy Grail of electronics assembly.
Fortunately, such a breakthrough has occurred. SAFI-Tech has patented a supercooling technology that creates micro-capsules of molten solder that remain liquid at temperatures far below the melting point of the solder. This technology enables soldering even at room temperature. Figure 1 shows circuits printed on the petal of a rose at room temperature.
Figure 1. Circuit lines printed on a rose with SAFI-Tech’s low temperature solder technology.
Indium Corporation and SAFI-Tech have just announced a partnership to explore market applications and the development of new products with this technology.
Commenting on this announcement, Indium Corporation's President and COO, Ross Berntson said, “We're always looking for innovative materials solutions that can give our customers ways to overcome current limitations of solder products. SAFI-Tech's supercooling platform is a unique approach that has the potential to be a solution across a variety of applications.”
Ian Tevis, SAFI-Tech's President, co-founder, and co-inventor, said, “Indium Corporation is a world leader and innovator in electronics solder products. Our partnership with Indium will allow customers to explore the unique opportunities possible with our supercooled solder materials.”
It’s likely not an overstatement to say that this technology has the potential to be one of the biggest breakthroughs in the history of soldering.