Lenovo has announced that it has developed a Low Temperature Solder (LTS) process which will improve PC manufacturing by conserving energy and increasing reliability. Older, lead-based soldering was abandoned more than 10 years ago, and since then the industry has been searching for a solution to reduce heat, power consumption and the carbon emissions of the tin-based solder process which is used today.
Lenovo had investigated many combinations of solder paste materials composed of a mixture of tin, copper, bismuth nickel and silver, plus specific compositions of flux material and different profiles of time and heat temperatures. In typical electronics assembly surface mount technology (SMT) is used and the solder and flux mixture is first printed on the face of the circuit board. The components are then added and heat is applied to melt the solder mixture, securing and connecting the components to the board. With the new LTS process, soldering heat is applied at maximum temperatures of 180 degrees Celsius, a reduction of 70 degrees from the previous method.
After validation of the procedure, Lenovo discovered a significant reduction in carbon emissions as a result of using the new process. The procedure is already in production for ThinkPad E series and the fifth generation X1 Carbon. During this year, Lenovo intends to implement the new LTS process on eight SMT lines and estimates savings of up to 35% on carbon emissions. By the end of 2018, Lenovo aims to have 33 SMT lines with two ovens per line using this new process, giving an estimated annual saving of 5,956 tonnes of CO2. To put this into perspective, the equivalent reduction in CO2 emissions is equal to the consumption of 670,170 gallons of petrol per year.
