Indium Blog

Transitioning to Low- or Mid-Temperature Solders Can Reduce your Carbon Footprint

  • Indium Corporation

  • Typical analyses of low- and mid-temperature solders focuses on improvements to important metrics such as shock resistance and component resilience. What is less known–and even less well-quantified–is that these solders also present a significant environmental benefit. A recent Indium Corporation study with Heller Industries analyzed a variety of solder alloy types and peak reflow temperatures to find how the emissions profile changes across possible options. A key result was that changing solder alloy type strongly affects the total emissions, which can be leveraged in decarbonization efforts.

    One of the primary drivers of emissions within printed circuit board assembly is energy. The assembly process is energy intensive as the reflow ovens demand sufficient heat to operate. Relying on an energy-intensive process in today’s regulatory and investing environment adds risk because of how low-emissions technologies are favored. Tax credits and ESG compatibility are shifting consumer behavior to those processes which require less emissions. Considering the time-horizon of the U.S. Inflation Reduction Act extends into the 2030’s–and supply chains are adjusting to this new environment–being a laggard in the field is to be avoided. A reasonable goal then is to utilize less energy across the assembly process and reduce emissions where at all possible. This is cannot always be done through process optimization–high-temperature solder alloys have a well-defined energy requirement that is hard to circumvent. Such a barrier would be problematic IF the process itself was the only decision-lever for decarbonization. Luckily, another option exists with proven results.

    Transitioning to using low-temperature solder alloys can significantly reduce the energy demand of the PCB assembly process. It could be cheaper and more environmentally sound to move to a new technology altogether rather than stay in the status quo. This has parallels across many different sectors. For steel decarbonization, a blast furnace can be made more efficient to a point, but moving to an electric arc furnace creates a step change in emissions reductions. Similarly, internal combustion engine cars have been getting more efficient for decades, but electric vehicles provide a step change in emissions reductions under moderate grid decarbonization. Peak solder temperature can be thought about in a similar vein. SAC-type solders can be optimized to a point, but only transitioning to a different solder type yields strong decreases in both emissions and costs.

    Table 6 - Energy Consumption of Profiles Under Light Loading Test Conditions.

    When deciding on decarbonization strategies and cost-cutting measures, it is worthwhile to think of low- or mid-temperature solders as a transition point if the application permits. These changes have short-term fiscal and environmental benefits while helping shield companies from the risk that future regulatory environments pose. Any interested parties should get in contact with us to discuss if this is a right avenue for you and how our products can help. We look forward to speaking with you!