Importance of Low Temperature Soldering Process

Posted by Alphaassembly on July 26th, 2017

Low temperature soldering is used in applications where temperature sensitive components are involved. Low temperature soldering is ideal where higher reflow temperatures may cause failures. The melting temperatures for soldering alloys used in the soldering process often range between 47°C to 1064°C. Low temperature soldering alloys usually melt at temperatures less than 180°C. Low temperature soldering is composed of alloys and metals that are used in various joining applications, particularly in electronics interconnect. When selecting a soldering alloy to match the needed temperature requirements, a few things should be considered like the components’ temperature threshold, device’s final operating temperature, necessary thermal properties, the possibility of CTE (Coefficient of Thermal Expansion) mismatch, and other specifications, like the temperature requirements for lead-free soldering.

Low temperature soldering is required for MEMS (Micro-Electro-Mechanical System) devices, some types of III/V semiconductors, and crystal oscillators. It is also used in low-Tg or low-melting flex circuitry, which are common in smartwatches, IoT (Internet of Things) devices, and cellphones. Many devices, like BGAs (Ball Grid Arrays), also use low temperature soldering to avoid NWO (Non-Wet open) failures, and HIP (Head in Pillow) failures. Low temperature soldering is suitable for step-soldering, too, when a low temperature, secondary reflow process is necessary after a standard SAC or eutectic soldering process. Low temperature soldering is also used in the manufacturing of fire detection devices, thermometers for food preparation, and other temperature sensitive devices to meet the health and safety requirements. Some types of electrical fuses use a low-melting alloy, too.

Using a low temperature solder in a through-hole process replaces two SMT processes and the wave soldering step, hence, adding value and resulting in a lesser total cost of ownership. By removing the wave soldering step, the use of low temperature soldering helps save energy, minimize labor, and reduce material costs. Low temperature soldering enhances secondary soldering processing to enable rework on certain components.

Some well formulated lead-free soldering alloys have lower temperature melting point too. They also show temperature resistance when undergoing accelerated thermal cycles. The use of lead-free alloys in electronic manufacturing was brought on by WEEE (Waste Electrical and Electronic Equipment) and RoHS (Restriction of Hazardous Substances) initiatives.

About the Author:

Alpha Assembly Solutions Inc. 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.