Those involved in manufacturing industrial equipment and smart appliances are well aware that the service life and measurement reliability of temperature sensors depend not only on the accuracy of the internal temperature-sensing chip but also on the oxidation resistance of the single-ended lead pins, which directly determine both batch welding yield and long-term operational stability.
Many companies frequently encounter a common issue: when sensors are stored for extended periods or placed in humid environments, their pins gradually blacken and oxidize, significantly reducing solderability during subsequent assembly processes such as component insertion or wave soldering.
Weldability refers to a metal pin’s ability to be uniformly and firmly wetted by solder. Once an oxide film forms, solder adhesion becomes difficult, leading to issues such as poor solder joints or cold soldering; subsequently, equipment may experience poor contact or intermittent temperature readings during operation.
Currently, there are two main types of pins used for temperature sensors in the industry: those coated with tin wire and those coated with magnesium wire.
Tin-coated pins are cost-effective, suitable for short-term conventional storage and instant soldering, but exhibit poor weather resistance. In humid environments, prolonged storage, or outdoor conditions, they rapidly oxidize and blacken, resulting in high rates of repair needs and scrap due to re-soldering.
Magnesium-plated wire pins exhibit significantly superior moisture resistance, corrosion resistance, and aging resistance compared to tin-plated counterparts, with a markedly reduced oxidation rate. They maintain excellent weldability even under extreme temperature cycles, high-humidity storage conditions, or harsh outdoor environments, making them ideal for industrial applications requiring long-term stockpiling and high reliability.
Many people ask: Can sensors that have already turned black and oxidized still be used?
In fact, pin oxidation only affects soldering conductivity and does not impair the temperature-measuring core function of the internal temperature-sensing chip; the measurement accuracy remains unaffected.
The primary risk lies in the reliability of electrical connections and the oxide layer’s ability to prevent solder penetration; mass production often introduces latent quality defects.
For mild oxidation, grind the surface fine to remove the oxide layer and use it with flux; for severe blackening, replace the component directly to prevent contamination of finished products and subsequent rework.
To mitigate pin oxidation at the source, standardized operating procedures and storage practices must be implemented: operators should wear gloves when handling components to prevent chemical corrosion caused by hand sweat; idle sensors shall be sealed in anti-static, moisture-proof bags and stored in a dry environment with constant temperature and humidity, away from water vapor and corrosive acidic or alkaline environments.
Sourcelin Electronics offers a comprehensive range of magnesium-coated wire high-temperature oxidation-resistant sensors, along with professional material selection guidance, storage protection solutions, and on-site welding process assistance, helping enterprises effectively prevent quality defects caused by pin oxidation.
