Uyemura International Corp.'s GHS-51 process is designed to prevent whisker formation in electroplated tin for 22,000 hours—and longer.
This high-speed electrolytic process represents a breakthrough in the control of tin whiskers, the company says. Whisker crystals of tin and tin-based alloys are the most common culprits in the short circuiting of electronic components. Most often, the cause of tin whisker formation is compressive stress. The technology developed by Uyemura is designed to dissipate compressive stress, preventing whisker formation.
GHS-51 uses a high purity anode, and is ideally suited for connectors and semiconductor lead frames. It offers high deposition speeds for rackless and reel-to-reel processing, and high deposition efficiency over a wide current density range. The bath is lead- and fluoride-free and foam-resistant. Operating range is 113–131°F, with 122° optimum temperature.
The GHS-51 film has a uniform white matt appearance; appearance after reflow is described as excellent. Carbon and sulfur concentrations in the film are very low, and control over liquid level is easy. The film is heat-resistant, with excellent solderability, the company says.