Microsemi Corporation introduced the industry's smallest hermetic surface mount package for power transistors and diodes. Microsemi pioneered the development of the new industry-standard U4 package, which has achieved Defense Logistics Agency (DLA) qualification for a range of products. The devices assembled as vehicles for this package qualification included medium power NPN and PNP bipolar transistors. Microsemi will also pursue qualifications for additional device types to support customer-specific requirements.
The compact U4 is 70 percent smaller than its U3 predecessor and available now exclusively from Microsemi. The package is constructed with aluminum nitride ceramic, which provides excellent heat dissipation. This is particularly important for small products such as power supplies, converters and regulators which operate at high current rates that can cause overheating issues.
"Microsemi created the hermetic U4 package to provide defense contractors with a rugged surface mount packaging solution for space-constrained products used in military environments," said Simon Wainwright, vice president of Marketing and Business Development for Microsemi's HiRel Group. "We have been serving the defense sector for more than 50 years, and will continue to build on our track record of innovating solutions for applications where exceptional performance and reliability are vital."The U4 has a typical power rating of 5W-15W (@ Tc=25°C) and is the smallest, hermetic surface mount package in its power category. Packaged parts are compatible with current pick-and-place assembly processes and are offered in tape-and-reel format.