Highly reliable and cost effective thick film substrates for power LEDs

This paper presents Thick Printed Copper (TPC) as substrate technology for High Brightness LEDs, which features a strongly improved reliability combined with a significant cost advantage over incumbent technologies for High Brightness LED substrates. The advantages of TPC over Direct Bonded Copper (DBC) and Direct Plated Copper (DPC) substrates will be demonstrated by thermal shock test results and a demonstration of the versatile design options. The good thermal performance of TPC is demonstrated by comparative Finite Element Modelling of TPC and DBC substrates. A detailed review is given discussing the different copper to ceramic bonding mechanisms, which prevent void formation and are responsible for the excellent thermo-mechanical reliability.