High Reliability Challenges with Cu Wire Bonding for Automotive Devices in the AEC-Q006

Copper (Cu) wires are increasingly used in semiconductor devices to provide cost-effective packaging. With its excellent electrical properties, copper has higher mechanical properties than gold (Au) wire. Many of the challenges for Cu wire have been and are being evaluated to meet the stringent quality requirements of the automotive industry. In July 2016, the AEC-Q006 Revision-A document was published by the Automotive Electronics Council (AEC), which specifies the minimum requirements for qualification of Cu wire interconnections used in automotive electronics applications. This paper presents the reliability test results of Cu wire materials which are palladium coated on Cu (PCC), Au-coated on PCC (AuPCC) and Alloyed Cu wire. All test products were covered with a sulfur-free epoxy molding compound (EMC) that was recommended for automotive package evaluations. In this study, the reliability test vehicles followed AEC-Q006 requirements to evaluate Cu wire capabilities. The reliability test items included high-temperature storage (HTS) @175°C up to 2000 hrs, temperature cycling (TC) 'H' up to 3000X and unbiased highly accelerated stress test (UHAST) up to 192 hrs. Wire pull test, stitch pull test and ball shear test data were collected every reading point after molding compound decapsulation. The reliability test results for Cu wires were verified to meet AEC-Q006 requirements. The data shows that Cu wires can be used for applications in automotive industry.