Effect of Temperature on the Die Shear Strength of a Au-Sn SLID Bond
- PDF / 298,708 Bytes
- 3 Pages / 593.972 x 792 pts Page_size
- 39 Downloads / 198 Views
a rapid growth in the demand for reliable high temperature (HT) electronic devices. In applications like engine control, space exploration, drilling, and well intervention systems, the requirements for HT stability is becoming more stringent. Wide-bandgap semiconductors, in particular silicon carbide (SiC), are commonly considered as the semiconductor of choice for HT applications.[1,2] Reliable HT die attach and interconnect technologies, i.e., the mechanical support and conductive path required to achieve connection from a circuit element to the rest of the circuit, are also emerging. Several alternatives exist, where Au-Sn solid–liquid interdiffusion (SLID) is an established technology.[3–7] Methods to test and characterize the reliability of HT die attach and interconnect technologies typically consist of high temperature storage (HTS) and thermal cycling (TC) followed by bond strength quantification, electrical resistance measurements, cross-sectional analysis, and fractography.[3,6–11] Even though the HTS and TORLEIF ANDRE´ TOLLEFSEN, Research Scientist, is with the SINTEF ICT Instrumentation, Oslo, Norway, and also with the Institute for Micro and Nanosystems Technology, Vestfold University College, Borre, Norway. Contact e-mail: [email protected] OLE MARTIN LØVVIK, Senior Scientist, is with the SINTEF Materials and Chemistry, Oslo, Norway, and also with the Department of Physics, University of Oslo, Oslo, Norway. KNUT AASMUNDTVEIT, Associate Professor, is with the Institute for Micro and Nanosystems Technology, Vestfold University College. ANDREAS LARSSON, Senior Scientist, is with the SINTEF ICT Instrumentation. Manuscript submitted January 15, 2013. Article published online April 17, 2013 2914—VOLUME 44A, JULY 2013
TC are performed at the intended application temperatures, the characterization is mainly performed at room temperature (RT). This is believed to be tolerable as long as the investigated die attach and/or interconnect technology is stable in the temperature range between RT and application temperature, i.e., it has no known phase transition it the temperature range. In this work, the bond strength, or more precisely, the die shear strength, has been measured as a function of temperature from RT to 573 K (300 C). Remarkably, the shear strength is greatly reduced with increasing temperature. An optimized HT die attach and interconnect bond for a Cu/Si3N4/Cu/Ni–P//Au/Au-Sn/Au//Ni/Ni2Si/SiC package (representing a SiC transistor assembled onto a Si3N4 substrate utilizing Au-Sn SLID) was fabricated. The mechanical properties of the bond were optimized with respect to the SLID composition. It was found that the maximum strength (as measured at room temperature) was obtained with a considerable surplus of Au. Details about the processing conditions can be found in an earlier published work.[5] The samples were die shear tested in a NordsonDage 4000Plus shear tester with a 200-kgf load cartridge. A test height of 110 lm above the substrate and a test speed of 10 lm/s were applied. Four sample
Data Loading...
