| 학회 | 한국재료학회 |
| 학술대회 | 2019년 가을 (10/30 ~ 11/01, 삼척 쏠비치 호텔&리조트) |
| 권호 | 25권 2호 |
| 발표분야 | 특별심포지엄3. 고성능/친환경 첨단접합소재 및 기술 심포지엄-오거나이저:이성희(목포대) |
| 제목 | 고효율 전기자동차용 Solid-state 접합소재 및 공정 |
| 초록 | Power electronic device manufacturings have still used Pb-Sn soldering with high Pb contents as a common interconnection technology because of the exemptation of environment regulations, although environment regulations such as RoHS directives have brought the remarkable change from Pb-Sn soldering to Pb-free soldering in the general electronic industry. In recent years, power electronic devices move to post-silicon wide band-gap (WBG) semiconductors like SiC or GaN for higher efficiency. SiC power devices, in particular, has lower On-resistance, higher switching speed, and higher heat dissipation that allows to miniaturize the power modules applied to electric vehicle with high efficiency. However, Pb-Sn soldering is too hard to apply in SiC power devices because the junction temperature of SiC devices has passed over 300 ˚C. SiC power devices have seeking carefully for an alternative interconnection technology to be particularly acceptable for SiC or GaN. Some interconnections have been proposed along with power device development toward the integrated power module usable at high operation temperature. Among many interconnection candidates to replace high-Pb solder material, the die-attach method using Ag material, has been developed most actively. Ag material has high melting point with high heat and electrical conductivities, suitable for the SiC power package and modules at high operation temperature. Although die-attach method using Ag thin fim can be applied in wafer-to-wafer bonding or LED bonding, Ag paste sintering method has been usually developed in SiC power module for high relibility. Even if Cu paste sintering has been proposed in SiC power module, it is too difficult to prevent Cu oxidation during Cu paste fabrication. In transitional liquid phase sintering (TLPS) method, it essentially requires considerably high bonding temperature and pressure that involves potential reliability risks particularly for SiC power module. We have developed Ag pressureless sintering process as an alternative interconnection technology to apply in the power module. SiC devices and DBC pattern were designed to drive low-power 3-phase motor system. Ag paste was printed on direct bonded copper (DBC) substrate by screen printer and the SiC MOSFETs and diodes were mounted on Ag paste. The specimens were then inserted in N2 oven, and heated at relatively low temperature of 250 ˚C without any pressure. Voids in chip bonded area were inspected by X-ray equipment and die-shear strength of the bonded specimens were measured, and evaluated as a function of the initial vacuum values as well as the void concentration. Interface microstructure was also observed by scanning electron microscopy. On the basis of our results, we can realize reliable SiC power module by controlling Ag sintering process. |
| 저자 | 오철민 |
| 소속 | 전자부품(연) |
| 키워드 | <P>전기자동차; Solid-state; 접합소재; 접합공정</P> |
