IXAN0031 New ISOPLUS247TM Power Package Features 2500V Internal Isolation Revolutionary Approach Improves Thermal Conductance and Reliability pability because the thermal expansion coefficient IXYS Corporation has introduced a new, isoof the silicon die matches that of the DCB; lated plastic encapsulated package for all types of 6. Small chip-to-heatsink stray capacitance for discrete power semiconductors, one which promreduced EMI/RFI emissions; ises to change the way power devices are attached 7.The DCB substrate can be etched like a PC to heatsinks. The new ISOPLUS247TM has an inboard allowing for more circuit configurations than ternally isolated mounting tab with a 2500V(RMS) normally found in a non-isolated TO-247, e.g. epitaxial ultra-fast recovery diodes and Schottky connected common anode or in series, multiple diPlastic housing Silicon die odes in series, MOSFET connected in series with a Schottky diode with or without an antiparallel diode. The primary advantage of ISOPLUS247 packaging is the very low thermal resistance achievable in DCB lead frame a rugged, high voltage, isolated mounting system. Table 1 compares the thermal resistance of a 55A/ 500V MOSFET chip in the ISOPLUS247 package Figure 1: Cut-away view of the ISOPLUS247 package (IXFR55N50) to the hole-less TO-247 version (IXFX55N50) when isolated with various interface isolation voltage rating. The package meets the stanmaterial. Figure 2 shows the allowable current handard JEDEC TO-247 outline and is intended for dling capabilities of the various mounting conditions. pressure mounting applications since there is no Inspection of this table shows that depending mounting screw hole. As can be seen in Figure 1, the usual copper lead frame has been replaced by a upon the mounting technique, allowable output curdirect-copper-bonded (DCB) alumina substrate rent can be increased by about 50% for the same juncpossessing both high thermal conductance and high tion temperature. Conversely, the chip can run up to 29OC cooler for the same operating conditions that electrical isolation (2500V). translates into more reliable operation. Because there There are multiple advantages to this isolated is such a potentially large decrease in junction-to-case and hole-less packaging concept. thermal resistance, it may be possible to use a smaller 1. The dielectric breakdown voltage of the DCB chip for the same current, which would more than is 6,000V although the package is only rated to cover for the extra price (approximately $0.50 in pro2500V(RMS) due to the creep and strike distances duction volumes) for the internal isolation. of the TO-247 outline; IXYS plans on introducing over 100 new part 2. The electrical insulation barrier is plastic encapsulated and therefore protected from the envi- types in this revolutionary package during 1999. Initial product will consist of high power MOSFETs ofronment; 3.Very low, isolated thermal resistance junction- fering the industrys lowest on-resistance for this packto-heatsink due to the use of DCB and only one age outline. Future product will include IGBTs, IGBTs non-soldered interface between the silicon chip co-packaged with diodes, and ultra-fast and Schottky and the heatsink; diodes. 4.Ease of assembly due to pressure mounting (no For more information, contact Mr. Ralph Locher screws) and no additional isolation interface maat (408) 982-4384. terial required for mounting to a heatsink; 5.Increased temperature and power cycling ca- © 1999 IXYS Corporation IXYS Corporation 3540 Bassett St; Santa Clara, CA 95054 Tel: 408-982-0700; Fax: 408-496-0670 IXYS Semiconductor GmbH Edisonstr. 15; D-68623 Lampertheim, Germany Tel: +49-6206-503-0; Fax: +49-6206-503627 IXAN0031 3DUW7\SH ,VRODWLRQ 7KLFNQHVV 0DWHULDO ,VRODWLRQ 5WKMV 9ROWDJH 3G# 7M & ,G# 7M & 7M# ,GF $ 7V & 7V & 7V & PP N9 .: : $ & ,;)51 ,QWHUQDO DOXPLQD '&% ,;);1 ([WHUQDO DOXPLQD'&% ,;);1 .DSWRQ ,;);1 ,06 ,;);1 6,/3$' 70 ,;);1 6RIWIDFH70 SIL-PAD is a trademark of Bergquist Co. Table: Performance Comparison of ISOPLUS247 IXFR55N50 to IXFX55N50 Mounted Using Various Interface Materials Figure 2: Graphical comparison showing the current handling capability of the ISOPLUS247 IXFR55N50 MOSFET vs the IXFX55N50 MOSFET as a function of heatsink mounting conditions. 7- 2& 'UDLQ&XUUHQW$PSHUHV ,;)51 ,;);1H[W'&% ,;);1,06 ,;);1.DSWRQ ,;);16,/3$' 2 +HDWVLQN7HPSHUDWXUH & IXYS Corporation 3540 Bassett St; Santa Clara, CA 95054 Tel: 408-982-0700; Fax: 408-496-0670 IXYS Semiconductor GmbH Edisonstr. 15; D-68623 Lampertheim, Germany Tel: +49-6206-503-0; Fax: +49-6206-503627