High-performance power-module for hybridand electric vehicles

Transkript

1 Advanced Packaging Conference, Semicon High-performance power-module for hybridand electric vehicles Dr. Eckart Geinitz, Dr. T. Jacke, Dr. D. Michels, G. Braun, Dr. St. Keil Robert Bosch GmbH AE/PJ-PSC Robert Bosch GmbH Alle Rechte vorbehalten, auch bzgl. jeder Verfügung, Verwertung, Reproduktion,

2 Outline Introduction A new package design for power modules Thermal performance of the new power module Reliability aspects Summary 2 AE/PJ-PSC Robert Bosch GmbH Alle Rechte vorbehalten, auch bzgl. jeder Verfügung, Verwertung, Reproduktion,

3 Interdependency (HEV & EV power-inverter) DC/AC-Inverter focus: costs, power-density, box-volume, weight power-density, costs, EMC, robustness MCPP focus: thermal-avt Rth, Zth e le ctric-avt inductance robustness temp.cycles Power-Switches (IGBT, S ic) focus: static & dynamic power-losses, tailored for MCPP integration cooling-e ffort, energy-e fficie ncy, mila ge & costs Vertically integrated development is key success factor for Power Electronics 3

4 IGBT-Power-module : Innovation Steps Thermal balance: R I 2 2 DS,on AIT heat generation in chip + R I heat generation in package + P switch s witching losses = R T junction th,chip T + R cooling cooler th,package Previous Generation (2011) Current Generation (2013) Enhanced reliability and robustness due to mold package. Cost intense wire bond connections of power contact. Direct Bonded Copper (DBC) substrate. Ve ry good cooling performance due to twosided soldering of chips and massive Cu substrates. Power-bond-free: enhanced reliability. Low package resistance and inductance. Improved IGBT with on-chip current sensor for lowest losses. 4

5 Thermal re s is tivity for a typical inverter design Exa mple for Rth-stack junction /water SC solder DBC Module TIM* Cooler Rth-Percentage of TIM * and Cooler in re la tion to the total Rth is >80% 5 AE/PJ-PSC Robert Bosch GmbH Alle Rechte vorbehalten, auch bzgl. jeder Verfügung, Verwertung, Reproduktion, TIM*: Thermal interface Material

6 Influence of Module Design on Rth of TIM and Cooler A1 A2 SC and Solder Copper Isolation/TIM Cooler Rth Stack [K/W] 4,5 4 3,5 3 2,5 2 1,5 1 0,5 Influence of Spreading on Rth Stack ohne No spreading Spreizung Spreizung Spreading: 3.5mm 3,5mm Spreizung Spreading: 10mm mm 0 0 0,5 1 1,5 2 2,5 3 Rthi TIM [d/lambda] Measure for Spreading Dis ta nce to edge P T1 d λ th T2 6

7 Effe ct of Clip s oldering on Zth and Rth IGBT Diode S imula tion of effect of Clip on Zth and Rth Zth With Clip Without Clip Cooling Rth Cooling 7

8 Comparison of thermal resistance Measurement with Thermal paste and dummy cooler* Z th (K/W) 70% > 30% puls e duration (s) *IGBT, same SC area 8

9 Modulentwicklung PM3 Relia bility: S older degradation DBC CTE: 7 ppm/k Si-Chip CTE: 2-3 ppm/k Cu CTE: 17 ppm/k Testmodul No s older degradation detectable 0,048-40/175 C, 15/60 min 1000 ptw No s ignificant Zth Change No Change in el. parameter More than 3000 ptw ( C) Zth@75ms (K/W) 0,046 0,044 0,042 0,040 +0,0% +0,1% -0,3% Alle Abweichungen bezogen auf Nullstand 0 ptw 500 ptw 750 ptw 1000 ptw 9 Inte rn AE/PJ-PM Robert Bosch GmbH Alle Rechte vorbehalten, auch bzgl. jeder Verfügung, Verwertung, Reproduktion,

10 Effe ct of Mold for Relia bility (s older degradation) S imula tion of creepage of s older 500 TW 1000 TW Without Mold With Mold Theoretical improvement in pa s s ive temperature cycle s : cycles (-40 bis 150 C) 10

11 Relia bility a ls o depends on s older material 11

12 Warpage max. warpage (µm) Warpage measurements temperature ( C) DBC based New Design Ve ry little warpage because of massive copper s inks Only s light change of warpage over temperature Only thin TIM la ye r necessary Little pump out 12

13 IGBT-MCPP : Technical Features molded IGBT half bridge module for HEV/EV very high power density & easy handling latest IGBT-technology optimized for HEV + EV-applications max. voltage: Ubd = 650 V nom. current: I nom C = 600 A or 300 A integrated Free Wheeling Diodes Integrated current- sensor & temperature sensor (NTC) 63 mm x 57 mm x 7.5 mm temperature range in operation mode: -40 C to C Pb-free (ROHS compliance) & Halogen-free (IEC ) 13

14 Summary A Power-bond- free module with an improved IGBT was introduced that has low package resistance and inductance The Rth/Zth of the stack Junction to heatsink was significantly reduced with a new copper based substrate Doublesided soldering and molding leads to a higher reliability as regards solder degradation The new package has very low warpage that allows thinner TIM layers and leads to very little pumpout 14 AE/PJ-PSC Robert Bosch GmbH Alle Rechte vorbehalten, auch bzgl. jeder Verfügung, Verwertung, Reproduktion,