Technical Article

PFC-Integrated IPM for Low-Power Devices

June 01, 2020 by Jaewook Lee

This article discusses Infineon's highly integrated power module for low-power devices with a single PFC stage and three-phase inverter.

Infineon is offering a 600 V, 20 A highly integrated intelligent power module (IPM, IM564-X6D) for low-power drives. A single-boost PFC stage using CoolMOS™ and a three-phase inverter are integrated in a miniaturized DIP (dual-in-line package) transfer-molded package. With this IPM, the size and cost of the system can be dramatically reduced.

To meet the tightened regulations [1] and the strong demand for compact sizes, higher power density and simple assembly processes, Infineon Technologies has developed a family of 600 V, 15 A rated PFC-integrated IPMs (IFCM15P60GD, IFCM15S60GD) [2]. Recently, a new 600 V, 20 A rated PFC-integrated IPM (IM564-X6D) has been developed for increasing power density. This new IPM incorporates a three-phase inverter stage and a PFC stage using CoolMOS in one package with a DCB substrate (Figure 1).

 

Block diagram of PFC-integrated CIPOS™ Mini IPM
Figure 1: Block diagram of PFC-integrated CIPOS™ Mini IPM

 

The inverter stage is built with six 600 V rated TRENCHSTOP™ IGBTs, six emitter-controlled diodes and an SOI (silicon-on-insulator) gate driver. The PFC stage consists of a 600 V rated CoolMOS MOSFET and a 650 V rated rapid-switching emitter-controlled diode that has fast and soft switching characteristics. DCB (direct copper bond) substrate is adopted for good thermal performance considering the small package size. With this new IPM, reduced PCB and heatsink sizes and simplified assembly processes can also be achieved.

 

External view and circuit configuration

The package designs of the new high-level IPM are shown in Figure 2. The new IPM provides a compact Infineon Technologies CIPOS™ (Control Integrated POwer System) Mini IPM package measuring 21 mm x 36 mm. All of the semiconductor chips are optimized for the package, and owing to the DCB substrate, it has excellent heat dissipation characteristics.

 

Design of PFC-integrated CIPOS™ Mini IPM measuring 21 mm x 36 mm
Figure 2: Design of PFC-integrated CIPOS™ Mini IPM measuring 21 mm x 36 mm

 

Inverter and power devices

The internal circuit of inverter devices is composed of six 600 V rated Infineon´s TRENCHSTOP technology IGBTs and anti-parallel freewheeling diodes in a three-phase inverter structure. In particular, the TRENCHSTOP IGBTs and anti-parallel diodes are designed for fast switching without excessive ringing, and have much lower overall losses.

A silicon-on-insulator (SOI) gate driver IC is used for the CIPOS IPM modules to improve integration, reliability and performance. This six-channel single SOI gate driver IC has a special inter-lock function for shoot-through protection and shut-down of all outputs when a fault such as overcurrent or under voltage occurs. Also, it provides an integrated bootstrap circuit and additional sleep function. This sleep function helps to increase the stability and robustness of the IPM [3]. The SOI gate driver IC helps to optimize IGBT switching, and provides inter-lock, under-voltage lockout (UVLO) of the drive supply and over current protection functions.

 

PFC boost switch and diode

A 600 V CoolMOS P7 MOSFET is used for the new 20 A PFC-integrated CIPOS Mini IPM, which is typically 86 mΩ at 25°C of junction temperature and 20 A of drain current. It combines the benefits of a fast switching SJ MOSFET with excellent ease of use, e.g. very low ringing tendency, outstanding commutation ruggedness, and excellent ESD capability. Furthermore, it has a simplified thermal management due to extremely low switching and conduction losses.

The rapid emitter-controlled diode from Infineon is optimized to work in harmony with CoolMOS as a boost diode in PFC topology. Rapid diode advancement in thin wafer technology helps to maintain a stable VF overtemperature. And it has low forward voltage and low reverse-recovery current.

 

Package

The compact intelligent power module applies a thermal substrate of DCB for high thermal performance, and an aluminum-wire bonding method for electrical and mechanical connection. The thermal substrate, DCB, is composed of a ceramic plate with high thermal conductivity and copper plates.

 

No Product Voltage [V] Current @25ºC [A] Max. PFC fsw [kHz] Pmot @10kHz [kW]
1 IFCM10S60GD 600 10 20 1.2
2 IFCM10P60GD 600 10 40 1.2
3 IFCM15S60GD 600 15 20 1.8
4 IFCM15P60GD 600 15 40 1.8
5 IM564-X6D 600 20 Up to 150 2.4
Table 1: CIPOS™ Mini PFC-integrated IPM family

 

Power switches are attached on the one side of the DCB, and the other side is exposed to the surface of the package. This technique contributes to improving thermal performance and thermal dissipation capability to achieve excellent solutions for motor drives. Thermal performance Tc(INV) is a case temperature of the high side W phase IGBT in the inverter and Tc(PFC) is a case temperature of the PFC MOSFET in PFC. Figure 3 shows a thermal performance comparison between new 600 V, 20 A IPM (IM564-X6D) and an existing 600 V, 15 A IPM (IFCM15P60GD) with PFC controller of ICE2PCS05G at PIN=2 kW, PF(Input)=0.99, VIN=220 V / 60 Hz, VDC=400 V, Fsw(INV)=5 kHz, Fsw(PFC)=40 kHz, SVPWM, MI= .69, VDD=15 V, Rg=10 Ω, Ta=25°C. ∆TCA_PFC (where ∆TCA_PFC=Tc(PFC)-Ta) of IM564-X6D is lower than that of IFCM15P60GD by about 17.5°C. The test result shows better thermal performance of the new 600 V 20 A IPM.

 

Thermal performance of new integrated IPM
Figure 3: Thermal performance of new integrated IPM

 

CIPOS Mini PFC family, which has a compact form factor with PFC-integrated IPM, perfectly fits in the space constraint applications, especially air conditioners, fans, pumps, and motor drives below 3 kW. Unlike other families with IGBT-based PFC, the new PFC-integrated IPM, IM564-X6D, incorporates a CoolMOS power MOSFET and a rapid switching diode for the PFC stage to increase PFC switching frequency up to 150 kHz. This enables a significant inductor size reduction for high power density with a reduced system form factor.

 

Conclusion

This new PFC-integrated IPM (IM564-X6D) is an optimized solution with inverters and PFC topologies for variable-speed motor drives such as room air conditioners and low-power drives. Since all semiconductor chips are optimized and integrated in the existing CIPOS Mini IPM package, development time can be shortened, and space reduced. Since the new IPM has been adapted and optimized for PFC systems using CoolMOS P7 MOSFET, switching and conduction losses are very small, and switching is possible up to 150 kHz. References [1] IEC 61000-3-2:2014: Limits for harmonic current emissions [2] H Jang, B Choo, J Lee, M Lee, D Chung: New High Level Integrated Intelligent Power Module with Three Phase Inverter and Power Factor Correction Topologies Optimized for Home Appliances, PCIM Europe 2016, Nuremberg, Germany [3] T Kim, M Lee, J Lee, D Chung: Protection Features of Intelligent Power Module against Transient State, PCIM Europe 2016, Nuremberg, Germany

 

About Infineon

Infineon Technologies AG is a world leader in semiconductor solutions that make life easier, safer and greener. Microelectronics from Infineon is the key to a better future. In the 2019 fiscal year (ending 30 September), the Company reported sales of €8.0 billion with about 41,400 employees worldwide. Infineon is listed on the Frankfurt Stock Exchange and in the USA on the over-the-counter market OTCQX International Premier.

 

This article originally appeared in the Bodo’s Power Systems magazine.