Infineon EVAL-IGBT-1200V-TO247PLUS User Manual

AN2017-44

1200V HighSpeed 3 IGBT in TO-247PLUS
Evaluation Board

User Manual

About this document

Scope and purpose

This application note is a user guide for the 1200V HighSpeed 3 IGBT in TO-247PLUS evaluation board.
It explains the board’s hardware and provides detailed instructions on how to use it for addressing
various measurement tasks. Finally, practical examples demonstrate the benefits of both, TO-247PLUS
and TO-247PLUS 4pin packages.

Intended audience

This document is intended for owners and users of the evaluation board.

Table of Contents

About this document .............................................................................................................................. 1

Table of Contents ................................................................................................................................... 1

1 Introduction .......................................................................................................................... 3

1.1 Purpose of the board .............................................................................................................. 3

1.2 Scope of delivery .................................................................................................................... 4

2 Hardware ............................................................................................................................... 5

2.1 Circuit and main components ................................................................................................. 5

2.2 Recommended accessories ................................................................................................... 6

3 Usage .................................................................................................................................... 8

3.1 Settings .................................................................................................................................. 8

3.1.1 Replacing switches or diodes ............................................................................................ 8

3.1.2 Changing between 3pin and 4pin packages ................................ ...................................... 9

3.1.3 Tuning gate voltages and resistors .................................................................................. 10

3.1.4 Adjusting and monitoring the heat sink temperature ........................................................ 11

3.2 Operation ............................................................................................................................. 11

3.2.1 Configurations ................................................................................................................. 11

3.2.2 Switching loss measurements ......................................................................................... 13

3.2.3 Efficiency or temperature measurements ......................................................................... 14

4 Examples ............................................................................................................................ 15

4.1 Turn-on loss reduction with a 4pin package ......................................................................... 15

4.2 Substituting parallel 40A devices with a 75A device ............................................................. 16

5 Appendix ............................................................................................................................. 18

5.1 Schematic drawing ............................................................................................................... 18

5.2 Board layout ......................................................................................................................... 19

5.3 Bill of materials ..................................................................................................................... 21

References ............................................................................................................................................ 24

Revision History ................................................................................................................................... 25

Application Note Please read the Important Notice and Warnings at the end of this document Revision 1.0

www.infineon.com 2017-11-15

1200V HighSpeed 3 IGBT in TO-247PLUS Evaluation Board

User Manual

Introduction

Dangerous Equipment!

High Voltage

Do NOT touch the board during operation.

Depending on the configuration of the board and the chosen

supply-voltage, life-threatening voltages might be present!

Even brief accidental contact during operation

might result in severe injury or death!

Always make sure that the capacitors are discharged

before touching the board.

Only qualified personnel are allowed to handle this board!

Read the instructions provided in this application note before putting

the evaluation board into operation

The board described is an evaluation board dedicated for laboratory environment only. It operates at
high voltages and must only be operated by qualified and skilled personnel familiar with all applicable
safety standards.

Application Note 2 Revision 1.0
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1200V HighSpeed 3 IGBT in TO-247PLUS Evaluation Board

User Manual

Introduction

(a)

(b)

1 Introduction

The evaluation board EVAL-IGBT-1200V-TO247PLUS was developed as a test platform for 1200V
IGBTs in TO-247PLUS and TO-247PLUS 4pin packages but can also be used for standard TO-247 and
TO-247 4pin packages.

This introductory section provides an overview of the potential applications of the evaluation board and
lists the components included in the delivery.

1.1 Purpose of the board

The main motivation to develop the evaluation board shown in Figure 1 was to have one universal test
platform for 1200V IGBTs in TO-247 as well as TO-247PLUS packages with three as well as four leads.
It allows evaluating the advantages provided by the larger lead frame area of the TO-247PLUS package
as well as the performance improvement given by the Kelvin emitter connection of the TO-247PLUS 4pin
package. For detailed information on these packages refer to application notes [1] and [2], respectively.

Figure 1 Evaluation board and devices under test: (a) 1200V HighSpeed 3 IGBT in TO-247PLUS

Evaluation Board, (b) TO-247PLUS and TO-247PLUS 4pin package

Two different modes of operation can be implemented with this board. First, it can be used to investigate
the switching behavior and measure the switching losses of IGBTs and diodes at different conditions.
Parameters like the DC link voltage, the load current, the device temperature as well as the gate
voltages and resistors are easily adjustable. If desired, snubbers can be assembled as well. Second, the
board can be operated as a step-up or step-down DC/DC converter. Thus, it is possible to characterize
and run devices in a continuous mode of operation in the same setup.

Care was taken to minimize the parasitic inductances and capacitances of this board wherever possible.
If needed, board users can tune the parasitic circuit elements by simply adding small capacitances and
inductances.

Application Note 3 Revision 1.0
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Introduction

1.2 Scope of delivery

The evaluation board is delivered together with spare parts and complete documentation in an
environmentally friendly carton box as illustrated in Figure 2. As depicted, the carton box contains:

 Evaluation board EVAL-IGBT-1200V-TO247PLUS with a size of 172mm x 133mm x 72mm (LxWxH)
 1200V HighSpeed 3 IGBTs IKQ50N120CH3, IKQ75N120CH3, IKY50N120CH3 and IKY75N120CH3
 1ED Compact isolated gate-driver ICs 1EDI60I12AH in a 300mil wide-body package
 USB flash drive containing all related application notes and data sheets
 Wire-to-board plugs for connecting the evaluation board to sources and loads

Figure 2 Scope of delivery: evaluation board, spare parts and USB drive with documentation

For high accuracy switching loss measurements, it is highly recommended to use these additional
components which are not included in the delivery:

 Coaxial shunt SDN-414-xxx (IB Billmann) for high accuracy current measurements
 Probe adapter A-PCB-5,0-L (PMK) for connecting a passive high voltage oscilloscope probe
 Probe adapters PK106-4 (LeCroy) for connecting passive low voltage oscilloscope probes

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1200V HighSpeed 3 IGBT in TO-247PLUS Evaluation Board

User Manual

Hardware

(a)

(b)

2 Hardware

This section provides a short description of the board hardware. First, it explains the power circuitry, the
main components and the connectors. Then, the application of the recommended accessories is
discussed.

2.1 Circuit and main components

As shown in the block diagram of Figure 3, the evaluation board essentially is a half bridge converter
consisting of two IGBTs, S1 and S2. Due to the clip-based heat sink mounting and the universal socket
on the PCB it is possible to assemble standard TO-247 and TO-247PLUS packages with three as well
as four leads.

The switches are driven using EiceDriver™ 1ED Compact driver ICs. Due to the robust nature of the
coreless transformer technology combined with the 300mil wide-body package, these drivers are well
suited for applications that require high voltages, frequencies and switching speeds. Both drivers are
controlled with independent PWM signals on the connectors SIG-HS and SIG-LS. The driving voltages
are provided using the 12V auxiliary supply and isolated DC/DC converters.

For versatility reasons, the evaluation board was equipped with input and output capacitors Cin and C

out

as well as a load inductor L. While the input capacitor and the load inductor where designed having
mainly switching loss measurements in mind, the output capacitor is required for continuous operation,
for instance as a buck converter. The provided filter inductor might not meet the requirements for the
latter case but it is straightforward to replace it with a custom solution.

The same applies to the heat sink: its size and shape reveals that it cannot provide the cooling
performance required for continuous operation. Rather, it is intended to serve as a heating element for
performing high temperature switching loss measurements. Using the power resistor R
thermistor R

, the heat sink temperature can be adjusted and monitored, respectively. Again, it is

NTC

and the

POW

easily possible to replace the provided heat sink with a high performance solution.

Figure 3 Overview of the board schematics (a) and components (b)

Application Note 5 Revision 1.0
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1200V HighSpeed 3 IGBT in TO-247PLUS Evaluation Board

User Manual

Hardware

(a)

(b)

An experimental analysis of a device’s switching behavior requires oscilloscope measurements of the
gate voltage, the collector-emitter voltage as well as the collector current. While voltage measurements
are straightforward, current measurements are more difficult to do, particularly in the presence of steep
current slopes. This evaluation board contains a basic SMD shunt resistor solution. It gives an
impression of the collector current waveform but is not considered an ideal solution for high accuracy
measurements.

2.2 Recommended accessories

The introductory section already clarified which components are delivered with the evaluation board and
which are not. Although the board can be used for switching loss measurements right away, it is strongly
recommended to use additional components for the highest accuracy and signal quality.

Coaxial shunt

Performing oscilloscope measurements of an IGBT’s collector current waveform is typically a non-trivial
task, particularly during switching events where extremely steep current slopes of several Amperes per
nanosecond are reached. An ideal current measurement for this purpose would be non-invasive – at
least it should not require significant changes of the circuit – and have a very high bandwidth.

By default, this evaluation board contains a 50mΩ metal foil SMD shunt resistor and an RC low-pass
filter in order to suppress disturbances caused by parasitic circuit elements. Due to the substantial
filtering, this approach might be considered a current estimation rather than a measurement. For high
accuracy measurements it is recommended to use a coaxial shunt SDN-414-xxx.[3] It has a bandwidth in
the gigahertz range and can be connected to any oscilloscope with a standard BNC cable.

To assemble the coaxial shunt:

1. Unsolder the 50mΩ metal foil resistor R201 and the 100Ω thin film resistor R200 on the bottom side
of the board.

2. Optionally, remove the capacitor C201 and the probe adapter Id2 as they are inoperable.

3. Strip the isolation at the central terminal of the shunt and solder it to the PCB.

As visible in Figure 4, the shunt should be positioned as close to the PCB as possible to minimize
parasitic inductances.

Figure 4 Recommended accessories for switching loss measurements: (a) pictures of the

components, (b) assembly of the components on the board

Application Note 6 Revision 1.0
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1200V HighSpeed 3 IGBT in TO-247PLUS Evaluation Board

User Manual

Hardware

25°C

100°C

800V

400V

800V

400V

Turn-On

Turn-Off

Table 1 compares waveforms as well as switching losses measured with the metal foil SMD resistor and
the coaxial shunt at various temperatures and voltages. As all measurements are done with exactly the
same semiconductor devices, the differences can be attributed to the different current sensors. It is
clearly visible that the SMD solution estimates the basic waveform of the collector current relatively well.
However, the exact determination of switching slopes and losses requires a coaxial shunt.

Table 1 Comparison of the coaxial (black) and the SMD shunt (red) at various conditions. The

double pulse tests were performed with IKY75N120CH3.

Oscilloscope probe adapters

In contrast to current measurements, the acquisition of voltage waveforms is straightforward. By
selecting the emitter potential of the low side IGBT S2 as common ground, the gate voltage, the collector­emitter voltage and the collector current can be measured with ordinary passive probes.

While voltage probes can be connected using grounding wires and clips, the use of PCB adapters is
considered advantageous for several reasons. First and foremost, the grounding of the probe is
improved which leads to a proper and reproducible signal quality, especially in the presence of
disturbances caused by switching transients. Additionally, connecting the probes becomes more
convenient and less error-prone.

The evaluation board was designed to accommodate one PMK high voltage probe adapter A-PCB-5,0-L
and two LeCroy low voltage probe adapters PK106-4 [4][5]. They share the emitter of the low-side switch
as common ground and measure the voltage on the collector, on the gate and on the Kelvin connection
terminal, respectively. Assembling the probe adapters can be done as depicted in Figure 4.b.

Application Note 7 Revision 1.0
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1200V HighSpeed 3 IGBT in TO-247PLUS Evaluation Board

User Manual

Usage

(a)

(b)

(c)

(d)

3 Usage

Due to its flexibility, the evaluation board can address a variety of measurement problems. While the
previous sections explained the basic purpose as well as the hardware of the board, this section
provides detailed instructions on how to set it up and operate it. Section 3.1 describes how to modify
certain board settings, section 3.2 deals with the preparation and execution of different experiments.

3.1 Settings

The evaluation board is capable of testing TO-247 and TO-247PLUS packages with three as well as four
leads under many different conditions. This section provides exemplary instructions on how to assemble
different package variants and make the most important adjustments, particularly in the driving circuitry.

Attention: Prevent potential exposure to hazardous voltages by turning off all power supplies

and discharging the DC link capacitors before undertaking any of the modifications
described in the remainder of this section.

3.1.1 Replacing switches or diodes

A PCB is subject to severe thermomechanical stress when soldering and unsoldering components. As a
consequence, the adhesion between the copper layers and the core material gets weaker and
eventually, copper pads or traces may lift off and break. In order to allow a large number of IGBT and
diode replacements, this evaluation board uses press fit pins for connecting the TO packages and the
PCB. As the device is not soldered directly to the board but to the pins, the stress to the PCB is limited.

There are several ways of removing the TO packages from the heat sink and the board. A simple
approach is to cut the package leads, remove the package body from the heat sink and unsolder one
lead after another from the press fit pins. Figure 5 illustrates a different strategy where the
semiconductor device remains intact.

1. Put the board in an upright position so that the IGBT packages face upwards (a).

2. Push a flat screw driver between the clip and the package body and twist it to pull the clip out of the
heat sink’s groove (b).

3. Use two soldering irons to heat up all leads at the same time. When the solder melts on all leads,
gently pull the package away from the board (c).

4. Finally, clean the press fit pins using solder wick (d).

Figure 5 Disassembling a device from the heat sink and the PCB

The assembly of a new device is easier. Figure 6 presents a possible sequence of steps.

1. Prepare the TO package by cutting the leads to a length of around 5mm (a).

2. Place the package freely and perfectly flat on the heat sink (b).

3. Put the spring clip on the package and the heat sink groove and fasten it using pliers (c).

4. Solder one lead after the other to the press fit pins (d).

Application Note 8 Revision 1.0
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