Application Note
8
Revision 1.0
2017-11-15
1200V HighSpeed 3 IGBT in TO-247PLUS Evaluation Board
User Manual
Usage
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).
(a)
(b)
(c)
(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).