Fuji Electric X Series Instructions for use

© Fuji Electric Co., Ltd. All rights reserved.MT6MMT6M15962a
Application Manual
Fuji 7th Generation IGBT-IPM
X Series
Oct. 2021

MT6M15962a © Fuji Electric Co., Ltd. All rights reserved. 1
Warning:
This manual contains the product specifications, characteristics, data, materials, and structures as of
October 2021.
The contents are subject to change without notice for specification changes or other reasons. When
using a product listed in this manual, be sure to obtain the latest specifications.
All applications described in this manual exemplify the use of Fuji's products for your reference only.
No right or license, either express or implied, under any patent, copyright, trade secret or other
intellectual property right owned by Fuji Electric Co., Ltd. is (or shall be deemed) granted. Fuji Electric
Co., Ltd. makes no representation or warranty, whether express or implied, relating to the
infringement or alleged infringement of other's intellectual property rights which may arise from the use
of the applications described herein.

MT6M15962a © Fuji Electric Co., Ltd. All rights reserved. 2
(1) During transportation and storage
Keep locating the shipping carton boxes to suitable side up. Otherwise, unexpected stress might
affect to the boxes. For example, bend the terminal pins, deform the inner resin case, and so on.
When you throw or drop the product, it gives the product damage.
If the product is wet with water, that it may be broken or malfunctions, please subjected to sufficient
measures to rain or condensation.
Temperature and humidity of an environment during transportation are described in the
specification sheet. There conditions shall be kept under the specification.
(2)Assembly environment
Since this power module device is very weak against electro static discharge, the ESD
countermeasure in the assembly environment shall be suitable within the specification described in
specification sheet. Especially, when the conducting pad is removed from control pins, the product
is most likely to get electrical damage.
(3)Operating environment
If the product had been used in the environment with acid, organic matter, and corrosive gas
(hydrogen sulfide, sulfurous acid gas), the product's performance and appearance can not be
ensured easily.
Cautions

MT6M15962a
1.
Guidelines for heat sink selection
5-
2
2.
Notice for heat sink selection
5-
2
3.
Mounting instruction of the IPM
5-
3
Chapter 5 Cooling Design
© Fuji Electric Co., Ltd. All rights reserved. 5-1

MT6M15962a
1. Guidelines for heat sink selection
© Fuji Electric Co., Ltd. All rights reserved.
•To safely operate the IGBT, it is necessary that the junction temperature Tvj should not exceed 175°C.
•Additionally, the case temperature Tcshould not exceed 125°C.
•Carry out thermal design with sufficient margins so that the junction temperature Tvj never exceeds
175°C even during an abnormality such as overload.
•There is a risk of thermal destruction if the IGBT is operated at a temperature above 175°C.
Although the TjOH protection function in the IPM activates when the junction temperature exceeds
175°C, however, there is a possibility that the protection cannot work if the temperature rises rapidly.
As with the IGBT, junction temperature of FWD should not exceed 175°C too.
•The heat sink temperature should be measured just below the center of the chip.
Please refer to the IPM specification sheet for the chip layout drawing.
In addition, please refer to the following documents.
Fig.5-1 Flatness of heat sink surface
This chapter describes the cooling design of the X series IPM.
5-2
2. Notice for heat sink selection
[IGBT Module Application Manual RH984]
•Power dissipation loss calculation
•Selecting heat sinks
•Heat sink mounting precautions
•Troubleshooting
[Reason]
•Concave: There will be a gap between
the heat sink surface and the base
plate of the IPM, and the heat transfer
performance becomes worse (contact
thermal resistance Rth(c-s) increases).
•Convex (larger than +50μm): The
copper base of the IPM may be
deformed and the internal insulation
substrate may crack due to
mechanical stress.
Although a guideline for heat sink selection is described in the IGBT Module Application Manual
(RH984), please pay attention to the flatness of the heat sink surface.
It is recommended that flatness of the heat sink surface is within ±50μm per 100mm between the
screw mounting points and the surface roughness is within 10μm.
If the heat sink surface is concave or convex, the contact thermal resistance (Rth(c-s)) will be increased.
IPM Compound
coated face
Between screw mounting points

MT6M15962a
3. Mounting instruction of the IPM
© Fuji Electric Co., Ltd. All rights reserved.
3.1 Layout of IPMs on a heat sink
The thermal resistance varies depending on the IPM mounting position. Please note the following :
•When one IPM is mounted to a heat sink, it is recommended to place the IPM on the center of the
heat sink to minimize the thermal resistance.
•When multiple IPMs are mounted to a single heat sink, the IPMs location and layout should be
designed in consideration of the generated losses and the spread and flow of heat on the heat sink.
Allocate the largest area to the IPM which generates the largest loss.
3.2 Application of thermal grease
To reduce the contact thermal resistance, apply thermal grease between the IPM and the heat sink
mounting surface.
The general methods of applying thermal grease is applying using a stencil mask and applying with a
roller.
The purpose of the thermal grease is to promote heat transmission to the heat sink, but the grease
has a limited thermal capacity. Therefore, if the thermal grease thickness is larger than the appropriate
thickness, the grease layer prevents the heat transfer from the IPM to the heat sink and the junction
temperature will be increased. On the other hand, if the thermal grease thickness is less than the
appropriate thickness, non contact part such as a void area, a gap or space may be generated and
cause an increase of the contact thermal resistance. Therefore thermal grease should be applied in
appropriate thickness.
If the thermal grease thickness is inadequate, the thermal dissipation will be poor, and in the worst
case, there is a possibility of IPM breakdown due to the junction temperature exceeding 175°C.
Application of thermal grease using a stencil mask is recommended so that uniform thickness can be
achieved. Figure 5-2 shows an example of thermal grease application using a stencil mask. The basis
of this method is applying specified weight of thermal grease to the base plate of the IPM using a
stencil mask.
It is possible to achieve a uniform thermal grease thickness by mounting the IPM with thermal grease
to the heat sink and tightening screws with the recommended torque for each product.
Fuji Electric can provide recommended stencil mask designs upon customer’s request.
5-3

MT6M15962a © Fuji Electric Co., Ltd. All rights reserved. 5-4
Fig.5-2 Outline of a thermal grease application method
Guide pins for IGBT Guide pins for Frame Guide holes for bottom tool

MT6M15962a © Fuji Electric Co., Ltd. All rights reserved.
Assuming that the thermal grease thickness is uniform, the required thermal grease weight is given
by the following equation.
Calculate the thermal grease weight that corresponds to the required thermal grease thickness from
this equation, and apply the thermal grease. The recommended thermal grease thickness after
spreading of thermal grease is 100μm. Also please note that the optimum thermal grease thickness
varies depending on the characteristics of the thermal grease used and the application method.
Table 5-1 shows the base plate area of IPMs.
5-5
Table5-1 Base plate area of IPM
Package Base plate area (cm2)
P639 14.74
P629 21.71
P626, P644 22.77
P636, P638 41.17
P630 55.67
P631 141.24
Thermal grease
thickness (μm)
Thermal grease
weight (g) x 104Base plate area of module (cm2)
=Density of thermal
grease (g/cm3)
x x

MT6M15962a © Fuji Electric Co., Ltd. All rights reserved.
3.3 Screw tightening
Figure 5-3 shows screw-tightening procedures when mounting an IPM to a heat sink. It is
recommended to tighten all screws with the specified tightening torque.
The specified tightening torque is described in the specification. If the screw tightening torque is
insufficient, the contact thermal resistance may increase and screws loosening may occur during
operation. On the other hand, if the screw tightening torque is excessive, the case may be damaged.
3.4 IPM mounting direction
When an IPM is mounted on an extruded heat sink, it is recommended that the IPM is mounted in
parallel to the extrusion direction as shown in Figure 5-3. The purpose is to reduce the effect of heat
sink deformation.
5-6
Torque Order
1st time (initial tightening)
2nd time (permanent tightening) 1/3 of specified torque 100% of specified torque ①→②
②→①
Fig.5-3 IPM mounting method
(a) IPM with 2-points mounting
(b) IPM with 4-points mounting
IPM
IPM
Extruding direction
Heat sink Screw
position
Extruding direction
Heat sink
Screw
position
Torque Order
1st time (initial tightening)
2nd time (permanent tightening) 1/3 of specified torque 100% of specified torque ①→②→③→④
④→③→②→①

MT6M15962a © Fuji Electric Co., Ltd. All rights reserved. 5-7
Fig.5-4 Measuring the case temperature
3.5 Verification of chip temperature
After selecting a heat sink and the IPM mounting position is decided, measure the Tc(directly below
the chip) and Tf(directly below the chip), and verify the chip junction temperature (Tvj).
Figure 5-4 shows an example of how to accurately measure the case temperature (Tc). Please
measure the case temperature directly below the chip. The chip location is described in the
specification.
Please verify that the case temperature does not exceed 125°C, the chip junction temperature does
not exceed 175°C and the thermal design meets the required life time of the system.
Tc
Tf