< Dual-In-Line Package Intelligent Power Module >
Series Application note
Publication Date: September 2016
27
Table 2-4-2 Mounting torque and heat sink flatness specifications
Item
Condition
Min.
Typ.
Max.
Unit
Mounting torque
Screw : M4
0.98
－
1.47
N
･
m
Flatness of outer heat sink
Refer Fig.2-4-2
-50
－
+100
μm
(note): Recommend to use plain washer (ISO7089-7094) in fastening the screws.
Fig.2-4-2 Measurement positions of heat radiation part flatness
In order to get effective heat dissipation, it is necessary to enlarge the contact area as much as possible to
minimize the contact thermal resistance. Regarding the heat sink flatness (warp/concavity and convexity) on the
module installation surface, the surface finishing-treatment should be within Rz12.
Evenly apply thermally-conductive grease with 100
μ-200μm thickness over the contact surface between a
module and a heat sink, which is also useful for preventing corrosion. Furthermore, the grease should be with
stable quality and long-term endurance within wide operating temperature range. The contacting thermal
resistance between DIPIPM case and heat sink Rth(c-f) is determined by the thickness and the thermal
conductivity of the applied grease. For reference, Rth(c-f) is about 0.25K/W (per chip
, grease thickness: 20μm,
thermal conductivity: 1.0W/m·k). When applying grease and fixing heat sink, pay attention not to take air into
grease. It might lead to make contact thermal resistance worse or loosen fixing in operation.
+
-
- +
Measurement position
Outer heatsink
Meas
ur
e
ment
pos
iti
o
n
Aluminum Heatsink
