<Dual-In-Line Package Intelligent Power Module>
1200V Mini DIPIPM with BSD Series APPLICATION NOTE
Publication Date: September 2015
25
Fig.2-4-2 Measurement point of heat sink flatness(PSSxxS71F6)
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
-200
μ
m 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 0.3K/W (per 1/6 module, grease thickness:
20
μ
m, 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.
2.4.3 Soldering Conditions
The recommended soldering condition is mentioned as below.
(Note: The reflow soldering cannot be recommended for DIPIPM.)
(1) Flow (wave) Soldering
DIPIPM is tested on the condition described in Table 2-4-3 about the soldering thermostability, so the
recommended conditions for flow (wave) soldering are soldering temperature is up to 265°C and the
immersion time is within 11s.
However, the condition might need some adjustment based on flow condition of solder, the speed of the
conveyer, the land pattern and the through hole shape on the PCB, etc.
It is necessary to confirm whether it is appropriate or not for your real PCB finally.
Table 2-4-3 Reliability test specification
Item Condition
Soldering thermostability
260±5°C, 10±1s
+
-
- +
Measurement
p
art
for
heat
sin
k
flatness
Measurement part
for heat sink flatness
Outer heat sink
