MT6M16534
© Fuji Electric Co., Ltd. All rights reserved.
6-2
• When mounting the product to a heat sink, the following fastening order is recommended. Uneven
fastening due to excessive torque might lead to destruction or degradation of the chip.
• Standard: Metric screw JIS B 1111
• Screw length: 16mm
• Screw head shape: Pan shape (head diameter 7.8 mm)
• Material: Stainless
• Use flat washers (JIS B1258 recommended). Washer head type screws can be used as well.
• The mounting (tightening) that support the load of structure such as heat sink or printed circuit
board by the product should be avoided.
• When mounting this product together with other components to the heat sink, ensure the flatness of
the components mounted on the printed circuit board before mounting.
3
Mounting (tightening)
2
Shape
Fig. 6-2 The measurement point of heat sink flatness
• As shown in Fig. 6-2, the heat sink flatness should be 0μm/100mm to +100μm/100mm, and the
surface roughness (Rz) should be less than 10
μm.
• If the heat sink surface is concave, a gap occurs between the heat sink and the product, leading to
deterioration of cooling efficiency.
• If the flatness is +100μm/100mm or more, the aluminum base of the product is deformed and cracks
could occur in the internal isolating substrates.
Fig. 6-3 Recommended screw fastening procedure
+
-
External Heat sink
100um
1
2
Note: the pre-screwing torque is set to 30% of the final screwing torque rating.
Recommended:
Pre-screwing: 1
2
Final screwing: 2
1
