LV5686PVC

No.A2122-13/14

HZIP15 Heat sink attachment

Heat sinks are used to lower the semiconductor device junction temperature by leading the head generated by the device to

the outer environment and dissipating that heat.

a. Unless otherwise specified, for power ICs with tabs and power ICs with attached heat sinks, solder must not be

applied to the heat sink or tabs.

b. Heat sink attachment

• Use flat-head screws to attach heat sinks.

• Use also washer to protect the package.

• Use tightening torques in the ranges 39-59Ncm(4-6kgcm) .

• If tapping screws are used, do not use screws with a diameter larger

than the holes in the semiconductor device itself.

• Do not make gap, dust, or other contaminants to get between the

semiconductor device and the tab or heat sink.

• Take care a position of via hole .

• Do not allow dirt, dust, or other contaminants to get between the

semiconductor device and the tab or heat sink.

• Verify that there are no press burrs or screw-hole burrs on the heat sink.

• Warping in heat sinks and printed circuit boards must be no more than

0.05 mm between screw holes, for either concave or convex warping.

• Twisting must be limited to under 0.05mm.

• Heat sink and semiconductor device are mounted in parallel.

Take care of electric or compressed air drivers

• The speed of these torque wrenches should never exceed 700 rpm,

and should typically be about 400 rpm.

c. Silicone grease

• Spread the silicone grease evenly when mounting heat sinks.

• Sanyo recommends YG-6260 (Momentive Performance Materials Japan LLC)

d. Mount

• First mount the heat sink on the semiconductor device, and then mount that assembly on the printed circuit board.

• When attaching a heat sink after mounting a semiconductor device into the printed circuit board, when tightening

up a heat sink with the screw, the mechanical stress which is impossible to the semiconductor device and the pin

doesn't hang.

e. When mounting the semiconductor device to the heat sink using jigs, etc.,

• Take care not to allow the device to ride onto the jig or positioning dowel.

• Design the jig so that no unreasonable mechanical stress is applied to the semiconductor device.

f.

Heat sink screw holes

• Be sure that chamfering and shear drop of heat sinks must not be larger than the diameter of screw head used.

• When using nuts, do not make the heat sink hole diameters larger than the diameter of the head of the screws used.

A hole diameter about 15% larger than the diameter of the screw is desirable.

• When tap screws are used, be sure that the diameter of the holes in the heat sink are not too small. A diameter about

15% smaller than the diameter of the screw is desirable.

g. There is a method to mount the semiconductor device to the heat sink by using a spring band. But this method is not

recommended because of possible displacement due to fluctuation of the spring force with time or vibration.

Binding head

machine screw

Countersunk head

mashine screw

Heat sink

gap

Via hole