AN533

Through-hole packages

11/22

4.

Never bend the leads laterally (Figure 9).

Figure 9.

Bending the leads laterally (not allowed)

5.

Never bend the leads more than 90° and never bend more than once.

6.

Make sure that the bending / cutting tool does not damage the leads.

1.5.2

Using a heatsink

Mounting surface preparation

●

The mounting surface should be flat, clean and free of burrs and scratches.

●

The use of a thin layer of thermal silicone grease ensures a very low contact thermal

resistance between the component and the heatsink. An excessively thick layer or a

excessively viscous silicone grease may have the opposite effect and cause the

deformation of the tab.

●

The planarity of the contact surface between device and heatsink must be very low

(less than 50 µm for TO-220AB).

Insertion

If the heatsink is mounted on the PC board, it should be attached to the component before

the soldering process of the leads.

Mounting techniques

Mounting must be done carefully. Excessive stress may induce distortion of the tab and as a

consequence mechanical damage on the die.

Soldering: It is not recommended for through-hole packages.

Incorrect