Transistor Package

TO-220 Package

Transistor Package TO-220 Case style [5-Terminals, Straight leads]

TO-220 Transistor Package drawing, 5-Terminal front and back view
TO-220 5-Terminal Package Drawing

Tab mount. A type of package which provides a method of readily attaching one surface of the semiconductor device to a heat dissipater [heat sink] to achieve thermal management of the case temperature. Other factors that may effect the mounting include using a Mica washer, copper washer, and thermal grease. In many cases a large heat sink is attached to the metal tab, in other cases the TO-220 is installed near the side of a PWB and the tab is attached to an infinite heat sink as in the panel of a metal chassis or case.
When attached to a PWB a copper pad or island should be located underneath the thermal tab of the TO-220.
Use a washer between the tab and the screw, or use a screw with a large diameter head, and do not over-tighten. If the tab is bent, becomes deformed or non-flat then the surface area between the metal tab and the heat sink will be reduced. Also don't counter-sink the hole in the board or heat-sink, as the screw would not use it and it's not required.

In many cases when a device is offered in a straight lead TO-220 package, the same device is offered in a bent and staggered lead TO-220 package.
Unlike the 3-Terminal TO-220 Package, the 5-lead package is used for semiconductors other than transistors or FETs; for example, Voltage regulators having control pins.

5-Lead TO-220 Package Dimensions
5-Lead TO-220 Transistor Package Dimensions

The surface mount version of a 5-lead TO-220 is the 5-Terminal TO-263.
There are also other sizes of the TO-263 package.

Regardless of the number of pins [shown to the left], the TO-220 package is widely used with voltage regulators and to a lesser extent power amplifiers.


Related topics:
Transistor Derating Guidelines
Including Thermal definitions

Types of Transistor cases
Manufacturers of FETs and BJTs
Thermal Compounds

Related TO-220 Packages
3-Terminal TO-220 Package
5 Staggered-Lead TO-220
7-Terminal TO-220 Package

Extruded-Finned Heat Sink
Vertical Heat Sink

TO-220 Packages

3-terminal TO-220
5-terminal TO-220
7-terminal TO-220
11-terminal TO-220
15-terminal TO-220
27-terminal TO-220

Larry's Web Page

Electronic Parts and Equipment Distributors Electronic Component Manufacturers OEM Electronic Equipment Manufacturers EDA Software Producers CAD/CAE Software Engineering Standards, EE Publications Interface/Embedded Computer Bus Electronic Engineering Design Data Engineering Reference Information.
DistributorsComponents Equipment Software Standards Buses Design Reference
Modified 6/13/15
© 1998 - 2016 All rights reserved Larry Davis