TO-66 Transistor Packages

TO-66 Package

Transistor Package TO-66 Case style, 2-Leads, 3-Terminal package.

TO-66 graph providing lead identification
TO-66 Package, Flange Mount

The TO-66 style case is a through-hole device in a metal package, similar to a number of other packages, including the TO-23 Case package, or TO-3 Case or TO-213AA case.
The diagram above shows the normal 2-terminal TO-66 pin locations, with the case used by the collector. The picture below shows the normal case attachment method for the TO-66 metal can. Note that the collector lead or metal case of the TO-66 is attached to a metal heat sink via two screws. A variant of this depiction uses a 3-Terminal TO-66 Package.

Case mount. [Flange Mount] A type of package which provides a method of readily attaching one surface of the semiconductor device to a heat dissipater to achieve thermal management of the case temperature. The case of a 2-Terminal TO-66 device is connected to the Collector to aid in heat dissipation.

Case temperature. Case temperature is that temperature measured at a specified point on the case of a semiconductor device.

TO-3 Transistor Package
TO-3 Metal Case

Normal TO-66 heatsinks are a Black Anodized Aluminum Alloy with 2 mounting holes. However any metal panel or metal plate may be used as a heat sink. In fact in many cases the TO-66 package is mounted external to a chassis to allow for better air flow [assuming a metal chassis. A possible heat sink is above, in the standard diamond shape conforming to the shape of the TO-66 outline. The actual length of the fins will vary depending on the heat sink purchased, but the physical size of the heat sink will conform to the body of the TO-66 [or just larger].

2-Terminal TO-66 Semiconductors;
The TO-66 package normally holds a high power Transistor;
NPN Power Transistor; 2N3584, 2N3585, 2N3739, 2N5660, 2N5661, 2N3766, 2N3767, 2N3879
NPN Power Switching Transistor; 2N5664 and 2N5665
NPN Power Darlington Transistor; 2N6300 and 2N6301
PNP Power Transistor; 2N3740, 2N3741
PNP High-Power Switching Transistor; 2N6211, 2N6212, 2N6213, 2N6213A
PNP Power Darlington Transistor; 2N6298 and 2N6299

Package Style:
Diamond Base Outline
.200 Pin Spacing

Black anodize diamond shaped basket heat sink
TO-66 Heatsink

TO-66 Package
TO-66 Table of Dimensions

Related topics:
Types of Transistor cases
Heat Sink Manufacturers
Transistor Derating Guidelines
Manufacturers of FETs and BJTs

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