Transistor Package TO-66 Case style
TO-66 Package, Flange Mount
The TO-66 style case is a through-hole device in a metal package, similar to a TO-23 Case package, or TO-3 Case package or TO-213AA case.
The diagram above shows the normal TO-66 terminal 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.
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 the TO-66 device is connected to the Collector. Case temperature. Case temperature is that temperature measured at a specified point on the case of a semiconductor device. |
 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.
The TO-66 package normally holds a high power Transistor.
