8-Lead Metal Can
Transistor Can Package TO-39 Case, Through-Hole
8-Terminal TO-39 Package
The TO-39 package is a through-hole device [metal can].
This example of a TO-39 metal can contains an Operational Amplifier [Current Amplifier] and has eight terminals; Input, Output, two Vcc terminals, two Ground terminals, and two No Connect [NC] terminals. Although any component could also use the same package, the current amplifier is just a single example.
Also refer to Manufacturers of Operational Amplifiers.
Normal heat-sinks for the TO-39 will snap-on or clip-on to the top of the metal case, other solid aluminum heat-sink slide over the top of the TO-39. None of the terminal or leads of this package are connected to the case, unlike other examples of a TO-39 package. So there is no issue with the heat sink being electrical connected to a pin. A number of different heat sinks are shown on the different pages covering transistor packages, including many styles for metal cans. Most heat sinks that are used for one style of metal can will also work or other versions, as many are compression fit to the top of the package.
Unlike a 3 terminal TO-39, the 8 lead version is not that common [as it once was]. However the data is offered here regardless of how often the part is really used. The physical package dimensions are given as minimum and maximum values in the table.