TO headers, also known as transistor outline headers, are a type of electronic package used in the semiconductor industry to house and protect semiconductor devices such as transistors, diodes, and voltage regulators. They are named after their transistor outline (TO) shape, which consists of a cylindrical body with leads extending from one end.
TO headers are typically made of metal, such as aluminum or copper, and have a hermetic seal to protect the enclosed semiconductor device from external elements such as moisture, dust, and mechanical stress. They are designed to handle high power and high-frequency applications, making them suitable for use in power supplies, audio amplifiers, and radio frequency (RF) applications.
The leads of TO headers are typically either through-hole or surface mount, depending on the specific application. Through-hole leads are inserted into holes on a printed circuit board and soldered in place, while surface mount leads are soldered directly to the surface of the board.
TO headers are available in various sizes and shapes, each with different electrical and thermal characteristics to suit different applications. They also come in different versions, such as TO-220, TO-247, and TO-263, each with a specific pin configuration and power rating.
Overall, TO headers play a critical role in protecting and ensuring the reliable operation of semiconductor devices in high-power and high-frequency applications, making them a vital component in the semiconductor industry.