TO series headers are used for receiving, transmitting, and sensing, covering the packaging needs of lasers, detectors, sensors, etc. These products are widely used in automotive electronics, optical communications, medical devices, and public safety.
The TO (Transistor-Outline) package consists of a header and a cap assembly. The header serves as the base of the package, providing electrical connections for semiconductor components, while the cap facilitates smooth optical signal transmission. These two components form a hermetically sealed enclosure that protects the sensitive semiconductor elements inside from external environmental influences.
Our TO series includes TO46, TO56, TO38, TO39, TO33, TO60, TO52, TO18, TO5, TO9, and TO3 headers, and we can also provide professional customization based on customer drawings.
TO Packaging: Also known as coaxial packaging, this configuration aligns the laser chip, lens, and optical fiber along the same optical axis. Transmitter TO packages typically employ the TO56 standard, where "56" denotes the outer diameter size of the TO header, measuring 5.6mm.
Unlike the TO56, where "56" refers to the 5.6mm outer diameter of the TO header, the "46" in TO46 denotes the 4.6mm diameter of the TO cap. The header diameter of the TO46 is slightly larger than the cap diameter only at the welded joint area, resulting in a more compact overall size compared to the TO56. This design difference arises because the TO56 header is designed to participate in welding processes—either laser welding around the header circumference or resistance welding on the header platform—whereas the TO46 utilizes adhesive bonding, requiring only sufficient glue contact area between the header and cap.
Figure 1: TO46 product
Figures 2 & 3: Exploded views of the 4-pin and 5-pin configurations (same as above).
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