PC Package Installation

To-5, To-8 Header Installation

Figure 1 is typical of the installation of TO-5, TO-8 and similar packages. Since the leads are flexible, they can be passed through a hole in a PC board, bent over and soldered directly to the track or ground plane. This eliminates the need for eyelets or plated through holes. For such installations or with signal paths on the top side of the board, extra care must be taken to not short circuit the signal pins to the case.

Figure 1. Mounting TO-5 Package (4 pin)

Figure 2. Mounting Relay Package (& Meri-Pac)

For a more mechanically sound installation and maximum protection against vibration and shock, TO-5 packages with #2-56 threaded studs are available, however, a flatpack or Meri-Pac is preferred for the most severe environments.

Meri-Pac and Relay Packages Installation

The leads on the Meri-Pac and Relay packages are rigid and should not be drastically bent or the integrity of the glass seals will be compromised. Plated through holes or eyelets are desirable to ensure a reliable connection.

Clearance of at least O.125"(3.18mm) diameter must be allowed in the mounting surface ground plane for all signal pins, and all grounding pins should be soldered to the ground plane. At higher frequencies, additional grounding using conductive epoxy is desirable.

The Half Relay Header is used in both 4 and 8 pin forms. The 4 pin version is popularly used to "lay down" to the PC board to provide a low profile installation, and should be mounted with additional support, as shown in Figure 6. Both 4 and 8 pin versions use soft, flexible leads, so can also be installed as the TO-S package shown in Figure 1.

Figure 3. Half Relay Header Installation