What is a pin header?

What is a pin header?

A pin header, or header, is a male connector with one or two rows of metal pins attached to a plastic base. Pin headers with more than two rows are available from some manufacturers. The pins are spaced in uniform intervals (commonly 2.54 mm or 0.1 inch apart) but many spacings are available depending on the application. The female counterpart is sometimes referred to as a female socket header.

The original pin header was manufactured by Berg Electronics Corporation (now part of Amphenol) and, as a result, pin headers are sometimes called Berg connectors. Today, they are manufactured by many companies.

Pin headers are typically through-hole devices (THD). That is, the pins are inserted through holes drilled in the PCB and soldered on the opposite side. However, some headers are surface mount devices (SMD). In this case, the pins are bent 90° and mounted (soldered) directly to the surface of the PCB.

Headers can be straight (vertical) or right-angle (to connect two PCBs horizontally).

Design Notes

Pin headers are sold in long strips, typically with 36, 40, or 50 pins. The strips can be cut to the required length (number of pins). The availability of various pin lengths minimizes labor during PCB assembly.

Header types are characterized by pitch (the distance between the center of one pin to the the center of the next pin). Common header pitches are:

• 5.08 mm (0.200 in)
• 1.27 mm (0.050 in)
• 3.96 mm (0.156 in)
• 2.54 mm (0.100 in) with 0.64 mm (0.025 in) square pins or precision machined 0.50 mm (0.020 in) round pins
• 2.00 mm (0.079 in) with 0.50 mm (0.020 in) square pins

Headers are also defined by the number of pins wide by the number of rows. For example, a header that has two rows of eight pins is identified as an 8×2 header.

Preventing incorrect placement

• A shrouded header, also called a box header, has a plastic guide box (shroud) around it with a square notch that ensures the connector cannot be placed the wrong way around. Shrouded headers are used with insulation-displacement connectors (IDC) for ribbon cables.
• Filling or blocking one of the holes in the socket, called polarizing, also prevents mismating. One pin of a wrong pin header, or a pin header rotated with the wrong orientation, hits the obstruction to prevent a wrong connection from being made.

Pin numbering

Pins are numbered (counted) from the bottom of the row to the top, then picked up at the bottom of the next row. For male headers, start on the left and for female headers, start on the right. For headers attached to ribbon cables, the pins are numbered linearly across the cable. In a two-row header, pins in one row have odd numbers and pins in the other row have even numbers.

Markets, Sectors, and Applications

Pin header connectors are used in PCBs in a variety of electronics, electrical appliances and devices, and meters.