A request we commonly get here at Digi-Key is for “pinheaders”, or simply headers. These are a very useful and common electronic component. There can, however, be some confusion regarding these parts and the terms used to describe them you may be unfamiliar with. This post will explain some of the common terminology for headers and illustrate what those terms mean so that you can search for the connector that best suits your needs with confidence.
Pin header – A pin header is a connector affixed to a PCB that has male pin contacts. These are also known as Berg, Bergstrips, or Bergstik connectors. Those terms are not often used since it’s a brand name, and there are many more manufacturers who make similar connectors today. These can be found on our site at the following link: https://www.digikey.com/products/en/connectors-interconnects/rectangular-connectors-headers-male-pins/314
Here are some examples:
Socket header – A socket header, like a pin header, is a connector affixed to a PCB, but these have female socket contacts, rather than male pin contacts. These can be found on our site at the following link: https://www.digikey.com/products/en/connectors-interconnects/rectangular-connectors-headers-receptacles-female-sockets/315
Some examples of these can be seen here:
Now, let’s discuss some key specifications used when searching for these connectors.
Pitch – This is the measurement from the center of one contact to the center of the contact next to it. Common pitch measurements are 2.54mm (0.1 inch), 2.0mm (0.079 inch), and 1.27mm (0.05 inch), but there are many other options available. For more detailed information on pitch, and how to measure it, please see our TechForum post on Pitch of a Connector
Number of Rows – While single and double row are the most common options available, there are multiple row headers, especially in more specialized connector series.
Row spacing – Similar to pitch, row spacing is the measurement from the center of one row to the center of the next row. Most often, this measurement matches the pitch, but, since this is not always the case, it should be measured to verify.
Number of positions – This is usually based on the total positions in one connector, not on the number of positions per row, and would be measured the same way. In the previous photo, the connector shown would be considered 16 positions, though it has 8 positions per row. Outside Digi-Key, you may see a connector described or specified in grid format though, such as “2x8” for the above drawing. “2x8” “1x16” and “16-position header” all have the same number of positions.
Orientation – The more normal orientation for headers is vertical, where the contacts are perpendicular with the PCB, but many applications require that a connector be right angle, where the contacts are parallel with the surface of the PCB. Knowing which is needed for your application can help narrow the search options considerably. Examples below.
Mounting – How the connector is affixed to the PCB is referred to as the mounting. The most common methods for mounting are surface mount (where the terminations are made on the surface of the PCB to solder pads), and through hole (where the contacts pass through a hole in the PCB and are soldered in place from the rear).
Plating – In most cases, the contacts in headers are plated to reduce the chances of the contacts corroding or oxidizing over time, inhibiting their electrical conductivity. The most common plating options are pure Tin, or Gold. Gold has the best resistance to corrosion or oxidation, as well as better electrical conductivity, but it can add cost to the product, and is not as suited to repeated mating cycles as Tin, as some is worn away with each mating cycle. The thicker the Gold plating is, the more mating cycles it will be able to endure, but the cost can also increase, respectively.
Shrouding – Headers can have plastic walls. This shrouding can protect the contacts when not mated, used for keying, or for mechanical latching purposes. Shrouds can be on one side only, two (generally opposed) sides, three sides, or all four sides of the pins.
While these are not all the considerations that can be taken into account when selecting a header, they will certainly narrow your search to a much shorter list.