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The Value of Using Connector Pins and Pin Headers on PCBs

Posted by Bead Electronics on Jan 20, 2022 2:00:00 PM


Printed circuit boards (PCBs), sometimes referred to as printed wiring boards (PWBs), were some of the first forms of connecting devices in the early days of electronics.

While the use and applications of PCBs have evolved a lot since their invention, their format and processing are now established and consistent. The insertion and soldering of pins into PCBs have been a staple of this field, creating one cohesive unit. Pins and pin headers provide an opportunity to simplify the insertion process and their customizability makes it possible to further optimize a pin layout and an insertion process.

What is a Header on a PCB?

First and foremost, a PCB is a vital part of most electronic devices across many applications from automotive, computer, industrial, medical, military, telecommunications, and others as well as the impact on the manufacturing process.

These PCBs are the circuits that power and direct via signals the devices they're connected to.

PCB design and manufacturing often use a system of pins or pin headers and receptacles/sockets to hold the systems together electronically, electrically, and mechanically.

Headers are often referred to as part of a two-piece connection system and thus consist of two pieces which are usually referred to as "male" (header) and "female." (receptacle, socket). The distinction is made based on the design of the pins and the receptacles. The male portions of the headers feature the pins, which insert or connect into the receptacle portion known as the female.

Connecting PCBs can be done with wire to PCBs or more typically with PCB mounted pins and pin headers mating to PCB mounted receptacles. The mating of pins and headers to receptacles provides many connecting design options including right angle to straight (most common)—a right angle to a right angle—and straight to straight which is commonly referred to as stacking or mezzanine and is gaining in popularity.

A header can also function like a one-piece design where the individual pins or headers at opposite ends are connected to mating PCBs.

This is the basic design and layout of traditional PCB interconnecting.

So why is a header so important to PCB connecting and manufacturing and assembly?

bead-pcb header

Why Do Headers Matter?

With the pin options and socket options, a PCB board can have multiple electronic and/or electrical connections. This can be accomplished without the need for multiple block connectors.

The PCB pins and headers allow the connections to all occur in the desired layout and are easily adapted to suit a variety of needs and uses. The value of pins and pin headers comes from both the design flexibility it allows as highlighted previously as well as the range of processing available to terminate headers to a PCB.

Here are some of the forms of processing for header PCB terminations:

Through-Hole Technology (THT)

THT refers to through-hole technology, which includes wave soldering, selective soldering, or hand (manual) soldering. Wave soldering is a relatively quick and familiar form of soldering.

In this technique, a wave of solder flows under the backend of the PCB with the component leads (tails) are soldered to the PCB. Most THT soldering enables solder processing on one side of the PCB. Additional soldering on the other side would have to be selective soldered or hand soldered.

Wave soldering and selective soldering (programmed semi-automated, point-to-point soldering) essentially replace slow hand soldering of the pins in place. Edits can be made by hand but this is time-consuming and tedious. Hand soldering has its value in prototype and low volume PCB processing as well as low capital cost.

Through-Hole Reflow (Pin and Paste)

This system is sometimes thought of as the in-between method for surface mount technology. This is because it combines the standard process of surface mounting with the strength of through-hole technology.

The reflow oven requires that the through-hole components have materials (e.g. plastic) that are compatible with more costly, high temperature processing components such as liquid crystal polymer (LCP; FR-4) for the insulator.

In the case of using a through-hole component such as a header pin, there is compatibility to both the high heat process and the materials (all-metal pins or high-temperature compatible insulators).

Pins and pin headers can be designed with retention features such as stars or knurls or on the edge for square and round pins. These retention features enable pins and pin headers to be used in several of the processing options.

Individual pins packaged end-to-end or side-by-side can be inserted by insertion machines or a manual press for inserting the pins into the PCB holes for PCB termination.

It is also possible to bowl-feed pins to an insertion head for interference fit termination.

Surface Mount Termination or Technology (SMT)

SMT is an important part of the PCB circuity as it impacts component design, packaging, and processing conditions. Of significant value is that It enables the use of both the top and bottom sides of the PCB.

Material compatibility is key as SMT typically requires a high heat profile during processing. Packaging options include tape and reel for a pick and place assembly line which is picking the component out of the tape and reel and placing it down on the already solder pasted pad for each SMT component.

Trays are also an option for pick and place with a vacuum pickup or a gripper pickup and placement. Pins and pin headers can be packaged in tape and reel or in trays.

Press-Fit Terminations

Solderless, press-fit terminations enable the designer to utilize a compliant pin or PCB tail design which makes a mechanical and electrical connection to a PCB hole without soldering and is done as a cold process.

While the processing of the component to the PCB is much simpler, the pins or sockets are typically more costly. As in the through-hole reflow, again individual pins packaged end-to-end or side-by-side can be inserted by insertion machines or a manual press for inserting the pins into the PCB holes for PCB termination.

It is also possible to bowl-feed pins to an insertion head for press-fit termination. While presented here as individual options for PCBs, pins, packaging, and processing options, some of these options can be designed together.

What About Custom Pins and Pin Headers?

Custom individual pins or pin headers with FR-4 or another holding base can reduce the cost and limitations of fixed-size molded headers.

Whether single row or double row or other grid configuration, pins and headers provide design and manufacturing flexibility. FR-4 pin headers are easily customized in notched panels and then can be separated and then provided in preferred packaging such as tape and reel, loose/bulk packaging, or others.

The designer then has the option to design an enclosure around the pin fields to emulate a desired input/output (I/O).

Working with a high-quality interconnect pins manufacturer helps speed things along while making sure parts are not only being delivered on time but on budget.

Bead Electronics focuses on bringing the ease and quality technology you need. Contact us today to find the right pins and pin headers in your price range.

Topics: PCB Contact Pins, Custom Connectors, Bead Electronics, Bead Industries, PCB Design, Aerospace, Pin Insertion, Defense

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