Page 15 - ConnectorSupplier.com - How-to-Specify Handbook

How to Specify Spring Probe Connectors
Gina Prieto, Key Accounts Director, Smiths Interconnect
Connectors that utilize spring probe contact technology offer a number of advantages over those that incorporate other types of contacts, including: enhanced compliance, blind mating, space savings, impressive cycle life (up to 300,000 cycles), and high misalignment tolerances. However, what truly sets spring probe contacts apart is their design exibility, which makes them suitable for a vast range of applications. Still, with so many signal and power probe contact options available on today’s market, choosing the right one can be a daunting task. Although it’s always best to engage with a connector supplier’s experienced applications engineers to ensure the selection of an optimum application-speci c solution, the following explanations and recommendations can help make the most of that conversation.
The design process for spring probe connectors, like all others, begins with the basics: identifying the physical arrangement of the contacts and the size and type of connector housing. The envelope allocated to the connector, the distance between boards, and the required number of signal and power contacts will automatically determine minimum contact spacing and maximum contact length. While probes can be very low pro le — down to 1.75mm compressed — and very dense, with 1mm spacing, choosing larger options whenever available will result in a more robust and higher performing connector.
Figure 1: Custom spring probe connectors
Spring probes aren’t limited to straight-on, face-to-face mating. They are also available with both bayonet and toe- in engagements, which makes them especially useful in applications where space is at a premium. The wiping action associated with these mating con gurations also acts as a means of self-cleaning, as it effectively removes contaminants and assists in the maintenance of a stable contact resistance. Probes can mate to plated pads on a printed circuit board (PCB), target pins, or contact pads on the exterior of a device, but the type of engagement speci ed will vary depending on the choice of mating surface.
Spring probes also offer termination exibility with through-hole, surface mount, and solder bucket options, and, in addition to PCBs, can be terminated to cables or ex circuits. However, the greatest space savings is achieved with compression mounting, which creates a one-piece solderless connector solution.
In addition to their low pro le and high mating and termination exibility, spring probe contacts offer: high cycle life, blind mating connection compatibility, a high compliance ratio, and robust resistance to mechanical shock and vibration. Combined, these bene ts make spring contact technology well suited for use in alternative energy, commercial aviation, defense, EV, HEV, industrial, medical, space, and test and measurement applications.
15