The Marriage of Elastomers and Spring Pins: Hybrid PariProbes®

Historically, spring probes have been used for test sockets and compliant interconnects. So have elastomers. But, they usually don’t get teamed-up. When they do, in the form of the patent-pending Hybrid PariProbe®, the results are quite unique.

 

What

High Bandwidth

High Compliance

High Power

Low Profile

Why, How, and How Much

The contacts are very short, with low self inductance and low contact resistance.

Compliance is about 25% of the overall contact length.

Made possible by the right materials, and low contact resistance.

< 2mm overall.

 

PariProbe® Hybrid Concept Machined Stretch Frame

A simple PariProbe® is a solid metal probe that is positioned between the PariPoser® material and the DUT (Device Under Test) to accommodate unusual shapes of a DUT. (for example: the round shape of BGA solder balls) A Hybrid PariProbe® adds a compression spring to the probe, to increase the compliance per contact.

The Hybrid PariProbe® assembly starts with a sheet of PariPoser® anisotropic elastomer material in a stretch frame. The frame and the material become the base of the socket or the connector, and retain the short spring probes in the one-piece socket body. When the top plunger is compressed,  current is passed through the spring probe, then through the elastomer, and on to the PCB.

 

Molded Stretch Frame   Cross Section of Probe One-piece socket body

 

Here’s how it works:

Stretch Frame The PariPoser® material is pulled taut and glued to the frame to make it easy to handle and attach to the socket body.
Socket Body The one-piece socket body is typically custom machined to retain the spring probe, and to mechanically interface the DUT.
External Spring The large amount of compliance per contact position comes from the compression spring. Putting the compression spring on the OD of the probe’s barrel creates a signal path through the central core of the probe – and then directly through the elastomer. That keeps the CRES (Contact Resistance) low.
Bottom Plunger The bottom of the probe barrel pushes directly on the PariPoser® elastomer, so no bottom plunger is needed. That saves costs, shortens the overall contact length, and prevents mechanical wear on the PCB (Printed Circuit Board) pad.
Top Plunger The top plunger tip can take any shape or coating that is required for the DUT.
Sealed Bottom The sheet of PariPoser® elastomer along the entire surface of the socket bottom seals the socket from the PCB and prevents contamination.