Flying Probe - Indirect Testing vs. Military


Reading time ( words)

Introduction

The use of flying probe testers has become increasingly popular in recent times, mainly due to the affordability of the equipment and also the reduced cost of testing, as no dedicated or “bed of nails” fixture is required. When using flying probes to test military product, one must be diligent to make sure the test method is allowable. Grid test machines provide full net to net testing for isolation of all nets and full continuity of individual nets.  This is referred to as full simultaneous test.  When a flying probe is used there are two modes of operation: Direct or indirect.

Direct Testing

When a direct test is used the machine will test every board in resistance mode, meaning that every net will be resistively tested for both opens and shorts. Each board will take the same time to test. When the isolation (shorts) test is performed, nets will be tested using an adjacency window. This is different than a bed of nails whereby which each net is tested simultaneously to all other nets using the voltage and isolation resistance thresholds. With a flying probe only nets within the adjacency window are tested to others. Industry accepted practice for this adjacency window is 0.050” (1.27 mm). Also to be considered is the type of adjacency used.  Standard practice is X,Y adjacency or “line of sight,” meaning only on the same layer. If Z-axis adjacency is added, the adjacency window becomes three-dimensional and isolation testing is done not only on the same layer, but within the adjacency window on layers above and below.

Read the full column here.


Editor's Note: This column originally appeared in the June 2014 issue of The PCB Magazine.

Share

Print


Suggested Items

Your Greatest Competition is Yourself

01/20/2021 | Barry Matties, I-Connect007
It really doesn’t matter who you think your external competitors are, because the only competitor that really matters is you. Of course, you will look externally to stay on top of latest trends, but when it comes to competition, just competing with yourself is a win. When you look at yourself as your greatest competitor you will start with a huge advantage: you already have great intel on how “your competition” thinks. Ask yourself, “What can I do to displace my ‘competitor’ and create something much better?”

Mentor’s User2User Conference Focuses on Semiconductor Development

11/25/2020 | Happy Holden, I-Connect007
Mentor conducted its annual User2User Conference virtually this year on November 10. In a departure from past U2U conferences, this event was focused primarily on developing semiconductor advances. Happy Holden reports on all the details.

PC Technological Advances in 2020

11/24/2020 | Dan Feinberg, I-Connect007
With CES quickly approaching, which is perhaps the largest technology event globally that is also going virtual this year, key component and sub-assembly companies are not waiting to announce their next generation of components. Dan Feinberg details new components and performance advances, as well as why you should consider building your own PC.



Copyright © 2021 I-Connect007. All rights reserved.