INGUN Probe FAQs
What is Grid?
Grid is the distance between two test points on a PCB/DUT, the distance between two component pins or connectors. Based on the test probes, this is defined as the middle of one mounting hole to the middle of the next mounting hole on the probe plate. There are internationally recognized grid distances in which manufacturers of PCBs and connectors are being observed. The grid unit is based on the imperial units and is given in inches. Because the grid size is sometimes very small, the grid dimension 1/1000 inch is used and this is also denoted as "Mil".
The most common grid dimensions are:
40 Mil = 1.0 mm
50 Mil = 1.27 mm
75 Mil = 1.91 mm
100 Mil = 2.54 mm
Does High Spring force ensures reliable contact?
The spring force should simultaneously be as low as possible in order to minimize the stress placed on the device under test, but also as high as necessary to guarantee a reliable electrical contact. Furthermore, other criteria, such as tip style, test environment, etc. must be taken into consideration in order to select the correct spring force.
Contact with Standard Probe (Left) vs Contact with High Energy Probe (Right)
What is the difference between receptacles with Press-ring and Receptacles with Collar?
Turned receptacles with a defined collar or a receptacle with a press-ring (end designation "G") are used to regulate the installation height of test probes. Turned receptacles are pressed into the assembly borehole up to the collar, which acts as a stopper to achieve a defined installation height. The press-ring receptacles can also be installed using the press-ring as a stopper, but with the press-ring countersunk in the borehole making the installation height adjustable. The main difference between receptacles with and without a press-ring is the production process. Barrels with press-rings are deep drawn and have a compressed collar, with has elastic properties. Receptacles without press-rings are produced using traditional turning methods to hollow out solid material, which means the collar is rigid and cannot countersunk in assembly boreholes.
When should threaded test probes be used?
Threaded test probe have the special designation "M" and are screwed into the receptacle rather that pressed in. These type of receptacles are used in particularly challenging test conditions, such as installation in a test set-up subject to vibrations, or to top-down installation, this ensure that the test probes is secured in the receptacle.