PCB Flying Probe test operation skill

- Aug 20, 2016-

    Flying needle test operation in the alignment, fixed frame, cross board test and other test techniques to test the warping board, for peer reference.

First, the alignment

     The first thing to talk about is the selection of the alignment point, generally only pick the diagonal of the two holes as the point of the point can be, (natural to be selected in the edge, is also a number of left from the number of the first few holes?) and not to bother IC. The benefits of doing so is less point counterpoint, para spend less time, generally speaking, etching is always a lateral erosion, so choose pad point alignment is not very accurate. If really appear a lot of open, do not immediately stop, open circuit test to the short-circuit test to stop, because then you can already see the open circuit error, you can according to the error of position in the alignment point.

     Talk about manual rotoscoping, strict, said hole is in the center of the pad, then alignment is to try to put in the center of the pad, or as far as possible and holes are overlapped? If you want to test a plurality of holes, then choose the latter, if IC, especially IC is prone to false when open, you need to put the counterpoint holes in the middle of the pad.

Two, fixed frame

     Fixed frame is fixed test bracket, with the border data is represented by two boxes, outside the box is the border, for such a plate, size can directly use the machines are given, for the data with no border is represented by a box, we can show board this command (in the direction of plate will be used) see in sidelined most tested pads which, control board, its distance to the edge of the board is how much, in order to compensate.

Three, hit the fork

     For the fight plate, can measure selected odd, we can use this function to realize the butt plate to plate edge distance is too small to test the spell plate test. The method is to board who have welding disc tray file unable to test the odd crossing accidents, after testing the tray to test the odd fixed plate, select the test time is measured, so that we can through the second test to test the whole plate. As a result, we should be flexible in using the devices that are available to the device, in order to complete some special needs.

Four, warp

     Warpage solution to support structure will have a direction of size is too large, especially in the other direction relative size is small, the board on the testing machine when naturally occurring warpage caused by gravity, and we fly needle machine in a small problem, X direction of larger size, but only placed a plate bracket, and the small size of the Y direction can put 3 board piece, so the choice of machine to be measured in square set to machine the X direction, the best hand finishing, the plate is rotated 90 degrees, making it rectangular to put in the Y direction, this can to some degree on the board in the test.

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