PCB Flying Probe Testing Technology (2)

Method Two

1: Import the layer file, check, arrange, align, etc., and then rename the two outer layers to fronrear. Rename the inner layer to ily02, ily03, ily04neg (if it is a negative film), rear, rearmneg.

2: Add three layers, copy the two solder mask layers and the drilling layer to the added three layers respectively, and change the names to fronmneg, rearmneg, mehole. Those with blind and buried holes can be named met01-02.,met02- 05, met05-06, etc.

3: Delete the LINE or other stuff that affects the network, and then convert the PAD corresponding circuit layer of the solder mask layer into PAD.

4. Merge the positive and negative films, keeping the positives. The hole attribute of the MEHOLE layer is changed to PAD, after editing each layer OK, then output each layer in GENESIS.

5. fron, ily02, ily03, ily04neg, ilyo5neg, rear, fronmneg, rearmneg, meholemet01-02, met02-09, met09-met to define each layer, then perform network analysis, and will run out of the test point save.

6: Import the *.ezf file saved by EZFIXTURE into EZPROBE, select the smallest probe to execute the minute hand, and then output the C01 of the drill belt, and read S01 into GENESIS.

7: Change C01 and S01 to round with D code of 8mil, first mirror C01, and then COPY them to the fronmneg and rearmneg layers respectively. We call the fronneg the front layer test point and the rearmneg the back test point. Activate all layers and move to 10,10mm.

8: The output gerber files are named fron, ily02, ily03, ily04neg, ilyo5neg, rear, fronmneg, rearmneg, meholemet01-02, met02-09, met09-met10 layers.

It is better to use this method to make test files than the first method, because it can save a lot of time for testing.

In general, EDIAPV is used to generate network and test files. Sometimes PCB Gerber is too dense, and it is easy to short circuit. Also, some GENESIS outputs come to GERBER, but EDIAPV cannot recognize it, so sometimes it will cause open circuit or short circuit.

About the time it takes to test the board:

When the tester tests the circuit board, the time required for each board is different, because the number of points and the network of each board are different. The time of the test is mainly calculated according to these two items.

Doing a test file will generate a Report file, which contains the theoretical time of the board test.

The exact time to test each board (usually based on the hard board) is when testing an OK block, and the test time of the testing machine shall prevail.

Generally speaking, the actual time is basically the same as the theoretical time. And the FX3000 series flying probe tester has been improved in many aspects, the accuracy has been improved, and the test speed can be increased by about 20%. The reasons for the speed of the FX3000 series flying probe tester are as follows:
1. Speed ​​adjustment: Usually, the XY axis drive speed is adjusted to 70000, and the fastest speed is not more than 80000. The Z axis drive speed is adjusted to 7000, and the fastest speed is not more than 8000. Otherwise, the performance of the machine will be affected, and there will be phenomena such as step drop.
2. Shorten the waiting time after injection and return needle when testing the board.
3. Reduce the Z-axis lifting height: The range of the Z-axis lifting height is between 120-360, usually set between 180-280, the larger the Z-axis lifting data, the slower the speed. But if the promotion data of the Z-axis is too small, there will be scrapers and other phenomena.
4. When there is a problem during the test, the test time will be relatively increased. For example, if there is an open circuit in the test, when the retest is OK, the test machine will automatically restore the short circuit between the open circuit network and the adjacent network, and the test time will increase relatively. When an uncertain short circuit occurs, the test time will increase. There are many problems in the test, mainly depends on whether the quality of the PCB produced by the manufacturer is more open, short-circuited and whether the surface treatment conductivity is good, and whether the setting of the operator’s reference point is reasonable, which requires the operator’s test experience.5. The characteristics of the board will also affect the test time.

For example: The test points of some boards are too close to the edge of the board and some flexible boards, and a special support frame needs to be used to fasten and support them. If the fixation is not good and the board shakes back and forth, then the Z axis should be increased height during the test which will increases test time.