Electronic PCB board must be one of the most important parts for all electronic products. PCB is made of FR4 substrate covered by the copper pattern that customer designed and soldermask color will cover on the copper to prevent copper oxidation. For the exposed pads, there will be surface treatment, such as ENIG, HASL, OSP, which is used to protect the pads from oxidation and will also enhance the solderability. To ensure the quality of PCB board, many test steps will be performed at Linked Electronics, the PCB and PCBA service provider, to guarantee the best quality of the products. Of all the steps, AOI test and final e-test must be the most critical test for electronic PCB board.
AOI test is what we used for multilayer inner layers inspection to prevent open or short circuits. And there are two types of e-test at final steps, one is flying probe and the other is fixture. Today, Linked Electronics will make a brief comparison of the two-test method.
Flying Probe Test
Flying probe( fixtureless test) is the best option for prototype electronic PCB board and small volume PCB circuit board production.
There will be 4,6 or 8 probe which will make contract with the test points such as SMD pins, pads and vias. And test for open or short circuits. And other electrical parameters such as the polarity, resistance and capacitance.
Advantages of flying probe for PCB manufacturing:
1.High precision, it can test 0.05mm pitch or even smaller.
2.No fixture cost, which is very expensive for electronic PCB board of prototypes.
3.Idea choice for PCB prototypes. Once fixture is made, it cannot be changed. If the PCB design is changed, it will be very expensive to make a new one.
4.Comparatively low cost for PCB samples.
Disadvantages of flying probe for PCB manufacturing:
1.Low speed. The flying probe test is using a probe which will inspect each pad which is much slower than a fixture.
2.Dielectric Withstand Voltage Test is not available with flying probe. For multilayer high precision PCB board, there are risk to use flying probe.
3.Not suitable for mass PCB orders.
4.The accuracy is not good as fixture.
5.Test fee charge every time when PCBs are ordered.
Fixture test is one of the most universal test method in PCB board manufacturing industry. hich is generally used for high volume PCB production.
We use a jig that is what we call fixture to test the PCB functionality, if there are any short or open circuits. And insulation strength test and impedance test can also be realized by the fixture. One of the distinct characteristics compared with flying probe is the high speed with great accuracy.
Advantages of fixture test for PCB manufacturing:
1.Very high accuracy compared with flying probe test
2.Fast speed, all points are tested simultaneously, which is much faster than flying probe.
For example, the same PCB board might takes about 20 minutes to complete the flying probe test but for fixture, it will take only about 10 seconds.
3.Charged one time only, if no design is changed, no cost will be charged for repeat PCB orders.
Disadvantages of fixture test for PCB manufacturing:
1.Not suitable for PCB samples.
2.High cost if there’s no repeat orders.
At Linked Electronics, our sales team will ask customer about the PCB volume or if any repeat orders for this in the coming month. Based on these information, selection of the testing method will be made by our professional PCB manufacturing team in China and confirmed on your side. All PCBs are 100% e-test at our factory which will guarantee the best quality electronics PCB are made by the China PCB manufacture Linked Electronics. We look forward to hearing from you.
Contact Person: Mr. Jonathan
Tel: +86 755 2553 8256