What are the Commonly used Inspection Methods for PCB?

In order to ensure the quality of PCB, a variety of detection methods will be used in the production process to detect possible problems or defects. What are the commonly used detection methods for PCB?

1. Manual Visual Inspection

The inspector will use a magnifying glass or calibrated microscope to check whether the PCB is qualified or not. Generally, it is to check whether there are obvious defects in the appearance PCB, pad, solder mask ink, and outer layer traces.

2. Online Testing

By inspecting electrical properties to find defects and testing analog, digital and mixed-signal components to ensure they meet specifications, bed of needles and flying probe testers are used for testing.

3. Functional Test

The general functional test is the last step before the final manufacturing, mainly to conduct a comprehensive test on the functional modules of the PCB to confirm the quality of the PCB.

4. Automatic Optical Inspection

Automatic optical inspection is based on the principle of optics and comprehensively adopts various technologies such as image analysis, computer and automatic control to detect and deal with defects encountered in production. It is a relatively new method of confirming defects. AOI is typically used before and after reflow and before electrical testing to improve yields during electrical processing or functional testing, where the cost of correcting defects is much lower than after final testing.

5. Size detection

Use the two-dimensional image measuring instrument to measure the hole position, length, width, position and other dimensions. Some PCB are small, thin and flexible products. Contact measurement is easy to produce deformation and cause inaccurate measurement. The two-dimensional image measuring instrument has become the best high-precision dimensional measuring instrument. After programming, the image measuring instrument can realize fully automatic measurement, which not only has high measurement accuracy, but also greatly shortens the measurement time and improves the measurement efficiency.

HoYoGo is an international, professional and reliable PCB manufacturer, we have our won factory, advanced machines, experienced technicians and a number of quality personnel, strictly control every quality threshold, and can guarantee delivery to customers the quality and reliability of each product. If you have relevant demands, please contact us!