In the PCB industry, manufacturers have many methods for PCB inspection. For example: signal injection method, substitution method, offline Inspection, online inspection, parameter test method, waveform observation method, visual inspection method, signal tracking method, AC short circuit method, separation test method, etc.
The intelligent detection method of the circuit board needs to select the online test method according to the specific characteristics of the PCB board, in order to combine one or more processes, complement each other, and make comprehensive utilization.
First, use the idea of virtual instruments on the PCB to establish related application software, that is, implement various functions of traditional instruments through software, including oscilloscopes, signal generators, and various mathematical processes on the collected data. During the test, the digital signal is given by the test software.
Then, the PCB test system will have new design ideas. Adopt the design idea of automatic test system and virtual instrument based on USB bus to give full play to the role of computer. Try to replace the traditional instrument with a computer to reduce the volume of the instrument itself, reduce development costs, and improve development efficiency.
Next, after the D/A conversion, the analog excitation signal required for the test is applied to the test system, and then the test circuit is sent to the switch matrix through the test bus. When the switch matrix is connected to the switch matrix, it is controlled by the microprocessor to turn on and off. The tested PCB board is fixed on the needle bed, and the signal is applied to the corresponding position of the printed circuit board. The signal is pressed to the corresponding position on the printed circuit board, and its response is measured by the test circuit. Then the collected analog quantity is sent to the core controller, and the corresponding digital quantity is obtained through A/D conversion, and then fed back by the software on the PCB machine and processed by the PCB machine to determine whether the PCB board is qualified.
This online testing technology breaks through the previous method of inspecting circuit boards with the naked eye. The online testing technology has high efficiency and low missed detection rate, which realizes the automation of the detection field. The detection system adopts the idea of combining with virtual instruments, which reduces the hardware design and reduces the cost of the entire system.
SHENZHEN HOYOGO ELECTRONIC TECHNOLOGY CO., LTD. is an international, professional, reliable PCB manufacturer. We have 2 production bases with a monthly production capacity of 500,000 square meters. One-stop PCB product supply and solution. And HOYOGO have a management team with 25 years of average industry experience and reliable quality assurance.