PCB Tech - About PCB board online simulation test technology

The PCB board test system will have a new design idea. The design idea of an automatic test system based on the USB bus and a virtual instrument will be adopted to give full play to the role of the computer. The idea of replacing the traditional instrument with a computer as much as possible, thereby reducing the size of the instrument The volume of itself reduces the development cost, thereby improving the efficiency of development.

The new PCB board automatic test idea is to establish relevant application software on the computer, adopt the idea of virtual instrument, that is, realize various functions of traditional instruments through software, including oscilloscope, signal generator, and various mathematical processing of collected data Wait. During the test, a digital signal is given through the test software.

After 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. The switch matrix is connected to the switch matrix and controlled by the microprocessor to turn on and off. The test PCB board is fixed on the needle bed, the excitation signal is applied to the corresponding position of the printed circuit board, the response is measured by the test circuit, and the collected analog quantity is sent to the core control.

After A/D conversion, the corresponding The digital quantity is fed back by the software on the computer and processed by the computer to determine whether the PCB board is qualified.

On-line testing technology has broken through the previous method of using human eyes to detect circuit boards. On-line testing technology has high efficiency and low missed detection rate, and realizes the automation of the detection field. This detection system adopts the idea of combining with virtual instruments, which reduces the design of hardware and reduces the cost of the entire system.

The basic method of on-line testing of PCB board analog components and the testing method of diodes and transistors. This testing system is suitable for the application of small and medium-sized enterprises. It reduces the number of unqualified products entering the next process, thereby reducing the amount of product rework, improving production efficiency, reducing the total cost of manufacturing, and increasing the profit of the enterprise. It is currently a widely used testing technology and is an efficient, High-speed, high-precision detection method.

At present, PCB boards are used in the field of automatic testing of printed circuit boards with a wide variety of tests, including testing without components and testing with components. Currently, the more commonly used testing methods are: continuity testing, in-circuit testing, and functional testing, Edge test, optical test and X-ray inspection, etc. On-line testing is based on the specific characteristics of the PCB board, selecting an appropriate testing method to combine one or more processes together, complementing each other and making comprehensive use.