Why Do We Need To Do PCBA Testing After Circuit Board Processing?

PCBA testing is a key step to ensure production and delivery quality, which determines the final performance of the product. Its purpose is to find out poorly assembled circuit boards by full-function testing when simulating the actual assembly of circuit boards into the whole machine, so as to find out all possible defective circuit assembly boards before assembling them into the computer. In order to avoid defects found after the whole machine is assembled, it is completely dismantled and reorganized, resulting in waste of working time and waste of materials.

What is the testing principle of PCBA?

PCBA testing refers to making FCT test fixtures according to the test points, procedures and test steps designed by customers, and then placing the PCBA board on the FCT test bench to complete the testing process. The testing principle of PCBA is to connect the test points on the PCBA board through the FCT test bench to form a complete path, connect the computer and the burner, and upload the MCU program. The MCU program will capture the user's input action (for example, press and hold the switch for 3 seconds), control the switch of the nearby circuit (such as LED flashing), or drive the motor to rotate through calculation. By observing the voltage and current values between the test points on the FCT test bench and verifying whether these input and output actions are consistent with the design, the test of the entire PCBA board can be completed.

What design files are needed to make a PCBA test bench?

To make a PCBA test bench (usually called an FCT functional test bench), customers need to provide the test points of the PCBA board, the standard voltage/current values between the test points, the allowable error range, the test steps, and other instruction files.

What is the difference between ICT and FCT in PCBA testing?

PCBA testing is a key step to ensure the quality of delivery. Generally, customers need to provide a test plan, including test points, procedures, test steps, etc. PCBA electronic manufacturers should conduct corresponding ICT and FCT tests according to the design files. ICT (circuit test) is mainly aimed at the component level. By contacting the pins of each component on the PCBA board and measuring whether its value is consistent with the nominal value, it is a very important means to detect the value and polarity of resistors, capacitors, inductors and other components.
However, with the rapid development of the process capabilities of the electronics industry, ICT testing has become less and less, because the quality of many components can reach below 50ppm, which fully meets the process yield of electronic products. At this time, FCT (functional test) is particularly important. The PCBA manufacturer will release the FCT test bench according to the design file, place the PCBA board on the test bench, capture the test points on the PCBA board, write the program through the burner, and then simulate the input and output actions of the product to achieve the test purpose. In some cases, the upper computer software is also required to cooperate. FCT testing is a functional test close to the product level, which can effectively cover the product performance range and is a very effective means.