What is PCB Assembly and PCBA testing

The process flow of PCBA patch processing is very complicated, including PCB board manufacturing process, component procurement, and inspection,SMT patch assembly, DIP plug-in, PCBA testing, and other important processes. The PCBA test is the entire PCBA?The most critical quality control link in the processing process

determines the product’s final use performance.

Table of Contents:

1. What is PCBA?

2. What is PCBA testing

3. The PCBA test meaning

4. Principle of PCBA Testing

5. PCBA Test type

1. What is PCBA?

PCBA is the abbreviation of PrintedCircuitBoard+Assembly. That is to say, PCBA is the entire process of passing through the PCB blank boar SMT, and then passing through the DIP plug-in.

Note: SMT and DIP Freewing RC airplaneare both ways to integrate parts on the PCB. The main difference is that SMT does not need to drill holes on the PCB. In DIP, the PIN pins of the parts need to be inserted into the holes that have been drilled.

SMT (SurfaceMountedTechnology) surface mount technology mainly uses mounters to mount some tiny parts on the PCB. The production process is PCB board positioning, solder paste printing, mounting machine mounting, reflow oven, and Make inspection.

DIP stands for "plug-in," that is, inserting parts on the PCB board. This is the integration of parts in the form of plug-ins when some parts are larger in size and are not suitable for placement technology. Atten soldering gunThe main production process is sticking adhesive, plug-in, inspection, wave soldering, printing, and finished inspection.

Basically, the PCB can only be regarded as a component. The PCB is an important component of the whole PCBA. The PCB must be soldered with IC, resistors, capacitors, inductors, connectors, and other parts to become a PCBA.

They look like this, respectively, as follows:

2. What is PCBA testing?

PCBA Test refers to the electrical continuity of the PCBA circuit board mounted with electronic components and the test based on the input and output values.

3. The PCBA test meaning

In the design of PCB circuit boards, there are numerical relationships such as voltage and current between different test points. However, the process flow of PCBA production and processing is very complicated, including multiple important processes such as PCB board manufacturing process, component procurement, and inspection, SMT patch assembly, DIP plug-in, PCBA testing, etc. During the production process, it may be due to equipment or operations. Various problems occur improperly, so it is necessary to use professional test equipment or manual operation of a multimeter to test the test points to verify whether the actual PCBA board meets the design requirements and ensure that each product does not have quality problems.

PCBA Test is a key step to ensure the quality of production and delivery. The FCT PCB test fixture is made according to the test points, procedures, and test steps designed by the customer, and then the PCBA board is placed on the FCT test rack to complete the test.

4. Principle of PCBA Testing

Connect the test points on the PCBA board through the FCT test frame 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 actions (such as long-pressing the switch for 3 seconds), and control the on and off of the side circuit (such as LED flashing) or drive the motor to rotate through calculations. By observing the voltage and current values??between the test points on the FCT test frame and verifying whether these input and output actions are consistent with the design, the test of the entire PCBA board is completed.

5. PCBA Test type

PCBA testing mainly includes five forms: ICT test, FCT test, aging test, fatigue test, and test under harsh environment.

The ICT (In-Circuit Test) test mainly includes circuit continuity, voltage, and current values, fluctuation curves, amplitude, noise, etc., and does not involve function keys or input and output tests.

For FCT (Functional Test) testing, you need to first burn the prepared microcontroller (MCU) program into the program IC through a burner (such as ST-Link, JTAG) to simulate the function of the entire PCBA board, such as after pressing a button, The LED light is on; press the two buttons at the same time to restore the factory settings and so on. So as to find out the problems in the hardware and software, and equip with necessary patch processing production jigs and test racks.

Burn-in test (Burn-In Test) is mainly to perform long-term and periodic simulation of user input and output on PCBA boards that have been programmed, and FCT passed to test their durability and welding reliability. Only electronic products that have passed the aging test can be sold in batches.

The fatigue test is mainly to sample the PCBA board, and perform the high-frequency and long-term operation of the function, observe whether there is failure, and judge the probability of failure in the test, so as to feedback the working performance of the PCBA board in the electronic product.

The test in harsh environments is mainly to expose the PCBA board to extreme temperature, humidity, drop, splashing, and vibration, and obtain the test results of random samples, thereby inferring the reliability of the entire PCBA board batch product.