How important is PCBA testing?

Briefly, people's lives can not live without electronic products, electronic products can not be separated from the circuit board, the circuit board can not be 

separated from the PCBA test.

And what is PCBA testing?

Distinguish between PCB and PCBA

PCB is known as Printed Circuit Board, that is, the printed circuit board, referred to as the circuit board.

PCBA is known as Printed Circuit Board Assembly, that is, the PCB air board after SMT on the piece, and then after the DIP plug-in the entire process.

What is PCBA testing？

The process of  PCBA processing is very complex, including PCB board process, component procurement and inspection, SMT assembly, DIP plug-in, PCBA 

testing and other important processes. In particular, PCBA testing is a key step to ensure the quality of production delivery, which determines whether the final performance of the product is up to standard.  Its purpose is to catch out the badly assembled circuit boards, through the simulation of the full function test when the circuit board is actually assembled into  the whole machine, in order to catch out all the possible defects of the circuit assembly board before assembling into the whole machine,  to avoid the badly assembled into the whole machine,  but also all the disassembly and reorganization resulting in waste of time and loss of materials.

PCBA testing mainly includes ICT testing, FCT testing, Aging testing, Harsh environment testing and Fatigue testing.

1, ICT that automatic in-circuit test, is a modern PCB manufacturer necessary test equipment. It is mainly through the test probe contact PCB layout (generally 

refers to the PCB design) out of the test point to detect the PCBA line open, short circuit, all parts of the fault situation, and clearly inform the staff.

ICT has a wide range of use, high measurement accuracy, and clear instructions for detected problems, making it very easy for even workers with average 

electronics skills to handle problematic PCBAs. The use of ICT can greatly improve production efficiency and reduce production costs.

2, FCT (functional test) it refers to the test PCBA board to provide a simulated operating environment, so that it works in a variety of design states, so as to

obtain the parameters of each state to verify the function of the PCBA board good or bad test method.

3, Aging test is to simulate the product in the real use conditions involved in a variety of factors on the product to produce aging conditions to strengthen the

test process. PCBA board can be used according to a long time power-on test to simulate customer use, input / output aspects of the test to ensure that its 

performance to meet market demand. In special cases, it is also necessary to expose the PCBA board to a specific temperature and humidity environment for.

4, Harsh environment test is mainly to expose the PCBA board to extreme values of temperature  ,  humidity,  drop,  splash,  vibration, to obtain test results of random samples, so as to infer the reliability of the entire PCBA board batch products.

5, Fatigue test is mainly a sample of PCBA board, and the function of high-frequency, long-time operation, to observe whether the failure, to determine the

 probability of failure of the test, so as to feedback the work performance of the PCBA board within the electronic products.

PCBA test instruments

X-ray

X-ray testing, or X-ray inspection, which uses low-energy X-rays to quickly detect open circuits, short circuits, empty solders, solder leaks and other problems in circuit boards.

X-ray is mainly used to detect defective circuit boards with ultra-fine pitch and ultra-high density, as well as defects such as bridges, missing chips, and 

misalignment generated during the assembly process. It can also use tomography to detect internal defects in IC chips. This is the only way to test the quality  of ball grid arrays and solder ball bonding. The main advantage is that BGA solder quality and embedded components can be inspected without the expense of fixtures.

AOI

AOI uses a single 2D camera or two 3D cameras to take a photo of the PCB and then compares the board photo with a detailed schematic. If the board does not match the schematic to some extent, the board mismatch is flagged for inspection by a technician and AOI can detect faulty problems in a timely manner.

SPI solder paste inspection machine (PCBA defect detection vision equipment)

SPI solder paste inspection machine is a device that measures the distribution of thickness, area and volume of solder paste (red glue) printed on PCB boards 

using laser non-contact 3D scanning intensive sampling technology.

Detection items: volume, area, height, XY offset, shape.

Detection of defective types: missed print, more tin, less tin, even tin, offset, bad shape.