X-Ray Inspection AXI AXI is a new test technology that has emerged in recent years. When the assembled circuit board (PCBA) enters the inside of the machine along the rail, there is an X-Ray transmitter tube located above the board, and the X-rays emitted through the board are accepted by the detector (usually a camcorder) placed below. X-rays are absorbed in large quantities, and a good image is produced as a black spot (as shown in Figure 2), making the analysis of the solder joint quite intuitive, so a simple image analysis algorithm can automatically and reliably check for defects in the solder joint.   Advantages and disadvantages of AXI testing Advantages. (1) Up to 97% coverage of process defects. Defects that can be inspected include: dummy solder, bridging, standing stones, insufficient solder, air holes, device leakage, etc. Especially, X-RAY can also inspect solder joint hidden devices such as BGA and CSP. (2) Higher test coverage. It can check the places that cannot be checked by naked eye and in-line test. For example, if the PCBA is judged to be faulty and the PCB inner alignment is suspected to be broken, X-RAY can check it quickly. (3) The preparation time of the test is greatly reduced. (4) Defects that cannot be reliably detected by other testing means can be observed, such as: false soldering, air holes and molding, etc. (5) Only one inspection is required for double-sided and multilayer boards (with delamination function). (6) Provides relevant measurement information that can be used to evaluate the production process. Such as solder paste thickness, amount of solder under the solder joint, etc. Disadvantages: AXI technology cannot test for defects and faults in the electrical performance of the circuit. Now the application of BGA is more and more, the market requirements for the detection of BGA is also increasing, and even require 100% detection, hoping that in the automatic online detection of PCB board defects, detection speed is faster. But in the PCB assembly plant, the use of off-line X-ray inspection. Rarely used online X-ray detection. There are several reasons, * the biggest problem is the higher price of online X-ray inspection equipment; ** is the automatic online detection of defects in this machine is poor, a lot of misjudgment; third is its detection speed is relatively slow. X-ray inspection is usually used in the AOI detection of components that can not be detected, a board of many components can be detected with AOI, while the bubble can only be seen with X-ray. A large board, there are usually thousands of resistors, capacitors. bga may only be about one to three, these bga can be detected with x-ray. aoi detection speed is very fast, two-dimensional x-ray detection speed is also very fast, if you do three-dimensional processing, the speed will be a little slower. Now BGA less, so do BGA detection, you can use more AXI detection, that is, when doing the slicing process, you can do more layering process. In summary, axi and aoi combined use is the trend of industry development.

X-Ray Inspection AXI

AXI is a new test technology that has emerged in recent years. When the assembled circuit board (PCBA) enters the inside of the machine along the rail, there is an X-Ray transmitter tube located above the board, and the X-rays emitted through the board are accepted by the detector (usually a camcorder) placed below. X-rays are absorbed in large quantities, and a good image is produced as a black spot (as shown in Figure 2), making the analysis of the solder joint quite intuitive, so a simple image analysis algorithm can automatically and reliably check for defects in the solder joint.
 
Advantages and disadvantages of AXI testing
Advantages.
(1) Up to 97% coverage of process defects. Defects that can be inspected include: dummy solder, bridging, standing stones, insufficient solder, air holes, device leakage, etc. Especially, X-RAY can also inspect solder joint hidden devices such as BGA and CSP.
(2) Higher test coverage. It can check the places that cannot be checked by naked eye and in-line test. For example, if the PCBA is judged to be faulty and the PCB inner alignment is suspected to be broken, X-RAY can check it quickly.
(3) The preparation time of the test is greatly reduced.
(4) Defects that cannot be reliably detected by other testing means can be observed, such as: false soldering, air holes and molding, etc.
(5) Only one inspection is required for double-sided and multilayer boards (with delamination function).
(6) Provides relevant measurement information that can be used to evaluate the production process. Such as solder paste thickness, amount of solder under the solder joint, etc.

Disadvantages: AXI technology cannot test for defects and faults in the electrical performance of the circuit.

Now the application of BGA is more and more, the market requirements for the detection of BGA is also increasing, and even require 100% detection, hoping that in the automatic online detection of PCB board defects, detection speed is faster. But in the PCB assembly plant, the use of off-line X-ray inspection. Rarely used online X-ray detection. There are several reasons, * the biggest problem is the higher price of online X-ray inspection equipment; ** is the automatic online detection of defects in this machine is poor, a lot of misjudgment; third is its detection speed is relatively slow.
X-ray inspection is usually used in the AOI detection of components that can not be detected, a board of many components can be detected with AOI, while the bubble can only be seen with X-ray. A large board, there are usually thousands of resistors, capacitors. bga may only be about one to three, these bga can be detected with x-ray. aoi detection speed is very fast, two-dimensional x-ray detection speed is also very fast, if you do three-dimensional processing, the speed will be a little slower. Now BGA less, so do BGA detection, you can use more AXI detection, that is, when doing the slicing process, you can do more layering process.

In summary, axi and aoi combined use is the trend of industry development.