X-ray for BGA chip welding inspection

Date：2021-08-12 17:21:00Views：1383

As a model of small devices, BGA devices are widely used in electronic products in recent years. Compared with QFP package device or PLCC package device, BGA device has many advantages, such as more pins, smaller inductance and capacitance between pins, good pin coplanarity, good electrical performance and heat dissipation performance.

Although BGA device has many advantages, its disadvantages are also obvious: that is, after the BGA device is welded, since all solder joints are below the abdomen of the device body, the traditional visual method can not be used to observe and inspect the welding quality of all solder joints, and AOI (automatic optical inspection) equipment can not be used to judge the appearance quality of solder joints. At present, X-ray detection equipment is used to detect the physical structure of BGA device solder joints.

X-ray testing equipment realizes the quality inspection of BGA device welding joints through X-ray real-time imaging technology. X-rays cannot penetrate high-density and thick substances such as tin and lead, so they can form dark images, while X-rays can easily penetrate low-density and thin substances such as printed boards and plastic packaging, and will not form images. This phenomenon can judge the welding quality of BGA from the image.

The solder joint defects of BGA devices mainly include solder bridging, solder beads, voids, dislocation, open circuit, loss of solder balls, fracture of welded joints, false soldering, etc.

Because the final result of solder bridging is electrical short circuit, there should be no solder bridging between adjacent solder balls after BGA device is welded. This defect is obvious when X-ray inspection equipment is used for inspection. The continuous connection between solder balls can be seen in the image area, which is easy to observe and judge. False welding defects can also be detected by rotating the X-ray angle, so as to take effective measures to avoid them in time.

Using X-ray detection equipment to detect the welding quality of BGA devices is a cost-effective detection method. With the development of new technology, ultra-high resolution and intelligent -ray detection equipment can not only provide time-saving, labor-saving and reliable guarantee for bag equipment assembly, but also play an important role in electronic product fault analysis and improve fault removal efficiency.