X-ray real-time imaging technology is a non-destructive testing technology that uses X-ray receiving devices and monitors to replace the film in traditional radiography to obtain X-ray images. The invisible X-rays are converted into digital or analog signals using an X-ray receiving device, and then presented on the monitor after imaging and processing. The X-ray image shows a difference in brightness and darkness based on the principle that X-rays show different degrees of attenuation when penetrating different substances. The image processing system overcomes the difficulties of image brightness and darkness caused by different X-ray sources and X-ray detectors, different density of welding layer materials, uneven thickness, etc., and the difficulty of layer segmentation, and divides the image into two layers: pads and voids. The image processing system calculates the ratio of the void area in the void layer to the pad area in the pad layer, that is, the void rate of the welding layer, to achieve the purpose of welding quality inspection of the primary welding and secondary welding layers of the DBC substrate.