X-ray detector(Flat Panel Detector)
Technology content of X-ray
SEC Co., Ltd / SEC Europe Head Offcie /Automated X-ray Inspection/ Nanotech Digital GmbH / Technology
1) Imaging System
The irradiation can be inspected in real time through the monitor by using an FPD (Flat Panel Detector). Although this method has a disadvantage of less resolution compared to the use of film, it has an advantage inspecting a large quantity of products because detection can be made immediately. Although this type of system requires a large initial investment cost, it is more economical than that of film type because it can inspect a large number of items.
This inspection uses the nature of photosensitivity of X-rays against films. Although this method yields a high resolution compared to other methods, it takes a long time to detect irradiation because it requires film development. It is not economical to take multiple images.
3) Fluorescent Screen
The fluorescent screen changes to a fluorescent color if X-rays are applied to the screen and the real-time reading of the inspected result is possible through the monitor. This method is rarely used due to its low resolution.
Radiation Detection Methods
High performance SEC X-ray tube
The FPD converts X-rays to electric signals and sends the signals to a TFT display that uses pixels to produce an image. Based on the presence of the scintillator that converts X-rays into visible rays, the FPD is classified into direct conversion FPD and indirect conversion FPD.
Indirect conversion detector: First converts X-rays into visible rays with an aid of scintillator and converts the rays into electric signals by using the a-Si array that is an amorphous semiconductor. Electric signals converted by each pixel are saved on pixels of the TFT array and they are transmitted to the computer with a high speed through the optic fiber.
Direct conversion detector: X-rays are directly converted into electric charges. Because there is no scintillator, a-Se is used instead of a-Si. A pair of electron-holes is formed on a-Se with aid of X-rays, and electric signals are transmitted by applying high voltage bias on both sides.