Discussion on Batch Quality Control of Uncooled Infrared Thermal Imager

With the rapid development of the economy and the continuous improvement of the level of science and technology, infrared technology has made great progress and has been widely used in many fields. The development of infrared technology has experienced a tortuous process. It first appeared in 1966. The United States produced the first FLIR (Front-Vision Infrared) system. After nearly 50 years of development, today's various infrared imaging products are active. In various industries. At present, an uncooled infrared camera with UFPA (uncooled focal plane array) as the core is widely used in the market. This paper mainly studies and analyzes the batch quality control of uncooled infrared camera.

1. Control of product batch production process

For the batch production of uncooled infrared thermal imaging products, it has a systematic specific process, which mainly has the following steps: quality control of component purchase, inspection of parts processing, inspection of assembly and debugging process , the inspection of the whole machine and the test of environment and reliability, as shown in Figure 1:

From the above figure, we can find that there are three stages in the batch process control of uncooled thermal imaging cameras. The three stages are the quality control of the incoming goods, the quality control of the production process, and the inspection and testing of the finished products. These three stages can be subdivided into five processes, namely the five processes mentioned above. The specific work is shown in Table 1:

2. Key technical analysis of product batch production process control

In principle, the uncooled thermal imaging camera is actually a photoelectric imaging instrument that converts the infrared light emitted by the target to a certain extent, making it a visible image. It is composed of multiple components, mainly composed of Infrared lens, infrared detector, signal processing circuit, video display, etc. In the process control of uncooled thermal imaging cameras, there are several very critical technologies. It can be said that these technologies are the pillars of the operation of the batch production process control. Below we will carry out some degree on these technologies. Elaboration and analysis.

2.1 Quality control of electronic components

When measuring and evaluating the performance of optoelectronic imaging products, the signal-to-noise ratio is often used as an important evaluation index. Therefore, in order to obtain satisfactory image quality, it is necessary to work on the signal-to-noise ratio of the video signal. For the uncooled thermal imaging camera, the target signal is very weak, so the microbolometer needs to be used effectively. The microbolometer has a high sensitivity. It is precisely because of the high sensitivity that it is necessary to pay special attention to the noise that needs to be added to the signal processing circuit. Only in this way can the signal-to-noise ratio of the final signal be effectively improve. At the same time, in order to guarantee the amount of noise brought by the processing circuit, electronic components with better quality and higher performance should also be used. In the uncooled thermal imaging camera, it uses a wide variety of devices. In addition, many devices have high requirements for monitoring equipment and conditions. These problems make the monitoring of electronic components in the incoming inspection. There are great difficulties.

2.2 Quality Control of Optical Components

For the uncooled thermal imaging camera optical lens system, the basic task is to form a thermal image of the corresponding target on the UFPA. To achieve this goal effectively, the spatial resolution and temperature resolution of the instrument must be achieved. Make an effective guarantee. Under the current conditions, in the process control of optical components of uncooled thermal imaging cameras, there are very strict technical requirements for the performance of optical components. Under normal circumstances, the assembled infrared lenses will be subjected to a certain degree of MTF, focal length, Testing of key optical performance parameters such as field of view and transmittance.

3. How to effectively strengthen the quality control of the product batch production process

3.1 Strengthen the quality control of product parts and components

According to the above explanation, we can know that in the semi-finished product stage or the finished product stage, if a component or component has a problem and causes a certain quality problem, this quality problem is difficult to analyze, and often it is impossible to start. It will also bring a lot of economic losses. For example, if the quality of the device used in the power switch of the product is not good, and the bulk is large and there is no effective detection means, etc., in the various environmental tests in which the product enters the later stage, it is likely that a certain degree of problems will occur. Serious people make the product difficult to run. However, this kind of problem is difficult to analyze. Not only that, but also the entire signal processing circuit board is invalidated due to the quality problem of a certain component. In actual life, this kind of example is not rare. Therefore, effective quality control of parts and components of products is required.

3.2 Strengthen the quality control of the batch production process

In order to effectively strengthen the quality control of the batch production process, we need to do the following work: 1 In the early stage of batch production, reasonable and effective planning of related work, at the same time, related plans are needed. Design and review to a certain degree of organization; 2 effectively equip the necessary tooling equipment, and on this basis, effectively improve the automation level of the production process; 3 attach importance to the training of relevant process personnel and technicians, improve their professional knowledge And skills, but also should improve the quality of the preparation of process documents; 4 set up the necessary process control points, strict quality control of some key processes, and make inspection records.

3.3 Improve on-site testing methods

To improve the means of on-site inspection, it is necessary to deepen the research on the method of infrared parameter test. The specific method is as follows: configure the black body and infrared collimator for the batch production site, so that the batch debugging and process can be performed. The inspection plays a very advantageous role; the portable test fixture is effectively configured to facilitate the inspection in the product test; in addition, the research on the infrared test technology should be strengthened to a certain extent. To effectively improve the accuracy and reliability of test results.