Date：2022-03-29 16:53:05

When a mechanical part loses its due function, it is said to be invalid. There are many reasons for failure, such as fracture, deformation, surface wear and so on. The so-called failure mainly refers to the phenomenon that the part loses its specified function due to the change of its size, shape or material structure and performance for some reason. In order to help you have an in-depth understanding, this paper will summarize the relevant knowledge of part failure analysis. If you are interested in what this article will cover, read on. View >>

Date：2022-03-29 16:41:43

IC chip, English name integrated circuit chip, is to put the integrated circuit formed by a large number of microelectronic components (transistors, resistors, capacitors, etc.) on a plastic base to make a chip. At present, the quality of IC chips plays a very important role in the whole electronic products. It directly affects the quality problems of the whole products after they go on the market. So for the purchasing staff, how to correctly detect the quality of IC chips? This paper briefly introduces several methods. View >>

Date：2022-03-28 14:50:52

Under the action of external load, the metal breaks when the stress reaches the breaking strength of the material. The fracture process of metal materials generally has three stages: crack initiation, crack metastable propagation and unstable propagation, and finally fracture. Metal components may crack and initiate cracks under different conditions in material manufacturing, component forming or use stages; Under the influence of different environmental factors and bearing state, the crack propagates until fracture. View >>

Date：2022-03-28 14:38:08

When mechanical parts lose their working capacity or fail to meet the design requirements for some reasons, it is called failure. The failure of mechanical parts does not simply mean damage, which can be summarized into three situations: completely unable to work; Although it can work, its performance is poor and exceeds the specified index; Serious injury and loss of ability to work safely. In order to prevent the failure of parts, it is necessary to analyze the failure of parts, that is, by judging the failure form of parts, determining the failure mechanism and causes of parts, selecting materials pertinently, determining reasonable processing routes, and putting forward failure prevention measures. View >>

Date：2022-03-28 14:29:30

Capacitor is an indispensable part of circuit or power equipment. And there are many kinds of capacitors, ceramic capacitor is one of them. The reason why the capacitor will leak electricity is that the dielectric material between the two poles of the capacitor cannot be absolutely insulated, but can only be relatively insulated. Therefore, there is leakage current in some capacitors. View >>

Date：2022-03-28 14:26:27

Field effect transistor is abbreviated as FET, which can be divided into junction field effect transistor (JFET) and insulated gate field effect transistor (MOSFET). We usually call it MOS transistor for short. The MOS tube can be divided into enhanced and depleted, and the enhanced MOS tube is commonly used in our common motherboard. FET is a voltage controlled semiconductor device in which most carriers participate in conduction. It has the advantages of high input resistance (107 ~ 1015 Ω), low noise, low power consumption, large dynamic range, easy integration, no secondary breakdown phenomenon, wide safe working area and so on. It has become a strong competitor of bipolar transistor and power transistor. View >>

Date：2022-03-25 15:14:58

The basic principle of performance testing is: the earlier the problem is found, the easier it is to locate the problem and repair the problem. Therefore, performance testing can run through all stages of the software development life cycle. For example, unit testing can test the functional accuracy under multithreading concurrency, each API also needs to be tested and evaluated, the data size and cache usage of the modules used need to be taken into account in the integration test, and the relevant global performance indicators need to be measured from the perspective of user load in the system test. So, when will performance testing be carried out? What is the purpose of performance testing? View >>

Date：2022-03-25 15:08:27

Any task must first confirm the goal of the task. If you don't know the goal, the result of any effort may not be the final desired result. The same is true of performance test. In the past, although testers have been serious and responsible for the test work from beginning to end, after the test report is released, everyone always feels that there are deficiencies in the United States and has doubts about the test results, especially in the performance comparison test for different test objects with a long time span, there are more or less the following problems: View >>

Date：2022-03-25 15:01:00

Micro controller unit (MCU), also known as single chip microcomputer or single chip microcomputer, is to appropriately reduce the frequency and specification of central process unit (CPU), and integrate peripheral interfaces such as memory, counter, USB, a / D conversion, UART, PLC, DMA and even LCD drive circuit on a single chip to form a chip level computer, Do different combination control for different applications. View >>

Date：2022-03-23 16:21:12

There are many kinds of laboratory certification, such as CMA, CNAs, GMP, QS, etc. first of all, it depends on which kind of certification you want to pass. Generally, the laboratory has passed CMA and CNAs certification, and the purification workshop has passed GMP and QS certification. The quality inspection report of products must be stamped with CNAs and CMA chapters, which requires that many laboratories in relevant industries must pass CNAs (laboratory accreditation) and CMA (qualification accreditation). CMA metrological certification and CNAs laboratory accreditation are commonly used as certification of test reports. There are both similarities and differences between them. View >>