What are the integrated circuit test instruments? Introduction to the composition and structure of integrated circuit testers

　　What is an IC tester?

　　Integrated circuit testers are special instruments for testing integrated circuits. Integrated circuit testing is one of the key means to ensure the performance and quality of integrated circuits. Integrated circuit testing technology is one of the three major supporting technologies for the development of the integrated circuit industry. Therefore, integrated circuit testers as a testing category are highly valued by many countries. Over the past 40 years, with the development of integrated circuits to the fourth generation, integrated circuit testers have also developed from initially testing small-scale integrated circuits to testing medium-scale, large-scale and ultra-large-scale integrated circuits. In the 1980s, ultra-large-scale integrated circuit testers entered their heyday.

　　What types of integrated circuit test instruments are there?

　　There are many types of integrated circuit test instruments. When choosing, you must weigh them from many aspects according to your needs. Otherwise, you will lose sight of the big picture, waste time and money, and get half the result with twice the effort! Given the diversity of integrated circuits themselves, there is also a diversity of integrated circuit test instruments.

　　First, the performance parameters of integrated circuits include DC parameters, AC parameters and functions (including static functions and dynamic functions), so there are DC parameter testers, AC parameter testers, and functional testers. But in most cases, DC parameter and functional tests are combined together, which is the basic structure of a typical integrated circuit tester.

　　Second, different types of integrated circuits have very different functions and therefore require different integrated circuit testers.

　　Generally, integrated circuits are divided into three major categories: digital integrated circuits, analog integrated circuits and mixed-signal integrated circuits.

　　Digital integrated circuits include logic integrated circuits, memory integrated circuits, and application-specific integrated circuits (ASICs). Correspondingly, there are logic integrated circuit testers, memory testers, and digital integrated circuit testers that have the ability to test all of the above digital circuits.

　　Analog integrated circuits include general (mostly DC or low-frequency) analog integrated circuits and radio frequency analog integrated circuits. Generally, the output and use of radio frequency or microwave integrated circuits are more specialized, and there are not many specialized instrument models. General analog integrated circuits have a wide variety of types and uses, and there are many models. There are also many specialized testers, such as operational amplifier testers, integrated power circuit testers, etc.

　　A mixed-signal integrated circuit is an integrated circuit that contains both digital circuits and analog circuits, such as digital-to-analog converters and analog-to-digital converters.

　　Third, the integration of integrated circuits is different, and the test requirements are different. Considering performance and economy, there are different test instruments for selection. Typically, they are divided into four levels: small-scale integrated circuits (SSI), medium-scale integrated circuits (MSI), large-scale integrated circuits (LSI), and very large-scale integrated circuits (VLSI).

　　Fourth, the testing requirements for integrated circuit development, production, and use are different. Due to performance and economic requirements, there are different types of testing instruments. Commonly used in integrated circuit research, design, and trial production are integrated circuit DC parameter analyzers, integrated circuit high-definition functional testers, integrated circuit integrated test systems, and integrated circuit verification and testers. In integrated circuit mass production, high-efficiency integrated circuit automatic test systems are used.

　　In electronic equipment factories, it is necessary to use an economical and effective integrated circuit test instrument to perform face detection tests on purchased integrated circuits. In electronic product maintenance departments, it is usually necessary to use a simple integrated circuit tester to perform simple identification tests on suspected integrated circuits.

　　Fifth, according to the different testing needs in the above-mentioned occasions, in terms of appearance, there are large and medium-sized floor-standing integrated circuit automatic testing systems, medium and small desktop integrated circuit testers, and portable simple integrated circuit testers.

　　Integrated Circuit Tester Composition

　　The overall structure of the integrated circuit tester is shown in the figure:

　　The entire system adopts a slot-type structure mechanically. All system boards are inserted into the chassis backplane through the system slots. The system bus on the chassis backplane is connected to the computer PCI bus through the PCI interface board [3]. There are 12 slots on the chassis backplane, one for the system control board, one for the power module, and the remaining 10 are general slots. Any system board can be inserted according to test needs. The device under test (DUT) is connected to the tester through the relay matrix board. The relay matrix board completes the switching between the device under test (DUT) and each channel of the tester [3]. The tester is connected to the computer through the PCI bus, and the control of the entire system is completed by the computer. The system can complete the test of two devices under test (DUT) at a time.

　　At which stages should integrated circuit testing be carried out?

　　It can be divided into three aspects.

　　For integrated circuit products, testing is required in three stages: research, design, trial production, and production.

　　The first is during the research, design, and trial production phase of integrated circuits. Testing is used to determine whether the logic design, circuit design, layout design, and process design of the integrated circuit are correct and reasonable. Testing is also used to check whether the predetermined performance, indicators, and working environment conditions have been achieved.

　　These tests are repeated in each sub-cycle of research, design and trial production. The design is constantly modified through testing to finally meet the various design requirements. At the end of this stage, the finished product needs to be fully identified and tested.

　　The second is that during the mass production stage of integrated circuits, mass-produced integrated circuits must be tested on the production line.

　　The third is testing from the perspective of quality, reliability and product management, including integrated circuit aging testing; testing for quality management; and testing based on factory control.

　　The development and production of electronic products using integrated circuits as devices usually also require testing in the following two stages.

　　First, during the product design and development phase, it is necessary to conduct selection tests on the integrated circuits planned to be used, and select the integrated circuits with the best performance-price ratio from integrated circuits of different manufacturers, series and models through selection tests (this test is also performed when selecting alternative integrated circuits).

　　Second, during the product production stage, the integrated circuits entering the factory must be tested for acceptance to ensure that the integrated circuits installed meet the requirements. If an abnormality is found during the debugging and maintenance of the entire product, the relevant integrated circuits must be tested to determine the cause of the failure and decide whether to replace the corresponding integrated circuits.

　　For departments or units that repair electronic products, a common problem they encounter during repairs is whether there is a problem with the integrated circuit. In this case, the suspected integrated circuit needs to be tested.

　　Tips for choosing integrated circuit test instruments

　　Since the price of integrated circuit testers is quite high, many units in my country are very cautious before deciding to buy them. Most of them will send people to conduct multi-party research and make multiple arguments before making up their minds to buy. However, a large number of examples show that the proportion of unsatisfactory results is about 70%. The so-called unsatisfactory results refer to situations such as unsuitable, insufficient, poorly used, overpriced, and poorly purchased. It is recommended to make the following analysis when purchasing.

　　First of all, you must be clear about your test requirements, including: the nature of the test task. For example, for aviation? Aviation? Military? General use... The nature of the task is important, the test requirements are high, and you must choose a high-grade category; the category of the test object. According to the category summary, decide what kind of tester to use. Here it should be noted that: in fact, there is no integrated circuit tester in the world that can test all types of integrated circuits. Combine the test object category with the test, and consider the speed and level of the selected integrated circuit tester. In addition, you must determine the purpose of purchasing the integrated circuit tester. If it is for maintenance, you can naturally use an ordinary desktop or simple type; if it is for production, you can naturally buy a production type in batches; if it is for research and design or identification arbitration selection test, you should choose a high-resolution, high-uncertainty type.

　　Second, clarify the definition of the performance indicators of the integrated circuit tester and the necessary information from the manufacturer. This work is called "knowing the enemy". In this regard, there are several things to pay special attention to. First, the number of test channels given by some manufacturers is not clearly defined. At present, it is generally input/output channels. Second, the test rate given by many manufacturers is not accurate. Real manufacturers use the data rate that can be achieved under various conditions as the published indicator. Third, resolution and uncertainty. Real manufacturers use the maximum configuration indicator of their system as the published indicator.