Introduction
Automatic test system, ATS, AutomaticTestSystem automatic test system
ATE,AutomaticTestEquipment automatic test equipment
A kind of automatic assembly circuit board Test systems, such as ICT (In-CircuitTestSystem), are commonly called in-circuit testers in Chinese (here refers to assembled circuit board online testers), which are mainly used for the testing of assembled circuit boards (PCBA). "Online" here is a literal translation of "In-Circuit", which mainly refers to electronic components on the line (or on the circuit). Online testing is a testing technology that does not disconnect the circuit and does not remove the component pins. "Online" reflects that ICT focuses on detecting circuit board assembly problems by testing the components on the circuit or the open and short circuit status.
The main global ICT automatic test equipment manufacturers are Agilent Technologies (USA), Teradyne (USA), CheckSum (USA), AEROFLEX (USA), Winchy Yingqi, Hioki (Japan), IFR (AEROFLEX M&A), Takaya (Japan), Tescon (Japan), Okano (Japan), Isshin (Taiwan), JET (Jiezhi), Tr (Detai), SRC Galaxy, Concord, Rohde&Schwarz, Scorpion, Brands such as Shindenski, SPEA, Tecnost-MTI, Testronics, WKTest, Schuhll, Viper, TTI, NI, APM (All Day Technology), etc. Different brands of ICT have the same or similar testing principles. Around the 1980s, Japan simplified and miniaturized similar products in the United States, and changed it to use a pneumatic press type, represented by Japan’s TESCON and OKANO, which made ICT simple and easy to use and low-cost, making it indispensable for electronics factories. The necessary testing equipment is lacking, and quickly popularized. In the 1980s, Taiwan gradually became an important base for electronic OEM manufacturing from the source of fake electronic computers, which was a global headache for the West. In the late 1980s and early 1990s, Taiwan began to completely imitate TESCON testers and launched presses of many brands. The lower prices of ICTs have forced Japan’s TESCON, which had the world’s largest market share, to fade out of the market and greatly increased its market share due to the development of Taiwan’s electronics foundry industry. Since the 1970s, similar static testers have been developed in China. In 1993, local Chinese brands led Japan, South Korea, Taiwan and Hong Kong to develop the first windows version of ICT in Asia. Today, American Teradyne and Agilent are still leading brands and have become the de facto standards for such technologies!
It is worth mentioning that in the past ten years, foreign businessmen, especially Taiwan businessmen, have The most critical and most expensive test host (ranging from tens of thousands to hundreds of thousands of yuan) was smuggled into mainland China through an ultra-low price (thousands of yuan) declaration, and then a large mechanical casing was added in the country, which was doubled to Dozens of times the price is sold on the market, this practice has evaded hundreds of millions of tariffs. The cost of equipment produced by domestic equipment manufacturers through normal customs declaration and imported parts and accessories will even be much higher than that of foreign-funded factories. Therefore, the illegal smuggling of foreign brands makes its test equipment not at a disadvantage in terms of cost, and sometimes even at an advantage. This is undoubtedly extremely unfair to honest domestic test equipment manufacturers. What is gratifying is that today, the Chinese people's attitude of advocating foreign products and discriminating against domestic products is being reversed. Foreign-funded enterprises have also changed their practice of purchasing only foreign equipment and are willing to buy more domestic equipment with higher cost performance. The equipment manufacturing industry is a basic industry that provides technical equipment. It involves the core competitiveness of a country and a region, and it is a source of enhancing national self-confidence. With the continuous enhancement of China's soft power, it is believed that China's local automatic test equipment brands will usher in greater development through transformation, upgrading and continuous innovation.
Development overview
The research and development of automatic test equipment (ATE) began in the 1950s. Modern test content is becoming more and more complex, the test workload is increasing rapidly, and the time required to complete the test is getting shorter and shorter. It is difficult for manual testing to meet these requirements, and the automatic test technology has been developed rapidly. More complete automatic test equipment came out after the use of electronic computers in the 1960s.
The development of automatic test equipment has gone through three stages. ①Using special test equipment: This kind of system is more complicated, the development workload is large, the cost is high, and the adaptability is poor. When the test content is changed, the interface must be redesigned (including the interface between the instrument and the instrument and the interface between the instrument and the computer) . Dedicated test equipment is only used to conduct a large number of repetitive tests, rapid tests or complex tests, or to test places that require extremely high test reliability, hinder the health of testers, and are inaccessible to testers. ②Using standardized general-purpose interface bus (GPIB) to connect related equipment, each component in the system is equipped with standardized interface functions, and is connected with a unified passive bus cable. There is no need to design the interface by yourself, and the test content can be changed, added or deleted flexibly. In these two stages, the computer is mainly responsible for the control, calculation and data processing tasks of the system. It is basically the process of simulating manual testing, and it is not yet able to give full play to the functions of the computer. ③Integrate the computer with the test equipment, replace some of the hardware functions in the traditional equipment with computer software, and use the computer to generate excitation, complete the test function, and generate the test program.
Composition
In different technical fields, test content, requirements, conditions and automatic test systems are different, but they are all test activities that use computers instead of humans. The general automatic test system includes the controller, excitation source, measuring instrument (or sensor), switch system, man-machine interface and the unit under test-machine interface and other parts.
①Controller
Generally, it is a small computer, a microcomputer or a calculator (that is, a dedicated bus controller). The controller should have test program software to manage the test process, control the data flow, accept the measurement results, process the data, check the reading error, complete the calculation, and send the results to the display or printer.
②Excitation source
It is the signal source, which provides the input signal to the unit under test. It can be a power supply, function generator, digital-to-analog converter, frequency synthesizer, etc.
③Measuring instrument
Used to measure the output signal of the unit under test. It can be an analog-to-digital converter, frequency counter, digital multimeter or other measuring device.
④Switch system
Used to specify the signal transmission route between the unit under test and other components in the automatic test system.
⑤Man-machine interface
Used to establish the connection between the controller and the operator. It can be a part of the controller, it can also be a switch, keyboard, indicator light, display, etc. on the console. The operator can transmit the data to the controller through the keyboard or the switch, and the controller transmits the data, results and operation requirements to the display such as cathode ray tube, light emitting diode or indicator group. If necessary, the test results can be output to the printer to make a hard copy.
⑥Machine interface of the tested unit
Used to establish the connection between the tested unit and the controller.
Fault Diagnosis
The advanced test system is equipped with a fault diagnosis program package, which can automatically judge the fault based on the information obtained during the test. When a fault occurs, it can automatically find the location of the fault. In the case that the test fails, the automatic test system automatically switches from the test program to the diagnostic program. The methods of automatic fault diagnosis are roughly divided into two categories.
①Guide detection method: The operator finds the fault point by point according to the detection instructions displayed by the automatic test system.
②Characteristic analysis method: When the characteristic of the tested node is not correct, the operator verifies the characteristic of the previous circuit under the guidance of the program.
Reliability
The reliability of an automatic test system refers to its ability to detect errors and failures of the tested object. Due to the extremely fast automatic test speed, it is difficult to distinguish between the various test steps, and it is difficult to detect faults. Because the key part of the test is unattended, no one notices the errors in the test program and the circuit diagram of the unit under test. Therefore, the hardware and software of the automatic test system should have good reliability to ensure the reliability of the system.
The design, use, maintenance and management of automatic test systems are all extremely complex subjects. Advanced components, computers, robots and artificial intelligence technologies promote the development of automatic test systems in the direction of digitization and intelligence.
Example of automatic test system
The automatic test technology used in printed circuit boards has developed rapidly, especially the printed board online test system (ATE) is widely used in printed board light boards And the production, testing and maintenance of printed circuit boards of various products, as shown on the right. ATE testing methods can be divided into two categories: contact testing and non-contact testing. The contact test is divided into online test, functional test, BIST and boundary scan test, etc.; non-contact test can be divided into non-vector test, automatic visual test, infrared thermal image test, X-ray and laser test. With the application of computer technology and VXI bus technology, ATE and functional testing of various printed circuit boards built on the VXI test platform have also developed rapidly. As a result, there are constant requirements for the tooling (fixture) needed in the test process, so the circuit board tester (also known as the electronic test tooling) came into being.
The hardware can be controlled by calling the software, which can be flexibly upgraded and secondary development. Combining the hardware resources of the system, connect the signal to be tested in the corresponding interface, then call the corresponding subroutine and set the channel to form a model, and the software will execute in sequence according to the edited steps when the software is running.
Common test items:
Common power test items:
1.ACNoiseCarryThroughTest (ACNoise noise test)
2.CombineRegulation (conditions Continuous change test)
3.CrossRegulation (conditional cross test)
4.CycleDropoutTest (cyclic disturbance test)
5.DynamicTest (dynamic test)
p>6.ExtendedMeasurementTest (external point voltage test)
7.ExternalWaveTest (external point waveform test)
8.ExtraTimingTest (external point timing test)
9.FinRampTest (input voltage frequency slope test)
10.HoldOnAdjust (adjustment item)
11.HoldUp&SequenceTest (shutdown sequence test)
12.Input/OuputTest (input/output performance test)
13.LineRegulationTest (input voltage variation test)
14.LoadRegulationTest (load variation test)
15.OLPTest (overload protection)
16.OVP/UVPTest (overvoltage/undervoltage test)
17.SetUpFunction (internal state setting)
18.ShortCircuitTest (short circuit test)
19.StaticTest (static test)
20.SyncDynamicTest (synchronous dynamic test)
21.SyncDynamic2 (synchronous dynamic Test 2)
22.TotalRegulationTest (total effect test)
23.TurnOn&SequenceTest (turn on sequence test)
24.VinRampTest (input voltage slope Test)
25.CommunicationTest (communication test)
26. Total harmonic distortion
27. Current harmonic test
28 .Maximum power tracking (MPPT) input voltage test (PV specific)
29. Maximum power tracking (MPPT) input power test (PV specific)
30. Overvoltage protection/under Voltage protection trip time test (P V-specific)
31. Trip time test of over-frequency protection/under-frequency protection (PV-specific)
32. Anti-islanding trip time test (PV-specific)
33. Over-voltage protection/under-voltage protection
34. Over-frequency protection/under-frequency protection
35. Anti-islanding protection test (PV-specific)
36. Maximum power tracking (MPPT) accuracy test (PV-specific)
White goods field
Refrigerator main control board function test
1. Voltage and current measurement
2. LED lighting detection
3. Button detection
4. Communication interface automatic detection
5. Automatic power detection
6. Output signal detection
Functional test of air conditioner main control board
1. Voltage, Current measurement
2. Automatic buzzer detection
3. Automatic detection of indicator light
4. Automatic detection of button
5. Automatic detection of motor frequency amplitude
6. Automatic detection of digital tube and display panel light display
7. Automatic detection of communication interface
8. Analog remote control detection
Function test of washing machine main control board
1. Control panel short circuit protection
2. Display panel detection
3. Motor speed and direction test
4. Automatic water level detection
5. Button and touch screen automatic test
6. Water discharge function test
7. Water temperature automatic test
8. Drying test
9. Automatic test of buzzer
Television/monitor main control board test
1. Flash program burning
2. Circuit short circuit test
3. Voltage and current test
4. CVBS image function test
5. S-Video image function test
6. YPbPr/YCbCr image function test
p>7. Image and audio function detection of digital TV
8. HDMI image and audio function detection
9. USB storage function detection
10. Function test of audio channel
Function test of DVD/VCD main control board
1. Scan barcode
2 .Circuit short circuit test
3. Voltage and current test
4. CVBS image function test
5. S-Video image function test
6. YPbPr/YCbCr image function detection
7. Digital TV Image and audio function detection of HDMI
8. HDMI image and audio function detection
9. USB storage function detection
10. Function detection of audio channel
Function test of main control board of induction cooker
1. Key point voltage and current detection (AC current option)
2. Bee Buzzer detection
3. Button detection
4. LED lighting detection
5. Digital tube and display panel detection (optional)
6. Power detection (optional)
Function test of the main control board of the set-top box
1. Barcode scanning
2 .Key point voltage and current detection
3.HDMI output detection
4. CVBS output detection
5.YUV output detection
6 .S-Video, SCART detection
7. Audio (R/L) function detection
Digital power amplifier main control board function test
1. Voltage and current detection of key points
2. Power detection
3. Input analog audio signal (R/F channel), and affect signal frequency, signal distortion, Signal-to-noise ratio, signal amplitude, channel balance, treble and bass, etc. are tested
4. Input digital audio signal (COAX channel), and also check signal frequency, signal distortion, and signal-to-noise ratio. Signal amplitude, channel balance, treble and bass, etc. are tested
5. Input digital audio signal (OPT channel), and the same applies to signal frequency, signal distortion, signal-to-noise ratio, and signal Amplitude, channel balance, high and low sounds, etc. are tested
Soymilk machine main control board function test
1. Voltage and current measurement (AC current selection Equipped)
2. Button function automatic detection
3. LED lighting detection
4. Buzzer automatic detection
5 . Heating pipe work detection, motor work detection
6. Anti-dry burning function detection, anti-dropout function detection
Water heater main control board function test
p>1. Barcode scanning function, online programming
2. Voltage and current measurement (optional AC current)
3. Secondary pressure adjustment, setting Vmax , Vmin
4. Proportional valve voltage detection, system water pressure detection, heating sensor detection
5. Wind pressure detection, accidental flameout detection, overheating protection detection
6. Sanitary water temperature sensor detection, antifreeze function detection
7. Sanitary water priority function detection, heating function detection
8. Power detection
9. Digital tube and display panel detection
Automotive electronics:
Automotive electronics field control panel test
1. Automotive window controller test
2. Brake pressure test
3. Car instrument system circuit board test
4. Power circuit test
5. Start circuit test
....... .....................
The actual test items can be customized according to actual needs. As long as they are items that can be tested manually, they are It can be realized by adding automatic testing; at the same time, automatic testing has gradually developed from off-line (Off-Line) to on-line automatic testing equipment;