Automatic test equipment

From Wikipedia, the free encyclopedia

Jump to: navigation, search
 This article should be divided into sections by topic, to make it more accessible. Please help by adding section headings in accordance with Wikipedia's style guidelines. (November 2009)
This article is missing citations or needs footnotes. Please help add inline citations to guard against copyright violations and factual inaccuracies. (December 2007)

Automatic/automated test equipment (ATE) is any automated device that is used to quickly test printed circuit boards, integrated circuits, or any other related electronic components or modules.

Nowadays, ATE devices are essentially always controlled by computers although in the past, custom-designed controllers or even relay controls were used.

An ATE system can be as simple as a digital multi-meter (DMM) whose operating mode and measurements are controlled and analyzed by a computer, or as complex as a system containing dozens of complex test instruments capable of automatically testing and diagnosing faults in complex electronic systems, such as very sophisticated flying-probe testers.

ATE systems that are used to test Semiconductor devices are called Semiconductor ATE. Such systems can test a wide range of electronic devices and systems, from simple components (resistors, capacitors, and inductors) to integrated circuits (ICs), printed circuit boards (PCBs), and complex, completely-assembled electronic systems.

Semiconductor ATE as used today comprises instruments that use Digital Signal Processing to measure a wide range of parameters. For example, assume we have to measure a voltage at the lead of a semiconductor device. The instruments in the ATE sample the voltage in the device and send it to a computer. The computer then process the signal and return the value.

This example shows that conventional instruments like a moving iron or coil may not be used in many ATEs. There are several advantages of Digital Signal Processing to measure the parameters. One of them is time. For example, if we have to calculate the peak of a signal and other parameters of the signal, then we have to employ a peak detector as well as other individual instruments to test individual parameters. But if the DSP based instruments are used then all we have to do is sample the signal and calculate many of these parameters internally. That way we save time.

Semiconductor ATE consists of several instruments; among them are Digital Power Supply(DPS), Parametric Measurement Unit(PMU), Arbitrary Waveform Generators(AWG), Digitizer, Digital IOs, utility supply. Each of these instruments performs different measurements. All of these instruments have to be synchronized together for a variety of reasons, one of which is that it would enable them to source and capture waveforms very precisely - a basic requirement in DSP-based ATE.

The Semiconductor ATE architecture in general consists of master controller which synchronizes several other instruments which are listed above. All the semiconductor devices in general have to be tested, after being fabricated. Because even if small number of defective devices end up with consumer, the manufacturers loss would be high.

But testing the device for all the parameter may or may not be required depending on the device functionality and end user. For example if the device finds application in medical or life saving products then many of its parameter may have to be tested, some of the parameter have to be guaranteed. But deciding on the parameters to tested is a complex decision, if the device is a complex digital device, with thousands of gates, then test fault coverage have to be calculated.

Here again the decision is complex based on test economics, again that is based on frequency, number of IOs in the device and end application.

Semiconductor ATE and ATE in general consists of source and capture instruments synchronized together, this arrangement to synchronize is essential. The DSP based signal generation would require number of sample patterns to be calculated and be sent.

ATE is widely used in the electronic manufacturing industry to test electronics components and systems after they are fabricated. ATE is also used to test avionics systems on commercial and military aircraft. ATE systems are also used to test the electronic modules in today’s automobiles.

ATE systems typically interface with an automated placement tool, called a Handler, that physically places the Device Under Test so that it can be measured by the equipment. Also the interface can be an Interface Test Adapter (ITA). This adapter might be a device just making electronic connections between the ATE and the Unit Under Test (UUT), but also it might contain additional circuitry to adapt signals between the ATE and the UUT and has physically facilities to mount the UUT.

The computer of the ATE is programmed with common computer languages with additional statements to control the ATE equipment. Also some dedicated computer languages exists like ATLAS.

Over the past four decades, ATE has grown from specialized systems for electronics test applications to a wide range of applications in all facets of the electronics industry.

Many ATE platforms used in the semiconductor industry output data using Standard Test Data Format (STDF) and perform multi-site test.

[edit] Typical vendors


[edit] Also See

[edit] External links

Stub icon This electronics-related article is a stub. You can help Wikipedia by expanding it.
Retrieved from "http://en.wikipedia.org/wiki/Automatic_test_equipment"
Languages