Test Methodology Using Parametric Measurement Unit for ATE Systems

Automated Test Equipment systems, popularly called ATE systems, help ensure the effective working of devices, check their performance characteristics, and reduce their cost. Learn how Parametric Measurement Unit (PMU) strengthens the effectiveness of ATE using comparator, driver, and active load.

Semiconductor devices like CMOS have been used in several industries. Developed in the advanced CMOS technology, they help create integrated circuits to be used in a variety of applications, ranging from batteries to x-ray technology. 

In the effective working of CMOS devices, ATE systems play an important role. Also known as testers, the systems allow manufacturers to test a device from different perspectives. 

PMU in ATE Systems

Using ATE systems, manufacturers can ensure the working of devices. Also, they help decrease the testing cost and guarantee satisfactory results. ATE PMU works to supply high currents and voltages required to control the test patterns in the test system. The measured results from the test methodology using PMU turned out to be meeting the target specifications with high accuracy.

The PMU is effective to measure positive and negative voltages and currents in four different modes. 

1. Force Voltage/Measure Current (FVMI)
2. Force Voltage/Measure Voltage (FVMV)
3. Force Current/Measure Voltage (FIMV)
4. Force Current/Measure Current (FIMI)

The PMU gets input in the form of the force parameter as input, which is driven to the DUT. The output is the measure parameter, and it is measured at the DUT. 

In the FVMI mode, the Parametric Measurement Unit measures current as current on a single pin of the device under construction, where the unit measures current by applying force onto the pin. 

Integration Methodology

If the PMU is taken as a separate unit or IC from Comparator, Driver, and Active Load, isolated output capacitance can be noticed from the test path. For integration on the same, it is essential to minimize the output capacitance of the unit.

The unit’s output capacitance can be determined by considering all individual capacitances of the IC tied to the DUT.

Applications of PMU

The unit plays an integral role in measuring voltages and currents in a device under test. In other words, PMU can be described as a key component to test a device’s DC characteristics.

The test system architecture of the DUT includes either a PMU with PE ICs or a PMU for each pin – PPMU – of the device. Using the PPMU architecture, manufacturers can significantly reduce the test time and help deliver exceptional results. 

The different modes of the unit are based on whether the PMU output pin forces current or voltage. The unit comes with current clamps to ensure that transient currents are avoided when the unit is in the FV mode. 

In the End

Today, manufacturers use wide voltage PMU to test their devices for different voltage requirements. When getting the unit for ATE, it is necessary to make sure that they are based on the latest CMOS technology and support a range of applications.