JPH11218565A - Semiconductor test device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor test device capable of observing the waveform of power source voltage and power source current in accordance with the function of a DUT(device under testing) by using the graphic indication function of digital input/output signal of the DUT. SOLUTION: In the semiconductor test device having the graphic indication function of digital input/output signals of a DUT, a resistor R inserted in series in a power source supplying to the DUT, a relay RL1 short-circuiting/opening the two ends of the resistor R, a switching relay RL2 for selectively outputting one of voltage waveform signals at the two ends of the resistor R, and a buffer means 40 converting the impedance of the output of the switching relay RL2, are provided. In accordance with the function of the DUT, waveform observation of the power source voltage and source current is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor test apparatus capable of observing a power supply voltage and a power supply current waveform of a device under test.

[0002]

2. Description of the Related Art An example of the prior art will be described with reference to FIGS. First, an outline of the semiconductor test apparatus will be described. As shown in FIG. 3, the configuration of the semiconductor test apparatus includes a workstation 10 and a semiconductor test apparatus main body 1.
1 and a test head 12.

The workstation 10 is an engineering workstation having, for example, a display as display means and a keyboard as input means, and serves as an interface with an operator.

The semiconductor test apparatus main body 11 includes a tester processor for controlling the entire system including peripheral devices, various units for generating and testing test signals, and a power supply for supplying various voltages.

The test head 12 has a built-in pin electronics pin card, which is an electronic circuit for each test pin, and serves as an interface with a device under test (hereinafter referred to as a DUT).

Further, the signal of the pin electronics and the power supply to be supplied to the device under test and the peripheral circuit are electrically connected to the performance board 13 mounted on the test head 12 by a large number of pogo pins or connectors.

Here, the pin electronics means DU.
A dedicated measurement circuit connected to each pin of T includes a driver, a comparator, and the like. Also, with pogo pins,
Signals are transmitted by contacting the pads of the performance board 13 with elastic metal pins provided on the upper part of the pin card.

[0008] Then, the semiconductor test apparatus inserts the DUT into the IC socket 14 mounted on the performance board 13.
20 is being tested.

Next, observation of the waveforms of the power supply voltage VDD and the power supply current IDD of the DUT 20 will be described. Some semiconductor test apparatuses have a function of sampling the input / output waveform of a digital signal at each signal pin of the DUT with a comparator and displaying the waveform on the display of the workstation 10 graphically.

However, the digital values of the power supply voltage VDD and the power supply current IDD at the power supply pins of the DUT 20 can be measured, but their waveforms cannot be observed. Therefore, as shown in FIG. 4, the oscilloscope 30 is used to observe the power supply voltage VDD of the DUT 20 with a voltage probe and the power supply current IDD with a current probe.

However, due to the diversification of the DUT 20 and the increase in the number of pins, there is a case where the standard performance board 13 cannot cope with the DUT 20 and is manufactured according to a custom specification. Therefore, it is difficult to connect a probe to measure the power supply voltage VDD and the power supply current IDD.

Further, since there is no area on the test head side of the performance board 13, a probe cannot be directly applied. Therefore, as shown in FIG. 5, when measuring the power supply voltage VDD and the power supply current IDD of the PGA device as the DUT 20, for example, a thin lead wire 22 is wound around the foot of the PGA device, but this is not easy. Here, the PGA (Pin Grid Array) device is a device in which pins are arranged in a plane on the bottom surface of the package.

Further, due to the increase in the number of pins of the device, power is also supplied from a plurality of pins, making it impossible to measure the power supply current IDD.

[0014]

As described above, D
An external oscilloscope is required to analyze the waveforms of the power supply voltage VDD and the power supply current IDD of the UT.
In many cases, it is difficult to extract signals due to the increase in the number of pins and diversification, which is inconvenient in practical use. Further, when the power supply of the DUT is supplied by a plurality of pins, there is a problem that the power supply current IDD cannot be measured. Accordingly, the present invention has been made in view of such a problem, and an object of the present invention is to use a graphic display function of a digital input / output signal of a DUT so that the waveform of a power supply voltage VDD or a power supply current IDD can be adjusted in accordance with the operation of the DUT. It is an object of the present invention to provide a semiconductor test device capable of observing the temperature.

[0015]

The first object of the present invention to achieve the above object is to provide a semiconductor test apparatus having a graphic display function of digital input / output signals of a device under test. A resistor inserted in series with a power supply to be supplied, a relay for short-circuiting / opening both ends of the resistor, a switching relay for selectively outputting one of voltage waveform signals at both ends of the resistor, and an output of the switching relay. A gist of the present invention is a semiconductor test apparatus including a buffer means for converting impedance and capable of observing a waveform of a power supply voltage and a power supply current in accordance with the operation of the device under test.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in the following examples.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 3, the semiconductor test apparatus includes a workstation 10, a semiconductor test apparatus main body 11, and a test head 12 on which a performance board 13 is mounted, and has a graphic display function of digital input / output signals of a DUT. Use a semiconductor test device having Further, in the semiconductor test apparatus of the present invention, the detection circuit shown in FIG. 1 is provided. Then, corresponding to the test of the DUT 20, the waveforms of the power supply voltage VDD and the power supply current IDD are observed.

First, the circuit shown in FIG. 1 will be described. A relay RL1 that inserts a resistor R into a power line (Force) applied from the device power supply to the DUT 20 and shorts / opens both ends of the resistor R, a relay RL2 that selects and outputs a voltage between both ends of the resistor R, A buffer module 40 is provided.

The resistor R has a power supply current I flowing through the DUT 20.
In order to determine the voltage difference due to DD, a high-precision low resistance of, for example, 0.5Ω is used. However, the resistance value of the resistor R is set so that the potential difference of the power supply current IDD with respect to the peak current falls within the voltage range of the comparator 52.

The relays RL1 and RL2 are controlled by a relay control signal supplied to the performance board 13 using, for example, a reed relay.

The buffer module 40 is a buffer means, for example, a buffer having a gain of 0 which receives a detection voltage at a high impedance in order to prevent a leak current to the measurement system and converts it into a 50Ω measurement system output impedance. In addition. An active probe or the like may be used as the buffer module 40.

The output signal of the buffer module 40 is output to the unused pin electronics 50 which has not been tested.
Is received by the comparator 52.

On the other hand, in a semiconductor test apparatus having a graphic display function, a comparator 52 of a pin electronics 50 obtains a pass / fail boundary line while changing a strobe value (time) and a comparison voltage value to obtain a work waveform as a sampling waveform. It can be observed on the display of the station 10.

Here, the strobe is to read a signal at a certain time, and the signal can be extracted in the same manner as the sampling of the signal by continuously changing the strobe value in a minute time unit. For example, test rate 8n
As s, sampling is performed while changing the strobe at 32 ps.

Next, a method of observing the waveforms of the power supply voltage VDD and the power supply current IDD will be described. The waveform of the power supply voltage VDD can be observed by opening the relay RL1 and setting the relay RL2 to the a side, and sampling and displaying the voltage waveform at that time.

When the waveform of the power supply current IDD is to be observed, the relay RL1 is opened and the relay RL2 is opened.
Is the voltage Va when the relay is set to the a side, and the voltage Vb when the relay RL2 is set to the b side.
The voltage waveform at that time is sampled and displayed as shown in FIG.

Next, IDD is obtained from the sampled data shown in FIGS. 2A and 2B by the operation of the following equation (1). IDD = (Vb−Va) / R (1) Then, as shown in FIG. 2C, the calculated result is displayed on the display of the workstation 10 as the power supply current IDD to observe the waveform. .

Here, one comparator 52 calculates the difference voltage because two comparators are used.
If a and Vb are sampled at the same time, collective data can be obtained, but a variation in frequency characteristics between comparators results in a waveform error. When the power supply voltage VDD and the power supply current IDD of the DUT 20 are not measured,
The relay RL1 is short-circuited so that the effect of the resistor R does not affect the test result.

When the DUT 20 has about 256 pins, the power supply terminal generally has 16 to 32 pins. A plurality of device power supplies to be supplied to these DUTs 20 are also supplied. In that case, the same can be realized by using a plurality of detection circuits and a plurality of comparators.

[0030]

The present invention is embodied in the form described above and has the following effects. That is,
Since the waveform observation of the power supply voltage VDD and the power supply current IDD can be performed in parallel with the input / output signal analysis of the DUT using the conventional digital signal analysis function, there is an effect that the observation can be performed according to the operation of the DUT. In addition, since the digital signal analysis function uses the pin electronics of the semiconductor test device, there is an effect that the waveforms of the power supply voltage VDD and the power supply current IDD can observe a transient state at high speed in real time.

[Brief description of the drawings]

FIG. 1 is a main part circuit diagram of a semiconductor test apparatus of the present invention.

FIG. 2 is a waveform observation diagram of the semiconductor test device of the present invention.

FIG. 3 is a configuration diagram of a semiconductor test apparatus.

FIG. 4 is a waveform observation diagram by a conventional semiconductor test device.

FIG. 5 is a signal extraction diagram when a PGA device is used as a DUT.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Workstation 11 Semiconductor test apparatus main body 12 Test head 13 Performance board 14 IC socket 20 DUT 30 Oscilloscope 31 Voltage probe 32 Current probe 40 Buffer module 50 Pin electronics 51 Driver 52 Comparator

Claims (1)

[Claims] 1. A semiconductor test apparatus having a graphic display function of a digital input / output signal of a device under test, a resistor inserted in series with a power supply supplied to the device under test, and a relay for short-circuiting / opening both ends of the resistor. A switching relay for selectively outputting any one of the voltage waveform signals at both ends of the resistor; and buffer means for converting the impedance of the output of the switching relay; and a power supply voltage corresponding to the operation of the device under test. A semiconductor test apparatus characterized by the ability to observe the waveforms of power and power supply current.