JP2003043120A - Ic tester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an IC tester capable of carrying out a test while reducing influence of noise. SOLUTION: By means of this improved IC tester, a test signal is given to a test object, and the test object is tested according to an output from itself. This device is provided with an amplifier inputting an output from the test object, turning a phase of noise in the test signal into an opposite phase, and using an output as an output of the test object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC tester for testing an object to be tested, for example, a comparator, an A / D converter, a D / A converter, an audio IC, an LSI, etc., while suppressing the influence of noise. The present invention relates to an IC tester that can be used.

[0002]

2. Description of the Related Art An IC tester gives a test signal to an object to be tested (hereinafter referred to as DUT) such as an IC and an LSI, and judges whether the DUT is good or bad by the output of the DUT. Such a device is shown and described in FIG.

In FIG. 6, a main body 1 is provided with a control unit, a signal generation unit, a measurement unit, etc., which are not shown, and controls the entire apparatus, generates signals, measures signals, and the like.

The test head 2 comprises a main body 1 and cables 3,
4, a plurality of pin electronics boards (not shown) having drivers, comparators, etc. are provided.

The performance board 5 is electrically connected to the test head 2, electrically connected to the pin electronics board, and the DUT 6 is attached and electrically connected. Here, if the DUT 6 is a package,
A socket is provided on the performance board 5, and the DU
When T6 is a wafer, the performance board 5 is provided with a probe.

The electrical connection relationship will be further described with reference to FIG. In FIG. 7, the output pin 11 of the main body 1 is electrically connected to the input end of the DUT 6 via the cable 3, the test head 2, and the performance board 5. And
The input pin 12 of the main body 1 is electrically connected to the output end of the DUT 6 via the cable 4, the test head 2, and the performance board 5.

The operation of such a device will be described below.
Here, the DUT 6 is a device for analog input / output.

The test head 2 is connected to a carrier device (handler, prober, etc.) not shown, and the carrier device is a DU.
The T6 is transported and electrically connected to the performance board 5.

The main body 1 outputs an analog test signal (AC) from the output pin 11 and inputs it to the input end of the DUT 6 via the cable 3, the test head 2 and the performance board 5. Then, the DUT 6 outputs an analog signal (alternating current) based on the input test signal, and inputs it to the input pin 12 of the main body 1 via the performance board 5, the test head 2, and the cable 4. And the main body 1
Judges pass / fail based on the signal from the DUT 6.

Then, the carrier device switches the DUT 6 and electrically connects it to the performance board 5. By repeating such an operation, the DUT 6 is tested.

[0011]

SUMMARY OF THE INVENTION In such a device,
The cables 3 and 4 are long in order to connect to the carrier device, and there is a jump of common noise due to a ground loop in the cables 3 and 4 from the main body 1 to the test head 2. As a countermeasure against this, a signal and a ground are received by a floating portion in a portion of the main body 1 and the test head 2 that receives a signal to prevent the influence of common noise.

In the conventional DUT6 test, THD
(Total Harmonic Distortion) ＋ N (Noise) and S / N are 8
In the test up to 0 [dB], there was no problem with noise countermeasures by floating. However, in recent years, due to the higher precision of ICs and LSIs used in mobile phones and digital sound equipment (audio equipment such as CD, MD, DVD, etc.), it is necessary to test THD + N and S / N up to 100 [dB]. Caused a problem of low noise that cannot be prevented by preventing common noise due to floating.

Further, there is a jump of digital noise, mainly pulse noise, generated when the tester is controlled by the main body 1, the test head 2 and the performance board 5. Until the measurement, if the control of the tester was stopped, digital noise did not occur, and there was no noise problem. However, since the control operation is performed at the time of measurement, digital noise is generated, resulting in a measurement error. For example, A / D
When testing a converter, a D / A converter, a comparator, etc., a good product was judged to be defective due to pulse noise.

Therefore, an object of the present invention is to realize an IC tester which can be tested while suppressing the influence of noise.

[0015]

According to a first aspect of the present invention, an output of a device under test is input to an IC tester for applying a test signal to the device under test and performing a test of the device under test by the output of the device under test. Then, the noise of the test signal is reversed in phase,
It is characterized in that an amplifier whose output is the output of the device under test is provided.

A second aspect of the present invention is an IC tester which applies a test signal to a balance conversion circuit and tests the balance conversion circuit by the output of the balance conversion circuit, inputs the positive phase output of the balance conversion circuit, and performs the test. Input the inverting amplifier that makes the noise of the signal the opposite phase and the output as the output of the balance conversion circuit, and the opposite phase output of the balance conversion circuit,
An amplifier having an output as the output of the balance conversion circuit is provided.

According to a third aspect of the present invention, in an IC tester for applying a test signal to a device under test to test the device under test with an analog output of the device under test, the output of the device under test is applied to a positive terminal or a negative terminal. Input the desired voltage that passes through the same path as the test signal to the negative or positive terminal opposite to the terminal that inputs the output of the device under test, and use the operational amplifier that outputs the output of the device under test. It is characterized by being provided.

According to a fourth aspect of the present invention, in an IC tester for applying an analog test signal to a device under test and performing a test on the device under test with an output of the device under test, the test signal is input to a plus terminal or a minus terminal. , A desired voltage that passes through almost the same path as the test signal is input to a negative terminal or a positive terminal opposite to the terminal for inputting the test signal,
An operational amplifier that outputs a test signal to the device under test is provided.

A fifth aspect of the present invention is the test head according to any one of the first to fourth aspects of the present invention, in which at least one of an inverting amplifier, an amplifier, and an operational amplifier is electrically connected to an object to be tested. It is characterized in that it is provided on the side.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a block diagram showing a first embodiment of the present invention. Here, the same parts as those in FIGS. Needless to say, the overall configuration is the same as in FIG.

In FIG. 1, an amplifier 61 is provided in the DUT 6 and is electrically connected to the input end through the output pin 11 of the main body 1, the cable 3, the test head 2 and the performance board 5, and the input is multiplied by 1. Amplify to. Inverting amplifier 5
1 is provided on the performance board 5, the input end is electrically connected to the output end of the amplifier 61 of the DUT 6, and the input pin 12 of the main body 1 is electrically connected via the performance board 5, the test head 2, and the cable 4. Connected to the input
Amplify 1x.

Here, it goes without saying that the signal generating section and the measuring section (not shown) of the main body 1 electrically connected to the output pin 11 and the input pin 12 are operated by the same power source. .

The operation of such a device will be described below.
The main body 1 outputs an analog test signal (AC) from the output pin 11 to the cable 3. When the test signal passes through the cable 3, common noise is mixed into the test signal.
The test signal mixed with common noise is
Input to the input end of the DUT 6 via the performance board 5. Then, the amplifier 61 of the DUT 6 amplifies the input test signal by a factor of 1 and outputs an analog signal (AC).

The inverting amplifier 51 converts this analog signal into
It is amplified by -1 and output to the cable 4 via the performance board 5 and the test head 2. When the analog signal passes through the cable 4, common noise is mixed into the analog signal again. At this time, the noise mixed when passing through the cable 3 is inverted by the inverting amplifier 51, so that the noise is canceled together with the noise mixed in the cable 4. Therefore, as the analog signal input from the cable 4 to the input pin 12, a signal in which noise is not mixed is input. And the main body 1 is a DUT 6
Based on the signal from, the quality is judged.

In this way, the inverting amplifier 51 inverts the common noise mixed in the cable 3 on the input side,
Since the signal has a phase opposite to that of the noise carried by the cable 4 on the measurement side, the noises cancel each other out, and the test can be performed with a signal having no noise. Thereby, a highly accurate test can be performed.

As measures against low noise, the conventional cable 3,
Although the noise was suppressed by adjusting the positional relationship of 4, this adjustment was delicate and required know-how. Also, when the test environment changes, the noise also changes and the noise increases, deteriorating the test accuracy. However, the inverting amplifier 51 does not require adjustment of the positional relationship between the cables 3 and 4, no know-how is required, and the test can be performed accurately without affecting the test environment.

The common noise has been described above, but in the case of digital noise as well, the noise is canceled in the same manner except that the position where the noise is mixed is different.

[Second Embodiment] FIG. 2 is a block diagram showing a second embodiment of the present invention. Here, the same components as those described above are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 2, the DUT 7 is a BTL (Bridge
d Transless circuit, which is provided on the performance board 5 and has an amplifier 71 and an inverting amplifier 72. The amplifier 71 electrically connects the input end to the cable 3 via the performance board 5 and the test head 2 and amplifies it by a factor of 1. The inverting amplifier 72 electrically connects the input end to the cable 3 via the performance board 5 and the test head 2, and amplifies the input end by -1. The inverting amplifier 52 is provided on the performance board 5, and the DU
The input end is electrically connected to the output end of the amplifier 71 of T7,
-1 times amplification. The amplifier 53 is provided on the performance board 5, electrically connects the input end to the output end of the inverting amplifier 72 of the DUT 7, and amplifies the output by a factor of 1.

The cable 41 has one end electrically connected to the output end of the inverting amplifier 52 via the performance board 5 and the test head 2, and the other end connected to the input pin 1 of the main body 1.
Electrically connect to 3. The cable 42 has one end electrically connected to the output end of the amplifier 53 via the performance board 5 and the test head 2, and the other end electrically connected to the input pin 14 of the main body 1. The cables 41 and 42 form the cable 4. Also, a configuration may be used in which one cable 4 is switched by the switcher to replace the cables 41 and 42.

Here, similar to the device shown in FIG. 1, the main body 1 electrically connected to the output pin 11 and the input pins 13 and 14.
It goes without saying that the signal generating section and the measuring section of 1 are operated by the same power source.

The operation of such a device will be described below.
The main body 1 outputs an analog test signal (AC) from the output pin 11 to the cable 3. When the test signal passes through the cable 3, common noise is mixed into the test signal.
The test signal mixed with common noise is
Input to the input end of the DUT 7 via the performance board 5. Then, the amplifier 71 of the DUT 7 amplifies the input test signal by a factor of 1 and outputs the analog signal (AC) as a positive phase output. In addition, the inverting amplifier 72 of the DUT 7 amplifies the input test signal by -1 to generate an analog signal (AC).
Is the reverse phase output.

Then, the inverting amplifier 52 outputs the positive phase output-
The signal is amplified by 1 and output to the cable 41 via the performance board 5 and the test head 2. When the positive phase output passes through the cable 41, common noise is mixed into the positive phase output. At this time, since the noise mixed when passing through the cable 3 is inverted by the inverting amplifier 52, the noise is canceled together with the noise mixed in the cable 41. Therefore, the positive phase output input from the cable 41 to the input pin 13 is a signal in which noise is not mixed.

Further, the amplifier 53 amplifies the reverse phase output by a factor of 1 and outputs it to the cable 42 via the performance board 5 and the test head 2. Reverse phase output is cable 4
When passing through 2, common noise is mixed in the reverse phase output. At this time, since the noise mixed when passing through the cable 3 is inverted by the inverting amplifier 72 of the DUT 7, the noise is canceled together with the noise mixed in the cable 42. Therefore, as the anti-phase output input from the cable 42 to the input pin 14, a signal in which noise is not mixed is input.

Then, the main body 1 makes a pass / fail judgment based on the positive phase output and the negative phase output from the DUT 7.

As described above, since the inverting amplifier 52 and the amplifier 53 are provided on the positive phase output and the negative phase output of the DUT 7, respectively, and the amplifier 53 is also provided on the negative phase output side, the output load is the same and the test conditions are the same. Since they are the same, an accurate test can be performed.

Here, similar to the device shown in FIG. 1, common noise has been described, but in the case of digital noise,
The noise is canceled in the same way except that the position where the noise is mixed is different.

[Third Embodiment] FIG. 3 is a block diagram showing a third embodiment of the present invention. Here, the same components as those described above are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 3, the cables 31 and 32 constitute the cable 3, and the output pins 15 and 1 of the main body 1 respectively.
6 is electrically connected to one end. The DUT 8 is provided on the performance board 5 and has a D / A converter 81. The D / A converter 81 electrically connects the input end to the other end of the cable 31 via the performance board 5 and the test head 2, and outputs two channels of Lch and Rch.

The operational amplifiers 54 and 55 are provided on the performance board 5, and the plus ends are electrically connected to the Lch and Rch output ends of the D / A converter 81, respectively, and the test head 2 and the performance board 5 are used. Then, the negative terminal is electrically connected to the other end of the cable 32. The cables 41 and 42 have one ends electrically connected to the output ends of the operational amplifiers 54 and 55, respectively.

Here, similarly to the apparatus shown in FIGS. 1 and 2, the signal generating section and the measuring section (not shown) of the main body 1 electrically connected to the output pin 16 and the input pins 13 and 14 are the same. It goes without saying that it operates with a power supply.

The operation of such a device will be described below.
The main body 1 sends a digital test signal from the output pin 15 to the cable 31, the test head 2 and the performance board 5.
To the DUT 8 via. The D / A converter 81 of the DUT 8 outputs an analog signal of two systems of Lch and Rch based on the test signal.

At the same time, the main body 1 outputs a desired voltage, here a DC voltage of 0 V (other than ground), to the cable 32 from the output pin 16 which makes the power supply the same as the input pins 13 and 14. When the voltage from the output pin 16 passes through the cable 32, common noise mixes in the test head 2,
Via the performance board 5, operational amplifiers 54, 5
Input to the minus end of 5.

Since the operational amplifier 54 inputs the Lch output of the D / A converter 81 to the plus end and the voltage passed through the cable 32 is input to the minus end, it is mixed with the voltage passed through the cable 32. Noise is mixed in the Lch output in the opposite phase and is output. Similarly, the operational amplifier 55 inputs the Rch output of the D / A converter 81 to the positive end, and the voltage passed through the cable 32 is input to the negative end, so that it is mixed with the voltage passed through the cable 32. The noise has the opposite phase and is mixed with the Rch output and output.

When the outputs of the operational amplifiers 54 and 55 pass through the cables 41 and 42, respectively, common noise is mixed with the outputs. At this time, the noise mixed in the voltage passing through the cable 32 is mixed in the outputs of the operational amplifiers 54, 54 in the opposite phase, so that the noise is canceled together with the noise mixed in the cables 41, 42. Therefore, the signals input from the cables 41 and 42 to the input pins 13 and 14 are signals in which noise is not mixed. Then, the main body 1 makes a pass / fail judgment based on the output from the DUT 8.

As described above, even when the test signal is digital and the noise is irrelevant, the signal mixed with noise is substituted on the same path as the test signal, and the signal mixed with noise is input to the operational amplifiers 54 and 55. Antiphase noise is mixed with the output of the DUT 8. As a result, cable 4
It is possible to perform a test with a signal that cancels out noises riding on 1, 42 and has no noise.

Similar to the device shown in FIGS. 1 and 2, common noise has been described above. However, in the case of digital noise, the noise is canceled in the same manner except that the position where the noise is mixed is different.

[Fourth Embodiment] FIG. 4 is a block diagram showing a fourth embodiment of the present invention. Here, the same components as those described above are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 4, the DUT 9 is provided on the performance board 5 and has an amplifier 91. The amplifier 91 electrically connects the input end to the output pin 11 of the main body 1 via the performance board 5, the test head 2, and the cable 3 and amplifies the input twice. Inverting amplifier 56
Is provided on the performance board 5, electrically connects the input end to the output end of the amplifier 91 of the DTU 9, and electrically connects to the input pin 12 of the main body 1 via the performance board 5, the test head 2 and the cable 4. Connected to the input
Amplify 1/2 times.

The operation of such a device will be described below.
The main body 1 outputs an analog test signal (AC) from the output pin 11 to the cable 3. When the test signal passes through the cable 3, common noise is mixed into the test signal.
The test signal mixed with common noise is
Input to the input end of the DUT 9 via the performance board 5. The amplifier 91 of the DUT 9 doubles the input test signal and outputs an analog signal (AC). At this time, noise is also doubled.

The inverting amplifier 56 outputs this analog signal.
It is amplified by -1/2 and output to the cable 4 via the performance board 5 and the test head 2. As a result, the noise is returned to the original magnification. When the analog signal passes through the cable 4, common noise is mixed into the analog signal again. At this time, since the noise mixed when passing through the cable 3 is inverted by the inverting amplifier 56,
The noise is canceled together with the noise mixed in the cable 4. Therefore, as the analog signal input from the cable 4 to the input pin 12, a signal in which noise is not mixed is input. Then, the signal input to the input pin 12 of the main body 1 is 1/0 from the output of the amplifier 91 of the DUT 9.
Since it is doubled, the quality is determined by performing calculation to the original magnification or the like.

As described above, even if the test signal is amplified by the desired magnification inside the DUT 9, the inverting amplifier 56 restores the original magnification, so that the influence of noise can be removed.

Similar to the device shown in FIGS. 1 to 3, the common noise has been described. However, in the case of digital noise, the noise is canceled in the same way except that the position where the noise is mixed is different.

[Fifth Embodiment] FIG. 5 is a block diagram showing a fifth embodiment of the present invention. Here, the same components as those described above are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 5, the output pin 17 is provided on the main body 1 and is electrically connected to one end of the cable 31. The operational amplifier 57 is provided on the performance board 5, and has its positive end electrically connected to the other end of the cable 31,
The minus end is electrically connected to the other end of the cable 32.
The DUT 10 is provided on the performance board 5,
It has resistors R1 and R2 and a comparator 101. Resistance R
1, R2 are connected in series and divide the voltage. The comparator 101 has a positive end connected to the output end of the operational amplifier 57 and a negative end connected to a connection point of the resistors R1 and R2.
Performance board 5, test head 2, cable 4
The output end is connected to the input pin 19 of the main body 1 via.

Here, it goes without saying that the output pins 16 and 17 are output from the same signal generator (same power supply).

The operation of such a device will be described below.
The main body 1 outputs an analog test signal from the output pin 17 to the cable 31, the test head 2 and the performance board 5.
To the positive terminal of the operational amplifier 57 via. At this time, digital noise and pulse noise generated when the tester is operated are mixed in the path of the main body 1 and the test head 2.

At the same time, the main body 1 applies a desired voltage from the output pin 16, here, a DC voltage of 0 V (other than ground), to the cable 32, the test head 2 and the performance board 5.
Is input to the negative terminal of the operational amplifier 57 via.
At this time, similarly, digital noise generated when the tester is operated is mixed in the signal path in the main body 1 and the test head 2.

Then, the operational amplifier 57 cancels noise due to the noises of the signals input to the plus and minus ends, and outputs it to the DUT 10. The comparator 101 of the DUT 10 compares the test signal with the divided voltage of the resistors R1 and R2, and outputs it to the input pin 19 via the cable 4. Then, the main body 1 makes a pass / fail determination based on the output from the DUT 10.

For example, when the object to be tested is an A / D converter and the noise is at a level of 100 [dB], the case where it is affected is when the A / D converter is 17 [bit] or more.

When the DUT 10 is composed of the comparator 101, the digital noise is pulse noise, so that the value easily changes, and the non-defective product is determined to be defective.

Therefore, a voltage in which noise is mixed in the same path as the test signal is input to the operational amplifier 57, and the test signal is mixed with the noise having the opposite phase. As a result, noises cancel each other out, and an accurate test can be performed with a test signal having no noise.

Although the digital noise has been described above, it is needless to say that even in the case of common noise, the noise is canceled in the same way, only at the position where the noise is mixed.

The present invention is not limited to this, and the inverting amplifiers 51, 5 are mounted on the performance board 5.
2, 56, the amplifier 53, and the operational amplifiers 54, 55, 57 are provided, but the configuration may be provided in the test head 2.

When the DUT is an analog input / output, and the inside is not only an amplifier circuit, operational amplifiers 54, 55 and 57 of the device shown in FIGS. 3 and 5 may be combined and provided on the input / output side of the DUT. .

Then, the operational amplifier 5 of the device shown in FIG.
The connection relationship between the plus terminals and the minus terminals of 4, 55 may be reversed. In this case, since the outputs of the operational amplifiers 54 and 55 are inverted, the main body 1 side may perform an operation or the like to determine whether the test target is good or bad.

Further, the case of alternating current as the analog signal has been described, but it goes without saying that it may be direct current. In this case, a signal different from the signal actually output by the DUT in the main body 1 is obtained, but it goes without saying that the main body 1 side may be configured to perform the calculation.

[0069]

The present invention has the following effects. According to claims 1, 2 and 5, the noise mixed in the test signal is inverted by the amplifier and becomes a signal having a phase opposite to that of the noise carried by the output of the object to be tested. The test can be performed with a signal that has no.

Further, the adjustment of the positional relationship of the cables is unnecessary, no know-how is required, and the test environment is not affected.
The test can be performed accurately.

According to the second and fifth aspects, since the inverting amplifier and the amplifier are provided on the positive phase output and the negative phase output of the balance conversion circuit, respectively, and the amplifier is also provided on the negative phase output side, the output loads are the same. Since the test conditions are the same, an accurate test can be performed.

According to the third and fifth aspects, a signal mixed with noise is substituted for on the substantially same path as the test signal, the signal mixed with noise is input to the operational amplifier, and noise of opposite phase is output to the output of the object to be tested. To mix. As a result, the noise riding on the output of the device under test is canceled out, and the test can be performed with a signal having no noise.

According to the fourth and fifth aspects, the signal mixed with noise and the signal mixed with noise are input to the operational amplifier in the almost same path as the test signal, and the test signal is mixed with the noise having the opposite phase. As a result, the noise carried on the test signal cancels each other out, and the test can be performed with the noise-free test signal.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a third exemplary embodiment of the present invention.

FIG. 4 is a configuration diagram showing a fourth exemplary embodiment of the present invention.

FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of an IC tester.

FIG. 7 is a diagram showing a configuration of a conventional IC tester.

[Explanation of symbols]

1 body 3,31,32,4,41,42 cable 6-10 DUT 51, 52, 56 Inverting amplifier 53 amplifier 54,55,57 operational amplifier

Claims (5)

[Claims] 1. An IC tester that applies a test signal to a device under test and tests the device under test with the output of the device under test, inputs the output of the device under test, and makes the noise of the test signal antiphase. An IC tester having an amplifier whose output is an output of a device under test. 2. An IC tester which applies a test signal to a balance conversion circuit and tests the balance conversion circuit by the output of the balance conversion circuit, wherein a positive phase output of the balance conversion circuit is input to reverse the noise of the test signal. An IC tester provided with an inverting amplifier which is in phase and whose output is the output of a balance conversion circuit, and an amplifier which inputs the negative phase output of the balance conversion circuit and uses the output as the output of the balance conversion circuit. 3. An IC tester for applying a test signal to a device under test to test the device under test with an analog output of the device under test, wherein the output of the device under test is input to a positive terminal or a negative terminal to perform the test. A desired voltage that passes through almost the same path as the signal is input to the negative or positive terminal opposite to the terminal that inputs the output of the device under test, and an operational amplifier is provided to output the output of the device under test. IC to
Tester. 4. An analog test signal is applied to a device under test, and an output of the device under test is used to perform a test on the device under test.
In the C tester, the test signal is input to a plus terminal or a minus terminal, and a desired voltage that passes through almost the same path as the test signal is input to a minus terminal or a plus terminal opposite to the terminal for inputting the test signal, An IC tester comprising an operational amplifier for outputting a test signal to a device under test. 5. The inverting amplifier, the amplifier, or at least one of the operational amplifiers is provided on the side of the test head that is electrically connected to the device under test.
The IC tester according to any one of 1.