WO1999040446A1 - Current measuring method, current sensor, and ic tester using the same current sensor - Google Patents

Current measuring method, current sensor, and ic tester using the same current sensor Download PDF

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Publication number
WO1999040446A1
WO1999040446A1 PCT/JP1998/000479 JP9800479W WO9940446A1 WO 1999040446 A1 WO1999040446 A1 WO 1999040446A1 JP 9800479 W JP9800479 W JP 9800479W WO 9940446 A1 WO9940446 A1 WO 9940446A1
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WO
WIPO (PCT)
Prior art keywords
current
optical
light
under test
test
Prior art date
Application number
PCT/JP1998/000479
Other languages
French (fr)
Japanese (ja)
Other versions
WO1999040446A8 (en
Inventor
Toshiyuki Okayasu
Original Assignee
Advantest Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Advantest Corporation filed Critical Advantest Corporation
Priority to GB9923232A priority Critical patent/GB2340233A/en
Priority to PCT/JP1998/000479 priority patent/WO1999040446A1/en
Priority to DE19882306T priority patent/DE19882306T1/en
Priority to CN98803958.3A priority patent/CN1252130A/en
Priority to KR1019997009086A priority patent/KR20010006008A/en
Priority to TW087103066A priority patent/TW359753B/en
Publication of WO1999040446A1 publication Critical patent/WO1999040446A1/en
Publication of WO1999040446A8 publication Critical patent/WO1999040446A8/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/28—Testing of electronic circuits, e.g. by signal tracer
    • G01R31/2851—Testing of integrated circuits [IC]
    • G01R31/2855—Environmental, reliability or burn-in testing
    • G01R31/2872—Environmental, reliability or burn-in testing related to electrical or environmental aspects, e.g. temperature, humidity, vibration, nuclear radiation
    • G01R31/2879—Environmental, reliability or burn-in testing related to electrical or environmental aspects, e.g. temperature, humidity, vibration, nuclear radiation related to electrical aspects, e.g. to voltage or current supply or stimuli or to electrical loads
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
    • G01R1/02—General constructional details
    • G01R1/06—Measuring leads; Measuring probes
    • G01R1/067—Measuring probes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/24—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices
    • G01R15/241—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-modulating devices using electro-optical modulators, e.g. electro-absorption
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
    • G01R19/16571—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current

Definitions

  • the present invention relates to a current measurement method capable of adopting a wide measurement range by using an optical modulator, a current sensor configured using the current measurement method, and an IC test apparatus using the current sensor.
  • An IC tester that measures a small current at rest at the power supply terminal of the IC under test composed of a die IC at high speed, and determines the quality of the IC based on whether the measured current value falls within the normal range.
  • Figure 15 shows an example of the test method.
  • a predetermined power supply voltage V DD is applied to the power supply terminal T VDD of the IC under test 11 from the DC power supply 12 through the current measuring means 13.
  • the current measuring means 13 includes a shunt resistor SR for converting a current into a voltage, a differential amplifier DF for extracting a potential difference generated between both ends of the shunt resistor SR as a voltage value, and a differential amplifier DF. It consists of a limiter diode D connected in parallel to the input terminal.
  • the voltage signal output from the differential amplifier DF is sampled and held by the sample and hold circuit 14 at a predetermined timing, the sampled and held voltage is AD converted by the AD converter 15, and the digital output is measured as a current measurement result. And outputs the result to the arithmetic processing unit 16 to determine whether the measured current value is within a predetermined range.
  • the inside of the IC under test 11 is generally constituted by a CMOS circuit. It is a target.
  • the CMOS type circuit has an N-channel FET and a P-channel FET that are connected in a complementary manner, and both of them are alternately turned on and off, and the signal is inverted. Execute transmission.
  • a relatively large current flows when the complementary-connected FETs invert the state of each other, and when the state is stabilized, the current (generally referred to as a leak current) sharply decreases to a minute value. That is, the current flows in a pulse shape as shown by the dotted line in FIG.
  • Peak of high current pulses I PL flowing in pulses is reached in large scale numbers in IC A, the leakage current I s flowing through a stationary state is approximately several / i A.
  • the leakage current I s flowing while the FET state is stable falls within a normal range. Therefore it is necessary to accurately measure the leakage current I s.
  • a phenomenon that stabilizes at the target leakage current value (hereinafter, this phenomenon is referred to as settling) occurs.
  • Ri by the fact that this set ring occurs, the timing of the falling edge of the high current pulse I PL ⁇ .
  • the measurement point PT can be set only after a lapse of at least a time TS (hereinafter, this time TS is referred to as a settling time). So within the settling time TS The correct current value cannot be measured.
  • the current Is flowing through the power supply terminal T VDD of the IC under test 11 when the IC under test 11 is at rest is measured, and the presence or absence of a large value of leak current that should not flow naturally Is checked to determine whether the IC is good or not. Whether or not a fault location inside the IC is reflected in the leakage of the power supply current depends on the logic state of the fault location. Therefore, it is necessary to measure the power supply current each time while changing the combination of logic states inside the IC. To change the combination of logic states, the IC under test 11 must be inverted. Since the large current pulse IPL always flows when the IC under test 11 is operated, the leakage current IS after the state change is measured after the settling time TS has elapsed.
  • the measurement period T Es for repeating the state change and the measurement of the leakage current I s is affected by the length of the settling time T S.
  • the settling time TS is long, the cycle of changing the state of the IC under test 11 cannot be shortened, so that the measurement cycle TES of the leak current I s becomes long, and all the states of the ICI 1 under test are tested.
  • the time is long. As ICs tend to increase in size, the time required for testing increases.
  • the DC power supply 12 and the current measuring means 13 are arranged near the IC 11 under test, that is, in a portion called a test head, and the output signal of the differential amplifier DF is output from the test head by a cable or the like.
  • the signal is transmitted to the measuring instrument main body that is located at a distance, sample hold and AD conversion are executed on the measuring instrument main body side, and the arithmetic processing unit 16 compares and judges the quality. For this reason, when the distance between the test head and the measuring instrument body becomes long, it is susceptible to the influence of the capacitance of the signal transmission line, parasitic inductor, external noise, etc., and there is a disadvantage that the measurement accuracy is deteriorated.
  • a first object of the present invention is to provide a current measurement method having a wide current measurement range, that is, a wide dynamic range, so that the above-described settling does not occur, and therefore, for a very short time immediately after a large current pulse. It proposes a current measurement method capable of measuring a quiescent current, a current sensor using the current measurement method, and an IC test apparatus using the current sensor.
  • a second object of the present invention is to increase the distance between the test head and the measuring instrument body.
  • it proposes a current measurement method that is not affected by the signal transmission path, and therefore has little deterioration in measurement accuracy, and an IC test apparatus using this method. Disclosure of the invention
  • a current to be measured in which a large current having a large amplitude in a pulse form and a small current are alternately repeated is converted into a voltage signal, and this voltage signal is applied to an electric field application electrode of an optical modulator.
  • the optical modulator modulates the light, interferes the modulated light with the unmodulated light to obtain interference light, and converts the intensity of the interference light into an electric signal by a photodetector, thereby obtaining an optical signal. It proposes a current measurement method that extracts electric signals corresponding to the measured current value.
  • the optical modulator does not saturate even when a large-amplitude electric field is applied, and there is no settling even immediately after a large-amplitude pulsed voltage signal is applied. .
  • the leakage current I s should be measured without being affected by the settling. Can be.
  • the present invention further proposes an Ic test apparatus to which the current measuring method is applied.
  • the IC test apparatus proposed in the present invention measures the leakage current at rest in each state while changing the state of the CMOS type IC, and determines whether the leakage current at rest is greater than a specified value.
  • the leak current can be measured immediately without being affected by settling, and the state of Ic under test can be measured at high speed.
  • the inversion can be performed, and the leakage current in each inversion state can be measured.
  • a test head on which the IC under test is mounted can be connected to the measuring instrument main body that executes a process such as a current value comparison operation by an optical waveguide. Therefore, the optical waveguide is not affected by the capacitance, the parasitic inductor, and the external induction noise. As a result, the distance between the test head and the measuring Even if this is not the case, the advantage is obtained that the measurement accuracy can be maintained in a good state.
  • FIG. 1 is a plan view for explaining a current measuring method according to the present invention and a current sensor using the current measuring method.
  • FIG. 2 is a plan view for explaining the current measuring method and the operation of the optical modulator used in the current sensor according to the present invention.
  • FIG. 3 is a waveform chart for explaining the operation of the optical modulator shown in FIG.
  • FIG. 4 is a waveform chart for explaining the operation of the embodiment shown in FIG.
  • FIG. 5 is a plan view showing a modified example of the current sensor shown in FIG.
  • FIG. 6 is a plan view for explaining another example of the current measuring method according to the present invention.
  • FIG. 7 is a perspective view showing an example of a specific structure of an optical modulator used for a current sensor according to the present invention.
  • FIG. 8 is a plan view for explaining an example of an IC test apparatus using the current sensor according to the present invention.
  • FIG. 9 is a waveform chart for explaining the operation of the embodiment shown in FIG.
  • FIG. 10 is a plan view for explaining a modified embodiment of the embodiment shown in FIG.
  • FIG. 11 is a waveform chart for explaining the operation of the embodiment shown in FIG.
  • FIG. 12 is a plan view for explaining a modified embodiment of the embodiment shown in FIG.
  • FIG. 13 is a perspective view for explaining still another modified embodiment of the embodiment shown in FIG.
  • FIG. 14 is a plan view for explaining a modified embodiment of the IC test apparatus according to the present invention.
  • Figure 15 is a connection diagram for explaining the conventional technology.
  • FIG. 16 is a waveform chart for explaining the operation of the conventional technique shown in FIG. BEST MODE FOR CARRYING OUT THE INVENTION
  • the circuit to be measured to output the measured current I M in FIG, 2 0 indicates a current sensor for measuring the value of the measured current IM by the current measuring method proposed in this invention.
  • the measured current I is supplied to the current-to-voltage converter 30, the voltage signal VS generated in the current-to-voltage converter 30 is input to the optical modulator 40, and the voltage signal VS is It proposes a current measurement method that converts the intensity of the interference light into an electric signal, and converts the intensity of the interference light into an electric signal to measure the measured current I.
  • the current sensor 20 includes the substrate 21, the current-to-voltage converter 30 mounted on the substrate 21, and the optical modulator 40 mounted on the substrate 21 similarly.
  • a voltage VS corresponding to the current I M to be measured is generated by the current-to-voltage converter 30, and this voltage VS is applied to the optical modulator 40.
  • the branching interference type optical modulator 40 for example, a branch interference type optical modulator shown in FIG. 2 can be used.
  • the branching interference type optical modulator 40 includes an optical branching section 42 for branching the optical waveguide, an optical multiplexing section 43, and two optical sections formed between the optical branching section 42 and the optical multiplexing section 43. It is composed of optical waveguides 44A, 44B and electric field applying electrodes 45, 46, 47 formed on both sides of the two optical waveguides 44A, 44B.
  • Optical branch unit 4 2, optical multiplexer 4 3, the optical waveguide 4 4 A, 4 4 B respectively e.g. Nio lithium Bed acid (L i N b 0 3) dielectric substrate 4 1 composed of such, for example, titanium And the like can be diffused.
  • an optical waveguide such as an optical fiber is provided at the input end 49 A and the output end 49 B of the light exposed on the end face of the dielectric substrate 41.
  • a light source 51 such as a laser diode was coupled to the other end of the input optical waveguide 22 optically coupled to the input end 49 A, and was coupled to an output end 49 B.
  • a photodetector 53 such as a photodiode is coupled to the other end of the output optical waveguide 23.
  • the light source 51 is driven to a lighting state by the light source driving circuit 52.
  • This example shows a case where the motor is driven by a DC power supply. Therefore, the light source 51 enters a constant amount of laser light into the input optical waveguide 22.
  • a detection circuit 54 is connected to the photodetector 53, and the intensity of light emitted from the output optical waveguide 23 is converted into an electric signal and extracted.
  • the voltage VS generated in the current-to-voltage converter 30 is applied to one pair of the electric field application electrodes 45, 46, and 47.
  • the voltage VS generated in the current-to-voltage converter 30 is applied between the electric field applying electrodes 45 and 46, and the pair of the electric field applying electrodes 45 and 47 is The case where no electric field is applied by connecting the electrodes 45 and 47 in common is shown.
  • the optical waveguide 44A to which the electric field is applied has a phase with the light.
  • the light that is modulated and passes through the other electric field-side optical waveguide 44B passes without modulation.
  • the optical modulation characteristic shown in A shows a case where the optical path lengths of the optical waveguides 44 A and 44 B are the same, but between one optical path length and the other optical path length, only one to four wavelengths of the light propagating.
  • the value of the current to be measured I M can be specified simply by measuring the voltage between these values.
  • the circuit 54 can measure a voltage corresponding to a current value without saturation even without a limiter circuit. As a result, since the settling phenomenon even after a large current pulse I PL as shown in FIG. 4 is not generated, timing T. falling of a large current pulse I PL After a short period of time, the small current I s can be measured, and the high-speed test can be performed by measuring the leakage current flowing when the COMS type IC is at rest and using the IC test equipment to judge the quality of the IC under test. Is obtained.
  • the detection sensitivity of the current sensor 20 is proportional to the electrode length L of the electric field application electrodes 45, 46, and 47, and is inversely proportional to the gap between the electrodes, so that the electrode gap is narrow and the electrode length L is long. Desired sensitivity can be obtained.
  • the detection sensitivity can also be increased by increasing the light emission intensity of the light source 51 as necessary.
  • the detection sensitivity can be doubled by differentially applying the voltage VS to the two optical waveguides 44A and 44B.
  • FIG. 6 shows another embodiment of the current measuring method according to the present invention.
  • the photodetector 53 By inputting and detecting the transmission amount of the light pulse 56 by the photodetector 53, the measured value at the target timing position can be accurately measured.
  • the timing position to be measured is determined by the application timing of the light pulse 56. Therefore, by restricting the pulse width of the light pulse 56 to be narrow, the position of the measurement timing can be set with high resolution.
  • the photodetector 53 only needs to measure the total amount of transmitted light. Therefore, an integrating circuit 57 is provided on the output side of the detecting circuit 54, and by measuring the integrated voltage integrated in the integrating circuit 57, the measured current The value of IM can be measured. Therefore, the response speed of the photodetector 53 is Not required. Therefore, in addition to requiring high-speed operation only for the optical switch 55, other elements and circuits can achieve high-resolution measurement timing resolution without requiring high-speed operation.
  • FIG. 7 shows an example of a specific implementation structure of the current sensor 2 ().
  • the substrate 21 can be made of, for example, an insulating material such as a ceramic.
  • a resistive film 31 constituting the current-to-voltage converter 30 is formed on one surface of the substrate 21 while forming the same.
  • the electrodes 32, 33 are formed on both ends of the resistive film 31.
  • the ends of the electrodes 32, 33 are electrically connected to the current measuring terminals 34, 35, respectively.
  • the converter 30 is constituted.
  • the substrate 21 can be formed in a shape having a side of about 10 mm ⁇ 10 mm.
  • the current sensor 20 can be configured by mounting the dielectric substrate 41 configuring the optical modulator 40 on a blank portion of the surface on which the current-to-voltage converter 30 is formed.
  • Each of the electrodes 32 and 33 and the electric field applying electrodes 45 and 46 constituting the optical modulator 40 can be electrically connected by, for example, a bonding wire BF or the like.
  • a bonding wire BF By forming the current sensor 20 into a card as shown in FIG. 7, it is effective when applied to an IC test device described below.
  • FIG. 8 shows an example of an IC test apparatus to which the current measuring method and the current sensor 20 according to the present invention are applied.
  • This embodiment shows a case where the current sensor 20 described with reference to FIGS. 1 to 6 is applied to an IC test apparatus.
  • the common terminal T vss Given supply voltage V DD from the DC power source 1 2 to the power supply terminal T VD D of the test IC 1 1, the common terminal T vss is connected to the common potential point.
  • the current-to-voltage converter 30 generates a voltage VS corresponding to the value of the current I DD .
  • This voltage VS is applied between the electric field application electrodes 45 and 46, and the optical modulator 40 gives optical modulation corresponding to the current flowing through the power supply terminal T VDD of the IC 11 under test.
  • the photodetector 53 converts the emission intensity of the light emitted from the output optical waveguide 23 into an electric signal, and outputs the electric signal from the detection circuit 54 as a voltage signal.
  • the voltage signal output from the detection circuit 54 is converted to a sampling pulse TGP output from the pattern generator 58 by the sample and hold circuit 14 at the timing when the ICI 1 under test is stationary. Therefore, sample and hold, the sampled and held voltage value is subjected to AD conversion by the AD conversion means 15, and the AD converted digital signal is input to the arithmetic processing unit 16 so that the digital value falls within a desired voltage range. It is determined whether or not the IC under test 11 is good or not.
  • the pattern generator 58 supplies a drive signal to the IC under test 11 to convert the state of the IC under test 11 one step at a time, and the value of the power supply current I DD in the quiescent state of each step falls within a predetermined range. Test whether it is
  • the sample-and-hold circuit 14 applies a sampling pulse TGP to the sample-and-hold circuit 14 at a timing TST slightly after the falling timing of the large current pulse IPL flowing through the IC under test 11 as shown in FIG. the minute current I s in each still state after the test IC 1 1 is inverted operation one stearyl-up was measured at each step, it is determined compared to quality with a set value previously set by the processor 1 6.
  • the IC tester be tested IC 1 1 consumes intermittent large-current pulse I PL, current sensor 2 0 and
  • the detection circuit 54 can be operated without being saturated. ⁇ Tsu Te, according to the embodiment shown in FIG.
  • the sample and hold circuit 1 4 can be sampled and held by the immediately following slight time T ST since the fall of the data Imingu high current pulses I PL, it is possible to complete the measurement in a short time. Therefore, since the cycle TES of the inversion operation of the IC under test 11 can be shortened, even if all the states of the IC under test 11 are tested, the benefit of shortening the time required for the test can be obtained. Further, according to the embodiment shown in FIG.
  • an optical switch 55 is connected to an input optical waveguide 22 connecting the light source 51 and the optical modulator 40, and the optical switch 55 is turned on in synchronization with the timing to be measured.
  • a case is shown in which the optical pulse 56 (see FIG. 11B) is applied to the optical modulator 40 in synchronization with the timing to be measured by turning off.
  • an integrating circuit 57 is provided on the output side of the detecting circuit 54, and the integrating circuit 57 integrates the total amount of light received by the photodetector 53.
  • the integrated voltage INTV (FIG. 11C) ) Is sampled and held by the sample-and-hold circuit 14 in synchronization with the sampling pulse TGP (Fig. 11D), and the sample-and-hold voltage is AD-converted by the AD converter 15 and input to the arithmetic processing unit 16. Can be configured.
  • the integration voltage I NTV of the integration circuit 57 is reset by a reset pulse R SP shown in FIG. 11E every time sampling is completed.
  • the measurement timing is determined by the application timing of the optical pulse 56 as described above with reference to FIG. . Therefore, by reducing the pulse width of the optical pulse 56, there is obtained an advantage that the resolution in the time axis direction of the measurement timing can be increased. Furthermore, according to this embodiment, since the photodetector 53, the detection circuit 54, and the sample hold circuit 14 need only obtain a value corresponding to the total amount of light received by the photodetector 53, high-speed response can be achieved. Is not required. Therefore, there is also obtained an advantage that it can be constituted by an inexpensive element that does not operate at high speed.
  • FIG. 12 shows an embodiment for testing an IC having a plurality of power supply terminals TVDD .
  • the drive circuits of the pattern generator 58 and the light source 51 and the internal structure of the current sensor 20 are omitted.
  • a number of current sensors 20 corresponding to the number of power supply terminals T VDD of the IC under test 11 are prepared. That is, in this embodiment, four current sensors 20 are prepared, one end of the current-to-voltage converter 30 of each current sensor 20 is connected to the positive voltage terminal of the DC power supply 12, and the current-to-voltage conversion is performed. Connect the other end of the unit 30 to each power supply terminal T VDD .
  • the input optical waveguide 22 and the output optical waveguide 23 leading to the optical modulator 40 are connected in series, a light source 51 is optically coupled to one end of the serially connected optical waveguide, and the other end is connected to the other end.
  • the photodetector 53 is optically coupled.
  • the light incident on the photodetector 53 has a light amount corresponding to the sum of the light modulation amounts received by the four current sensors 20, and the light amount is equal to each light It corresponds to the total value of the current flowing through the source terminal TVDD . Therefore, an addition means is configured in the optical system, and the total sum of the currents flowing through the plurality of power supply terminals TVDD is measured by one light source 51, one photodetector 53, and one detection circuit 54. it can be can Rukoto is determined whether the sum of the currents flowing through the power supply terminal T VD D is in the range of normal values.
  • FIG. 13 shows a modified embodiment of FIG. This embodiment shows an embodiment in which a probe 63 is brought into contact with an electrode portion of an IC chip 62 formed on a wafer 61 to directly test the IC in a chip state.
  • the probe 63 is supported by projecting toward the center of the ring-shaped probe force probe 64, and the tip of each probe 63 is brought into contact with each electrode portion of the chip formed on the wafer 61.
  • the power supply current and the drive signal are supplied through each probe 63, and the power supply current is measured on the power supply 12 side.
  • the current sensor 20 is mounted in the middle of the probe 63, and the optical signal optically modulated by the current sensor 20 is transmitted through the optical waveguide 23 and received by the optical detector 53. It should be done.
  • the probe card 64, the light source 51, the light detector 53, the detection circuit 53, the detection circuit 54, and the sample hold are not disturbed by extraneous electromagnetic waves even if the extension distance of the optical waveguide 23 is long. Even if the circuit 14 etc. is housed in a measuring instrument placed away from the installation position (test head) of the IC under test 11, the IC in the chip state can be tested without being affected by external electromagnetic waves. It can be carried out.
  • FIG. 14 shows a modification of the current measuring method.
  • an embodiment aiming at removing the influence of the drift of the light emission amount of the light source 51 and removing the offset voltage of the photodetector 53 will be described.
  • an optical splitter 65 is connected to the input optical waveguide 22 on the side of the light source 51, and one of the lights split by the optical splitter 65 is input to the optical modulator 40, and the other. Is passed through a correction optical waveguide 66 formed adjacent to the optical modulator 40, and the emitted light is
  • the photodetector 5 3B receives light, and a voltage signal corresponding to the amount of received light is fed back to the drive circuit 52 of the light source 51 to stabilize and control the light emission intensity of the light source 51.
  • Subtraction circuit 67 subtracts the voltage signal corresponding to the amount of light received at 3 A and 53 B Thus, the offset voltage generated in the photodetector 53 A and the detection circuit 54 A can be removed.
  • the optical branching device 65 since the light branched by the optical branching device 65 is made to pass through the optical waveguide for correction 66 formed adjacent to the optical modulator 40, the optical waveguide for correction 66 is used. Since the passing light is affected by the same temperature as the light passing through the optical modulator 40, there is an advantage that the fluctuation of the optical modulation characteristic of the optical modulator 40 due to the temperature fluctuation of the dielectric substrate 41 can be removed.
  • the current measuring method according to the present invention is suitable for measuring a leak current flowing through a power supply terminal of a CMOS type IC, and determines whether the IC is good or not based on whether or not the leak current is within a specified range. It is suitable for application to a test apparatus.
  • the measured current value detected by the current sensor 20 is transmitted through the output optical waveguide 23, and therefore, there is no possibility that the output optical waveguide 23 will be subjected to various electrical disturbances. Therefore, even if the distance between the test head and the measuring instrument body is greatly increased, there is an advantage that the measurement accuracy of the minute current can be maintained at a high accuracy state.

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  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
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Abstract

A current measuring method which has the steps of converting a current to be measured into a voltage signal, phase-modulating the light, which permeates through an optical modulator, by this voltage signal, obtaining interference light by allowing the phase-modulated light to interfere with non-phase-modulated light, and measuring the object current on the basis of the intensity of the interference light. An IC tester is also proposed which is adapted to measure a current flowing in a power source terminal of an IC to be tested, by using this current measuring method, and judge that the object IC is defective when the resultant current value is larger than a predetermined value.

Description

明 細 書 電流測定方法、 電流センサ及びこの電流センサを用いた I c試験装置 技術分野  Description Current measurement method, current sensor and Ic test equipment using this current sensor
この発明は光変調器を利用することによって測定レンジを広く採ることができ る電流測定方法と、 この電流測定方法を用いて構成した電流センサ及びこの電流 センサを利用した I C試験装置に関し、 特に C M O S型 I Cで構成される被試験 I cの電源端子に流れる静止時の微小電流を高速度に測定し、 測定した電流値が 正常な範囲に入るか否かによって I Cの良否を判定する I C試験装置に関する。 背景技術  The present invention relates to a current measurement method capable of adopting a wide measurement range by using an optical modulator, a current sensor configured using the current measurement method, and an IC test apparatus using the current sensor. An IC tester that measures a small current at rest at the power supply terminal of the IC under test composed of a die IC at high speed, and determines the quality of the IC based on whether the measured current value falls within the normal range. About. Background art
従来より、 被試験 I cに流れる電流を測定し、 被試験 I Cの電源端子に流れる 電流が規定の範囲に入っているか否かにより、 その I Cが正常か否かを測定する 試験方法がある。  Conventionally, there is a test method in which a current flowing through the Ic under test is measured, and whether the Ic is normal is measured based on whether the current flowing through the power supply terminal of the Ic under test falls within a specified range.
図 1 5にその試験方法の一例を示す。 被試験 I C 1 1の電源端子 T VDD に直流 電源 1 2から電流測定手段 1 3を通じて所定の電源電圧 V DDを与える。 電流測定 手段 1 3は電流を電圧に変換するためのシャント抵抗器 S Rと、 このシャント抵 抗器 S Rの両端に発生する電位差を電圧値として取り出す差動増幅器 D Fと、 こ の差動増幅器 D Fの入力端子に並列接続したリミッタ用ダイォード Dとによって 構成される。 Figure 15 shows an example of the test method. A predetermined power supply voltage V DD is applied to the power supply terminal T VDD of the IC under test 11 from the DC power supply 12 through the current measuring means 13. The current measuring means 13 includes a shunt resistor SR for converting a current into a voltage, a differential amplifier DF for extracting a potential difference generated between both ends of the shunt resistor SR as a voltage value, and a differential amplifier DF. It consists of a limiter diode D connected in parallel to the input terminal.
差動増幅器 D Fから出力される電圧信号はサンプルホールド回路 1 4で所定の タイミングでサンプルホールドされ、 このサンプルホールドされた電圧を A D変 換器 1 5で A D変換し、 そのディジタル出力を電流測定結果として出力し、 演算 処理装置 1 6に入力して電流測定値が所定の範囲に入っているか否かを判定する ここで、 被試験 I C 1 1の内部は C M O S型回路で構成されるのが一般的であ る。 C MO S型回路はよく知られているように Nチヤンネル型 F E Tと Pチャン ネル型 F E Tとが相補接続され、 双方が交叉にオンとオフの状態に反転して信号 の伝送を実行する。 このため、 相補接続された FETが互いに状態を反転すると き比較的大きな電流が流れ、 状態が安定すると、 電流 （一般的にリーク電流と呼 ぶ場合もある） は微小値に激減する。 つまり、 図 1 6に点線で示すようにパルス 状に電流が流れる。 The voltage signal output from the differential amplifier DF is sampled and held by the sample and hold circuit 14 at a predetermined timing, the sampled and held voltage is AD converted by the AD converter 15, and the digital output is measured as a current measurement result. And outputs the result to the arithmetic processing unit 16 to determine whether the measured current value is within a predetermined range. Here, the inside of the IC under test 11 is generally constituted by a CMOS circuit. It is a target. As is well known, the CMOS type circuit has an N-channel FET and a P-channel FET that are connected in a complementary manner, and both of them are alternately turned on and off, and the signal is inverted. Execute transmission. For this reason, a relatively large current flows when the complementary-connected FETs invert the state of each other, and when the state is stabilized, the current (generally referred to as a leak current) sharply decreases to a minute value. That is, the current flows in a pulse shape as shown by the dotted line in FIG.
パルス状に流れる大電流パルス I PLの尖頭値は規模が大きい I Cでは数 Aに達 し、 静止状態で流れるリーク電流 I s は数/ i A程度となる。 被試験 I C 1 1が正 常か否かを判定するには、 FETの状態が安定している状態で流れるリーク電流 I s が正規の範囲に入るか否かにより判定する。 従ってリーク電流 I s を正確に 測定する必要がある。 Peak of high current pulses I PL flowing in pulses is reached in large scale numbers in IC A, the leakage current I s flowing through a stationary state is approximately several / i A. In order to determine whether or not the IC under test 11 is normal, it is determined whether or not the leakage current I s flowing while the FET state is stable falls within a normal range. Therefore it is necessary to accurately measure the leakage current I s.
このため従来は差動増幅器 DFの入力側にリミッタ用ダイオード Dを接続し、 このリミッタ用ダイォード Dによってシャント抵抗器 S Rに流れる大電流パルス I PLをバイパスさせ、 シャント抵抗器 S Rに流れる電流を制限して差動増幅器 D Fに入力される電圧信号の振幅を制限し、 差動増幅器 D Fが飽和しない範囲で動 作させ、 リーク電流 I s を測定している。 Therefore conventionally connects the limiter diode D on the input side of the differential amplifier DF, bypass the high current pulses I PL flowing to the shunt resistor SR This limiter Daiodo D, limits the current flowing to the shunt resistor SR Then, the amplitude of the voltage signal input to the differential amplifier DF is limited, the differential amplifier DF is operated within a range not saturated, and the leak current Is is measured.
従って図 1 6に示す例では、 被試験 I C 1 1が反転動作する期間に流れる大電 流パルス I PLはリミッタ用ダイオード Dでバイパスさせ、 リーク電流 I s が流れ る期間ではリミッタ用ダイオード Dをオフの状態にさせ、 リーク電流 I s がシャ ント抵抗器 S Rに流れている状態で、 このシャント抵抗器 S Rに発生する電圧を 差動増幅器 DFを通じて取り出し、 サンプルホールド回路 1 4と AD変換器 1 5 により AD変換して演算処理装置 1 6に入力して良否の判定を行っている。 ところで、 リミッタ用ダイオード Dを接続すると、 新たに以下に説明するよう な不都合が生じる。 つまり、 リミッタ用ダイオード Dを接続した場合には、 ダイ ォード固有の蓄積キャリア及び接合容量により大電流パルス I PLの直後は電流の 切れが悪く、 図 1 6に示すように大電流パルス I PLの立下りのタイミング T。 か ら或る時間 TSを経過して、 目的とするリーク電流値に安定する現象 （以下この 現象をセットリングと称す） が発生する。 このセットリングが発生することによ り、 大電流パルス I PLの立下りのタイミング Τ。 から少なくとも時間 TS (以下 この時間 TSをセットリングタイムと称する） を経過した後でないと測定ポイン ト PTを設定することはできない。 つまりセットリングタイム TSの範囲内では 正しい電流値を測定できないことになる。 In the example shown in FIG. 1 6, therefore, high current pulse I PL flowing in the period under test IC 1 1 is inverted operation is bypassed by the limiter diode D, the leakage current I s is a limiter diode D is the flow Ru period Turn off, and with the leak current Is flowing through the shunt resistor SR, take out the voltage generated in this shunt resistor SR through the differential amplifier DF, and sample and hold the circuit 14 and the AD converter 1 The signal is subjected to AD conversion by 5 and input to the arithmetic processing unit 16 to determine pass / fail. By the way, when the limiter diode D is connected, the following disadvantages newly arise. That is, when connecting the limiter diode D is, immediately after the high-current pulse I PL by the die Odo specific storage carrier and junction capacitance poor off current, a large current pulse I PL as shown in FIG. 1 6 Fall timing T. After a lapse of a certain time TS, a phenomenon that stabilizes at the target leakage current value (hereinafter, this phenomenon is referred to as settling) occurs. Ri by the fact that this set ring occurs, the timing of the falling edge of the high current pulse I PL Τ. The measurement point PT can be set only after a lapse of at least a time TS (hereinafter, this time TS is referred to as a settling time). So within the settling time TS The correct current value cannot be measured.
しかも、 この試験方法では被試験 I C 1 1が静止状態にあるときの被試験 I C 1 1の電源端子 T VD D に流れる電流 I s を測定し、 本来流れるはずがない大きい 値のリーク電流の有無を検査して I Cの良否を判定するものであるから、 I C内 部の故障個所が電源電流のリークに反映されるか否かは、 その故障個所の論理状 態に依存する。 従って I C内部の論理状態の組合せを変えながらその都度、 電源 電流を測定する必要がある。 論理状態の組合せを変えるには、 被試験 I C 1 1を 反転動作させなければならないことになる。 被試験 I C 1 1を動作させると必ず 大電流パルス I P Lが流れるため、 状態変更後のリーク電流 I S の測定はセットリ ング時間 T Sを経過してからとなる。 In addition, in this test method, the current Is flowing through the power supply terminal T VDD of the IC under test 11 when the IC under test 11 is at rest is measured, and the presence or absence of a large value of leak current that should not flow naturally Is checked to determine whether the IC is good or not. Whether or not a fault location inside the IC is reflected in the leakage of the power supply current depends on the logic state of the fault location. Therefore, it is necessary to measure the power supply current each time while changing the combination of logic states inside the IC. To change the combination of logic states, the IC under test 11 must be inverted. Since the large current pulse IPL always flows when the IC under test 11 is operated, the leakage current IS after the state change is measured after the settling time TS has elapsed.
従って、 状態変更とリーク電流 I s の測定を繰り返す測定周期 T E Sはセット リングタイム T Sの長短によって影響を受ける。 つまりセットリングタイム T S が長ければ被試験 I C 1 1の状態を変更する周期を短くすることができないため 、 リーク電流 I s の測定周期 T E Sも長くなり、 被試験 I C I 1の全ての状態を 試験する時間は長くなる不都合が生じる。 I Cは益々規模が増大する傾向にある ため、 試験に要する時間は益々長くなる不都合が生じる。  Therefore, the measurement period T Es for repeating the state change and the measurement of the leakage current I s is affected by the length of the settling time T S. In other words, if the settling time TS is long, the cycle of changing the state of the IC under test 11 cannot be shortened, so that the measurement cycle TES of the leak current I s becomes long, and all the states of the ICI 1 under test are tested. There is a disadvantage that the time is long. As ICs tend to increase in size, the time required for testing increases.
更に従来は直流電源 1 2と電流測定手段 1 3は被試験 I C 1 1の近傍、 つまり テストへッドと呼ばれる部分に配置され、 差動増幅器 D Fの出力信号をケーブル 等でテストへッドから離れて配置される測定器本体に伝達し、 測定器本体側でサ ンプルホールドと A D変換を実行し、 演算処理装置 1 6で比較判定して良否を判 定している。 このため、 テストヘッドと測定器本体との間の距離が長くなると、 信号伝送路の静電容量、 寄生インダクタ、 外来誘導雑音等の影響を受けやすくな り、 測定精度を悪化させる欠点もある。  Further, conventionally, the DC power supply 12 and the current measuring means 13 are arranged near the IC 11 under test, that is, in a portion called a test head, and the output signal of the differential amplifier DF is output from the test head by a cable or the like. The signal is transmitted to the measuring instrument main body that is located at a distance, sample hold and AD conversion are executed on the measuring instrument main body side, and the arithmetic processing unit 16 compares and judges the quality. For this reason, when the distance between the test head and the measuring instrument body becomes long, it is susceptible to the influence of the capacitance of the signal transmission line, parasitic inductor, external noise, etc., and there is a disadvantage that the measurement accuracy is deteriorated.
この発明の第 1の目的は電流の測定範囲が広く、 つまりダイナミックレンジが 広い電流測定方法を提案することにより、 上記したセットリングの発生がなく、 従って大電流パルスの直後の極めて短時間の間に静止電流を測定することができ る電流測定方法と、 この電流測定方法を用いた電流センサ及びこの電流センサを 用いた I C試験装置を提案するものである。  A first object of the present invention is to provide a current measurement method having a wide current measurement range, that is, a wide dynamic range, so that the above-described settling does not occur, and therefore, for a very short time immediately after a large current pulse. It proposes a current measurement method capable of measuring a quiescent current, a current sensor using the current measurement method, and an IC test apparatus using the current sensor.
この発明の第 2の、目的はテストへッドと測定器本体との間の距離が長くなつて も、 信号伝送路で受ける影響がなく、 従って測定精度の劣化が少ない電流測定方 法及びこの方法を用いた I C試験装置を提案するものである。 発明の開示 A second object of the present invention is to increase the distance between the test head and the measuring instrument body. In addition, it proposes a current measurement method that is not affected by the signal transmission path, and therefore has little deterioration in measurement accuracy, and an IC test apparatus using this method. Disclosure of the invention
この発明ではパルス状の大きい振幅の大電流と、 微小電流とが交互に繰り返さ れる被測定電流を電圧信号に変換すると共に、 この電圧信号を光変調器の電界印 加電極に与え、 電圧信号により光変調器において光に変調を加え、 変調された光 と変調されない光とを千渉させて干渉光を得、 この干渉光の強度を光検出器によ つて電気信号に変換することにより、 被測定電流の値に対応した電気信号として 取り出す電流測定方法を提案するものである。  According to the present invention, a current to be measured in which a large current having a large amplitude in a pulse form and a small current are alternately repeated is converted into a voltage signal, and this voltage signal is applied to an electric field application electrode of an optical modulator. The optical modulator modulates the light, interferes the modulated light with the unmodulated light to obtain interference light, and converts the intensity of the interference light into an electric signal by a photodetector, thereby obtaining an optical signal. It proposes a current measurement method that extracts electric signals corresponding to the measured current value.
この発明による電流測定方法によれば、 光変調器は大振幅の電界が与えられて も飽和することなく、 また大振幅のパルス状の電圧信号が与えられた直後でもセ ットリングの発生は全くない。  According to the current measuring method of the present invention, the optical modulator does not saturate even when a large-amplitude electric field is applied, and there is no settling even immediately after a large-amplitude pulsed voltage signal is applied. .
従って、 大電流パルス I P Lと静止状態で流れるリーク電流 I S との比が大きく ても、 また大電流パルス I P Lが流れた直後でも、 セットリングに影響されずにリ ーク電流 I s を測定することができる。  Therefore, even if the ratio between the large current pulse IPL and the leakage current IS flowing in the stationary state is large, or immediately after the large current pulse IPL flows, the leakage current I s should be measured without being affected by the settling. Can be.
この発明では、 更にこの電流測定方法を適用した I c試験装置を提案するもの である。 この発明で提案する I C試験装置は C OM S型 I Cの状態を変更しなが ら各状態における静止時におけるリーク電流を測定し、 この静止時におけるリー ク電流が規定値より大きいか否かにより被試験 I Cの良否を判定する I C試験装 置において、 被試験 I Cの状態を変更した直後でもセットリングに影響されずに 直ちにリーク電流を測定することができ、 被試験 I cを高速で状態を反転させ、 各反転状態におけるリーク電流を測定することができる。  The present invention further proposes an Ic test apparatus to which the current measuring method is applied. The IC test apparatus proposed in the present invention measures the leakage current at rest in each state while changing the state of the CMOS type IC, and determines whether the leakage current at rest is greater than a specified value. In the IC test equipment that determines the quality of the IC under test, even after the state of the IC under test is changed, the leak current can be measured immediately without being affected by settling, and the state of Ic under test can be measured at high speed. The inversion can be performed, and the leakage current in each inversion state can be measured.
よって、 この発明による I C試験装置によれば規模が大きい I Cであっても、 試験に要する時間を短時間に済ませることができる利点が得られる。  Therefore, according to the IC test apparatus according to the present invention, there is an advantage that the time required for the test can be shortened even for an IC having a large scale.
更に、 この発明によれば被試験 I Cを搭載したテストへッドと電流値の比較演 算等の処理を実行する測定器本体との間は光導波路によって結ぶことができる。 従って、 光導波路は静電容量或いは寄生インダクタ、 更には外来誘導雑音等の影 響を受けることがない。 この結果、 テストヘッドと測定器本体との間の距離が長 くなつても測定精度を良好な状態に維持することができる利点が得られる。 図面の簡単な説明 Further, according to the present invention, a test head on which the IC under test is mounted can be connected to the measuring instrument main body that executes a process such as a current value comparison operation by an optical waveguide. Therefore, the optical waveguide is not affected by the capacitance, the parasitic inductor, and the external induction noise. As a result, the distance between the test head and the measuring Even if this is not the case, the advantage is obtained that the measurement accuracy can be maintained in a good state. BRIEF DESCRIPTION OF THE FIGURES
図 1はこの発明による電流測定方法及びこの電流測定方法を用いる電流センサ を説明するための平面図。  FIG. 1 is a plan view for explaining a current measuring method according to the present invention and a current sensor using the current measuring method.
図 2はこの発明による電流測定方法及び電流センサに用いる光変調器の動作を 説明するための平面図。  FIG. 2 is a plan view for explaining the current measuring method and the operation of the optical modulator used in the current sensor according to the present invention.
図 3は図 2に示した光変調器の動作を説明するための波形図。  FIG. 3 is a waveform chart for explaining the operation of the optical modulator shown in FIG.
図 4は図 1に示した実施例の動作を説明するための波形図。  FIG. 4 is a waveform chart for explaining the operation of the embodiment shown in FIG.
図 5は図 1に示した電流センサの変形実施例を示す平面図。  FIG. 5 is a plan view showing a modified example of the current sensor shown in FIG.
図 6はこの発明による電流測定方法の他の例を説明するための平面図。  FIG. 6 is a plan view for explaining another example of the current measuring method according to the present invention.
図 7はこの発明による電流センサに用いる光変調器の具体的構造の一例を示す 斜視図。  FIG. 7 is a perspective view showing an example of a specific structure of an optical modulator used for a current sensor according to the present invention.
図 8はこの発明による電流センサを用いた I C試験装置の一例を説明するため の平面図。  FIG. 8 is a plan view for explaining an example of an IC test apparatus using the current sensor according to the present invention.
図 9は図 8に示した実施例の動作を説明するための波形図。  FIG. 9 is a waveform chart for explaining the operation of the embodiment shown in FIG.
図 1 0は図 8に示した実施例の変形実施例を説明するための平面図。  FIG. 10 is a plan view for explaining a modified embodiment of the embodiment shown in FIG.
図 1 1は図 1 0に示した実施例の動作を説明するための波形図。  FIG. 11 is a waveform chart for explaining the operation of the embodiment shown in FIG.
図 1 2は図 8に示した実施例の変形実施例を説明するための平面図。  FIG. 12 is a plan view for explaining a modified embodiment of the embodiment shown in FIG.
図 1 3は図 8に示した実施例の更に他の変形実施例を説明するための斜視図。 図 1 4はこの発明による I C試験装置の変形実施例を説明するための平面図。 図 1 5は従来の技術を説明するための接続図。  FIG. 13 is a perspective view for explaining still another modified embodiment of the embodiment shown in FIG. FIG. 14 is a plan view for explaining a modified embodiment of the IC test apparatus according to the present invention. Figure 15 is a connection diagram for explaining the conventional technology.
図 1 6は図 1 5に示した従来の技術の動作を説明するための波形図。 発明を実施するための最良の形態  FIG. 16 is a waveform chart for explaining the operation of the conventional technique shown in FIG. BEST MODE FOR CARRYING OUT THE INVENTION
図 1を用いてこの発明による電流測定方法及びこの電流測定方法を用いた電流 センサの構成及びその動作を説明する。 図中 1 0は被測定電流 I M を出力する被 測定回路、 2 0はこの発明で提案する電流測定方法によって被測定電流 I M の値 を測定する電流センサを示す。 この発明による電流測定方法は被測定電流 I を電流—電圧変換器 3 0に与え 、 この電流一電圧変換器 3 0に発生する電圧信号 V Sを光変調器 4 0に入力し、 電圧信号 V Sを干渉光に変換し、 干渉光の強度を電気信号に変換して被測定電流 I を測定する電流測定方法を提案するものである。 The configuration and operation of a current measuring method according to the present invention and a current sensor using the current measuring method will be described with reference to FIG. 1 0 the circuit to be measured to output the measured current I M in FIG, 2 0 indicates a current sensor for measuring the value of the measured current IM by the current measuring method proposed in this invention. In the current measuring method according to the present invention, the measured current I is supplied to the current-to-voltage converter 30, the voltage signal VS generated in the current-to-voltage converter 30 is input to the optical modulator 40, and the voltage signal VS is It proposes a current measurement method that converts the intensity of the interference light into an electric signal, and converts the intensity of the interference light into an electric signal to measure the measured current I.
つまり、 この発明による電流センサ 2 0は基板 2 1と、 この基板 2 1に搭載し た電流一電圧変換器 3 0と、 同様に基板 2 1に搭載された光変調器 4 0とによつ て構成され、 電流一電圧変換器 3 0によって被測定電流 I M の に対応した電圧 V Sを発生させ、 この電圧 V Sを光変調器 4 0に印加する。 That is, the current sensor 20 according to the present invention includes the substrate 21, the current-to-voltage converter 30 mounted on the substrate 21, and the optical modulator 40 mounted on the substrate 21 similarly. A voltage VS corresponding to the current I M to be measured is generated by the current-to-voltage converter 30, and this voltage VS is applied to the optical modulator 40.
光変調器 4 0としては例えば図 2に示す分岐干渉型の光変調器を用いることが できる。 分岐干渉型の光変調器 4 0は光導波路を分岐する光分岐部 4 2と、 光合 波部 4 3と、 これら光分岐部 4 2と、 光合波部 4 3の間に形成した 2本の光導波 路 4 4 A， 4 4 Bと、 この 2本の光導波路 4 4 A， 4 4 Bのそれぞれの両側に形 成した電界印加電極 4 5， 4 6， 4 7とによって構成される。  As the optical modulator 40, for example, a branch interference type optical modulator shown in FIG. 2 can be used. The branching interference type optical modulator 40 includes an optical branching section 42 for branching the optical waveguide, an optical multiplexing section 43, and two optical sections formed between the optical branching section 42 and the optical multiplexing section 43. It is composed of optical waveguides 44A, 44B and electric field applying electrodes 45, 46, 47 formed on both sides of the two optical waveguides 44A, 44B.
光分岐部 4 2， 光合波部 4 3， 光導波路 4 4 A， 4 4 Bはそれぞれ例えばニォ ブ酸リチウム （L i N b 0 3 ) 等によって構成される誘電体基板 4 1に、 例えば チタン等を拡散させて形成することができる。 誘電体基板 4 1の端面に露出して 形成される光の入射端 4 9 Aと出射端 4 9 Bに例えば光ファイバのような光導波 路を入力用光導波路 2 2、 出力用光導波路 2 3として光学的に結合し、 入射端 4 9 Aに結合した入力用光導波路 2 2の他端側に例えばレーザーダイォードのよう な光源 5 1を結合させ、 出射端 4 9 Bに結合させた出力用光導波路 2 3の他端側 には例えばフォトダイォードのような光検出器 5 3を結合させる。 Optical branch unit 4 2, optical multiplexer 4 3, the optical waveguide 4 4 A, 4 4 B respectively e.g. Nio lithium Bed acid (L i N b 0 3) dielectric substrate 4 1 composed of such, for example, titanium And the like can be diffused. For example, an optical waveguide such as an optical fiber is provided at the input end 49 A and the output end 49 B of the light exposed on the end face of the dielectric substrate 41. A light source 51 such as a laser diode was coupled to the other end of the input optical waveguide 22 optically coupled to the input end 49 A, and was coupled to an output end 49 B. A photodetector 53 such as a photodiode is coupled to the other end of the output optical waveguide 23.
光源 5 1は光源駆動回路 5 2によって点灯状態に駆動する。 この例では直流電 源によって駆動させた場合を示す。 従って、 光源 5 1は一定光量のレーザー光を 入力用光導波路 2 2に入射する。 光検出器 5 3には検出回路 5 4を接続し、 出力 用光導波路 2 3から出射される光の強度を電気信号に変換して取り出す。  The light source 51 is driven to a lighting state by the light source driving circuit 52. This example shows a case where the motor is driven by a DC power supply. Therefore, the light source 51 enters a constant amount of laser light into the input optical waveguide 22. A detection circuit 54 is connected to the photodetector 53, and the intensity of light emitted from the output optical waveguide 23 is converted into an electric signal and extracted.
電界印加電極 4 5， 4 6， 4 7の一方の対に電流—電圧変換器 3 0に発生する 電圧 V Sを印加する。 図 1に示す例では、 電界印加電極 4 5と 4 6の間に電流— 電圧変換器 3 0に発生する電圧 V Sを印加し、 他方の電界印加電極 4 5と 4 7の 対にはこれらの電極 4 5と 4 7の間を共通接続して無電界を与えた場合を示す。 このように 2分岐した光の一方の光導波路 44 Aに電界を印加し、 他方の光導 波路 44 Bには無電界を印加することにより、 電界が与えられた光導波路 44 A 側では光に位相変調が与えられ、 他方の無電界側の光導波路 44 Bを通過する光 は無変調で通過する。 光導波路 44 A側で受けた光の位相変調により光合波部 4 3で光の干渉が発生し、 出力用光導波路 23に出射される光の強度が変化する。 この様子を図 2及び図 3を用いて説明する。 入力用光導波路 22に入射する光 強度を P inと、 出力用光導波路 23に出力される光強度を Ρ。υτ ， 電界印加電極 4 5と 46に与える電圧を VSとすると、 この印加電圧 VSを変化させると、 出 力用光導波路 23に出射される光強度 Ρ。υτ は図 3 Αに示すように COS曲線に 沿って変化する。 つまり、 印加電圧 VSが VS = 0のとき、 POUT =P inとなり 、 VSを徐々に +方向または一方向に変化させると出射量は COS曲線に沿って 徐々に低減し、 或る電圧において出射光量は 0に達する。 印加電圧 VSを更に増 加させると出射強度 Ρουτ は C 0 S曲線に沿って徐々に増加し、 或る電圧に達す ると出射強度 Ρουτ は 1 , つまり POUT =Pinの状態となる。 以後 VSの変化に 対して出射強度 Ρουτ は 1と 0の間を往復する光変調特性を呈する。 なお、 図 3The voltage VS generated in the current-to-voltage converter 30 is applied to one pair of the electric field application electrodes 45, 46, and 47. In the example shown in FIG. 1, the voltage VS generated in the current-to-voltage converter 30 is applied between the electric field applying electrodes 45 and 46, and the pair of the electric field applying electrodes 45 and 47 is The case where no electric field is applied by connecting the electrodes 45 and 47 in common is shown. By applying an electric field to one optical waveguide 44A of the two-branched light and applying no electric field to the other optical waveguide 44B, the optical waveguide 44A to which the electric field is applied has a phase with the light. The light that is modulated and passes through the other electric field-side optical waveguide 44B passes without modulation. Due to the phase modulation of the light received on the optical waveguide 44A side, light interference occurs in the optical multiplexing section 43, and the intensity of the light emitted to the output optical waveguide 23 changes. This situation will be described with reference to FIGS. And P in the intensity of light incident on the input optical waveguide 22, the intensity of light output to the output optical waveguide 23 [rho. υτ , when the voltage applied to the electric field applying electrodes 45 and 46 is VS, when this applied voltage VS is changed, the light intensity emitted to the output optical waveguide 23 Ρ. υτ changes along the COS curve as shown in Figure 3 3. In other words, when the applied voltage VS is VS = 0, P OUT = P in , and when VS is gradually changed in the + direction or one direction, the emission amount gradually decreases along the COS curve, and the emission at a certain voltage The light amount reaches 0. When the applied voltage VS is further increased, the emission intensity Ρουτ gradually increases along the C 0 S curve, and when a certain voltage is reached , the emission intensity Ρουτ becomes 1, that is, P OUT = P in . Thereafter, the output intensity ΡοΡτ exhibits an optical modulation characteristic that reciprocates between 1 and 0 in response to a change in VS. Figure 3
Aに示した光変調特性は光導波路 44 Aと 44 Bの光路長が等しい場合を示すが 、 一方の光路長と他方の光路長の間に、 伝播する光の波長の 1ノ4波長分だけ差 を持たせるか又は一方の光導波路 44 A又は 44 Bの何れか一方にバイアス電界 を与えることにより、 光変調特性は図 3 Bに示すように印加電圧 VSの変化に対 して S i n曲線に沿う特性となる。 つまり、 印加電圧 VS = 0を中心に急激に変 化する特性が得られる。 従って、 以下の説明では光変調器 40は光導波路 44 A と 44 Bの光路長に 1 /4波長の光路差を与え、 図 3 Bの変調特性で動作するも のとする。 The optical modulation characteristic shown in A shows a case where the optical path lengths of the optical waveguides 44 A and 44 B are the same, but between one optical path length and the other optical path length, only one to four wavelengths of the light propagating. By giving a difference or by applying a bias electric field to either one of the optical waveguides 44 A or 44 B, the light modulation characteristic changes as shown in Figure 3B with respect to the change in applied voltage VS. It follows the characteristic. That is, a characteristic is obtained in which the voltage changes rapidly around the applied voltage VS = 0. Accordingly, in the following description, it is assumed that the optical modulator 40 gives an optical path difference of 1/4 wavelength to the optical path lengths of the optical waveguides 44A and 44B and operates with the modulation characteristic of FIG. 3B.
以上説明した光変調器 40の変調特性から明らかなように、 光変調器 40は如 何なる電界入力に対しても出射光の強度 Ρουτ は P out =P inの状態と 0の間の 値、 つまり Ρουτ /P in= 1と、 POUT /P in= 0の間で表され、 図 1に示した 検出回路 54は Ρουτ ノ Pin= lと、 Ρουτ / P i n = 0の値の間の電圧を測定す るだけで被測定電流 I M の値を特定できることになる。 As is apparent from the modulation characteristics of the optical modulator 40 described above, the intensity of the emitted light は ουτ is a value between the state of P out = P in and 0 for any electric field input. , i.e. the Ρ ουτ / P in = 1, P OUT / P in = 0 is expressed between the detection circuit 54 and [rho Omikuron'upushirontau Bruno P in = l shown in FIG. 1, Ρ ουτ / P i n = 0 The value of the current to be measured I M can be specified simply by measuring the voltage between these values.
つまり、 被測定電流 I M の値が大きい場合には出射強度 P。ut が例えば 0に達 する回数を計数し、 最終値の Ρουτ P i n = 1と、 POUT ZP in=0との間の値 を測定すれば、 その電流値を求めることができる。 また微小電流 I s に対しても 、 POUT ZP in= lと、 POUT /P I N= 0との間の値で電流値を求めることがで きる。 従って検出回路 54は電流一電圧変換器 30に如何なる値を持つ電流が与 えられても、 POUT /Pin= lと、 POUT /Pin=0の間の電圧しか入力されな がら検出回路 54はリミッタ回路が無くとも飽和することなく電流値に対応した 電圧を測定することができる。 この結果、 図 4に示すような大電流パルス I PLの 直後でもセットリング現象が発生しないから、 大電流パルス I PLの立下りのタイ ミング T。 からわずかな時間が経過すれば微小電流 I s を測定することができ、 COMS型 I Cの静止時に流れるリーク電流を測定して被試験 I Cの良否を判定 する I C試験装置に利用することにより高速試験が可能となる利点が得られる。 なお、 電流センサ 20の検出感度は電界印加電極 45， 46， 4 7の電極長 L に比例し、 電極相互の間隙に反比例するので電極間隙を狭く、 電極長 Lを長く採 ることによつて所望の感度を得ることができる。 また必要に応じて光源 5 1の発 光強度を強めることによつても検出感度を高めることができる。 In other words, if the value of the current to be measured IM is large, the emission intensity is P. ut reaches 0 The number of times of counting, the Ρ ουτ P i n = 1 of the final value, by measuring a value between P OUT ZP in = 0, it is possible to obtain the current value. Also even for very small current I s, as possible out to obtain a current value by a value between P OUT ZP in = a l, POUT / P IN = 0 . Therefore, the detection circuit 54 detects no matter what current is given to the current-to-voltage converter 30, while only a voltage between P OUT / P in = l and P OUT / P in = 0 is input. The circuit 54 can measure a voltage corresponding to a current value without saturation even without a limiter circuit. As a result, since the settling phenomenon even after a large current pulse I PL as shown in FIG. 4 is not generated, timing T. falling of a large current pulse I PL After a short period of time, the small current I s can be measured, and the high-speed test can be performed by measuring the leakage current flowing when the COMS type IC is at rest and using the IC test equipment to judge the quality of the IC under test. Is obtained. Note that the detection sensitivity of the current sensor 20 is proportional to the electrode length L of the electric field application electrodes 45, 46, and 47, and is inversely proportional to the gap between the electrodes, so that the electrode gap is narrow and the electrode length L is long. Desired sensitivity can be obtained. The detection sensitivity can also be increased by increasing the light emission intensity of the light source 51 as necessary.
更に、 図 5に示すように 2本の光導波路 44 Aと 44 Bに電圧 V Sを差動的に 印加することにより検出感度を倍加することができる。  Further, as shown in FIG. 5, the detection sensitivity can be doubled by differentially applying the voltage VS to the two optical waveguides 44A and 44B.
図 6はこの発明による電流測定方法の他の実施例を示す。 この実施例では光源 5 1側に、 光スィッチ 55を介挿し、 この光スィッチ 55にスイッチングパルス SWPを与えることにより、 光変調器 40に入力する光を測定のタイミングに合 わせて光パルス 56として入力し、 その光パルス 56の透過量を光検出器 53に よって検出することにより目的とするタイミング位置の被測定値を精度よく測定 することができる。 FIG. 6 shows another embodiment of the current measuring method according to the present invention. The light source 5 1 side in this embodiment, interposed light switch 55, by giving the switching pulse SWP to the optical switch 55, the light input to the optical modulator 40 to the timing of the measurement to fit as light pulses 56 By inputting and detecting the transmission amount of the light pulse 56 by the photodetector 53, the measured value at the target timing position can be accurately measured.
つまり、 測定すべきタイミング位置は光パルス 56の印加タイミングによって 決定される。 従って、 光パルス 56のパルス幅を狭く制限することにより、 その 測定タイミングの位置を分解能よく設定することができる。 光検出器 53側では 透過した光の総量を測定すればよいから、 検出回路 54の出力側に積分回路 5 7 を設け、 この積分回路 57に積分される積分電圧を測定すれば、 被測定電流 I M の値を測定することができる。 よって、 光検出器 53側では応答速度に高速性は 要求されない。 従って、 光スィッチ 5 5だけに高速動作を要求する他に、 他の素 子及び回路は高速性を要求することなく、 測定タイミングの分解能が高い測定を 実現することができる。 That is, the timing position to be measured is determined by the application timing of the light pulse 56. Therefore, by restricting the pulse width of the light pulse 56 to be narrow, the position of the measurement timing can be set with high resolution. The photodetector 53 only needs to measure the total amount of transmitted light. Therefore, an integrating circuit 57 is provided on the output side of the detecting circuit 54, and by measuring the integrated voltage integrated in the integrating circuit 57, the measured current The value of IM can be measured. Therefore, the response speed of the photodetector 53 is Not required. Therefore, in addition to requiring high-speed operation only for the optical switch 55, other elements and circuits can achieve high-resolution measurement timing resolution without requiring high-speed operation.
図 7は電流センサ 2 ()の具体的実施構造の一例を示す。 基板 2 1としては、 例 えばセラミックのような絶縁材で構成することができ、 この基板 2 1の一方の面 に電流一電圧変換器 3 0を構成する抵抗膜 3 1を被着形成すると共に、 この抵抗 膜 3 1の両端に電極 3 2， 3 3を被着形成し、 この電極 3 2， 3 3の端部を電流 測定端子 3 4， 3 5に電気的に接続して電流一電圧変換器 3 0を構成する。 基板 2 1は一辺が 1 O mm X 1 0 mm程度の形状で構成することができる。 電流一 電圧変換器 3 0が形成された面の空白の部分に光変調器 4 0を構成する誘電体基 板 4 1を搭載して電流センサ 2 0を構成することができる。 電極 3 2と 3 3のそ れぞれと光変調器 4 0を構成する電界印加電極 4 5 , 4 6との間は、 例えばボン ディングワイヤ B F等によって電気的に接続することができる。 電流センサ 2 0 を図 7に示したようにカード化することにより以下に説明する I C試験装置に適 用する場合に有効である。  FIG. 7 shows an example of a specific implementation structure of the current sensor 2 (). The substrate 21 can be made of, for example, an insulating material such as a ceramic. A resistive film 31 constituting the current-to-voltage converter 30 is formed on one surface of the substrate 21 while forming the same. The electrodes 32, 33 are formed on both ends of the resistive film 31. The ends of the electrodes 32, 33 are electrically connected to the current measuring terminals 34, 35, respectively. The converter 30 is constituted. The substrate 21 can be formed in a shape having a side of about 10 mm × 10 mm. The current sensor 20 can be configured by mounting the dielectric substrate 41 configuring the optical modulator 40 on a blank portion of the surface on which the current-to-voltage converter 30 is formed. Each of the electrodes 32 and 33 and the electric field applying electrodes 45 and 46 constituting the optical modulator 40 can be electrically connected by, for example, a bonding wire BF or the like. By forming the current sensor 20 into a card as shown in FIG. 7, it is effective when applied to an IC test device described below.
図 8はこの発明による電流測定方法と電流センサ 2 0を応用した I C試験装置 の一例を示す。 この実施例では図 1乃至図 6を用いて説明した電流センサ 2 0を I C試験装置に適用した場合を示す。 被試験 I C 1 1の電源端子 T VD D に直流電 源 1 2から電源電圧 V D Dを与え、 共通端子 T v s s は共通電位点に接続する。 この 電源供給路上にこの発明による電流センサ 2 0を構成する電流一電圧変換器 3 0 を直列に挿入し、 被試験 I C 1 1の電源端子 T VD D に流れる電流 I DDを電流—電 圧変換器 3 0に流し、 電流一電圧変換器 3 0に電流 I DDの値に対応した電圧 V S を発生させる。 この電圧 V Sを電界印加電極 4 5と 4 6との間に印加し、 光変調 器 4 0において被試験 I C 1 1の電源端子 T VDD に流れる電流値に対応した光変 調を与える。 FIG. 8 shows an example of an IC test apparatus to which the current measuring method and the current sensor 20 according to the present invention are applied. This embodiment shows a case where the current sensor 20 described with reference to FIGS. 1 to 6 is applied to an IC test apparatus. Given supply voltage V DD from the DC power source 1 2 to the power supply terminal T VD D of the test IC 1 1, the common terminal T vss is connected to the common potential point. The current first voltage converter 3 0 constituting the current sensor 2 0 according to the invention in the power supply path inserted in series, a current a current I DD flowing to the power supply terminal T VD D of the test IC 1 1 - voltage conversion The current-to-voltage converter 30 generates a voltage VS corresponding to the value of the current I DD . This voltage VS is applied between the electric field application electrodes 45 and 46, and the optical modulator 40 gives optical modulation corresponding to the current flowing through the power supply terminal T VDD of the IC 11 under test.
光検出器 5 3は出力用光導波路 2 3から出射される光の出射強度を電気信号に 変換し、 検出回路 5 4から電圧信号として出力する。 検出回路 5 4から出力され る電圧信号をサンプルホールド回路 1 4で被試験 I C I 1が静止状態にあるタイ ミングで例えばパターン発生器 5 8から出力されるサンプリングパルス T G Pに よってサンプルホールドし、 そのサンプルホールドした電圧値を A D変換手段 1 5で A D変換し、 その A D変換したディジタル信号を演算処理装置 1 6に入力し て、 そのディジタル値が所望の電圧範囲に入っているか否かを判定して被試験 I C 1 1の良否を判定する。 The photodetector 53 converts the emission intensity of the light emitted from the output optical waveguide 23 into an electric signal, and outputs the electric signal from the detection circuit 54 as a voltage signal. The voltage signal output from the detection circuit 54 is converted to a sampling pulse TGP output from the pattern generator 58 by the sample and hold circuit 14 at the timing when the ICI 1 under test is stationary. Therefore, sample and hold, the sampled and held voltage value is subjected to AD conversion by the AD conversion means 15, and the AD converted digital signal is input to the arithmetic processing unit 16 so that the digital value falls within a desired voltage range. It is determined whether or not the IC under test 11 is good or not.
パターン発生器 5 8は被試験 I C 1 1に駆動信号を与え、 被試験 I C 1 1の状 態を 1ステップずつ転換させ、 各ステップの静止状態における電源電流 I D Dの値 が所定の範囲に入っているか否かを試験する。 The pattern generator 58 supplies a drive signal to the IC under test 11 to convert the state of the IC under test 11 one step at a time, and the value of the power supply current I DD in the quiescent state of each step falls within a predetermined range. Test whether it is
サンプルホールド回路 1 4は図 9に示すように被試験 I C 1 1に流れる大電流 パルス I P Lの立下りのタイミングからわずか経過したタイミング T S Tでサンプル ホールド回路 1 4にサンプリングパルス T G Pを与え、 被試験 I C 1 1が 1ステ ップずつ反転動作した後の各静止状態における微小電流 I s を各ステップごとに 測定し、 演算処理装置 1 6で予め設定した設定値と比較し良否を判定する。 図 8に示したように、 この発明による電流センサ 2 0を I C試験装置に用いる ことにより、 被試験 I C 1 1が間欠的に大電流パルス I P Lを消費しても、 電流セ ンサ 2 0及び検出回路 5 4を飽和させることなく動作させることができる。 従つ て、 図 8に示した実施例によれば、 大電流パルス I P Lの直後のタイミング T S Tで サンプルホールド回路 1 4を動作させサンプルホールドすると共に、 A D変換器 1 4で A D変換して演算処理装置 1 6で被試験 I C I 1の良否を判定することが できる。 この場合、 サンプルホールド回路 1 4は大電流パルス I P Lの立下りのタ ィミングからわずかな時間 T S Tの直後にサンプルホールドすることができ、 短時 間に測定を完了することができる。 よって被試験 I C 1 1の反転動作の周期 T E Sを短くできるから、 被試験 I C 1 1の全ての状態を試験しても試験に要する時 間を短くできる実益を得ることができる。 また、 図 8に示した実施例によれば、 入力用光導波路 2 2と出力用光導波路 2 3を長く延長しても、 外来電磁波からの 影響を受けることがないから、 光検出器 5 3を被試験 I C 1 1から大きく離して 配置しても測定精度が低下することがない。 従って光検出器 5 3を試験装置本体 に格納して I C試験装置を構成しても試験精度が低下することはない。 The sample-and-hold circuit 14 applies a sampling pulse TGP to the sample-and-hold circuit 14 at a timing TST slightly after the falling timing of the large current pulse IPL flowing through the IC under test 11 as shown in FIG. the minute current I s in each still state after the test IC 1 1 is inverted operation one stearyl-up was measured at each step, it is determined compared to quality with a set value previously set by the processor 1 6. As shown in FIG. 8, by using the current sensor 2 0 according to the present invention the IC tester, be tested IC 1 1 consumes intermittent large-current pulse I PL, current sensor 2 0 and The detection circuit 54 can be operated without being saturated.従Tsu Te, according to the embodiment shown in FIG. 8, the sample and hold by operating the sample-and-hold circuit 1 4 at timing T ST immediately after the large current pulse I PL, and AD conversion by the AD converter 1 4 The acceptability of the ICI 1 under test can be determined by the arithmetic processing unit 16. In this case, the sample and hold circuit 1 4 can be sampled and held by the immediately following slight time T ST since the fall of the data Imingu high current pulses I PL, it is possible to complete the measurement in a short time. Therefore, since the cycle TES of the inversion operation of the IC under test 11 can be shortened, even if all the states of the IC under test 11 are tested, the benefit of shortening the time required for the test can be obtained. Further, according to the embodiment shown in FIG. 8, even if the input optical waveguide 22 and the output optical waveguide 23 are extended long, they are not affected by extraneous electromagnetic waves. The measurement accuracy does not decrease even if the IC is placed far away from the IC under test 11. Therefore, even if the photodetector 53 is stored in the test apparatus main body to constitute an IC test apparatus, the test accuracy does not decrease.
図 1 0は光源 5 1 と光変調器 4 0との間を結ぶ入力用光導波路 2 2に光スィッ チ 5 5を接続し、 この光スィツチ 5 5を測定すべきタイミングに同期させてオン 、 オフ動作させることにより、 測定すべきタイミングに同期して光パルス 5 6 ( 図 1 1 B参照） を光変調器 4 0に印加する構成とした場合を示す。 In Fig. 10, an optical switch 55 is connected to an input optical waveguide 22 connecting the light source 51 and the optical modulator 40, and the optical switch 55 is turned on in synchronization with the timing to be measured. A case is shown in which the optical pulse 56 (see FIG. 11B) is applied to the optical modulator 40 in synchronization with the timing to be measured by turning off.
この場合には、 検出回路 5 4の出力側に積分回路 5 7を設け、 この積分回路 5 7により光検出器 5 3で受光する光の総量を積分させ、 その積分電圧 I N T V ( 図 1 1 C参照） をサンプルホールド回路 1 4でサンプリングパルス T G P (図 1 1 D ) に同期してサンプルホールドさせ、 そのサンプルホールド電圧を A D変換 器 1 5で A D変換して演算処理装置 1 6に入力させるように構成することができ る。 積分回路 5 7の積分電圧 I N T Vはサンプリング終了毎に図 1 1 Eに示すリ セットパルス R S Pによってリセットされる。  In this case, an integrating circuit 57 is provided on the output side of the detecting circuit 54, and the integrating circuit 57 integrates the total amount of light received by the photodetector 53. The integrated voltage INTV (FIG. 11C) ) Is sampled and held by the sample-and-hold circuit 14 in synchronization with the sampling pulse TGP (Fig. 11D), and the sample-and-hold voltage is AD-converted by the AD converter 15 and input to the arithmetic processing unit 16. Can be configured. The integration voltage I NTV of the integration circuit 57 is reset by a reset pulse R SP shown in FIG. 11E every time sampling is completed.
このように、 光パルス 5 6を光変調器 4 0に入力する構成とした場合には、 先 に図 6で説明したように測定タイミングは光パルス 5 6の印加タイミングによつ て決定される。 従って光パルス 5 6のパルス幅を狭くすることにより、 測定タイ ミングの時間軸方向の分解能を高く採ることができる利点が得られる。 更に、 こ の実施例によれば光検出器 5 3， 検出回路 5 4， サンプルホールド回路 1 4は光 検出器 5 3が受光する光の総量に相当する値を求めればよいから、 高速応答性は 要求されない。 従って、 高速動作しない安価な素子によって構成することができ る利点も得られる。  As described above, when the optical pulse 56 is input to the optical modulator 40, the measurement timing is determined by the application timing of the optical pulse 56 as described above with reference to FIG. . Therefore, by reducing the pulse width of the optical pulse 56, there is obtained an advantage that the resolution in the time axis direction of the measurement timing can be increased. Furthermore, according to this embodiment, since the photodetector 53, the detection circuit 54, and the sample hold circuit 14 need only obtain a value corresponding to the total amount of light received by the photodetector 53, high-speed response can be achieved. Is not required. Therefore, there is also obtained an advantage that it can be constituted by an inexpensive element that does not operate at high speed.
図 1 2は電源端子 T VD D を複数具備した構造の I Cを試験する場合の実施例を 示す。 図 1 2ではパターン発生器 5 8及び光源 5 1の駆動回路、 電流センサ 2 0 の内部構造を省略して示している。 FIG. 12 shows an embodiment for testing an IC having a plurality of power supply terminals TVDD . In FIG. 12, the drive circuits of the pattern generator 58 and the light source 51 and the internal structure of the current sensor 20 are omitted.
この実施例では被試験 I C 1 1の電源端子 T VD D の数に対応した数の電流セン サ 2 0を用意する。 つまり、 この実施例では 4個の電流センサ 2 0を用意し、 各 電流センサ 2 0の電流一電圧変換器 3 0の一端を直流電源 1 2の正極電圧端子に 接続すると共に、 電流一電圧変換器 3 0の他端側を各電源端子 T VDD に接続する 。 これと共に、 光変調器 4 0に通じる入力用光導波路 2 2と出力用光導波路 2 3 を直列接続し、 その直列接続した光導波路の一端側に光源 5 1を光結合させ、 他 端側に光検出器 5 3を光結合させる。 In this embodiment, a number of current sensors 20 corresponding to the number of power supply terminals T VDD of the IC under test 11 are prepared. That is, in this embodiment, four current sensors 20 are prepared, one end of the current-to-voltage converter 30 of each current sensor 20 is connected to the positive voltage terminal of the DC power supply 12, and the current-to-voltage conversion is performed. Connect the other end of the unit 30 to each power supply terminal T VDD . At the same time, the input optical waveguide 22 and the output optical waveguide 23 leading to the optical modulator 40 are connected in series, a light source 51 is optically coupled to one end of the serially connected optical waveguide, and the other end is connected to the other end. The photodetector 53 is optically coupled.
このように構成することにより、 光検出器 5 3に入射される光は 4個の電流セ ンサ 2 0において受けた光変調量の総和に対応した光量となり、 その光量は各電 源端子 T VD D に流れる電流の総和の値に対応する。 従って、 光学系において加算 手段が構成され、 1個の光源 5 1 と 1個の光検出器 5 3と、 1個の検出回路 5 4 によって複数の電源端子 T VD D を流れる電流の総和を測定することができ、 各電 源端子 T VD D に流れる電流の総和が正常値の範囲に入っているか否かを判定させ ることができる。 With this configuration, the light incident on the photodetector 53 has a light amount corresponding to the sum of the light modulation amounts received by the four current sensors 20, and the light amount is equal to each light It corresponds to the total value of the current flowing through the source terminal TVDD . Therefore, an addition means is configured in the optical system, and the total sum of the currents flowing through the plurality of power supply terminals TVDD is measured by one light source 51, one photodetector 53, and one detection circuit 54. it can be can Rukoto is determined whether the sum of the currents flowing through the power supply terminal T VD D is in the range of normal values.
図 1 3は図 1 2の変形実施例を示す。 この実施例ではウェファ 6 1に形成した I Cチップ 6 2の電極部分にプローブ 6 3を接触させ、 チップの状態にある I C を直接試験する場合の実施例を示す。  FIG. 13 shows a modified embodiment of FIG. This embodiment shows an embodiment in which a probe 63 is brought into contact with an electrode portion of an IC chip 62 formed on a wafer 61 to directly test the IC in a chip state.
一般的にはリング形状のプローブ力一ド 6 4にプローブ 6 3が中心方向に向か つて突出して支持され、 各プローブ 6 3の先端をウェファ 6 1に形成したチップ の各電極部分に接触させ、 各プローブ 6 3を通じて電源電流の供給及び駆動信号 の供給を実行し、 電源電流の測定は電源 1 2側において行っている。  In general, the probe 63 is supported by projecting toward the center of the ring-shaped probe force probe 64, and the tip of each probe 63 is brought into contact with each electrode portion of the chip formed on the wafer 61. The power supply current and the drive signal are supplied through each probe 63, and the power supply current is measured on the power supply 12 side.
これに対し、 この発明ではプローブ 6 3の途中に電流センサ 2 0を搭載させ、 この電流センサ 2 0で光変調された光信号を光導波路 2 3を通じて伝送し、 光検 出器 5 3に受光させればよい。  On the other hand, in the present invention, the current sensor 20 is mounted in the middle of the probe 63, and the optical signal optically modulated by the current sensor 20 is transmitted through the optical waveguide 23 and received by the optical detector 53. It should be done.
この場合も、 光導波路 2 3の延長距離を長く採っても外来電磁波等によって乱 されることがないから、 プローブカード 6 4と光源 5 1及び光検出器 5 3， 検出 回路 5 4， サンプルホールド回路 1 4等を被試験 I C 1 1の設置位置 （テストへ ッド） から離れて配置した測定器本体に収納しても外来電磁波等の影響を受ける ことなく、 チップ状態にある I Cの試験を行うことができる。  Also in this case, the probe card 64, the light source 51, the light detector 53, the detection circuit 53, the detection circuit 54, and the sample hold are not disturbed by extraneous electromagnetic waves even if the extension distance of the optical waveguide 23 is long. Even if the circuit 14 etc. is housed in a measuring instrument placed away from the installation position (test head) of the IC under test 11, the IC in the chip state can be tested without being affected by external electromagnetic waves. It can be carried out.
図 1 4は電流測定方法の変形例を示す。 この実施例では光源 5 1の発光量のド リフトによる影響及び光検出器 5 3のオフセット電圧の除去等を目的とした実施 例を示す。  FIG. 14 shows a modification of the current measuring method. In this embodiment, an embodiment aiming at removing the influence of the drift of the light emission amount of the light source 51 and removing the offset voltage of the photodetector 53 will be described.
この実施例では光源 5 1側の入力用光導波路 2 2に光分岐器 6 5を接続し、 こ の光分岐器 6 5で分岐した光の一方を光変調器 4 0に入力すると共に、 他方の光 を光変調器 4 0に隣接して形成した補正用光導波路 6 6に通し、 その出射光を第 In this embodiment, an optical splitter 65 is connected to the input optical waveguide 22 on the side of the light source 51, and one of the lights split by the optical splitter 65 is input to the optical modulator 40, and the other. Is passed through a correction optical waveguide 66 formed adjacent to the optical modulator 40, and the emitted light is
2の光検出器 5 3 Bで受光し、 この受光量に対応した電圧信号を光源 5 1の駆動 回路 5 2に帰還させ、 光源 5 1の発光強度を安定化制御すると共に、 光検出器 5The photodetector 5 3B receives light, and a voltage signal corresponding to the amount of received light is fed back to the drive circuit 52 of the light source 51 to stabilize and control the light emission intensity of the light source 51.
3 Aと 5 3 Bで受光した光量に対応した電圧信号を減算回路 6 7で減算すること により、 光検出器 5 3 Aと検出回路 5 4 Aで発生するオフセット電圧を除去する ことができる。 Subtraction circuit 67 subtracts the voltage signal corresponding to the amount of light received at 3 A and 53 B Thus, the offset voltage generated in the photodetector 53 A and the detection circuit 54 A can be removed.
従って、 減算回路 6 7でオフセット電圧を除去した電圧信号をサンプルホール ド回路 1 4， A D変換器 1 5を通じて演算処理装置 1 6に入力することにより、 オフセット電圧を除去した測定値を得ることができる。 また、 この実施例によれ ば光分岐器 6 5で分岐した光を光変調器 4 0に隣接して形成した補正用光導波路 6 6を通過させる構成としたから、 補正用光導波路 6 6を通過する光は光変調器 4 0を通過する光と同じ温度の影響を受けるため、 誘電体基板 4 1の温度変動に 伴う光変調器 4 0の光変調特性の変動分も除去できる利点が得られる。 産業上の利用可能性  Therefore, by inputting the voltage signal from which the offset voltage has been removed by the subtraction circuit 67 to the arithmetic processing unit 16 through the sample hold circuit 14 and the AD converter 15, a measured value from which the offset voltage has been removed can be obtained. it can. Further, according to this embodiment, since the light branched by the optical branching device 65 is made to pass through the optical waveguide for correction 66 formed adjacent to the optical modulator 40, the optical waveguide for correction 66 is used. Since the passing light is affected by the same temperature as the light passing through the optical modulator 40, there is an advantage that the fluctuation of the optical modulation characteristic of the optical modulator 40 due to the temperature fluctuation of the dielectric substrate 41 can be removed. Can be Industrial applicability
以上説明したように、 この発明による電流測定方法によれば過大電流に対して 検出される電気信号は光源 5 1の発光強度 P i nと光検出器 5 3の受光強度 P OU T の比が P OU T / P i n = 1の状態と、 P OU T / P i n = 0の状態を往復するだけであ るから、 検出回路側にリミット回路を必要としない。 よって過大電流が流れた直 後に電流が 0付近に戻ってもセットリング現象が発生することなく、 直ちに目標 値に安定する。 従って、 大電流パルス I P Lと微小電流 I s が流れる現象が高速で 繰り返されても、 大電流パルス I P Lの直後でも安定して微小電流 I s を正確に測 定することができる。 As described above, the ratio of the electrical signal detected against overcurrent according to the current measuring method according to the invention the light source 5 1 of the emission intensity P i n and the received light intensity of the light detector 5 3 P OU T is the state of P OU T / P in = 1 , since Ru der only reciprocates the state of P OU T / P in = 0 , do not require limit circuit to the detection circuit side. Therefore, even if the current returns to around 0 immediately after the excessive current flows, the settling phenomenon does not occur and the target value is immediately stabilized. Therefore, even phenomena large current pulse I PL and the minute current I s flows is repeated at a high speed, it is possible to measure accurately the stable small current I s even immediately after the large current pulse I PL.
この結果、 この発明による電流測定方法は C M O S型構造の I Cの電源端子に 流れるリーク電流を測定する場合に適し、 リーク電流が規定の範囲に入っている か否かにより I Cの良否を判定する I C試験装置に適用して好適である。  As a result, the current measuring method according to the present invention is suitable for measuring a leak current flowing through a power supply terminal of a CMOS type IC, and determines whether the IC is good or not based on whether or not the leak current is within a specified range. It is suitable for application to a test apparatus.
更に、 この発明では電流センサ 2 0で検出した電流測定値は出力用光導波路 2 3を通じて伝送されるから、 出力用光導波路 2 3において各種の電気的障害を受 けるおそれはない。 従って、 テス トヘッドと測定器本体との間を大きく離しても 、 微小電流の測定精度を高精度の状態に維持することができる利点も得られる。  Further, according to the present invention, the measured current value detected by the current sensor 20 is transmitted through the output optical waveguide 23, and therefore, there is no possibility that the output optical waveguide 23 will be subjected to various electrical disturbances. Therefore, even if the distance between the test head and the measuring instrument body is greatly increased, there is an advantage that the measurement accuracy of the minute current can be maintained at a high accuracy state.

Claims

請求の範囲 The scope of the claims
1 . 被測定電流を電流一電圧変換器によって電圧信号に変換し、 この電圧信号に よつて光変調器を透過する光に位相変調を与え、 この位相変調された光と位相変 調されない光を干渉させて干渉光を得、 この干渉光の強度を電気信号に変換して 上記被測定電流の値を特定することを特徴とする電流測定方法。 1. The current to be measured is converted into a voltage signal by a current-to-voltage converter, and the light transmitted through the optical modulator is phase-modulated by the voltage signal, and the phase-modulated light and the light that is not phase-modulated are converted. A current measurement method comprising: obtaining interference light by causing interference; converting the intensity of the interference light into an electric signal to specify the value of the measured current.
2 . 請求項 1記載の電流測定方法において、 上記光変調器に与える光を測定タイ ミングに合致して発生した光パルスとし、 この光パルスの透過光量を積算して被 測定電流値を求めることを特徴とする電流測定方法。  2. The current measuring method according to claim 1, wherein the light to be given to the optical modulator is an optical pulse generated in accordance with a measurement timing, and the transmitted light amount of the optical pulse is integrated to obtain a measured current value. A current measuring method characterized by the above-mentioned.
3 . 誘電体基板に光分岐部、 光合波部及びこれら光分岐部と光合波部との間に形 成された 2本の光導波路、 これら 2本の光導波路の一方と他方のそれぞれを挟ん で形成した 2組の電界印加電極対とによつて構成した分岐干渉型の光変調器と、 被測定電流を電圧信号に変換する電流一電圧変換器と、 上記光変調器と電流電圧 変換器を支持する基板と、 上記光変調器に光を与える入力用光導波路と、 上記光 変調器から出射される干渉光を取り出す出力用光導波路とを具備して構成したこ とを特徴とする電流センサ。  3. An optical branch, an optical multiplex, and two optical waveguides formed between the optical multiplex and the optical multiplex on the dielectric substrate. One and the other of the two optical waveguides are sandwiched between them. A branching interference type optical modulator composed of two electric field applying electrode pairs formed by the above, a current-to-voltage converter for converting a current to be measured into a voltage signal, the above-mentioned optical modulator and a current-to-voltage converter A substrate for supporting the optical modulator, an input optical waveguide for supplying light to the optical modulator, and an output optical waveguide for extracting interference light emitted from the optical modulator. Sensor.
4 . 請求項 3記載の電流センサにおいて、 上記光変調器を形成した誘電体基板に 上記光変調器に隣接して補正用光導波路を設け、 この補正用光導波路を透過する 光で得られる電気信号によって、 上記光変調器を透過する光で得られる電気信号 を補正することを可能とした電流センサ。  4. The current sensor according to claim 3, wherein a correction optical waveguide is provided adjacent to the optical modulator on the dielectric substrate on which the optical modulator is formed, and electricity obtained by light transmitted through the correction optical waveguide is provided. A current sensor capable of correcting an electric signal obtained by light transmitted through the optical modulator by a signal.
5 . 被試験 I Cの電源端子に流れる電流を測定し、 上記電源端子に流れる電流が 規定値より大きいか否かによって被試験 I Cの良否を判定する I C試験装置にお いて、  5. Measure the current flowing in the power supply terminal of the IC under test, and judge the quality of the IC under test based on whether the current flowing in the power supply terminal is greater than the specified value.
上記電源端子に流れる電流を上記請求項 3で規定した電流センサの電流一電圧 変換器に供給し、 上記電流センサの出力用光導波路を通じて出射される干渉光の 出射強度を光検出器によつて電気信号に変換し、 この電気信号の大小を設定値と 比較して上記被試験 I Cの良否を判定する構成としたことを特徴とする I C試験  The current flowing through the power supply terminal is supplied to the current-to-voltage converter of the current sensor defined in claim 3, and the emission intensity of the interference light emitted through the output optical waveguide of the current sensor is detected by a photodetector. An IC test characterized by converting the electric signal into an electric signal and comparing the magnitude of the electric signal with a set value to judge the quality of the IC under test.
6 . 被試験 I Cの電源端子に流れる電流を測定し、 上記電源端子に流れる電流が 規定値より大きいか否かによって被試験 I Cの良否を判定する I C試験装置にお いて、 6. Measure the current flowing through the power supply terminal of the IC under test, In an IC tester that determines the quality of an IC under test based on whether it is greater than a specified value,
上記電源端子に流れる電流を上記請求項 4で規定した電流センサの電圧一電流 変換器に供給し、 上記電流センサの出力用光導波路を通じて出射される干渉光の 出力強度を第 1光検出器によって第 1電気信号に変換すると共に、 上記電流セン サに設けた補正用光導波路を透過した光の強度を第 2光検出器で第 2電気信号に 変換し、 上記第 1電気信号と第 2電気信号を演算処理して第 1電気信号を補正し 、 第 1電気信号の大小を設定値と比較して上記被試験 I Cの良否を判定する構成 としたことを特徴とする I C試験装置。  The current flowing through the power supply terminal is supplied to the voltage-current converter of the current sensor defined in claim 4, and the output intensity of the interference light emitted through the output optical waveguide of the current sensor is determined by the first photodetector. In addition to the conversion into the first electric signal, the intensity of the light transmitted through the correction optical waveguide provided in the current sensor is converted into a second electric signal by the second photodetector, and the first electric signal and the second electric signal are converted. An IC test apparatus characterized in that the first electric signal is corrected by performing arithmetic processing on the signal, and the magnitude of the first electric signal is compared with a set value to determine the quality of the IC under test.
7 . 請求項 5または 6記載の I C試験装置の何れかにおいて、 被試験 I Cは大電 流を消費する状態と、 微小電流を消費する状態とを高速で繰り返し、 電流の測定 は主に微小電流を測定対象とすることを特徴とする I C試験装置。  7. The IC test apparatus according to claim 5, wherein the IC under test repeatedly consumes a large current and consumes a small current at a high speed, and the measurement of the current is mainly performed by the small current. An IC test device characterized by measuring a target.
8 . 請求項 5または 6記載の I C試験装置の何れかにおいて、 被試験 I Cが複数 の電源端子を具備する場合に被試験 I Cの電源端子ごとに電流センサを設け、 各 電源端子ごとに電流を測定する構造としたことを特徴とする I C試験装置。  8. In the IC test apparatus according to claim 5 or 6, when the IC under test has a plurality of power supply terminals, a current sensor is provided for each power supply terminal of the IC under test, and a current is supplied to each power supply terminal. An IC test device characterized by a structure for measuring.
9 . 請求項 5または 6記載の I C試験装置の何れかにおいて、 被試験 I Cが複数 の電源端子を具備する場合に、 被試験 I Cの電源端子ごとに電流センサを設ける と共に、 上記電流センサの各光導波路を光学的に直列接続し、 上記複数の電源端 子を流れる電流の和を光の変調量によって求める構造としたことを特徴とする I C試験装置。  9. In the IC test apparatus according to claim 5 or 6, when the IC under test has a plurality of power terminals, a current sensor is provided for each power terminal of the IC under test, and each of the current sensors is provided. An IC test apparatus characterized in that optical waveguides are optically connected in series, and the sum of the currents flowing through the plurality of power supply terminals is determined by the amount of light modulation.
1 0. 請求項 5または 6記載の I C試験装置の何れかにおいて、 上記光変調器に 測定タイミングごとに光パルスを与え、 この光パルスの変調量を光検出器で検出 し、 各測定タイミングごとに電流値を測定する構造としたことを特徴とする I c  10. The IC test apparatus according to claim 5, wherein an optical pulse is applied to the optical modulator at each measurement timing, and a modulation amount of the optical pulse is detected by a photodetector. I c characterized by a structure that measures the current value
1 1. 請求項 5または 6記載の I C試験装置の何れかにおいて、 上記電流センサ をプローブカードから突出して支持した測定用プローブに搭載し、 半導体ゥエフ ァに形成された I Cチップの端子部分に上記測定用プローブの先端を接触させて I Cチップを試験する構造とした I C試験装置。 1 1. The IC testing apparatus according to claim 5, wherein the current sensor is mounted on a measurement probe that is supported by projecting from a probe card, and the current sensor is mounted on a terminal portion of an IC chip formed on a semiconductor device. An IC testing device with a structure that tests the IC chip by bringing the tip of the measurement probe into contact.
1 2. 請求項 6記載の I C試験装置において、 上記光変調器に隣接して設けた補 正用光導波路を透過した光で得られる電気信号を光源駆動回路に与え、 光源の発 光強度を安定化して被試験 I Cに流れる電流を測定する構造としたことを特徴と する I c試験装置。 1 2. The IC test apparatus according to claim 6, wherein a supplementary device is provided adjacent to the optical modulator. An Ic test device characterized by a structure in which an electric signal obtained by light transmitted through the primary optical waveguide is supplied to a light source drive circuit, the light emission intensity of the light source is stabilized, and the current flowing through the IC under test is measured. .
PCT/JP1998/000479 1998-02-05 1998-02-05 Current measuring method, current sensor, and ic tester using the same current sensor WO1999040446A1 (en)

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DE19882306T DE19882306T1 (en) 1998-02-05 1998-02-05 Current measurement method, current sensor and IC tester working using the current sensor
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KR1019997009086A KR20010006008A (en) 1998-02-05 1998-02-05 Current measuring method, current sensor, and ic tester using the same current sensor
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104569544A (en) * 2013-10-07 2015-04-29 姚晓天 Faraday current and temperature sensors
CN109709384A (en) * 2018-12-13 2019-05-03 北京航天时代光电科技有限公司 A kind of current sensor using integrated light channel structure
KR20220043433A (en) * 2020-09-29 2022-04-05 엘아이지넥스원 주식회사 APPARATUS AND METHOD FOR DETECTING A MALFUNTION OF FET(Field Effect Transistor)
US11333688B2 (en) 2016-02-16 2022-05-17 Xiaotian Steve Yao Reflective current and magnetic sensors based on optical sensing with integrated temperature sensing

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101958263B (en) * 2009-07-14 2013-01-02 致茂电子(苏州)有限公司 Semiconductor grain point measurement machine test method and semiconductor grain point measurement machine
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CN115856396B (en) * 2022-12-09 2023-08-29 珠海多创科技有限公司 Sensing probe module, non-contact voltage measurement circuit, non-contact voltage measurement method and electronic equipment
KR102535830B1 (en) * 2023-04-11 2023-05-26 주식회사 수산이앤에스 A system for testing optical converter

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50120980A (en) * 1974-03-11 1975-09-22
JPS59155764A (en) * 1983-02-24 1984-09-04 Yokogawa Hokushin Electric Corp Photovoltometer
JPS59218915A (en) * 1983-05-27 1984-12-10 Yokogawa Hokushin Electric Corp Light guide type sensor
JPS6237940A (en) * 1985-08-12 1987-02-18 Nippon Denshi Zairyo Kk Probe card
JPS6246268A (en) * 1985-08-23 1987-02-28 Nippon Denshi Zairyo Kk Probe card
JPS6478169A (en) * 1987-09-19 1989-03-23 Yaskawa Denki Seisakusho Kk Photosensor device
JPH04172260A (en) * 1990-11-05 1992-06-19 Toyota Central Res & Dev Lab Inc Apparatus for measuring strength of electromagnetic field
JPH0574911A (en) * 1991-09-13 1993-03-26 Nippon Telegr & Teleph Corp <Ntt> Tester and testing method for integrated circuit
JPH0989961A (en) * 1995-09-26 1997-04-04 Tokin Corp Electric field detecting device

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50120980A (en) * 1974-03-11 1975-09-22
JPS59155764A (en) * 1983-02-24 1984-09-04 Yokogawa Hokushin Electric Corp Photovoltometer
JPS59218915A (en) * 1983-05-27 1984-12-10 Yokogawa Hokushin Electric Corp Light guide type sensor
JPS6237940A (en) * 1985-08-12 1987-02-18 Nippon Denshi Zairyo Kk Probe card
JPS6246268A (en) * 1985-08-23 1987-02-28 Nippon Denshi Zairyo Kk Probe card
JPS6478169A (en) * 1987-09-19 1989-03-23 Yaskawa Denki Seisakusho Kk Photosensor device
JPH04172260A (en) * 1990-11-05 1992-06-19 Toyota Central Res & Dev Lab Inc Apparatus for measuring strength of electromagnetic field
JPH0574911A (en) * 1991-09-13 1993-03-26 Nippon Telegr & Teleph Corp <Ntt> Tester and testing method for integrated circuit
JPH0989961A (en) * 1995-09-26 1997-04-04 Tokin Corp Electric field detecting device

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104569544A (en) * 2013-10-07 2015-04-29 姚晓天 Faraday current and temperature sensors
US10281342B2 (en) 2013-10-07 2019-05-07 Xiaotian Steve Yao Faraday current and temperature sensors
US11333688B2 (en) 2016-02-16 2022-05-17 Xiaotian Steve Yao Reflective current and magnetic sensors based on optical sensing with integrated temperature sensing
CN109709384A (en) * 2018-12-13 2019-05-03 北京航天时代光电科技有限公司 A kind of current sensor using integrated light channel structure
KR20220043433A (en) * 2020-09-29 2022-04-05 엘아이지넥스원 주식회사 APPARATUS AND METHOD FOR DETECTING A MALFUNTION OF FET(Field Effect Transistor)
KR102451032B1 (en) 2020-09-29 2022-10-05 엘아이지넥스원 주식회사 APPARATUS AND METHOD FOR DETECTING A MALFUNTION OF FET(Field Effect Transistor)

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DE19882306T1 (en) 2000-04-27
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