TWI461706B - Impedance measurement device - Google Patents

Description

Electrical impedance measuring device

The present invention relates to an electrical impedance measuring device.

Referring to Fig. 4, the conventional electrical impedance measuring apparatus shown in Fig. 4 can measure the electrical impedance of the first electrical resistance member Z1 among the first to third electrical resistance members Z1 to Z3 constituting the triangular circuit. The potential of the first conductive path L1 electrically connecting the first electrical resistance member Z1 and the second electrical resistance member Z2 and the potential of the second conductive path L2 electrically connected to the third electrical resistance member Z2 and the third electrical resistance member Z3 are induced. The reference potential (ground potential in the example of Fig. 4) measures the electrical impedance of the first electrical resistance member Z1. The potential of the first and second conductive paths L1 and L2 is induced to the reference potential (ground potential) in order to prevent the influence of the electrical impedance measurement of the first electrical resistance member Z1 during the electrical impedance measurement, and to prevent current from flowing to the first 2 electrical impedance component Z2.

The potential sensing circuit 11 is used to induce the potential of the first conductive path L1 to the ground potential. The potential sensing circuit 11 includes a comparator 111 and a variable power supply unit 112. The positive side input terminal of the comparator 111 is electrically connected to the first conductive path L1 via the contact pin P1, and the negative side input terminal is electrically connected to the reference potential (ground potential). The output signal output from the output terminal of the comparator 111 is given to the variable power supply unit 112 as a control signal. The variable power supply unit 112 changes the current output through the two output terminals in accordance with the output signal of the comparator 111. One of the two output terminals of the variable power supply unit 112 is electrically connected to the first conductive path L1 via the contact pin P2, and the other is electrically connected to the reference potential (ground potential). Then, when the potential of the first conductive path L1 fluctuates to the positive side or the negative side with respect to the ground potential, the comparator 111 outputs an output signal that should be varied, and the variable power supply unit 112 transmits the two output terminals based on the output signal. The current is output to offset the fluctuation of the potential of the first conductive path L1 with respect to the ground potential. Thereby, the potential of the first conductive path L1 can be frequently sensed. Ground potential.

The ground conductor 12 connected to the ground potential is electrically connected to the second conductive path L2 through the contact pin P3, and the potential of the second conductive path L2 is further induced to the ground potential.

The electric power for electrical impedance measurement is supplied from the power supply unit 13 to the first electrical resistance member Z1 through the third conductive path L3. The power supply unit 13 outputs electric power for electrical impedance measurement of the first electrical resistance member Z1 (for example, an AC current of a fixed output) via the two output terminals. One of the two output terminals is electrically connected to the third conductive path L3 through the current detecting portion 14 and the contact pin P4, and the other is connected to the ground potential. The current detecting unit 14 can detect the current value supplied from the power supply unit 13 to the first electrical resistance member Z1.

The potential difference detecting unit 15 can detect the potential difference that the power supply unit 13 supplies to the first electrical resistance member Z1 through the third conductive path L3. One of the two input terminals of the potential difference detecting portion 15 is electrically connected to the third conductive path L3 via the contact pin P5, and the other is electrically connected to the reference potential (ground potential). Thereby, the potential difference detecting unit 15 detects the potential difference applied to the first reactance member Z1 as the difference between the potential of the third conductive path L3 and the reference potential (ground potential).

Then, as described above, the potentials of the first and second conductive paths L1 and L2 are induced to the ground potential, and the power supply unit 13 transmits the alternating current to the first electrical resistance member Z1 through the third conductive path L3. The electric current and the potential difference given by the electric resistance member Z1 are detected by the current detecting unit 14 and the potential difference detecting unit 15, and the electric impedance of the first electric resistance member Z1 can be calculated based on the detection result.

Further, a conventional technique can be exemplified by Patent Document 1 below.

[Practical Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Unexamined Publication No. Sho 61-46474

However, in the above-described conventional technique of FIG. 4, the ground lead 12 electrically connected to the ground potential is electrically connected to the second conductive path L2 through the contact pin P3, whereby the potential of the second conductive path L2 is induced to the ground potential. Therefore, the influence of the resistance value of the grounding conductor 12 causes the potential of the second conductive path L2 to be separated from the reference potential (ground potential) to the positive side or the negative side, and the amplitude of the deviation is along with the length of the grounding conductor 12 and The problem of the change in the resistance value per unit length. As a result, an excessive current flows through the second electrical resistance member Z2 during the electrical impedance measurement, and the electrical impedance of the first electrical resistance member Z1 cannot be accurately measured.

Further, since the ground lead 12 is electrically connected to the ground potential through the second conductive path L2, the lead path after the ground lead 12 has a predetermined capacitance, so that power is supplied from the power supply unit 13 to the second conductive path L2. The settling time is required until the potential is stabilized. In order to secure the charging time, the timing of the impedance measurement of the first electrical resistance member Z1 is delayed, and the time required for the electrical impedance measurement is prolonged.

Further, when a switching element (for example, a semiconductor switching element) is inserted into the grounding conductor 12, there is a problem that the current flowing through the grounding conductor 12 tends to deteriorate the switching element.

Therefore, the problem to be solved by the present invention is to provide an electrical impedance measuring apparatus which will measure the electrical impedance of a first electrical resistance member among the first to third electrical resistance members constituting the triangular circuit. The current suppression between the second electrical impedance member and the third electrical resistance member is zero, so that the electrical impedance of the first electrical impedance member can be accurately measured, and the electrical resistance measurement speed can be improved and the life of the switching element can be extended.

In order to solve the above problems, a first aspect of the present invention provides an electrical impedance measuring apparatus that configures a triangular circuit with first to third electrical resistance members electrically connected by first to third conductive paths, and the first The potential of the first conductive path electrically connected to the second impedance member and the potential of the second conductive path electrically connected to the third electrical resistance member are induced to a reference potential, and further The electrical impedance of the first electrical impedance member is measured, and the first operational amplifier includes an output terminal electrically connected to the second conductive path, an inverting input terminal, and a non-electrical connection to a predetermined reference potential. Inverting the input terminal; the power supply unit is electrically connected to the third conductive path, and applies electric power for electrical impedance measurement to the third conductive path, and the third conductive path causes the first electrical impedance member and the third electrical resistance member And an electrical characteristic detecting unit that detects the first electrical impedance structure for measuring an electrical impedance of the first electrical resistance member when the power supply unit applies the electric power to the third conductive path The electrical characteristics of the piece.

Further, in the electrical impedance measuring apparatus according to the second aspect of the present invention, the electrical impedance measuring apparatus according to the first aspect of the present invention, further comprising: a second operational amplifier provided with an output terminal electrically connected to the first conductive path And the inverting input terminal, and the non-inverting input terminal electrically connected to the predetermined ground wire.

According to a third aspect of the present invention, in the electrical impedance measuring apparatus according to the first aspect of the present invention, the first to third electrical impedance members and the first to third conductive paths are inspected. A multi-array is disposed on the substrate, the electrical impedance measuring device further includes: a multi-pin jig provided with a plurality of contact pins respectively contacting the first to third conductive paths of the plurality of arrays; and a connection switching portion provided The plurality of switching elements switch electrical connection between the contact pins of the multi-pin jig and the output terminal of the first operational amplifier, the inverting input terminal, the non-inverting input terminal, and the power supply unit.

According to the electrical impedance measuring apparatus of the first aspect of the present invention, the potential of the second conductive path between the second electrical impedance member and the third electrical resistance member is reliably induced to the reference potential by the first operational amplifier. The potential of the second conductive path becomes the reference potential similarly to the potential of the first conductive path. Thereby, the current flowing to the second electrical resistance member can be surely suppressed to zero during the electrical impedance measurement, so that the electrical impedance of the first electrical resistance member can be accurately measured.

Further, when the potential of the second conductive path deviates from the reference potential, the first operational amplifier suppresses the potential fluctuation instantaneously and returns the potential of the second conductive path to the reference potential. Therefore, even when the power supply unit starts supplying electric power to the third conductive path, the potential of the second conductive path can be stably maintained at the reference potential. As a result, immediately after the power supply unit supplies electric power to the third conductive path, the electrical characteristic detecting unit detects the electrical characteristics of the first electrical impedance member, and performs the electrical impedance measurement of the first electrical impedance member, thereby achieving the electric power generation. The purpose of high-speed impedance measurement.

In addition, the current flowing between the second conductive path and the inverting input terminal and the output terminal of the first operational amplifier is very high compared to the current flowing through the second conductive path L2 and the ground lead 12 of the prior art of FIG. Therefore, even when a switching element (for example, a semiconductor switching element) is inserted into a lead wire that electrically connects the second conductive path to the inverting input terminal and the output terminal of the first operational amplifier, the switch can be made The purpose of the component's service life is increased.

According to the electrical impedance measuring apparatus of the second aspect of the present invention, the potential of the first conductive path between the first electrical impedance member and the second electrical resistance member is reliably induced to the reference potential by the second operational amplifier, so that The potential of 1 and the second conductive path also becomes the reference potential. Thereby, it is possible to more reliably suppress the current flowing to the second electrical resistance member to zero during the electrical impedance measurement, and to more accurately measure the electrical impedance of the first electrical resistance member.

Further, the effect obtained by using the first operational amplifier for the second conductive path described above can be further enhanced (the electrical impedance measurement is accelerated and the life of the switching element is increased).

An electrical impedance measuring device according to a third aspect of the present invention is an electrical impedance measuring device using a multi-pin jig, which uses a plurality of wires electrically connected to a multi-pin jig and a switching element interposed in the lead. Therefore, according to the configuration of the first operational amplifier of the present invention, the influence on the wires and the switching elements can be further reduced as compared with the case of using the conventional structure shown in FIG.

A substrate inspection device 21 as an electrical impedance measurement device according to an embodiment of the present invention will be described with reference to Figs. 1 and 2 . The substrate inspection device 21 can measure and inspect any of the first to third electrical resistance members Z1 to Z3 provided on the inspection substrate 22 so as to constitute a triangular circuit as shown in FIG. 1 (here, the first electrical impedance The electrical impedance of component Z1). The first to third electrical resistance members Z1 to Z3 constituting the complex array triangular circuits S1, S2, ... (hereinafter, the symbol "S" is used only when the triangular circuits are collectively referred to as the triangular circuits) are provided on the substrate 22 to be inspected.

The first to third electrical resistance members Z1 to Z3 of the respective sets S have connection portions on one side and the other side, and are electrically connected to each other by the first to third conductive paths L1 to L3 to constitute a triangular circuit. More specifically, the one side connection portion of the first electric resistance member Z1 and the other side connection portion of the second electric resistance member Z2 are electrically connected by the first conductive path L1, and the one side connection portion of the second electric resistance member Z2 The other side connection portion of the third electric resistance member Z3 is electrically connected by the second conductive path L2, and the other side connection portion of the third electric resistance member Z3 and the other side connection portion of the first electric resistance member Z1 are 3 conductive path L3 is electrically connected.

Here, the measurement of the electrical impedance of the first electrical resistance member Z1 is performed by the first The potentials of the second conductive paths L1 and L2 are induced to a predetermined reference potential (the ground potential in the present embodiment). The potentials of the first and second conductive paths L1 and L2 are induced to the reference potential (ground potential) in order to prevent current from flowing to the second electrical resistance member Z2 to avoid electricity to the first electrical resistance member Z1 during electrical impedance measurement. Impedance measurement has an impact.

As shown in FIGS. 1 and 2, the substrate inspection device 21 includes a multi-pin jig 31, a connection switching unit 32, a potential sensing circuit 33, an operational amplifier 34 corresponding to the first operational amplifier, a power supply unit 35, and a current check. The output unit 36, the potential difference detecting unit 37, and the control unit 38. The current detecting unit 36 and the potential difference detecting unit 37 correspond to the electrical characteristic detecting unit of the present invention.

As shown in FIG. 2, the multi-pin jig 31 includes a plurality of conductive contact pins P having electrical conductivity, and a holding member 311 that ensures that the plurality of contact pins P are insulated from each other and holds the plurality of contact pins P. As shown in FIG. 1, the plurality of contact pins P can simultaneously contact the first to third electrical connections between the first to third electrical resistance members Z1 to Z3 of the complex array S provided in the substrate 22 to be inspected. 3 conductive paths L1 ~ L3.

A set of S is observed to illustrate the configuration of the contact pin P. The contact pins P corresponding to the respective sets S include contact pins P11 and P12 that are in contact with the first conductive path L1, contact pins P13 and P14 that are in contact with the second conductive path L2, and contact pins P15 that are in contact with the third conductive path L3. , P16.

The connection switching unit 32 includes a plurality of switching elements (for example, semiconductor switching elements) SW that are switched between ON and OFF by the control of the control unit 38. Then, by switching the switching element SW ON and OFF, the respective contact pins P of the multi-pin jig 31 and the respective connection portions on the apparatus main body side (here, the positive side input terminal of the comparator 331 to be described later, the variable power supply) are switched. The electrical connection relationship between the one-side output terminal of the unit 332, the inverting input terminal of the operational amplifier 34, the output terminal, the one-side output terminal of the power supply unit 35, and the one-side input terminal of the potential difference detecting unit 37. In this embodiment, the plurality of switching elements SW, each of the plurality of contact pins P provided by the multi-pin jig 31 corresponding to each of the sets S of the triangular circuits provided by the inspected substrate 22, and corresponding to the contact pins P of any one of the sets S and the respective connecting portions on the device body side Switch ON and OFF in the same way as the electrical connection.

In addition, in the structure shown in FIG. 1, the electrical impedance measurement is performed only on the first electrical resistance member Z1 of each of the first to third electrical resistance members Z1 to Z3 of each group S, but the connection switching portion 32 may be additionally provided. The number of switching elements SW and the wiring path are measured for electrical impedance with respect to the second and third electrical resistance members Z2 and Z3.

The potential sensing circuit 33 is a member for inducing the potential of the first conductive path L1 of each group S to the reference potential (ground potential), and includes a comparator 331 and a variable power supply unit 332. The positive side input terminal of the comparator 331 is electrically connected to the first conductive path L1 in each group S through the contact pin P11 provided in the corresponding group S of the connection switching unit 32 and the multi pin holder 31, and the negative side input terminal is The reference potential (ground potential) is electrically connected. The output signal output from the output terminal of the comparator 331 is supplied to the variable power supply unit 332 as a control signal. The variable power supply unit 332 changes the current output through the two output terminals in accordance with the output signal of the comparator 331 (the output voltage may be changed instead of the current).

One of the two output terminals of the variable power supply unit 332 is electrically connected to the first conductive path L1 in each group S through the contact pin P12 provided in the corresponding group S of the connection switching unit 32 and the multi-pin jig 31, and the other is electrically connected to the other. Electrically connected to the reference potential (ground potential). Then, when the potential of the first conductive path L1 fluctuates toward the positive side or the negative side with respect to the ground potential, the comparator 331 changes the output output signal, and the variable power supply unit 332 transmits the output through the two output terminals based on the output signal. The current cancels the fluctuation of the potential of the first conductive path L1 from the ground potential. Thereby, the potential of the first conductive path L1 is often induced as a reference potential (ground potential).

The operational amplifier 34 is a member for inducing the potential of the second conductive path L2 of each group S to the reference potential (ground potential). Inverting input of operational amplifier 34 The contact pins P13 provided in the respective sets S of the connection switching unit 32 and the multi-pin jig 31 are electrically connected to the second conductive path L2 in each group S. Further, the non-inverting input terminal is electrically connected to a reference potential (ground potential). Further, the output terminal is electrically connected to the second conductive path L2 in each of the sets S through the contact pin P14 provided in the respective sets S of the connection switching unit 32 and the multi-pin jig 31.

When the potential of the second conductive path L2 deviates from the reference potential (ground potential), the potential fluctuation of the second conductive path L2 is supplied to the inverting input terminal of the operational amplifier 34, and the potential fluctuation is offset. The current (or voltage) is instantaneously supplied from the output terminal of the operational amplifier 34 to the second conductive path L2. Thereby, the potential fluctuation of the second conductive path L2 is suppressed by the operational amplifier 34 at an instant, and the potential of the second conductive path L2 is returned to the reference potential (ground potential).

The power supply unit 35 outputs electric power (for example, a fixed output AC current) necessary for measuring the electric impedance of the first electric resistance member Z1 of each group S through the two output terminals under the control of the control unit 38. One of the two output terminals of the power supply unit 35 transmits the contact pin P15 provided in the corresponding group S of the current detecting unit 36, the connection switching unit 32, and the multi-pin jig 31, and the third conductive path in each group S. L3 is electrically connected and the other is electrically connected to the ground potential. In the present embodiment, the power supply unit 35 outputs a fixed output AC current, but the power supply unit 35 may output a fixed output AC voltage, a current value, or a voltage value that varies periodically with a fixed amplitude and periodic fluctuation. DC voltage. Alternatively, when only the resistance value of the first electrical resistance member Z1 is measured, the power supply unit 35 may use a fixed current source or a fixed voltage source.

The current detecting unit 36 is inserted into a lead wire that connects the output terminal on the power supply unit 35 side to the connection switching unit 32, and can detect that the power supply unit 35 is supplied to the first electrical resistance member Z1 through the third conductive path L3 of each group S. The current value (for example, an alternating current value) is given to the control unit 38.

The potential difference detecting unit 37 can detect the third conductive portion of the power supply unit 35 that transmits the respective groups S The path L3 is supplied with a potential difference (for example, an alternating potential difference) of the first electrical resistance member Z1, and the detection result is given to the control unit 38. One of the two input terminals of the potential difference detecting unit 37 is electrically connected to the third conductive path L3 in each group S through the contact pin P16 provided in the corresponding group S of the connection switching unit 32 and the multi-pin jig 31, and the other is electrically connected to the other. Electrically connected to the reference potential (ground potential). Therefore, the potential difference applied to the first electrical resistance member Z1 is detected by the potential difference detecting unit 15 as the difference between the potential of the third conductive path L3 and the reference potential (ground potential). In another embodiment of the technical feature, for example, the other input terminal of the potential difference detecting unit 37 may be connected to the reference potential (ground potential), and may be transmitted through the connection switching unit 32 together with the positive input terminal of the comparator 331. The contact pins P11 provided in the respective sets S of the multi-pin jig 31 are electrically connected to the first conductive path L1 of each of the sets S.

Further, in the present embodiment, both the current detecting unit 36 and the potential difference detecting unit 37 are provided, but the current applied to the first electrical resistance member Z1 can be obtained based on the output current value or the output voltage value of the power supply unit 35. When the value or the value of the voltage is used, one of the current detecting unit 36 and the potential difference detecting unit 37 may be omitted.

The control unit 38 handles the control of the substrate inspection device 21 and the inspection process of the substrate 22 to be inspected. Specifically, for example, the control unit 38 turns ON and OFF the respective switching elements SW of the connection switching unit 32 so that any one of the plurality of triangular circuit groups S provided on the substrate 22 to be inspected is sequentially connected to the respective connection portions on the apparatus main body side. The power supply unit 35 supplies electric power for electrical impedance measurement to the first electrical resistance member Z1 of each group S. Then, the control unit 38 calculates the electrical impedance of the first electrical impedance member Z1 based on the current value and the potential difference value of the first electrical resistance member Z1 applied to each of the groups S detected by the current detecting unit 36 and the potential difference detecting unit 37. Based on the calculation result, the first electrical impedance member Z1 and the substrate 22 to be inspected are determined.

The inspection by the substrate inspection device 21, for example, turns on and off the respective switching elements SW of the connection switching unit 32 so that each of the plurality of triangular circuit groups S provided on the substrate 22 to be inspected is connected to the device body side. The department is in turn. at this time, Each of the connection portions on the apparatus main body side (the positive side input terminal of the comparator 331 , the one side output terminal of the variable power supply unit 332 , the inverting input terminal and the output terminal of the operational amplifier 34 , and the one side output terminal of the power supply unit 35 , and The one-side input terminal of the potential difference detecting portion 37 passes through the contact pins P11 to P16 of the triangular circuit group S corresponding to the inspection target at the time point of the plurality of contact pins P of the connection switching portion 32 and the multi-pin jig 31, and corresponds to The first to third conductive paths L1 to L3 of the inspection target group S are sequentially turned on.

Then, the first electrical impedance member Z1 of the inspection target group S is supplied with electric power (for example, an alternating current) for electrical impedance measurement through the first conductive path L1 by the power supply unit 35, and the current detecting unit 36 and the potential difference detecting unit are provided. The current value and the potential difference value given to the first electrical resistance member Z1 are detected, and the control unit 38 determines the quality of the first electrical resistance member Z1 based on the detected current value and the potential difference value. After the inspection of a group of S is completed, the next set of S is set as the inspection object, and the inspection is sequentially performed to the last group S.

As described above, according to the present embodiment, the potential of the second conductive path L2 between the second electrical resistance member Z2 and the third electrical resistance member Z3 constituting the triangular circuit can be reliably sensed as a reference by the operational amplifier 34. The potential (ground potential) causes the potential of the second conductive path L2 to be the reference potential (ground potential) similarly to the potential of the first conductive path L1. In the case of the electrical impedance measurement, the current flowing to the second electrical resistance member Z2 can be reliably suppressed to zero, and the electrical impedance of the first electrical resistance member Z1 can be accurately measured.

When the potential of the second conductive path L2 is deviated from the reference potential, the potential fluctuation can be instantaneously suppressed by the operational amplifier 34, and the potential of the second conductive path L2 can be returned to the reference potential (ground potential). Therefore, even when the power supply unit 35 starts supplying electric power to the third conductive path L3, the potential of the second conductive path L2 can be stably maintained at the reference potential (ground potential). As a result, after the power supply unit 35 supplies electric power to the third conductive path L3, the current detecting unit 36 and the potential difference detecting unit can be immediately activated. The current value and the potential difference value given to the first electrical resistance member Z1 are detected, and the electrical impedance measurement of the first electrical resistance member Z1 is performed, and the purpose of measuring the electrical impedance and determining the operation of the electrical impedance is further improved.

In addition, the second conductive path L2 of the delta circuit flowing through each group S and the inverting input terminal of the operational amplifier 34 and the current flowing through the second conductive path L2 and the ground lead 12 of the prior art of FIG. 4 Since the current between the output terminals is extremely small, it is possible to achieve a switching element of the connection switching portion 32 that is inserted in a wire that electrically connects the second conductive path L2 and the inverting input terminal and the output terminal of the operational amplifier 34. The service life of components such as SW (for example, semiconductor switching elements) is increased.

Further, in the substrate inspection device 21 of the present embodiment, in the device using the multi-pin jig 31, a plurality of wires electrically connected to the multi-pin jig 31 and a switching element interposed in the wire are used. Therefore, according to the configuration of the operational amplifier 34 of the present embodiment, the influence on the wires and the switching elements can be further reduced as compared with the case of using the conventional structure shown in FIG.

A modified embodiment of the substrate inspection device 21 of the present embodiment will be described with reference to Fig. 3 . In the substrate inspection apparatus 21a of the modified embodiment of FIG. 3, the potential of the first conductive path L1 of each group S is induced to a reference potential (ground potential) by using the operational amplifier 41 instead of the potential sensing circuit 33. This operational amplifier 41 corresponds to the second operational amplifier of the present invention.

The inverting input terminal of the operational amplifier 41 is electrically connected to the first conductive path L1 in each group S through the contact pin P11 provided in the corresponding group S of the connection switching unit 32 and the multi-pin jig 31. Further, the non-inverting input terminal is electrically connected to a reference potential (ground potential). Further, the output terminal is electrically connected to the first conductive path L1 in each of the sets S through the contact pin P12 provided in the corresponding group S of the connection switching unit 32 and the multi-pin jig 31.

By the operational amplifier 41, the potential of the first conductive path L1 of each group S is reliably induced to the reference potential (ground potential), and the potentials of the first and second conductive paths L1 and L2 are similarly set to the reference potential ( Ground potential). Therefore, in the electrical impedance measurement, the current flowing to the second electrical resistance member Z2 can be more reliably suppressed to zero, and the electrical impedance of the first electrical resistance member Z1 can be more accurately measured. Further, the effect obtained by using the operational amplifier 34 for the second conductive path L2 described above can be further enhanced (the speed of the electrical impedance measurement can be increased and the life of the switching element can be increased).

11‧‧‧ Potential sensing circuit

111‧‧‧ comparator

112‧‧‧Variable Power Supply Department

12‧‧‧Grounding conductor

13‧‧‧Power Supply Department

14‧‧‧ Current Detection Department

15‧‧‧potential difference detection department

21, 21a‧‧‧ substrate inspection device

22‧‧‧Inspected substrate

31‧‧‧Multi-pin fixture

311‧‧‧ Keeping components

32‧‧‧Connection Switching Department

33‧‧‧ Potential sensing department

331‧‧‧ Comparator

332‧‧‧Variable Power Supply Department

34‧‧‧Operational Amplifier

35‧‧‧Power Supply Department

36‧‧‧ Current Detection Department

37‧‧‧potential difference detection department

38‧‧‧Control Department

41‧‧‧Operational Amplifier

L1‧‧‧1st conductive path

L2‧‧‧2nd conductive path

L3‧‧‧3rd conductive path

P, P1~P5, P11~P16‧‧‧ contact pin

S1, S2‧‧‧ circuit group

Z1‧‧‧1st electrical impedance component

Z2‧‧‧2nd electrical impedance component

Z3‧‧‧3rd electrical impedance component

SW‧‧‧Switching elements

Fig. 1 is a view showing an electrical configuration of a substrate inspecting apparatus as an electrical impedance measuring apparatus according to an embodiment of the present invention.

2 is a side view of the multi-pin jig provided in the substrate inspection apparatus of FIG. 1.

Fig. 3 is a view showing a modified embodiment of the substrate inspecting apparatus of Fig. 1.

Fig. 4 is a structural view showing a conventional electrical impedance measuring device.

21‧‧‧Substrate inspection device

22‧‧‧Inspected substrate

32‧‧‧Connection Switching Department

33‧‧‧ Potential sensing department

331‧‧‧ Comparator

332‧‧‧Variable Power Supply Department

34‧‧‧Operational Amplifier

35‧‧‧Power Supply Department

36‧‧‧ Current Detection Department

37‧‧‧potential difference detection department

38‧‧‧Control Department

L1‧‧‧1st conductive path

L2‧‧‧2nd conductive path

L3‧‧‧3rd conductive path

P11~P16‧‧‧ contact pin

S1, S2‧‧‧ circuit group

Z1‧‧‧1st electrical impedance component

Z2‧‧‧2nd electrical impedance component

Z3‧‧‧3rd electrical impedance component

SW‧‧‧Switching elements

Claims (3)

An electrical impedance measuring device that forms a triangular circuit with first to third electrical resistance members electrically connected by first to third conductive paths, and electrically connects the first electrical resistance member and the second electrical resistance member The potential of the first conductive path and the potential of the second conductive path electrically connected to the third electrical impedance member are induced to a reference potential, and the electrical impedance of the first electrical impedance member is measured. The first operational amplifier includes an output terminal electrically connected to the second conductive path and an inverting input terminal, and a non-inverting input terminal electrically connected to a predetermined reference potential; and a power supply unit, and the third The conductive path is electrically connected, and electric power for electrical impedance measurement is applied to the third conductive path, the third conductive path electrically connects the first electrical resistance member and the third electrical resistance member, and an electrical characteristic detecting unit When the electric power is applied to the third conductive path by the power supply unit, the electrical characteristics of the first electrical resistance member for measuring the electrical impedance of the first electrical resistance member are detected. The electrical impedance measuring apparatus according to claim 1, further comprising: a second operational amplifier having an output terminal and an inverting input terminal electrically connected to the first conductive path, and electrically connected to a predetermined ground line Non-inverting input terminal. The electrical impedance measuring apparatus according to claim 1, wherein the first to third electrical resistance members and the first to third conductive paths are provided with a plurality of arrays on the substrate to be inspected; and the electrical impedance measuring device further comprises: a multi-pin tool holder having a plurality of contact pins respectively in contact with the first to third conductive paths of the plurality of arrays; and a connection switching portion having a plurality of switching elements for switching the contacts of the multi-pin tool holder The pin is electrically connected to the output terminal of the first operational amplifier, the inverting input terminal, the non-inverting input terminal, and the power supply unit.