KR102247989B1 - Resistance measuring apparatus, substrate test apparatus, test method and method of maintaining jig for test - Google Patents

Abstract

(Problem) A resistance measuring apparatus, a substrate inspection apparatus, an inspection method, and a maintenance method of an inspection jig are provided in which it is easy to determine whether a probe is good or bad.
(Solution means) Current probes Pc1 and Pc2 and voltage probes Pv1 and Pv2 are brought into contact with the conductor pattern M, and the first current Ip is applied to the conductor pattern M by the current probes Pc1 and Pc2. When is allowed to flow, the first voltage Vp measured by the voltage probes Pv1 and Pv2 is obtained, and the current probes Pc1 and Pc2 provide the conductor pattern M in a direction opposite to the first current Ip. 2 When the current Im is made to flow, the second voltage Vm measured by the voltage probes Pv1 and Pv2 is acquired, and the current is not allowed to flow through the conductor pattern M by the current probes Pc1 and Pc2. In the state, a third voltage Vo measured by the voltage probes Pv1 and Pv2 is obtained, and the probe is related to the first voltage Vp, the second voltage Vm, and the third voltage Vo. It was made to judge good or bad.

Description

Resistance measuring apparatus, board inspection apparatus, inspection method, and maintenance method of inspection jig {RESISTANCE MEASURING APPARATUS, SUBSTRATE TEST APPARATUS, TEST METHOD AND METHOD OF MAINTAINING JIG FOR TEST}

The present invention relates to a resistance measurement device that performs resistance measurement, a substrate inspection device using the resistance measurement device, an inspection method related to a probe used in these devices, and a maintenance method of an inspection jig.

Conventionally, in order to inspect a wiring pattern formed on a substrate such as a printed wiring board, measuring the resistance value of the wiring pattern has been performed. In the inspection of the wiring pattern, it is necessary to detect not only the presence or absence of a disconnection, but also a defect that does not lead to a disconnection, such as a thinner wiring pattern or a thinner wiring pattern. In order to detect a defect that has not reached such a disconnection, it is necessary to perform resistance measurement with high accuracy. As such a high-precision resistance measurement method, a substrate inspection apparatus using a four-terminal measurement method is known (see, for example, Patent Document 1).

In the four-terminal measurement method, two current probes for flowing a resistance measurement current to a resistance measurement point and two voltage probes for measuring a voltage at the resistance measurement point are used. Thereby, since the current for resistance measurement does not flow through the voltage probe, the voltage drop due to the resistance of the voltage probe itself is reduced, and high-precision resistance measurement is possible.

Japanese Patent Application Publication No. 2012-013590

However, with the passage of time, an oxide film may be formed on the probe needle of the above-described voltage probe or the electrode for connecting the probe needle to the voltmeter. When an oxide film is formed on a probe needle or electrode, a rectifying action and a resistance component occur. Therefore, when resistance measurement is performed using a voltage probe having an oxide film formed thereon, the measurement accuracy of the resistance value is lowered. And, if the board|substrate inspection is performed based on the resistance measurement value of which the precision was reduced, the inspection precision of a board|substrate is deteriorated. Therefore, it is necessary to remove the oxide film by cleaning the voltage probe on which the oxide film is formed.

Further, as an error factor generated in the voltage probe, there is an electromotive force generated by the Seebeck effect in addition to the oxide film. Since the electromotive force due to the Seebeck effect and the rectifying action due to the oxide film both have polarities, it is difficult to distinguish them. Therefore, there is a problem in that it is difficult to detect that a defect in which an oxide film is formed in the voltage probe has occurred.

It is an object of the present invention to provide a resistance measuring device in which it is easy to determine whether a probe is good or bad, a substrate inspection device using the resistance measuring device, an inspection method related to a probe, and a maintenance method for an inspection jig.

A resistance measuring device according to the present invention is a resistance measuring device for measuring a resistance value of a conductor, and a first and second probe for contacting the conductor, and a predetermined value for the conductor by the first and second probes. A first voltage acquisition unit that acquires a first voltage generated in the conductor when a first current flows, and a second current in a direction opposite to the first current flows through the conductor through the first and second probes. A second voltage acquisition unit that acquires a second voltage generated in the conductor at the time of operation, and a third voltage generated in the conductor in a state in which no current flows through the conductor by the first and second probes. And a third voltage acquisition unit acquired by the first and second probes, and a determination unit that determines whether or not the first and second probes are good or bad based on the first, second, and third voltages.

In addition, the inspection method according to the present invention is an inspection method for inspecting defects related to the first and second probes for contacting a conductor, wherein the first and second probes are brought into contact with the conductor, and a predetermined value is applied to the conductor. A first voltage acquisition step of acquiring a first voltage measured by the first and second probes when the first current of is flowed, and the first current in the conductor by the first and second probes A second voltage acquisition step of acquiring a second voltage measured by the first and second probes when flowing a second current in the reverse direction, and not allowing a current to flow through the conductor by the first and second probes. In a state, a third voltage acquisition process of acquiring a third voltage measured by the first and second probes, and on the first and second voltage probes based on the first, second and third voltages. It includes a judgment step of determining good or bad.

In addition, the maintenance method for an inspection jig according to the present invention is a maintenance method for an inspection jig including first and second probes for contacting a conductor, wherein the first and second probes are brought into contact with the conductor, A first voltage acquisition step of acquiring a first voltage measured by the first and second probes when a predetermined first current is passed through the conductor, and the second voltage is applied to the conductor by the first and second probes. A second voltage acquisition step of acquiring a second voltage measured by the first and second probes when a second current in a direction opposite to that of the first current flows, and a current to the conductor by the first and second probes. A third voltage acquisition process of acquiring a third voltage measured by the first and second probes while not flowing, and cleaning of the inspection jig based on the first, second and third voltages It includes a determination process to determine whether or not it is necessary.

According to these resistance measuring devices, inspection methods, and maintenance methods of inspection jigs, the first voltage generated in the conductor when the first current is passed through the conductor to be measured resistance and the first current in the conductor are reversed. A second voltage generated in the conductor when the second current is passed and a third voltage generated in the conductor in a state in which no current flows through the conductor are obtained using the first and second probes. The first, second, and third voltages are symmetrical in relation between the first voltage and the third voltage, and the relationship between the second voltage and the third voltage, unless an oxide film is formed on the first and second probes. Exhibits a characteristic characteristic. On the other hand, when an oxide film is formed on the first and second probes and becomes a defective state, the symmetry of the relationship between the first voltage and the third voltage and the relationship between the second voltage and the third voltage is disturbed by the rectifying action of the oxide film. All. Therefore, it is possible to easily determine whether the first and second probes are good or bad based on the first, second, and third voltages. In addition, when an oxide film is formed on the first and second probes, resulting in a defective state, it is considered that it is necessary to clean the inspection jig including the first and second probes. Thus, the determination unit can determine whether or not cleaning of the inspection jig is necessary based on the first, second, and third voltages.

In addition, the first probe includes a first current probe for flowing a current through the conductor, and a first voltage probe for detecting a voltage generated in the conductor by the current, and the second probe includes the A second current probe for flowing a current through a conductor, and a second voltage probe for detecting a voltage generated in the conductor by the current, and the first voltage acquisition unit comprises: between the first and second current probes The first voltage measured by the first and second voltage probes is acquired when the first current is passed to, and the second voltage acquisition unit includes the first current between the first and second current probes. Acquires the second voltage measured by the first and second voltage probes when a second current in a direction opposite to and flows, and the third voltage acquisition unit receives a current between the first and second current probes. It is preferable to acquire the third voltage measured by the first and second voltage probes in a state in which no flow is made.

According to this configuration, in a resistance measuring device comprising the first and second current probes, and the first and second voltage probes, and capable of measuring resistance by a four-terminal measurement method, the quality of the first and second voltage probes Can be easily determined.

Further, the determination unit includes a first point represented by the first current and the first voltage, and a second point represented by the second current and the second voltage on a two-dimensional plane using the current and the voltage as parameters. When the point and the third point indicated by the current value of zero and the third voltage are not disposed on a substantially straight line, it is preferable to determine that there is a defect relating to the first and second probes.

According to this configuration, the first, second, and third voltages are arranged on a straight line on a two-dimensional plane with current and voltage as parameters, unless an oxide film is formed on the first and second probes. On the other hand, when an oxide film is formed on the first and second probes and becomes a defective state, the first, second and third points are not disposed on a straight line due to the rectifying action of the oxide film. Thus, when the first, second, and third points are not disposed on a substantially straight line, the determination unit can easily determine that there is a defect relating to the first and second probes.

Further, it is preferable that the first current and the second current have an absolute value equal to each other.

According to this configuration, it becomes easy to simplify the determination process of the good or bad with respect to the first and second probes by the determination unit.

In addition, the determination unit, a difference between a first difference value, which is a difference between the first voltage and the third voltage, and a second difference value, which is a difference between the second voltage and the third voltage, exceeds a preset determination threshold value. If so, it may be determined that there is a defect relating to the first and second probes.

According to this configuration, the first current and the second current are currents whose absolute values are equal to each other and whose directions are opposite. In this case, if the first, second, and third points are arranged on a straight line, the first difference value and the second difference value become equal. Accordingly, when the difference between the first difference value and the second difference value becomes larger than the preset determination threshold value, it can be easily determined that there is a defect relating to the first and second probes.

Further, the substrate inspection apparatus according to the present invention performs inspection of the substrate based on the voltage measured by the first and second probes using the above-described resistance measuring apparatus and a wiring pattern formed on the substrate as the conductor. It has a board|substrate inspection part to perform.

According to this configuration, it is possible to easily determine whether or not the probe used for inspection of the substrate is good or bad.

The resistance measuring apparatus, the substrate inspection apparatus, and the inspection method having such a configuration can easily determine whether the probe is good or bad.

1 is a block diagram showing an example of a configuration of a substrate inspection device including a resistance measuring device according to an embodiment of the present invention.
2 is a flowchart showing an example of the operation of the substrate inspection apparatus using the inspection method according to the embodiment of the present invention.
3 is an equivalent circuit diagram for explaining an oxide film generated in a voltage probe.
4 is a timing chart for explaining an inspection method. (a) shows a case where the voltage probe P is a good product (no oxide film is formed), and (b) shows a case where the voltage probe is defective (an oxide film is formed).
5 is an explanatory diagram for explaining a determination method by a determination unit. (a) shows a case where the voltage probe P is a good product (no oxide film is formed), and (b) shows a case where the voltage probe is defective (an oxide film is formed).
6 is a block diagram showing another example of the substrate inspection apparatus.

Hereinafter, embodiments according to the present invention will be described based on the drawings. In addition, configurations denoted by the same reference numerals in each drawing indicate the same configuration, and the description thereof is omitted. 1 is a block diagram showing an example of a configuration of a substrate inspection apparatus including a resistance measuring device according to an embodiment of the present invention.

The substrate inspection apparatus 1 shown in FIG. 1 includes a constant current source 2, an ammeter 3, a voltmeter 4, a current probe (Pc1 (first current probe)), and a current probe (Pc2 (second current probe)). ), a voltage probe (Pv1 (first voltage probe)), a voltage probe (Pv2 (second voltage probe)), a switch (A1, A2, B1, B2, C1, C2), and a control unit 5. The board inspection apparatus 1 is adapted to measure resistance by a four-terminal measurement method.

The current probe Pc1 includes a probe needle 11, a connection electrode 12, and a cable 13. The current probe Pc2 is provided with the probe needle 21, the connection electrode 22, and the cable 23. The voltage probe Pv1 includes a probe needle 31, a connection electrode 32, and a cable 33. The voltage probe Pv2 includes a probe needle 41, a connection electrode 42, and a cable 43. The current probes Pc1 and Pc2 and the voltage probes Pv1 and Pv2 are configured as inspection jigs that can be detachable from the substrate inspection apparatus 1 or the resistance measurement apparatus, for example.

The probe needles 11, 21, 31, 41 are, for example, wire-shaped contacts having elasticity (flexibility) having a diameter of about 100 µm to 200 µm. The probe needles 11, 21, 31, 41 are formed of, for example, tungsten, hight steel (SKH), beryllium copper (Be-Cu), and other metals and other conductors.

The tip portions of the probe needles 11 and 31 are in contact with one end portion M1 of the conductor pattern M. The tip ends of the probe needles 21 and 41 are in contact with the other end portion M2 of the conductor pattern M. In Fig. 1, the conductor pattern M is conceptually described. The conductor pattern M may be a wiring pattern of a substrate to be inspected, or may be an inspection conductor for inspecting the voltage probes Pv1 and Pv2.

The connection electrodes 12, 22, 32, 42 are electrodes for connecting the probe needles 11, 21, 31, 41 to the cables 13, 23, 33, 43. The rear end portions of the probe needles 11, 21, 31, 41 come into contact with the connection electrodes 12, 22, 32, 42 and come into contact with the connection electrodes 12, 22, 32, 42.

The switches A1, A2, B1, B2, C1, C2 are various switching elements such as semiconductor switches such as transistors and relay switches. The switches A1, A2, B1, and B2 are changeover switches for switching the direction of the current flowing through the conductor pattern M through the current probes Pc1 and Pc2. The switches C1 and C2 switch the presence or absence of connection of the probe needles 31 and 41 to the voltmeter 4. The switches A1, A2, B1, B2, C1, C2 are turned on and off according to a control signal from the control unit 5.

The constant current source 2 is a constant current circuit that causes a constant current to flow through the conductor pattern M. The ammeter 3 measures a current value supplied from the constant current source 2 to the conductor pattern M. The constant current source 2 adjusts the output current so that the current value measured by the ammeter 3 becomes a preset measurement current value Is, for example, so that the measurement current of a constant measurement current value Is Prints. The measurement current value Is is, for example, 20 mA.

The probe needle 11 is connected to one output terminal of the constant current source 2 through the connection electrode 12, the cable 13, and the switch A1, and the connection electrode 12, the cable 13, It is connected to the other output terminal of the constant current source 2 through the switch B1 and the ammeter 3. The probe needle 21 is connected to one output terminal of the constant current source 2 through a connection electrode 22, a cable 23, and a switch B2, and the connection electrode 22, the cable 23, and It is connected to the other output terminal of the constant current source 2 through the switch A2 and the ammeter 3.

The probe needle 31 is connected to one input terminal of the voltmeter 4 via a connection electrode 32, a cable 33, and a switch C1. The probe needle 41 is connected to the other input terminal of the voltmeter 4 via a connection electrode 42, a cable 43, and a switch C2.

The voltmeter 4 measures the voltage detected by the voltage probes Pv1 and Pv2, and outputs the measured value to the control unit 5.

The control unit 5 includes, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a RAM (Random Access Memory) that temporarily stores data, and a ROM (Read Only Memory) that stores a predetermined control program. Or a storage unit such as a hard disk drive (HDD), and peripheral circuits thereof. Then, the control unit 5, for example, by executing a control program stored in the storage unit, the first voltage acquisition unit 51, the second voltage acquisition unit 52, the third voltage acquisition unit 53, the plate It functions as the positive and negative 54, the resistance calculating part 55, and the board|substrate inspection part 56.

The first voltage acquisition unit 51 flows the first current Ip in the direction from the current probe Pc1 to the current probe Pc2 through the conductor pattern M by the voltage probes Pv1 and Pv2. The measured first voltage Vp is obtained. The first current Ip can be, for example, 20 mA.

The second voltage acquisition unit 52 may have caused the second current Im to flow in a direction from the current probe Pc2 in a direction opposite to the first current Ip to the current probe Pc1 in the conductor pattern M. At this time, the second voltage Vm measured by the voltage probes Pv1 and Pv2 is obtained. The second current Im can be, for example, -20 mA whose absolute value is the same as that of the first current Ip and has an opposite polarity.

The third voltage acquisition unit 53 acquires the third voltage Vo measured by the voltage probes Pv1 and Pv2 in a state in which no current flows between the current probes Pc1 and Pc2.

The determination unit 54 includes a first difference value Vd1, which is an absolute value of the difference between the first voltage Vp and the third voltage Vo, and the difference between the second voltage Vm and the third voltage Vo. When the difference value (Vd (= Vd1-Vd2)), which is the difference between the second difference value (Vd2), which is the absolute value of, exceeds the preset determination threshold value (Vth), a defect with respect to the voltage probes Pv1, Pv2 It is determined that there is.

Further, the determination unit 54 may determine whether or not cleaning of the inspection jig including the voltage probes Pv1 and Pv2 is necessary.

The resistance calculator 55 calculates the resistance value Rx of the conductor pattern M based on the first voltage Vp, the second voltage Vm, the first current Ip, and the second voltage Vm. Calculate. Specifically, when the absolute values of the first current Ip and the second current Im are equal, if the current value is Ia, the resistance calculation unit 55 is based on the following equation (1). The resistance value Rx can be calculated.

Rx = (Vp-Vm)/(Ia × 2) = (Vp-Vm)/(20 ㎃ × 2)... (One)

Further, it is preferable that the internal resistance Ri of the voltage probes Pv1 and Pv2 is accurately measured in advance, and the resistance calculating unit 55 corrects the resistance value Rx based on the internal resistance Ri. Specifically, the resistance calculation unit 55 may calculate the resistance value Rx based on the following equation (2). According to the formula (2), the calculation accuracy of the resistance value Rx can be improved.

Rx = {(Vp-Vm)/(Ia × 2)}-Ri... (2)

The substrate inspection unit 56 is based on the resistance value Rx calculated by the resistance calculating unit 55 based on the first voltage Vp and the second voltage Vm measured by the voltage probes Pv1 and Pv2. Thus, the substrate on which the conductor pattern M is formed is inspected. Specifically, the substrate inspection unit 56 compares the resistance value Rx with a reference value stored in advance in the storage unit, for example, and when the resistance value Rx exceeds the reference value, the substrate is regarded as defective. Judge.

Next, the operation of the board|substrate inspection apparatus 1 which implements the inspection method or the maintenance method of the inspection jig concerning one embodiment of the present invention will be described. 2 is a flowchart showing an example of the operation of the substrate inspection apparatus 1 using the inspection method according to the embodiment of the present invention. 3 is an equivalent circuit for explaining an oxide film generated in the voltage probes Pv1 and Pv2. The equivalent circuit shown in FIG. 3 conceptually shows the contact portion when an oxide film is formed in the contact portion between the probe rear end X1 of the probe needle 31 and the electrode surface X2 of the connection electrode 32, for example. It is an equivalent circuit.

As shown in Fig. 3, when a defect occurs in which an oxide film is formed in the contact portion between the rear end of the probe X1 and the electrode surface X2, the power supply for generating thermoelectric power due to the Seebeck effect ( An equivalent circuit in which the series circuit of Vc and the resistor Rvc and the series circuit of the diode Dc and the resistor Rdc generated by the rectifying action of the oxide film are connected in parallel is formed.

In this way, the rectification action generated by the formation of the oxide film cannot be canceled even by the above-described equations (1) and (2), so the measurement accuracy of the resistance value Rx is lowered. Moreover, since the oxide film is formed with the passage of time afterwards, the resistance component generated by the oxide film is not included in the internal resistance Ri measured in advance. Therefore, the resistance calculation unit 55 cannot exclude the influence of the oxide film even by equation (2).

Thus, the substrate inspection apparatus 1 inspects whether or not a defect in which an oxide film is formed in the voltage probes Pv1 and Pv2 has occurred by the following inspection method. Thereby, if it is known that the oxide film is formed on the voltage probes Pv1 and Pv2, it becomes possible to remove the oxide film by cleaning.

4 is a timing chart for explaining the inspection method and the maintenance method of the inspection jig. (a) shows the case where the voltage probes Pv1 and Pv2 are good products (no oxide film is formed), and (b) shows the case where the voltage probes Pv1 and Pv2 are defective (oxide film is formed). have. The solid line represents the potential of the probe needle 31 and the dotted line represents the potential of the probe needle 41. Hereinafter, the flowchart shown in FIG. 2 will be described with reference to FIG. 4.

First, the current probe Pc1 and the voltage probe Pv1 are in contact with one end M1 of the conductor pattern M, and the current probe Pc2 and the voltage probe Pv2 are the other end of the conductor pattern M. M2) is in contact.

Then, the third voltage acquisition unit 53 turns off the switches A1, A2, B1, B2, removes the constant current source 2 from the current probes Pc1, Pc2, and provides a current to the conductor pattern M. Do not flow. Further, the third voltage acquisition unit 53 turns on the switches C1 and C2 to connect the voltage probes Pv1 and Pv2 to the voltmeter 4, and the third voltage Vo by the voltmeter 4 Is measured (step S1: timing T1). At this time, the electromotive force due to the Seebeck effect is measured as the third voltage Vo.

Next, the first voltage acquisition unit 51 turns on the switches A1 and A2 and turns off the switches B1 and B2 to connect the constant current source 2 to the current probes Pc1 and Pc2, and The first current Ip is made to flow from the circle 2 to the conductor pattern M through the current probes Pc1 and Pc2 (timing T2). And the 1st voltage acquisition part 51 makes the 1st voltage Vp measure by the voltmeter 4 by turning on the switches C1 and C2 (step S2: timing T3).

Next, the second voltage acquisition unit 52 turns off the switches A1 and A2 and turns on the switches B1 and B2 to connect the constant current source 2 to the current probes Pc1 and Pc2 in the reverse direction. , From the constant current source 2, through the current probes Pc1 and Pc2, a second current Im in a direction opposite to the first current Ip is made to flow through the conductor pattern M (timing T4). Then, the second voltage acquisition unit 52 turns on the switches C1 and C2 to measure the second voltage Vm with the voltmeter 4 (step S3: timing T5).

Next, the determination unit 54 calculates the difference value Vd based on the following equations (3), (4), and (5) (step S4).

Vd1 = Vp-Vo… (3)

Vd2 = Vo － Vm… (4)

Vd =｜Vd1 － Vd2｜… (5)

5 is an explanatory diagram for explaining the determination method by the determination unit 54. (a) shows the case where the voltage probes Pv1 and Pv2 are good products (no oxide film is formed), and (b) shows the case where the voltage probes Pv1 and Pv2 are defective (oxide film is formed). have. In FIG. 5, on a two-dimensional plane with the current I as the horizontal axis and the voltage V as the vertical axis, the first point P1 represented by the first current Ip and the first voltage Vp, and the second The second point P2 represented by the current Im and the second voltage Vm, and the third point P3 represented by the current value zero and the third voltage Vo are plotted.

When the voltage probes Pv1 and Pv2 are good products (no oxide film is formed), as shown in Fig. 5(a), the first point P1, the second point P2, and the third point P3 It is disposed on an approximately straight line L. On the other hand, when the voltage probes Pv1 and Pv2 are defective (the oxide film is formed), as shown in Fig. 5(b), the first point P1, the second point P2, and the third point P3 ) Is not placed on a straight line.

Accordingly, the determination unit 54 checks whether the first point P1, the second point P2, and the third point P3 are arranged on a substantially straight line, and the first point P1, the first point P1, When the two points P2 and the third point P3 are not arranged on a straight line, it can be determined that the voltage probes Pv1 and Pv2 are in a defective state in which an oxide film is formed.

Here, when the absolute values of the first current Ip and the second current Im are equal to each other, the first point P1, the second point P2, and the third point P3 are arranged on a straight line. , As shown in Fig. 5(a), the first difference value Vd1 and the second difference value Vd2 become equal. If the first difference value Vd1 and the second difference value Vd2 are equal, the difference value Vd becomes zero from the equation (5).

Therefore, the determination unit 54 compares the difference value Vd with the preset determination threshold value Vth (step S5), and if the difference value Vd does not reach the determination threshold value Vth (at step S5) Yes), the voltage probes Pv1, Pv2 are determined to be good products (step S6), and if the difference value (Vd) is equal to or greater than the determination threshold value (Vth) (No in step S5), the voltage probes Pv1, Pv2 are It is determined that it is defective (step S7). The determination threshold Vth is appropriately set in consideration of the accuracy of voltage measurement by the voltmeter 4 and the accuracy of the output current by the constant current source 2.

Further, when it is determined that the voltage probes Pv1 and Pv2 are defective, it is considered that it is necessary to clean the voltage probes Pv1 and Pv2 to remove the oxide film. Therefore, the determination unit 54 compares the difference value Vd with the preset determination threshold value Vth (step S5), and if the difference value Vd does not reach the determination threshold value Vth (at step S5) Yes), it is determined that it is not necessary to clean the inspection jig including the voltage probes Pv1 and Pv2 (step S6), and if the difference value Vd is equal to or greater than the determination threshold value Vth (No in step S5), You may determine that the voltage probes Pv1 and Pv2 need to be cleaned.

Then, the determination unit 54 displays the determination result on a display device not shown, so that when it is determined that the voltage probes Pv1 and Pv2 are defective, it is necessary to clean the voltage probes Pv1 and Pv2. When it is determined that there is, the user can remove the oxide film by cleaning the voltage probes Pv1 and Pv2, so that a decrease in resistance measurement accuracy and a decrease in substrate inspection accuracy due to the oxide film can be eliminated.

In addition, the absolute values of the first current Ip and the second current Im need not be equal to each other, and the determination unit 54 includes the first point P1, the second point P2, and the third Based on whether or not the point P3 is disposed on a substantially straight line, the voltage probes Pv1 and Pv2 may be configured to determine whether or not the oxide film is in a defective state.

In addition, an example of a resistance measuring apparatus according to a four-terminal measurement method including a current probe Pc1 and a voltage probe Pv1 as a first probe, and a current probe Pc2 and a voltage probe Pv2 as a second probe is described. Although shown, for example, as shown in FIG. 6, instead of the current probe Pc1 and the voltage probe Pv1, a first probe Pr1 shared for current supply and voltage measurement is provided, and a current probe Pc2 and Instead of the voltage probe Pv2, it may be configured to include a second probe Pr2 that is used for current supply and voltage measurement.

Moreover, the board|substrate inspection apparatus 1, 1a may not include the board|substrate inspection part 56, and may be comprised as a resistance measuring apparatus, such as a tester, for example. In addition, the first voltage acquisition unit 51, the second voltage acquisition unit 52, the third voltage acquisition unit 53, and the determination unit 54 are built-in in the substrate inspection apparatus 1, 1a or the resistance measurement apparatus. It is not limited to this example. For example, a voltage probe (Pv1, Pv2) or an inspection jig holding these probes may be configured to be detachable from the device body, and the probe or test jig removed from the device body may be inspected by the above-described inspection method. do.

1, 1a: board inspection device (resistance measuring device)
2: constant current source
3: ammeter
4: Voltmeter
5: control unit
11, 21, 31, 41: probe needle
12, 22, 32, 42: connection electrode
13, 23, 33, 43: cable
51: first voltage acquisition unit
52: second voltage acquisition unit
53: third voltage acquisition unit
54: judgment unit
55: resistance calculation unit
56: board inspection unit
A1, A2, B1, B2, C1, C2: switch
Im: second current
Ip: first current
M: Conductor pattern (conductor)
M1: one end
M2: the other end
P1: 1st point
P2: 2nd point
P3: 3rd point
Pc1: current probe (first current probe)
Pc2: current probe (second current probe)
Pr1: first probe
Pr2: second probe
Pv1: voltage probe (first voltage probe)
Pv2: voltage probe (second voltage probe)
Rx: resistance value
Vd: difference value
Vd1: first difference value
Vd2: second difference value
Vm: second voltage
Vo: third voltage
Vp: first voltage
Vth: judgment threshold

Claims (8)

As a resistance measuring device for measuring the resistance value of a conductor,
First and second probes for contacting the conductor,
A first voltage acquisition unit that acquires a first voltage generated in the conductor when a predetermined first current is passed through the conductor by the first and second probes;
A second voltage acquisition unit that acquires a second voltage generated in the conductor when a second current in a direction opposite to the first current flows through the conductor by the first and second probes;
A third voltage acquisition unit for acquiring a third voltage generated in the conductor by the first and second probes in a state in which no current flows through the conductor by the first and second probes;
And a determination unit that determines whether or not the first and second probes are good or bad based on the first, second and third voltages,
The first current and the second current are equal to each other in absolute values of current values,
When a difference between a first difference value, which is a difference between the first voltage and the third voltage, and a second difference value, which is a difference between the second voltage and the third voltage, exceeds a preset determination threshold value. And it is determined that there is a defect with respect to the first and second probes. As a resistance measuring device for measuring the resistance value of a conductor,
First and second probes for contacting the conductor,
A first voltage acquisition unit that acquires a first voltage generated in the conductor when a predetermined first current is passed through the conductor by the first and second probes;
A second voltage acquisition unit that acquires a second voltage generated in the conductor when a second current in a direction opposite to the first current flows through the conductor by the first and second probes;
A third voltage acquisition unit for acquiring a third voltage generated in the conductor by the first and second probes in a state in which no current flows through the conductor by the first and second probes;
And a determination unit that determines whether or not the first and second probes are good or bad based on the first, second and third voltages,
The determination unit includes a first point represented by the first current and the first voltage, a second point represented by the second current and the second voltage, on a two-dimensional plane using the current and the voltage as parameters, , When a current value of zero and a third point indicated by the third voltage are not arranged on a straight line, it is determined that there is a defect relating to the first and second probes. The method of claim 2,
The first probe,
A first current probe for flowing a current through the conductor,
A first voltage probe for detecting a voltage generated in the conductor by the current,
The second probe,
A second current probe for flowing a current through the conductor,
A second voltage probe for detecting a voltage generated in the conductor by the current,
The first voltage acquisition unit acquires the first voltage measured by the first and second voltage probes when the first current flows between the first and second current probes,
The second voltage acquisition unit acquires the second voltage measured by the first and second voltage probes when a second current in a direction opposite to the first current flows between the first and second current probes. and,
The third voltage acquisition unit acquires the third voltage measured by the first and second voltage probes in a state in which no current flows between the first and second current probes. The resistance measuring device according to any one of claims 1 to 3, and
A substrate inspection apparatus comprising a substrate inspection unit that inspects the substrate based on a voltage measured by the first and second probes using a wiring pattern formed on the substrate as the conductor. As an inspection method for inspecting defects related to the first and second probes for contacting a conductor,
A first voltage acquisition step of acquiring a first voltage measured by the first and second probes when the first and second probes are brought into contact with the conductor and a predetermined first current is passed through the conductor; and
A second voltage acquisition step of acquiring a second voltage measured by the first and second probes when a second current in a direction opposite to the first current flows through the conductor by the first and second probes; and ,
A third voltage acquisition step of acquiring a third voltage measured by the first and second probes in a state in which no current flows through the conductor by the first and second probes; and
A determination step of determining good or bad with respect to the first and second probes based on the first, second and third voltages,
The first current and the second current are equal to each other in absolute values of current values,
In the determination process, a difference between a first difference value, which is a difference between the first voltage and the third voltage, and a second difference value, which is a difference between the second voltage and the third voltage, exceeds a preset determination threshold. In this case, it is determined that there is a defect with respect to the first and second probes. As an inspection method for inspecting defects related to the first and second probes for contacting a conductor,
A first voltage acquisition step of acquiring a first voltage measured by the first and second probes when the first and second probes are brought into contact with the conductor and a predetermined first current is passed through the conductor; and
A second voltage acquisition step of acquiring a second voltage measured by the first and second probes when a second current in a direction opposite to the first current flows through the conductor by the first and second probes; and ,
A third voltage acquisition step of acquiring a third voltage measured by the first and second probes in a state in which no current flows through the conductor by the first and second probes; and
A determination step of determining good or bad with respect to the first and second probes based on the first, second and third voltages,
The determination step includes a first point represented by the first current and the first voltage, and a second point represented by the second current and the second voltage on a two-dimensional plane using the current and the voltage as parameters. And, when the third point indicated by the current value of zero and the third voltage is not disposed on a straight line, it is determined that there is a defect relating to the first and second probes. As a maintenance method of a jig for inspection comprising first and second probes for contacting a conductor,
A first voltage acquisition step of acquiring a first voltage measured by the first and second probes when the first and second probes are brought into contact with the conductor and a predetermined first current is passed through the conductor; and
A second voltage acquisition step of acquiring a second voltage measured by the first and second probes when a second current in a direction opposite to the first current flows through the conductor by the first and second probes; and ,
A third voltage acquisition step of acquiring a third voltage measured by the first and second probes in a state in which no current flows through the conductor by the first and second probes; and
A determination step of determining whether or not cleaning of the inspection jig is necessary based on the first, second and third voltages,
The first current and the second current are equal to each other in absolute values of current values,
In the determination process, a difference between a first difference value, which is a difference between the first voltage and the third voltage, and a second difference value, which is a difference between the second voltage and the third voltage, exceeds a preset determination threshold. In this case, the maintenance method of the inspection jig is determined that the inspection jig needs to be cleaned. As a maintenance method of a jig for inspection comprising first and second probes for contacting a conductor,
A first voltage acquisition step of acquiring a first voltage measured by the first and second probes when the first and second probes are brought into contact with the conductor and a predetermined first current is passed through the conductor; and
A second voltage acquisition step of acquiring a second voltage measured by the first and second probes when a second current in a direction opposite to the first current flows through the conductor by the first and second probes; and ,
A third voltage acquisition step of acquiring a third voltage measured by the first and second probes in a state in which no current flows through the conductor by the first and second probes; and
A determination step of determining whether or not cleaning of the inspection jig is necessary based on the first, second and third voltages,
The determination step includes a first point represented by the first current and the first voltage, and a second point represented by the second current and the second voltage on a two-dimensional plane using the current and the voltage as parameters. And, when the third point indicated by the current value of zero and the third voltage is not arranged on a straight line, it is determined that the inspection jig needs to be cleaned.

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