JPWO2020116236A1 - Inspection equipment, inspection methods, and programs for inspection equipment - Google Patents

Abstract

This is an inspection method for inspecting the inspection target portion A in which a plurality of current paths A1 and A2 having diode characteristics are connected in parallel. The first current value Ia includes a measurement processing step of measuring the voltage between both ends as the first voltage value Va, and the first current value Ia is equal to or less than the current value at which the voltage between both ends of the normal inspection target portion A becomes substantially the on-voltage Von. be.

Description

The present invention relates to an inspection device for inspecting a conductive path, an inspection method, and a program for the inspection device.

Conventionally, a substrate for measuring the resistance value of the inspection target from the current value and the voltage value by passing a measurement current through the wiring or the like of the inspection target provided on the circuit board and measuring the voltage generated in the inspection target. An inspection device is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-117991

By the way, there are cases where a circuit board in which components are mounted on a board, a component-embedded board in which components are built in the board, a semiconductor board on which a circuit is formed, or the like is inspected. In such a case, a diode or a plurality of current paths having diode characteristics similar to those of a diode may be connected in parallel.

For example, when two ordinary conductor patterns are connected in parallel and the resistance value of this parallel circuit is measured by the above-mentioned board inspection device, if one of the two is broken, the resistance value is doubled. .. Therefore, if one of the two conductor patterns connected in parallel is disconnected, the disconnection can be detected based on the resistance value.

However, the diode has a non-linear relationship between current and voltage, and even if one of the two diodes connected in parallel is disconnected, the voltage generated with respect to the current passed for resistance measurement is Almost no change.

Therefore, when a plurality of diodes are connected in parallel, when this is inspected by the above-mentioned substrate inspection device, even if some of the diodes are disconnected, it is difficult to detect the disconnection, which is inconvenient.

An object of the present invention is to provide an inspection device, an inspection method, and a program for an inspection device in which a plurality of diodes are connected in parallel to facilitate inspection of an inspection target.

The inspection device according to an example of the present invention has a diode characteristic in which the change in current with respect to the change in voltage when the forward voltage exceeds the on-voltage is larger than that in the case where the forward voltage is less than the on-voltage. It is an inspection device for inspecting an inspection target part in which a plurality of current paths having a plurality of current paths are connected in parallel, and is preset as a current supply part capable of supplying a current and a voltage measuring part capable of measuring a voltage. The first current value is provided with a measurement processing unit for measuring the voltage between the two ends as the first voltage value while allowing the current of the first current value to flow between the two ends by the current supply unit. Is equal to or less than the current value at which the voltage between both ends of the normal inspection target portion becomes substantially the on-voltage.

Further, in the inspection device according to the example of the present invention, the change in the current with respect to the change in the voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage. It is an inspection device for inspecting an inspection target part in which a plurality of current paths having diode characteristics are connected in parallel, and is substantially a voltage supply part capable of outputting a voltage, a current measuring part capable of measuring a current, and substantially The voltage of the first voltage value preset below the on-voltage is applied between both ends of the inspection target portion by the voltage supply unit, and the current flowing between the both ends is applied by the current measuring unit to the first current value. It is provided with a measurement processing unit for measuring as.

Further, in the inspection method according to an example of the present invention, the change in current with respect to the change in voltage when the forward voltage exceeds the on-voltage is larger than that in the case where the forward voltage is less than the on-voltage. This is an inspection method for inspecting an inspection target portion in which a plurality of current paths having diode characteristics are connected in parallel, and a voltage of the first current value set in advance is passed between the ends and a voltage between the ends is applied. The first current value includes a measurement processing step of measuring as the first voltage value, and the first current value is equal to or less than the current value at which the voltage between both ends of the normal inspection target portion becomes substantially the on-voltage.

Further, in the inspection method according to an example of the present invention, the change in current with respect to the change in voltage when the forward voltage exceeds the on-voltage is larger than that in the case where the forward voltage is less than the on-voltage. This is an inspection method for inspecting an inspection target portion in which a plurality of current paths having diode characteristics are connected in parallel. It includes a measurement processing step of measuring the current flowing between both ends as the first current value while applying the voltage between both ends.

Further, in the inspection device according to an example of the present invention, the change in current with respect to the change in voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage. An inspection device for inspecting an inspection target portion in which a plurality of current paths having diode characteristics are connected in parallel, and one of the current and the voltage is subjected to a plurality of times with different values at both ends of the inspection target portion. The current that is supplied in between, measures the other of the current or voltage between the ends during each period in which the one is supplied, and turns on the current to be inspected based on the measured change in the other. It is provided with a measurement processing unit for acquiring the above and a determination unit for determining the quality of the inspection target unit based on the current acquired by the measurement processing unit.

Further, in the inspection method according to an example of the present invention, the change in current with respect to the change in voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage. This is an inspection method for inspecting an inspection target portion in which a plurality of current paths having diode characteristics are connected in parallel, and both ends of the inspection target portion are subjected to a plurality of times with different values of either current or voltage. The current that is supplied in between, measures the other of the current or voltage between the ends during each period in which the one is supplied, and turns on the current to be inspected based on the measured change in the other. Includes a measurement processing step of acquiring the above and a determination step of determining the quality of the inspection target unit based on the current acquired by the measurement processing unit.

Further, the program for an inspection device according to an example of the present invention is a program for an inspection device for operating the above-mentioned inspection device, and causes a computer to function as the measurement processing unit.

It is a block diagram which shows an example of the structure of the inspection apparatus which uses the inspection method which concerns on one Embodiment of this invention. It is a conceptual diagram which shows another example of the part to be inspected. It is a graph which shows an example of the current-voltage characteristic when the current is passed through the part to be inspected in the forward direction. It is a flowchart which shows an example of the operation of the on-voltage search unit shown in FIG. It is a flowchart which shows an example of the operation of the on-voltage search unit shown in FIG. It is explanatory drawing which shows an example of the measurement information. It is explanatory drawing which shows an example of an inclination and a ratio. It is a flowchart which shows an example of the inspection method by the measurement processing unit and the determination unit shown in FIG. It is a graph which shows an example of the current-voltage characteristic when the current flows in the forward direction through the inspection target part which connected three current paths in parallel. It is a block diagram which shows another example of the inspection apparatus shown in FIG. It is a block diagram which shows an example of the structure of the inspection apparatus which concerns on 2nd Embodiment. It is a flowchart which shows an example of the operation of the reference inclination acquisition part shown in FIG. It is explanatory drawing for demonstrating the operation of the reference inclination acquisition unit, the measurement processing unit, and the determination unit shown in FIG. It is a flowchart which shows an example of the operation of the measurement processing unit and the determination unit shown in FIG. It is explanatory drawing for demonstrating the operation of the reference inclination acquisition unit, the measurement processing unit, and the determination unit shown in FIG. It is a flowchart which shows an example of the operation of the measurement processing part and the determination part which concerns on 3rd Embodiment. It is a flowchart which shows an example of the operation of the measurement processing part and the determination part which concerns on 3rd Embodiment. It is explanatory drawing for demonstrating the operation of the measurement processing part and the determination part which concerns on 3rd Embodiment. It is a flowchart which shows the modification of the operation of the measurement processing part and the determination part which concerns on 3rd Embodiment. It is explanatory drawing for demonstrating the operation of the measurement processing part and the determination part which concerns on 3rd Embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. It should be noted that the configurations with the same reference numerals in the respective figures indicate that they are the same configurations, and the description thereof will be omitted.
(First Embodiment)

The inspection device 1 shown in FIG. 1 includes a current supply unit 2, a voltage measurement unit 3, a current measurement unit 4, probes Pr1 and Pr2, and a control unit 5. The inspection device 1 may be a substrate inspection device that inspects a substrate, or may be a semiconductor inspection device that inspects a semiconductor wafer or the like. FIG. 1 shows a state in which the probes Pr1 and Pr2 of the inspection device 1 are brought into contact with the circuit board 100 to be inspected.

The circuit board 100 includes, for example, a wiring board 101 and a component 102 mounted on the surface of the wiring board 101. The wiring board 101 is a so-called printed wiring board. Wiring patterns W1 to W8 are formed on the surface of the wiring board 101.

The wiring board 101 includes, for example, a printed wiring board, a film carrier, a flexible substrate, a ceramic multilayer wiring board, a semiconductor substrate such as a semiconductor chip and a semiconductor wafer, a package substrate for a semiconductor package, an electrode plate for a liquid crystal display or a plasma display, and the like. It may be an intermediate substrate in the process of manufacturing the substrate of the above, or a so-called carrier substrate. Further, the circuit board 100 may be, for example, a board with built-in components, or may be, for example, a semiconductor board in which circuit elements are formed by a semiconductor process. The inspection target of the inspection device 1 may be a substrate, a semiconductor wafer, a semiconductor element, or the like. The wiring board 101 is provided with an inspection target portion A to be inspected.

The component 102 includes diodes D1 and D2 and terminals T1 to T4. The anode of the diode D1 is connected to the terminal T1 and the cathode is connected to the terminal T2. The anode of the diode D2 is connected to the terminal T3 and the cathode is connected to the terminal T4. The diodes D1 and D2 may be, for example, protection diodes built in a semiconductor integrated circuit (IC).

The component 102 may be various components such as a semiconductor integrated circuit, a semiconductor element, a diode element, a diode array, and an LED (Light Emitting Diode). The diode has a characteristic that the current flowing at a certain voltage suddenly increases when the voltage applied in the forward direction is gradually increased. The voltage at which this current increases rapidly is called the on-voltage.

The component 102 may have a non-linear characteristic (hereinafter referred to as a diode characteristic) in which the current flowing when a voltage exceeding the on voltage is applied, which is similar to the diode, is not necessarily the diode itself. It does not have to be. Although FIG. 1 shows an example in which a single component 102 includes two diodes D1 and D2, the diodes D1 and D2 may be individual components. For example, the diode D1 and the diode D2 are included in separate ICs or the like, and may be connected in parallel by external wiring. Further, the number of diodes may be three or more.

Further, the diodes D1 and D2 are not limited to those intentionally formed as diode elements. The diodes D1 and D2 may be a protection diode of a semiconductor element, a parasitic diode, or the like, or may have diode characteristics due to an oxide film at a junction of wirings or a junction of dissimilar materials. It is not limited to the example of being attached to the diode.

Pads Pa1 to Pa4 are formed at one end of the wiring patterns W1 to W4. The pad Pa1 is connected to the terminal T1, the pad Pa2 is connected to the terminal T2, the pad Pa3 is connected to the terminal T3, and the pad Pa4 is connected to the terminal T4. The other end of the wiring pattern W1 and the other end of the wiring pattern W3 are connected by the wiring pattern W5, and the other end of the wiring pattern W2 and the other end of the wiring pattern W4 are connected by the wiring pattern W6. A wiring pattern W7 extends from the wiring pattern W5, and a pad Pa5 is provided at the tip of the wiring pattern W7. A wiring pattern W8 extends from the wiring pattern W6, and a pad Pa6 is provided at the tip of the wiring pattern W8.

As a result, the current path A1 in which the wiring pattern W1, the diode D1 and the wiring pattern W2 are connected in series is formed, and the current path A2 in which the wiring pattern W3, the diode D2, and the wiring pattern W4 are connected in series is formed. .. The current paths A1 and A2 correspond to an example of a current path having diode characteristics. The current paths A1 and A2 are connected in parallel by wiring patterns W5 and W6.

The circuit portion from the pad Pa5 to the pad Pa6 is designated as the inspection target portion A. In the present embodiment, the inspection target portion A, which is the inspection target of the inspection device 1, is a circuit provided between the pads Pa5 and the pads Pa6. That is, one end of the inspection target portion A is a pad Pa5, and the other end is a pad Pa6. When the diodes D1 and D2 are built in the semiconductor integrated circuit, the diodes D1 and D2 may be connected in parallel in the semiconductor integrated circuit.

The probes Pr1 and Pr2 are moved by a moving mechanism (not shown) and come into contact with pads Pa5 and Pa6 set in advance as inspection points. The inspection device 1 may be configured to include, for example, several hundred to several thousand probes held in a multi-needle shape. Then, the probes Pr1 and Pr2 are selected from the multi-needle probe by a switching circuit (not shown), and the probes Pr1 and Pr2 are connected to the current supply unit 2, the voltage measurement unit 3, and the current measurement unit 4. It may be a configuration. Further, the probes Pr1 and Pr2 may be so-called flying probes whose positions can be moved arbitrarily.

FIG. 2 shows an example of a case where two diodes built in the semiconductor integrated circuit 103 are connected in parallel in the semiconductor integrated circuit 103. In FIG. 2, as an example of the input / output port, the circuit around the input port is shown as the semiconductor integrated circuit 103. The semiconductor integrated circuit 103 includes an input buffer 104, protection diodes D3 to D6, a signal input terminal T5, a power supply terminal V +, and a power supply terminal V−.

The input terminal of the input buffer 104 is connected to the signal input terminal T5, the anode of the protection diodes D3 and D4, and the cathode of the protection diodes D5 and D6. The cathodes of the protection diodes D3 and D4 are connected to the power supply terminal V +, and the anodes of the protection diodes D5 and D6 are connected to the power supply terminal V−. The signal input terminal T5, the power supply terminal V +, and the power supply terminal V-are connected to, for example, pads Pa7, Pa8, and Pa9 provided on an IC socket or a substrate, respectively.

When the circuit portion from the pad Pa7 to the pad Pa8 is designated as the inspection target portion B, the probe Pr1 may be brought into contact with the pad Pa7, and the probe Pr2 may be brought into contact with the pad Pa8 to operate the inspection device 1. When the circuit portion from the pad Pa9 to the pad Pa7 is designated as the inspection target portion C, the probe Pr1 is brought into contact with the pad Pa9 and the probe Pr2 is brought into contact with the pad Pa7 as shown in parentheses in FIG. You just have to make it work. The probes Pr1 and Pr2 may be brought into direct contact with the signal input terminals T5 and the power supply terminals V + and V−. The probes Pr1 and Pr2 do not need to be physically moved, and their connection relationships may be changed by using a switching circuit or the like as described later.

The current supply unit 2 is configured by using, for example, a constant current circuit. The positive electrode of the current supply unit 2 is connected to the probe Pr1, and the negative electrode of the current supply unit 2 is connected to the probe Pr2. As a result, the current supply unit 2 supplies the diodes D1 and D2 with a forward current according to the control signal from the control unit 5.

The voltage measuring unit 3 is a so-called voltmeter, and is configured by using, for example, an analog-digital converter and a voltage dividing circuit. The voltage measuring unit 3 measures the voltage between the probes Pr1 and Pr2, that is, the voltage between both ends of the inspection target unit A in which the probes Pr1 and Pr2 are in contact, and outputs a signal indicating the measured voltage to the control unit 5.

The current measuring unit 4 is a so-called ammeter, and is configured by using, for example, an analog-digital converter, a shunt resistor, a Hall element, or the like. The current measuring unit 4 measures the current flowing between the probes Pr1 and Pr2, that is, the current flowing through the inspection target unit A in which the probes Pr1 and Pr2 are in contact, and outputs a signal indicating the measured current to the control unit 5.

The control unit 5 is a so-called microcomputer, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a RAM (Random Access Memory) that temporarily stores data, and a non-volatile flash memory or HDD (Hard). A storage unit 54 including a Disk Drive) and the like, and peripheral circuits thereof and the like are provided. The storage unit 54 stores in advance a program for an inspection device according to an embodiment of the present invention. Then, the control unit 5 functions as the measurement processing unit 51, the determination unit 52, and the on-voltage search unit 53 by executing the inspection device program stored in the storage unit 54.

The measurement processing unit 51 causes the current of the preset first current value Ia to flow between the probes Pr1 and Pr2 by the current supply unit 2, and first causes the voltage between the probes Pr1 and Pr2 by the voltage measurement unit 3. It is measured as a voltage value Va. The first current value Ia is preset to be equal to or lower than the reference current value IS, which is the current value at which the voltage between both ends of the normal inspection target portion A becomes substantially the on-voltage. The measurement processing unit 51 controls the current supply unit 2 so that the current value measured by the current measurement unit 4 becomes equal to the first current value Ia, so that the current of the first current value Ia is transmitted from the current supply unit 2. It may be output.

It should be noted that the current value at which the on-voltage is substantially turned on means that a difference in measurement error or degree of variation is allowed. The first current value Ia may be a value in the range of, for example, about -10% to + 10% with respect to the current value at which the on-voltage is accurately turned on.

The determination unit 52 determines the quality of the inspection target unit A based on the first voltage value Va measured by the voltage measurement unit 3.

The on-voltage search unit 53 searches for the on-voltage Von of the inspection target unit A from a reference sample of the circuit board 100, which is different from the circuit board 100 to be inspected. The on-voltage Von of the reference sample is used to determine the determination reference and the first current value Ia of the determination unit 52.

The on-voltage search unit 53 causes the current supply unit 2 to pass a current between the probes Pr1 and Pr2 a plurality of times while making the current value different. Then, the on-voltage search unit 53 causes the voltage measuring unit 3 to measure the voltage between the probes Pr1 and Pr2 during each period in which each current flows, and based on the changes in the measured plurality of voltages, the on-voltage searching unit 53 of the inspection target unit A. Search for on-voltage Von.

Next, the operation of the inspection device 1 configured as described above will be described with reference to FIGS. 3 to 5. The graph G1 shown in FIG. 3 shows a graph when the inspection target portion A is normal, and the graph G2 shows a graph when one of the current paths A1 and A2 is broken. Hereinafter, the characteristics of the diode D1 and the diode D2 are assumed to be substantially equal. The current-voltage characteristics of FIG. 3 and the inspection target portion A, which will be described later, are merely examples, and are not limited thereto.

In the following flowchart, the same operation is assigned the same step number and the description thereof will be omitted.

First, for example, a user mounts a normal circuit board as a reference sample on a mounting table (not shown). Then, the on-voltage search unit 53 brings the probe Pr1 into contact with the pad Pa5 and the probe Pr2 into contact with the pad Pa6 (step S1).

Next, the on-voltage search unit 53 substitutes 1 for the variable k and sets the current value I (k) as the initial value, for example, 0.1 mA (step S2). The variable k is a reference number for associating the current value I with the voltage value V, the current value I (k) indicates the current value I of the k number, and the voltage value V (k) indicates the voltage value V of the k number. , The current value I and the voltage value V of the same number correspond to each other. Although the unit of the current value I and the voltage value V may be omitted, the unit of the current value I is milliampere (mA) and the unit of the voltage value V is volt (V).

Next, the on-voltage search unit 53 causes the current supply unit 2 to flow a current having a current value I (k) between the probes Pr1 and Pr2, and during the period in which the current is flowing, the voltage measuring unit 3 causes the probe to flow. The voltage between Pr1 and Pr2 is measured as a voltage value V (k) (step S3).

Hereinafter, the measurement processing unit 51, the determination unit 52, the on-voltage search unit 53, etc. supply the current by the current supply unit 2, and the measurement processing unit 51, the determination unit 52, the on-voltage search unit 53, etc. simply supply the current. The measurement processing unit 51, the determination unit 52, the on-voltage search unit 53, or the like causes the voltage measurement unit 3 to measure the voltage simply by the measurement processing unit 51, the determination unit 52, or the on-voltage. It is described that the search unit 53 or the like measures the voltage, and the measurement processing unit 51 simply determines that the measurement processing unit 51, the determination unit 52, or the on-voltage search unit 53 or the like measures the current by the current measurement unit 4. It is described that the unit 52, the on-voltage search unit 53, or the like measures the current.

As a result, the on-voltage search unit 53 sets the voltage between the pads Pa5 and Pa6 to the voltage value V (k) while the current of the current value I (k) is flowing between the pads Pa5 and Pa6 of the inspection target unit A. ). The on-voltage search unit 53 stores the voltage value V (k) measured in this way in the storage unit 54 as measurement information in association with the number k and the current value I (k).

FIG. 6 shows the measurement information measured in step S3 and step S5 described later. If the normal inspection target portion A in which the current paths A1 and A2 are not broken has the characteristics shown in the graph G1, 0.033V is measured for a current of 0.1mA.

Next, the on-voltage search unit 53 adds 1 to the variable k. Further, the on-voltage search unit 53 adds 0.1 to the current value I (k-1), that is, the previously set current value to obtain a new current value I (k) (step S4). As a result, the voltage value can be measured while increasing the current value by 0.1 mA. The smaller the amount of increase in the current value, the higher the on-voltage acquisition accuracy, but the longer the processing time. Therefore, the amount of increase in the current value is not limited to 0.1 mA, and may be appropriately set depending on the balance between accuracy and processing time.

Next, the on-voltage search unit 53 causes a current of the current value I (k) to flow between the probes Pr1 and Pr2 in the same manner as in step S3, and the voltage between the probes Pr1 and Pr2 during the period in which the current is flowing. Is measured as a voltage value V (k) (step S5). The on-voltage search unit 53 stores the voltage value V (k) measured in this way in the storage unit 54 as measurement information in association with the number k and the current value I (k).

Now, since the current value I (k) is 0.2 mA, 0.065 V is measured for a current of 0.2 mA according to the graph G1.

Next, the on-voltage search unit 53 calculates the slope r (k-1) based on the following equation (1) (step S6).

Slope r (k-1) = {I (k) -I (k-1)} / {V (k) -V (k-1)} ... (1)

Now, since k = 2, I (2) = 0.2, I (1) = 0.1, V (2) = 0.065, and V (1) = 0.033, the slope r (1) = {I (2) -I (1)} / {V (2) -V (1)} = (0.2-0.1) / (0.065-0.033) = 3.13 ..

The on-voltage search unit 53 stores the inclination r (k-1) thus obtained in the storage unit 54 as inclination information.

Next, the on-voltage search unit 53 compares the current value I (k) with 1.0 mA (step S7). If the current value I (k) is less than 1.0 mA (NO in step S7), steps S4 to S7 are repeated again.

On the other hand, if the current value I (k) is 1.0 mA or more (YES in step S7), the on-voltage search unit 53 sets k-1 to the number of data n which is the number of slope r (step S8), and steps. Move to S11. The current value to be compared with the current value I (k) may be set to a value larger than the current value expected to obtain the on-voltage, and is not limited to 1.0 mA.

As described above, by the processing of steps S1 to S7, a current is passed between both ends of the inspection target portion A a plurality of times while changing the current value, and the voltage between both ends of the inspection target portion A is generated during each period in which each current flows. It will be measured.

FIG. 7 is an explanatory diagram of the slope r calculated by the on-voltage search unit 53 shown in FIG. 1 and the ratio R described later. Since the number of data n is 9, the slopes r (1) to r (9) corresponding to k = 1 to 9 are stored in the storage unit 54.

As described above, by the processing of steps S2 to S7, the on-voltage search unit 53 causes the current to flow between the probes Pr1 and Pr2 a plurality of times while making the current values different, and between the probes Pr1 and Pr2 during each period when each current flows. Measure the voltage.

Next, in step S11, the on-voltage search unit 53 substitutes 2 for the variable k (step S11).

Next, the on-voltage search unit 53 calculates the ratio R (k) based on the following equation (2) (step S12), and if k is less than n (NO in step S13), the variable k is set to 1. Addition (step S14), steps S12 and S13 are repeated, and when k becomes n (YES in step S13), the process proceeds to step S15. As a result, the ratios R (2) to R (n) corresponding to the numbers 2 to n are calculated.

Ratio R (k) = r (k) / r (k-1) ... (2)

In step S15, the on-voltage search unit 53 searches for the maximum R (m) of the ratios R (2) to R (n) as the ratio R corresponding to the on-voltage Von (step S15). The on-voltage search unit 53 acquires the number m from the maximum searched ratio R (m). Since the number m is the number of the voltage value V (m) corresponding to the on-voltage Von, searching for the maximum ratio R (m) is nothing but searching for the on-voltage Von.

In the example of FIG. 7, the maximum is R (8) = 4.2. Therefore, the number m = 8.

Next, the on-voltage search unit 53 refers to the measurement information stored in the storage unit 54 in step S5, and stores V (m) as the on-voltage Von in the storage unit 54 (step S16). In the example shown in FIG. 6, since the voltage value V (8) of 8 having the same number as m is 0.30 V, the on-voltage Von is 0.30 V. The on-voltage Von is a voltage at which the flowing current rapidly increases when the voltage applied to the inspection target portion A in the forward direction is gradually increased.

Further, the on-voltage search unit 53 calculates the first current value Ia based on the following equation (3) and stores it in the storage unit 54 (step S17). The first current value Ia is an on-current that is turned on by the inspection target portion A in which any one of the plurality of current paths A1 and A2 is disconnected.

First current value Ia = I (m) × (Q-1) / Q ・ ・ ・ (3)
However, Q is the number of parallel current paths having diode characteristics.

Now, the number of parallel parts A to be inspected is 2, and in the example shown in FIG. 6, the current value I (8) of 8 having the same number as m is 0.8 mA. Therefore, from the equation (3), the first current value Ia = 0.8 / 2 = 0.4 mA.

Here, I (m) is substantially equal to the reference current value IS. Therefore, it is preferable that the on-voltage search unit 53 stores I (m) in the storage unit 54 as the reference current value IS in step S17.

The first current value Ia may be substantially equal to the on-current on which the inspection target portion A in which any one of the plurality of current paths A1 and A2 is disconnected is turned on. The fact that the first current value Ia is substantially equal to the on-current means that, for example, the error of I (m) acquired in steps S1 to S17 between the first current value Ia and the on-current, the voltage measuring unit. The purpose is to allow a degree of difference caused by the measurement error of 3 or the current measuring unit 4, the output error of the current supply unit 2, and the like. The first current value Ia may be, for example, a value in the range of about -10% to + 10% with respect to the on-current.

As for the on-voltage Von, if the characteristics of the diode D1 and the diode D2 are substantially the same, as shown in FIG. 3, the on-voltage Von of the normal inspection target part A shown in the graph G1 and the defective inspection target part A shown in the graph G2 Is approximately equal to the on-voltage Von of. The first current value Ia is a current value (0.4 mA in the graph G2) at which the voltage between both ends of the defective inspection target portion A becomes the on-voltage Von. On the other hand, as shown in FIG. 3, the current value (0.8 mA in the graph G1) at which the voltage between both ends of the normal inspection target portion A becomes the on-voltage Von is the voltage between both ends of the defective inspection target portion A. It becomes larger than the current value that becomes the on-voltage Von. Therefore, the first current value Ia obtained by the processing of steps S1 to S17 is equal to or less than the reference current value IS.

In steps S1 to S17, a normal circuit board is used as a reference sample, and an example of obtaining the first current value Ia of the inspection target portion A in which one of the current paths A1 and A2 is broken by calculation is shown in step S17. rice field. However, in step S1, a defective circuit board in which one of the current paths A1 and A2 is actually disconnected may be used, and in step S17, I (m) may be used as it is as the first current value Ia.

As described above, by the processing of steps S6 to S17, the on-voltage search unit 53 acquires the on-voltage von of the inspection target unit A of the reference sample based on the changes of the plurality of voltage values V (1) to V (10). be able to.

Next, the on-voltage search unit 53 measures the voltage between the probes Pr1 and Pr2 as the voltage value Vg while passing the current of the first current value Ia between the probes Pr1 and Pr2 (step S18). As a result, the on-voltage search unit 53 measures the voltage between the pads Pa5 and Pa6 as the voltage value Vg while the current of the first current value Ia is flowing between the pads Pa5 and Pa6 of the inspection target unit A. ..

Now, since the first current value Ia is 0.4 mA, 0.14 V can be obtained as the voltage value Vg according to the example of the graph G1 in FIG.

Next, the on-voltage search unit 53 calculates a determination voltage Vref for determining the quality of the inspection target unit A based on the voltage value Vg, and stores this in the storage unit 54 (step S19). Specifically, for example, when a variation in the voltage value Vg or a measurement error is assumed to be up to 10%, the determination voltage Vref is calculated by multiplying the voltage value Vg by 1.1. Now, since the voltage value Vg is 0.14V, 0.15V can be obtained as the determination voltage Vref.

As a result, a determination voltage Vref that can be correctly determined can be obtained even when an error occurs due to manufacturing variation or measurement error with respect to the voltage value Vg.

As described above, by the processing of steps S1 to S19, the first current value Ia and the determination voltage Vref are stored in the storage unit 54, that is, set in advance.

The inspection device 1 does not necessarily have to include the on-voltage search unit 53. For example, the user may experimentally acquire the first current value Ia and the determination voltage Vref by the same method as in steps S1 to S19, store them in the storage unit 54, and set them in advance. Alternatively, the user may draw the graphs G1 and G2 shown in FIG. 3 and store the first current value Ia and the determination voltage Vref read from the graphs G1 and G2 in the storage unit 54 and set them in advance. ..

Next, the operations of the measurement processing unit 51 and the determination unit 52 shown in FIG. 1 will be described with reference to FIG. First, for example, a user places a circuit board 100 to be inspected on a mounting table (not shown). Then, the measurement processing unit 51 brings the probe Pr1 into contact with the pad Pa5 and the probe Pr2 into contact with the pad Pa6 (step S21).

Next, the measurement processing unit 51 reads the first current value Ia from the storage unit 54. Then, the measurement processing unit 51 measures the voltage between the probes Pr1 and Pr2 as the first voltage value Va while passing the current of the first current value Ia between the probes Pr1 and Pr2 (step S22). As a result, the measurement processing unit 51 measures the voltage between the pads Pa5 and Pa6 as the first voltage value Va while the current of the first current value Ia is flowing between the pads Pa5 and Pa6 of the inspection target unit A. do.

Now, since the first current value Ia is 0.4 mA, according to the example shown in FIG. 3, if the inspection target portion A is normal, 0.14 V is measured as the first voltage value Va as shown in the graph G1. If the inspection target portion A is defective, 0.30 V is measured as the first voltage value Va as shown in the graph G2.

Next, the determination unit 52 reads the determination voltage Vref from the storage unit 54. Then, the determination unit 52 compares the first voltage value Va with the determination voltage Vref (step S23). Then, if the first voltage value Va is equal to or less than the determination voltage Vref (YES in step S23), the determination unit 52 determines that the inspection target unit A is normal (step S24). The determination unit 52 displays the determination result on a display device (not shown), transmits it to the outside to notify the determination result, or stores the determination result in the storage unit 54 (step S26), and ends the process.

In the example shown in FIG. 3, if the inspection target portion A is normal, the first voltage value Va is 0.14 V from the graph G1 and is equal to or less than the determination voltage Vref (= 0.15 V) (YES in step S23). It is correctly determined that the inspection target portion A is normal.

On the other hand, if the first voltage value Va exceeds the determination voltage Vref (NO in step S23), the determination unit 52 determines that the inspection target unit A is defective (step S25). The determination unit 52 displays the determination result on a display device (not shown), transmits it to the outside to notify the determination result, or stores the determination result in the storage unit 54 (step S26), and ends the process.

In the example shown in FIG. 3, if the inspection target portion A is defective, the first voltage value Va becomes 0.30 V from the graph G2 and exceeds the determination voltage Vref (= 0.15 V) (NO in step S23), so that it is correct. The inspection target portion A is determined to be defective.

Here, the first current value Ia causes the current of the first current value Ia to flow through the inspection target portion A in which one of the plurality of current paths is disconnected by the processing of steps S1 to S17, that is, the defective inspection target portion A. When this is done, the voltage between both ends of the inspection target portion A is set to a current value that substantially becomes the on-voltage Von.

As a result, as shown in FIG. 3, the voltage between both ends of the inspection target portion A when the current of the first current value Ia is passed through the inspection target portion A is 0 in the normal inspection target portion A (graph G1). Since it is .14V and 0.30V in the defective inspection target part A (graph G2), the voltage difference Vd1 is 0.16V.

On the other hand, if the first current value Ia is a current in which the voltage between both ends of the inspection target portion A becomes substantially the on-voltage Von when the current of the first current value Ia is passed through the normal inspection target portion A. When the values are set, for example, in the case of FIG. 3, the first current value Ia is 0.8 mA, and the voltage between both ends of the inspection target portion A is 0. Since 30V is 0.32V in the defective inspection target portion A (graph G2), the voltage difference Vd2 is 0.02V.

That is, in the example shown in FIG. 3, when the current of the first current value Ia is passed through the defective inspection target portion A, the voltage between both ends of the inspection target portion A is substantially on voltage. By setting the current value to be Von, the voltage between both ends of the inspection target part A becomes substantially the on-voltage Von when the current of the first current value Ia is passed through the normal inspection target part A. The difference between the first voltage value Va at the time of normal operation and that at the time of failure is larger than the case of setting to Vd1 / Vd2 = 0.16 / 0.02 = 8 times.

The larger the difference between the first voltage value Va at the time of normal and the time of failure, the easier it is to determine whether or not it is normal. Therefore, the first current value Ia is set to a current value at which the voltage between both ends of the inspection target portion A becomes substantially the on-voltage Von when the current of the first current value Ia is passed through the defective inspection target portion A. By doing so, the voltage between both ends of the inspection target portion A becomes substantially the on-voltage Von when the current of the first current value Ia is passed through the normal inspection target portion A, as compared with the case of setting the current value. It is possible to facilitate the determination of whether or not it is normal.

The first current value Ia is a current value at which the voltage between both ends of the inspection target portion A becomes substantially an on-voltage Von when the current of the first current value Ia is passed through the defective inspection target portion A. It does not have to be. For example, the first current value Ia is set to a current value smaller than the reference current value IS (0.8 mA in FIG. 3). Further, when the first current value Ia is passed through the defective inspection target portion A with the current of the first current value Ia, the voltage between both ends of the inspection target portion A becomes substantially an on-voltage Von (FIG. The current value is 0.4 mA) or more of 3. By doing so, from FIG. 3, the voltage difference between the graph G1 in the normal state and the graph G2 in the defective state becomes larger than that in the case where the first current value Ia exceeds 0.8 mA, and therefore the determination becomes easy. You can see that.

Further, from FIG. 3, even when the first current value Ia is smaller than 0.4 mA and the current value is 0.1 mA or more, it is more normal than when the first current value Ia exceeds 0.8 mA. It can be seen that the difference between the first voltage value Va at the time of failure and the first voltage value Va becomes large, and therefore the determination becomes easy.

The inspection device 1 does not necessarily have to include the determination unit 52, and steps S23 to S25 may not be executed. Since the information indicating whether or not the inspection target unit A is normal is reflected in the first voltage value Va, the inspection of the inspection target unit A can be performed by obtaining the first voltage value Va by the measurement processing unit 51. It will be easier.

Further, although the inspection target unit A shows an example in which two current paths A1 and A2 are connected in parallel, the number of current paths connected in parallel may be three or more. For example, when the current paths A3 shown in the figure are connected in parallel in addition to the current paths A1 and A2, if the characteristics of the current path A3 are substantially the same as those of the current paths A1 and A2, the current-voltage characteristics are shown in FIG. It is indicated by 9.

Graph G3 shown in FIG. 9 shows the characteristics in the normal state, graph G4 shows the characteristics when one of the three current paths is disconnected, and graph G5 shows the characteristics when two of the three current paths are disconnected. Shown. Graph G5 is the same as graph G2 when one current path is disconnected in FIG. 3 in which two current paths A1 and A2 are connected in parallel.

In this way, even when the three current paths are connected in parallel, the on-voltage search unit 53 performs the on-voltage Von, the determination voltage Vref, and the first current value Ia by the same processing as in steps S1 to S19. Can be obtained.

In this case, the on voltage Von = 0.30V, the first current value Ia = 0.80mA, the voltage value Vg = 0.195V, and the determination voltage Vref = 0.215V. Then, based on the determination voltage Vref (= 0.215V) and the first current value Ia (= 0.8mA) thus obtained, the first voltage value Va is performed by the same processing as in steps S21 to S25. Can be measured and the inspection target part can be inspected.

In this case, when the first current value Ia is passed through the inspection target portion A in which only one of the plurality of current paths is disconnected, the voltage between both ends of the inspection target portion A is increased. By setting the current value to be substantially the on-voltage Von, the voltage difference Vd3 between the determination voltage Vref and the first voltage value Va in the defective graph G4 becomes 0.30-0.215 = 0.085V.

On the other hand, for the first current value Ia of the inspection target portion A in which the remaining current path other than one of the plurality of current paths is disconnected, step S17 is set to the first current value Ia = I (m) / Q. Demanded by. The first current value Ia obtained by I (m) / Q is the case where the current of the first current value Ia is passed through the inspection target portion A in which the residual current path other than one of the plurality of current paths is disconnected. In addition, the voltage between both ends of the inspection target portion A becomes a current value that substantially becomes the on-voltage Von. In this case, as shown in parentheses in FIG. 9, the first current value Ia is 0.40 mA, the voltage value Vg is 0.09 V, and the determination voltage Vref = 0.10 V. The voltage difference Vd4 from one voltage value Va is 0.14-0.10 = 0.04V.

That is, the voltage difference Vd3 is larger than the voltage difference Vd4. Therefore, rather than obtaining the first current value Ia based on the inspection target portion A in which the remaining current paths other than one of the plurality of current paths are disconnected, the inspection target portion in which only one of the plurality of current paths is disconnected is obtained. When the first current value Ia is obtained based on A, the difference between the first voltage value Va at the time of normal operation and the value of the first voltage value Va at the time of failure becomes larger, and it is easier to determine whether or not it is normal.

Therefore, when the current of the first current value Ia is passed through the inspection target portion A in which only one of the plurality of current paths is disconnected, the voltage between both ends of the inspection target portion A is substantially the same. It is more preferable to set the current value so that the on-voltage is Von.

On the other hand, as shown in FIG. 9, the voltage difference Vd4 is larger than the voltage difference Vd5 between the normal graph G3 and the defective graph G4 when the first current value Ia is set to the reference current value IS or more. Therefore, when a current having the first current value Ia is passed through the inspection target portion A in which the remaining current paths other than one of the plurality of current paths are disconnected, the voltage between both ends of the inspection target portion A is substantially changed. Even when the current value is set to the on-voltage Von, the effect of facilitating the determination of normality can be obtained.

Further, when a current is passed through the inspection target portion A in which the remaining current paths other than one of the plurality of current paths are disconnected, the voltage between both ends of the inspection target portion A becomes substantially an on-voltage Von. Let be the defective current value IE. Then, a normal graph G3 and a defective graph when the first current value Ia is set to a current range smaller than the reference current value IS (= 1.2 mA) and equal to or greater than the defective current value IE (= 0.4 mA). As shown in FIG. 9, the voltage difference from G4 is larger than the voltage difference Vd5, and therefore it is easy to determine whether or not it is normal.

Therefore, a current range smaller than the reference current value IS and equal to or greater than the defective current value IE can be suitably used as the first current value Ia.

Further, although an example of measuring the first voltage value Va generated in the inspection target portion A by passing a current having the first current value Ia through the inspection target portion A is shown, the following may be used. That is, as shown in FIG. 10, the inspection device 1c may include, for example, a voltage supply unit 2c such as a constant voltage power supply circuit instead of the current supply unit 2. Then, the measurement processing unit 51c applies the first voltage value Va of substantially on-voltage Von or less to the inspection target unit A by the voltage supply unit 2c, and causes the first current value Ia generated in the inspection target unit A. It may be measured by the current measuring unit 4. Then, the determination unit 52c may determine the quality of the inspection target unit A based on the first current value Ia measured by the current measurement unit 4.

Since the information indicating whether or not the inspection target unit A is normal is reflected in the first current value Ia obtained in this way, the measurement processing unit 51 obtains the first voltage value Va. The inspection of the inspection target part A becomes easy.
(Second Embodiment)

Next, the inspection device 1a according to the second embodiment of the present invention will be described with reference to FIG. The inspection device 1a shown in FIG. 11 has a different configuration of the control unit 5a from the inspection device 1 shown in FIG. The control unit 5a further includes a reference inclination acquisition unit 55. The measurement processing unit 51a, the determination unit 52a, and the on-voltage search unit 53a operate differently from the measurement processing unit 51, the determination unit 52, and the on-voltage search unit 53.

Further, the inspection device 1a does not have to include the on-voltage search unit 53a like the inspection device 1. Since other configurations are the same as those of the inspection device 1 according to the first embodiment, the description thereof will be omitted, and the characteristic points of the present embodiment will be described below.

The on-voltage search unit 53a stores the first current value Ia in the storage unit 54 by setting the first current value Ia = I (m) in step S17 shown in FIG. Further, the on-voltage search unit 53a does not need to execute steps S18 and S19. In other respects, it is the same as the on-voltage search unit 53.

According to the on-voltage search unit 53a, similarly to the on-voltage search unit 53, the on-voltage Von of the inspection target unit A is searched, and the searched on-voltage Von and the first current value Ia are stored in the storage unit 54. This is preset.

The reference slope acquisition unit 55 acquires the slope of the current-voltage characteristic in the region where the voltage between both ends of the inspection target unit A of the normal reference sample is on or less than the on-voltage Von as the reference slope rs.

The measurement processing unit 51a measures the voltage between the pads Pa5 and Pa6 as the first voltage value Va while passing the current of the first current value Ia between the pads Pa5 and Pa6, and the second current smaller than the first current value Ia. The voltage between the pads Pa5 and Pa6 is measured as the second voltage value Vb while the current of the value Ib is passed between the pads Pa5 and Pa6.

The determination unit 52a is based on the ratio of the difference between the first current value Ia and the second current value Ib and the difference between the first voltage value Va and the second voltage value Vb, that is, the current of the inspection target unit A- The quality of the inspection target portion A is determined based on the slope rt of the voltage characteristic. Specifically, the determination unit 52a determines the quality of the inspection target unit A by comparing the inclination rt with the reference inclination rs.

Next, the operations of the reference tilt acquisition unit 55, the measurement processing unit 51a, and the determination unit 52a configured as described above will be described with reference to FIGS. 12 and 13.

First, for example, a user mounts a normal circuit board 100 as a reference sample on a mounting table (not shown). Then, the reference inclination acquisition unit 55 brings the probe Pr1 into contact with the pad Pa5 and the probe Pr2 into contact with the pad Pa6 (step S31).

Next, the reference inclination acquisition unit 55 reads out the on-voltage Von of the normal inspection target unit A from the storage unit 54, and sets the first voltage value Va to a value equal to the on-voltage Von (step S32).

Next, the reference inclination acquisition unit 55 reads out the first current value Ia of the normal inspection target unit A from the storage unit 54, and sets a value smaller than the first current value Ia as the second current value Ib (step). S33). For example, in the example shown in FIG. 13, the first voltage value Va = on voltage Von = 0.30 V, and the first current value Ia = 0.8 mA. In the graph G1 of the normal inspection target portion A, the point at the coordinates (Va, Ia) = (0.30, 0.8) is shown as the point P1.

The reference inclination acquisition unit 55 can set the second current value Ib to 0.3 by subtracting a preset number, for example, 0.5 from, for example, 0.8, which is the first current value Ia. can. Alternatively, the reference inclination acquisition unit 55 obtains the first current value Ia by multiplying the first current value Ia by a coefficient larger than 0 and smaller than 1 such as by multiplying the first current value Ia by 1/2 or 1/3. The two current values Ib may be obtained.

Next, the reference inclination acquisition unit 55 causes a current having a second current value Ib to flow between the probes Pr1 and Pr2, and sets the voltage between the probes Pr1 and Pr2 as the second voltage value Vb during the period in which the current is flowing. Measure (step S34). When the second current value Ib is, for example, 0.3 mA, 0.10 V is obtained as the second voltage value Vb in the graph G1 of the normal inspection target portion A shown in FIG. In the graph G1 of the normal inspection target portion A, the point at the coordinates (Vb, Ib) = (0.10, 0.3) is shown as a point P2.

Next, the reference inclination acquisition unit 55 calculates the reference inclination rs based on the following equation (4) (step S35).

Reference slope rs = (Ia-Ib) / (Va-Vb) ... (4)

In the case of the graph G1 in FIG. 13, the reference slope rs = (0.8-0.3) / (0.30-0.10) = 2.5.

The reference slope rs corresponds to the slope of the straight line connecting the points P1 and P2 in the graph G1 of the normal inspection target portion A. The reference inclination acquisition unit 55 sets in advance by storing the second current value Ib and the reference inclination rs obtained in steps S31 to S35 in the storage unit 54, and ends the process.

The inspection device 1a does not necessarily have to include the reference inclination acquisition unit 55. For example, the user may experimentally acquire the reference inclination rs by the same method as in steps S31 to S35, store it in the storage unit 54, and set it in advance. Alternatively, the user draws the graph G1 shown in FIG. 13, reads the slope of the straight line L1 as the reference slope rs, stores the read reference slope rs and the second current value Ib in the storage unit 54, and sets them in advance. It may be.

With reference to FIG. 14, first, for example, a user places a circuit board 100 to be inspected on a mounting table (not shown). Then, the measurement processing unit 51a brings the probe Pr1 into contact with the pad Pa5 and the probe Pr2 into contact with the pad Pa6 (step S41).

Next, the measurement processing unit 51a reads the first current value Ia from the storage unit 54. Then, the measurement processing unit 51a causes a current of the first current value Ia to flow between the probes Pr1 and Pr2, and measures the voltage between the probes Pr1 and Pr2 as the first voltage value Va during the period in which the current is flowing. (Step S42). For example, in the case of FIG. 13, if the inspection target portion A is normal, the first voltage value Va = 0.30V is measured at the point P1 in the graph G1. On the other hand, if any of the current paths A1 and A2 is disconnected and the inspection target portion A is defective, the first voltage value Va = 0.32V is measured at the point P3 in the graph G2.

Next, the measurement processing unit 51a reads the second current value Ib from the storage unit 54. Then, the measurement processing unit 51a causes a current having a second current value Ib to flow between the probes Pr1 and Pr2, and measures the voltage between the probes Pr1 and Pr2 as the second voltage value Vb during the period in which the current is flowing. (Step S43). For example, in the case of FIG. 13, if the inspection target portion A is normal, the second voltage value Vb = 0.10V is measured at the point P2 in the graph G1. On the other hand, if any of the current paths A1 and A2 is broken and the inspection target portion A is defective, the second voltage value Vb = 0.22V is measured at the point P4 in the graph G2.

Next, the determination unit 52a calculates the slope rt based on the following equation (5) (step S44).

Slope rt = (Ia-Ib) / (Va-Vb) ... (5)

The slope rt indicates the slope of the straight line L1 connecting the points P1 and P2 in the graph G1 if the inspection target portion A is normal. On the other hand, if the inspection target portion A is defective, the slope rt indicates the slope of the straight line L2 connecting the points P3 and P4 in the graph G2. As is clear from the straight lines L1 and L2 in FIG. 13, when the inspection target portion A is defective, the inclination rt becomes larger than when it is normal.

According to the example shown in FIG. 13, when the inspection target portion A is normal, the inclination rt = (0.8-0.3) / (0.30-0.10) = 2.5. On the other hand, when the inspection target portion A is defective, the inclination rt = (0.8-0.3) / (0.32-0.22) = 5.

Next, the determination unit 52a calculates the determination value rth for determining the quality of the inspection target unit A based on the reference inclination rs (step S45). Specifically, for example, when a variation in the reference slope rs or a measurement error is assumed to be up to 10%, the determination value rth is calculated by multiplying the reference slope rs by 1.1. For example, if the reference slope rs = 2.5, the determination value rth = 2.5 × 1.1 = 2.75.

As a result, a determination value rth that can be correctly determined can be obtained even when an error occurs due to manufacturing variation or measurement error with respect to the reference inclination rs.

Next, the determination unit 52a compares the inclination rt with the determination value rt (step S46). Then, if the inclination rt is equal to or less than the determination value rt (NO in step S46), the determination unit 52a determines that the inspection target unit A is normal (step S47). The determination unit 52a displays the determination result on a display device (not shown), transmits it to the outside to notify the determination result, or stores the determination result in the storage unit 54 to end the process.

On the other hand, if the inclination rt exceeds the determination value rth (YES in step S46), the determination unit 52a determines that the inspection target unit A is defective (step S48). The determination unit 52a displays the determination result on, for example, a display device (not shown), transmits the determination result to the outside to notify the determination unit, or stores the determination result in the storage unit 54 to end the process (step S26).

In the example shown in FIG. 13, if the inspection target portion A is normal, the slope rt is 2.5 as described above, and the determination value rt = 2.75 or less (NO in step S46), so that the inspection target is correctly inspected. Part A is determined to be normal. On the other hand, if the inspection target portion A is defective, the inclination rt becomes 5 as described above, and the determination value rt = 2.75 is exceeded (YES in step S46), so that the inspection target portion A is correctly determined to be defective. Will be done.

In the formula (5), (Ia-Ib) is the difference between the first current value Ia and the second current value Ib, and (Va-Vb) is the difference between the first voltage value Va and the second voltage value Vb. Therefore, the gradient rt is the ratio of the difference between the first current value Ia and the second current value Ib and the difference between the first voltage value Va and the second voltage value Vb. Therefore, the determination unit 52a is inspected based on the slope rt, which is the ratio of the difference between the first current value Ia and the second current value Ib and the difference between the first voltage value Va and the second voltage value Vb. Judge the quality of A.

As described above, according to steps S41 to S48, the first current value Ia is set to the current value at which the on-voltage Von can be substantially obtained in the normal inspection target portion A, and the second current value Ib is the first current value. The current value is set to be smaller than Ia. As a result, the point P1 corresponding to the on-voltage Von in the normal inspection target portion A becomes the end on the high voltage / high current side in the straight line L1, and the point P2 becomes the end on the low voltage / low current side in the straight line L1. ..

Then, since the first voltage value Va and the second voltage value Vb are acquired based on the first current value Ia and the second current value Ib, if the inspection target portion A is defective, the inspection target portion A is defective. As shown in the graph G2 of FIG. 13, the point P3 corresponding to the first current value Ia is located on the higher voltage side than the on-voltage side of the graph G2, that is, in the region where the graph G2 rises steeply and has a large slope.

As a result, the straight line L2 when the inspection target portion A is defective has a larger inclination rt than the straight line L1 when the inspection target portion A is normal. Therefore, according to steps S41 to S48, it is easy to inspect the inspection target portion A based on the inclination rt of the straight lines L1 and L2.

Although the inspection target unit A shows an example in which two current paths A1 and A2 connected in parallel are connected in parallel, the number of current paths connected in parallel may be three or more. For example, when the current paths A3 shown in the figure are connected in parallel in addition to the current paths A1 and A2, if the characteristics of the current path A3 are substantially the same as those of the current paths A1 and A2, the current-voltage characteristics are shown in FIG. It is indicated by 15.

The graphs G3, G4, and G5 shown in FIG. 15 are the same as the graphs G3, G4, and G5 shown in FIG.

In this way, even when the three current paths are connected in parallel, the on-voltage search unit 53a changes the upper limit of the current value from 1.0 to 1.4 in step S7, so that the normal state is achieved. The on-voltage Von (= 0.30V) and the first current value Ia (= 1.2mA) in the graph G3 of the above can be acquired.

Then, based on the first current value Ia (= 1.2 mA) thus obtained, the reference inclination acquisition unit 55 calculates the reference inclination rs by the same processing as in steps S31 to S35 shown in FIG. be able to. In the graph G3 shown in FIG. 15, an example is shown in which 1/3 of the first current value Ia is set to the second current value Ib (= 0.4 mA) in step S33. In the case of the graph G3, the points of the first current value Ia (= 1.2 mA) and the first voltage value Va (= 0.30 V) are the points P5, the second current value Ib (= 0.4 mA), and the second voltage value. The point of Vb (= 0.09V) is the point P6. The slope of the straight line L3 connecting the points P5 and P6, that is, the reference slope rs = (1.2-0.4) / (0.30-0.09) = 3.8.

Further, the measurement processing unit 51a and the determination unit 52a can correctly determine the defects in the graphs G4 and G5 by the same processing as in steps S41 to S48 shown in FIG. For example, in the case of the graph G4, the points of the first current value Ia (= 1.2 mA) and the first voltage value Va (= 0.31 V) are the points P7, the second current value Ib (= 0.4 mA), and the second. The point of the voltage value Vb (= 0.14V) is the point P8. The slope rt = (1.2-0.4) / (0.31-0.14) = 4.7 of the straight line L4 connecting the points P7 and P8.

Therefore, the slope rt (= 4.7) of the straight line L4 is larger than the determination value rth (= 3.8 × 1.1 = 4.2) (YES in step S46), so that the determination unit 52a is the graph G4. It can be determined that the inspection target portion A of the above is correctly defective.

For example, in the case of the graph G5, the points of the first current value Ia (= 1.2 mA) and the first voltage value Va (= 0.33 V) are the points P9, the second current value Ib (= 0.4 mA), and the second. The point of the voltage value Vb (= 0.30V) is the point P10. The slope rt = (1.2-0.4) / (0.33-0.30) = 26.7 of the straight line L5 connecting the points P9 and P10.

Therefore, since the slope rt (= 26.7) of the straight line L5 is larger than the determination value rth (= 4.2) (YES in step S46), the determination unit 52a correctly defectives the inspection target unit A of the graph G5. Can be determined to be.
(Third Embodiment)

Next, the inspection device 1b according to the third embodiment of the present invention will be described. The configuration of the inspection device 1b is shown in FIG. 1 as in the first embodiment. In FIG. 1, a configuration different from that of the inspection device 1 is coded in parentheses. The inspection device 1b according to the third embodiment has a different configuration of the control unit 5b from the inspection device 1 according to the first embodiment. The operation of the measurement processing unit 51b and the determination unit 52b of the control unit 5b is different from that of the measurement processing unit 51 and the determination unit 52. Further, the control unit 5b includes an on-voltage search unit 53a similar to the control unit 5a instead of the on-voltage search unit 53.

Since other configurations are the same as those of the inspection device 1 according to the first embodiment, the description thereof will be omitted, and the characteristic points of the present embodiment will be described below.

The measurement processing unit 51b causes a current to flow between the probes Pr1 and Pr2 a plurality of times while making the current values different, measures the voltage between the probes Pr1 and Pr2 during each period in which each current flows, and the measured plurality of measurements. The on-current Ion when the inspection target portion A is turned on is acquired based on the change in voltage.

The determination unit 52b determines the quality of the inspection target unit A based on the on-current Ion.

Next, the operation of the inspection device 1b configured as described above will be described. First, as described above, the on-voltage search unit 53a searches for the on-voltage Von of the inspection target unit A, and the first current value Ia corresponding to the searched on-voltage Von is stored in the storage unit 54. It is set in advance. In the third embodiment, the on-voltage search unit 53a does not have to execute step S16.

With reference to FIGS. 16 to 18, for example, a user mounts a circuit board 100 to be inspected on a mounting table (not shown). Then, the measurement processing unit 51b brings the probe Pr1 into contact with the pad Pa5 and the probe Pr2 into contact with the pad Pa6 (step S51). Hereinafter, steps S2 to S8 and S11 to S15 similar to those in FIGS. 4 and 5 are executed by the measurement processing unit 51b.

By the processing of steps S2 to S7, the measurement processing unit 51b causes a current to flow between the probes Pr1 and Pr2 a plurality of times while making the current values different, and measures the voltage between the probes Pr1 and Pr2 during each period when each current flows. do.

Next, the measurement processing unit 51b acquires the number m corresponding to the on-voltage Von from the maximum ratio R (m) obtained in step S15. Then, the measurement processing unit 51b refers to the measurement information stored in the storage unit 54 in step S5, and sets the current value I (m) of the number m as the on-current Ion (step S61). In the example shown in FIG. 18, 0.8 mA is obtained as the on-current Ion when the normal inspection target part A is measured, and 0.4 mA is obtained as the on-current Ion when the defective inspection target part A is measured. Will be obtained.

As described above, by the processing of steps S6 to S61, the measurement processing unit 51b can acquire the on-current ion of the inspection target unit A based on the change of n voltage values V (1) to V (n). ..

Next, the determination unit 52b sets the on-current I (m) of the normal inspection target unit A stored in the storage unit 54 in step S17 shown in FIG. 5 by the on-voltage search unit 53a as the first current value Ia. Based on this first current value Ia, a determination value Iref for determining the quality of the inspection target portion A is calculated (step S62). Specifically, for example, when a variation in the first current value Ia or a measurement error is assumed to be up to 10%, the determination value Iref is calculated by multiplying the first current value Ia by 0.9. In the example of the graph G1 shown in FIG. 18, since the first current value Ia = 0.8, the determination value Iref = 0.8 × 0.9 = 0.72.

As a result, a determination value Iref that can be correctly determined can be obtained even when an error occurs due to manufacturing variation or measurement error with respect to the on-current Ion.

Next, the determination unit 52b compares the on-current Ion with the determination value Iref (step S63). Then, if the on-current Ion exceeds the determination value Iref (YES in step S63), the determination unit 52b determines that the inspection target unit A is normal (step S64). The determination unit 52b displays the determination result on a display device (not shown), transmits it to the outside to notify the determination result, or stores the determination result in the storage unit 54 to end the process (step S26).

On the other hand, if the on-current Ion is equal to or less than the determination value Iref (NO in step S63), the determination unit 52b determines that the inspection target unit A is defective (step S65). The determination unit 52b displays the determination result on a display device (not shown), transmits it to the outside to notify the determination result, or stores the determination result in the storage unit 54 to end the process.

In the example shown in FIG. 18, if the inspection target portion A is normal, the on-current Ion is 0.8 as shown in the graph G1 and exceeds the determination value Iref = 0.72 (YES in step S63). , It is correctly determined that the inspection target portion A is normal. On the other hand, if the inspection target portion A is defective, the on-current Ion is 0.4 as shown in the graph G2, and the determination value Iref = 0.72 or less (NO in step S63), so that the inspection target portion A is correctly inspected. Is determined to be defective.

As described above, according to the processes of steps S51 to S65, the quality of the inspection target portion A can be correctly determined, and therefore it is easy to inspect the inspection target portion A.

An example in which a current is passed between the probes Pr1 and Pr2 in step S5 a plurality of times while different current values are shown in step S4 shown in FIG. 16, and the voltage between the probes Pr1 and Pr2 is measured during each period in which each current flows. However, for example, by executing steps S2a to S5a, S7a instead of steps S2 to S5 and S7 as shown in FIG. , Pr2 may be applied and the current flowing between the probes Pr1 and Pr2 may be measured during each period in which each voltage is applied. Even in this case, by the processing of steps S6 to S61, the measurement processing unit 51b sets the on-current ion of the inspection target unit A based on the change of n current values I (1) to I (n). Can be obtained.

Although the inspection target unit A shows an example in which two current paths A1 and A2 are connected in parallel, the number of current paths connected in parallel may be three or more. For example, when the current paths A3 shown in the figure are connected in parallel in addition to the current paths A1 and A2, if the characteristics of the current path A3 are substantially the same as those of the current paths A1 and A2, the current-voltage characteristics are shown in FIG. It is indicated by 20.

The graphs G3, G4, and G5 shown in FIG. 20 are the same as the graphs G3, G4, and G5 shown in FIG.

In this way, even when the three current paths are connected in parallel, the on-voltage search unit 53a changes the upper limit of the current value from 1.0 to 1.4 in step S7, so that the normal state is achieved. The first current value Ia (= 1.2 mA) in the graph G3 of the above can be acquired.

Then, the measurement processing unit 51b can acquire the on-current Ion by the processing of steps S51 to S61 shown in FIGS. 16, 17, and 19. The determination unit 52b can determine the quality of the inspection target unit A by the processing of steps S61 to S65 shown in FIG. 17 based on the on-current Ion and the first current value Ia. When the first current value Ia = 1.2 mA, the determination value Iref = 1.2 × 0.9 = 1.08 (step S62).

In the case of the graph G3, since the on-current Ion (= 1.2) exceeds the determination value Iref (= 1.08) (YES in step S63), the inspection target portion A of the graph G3 is correctly determined to be normal. Can be done (step S64). In the case of the graph G4, since the on-current Ion (= 0.8) is equal to or less than the determination value Iref (= 1.08) (NO in step S63), the inspection target portion A of the graph G4 can be correctly determined to be defective. Yes (step S65). In the case of the graph G5, since the on-current Ion (= 0.4) is equal to or less than the determination value Iref (= 1.08) (NO in step S63), the inspection target portion A of the graph G5 can be correctly determined to be defective. Yes (step S65).

That is, in the inspection device according to the example of the present invention, the change in the current with respect to the change in the voltage when the forward voltage exceeds the on voltage is larger than the change in the current when the forward voltage is less than the on voltage. An inspection device for inspecting an inspection target part in which a plurality of current paths having diode characteristics are connected in parallel, and a current supply part capable of supplying a current and a voltage measuring part capable of measuring a voltage are set in advance. A measurement processing unit is provided, wherein the current of the first current value is made to flow between the two ends by the current supply unit, and the voltage between the two ends is measured as the first voltage value by the voltage measurement unit. The current value is equal to or less than the current value at which the voltage between both ends of the normal inspection target portion becomes substantially the on-voltage.

Further, in the inspection method according to an example of the present invention, the change in current with respect to the change in voltage when the forward voltage exceeds the on-voltage is larger than that in the case where the forward voltage is less than the on-voltage. This is an inspection method for inspecting an inspection target portion in which a plurality of current paths having diode characteristics are connected in parallel, and a voltage of the first current value set in advance is passed between the ends and a voltage between the ends is applied. The first current value includes a measurement processing step of measuring as the first voltage value, and the first current value is equal to or less than the current value at which the voltage between both ends of the normal inspection target portion becomes substantially the on-voltage.

Due to its characteristics, the inspection target portion having the diode characteristic has a slight change in the voltage with respect to the flowing current in the region where the voltage between both ends exceeds the on voltage. According to these configurations, when a first current value equal to or less than the current value at which the voltage between both ends of a normal inspection target portion becomes substantially on voltage flows to the inspection target portion, between both ends of the inspection target portion. The voltage of is measured as the first voltage value. Then, in the region where the voltage between both ends of the normal inspection target portion does not exceed the on-voltage, the voltage generated between both ends of the current of the first current value flowing through the inspection target portion is measured as the first voltage value. Therefore, the change in the first voltage value when any one of the plurality of current paths is broken appears greatly. Therefore, since the information indicating whether or not the inspection target portion is normal is reflected in the first voltage value, the inspection of the inspection target portion becomes easy by obtaining the first voltage value.

Further, it is preferable to further include a determination unit for determining the quality of the inspection target unit based on the first voltage value.

According to this configuration, it is possible to determine the quality of the inspection target portion based on the first voltage value.

Further, in the inspection device according to the example of the present invention, the change in the current with respect to the change in the voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage. It is an inspection device for inspecting an inspection target part in which a plurality of current paths having diode characteristics are connected in parallel, and is substantially a voltage supply part capable of outputting a voltage, a current measuring part capable of measuring a current, and substantially The voltage of the first voltage value preset below the on-voltage is applied between both ends of the inspection target portion by the voltage supply unit, and the current flowing between the both ends is applied by the current measuring unit to the first current value. It is provided with a measurement processing unit for measuring as.

Further, in the inspection method according to an example of the present invention, the change in current with respect to the change in voltage when the forward voltage exceeds the on-voltage is larger than that in the case where the forward voltage is less than the on-voltage. This is an inspection method for inspecting an inspection target portion in which a plurality of current paths having diode characteristics are connected in parallel. It includes a measurement processing step of measuring the current flowing between both ends as the first current value while applying the voltage between both ends.

According to these configurations, the first voltage is applied between both ends of the inspection target portion instead of the first current, and the current flowing between both ends of the inspection target portion is measured as the first current instead of the first voltage. .. Even in this case, the measured first current reflects information indicating whether or not the inspection target portion is normal, so that the inspection target portion can be easily inspected by obtaining the first current. Become.

Further, it is preferable to further include a determination unit for determining the quality of the inspection target unit based on the first current value.

According to this configuration, it is possible to determine the quality of the inspection target portion based on the first current value.

Further, in the normal inspection target portion, it is preferable that the plurality of current paths are all conducting.

If the plurality of current paths connected in parallel are all conducting, the inspection target portion is normal.

Further, the first current value is obtained at both ends of the inspection target portion when the current of the first current value is passed through the inspection target portion in which the residual current path other than one of the plurality of current paths is disconnected. It is preferable that the voltage between them is substantially equal to or higher than the current value at which the on voltage is obtained.

According to this configuration, the first current value is equal to or less than the current value at which the voltage between both ends of the normal inspection target portion becomes substantially the on-voltage, and the residual except for one of the plurality of current paths. The current range is set in advance to be equal to or greater than the current value at which the voltage between both ends of the inspection target portion becomes substantially the on-voltage when the current of the first current value is passed through the inspection target portion whose current path is broken. There is. Such a current range is suitable as the first current value.

Further, as for the first current value, when a current of the first current value is passed through the inspection target portion in which only one of the plurality of current paths is disconnected, the voltage between both ends of the inspection target portion is substantially the same. It is preferable that the value is equal to or higher than the current value at which the on-voltage is obtained.

According to this configuration, the first current value is equal to or less than the current value at which the voltage between both ends of the normal inspection target portion becomes substantially the on-voltage, and only one of the plurality of current paths is disconnected. The current range is set in advance to be equal to or higher than the current value at which the voltage between both ends of the inspection target portion becomes substantially the on-voltage when the current of the first current value is passed through the inspection target portion. Such a current range is suitable as the first current value.

Further, as for the first current value, when a current of the first current value is passed through the inspection target portion in which only one of the plurality of current paths is disconnected, the voltage between both ends of the inspection target portion is substantially the same. It is preferable that the current value is the on-voltage.

According to this configuration, the voltage between both ends of the inspection target portion is substantially the first current value when the current of the first current value is passed through the inspection target portion in which only one of the plurality of current paths is disconnected. The current value that becomes the on-voltage is preset. In this case, the first current value is higher than the case where the voltage between both ends of the inspection target portion is substantially on-voltage when the current of the first current value is passed through the normal inspection target portion. , The difference in the first voltage value obtained between normal and defective is large. Therefore, it becomes easier to judge the quality of the inspection target portion based on the first voltage value.

Further, the first current value is a current value at which the voltage between both ends of the normal inspection target unit is substantially the on-voltage, and the measurement processing unit uses the current of the first current value as the current. The voltage between both ends is measured as the first voltage value by the voltage measuring unit while being passed between the two ends by the supply unit, and the current having a second current value smaller than the first current value is measured by the current supply unit. The voltage between both ends is measured as a second voltage value by the voltage measuring unit while flowing between both ends, and the inspection device uses the difference between the first current value and the second current value and the first voltage. It is preferable to further include a determination unit for determining the quality of the inspection target unit based on the ratio of the difference between the value and the second voltage value.

According to this configuration, the difference between the first current value and the second current value and the ratio of the difference between the first voltage value and the second voltage value are the first current in the current-voltage characteristic graph of the inspection target part. It represents the slope of a straight line connecting the point where the value and the first voltage value intersect and the point where the second current value and the second voltage value intersect. Then, this inclination is larger in the inspection target portion in which one of the plurality of current paths is broken than in the normal inspection target portion. Therefore, the determination unit can determine the quality of the inspection target unit based on the above inclination.

Further, the current supply unit causes a current to flow between the two ends a plurality of times while making the current value different, and the voltage measuring unit measures the voltage between the two ends during each period in which the current flows, and the measurement is performed. It is preferable to further include an on-voltage search unit that searches for the on-voltage of the inspection target unit based on the plurality of voltage changes.

According to this configuration, it is possible to search for the on-voltage of the inspection target portion whose characteristics are unknown.

Further, in the inspection device according to an example of the present invention, the change in current with respect to the change in voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage. An inspection device for inspecting an inspection target portion in which a plurality of current paths having diode characteristics are connected in parallel, and one of the current and the voltage is subjected to a plurality of times with different values at both ends of the inspection target portion. The current that is supplied in between, measures the other of the current or voltage between the ends during each period in which the one is supplied, and turns on the current to be inspected based on the measured change in the other. It is provided with a measurement processing unit for acquiring the above and a determination unit for determining the quality of the inspection target unit based on the current acquired by the measurement processing unit.

Further, in the inspection method according to an example of the present invention, the change in current with respect to the change in voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage. This is an inspection method for inspecting an inspection target portion in which a plurality of current paths having diode characteristics are connected in parallel, and both ends of the inspection target portion are subjected to a plurality of times with different values of either current or voltage. The current that is supplied in between, measures the other of the current or voltage between the ends during each period in which the one is supplied, and turns on the current to be inspected based on the measured change in the other. Includes a measurement processing step of acquiring the above and a determination step of determining the quality of the inspection target unit based on the current acquired by the measurement processing unit.

The current that the inspection target portion turns on is larger in the normal inspection target portion than in the inspection target portion in which a disconnection occurs in one of the plurality of current paths. Therefore, according to these configurations, the current at which the inspection target portion is turned on is acquired, and the quality of the inspection target portion can be determined based on the current.

Further, the program for an inspection device according to an example of the present invention is a program for an inspection device for operating the above-mentioned inspection device, and causes a computer to function as the measurement processing unit.

According to this program, the above-mentioned inspection device can be operated by causing the computer to function as the measurement processing unit.

An inspection device, an inspection method, and a program for an inspection device having such a configuration facilitate inspection of an inspection target in which a plurality of diodes are connected in parallel.

This application is based on Japanese Patent Application No. 2018-228479 filed on December 6, 2018, the contents of which are included in the present application. In addition, the specific embodiment or example made in the section of the mode for carrying out the invention merely clarifies the technical content of the present invention, and the present invention is described in such a specific example. It should not be construed in a narrow sense.

1,1a, 1b Inspection device 2 Current supply unit 3 Voltage measurement unit 4 Current measurement unit 5,5a, 5b Control unit 51, 51a, 51b Measurement processing unit 52, 52a, 52b Judgment unit 53, 53a On-voltage search unit 54 Storage Part 55 Reference tilt acquisition part 100 Circuit board 101 Wiring board 102 Parts A, B, C Inspected parts A1, A2, A3 Current path D1, D2 Diode G1, G2, G3, G4, G5 Graph I Current value Ia First current Value Ib Second current value Ion On current Iref Judgment value IS Reference current value L1, L2, L3, L4, L5 Straight line P1 to P10 Point Pa1 to Pa6 Pad Pr1, Pr2 Probe R Ratio T1 to T4 Terminal V Voltage value Va First Voltage value Vb Second voltage value Vd1, Vd2 Voltage difference Vg Voltage value Von On voltage Vref Judgment voltage W1 to W8 Wiring pattern rs Reference tilt rt Tilt rth Judgment value

Claims (15)

A plurality of current paths having diode characteristics in which the change in current with respect to the change in voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage are connected in parallel. It is an inspection device for inspecting the part to be inspected.
A current supply unit that can supply current and
A voltage measuring unit that can measure voltage and
A measurement processing unit is provided, in which a preset first current value is passed between the two ends by the current supply unit, and the voltage between the two ends is measured as the first voltage value by the voltage measurement unit.
The first current value is an inspection device in which the voltage between both ends of the normal inspection target portion is substantially equal to or less than the current value at which the on-voltage is obtained. The inspection device according to claim 1, further comprising a determination unit for determining the quality of the inspection target unit based on the first voltage value. A plurality of current paths having diode characteristics in which the change in current with respect to the change in voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage are connected in parallel. It is an inspection device for inspecting the part to be inspected.
A voltage supply unit that can output voltage and
A current measuring unit that can measure current and
A voltage having a first voltage value set to substantially equal to or lower than the on-voltage is applied between both ends of the inspection target unit by the voltage supply unit, and a current flowing between the both ends is first applied by the current measurement unit. An inspection device including a measurement processing unit that measures a current value. The inspection device according to claim 3, further comprising a determination unit for determining the quality of the inspection target unit based on the first current value. The first current value is set between both ends of the inspection target portion when a current of the first current value is passed through the inspection target portion in which the residual current path other than one of the plurality of current paths is disconnected. The inspection device according to claim 1 or 2, wherein the voltage is substantially equal to or higher than the current value at which the on-voltage is obtained. With respect to the first current value, when a current of the first current value is passed through the inspection target portion in which only one of the plurality of current paths is disconnected, the voltage between both ends of the inspection target portion is substantially the same. The inspection device according to claim 1 or 2, wherein the on-voltage current value is equal to or higher than the current value. With respect to the first current value, when a current of the first current value is passed through the inspection target portion in which only one of the plurality of current paths is disconnected, the voltage between both ends of the inspection target portion is substantially the same. The inspection device according to claim 6, which is a current value that becomes the on-voltage. The first current value is a current value at which the voltage between both ends of the normal inspection target portion substantially becomes the on-voltage.
The measurement processing unit further causes a current having a second current value smaller than the first current value to flow between the two ends by the current supply unit, and causes the voltage between the two ends to flow to the second voltage value by the voltage measuring unit. Let me measure as
The inspection device determines the quality of the inspection target portion based on the difference between the first current value and the second current value and the ratio of the difference between the first voltage value and the second voltage value. The inspection device according to claim 1, further comprising a determination unit. A current was passed between the two ends by the current supply unit a plurality of times with different current values, and the voltage between the two ends was measured by the voltage measuring unit during each period when the currents flowed, and the measurement was performed. The inspection device according to any one of claims 1 to 8, further comprising an on-voltage search unit that searches for the on-voltage of the inspection target unit based on a plurality of changes in voltage. The inspection device according to any one of claims 1 to 9, wherein the normal inspection target portion is the inspection device in which the plurality of current paths are all conducting. A plurality of current paths having diode characteristics in which the change in current with respect to the change in voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage are connected in parallel. It is an inspection method that inspects the part to be inspected.
A measurement processing step of measuring the voltage between the two ends as the first voltage value while passing a current of a preset first current value between the two ends is included.
The inspection method in which the first current value is equal to or less than the current value at which the voltage between both ends of the normal inspection target portion becomes substantially the on-voltage. A plurality of current paths having diode characteristics in which the change in current with respect to the change in voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage are connected in parallel. It is an inspection method that inspects the part to be inspected.
It includes a measurement processing step of measuring a current flowing between both ends of the inspection target portion as a first current value while applying a voltage having a first voltage value set to substantially equal to or lower than the on voltage between both ends of the inspection target portion. Inspection method. A plurality of current paths having diode characteristics in which the change in current with respect to the change in voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage are connected in parallel. It is an inspection device for inspecting the part to be inspected.
One of the current or voltage is supplied between both ends of the inspection target portion a plurality of times with different values, and the other of the current or voltage between both ends is measured during each period in which the one is supplied. Then, the measurement processing unit that acquires the current that the inspection target unit turns on based on the measured change of the other, and the measurement processing unit.
An inspection device including a determination unit that determines the quality of the inspection target unit based on the current acquired by the measurement processing unit. A plurality of current paths having diode characteristics in which the change in current with respect to the change in voltage when the forward voltage exceeds the on voltage is larger than that in the case where the forward voltage is less than the on voltage are connected in parallel. It is an inspection method for inspecting the part to be inspected.
One of the current or voltage is supplied between both ends of the inspection target portion a plurality of times with different values, and the other of the current or voltage between both ends is measured during each period in which the one is supplied. Then, the measurement processing step of acquiring the current that the inspection target portion is turned on based on the measured change of the other, and the measurement processing step.
An inspection method including a determination step of determining the quality of the inspection target unit based on the current acquired by the measurement processing unit. A program for an inspection device for operating the inspection device according to any one of claims 1 to 10 and 13.
A program for an inspection device that causes a computer to function as the measurement processing unit.

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