JPH10186003A - Component inspecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a device and reduce the cost by specifying the voltage range of a current source which may be dropped by the operation of an active element when the output current of a prescribed current value is outputted from the current source within a reference voltage range, and inspecting the quality of the active element based on the output voltage. SOLUTION: An operator specifies an allowable range, e.g. ±20%, for the voltage value of the output voltage V0 stored in a memory as a reference daum. A CPU calculates a reference voltage range and stores it in the memory. An output current of a prescribed current value is fed to the equivalent input circuit of an active element 23, e. g. a photodiode 24 and the equivalent output circuit, e.g. a photo-transistor 25, from a constant-current source 21, and the active element 23 is judged as satisfactory when the voltage value of the output voltage V0 of the constant-current source 21 measured by a voltage measuring circuit 22 is within the prescribed reference voltage range. This device can be miniaturized and the cost can be reduced without requiring a constant-voltage source, a resistor, and a relay.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board, a hybrid board, and an MCA (Multi Chip Module).
More particularly, the present invention relates to a component inspection apparatus suitable for inspecting an active element mounted on a circuit board or the like. .

[0002]

2. Description of the Related Art For example, an inspection device 71 shown in FIG. 5 is conventionally known as a component inspection device configured to inspect the quality of an active element of this type. This inspection device 71
Are n pin probes 3a, 3b, 3c, 3d.
(Hereinafter, referred to as “pin probe 3” when not distinguished) and a constant current that outputs a constant current via a set of pin probes 3, 3 selected from a plurality of pin probes 3, 3,. A constant voltage source 72 that outputs a constant voltage via another selected set of pin probes 3 and 3, and a voltage that measures the voltage between the pin probes 3 and 3 to which the constant voltage is applied. The constant voltage source 72 includes a resistor 74 for limiting a current based on a constant voltage output from the constant voltage source 72, and a relay 75 for controlling connection of the constant voltage source 72.

In the inspection apparatus 71, for example, when inspecting the photocoupler 23, first, as shown in FIG.
By operating the relay 75, a series circuit of the resistor 74 and the constant voltage source 72 is connected in parallel to the voltmeter 73. Next, the pin probes 3a and 3b contacting between the anode and the cathode of the photodiode 24 in the photocoupler 23 are selected and connected to the constant current source 21 and are also contacted between the collector and the emitter of the phototransistor 25, respectively. Pin probe 3c, 3
Select d and connect to voltmeter 73. Next, the constant voltage source 7
2 is applied between the collector and the emitter of the phototransistor 25 via the resistor 74.

Next, the current value of the constant current source 21 is set to a predetermined current value I _11, and the indicated value V ₁₁ of the voltmeter 73 at this time is read. At this time, when the indicated value V ₁₁ is within a predetermined allowable range, the photodiode 24 conducts and the phototransistor 25 operates normally, thereby causing a voltage drop due to the resistor 74. Is determined to be non-defective. On the other hand, if it is not within the allowable range, either the photodiode 24 or the phototransistor 25 does not operate normally, so that it is determined to be defective.

When testing a passive element such as a resistor, the relay 75 is first deactivated to disconnect the constant voltage source 72 from the voltmeter 73. Then
The pin probes 3 connected to both ends of the resistance to be inspected are selected and connected to the constant current source 21, and the constant current source 21 and the voltmeter 73 are connected in parallel in the apparatus. Then, a constant current is supplied I ₁₂ of a predetermined value to be inspected resistance from the constant current source 21, reads the command value V ₁₂ of the voltmeter 73 at this time. At this time, an instruction value V ₁₂ is, when in the predetermined allowable range determined in advance, because it has a normalized resistance value is determined as non-defective. On the other hand, when it is not within the allowable range, it does not have a regular resistance value, and is determined to be defective. As described above, the conventional inspection device 71 controls the relay 75 to simultaneously use the constant current source 21, the constant voltage source 72, and the voltmeter 73 when inspecting the active element, When inspecting the device, the constant voltage source 72
Is disconnected from the voltmeter 73, the constant current source 21
And two voltmeters 73, so that both active and passive elements can be tested with one device.

[0006]

However, the conventional inspection apparatus 71 has the following problems. First, today, competition in miniaturization and low price of devices is intensifying, and achieving miniaturization and low price is an urgent issue. On the other hand, in the conventional inspection apparatus 71, in order to inspect the active element, a constant voltage source 72 which is unnecessary at the time of inspecting the passive element, and a relay 75 for controlling the switching of the constant voltage source 72 are provided. Since the resistor 74 is required, there is a problem that the size and cost of the device are correspondingly increased. Secondly, for example, when inspecting all circuit components on a circuit board on which a passive element and an active element are mixed, it is necessary to control the switching of the relay 75 according to the type of the circuit component. There is a problem that the inspection time is lengthened by the accumulation of the switching control time.

[0007] The present invention has been made in view of the above problems, and has as its main object to provide a component inspection apparatus capable of reducing the size and cost of the apparatus and reducing the inspection time.

[0008]

According to a first aspect of the present invention, a control current supplied to an equivalent input circuit controls a current value of an output circuit side current flowing in an equivalent output circuit. Source device capable of supplying an output current as a control current and an output circuit side current to an equivalent input circuit and an equivalent output circuit, and a voltage measurement for measuring an output voltage of the current source A non-defective element when the output voltage measured by the voltage measuring unit is within a predetermined reference voltage range when an output current having a predetermined current value is supplied from the current source to the equivalent input circuit and the equivalent output circuit. And a pass / fail judgment unit for judging whether or not the judgment is affirmative.

Generally, when the load impedance connected to the current source decreases, the output voltage at the output terminal of the current source decreases. On the other hand, as the output current of a predetermined current value output from the current source, for example, by setting the current higher than the minimum control current required for the active element to operate in the linear operation region, In the active element, the output circuit side current tends to flow in the equivalent output circuit, so that the impedance of the equivalent output circuit decreases. Therefore, the output voltage of the current source in this case drops to a predetermined voltage. Conversely, when the active element is defective, the output voltage does not decrease because the impedance of the equivalent output circuit does not decrease even if the same value of output current is supplied. As described above, when the output current of the predetermined current value is output from the current source, by defining the output voltage range of the current source that will be reduced by the activation of the active element as the reference voltage range, It is possible to inspect the quality of the active element based on the output voltage.

According to a second aspect of the present invention, there is provided a component inspection apparatus.
The described component inspection apparatus includes a data generation unit that activates a non-defective active element and generates reference data for determining a reference voltage range based on an output voltage with respect to an output current of a current source during the operation. It is characterized by the following.

Reference data for defining the reference voltage range is obtained by calculation based on data described in a catalog or the like of the active element to be inspected, or generated based on an experimental value using an apparatus different from the parts inspection apparatus. Or you may. On the other hand, in this component inspection apparatus, it is possible to cancel the error between the measurement value at the time of generation of the reference data and the measurement value at the time of inspection by using the current source and voltage measurement unit actually used at the time of inspection. Therefore, compared with the case where reference data is generated using another device,
Accurate inspection can be performed.

According to a third aspect of the present invention, there is provided a component inspection apparatus.
In the above-described component inspection apparatus, the data generation unit controls the current value of the output current, and generates reference data by inputting an output voltage corresponding to the output current from the voltage measurement unit.

[0013] In this component inspection apparatus, the data generation unit includes:
The current of a current source provided in the device is controlled, and reference data is automatically generated based on the output voltage of the current source measured by a voltage measurement unit also provided in the device. Therefore, it is possible to generate simple and accurate reference data.

According to a fourth aspect of the present invention, there is provided a component inspection apparatus.
In the above-described component inspection apparatus, the data generation unit generates, as reference data, an output voltage with respect to the output current in a region where the output circuit-side current changes substantially linearly with respect to the control current.

An output voltage for an arbitrary output current in an operation region where the active element is operating may be used as reference data. On the other hand, in this component inspection apparatus, an output voltage with respect to the output current in a region where the output circuit side current changes substantially linearly with respect to the control current is generated as reference data. As a result, it is possible to avoid using the output voltage in the initial operation region in which the active element starts to operate and the output voltage in the saturation region in which the output circuit side current is saturated as the reference data. An accurate pass / fail inspection can be performed.

According to a fifth aspect of the present invention, there is provided a component inspection apparatus.
5. The component inspection apparatus according to any one of items 1 to 4, wherein the current source is a constant current source.

The current source may be constituted by connecting a constant voltage source and a current limiting resistor in series, but a current value measuring means is required to set the output current to an accurate value. There is. In this component inspection apparatus, by setting the output current of the constant current source, the output current can be set quickly, easily, and accurately when generating the reference data and when inspecting.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a component inspection apparatus according to the present invention will be described below by taking a circuit board inspection apparatus as an example and referring to the accompanying drawings. Note that the same components as those of the conventional inspection device 71 are denoted by the same reference numerals, and detailed description thereof will be omitted.

A circuit board inspection apparatus 1 shown in FIG. 1 has n pins for contacting n circuit patterns P, P,... Formed on one surface of a circuit board 2 and separated from each other. Probes 3, 3, ... are provided. Each pin probe 3 is configured to be able to support the circuit board 2 by fixing its base to a board support (not shown) so that the tip thereof faces upward. Cables 4 are connected to the bases of the pin probes 3, and these cables 4 are connected to a switching unit 17 described later.

Next, the electrical configuration and function of the circuit board inspection apparatus 1 will be described with reference to FIG.

The circuit board inspection apparatus 1 includes a CPU 11, a memory 12, a keyboard 13, and a CRT 14 corresponding to a pass / fail determination unit and a data generation unit in the present invention. These are actually configured by a personal computer, and FIG. 1 shows a functional configuration. CPU11, the resistance of the passive element on the basis of the digital data D _D generated by the A / D converter 16 to be described later, the measurement and the capacitance and inductance, by inspecting the characteristics of the active element, the circuit board 2 is determined. The memory 12 stores the pattern number of the circuit pattern P contacting each pin probe 3, reference data for inspection of circuit components B such as passive elements and active elements connected to the circuit pattern P (reference voltage range in the present invention). Etc.), part numbers, circuit patterns P,
The resistance value between P, the position of each circuit pattern P and the circuit component B, the planar shape, and the like are stored. In this case, these pieces of information are input from the keyboard 13 or a mouse (not shown) in advance before the inspection of the circuit board 2. CRT
14 is a circuit pattern P stored in the memory 12
CPU and layout drawing of circuit components B
Project under 11 controls.

The circuit board inspection apparatus 1 includes a measurement board 15, an A / D conversion unit 16, and a switching unit 17. As shown in the measurement system schematic diagram of FIG. 4A, the measurement board 15 includes a current source 21 corresponding to a current source and a constant current source according to the present invention, and a voltage measuring circuit corresponding to a voltage measuring unit according to the present invention. 22. Measurement board 15
In accordance with measurement control signals S ₁₁ outputted from the CPU 11, a constant current source to the pin probe 3 via the switching section 17 21
Is output (corresponding to the output current in the present invention). On the other hand, the voltage measurement circuit 22
Then, the voltage value of the output voltage Vo of the constant current source 21 input via the switching unit 17 is measured. The A / D conversion unit 16
Converting the measured value measured by the voltage measurement circuit 22 of the measurement board 15 to the digital data D _D. in this case,
A / D converter 16, each time the completion of the conversion for the individual measured values are sequentially input, and outputs a conversion end signal S ₁₂ with respect to CPU 11. Meanwhile, CPU 11, every time the conversion end signal S ₁₂ is outputted, go to read the digital data D _D latched by the A / D converter 16. The switching unit 17 includes a switching control signal S ₁₃ output from the CPU 11.
Are connected to the output terminal of the constant current source 21, the input terminal of the voltage measurement circuit 22, and the ground G of the constant current source 21 and the voltage measurement circuit 22.

Next, the inspection of the circuit board 2 in the circuit board inspection apparatus 1, particularly, the inspection of the active element will be described with reference to FIGS.

First, prior to the inspection of the circuit board 2, a data absorption process for generating reference data from the circuit board 2 is performed. In this process, first, as shown in FIG.
The non-defective circuit board 2 is set on the pin probes 3, 3,... (Step 31). Then, the circuit pattern P of the circuit board 2, in a state where the pin probe 3,3 · to P · contacted respectively, CPU 11 is, by outputting the switching control signals S _13, the switching portion 17, two pairs Are selected. In this case, the switching unit 17
For example, when absorbing the reference data from the photocoupler 23, as shown in FIG. 4A, a pair of pin probes 3a, 3b and a pair of pin probes 3c and 3d that are in contact with the collector and the emitter, respectively, which are equivalent output circuits of the phototransistor 25.
Next, the switching unit 17 commonly connects the pin probes 3a and 3c to the output terminal of the constant current source 21 and the input terminal of the voltage measurement circuit 22, and connects the pin probes 3b and 3d to the constant current source 21.
And to the ground G of the voltage measuring circuit 22.
Next, the open voltage of the constant current source 21 is set (step 32). In this case, the open circuit voltage is set to a voltage (for example, 2 V) that is lower than the anode-cathode rated voltage of the photodiode 24 and the collector-emitter rated voltage of the phototransistor 25.

Next, when the number of times of data absorption and the increased current value (for example, 0.1 mA) are set by the operator (step 33), the CPU 11 sets the number of times of absorption as a count value n in an internal counter. At the same time, the increased current value is stored in the memory 12. In this case, the number of times of absorption means the number of times of measurement of the output voltage Vo of the constant current source 21 performed by the CPU 11, and the increased current value is the value of the constant current source 21 in the next measurement after one measurement is performed.
Means a current value that increases the constant current Io in a stepwise manner.
Next, an initial current (for example, 1 mA) is output from the constant current source 21 (step 34), and the voltage value of the output voltage Vo of the constant current source 21 (that is, the voltage between the collector and the emitter of the phototransistor 25) is determined. The voltage measurement circuit 22 measures the voltage. Next, the A / D converter 16 sets the voltage measurement circuit 22
The voltage value of the measured output voltage Vo is converted into digital data D _D by, CPU 11 can read the voltage value of the output voltage Vo by inputting the converted digital data (step 35). Next, the CPU 11 determines whether or not the read value has dropped below the open-circuit voltage (step 36). When determining reduced and includes a current value I ₁ of the constant current Io at that time, to absorb the voltage value V ₁ as data in the output voltage Vo (step 37). On the other hand, when it is determined that the count has not decreased and when the data has been absorbed, it is determined whether or not the count value of the counter has reached the value n (step 38). At the same time, the constant current Io of the constant current source 21 is increased by the increased current value (step 39).

Next, the voltage value of the output voltage Vo of the constant current source 21 at the current value when the constant current Io is increased is read (step 35), and the aforementioned steps 36 to 38 are performed.
repeat. When it is determined in step 38 that the count value has reached the value n, a process for creating inspection data is executed (step 40). In the process of creating the inspection data, the CPU 11 first determines the phototransistor from the voltage value of the output voltage Vo of the constant current source 21 when the read value falls below the open circuit voltage (that is, when the phototransistor 25 is activated). The voltage range up to the voltage value of the output voltage Vo in a state where the current (corresponding to the output circuit side current in the present invention) flowing through the circuit 25 is saturated is obtained. Next, the current value Im of the constant current Io in a region where the current flowing through the phototransistor 25 changes almost linearly with respect to the control current flowing through the photodiode 24 within the voltage range.
When, it is stored in the memory 12 and the voltage value V _m of the output voltage Vo of the constant current source 21 at that time as the reference data. It should be noted that whether or not the current flowing through the phototransistor 25 is in a linearly changing region is determined by the output voltage V
It can be determined by monitoring the voltage value of o. Specifically, when the voltage value of the output voltage Vo decreases when the constant current Io increases, it is determined that the current flowing through the phototransistor 25 changes linearly, and the constant current Io is increased. Also, when the voltage value of the output voltage Vo does not decrease, it is determined that the phototransistor 25 is operating in a saturated state.

In the data absorption process, in addition to the data absorption of the photocoupler 23, the resistance value between the circuit patterns P and P is measured and stored in the memory 12. This data absorption processing may be performed on a plurality of good circuit boards 2, and the average value of the absorbed data may be used as the reference data. By doing so, it is possible to cope with variations in the circuit components B mounted on the circuit board 2. Furthermore, when the voltage value of the output voltage Vo of the constant current source 21 does not decrease in step 35 of the above-described data absorption processing, the open-circuit voltage may be changed and the data absorption processing may be performed again.

Next, an inspection process for actually inspecting the circuit board 2 to be inspected will be described with reference to FIG.

First, an allowable voltage range of the output voltage Vo is set by the operator (step 5).
1). More specifically, in the step 51, the operator, with respect to the voltage value V _m of the output voltage Vo stored in the memory 12 as the reference data, the permissible range (e.g., ± 20%) is designated. Thereby, the CP
U 11 calculates a reference voltage range from 0.8 × V _{m to} 1.2 × V _m, and stores the calculated reference voltage range in the memory 12. Next, the open circuit voltage of the constant current source 21 is set to a voltage value equal to the open circuit voltage set in the data absorption processing (step 52). Next, when the same type of circuit board 2 to be inspected is set on the pin probes 3, 3,... (Step 53), the CPU 11
1 of the constant current Io, is set to the current value I _m of the reference data (step 54). Then, the CPU 11 outputs the output voltage V measured by the voltage measurement circuit 22 at this time.
The voltage value V _{CEm of} o is read (step 55).

Next, the CPU 11 determines whether or not the voltage value V _CEm is within the reference voltage range (step 5).
6). If it is determined that the voltage is within the reference voltage range, a non-defective code is set (step 57). If it is determined that the voltage is not within the allowable voltage range, a defective code is set (step 58). Thereafter, the other circuit components B are also inspected (step 59), and when the inspection is completed for all the circuit components B, the inspection result is displayed on the CRT 14 (step 60). In this case, when at least one defective product code is set, the fact that the board is defective is displayed, and when no defective product code is set, the fact that it is a good board is displayed. When a defective board is displayed on the CRT 14, the CPU 11 uses the circuit pattern P or the circuit component B.
Can also be displayed together. In such a case, the operator can easily specify the defective part. Thereafter, the CPU 11 determines whether a predetermined number of circuit boards 2 to be inspected have been inspected (step 61). If it is determined that the inspection of the predetermined number of circuit boards 2 has not been completed, the next inspection is performed. When the target circuit board 2 is set (step 53), steps 54 to 60 described above are repeated. On the other hand, when it is determined that a predetermined number of circuit boards 2 have been inspected, the inspection processing ends.

The active elements that can be inspected by the circuit board inspection apparatus 1 are not limited to the photocoupler 23, but can be, for example, transistors and FETs. In this case, as shown in FIG. 4B, after selecting the pin probes 3a, 3c and 3d which are in contact with the base, collector and emitter of the transistor 26, respectively,
Data absorption and inspection can be performed in the same manner as the data absorption processing and inspection processing described above.

As described above, according to the circuit board inspection apparatus 1 of the present embodiment, the output current _Im having the predetermined current value from the constant current source 21 is supplied to the equivalent input circuit (for example, the photodiode 24) of the active element and the equivalent output. When the voltage value of the output voltage Vo of the constant current source 21 measured by the voltage measuring circuit 22 at this time is within a predetermined reference voltage range, the active element is determined to be non-defective. Thus, the constant voltage source 7 in the conventional inspection device 71
2. The need for the resistor 74 and the relay 74 can be obviated, whereby the size and cost of the device can be reduced. In addition, since the switching control of the relay 75 can be omitted, the inspection time can be shortened.

The present invention is not limited to the above embodiment. For example, the component inspection device according to the present invention is applicable not only to the inspection of the circuit component B mounted on the circuit board 2 but also to an inspection device that inspects the circuit component alone. In this case, a clip-type contact is used in place of the pin probe 3, so that the constant current source 21 and the voltage measurement circuit 22 are used.
Can be connected to the circuit component B.

Further, the output of the constant current source 21 when the constant current output from the constant current source 21 is a predetermined current value can be obtained from the data sheet of the active element without performing the data absorption processing described in the present embodiment. After calculating the voltage value of the voltage Vo, the operator may store the voltage Vo in the memory 12 using the keyboard 13. However, when the CPU 11 automatically generates the reference data as in the present embodiment, it is possible to save labor. In the data absorption treatment, by using a constant current source 21 and the voltage measurement circuit 22 is actually used in the inspection process, the voltage value of the current value I _m and the output voltage of the reference data V
_Since the error between _m and the current value _Im , which is the set value at the time of the inspection processing, and the voltage value V _CEm , which is the measured value, can be canceled out, an accurate inspection can be performed.

[0035]

As described above, according to the component inspection apparatus of the first aspect, for example, when an output current having a predetermined current value is output from a current source, the output current is reduced by activating the active element. By defining the voltage range of the current source as a reference voltage range, it is possible to inspect the quality of the active element based on the output voltage of the current source. As a result, the constant voltage source 72 and the like in the conventional inspection device 71 can be made unnecessary, so that the size and cost of the device can be reduced. Further, since the switching control of the relay 75 in the conventional inspection device 71 can be made unnecessary, the inspection time can be shortened.

According to the second aspect of the present invention, by using the current source and the voltage measuring unit actually used at the time of the inspection, the measured value at the time of generating the reference data and the measured value at the time of the inspection can be obtained. Can be canceled out, whereby an accurate inspection can be performed as compared with a case where reference data is generated using another device.

According to the third aspect of the present invention, the data generating section controls the current of the current source provided in the apparatus, and controls the current by the voltage measuring section also provided in the apparatus. By automatically generating the reference data based on the measured output voltage of the current source, simple and accurate reference data can be generated.

Further, according to the component inspection apparatus of the fourth aspect, the output voltage with respect to the output current is generated as the reference data in the region where the output circuit side current changes substantially linearly with respect to the control current, so that the active circuit is activated. An accurate quality inspection of the element can be performed.

According to the component inspection apparatus of the fifth aspect, by setting the output current of the constant current source, the output current can be set quickly and easily when generating the reference data and when inspecting. In addition, it can be performed accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram of a circuit board inspection device according to an embodiment of the present invention.

FIG. 2 is a flowchart of a data absorption process in the circuit board inspection device according to the embodiment of the present invention.

FIG. 3 is a flowchart of an inspection process in the circuit board inspection apparatus according to the embodiment of the present invention.

FIG. 4A is a schematic diagram of a measurement system schematically illustrating a data absorption process and an inspection process for a photocoupler, and FIG. 4B is a measurement diagram illustrating a measurement process of a transistor when the data absorption process and an inspection process are performed. 1 is a schematic diagram of a measurement system showing an outline of a system.

FIG. 5 is a schematic diagram of a measurement system schematically showing a measurement system in a conventional inspection apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Circuit board inspection apparatus 11 CPU 15 Measurement board 21 Constant current source 22 Voltage measurement circuit 23 Photocoupler 24 Photodiode 25 Phototransistor

Claims (5)

[Claims] 1. A component inspection apparatus capable of inspecting an active element for controlling a current value of an output circuit side current flowing through an equivalent output circuit, wherein a control current supplied to an equivalent input circuit is provided. A current source capable of supplying an output current as the control current and the output circuit side current, a voltage measurement unit that measures an output voltage of the current source, and the output current having a predetermined current value is supplied from the current source to the output source. A pass / fail determination unit that determines the active element as a non-defective product when the output voltage measured by the voltage measurement unit is within a predetermined reference voltage range when supplied to the equivalent input circuit and the equivalent output circuit. A parts inspection apparatus characterized by: 2. A data generator for operating a non-defective active element and generating reference data for determining the reference voltage range based on the output voltage with respect to the output current of the current source during the operation. The component inspection apparatus according to claim 1, further comprising: 3. The data generator controls the current value of the output current, and generates the reference data by inputting the output voltage corresponding to the output current from the voltage measuring unit. The component inspection apparatus according to claim 2, wherein 4. The data generating section generates the output voltage for the output current as the reference data in a region where the output circuit side current changes substantially linearly with respect to the control current. The component inspection apparatus according to claim 3, wherein 5. The component inspection apparatus according to claim 1, wherein the current source is a constant current source.