KR101706465B1

KR101706465B1 - Printed circuit board inspection apparatus and method

Info

Publication number: KR101706465B1
Application number: KR1020150105732A
Authority: KR
Inventors: 겐고 즈치다; 야스시 미야케
Original assignee: 야마하 파인 테크 가부시키가이샤
Priority date: 2014-07-29
Filing date: 2015-07-27
Publication date: 2017-02-13
Also published as: JP2016033511A; TWI598604B; JP6095735B2; KR20160014540A; TW201604564A; CN105319476A; CN105319476B

Abstract

According to the present invention, there is provided an electrical inspection apparatus for a printed circuit board which inspects a defective conductor pattern by applying an electrical signal to a conductor pattern formed on a printed circuit board. The electrical inspection apparatus includes a first probe contacting one end of the conductor pattern, A first connection device for connecting the first probe to the constant current source and a second connection device for connecting the second probe to the reference potential of the constant current source, And a measuring circuit for measuring the potential of the first probe with respect to the reference potential of the constant current source.

Description

PRINTED CIRCUIT BOARD INSPECTION APPARATUS AND METHOD [0002]

The present invention relates to an apparatus for inspecting an electrical state of a conductor pattern of a printed board and a method of inspecting the apparatus.

This application claims priority based on Japanese Patent Application No. 2014-153493 filed on July 29, 2014, the content of which is incorporated herein by reference.

When inspecting an electrical state such as disconnection of a conductor pattern on a printed board, in general, conducting probes are brought into contact with both ends of a conductor pattern to conduct an electric connection. In the case where one terminal of the conductor pattern is covered with an insulating film, The inspection probe may not be brought into direct contact with the conductor pattern. In such a case, as described in Patent Documents 1 and 2, the inspection probe is inspected in a non-contact state with the conductor pattern.

Patent Document 1 discloses a method of inspecting a substrate applied to a flexible printed circuit board or the like in which a probe is brought into contact with one electrode group to be inspected of a conductor pattern and a noncontact sensor is disposed close to the other electrode group to be inspected of the conductor pattern, (Or electromagnetic waves) with respect to the electrode to be inspected by the non-contact sensor, thereby judging defects such as disconnection of each conductor pattern.

In Patent Document 2, a probe is electrically connected to each of a plurality of conductor patterns on a printed board, a sensor for detecting an inspection signal is electrostatically capacitively coupled to a plurality of conductor patterns in a noncontact manner, And the conduction state of the conductor pattern is determined by the maximum value of the transient current flowing to the sensor.

Japanese Patent No. 2994259 Japanese Patent No. 3361311

However, even in the method described in any patent document, since the probe for detecting the electric signal is disposed in a non-contact manner with respect to the conductor pattern and does not directly contact the conductor pattern, there is a possibility that the signal can not be reliably detected.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and provides a printed board inspection apparatus and an inspection method capable of reliably detecting a signal by making a probe for detecting an electric signal in direct contact with a conductor pattern, to provide.

A printed board inspection apparatus according to the present invention is an inspection apparatus for a printed board which inspects a defective conductor pattern by applying an electric signal to a conductor pattern formed on a printed board, A second probe disposed at the other end of the conductor pattern with an insulator interposed therebetween, a constant current source, a first connecting device for connecting the first probe to the constant current source, A second connecting device for changing an electrical connection state of the second probe and a measuring circuit for measuring a potential of the first probe with respect to a reference potential of the constant current source.

In the method of inspecting a printed circuit board according to the present invention, a first probe is directly brought into contact with one end of a conductor pattern, a second probe is arranged with an insulator at the other end of the conductor pattern, The electric connection state of the second probe with respect to the reference potential of the constant current source is changed at a time T2 that has elapsed after a predetermined time t12 from the time T1, A defect of the conductor pattern is judged from the measurement result of the potential of the first probe with respect to the reference potential.

In this printed board inspection method, when the electrical connection state of the second probe with respect to the reference potential of the constant current source is changed, when the potential displacement amount at one end of the conductor pattern is changed per predetermined unit time tu, It can be determined that the product is good.

In the present invention, the first probe is brought into contact with one end portion of the conductor pattern, and the second probe is arranged with the other end portion of the conductor pattern through the insulator so that the electrical connection state of the second probe side is changed, Is measured. That is, since the electric signal of the first probe in contact with the conductor pattern is detected, the electric signal can be reliably detected, and accurate substrate inspection can be performed.

In this case, when the other end of the conductor pattern is exposed on the surface of the printed circuit board, the insulator disposed on the other end of the conductor pattern of the printed circuit board is disposed on the other end of the conductor pattern. When the end portion is covered with the insulating film, the insulating film may be an insulator, and the second probe may be disposed on the insulating film.

Further, the second connection device can change the connection state of the second probe by connecting or disconnecting the second probe with respect to the reference potential of the constant current source.

Further, both the first probe and the second probe may be arranged on one side of the printed board and on the opposite side of the printed board.

In the printed board inspection apparatus of the present invention, a capacitor having a predetermined capacitance is provided between the second probe and the second connection device, or between the second probe and the reference potential of the constant current source It may be connected.

The presence of the capacitor makes it possible to increase the amount of displacement of the potential at the first probe side, thereby enabling more accurate inspection.

The printed board inspection apparatus of the present invention may have a configuration in which the third probe for connecting the first probe to the reference potential of the constant current source through the first connection device.

In the printed board inspection method of the present invention, the first probe is connected to the reference potential of the constant current source at a time T3 before the predetermined time t31 from the time T1, and the predetermined time t14 is elapsed from the time T1 to the time T2 And the first probe and the reference potential may be set in a blocking state at a time T4 that is earlier than the reference potential.

By connecting the first probe to the reference potential and discharging the charge charged in the wiring portion or the like prior to measurement of the potential, the influence of charging can be eliminated, and the current from the constant current source can be stabilized in a short time, can do.

In the printed-circuit board inspecting apparatus of the present invention, the conductor plate which is in contact with the conductor pattern of the printed board through the insulating plate may be connected to the reference potential of the constant-current source.

It is possible to inspect the failure of the contact state of the first probe with respect to the conductor pattern so that the accurate inspection can be performed in a state in which the first probe is in contact with the conductor pattern.

In this case, the insulating plate may be prepared separately from the printed board. However, if there is a portion covered with the insulating film on the surface of the printed board, the insulating film may be used as an insulating plate and the conductive plate may be contacted thereon.

According to the present invention, since a probe for detecting an electric signal is inspected in a state in which it is in direct contact with a conductor pattern, a signal can be reliably detected, and accurate inspection can be performed.

1 is a block diagram showing a schematic configuration of a first embodiment of a printed board inspection apparatus according to the present invention.
Fig. 2 is a side view showing a wiring state of the printed board according to the printed board inspection apparatus of Fig. 1; Fig.
3 is a flowchart showing a printed board inspection method in the first embodiment.
4 is an electrical characteristic diagram showing a temporal change of the potential of the first probe when the conductor pattern is good in the first embodiment.
Fig. 5 is an electrical characteristic diagram showing a temporal change of the potential of the first probe when the conductor pattern is defective in the first embodiment. Fig.
6 is another electric characteristic diagram when the conductor pattern is good in the first embodiment.
7 is another electric characteristic diagram when the conductor pattern is defective in the first embodiment.
Fig. 8 is a block diagram showing a schematic configuration of a second embodiment of a printed board inspection apparatus according to the present invention.
Fig. 9 is a side view showing a wiring state of the printed board according to the printed board inspection apparatus of Fig. 8; Fig.
10 is a block diagram showing a schematic configuration of a third embodiment of a printed-circuit board inspection apparatus according to the present invention.
Fig. 11 is a side view showing a wiring state of the printed board according to the printed board inspection apparatus of Fig. 10; Fig.
12 is a block diagram showing a schematic configuration of a fourth embodiment of the apparatus for inspecting a printed board according to the present invention.
13 is a side view showing a wiring state of the printed board according to the printed board inspection apparatus of FIG.
14 is a flowchart showing a printed board inspection method in the fourth embodiment.
Fig. 15 is an electrical characteristic diagram showing a temporal change of the potential of the first probe when the conductor pattern is good in the fourth embodiment. Fig.
16 is an electric characteristic diagram showing a temporal change in the potential of the first probe when the conductor pattern is defective in the fourth embodiment.
17 is another electric characteristic diagram when the conductor pattern is good in the fourth embodiment.
18 is another electric characteristic diagram in the case where the conductor pattern is defective in the fourth embodiment.
Fig. 19 is a block diagram showing a schematic configuration of a fifth embodiment of a printed board inspection apparatus according to the present invention.
20 is a side view showing a wiring state of the printed board according to the printed board inspection apparatus of FIG. 19;
21 is a flowchart showing a printed board inspection method in the fifth embodiment.
22 is an electric characteristic diagram showing a temporal change in the potential of the first probe when the conductor pattern is good in the fifth embodiment.
23 is an electric characteristic diagram showing a temporal change in the potential of the first probe when the conductor pattern is defective in the fifth embodiment.
24 is another electric characteristic diagram when the conductor pattern is good in the fifth embodiment.
25 is another electric characteristic diagram when the conductor pattern is defective in the fifth embodiment.
26 is an electric characteristic diagram when the first probe is in contact with the conductor pattern in the fifth embodiment.
27 is another electric characteristic diagram when the first probe is in contact with the conductor pattern in the fifth embodiment.
28 is a block diagram showing a configuration of a sixth embodiment of the apparatus for inspecting a printed board according to the present invention.
FIG. 29 is a side view showing the wiring state of the printed board according to the printed board inspection apparatus of FIG. 28; FIG.
30 is a block diagram showing a configuration of a seventh embodiment of the apparatus for inspecting a printed board according to the present invention.
31 is a side view showing a wiring state of the printed board according to the printed board inspection apparatus of FIG. 30;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[About printed circuit board]

In the printed board 1 to be inspected in the following embodiments, various conductor patterns E1 to E4 are formed on the surface or inside of the plate-like insulating layer 2. The insulating layer 2 may be a single layer or a plurality of layers. When the insulating layer 2 includes a plurality of layers, the conductor patterns E1 to E4 also have a multilayer structure and are connected between upper and lower layers by via holes and through holes. Both end portions (electrode portions) of the respective conductor patterns E1 to E4 are formed on the surface of the insulating layer 2. In this case, both end portions of the conductor patterns E1 to E4 may be formed either on one side or on the other side of the printed board 1, or on both sides thereof. At least one of the conductor patterns E1 to E4 is exposed on the surface of the printed board 1. [ The other end may be exposed on the surface of the printed board 1 or may be covered by an insulating film.

In the drawings of the following embodiments, the printed circuit board 1 has conductor patterns E1 to E4 formed on the upper surface of the insulating layer 2, and both ends of each conductor pattern E1 to E4 are connected to the insulating layer 2 as shown in FIG.

[First Embodiment]

As shown in Figs. 1 and 2, the printed-circuit board inspection apparatus 11 according to the first embodiment is for inspecting a plurality of conductor patterns E1 to E4 of the printed board 1, A plurality of first probes P1 to P4 which are in direct contact with one end of each of the conductor patterns E1 to E4 exposed on the printed circuit board 1 and a plurality of first probes P1 to P4 which are in direct contact with the other ends of the conductor patterns E1 to E4 A plurality of second probes P5 to P8 individually contacting with each other via the insulator 13 and a plurality of changeover switches A1 to A4 for connecting the first probes P1 to P4 to the constant current source 12, A second connecting device 15 having a plurality of change-over switches B1 to B4 for respectively connecting second probes P5 to P8 to a reference potential (usually ground potential) of the constant current source 12, In the first probe P1 relative to the reference potential of the circle 12 A constant current source control section 17 for controlling the constant current source 12, a connection device control section 18 for controlling each connection device, and a measurement circuit 16 for connecting the measurement circuit 16 and the constant current source 12, A main control unit 21 for controlling these control units and potential measurement units, and a display device 22. The A / D conversion unit 19, the potential measurement unit 20, The main control unit is provided with a CPU, a memory, a check condition setting unit, a check determination unit, and a data communication unit with each unit.

The printed board inspection apparatus 11 makes the first probes P1 to P4 come into direct contact with one end of the conductor patterns E1 to E4 exposed from the insulating layer 2 of the printed board 1, P5 to P8 are arranged at the other ends of the conductor patterns E1 to E4 with an insulator 13 interposed therebetween.

As described above, the other end portions of the conductor patterns E1 to E4 may be covered by the insulating film or the case where they are exposed on the surface of the printed board 1, When the second probes P5 to P8 are disposed with a proper insulator 13 interposed therebetween and the other end of the conductor patterns E1 to E4 is covered with an insulating film, the insulating film is used as the insulator 13, Two probes P5 to P8 are brought into contact with each other so as to be arranged with the insulator 13 interposed therebetween. In the illustrated example, the second probes P5 to P8 are disposed at the ends of the conductor patterns E1 to E4 with the insulator 13 interposed therebetween.

As described above, the first probes P1 to P4 and the second probes P5 to P8 are arranged so that any one of the change-over switches A1 to A4 of the first connecting device 14 is connected, The current is supplied to any one of P1 to P4. As a result, electricity is accumulated in the electrostatic capacity of the wiring portion or the like of the apparatus including any one of the conductor patterns E1 to E4. As a result, the measurement circuit (the first to fourth probes P1 to P4) (The potential of any one of the first probes P1 to P4 relative to the reference potential of the constant current source 12) is raised.

B2, B3 or B4 connected to any one conductor pattern (selected conductor pattern) connected to the constant current source 12 out of the changeover switches B1 to B4 of the second connecting device 15, . If the selected conductor patterns E1 to E4 are normal, the potential measured by the measuring circuit 16 changes due to the operation of the second connecting device 15. [ When disconnection occurs in the selected conductor patterns E1 to E4, the potential measured by the measuring circuit 16 does not change even if the second connecting device 15 is operated. By detecting the presence or absence of a change in the potential, it is possible to select any one of the conductor patterns E1 to E4 to be sequentially inspected in this manner, and to identify the defects of the selected conductor patterns E1 to E4.

Details of this inspection will be described with reference to the flowchart of FIG. In the following description, a description will be given for each step in accordance with a code attached to each step of the flowchart.

Step S1: First, the first probes P1 to P4 are directly brought into contact with one ends of the conductor patterns E1 to E4. Also, the second probes P5 to P8 are arranged with the insulator 13 interposed therebetween at the other end of the conductor patterns E1 to E4.

Step S2: After arranging the probes P1 to P4 and P5 to P8, any one of the changeover switches A1 to A4 of the first connecting device 14 is turned on at the time T1 (see Fig. 4, etc.) Current is passed from the constant current source 12 to any one of P1 to P4. Thus, charging is started to the electrostatic capacity of any one of the conductor patterns E1 to E4 connected to the first probe to which the current is supplied and the wiring portion of any one of the first probes P1 to P4 supplied with current , The potential measured by the measuring circuit 16 rises.

Step S3: The changeover switches B1, B2, B3 connected to the selected conductor pattern E1, E2, E3 or E4 among the changeover switches B1 to B4 of the second connecting device 15 at the time T2 after a predetermined time t12 from the time T1 B4 are operated to change the connection state of any one of the second probes P5 to P8 with respect to the reference potential of the constant current source 12. [ When the changeover switches B1 to B4 of the second connection device 15 are in the OFF state, one of them is turned on, or when the changeover switches B1 to B4 are in the ON state, One of them is turned OFF.

Step S4: It is judged from the measurement result of the measuring circuit 16 whether or not the potential displacement amount per unit time tu of the one end of the selected conductor pattern E1, E2, E3 or E4 has changed and judges that the potential displacement amount per unit time tu has changed (In the case of "YES"), the process proceeds to S5, and if it is not determined that the potential displacement amount per unit time tu has changed (in the case of "NO"), the process proceeds to S8.

As shown in FIG. 4, at the time T2 at which the potential of one end of the selected conductor pattern E1, E2, E3, or E4 rises, the electric potential displacement amount (In Fig. 4, the potential displacement amount is small), the routine goes to step S5. When the potential displacement amount does not change as shown in Fig. 5, the routine goes to step S8. This change in the displacement amount is because the capacitance with respect to the reference potential of the conductor patterns E1 to E4 changes. Fig. 4 shows an example in which the capacitance is increased.

On the other hand, Fig. 5 shows a case in which no change in the potential displacement amount is confirmed even when the second connection device 15 is operated at time T2, and in this case, the process proceeds to step S8.

In addition, with respect to the operation of the second connecting device 15, whether the changeover switches B1 to B4 are switched from OFF to ON or from ON to OFF can be selected according to the characteristics of the substrate 1 to be inspected. An operation method in which a change becomes large may be employed.

Step S5: It is judged whether or not the potential of one end of the conductor pattern E1, E2, E3 or E4 selected just before the second connection device 15 is activated reaches the open-circuit voltage V ₀ of the constant current source 12, when determined that it reaches the open-circuit voltage V ₀ ( "Yes" case) in the case is not determined that it proceeds to a step S6, reaches open-circuit voltage V ₀ (the case of "No"), the program proceeds to step S7.

In the example shown in Figs. 4 and 5, the potential in the time T2 point, open-circuit voltage V In although not to _zero reached, the example shown in Figs. 6 and 7, and it electric potential is reaching up to the open potential V ₀ to the time T2 , And in this case, the flow advances to step S6.

Step S6: It is judged whether or not the potential at one end of the selected conductor pattern E1, E2, E3 or E4 has been displaced in the descending direction. If it is determined that the displaced in the descending direction (YES) (In the case of "NO"), the flow advances to step S8.

6, the potential has reached the open-circuit voltage V ₀ of the constant current source 12 before the time T2, and the potential is instantaneously lowered by the operation of the second connection device 15 (that is, the potential displacement amount is "0 Quot; is changed to a direction in which the potential is lowered). When the potential falls as shown in Fig. 6, the process proceeds to step S7. When the electrostatic capacitance with respect to the reference potential of the conductor patterns E1 to E4 is changed, the potential changes. FIG. 6 shows an example in which the capacitance is increased.

On the other hand, if there is no change from the open-circuit voltage V ₀ even if the second connection device 15 is operated as shown in Fig. 7, the process proceeds to step S8.

Step S7: It is judged that the selected conductor pattern E1, E2, E3 or E4 is good.

Step S8: It is judged that the selected conductor pattern E1, E2, E3 or E4 is a defective product.

That is, the amount of displacement of the potential at one end of the conductor patterns E1 to E4 in which the first probes P1 to P4 are directly in contact is smaller than the amount of displacement of the second probes P5 to P8 The conductor patterns E1 to E4 are good. If the potential displacement amount does not change, it is determined that the conductor patterns E1 to E4 are defective due to disconnection or the like.

As described above, since the potential is measured at the first probes P1 to P4 which are in direct contact with the conductor patterns E1 to E4, the potential displacement amount can be reliably detected, and accurate inspection can be performed.

In the first embodiment described above, any one of the conductive patterns E1 to E4 is selected by sequentially closing any one of the change-over switches A1 to A4 of the first connecting device 14, and the selected conductive patterns E1 and E2 E2, E3 or E4 are checked one by one by operating the changeover switches B1, B2, B3 or B4 connected to E3 or E4. However, the changeover switches A1 to A4 of the first connection device are all closed at the same time, and then the changeover switches B1 to B4 of the second connection device 15 are operated in order, and the change of the potential at that time is transmitted to the measurement circuit 16 The conduction states of the conductive patterns E1, E2, E3, and E4 may be checked one by one. Further, any one of the change-over switches A1 to A4 of the first connecting device 14 is sequentially closed to select any one of the conductive patterns E1 to E4, and the change-over switches B1 to B4 of the second connecting device 15 All of the conductive patterns E1, E2, E3, and E4 may be operated at the same time, and the change in potential at that time may be detected by the measuring circuit 16 to check the conduction states of the conductive patterns E1, E2, E3 or E4 one by one.

When it is checked whether all of the conductive patterns E1 to E4 of the printed board 1 are good, all of the change-over switches A1 to A4 of the first connecting device are simultaneously closed at the same time, All of the changeover switches B1 to B4 may be operated at the same time, and the change of the potential at that time may be detected by the measuring circuit 16. [ The same is true for the second to fifth embodiments described later.

[Second Embodiment]

8 and 9 show the printed board inspection apparatus 31 of the second embodiment. In the printed board inspection apparatus 31, the switching between the second probes P5 to P8 and the second connection apparatus 15 Capacitors C1 to C4 having a predetermined capacitance are provided between the switches B1 to B4, respectively.

In the second embodiment, the rest of the configuration is the same as that of the first embodiment, and the same reference numerals are attached thereto, and a description thereof is omitted. The printed board inspection method by the printed board inspection apparatus 31 of the second embodiment is the same as that of the first embodiment shown in Fig. 3, and the time varying state of the potentials of the first probes P1 to P4 And the absolute value thereof are the same as those in the first embodiment shown in Figs. 4 to 7, and the description thereof will be omitted. Also in each of the following embodiments, the same components as those of the preceding embodiments are denoted by the same reference numerals, and the description thereof is simplified.

In the first embodiment, a potential displacement occurs during operation of the second connection device 15 due to the electrostatic capacity of the wiring portion itself including the floating capacitance. In the second embodiment, the second probes P5 to P8 The capacitors C1 to C4 having a predetermined capacitance are provided between the first connection device 15 and the second connection device 15 so that the change in capacitance when the second connection device 15 is operated can be increased and the amount of displacement It is possible to perform a more accurate inspection.

[Third embodiment]

10 and 11 show the printed-circuit board inspection apparatus 41 of the third embodiment. In the second embodiment described above, the second probes P5 to P8 and the respective changeover switches B1 of the second connecting device 15 B4 of the second connection device 15 and the reference potentials of the constant current source 12 are provided between the switches B3 and B4 of the second connection device 15, And capacitors C5 to C8 having a predetermined capacitance are respectively provided in the capacitors C5 to C8. The positions where the capacitors C5 to C8 are provided are different from those of the second embodiment, and the other structures are the same as those of the second embodiment.

Therefore, in the third embodiment, the capacitors C5 to C8 provided between the reference potentials of the second connection device 15 and the constant current source 12 change the electrostatic capacitance when the second connection device 15 is operated So that the displacement amount of the potential can be increased to perform more accurate inspection.

In addition to the above-described second embodiment and the third embodiment, it is also possible to switch between the angle switches B 1 to B 4 of the second probes P 5 to P 8 and the second connection device 15, The capacitors C1 to C4 and C5 to C8 may be provided between the switches B1 to B4 and the reference potential of the constant current source 12, respectively.

[Fourth Embodiment]

12 and 13 show a printed board inspection apparatus 51 according to the fourth embodiment. This printed-circuit board inspecting apparatus 51 is provided between the first connecting apparatus 14 and the reference electric potential of the constant current source 12 with respect to the printed-circuit board inspecting apparatus 11 of the first embodiment, 3 connecting device 23 are provided. Other configurations are the same as those in the first embodiment.

Fig. 14 shows a flowchart of a printed board inspection method using the printed board inspection apparatus 51 of the fourth embodiment. In this flowchart, the same steps as those in the flowchart of FIG. 3 are denoted by the same reference numerals, and the description thereof is simplified, and the different steps are mainly described.

The change in the potential of the first probe (one end of the conductor pattern) is shown in Figs. 15 to 18. These Figs. 15 to 18 correspond to Figs. 4 to 7 of the first embodiment.

S11: The third connection device 23 is brought into a conductive state at time T3 before time t31 from time T1. Thus, when the changeover switch S of the third connection device 23 is turned ON, and charges are charged in the wiring portion of the first connection device 14 or the like, the charge is released.

S12: The time when the predetermined time t14 has elapsed from the time T1, and the time when the time T4 before the time T2 is reached, the third connecting device 23 is turned off (the switch S is turned OFF). Since the first connecting device 14 is turned on before the step S12, the third connecting device 23 is turned off in this step S12 so that the charging is started on the first probes P1 to P4 side, 15 to 18, the potentials on the first probes P1 to P4 side rise.

15 and 16 show a state in which the potentials of the first probes P1 to P4 are elevated when the second connecting device 15 is operated. In the case shown in Fig. 15, at the time T2, The process proceeds to S5. In the case shown in Fig. 16, since the potential displacement amount is not changed at the time T2, the process proceeds to S8.

17 and 18 show a case in which the potential at one end of the conductor patterns E1 to E4 reaches the open voltage V ₀ of the constant current source 12 immediately before the second connecting device 15 is activated, As shown in Fig. 18, when there is no change in the potential at time T2, the process proceeds to S8.

In this fourth embodiment, by providing the third connecting device 23, even when the electrostatic capacity portion in the wiring portion or the like is charged, the inspection can be started after discharging by the third connecting device 23 Therefore, the potentials of the first probes P1 to P4 can be more accurately measured. Since the first connecting device 14 is connected in a state where the first probes P1 to P4 are connected to the reference potential by the third connecting device 23 and then the third connecting device 23 is cut off, The value of the current from the constant current source 12 for the patterns E1 to E4 can be stabilized in a short period of time and a faster inspection can be performed.

[Modification of Fourth Embodiment]

The printed board inspection apparatus 51 according to the fourth embodiment shown in Figs. 12 and 13 has a basic configuration, and the second probes P5 to P8 and the second probes P5 to P8, as shown in Figs. 8 and 9, The capacitors C1 to C4 may be arranged between the changeover switches B1 to B4 of the second connecting device 15, respectively.

10 and 11, the capacitors C5 to C8 may be disposed between the reference switches B1 to B4 of the second connection device 15 and the reference potential of the constant current source 12, respectively.

These two capacitors C1 to C4 and C5 to C8 may be arranged.

In any case, it is possible to make more precise inspections by increasing the amount of displacement of the potential as long as the capacitors C1 to C4 or C5 to C8 are provided.

[Fifth Embodiment]

19 and 20 show a printed board inspection apparatus 61 according to the fifth embodiment. In this printed-circuit board inspecting apparatus 61, first probes P1 to P4 which are in direct contact with one end of the conductor patterns E1 to E4 of the printed circuit board 1, and insulators 13 at the other end of the conductor patterns E1 to E4 And a conductor plate 25 connected to the reference potential of the constant current source 12, in addition to the second probes P5 to P8 arranged. 19 and 20, both of the first probes P1 to P4 and the second probes P5 to P8 are disposed on one side of the printed board 1, and the conductor plate 25 is disposed on one side of the printed board 1, (2) of the other surface of the substrate (1) and connected to the reference potential of the constant current source (12). In this case, although the conductor plate 25 is formed to have a size capable of contacting the entire surface of the insulating layer 2 of the printed substrate 1, at least a portion of the conductor patterns E1 to E4 to be inspected is covered with the insulating layer 2 As shown in Fig.

When both ends of the conductor patterns E1 to E4 are formed on both sides of the printed board 1 as described in the above section of the [printed board], the second probes P5 to P8 are electrically connected to the conductor plate 25 And disposed on the same side with the insulating layer interposed therebetween at positions where the conductor plate 25 is avoided.

21, the first probe P1 to P4 are brought into direct contact with one end of the conductor patterns E1 to E4 in the initial preparation for inspection, And the second probes P5 to P8 are provided with the conductor plate 25 on the surface of the insulating layer 2 of the printed board 1 when the conductor patterns E1 to E4 are disposed with the insulator 13 interposed therebetween (S15) are the same as those after the flow chart S2 of FIG.

By arranging the conductor plate 25, the first connection device 14 is made conductive at the time T1 and the current is flowed from the constant current source 12 to the first probes P1 to P4 (S2), and the conductor patterns E1 to E4 And the conductive plate 25, so that the potential detected by the measuring circuit 16 rises. Subsequently, the second connection device 15 is operated at time T2 to change the connection state of the second probes P5 to P8 with respect to the reference potential of the constant current source 12.

22 is a graph showing the relationship between the capacitance of the first probes P1 to P4 when the second connection device 15 is activated when the capacitance of the wiring portion is extremely small as compared with the capacitance between the conductor patterns E1 to E4 and the conductive plate 25 The connection states of the capacitances of the wiring portions including the conductor patterns E1 to E4 are changed with respect to the capacitance between the conductor patterns E1 to E4 and the conductor plate 25 so that the conductor patterns E1 to E4 are good. The potential displacement amount per unit time tu decreases with apparent capacitance change. When the electrostatic capacitance with respect to the reference potential of the conductor patterns E1 to E4 is changed, the potential displacement amount is changed. Fig. 22 shows an example in which the capacitance is increased.

In the case where the conductor patterns E1 to E4 are defective, there is no change in the potential displacement amount even when the second connecting device 15 is operated as shown in Fig. 23, and the state before the second connecting device 15 is maintained do.

On the other hand, when the electrostatic capacitance of the wiring portion is larger than the electrostatic capacitance between the conductor patterns E1 to E4 and the conductive plate 25, or between the electrostatic capacitance between the conductor patterns E1 to E4 and the conductive plate 25 and the electrostatic capacitance of the wiring portion In the case where the conductor patterns E1 to E4 are good, the potential of the first probes P1 to P4 is slightly lowered by operating the second connecting device 15 as shown in Fig. 24, The potential increases by a smaller displacement amount. When the electrostatic capacitance with respect to the reference potential of the conductor patterns E1 to E4 is changed, the potential changes. Fig. 24 shows an example in which the capacitance is increased.

If the conductor patterns E1 to E4 are defective, there is no change in the potential displacement amount even when the second connecting device 15 is operated as shown in Fig. 25, and the state before the second connecting device 15 is operated is maintained do.

The capacitance between the conductor patterns E1 to E4 and the conductive plate 25 is larger than the capacitance between the conductor patterns E1 to E4 and the conductive plate 25 and the capacitance between the conductor patterns E1 to E4 and the conductive plate 25 and the capacitance of the wiring portion, The amount of potential displacement per time tu before the second connecting device 15 is operated is small and therefore it takes time until the potential of the first probes P1 to P4 reaches the open voltage V ₀ , The case where the potential has reached the open-circuit voltage V ₀ of the constant current source 12 is not exemplified. However, when the potential reaches the open-circuit voltage V ₀ of the constant current source 12 before the time T2, and similarly, a case where the conductive pattern E1 to E4 is a non-defective product in the case is changed to be reduced from the open-circuit voltage V _0, that does not change from the open-circuit voltage V _0, the conductive pattern E1 to E4 is defective.

[Modification of the fifth embodiment]

In the case of the fifth embodiment shown in Figs. 19 and 20, the printed-circuit board inspecting apparatus 61 shown in these figures has a basic configuration, and the second embodiment shown in Figs. 8 and 9 and the second embodiment shown in Figs. Similarly, the capacitors C1 to C4 may be disposed between the second switches P5 to P8 and the changeover switches B1 to B4 of the second connecting device 15, respectively.

These two capacitors C1 to C4 and C5 to C8 may be arranged.

In any case, it is possible to perform more accurate inspection by increasing the displacement amount of the potential by the provision of the capacitors C1 to C4 or C5 to C8.

The third connecting device 23 having the change-over switch S may be provided between the first connecting device 14 and the reference potential of the constant current source 12 as in the fourth embodiment shown in Figs. 12 and 13 .

By providing the third connecting device 23, even when the electrostatic capacitance portion such as the conductor patterns E1 to E4 is charged, since the inspection can be started after discharging by the third connecting device 23, The value of the current from the constant current source 12 with respect to the conductor patterns E1 to E4 can be stabilized in a short period of time so that the inspection can be carried out faster and a more accurate inspection can be carried out .

In the fifth embodiment and its modifications, it is also possible to detect whether the first probes P1 to P4 are in contact with the conductor patterns E1 to E4 securely.

Fig. 26 is a diagram showing a case where the capacitors C1 to C4 are disposed between the switches B1 to B4 of the second probes P5 to P8 and the second connecting device 15, respectively, in the fifth embodiment shown in Figs. 19 and 20 Or the case where the capacitors C5 to C8 are respectively disposed between the changeover switches B1 to B4 of the second connecting device 15 and the reference potentials of the constant current source 12, When P4 is in contact with the conductor patterns E1 to E4, the total electrostatic capacity of the outer appearance is reduced by the electrostatic capacitance between the first probes P1 to P4 and the conductor patterns E1 to E4, so that the potential abruptly rises at time T1, Reaches the open-circuit voltage V ₀ immediately. The contact state of the first probes P1 to P4 can be detected by detecting the rising state of this potential.

27 shows a case where the third connecting device 23 is incorporated in the fifth embodiment. When current is supplied to the first probes P1 to P4 (time T4 When the first probes P1 to P4 are in contact failure, the potential suddenly rises as in Fig. 26, so that the contact state of the first probes P1 to P4 can be detected by detecting the rising state.

When the contact failure of the first probes P1 to P4 is detected from the rising state of the potential, the contact position and posture of the first probes P1 to P4 may be adjusted again.

[Sixth Embodiment]

Next, the printed-circuit board testing apparatus 71 of the sixth embodiment will be described with reference to Figs. 28 and 29. Fig.

The printed-circuit board inspection apparatus 71 of the sixth embodiment integrates the changeover switches A1 to A4 of the first connecting device 14 in the printed-circuit board testing apparatus 11 of the first embodiment into a single changeover switch A1 And a first connecting device 14 '. That is, the plurality of first probes P1 to P4 are connected in parallel to the changeover switch A1. By closing the changeover switch A1, a plurality of first probes P1 to P4 are simultaneously connected and a current is simultaneously supplied from the constant current source 12 to the plurality of first probes P1 to P4.

As a result, electric charges are accumulated in the capacitance of the wiring portion and the like of the device including the conductor patterns E1 to E4. As a result, the electric potentials measured by the measuring circuit 16 connected to the first probes P1 to P4 The potential of the first probes P1 to P4 relative to the reference potential of the circle 12).

Subsequently, the changeover switches B1 to B4 of the second connecting device 15 are sequentially operated. If the conductor patterns E1 to E4 are normal, the potential measured by the measuring circuit 16 changes due to the operation of the second connecting device 15. [ When disconnection occurs in the conductor patterns E1 to E4, the potential measured by the measuring circuit 16 does not change even if the second connecting device 15 is operated. By detecting the presence or absence of a change in the potential, it is possible to identify the defects of the conductor patterns E1 to E4.

In the above-described sixth embodiment, the first connecting device 14 'which integrates the change-over switches A1 to A4 of the first connecting device 14 of the printed-circuit board testing device 11 of the first embodiment into the single change- ). This configuration is the same as the first embodiment of the printed board inspection apparatus of the second embodiment (FIG. 8), the third embodiment (FIG. 10), the fourth embodiment (FIG. 12), and the fifth embodiment It is also applicable to the connection device 14.

[Seventh Embodiment]

Next, the printed-circuit board testing apparatus 81 of the seventh embodiment will be described with reference to Figs. 30 and 31. Fig.

The printed board inspection apparatus 81 of the seventh embodiment integrates the changeover switches B1 to B4 of the second connecting device 15 in the printed board inspection apparatus 11 of the first embodiment into a single changeover switch B1 And a second connecting device 15 '. That is, the plurality of second probes P5 to P8 are connected in parallel to the changeover switch B1. By closing the changeover switch B1, the plurality of second probes P5 to P8 are simultaneously grounded.

According to this configuration, any one of the change-over switches A1 to A4 of the first connecting device 14 is sequentially closed to select any one of the conductive patterns E1 to E4, and the switching of the second connecting device 15 ' The conduction state of the conductive patterns E1, E2, E3, or E4 can be checked by operating the switch B1 and detecting the change of the potential at that time by the measuring circuit 16. [

In the above-described seventh embodiment, the changeover switches B1 to B4 of the second connection device 15 in the printed-circuit board inspection apparatus 11 of the first embodiment are integrated into the single connection switch B1, (15 '). This configuration is the same as the second connection of the printed board inspection apparatus of the second embodiment (FIG. 8), the third embodiment (FIG. 10), the fourth embodiment (FIG. 12), and the fifth embodiment It is also applicable to the device 15.

Further, when the second connecting device 15 'having the single changeover switch B1 is applied to the printed board inspection apparatus of the second embodiment, the plurality of capacitors C1 to C4 are used as one capacitor, and the second probes P5 to P5 P8 and the second connection device 15 '. Similarly, when the second connecting device 15 'having the single changeover switch B1 is applied to the printed board inspection apparatus of the third embodiment, the plurality of capacitors C5 to C8 are used as one capacitor having a large capacity, 2 connecting device 15 'and the ground.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention.

For the predetermined times t12, t31, t14, and tu, it is possible to set an optimal time in accordance with the electrical characteristics of the printed board, and by this adjustment, the change of the potential displacement amount at one end of the conductor patterns E1 to E4 can be detected more quickly And accurate substrate inspection can be performed quickly.

Also, with respect to the capacitances of the capacitors C1 to C4 and C5 to C8, it is possible to surely detect the change of the potential displacement amount at one end of the conductor patterns E1 to E4 more quickly by setting an optimum value matching the electric characteristics of the printed board, Accurate substrate inspection can be performed quickly.

1: printed board
2: Insulating layer
E1 to E4: Conductor pattern
11: Printed board inspection device
12: constant current source
13: Insulator
14: First connection device
15: second connecting device
16: Measurement circuit
17: Constant current source control
18:
19: A / D conversion section
20:
21: Main control device
22: Display device
23: Third connection device
25: conductor plate
P1 to P4: First probe
P5 to P8: a second probe
A1 to A4: changeover switch
B1 to B4: changeover switch
C1 to C4: capacitors
C5 to C8: Capacitors
S: Conversion switch
31, 41, 51: Printed board inspection apparatus

Claims

An electrical inspection apparatus for a printed circuit board which inspects a defective conductor pattern by applying an electrical signal to a conductor pattern formed on a printed board, the electrical inspection apparatus comprising: a first probe contacting one end of the conductor pattern; A first connection device for connecting the first probe to the constant current source; and a second connection device for connecting the second probe to the reference potential of the constant current source, And a measuring circuit for measuring a displacement amount of the first probe relative to a reference potential of the constant current source when the electrical connection state of the second probe is changed, Printed board inspector.

The method according to claim 1,
A capacitor having a predetermined capacitance is connected to either or both of the second probe and the second connection device or between the second probe and the reference potential of the constant current source. Device.

3. The method according to claim 1 or 2,
And a third connecting device for connecting the first probe to the reference potential of the constant current source via the first connecting device.

An electrical inspection apparatus for a printed circuit board which inspects a defective conductor pattern by applying an electrical signal to a conductor pattern formed on a printed board, the electrical inspection apparatus comprising: a first probe contacting one end of the conductor pattern; A first connection device for connecting the first probe to the constant current source; and a second connection device for connecting the second probe to the reference potential of the constant current source, A measuring circuit for measuring a displacement amount of the first probe relative to a reference potential of the constant current source when the electrical connection state of the second probe is changed; And a conductive plate which is in contact with the conductor pattern via an insulator and is connected to a reference potential of the constant current source, And the printed board is inspected.

The first probe is brought into direct contact with one end of the conductor pattern and the second probe is arranged with the insulator interposed between the other end of the conductor pattern and a current is passed from the constant current source to the first probe at time T1, The electrical connection state of the second probe with respect to the reference potential of the constant current source is changed at a time T2 after a predetermined time t12 from the time T1 and the potential of the first probe relative to the reference potential of the constant current source at the time of the change And judging a defect of the conductor pattern from a measurement result of the displacement amount.

6. The method of claim 5,
When the electrical connection state of the second probe with respect to the reference potential of the constant current source is changed, when the potential displacement amount at one end of the conductor pattern is changed per predetermined unit time tu, it is determined that the conductor pattern is good The method comprising the steps of:

The method according to claim 5 or 6,
The first probe is connected to the reference potential of the constant current source at a time T3 before the predetermined time t31 from the time T1, and at a time T4 before the time T2 after elapse of a time t14 shorter than the time t12 from the time T1, Wherein the first probe and the reference potential are in a cutoff state.

5. The method of claim 4,
A capacitor having a predetermined capacitance is connected to either or both of the second probe and the second connection device or between the second probe and the reference potential of the constant current source. Device.

The method according to claim 4 or 8,
And a third connecting device for connecting the first probe to the reference potential of the constant current source via the first connecting device.