JP4691623B2 - Circuit board inspection method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board inspection method and apparatus, and more particularly to a circuit board inspection method and apparatus for supplying a current in a non-contact manner to a circuit board inspection portion and inspecting the connection state of an integrated circuit to the circuit board. It is about.
[0002]
[Prior art]
When mounting an integrated circuit such as an IC or LSI on a circuit board such as a printed circuit board, it is necessary to inspect whether or not these integrated circuits are correctly connected to the circuit pattern of the printed circuit board by soldering or the like. After the integrated circuit is mounted, the circuit board is inspected. A conventional example of such a circuit board inspection technique is shown in FIG. In this conventional example, among the circuit patterns of the printed circuit board 2 on which the integrated circuit 1 is mounted, the power supply device 4 that supplies the inspection current is connected to the input side circuit pattern 3 that is conducted to the input side of the integrated circuit 1. On the other hand, whether or not the sensor 6 on the output side detects an electrical output by connecting the sensor 6 to the output side circuit pattern 5 that is conducted to the output side of the integrated circuit 1 and supplying a predetermined current from the power supply device 4. If the sensor 6 operates, the integrated circuit 1 is correctly mounted (connected), but if the sensor 6 does not operate, the connection between the integrated circuit 1 and the printed circuit board 2 is defective. Deciding. The connection of the power supply device 4 to the input side circuit pattern 3 of the printed circuit board 2 or the connection of the sensor 6 to the output side circuit pattern 5 is performed using a driving mechanism of the inspection device.
[0003]
[Problems to be solved by the invention]
However, in the above conventional circuit board inspection method, the terminal of the power supply device 4 is connected to the input side circuit pattern 3 of the printed circuit board 2 on the input side of the integrated circuit 1 and the terminal of the sensor 6 is connected to the printed circuit board 2. Since it must be connected to the output side circuit pattern 5 and the connection between each terminal and the patterns 3 and 5 must be made accurately, the output of the integrated circuit 1 cannot be obtained for the current input. There is a problem that an erroneous inspection result appears due to an error in the above or a deviation in operation. Further, since a current is supplied from the outside to the integrated circuit 1 mounted, an excessive current may be supplied to the integrated circuit 1 from the power supply device 4 for some reason. If the power supply device 4 integrates an excessive current. When supplied to the circuit 1, the integrated circuit 1 may be destroyed due to the excessive current.
[0004]
The present invention has been made in view of the above-described conventional problems. The first object of the present invention is to reduce the number of connection points between the circuit board pattern to be inspected and the terminals of various components on the inspection side as much as possible. It is to improve the reliability of the connection operation in the inspection of the circuit board.
[0005]
A second object of the present invention is to make the mounted integrated circuit itself generate a current, and to prevent the integrated circuit from being damaged by an excessive current from the outside.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a method for inspecting a circuit board, in which an integrated circuit mounted on a printed circuit board is placed in a magnetic field or electric field, and the integrated circuit intersects the direction of the magnetic field or electric field. By switching the direction of the magnetic field or electric field without moving the integrated circuit, the electromotive force is generated in the integrated circuit, and this electromotive force is generated by a sensor connected to the terminal of the printed circuit board that is conducted to the integrated circuit. The gist is that the connection state of the integrated circuit to the printed circuit board is detected.
[0007]
Further, the present invention provides, as a circuit board inspection apparatus, a magnetic field generating means that has two magnetic pole members arranged at a predetermined interval and generates a magnetic field between these magnetic pole members, and two magnetic field generating means. A stage that can move between two magnetic pole members in a direction that intersects the direction of the magnetic field, a drive member that moves the stage, and a sensor that is connected to the terminal of the printed circuit board that is connected to the integrated circuit Is the gist. With this configuration, the stage is moved by the driving member to generate an electromotive force in the integrated circuit, and the electromotive force is detected by the sensor to detect the connection state of the integrated circuit to the printed circuit board. Is a summary. Moreover, it is good also as a circuit board test | inspection apparatus which has the structure similar to the test | inspection apparatus which generate | occur | produces this magnetic field, and performs a circuit test | inspection by generating an electric field.
[0008]
Further, the stage is fixed without being moved, and a pole switching member for alternately switching the polarity between the two pole members of the magnetic pole generating means or the electrode generating means is provided, and the magnetic pole between the two pole members is provided by the pole switching member. Alternatively, an electromotive force may be generated in the integrated circuit by alternately switching electrodes, and the electromotive force may be detected by the sensor to detect the connection state of the integrated circuit to the printed circuit board.
[0009]
Further, in the present invention, an electric field is generated by a predetermined electric circuit, and a printed circuit board on which the integrated circuit is mounted is movably installed in the electric field, and the integrated circuit is moved in the electric field, or the integrated circuit is The gist is that an electromotive force is generated in an integrated circuit by switching the direction of the electric field fixedly installed in the electric field.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
FIG. 1 is a perspective view showing a schematic configuration of a circuit board inspection apparatus according to a first embodiment of the present invention. The inspection apparatus according to this embodiment includes two magnetic pole members 11 and 12 arranged at a predetermined interval, an electromagnet 13 as a magnetic field generating means for generating a magnetic field between the magnetic pole members 11 and 12, The stage 14 is disposed between the two magnetic pole members 11 and 12. In this embodiment, of the two magnetic pole members 11 and 12, the upper magnetic pole member 11 is a magnetic pole member for N pole, and the lower magnetic pole member 12 is a magnetic pole member for S pole. The electromagnet 13 has coils 15 and 16 wound around the magnetic pole members 11 and 12 to generate the determined magnetic poles, respectively, and a DC power supply device 17 is connected to the coils 15 and 16. The stage 14 is disposed between the magnetic pole members 11 and 12 so as to be movable in a direction intersecting the direction of the magnetic field or electric field. For this purpose, the stage 14 is placed on, for example, a rail 18 extending in the direction of arrow A in FIG. 1 and can move along the rail 18. Further, the stage 14 is operatively connected to a stage driving member 19 that drives the stage 14 to move. The stage 14 is reciprocated (moved) in the direction of arrow A by operating the stage drive member 19. A printed circuit board 21, which is an electric circuit to be inspected, on which an integrated circuit 20 is mounted is mounted on the stage 14, and a sensor 22 is connected to a terminal (pattern) that is connected to the integrated circuit 20 of the printed circuit board 21. The
[0011]
The operation of the circuit board inspection apparatus having such a configuration will be described below. First, the printed circuit board 21 on which the integrated circuit 20 is mounted is placed on the stage 14 of the circuit board inspection apparatus. Then, the current is passed through the power supply device 17 to cause the upper magnetic pole member 11 to generate an N pole and to cause the lower magnetic pole member 12 to generate an S pole. Next, the stage 14 is reciprocated along the rail 18 by the stage driving member 19. By moving the integrated circuit 20 in the magnetic field generated between the upper magnetic pole member 11 and the lower magnetic pole member 12 in a direction substantially perpendicular to (intersecting with) the direction of the magnetic field, the integrated circuit 20 Generates an electromotive force according to Fleming's law (right-hand rule). Therefore, the electromotive force generated in the integrated circuit 20 is detected by the sensor 22 to detect the connection state of the integrated circuit 20 to the printed board 21.
[0012]
In this way, if the connection state between the pattern of the integrated circuit 20 and the printed circuit board 21 is inspected, the current generated by the integrated circuit 20 itself is used instead of supplying current to the integrated circuit 20 from the outside. The terminal connection to the integrated circuit 20 for supplying current is not necessary and the operation is easy, and the circuit configuration for inspection becomes simpler. Further, there is no inconvenience that an excessive current is supplied to the integrated circuit 20 from the outside and the integrated circuit 20 is damaged.
[0013]
(Embodiment 2)
FIG. 2 is a perspective view showing a schematic configuration of a circuit board inspection apparatus according to the second embodiment of the present invention. The inspection apparatus according to this embodiment basically has the same configuration as the inspection apparatus according to the first embodiment. The difference from the inspection apparatus according to the first embodiment is that the stage 14 is not movable and is fixed, and the two magnetic pole members 11 and 12 are fixed for the N pole and the S pole. Rather than being determined, the N and S poles are set alternately between the two magnetic pole members 11 and 12 so as to be opposite to each other. In order to alternately generate such N poles and S poles, an AC power supply device 25 is connected to the coils 15 and 16 instead of the DC power supply device 17.
[0014]
In the operation in this embodiment, the printed circuit board 21 on which the integrated circuit 20 is mounted is placed on the fixed stage 14. Then, current is passed through the AC power supply device 25 to cause the upper magnetic pole member 11 and the lower magnetic pole member 12 to generate N poles and S poles alternately and opposite to each other. In this way, by alternately generating the N pole and the S pole in the upper magnetic pole member 11 and the lower magnetic pole member 12, the magnetic field in which the magnetic field lines extend in opposite directions to each other is generated alternately in a short time interval for the integrated circuit 20. Apparently, the integrated circuit 20 moves in a certain magnetic field generated between the upper magnetic pole member 11 and the lower magnetic pole member 12 in a direction substantially perpendicular to the direction of the magnetic field (crossing direction). It becomes the same situation as you do. As a result, an electromotive force is generated in the integrated circuit 20 according to Fleming's law (right-hand law). Therefore, the electromotive force generated in the integrated circuit 20 is detected by the sensor 22 to detect the connection state of the integrated circuit 20 to the printed board 21.
[0015]
In this way, if the connection state between the pattern of the integrated circuit 20 and the printed circuit board 21 is inspected, the current generated by the integrated circuit 20 itself is used instead of supplying current to the integrated circuit 20 from the outside. The terminal connection to the integrated circuit 20 for supplying current is not necessary and the operation is easy, and the circuit configuration for inspection becomes simpler. Further, there is no inconvenience that an excessive current is supplied to the integrated circuit 20 from the outside and the integrated circuit 20 is damaged.
[0016]
In the first and second embodiments, an electromotive force is generated in the integrated circuit 20 by adopting a method in which a magnetic field is generated by the electromagnet 13. The magnetic poles are replaced with electrode pairs, an electric field is generated between the electrodes by a predetermined electric circuit, and the printed circuit board 21 on which the integrated circuit 20 is mounted is movably installed in the electric field. Alternatively, the integrated circuit 20 may be fixed in the electric field and the direction of the electric field may be switched to generate an electromotive force in the integrated circuit 20. Such a configuration, operation, and effect can be performed in substantially the same manner as the first and second embodiments described above.
[0017]
As yet another aspect, a thermocouple in which a circuit to be inspected is incorporated instead of the magnetic pole or the like, and a thermoelectromotive force is generated by applying a predetermined heat to an integrated circuit or a junction other than the integrated circuit. You may make it determine whether an integrated circuit is correctly connected to the printed circuit board by measuring an electromotive force.
[0018]
In addition, when using any of magnetic poles, electrodes or thermocouples, not only the state of connection of the integrated circuit to the printed circuit board described in the above embodiment, but also the quality of the wiring pattern of the printed circuit board itself, and further the lead wire It is also possible to determine whether or not the connection is good.
[0019]
【The invention's effect】
As described above, according to the present invention, an integrated circuit mounted on a printed circuit board is placed in a magnetic field or electric field, and the integrated circuit is moved in a direction crossing the direction of the magnetic field or electric field, or An integrated circuit generates an electromotive force in the integrated circuit by switching the direction of a magnetic field or an electric field without moving the integrated circuit, and the electromotive force is detected by a sensor connected to a terminal of a printed circuit board that is conducted to the integrated circuit. The connection status to the printed circuit board and the quality of various circuit connections are detected, which eliminates the need for terminal connection to the integrated circuit for supplying current and facilitates operation, as well as for inspection. The circuit configuration becomes simpler. Further, there is an effect that an inconvenience that an excessive current is supplied to the integrated circuit from the outside and the integrated circuit is damaged does not occur.
[0020]
In addition, an electric field is generated by a predetermined electric circuit, and a printed circuit board on which the integrated circuit is mounted is movably installed in the electric field, and the integrated circuit is moved in the electric field, or the integrated circuit is moved in the electric field. A similar test can be performed by generating an electromotive force in the integrated circuit by switching the direction of the electric field by fixedly installing to the circuit.
[0021]
Further, it is possible to detect the connection state of the integrated circuit to the printed circuit board and the connection of various circuits using a thermocouple.
[Brief description of the drawings]
FIG. 1 is a perspective view of a circuit board inspection apparatus according to a first embodiment of the present invention.
FIG. 2 is a perspective view of a circuit board inspection apparatus according to a second embodiment of the present invention.
FIG. 3 is a plan view showing an example of a conventional circuit board inspection apparatus.
[Explanation of symbols]
11 (Upper) Magnetic pole member 12 (Lower) Magnetic pole member 13 Electromagnet 14 Stages 15 and 16 Coil 17 DC power supply 18 Rail 19 Driving member 20 Integrated circuit 21 Printed circuit board 22 Sensor 23 Pattern 25 AC power supply

Claims (1)

An electric field generating means having two electrode members arranged at a predetermined interval and generating an electric field between these electrode members, and an electric field direction between the two electrode members of the electric field generating means. movably disposed in the direction of the stage for the measured object support for supporting the printed circuit board Integrated circuit is mounted, and a drive member for moving in a direction intersecting the stage with respect to the direction of the field, and a sensors connected to terminals of the printed circuit board to be electrically connected to the integrated circuit, the voltage is generated on the integrated circuit by moving the stage by the driving member, the printed integrated circuit this voltage is detected by the sensor A circuit board inspection apparatus characterized in that a connection state to a board is detected.

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