JP2010276344A - Electric test system and electric test method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric test system and method, efficiently performing a short circuit checking inspection and a capacitor reverse mounting checking inspection. <P>SOLUTION: The electric test system is equipped with: an electric test device; and an electronic device to be tested by the electric test device. The electronic device includes a plurality of electronic elements divided into respective groups and switches, at least one of which is provided for each group and switches electric connection between the electronic element and at least one of power supply wiring and ground wiring. At least one of the plurality of electronic elements is a polar capacitor. The electric test device has: a switch control circuit controlling the switching of the switch; a short detection circuit detecting the presence of short between the power supply wiring and the ground wiring in the group; a reverse mounting detection circuit detecting the mounting direction of the polar capacitor; and a power supply circuit supplying power to the power supply wiring and the ground wiring. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrical test system and an electrical test method for an electronic device, and more particularly to an electrical test system and an electrical test method for confirming a short circuit location of a circuit and a polarity direction of a polar capacitor.

  In an electronic device, an electrical test (in-circuit test) is performed after manufacturing. In an electrical test, for example, when a short circuit is detected between the power source and the ground, the short circuit location is identified by checking for a short circuit between the power source and the ground while removing each electronic element connecting the power source and the ground. I was going. Further, in the confirmation inspection of the polarity direction (reverse mounting) of the polar capacitor connected between the power source and the ground, the confirmation of the connection direction of the capacitor is performed by visual inspection one by one.

  For example, Patent Document 1 discloses a technique for inspecting reverse mounting of a polar capacitor. In the electrolytic capacitor polarity detection device described in Patent Document 1, an electrode lead determined as a negative side on the substrate is connected to the amplifier output side, and the loop between the input and output becomes a negative feedback loop on the amplifier input side. And a capacitor to be tested, and an alarm device that warns that the connection is reverse when the amplifier output voltages at two time points after a predetermined time have differed by a predetermined value or more.

Japanese Patent Laid-Open No. 3-136322 JP 2001-60653 A

  The following analysis is given from the perspective of the present invention.

  In order to identify a short circuit between the power source and the ground, it is necessary to remove a single electronic element between the power source and the ground and perform a short check to require a huge amount of time and man-hours. In addition, when the electronic element is mounted again after removing the electronic element, a new problem may occur. Even in the visual confirmation of the reverse mounting of the capacitor, the confirmation work takes time and there is a risk of check omission.

  In the electrolytic capacitor polarity detection device described in Patent Document 1, it is impossible to confirm the presence or absence of a short circuit between the power source and the ground. Also, in the reverse mounting confirmation inspection of capacitors, it takes time to inspect the capacitors to be inspected one by one.

  An object of the present invention is to provide an electrical test system and an electrical test method capable of efficiently performing a short-circuit confirmation test and a capacitor reverse mounting confirmation test.

  According to a first aspect of the present invention, there is provided an electrical test system including an electrical test apparatus and an electronic device to be tested by the electrical test apparatus. The electronic device includes a plurality of electronic elements divided into groups, and at least one switch arranged in each group, and a switch that opens and closes an electrical connection between at least one of a power supply wiring and a ground wiring and the electronic element. . At least one of the plurality of electronic elements is a polar capacitor. The electrical test equipment includes a switch control circuit that controls the opening and closing of the switch, a short detection circuit that detects the presence or absence of a short circuit between the power supply wiring and the ground wiring in the group, and a reverse mounting detection circuit that detects the mounting direction of the polar capacitor. And a power supply circuit for supplying power to the power supply wiring and the ground wiring.

  According to a second aspect of the present invention, a short detection step for detecting a short in each group in which at least one electronic element is arranged, a reverse mounting detection step for detecting reverse mounting of a polar capacitor among the electronic elements, An electrical test method is provided. The short detection step includes a step of cutting off an electrical connection between the electronic element and at least one of the power supply wiring and the ground wiring, and a step of detecting the presence or absence of a short between the power supply wiring and the ground wiring in each group. . The reverse mounting detection step includes a step of charging a polar capacitor in the electronic device, a step of cutting off an electrical connection between the electronic device and at least one of the power supply wiring and the ground wiring, and a power supply wiring and a ground wiring in the group. Measuring a voltage drop rate of the first and second steps, and detecting whether the voltage drop rate is within a predetermined range.

  The present invention has at least one of the following effects.

  In the present invention, each group is electrically cut off to check whether there is a short circuit. It is also possible to test a plurality of groups at once. As a result, it is possible to specify a short-circuited portion in a short time.

  In the present invention, if the electronic element is a polar capacitor, the presence / absence of reverse mounting is checked for each group. It is also possible to test a plurality of groups at once. As a result, it is possible to specify in a short time whether or not reverse mounting exists in a plurality of groups. Further, it is possible to prevent overmounting of reverse mounting as in the case of visual confirmation.

1 is a schematic configuration diagram showing an embodiment of an electrical test system of the present invention. The flowchart for detecting the presence or absence of a short circuit. The flowchart for detecting the presence or absence of reverse mounting of an electronic element. The graph for demonstrating voltage drop speed comparison.

  An embodiment of the electrical test system of the present invention will be described. In FIG. 1, the schematic block diagram which shows one Embodiment of the electrical test system of this invention is shown.

  The electrical test system 1 of the present invention includes an electrical test apparatus 10 and an electronic device 40 that is a device under test to be tested by the electrical test apparatus 10.

  The electrical test apparatus 10 includes a power supply circuit 11, a switch control circuit 12, a short detection circuit 13, and a reverse mounting detection circuit 14. The reverse mounting detection circuit 14 includes a voltage measurement circuit 15 and a voltage drop speed comparison circuit 16.

  The electronic device 40 includes a printed circuit board having a power supply wiring 41 and a ground wiring 42, and electronic elements 52, 62, and 72 mounted on the printed circuit board. The electronic elements 52, 62 and 72 may be active elements such as semiconductor elements or passive elements such as capacitors. In the following description, the electronic elements 52, 62 and 72 will be described as polar capacitors. The electronic elements 52, 62, 72 are grouped. For example, in the form shown in FIG. 1, the electronic elements 52, 62, and 72 are divided into a first group 50, a second group 60, and a third group 70, respectively. That is, the first group 50 includes at least one first electronic element 52, the second group 60 includes at least one second electronic element 62, and the third group 70 includes at least one third electron. An element 72 is included. The number of groups and the number of electronic elements in each group can be set as appropriate.

  The electronic device 40 includes switches 51, 61, and 71 that open and close at least one of the power supply wiring 41 and the ground wiring 42 in each group. In the form shown in FIG. 1, the first group 50 has at least one first switch 51 in the power supply wiring 41, and the second group 60 has at least one second switch 61 in the power supply wiring 41, The third group 70 includes at least one third switch 71 in the power supply wiring 41. The first to third groups 50, 60, 70 each have measurement points 53a, 53b, 63a, 63b, 73a, 73b for electrical measurement of each group.

  The power supply circuit 11 is a power supply circuit that supplies power necessary for a short check of the electronic device 40 and a reverse mounting check of the electronic elements 52, 62, and 72. When checking reverse mounting of the electronic elements 52, 62, and 72, the power supply circuit 11 supplies power when at least the capacitor is fully charged. When performing the electrical test, the first power supply terminal 11 a of the power supply circuit 11 is electrically connected to the second power supply terminal 41 a provided in the power supply wiring 41 of the electronic device 40, and the first power supply circuit 11 is connected to the first power supply terminal 11 a. The ground terminal 11 b is electrically connected to a second ground terminal 42 a provided on the ground wiring 42 of the electronic device 40.

  The switch control circuit 12 controls opening and closing of the first to third switches 51, 61, 71 of the electronic device 40. The first switch terminal 12 a of the switch control circuit 12 is electrically connected to the second switch terminal 81 a provided in the first to third switches 51, 61, 71 of the electronic device 40. The first to third switches 51, 61, 71 of the electronic device 40 are normally closed (ON state) when the electrical test by the electrical test device 10 is not performed, for example, during normal operation of the electronic device 40. Is set to

  In each group 50, 60, 70, the short detection circuit 13 determines whether there is a short circuit between the power supply wiring 41 and the ground wiring 42, that is, between the first measurement points 53a, 63a, 73a and the second measurement points 53b, 63b, 73b. To detect. The first power supply side terminal 13 a of the short detection circuit 13 is electrically connected to the second power supply side terminal 91 a provided at the first measurement points 53 a, 63 a, 73 a of the electronic device 40, and the first detection side of the short detection circuit 13 is connected. The ground side terminal 13b is electrically connected to a second ground side terminal 91b provided at the second measurement points 53b, 63b, 73b of the electronic device 40. The short detection circuit 13 is preferably one that can measure the presence / absence of a short circuit simultaneously for all groups 50, 60, 70 or collectively.

  The voltage measurement circuit 15 measures the voltage between the power supply line 41 and the ground line 42, that is, between the first measurement points 53a, 63a, and 73a and the second measurement points 53b, 63b, and 73b in each group 50, 60, and 70. . The first power supply side terminal 15 a of the voltage measurement circuit 15 is electrically connected to the second power supply side terminal 91 a provided at the first measurement points 53 a, 63 a, 73 a of the electronic device 40, and the first of the voltage measurement circuit 15 is set. The ground side terminal 15b is electrically connected to a second ground side terminal 91b provided at the second measurement points 53b, 63b, 73b of the electronic device 40. The voltage measuring circuit 15 is preferably one that can measure the voltage between the power source and the ground at the same time or all at once in all groups 50, 60, 70.

  The voltage drop speed comparison circuit 16 is used when the voltage drop speeds of the polar electronic elements (polar capacitors) 52, 62, 72 and the electronic elements 52, 62, 72 are normally mounted (without reverse mounting). Compare the voltage drop rate.

  Next, the operation of the electrical test system of the present invention and the electrical test method will be described.

  FIG. 2 shows a flowchart for detecting the presence or absence of a short circuit. First, the power supply circuit 11 is electrically connected to the power supply wiring 41 and the ground wiring 42. In addition, the switch control circuit 12 and the first to third switches 51, 61, 71 are electrically connected.

  When checking for the presence or absence of a short circuit, the switch control circuit 12 sets all the first to third switches 51, 61, 71 to an open state (OFF state) (S11). Thereby, each group is electrically separated from other groups and the power supply circuit 11. Next, the short detection circuit 13 establishes conduction between the first measurement points 53a, 63a, 73a and the second measurement points 53b, 63b, 73b in the first to third groups 50, 60, 70 (preferably simultaneously or collectively). Measure) (S12). If no continuity is detected in each group, there is no short in the electronic device 40. On the other hand, when there is a group in which conduction is confirmed, there is a short circuit between the power supply and the ground in the group. At this time, measures against a short circuit such as removing the electronic device 40 from a normal product or repairing a shorted part are taken (S14).

  FIG. 3 shows a flowchart for detecting the presence or absence of reverse mounting of the electronic element. When checking reverse mounting of the electronic element, the switch control circuit 12 sets all the first to third switches 51, 61, 71 to the closed state (ON state) (S21). Next, power is supplied by the power supply circuit 11 until all of the first to third electronic elements 52, 62, 72 are fully charged (S22). Next, the first to third switches 51, 61, 71 are all opened (OFF state) by the switch control circuit 12 (S23). As a result, the discharge of the charges accumulated in the first to third electronic elements 52, 62, 72 is started. At this time, the voltage drop rate of each group is measured by the voltage measurement circuit 15 (S24). For example, in each group, the time until the voltage between the first measurement points 53a, 63a, 73a and the second measurement points 53b, 63b, 73b becomes a predetermined voltage or the time until the predetermined voltage drop is measured. .

  FIG. 4 shows a graph for explaining a voltage drop speed comparison when detecting electronic elements reversely mounted in a predetermined group. In FIG. 2, the vertical axis represents the voltage (V) between the first measurement points 53a, 63a, 73a and the second measurement points 53b, 63b, 73b, and the horizontal axis represents the first to third electronic elements 52, 62, 72. This is the time (T) from the discharge. Graph A is a voltage drop graph in the case where there is no reverse mounting electronic element in the group, and is a reference for comparison. A graph B is a graph of a voltage drop between the first measurement points 53a, 63a, 73a and the second measurement points 53b, 63b, 73b measured by the voltage measurement circuit 15. When a polar capacitor is reversely mounted, even if power is supplied, the reversely mounted capacitor is not charged, so the discharge time of the reversely mounted capacitor is shorter than that of a properly mounted capacitor. Therefore, the presence or absence of reverse mounting can be detected by comparing the two.

For example, when checking the presence or absence of the reversely mounted electronic element 52 in the first group 50, first, voltage drop data (for example, when there is no reversely mounted electronic element in the first group in the voltage drop speed comparison circuit 16) , Time T ₁ ) (corresponding to graph A in FIG. 4) until the voltage V ₁ drops to voltage V ₂ is stored. Next, in S24, (corresponding to the graph B in FIG. 4) to a voltage by the measuring circuit 15 measures the time _{T 2} of the from the voltage _{V 1} of the time discharge start until a predetermined voltage _{V 2.} The voltage drop speed comparison circuit 16 compares the measured time T ₂ with the time T ₁ required to change from the voltage V ₁ to the voltage V ₂ when there is no reversely mounted electronic element 52. At this time, when the difference ΔT between the time T ₁ and the time T ₂ is equal to or smaller than a predetermined value, it is determined that there is no electronic element 52 that is reversely mounted in the first group 50. On the other hand, when the difference ΔT between the time T ₁ and the time T ₂ exceeds a predetermined value, it is determined that there is an electronic device 52 that is reversely mounted in the first group 50. Such a check is performed for each group (preferably simultaneously or collectively), and it is confirmed whether there is an electronic device reversely mounted in each group. When the presence of reverse mounting is confirmed, measures against reverse mounting such as removing the electronic device 40 from the normal product or correcting the reverse mounting are performed (S26).

  According to the present invention, it is possible to identify a short-circuited portion in a short time by electrically disconnecting between groups and confirming the presence or absence of a short-circuit. Further, when the electronic element is a polar capacitor, it is possible to specify the presence / absence of reverse mounting and its location in a short time. Further, it is possible to prevent overmounting of reverse mounting as in the case of visual confirmation.

  The electrical test system and electrical test method of the present invention have been described based on the above embodiment, but are not limited to the above embodiment, and are within the scope of the present invention and the basic technology of the present invention. It goes without saying that various modifications, changes and improvements can be included in the above embodiment based on the idea. Further, various combinations, substitutions, or selections of various disclosed elements are possible within the scope of the claims of the present invention.

  Further problems, objects, and developments of the present invention will become apparent from the entire disclosure of the present invention including the claims.

DESCRIPTION OF SYMBOLS 1 Electrical test system 10 Electrical test apparatus 11 Power supply circuit 11a 1st power supply terminal 11b 1st ground terminal 12 Switch control circuit 12a 1st switch terminal 13 Short detection circuit 13a 1st power supply side terminal 13b 1st ground side terminal 14 Reverse Mounting detection circuit 15 Voltage measurement circuit 15a First power supply side terminal 15b First ground side terminal 16 Voltage drop speed comparison circuit 40 Electronic device 41 Power supply wiring 41a Second power supply terminal 42 Ground wiring 42a Second ground terminal 50, 60, 70 First 1st-3rd group 51, 61, 71 1st-3rd switch 52, 62, 72 1st-3rd electronic element 53a, 63a, 73a 1st measurement point 53b, 63b, 73b 2nd measurement point 81a 2nd switch Terminal 91a Second power supply side terminal 91b Second ground side terminal

Claims (6)

An electrical test device, and an electronic device to be tested by the electrical test device,
The electronic device includes a plurality of electronic elements divided into groups, at least one switch arranged in each group, and a switch that opens and closes an electrical connection between at least one of a power supply wiring and a ground wiring and the electronic elements, Have
At least one of the plurality of electronic elements is a polar capacitor,
The electrical test apparatus detects a switch control circuit that controls opening and closing of the switch, a short detection circuit that detects the presence or absence of a short circuit between a power supply wiring and a ground wiring in the group, and a mounting direction of the polar capacitor. An electrical test system comprising: a reverse mounting detection circuit; and a power supply circuit for supplying power to a power supply wiring and a ground wiring.   The reverse mounting detection circuit includes a voltage measuring circuit that measures a voltage between a power supply wiring and a ground wiring in the group, a voltage change measured by the voltage measuring circuit, and a voltage when the polar capacitor is properly mounted. The electrical test system according to claim 1, further comprising a voltage drop time comparison circuit that compares the change.   The electrical test system according to claim 1, wherein the short detection circuit collectively detects the presence or absence of a short in each group.   The electrical test system according to any one of claims 1 to 3, wherein the reverse mounting detection circuit collectively detects the presence or absence of reverse mounting of the polar capacitors in each group. A short detection step of detecting a short in each group in which at least one electronic element is arranged;
A reverse mounting detection step of detecting reverse mounting of a polar capacitor among the electronic elements,
The short detection step includes
Cutting off the electrical connection between the electronic element and at least one of the power supply wiring and the ground wiring;
Detecting the presence or absence of a short circuit between the power supply wiring and the ground wiring in each group,
The reverse mounting detection step includes
Charging a polar capacitor of the electronic elements;
Cutting off the electrical connection between the electronic element and at least one of the power supply wiring and the ground wiring;
Measuring a voltage drop rate of the power supply wiring and the ground wiring in the group;
Detecting whether or not the voltage drop rate is within a predetermined range.   6. The electrical test according to claim 5, wherein the predetermined range is determined based on a voltage drop rate of a power supply wiring and a ground wiring in the group when the polar capacitor is properly mounted. Method.

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