JP4417762B2 - Circuit wiring inspection method and apparatus - Google Patents

Description

  The present invention relates to a circuit wiring inspection method and an apparatus therefor, and more specifically, to a technique for inspecting the disconnection of a plurality of branch wirings branched from a trunk wiring and the presence or absence of a short circuit between the branch wirings.

  One inspection item of circuit wiring is a wiring pattern disconnection (open) inspection and a short-circuit inspection between adjacent wiring patterns. That is, when there is a wiring pattern formed adjacent to the circuit board, the disconnection inspection measures each resistance value R between the end points of each wiring pattern, and if R≈0, there is no disconnection; if R≈∞, It is determined that there is a break.

  In addition, the short-circuit inspection between the wiring patterns is performed by measuring the resistance value R between the end point of one wiring pattern and the end point of the other wiring pattern, and if R≈∞, there is no short circuit between the patterns, and if R≈0. It is determined that there is a short circuit between the patterns.

  By the way, for example, in a double-sided circuit board (multilayer circuit board) having through holes, a circuit pattern in which a plurality of branch wirings P1 to PN are branched out from the trunk wiring M as shown in FIG. It can be seen.

  That is, assuming that each of the branch wirings P1 to PN is a wiring that is connected to both front and back surfaces of the circuit board through a through hole (not shown), when the plating wiring is formed in the through hole by electrolytic plating, each branch wiring P1 A trunk wiring M for electrolytic plating is formed in common for PN. Note that the trunk wiring M is formed on the discarded substrate portion and is finally disconnected from the branch wirings P1 to PN.

  In this case, each of the branch wirings P1 to PN is connected to the trunk wiring M at one end thereof (the trunk side end point). Inspection is performed. For example, as shown in FIG. 3A, in order to inspect the disconnection / short circuit of the adjacent branch wirings P1 and P2, the resistance value between the opposite trunk end points P1a and P2a is measured by a low resistance measuring instrument. .

  Then, by comparing the measured value R with a predetermined threshold value ± Th set in advance, the presence / absence of disconnection / short circuit is inspected. The threshold value ± Th is set based on a reference value obtained from a non-defective substrate.

  That is, as shown in FIG. 3B, when the branch wirings P1 and P2 are short-circuited, the resistance value R becomes low and deviates from the threshold value ± Th. Thereby, it is determined that there is a short circuit between the branch wirings. Further, as shown in FIG. 3C, if any one of the branch wirings (branch wiring P2 in this example) is disconnected, R≈∞, so that it is determined that there is a disconnection.

  The resistance measurement is performed by bringing the measurement probe of the resistance measuring instrument into contact with the end point of the wiring pattern. As schematically shown in FIG. 3D, for example, the contact position of the probe with respect to the end point P1a is the reference from the non-defective substrate. When the value is obtained, it is the position indicated by the solid line, but if it is shifted as indicated by the chain line position during actual inspection, the resistance value between the probes changes, so that accurate measurement cannot be performed and a determination error occurs. Sometimes.

  Further, even if the probe contact position does not have the above-described deviation and the resistance value of the wiring pattern can be measured accurately, if a manufacturing error (such as variation in line width) at the time of wiring pattern formation is large, It becomes difficult to set an optimum threshold value.

  By the way, due to manufacturing errors at the time of wiring pattern formation, for example, when the line width is wide, it may be almost the same as the resistance value of the short-circuited pattern. The value cannot be set.

  As an example, if the resistance value of a wiring pattern is set to 100 mΩ as a reference and the threshold value is set to 90 to 110 mΩ of ± 10%, for example, a wiring pattern having a resistance value of about 120 mΩ is short-circuited to an adjacent wiring pattern to 110 mΩ. If it becomes, it will be judged that it is non-defective although it is short-circuited.

  In addition, when setting the threshold value, it is necessary to find a circuit board with a non-defective wiring pattern in advance by visual inspection and measure its resistance value. Cannot be performed from the first sheet.

  Furthermore, since the short circuit detection by resistance measurement needs to capture a minute resistance change, the influence of the contact resistance of the measurement probe becomes a problem. For this reason, the four-terminal method is used for measuring minute resistance, but the measurement probe of the four-terminal method is more expensive than other probes, and probing to a wiring pattern with a narrow pitch becomes difficult.

  In order to solve these problems, the present applicant has proposed the following invention in Patent Document 1. Referring to FIG. 4, in the invention according to Patent Document 1, when inspecting a short circuit and disconnection between adjacent branch wirings of a plurality of branch wirings P <b> 1 to PN connected to the trunk wiring M, one voltage generator 11 is used. A voltage measurement reference point X is set at a predetermined location on the trunk wiring M under a state in which a voltage is applied to the opposite trunk end point P1a of the branch wiring P1, and the voltmeters 21 and 22 counteract the other branch wiring P2. The voltage V1 between the trunk side end point P2a and the voltage measurement reference point X and the voltage V2 between the trunk side end point P2b of the other branch wiring P2 and the voltage measurement reference point X are measured, and these voltages V1 , V2 is used to determine whether or not there is a short circuit / disconnection.

  According to this, high-precision inspection can be performed without the inspection accuracy being affected by the probing position with respect to the end point of the wiring pattern. In addition, since it is not necessary to collect data that is a criterion for determination from non-defective substrates in advance, it is possible to perform a disconnection / short circuit inspection of an adjacent pattern from the first circuit board that is created.

  Furthermore, since it is not affected by the contact resistance of the measurement probe, a normal inexpensive measurement probe can be used, and it is not necessary to probe four measurement probes per line as in the 4-terminal method, so that it is narrow. Pitch wiring patterns can be easily measured.

JP 2003-255007 A

  However, the invention according to Patent Document 1 has the following problems. That is, the trunk wiring M is often provided with a resist film as shown by an imaginary line frame in FIG. Therefore, in such a case, it is impossible to probe the voltage measurement reference point X and the trunk side end point of the branch wiring, and it is impossible to inspect the short circuit / disconnection.

  Accordingly, an object of the present invention is to enable disconnection / short-circuit inspection of each branch wiring even when the trunk wiring is covered with a resist film in the circuit wiring in which a plurality of branch wirings are drawn from the trunk wiring. There is.

In order to solve the above-described problem, an invention according to claim 1 of the present application includes a trunk wiring and a plurality of branch wirings led out from the trunk wiring in a branch shape, and each of the branch wirings has a lead of a mounting component. A circuit wiring provided with two end points as lands used for electrode connection or as signal input / output units is to be inspected, and without probing to the main wiring, between the two end points of each branch wiring. Circuit wiring inspection method for inspecting presence / absence of disconnection and presence / absence of short circuit between two end points on one branch wiring side and between two end points on the other branch wiring side of the two adjacent branch wirings The inspection signal generation means including a signal output detection unit, and an inspection signal detection means, and connecting the inspection signal generation means between the two end points on the one branch wiring side to make a signal generation state, the above Inspection signal detecting means is connected between the two end points on the other branch wiring side, and an inspection signal supplied between the two end points on the one branch wiring side from the inspection signal generating means in the signal output detection unit Is detected, it is determined that there is a break between the two end points on the one branch wiring side, and if the inspection signal is detected between the two end points on the other branch wiring side by the inspection signal detection means, It is characterized in that a short circuit is determined between the two end points on the other branch wiring side and between the two end points on the one branch wiring side.

In order to solve the above problems, the invention according to claim 2 of the present application may include a trunk line and a plurality of branch wirings that are drawn to branch from the main wiring, mounted parts to each of the branch wirings The circuit wiring provided with two end points as lands used for connecting lead electrodes or as signal input / output parts is to be inspected, and the two end points of each branch wiring are not probed into the main wiring. And whether there is a short circuit between two end points on the first branch wiring side and between two end points on the second branch wiring side of the adjacent first and second branch wirings. In the circuit wiring inspection method, the inspection signal generation means including a signal output detection unit and the inspection signal detection means are provided, and the inspection signal generation means is positioned on the anti-trunk wiring side of the first branch wiring. One end point and a given The test signal detection means is connected between two end points on the other branch wiring side and connected to the three branch wirings, and the first branch wiring is connected by the signal output detection unit. When the inspection signal supplied between the one end point of the first branch wiring and the third branch wiring is not detected, it is determined that there is a disconnection between the two end points on the first branch wiring side, and the inspection signal detecting means detects the other If the inspection signal is detected between two end points of the other branch wiring, it is determined that there is a short circuit between the two end points on the other branch wiring side and between the two end points on the one branch wiring side. It is characterized by doing.

  The invention according to claim 3 of the present application is characterized in that the inspection signal generating means is a current generator and the inspection signal detecting means is a voltage measuring device. The invention according to claim 4 of the present application is characterized in that the test signal generating means is a voltage generator and the test signal detecting means is a voltage measuring device, and the invention according to claim 5 of the present application is the above-described invention. A current detection resistor is used for the signal output detection unit.

In order to solve the above problems, the invention according to claim 6 of the present application includes a main wiring, and a plurality of branch wirings that are drawn to branch from the main wiring, mounted parts to each of the branch wirings The circuit wiring provided with two end points as lands used for connecting lead electrodes or as signal input / output parts is to be inspected, and the two end points of each branch wiring are not probed into the main wiring. Circuit wiring for inspecting whether there is a disconnection between them and whether there is a short circuit between two end points on one branch wiring side and between two end points on the other branch wiring side of the two adjacent branch wirings In the inspection apparatus, an inspection signal generating means that includes a signal output detector and supplies an inspection signal between the two end points on the one branch wiring side, and an inspection signal connected between the two end points on the other branch wiring side Detection means; Serial signal output detector and disconnection on the basis of the detection signal from the test signal detecting means, is characterized in that it comprises a determining control means the presence or absence of a short circuit.

In order to solve the above-mentioned problem, an invention according to claim 7 of the present application includes a trunk wiring and a plurality of branch wirings led out from the trunk wiring in a branch shape, and each of the branch wirings is mounted. The circuit wiring provided with two end points as lands used for connecting lead electrodes or as signal input / output parts is to be inspected, and the two end points of each branch wiring are not probed into the main wiring. Circuit wiring for inspecting whether there is a disconnection between them and whether there is a short circuit between two end points on one branch wiring side and between two end points on the other branch wiring side of the two adjacent branch wirings In the inspection apparatus, an inspection signal generating unit that includes a signal output detection unit and supplies an inspection signal between one end point located on the anti-trunk wiring side of the one branch wiring and a predetermined third branch wiring; The other branch wiring side Inspection signal detection means connected between two end points, and control means for determining the presence or absence of a disconnection or a short circuit based on detection signals from the signal output detection unit and the inspection signal detection means It is said.

  The invention according to claim 8 of the present application is that, when the output signal from the signal output detection unit is a signal that does not detect the inspection signal, the control means is between two end points on the one branch wiring side. When it is determined that there is a disconnection and the inspection signal is detected by the inspection signal detection means, between the two end points on the other branch wiring side and between the two end points on the one branch wiring side It is characterized by determining that there is a short circuit.

  The invention according to claim 9 of the present application is characterized in that the inspection signal generation means is a current generator, the inspection signal detection means is a voltage measurement device, and a current detection resistor is used for the signal output detection section. .

  According to the present invention, the inspection signal generation means and the inspection signal detection means need only be connected to the end points of each branch wiring, and it is not necessary to perform probing on the trunk wiring. Therefore, even if the trunk wiring is covered with a resist film, It is possible to inspect for disconnection / short circuit of branch wiring.

  In addition, it is ensured that there is no disconnection between the end points of each branch wiring that is left on the product substrate side and is actually used, and whether there is a short circuit between one end point of the two adjacent branch wirings and the other end point. Can be inspected.

  Next, the present invention will be described with reference to the first embodiment of FIG. 1 and the second embodiment of FIG. 2, but the present invention is not limited to this.

  FIG. 1A is a schematic view showing an example of a circuit wiring to be inspected by the present invention and an inspection apparatus used in the present invention. FIG. The state which is carried out is typically shown in a perspective view.

  The above-described circuit wiring to be inspected includes a trunk wiring M and a plurality of branch wirings drawn out from the trunk wiring M, but only two adjacent branch wirings P1 and P2 are shown here. The trunk wiring M is formed to perform, for example, electrolytic plating on each branch wiring portion. In this example, the trunk wiring M is wired to the discarded board portion 110 of the circuit board 100 and finally separated from the circuit board 100.

  Each of the branch wirings P1 and P2 includes two end points P1x and P1y; P2x and P2y on the same line. In this example, the circuit board 100 is a double-sided board, one end point P1x, P2x is arranged on the substrate surface 101 side, and the other end point P1y, P2y is arranged on the substrate back surface 102 side of the circuit board 100. The present invention includes a case where each branch wiring has three or more end points.

  The end points P1x and P1y on the branch wiring P1 side are connected via the plating wiring in the through hole 103, and the end points P2x and P2y on the branch wiring P2 side are similarly connected via the plating wiring in the through hole 104. . An end point is a land used as a connection part for a lead electrode of a mounted component or a signal input / output part, and its shape may be arbitrarily designed such as a square pattern or a round pattern.

  In the present invention, in a state where the branch wirings P1 and P2 are connected to the main wiring, they are inspected for disconnection / short circuit. Therefore, the inspection apparatus of the present invention includes inspection signal generation means, inspection signal detection means, and control means including a signal output detection unit.

  In this example, the current generator 10 is used as the inspection signal generating means. In the case of the current generator 10, a current detection resistor 11 is generally used for the signal output detection unit. Usually, since the current generator 10 outputs a current through a resistor, the resistance on the output side is set as a current. It can be used as the detection resistor 11. The current generator 10 may be either direct current or alternating current.

  In this example, the voltage measuring device 20 is used as the inspection signal detecting means. As the control means, a CPU (Central Processing Unit), a microprocessor, or a microcomputer can be used. Here, the control means is shown as a block to which reference numeral 30 is attached.

  The control unit 30 obtains information from the current generator (inspection signal generation unit) 10 and the voltage measuring device (inspection signal detection unit) 20 to determine whether there is a disconnection or a short circuit, and displays the inspection result on the display unit 31. To do. The display means 31 may be a display such as a liquid crystal panel or a printer.

  When inspecting disconnection / short circuit of two adjacent branch wirings P1 and P2 included in the circuit wiring to be inspected, two current supply probes drawn from the current generator 10 in this first embodiment. 10a and 10b are brought into contact with the end points P1x and P1y on one branch wiring P1 side, and the two voltage detection probes 20a and 20b drawn from the voltage measuring device 20 are connected to the end point P2x on the other branch wiring P2 side. And P2y.

  Based on information from the current generator 10 and information from the voltage measuring device 20, the control means 30 determines whether the branch wirings P <b> 1 and P <b> 2 are disconnected or short-circuited. That is, when a current is generated from the current generator 10, when a voltage is generated in the current detection resistor 11 and the reading value of the voltage measuring device 20 is 0V, one branch wiring P1 This means that the current I1 flows between the end points P1x and P1y on the side, and no current flows between the end points P2x and P2y on the other branch wiring P2 side.

  Therefore, the control means 30 determines that there is no disconnection between the end points P1x and P1y on the one branch wiring P1 side, and between the end points P1x and P1y on the one branch wiring P1 side and the end point P2x on the other branch wiring side. It is determined that there is no short circuit between P2y. That is, it is determined that the product is a non-defective product and the result is displayed on the display unit 31.

  On the other hand, when a voltage is generated in the current detection resistor 11 and the reading value of the voltage measuring device 20 is not 0 V, there is a short-circuit portion as shown by a chain line in FIG. It means that the current I2 flows between the end points P2x and P2y of the other branch wiring P2 from the side. The short-circuit current I2 is returned from the branch wiring P2 to the branch wiring P1 via the trunk wiring M.

  Therefore, the control means 30 determines that there is a short circuit between the end points P1x and P1y on the one branch wiring P1 side and between the end points P2x and P2y on the other branch wiring P2 side, and the display means 31 is defective. Display.

  When no current is generated in the current detection resistor 11 even though current is generated from the current generator 10, the control means 30 does not flow current between the end points P1x and P1y on the one branch wiring P1 side. For this reason, it is determined that there is a break between the end points P1x and P1y, and the display means 31 displays that the product is defective.

  In addition, since it may be considered that the end points P2x and P2y on the other branch wiring P2 side are disconnected as a factor that the reading value of the voltage measuring device 20 indicates 0 V, the inspection of the branch wirings P1 and P2 is completed after the inspection. The branch wiring P2 and the branch wiring P3 (not shown) adjacent thereto are inspected. This is repeated sequentially.

  Next, the second embodiment of FIG. 2 will be described. Also in the second embodiment, the current generator 10 is used as the inspection signal generating means, and the voltage measuring device 20 is used as the inspection signal detecting means. In FIG. 2, the control means 30 is not shown.

  In this second embodiment, when inspecting disconnection / short circuit of two adjacent branch wirings P1 and P2, if one branch wiring P1 is a first branch wiring and the other branch wiring P2 is a second branch wiring, Separately, the third branch wiring PN is used. The third branch wiring PN may be a branch wiring adjacent to the branch wirings P1 and P2, or may be a branch wiring positioned at the end, and may be arbitrarily selected as long as it is a branch wiring connected to the trunk wiring M.

  One of the current supply probes 10a of the current generator 10 is located on the side opposite to the main trunk line M of the branch wiring that is located far from the third branch wiring PN of the first and second branch wirings P1 and P2. (In this case, the end point P1y on the anti-trunk line M side of the first branch wiring P1). The other current supply probe 10b is brought into contact with the third branch wiring PN. The contact point with respect to the third branch wiring PN may be either the end point PNx or PNy, but the end point PNx on the main wiring M side is preferable.

  The voltage detection probes 20a and 20b of the voltage measuring instrument 20 are brought into contact with the end points P2x and P2y of the second branch wiring P2 as in the first embodiment. The method for determining the presence or absence of disconnection / short circuit is the same as in the first embodiment.

  That is, when a current is generated from the current generator 10, a voltage is generated in the current detection resistor 11, and when the reading value of the voltage measuring device 20 is 0V, the first branch wiring P1. This means that the current I3 flows from the end point P1y to the end point P1x → the trunk line M → the third branch line PN, and no current flows between the end points P2x and P2y on the second branch line P2 side.

  Accordingly, it is determined that there is no disconnection between the end points P1x and P1y on the first branch wiring P1 side, and between the end points P1x and P1y on the first branch wiring P1 side and between the end points P2x and P2y on the second branch wiring side. It can be determined that there is no short circuit in between.

  On the other hand, when a voltage is generated in the current detection resistor 11 and the reading value of the voltage measuring device 20 is not 0 V, there is a short-circuited portion as shown by a chain line in FIG. It means that the current I4 flows between the end points P2x and P2y of the two-branch wiring P2. The short-circuit current I4 flows from the second branch wiring P2 → the trunk wiring M → the third branch wiring PN. Therefore, it can be determined that there is a short circuit between the end points P1x and P1y on the first branch wiring P1 side and the end points P2x and P2y on the second branch wiring P2 side.

  When no current is generated in the current detection resistor 11 even though current is generated from the current generator 10, no current flows between the end points P1x and P1y on the first branch wiring P1 side. For this reason, it may be determined that there is a disconnection between the end points P1x and P1y. When the inspection of the first branch wiring P1 and the second branch wiring P2 is completed, the inspection of any one of the branch wirings and the branch wiring adjacent thereto is performed as in the first embodiment. This is repeated sequentially.

  In the first and second embodiments, the current supply probes 10a and 10b and the voltage detection probes 20a and 20b are either a fixed probe implanted in a pin board or a flying probe movable in the XY direction. There may be.

  In the second embodiment, when a flying probe is used, the third branch wiring PN is preferably a branch wiring arranged at the end. According to this, it is only necessary to move the other current supply probe 10b to another branch wiring when inspecting the third branch wiring PN and the branch wiring adjacent thereto.

  In the first and second embodiments, the current generator is used as the inspection signal generating means, but a voltage generator may be used instead of the current generator. Even in this case, a current detection resistor can be used as the signal output detection unit.

  In addition, the circuit wiring to be inspected in the first and second embodiments is formed across the front and back surfaces of the double-sided circuit board via the through-hole wiring as shown in FIG. Even in the case of being formed, it can be inspected by the present invention.

(A) is a schematic diagram showing an example of a circuit wiring to be inspected in the first embodiment of the present invention and an inspection apparatus used in the present invention, and (b) is a diagram showing that the circuit wiring to be inspected is formed on a circuit board. FIG. The schematic diagram for demonstrating 2nd Example of this invention. (A)-(d) The schematic diagram for demonstrating the disconnection and short circuit inspection by the resistance measuring method of the branch wiring branched from the trunk wiring. The schematic diagram for demonstrating the disconnection and short circuit inspection by another prior art of the branch wiring branched from the trunk wiring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Current generator 10a, 10b Current supply probe 20 Voltage measuring device 20a, 20b Voltage detection probe 30 Control means 31 Display means M Trunk wiring P1, P2, PN Branch wiring P1x, P1y, P2x, P2y, PNx, PNy End point

Claims (9)

A trunk wiring and a plurality of branch wirings led out from the trunk wiring, and each of the branch wirings has two lands used as lead electrodes for mounting components or as signal input / output portions . The circuit wiring provided with the end points is to be inspected, and without probing the trunk wiring, the presence or absence of disconnection between the two end points of each branch wiring and one of the two adjacent branch wirings In the circuit wiring inspection method for inspecting the presence or absence of a short circuit between the two end points on the wiring side and the two end points on the other branch wiring side,
A test signal generation means including a signal output detection unit; and a test signal detection means, wherein the test signal generation means is connected between two end points on the one branch wiring side to be in a signal generation state, and Connecting the signal detection means between the two end points on the other branch wiring side;
When the signal output detection unit does not detect the inspection signal supplied between the two end points on the one branch wiring side from the inspection signal generating means, it is determined that there is a break between the two end points on the one branch wiring side. And
When the inspection signal is detected between the two end points on the other branch wiring side by the inspection signal detection means, the two end points on the other branch wiring side and between the two end points on the other branch wiring side A circuit wiring inspection method characterized in that it is determined that there is a short circuit between the two. A trunk wiring and a plurality of branch wirings led out from the trunk wiring, and each of the branch wirings has two lands used as lead electrodes for mounting components or as signal input / output portions . The circuit wiring provided with the end points is to be inspected, and without probing the trunk wiring, the presence or absence of disconnection between the two end points of each branch wiring and the adjacent first and second two branch wirings Circuit wiring inspection method for inspecting whether or not there is a short circuit between two end points on the first branch wiring side and between two end points on the second branch wiring side,
A test signal generating means including a signal output detection section, the inspection and a signal detection means, one end point and a predetermined third branch located in the counter-trunk line side of the test signal generating means said first branch wirings A signal generating state by connecting to the wiring, and connecting the inspection signal detecting means between the two end points on the other branch wiring side,
When the inspection signal supplied between the one end point of the first branch wiring and the third branch wiring is not detected by the signal output detection unit, there is a break between the two end points on the first branch wiring side And when the inspection signal is detected between the two end points of the other branch wiring by the inspection signal detection means, the two end points on the other branch wiring side and the one branch wiring side A circuit wiring inspection method, characterized in that a short circuit is determined between two end points.   3. The circuit wiring inspection method according to claim 1, wherein the inspection signal generating means is a current generator, and the inspection signal detecting means is a voltage measuring device.   3. The circuit wiring inspection method according to claim 1, wherein the inspection signal generating means is a voltage generator, and the inspection signal detecting means is a voltage measuring device.   5. The circuit wiring inspection method according to claim 3, wherein a current detection resistor is used for the signal output detection unit. A trunk wiring and a plurality of branch wirings led out from the trunk wiring, and each of the branch wirings has two lands used as lead electrodes for mounting components or as signal input / output portions . The circuit wiring provided with the end points is to be inspected, and without probing the trunk wiring, the presence or absence of disconnection between the two end points of each branch wiring and one of the two adjacent branch wirings In the circuit wiring inspection apparatus for inspecting the presence or absence of a short circuit between the two end points on the wiring side and the two end points on the other branch wiring side,
A test signal generating means for supplying a test signal between the two end points on the one branch wiring side, including a signal output detection unit; and a test signal detection means connected between the two end points on the other branch wiring side; A circuit wiring inspection apparatus comprising: control means for determining the presence or absence of a disconnection or a short circuit based on detection signals from the signal output detection unit and the inspection signal detection means. A trunk wiring and a plurality of branch wirings led out from the trunk wiring, and each of the branch wirings has two lands used as lead electrodes for mounting components or as signal input / output portions . The circuit wiring provided with the end points is to be inspected, and without probing the trunk wiring, the presence or absence of disconnection between the two end points of each branch wiring and one of the two adjacent branch wirings In the circuit wiring inspection apparatus for inspecting the presence or absence of a short circuit between the two end points on the wiring side and the two end points on the other branch wiring side,
A test signal generating means for supplying a test signal between one end point located on the side opposite to the trunk wiring of the one branch wiring and a predetermined third branch wiring, including a signal output detector; and the other branch Inspection signal detection means connected between two end points on the wiring side, and control means for determining the presence or absence of disconnection or short circuit based on detection signals from the signal output detection section and the inspection signal detection means. A circuit wiring inspection apparatus characterized by that.   If the output signal from the signal output detection unit is a signal that does not detect the inspection signal, the control means determines that there is a break between the two end points on the one branch wiring side, and detects the inspection signal. When the inspection signal is detected by the means, it is determined that there is a short circuit between the two end points on the other branch wiring side and between the two end points on the one branch wiring side. The circuit wiring inspection apparatus according to claim 6 or 7.   9. The method according to claim 6, wherein the inspection signal generation means is a current generator, the inspection signal detection means is a voltage measuring device, and a current detection resistor is used for the signal output detection unit. The circuit wiring inspection apparatus according to 1.

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