JPH0643744Y2 - Electric circuit continuity / short circuit inspection machine - Google Patents

Description

[Detailed description of the device] "Industrial application field" This device is intended for electrical parts having a plurality of independent electric circuits such as connectors and switches, and wiring patterns in which the input side and the output side are one-to-one independent. The present invention relates to an electric circuit continuity / short circuit inspection machine for inspecting the electric continuity / short circuit state of each electric circuit of a wiring board such as a board or a harness product.

"Prior Art" As conventional conduction / short-circuit state inspection methods of this kind, there are a simple inspection method and an arithmetic processing method.

In the simple inspection method, the continuity inspection and the short-circuit inspection are performed separately, and the continuity inspection is performed as shown in FIG. 6A. One end a, b, c, of one of the plurality of electric paths A, B, C, ... ... is connected to the ground, and the other ends a ', b', c ', ... of the electric paths A, B, C, ... are connected to the detection side terminals 12 ₁ , 1
2 ₂ , 12 ₃ , ... Connected to the detection side terminals 12 ₁ , 12 ₂ ,
12 ₃ are connected to a common power supply terminal 15 through resistors 13 ₁ , 13 ₂ , 13 ₃ , ... and light emitting diodes 14 ₁ , 14 ₂ , 14 ₃ , ..., respectively, and a voltage is applied (pulled up). ),
When the inspection is started, if the electric path is normal (conduction), the detection side terminal falls to the ground, current flows through the light emitting diode to emit light, and it is judged as good, but the electric path is abnormal (non-conduction). If so, the detection-side terminal to which the electric path is connected does not drop to the ground and is open, so that no current flows in the light-emitting diode and it is determined to be defective. All the detection side terminals 12 ₁ , 12 ₂ , 12 ₃ , ... Are connected to the NOR circuit 16, and the output side of the NOR circuit 16 is connected to the power supply terminal 15 through the inverting circuit 17 and the light emitting diode 18. The light emitting diode 18 emits light when all the electric paths A, B, C, ... Are good, but the light emitting diode 18 does not emit light if any one of them is defective. The quality of the entire light emitting diode 18 is determined.

As shown in Fig. 6B, the short-circuit inspection is performed with even-numbered electric circuits A, C, ...
, One end a, c, ... of the odd-numbered electric circuit B, D, ... is connected to the detection side terminal, and this detection side terminal is common It is connected to the power supply terminal 15 through the light emitting diode 19. If there is a short circuit between the even-numbered electric paths A, C, ... And the odd-numbered electric paths B, D, ... For example, if the electric paths D, E are short-circuited to each other as shown in the figure, the light emitting diode 19 It emits light and can detect a short circuit failure. If there is no short circuit, the light emitting diode 19 does not emit light.

As shown in FIG. 7, a computer 21 such as a personal computer reads out an inspection pattern previously matched to the product 11 to be inspected from a storage unit 22 such as a magnetic disk, and the computer 21 also stores the program data as shown in FIG. Through the I / O interface sections 23 and 24, a specified electric potential is applied to any one end of the electric paths A, B, C ,. The condition of the electric circuit at the end,
That is, the potential changes due to conduction, disconnection, and short circuit, and these are read into the computer 21 as data via the I / O interface units 23 and 24. These are sequentially connected to the electric circuits A, B,
For each end of C, ..., all data obtained thereby are subjected to arithmetic processing to determine the quality of each electric path. The determination result is displayed as a message on the display unit 25 such as a CRT.

[Problems to be Solved by the Invention] Although the conventional simple method shown in FIG. 6 has a simple circuit configuration and can be manufactured at low cost, the continuity test and the short circuit test cannot be performed at the same time. Further, when the disconnection and the short circuit are combined as shown by F31 and F41 in FIG. 5, this cannot be detected by the continuity test. Further, there is a defect that the short circuit of the electric circuits C and E shown in FIG. 6B cannot be detected by the short circuit inspection.

On the other hand, the conventional arithmetic processing system shown in FIG. 7 can simultaneously test the continuity test and the short-circuit test, and can judge all the continuity and short-circuits of the electric circuit, but it has a drawback that the circuit configuration is complicated and expensive.

Therefore, the object of the present invention is that the circuit configuration does not become so complicated, it can be made relatively inexpensively, the continuity inspection and the short-circuit inspection can be performed at the same time, and the labor is not required twice. It is possible to inspect all kinds of defective states including compound defects such as disconnection and short circuit, that is, whether it is disconnection defect or short circuit defect,
And the electric circuit continuity that can indicate the defective point.
It is to provide a short-circuit inspection machine.

[Means for Solving the Problem] According to the present invention, the pulse from the pulse oscillation circuit is counted by the ring counter, and the N counter output terminals sequentially output the pulses with a time difference. The pulse of the output terminal is supplied to one end of each of the N electric paths of the inspected product, and the output of the other end of the N electric paths of the inspected product and the output of the corresponding output terminal of the ring counter are each N To the corresponding ones of the N first AND circuits. The respective outputs of the N exclusive OR circuits and the outputs of the corresponding output terminals of the ring counter are supplied to the corresponding ones of the N first AND circuits. A disconnection signal is output from the first AND circuit that is respectively supplied and corresponds to the disconnected electrical path, and the output of the N exclusive OR circuits and the inverted output of the corresponding output terminal of the ring counter are N. A short circuit signal is output from the second AND circuit that is respectively supplied to the corresponding ones of the second AND circuits and that corresponds to the short-circuited electric circuit.

"Embodiment" FIG. 1 shows an embodiment of the present invention. A pulse oscillation circuit 31 is provided, and the output pulse of the pulse oscillation circuit 31 is counted by the ring counter 32. As indicated by P ₁₀ in FIG. 2, pulses having a time difference are sequentially output to the output terminals A ₀ , B ₀ , C ₀ , ... Of the ring counter 32. Output terminal A ₀ , B ₀ , C
₀ , ... Outputs are input interface circuits 33a, 33b, 33
Each end a, b, c, of the electric circuit A, B, C, ...
Are supplied to each. Input interface circuit 33
a, 33b, 33c, ... Inverting circuits 34a, 34b, 34c ,.
, And each output side of each inverting circuit 34a, 34b, 34c, ... Is connected to a power supply terminal 36 through a resistor 35a, 35b, 35c ,.

The respective outputs of the other ends a ', b', c ', ... Of the electric paths A, B, C, ... Are passed through the output interface circuits 37a, 37b, 37c, ... And the exclusive OR circuits 38a, 38b, 38c. , ... is supplied to one input. Inverter circuits 39a, 39b, 39c, ... Are inserted in series in the output interface circuits 37a, 37b, 37c, .., and input terminals of the rotating circuits 39a, 39b, 39c ,. …
It is configured to be connected to the power supply terminal 36 through. Terminal
The inspection start signal from 42 is supplied to the gates 43a, 43b, 43c, ... And the outputs of the output terminals A ₀ , B ₀ , C ₀ , ... Of the ring counter 32 are supplied to these gates 43a, 43b, 43c ,. Supplied. The outputs of the gates 43a, 43b, 43c, ... Are supplied to the other inputs of the exclusive OR circuits 38a, 38b, 38c ,.

In the configuration so far, for example, when a pulse is generated at the output terminal A ₀ , the electric path A is set to the low level through the inverting circuit 34a, and if the electric path A is not broken, the input side of the inverting circuit 39a also becomes the low level and the inverting circuit The output A ₁ of 39a becomes high level, and this matches the output pulse of the gate 43a,
The output of the exclusive OR circuit 38a is at a low level. That is, when the electric lines A, B, C, ... Are normal, as shown in (1) Normal in FIG. 2, the outputs A ₁ , B ₁ , C ₁ ,, of the output interface circuits 37a, 37b, 37c ,. , A pulse is generated corresponding to each pulse of the output terminals A ₀ , B ₀ , C ₀ , ... Of the ring counter 32, and the outputs of the exclusive OR circuits 38a, 38b, 38c ,. Is. For example, if the circuit B is broken as shown by (2) disconnection in FIG. 2, the output B ₁ of the output interface circuit 37b remains low level when a pulse is generated at the output terminal B ₀ of the ring counter 32. Therefore, a pulse is generated at the output of the exclusive OR circuit 38b. Further, for example, when the electric circuits B and C are short-circuited as shown in (3) Short circuit in FIG. 2, when a pulse is generated at any of the output terminals B ₀ , C ₀ of the ring counter 32, the electric circuit is Since A, B, and C are all at a low level, output pulses are generated at the outputs B ₁ and C ₁ of the output interface circuits 37b and 37c. Therefore, when a pulse is output from the output terminal B ₀ , the exclusive OR circuit When the output pulse is generated at 38c and the pulse at the output terminal C ₀ , the output pulse is generated at the exclusive OR circuit 38b. Similarly, in the case of (4) disconnection / short circuit in FIG. 2, an output pulse is generated from the exclusive OR circuit 38b at each pulse of the output terminals B ₀ and C ₀ ,
(5) In the case of disconnection and short-circuit, the exclusive OR circuit 38b, an output pulse from both the 38c occurs at the output terminal B ₀ pulse. In other words, if there is a disconnection or short circuit, be sure to use the exclusive OR circuit.
An output pulse is generated from the corresponding one of 38a, 38b, 38c, ....

Outputs of the exclusive OR circuits 38a, 38b, 38c, ... And a gate 43
The logical product of the outputs of a, 43b, 43c, ... Is taken by the first AND circuits 44a, 44b, 44c ,. (2) in Fig. 2,
As shown in (4) and (5), when the electric circuit B is disconnected,
When a pulse is generated at the output terminal B ₀ , a pulse is generated at the output of the first AND circuit 44b corresponding to the electric circuit B, and this becomes a disconnection signal.

The outputs of the gates 43a, 43b, 43c, ... Are inverting circuits 45a, 45b, 45c,
Are inverted by ..., and the logical products of the respective outputs of the inverting circuits 45a, 45b, 45c, ... and the respective outputs of the exclusive OR circuits 38a, 38b, 38c, ... are respectively formed by the second AND circuits 46a, 46b, 46c ,. Taken in ... Second
As shown in (3), (4), and (5) in the figure,
When a short circuit occurs between the output terminals B ₀ and C _{0 in} the case of (3)
When a pulse is generated on each of the second AND circuits 46c, 46
When the pulse is generated from b, respectively, when the pulse is generated at the output terminal C ₀ in the case of (4), the pulse is generated from the second AND circuit 46b, and when the pulse is generated at the output terminal B ₀ in the case of (5). , Pulses are generated from the second AND circuit 46c, and these pulse short circuit signals are generated.

Since the disconnection signal and the short circuit signal are pulses and transient, the output disconnection signals of the first AND circuits 44a, 44b, 44c, ... Are stored in the memory circuits 47a, 47b, 47c ,. The output short-circuit signals of the second AND circuits 46a, 46b, 46c, ... Are stored in the storage circuits 48a, 48b, 48c ,. These memory circuits are previously cleared by the reset signal from the terminal 49 before the inspection is started. Each output side of the storage circuits 47a, 47b, 47c, ...
The memory circuits 48a, 48 are connected to the power supply terminal 36 through 51c, ....
Each output side of b, 48c, ... Is connected to the power supply terminal 36 through an inverting circuit, and further through light emitting diodes 52a, 52b, 52c ,. For example, when the disconnection signal is stored in the storage circuit 47b, its output becomes high level, and this is inverted by the inversion circuit, so that the light emitting diode 51b emits light and it is displayed that the electric circuit B is disconnected.

The outputs of the exclusive OR circuits 38a, 38b, 38c, ... Are OR circuits 53
The output of the OR circuit 53 is supplied to the memory circuit 55 through the gate 54 to which the start signal of the terminal 42 is applied. The memory circuit 55 has been cleared in advance by a reset signal at the terminal 49. If no pulse is generated from any of the exclusive OR circuits 38a, 38b, 38c, ... When a pulse is generated from any one of the circuits 38a, 38b, 38c, ..., The defective product display portion 57 is turned on by the output of the memory circuit 55, and it is displayed that the defective product is present as a whole.

A more specific configuration example of FIG. 1 is shown by attaching the same reference numerals to the portions corresponding to FIG. The ring counter 32 is a hexadecimal counter, that is, the number of target electric circuits of the inspection object 11 is six circuits. The ring counter 32 sequentially outputs a pulse in the negative direction to each output terminal.
At one end a, a temporary point of 0 V is applied, at the other ends b to f, 5 V is applied, and at the next time point, 0 b is applied only to the end b and 5 V is applied to the other end. The same operation is performed thereafter. When the microswitch 58 is operated, the flip-flop 59 is inverted and the start signal appears at the terminal 42 as a high level. Memory circuits 47a to 47f, 4
Each of 8a to 48f is composed of a set-reset type flip-flop. The memory circuit 55 is also a flip-flop. The reset signal is generated from the flip-flop 62 by operating the push-button switch 61 of the illumination switch for displaying the defective product, the reset signal is output to the terminal 49, and the memory circuits 47a to 47f, 48a to 48f, 55 are reset. That is, when the inspection is completed and the defective product is displayed, the display appears, and when the operation for deleting the defective product display is performed, the reset is performed. A buzzer 62 is provided in parallel with the defective product display section 57. If the product is defective, the buzzer 62 sounds and the switch 61
Continue until reset by. A timer 63 is provided in parallel with the non-defective product display section 56, and when the inspection result is non-defective, the output of the timer 63 causes the buzzer 64 to sound for a short time. When the power switch 65 is turned on, the commercial power output is supplied to the DC power supply 66, applying a voltage of 5V to each part and the power lamp.
67 lights up.

FIG. 4 shows an example of the front panel of this inspection machine. The broken-line display light emitting diodes 51a to 51f are arranged, and the short-circuit display light emitting diodes 52a to 52f are arranged side by side. A non-defective product display unit 56 and a defective product display unit 57 are also provided. Defective product display 57
An illuminated push button switch is used for the reset switch.

FIG. 5 shows the display of the continuity inspection result by the conventional simple inspection system, the display of the inspection result by the inspection machine of the present invention, and the display of the inspection result by the conventional arithmetic processing system for various electric circuit states. The shaded parts in the figure indicate that they are lit. In the conventional continuity inspection method, all the light emitting diodes are lit up and cannot be detected in (3) short circuit and (4) disconnection / short circuit. However, in the inspection machine of the present invention, these are displayed separately, and for each disconnection / short circuit of (4) and (5), each disconnection position and the short circuit position are displayed.

Although the output of the ring counter 32 is supplied to the exclusive OR circuit or the like through the gates 43a, 43b, 43c, ... Which are opened / closed by the inspection start signal in the above description, the gates 43a, 43b, 43c ,. . Memory circuits 47a, 47b, 47c, ..., 48a, 48b, 48c, ...,
55 are provided to make the display easy to see, and may be omitted.

"Effect of the Invention" As described above, the inspection machine of the present invention has a simple structure and can therefore be manufactured at a low cost. Moreover, the continuity inspection and the short-circuit inspection can be performed in a single inspection. In addition, it is possible to detect individual disconnection defects and short circuit defects separately, and it is possible to detect compound defects including their positions.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a time chart showing output waveforms of respective parts in the case where the electric circuit is normal and in a defective state in the configuration of FIG. 1, and FIG. FIG. 4 is a diagram showing a more specific embodiment of the invention, FIG. 4 is a diagram showing an example of a front panel of an inspection machine corresponding to the embodiment, and FIG. 5 is a conventional method for displaying inspection results for various electric circuit states. And FIG. 6 is a diagram showing the case of the inspector of the present invention, FIG. 6 is a diagram showing a conventional simple inspection system, and FIG. 7 is a block diagram showing a conventional arithmetic processing system.

Claims (1)

[Scope of utility model registration request] 1. A pulse oscillating circuit and pulses from the pulse oscillating circuit are counted, pulses having a time lag are sequentially generated at N output terminals, and the pulses at these output terminals are respectively output from the N pieces of the inspection object. A ring counter supplied corresponding to one end of the electric path, an output of the other end of the N electric paths of the product to be inspected, and an output of the corresponding output terminal of the ring counter supplied with N exclusive The OR circuit, the outputs of the N exclusive OR circuits and the output of the corresponding output terminal of the ring counter are respectively supplied, and when the corresponding electric circuit is disconnected, N which outputs a disconnection signal is output.
When the respective first AND circuits, the outputs of the N exclusive OR circuits and the inverted output of the corresponding output terminals of the ring counter are respectively supplied and the corresponding electric circuits are short-circuited, a short circuit signal is output. An electric circuit continuity / short circuit inspection machine comprising N second AND circuits for outputting.