JPH0436350B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a printed circuit board inspection device, and particularly to a printed circuit board inspection device suitable for automatically inspecting many types of printed circuit boards.

[Prior art] A printed circuit board has a flat plate made of an insulating material, etc.
For example, electronic circuits formed of digital circuits, analog circuits, memory circuits, etc. are incorporated using printed wiring. Printed circuit boards incorporating electronic circuits with various unitized functions are widely used. Such printed circuit boards are formed, for example, in the same shape/dimensions, and the external connection terminals are standardized.

As a means of inspecting the performance of the printed circuit board formed in this way, a test control section including a microprocessor equipped with a keyboard, display/recording device, etc. ) is connected to an external terminal, and the test control section is operated to test a board to be tested.

In order to test the performance of many types of printed circuit boards using such conventional printed circuit board testing equipment, first connect the boards to be tested one by one to the testing equipment, and check the type of function of the electronic circuit of the board to be tested. A staff member makes a judgment and operates the keyboard to input an inspection command for the inspection content according to the type.

[Problems to be Solved by the Invention] However, when inspecting many types of mass-produced printed circuit boards, the conventional printed circuit board inspection equipment, in which a worker inputs an inspection command with inspection contents according to the type, is difficult to operate. The problem was that it was not only complicated, but also prone to operational errors.

Therefore, as described in, for example, Japanese Unexamined Patent Application Publications No. 54-29539 and No. 56-119864, a method has been proposed in which an identification code generating means indicating the type of the board to be tested is provided.

However, since these methods assume that each board under test is connected to the connector one by one and tested, the time required to replace the board under test is much longer than the time the test control unit is actually operating. However, systems that require continuous inspection of a large number of printed circuit boards have the drawback of poor workability and inefficiency.

On the other hand, Japanese Patent Application Laid-Open No. 55-58470 discloses a method for testing printed circuit boards, in which a necessary test pattern is selected in advance for each housing state in accordance with the printed circuit board storage state of the Shelf device, and each A printed circuit board detection device is provided corresponding to the printed circuit board storage condition, and the detection signal from each detection device is sent to a discrimination circuit that determines the printed circuit board storage condition in the shelf device. Based on the discrimination result, a test pattern program is selected. We are proposing a method for testing specified printed circuit boards.

In this method, as a printed circuit board detection device,
A first detection device is comprised of a photo sensor or a mechanical contact switch consisting of a light emitting element and a light receiving element, and detects the presence or absence of a printed circuit board, and a voltage detector is provided at a predetermined jack terminal position of the printed circuit board, and is housed in a slot. A second detection device is used to detect whether the printed circuit board is correct or not and the type thereof. That is, the first detection device that detects the presence or absence of a printed circuit board and the second detection device that detects the correctness and type of the contained printed circuit board are provided separately, which is wasteful in terms of installation space and cost. It was a lot.

The purpose of the present invention is to determine the presence or absence of a printed circuit board and its type based on the detection signal from a single detection means, and to automatically and continuously test the performance of multiple printed circuit boards of various types without any problems. An object of the present invention is to provide a printed circuit board inspection device.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides a plurality of connectors into which a plurality of printed circuit boards to be tested are arbitrarily inserted, and a method for detecting the presence or absence and type of printed circuit boards through the connectors. An identification interface circuit that sends and receives signals for identifying the In the printed circuit board inspection apparatus, the printed circuit board includes a controller for inspecting the printed circuit board,
A transistor with its emitters grounded, multiple input terminals that take in signals from the identification interface circuit, a decoder that determines the signal pattern of the input terminals and applies a corresponding voltage to the base of the transistor, and a printed circuit that is connected to the collector of the transistor. an output terminal for outputting a voltage signal corresponding to the type of the board to the identification interface circuit, and means for the identification interface circuit to send the pattern signal to the input terminal of the printed circuit board via the connector;
and means for receiving a voltage signal corresponding to the type of printed circuit board from the output terminal and transmitting it to the control section, and the control section checks the presence or absence of the printed circuit board based on the presence or absence of a collector voltage at the output terminal before sending the pattern signal. The present invention proposes a printed circuit board inspection device equipped with means for applying a pattern signal to the inserted printed circuit board from an identification interface circuit and determining the type of the printed circuit board based on the collector voltage of the transistor.

[Operation] In the present invention, first, the collector voltage at the output terminal of the printed circuit board before sending the pattern signal is detected. Before sending the pattern signal, no voltage is applied to the base of the transistor whose emitter is grounded, so the transistor is off and the voltage at the output terminal connected to its collector remains high. Conversely, if the printed circuit board is not inserted, the output terminal itself is not connected to the connector, so no voltage signal is sent to the identification interface circuit. In this way, by detecting the presence or absence of the collector voltage before sending the pattern signal at the connector to which the output terminal of the printed circuit board is to be connected, it is possible to confirm the presence or absence of the printed circuit board.

Next, when a pattern signal is applied from the identification interface circuit to the inserted printed circuit board, the decoder discriminates the signal pattern and applies a corresponding voltage to the base of the transistor. As a result, a voltage corresponding to the type of printed circuit board is generated at the collector of the transistor. The control unit that receives this voltage signal via the identification interface circuit determines the type of printed circuit board based on the voltage signal.

Therefore, in the present invention,
The collector voltage of a transistor whose emitter is grounded can be identified without separately providing a first detection device for determining the presence or absence of a printed circuit board and a second detection device for determining the type of printed circuit board as in No. 58470. Only one contact point is required for the connector connected to the interface circuit, and the means for detecting the collector voltage can be used both to determine the presence or absence of a printed circuit board and to determine the type of printed circuit board, which is wasteful in terms of installation space and cost. There is no

[Example] Next, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of an embodiment of the printed circuit board inspection device according to the present invention, and FIG.
The figure is a block diagram showing the main parts of the embodiment of FIG. 1 in more detail.

In FIG. 1, a control section 1 includes a microprocessor, an interface circuit for signal processing and signal conversion, a memory circuit, etc., although not shown here. A plurality of (three in this case) test boards 2A, 2B, and 2C are connected to the control unit 1 via an address bus 3, a data bus 4, and a control bus 5. Identification units 6A, 6B, and 6C provided on the test boards 2A, 2B, and 2C, respectively, are connected to an identification interface circuit 8 via an identification bus 7.

Identification parts 6A, 6 of test boards 2A, 2B, 2C
As shown in FIG. 2, B and 6C are formed according to the type of each board to be tested. In the identification section 6A, the terminal _D1 of the input terminal 24A consisting of terminals _D1 to _D4 is connected to the input terminal of the decoder 25A, and the output terminal of the decoder 25A is connected to the base of the transistor 28A. The emitter of the transistor 28A is grounded, and the control voltage Vc is applied to the collector via series-connected resistors 26A and 27A. Resistors 26A and 27
The connection point with A is connected to the output terminal 23A. Other identification units 6B, 6C, ... are configured similarly to 6A, but input terminals D ₁ to D ₄ and decoder 2
The connection to 5A differs depending on the type of board to be tested.

Output terminals 23A to 23C of identification units 6A to 6C
are connected to the selector 29 of the identification interface circuit 8 by the identification bus 7 via the connector CN, and the receiving section 30 is connected to the selector 29 of the identification interface circuit 8.
is connected. The input terminals 24A to 24C
Each terminal is connected to the identification interface circuit 8 by the identification bus 7 via the connector CN, as described above.
It is connected to an identification detection section 32 through a signal conversion section 31 . The identification interface circuit 8 is connected to the control section 1 via a signal bus. Control unit 1
A memory device 33 inside stores a test program determined according to the type of board to be tested.

The operation of this embodiment configured as above will be explained next. FIG. 3 shows a test control procedure for a plurality of boards to be tested, including a plurality of different types, inserted into N connectors CN ₁ to _CNN (not shown) in this embodiment.

The start command performed in step 11 is to give a test start command from the keyboard of the input/output device 9. When the start command is given, the process moves to the next step 12, and the value of the CN counter for counting the order of the connectors CN in the control section 1 is incremented by +1 to become N+1. At step 13, -1 is added to the CN counter value to become N, and the process moves to step 14.

In step 14, it is confirmed whether the board to be tested is inserted into the first connector _CN1 . For example, if the board under test 2A is inserted into the connector CN ₁ , the transistor 28 of the identification section 6A is initially
Since A is cut off, the external terminal 23A is held at the control voltage Vc via the resistor 26A.
In this state, a logic 1 signal is input to the input terminal CN ₁ of the selector 29. This logic 1 signal is
It is converted into a 4-bit signal by the selector 29,
It is input to the receiving unit as 0001. If the board under test is not inserted, a signal of 0000 is input to the receiving section 30.

In synchronization with these signal inputs, the control section 1 is driven, and the signals from the receiving section 30 are taken in by scanning, and the microprocessor 34 determines whether or not a board to be tested is inserted.

Note that if the board under test is not inserted into connector CN ₁ , the process returns from step 14 to step 13, moves to step 14 again, and checks whether the board under test is inserted in the same way for the next connector CN ₂ . .

After confirming that the board to be tested has been inserted in this manner, the type of board to be tested is identified in step 15. The identification procedure is performed as follows.

For example, when it is confirmed that the board to be tested 2A is inserted into the connector CN ₁ , a command is given from the control section 1 to the identification detection section 32 of the identification interface circuit 8. The identification detection section 32 is the signal conversion section 31
An identification detection signal is transmitted to the identification section 6A of the board 2A to be tested. This identification detection signal consists of a 4-bit binary signal series determined according to the type of board to be tested, such as 0001,
Identification detection signals such as 0010 and 0100 are sequentially transmitted.

For example, the identification detection signal for the board under test 2A is
If it is defined as 0001, when the 0001 signal is input to the input terminal 24A of the identification section 6A, the signal is output from the decoder 25A, and the transistor 28A
becomes conductive, and the voltage at the output terminal 23A is reduced to a low level. In this way, when the identification detection signal matches, the identification section 6A is activated and a logic 0 signal is outputted to the selector 29 as an identification signal.

As a result, a 4-bit identification signal 0000 is received from the selector 29 into the receiving section 30. The control section 1 performs scanning and detects that the input signal of the reception section 30 changes to 0000, and identifies that the type of the board to be tested corresponds to the identification detection signal 0001. When the identification is completed, the inspection control program moves to step 16.

In step 16, the microprocessor 34 of the control section 1 selects and imports a test program corresponding to the identified type of the board 2A to be tested from the memory device 33, and reads the test program corresponding to the identified board 2A according to the procedure of the test program. A performance test of the test board 2A is performed. That is, the microprocessor 34 of the control section 1 converts the test signal specified in the test program by the interface circuit and outputs a signal suitable for the board under test 2A.

In step 17, the control section 1 receives response data output from the board 2A under test in response to the test signal, compares this response data with judgment data specified in the test program,
Judge performance.

In step 18, as a result of this judgment, if the performance of the board under test conforms to the judgment data, an OK signal is output, and if it does not conform, an NG signal is output.

When the OK signal is output, in step 19, an OK message based on the determination result is displayed/stored in the input/output device 9 and output to the operator.

On the other hand, if the NG signal is output, step 20
, an NG message based on the determination result is displayed/stored in the input/output device 9 and output to the worker.

After the operation of step 19 or 20 is completed,
In step 21, all connectors CN ₁ to
It is determined whether the inspection for C _N has been completed.
That is, if the value of the CN counter has not been cleared, the process returns to step 13 and tests are sequentially executed according to the procedure of the test control program similar to that described above.

In this way, the test boards 2B, 2C, . . . are also tested, and when the test up to the connector CN _N is completed, the CN counter is cleared and the process moves to step 22, where the test is completed and the testing device is stopped.

In this example, the type of board to be tested is inserted into multiple connectors in an arbitrary insertion order, insertion location, and number of boards to be inserted, and a predetermined test program corresponding to the type is selected, and each test Since the inspection is executed based on a program, performance inspections of multiple printed circuit boards, including different types of printed circuit boards, can be automatically and consecutively executed without errors.

In particular, since it can be executed automatically under the control of a single microprocessor, even when a board under test is replaced with one connector, it is possible to continue measuring the board under test connected to another connector. This greatly improves work efficiency compared to conventional equipment that replaces and inspects one sheet at a time.

Note that when identifying the type of board to be tested, an identification detection signal with a different code is sent to the boards to be tested that are sequentially connected, and the identification unit of each board to be tested outputs an identification detection signal in response to the identification detection signal. Since the method of identifying the type based on the signal is adopted, the wiring for the identification detection signal can be extremely simplified by connecting the connectors for each board to be tested in parallel to a mere 4-bit identification bus.

Furthermore, since the response identification signal only needs to be 1 bit, the configuration of the selector 29 is simplified.

Furthermore, the identification section has approximately the same simple configuration,
By simply changing the connection between the decoder and the input terminal, it is possible to provide the necessary differences for identification, and by increasing the number of bits of the identification detection signal, the number of types of identification can be greatly increased.

[Effects of the Invention] According to the present invention, it is possible to automatically and continuously perform performance tests on multiple types of printed circuit boards, prevent erroneous operations, and dramatically increase the amount of test processing. .

In particular, it is designed to check whether the printed circuit board to be tested is connected to the connector of the printed circuit board inspection equipment, and if there is a printed circuit board to be tested, to identify the type of the printed circuit board to be tested. It is possible to automatically and continuously check the insertion order, insertion location, number of printed circuit boards, and performance of printed circuit boards set in the device, improving the efficiency of testing a large number of printed circuit boards.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a printed circuit board inspection device according to the present invention, and FIG.
FIG. 3 is a block diagram showing the configuration of the main part of the embodiment in more detail, and FIG. 3 is a flowchart showing the inspection control procedure of the embodiment of FIG. DESCRIPTION OF SYMBOLS 1...Control part, 2...Test printed circuit board (test board), 3...Address bus, 4...Data bus, 5...
control bus, 6... identification section, 7... identification bus,
8... Identification interface circuit, 9... Input/output circuit, 23... Output terminal, 24... Input terminal, 25... Decoder, 26, 27... Resistor, 28... Transistor, 29... Selector, 30... Receiving section, 31... Signal conversion Part, 32...Identification detection part, 33...Memory device,
34...Microprocessor, 35...Connector.

Claims (1)

[Scope of Claims] 1. A plurality of connectors into which a plurality of printed circuit boards to be tested are arbitrarily inserted, and an identification interface circuit that sends and receives signals for identifying the presence or absence and type of the printed circuit boards through the connectors. and a control unit that determines the presence or absence and type of the printed circuit board based on the signal from the interface circuit, selects an inspection program corresponding to the type, and executes an inspection of the printed circuit board according to the procedure of the inspection program. A printed circuit board inspection apparatus comprising: a transistor whose emitter is grounded; a plurality of input terminals for receiving signals from the identification interface circuit; The identification interface circuit includes a decoder that applies voltage to the base of the transistor, and an output terminal that is connected to the collector of the transistor and outputs a voltage signal corresponding to the type of the printed circuit board to the identification interface circuit. The control unit includes means for sending a pattern signal to the input terminal of the printed circuit board via a connector, and means for receiving a voltage signal corresponding to the type of the printed circuit board from the output terminal and transmitting it to the control unit. is a means for confirming the presence or absence of the printed circuit board by the presence or absence of the collector voltage at the output terminal before sending the pattern signal, and a means for applying the pattern signal from the identification interface circuit to the inserted printed circuit board. A printed circuit board inspection device comprising: means for determining the type of the printed circuit board based on the collector voltage of a transistor.