JPS5944671A - Automatic testing device of printed board - Google Patents

Abstract

PURPOSE:To execute easily an operation test, by collecting a data from a normal board, storing it, and thereafter, connecting a board to be tested, and transmitting and receiving automatically input and output signals in accordance with whether a mode of the board to be tested is an input mode or an output mode. CONSTITUTION:When collecting a data, a switching circuit 14 is switched to a printed board containing unit 17 side A, and a signal of all points of a normal board 18 is fetched and is stored in a storing circuit 3. At the time of testing, the circuit 14 is switched to a B side. Subsequently, whether a board to be tested 2 is in an output mode or an input mode is discriminated by an interlocking circuit 10, and a data of the storing circuit 3 is outputted by a reference clock signal e1 outputted from a main controlling circuit 4. In this way, an input signal for executing the same operation as the time when collecting the data is generated automatically, and the input signal and the output signal are transmitted and received automatically, therefore, a work of an operation test is executed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in an automatic printed circuit board testing device for testing the operation of a digital cylinder board on which digital ICs and the like are mounted.

[Technical background of the invention]

FIG. 1 is a block diagram showing the configuration of a conventional printed circuit board automatic testing apparatus for testing the operation of a digital printed circuit board on which a digital IC is mounted.

In FIG. 1, reference numeral 1 denotes an operation panel as an operation unit for operating the automatic printed circuit board testing apparatus, and 2 denotes a printed circuit board to be tested (hereinafter simply referred to as the board to be tested). 3 is a memory circuit that stores data programmed for each cylinder board before testing the board 2 under test. Reference numeral 4 denotes a main control circuit for controlling each circuit constituting the automatic printed circuit board testing apparatus during programming and testing. Reference numeral 5 denotes an output data check circuit for determining the quality of the signal output from the board under test 2 during testing. Reference numeral 6 denotes an input data creation processing circuit for creating and processing signals to be input to the board under test 2 during testing. Reference numeral 7 denotes an output data interface circuit that converts the signal output from the board under test 2 into data that cannot be input to the output data check circuit 5. Reference numeral 8 denotes an input data interface circuit for converting the data output from the input data creation processing circuit 6 into a signal that can be input to the board under test 2.

In the automatic printed circuit board testing equipment configured as described above, the test operation procedure is as follows: First, the circuit operation of the board under test 2 is grasped in advance, and then the operation is performed using the unique programming method of this automatic printed circuit board testing equipment. Operate panel 11. The programming data obtained by this operation is passed through the main control circuit 4 and stored in the storage circuit 3 at 7. At the time of the test, a test signal is automatically input to the final test board 2 via the input data creation processing circuit 6 and the input data interface circuit 8, and the output signal as a response is input to the test board 2 for output data. The signal is received via the interface circuit 7, the output data check circuit 5 judges 17 whether the output signal is good or bad, and outputs and displays it externally.

[Problems with background technology]

However, with the test drive method using the conventional printed circuit board automatic test equipment described above, the test completely matches the circuit operation of the board under test 20! Since it is necessary to create a Rokrano 4, it is not possible to program unless the 20 circuits of the board under test are completely understood. Another problem is that it requires a lot of time because it involves programming.

1. Purpose of the invention] Invention 11: An automatic printed circuit board test that has been developed in order to solve the above-mentioned problems, and is capable of performing an operation test of a board under test while reducing time. The purpose is to provide equipment.

[Summary of the invention]

The printed circuit board opening %11 test device according to the present invention is composed of a signal extracting means, a memory circuit, a discrimination circuit, a control circuit, a comparison circuit, a display section, and an operation section, and is capable of testing a test device whose normal operation has been confirmed. A test board is stored in the signal extracting means, and a normal signal is stored in the memory circuit by operating the operating section to collect data.Next, during an automatic test, the test board is stored in the signal extraction means. After storing it in the drawer means and operating the operating section to automatically test the board under test, the above discrimination circuit determines whether the printed circuit board to be tested is in input mode or output mode. Then, the control circuit creates an input signal to be input to the board under test based on the normal signal stored in the storage circuit if it is in the input mode, and inputs it to the board under test in -F. However, if it is determined that it is the force output mode, control 1-7 is performed to prevent the output from the board under test from interfering with the normal signal that has not been stored in the storage circuit, and furthermore, the comparator circuit controls the The above purpose is achieved by successively comparing the signals sent and received from the printed circuit board to be tested and the normal signal stored in the above storage circuit, and if they do not match, a failure is displayed on the above display section. It is something.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows an example of the configuration of an automatic printed circuit board testing device according to the present invention. In FIG. 2, the same parts as those in FIG. Second
In the figure, 9 is a display unit that displays the pass/fail results of the ii test, and 1θ is an interlock circuit.

This interlock circuit 10 is a discriminator circuit for discriminating whether the board under test 2 is in the output mode or the input mode.
5 and a reference clock signal e output from the main control circuit 4.
1 to create an output signal e3 for outputting the data signal e2 stored in the storage circuit 3 to the board under test 2 through the switching circuit 12. Reference numeral 13 denotes a comparison circuit, which compares and checks whether the signal exchange between the board under test 2 and this printed circuit board automatic testing device matches the data output signal e2 stored in the storage circuit 3. It is something. Reference numeral 14 denotes a switching circuit consisting of a changeover switch, etc., which switches to the side A of the printed circuit board storage unit 17 during 5' sampling, and switches to the side B of the board to be tested 2 during a 1/2 test. J5 is a data driver circuit for taking out the operating signal from the printed circuit board storage unit 17 and transmitting the signal, and 16 is a data receiver circuit for receiving the signal.

In the above, the flint board storage unit 17 to which the normal board 18 is mounted, the data driver circuit 15, the data receiver circuit 16, the connector to which the test board 2 (not shown) is mounted, etc. constitute signal extraction means.

Next, a description will be given of the operation of the automatic printed circuit board testing apparatus configured as described above during testing. First, when collecting data, the switching circuit 14 is switched to the side A of the printed circuit board storage unit 17, the signals of all points of the normal circuit board 18 are extracted, and the operating status is stored in the memory circuit 2 at every fixed reference clock. I'll keep it. On the other hand, during testing, switching circuit 1
4 to the board under test 2 side B, and attach the board under test 2 to a connector (not shown) or the like.

At this time, the printed circuit board storage unit 17 used during data collection may be separated from the present printed circuit board automatic testing apparatus. It is also possible to temporarily store the data obtained during data collection on magnetic tape, etc., and reload it during testing. Then, operate the test mode using the operation panel 1.

The specific operation e (one will be explained in detail using the time chart shown in FIG. 3) below.

``First, we will explain the case where 201 points of the board under test are in manual mode and a signal of logic level ``1'' is input.First, the main control circuit 4 outputs the reference clock signal e.
1 is output.

(This reference clock signal e1 is a very fast clock, and the signal change of each component circuit is: This reference clock signal e1 is a very fast clock.
is synchronized with. ) At the falling edge of this reference clock signal eH, the read data signal e2 of the storage circuit 9 becomes °'
1'' is output from the interlock circuit 10 (M e3 becomes "O" each time the reference C1 clock signal ei falls, and the switching circuit 12 is turned off at time t). The output state of the board under test 2 at this time is the output signal e4 which is the output of the switching circuit 12.
, and the level check circuit 11 detects that it is in the input mode.

Note that this level check circuit 1 detects that the level of the output signal e4 is an intermediate level and sets the output signal e5 to 0''.The interlock circuit 0 detects that the level of the output signal e4 is at an intermediate level and sets the output signal e5 to 0. is O
n, the rise time t3 of the reference clock signal c1
In order to restore the output signal e3 to "1" at time t4, switching circuit No. 2 is turned on at time t4.
．． As a result, the output signal e2 of the memory circuit 3 appears as the output signal e4 via the switching circuit 12, so the output signal e5 of the level check circuit 1 returns to '1'' at time t5, and the memory circuit 3 data output signal 82°゛1'' is input.

Next, a case will be explained in which the board under test 8 enters the output mode and outputs a signal of logic level "1".The output signal e3 of the interlock circuit 10 changes to "°0" at the falling edge of the reference clock signal e1. Then, the switching circuit 12 is turned off, but at this time, the output signal e4 of the switching circuit J2, which is in the output mode, remains at "°J". That/ζ level check circuit 1
Therefore, the output signal e3 of the interlock circuit 10 remains at II ON at time t6.

Next, a case will be described in which when the board under test 2 is in the output mode, there is a change from PA1'' to PA0'' at a time not at the falling edge of the reference clock signal e1.

When the output signal of the switching circuit 12 turns ++ ON, that is, at time t7, the read data signal e2 of the storage circuit 3
However, at the falling edge of the next reference clock signal (11,
Since the data output signal e2 becomes "0" at time t8', the output signal e6 of the comparison circuit 13 returns to "0". Furthermore, when the time during which the output signal e6 of the comparator circuit 13 is 1'' is within the cycle of the reference clock signal e1, the main control circuit 4 does not detect a failure.

Next, we will explain the case where the board under test 2 changes from the output mode to the input mode and '0' is input. When the board under test 2 switches from outputting '0' to input mode, Since the switching circuit 12 is off, the level check circuit 11 immediately detects the input mode at time t9. Then, the input signal e5 of the interlock circuit 10 becomes 0#, and the interlock circuit 10 turns on the switching circuit 12.
output signal e3 at time tl.

Let it be Pa1'. As a result, '0' of the data signal e2 is input to the board under test 2 through the switching circuit 12, so the output signal e4 of the switching circuit 13 becomes '0' again at time tll, and the output signal e5 of the level check circuit 11 also becomes '0'. Time 1. □ becomes 1″.

Next, we will explain when the board under test 2 changes from the input mode to the output mode and outputs "0". At this time, the switching circuit 12 remains on, and the output signal e4 of the switching circuit 12 also changes. ° at time t13
It remains O#. From the state where the board under test 2 is outputting °°0'' in the output mode, it becomes the input mode.
The example in which "°1" is input is as shown from time t, 4 to time t17 in the time chart, and detailed explanation thereof will be omitted.

Next, the operation when the board under test 2 is defective and the defect is detected will be explained. Here, we will take as an example a malfunction in which the board under test 2 changes from the input mode to the output mode and outputs 0#. The output signal e4 of the switching circuit 12 remains at "0" at time t18, and the comparator circuit 13 detects a mismatch at time t19.The time length of this time t19 is longer than the period of the reference clock signal e1. Since the signal e7 becomes long, the main control circuit 4 outputs the signal e7 as '1' to indicate a failure on the display 9. When this output signal e7']'' is input to the display 9, an error message is displayed, and it can be confirmed that the board under test 2 is defective.

As explained above, this printed circuit board automatic test equipment automatically creates an input signal that operates in the same way as when collecting data for the board under test 2, and adds it as an input signal with almost no delay. I can do it. Further, when a defect is detected, a defect is automatically displayed and the switching circuit 12 is turned off to electrically isolate the board under test 2 from the automatic printed circuit board testing equipment, thereby reliably preventing a spread failure of the automatic printed circuit board testing equipment. I can do it.

Although the above automatic printed circuit board testing device uses the switching circuit 12 to switch between signal transmission and reception, it is also possible to use an element such as a three-chip IC, and the present invention can be modified without changing the gist of the invention. It can be implemented with various modifications.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to automatically create an input signal that operates in the same manner as when data is collected on the board under test, and it is possible to automatically send and receive input signals and output signals. As a result, it is possible to provide an extremely reliable printed circuit board automatic testing apparatus that can easily perform an operation test on a board under test while reducing the time required.

[Brief Description of the Drawings] Fig. 1 is a block diagram showing an example of a conventional printed circuit board operation testing device, Fig. 2 is a block diagram showing an embodiment of a printed circuit board automatic testing device according to the present invention, and Fig. 3 is a block diagram showing an example of a conventional printed circuit board operation testing device. 3 is a time chart for explaining the operation of the printed circuit board operation test apparatus shown in FIG. 2. FIG. 1...Operation A? Panel, 2... Board under test, 3...
Memory circuit, 4... Main control circuit, 5... Output data check circuit, 6... Input data creation processing circuit, 7
... Interface circuit for output data, 8 ... Interface circuit for input data, 9 ... Display device, 1
0... Interlock circuit, 1... Level check circuit, 12... Switching circuit, 13... Comparison circuit, 14... Switching circuit, 15... Data driver circuit, 16... Data receiver circuit, 17... Printed circuit board storage unit, 18... Normal board.

Claims (1)

[Scope of Claims] Signal extracting means for transmitting and receiving signals between a normally operating printed circuit board and a printed circuit board to be tested, and storing a normal signal from the normally operating printed circuit board obtained from the signal extracting means. and a memory circuit for controlling the printed circuit board under test, and the printed circuit board under test receives an operating state signal from the printed circuit board under test during an automatic test. a discrimination circuit for discriminating one of the output modes; and when the discrimination result by this discrimination circuit is an input mode, the input signal to be input to the printed circuit board under test is stored in the memory circuit; It is created and input to the printed circuit board to be tested, and in the pigeonhole in output mode, there is an interlock so that the output signal from the cylinder board to be tested and the normal signal stored in the memory circuit do not interfere with each other. a control circuit that controls operations and switching operations; a comparison circuit that compares the signal sent from the printed circuit board under test with the normal signal stored in the storage circuit; and a comparison result by the comparison circuit that is displayed. 1. An automatic printed circuit board testing device comprising: a display section for performing operations; and an operation section for executing operating operations.