JPH04367018A - Checking device for printed circuit board provided with keyboard signal line - Google Patents

Abstract

PURPOSE:To attain the automatic check of the keyboard function with synchronization with a test program of a tested PCB by adding a small quantity of hardware to a control board after changing slightly the test program. CONSTITUTION:The short circuits are successively produced among the key code signals via a relay 22 by the firmware processing of a microcomputer contained in a control board 11. Thus a state equivalent to the push of a key switch 21 is set and the key push simulation is carried out for a keyboard. The key code generated from the simulation is sent to a checked PCB 12 from the board 11 and then decided by a test program 121 contained in the PCB 12. Thus the error check is carried out.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an inspection device for printed wiring boards (PCBs) on which keyboard signal lines are arranged, and is particularly suitable for keyboard-related inspections (keyboard inspections). (inspection equipment).

0002

[Prior Art] In personal computers, etc.,
A printed wiring board (PCB) called a motherboard is used. The device that tests the functionality of this motherboard is
A device called a PCB inspection device is known. This P
One of the functional tests performed by the CB test device is a keyboard test. The purpose of this keyboard inspection is to check the keyboard-related circuits and keyboard signal lines on the motherboard (PCB).

Conventionally, keyboard inspection using a PCB inspection device has been carried out by an operator following instructions given via a display 51 by a test program 42 loaded onto a PCB (motherboard) 41 to be inspected, as shown in FIG. This was done by pressing a key.

That is, the operator follows the instructions displayed on the display 51 installed in the PCB inspection equipment.
Keys are pressed one after another on the keyboard 52 on the PCB inspection device. The keyboard signal generated by this is transmitted to the PCB4 under test.
1 and checking according to the test program 42, the keyboard is tested. If the operator presses all the instructed keys and no error occurs with respect to those keyboard signals, it is determined that the operation is normal. In other words, conventionally, a keyboard test has been performed by an operator performing key operations according to the instructions of the test program 42.

[0005]

According to the above-mentioned conventional example, the operator has to press approximately 10 types of keys in sequence without making mistakes, which requires skill. In addition, there are drawbacks such as a lot of troublesome operations and a long inspection time.

The present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide a printed wiring board (PCB) testing device that can automate keyboard testing by simply adding a small amount of hardware.

[0007]

[Means for Solving the Problems] The PCB inspection device of the present invention includes a switch circuit provided for each of several predetermined key switches on a keyboard and connected in parallel to the corresponding key switch, and a switch circuit connected to the corresponding key switch in parallel. An inspection jig with a control board containing a built-in microcomputer to simulate key presses by sequentially driving circuits in a pre-programmed order, and a printed wiring board to be inspected with keyboard signal lines installed. The present invention is characterized in that it includes a PCB to be tested that performs an error check by determining key codes sequentially sent from the control board in accordance with the simulation of the key presses.

[0008]

[Operation] In the above configuration, by sequentially turning on each switch circuit (for example, a relay circuit) by the firmware processing by the microcomputer built into the control board, the same state as when the key switch is turned on is set, and keyboard keystrokes are simulated. Do this. This on operation (
The key codes generated during the simulation (simulating keyboard keystrokes) are sequentially sent to the PCB to be tested (as if the keycodes were generated on the keyboard when a key was actually pressed). The PCB to be inspected judges these key codes one after another and performs an error check.

In this manner, by slightly modifying the test program on the PCB to be inspected and adding a switch circuit (relay circuit) to the control board, keyboard inspection can be realized in synchronization with the test program. This makes it possible to automate the keyboard function test, making it easier and faster to operate the PCB test device.

0010

Embodiment FIG. 1 is a diagram showing an embodiment of the present invention.

In the figure, reference numeral 11 is a control board that forms the center of the inspection jig, and includes a microcomputer 111 that performs control according to firmware. Reference numeral 12 is a PCB to be tested to which a keyboard can be connected, and a keyboard signal line and the like are arranged thereon. PCB to be inspected
12 is, for example, a motherboard of a personal computer.

The PCB 12 to be inspected is a test program 12.
1 and transfers control board control signals via line 13 according to the same program 121. Further, the control board 11 that has received the control board control signal from the PCB 12 to be tested uses the built-in microcomputer 111 to simulate keystrokes according to the firmware, and returns the keyboard signal to the PCB 12 to be tested via the line 14.

FIG. 2 is a diagram showing the principle of keyboard simulation. In the figure, reference numeral 21 is a keyboard switch (key switch), which is turned on when a corresponding key is pressed. In the conventional PCB inspection apparatus, an operator presses the key switch 21 (the corresponding key) to perform the inspection. In the PCB inspection apparatus according to the embodiment of the present invention, the keyboard is attached to the inspection apparatus (inspection jig thereof) because it is necessary for functional inspection other than keyboard inspection. In addition, in FIG. 2, the key switch 21
Although only one is shown, it goes without saying that there may be more than one.

Reference numeral 22 denotes a switch circuit, such as a relay, which is connected in parallel to the key switch 21, and in the on state short-circuits both contacts a and b of the key switch 21 (that is, short-circuits the key code signals). This is for simulating the depression of the key switch 21 (keystroke). In this embodiment, the relay 22 is turned on when the input signal is "High" and turned off when the input signal is "Low". Reference numeral 23 is a driver for driving the relay 22. This driver 23 is connected to the system on the control board 11 (the microcomputer 111 in FIG.
etc.). The above-mentioned sets of relays 22 and drivers 23 are provided corresponding to the number of key switches 21 targeted for keystroke simulation.

FIG. 3 is a diagram showing an interface circuit between the PCB 12 to be tested and the control board 11 in FIG. In the figure, reference numeral 31 is a foldback inspection board that is connected to the serial port of the PCB 12 to be tested, and is used for foldback inspection of the serial port (not directly related to the present invention). From this board 31 (pin 7,
Two signal lines from pin 1 (connected to pin 8) and pin 4 (connected to pins 6, 9) are brought out and connected to the control board 11 to initiate the keyboard test from the control board 12 to the PCB under test. 11.

Reference numeral 112 denotes a receiver on the control board 11, which receives a serial port signal from the PCB to be tested 12 sent via the return test board 31 and performs voltage conversion. Reference numeral 113 indicates a PIO (Parallel Input) on the control board 11.
/Output), inputs a signal converted into voltage by the receiver 112, and notifies the microcomputer 111 of FIG. The operation of the embodiment of the present invention will be explained below.

First, in the PCB 12 to be inspected, when the keyboard inspection item is entered while the test program 121 is being executed,
A control board control signal for starting keyboard testing is sent to the control board 11 via line 13. Figure 3
In this example, in order to notify the start of the keyboard test, pin 1 of the (serial port) of the PCB 31 to be tested is set to “High”.
h” and pin 4 is set to “Low”.

The states of both pins 1 and 4 of the PCB 31 to be tested are transmitted to the PIO 113 via the folding test board 31 and the receiver 112 built into the control board 11.
sent to. As a result, the level inverted state "Low" of pin 1 is taken into PD0 of the PIO 113, and the level inverted state "High" of pin 4 is taken into PD1.

Now, on the control board 11 side, (
The microcomputer 111 built into the board 11 is waiting for a keyboard test start notification from the PCB 12 to be tested. In the example of FIG. 3, on the control board 11 side (microcomputer 111 shown in FIG. 1), the signal PD0 of PIO 113 is always “Low” and P
The state in which D1 becomes "High" is monitored. If this condition appears (when a keyboard inspection start notification is sent from the PCB to be inspected 12), the control board 11 (built-in microcomputer 111)
simulates keyboard strokes at intervals preprogrammed by the firmware.

[0020] Here, keystroke simulation will be specifically explained. First, the principle of keystroke simulation is as shown in FIG. This short-circuits the key switch 21 to generate the same state as if the key switch 21 had been pressed.

Therefore, in the embodiment of the present invention, the relay 22, the driver 23, and the input signals to the driver 23 are prepared for each key switch 21 corresponding to the number of types of keys necessary for the keystroke test (keystroke simulation), and the input signals to the driver 23 are prepared. The board 11 (built-in microcomputer 111)
Each relay 22 is turned on one after another at intervals and in a sequence preprogrammed by firmware. When this relay 22 is turned on, a keyboard signal (key code) unique to the corresponding key switch 21 is generated and sent from the control board 11 via the line 14 to the PCB 12 to be tested.

The PCB 12 to be tested successively judges the key codes sequentially sent from the control board 11 according to the test program 121, and if no error occurs, the process ends normally. If an error occurs, the test program 121 stops at the location where the error occurred.

[0023]

[Effects of the Invention] As explained above, according to the present invention, the PC
In the B test, the keyboard function test is automated. Therefore, the operation of the PCB inspection device can be facilitated and the operation speed can be increased. Note that by synchronizing the PCB to be inspected and the control board and setting protocols such as commands and status, the PCB inspection can be further automated and speeded up.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing the operating principle of keyboard simulation.

FIG. 3 is a diagram showing an interface circuit between a PCB under test and a control board.

FIG. 4 is a diagram showing a conventional example.

[Explanation of symbols]

11...Control board, 12...PCB to be inspected, 21
...Key switch, 22...Relay (switch circuit), 23
...Driver, 31...Return inspection board, 111...Microcomputer, 121...Test program.

Claims (1)

[Claims] 1. A switch circuit provided for each of several predetermined key switches on a keyboard and connected in parallel to the corresponding key switch, and driving the switch circuits in order according to preprogrammed contents. an inspection jig having a control board with a built-in microcomputer for simulating key presses, and a printed wiring board to be inspected on which a keyboard signal line is arranged; A printed wiring board inspection apparatus comprising: a printed wiring board to be inspected having means for determining key codes sequentially sent from a control board and performing error checking.