JPH04190177A - Inspecting method of circuit board - Google Patents

Abstract

PURPOSE:To enable execution of detailed inspection by using a microprocessor for inspection and by setting conditions of the inspection jointly with an external inspection system. CONSTITUTION:A serial interface 6 is provided for inspection. Besides, a program wherein at least some of conditions of inspection are set in accordance with an instruction from an external inspection system 1 given through serial interfaces 5 and 6 is prepared in a microprocessor 7. The system 1 sets the conditions of inspection directly for an analog circuit 8 and a peripheral logic circuit 9 to be inspected, by a group 3 of input signal lines for inspection, while delivering the instruction through the interfaces 5 and 6 to the processor 7 of a circuit board 2 to be inspected. In accordance with the program prepared beforehand for the inspection, the processor 7 sets signals for the circuit 9 and a D/A converter 11 and informs the system 1 of completion the quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for inspecting a circuit board on which a logic circuit including a microprocessor and an analog circuit are interconnected and mounted.

[Conventional technology]

For example, in conventional large magnetic disk drives, there was limited mounting space, so circuit boards were created using independent boards for each function, or by making it possible to separate signal lines using multiple jumper plugs. Since the circuit can be divided when testing, testing conditions can be easily set. In the past, it was possible to conduct detailed inspections and diagnoses by manually applying a test signal to the input end of each divided circuit and monitoring the output signal at the output end.

However, in recent small magnetic disk drives, it is necessary to realize the functions of conventional large drives in a small mounting space, so each board has to be mounted with high density, and logic circuits and analog circuits are interconnected on one board. They are connected and cannot be separated to divide the circuit. Furthermore, since many functions are incorporated into microprocessors and LSIs, there are many signals that cannot be directly accessed from the outside. For these reasons, it has become difficult to directly set inspection conditions from an external inspection system for high-density mounting boards such as those mentioned above, and as a result, the inspection content may be insufficient. As a result, there are problems such as a decrease in the defect detection rate and the inability to identify the location of the failure.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a circuit board inspection method that solves the problems caused by the difficulty in setting inspection conditions.

[Means to solve the problem]

In the circuit board inspection method of the present invention, the microprocessor in the circuit board to be inspected is programmed so that at least some of the inspection conditions are set according to instructions from an external inspection system, and the external inspection system follows the instructions. The circuit board is tested by transmitting a signal to the microprocessor, setting some test conditions in the microprocessor, setting other test conditions directly to the circuit under test, and monitoring at least part of the signals of the circuit under test. conduct.

[Operation 1] Since the microprocessor in the circuit board to be inspected is used for inspection and the inspection conditions are set in collaboration with an external inspection system, detailed inspection can be performed.

[Embodiment 1] Next, an embodiment of the present invention will be described with reference to the drawings.

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

The test system 1 and the circuit board 2 to be tested are connected through serial interfaces 5 and 6 in addition to the normal test input signal line group 3 and output signal monitoring line group 4. The circuit board 2 to be tested includes a microprocessor 7, an analog circuit 8, a peripheral logic circuit 9, an A/D converter IO, and a D/D converter 10.
They are connected via an A converter 11.

The serial interface 6 is provided for inspection. The microprocessor 7 is prepared with a program in which a few (at least some) test conditions are set in accordance with commands from the external test system 1 via the serial interfaces 5 and 6.

Next, the operation of this embodiment will be explained.

During testing, the testing system 1 directly sets testing conditions for the analog circuit 8 and peripheral logic circuit 9, which are the circuits to be tested, using the testing input signal line group 3, and also sets the testing conditions directly for the analog circuit 8 and peripheral logic circuit 9, which are the circuits to be tested, and also controls the microcontroller of the circuit board 2 to be tested using the serial interface 5.6. Send command 2 to processor 7. The microprocessor 7 sets the signals of the peripheral logic circuit 9 and the D/A converter 11 in accordance with the program prepared in advance for inspection according to the command received, and notifies the inspection system 1 of the completion of the settings via the serial interface 5.6. Notice. After receiving the setting completion notification, the inspection system 1 performs measurement using the output signal monitoring line group 4 to determine pass/fail. When setting inspection conditions for scraping, the same sequence as described above is repeated. A/D converter lO if necessary
A command can also be created to report the readings to the inspection system I.

[Effects of the Invention] As explained above, the present invention utilizes a microprocessor in a circuit board to be tested for testing, and sets testing conditions in collaboration with an external testing system, thereby allowing external testing to be performed. This has the effect of allowing more detailed inspections to be performed compared to inspections performed solely by the system.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. ■...-Inspection system, 2...-Circuit board to be inspected, 3... Input signal line group for inspection, 4... Output signal monitoring line group, 5.6... Serial interface, 7... Microprocessor, 8... Analog circuit, 9... Peripheral logic circuit, lO... A/D converter, 11... I)/A converter. Patent applicant: Ibaraki NEC Co., Ltd.

Claims (1)

[Claims] 1. A method for inspecting a circuit board on which a logic circuit and an analog circuit including a microprocessor are interconnected and mounted, the microprocessor at least following instructions from an external inspection system. Some of the test conditions are programmed to be set, and the external test system issues the command to set some of the test conditions to the microprocessor, and directly sets other test conditions to the circuit under test;
A method for testing a circuit board, in which the circuit board is tested by monitoring at least part of the signals of the circuit under test.