JPH0526943A - Device and method for inspecting circuit pattern - Google Patents

Abstract

PURPOSE:To enable inspection in two different modes to be processed efficiently with one inspection device by measuring electrostatic capacitance of an inspection pattern and insulation resistance between GND net/power supply net pair inspection patterns for each probing to each inspection pad. CONSTITUTION:An inspection probe 9 is allowed to contact a signal pad 5 of a substrate 1, a grounding power supply connection wire where a grounding pad 6 and a power supply pad 7 are connected and an inspection probe 9 are connected to an electrostatic capacitance measuring equipment 10 for measuring electrostatic capacitance, and then the grounding power supply connection wire and the inspection probe 9 are switched from the electrostatic capacitance measuring equipment 10 to a connection with an insulation resistance measuring equipment 11, thus enabling insulation resistance to be measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit pattern inspecting apparatus and method, and more particularly to an apparatus and method for inspecting a circuit pattern for disconnection and short circuit and for inspecting insulation resistance between a GND / power supply net and each signal net.

[0002]

2. Description of the Related Art A conventional circuit pattern inspection method measures a capacitance value of a pattern to be inspected and compares it with a theoretical capacitance value calculated from line length data of the pattern. Items to inspect for disconnection and short circuit,
There are separate inspection items for measuring whether the insulation resistance value between the GND / power supply net and each signal net is measured, and whether or not it is within the insulation resistance standard. Has been done.

[0003]

In the conventional circuit pattern inspection method, the disconnection and short-circuit inspection of the pattern to be inspected and the insulation resistance inspection between the GND / power supply net and the signal net are independent inspections. Therefore, different inspection devices perform the inspection action twice on the same signal pattern. For this reason, the inspection time is doubled, and the number of probing of the inspection pattern is increased, which causes an increase in scratches.

[0004]

In a circuit pattern inspection apparatus according to the present invention, a ground pad electrically connected to a ground layer of a substrate and a power pad electrically connected to a power layer are electrically connected to form a ground power connection line. A GND power supply connection mechanism, an inspection probe for connecting to a signal pad conducting to the signal pattern of the substrate, a capacitance measuring device, an insulation resistance measuring device,
The ground power supply connection line and the inspection probe are connected to one and the other inputs of the capacitance measuring device or one and the other input of the insulation resistance measuring device.

In the method for inspecting a circuit pattern according to the present invention, a first step of bringing an inspection probe into contact with a signal pad electrically connected to a signal pattern on a substrate, and electrically connecting to a ground layer of the substrate after the first step. A ground power supply line connecting a ground pad and a power supply pad electrically connected to the power supply layer by a GND power supply connection mechanism is connected to one input of the capacitance measuring instrument and the inspection probe is connected to the other input to determine the capacitance. A second step of measuring, and a third step of measuring the insulation resistance by connecting the power supply connection line to one input of an insulation resistance measuring instrument and connecting the inspection probe to the other input after the first step.
And a fourth step of switching the connection between the ground power supply connection line and the inspection probe and the capacitance measuring instrument or the insulation resistance measuring instrument by a changeover switch between the second step and the third step. Is equipped with.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a circuit pattern inspection apparatus according to an embodiment of the present invention.

A circuit board 1 which is a substrate to be inspected has a GND layer 2 and a power supply layer 3, and these layers are connected to the outside and the GND.
It is connected through the D pad 6 and the power supply pad 7.

The signal pattern 4 having the inspection symmetry is also connected to the outside via the signal pad 5. In the circuit pattern disconnection / short-circuit inspection, it is effective to measure the electrostatic capacity of the signal pattern 4 and compare it with the theoretical value of the electrostatic capacity calculated from the design data. The GND layer 2 and the power supply layer 3 are used as the counter electrodes for capacitance measurement. The GND pad 6 and the power supply pad 7 for external connection are electrically connected by the GND-power supply connection mechanism 8 and are connected to the capacitance measuring device 10 via the changeover switch 13. The signal pattern 4 to be inspected is also electrically connected by probing the signal pad 5 with the inspection probe 9. Measurement system signal line 14
Is connected to the capacitance measuring device 10 via the changeover switch 13 and the capacitance between the GND layer 2 and the power supply layer 3 and the signal pattern 4 is measured.

Next, in the insulation test between the GND net and the power supply net and the signal pattern 4, the insulation resistance measuring instrument 11, the GND layer 2 and the power supply layer 3 are similarly passed through the GND-power supply connection mechanism 8 and the changeover switch 13. Connect. The signal pattern 4 is connected to the insulation resistance measuring instrument 11 via the changeover switch 13 via the probing of the inspection probe 9 to the signal pad 5, and the insulation resistance is measured. Here, for probing the signal pad 5 once for each signal pattern, a disconnection / short-circuit inspection of the pattern is performed, and an insulation resistance inspection is further performed. And a measurement path is selected via the changeover switch 13 by a command from here.
Each inspection is performed.

The operation of the circuit pattern inspection method using the apparatus shown in FIG. 1 will be described below with reference to the flow chart of FIG. When the inspection is started (step 15), the inspection data is read, the inspection probe 9 is positioned on the signal pad 5 (step 16), and the inspection pad is probed. Changeover switch 1 according to a command from control device 12
3 is switched (step 17), the capacitance measuring device 1
The measurement path is switched to the 0 side. Here, the capacitance of the inspection pattern is measured (step 18), and the quality of the pattern is determined (step 19). Judgment is “No”
If so, defective processing (step 25) is performed, and if “good”, the process proceeds to the insulation resistance measurement inspection.

In the insulation resistance test, the prober is left as it is, and in accordance with a command from the control device 12, the changeover switch 13 is changed over to change the measurement path to insulation resistance measurement (step 20), and the GND layer 2 and the power supply layer are measured. The insulation resistance of the 3-pair signal pattern 4 is measured (step 21). Based on this value, the insulation resistance is judged to be good or bad (step 22), and if the judgment is "not good", the defective processing is carried out (step 25), and if it is "good", the next pad is inspected as it is. Therefore, the next inspection pad data is read (step 23). Here, it is judged whether the end of the data has been detected (step 24), and "No".
If so, the next pad is continuously inspected and “Yes”
In that case, after the inspection result is edited (step 26), the result is output (step 27) and the inspection is ended (step 2).
8).

[0013]

As described above, according to the present invention, in the disconnection / short circuit inspection of the circuit pattern, the capacitance of the inspection pattern is measured and G is measured for each probing to each inspection pad.
By performing the insulation resistance measurement between the ND net / power net and the inspection pattern, the inspection in two different modes can be efficiently processed by one inspection device.

[Brief description of drawings]

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

2 is a flow chart showing a flow of inspection in the embodiment of FIG.

[Explanation of symbols]

1 circuit board 2 GND layer 3 power layers 4 signal patterns 5 signal pads 6 GND pad 7 Power pad 8 GND-Power connection mechanism 9 Inspection probe 10 Capacitance measuring device 11 Insulation resistance measuring instrument 12 Control device 13 Changeover switch 14 Measurement system signal line

Claims (2)

[Claims] 1. A GND power supply connection mechanism for electrically connecting a ground pad electrically connected to a ground layer of a substrate and a power pad electrically connected to a power layer to form a ground power connection line and a signal pattern of the substrate. An inspection probe for connecting to a signal pad, a capacitance measuring device, an insulation resistance measuring device, one of the capacitance measuring device and the other input of the capacitance measuring device and the ground power supply connection line and the inspection probe. A circuit pattern inspecting device, comprising: a changeover switch for connecting to one or the other input of an insulation resistance measuring device. 2. A first step of bringing an inspection probe into contact with a signal pad electrically connected to a signal pattern on a substrate, and the first step.
After the step (1), the grounding pad connecting to the grounding layer of the substrate and the powering pad conducting to the powering layer are connected by the GND power supply connection mechanism to the grounding power supply connecting line, which is connected to one input of the capacitance measuring device to perform the inspection. The second step of connecting the probe to the other input to measure the capacitance, and the step of connecting the power supply connection line to one input of the insulation resistance measuring device after the first step and connecting the inspection probe to the other The third step of measuring the insulation resistance by connecting to the input of the input terminal, and the ground power supply connection line and the inspection probe and the capacitance measuring device or the insulation by a changeover switch between the second and third steps. And a fourth step of switching the connection with the resistance measuring device.