JPH04236365A - Board inspecting apparatus - Google Patents

Abstract

PURPOSE:To inspect a printed wiring board without applying the damage due to the contact with a probe to the terminal of a circuit pattern when the continuity and discontinuity of the circuit pattern of the printed circuit board are inspected. CONSTITUTION:A control part 1 issues a command for positioning means 20, 21 to move the positions of respective pattern terminals 130, 131. The positioning part 21 brings a probe 40 into contact with the pattern terminal 131 and an electric field is generated between an electrode plate 10 and the wiring pattern connected to the probe 40 by a voltage source 5. An electric field sensor 3 is arranged in the vicinity of the pattern terminal 130 by the positioning part 20. The electric field sensor 3 obtaining laser beam from a laser device 7 through an optical fiber 122 changes the intensity of the laser beam by the electric field generated at the pattern terminal 130 to guide the laser beam to a photodetector 6 through an optical fiber 121. When there is disconnection in a wiring pattern 9, no electric field is generated at the pattern terminal 130 and a flaw can be detected.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a board inspection apparatus, and more particularly to a board inspection apparatus used for testing continuity and insulation of wiring patterns formed on an insulating substrate.

0002

2. Description of the Related Art As shown in FIG. 2, a conventional circuit board inspection apparatus includes a resistance meter 8 having probes 41 and 42 that contact wiring pattern ends 130 and 131 of a wiring pattern 9, respectively, and the positioning of the probes 41 and 42. Positioning sections 20 and 21, resistance meter 8, and positioning sections 20 and 21, respectively.
It is composed of a control section 1 that controls.

Generally, in board inspection, probes are brought into contact with the same or adjacent wiring patterns at the same time, and conduction or non-conduction between the probes is measured. In the conventional device shown here, the wiring pattern ends 132, 1 of any wiring pattern 9
The resistance between 33 and 33 is measured with a resistance meter 8 to determine continuity or non-continuity. At this time, the probes 41 and 42 are moved by the positioning sections 20 and 21 in accordance with a procedure stored in advance in the control section 1, and all wiring patterns formed on the substrate 11 are inspected for continuity or non-continuity. At this time, in order to perform a continuity test, it is important to achieve reliable contact between the probe and the end of the wiring pattern. However, it is difficult to apply conventional inspection equipment to the ends of wiring patterns that are still in the manufacturing process and do not have sufficient strength, or to connector terminals that cannot be damaged by probes.

0004

The conventional board inspection described above requires the use of a sharp probe to ensure reliable contact between the wiring pattern ends and the probes, which has the disadvantage of damaging the wiring pattern ends.

[0005]

[Means for Solving the Problems] A board inspection apparatus of the present invention comprises: a probe that contacts one side of a wiring pattern formed on a board to be inspected; a first positioning means for positioning the probe; and a first positioning means for positioning the probe; an electrode plate disposed adjacent to the substrate; means for applying voltage between the probe and the electrode plate; an electric field sensor disposed near the other end of the wiring pattern; and a second electrode plate for positioning the electric field sensor. The electric field sensor is characterized by comprising a positioning means, a means for supplying laser light to the electric field sensor via an optical fiber, and a light receiver for receiving the laser light from the electric field sensor.

[0006]

Embodiments Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.

According to the instructions from the control section 1, the wiring pattern end 131 of the wiring pattern 9 formed on the substrate to be inspected 11 is
The probe 40 is brought into contact with the positioning portion 21 . A voltage source 5 applies a voltage between the substrate 11 to be inspected and an electrode plate 10 disposed adjacent to the substrate 11 to be inspected. As a result, an electric field (lines of electric force) is generated between the wiring pattern 9 and the wiring pattern end 130. Here, the electric field sensor 3 is positioned adjacent to the wiring pattern end 130 by the positioning section 20 according to instructions from the control section 1. For example, as the electric field sensor 3,
There is one described on page 231 of the Sensor Application Technology Handbook (published by the Engineering Technology Center). Laser light is supplied to the electric field sensor 3 from a laser device 7 via an optical fiber 122. When the electric field sensor 3 is placed in an electric field, it polarizes the supplied laser light and further causes an intensity change. The laser light whose intensity has been changed according to the magnitude of the electric field is guided to the light receiver 6 via the optical fiber 121. The light receiver 6 detects changes in the intensity of the laser beam, that is, the wiring pattern end 1.
The presence of an electric field at 30 can be captured. If there is a break in the wiring pattern 9, the electric field will not reach the wiring pattern end 130, the electric field sensor 3 will not be in the electric field, and the light receiver 6
does not capture change. Electric field sensor 3 is connected to wiring pattern end 1
30, in other words, the fragile wiring pattern 130 will not be damaged.

[0008]

[Effects of the Invention] Instead of connecting a sharp probe and measuring resistance, the board inspection device of the present invention detects the electric field generated at the end of the wiring pattern using an electric field sensor, and can confirm continuity. Since it is no longer necessary to touch the probe with the probe, the end of the wiring pattern, which is fragile, can be inspected without being damaged.

[Brief explanation of the drawing]

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

FIG. 2 is a block diagram showing a conventional example.

[Explanation of symbols]

1 Control section 20 Positioning part 21 Positioning part 3 Electric field sensor 40 Probe 41 Probe 42 Probe 5 Voltage source 6 Photo receiver 7 Laser device 8 Resistance meter 9 Wiring pattern 10　　　Electrode plate 11　　　　Substrate 121 Optical fiber 122 Optical fiber 130 Weak wiring pattern edge 131 Wiring pattern end 132 Wiring pattern end 133 Wiring pattern end

Claims (1)

[Claims] 1. A probe that contacts one side of a wiring pattern formed on a substrate to be inspected, first positioning means for positioning the probe, and an electrode plate disposed adjacent to the substrate to be inspected. means for applying a voltage between the probe and the electrode plate; an electric field sensor disposed near the other end of the wiring pattern; a second positioning means for positioning the electric field sensor; and an optical fiber connected to the electric field sensor. 1. A substrate inspection apparatus comprising: means for supplying laser light through the electric field sensor; and a light receiver that receives the laser light from the electric field sensor.