JPS60259970A - Probe for resistance measurement - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resistance measuring probe that can accurately measure minute surface resistances.

In electronic devices that have a cathode ray tube (CRT) installed in the housing, the cathode ray tube or the IC for operating the cathode ray tube
In order to eliminate noise generated from printed circuit boards on which electronic components such as A method has been adopted in which a conductive film formed from paint is grounded.

By the way, if this conductive paint is not applied uniformly to a predetermined thickness, it will not be possible to remove noise sufficiently, and the method of detecting the applied thickness is to measure the surface of the conductive paint film applied inside the housing. The resistance value is measured and the thickness of the conductive coating film is detected based on this value.

[Conventional technology]

Conventionally, as a method for measuring the surface resistance of such a conductive coating film, as shown in FIG. 1, four electrode terminals IA, IB,
The IC and ID were brought into pressure contact with the surface of the conductive coating film 2, and a direct current was applied between the outer two electrode terminals IA and ID of the four electrode terminals IA, IB, IC, and 10. In the state, the four electrode terminals IA, 'IB, IC,10
The surface resistance of the conductive coating 1I82 was measured by measuring the potential difference between the two inner electrode terminals IB and IC, using a method called the four-probe measurement method. .

However, in the case of this method, if the measurement target has a relatively wide area, such as a conductive coating film, and the resistance value is expected to vary widely when viewed locally, microscopic observation from point to point is required. However, there were problems in that only a certain value could be obtained, and a large number of measurements had to be taken for averaging.

Therefore, the present inventors have previously proposed a resistance measurement probe in which the measurement pressure at the electrode terminal of the surface resistance measurement probe is constant. A plan view of such a conventional surface resistance measurement probe is shown in FIG. 2, and FIG.
FIG. 3 shows a cross-sectional view taken along line BB', and FIG. 4 shows a cross-sectional view taken along line BB' of FIG. 1. FIG.

As shown in FIGS. 3 and 4, conventional resistance measurement probes are parallel to each other, have the same length, are separated by a predetermined distance, and have surfaces that contact the object to be measured. A pair of electrode terminals 11A, I that are narrow like a sword blade.
IB is an insulating hexagonal base 1 made of acrylic resin.
2 using screws 13 or the like. A cylindrical fixing member 14 made of acrylic resin is installed perpendicularly to the base 12, and a steel spring 15 is wound around the fixing member 14. A cylindrical pressure member 16 made of acrylic resin or the like is installed, which moves along the circumference of the fixing member 14 while pressurizing the spring 15. In addition, the contact pressure of the electrode terminals 11A, IIB in contact with the object to be measured is caused by the stopper 17, such as a flat screw with a flat head, which penetrates the base 12 from the pressure member 16 and contacts the surface of the object to be measured. I'm trying to control it. Furthermore, a spring 1 is provided above the fixing member 14 and the pressing member 16.
A NAND 18 such that 5 does not extend upward is screwed to the fixing member 14.

When using such a surface resistance measurement probe to measure the surface resistance of a conductive coating coated on the inner surface of a casing in which a CRT is installed, the stopper 17 of this surface resistance measurement probe is attached to the conductive coating. The pressure member 16 is pressed down to press the electrode terminals 11A and IIB to the conductive coating film while pressurizing the spring 15. Then, the force that presses the spring 15 is controlled by the stone bar 17, so that the electrode terminals 11A and IIB come into contact with the conductive coating film with a predetermined pressure. Then, a conducting wire (not shown) is connected to the electrode terminals 11A and IIB, and the end of this conducting wire is connected to a resistance meter.
The length of 11B is d, and this electrode terminal 11A,
The length sandwiched by IIB is d, the thickness of the conductive coating of the object to be measured is tcIll, and this specific resistance is ρ(Ω-am
), the surface resistance R (Ω/hole) of this conductive coating film is as shown in equation (1).

R=ρ・(d/d−t)=ρ・(1/l)・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・
(11 Here, ρ is a unique value of the conductive coating film and is therefore known, and by measuring the surface resistance R (Ω/mouth) from equation (11), the thickness t of the conductive coating film can be immediately determined. Can be measured.

(Problems to be Solved by the Invention) However, in the conventional surface resistance measurement probe described above, the electrode terminals 11A and IIB are applied with a predetermined contact pressure along the uneven shape of the conductive coating inside the housing. Therefore, it was difficult to accurately measure the surface resistance of the conductive coating down to a value of 0.1 Ω/min.

[Means for solving problems]

The above problem consists of a base having a pair of measuring electrodes parallel to each other at a predetermined interval, a fixing member installed on the base with a spring around it, and a pressing member installed around the member and pressing the spring;
penetrating the base and being attached to the pressure member;
and a stopper that controls the pressing force of the spring by contact with the object to be measured G, and the contact portion of the pair of measurement electrodes with the object to be measured is covered with a net-like metal member. The problem is solved by the resistance measurement probe.

[Effect]

That is, the resistance measurement probe of the present invention has a conductive mesh metal member installed in the part of the conventional resistance measurement probe that comes into contact with the object to be measured, and a conductive coating coated on the inside of the housing. Even if it has an uneven shape, the mesh metal member contacts along the uneven shape, so that the electrode terminal contacts the object to be measured, such as a conductive coating, with a constant contact pressure, and the surface This allows surface resistance to be measured with high accuracy even for objects to be measured with small resistance values.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 5 is a perspective view showing an embodiment of the resistance measuring probe of the present invention. As shown in the figure, the resistance measuring probe of the present invention differs from conventional devices in that it has a pair of electrode terminals 11A,
The tip of IIB that comes into contact with the object to be measured is coated with a mesh metal member 21 having a mesh size of about 100 mesh. The fine metal wire forming the mesh metal member 21 is made of copper (Cu) or nickel (Ni) coated with gold (Au) and has a diameter of approximately 0.1 mm.
fi metal wire, and this mesh metal member 21
are fixed to the electrode terminals 11A and IIB using adhesive or screws 22. Furthermore, a conductive wire 23 is connected to this screw 22, and a resistance meter 24 is connected to the end thereof.

In this way, even if the surface of the conductive coating film applied to the inside of the casing in which the CRT is installed has an uneven shape, the surface of the conductive coating film that is coated on the inside of the case where the CRT is installed can be adjusted so that the surface of the conductive coating film is aligned with the uneven part of the conductive coating film. Since the mesh metal member 21 is in contact with the conductive coating film, the electrode terminals 11A and IIB are in contact with each other along the uneven shape of the surface of the conductive coating film.
The contact pressures of 1A and IIB contact the conductive coating film with uniform pressure, so that the value of surface resistance measured by the resistance measuring probe of the present invention becomes highly accurate.

〔Effect of the invention〕

As described above, according to the resistance measurement probe of the present invention, since the electrode contacts the part to be measured with a constant pressure, it is possible to accurately measure the surface resistance of the part to be measured which has minute surface resistance. It is extremely effective to use the resistance measuring probe of the present invention for measuring the surface resistance of a conductive coating coated on a housing in which a cathode ray tube is installed.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a conventional surface resistance measurement method, Fig. 2 is a plan view of a conventional surface resistance measurement probe, Fig. 3 is a sectional view taken along line A-A' in Fig. 2, 4 is a sectional view taken along line BB' in FIG. 2, and FIG. 5 is a perspective view of the surface resistance measuring probe of the present invention. In the figure, 11A and 11B are electrode terminals, 21 is a mesh metal member, 22 is a screw, 23 is a conductive wire, and 24 is a resistance meter. Fig. 1 Fig. 20 Fig. 3] 8

Claims (1)

[Claims] a base having a pair of measurement electrodes parallel to each other spaced apart from each other by a predetermined distance; a fixing member installed on the base and provided with a spring around the base; and a fixing member installed around the fixing member and provided with the spring. and a stopper that passes through the base and is attached to the pressure member and controls the pressing force of the spring by contacting the object to be measured, and 1. A probe for resistance measurement, characterized in that a contact portion of an electrode with an object to be measured is covered with a mesh-like metal member.