JP3359416B2 - Contact probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact probe, and more particularly, to a four-terminal measuring probe used in a substrate inspection machine such as an in-circuit tester, which can be used for a small area to be measured. The present invention relates to a contact probe that can simultaneously maintain a target strength.

[0002]

2. Description of the Related Art In a four-terminal measuring method, a constant current terminal for flowing a current to an object to be measured, which is a resistor, and a voltage detecting terminal for detecting a voltage drop state at that time are separately provided. It is performed using four leads,
According to this measuring method, the resistance of the lead wire can be measured without including it in the measured value, and therefore, it is widely used in digital multimeters, LCR meters, etc., which are high-precision resistance measuring instruments.

FIGS. 8 and 9 show the structure of a contact probe which has been conventionally used to cope with the four-terminal measuring method.

Among them, the contact probe shown in FIG. 8 is of a so-called parallel type, and as a whole, a plunger 1b having a voltage measuring pin 1a at its tip is moved into and out of a barrel 1c. A voltage measuring probe 1 which is urged and held freely, and a current measuring probe which is urged and held by a plunger 2b having a current measuring pin 2a at a tip thereof in a barrel 2c. The probe 2 is formed of a probe 4 and a sleeve 4 integrally holding the probe 1 and 2 with an insulator 3 interposed therebetween.

[0005] The contact probe shown in FIG.
It is a so-called coaxial type, and the whole is a plunger 5 having a voltage measuring pin 5a at the tip.
b in the barrel 5c by freely biasing its advance and retreat, and a voltage measuring probe 5, and the voltage measuring probe 5 is positioned at the center of the shaft with the insulator 6 interposed therebetween, and its periphery is Current measuring pin 7a arranged so as to surround it
And a sleeve 9 for holding the current measurement probe 7 in the axial direction freely by a spring member 8 interposed between the current measurement probe 7 and the current measurement probe 7. It is formed with.

[0006]

FIGS. 8 and 9 show an embodiment of the present invention.
The object to be measured can also be measured by the contact probe shown in (1) and (2) under the four-terminal measurement method.

However, the contact probes shown in FIGS. 8 and 9 are structurally complicated, so that there is a problem that the product cost is increased.

The contact probes shown in FIGS. 8 and 9 both have a relatively long pin-to-pin distance between the voltage measuring pin 1a or 5a and the current measuring pin 2a or 7a. It can cope with the case where the area of the contacted portion is relatively large, but cannot be used when the area of the contacted portion is small.

Further, if the diameter of the contact probe itself is reduced in order to cope with such a small area, the distance between the pins can be shortened, but the pins themselves become extremely thin and the durability is increased. Has disappeared, resulting in a problem that it is not practical.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and has a structural feature. A bar-shaped measuring pin formed by forming an insulating layer on the outer peripheral surface of the tip excluding at least the sharp contact portion with respect to the holding cylinder portion provided with the insulating film on the outer peripheral surface is protruded at the front end, and the rear end surface is the opening surface at the rear. A first probe for voltage measurement, which is retracted and held from the probe, and a probe pin having a sharp contact portion at the distal end portion of the first probe for voltage measurement, which is in contact with a rear end surface of the rod-shaped measurement pin, at an outer periphery thereof. A second probe for voltage measurement, which is held in a barrel portion provided with an insulating layer on the surface so as to be able to advance and retreat, and a cylindrical measurement pin is inserted into the distal end of the cylindrical main body portion with its sharp contact portion protruding to stop insertion. Current measurement probe A holder for holding the current measuring probe in the projecting direction while constantly holding the current measuring probe in a protruding direction, and facing the cylindrical measuring pin and the holding cylindrical portion from the cylindrical measuring pin. A current measuring probe by projecting the sharp contact portion of the rod-shaped measuring pin from the rear end side of the cylindrical main body portion so that the portions are electrically non-conductive. In that a first probe for voltage measurement and a second probe for voltage measurement are provided.

[0011]

For this reason, the voltage measurement on the measured portion is performed by bringing the sharp contact portion of the probe pin of the second voltage measurement probe into contact with the rear end face of the rod-shaped measurement pin of the first voltage measurement probe in the protruding direction. The pressing can be performed by pressing the sharp contact portion of the rod-shaped measuring pin which is urged against the measured portion.

At this time, the rod-shaped measuring pin is relatively retracted toward the current measuring probe, so that the sharp contact portion of the cylindrical measuring pin of the current measuring probe is eventually measured. As a result, the current can be measured for the measured part.

In addition, since the current measuring probe side is always urged in the protruding direction by a spring material interposed between the current measuring probe and the holder, the current measuring probe is used for voltage measurement with respect to the measured portion. The rod-shaped measurement pin and the cylindrical measurement pin for current measurement can be stably and reliably brought into simultaneous contact.

Therefore, while the whole structure is of the coaxial type, the rod-shaped measuring pin of the first voltage measuring probe formed with a small diameter has a tip end including a sharp contact portion when used. By retracting the current measuring probe into the sharp contact portion of the cylindrical measuring pin, the load applied in the axial direction can be transferred to the side of the cylindrical measuring pin, so that practical strength is given to the whole. In addition, it is possible to measure at a narrow pitch.

[0015]

FIG. 1 is an overall structural view showing an embodiment of the present invention. FIGS. 2 to 5 are views from the front end to the rear end to clarify the detailed structure of FIG. FIG.

According to FIG. 1 to FIG. 5, the whole is
A first voltage measuring first device provided with a sharp contact portion 13a at the distal end portion 13 of the rod-shaped measuring pin 12 for making contact with a measured portion.
The probe 11 and the sharp contact portion 23a that abuts on the rear end face 14 of the rod-shaped measurement pin 12 of the first voltage measurement probe 11 to regulate movement in the axial direction are connected to the probe pin 2.
Probe 2 for voltage measurement provided at the tip 23 of the second probe 2
1, a current measurement probe 31 having a cylindrical measurement pin 35 at the tip 33, and holding the first voltage measurement probe 11 and the second voltage measurement probe 21 arranged in series in a serial direction; It is composed of a holder section 41 for holding the current measuring probe 31 so as to be able to move forward and backward.

In this case, the first probe 11 for voltage measurement
Is a rod-shaped measuring pin 12 having an outer diameter of, for example, about 0.1 to 0.2 mm made of a suitable conductive cemented carbide material, and a suitable metal pipe material such as a stainless steel pipe holding the rod-shaped measuring pin 12. And a holding cylinder portion 16 made of

Among them, the rod-shaped measuring pin 12 is shown in FIG.
FIG. 7B is an enlarged view of the surrounding portion b in FIG.
As is clear from FIG. 5, an insulating layer 15 is formed on the outer peripheral surface of the tip portion 13 except for at least the sharp contact portion 13a by applying, for example, a polyimide tube or coating an appropriate insulating agent. The insulating layer 15
May be formed on the outer peripheral surface over the entire length excluding the sharp contact portion 13a and the rear end surface 14.

The holding cylinder portion 16 has an insulating film 18 made of an insulating synthetic resin material such as a polyimide tube, for example, in which a projecting portion 19 is protruded from each of a front end portion and a rear end portion and is attached. A sharp contact portion 13 is formed on the holding cylinder 16 formed in this manner.
a first probe for voltage measurement by holding the rod-shaped measurement pin 12 integrally under a state in which the front end portion 13 including a is protruded and the rear end surface 14 is slightly retracted from the opening surface 17 located at the rear portion. 11 are formed. In order to secure the application of the insulating film 18 to the side of the holding cylinder 16, the insulating film 18 is divided into at least two or more portions with the void portion 20 interposed therebetween as shown in the illustrated example. It is preferable that the adhesive can be smoothly supplied to the inner peripheral surfaces of the divided portions 18a and 18b.

The voltage measuring second probe 21 is formed by enlarging the surrounding part a in FIG. 6A, as shown in FIG. 7A. A probe pin 22 having a sharp contact portion 23a at the distal end portion 23 which is in contact with the rear end surface 14 of the measuring pin 12;
An insulating layer 25 formed by, for example, applying a polyimide tube or coating an appropriate insulating agent is held on a barrel portion 24 provided on an outer peripheral surface of the barrel so as to be able to advance and retreat via a biasing force of a spring material (not shown). It is formed by doing.

On the other hand, the current measuring probe 31 comprises the first voltage measuring probe 11 and the second voltage measuring probe 2.
1 and a cylindrical main body 32 made of an appropriate metal pipe material such as a stainless steel pipe material for freely holding the advance and retreat of the cylindrical main body 32. The cylindrical main body 32 is inserted and fixed to the distal end 33 of the cylindrical main body 32. And a cylindrical measuring pin 35. The outer peripheral surface of the cylindrical main body 32 on the side of the distal end portion 33 is subjected to an abrasion treatment such as coating with a fluororesin so that a one-side sliding contact layer 34 preferably having an insulating property is formed in advance. It is desirable to keep.

In this case, the cylindrical measuring pin 35 is made of a suitable conductive cemented carbide pipe material having an inner diameter of, for example, about 0.3 mm, and has a sharp contact formed by tapering the tip portion 36 thereof. Portion 36a, the sharp contact portion 36a
Are inserted and fastened in a state in which the distal end portion 36 including the above is projected from the distal end portion 33 of the tubular main body portion 32. The sharp contact portion 36a of the cylindrical measuring pin 35 has, for example, an outer diameter on the base end side of the taper of about 0.4 mm, and a blade such that the outer diameter of the contact edge located at the distal end of the taper substantially matches the inner diameter. It is desirable to form by cutting.

The holder section 41 includes a cylindrical holding section 42 made of an insulating material such as a synthetic resin for holding the cylindrical main body section 32 of the current measuring probe 31 so as to be able to freely advance and retreat in the axial direction. It is formed of a holder body 49 made of an insulating material such as a synthetic resin that integrally holds the cylindrical holding portion 42.

The cylindrical holding portion 42 has a length extending along the axial direction along the end face side of the distal end portion 43 and substantially corresponding to the advancing and retreating distance of the cylindrical main body portion 32 in the current measuring probe 31. The other side sliding contact layer 45 formed in a ring shape from a material having high wear resistance, such as a fluororesin, is provided on the inner peripheral surface of the enlarged diameter portion 44 provided under the support. desirable.

The rear end 46 of the cylindrical holding section 42
Is formed so that its outer diameter is smaller than that of other portions, and the rear end portion 3 of the tubular main body portion 32 is formed with respect to the rear end portion 46.
The distal end portion 40 of a spring material 40 formed by, for example, a tension coil spring or the like, which is disposed so as to lock the rear end portion 40b side in a concave portion 38 provided around the side 7.
a is fixed. The fastening structure at that time has a structure in which a groove 47 is formed spirally on the peripheral surface of the rear end portion 46 as shown in the illustrated example, and the front end portion 40a of the spring material 40 is engaged and fastened to this groove portion. In addition, 40 tip 40a of spring material
May be simply locked via a concave portion 48 provided around the rear end portion 46 of the cylindrical holding portion 42, or the rear end portion 46 of the cylindrical holding portion 42.
An appropriate fastening structure, such as fixing the protruding end portion of the spring material 40 to itself by burying it, can be adopted.

Further, the holder main body 49 is fitted to an appropriate portion of the cylindrical holding portion 42, for example, by fitting the cylindrical holding portion 4
2 are fixedly held together. In this case, at least the rear end 50 of the holder body 49 is
By disposing the cylindrical holding portion 42 so as to protrude in the axial direction from the rear end portion 46, it is possible to conceal the front end portion 40a of the spring member 40 fixed to the rear end portion 46 side. It is preferable to keep it.

Therefore, the current measuring probe 31
As shown in FIG. 6A, the spring member 40 is always urged to protrude along the axial direction with respect to the holder portion 41 by disposing the spring member 40 in the above arrangement relationship. It will be held while being performed.

Further, for the current measuring probe 31, the facing portions of the cylindrical measuring pin 35 and the holding cylindrical portion 16 are electrically connected to each other through the insulating layer 15 from the cylindrical measuring pin 35. The first probe 11 for voltage measurement, in which the sharp contact portion 13a of the rod-shaped measurement pin 12 is made to protrude from the cylindrical measurement pin 35 in a non-conductive state, and after the barrel portion 24 from the rear end side of the cylindrical main body 32 The whole is assembled by holding the voltage measuring second probe 21 having the end portion 26 projecting in a state of being directly connected in series.

Since the present invention is constructed as described above, the second probe 21 for voltage measurement is attached to the rear end face 14 of the rod-shaped measurement pin 12 of the first probe 11 for voltage measurement.
By pressing the sharp contact portion 23a of the probe pin 22 to press and urge it, the sharp contact portion 13a of the rod-shaped measurement pin 12 extruded in the protruding direction can be pressed against the portion to be measured.

In this state, when the holder 41 is pressed against the part to be measured, the current measuring probe 3 is pressed.
1 also moves in the same direction at the same time.
Is relatively retracted toward the current measuring probe 31. In the case where the one-side sliding contact portion 34 is provided on the side of the cylindrical main body portion 32 and the other-side sliding contact portion 45 is provided on the side of the cylindrical holding portion 42, the wear resistance must be enhanced. With this, the durability can be improved.

By continuing such a state, the sharp contact portion 36a of the cylindrical measuring pin 35 of the current measuring probe 31 eventually comes into contact with the measured portion.

Moreover, the side of the current measuring probe 31 is
Since it is always urged in the protruding direction by the spring material 40 interposed between the holder portion 41 and the
In addition to the rod-shaped measurement pin 12 functioning for voltage measurement, the cylindrical measurement pin 35 functioning for current measurement comes into stable and reliable contact with the measured portion at the same time. In addition, the rod-shaped measurement pin 12 and the cylindrical measurement pin 35
The insulating layers 15 interposed therebetween can establish a mutually electrically non-conductive relationship.

Therefore, while the whole structure is of the coaxial type, the rod-shaped measuring pin 13 of the first voltage measuring probe 11 formed under a very small diameter has a tip including a sharp contact portion 13a when used. The portion 13 side is relatively retracted into the sharp contact portion 36a of the cylindrical measuring pin 35 of the current measuring probe 31, so that the rod-shaped measuring pin 13 receives a load in the axial direction when it comes into contact with the measured portion. Can be transferred to the side of the cylindrical measuring pin 35, so that it is possible to perform measurement at a narrow pitch while giving practical strength to the whole.

The voltage measurement path from the first voltage measurement probe 11 to the second voltage measurement probe 21 and the current measurement path formed by the current measurement probe 31 are separated from each other by the insulating layer 15. In addition, since the insulating film 17 including the protruding portion 19 and the insulating layer 25 are interposed, each of them can be secured as two independent electrical paths that are not affected by other interference.

[0035]

As described above, according to the present invention, the sharp contact portion of the probe pin of the second probe for voltage measurement comes into contact with the rear end face of the rod-shaped measurement pin of the first probe for voltage measurement and protrudes. The tip of the cylindrical measuring pin of the current measuring probe is relatively retracted toward the current measuring probe while pressing the sharp contact portion of the rod-shaped measuring pin urged in the direction toward the measured portion. Since the contact part can also be brought into contact with the measured part, the rod-shaped measuring pin for voltage measurement and the cylindrical measuring pin for current measurement can be stably and surely brought into simultaneous contact with the measured part. it can.

For this reason, while the whole structure is of the coaxial type, the first voltage measuring first formed under a very small diameter.
The rod-shaped measurement pin of the probe measures the load load in the axial direction by retracting the tip end including the sharp contact portion relatively into the sharp contact portion of the cylindrical measurement pin in the current measurement probe when used. Can be passed on to the side of the pin,
Therefore, it is possible to perform measurement at a narrow pitch while providing practical strength in terms of structure.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention.

FIG. 2 is an enlarged view of a part on a front end side of an enlarged view divided into four parts from a front end side to a rear end side to clarify a detailed structure of FIG. 1;

FIG. 3 is an enlarged view of a lower central portion adjacent to a tip portion.

FIG. 4 is an enlarged view of an upper central portion adjacent to a lower central portion;

FIG. 5 is an enlarged view of a rear end portion adjacent to the upper central portion.

FIG. 6 is a configuration diagram showing a combined state of a current measuring probe and a holder unit in FIG. 1;

7 is a configuration diagram showing an arrangement relationship between a first probe for voltage measurement and a second probe for voltage measurement in FIG. 1;

8 is an enlarged partial explanatory view showing a main part in FIG. 7, in which (a) shows a mutual relationship when arranged in a serial direction, and (b) shows a first probe for voltage measurement. 3 shows a tip structure of a rod-like measuring pin on the side.

FIG. 9 is an explanatory view showing a conventional structure of a so-called parallel type four-terminal measuring probe.

FIG. 10 is an explanatory view showing a conventional structure of a so-called coaxial type four-terminal measuring probe.

[Explanation of symbols]

 Reference Signs List 11 first probe for voltage measurement 12 rod-shaped measurement pin 13 tip 13a sharp contact portion 14 rear end face 15 insulating layer 16 holding cylinder 17 opening surface 18 insulating film 18a, 18b division 19 protrusion 20 gap 21 voltage measurement 21 2 Probe 22 Probe Pin 23 Tip 23a Sharp Contact 24 Barrel 25 Insulating Layer 31 Current Measurement Probe 32 Cylindrical Main Body 33 Tip 34 One Side Sliding Layer 35 Cylindrical Measurement Pin 36 Tip 36a Sharp Contact 37 rear end portion 38 concave portion 40 spring material 40a front end portion 40b rear end portion 41 holder portion 42 cylindrical holding portion 43 front end portion 44 enlarged diameter portion 45 other side sliding contact portion 46 rear end portion 47 groove portion 48 concave portion 49 holder body Part 50 rear end

Claims (1)

(57) [Claims] 1. An insulating layer is formed on an outer peripheral surface of a front end portion excluding at least a sharp contact portion with respect to a holding cylinder portion provided with an insulating film formed on an outer peripheral surface of the front and rear end portions, each of which has a protruding projecting portion. The first probe for voltage measurement is formed by projecting the rod-shaped measurement pin formed at the front end portion and holding the rear end surface by retreating from the opening surface of the rear portion, and the rod-shaped measurement pin in the first probe for voltage measurement. A second probe for voltage measurement in which a probe pin having a sharp contact portion abutting on a rear end surface at a front end portion is held at a barrel portion provided with an insulating layer on its outer peripheral surface so as to be able to advance and retreat, and a cylindrical main body portion A current measuring probe in which a cylindrical measuring pin is inserted and secured by projecting the tip of the cylindrical contact pin to the tip of the current measuring probe, and the current measuring probe is moved in the projecting direction by an interposed spring material. Hold that holds while constantly energizing From the cylindrical measuring pin, the sharp contact portion of the rod-shaped measuring pin is formed so that the facing portions of the cylindrical measuring pin and the holding cylindrical portion are electrically non-conductive. A first probe for voltage measurement and a second probe for voltage measurement are applied to the current measurement probe by projecting the rear end of the barrel from the rear end of the main body.
A contact probe comprising a probe and a probe.