JPH06342012A - Probe for continuity test - Google Patents

Abstract

PURPOSE:To prevent the obstruction of continuity due to imperfact contact, in bringing a probe which in a component of the device for continuity test, into ocntact with a part to be measured, to carry out the continuity test. CONSTITUTION:A rotating direction reversing means of a plunger 3 consisting of a combination of a spiral body 12 and a guide 13 comprising a bottleneck part, or a combination of a pin-form projection and a dogleg guide groove is provided to a probe 10 for continuity test comprising a barrel 2, a plunger 3 having a probe 3A at an end thereof and a spring 4, the rotating direction of the plunger 3 pushed into a measuring object part is reversed in a way to the pushing stroke, and thereby the breakthrough of an insulating layer is easily done.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuity test probe for electric parts, and more particularly to a continuity test probe for measuring electrical characteristics of a printed circuit board on which a semiconductor device or the like is mounted. The present invention relates to an improvement of a contact type probe for breaking through a paste, a flux, or an oxide film adhered to the surface of a printed circuit board to ensure the measurement of a conductive state.

[0002]

2. Description of the Related Art A continuity test probe is used as a means for measuring the electrical characteristics of a semiconductor device or a printed circuit board for electronic equipment on which an IC, a resistor, a capacitor and the like are mounted.

Various types of continuity test probes are commercially available depending on the type, shape and size of the part to be measured. 4 to 6 are enlarged vertical cross-sectional views showing a conventional example of a continuity test probe, wherein the continuity test probe (1) is nickel-white or phosphorus whose surface is plated with Au. Inside the barrel (2) made of a conductive metal material such as bronze, the tip of the contact type probe (3
It has a built-in plunger (3) forming A) and a spring (4) for pressing and biasing the plunger (3) in the axial direction of the barrel (2). Plunger (3)
Is obtained by applying Rh or Au plating to the surface of a shaft-shaped member made of carbon steel or BeCu alloy,
As illustrated in FIG. 7, the tip portion is formed into a conductive probe, and correspondingly, a spring steel spring (4) used as a pressing biasing member of the plunger (3).
The surface of is also plated with Au.

A probe (3) formed at the tip of the plunger (3) is pressed by a spring (4).
A) is pressed against a measurement target portion of a semiconductor device or a printed circuit board for electronic equipment (none of which is shown) mounted with the semiconductor device, for example, an electrode pattern, etc. A conductive state is established between (1) and the semiconductor device or an electronic device on which the semiconductor device is mounted is measured.

[0005]

An object to be measured by pressing a probe (3A) against an external lead of a semiconductor device or an electrode pattern of a printed circuit board of an electronic device under the pressing force of a spring (4). The electrical characteristics of the parts are measured. At this time, if the pressing force of the probe (3A) is insufficient, the solder attached to the surface of the external lead of the semiconductor device or the electrode pattern of electronic equipment It becomes impossible to break through the insulating layer composed of the paste, flux or oxide film. As a result, the tip portion of the probe (3A) does not reach the measurement target portion of the semiconductor device or the electronic device, and it becomes impossible to measure the electrical characteristics in the poor contact state.

In order to prevent accidents due to such poor contact, a continuity test plug (1) shown in FIG.
A method of increasing the pressing load (spring constant) of the spring (4) that transmits the pressing force to the plunger (3) is being studied. However, when the pressing load of the spring (4) is increased, the piercing force of the insulating layer is increased, but the load applied to the measurement target site is increased, resulting in damage to the electrode pattern and damage to the plunger (3). Inconveniences such as deformation are likely to occur, and the service life of the continuity test probe (1) is shortened.

On the other hand, as a means for facilitating the piercing of the insulating layer in a state where the pressing load of the spring (4) is relatively reduced, one having a spiral shaft portion (5) as illustrated in FIG. Directional rotation type plunger (3 ')
And a plunger (3 ') including the spiral shaft portion (5).
A continuity test probe (1) has been proposed which comprises a barrel (2) having a squeezed guide groove (6) for rotating the whole in one direction when measuring the continuity state. FIG. 6 shows a modification of the continuity test plug (1) shown in FIG. 5. As an alternative to the spiral shaft (5), a plunger (3 ') is provided on the wall of the barrel (2). ) Is formed with a guide groove (5 ′) having a constant inclination angle with respect to the axial direction, and the plunger (6) slidably fitted in the barrel (2) in place of the guide groove (6). A protrusion (6 ') fitted into the guide groove (5') is provided on the side body surface of 3 ').

By using the one-way swivel type plunger (3 ') shown in FIG. 5 or 6, excessive pressing force which has been a problem in the continuity test probe (1) shown in FIG. To some extent, problems such as breakage of the measurement target portion and deformation of the probe (1) due to the addition of the are eliminated. However, when the plunger (3 ') swiveling in only one direction shown in FIGS. 5 and 6 is used, the plunger is
With the rotation of (3 '), micron-order chips are generated, and the chips are clogged between the contact type probe (3A) and the insulating layer pierced by this, and sliding resistance increases. As a result, the crushing force of the insulating layer by the plunger (3 ') decreases with the passage of time, the contact between the probe (3A) and the measurement target site is obstructed, and it becomes difficult to continue the continuity test.

[0009]

As a means for solving the above problems, according to the present invention, a conductive measuring probe is provided in a conductive barrel at a tip portion which is conductive and protrudes from one side end surface of the barrel. A continuity test probe including a formed plunger and a conductive spring for urging the plunger in the axial direction of the barrel.

[0010] A spiral plunger having a flat cross-sectional shape and in which the twisting direction is reversed at predetermined intervals along the longitudinal direction, and a squeezing portion functioning as a guide means of the spiral plunger are provided. The engagement structure with the barrel, or
An engaging structure of a pin-shaped projection provided on the side wall surface of the plunger and the container wall surface of the barrel and a guide groove whose inclination direction is reversed at a predetermined cycle along the longitudinal direction, and means for reversing the turning direction of the plunger. To form.

[0011]

A combination of a spiral plunger in which the twisting direction is reversed every predetermined period and a barrel provided with a compression portion, or a side wall surface of the plunger and a wall surface of the barrel for slidably supporting the wall surface. Using a combination of a pin-shaped projection provided on the and a guide groove whose inclination direction is reversed at a predetermined cycle, the plunger that is pushed toward the measured portion, for example, the electrode pattern of the electronic device is swung. By reversing the direction on the way of the pushing stroke and generating a frustum-like breaking force, the insulating layer formed on the surface of the measured site, for example, breaking through the soldering paste or flux, A probe formed on the tip end portion of the plunger is brought into close contact with the fixed part on the side by a predetermined pressing pressure to create a conductive state between the two.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of the present invention will be described below with reference to the accompanying FIGS. In the following description, the same components as those of FIGS. 4 to 7 showing the conventional technique are indicated by the same reference numerals in principle, and the description of the overlapping matters will be omitted. FIG. 1A is a vertical sectional view of a continuity test probe (10) showing a first embodiment of the present invention. The continuity test plug (10) has a conductive barrel (2) and a probe (3A) formed on the tip end portion of the conductive barrel (2) protruding from one end face (11) of the end face (11). Plunger (3)
And a conductive spring (4) for biasing the plunger (3) in the axial direction of the barrel (2). Then, at the base end side of the plunger (3) slidably fitted and supported in the barrel (2),
As shown in the enlarged views of (B), (C), and (D), a spiral body (12) having a flat cross-sectional shape and in which the twisting direction is reversed at predetermined intervals along the longitudinal direction is formed. Has been done. Corresponding to the spiral body (12), a guide (13) composed of a compression section is provided on the intermediate barrel of the barrel (2) as a means for reversing the turning direction of the spiral plunger (12). ing.

FIG. 2 is a perspective view showing a modified example of the continuity test probe (10) shown in FIG. 1. In this specific example, the spiral body (12) serves as the probe (3A). The guides (13), which are provided so as to be adjacent to each other and corresponding to this, were provided on the intermediate body portion of the barrel (2) in FIG. 1, are the end faces on the protruding side of the plunger (3) of the barrel (2). It is provided in part (2A). When a pushing stroke is applied to the plunger (3) under the action of a compressive load by the spring (4), the spiral body (12) engages with the guide (13). As a result, the plunger (3) reverses the turning direction at every predetermined section length on the way of pushing, so that a conical fracturing force is generated in the probe (3A). Plunger
By reversing the turning direction of (3) at a predetermined time cycle, the crushed fine particles generated in the measurement site move in the anti-weiring direction, that is, the anti-turning direction, and the insulating layer by the probe (3A) Breakthrough force is maintained at a substantially constant level. As a result, the probe (3A) surely comes into contact with the measured site.

FIG. 3A is a partial vertical sectional view of a continuity test probe (10) showing a third embodiment of the present invention. The point that the probe for continuity test (10) is composed of the barrel (2), the plunger (3) and the spring (4) for pressing and urging is the same as the specific example shown in FIGS. 1 and 2. However, in this specific example, the plunger (3)
The means for reversing the turning direction of the plunger at every predetermined section length on the way of the pushing stroke is a pin-shaped projection (14) provided on the side wall surface of the plunger (3) and the wall surface of the barrel (2). It is formed by a dogleg-shaped guide groove (15) provided in the. As shown in FIG. 3 (A), the guide groove (15) is drilled so that the inclination direction, that is, the winding direction of the spiral groove is reversed at every predetermined section length along the longitudinal direction of the barrel (2). The shape is selected. FIG. 3C is a vertical sectional view of a continuity test probe (10) showing a fourth embodiment of the present invention.
In this specific example, a pin-shaped protrusion (14A) is provided on the inner peripheral wall surface of the barrel (2), which is opposite to that shown in FIG. 3 (A), and correspondingly, the side of the plunger (3) is provided. A guide groove (15A) in which the inclination direction is reversed is provided on the peripheral wall surface at every predetermined section length along the longitudinal direction.

When a pushing stroke is applied to the plunger (3) under the action of a compressive load by the spring (4),
In the third specific example, the pin-shaped protrusion (14) and the guide groove (15) are engaged with each other, whereby a cone-like breaking force is generated in the probe (3A). Similarly to this, in the fourth specific example, the pin-shaped projection (14A) and the guide groove (15A) are engaged with each other when the plunger (3) is pushed in, whereby the swivel direction of the probe (3A) is maintained for a predetermined time. Invert at a cycle. By reversing the swirling direction of the plunger (3) at a predetermined time period during pushing, the crushed fine particles of the micron order generated at the measurement site move in the anti-weiring direction, that is, the anti-turning direction. , The breaking force of the insulating layer by the probe (3A) is maintained at a substantially constant level. As a result, the probe (3A) surely comes into contact with the measured site.

[0016]

【The invention's effect】 [Brief description of drawings]

FIG. 1A is a vertical cross-sectional view showing a first specific example of a conductive test probe according to the present invention, and FIG. 1B is a cross-sectional view taken along line I-I of FIG. (C) is a top view of the spiral plunger, (D) is a front view of the spiral plunger.

FIG. 2 is a perspective view showing a second specific example of the continuity test probe according to the present invention.

FIG. 3 (A) is a partial vertical cross-sectional view showing a third specific example of the continuity test probe according to the present invention, and FIG. 3 (B) is (A).
Is a cross-sectional view taken along line III-III in FIG. 3, (C) is a vertical cross-sectional view showing a fourth specific example of the continuity test probe according to the present invention, and (D) is line III-III in (C). Cross section along

FIG. 4 is a longitudinal sectional view showing a first conventional example of a continuity test probe.

FIG. 5 is a vertical sectional view showing a second conventional example of a continuity test probe.

FIG. 6 is a partial vertical cross-sectional view showing a third conventional example of a continuity test probe.

FIG. 7 is a front view illustrating the shape of the tip of the plunger and the probe portion.

[Explanation of symbols]

 2 Barrel 3 Plunger 3A Probe 4 Spring 10 Probe for continuity test 11 Side view of one side of barrel 12 Spiral body 13 Guide consisting of compression part 14 Pin-like protrusion 14A Pin-like protrusion 15 Guide groove 15A Guide groove

Claims (4)

[Claims] 1. A plunger having a conductive barrel formed with a probe for conductivity detection at a tip portion thereof which is conductive and protrudes from one side end surface of the barrel, and the plunger is arranged in the axial direction of the barrel. In a continuity test probe having a built-in conductive spring that presses and urges the spiral spring, the plunger has a flat cross-sectional shape, and the twist direction is reversed at predetermined intervals along the longitudinal direction. The spiral plunger on the intermediate barrel of the barrel.
A probe for continuity test, characterized in that a guide composed of a compression portion is provided as a turning direction reversing means. 2. A plunger, which is electrically conductive and has a probe for detecting continuity formed on a tip portion of the barrel which is electrically conductive and which projects from one side end surface of the barrel, and the plunger is provided with an axis line of the barrel. In a continuity test probe having a built-in conductive spring that biases and urges in the direction, the plunger has a flat cross-sectional shape, and the twisting direction is reversed at predetermined intervals along the longitudinal direction. The probe for continuity test is characterized in that a guide formed of a squeezing portion is provided at the end surface portion of the barrel on the protruding side of the plunger as a turning direction reversing means of the screwed plunger. . 3. A plunger having an electrically conductive barrel formed with a probe for conducting detection at a tip portion thereof which is electrically conductive and protrudes from one side end surface of the barrel, and the plunger is arranged in the axial direction of the barrel. In a continuity test probe having a built-in conductive spring that presses and urges, a pin-shaped protrusion is provided on the side wall surface of the plunger slidably supported in the barrel. Correspondingly, a guide groove whose inclination direction is reversed is formed at a predetermined section length along the longitudinal direction on the wall surface of the barrel facing the side wall surface of the plunger, and the guide groove and the pin-shaped projection are formed. A continuity test professional characterized in that the engaging structure forms a reversing means in the direction of rotation of the plunger.
Boo. 4. A plunger, which is conductive and has a probe for detecting continuity formed on a tip portion of the barrel which is conductive and protrudes from one side end surface of the barrel, and the plunger is provided with an axis line of the barrel. In a continuity test probe including a conductive spring that biases and urges in a direction, a predetermined section along the longitudinal direction is formed on a side wall surface of the plunger slidably supported in the barrel. A guide groove whose inclination direction is reversed for each length is formed. Correspondingly, a guide structure is formed on the inner wall surface of the barrel facing the side wall surface of the plunger by the engagement structure of the pin-shaped projection and the guide groove. A probe for continuity test, characterized in that it has means for reversing the turning direction of the probe.