JPS6221064A - Spring-contact type probe - Google Patents

Abstract

PURPOSE:To measure accurately electric characteristics, by suppressing reflection of a measuring signal generated when a probe contacts with a test piece. CONSTITUTION:A coaxial cable 8 of a probe is connected with a measuring apparatus 11. And, when a contact part 2a of a needle 2 is held in contact with a test piece 9 and HF voltage is applied to a test piece 9 of a specimen, by the contact pressure received by the contact part 2a, the needle 2 is subjected to axial repulsive force of a spring 3 and as the pressing force onto the test piece 9 is applied, contact with the test piece 9 is held positively. And, by action of the measuring unit in the ON condition, and by action of the resistance value of the terminal resistances 6a, 6b, reflection of the input signal is suppressed and the required impedance matching can be obtained. As the result, the input wave form remains intact available for measurements.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spring contact type probe, and more particularly to an improvement of a spring contact type probe used for measuring electrical characteristics of various circuit boards, particularly high frequency voltage characteristics.

[Conventional technology]

In recent years, rapid technological advances have been made in new media, OA, optical communications, semiconductors, etc., and with this, so-called "contact technology for contact points between parts" and "connection technology for connecting contacts" have been made. Technology (connection/
There is a strong demand for higher precision and higher performance of ``technology'' as a basic technology common to various new technologies. As a specific example, semiconductor/LSI inspection systems, especially the electrical characteristics of various circuit boards such as printed circuit boards and ceramic multi-board boards,
For example, in the inspection process of measuring high frequency voltage, contact type probes, especially spring contact type probes, which constitute the main part of the inspection equipment, have conventionally solved the problem of measuring the above-mentioned electrical characteristics without destroying the so-called contact technology and Although it is related to connection technology, it cannot sufficiently withstand the required usage conditions, such as usage conditions in the high frequency range and wide range of temperature conditions from extremely low temperatures to high temperatures, and it also picks up noise from outside the circuit. Since noise is generated from inside, the measurement results tend to lack the required accuracy and reliability, and there is a problem in that it is not possible to fully satisfy the usage and environmental conditions technically.

[Problem that the invention seeks to solve]

The present invention has been made by focusing on the problems of the conventional methods described above, and its purpose is to provide ultra-precise measurements that enable highly accurate and reliable measurements without destroying the electrical characteristics of test objects such as various circuit boards. The object of the present invention is to provide a spring contact type probe that is both large and low cost.

More specifically, an object of the present invention is to provide the above-mentioned spring contact, which can accurately measure electrical characteristics by suppressing the reflection of measurement signals that occur when a probe contacts a test piece, and which can be manufactured at low cost. The objective is to provide an expression probe.

[Means for Solving the Problems and Their Effects] In order to achieve the above object, the present invention provides a spring-contact type probe in the vicinity of the needle, specifically, in the center of the probe body from which the needle protrudes. By symmetrically arranging multiple resistors radially on the end surface perpendicular to the axis, it is possible to suppress the reflection of the input signal that occurs when the needle contacts the test piece, and to achieve the desired impedance matching. The main purpose of this method is to make it possible to measure the electrical properties of a test piece without disturbing the waveform.

〔Example〕

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention.

First, to explain the configuration, (1) is the probe tip;
A needle (2) formed with, for example, a sharp-shaped contact portion (2a) that contacts the test piece (9); The spring (3), which generates a spring repulsion force when pressure is applied and is crimped, and the needle (2) and spring (3) are inserted and fixed together at the center, and are made of Teflon or polyimide ceramic or the like. It is composed of a cylindrical dielectric (4) and an outer conductor (5) attached to the outside of the dielectric (4). Next, a pair of 2
A terminating resistor (6a) and (6b)
6) are arranged radially symmetrically on the terminal surface of the outer conductor (5) perpendicular to the central axis of the protruding needle (2), and electrically connect one end to the outer conductor (5) and the other. The end is connected to an internal conductor (not shown). Resistor (6a).

The thickness of (6b) is, for example, about several microns to several tens of microns.

(7) connects the probe tip (1) with the coaxial cable (8).
), and is electrically connected to the needle (2) and coaxial cable (8) by an internal conductor (not shown).

FIG. 2 is a circuit diagram, in which each wiring (A), (B) of the external conductor (5) and internal conductor, the inductance (L) of the conductor, and the capacitance (C1) of the dielectric (4) are measured. This shows that the resistance value (Zl) of the terminating resistor (6) is inserted in parallel to the capacitor (C1) in a circuit having a stray capacitor 1 (C2) of the device (11). (Zl) is the measuring device (1
1) is the impedance. Further, (10) is a power supply.

Next, the operation of this embodiment will be explained.

Now, the coaxial cable (8) of the probe is connected to the measuring device (11).
) (for example, a voltmeter), a high-frequency voltage is applied to a test piece (not shown) of the object to be inspected, and the contact part (2a) of the needle (2) is maintained in a connected state with the test piece. If the contact part (2a
) is applied to the needle (2), which generates a repulsive force of the spring (3) in the axial direction, and is pressed against the test piece, so that contact with the test piece is reliably maintained. When the measuring device is turned ON, as shown in FIG. 2, the resistance value (Zl) of the terminating resistor (6) suppresses the reflection of the input signal and achieves the desired impedance matching. As a result, the input waveform can be measured without being disturbed. Moreover, according to this embodiment, a fine resistor (6a) is used.

(6b) was placed near the needle (2) without taking up space, resulting in a compact probe structure.

Furthermore, instead of arranging two resistors forming a pair as in the above-mentioned embodiments, the terminating resistor (6) may be arranged in any plurality at equal intervals on the circumference. Therefore, various changes can be made without departing from the scope of the claims of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, by providing a terminating resistor near the needle provided in the spring contact type probe, the electrical characteristics of the object to be tested can be measured with high accuracy without disturbing the waveform of the measurement signal. Highly reliable measurements can be achieved, the structure allows for compact installation near the needle, and it can be manufactured easily at low cost, which has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a spring contact type probe provided with a terminating resistor, showing one embodiment of the present invention, and FIG. 2 is a circuit diagram with the terminating resistor added. (2)...Needle (5)...External conductor (6)...Terminal resistor (6a), (6b)...Resistance of terminal resistor (6) Body (7)...Connector part (8)・Old...Coaxial cable (9)...Test piece (1o)・
Old power source (11)... Measuring device

Claims (3)

[Claims] (1) It has a needle that forms a contact part, and a spring that is attached to the needle and is crimped by generating a spring repulsion force due to the contact pressure between the needle and the test piece, and the needle and spring are connected inside the dielectric material. A probe tip section is inserted into the probe tip section and the outside of the dielectric body is capped with an external conductor, a connector section is connected to the coaxial cable, and the probe section is integrally attached to the probe tip section via the connector section and electrically connected. A spring contact type probe comprising a coaxial cable connected to the needle, the spring contact type probe comprising a terminating resistor provided near the needle. (2) The terminating resistor shall consist of a plurality of resistors arranged at equal intervals on the circumference, arranged radially symmetrically on the termination surface of the external conductor perpendicular to the central axis of the protruding needle. The spring contact type probe according to claim 1, characterized in that: (3) The spring contact type probe according to claim 2, wherein the terminating resistor comprises a pair of two resistors.