JP2001221835A - Replacement needle of probe and probe using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a probe which achieves smaller electrostatic capacitance between a contact needle and an object to be measured, moreover, is easy in replacement of the contact needle, and can supply inexpensively a part to be replaced. SOLUTION: The replacement part of a probe is constituted of a cylindrical cap with one end thereof closed, and a contact needle which pierces the closed end face of the cap and is supported with one end thereof protruding to the inside of a hollow part of the cap, while the other end thereof protrudes to the outside of the closed end face of the cap. The body of the probe includes a cylinder part, which is fitted into the hollow part of the cap to maintain its engagement and an electrode which is mounted at the end of the cylinder and electrically conducts to the contact needle in contact therewith protruding to the inside of the hollow part of the cap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe for directly contacting a semiconductor integrated circuit formed on a semiconductor substrate, for example, and observing a potential of each part in the integrated circuit or a state of transmission of a signal.

[0002]

2. Description of the Related Art Conventionally, in the development stage of an integrated circuit device (hereinafter referred to as IC), the potential of each part in the IC or the propagation state of a signal is individually observed, and various data necessary for development are acquired. ing. FIG. 5 shows an example of a conventionally used probe. The probe shown in FIG. 5 includes a probe body 10 and a needle 20.

The probe body 10 includes an insulating tubular body 11, an electro-optic crystal body 12 attached to an opening at the tip of the insulating tubular body 11, a holder 13 attached to an exposed surface of the electro-optic crystal body 12, and It comprises. A conductive reflective surface is formed on the exposed surface of the electro-optic crystal body 12, and the holder 13 is bonded to the conductive reflective surface with a conductive adhesive. The holder 13 is made up of a permanent magnet, attracts the needle 20 by the magnetic attraction of the permanent magnet, and supports the needle 20 detachably. Therefore, the needle 20 is made of a highly durable magnetic material such as tungsten.

[0004] Here, the configuration and operation of a probe using the electro-optic crystal 12 will be briefly described. A light source 14, a light receiver 15, and a light receiver 1 are provided on the other end side of the insulating cylindrical body 11.
And a polarizing plate 16 for detecting the amount of polarization of light incident on the light source 5. The irradiation light PT1 emitted from the light source 14 is applied to the reflection surface of the electro-optic crystal 12, and the reflection light PT2 reflected on the reflection surface is incident on the light receiver 15 through the polarizing plate 16. When a voltage is applied to the reflection surface through the holder 13, the vibration surface of the reflected light PT2 is deflected, and a polarization angle is generated. The amount of rotation of the polarization angle is proportional to the applied voltage.
Therefore, the amount of rotation of the polarization angle of the reflected light is detected by the polarizer 16 and converted into the amount of light received by the light receiver 15, whereby the holder 1 is rotated.
3 can be taken out as an electric signal.

A probe of this type using the electro-optic crystal 12 has a feature that an input signal is extremely high, so that an electric signal can be taken out without imposing an electric burden on an object to be measured. Therefore, even if the tip of the needle 20 is brought into contact with, for example, the wiring pattern 31 of the IC formed on the semiconductor substrate 30, the waveform of the signal passing through the wiring pattern 31 is extracted as an electric signal without affecting the operation of the IC. be able to.

A reinforcing metal tube 1 is provided outside the insulating tubular body 11.
The metal tube 17 is fixed to a mounting portion of, for example, an automatic positioning device (not particularly shown), and is supported by the automatic positioning device so that the needle 20 contacts a desired wiring pattern or electrode of the IC. Let it. Alternatively, the tip of the needle 20 may be manually brought into contact with a wiring pattern of an IC while being supported by a manual manipulator. In this case, the operator who operates the manipulator monitors the surface on which the IC is formed with a microscope, and brings the tip of the needle 20 into contact with the target wiring pattern 31.

FIG. 6 shows another example of a conventional probe. The probe shown in FIG. 6 includes a printed board 41 on which an active element for impedance conversion such as an FET is mounted, and a linear needle 4 electrically connected to the printed board 41 and protruding therefrom.
2 is a resin block 43 for molding a lead-out portion of the printed board 41 and the linear needle 42,
And a shaft 44 projecting from the shaft 44.
Is inserted into and supported by the hollow portion 45A of the probe holder 45. In the example shown in FIG. 6 as well, the probe holder 45 is gripped by the mounting part of the automatic positioning device or a manual manipulator, and is automatically or visually positioned by a microscope to position the tip of the linear needle 42 with the IC. The measurement is performed by contacting the wiring pattern.

[0008]

The probe shown in FIG. 5 has a structure in which the needle 20 is magnetically attracted to and supported by the holder 13 composed of a magnet. Therefore, when the diameter of the needle 20 is reduced, the magnetic attraction force is reduced. Cannot be made thinner than the limit. Since the diameter of the needle 20 cannot be reduced, the capacitance C between the needle 20 and the wiring pattern 31 is reduced.
A large P occurs, and the presence of the capacitance CP deteriorates the waveform of the high-speed signal, thereby causing a disadvantage that it becomes difficult to capture a high-frequency signal.

On the other hand, according to the structure of the probe shown in FIG. 6, since the needle 42 has a fine line shape,
There is an advantage that the capacitance between the two can be reduced. However, according to the structure of this probe, when the needle 42 has deteriorated, that is, when the tip of the needle 42 has a round shape,
Since the tip of the needle 42 slides even when it comes into contact with the target wiring pattern 31, it is difficult to maintain the state in contact with the target wiring pattern. Therefore, if the tip of the needle 42 has become rounded, it must be replaced immediately. In order to replace the needle 42, it is necessary to replace the entirety from the shaft 44 to the resin block 43, the printed circuit board 41 and the like. In particular, the portion of the printed circuit board 41 is relatively expensive because an active element such as an FET exhibiting a high input impedance is mounted. Therefore, there is a disadvantage that the replacement part alone becomes expensive.

An object of the present invention is to propose a probe having a structure capable of reducing the generation of capacitance CP with a wiring pattern of an IC and reducing the cost required for needle replacement.

[0011]

According to the first aspect of the present invention, there is provided a cylindrical cap having one end closed, a cap penetrating the closed end face of the cap, one end protruding into a hollow portion of the cap, and the other end. And a contact needle protruding and supported outside the closed end face of the cap. According to claim 2 of the present description, an insulating tubular body that fits into the hollow portion of the cap according to claim 1 and maintains an engaged state, and is mounted at the opening position of the insulating tubular body, The present invention proposes a probe constituted by an electrode which comes into contact with an end of a contact needle protruding into the inside of the part and is electrically connected to the contact needle.

According to a third aspect of the present invention, in the probe according to the second aspect, the electro-optic crystal is stored in a hollow portion of the insulating tubular body, and a conductive reflection film is formed on an end face of the electro-optic crystal. An electrode is conductively bonded to the reflective film, light is radiated to the conductive bonded surface, and the light reflected by the reflective film is polarized according to the voltage applied through the contact needle, and the amount of polarized light is measured. We propose a probe with a structure to measure voltage. According to a fourth aspect of the present invention, in the probe according to the first aspect, a printed circuit board having an active element for impedance conversion is disposed in a hollow portion of the insulating tubular body, and a hollow portion of a cap is provided on an electrode mounted on the printed circuit board. We propose a probe that comes in contact with a protruding contact needle.

[0013]

According to the structure of the replacement needle according to the present invention, the contact needle can be mounted in a state of being electrically connected to the electrode on the probe side only by fitting the cap to the insulating cylindrical body constituting the probe body. . As a result, the exchange needle can be easily exchanged. In addition, since the replacement needle is simply composed of the cap formed of the insulating material and the contact needle formed of the wire supported by the cap, the replacement needle can be manufactured at low cost. Therefore, the cost required for replacement can be reduced, and the advantage that the operation cost can be reduced can be obtained.

Further, since the contact needle used for the replacement needle according to the present invention can be constituted by a linear body, the contact needle and the IC
Of the wiring pattern can be reduced. Therefore, even in the case of a probe of the type using an electro-optic crystal or a probe of the type in which a high input impedance type active element is mounted on a printed circuit board, a high-frequency signal can be captured without waveform deterioration. Benefits are obtained.

[0015]

FIG. 1 shows an embodiment of a probe according to the present invention. The embodiment shown in FIG. 1 shows an embodiment in which the present invention is applied to a probe of the type shown in FIG. Therefore, parts corresponding to those in FIG. 5 are denoted by the same reference numerals. Reference numeral 50 shown in FIG. 1 indicates an exchange needle proposed by the present invention.
Reference numeral 10 denotes a probe main body to which the replacement needle 50 is attached for practical use. The probe main body 10 has substantially the same structure as the structure shown in FIG. 5, but has a different structure only in that the holder 13 is changed to the electrode 18 at one point.

That is, the electro-optic crystal 12 is mounted in the hollow portion of the insulating tubular body 11, a conductive reflection film is formed on the exposed surface, and the electrode 18 is mounted on the reflection film with a conductive mounting agent. The electrode 18 can be configured by applying gold plating to a copper round bar, for example. On the other hand, the replacement needle 50 includes a cap 51 formed of an insulating material and a contact needle 52 formed of a wire supported by the cap 51. The cap 51 includes a cylindrical body 51A and a closing plate 51B for closing one end of the cylindrical body 51A.

A through hole is formed at the center position of the closing plate 51B. The contact needle 52 is made to penetrate the through hole, and the through hole is filled with an insulating adhesive 53 and solidified, and the contact needle 52 is attached to the cap 51. Fix it. As the linear contact needle 52, for example, a tungsten needle having a diameter of about 10 μm can be used. In addition, a cut groove is formed in the cylindrical body 51A constituting the cap 51 so as to face the axial direction by, for example, 180 °, and elasticity is given to the cylindrical body 51A in the diametric direction by the cut groove. It can be configured to be firmly fitted.

In the embodiment shown in FIG. 1, the contact needle 52 is projected obliquely from the axis of the cap 51 outside the cap 51, thereby securing the field of view of the microscope and improving the operability. The rear end 52A of the contact needle 52 is
1 and protrudes in the axial direction, and the protruding rear end 52
A is brought into contact with the electrode 18 provided on the probe body 10 side. By placing the cap 51 on the tip of the insulating tubular body 11, the rear end 52A of the contact needle 52 comes into contact with the electrode 18 as shown in FIG. 2, and the contact needle 52 is electrically connected to the electrode 18. The voltage signal can be applied to the electrode 18 from the wiring pattern by keeping the tip of the contact needle 52 in contact with the wiring pattern to be measured.

When the contact needle 52 is to be replaced, it can be replaced simply by removing the cap 51 from the insulating tubular body 11. Since the replacement needle 50 is composed of only the contact needle 52 and the cap 51, it can be an extremely inexpensive part, and an advantage that the cost required for operation can be reduced can be obtained. 3 and 4 show an embodiment in which the present invention is applied to a probe on which a printed circuit board 41 is mounted. In this embodiment, the printed circuit board 41 is inserted and fixed in the opening of the insulating tubular body 11, and a notch is formed in an end of the printed circuit board 41, and the columnar electrode 18 is inserted into the notch. A conductive pattern may be formed around the notch, and the electrode 18 may be fixed to the conductive pattern by, for example, soldering.

With this configuration, by fitting the cap 51 to the tip of the insulating tubular body 11, the rear end 52 A of the contact needle 52 attached to the cap 51 is
, And the contact needle 52 and the electrode 18 are maintained in an electrically connected state.

[0021]

As described above, according to the present invention, since the contact needle 52 is formed by a thin wire, the capacitance between the contact needle 52 and the semiconductor substrate on which the IC is formed can be reduced. Therefore, even a signal having a high frequency can be captured without deteriorating the waveform. Furthermore, even if the shape of the tip of the contact needle 52 is deteriorated, the part to be replaced is a part composed of the cap 51 and the contact needle 52, so that the part to be replaced can be provided at low cost. Therefore, an advantage that the cost required for operation can be reduced is obtained, and the effect is extremely large for practical use.

[Brief description of the drawings]

FIG. 1 is a side view partially showing a cross section for explaining an embodiment of the present invention.

FIG. 2 is a side view partially showing a cross section for explaining a state in which the cap shown in FIG. 1 is attached to a probe main body.

FIG. 3 is a sectional view for explaining a modified embodiment of the present invention.

4 is a front view of the probe main body shown in FIG. 3 as viewed from the front.

FIG. 5 is a sectional view for explaining a conventional technique.

FIG. 6 is a side view for explaining another example of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Probe main body 11 Insulated cylindrical body 12 Electro-optic crystal 18 Electrode 41 Printed circuit board 50 Replacement needle 51 Cap 51A Cylindrical body 51B Closure plate 52 Contact needle

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshihiko Hara 1-32-1 Asahimachi, Nerima-ku, Tokyo F-term in the Advantest Co., Ltd. (reference) 2G011 AA02 AC05 AC11 AC12 AE03 AE22 2G025 AA03 AB11 2G032 AA00 AF03 4M106 AA02 BA01 CA02 DD03 DD30

Claims (4)

[Claims] 1. A. First Embodiment B. a cylindrical cap having one end closed; A probe replacement needle constituted by: a contact needle penetrating the closed end face of the cap, one end protruding into the hollow portion of the cap, and the other end protruding outside the closed end face of the cap and supported. 2. An insulating tubular body that fits into the hollow portion of the cap according to claim 1 and maintains an engaged state. An electrode mounted at an opening position of the insulating tubular body and configured to be in contact with an end of the contact needle protruding into the hollow portion of the cap and to be electrically connected to the contact needle. 3. The probe according to claim 2, wherein an electro-optic crystal is stored in a hollow portion of the insulating tubular body, and a conductive reflection film is formed on an end face of the electro-optic crystal. Conductive bonding of the electrodes, irradiating the conductive bonding surface with light, generating polarized light corresponding to the voltage applied through the contact needle to the light reflected by the reflective film, measuring the amount of polarization of the reflected light Probe with a structure that measures voltage. 4. The probe according to claim 2, wherein a printed circuit board having an active element for impedance conversion mounted thereon is disposed in the hollow portion of the insulating tubular body, and an electrode mounted on the printed circuit board is provided in the hollow portion of the cap. A probe characterized in that it comes into contact with a protruding contact needle.