JP2002005958A - Measuring needle for probe card, probe card, and manufacturing method of measuring needle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring needle for a probe card, having a simple structure and capable of maintaining the functions such as conductivity of the measuring needle without damaging the measuring needle or without lowering the use efficiency of the probe card, and to provide a manufacturing method of the measuring needle and the probe card using the measuring needle. SOLUTION: A foreign matter deposition preventing layer 24 made of titanium boride is formed on the surface of an end part 22a of a measuring needle body 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring needle for a probe card, a probe card using the measuring needle, and a method for forming a measuring needle. Measuring needle forming method,
The present invention relates to a probe card using the measurement needle.

[0002]

2. Description of the Related Art A large number of semiconductor ICs formed on a wafer
A prober tester system has been used to perform an electrical characteristic test on the probe. This system is compatible with each semiconductor IC
And a probe card having a plurality of conductive measurement needles arranged in accordance with the electrode pattern. FIG. 3 shows an example of the probe card. As shown in the figure,
For example, a circular opening 10a is provided at the center of the probe card substrate 10 provided with printed wiring on the surface and inside. A fixing ring 12 made of ceramics or the like is arranged on the lower surface side of the probe card substrate 10 so as to surround the opening 10a. Further, on the lower surface side of the probe card substrate 10, a plurality of measuring needles 14 are fixed along the periphery of the fixing ring 12 as shown in the figure, and the fixed base ends are connected to the printed wiring terminals. Have been. The arm 14a of the measuring needle 14 extends toward the opening 10a. The arm portion 14a of each measuring needle 14 is bent in a substantially L-shape so that the tip is substantially perpendicular to the probe card substrate 10, and constitutes a stylus portion 14b that comes into contact with an electrode pad such as an IC wafer. An intermediate node, which is a part of the arm of each measuring needle 14, is attached to the fixing ring 12 by the resin 1
6, the measuring needles 14 are firmly positioned and held.

[0003] Therefore, when the continuity test or the function measurement is actually performed by the probe card, the stylus portion 14b of the measuring needle 14 is guided to each electrode pad of the IC wafer, and the spring property of the arm portion 14a is reduced. The stylus portion 14b is pressed against the electrode pad at a predetermined pressure by utilizing. As a result, the contact between the stylus portion 14b and the electrode pad is made well, and the IC
And so on can be efficiently and stably performed.

Incidentally, the tip of the measuring needle of such a probe card must be arranged in a pattern exactly corresponding to the electrode pattern of the IC chip to be measured. Also, the height accuracy must be strictly controlled. Similarly, to ensure good electrical conduction with each electrode pad, the contact resistance at the tip must also be properly managed.

However, as described above, when actually conducting a continuity test or function measurement, the measuring needle 14 of a probe card having a thin tip and bent into a substantially L-shape is used as an IC.
It is pressed against an electrode pad such as a wafer. At the time of the pressing, the measuring needle 14 may slide on the electrode pad to scrape off the base material (for example, aluminum or gold) of the electrode pad, and the scraps (foreign matter) that has been scraped may adhere to the measuring needle 14. In this case, the contact resistance of the measuring needle 14 becomes large due to the foreign matter, and it becomes impossible to perform an accurate continuity test or function measurement using a probe card thereafter. On the other hand, the applicant of the present application disclosed in the earlier application that, for example, the measuring needle 14 is pressed against a needle-point polished flat plate to polish and remove the adhered foreign matter, or only the foreign matter adhered to the measuring needle 14 using a laser beam. For incineration and removal.

[0006]

However, in the former case of the foreign matter removing method described above, there is a problem that the measuring needle 14 is worn or deformed during polishing, so that the foreign matter removing operation can be performed frequently. Did not. In the latter case, the measuring needle 14
Although it does not cause damage such as abrasion or deformation, the foreign matter removal system is relatively large. In addition, since both require periodic foreign substance removal operations, the foreign substance removal operation is a cause of a decrease in the use efficiency of the measurement needle (probe card) from the viewpoint of the efficiency of the continuity inspection or the function measurement, and the continuity inspection or the function measurement is performed. From the viewpoint of efficiency, improvement in foreign matter removal is desired.

The present invention has been made to solve such a problem, and has a simple configuration.
And without damaging the measuring needle, and also for a measuring needle for a probe card, a measuring needle forming method capable of maintaining functions such as conductivity of the measuring needle without reducing the use efficiency of the measuring needle and the probe card, and It is another object of the present invention to provide a probe card using the measurement needle.

[0008]

In order to achieve the above object, the present invention provides a probe card which measures electric characteristics of a substrate via electrodes formed on the substrate and which is provided with the electrodes. A measuring needle for a probe card that comes into contact with the measuring needle, wherein the measuring needle is formed of a conductive foreign matter adhesion preventing material that prevents foreign matter from adhering to the measuring needle.

According to this configuration, since the measuring needle is formed of the foreign matter adhesion preventing material, it is possible to prevent the foreign matter from adhering to the measuring needle, so that the foreign matter removing operation itself is unnecessary or
The required frequency can be significantly reduced, and functions such as conductivity of the measuring needle can be maintained without lowering the use efficiency of the measuring needle.

According to another aspect of the present invention, there is provided a probe card arranged on a probe card for measuring electrical characteristics of a substrate via an electrode formed on the substrate and contacting the electrode. A measuring needle main body having conductivity, and a conductive foreign matter adhesion preventing layer formed at least at a distal end portion of the measuring needle main body on the electrode facing side, which prevents foreign matter from adhering to the measuring needle and has conductivity. And characterized in that:

In order to achieve the above object, the present invention is characterized in that, in the above structure, the foreign matter adhesion preventing layer is formed of titanium boride.

According to this configuration, since the foreign substance can be prevented from adhering to the measuring needle by the foreign substance adhesion preventing layer, the foreign substance removing operation itself is unnecessary or the frequency of the operation can be remarkably reduced, and the use efficiency of the measuring needle can be reduced. It is possible to maintain the function of the measuring needle such as conductivity without lowering.

Further, in order to achieve the above object, the present invention is characterized in that the probe card has the probe card measuring needle having the above configuration.

[0014] According to this structure, since the foreign substance can be prevented from adhering to the measuring needle by the foreign substance adhesion preventing layer, the function of the probe card can be maintained and the use efficiency can be improved.

[0015] In order to achieve the above object, the present invention relates to a probe card measuring device arranged on a probe card for measuring electrical characteristics of a substrate via electrodes formed on the substrate and coming into contact with the electrodes. A method of forming a needle, comprising a step of forming a conductive foreign matter adhesion preventing layer which prevents foreign matter from being attached to a measuring needle and at least at a distal end of the conductive measuring needle main body on the electrode facing side. It is characterized by.

In order to achieve the above object, the present invention is characterized in that, in the above structure, the foreign matter adhesion preventing layer is formed by laser ablation of titanium boride.

According to this configuration, since the foreign substance can be prevented from adhering to the measuring needle by the foreign substance preventing layer, the foreign substance removing operation itself is unnecessary or the frequency of the operation can be remarkably reduced, and the use efficiency of the measuring needle can be reduced. The function such as conductivity of the measuring needle can be maintained without lowering. Further, the foreign matter adhesion preventing layer can be easily formed.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

FIG. 1 is an enlarged view of a tip side of a probe needle 20 (hereinafter simply referred to as a probe) of the present embodiment. The measuring needle 20 includes a linear and substantially L-shaped measuring needle body 22 formed of a conductive metal such as tungsten (W) or rhenium tungsten (ReW), and at least a tip 22 a ( IC to be measured
A conductive foreign matter adhesion preventing layer 24 formed on the surface of the wafer (on the side facing the electrode pads).

The foreign matter adhesion preventing layer 24 is preferably formed of, for example, titanium boride (TiB ₂ ).
Titanium boride is a solid with high hardness and is an electrical conductor having excellent oxidation resistance. Further, since the boride substance has a low affinity, when used as a coating material, it makes it difficult for surrounding substances to adhere to the surface thereof. That is, by coating the surface of the measuring needle body 22 with titanium boride,
For example, it is possible to prevent a base material (for example, aluminum or gold) that may be scraped from an electrode pad or the like to be measured when the measuring needle 20 is used from being attached to the measuring needle 20. Even if the foreign matter adheres to the foreign matter adhesion preventing layer 24, the adhesion force is extremely low.
Vibration or the like is applied to the measuring needle 2 to easily remove foreign matter.
0 can be separated and removed.

As described above, only the formation of the foreign matter adhesion preventing layer 24 does not cause any damage to the measuring needle 20 (such as abrasion due to polishing or bending due to the application of external force). The function such as the conduction performance of the measuring needle 20 can be maintained without the application.

FIG. 2 shows a conceptual diagram of a method of forming the measuring needle 20.

In this embodiment, the foreign matter adhesion preventing layer 24 of the measuring needle 20 is formed on the surface of the measuring needle main body 22 by, for example, a laser ablation method.

In the laser ablation method, a laser beam is focused on a target (coating material) to bring the target surface of the focusing section to a high-temperature and molten state, and the surface is explosively vaporized and vaporized. (Excited atoms
This is a phenomenon in which excited molecules and ions are released in a columnar shape, and the columnar particles (plume) diffuse and adhere and deposit on the surface to be coated to form a thin film.

In this embodiment, as shown in FIG. 2, the measuring needle main body 22 is fixedly arranged on the probe card substrate 10 as shown in FIG. 3 (the structure of the probe card is substantially the same as that of FIG. 3). An example of forming the foreign matter adhesion preventing layer 24 by laser ablation will be described.

First, the probe card substrate 10 is housed and fixed in the probe card protection shield 26. The probe card protection shield 26 has an opening 2 that can expose only the tip of the measurement needle main body 22 forming the foreign matter adhesion preventing layer 24.
6a. In this embodiment, a slit 28 having an opening 28a (slightly larger than the opening 26a in the embodiment) having a size corresponding to the opening 26a is disposed below the opening 26a. The probe card protection shield 26 and the slit 28 prevent the foreign matter adhesion preventing layer 24 from being formed on unnecessary portions of the probe card substrate 10 and erroneously irradiate the laser used in laser ablation or irradiate the laser. It is provided in order to prevent the influence of heat or the like that sometimes occurs on the probe card main body side. Further, below the slit 28, a target mounting table 30 for mounting a solid of titanium boride as a coating material is disposed. The target mounting table 30 can be moved in an arbitrary direction on a horizontal plane by a moving mechanism (not shown) in a state where the target mounting table 30 is inclined at a predetermined angle with respect to the slit 28, and laser light from a laser light source (not shown) The tilt angle can be changed in order to favorably condense the titanium oxide and easily form gaseous particles.

As described above, when the laser light is focused on the titanium boride solid placed on the target mounting table 30, the surface of the titanium boride is heated to a high temperature and molten state, and the surface explodes explosively. Evaporation and gaseous particles of titanium boride are released in columnar form. The columnar particles (plume) are diffused, and titanium boride particles adhere to and accumulate on the surface of the measurement needle 22 exposed through the opening 28a of the slit 28 and the opening 26a of the probe card protection shield 26, thereby preventing foreign matter from adhering. The layer 24 is formed.

As described above, the foreign matter adhesion preventing layer 24 is formed on a desired portion of the measuring needle main body 22 to complete the measuring needle 20 to which foreign matter hardly adheres. Although the measuring needle 20 is in direct contact with an electric pad or the like during use, as described above, since titanium boride is a substance having a high hardness, the foreign matter adhesion preventing layer 24 also has a high hardness, Wearability can be improved.

In this embodiment, an example is shown in which the foreign matter adhesion preventing layer 24 is formed at the tip portion of the measuring needle main body 22 (the portion in direct contact with an electric pad or the like and its vicinity). The foreign matter adhesion preventing layer 24 may be formed entirely. Further, in the forming method of FIG. 2, an example in which the foreign matter adhesion preventing layer 24 is formed by laser ablation after assembling the measuring needle main body 22 to the probe card 10 has been described, but the measuring needle main body before assembling to the probe card 10 is illustrated. 22, that is, the foreign matter adhesion preventing layer 24 may be formed on the single measuring needle body 22 by laser ablation.

Further, in this embodiment, titanium boride is shown as a coating material for forming the foreign matter adhesion preventing layer 24. However, any material having conductivity and low affinity may be used as in this embodiment. Effects can be obtained. The method of forming the foreign matter adhesion preventing layer 24 is also optional. For example, sputtering may be used as long as it can form a thin film having foreign matter adhesion preventing performance or conductive performance.

Further, in this embodiment, an example has been described in which the foreign matter adhesion preventing layer 24 is formed on the surface of the measuring needle main body 22 made of tungsten or the like. The same effect as that of the present embodiment can be obtained even if it is formed of titanium oxide or the like.

[0032]

According to the present invention, the adhesion of the foreign matter to the measuring needle can be prevented by the measuring needle formed of the foreign matter adhesion preventing material or the measuring needle having the foreign matter adhesion preventing layer.
The foreign matter removing operation itself is unnecessary or the frequency of the foreign matter removing operation can be remarkably reduced, and the function of the measuring needle such as conductivity can be maintained without lowering the use efficiency of the measuring needle and the probe card.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration concept of a measurement needle for a probe card according to an embodiment of the present invention.

FIG. 2 is an explanatory view illustrating a method for forming a foreign matter adhesion preventing layer of a measurement needle for a probe card according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a structure of a probe card.

[Explanation of symbols]

20 measuring needle, 22 measuring needle body, 22a tip, 2
4 Foreign matter adhesion prevention layer.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masanori Terada 1-10-14 Itabashi, Itabashi-ku, Tokyo Inside the Tokyo Cathode Research Laboratory Co., Ltd. (72) Inventor Maki Kanai 1-110-14 Itabashi, Itabashi-ku, Tokyo F-term in Tokyo Cathode Research Laboratories (reference) 2G003 AG03 AG12 AH05 2G011 AA02 AA17 AC13 AC14 AC21 4M106 AA01 BA01 BA05 BA14 DD03 DD10 DD18

Claims (6)

[Claims] 1. A probe card measuring needle arranged on a probe card for measuring electrical characteristics of a substrate via an electrode formed on the substrate and in contact with the electrode, wherein the measuring needle is the measuring needle. A measuring needle for a probe card, wherein the measuring needle is made of a conductive foreign matter adhesion preventing material which prevents foreign matter from adhering to the probe card. 2. A probe needle for a probe card, which is disposed on a probe card for measuring electrical characteristics of a substrate via electrodes formed on the substrate and comes into contact with the electrodes, comprising: a conductive needle main body having conductivity; A measurement needle for a probe card, comprising: a foreign matter adhesion preventing layer formed on at least a tip portion of the measurement needle main body on the electrode facing side to prevent foreign matter from adhering to the measurement needle and having conductivity. 3. The measuring needle according to claim 2, wherein the foreign matter adhesion preventing layer is formed of titanium boride. 4. A probe card comprising the probe card measuring needle according to any one of claims 1 to 3. 5. A method for forming a probe needle for a probe card which is arranged on a probe card for measuring electrical characteristics of a substrate via an electrode formed on the substrate and comes into contact with said electrode, comprising: a measurement having conductivity. A method for forming a measuring needle for a probe card, comprising a step of forming a conductive foreign matter adhesion preventing layer that prevents foreign matter from adhering to the measuring needle and that is formed on at least a tip portion of the needle body on the electrode facing side. 6. The method according to claim 5, wherein the foreign matter adhesion preventing layer is formed by laser ablation of titanium boride.