KR100510223B1 - Abrasive Material for the Needle Point of a Probe Card - Google Patents

Abstract

Abrasives for needle points of probe cards are disclosed that can effectively remove foreign matter adhering to the probe's instructions, protect the instructions from damage and deformation, and extend the probe life. The guide abrasive of the probe card includes an abrasive layer comprising a layer of micro powdered abrasive particles applied to a substrate, and a cushion layer having a buffering action and elasticity.

Description

Abrasive Material for the Needle Point of a Probe Card

BACKGROUND OF THE INVENTION Field of the Invention The present invention generally relates to an abrasive for cleaning a needle point of a probe card, particularly an abrasive capable of removing foreign matter adhering to the guidelines of a probe card used to measure electrical characteristics of a semiconductor chip formed on a semiconductor wafer. will be.

The probe of the probe card for measuring the electrical characteristics of the semiconductor chip formed on the semiconductor wafer is pressed against and contacted with the pad of the semiconductor chip. At this time, the aluminum powder peeled off from the pad of the semiconductor chip is attached to the tip (guide) of the probe. If the aluminum powder is not removed from the guide, the aluminum remaining on the guide is oxidized to aluminum oxide, increasing the resistance between the probe and the pad. Since the electrical contact is damaged, continuous defects occur and the electrical characteristics cannot be measured accurately. To this end, there is a method of cleaning the instructions by removing aluminum powder from any given number of probes. The following methods are used to remove aluminum powder.

(1) a method of using grinding stone (see Japanese Patent Application Publication Nos. 209896/1993, 9696/1992 and 2657/1988, and Japanese Utility Model Application Publication No. 11167/1992),

(2) a method of using a sand polished plate (Japanese Patent Application Publication Nos. 16,893 / 1993, 177849/1992, 105940/1991, 10176/1991, and 152034/1986, and Japanese Utility Model Application Publication No. 26772/1995),

(3) Method of using ceramic plate (Japanese Patent Application Publication Nos. 4969/1986 and 282829/1989, Japanese Utility Model Application Publication No. 55338/1986, Japanese Patent Application Publication No. 2939/1990, 55835/1989 and 170933/1988),

(4) a method of using abrasive particles (see Japanese Utility Model Application Laid-Open No. 97840/1986),

(5) a method of using frosted glass (see Japanese Patent Application Laid-Open No. 199141/1995), and

(6) A method of using a glass coating (see Japanese Patent Application Laid-Open No. 76242/1991).

In these methods, the instructions are pressed against the pads in the same manner as in probe operation to remove aluminum powder.

However, these methods have the following problems.

(1) the instructions are broken,

(2) The aluminum powder adhering to the gap gap cannot be removed because the interval range between the recessed portion and the iron portion of the surface of the ceramic plate is 1 to 12 μm, while the distance between the guides (contact surface) is about 0.35 μm. ,

(3) the instructions are abraded to shorten the life of the probe, and

(4) The shape of the instructions tends to deform under the same load (about 2.5 kgf) as in probe operation.

Also disclosed is a method of using a cleaning material in which a micropowdered abrasive is blended into a base material (see Japanese Patent Application Laid-Open No. 244074/1995).

In this way, the cleaning material can extend the life of the probe. However, the above problems (1), (2) and (4) cannot be solved even by using this cleaning material.

The present invention has been accomplished in view of this situation, and an object of the present invention is to provide a guide for a probe card that can effectively remove foreign substances adhering to the guide of the probe, avoid damage to the guide and modification thereof, and extend the life of the probe. It is to provide an abrasive.

Summary of the Invention

The above object in the present invention

An abrasive layer comprising a micropowdered abrasive grain layer applied to a substrate, and

Cushion layer having a cushioning action and elasticity

It can be achieved by providing an abrasive for guidance of the probe card comprising a.

In a preferred embodiment of the invention, the polishing layer surface in contact with the instructions of the probe card has an irregular pattern corresponding to the instructions pattern of the probe card, and the cushion layer is made of modacrylic resin.

1 is a schematic cross-sectional view of one embodiment of a guide abrasive of the probe card of the present invention.

Fig. 2 is a schematic cross-sectional view showing the relationship between the guide shape of the probe card and the abrasive layer shape in the present invention.

The invention will be explained in detail by one embodiment of the invention with reference to the accompanying drawings.

As shown in Figs. 1 and 2, the guiding abrasive of the probe card in the present invention has an abrasive layer 3 provided with micro powdered abrasive particles 5 arranged on a substrate 1, and a buffering action. And a cushion layer 4 having elasticity.

<Polishing layer>

The abrasive layer 3 used in the present invention comprises an abrasive grain layer 2 applied to the substrate 1.

<Base material>

The substrate 1 preferably provides a specific stiffness to the abrasive grain layer 2, since the abrasive of the present invention is mounted on a specific machine together with the probe card, and is automatically moved to mount and detach. Specifically, polyethylene terephthalate (PET), polyethylene naphthalate, vinyl chloride, polypropylene and pulp cloth are provided as materials for the base material 1.

The thickness of the substrate 1 is preferably, for example, in the range of 12 to 250 μm, but is not limited thereto.

<Polishing Particle Layer>

As the abrasive particles 5 in the resin (e.g., polyester resin) 7 used for the abrasive particle layer 2, the shape of the guide 6, which is part of the probe base 8, enhances lapping and cleaning efficiency. It is preferable to select and arrange particles of average particle diameter consistent with the irregular shape of the instruction (6). Preference is given to using particles having an average particle diameter of the same size or smaller than the spacing between the recessed portion and the convex portion (hereinafter referred to as “irregular spacing”) of the instruction (6). In the case of using the guideline 6 having an irregular spacing of 0.35 mu m, the surface roughness Sm of the abrasive layer is preferably less than 0.35 mu m. Moreover, it is preferable that the average particle diameter of the abrasive grain 5 is 0.5 micrometer-3 micrometers.

By means of the structure shown in FIG. 2, the tips of the abrasive grains 5 can be inserted into the convex portions of the instructions which match the irregularities of the instructions for effectively removing foreign matter.

Materials such as alumina, silicon carbide, chromium oxide, CBN, diamond powder, cerium oxide, silicon oxide (SiO ₂ ) and zirconium oxide (Zr ₂ O ₃ ) can be used for the abrasive grain layer 2, but are not limited thereto. .

In the application of the abrasive grain layer 2 on the substrate 1, for example, slurry coating such as gravure coating, knife coating or the like, electrostatic coating, droplet coating or the like can be used, but is not limited thereto. It is preferable to arrange the density distribution of the abrasive grains in the abrasive grain layer 2 according to the average particle diameter of the abrasive grains so that the surface shape of the abrasive layer 3 corresponds to the irregular shape of the guide 6.

The thickness of the substrate 1 is preferably in the range of 15 to 300 μm. When the thickness is less than 15 μm, the strength of the polishing layer 3 is reduced, and the polishing layer 3 tends to break. In addition, when the thickness exceeds 300 µm, handling characteristics are impaired.

Cushion floor

In the case of the cushion layer 4 used in the present invention, elasticity and cushioning action are required to avoid the deformation and damage of the guide when the abrasive layer 3 is in contact with the guide 6 and to extend the probe life.

The following material features are required for the cushion layer 4. For example, the preferred range of flexural modulus is from 1.2 x 10 ³ to 9.0 x 10 ³ kg / cm 2 when using foam as the cushion layer, and the preferred Shore hardness A ranges from rubber or modacrylic material as the cushion layer. 30 to 90 when used.

Specific examples of the material for the cushion layer 4 include acrylic resins, synthetic rubbers and foams.

With this structure, the pressure (load under pressure) applied between the cushion layer 4 and the guide 6 can be in the range of 0.3 to 0.5 kg / cm 2. The thickness is preferably in the range from 300 μm to 500 μm. If it is less than 300 m, the load due to pressure is overloaded, and if it is more than 500 m, it becomes difficult to handle the cushion layer itself.

As a method of laminating the abrasive layer 3 on the cushion layer 4, a method using pressure bonding or bonding, for example, hotmelt, can be used, but is not limited thereto.

The abrasive of the present invention has a two-layer structure consisting of an abrasive layer 3 and a cushion layer 4. Thus, the abrasive of the present invention has an appropriate stiffness, elasticity and a cushioning action. In addition, the present invention can provide the abrasive layer 3 and the cushion layer 4 independently, and combine them according to the features or specifications required for the probe card, thereby effectively providing the desired abrasive.

The invention will be explained in more detail by the following examples, which are not intended to limit the invention.

Provided as an abrasive layer an ultra fine film abrasive (Imperial Lapping Film (trade name) manufactured by Sumitomo 3M Ltd.) (aluminum oxide 0.0254 mm (1 mil) 1 μm DH)) This was prepared by combining abrasive particles composed of aluminum oxide with an average diameter of 0.1 μm and a polyester resin in a ratio of 4: 1, and applying the resulting mixed material to a polyethylene terephthalate film having a thickness of 24 μm by slurry coating. . Also provided as a cushion layer was a structural bonding tape (VHB Y-4910J (trade name) manufactured by Sumitomo 3M) having a thickness of 1.0 mm containing an acrylic resin as a main component and having an appropriate stiffness and a Shore hardness of 50. The abrasive of the present invention was prepared by laminating and compressing the ultrafine film abrasive and the structural bonding tape.

This abrasive was used to wrap and clean the instructions of the probe. As a result, the gap between the recessed portion and the convex portion of the polishing layer was reduced to less than 0.35 탆, and the pressure load could be reduced to about 0.3 kgf.

By using the abrasive to wrap and clean the instructions of the probe card, it was possible to wrap and clean the instructions without modifying the shape of the instructions to reduce the wear of the instructions, extend the probe life, and reduce the contact resistance.

As can be seen from the above description, the present invention provides a guide card abrasive of the probe card which can effectively remove the foreign matter attached to the guide of the probe, effectively protect the guide from damage and deformation, and prolong the probe life. Can be.

Claims (3)

An abrasive layer comprising a micropowdered abrasive grain layer applied to a substrate, and Cushion layer having a cushioning action and elasticity Includes, wherein the cushion layer is applied to the substrate of the abrasive layer abrasive for the needle point (needle point) of the probe card. The abrasive according to claim 1, wherein the abrasive layer surface in contact with the instructions of the probe card has an irregular pattern corresponding to the instructions pattern of the probe card. The abrasive according to claim 1 or 2, wherein the cushion layer is made of a modacrylic resin.