JP3923589B2 - Probe card needle tip cleaning method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a probe card needle tip cleaning method . More specifically, the present invention relates to a probe card tip cleaning method capable of suitably removing foreign matter adhering to the probe tip of a probe card for measuring electrical characteristics of a semiconductor chip formed on a semiconductor wafer.
[0002]
[Prior art]
A probe (probe) of a probe card for measuring various electrical characteristics of a semiconductor chip formed on a semiconductor wafer is brought into press contact with a pad of the semiconductor chip. At that time, the aluminum powder from which the pad has been scraped adheres to the tip (needle tip) of the probe. If this powder is not removed from the needle tip, the aluminum will be oxidized to aluminum oxide and the contact resistance between the probe and the pad will increase, resulting in poor electrical contact, poor conduction, and accurate characteristic evaluation. It becomes impossible. For this reason, every time probing is performed a predetermined number of times, the needle tip is cleaned to remove the powder. As a removal method,
1. Using a grindstone (Japanese Patent Laid-Open No. 5-209896, Japanese Patent Laid-Open No. 4-96342, Japanese Patent Laid-Open No. 63-2657, Japanese Utility Model Publication No. 4-11167)
2. Using polished flat plate (Japanese Patent Laid-Open Nos. 5-166893, 4-1777849, 3-105940, 3-10176, 61-152034, Japanese Utility Model No. 7-26772 3. Using ceramic plates (Japanese Patent Laid-Open Nos. 61-4969, 1-282829, 61-55338, 2-2-2939, (SHO 64-55835, JP 63-170933)
4). Using abrasive grains (Japanese Utility Model Laid-Open No. 61-97840)
5. Using polished glass (Japanese Patent Laid-Open No. 7-199141)
6). Using a glass coat (Japanese Patent Laid-Open No. 3-76242)
In other words, a method is used in which the tip of the needle is pressed in the same manner as in probing to remove aluminum powder.
[0003]
However, since the material used in the above technique is made of a hard material, during polishing cleaning (polishing),
1. The needle tip is damaged.
2. While the distance between the irregularities on the needle tip (contact surface) is about 0.35 μm, the distance between the irregularities on the surface of the ceramic plate or the like is 1 to 12 μm, so the aluminum powder adhering to the gap between the needle tips It cannot be removed.
3. The tip of the needle is worn away and the life of the probe is shortened.
4). With the pressure load (about 2.5 kgf) applied to the probe, the probe tip shape tends to deteriorate.
There was a problem.
[0004]
There is also provided a cleaning member in which a fine abrasive is mixed into an elastic base material (Japanese Patent Laid-Open No. 7-244074).
However, although this cleaning member can also extend the life of the probe, the problems 1, 2 and 4 remain unsolved.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described problems, and effectively removes foreign matter adhering to the needle tip, effectively prevents damage to the needle tip and deterioration of the shape, and keeps the probe life long. It is an object of the present invention to provide a probe card needle tip sharpening method that can be used.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in a probe card needle tip abrasive that removes foreign matter adhering to the probe card needle tip, a polishing layer in which a fine abrasive grain layer is disposed on a substrate; A probe card needle tip sharpening method comprising an elastic and buffering cushion layer is provided.
[0007]
As a preferred mode thereof, there is provided the probe card needle tip cleaning method wherein the surface of the polishing layer that contacts the probe card needle tip has an uneven shape corresponding to the shape of the probe card needle tip.
[0008]
Furthermore, as a preferred embodiment thereof, the probe card needle tip cleaning method is provided in which the cushion layer is made of an acrylic resin.
[0009]
[Embodiments of the Invention]
Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a sectional view schematically showing an embodiment of a probe card needle tip abrasive used in the present invention. FIG. 2 is a cross-sectional view schematically showing the correspondence between the shape of the polishing layer and the shape of the probe tip of the probe card in the present invention.
[0010]
As shown in FIGS. 1 and 2, the probe card needle tip abrasive used in the present invention includes a polishing layer 3 in which fine abrasive grains 5 are disposed on a substrate 1, and a cushion having elasticity and buffering properties. It is roughly composed of the layer 4.
1. Polishing Layer In the polishing layer 3 used in the present invention, a polishing abrasive grain layer 2 is disposed on a substrate 1.
(1) Substrate Since the abrasive used in the present invention is mounted on a dedicated machine together with the probe card and is automatically moved and detached, the substrate 1 can impart a certain rigidity to the entire abrasive. It is preferable. Specific examples include polyethylene terephthalate (PET), polyethylene naphthalate, vinyl chloride, polypropylene, paper, and cloth.
The thickness is not particularly limited as long as it can impart a certain rigidity to the abrasive, but is preferably 12 to 300 μm, for example. When the thickness is less than 12 μm, the strength of the polishing layer 3 becomes weak and may break, and when it exceeds 300 μm, handling becomes difficult.
[0011]
(2) Polishing abrasive grain layer As the abrasive grain 5 used for the polishing abrasive grain layer 2, the one having an average particle diameter that can make the shape of the surface of the polishing layer 3 correspond to the irregular shape of the needle tip 6, It is preferable to dispose in order to enhance the cleaning effect. For example, it is preferable to have an average particle diameter which is equal to or slightly smaller than the length of the unevenness of the needle tip 6 (for example, the distance from the convex to the convex). When the needle tip 6 having a concavo-convex distance of 0.35 μm is used, the surface roughness (Sm) of the polishing layer is preferably 0.35 μm or less. Moreover, it is preferable that the average particle diameter of the abrasive grains 5 is 0.5 μm to 3 μm.
By configuring in this way, as shown in FIG. 2, the tip of the abrasive grain 5 can penetrate into the recess corresponding to the shape of the concave portion of the needle tip, and foreign matter can be effectively removed. it can.
The material is not particularly limited, and for example, alumina, silicon carbide, chromium oxide, CBN, diamond powder, cerium oxide, SiO ₂ , Zr ₂ O ₃ or the like can be used.
[0012]
The method for disposing the abrasive grain layer 2 on the substrate 1 is not particularly limited. For example, slurry coating such as gravure coating and knife coating, electrostatic coating, and drop coating may be used. it can. In order to make the surface shape of the polishing layer 3 correspond to the concavo-convex shape of the needle tip 6, it is preferable to adjust the arrangement density according to the average particle size of the abrasive grains.
[0013]
The thickness of the abrasive grain layer is preferably 2 to 30 μm. If the thickness is less than 2 μm, the abrasive layer may be detached in a short time, and if it exceeds 30 μm, the production cost increases and the user needs are not met.
[0014]
2. Cushion Layer The cushion layer 4 used in the present invention prevents elasticity of the needle tip and deterioration of the shape when the polishing layer 3 comes into contact with the needle tip 6, and further retains the probe life. It is necessary to have a buffer property.
For this reason, as for the physical properties, the flexural modulus is 1.2 × 10 ^{3 to} 9.0 × 10 ³ kg / cm ² in the case of the foam system, and the shear hardness A is 30 in the case of rubber or acrylic. It is preferable that it is -90.
Specific examples include acrylic resins, synthetic rubbers, foams, and the like.
By doing in this way, the pressing force (pressure load) at the time of contact with the needle tip 6 can be set to 0.3 to 0.5 kgf.
The thickness is preferably 300 μm to 500 μm. If it is less than 300 μm, the pressing force becomes large, and if it exceeds 500 μm, handling becomes difficult.
[0015]
The method for laminating the cushion layer 4 and the polishing layer 3 is not particularly limited, and examples thereof include a method using a pressure-sensitive adhesive or an adhesive (for example, hot melt).
[0016]
Since the abrasive used in the present invention is composed of a two-layer structure of the abrasive layer 3 and the cushion layer 4, it has moderate rigidity, elasticity, and shock-absorbing properties. Can be provided in a convenient manner by providing them separately and combining them in a suitable combination with the characteristics and properties of the probe card.
[0017]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples.
Sumitomo 3M was prepared by slurry-coating abrasive grains made of aluminum oxide with an average particle diameter of 1.0 μm on a polyethylene terephthalate film with a thickness of 24 μm as a polishing layer and mixing with polyester resin in a ratio of 4: 1. Sumitomo 3M of Shore A50, which has precision film abrasives, product name: Imperial wrapping film (aluminum oxide, 1 mil 1 micron type DH) and cushioning layer with acrylic resin as the main component and moderate adhesiveness A structural joining tape manufactured by the company, product name: VHB Y-4910J (thickness: 1.0 mm) was superposed and applied by pressing.
As a result of sharpening the needle tip using this abrasive, the distance between the irregularities of the abrasive could be reduced to 0.35 μm or less, and the pressure load could be reduced to about 0.3 kgf. When this probe is used to polish the probe card needle tip, the probe card needle tip is sharpened without changing the shape of the probe card needle tip, reducing the wear on the probe card needle tip, It has become possible to extend the life of the probe and reduce the contact resistance.
[0018]
【The invention's effect】
As described above, according to the present invention, it is possible to effectively remove foreign matter adhering to the needle tip, to accurately evaluate the electrical characteristics of the semiconductor chip, and to effectively prevent breakage of the needle tip and deterioration of the shape. It is possible to provide a probe card tip sharpening method capable of maintaining a long probe life.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing an embodiment of a probe card needle tip abrasive used in the present invention.
FIG. 2 is a cross-sectional view schematically showing a correspondence relationship between the shape of a polishing layer and the shape of a probe tip of a probe card in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base material 2 Polishing abrasive grain layer 3 Polishing layer 4 Cushion layer 5 Polishing abrasive grain 6 Needle tip 7 Adhesive 8 Probe

Claims (2)

In the probe card needle tip cleaning method to remove foreign matter adhering to the probe card needle tip,
A polishing layer in which an abrasive grain layer made of fine particles having an average particle diameter equal to or smaller than the length of the convex-concave shape of the probe tip of the probe card is provided on the substrate, and elasticity and buffering properties Preparing an abrasive comprising a cushion layer having
And a step of pressing a probe tip of the probe card against the polishing layer to remove foreign matter adhering to the tip of the probe card. The probe card needle tip sharpening method according to claim 1, wherein the cushion layer is made of an acrylic resin.

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