KR100893877B1 - Method of polishing end portion of needle for probe card - Google Patents

Abstract

Disclosed is a needle polishing method for a probe card that can process a needle that is free of dust and foreign matter in an external environment. The abrasive may be applied onto the elastic sheet by providing an elastic sheet on the base plate in order to grind a needle that is less vulnerable to external environmental dust or foreign matter. The needle end can be polished by the provided elastic sheet and abrasive, and the polished needle end can make the probing operation accurate.

Probe card, needle, elastic sheet, abrasive

Description

Polishing method of needle end for probe card {METHOD OF POLISHING END PORTION OF NEEDLE FOR PROBE CARD}

The present invention relates to a needle polishing method for a probe card that can form a needle made of platinum or a similar material metal which is free of dust and foreign substances in an external environment, and can easily process an end portion of a platinum needle or the like.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for polishing a needle end for a probe card, and more particularly, to a method for polishing a needle that is processed to provide a needle that is free of external dust and foreign matter, and an apparatus for polishing a needle.

In general, a semiconductor chip manufactured in a wafer state has an integrated circuit (LDI) for driving a liquid crystal display device or an electrical die sorting (EDS) which inspects electrical characteristics before being assembled into a semiconductor package. Inspection). As a result of the EDS inspection, the good semiconductor chips are assembled into a liquid crystal display element driving integrated circuit (LDI) or a semiconductor package, and the defective semiconductor chips are discarded without being assembled. This EDS test is performed using a prober equipped with a probe card that can electrically contact a tester with various measuring devices built into a computer and a semiconductor chip under test.

The probe card is used as an intermediate connecting means for connecting the pad and the tester of the semiconductor chip to inspect the micro pattern of the semiconductor chip on the wafer and the characteristics of the electrode during the manufacturing process of the semiconductor device. It is in direct contact with the pad of the chip. Therefore, the characteristics of the electrical function of the semiconductor chip are examined in good and defective form.

Conventional probe cards are mainly made of tungsten and use needles containing rhenium (Re). When probing an object under test using these needles, foreign matters may appear on the needle probe, which may cause an error in checking the electrical function of the semiconductor chip. In order to solve this problem, a needle containing platinum is used, but in the case of the platinum needle, it is difficult to etch the needle end suitable for the area and size of the inspected object. That is, the needle end mainly made of tungsten, which is generally used, may be processed by etching, but platinum may provide difficulty in end processing while discoloring when etching due to the nature of the material. In addition, the semiconductor chip may be manufactured in a very small size, and the size of the needle should also be small to determine whether the manufactured semiconductor chip is defective. There is a problem that can not respond.

The present invention provides a needle polishing method for a probe card that can form a needle made of platinum or a similar material metal which is free of dust and foreign matters in an external environment, and can easily process an end portion of a platinum needle or the like.

The present invention provides a needle polishing method for a probe card which can process a thin and gentle needle at an end portion of a needle in contact with a test object.

The present invention can reduce the time and equipment required for repair or replacement when the repair or replacement is required due to dust or foreign matter in the external environment, and productivity can be improved.

According to a preferred embodiment of the present invention for achieving the above object of the present invention, the step of attaching an elastic sheet on the base plate, applying an abrasive on the elastic sheet, so that the needle end is in contact with the upper surface of the elastic sheet Positioning the needle on top of the elastic sheet, moving the base plate and the needle relatively in a horizontal state while maintaining contact, and polishing the end of the needle using the elastic sheet and the abrasive. The needle may be provided with a material having a difficult polishing process such as platinum or a metal having similar characteristics.

In the attaching the elastic sheet on the base plate, the elastic sheet may include an adhesive layer to be adhered to the base plate, and may include a soft sheet having elasticity on the adhesive layer. In this case, the soft sheet may be provided with a material such as foamed polyurethane, and when the needle end is polished, various soft sheets of elastic material may be provided to elastically polish the needle end.

Here, a support layer may be included between the adhesive layer and the soft sheet, and the support layer may serve to support and fix the soft adhesive layer and the soft sheet attached to the base plate. The support layer provided may be provided, for example, as a PET film, and various materials may be provided to support and fix the adhesive layer and the soft sheet.

An abrasive may be applied onto the provided elastic sheet, and the abrasive may be provided in a liquid state by mixing a solid powder of silicon, magnesium, nitrile, sulfur, and the like mixed with distilled water and isopropyl alcohol in a predetermined ratio. The abrasive provided may comprise a certain viscosity and may be adhered to the needle ends by the included viscosity. In addition, the abrasive is not only adhered to the needle end, but also adheres to the needle end top to allow the needle end to be polished in a hemispherical shape.

The abrasive applied on the elastic sheet may be applied within a height capable of uniformly polishing the needle end, and generally the abrasive applied may be applied within 5 μm on the elastic sheet.

The needle may be positioned on top of the elastic sheet such that the end of the needle contacts the elastic sheet to which the abrasive is applied. At this time, the soft sheet may be positioned by the end of the needle so that the upper surface can be recessed within 5㎛ 10㎛. The needle end may be in contact with the soft sheet to such an extent that it is not fixed to the elastic sheet or penetrates the soft sheet.

The base plate can be rotated to polish the needle ends in contact with the elastic sheet. The base plate makes it possible to polish the needle end with an abrasive provided on the elastic sheet while rotating in a trace such as a circle or an ellipse.

When the base plate is polished, the base plate and the needle may contact in a horizontal state, and when the base plate and the needle contact in the horizontal state, the needle may be uniformly polished. When the base plate rotates, the base plate may rotate within a range where the needle end is not deformed, and the speed at which the base plate rotates may rotate while maintaining the rotational speed of 3 RPM to 5 RPM or less.

Needles provided in conventional probe cards generally use needles provided with tungsten. Needles provided with tungsten may be stained with external dust and foreign matter after the probing operation, and as a result, the accuracy of the probing operation on the test object may be degraded. However, in the case of the needle provided with platinum according to the present invention, since the phenomenon of external dust and foreign matters can be reduced, the accuracy of the probing operation for the inspected object can be improved.

In addition, the present invention provides a method for polishing a needle for a probe card which can perform a precise probing operation by processing a needle having a thin and gentle contact surface in contact with the test object. That is, the probe card of the non-memory product has a very small size of the object under test, so it is difficult to perform a probing operation using a general needle. However, the needle used in the probe card of the present invention may be provided with a needle which is easy to probing a thin and small test subject.

 The present invention can reduce the time and equipment required for repair or replacement when repair or replacement is required due to dust or foreign matter in the external environment. Needle according to the present invention can reduce the foreign matter and external dust coming out after the probing operation, it is possible to reduce the time and manpower for removing the external dust and foreign matter. In addition, since the needle that needs to be repaired or replaced by external dust and foreign matter can be reduced, productivity can be improved.

Hereinafter, a polishing apparatus will be described with respect to a probe card needle end with reference to FIGS. 3 to 7. In addition, the same or equivalent reference numerals are given to the same or equivalent components as those described above, and detailed description thereof will be omitted.

3 and 4 are cross-sectional views showing a needle polishing device for a probe card according to an embodiment of the present invention, Figure 5 is an enlarged area A of Figure 4, Figure 6 needle using a needle polishing device for the probe card Is a cross-sectional view showing a state in which FIG. 7 is an enlarged view of region B of FIG.

Referring to FIG. 3, the needle polishing apparatus for the probe card may be provided with a base plate 300, and an elastic sheet 230 may be provided on the base plate 300.

The elastic sheet 230 may include an adhesive layer 236 on one surface of the elastic sheet 230 so as not to be separated on the base plate 300. The soft sheet 232 may be provided on the adhesive layer 236, and the soft sheet 232 may be broken when the base end 300, which will be described later, is polished while the needle end 275 is polished. It would be desirable to be formed of a resilient material to prevent deformation.

A support layer 234 may be provided between the adhesive layer 236 and the soft sheet 232. The support layer 234 may be provided with a resin of a material such as foamed polyurethane, for example, the flexible sheet 232 is flexible, the adhesive layer 236 is also composed of a flexible property that can be adhered to the base plate 300 The elastic sheet 230 may serve to be supported and fixed on the base plate 300. Therefore, the support layer 234 preferably has a certain shape strength, such as PET film, it can be variously changed according to the required specifications.

An abrasive 250 may be applied on the elastic sheet 230 to polish the needle end 275. The abrasive 250 may be a liquid abrasive in which a predetermined ratio of distilled water, isopropyl alcohol, and the like is mixed with powdered powder mixed with silicon, magnesium, sodium, and sulfur.

Here, the needle 270 may be a needle 270 formed of a platinum material. In general, needles for probe cards are used in which tungsten is the main raw material. When the probing operation is performed using a needle whose tungsten is the main raw material, foreign matters may come out on the end of the needle, and when the probing operation is performed by using the needles with the foreign material on the needle end, There is a problem that the probing operation is not performed. To solve this problem, a needle containing platinum may be used. However, in the case of platinum needle, it may be difficult to polish the end of the needle to fit the size and area of the object to be probed. That is, in the case of the conventional needle, the operation of melting the needle end by immersing the needle in the etchant to polish the needle end. When the platinum needle is immersed in the etching solution, the needle end 275 may melt as if burned out. Therefore, in the embodiment of the present invention will be described with an example of the abrasive 250 that can polish the needle end (275) containing platinum.

When the elastic sheet 230 is provided on the base plate 300, the step (S220) of applying the abrasive on the elastic sheet may pass. The abrasive 250 may be a powder powder mixed with silicon, magnesium, sodium, sulfur, and the like, and the provided abrasive 250 may be mixed with distilled water, isopropyl alcohol, and the like in a ratio to be provided on the elastic sheet 230. The provided abrasive 250 may have a certain viscosity, and the viscosity of the abrasive 250 may, when polishing the needle end 275, to the top of the needle end 275 to polish the needle end 275 into a hemispherical shape. It is possible to include a certain viscosity so that the abrasive can be bonded.

As shown in FIGS. 4 and 5, the needle end 275 may be in contact with the upper surface of the elastic sheet 230, where the elastic sheet 230 has a needle end 275 such as a sponge, for example, the elastic sheet. When a predetermined pressure is applied from the upper portion 230, the upper surface of the soft sheet 232 of the elastic sheet 230 may be recessed to a predetermined depth d1. In this case, the depth d1 of the soft sheet 232 recessed by the needle end 275 may be changed according to a required condition, but may generally be recessed within 5 μm or more and 10 μm, and the needle end 275 may be recessed. It may be desirable to recess so as not to pass through or secure to the soft sheet 232.

When the needle end 275 contacts the elastic sheet 230 by applying a predetermined pressure to the elastic sheet 230, an abrasive 250 having a predetermined viscosity may be attached to the needle end 275. At this time, the abrasive 250 may be bonded to a predetermined height (d2) in the vertical direction of the needle 270, the height (d2) to which the abrasive 250 is bonded is the degree of viscosity, elasticity of the provided abrasive 250 It may be changed according to the depth d1 and the like contacted with the sheet 230.

When the needle end 275 contacts the upper surface of the elastic sheet 230, the base plate 300 may rotate while the needle 270 maintains contact in a horizontal state. When the base plate 300 rotates, the needle end 275 may not be bent or deformed, and the needle 270 and the base plate 300 may be horizontal in order to uniformly polish the needle end 275.

When the base plate 300 rotates, the base plate 300 can be rotated by drawing traces of ellipses, circles, straight lines, etc., and the rotational speed at which the base plate 300 rotates is required to be 3 RPM or more and 5 RPM or less. Rotation can be changed according to conditions and specifications.

Meanwhile, referring to FIGS. 6 and 7, when the needle end 275 is polished by the abrasive 250 by rotating the base plate 300, the needle end 275 may be confirmed. When checking the needle end 275, it is possible to check whether the needle end 275 is polished in a semi-circular shape, it is possible to check that the provided needle 270 is uniformly polished. If the needle end 275 of the portion of the needle 270 to be inspected is not polished to a semicircular shape by polishing only a general cross section, or the provided needle 270 is not polished uniformly, the needle end 275 may be replaced. Can be polished

Meanwhile, the abrasive 250 may change from a liquid state to a solid state while polishing the needle end 275 earlier. Therefore, in order to regrind the needle end 275, the state of the abrasive 250 may be determined. At this time, it is determined whether the abrasive 250 is changed to a solid state, and the distilled water and isopropyl alcohol are added to the abrasive 250 changed to a solid state to be a liquid abrasive 250 again.

As described above, although described with reference to the preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

1 shows a probe card according to an embodiment of the present invention.

2 is a flowchart illustrating a needle polishing method for a probe card of the present invention.

3 and 4 are cross-sectional views showing a needle polishing device for a probe card according to an embodiment of the present invention.

FIG. 5 is an enlarged view of region A of FIG. 4.

Fig. 6 is a sectional view showing the state of the needle using the needle polishing apparatus for the probe card.

FIG. 7 is an enlarged view of region B of FIG. 6.

<Description of the symbols for the main parts of the drawings>

100: probe card 200: needle block

230: elastic sheet 250: abrasive

270: needle 300: base plate

Claims (16)

In the method of grinding the needle end for the probe card, Attaching an elastic sheet on the base plate; Applying an abrasive on the elastic sheet; Contacting an upper surface of the elastic sheet such that the needle end is immersed in the abrasive in a liquid state; And Polishing the end of the needle by rotating the base play while the base plate and the needle are in a horizontal state ; Polishing method of the end of the needle for a probe card comprising a. The method of claim 1, And attaching the elastic sheet on the base plate, wherein the elastic sheet includes an adhesive layer adhered to the base plate and comprises a soft sheet on the adhesive layer. The method of claim 2, The method of polishing the needle end of the probe card, characterized in that the soft sheet is provided with a foamed polyurethane resin having elasticity. The method of claim 3, A support layer supporting and fixing the adhesive layer and the foamed polyurethane between the adhesive layer and the soft sheet, And said support layer is provided as a PET film. delete delete delete The method of claim 1, In the step of applying an abrasive on the elastic sheet, the abrasive is applied to the elastic sheet within 5㎛, polishing method of the needle end for the probe card. The method of claim 1, For positioning the needle above the elastic sheet so that the needle end contacts the upper surface of the elastic sheet, the needle end is positioned so that the upper surface of the soft sheet is recessed within 5 µm or more and 10 µm . Polishing method of needle end. The method of claim 1, The base plate is rotated in one of the traces of a circle or an ellipse in the step of moving the base plate and the needle in a horizontal state while keeping the contact in a horizontal direction, and the abrasive is rotated simultaneously with the rotation of the base plate. And grinding said needle end while rotating in substantially the same direction as the base plate. The method of claim 10, And the needle end is polished to a hemispherical shape in the step of repeatedly moving the base plate and the needle while maintaining contact in a horizontal state. The method of claim 10, The needles are uniformly provided at regular intervals so that the abrasive polishes the needle ends substantially equally even when the base plate is rotated in the step of repeatedly moving the base plate and the needle while maintaining contact in a horizontal state. Polishing method of the end of the needle for a probe card, characterized in that. The method of claim 1, In the step of repeatedly moving the base plate and the needle while maintaining contact in a horizontal state, the base plate is rotated while maintaining at a rotational speed of 3 RPM to 5 RPM or less so that the needle end is rotated in a non-deformable range. A method for polishing a needle end for a probe card. In the apparatus for grinding the needle end for the lob card An elastic sheet attached to the base plate; And And an abrasive applied to the elastic sheet to polish the end of the needle . And the elastic sheet includes an adhesive layer and a soft sheet, and a support layer is further provided between the adhesive layer and the soft sheet . The method of claim 14, The abrasive is a needle end polishing device for a probe card, characterized in that for polishing the end of the needle formed of platinum . The method of claim 14, A group device that, as the rotating base plate in a horizontal position and said needle grinding the probe needle end, characterized in that the elastic sheet and the abrasive polishing the end of the needle.

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