JPH11111788A - Apparatus and method for polishing probe needle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively polish and clean the needle of a vertical type probe card by mounting a polishing Si wafer having conical holes on a wafer chuck. SOLUTION: The method comprises a probe 2 tip first polishing step 1 of slightly pressing the probe tip to other portion of a polishing wafer 6 surface than the conical holes and horizontally vibrating the probe card or polishing wafer 6 to polish it and remove a foreign matter such as Al oxide at the top of the probe 2, and probe tip second polishing step 2 of inserting the probe tip into the conical hole of the wafer 6 and almost vertically vibrating the probe card or wafer 6 to chamfer or sharpen the probe 2 tip or remove foreign matter such as Al oxide, thus facilitating removing foreign matter deposited on the probe tip.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polished wafer for removing foreign matter adhering to a tip of a probe needle (also referred to as a probe) of a vertical needle type probe card among probe cards used in a wafer test of a semiconductor IC. Things.

[0002]

2. Description of the Related Art Generally, in a process for manufacturing an IC, an LSI, etc., there is a wafer test process for testing whether individual chips on a wafer are good or defective. In this wafer test process, a probe card is usually mounted on a device called a prober, and a probe needle of the probe card is contacted with a predetermined pad (electrode) on a chip of a wafer.
It will be done. Specifically, the electrical connection further applies a certain pressure (called stylus pressure) between the probe needle and the pad after this contact (called an overdrive), and the probe needle removes aluminum oxide on the pad surface. And
This is achieved by contacting the underlying aluminum with low contact resistance.

[0003] Of these probe needles, Cantilever
An outline of the outer shape of the r-type probe card and the probe card is disclosed in Japanese Utility Model Laid-Open No. 57-146340. In the above-mentioned contact process, it is obvious that foreign matter such as aluminum oxide adhering to the tip of the probe needle adversely affects the electrical connection, and it is a fact that various measures are taken. For example, a probe needle polishing machine for pellet inspection disclosed in JP-A-56-119377,
And a probe tip cleaning member disclosed in Japanese Patent Application Laid-Open No. 7-244074 is provided with a resilient silicon rubber or the like in which a foreign substance such as aluminum oxide adhered to the tip of a probe needle is mixed with a fine abrasive such as an abrasive. By piercing the resin base material a predetermined number of times, the tip and side surface of the probe needle are scraped off, thereby removing aluminum oxide, which is a main cause of contact failure, and obtaining a good electrical contact.

Examples of using a wafer or a wafer-like object in a prober include a wafer prober disclosed in Japanese Patent Publication No. 57-59668 and Japanese Utility Model Application Laid-Open No. Sho 62-84.
There is a wafer prober disclosed in Japanese Patent Application Laid-Open No. 929, in which a V-shaped groove corresponding to the shape of a needle tip is provided on a polishing plate, and a probe card is moved up and down to slip aluminum in the groove to remove aluminum oxide. It is said that a good electrical contact is obtained. All of the above are C
The present invention relates to a method for polishing a needle tip of an anti-verber type probe card, and is not a prior art for polishing a needle of a vertical needle type probe card.

FIG. 12 is a cross-sectional view for explaining that probing at the time of a wafer test is performed by a probe card using a vertical needle. In the figure, a first guide plate 11 fixes a vertical probe needle 12. The second guide plate 13 is for positioning the vertical probe needles 12 on several test pads 5 on the wafer 14. And the first guide plate 1
The first and second guide plates 13 are integrally formed as a probe card. FIG. 13 is a plan view showing the test pad 15 on the wafer 14, and the vertical probe needle 12 is positioned at the center of the test pad 15. The wafer 14 includes an IC chip, and the wafer test is performed by contacting the vertical probe needle 12 with the test pad 15.

Generally, the first guide plate 11 and the second guide plate 13 are made of a material having the same thermal expansion coefficient as the wafer 14 including the IC, that is, a silicon wafer having holes formed therein. It has the feature that positioning is accurate in the environment. Even in the case of this vertical needle, polishing and cleaning work must be performed regularly because the aluminum oxide generated on the aluminum pad adheres to the tip of the needle and a contact failure occurs.
This must be done in the same way as for the ever type.

[0007]

Since the conventional probe device is constructed as described above, when polishing the needle of a vertical needle type probe card, the polishing and cleaning operations cannot be performed efficiently. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and there is provided a polishing wafer used in a wafer prober which is most suitable for polishing the needles of a vertical needle type probe card, and a polishing wafer for the polishing wafer. It is intended to provide and use.

[0009]

According to a first aspect of the present invention, there is provided a polishing apparatus for a probe needle, wherein a polishing wafer made of silicon having a mortar-shaped hole is mounted on a wafer chuck portion.

In the probe needle polishing apparatus according to a second aspect of the present invention, a through hole is provided between the bottom of the mortar-shaped hole and the back side of the polishing wafer.

In the probe needle polishing apparatus according to a third aspect of the present invention, the same number of mortar-shaped holes are provided at the same positions as the pads on the wafer.

According to a fourth aspect of the present invention, there is provided an apparatus for polishing a probe needle, wherein a mortar-shaped hole and a through hole are formed by electric discharge machining.

In the probe needle polishing apparatus according to a fifth aspect of the present invention, the surface of the polishing wafer and the inner surface of the mortar-shaped hole are coated with a hard abrasive such as diamond.

According to a sixth aspect of the present invention, there is provided a probe needle polishing apparatus in which a control program for a wafer prober for performing a polishing operation is combined with a probe card body.

According to a seventh aspect of the present invention, in the method for polishing a probe needle, as a first step, one of the probe needle and the wafer chuck portion is vibrated in a horizontal direction at a portion other than the mortar-shaped hole on the surface of the polishing wafer. In the second step, either the probe needle or the wafer chuck is vibrated in the vertical direction in the mortar-shaped hole to polish.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view for explaining that probing at the time of a wafer test is performed by a probe card using a vertical needle. In the figure, a first guide plate 1 fixes a vertical probe needle 2 and positions And the second guide plate 3 is a vertical probe needle 2
Is positioned on several test pads on the wafer 4. The first guide plate 1 and the second guide plate 3 are integrally formed as a probe card. FIG. 2 is a plan view showing a test pad 5 on the wafer 4.
Position. The wafer 4 includes an IC chip, and the wafer test is performed by bringing the vertical probe needle 2 into contact with the test pad 5.

Generally, the first guide plate 1 and the second guide plate 3 are made of a material having the same coefficient of thermal expansion as the wafer 4 including the IC, that is, a silicon wafer with holes.
It has the feature that positioning is accurate in all temperature environments.
FIG. 3 is a plan view for explaining a polishing wafer 6 for a vertical needle type probe card according to the present invention, and FIG. 4 is a sectional view of the polishing wafer 6 in the same manner. 7 is processed, and the polishing wafer 6
Is mounted on the wafer chuck of the wafer prober. The material of the polished wafer 6 is made of silicon, similarly to the wafer 4. The mortar-shaped hole 7 is formed by fine hole processing of several tens μmφ slightly larger than the tip diameter of the probe needle 2 and having a depth of several tens μm, and is generally made by electric discharge machining. In order to improve the polishing performance and the durability, the inner surface of the mortar-shaped hole 7 is coated with a hard abrasive, such as diamond, which is harder than aluminum oxide.

Next, a method of polishing the tip of the probe needle 2 of the vertical needle type probe card using the polishing wafer 6 according to the present invention will be described with reference to FIGS. FIG. 5 is a sectional view showing a state in which a vertical needle type probe card is set on a polishing wafer 6 in an apparatus such as a wafer prober in order to polish the tip of the probe needle 2, and FIG. FIG. 4 is a plan view showing a hole 7 in a shape. And
As shown in FIGS. 1, 2, 5, and 6, the same number of mortar-shaped holes 7 on the polishing wafer 6 can be formed at the same positions as the pads 5 with which the probe needles 2 make contact. it can.

FIG. 7 is a cross-sectional view for explaining the first step of the polishing operation of the tip of the probe needle 2 of the present invention. In the figure, a portion other than the mortar-shaped hole 7 on the surface of the polishing wafer 6 is shown. FIG. 7 shows a state in which the tip of the probe needle 2 is lightly pressed (this portion is also coated with diamond or the like to improve the polishing performance), as shown by an arrow A in FIG. Then, the probe card side or the polishing wafer 6 side is vibrated in the horizontal direction and polished to remove foreign matter such as aluminum oxide at the tip of the probe needle 2. Generally, this movement is easily achieved by using the movement function of the XY stage of the wafer prober. FIG. 8 is a side view showing an operation of removing a foreign substance 8 such as aluminum oxide attached to the tip of the probe needle 2.

FIG. 9 is a cross-sectional view for explaining the second step of the polishing operation of the tip of the probe needle 2 of the present invention. In the figure, the inside of the mortar-shaped hole 7 provided in the polishing wafer 6 is shown. FIG. 9 shows a state in which the tip of the probe needle 2 is advanced, and as shown by an arrow B in FIG. 9, the probe card side or the polishing wafer 6 side is mainly vibrated in the vertical direction to perform polishing. Chamfering or sharpening the tip of the metal, or removing foreign substances such as aluminum oxide. The shape of the tip of the probe needle 2 is closer to the initial shape than that after polishing shown in FIG. 8, and it is possible to exhibit higher quality contact performance. Generally, this movement is easily achieved by using the movement function of the Z stage of the wafer prober. FIG. 10 is a side view showing the operation of chamfering the tip of the probe needle 2 and the like.

As described above, the use of the polished wafer 6 of the present invention makes it possible to remove the foreign matter adhering to the tip of the probe needle 2 of the vertical needle type probe card, and furthermore, the tip shape to the initial one. It can be worked closer and achieve both higher contact reliability and longer service life.

Embodiment 2 FIG. FIG. 11 shows a polished wafer 6 for a vertical needle probe card according to Embodiment 2 of the present invention.
In the figure, a mortar-shaped hole 7 is formed at a position corresponding to the test pad 5 shown in FIG. 2, and a through-hole 9 connected to the mortar-shaped hole 7 is provided. Thus, the difference from the first embodiment is shown in FIG.
As shown in the figure, the bottom of the mortar-shaped hole 7 is a hole that passes through the plate of the polishing wafer 6 as it is. The size of the through hole 9 is made slightly smaller than the tip diameter of the probe needle 2. The through holes 9 allow the debris generated by the polishing operation of the foreign matter attached to the tip of the probe needle 2 to be discharged through the hot chuck portion of the wafer prober, so that the inside of the probe is less likely to be contaminated with dust. have. This polished wafer 6 is also a wafer 4
Similarly, the material is silicon.

As in the case of the first embodiment, the mortar-shaped hole 7 has a depth of several tens μm slightly larger than the tip diameter of the probe needle 2 and a depth of several tens μm, and penetrates to the back side of the plate. It is generally made by electrical discharge machining for machining holes.
Then, in order to improve the polishing performance and the durability, the inner surface of the mortar-shaped hole 7 is coated with a hard abrasive material harder than aluminum oxide such as diamond. Thus, if the polishing wafer 6 of the present invention is used,
Removal of foreign matter adhering to the tip of the probe needle 2 of the vertical needle type probe card, the tip shape can be processed close to the initial one, realizing both higher contact reliability and longer service life The result is that the inside of the probe is less contaminated with dust.

Embodiment 3 FIG. In recent years, the maintenance work of polishing the tip of the probe needle 2 which has become increasingly fine pitch has become important for preventing contact failure and preventing a decrease in yield. In this regard, the position and number of the probe needles 2 of the probe card are important. Wafer 6 having a mortar-shaped hole 7 depending on
If a control program for a wafer prober for performing a polishing operation using the polishing wafer 6 is attached to the probe card main body and is combined therewith, maintenance work becomes easier.

In the first to third embodiments, the center of the mortar-shaped hole 7 formed in the polishing wafer 6 and the center of the test pad 5 are aligned with each other. In the case of a type in which the tip of the needle slightly deviates from the center coordinate during the vertical movement of the operation, it is better to slightly shift the setting of the polishing wafer 6 to polish the tip of the needle into a conical shape, a shape closer to the initial stage.
Be able to process.

[0026]

According to the probe needle polishing apparatus and the polishing method according to the first and seventh aspects of the present invention, a polishing wafer made of silicon provided with a mortar-shaped hole is mounted on a wafer chuck portion. As a first step, either the probe needle or the wafer chuck portion is oscillated in the horizontal direction at a portion other than the mortar-shaped hole on the surface of the polished wafer, and the second step is a probe needle inside the mortar-shaped hole. Or because it was made to polish by vibrating any of the wafer chuck part in the vertical direction,
The foreign matter adhering to the tip of the probe needle can be easily removed, the shape of the tip can be processed close to the initial shape, and both higher contact reliability and long-term durability can be realized.

According to the probe needle polishing apparatus according to the second aspect of the present invention, since the through hole is provided between the bottom of the mortar-shaped hole and the back side of the polishing wafer, the inside of the probe is contaminated with dust. Less often.

According to the probe needle polishing apparatus of the third aspect of the present invention, the same number of mortar-shaped holes are provided at the same positions as the pads on the wafer, so that the probe needles can be efficiently used. Can be polished.

According to the probe needle polishing apparatus of the fourth aspect of the present invention, since the mortar-shaped hole and the through hole are formed by electric discharge machining, the hole can be easily formed.

According to the probe needle polishing apparatus according to the fifth aspect of the present invention, since the surface portion of the polishing wafer and the internal surface portion of the mortar-shaped hole are coated with a hard abrasive such as diamond, accurate polishing is possible. Can be polished.

According to the probe needle polishing apparatus according to the sixth aspect of the present invention, since the control program for the wafer prober for performing the polishing operation is combined with the probe card main body, the maintenance work for polishing the tip of the probe needle can be performed. It can be done easily.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a probe device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a test pad on a wafer according to the first embodiment of the present invention.

FIG. 3 is a plan view showing a polished wafer according to the first embodiment of the present invention.

FIG. 4 is a sectional view showing a polished wafer according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a probe needle polishing apparatus according to Embodiment 1 of the present invention.

FIG. 6 is a plan view showing a polished wafer according to the first embodiment of the present invention.

FIG. 7 is a sectional view showing a probe needle polishing apparatus according to Embodiment 1 of the present invention;

FIG. 8 is a side view showing the probe needle according to the first embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a probe needle polishing apparatus according to Embodiment 1 of the present invention.

FIG. 10 is a side view showing the probe needle according to the first embodiment of the present invention.

FIG. 11 is a sectional view showing a polished wafer according to a second embodiment of the present invention.

FIG. 12 is a sectional view showing a conventional probe device.

FIG. 13 is a plan view showing a test pad on a conventional wafer.

[Explanation of symbols]

2 probe needles, 4 wafers, 5 test pads, 6
Polished wafer, 7 mortar holes, 9 through holes.

Claims (7)

[Claims] An apparatus for polishing a probe needle, which is pressed against a pad surface on a wafer when performing a wafer test, wherein a polishing wafer made of silicon having a mortar-shaped hole is mounted on a wafer chuck portion. A polishing apparatus for a probe needle, characterized in that: 2. A through hole is provided between the bottom of the mortar-shaped hole and the back side of the polished wafer.
An apparatus for polishing a probe needle according to the above. 3. The probe needle polishing apparatus according to claim 1, wherein the same number of the mortar-shaped holes are provided at the same positions as the pads on the wafer. 4. The probe needle polishing apparatus according to claim 1, wherein the mortar-shaped hole and the through hole are formed by electric discharge machining. 5. The polishing apparatus according to claim 1, wherein a surface portion of the polishing wafer and an inner surface portion of the mortar-shaped hole are coated with a hard abrasive such as diamond.
The polishing apparatus for a probe needle according to any one of the above items. 6. The probe needle polishing apparatus according to claim 1, wherein a control program for a wafer prober for performing a polishing operation is combined with the probe card body. 7. A polishing method using the probe needle polishing apparatus according to any one of claims 1 to 6, wherein
As a first step, either the probe needle or the wafer chuck portion is oscillated in the horizontal direction at a portion other than the mortar-shaped hole on the surface of the polished wafer, and as a second step, the probe needle or the wafer is buried inside the mortar-shaped hole. A polishing method characterized in that polishing is performed by vibrating one of the chuck portions in a vertical direction.