METHOD FOR CLEANING PROBE TIP AND METHOD AND APPARATUS FOR FORMING PROBE TIP INTO CONICAL SHAPE

Abstract

Under the conditions that an abrasive cleaning gel film having an abrasive cleaning gel layer and being configured to be stuck to a surface or a container filled with a viscous fluid or a gel fluid in which fine abrasive grains are mixed and dispersed is attached to a vibrating surface of an ultrasonic transducer, and an axial direction of a probe for test is matched with a vibrating direction of the ultrasonic transducer, a tip of the probe is penetrated to a predetermined depth in the abrasive cleaning gel layer or the viscous fluid in which the fine abrasive grains are mixed and dispersed at a constant speed and then pulled up at a constant speed, whereby the tip of the probe can be formed into a conical shape.

Claims

1. A method and an apparatus for forming a tip of a probe for test into a conical shape, wherein under the conditions that an abrasive cleaning gel film having an abrasive cleaning gel layer and being configured to be stuck to a surface is adhered to a vibrating surface of an ultrasonic transducer and is ultrasonically vibrated, and an axial direction of the probe is matched with a vibrating direction of the ultrasonic transducer, an operation, in which the tip of the probe is penetrated to a predetermined depth in the abrasive cleaning gel layer at a constant speed and then pulled up at a constant speed, is performed one or more times to form the tip of the probe into the conical shape.

2. A method and an apparatus for forming a tip of a probe for test into a conical shape, wherein under the conditions that a container having a shallow bottom is fixed to a vibrating surface of an ultrasonic transducer and is filled with a viscous fluid or a gel fluid in which fine abrasive grains are mixed and dispersed to form a viscous fluid or gel fluid layer therein, and an axial direction of the probe is matched with a vibrating direction of the ultrasonic transducer, an operation, in which the tip of the probe is penetrated to a predetermined depth in the viscous fluid or gel fluid layer at a constant speed and then pulled up at a constant speed, is performed one or more times to form the tip of the probe into the conical shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is an explanatory view of a probe head configuration incorporating a plurality of wire probes as an application example of the present invention.

[0026] FIG. 2 is an explanatory view of a probe-tip-wear example of a probe head incorporating a plurality of wire probes as an application example of the present invention.

[0027] FIG. 3 is a state explanatory view at the start of application for explaining a method and an apparatus of the present invention.

[0028] FIG. 4 is an explanatory view for behavior of abrasive grains within a gel by ultrasonic vibration for explaining the effects of the present invention.

[0029] FIG. 5 is a state explanatory view at the end of application for explaining a method and an apparatus of the present invention.

[0030] FIG. 6 is an explanatory view of a chemical etching method as a conventional method for repairing a conical shape of a tip of a probe.

[0031] FIG. 7 is an explanatory view of a mechanical etching method using an abrasive cleaning gel as a conventional method for repairing a conical shape of a tip of a probe.

[0032] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0033] The embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, FIG. 3, FIG. 4 and FIG. 5.

MODE FOR CARRYING OUT THE INVENTION

[0034] FIG. 1 is an explanatory view of a vertical probe head 13 incorporating a wire probe 1 as an application example of the present invention. In FIG. 1, the wire probe 1 is composed of a cylindrical pin 2, an insulating coating 3 and a tip 4n having a conical shape.

[0035] A plurality of wire probes 1 are incorporated in the vertical probe head 13. A lower side of the wire probe 1 passes through a through hole 6 of a lower aperture plate 5, and an upper side of the wire probe 1, including the insulating coating 3, passes through a through hole 9 of an upper aperture plate 8. In this regard, the insulating coating 3 also serves to prevent the wire probe 1 from falling.

[0036] An upper end of the wire probe 1 is in contact with an upper electrode plate 10 arranged in an orderly manner on a printed circuit board 11. The printed circuit board 11 is fixed to the upper aperture plate 8 by bolts (not shown) via spacers 12a, 12b. Connecting members 7a and 7b connect the upper aperture plate 8 and the lower aperture plate 5.

[0037] The tip 4n of the wire probe 1 shown in FIG. 1 is a new product prior to pad test, and therefore has a sharp conical shape. However, if the tip repeatedly contacts several hundred thousand times with an electrode pad (not shown), the tip is worn and loses its sharp shape as shown in the tip 4w of FIG. 2. If the contact continuity test with the electrode pad is continued in this state, the following problems occur.

[0038] First, debris from the side of the electrode pad adheres to the tip, increasing the contact resistance. Second, since the tip does not have a sharp conical shape no longer, breaking the oxide film (not shown) on the surface of the electrode pad for the good continuity test cannot be performed.

[0039] According to the present invention, it is possible to provide a method for efficiently removing debris (not shown) adhering to the worn tip 4w as described above, and to efficiently restoring the tip shape to the sharp conical shape. Hereinafter, the configurations, operations and effects of the device for realizing the present invention will be described with reference to FIGS. 3, 4, and 5.

[0040] In FIG. 3, the abrasive cleaning gel 14 is composed of a fluid 16 which is in the form of a gel with abrasive grains 15 held densely. The abrasive cleaning gel 14 is supported by a support film 17, and further, an adhesive layer 18 is provided on a back surface of the support film 17. Thus, a protective film (not shown) of the adhesive layer 18, the adhesive layer 18, the support film 17 and the abrasive cleaning gel 14 constitute an abrasive cleaning gel film 19 which is commercially available.

[0041] The abrasive cleaning gel film 19 is attached to an upper surface of an ultrasonic diaphragm 20. A plurality of plate-mounted ultrasonic transducers 21 are provided on a lower surface of the ultrasonic diaphragm 20. Both ends of the ultrasonic diaphragm 20 are fixed to a mounting base 22 by bolts (not shown).

[0042] Each of the plate-mounted ultrasonic transducers 21 is supplied with an energy and a signal of ultrasonic vibration from an ultrasonic oscillator 24 via a cable 23, so that the ultrasonic diaphragm 20 is vibrated in a direction indicated by an arrow 25.

[0043] When the vertical probe head 13 moves up and down at a constant speed in the directions of the arrows 26 and 27, the worn tip 4w is regenerated into a sharp conical shape. The operation will be described with reference to FIG. 4.

[0044] In FIG. 4, when the abrasive cleaning gel 14 vibrations ultrasonically in the direction of the arrow 25, the abrasive grains 15 also vibrate ultrasonically in a direction indicated by an arrow 28. Due to the ultrasonic vibration of the abrasive grains 15, the tip of the wire probe 1 is subjected to repeated collisions with the abrasive grains 15, and is subjected to the mechanical etching.

[0045] When the wire probe 1 is moved up and down in the directions of the arrows 26 and 27 at the constant speed, the closer to the tip of the probe 1, the higher the frequency of the mechanical etching. That is, the tip 4w is repaired to have the conical shape. Thus, as shown in FIG. 5, the tip of the probe is repaired to have the sharp conical shape as shown in 4r of FIG. 5.

[0046] The vibration amplitude and the frequency of the ultrasonic vibration 25 are 30 microns (both amplitudes) and 25 kHz, respectively even when a general commercially available ultrasonic transducer is used. The vibration speed of the ultrasonic vibration is calculated in order to show the effect of the present invention.

[0047] Since the ultrasonic vibration is sinusoidal, the effective speed is expressed as V=r/(2). Thus, the effective speed is

V=0.015 mm225,000/sec/(2)=1,665 mm/sec=about 100 m/min.

[0048] Comparing the above speed with a speed of general whetstone polishing, it is comparable to high-speed polishing. That is, the speed of the mechanical etching according to the present invention is high, and the highly efficiency mechanical etching is possible.

[0049] The embodiment of the present invention has been described with emphasis on repairing the worn tip of the probe. However, the abrasive cleaning gel 14 is also used for cleaning debris adhered to the tip of the probe. Since the present invention has the high efficiency mechanical etching feature, it is possible to reliably remove the debris in a short time even in the cleaning of the debris fixed to the tip of the probe.

[0050] The effects of the present invention are summarized below. [0051] (1) It is possible to repair a shape of a tip of a probe made of a rare metal which is difficult to be chemically etched. [0052] (2) The chemical etching leading to environmental pollution is unnecessary. [0053] (3) It is possible to clean the tip of the probe and restore the shape of the tip in a short time by the mechanical etching using high-speed and high-efficiency ultrasonic vibration. As a result, the downtime of the expensive prober is reduced, which contributes to cost reduction and operation rate improvement of the semiconductor test process.

EXPLANATION OF REFERENCE NUMERALS

[0054] 1 Wire probe [0055] 2 Pin [0056] 3 Insulating coating [0057] 4n Tip before wear out [0058] 4w Worn tip [0059] 4r Shape-repaired tip [0060] 5 Lower aperture plate [0061] 6 Through hole [0062] 7a, 7b Connecting member [0063] 8 Upper aperture plate [0064] 9 Through hole [0065] 10 Upper electrode plate [0066] 11 Printed circuit board [0067] 12a, 12b Spacer [0068] 13 Vertical probe head [0069] 14 Abrasive cleaning gel [0070] 15 Abrasive grains [0071] 16 Fluid in gel form [0072] 17 Support film [0073] 18 Adhesive layer [0074] 19 Abrasive cleaning gel film [0075] 20 Ultrasonic diaphragm [0076] 21 Plate-mounted ultrasonic transducer [0077] 22 Mounting base [0078] 23 Cable [0079] 24 Ultrasonic oscillator [0080] 25 Ultrasonic vibration [0081] 26 Arrow [0082] 27 Arrow [0083] 28 Ultrasonic vibration of abrasive grains [0084] (29 to 50: Missing number) [0085] 51 Probe [0086] 51w Probe requiring regeneration [0087] 52 (Missing number) [0088] 53 Straight pin [0089] 54 Conical shape of tip [0090] 54w Worn tip cone [0091] 54r Regenerated conical tip [0092] 55 Table [0093] 56 Container [0094] 57 Chemical etchant [0095] 58 Arrow [0096] 59 Arrow [0097] 60 Abrasive cleaning gel [0098] 61 Abrasive grains [0099] 62 Fluid in gel form [0100] 63 Support film [0101] 64 Adhesive layer [0102] 65 Abrasive cleaning gel film [0103] 66 Arrow