JP2003300131A - Method and device for fine processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suggest a method and a device for fine processing relating to a fine processing technique using abrasive grains capable of especially processing a fine shape, and finishing a fine processing part having a complicated shape into a high quality face. <P>SOLUTION: According to the method and device for fine processing, a fine tool having a spherical tip end is used as an electrode, and the other electrode is placed at a bottom part of a workpiece. A liquid composition obtained by dispersing grind grains having an electric inductivity of 0.1-30 μm grain diameter in a solvent which is mainly composed of silicone oil having a viscosity of 1-1,000 cSt at 20°C is arranged between the tip of the fine tool and the workpiece under a close contactless condition. The fine tool is rotated at high speed and the grind grains are rolled and processed under such a condition that the grind grains are orientated while an alternating current with 0.3-5 kV/mm electric field strength and 0.1-100 Hz frequency is applied. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine processing technique using abrasive grains, and particularly to a fine processing method and a fine processing method capable of finishing a fine processed portion having a complicated shape into a high quality surface. Regarding the device.

[0002]

2. Description of the Related Art Microfabrication technology, which has grown to a high degree with the progress of semiconductor manufacturing technology, has come to be required in the manufacturing technology process of sophisticated industrial products. However, since the microfabrication technology requires a clean room in the manufacturing line and uses a more expensive semiconductor manufacturing apparatus, the initial investment and the operation and maintenance cost are also factors that increase the product price and impact the environment. However, until now, no fine processing technology has been provided to create a useful technology that can eliminate these and to lead to an inexpensive product. Further, if the sample is glass, processing with a diamond tool is appropriate, but the diamond tool is also expensive as a tool. Therefore, there is a current situation in which fine tools are not yet provided.

[0003]

An apparatus for holding and processing abrasive grains by a fine tool under an alternating high-voltage electric field can provide a fine processing apparatus which can be constructed in a small size. In other words, the processing environment and incidental facilities are an environment-friendly microfabrication method because the method is maintained from the method of maintaining the entire room with a good cleanness to the surrounding area where the device is mounted.

[0004]

The present invention has been proposed in view of the above, and a fine tool having a spherical tip is used as an electrode, and the other electrode is arranged at the lower part of a workpiece, and the tip of the fine tool is A silicone oil whose main component is a solvent having a viscosity of 1 to 1,000 cSt at 20 ° C. and a particle size of 0.1 to 3
A liquid composition in which abrasive grains having an electrical dielectric property of 0 μm are dispersed is arranged, and the electric field strength is ± 0.3 to 5 kV / mm and the frequency is 0.1.
It is a fine processing method characterized by rotating the fine tool at a high speed in a state in which the abrasive grains are oriented while applying an alternating electric field of 1 to 100 Hz to roll the abrasive grains for processing. Especially at the beginning, after applying a high frequency AC high voltage of 20Hz or more and 100Hz or less to adjust the position of the fine tool and the surface of the work part, the applied frequency is changed to 0.1 to 20Hz and the fine tool is operated at high speed. The method of rotating is desirable.

Further, according to the present invention, a fine tool having a spherical tip is integrally attached to a Z-axis table as an electrode, and the other electrode is an XY axis table, and the tip of the fine tool is X-axis.
-A solvent that is arranged in a non-contact manner on the Y-axis table, is movable and rotatable in the Z-axis direction, and is a solvent between the workpiece and the tip of the fine tool placed on the XY-axis table. The main component of is a silicone oil having a viscosity of 1 to 1,000 cSt at 20 ° C., and supplies a liquid composition in which abrasive grains having an electrical dielectric property of a particle diameter of 0.1 to 30 μm are dispersed in this solvent. The electric field strength between the electrodes is ± 0.3 to 5 kV / mm, and the frequency is 0.
The present invention also proposes a microfabrication device characterized by being capable of microfabrication by applying and controlling an AC electric field of 1 to 100 Hz.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid composition used in the present invention comprises the following solvent and abrasive grains. The solvent is 1 to 20 ° C.
A silicone oil having a viscosity of 1,000 cSt is used as a main component. Abrasive particles are insulating particles, semiconductor particles, and metal particles having a particle size of 0.1 to 30 μm and having electrical dielectric properties, and those having a particle size smaller than that depending on the processing width (1 to 50 μm) are used. . Regarding the electrical dielectric property of the abrasive grains, it is desirable that the relative permittivity of the abrasive grains is one or more larger than the relative permittivity of the solvent. As a result, a force is exerted (induced) on the abrasive grains due to the electric field gradient provided in the liquid composition. Since these abrasive grains are required to have workability (polishing / grindability), those having a hardness equal to or higher than the hardness of the work piece or having a mechanochemical action with the work piece are used. . Specifically, diamond, corundum, emery, garnet, silica stone, calcined dolomite,
Fused alumina, artificial emery, silicon carbide, zirconium oxide, cubic boron nitride cBN, etc., or chromium oxide or silicon oxide used for mechanochemical polishing, iron oxide, calcium oxide, magnesium oxide, cerium oxide, magnesium carbide, carbonic acid. Examples include barium. Then, the abrasive grains are mixed in the solvent and uniformly dispersed by an ultrasonic disperser or the like to obtain a liquid composition.

The AC electric field applied in the present invention has an electric field strength of ± 0.3 to 5 kV / mm, a frequency of 0.1 to 100 Hz,
The waveform is a square wave or a sine wave that swings positively and negatively when the rising is repeated at 30 to 500 V / μsec. If the applied frequency is less than 0.1 Hz, the abrasive grains may settle, and if the applied frequency exceeds 100 Hz, the abrasive grains cannot respond to the frequency and cannot move.

The fine tool used in the present invention has its tip used as a rotating electrode, and its material is not particularly limited. For example, a tungsten alloy system or cB is used.
It is possible to use a superhard material such as N material, a brittle material having conductivity, a conductive plastic, a copper alloy that advances processing while holding abrasive grains, and hardened steel. Further, the tip of this fine tool is formed to have a spherical shape. Further, although this fine tool is used as a rotary electrode, specifically, for example, an equipment mechanism such as an air spindle is attached, and the rotation speed at that time is 5,000 to 100,
It is desirable to set it to about 000 rpm.

The other electrode for the rotating electrode which doubles as the fine tool is arranged at the lower part of the workpiece, and this electrode is used as an XY axis table, and the vertical direction is the Z axis to move the fine tool. It may be controlled. The XY axis table may be a fixed electrode or a rotatable electrode.

In order to carry out the fine machining method of the present invention using such materials and equipment, the fine tool and the workpiece are arranged in close proximity and in a non-contact manner. (Z-axis direction distance) is the processing width (0.5 to 50μ)
m), which can be adjusted by, for example, attaching a CCD camera (100 to 1000 times) to a magnifying glass, photographing from the side of the micro tool, and attaching the micro tool integrally while displaying it on the monitor. Fine adjustment of the Z-axis table may be used to adjust to the set distance. Alternatively, a laser displacement meter may be provided. Of course, the liquid composition having the above composition is disposed between the fine tool and the workpiece. When the processed shape is a concave depression, it is desirable to arrange the fine tools in parallel (perpendicularly) to the Z-axis as shown in FIG. 2, but a linear shape with a uniform depth line width, etc. When forming an arbitrary concave portion, it is desirable to arrange the fine tool with an inclination of 10 to 80 degrees (80 to 10 degrees with respect to the Z axis) as shown in FIGS. That is, in the rotation of the fine tool, the peripheral speed becomes 0 at the center position in the arrangement as shown in FIG. 2 and the rolling operation of the abrasive grains is performed by the rotation other than the center, but the arrangement as shown in FIG. 1 and FIG. Then, the rolling operation of the abrasive grains can be exerted on the whole.

First, an AC high voltage having a high frequency of 20 Hz or more and 100 Hz or less is applied to cause the abrasive grains in the liquid composition to resonate, and between the electrodes (between the upper rotating electrode and the lower electrode), the The movement exhibits a slight vibration, becomes an orientation state, and the abrasive grains are held at the tip of the fine tool to prepare for processing. Here, the Z-axis table integrally attached with the fine tool is finely adjusted to reduce the distance between the electrodes.

Next, when the fine tool is rotated at a high speed and the applied frequency is changed to 0.1 to 20 Hz, the abrasive grains in the liquid composition actively move between the electrodes. That is, the tip of the fine tool, which is the rotating electrode, can be finely processed while holding the abrasive grains. In this fine processing, the centrifugal force generated by the rotation of the fine tool also gives a force to scatter the abrasive grains, but the Coulomb force is generated by the electric field and the abrasive grains that are the dielectric material do not scatter and are generated by the machining. Only scraps can be ejected out of the electric field by centrifugal force.
That is, it is a particularly effective processing method as a processing method that does not like the scattering of abrasive grains. Further, in this fine machining, the tip of the fine tool always maintains a non-contact state with the work piece, and since the work is done by the abrasive grains, friction is generated as in the case where the tool is brought into contact with the work piece. It does not generate heat and can perform more precise processing.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The microfabrication apparatus shown in FIG. 1 is an example in which an XY axis table 1 on which a slide glass, which is a workpiece 2, is placed is used as a lower fixed electrode. As the fine tool 4, a tungsten carbide type super hard material (super hard WC) was used, and the tip thereof had a spherical shape of R0.5 (diameter 1 mm) to serve as the upper rotating electrode. The distance between the workpiece 2 and (the tip of) the fine tool 4 can be adjusted with the Z-axis table 6 by attaching a magnifying glass to the CCD camera. In addition, cerium oxide that exhibits a mechanochemical effect on glass is used as abrasive grains having electrical dielectric properties, and cerium oxide having an average particle size of 5 to 10 μm is contained in silicone oil (solvent) having a viscosity of 100 cSt at a concentration of 30 wt %, And carefully dispersed with an ultrasonic disperser to obtain Liquid Composition 3. In addition, XY
A linear motor or the like may be used to rotate the shaft table 1, and a fine movement method may be finely moved using a piezoelectric element or the like. Further, regarding the θ-axis feed mechanism 7 used when a linear groove is machined as shown in FIG. 3, a fine tool (the tip thereof) 4 is angled and fixed using a motor, and reciprocated in the X-axis direction. A linear fine groove can be created by the movement. Further, the Z-axis feed mechanism 9 is configured such that coarse movement is performed by a motor and fine movement is performed by using a piezoelectric element. The precise feed here is a particularly important mechanism because it reflects the processing accuracy of the groove width to be created.

First, the distance between the tip of the fine tool 4 and the workpiece 2 is set to 40 μm using a CCD camera, and the upper rotary electrode (= tip of the fine tool 4) and the lower fixed electrode (= XY).
After dropping the liquid composition 3 between the axis table 1),
As an applied electric field, the frequency is 20 Hz from the AC high-voltage power supply 8 supplied,
Electric field strength ± 3.0 kV / mm AC high voltage is applied to promote the orientation of the abrasive grains in the liquid composition 3, and then the Z-axis feed mechanism 9 of the precision Z-axis table 6 is used (the tip of the fine tool). The distance between 4 and the workpiece 2 was narrowed by 10 μm. Next, the fine tool (the tip thereof) 4 was rotated by the air spindle 5 at 60,000 rpm for 1 minute for processing. The abrasive grains are held by (the tip of) the fine tool 4 by the electric field of 0.5 to 1.5, the scattering of the abrasive grains by the centrifugal force is suppressed, and only the processing waste is ejected out of the electric field.
A situation was observed in which processing was accelerated. The evaluation after processing was performed with an inverted microscope. The recesses obtained from this processing experiment are
It was possible to create a microfabricated portion having a bottom surface diameter of 10 μm and a top surface diameter of about 30 μm. Further, as shown in FIG. 3, when the θ-axis feed mechanism 7 is driven, the fine tool 4 has an angle, the fine tool 4 is rotated, and the XY axis table 1 is reciprocally moved in the front-rear direction, Due to the difference, a relative velocity was generated in the abrasive grains, and it was observed that the rolling motion worked and the processing proceeded.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be implemented in any manner as long as the configuration described in the claims is not changed.

[0016]

As described above, according to the fine machining method of the present invention, the arrangement of the abrasive grains can be controlled and held at the tip of the fine tool by the electric field, and the centrifugal force generated by the rotation of the tool. It is possible to suppress and maintain the scattering of the abrasive grains by the electric field, and further, the self-dressing and impact force processing can be promoted by the movement of the abrasive grains generated when the electric field polarity of the abrasive grains is switched. Further, the microfabrication apparatus of the present invention can realize downsizing of the apparatus, easily suppress accuracy compensation, and realize an apparatus with high processing accuracy and low cost. Then, there is a possibility that the scale of equipment installation for realizing the processing environment can be greatly reduced from the current level.

[Brief description of drawings]

FIG. 1 is a schematic view of a microfabrication device used in an example.

FIG. 2 is a schematic schematic view in which a state between a fine tool and a workpiece when engraving is enlarged and shown.

FIG. 3 is a schematic diagram showing an enlarged view of a state between a fine tool and a workpiece when the fine tool has an angle when performing linear groove machining.

[Explanation of symbols]

1 X-Y axis table 2 Work piece (slide glass) 3 Liquid composition 4 fine tools 5 Air spindle 6 Precision Z-axis table 7 θ-axis feed mechanism 8 supply AC high voltage power supply 9 Z-axis feed mechanism

Claims (2)

[Claims] 1. A fine tool having a spherical tip is used as an electrode, the other electrode is arranged under a workpiece, and while the tip of the fine tool and the workpiece are arranged in close proximity to each other, The main component of the solvent is silicone oil having a viscosity of 1 to 1,000 cSt at 20 ° C., and the particle size of the solvent is 0.1 to 3
A liquid composition in which abrasive grains having an electrical dielectric property of 0 μm are dispersed is arranged, and the electric field strength is ± 0.3 to 5 kV / mm and the frequency is 0.1.
A fine machining method characterized in that the fine tool is rotated at a high speed in a state in which the abrasive grains are oriented while applying an alternating electric field of 1 to 100 Hz to roll the abrasive grains for machining. 2. A fine tool having a spherical tip at the tip is integrally attached to a Z-axis table as an electrode, and the other electrode is X-
The Y-axis table is used, and the tip of the fine tool is arranged on the XY-axis table in a non-contact manner so as to be movable and rotatable in the Z-axis direction, and the workpiece placed on the XY-axis table. Between the tip of the micro tool and the tip of the fine tool is a silicone oil having a viscosity of 1 to 1,000 cSt at 20 ° C.
The solvent was supplied with a liquid composition in which abrasive grains having a particle size of 0.1 to 30 μm and having an electric dielectric property were dispersed, and an electric field intensity of ± 0.3 to 5 kV / mm and a frequency of 0.1 to between electrodes. A microfabrication device capable of performing microfabrication by applying and controlling an AC electric field of 100 Hz.