JP2007167969A - Scratch machining method and machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scratch machining method and machining device, forming a groove pattern at a level of several nm on the surface of a work, and performing polishing in a comparatively short time to be advantageous in cost. <P>SOLUTION: In this scratch machining method, a work (a sample 1) is fixed to a support bed 2, a polishing turning tool is confronted with the sample 1, and a magnetic polishing liquid 4 is supplied to a narrow gap between them. Non-magnetic abrasive is mixed with the magnetic polishing liquid 4 and a thickener such as α-cellulose is mixed. The polishing turning tool 3 is provided with a permanent magnet 31 opposite to the sample 1, and caused to perform motion in a predetermined locus on a plane by a driving means. A motion table 8 interlocking with the support bed 2 starts the motion in a reverse phase, thereby moving the sample 1 side in a reverse phase. The polishing liquid flows to enter mixing state, so that magnetic clusters generated by a magnetic field of the permanent magnet 31 press abrasives, the abrasives grind the surface of the sample 1 by relative motion to thereby suitably form a fine groove pattern. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a scratch processing method and a processing apparatus for forming a fine groove pattern on the surface of a processing target. More specifically, the present invention relates to a polishing tool facing a processing target and the periphery thereof. The present invention relates to an improvement in performing fluid polishing in the presence of a magnetic polishing liquid.

  In recent years, attention has been focused on a technique called a micro electro mechanical system, so-called MEMS (Micro Electro Mechanical Systems), and research and development have been actively promoted.

  MEMS generally refers to a small functional element that scales down a mechanical system to a minimum level, and that includes all components including an electronic circuit within a size of a sand grain. For example, there are devices including mechanical parts that physically move inside a semiconductor, such as a motor on a semiconductor, and the technical concept from electronics is central. In addition, MEMS refers to a wide range of technologies, and can be expected to be applied to a wide range of fields such as biotechnology, medical care, environmental analysis, automobiles, scientific plants, and information processing equipment.

  Regarding this MEMS, mechanical processing is performed on constituent materials such as machine element parts. For example, a thin film (magnetic film) of a permanent magnet is grown as a constituent material for using magnetism, a process is performed to scratch the surface of the magnetic film, and anisotropy is given along the direction of the scratch. Things have been done. That is, a groove pattern of about several μm is processed by digging in a linear shape with a needle like material on the magnetic film, which is called a scratch. Specifically, patterning using an electron beam has been attempted for this scratch processing.

  However, such conventional scratch processing techniques have the following problems. Patterning with an electron beam has a problem that processing takes time and costs increase. In addition, as in other fields of electronics technology, there is always a demand for miniaturization and miniaturization of devices even in MEMS. For this reason, about scratch processing, a groove of about several nm, that is, processing of several nm level is required.

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and the object is to form a groove pattern of several nanometers on the surface to be processed, to perform polishing in a relatively short time, and to reduce costs. An object of the present invention is to provide a scratch processing method and a processing apparatus therefor.

  In order to achieve the above-described object, the scratch processing method according to the present invention makes a fine groove by causing a polishing bite to face a processing target and performing fluid polishing in the presence of a magnetic polishing liquid around these tools. A scratch processing method for forming a pattern, wherein the polishing tool is provided with a magnetic field generating source for generating a magnetic field facing the processing object, and the magnetic polishing liquid is present between the polishing tool and the processing object. In this case, nonmagnetic abrasive grains are mixed, and either a polishing tool or an object to be processed is moved by a driving means that drives the moving motion of a predetermined locus on a plane, and at this time, a magnetic field is generated. A fine groove pattern was formed by fluid polishing by applying a temporally or fluctuating magnetic field to the magnetic polishing liquid by a source.

  Two driving means may be linked to each of the polishing tool and the object to be processed, and both the polishing tool and the object to be processed may be moved in opposite phases.

  Further, the scratch processing apparatus according to the present invention includes a polishing tool having a magnetic field generation source facing the processing object, a driving unit that performs a motion operation of a predetermined locus on a plane, the polishing tool, and the processing object. Supply means for supplying the magnetic polishing liquid to the gap between them, the driving means is linked to either the polishing tool or the object to be processed, the magnetic polishing liquid is mixed with non-magnetic abrasive grains, and the supply means is The magnetic polishing liquid is present between the polishing tool and the object to be processed, and the driving means is activated to cause either the polishing tool or the object to be processed to move in a predetermined path on the plane. Therefore, the magnetic polishing liquid is configured to apply a magnetic field that is constant or variable in time. And it is good to set it as the structure which makes two drive means, links | links with each of a grinding | polishing tool | tool, and each process object, and carries out the movement operation | movement of both a grinding | polishing tool | tool and a processing object in mutually opposite phases.

  The magnetic polishing liquid used in each invention is based on a fluid in which 10 to 95 wt% of ferromagnetic particles having a particle diameter of 1 to 800 μm are dispersed in a dispersion medium such as water or kerosene having a kinematic viscosity of about 0.01 to 100 mm 2 / s. In addition, spherical magnetite particles having a particle diameter of 10 to 50 nm are mixed with a composite fluid in which 5 to 90 wt% of a fluid uniformly dispersed in a dispersion medium such as water or kerosene having electrical insulation properties is mixed with a particle diameter of 0.01 to 100 μm. The non-magnetic abrasive grains are mixed, and a fibrous substance such as α-cellulose or a resin such as polyvinyl alcohol is mixed as a thickener in an amount of 5 to 90 wt%.

  Therefore, in the present invention, the polishing tool has a magnetic field generation source, and basically, either the polishing tool or the object to be processed performs a motion motion of a predetermined locus on the plane by the driving means. A magnetic polishing liquid exists between the polishing tool and the object to be processed. The magnetic polishing liquid contains non-magnetic abrasive grains, and a magnetic field generation source applies a time-dependent or variable magnetic field to the magnetic polishing liquid. Then, magnetic clusters are generated in the magnetic polishing liquid. Specifically, in the composition as described above, a large number of ferromagnetic particles (for example, iron particles) and magnetite particles are aggregated by a magnetic attractive force to form a magnetic cluster. Since the magnetic cluster is along the magnetic flux, a large number of needles stand in opposition to the object to be processed, whereby the abrasive grains present in the magnetic polishing liquid are pressed against the surface of the object to be processed. In addition, since there are abrasive grains entangled in the magnetic cluster, they are also pressed against the surface to be processed.

  In this state, the polishing tool and the object to be processed move relative to each other, whereby the abrasive grains move while contacting the surface of the object to be processed. For this reason, the abrasive grains are ground on the surface to be processed, and a fine groove pattern can be formed.

  In addition, when two drive means are used to move both the polishing tool and the object to be processed in opposite phases to each other, the relative movement between the two increases, which increases the polishing speed and further increases the time required for scratch processing. Can be shortened.

  The shape of the groove pattern corresponds to the motion movement of a predetermined locus on the plane by the driving means. For example, in a reciprocating linear motion, a large number of straight lines can be formed in parallel. And since scratch processing is grinding with abrasive grains in magnetic polishing liquid, the groove pattern width and depth depends on the conditions of fluid polishing such as abrasive grain diameter, magnetic polishing liquid concentration, magnetic field strength and processing time. Can be adjusted and controlled by appropriately setting. Further, since this scratch processing is grinding with abrasive grains in a magnetic polishing liquid, unlike the patterning with an electron beam, the processing is performed at a high speed, and an expensive device such as an electron beam generator is not required.

  In the scratch processing according to the present invention, basically, either the polishing tool or the object to be processed performs a motion movement of a predetermined locus on the plane by the driving means, and therefore, due to the action of the magnetic cluster generated in the magnetic polishing liquid. Fluid polishing can be performed to form a fine groove pattern. Since this scratch processing is grinding with abrasive grains in the magnetic polishing liquid, the width and depth of the groove pattern can be adjusted and controlled by appropriately setting the conditions of the fluid polishing. Further, since this scratch processing is grinding with abrasive grains in the magnetic polishing liquid, the processing is performed at a high speed, and an expensive apparatus such as an electron beam generator is not required. As a result, a groove pattern with a level of several nanometers can be appropriately formed on the surface to be processed, and polishing can be performed in a relatively short time, thereby reducing the cost.

  FIG. 1 shows a preferred embodiment of the present invention. The scratch processing apparatus according to the present embodiment fixes a processing target (sample 1) to a support base 2 and causes a polishing tool 3 to face the sample 1 in a non-contact manner, and a magnetic polishing liquid between them. 4 is provided, and the polishing tool 3 is caused to generate a magnetic field and move along a predetermined locus. The support base 2 is configured to perform a predetermined trajectory movement in reverse phase, fluidly polish with a magnetic cluster generated in the magnetic polishing liquid 4, and form a fine groove pattern.

  The magnetic polishing liquid 4 contains nonmagnetic abrasive grains. Specifically, the particle diameter of a fluid in which 10 to 95 wt% of ferromagnetic particles having a particle diameter of 1 to 800 μm are dispersed in a dispersion medium such as water or kerosene having a kinematic viscosity of about 0.01 to 100 mm 2 / s. Non-magnetic particles having a particle diameter of 0.01 to 100 μm in a composite fluid in which 5 to 90 wt% of a fluid in which spherical magnetite particles of 10 to 50 nm are uniformly dispersed in a dispersion medium such as water or kerosene having electrical insulation properties are mixed. Abrasive grains are mixed, and a fibrous material such as α-cellulose or a resin such as polyvinyl alcohol is mixed as a thickener in an amount of 5 to 90 wt%. The magnetic polishing liquid 4 is supplied to a space between the sample 1 and the polishing tool 3 by a supply means (not shown).

  The support 2 is assembled to the base 7 of the traverse device 6 via the spring screw 5. The traverse device 6 is assembled to the exercise table 8. A contact-type load cell 9 is disposed at the site of the spring screw 5. That is, by moving the base 7 of the traverse device 6, the vertical position of the support base 2 is initially set, and the movement of the predetermined trajectory is given by the exercise base 8, for example, reciprocating at a predetermined amplitude on the surface opposite to the polishing tool 3. A motion operation such as (vibration) is given, and the operation state is detected by the load cell 9.

  A polishing tool 3 is directed toward the support base 2 from above, and the polishing tool 3 is linked to a drive motor 10 to drive it. The drive motor 10 may be a drive mechanism such as a drilling machine, a lathe, an NC lathe, or a milling machine, and the shaft portion of the polishing tool 3 is attached to the chuck portion 11 connected to the output shaft. Thereby, the grinding tool 3 is configured to be attachable to and detachable from the chuck portion 11 (drive motor 10).

  In the polishing tool 3, a permanent magnet 31 is concentrically embedded in a cylindrical body 30 made of a nonmagnetic material, and the permanent magnet 31 faces the sample 1 (processing object). That is, the permanent magnet 31 acts as a magnetic field generating source that generates a magnetic field by acting a magnetic field on the magnetic polishing liquid 4 between the facing sample 1. The magnetic field generation source is not limited to the permanent magnet 31, and for example, an electromagnet can be preferably applied as long as it can act on the magnetic polishing liquid 4. The generation of the magnetic field does not need to be stationary in time, and may generate a magnetic field that varies in time.

  The exercise table 8 has a drive source (not shown) and is configured to move along a predetermined locus on the surface opposite to the polishing tool 3. A plurality of exercise modes are set for the exercise operation. There are a plurality of motion modes, such as a motion motion that reciprocates in a fixed direction and a motion motion that simply rotates around a fixed point on the surface opposite to the shaft portion of the polishing tool 3, and the motion motion by the motion table 8 is polishing. In the work, it is appropriately selected according to the fine groove pattern that requires processing. Further, the exercise table 8 is adapted to perform an exercise operation in a phase opposite to the exercise operation on the polishing tool 3 side.

  In order to polish the sample 1, first, the sample 1 is fixed to the support base 2, and the positional relationship of the sample 1 with respect to the upper polishing tool 3 is initially set. Then, the supply of the magnetic polishing liquid 4 to the gap between them is started, and then the drive motor 10 and the exercise table 8 are started, and both the polishing tool 3 and the sample 1 (support table 2) are reversed in phase. The magnetic polishing liquid 4 is brought into a stirring state. At this time, a magnetic field is applied to the magnetic polishing liquid 4 by a magnetic field generation source (permanent magnet 31), and a magnetic flux is generated between the sample 1 and the polishing tool 3 as shown in FIG. A magnetic cluster 12 is generated.

  In other words, since the permanent magnet 31 is embedded in the polishing tool 3, a magnetic field acts, a magnetic flux is generated between the permanent magnet 31 and the sample 1, and ferromagnetic particles (for example, iron particles) and magnetite particles are attracted by magnetic attraction. Many aggregate to form magnetic clusters 12. Since the magnetic cluster 12 is along the magnetic flux, a large number of needles are arranged in opposition to the sample 1. In the magnetic polishing liquid 4, α-cellulose 13 added as a thickener occupies a position in a woven state between the magnetic clusters 12, and further, nonmagnetic abrasive grains 14 are added. Some are entangled, but many of them are present on the surface of the sample 1 because the liquid is in a stirred state. Therefore, the abrasive grains 14 present in the magnetic polishing liquid 4 are pressed against the surface of the sample 1 by the magnetic clusters 12 arranged in a needle shape and the α cellulose 13 in a woven state. In addition, since there are abrasive grains 14 entangled in the magnetic clusters 12 and α-cellulose 13, they are also pressed against the surface of the sample 1.

  In this state, both the polishing tool 3 and the sample 1 (support base 2) move in opposite phases, so that the abrasive grains 14 move while contacting the surface of the sample 1 due to relative movement. The surface of 1 can be ground by the abrasive grains 14 to form a fine groove pattern. That is, scratch processing can be performed.

  When the magnetic field is stationary, the magnetic clusters 12 stand in line along the magnetic flux, and the alignment state is maintained by the magnetic force, so that the abrasive grains 14 can hit the surface (polishing surface) of the sample 1 appropriately to perform polishing. Further, when the magnetic field is fluctuating, the magnetic cluster 12 swings, and at this time, the abrasive grains 14 hit the polishing surface appropriately and can be polished. Thus, although the polishing tool 3 does not have an apparently effective grinding blade with respect to the sample 1, it can be polished by the pressing action of the magnetic cluster 12 and the α cellulose 13, and a fine groove pattern can be formed by fluid polishing. Formation can be performed.

  Since the magnetic polishing liquid 4 contains α-cellulose 13 as a thickener, the added thickener acts to hold the magnetic cluster 12, and as a result, many abrasive grains 14 come into contact with the surface of the sample 1. The situation can be promoted and polishing can be performed with high efficiency.

  In the present embodiment, both the polishing tool 3 and the sample 1 (support base 2) are moved in opposite phases, but only one of them may be moved. That is, the exercise table 8 may be removed, the sample 1 side may be fixed without being moved, and only the polishing tool 3 may be moved.

  The shape of the groove pattern corresponds to the motion movement of a predetermined locus on the plane by the driving means. For example, in a reciprocating linear motion, a large number of straight lines can be formed in parallel. Since the scratch processing is grinding with the abrasive grains 14 in the magnetic polishing liquid, the width and depth of the groove pattern are determined by the fluid size such as the particle diameter of the abrasive grains 14, the concentration of the magnetic polishing liquid 4, the strength of the magnetic field, and the processing time. It can be adjusted and controlled by appropriately setting the polishing conditions.

  In addition, since this scratch processing is grinding with the abrasive grains 14 in the magnetic polishing liquid, the processing is fast unlike the patterning by the electron beam, and an expensive device such as an electron beam generator is not required, and the cost is reduced. There is an advantage. Of course, since the polishing is performed by the magnetic cluster 12, the sample 1 can be polished without applying a large stress.

  That is, according to the scratch processing according to the present invention, grinding can be performed by the abrasive grains 14 in the magnetic polishing liquid, and as a result, a groove pattern of several nanometers can be appropriately formed on the surface to be processed. Since processing can be performed in a relatively short time, cost reduction can be achieved. Thereby, for example, a culture path such as a biomemory can be easily made.

  The sample was polished using the scratch processing apparatus shown in FIG. That is, in order to demonstrate the effect of the present invention, the sample (1) was polished under predetermined polishing conditions, and the scratch state of the sample (1) was evaluated. The magnetic polishing liquid (4) had the composition shown in Table 1, and the evaluation test was performed in a form in which the polishing tool (3) was simply rotated.

  Here, the magnetic polishing liquid (4) contains alumina having a particle diameter of 0.05 μm as nonmagnetic abrasive grains (14) and α-cellulose (13) as a thickener. The sample (1) was a boric acid glass (BK7) flat plate with dimensions of 10 mm in length, 10 mm in width, and 3 mm in thickness. The permanent magnet (31), which is a magnetic field generation source, had a cylindrical shape with a diameter of 5 mm and a height of 8 mm, and this was opposed to the sample (1) at an interval of 1 mm. The polishing tool (3) was operated for 5 minutes at a rotation speed of 500 rpm while supplying the magnetic polishing liquid (4) between the sample (1).

  As a result, as shown in FIG. 3, a groove pattern (scratch) that concentrically circulates on the surface of the sample (1) was obtained. FIG. 3 shows the result of image measurement of the surface of the sample (1) using an atomic force microscope (AFM), and it was confirmed that a large number of groove patterns could be formed concentrically. As shown in FIG. 4, it was confirmed that the groove pattern had a depth of about 10 nm and a width of about 0.2 nm.

  In this embodiment, since the polishing tool (3) is rotated, the groove pattern has a shape that concentrically circulates, but this can of course be formed in an appropriate shape. For example, when the polishing tool (3) is configured to reciprocate linearly, the groove pattern can be formed in a shape in which a number of straight lines are arranged in parallel.

  Since the scratch processing is grinding with the abrasive grains (14) in the magnetic polishing liquid, the width and depth of the groove pattern are determined by fluid polishing such as the particle diameter of the abrasive grains (14), the concentration of the magnetic polishing liquid (4), and the processing time. It is possible to adjust and control by appropriately setting these conditions.

  That is, in the configuration according to the present invention, grinding can be performed with the abrasive grains (14) in the magnetic polishing liquid, and as a result, a groove pattern of several nm level can be appropriately formed on the surface to be processed. The usefulness of the present invention was confirmed by examples.

It is a block diagram which shows suitable one Embodiment of the scratch processing apparatus which concerns on this invention. It is explanatory drawing which shows the fluid grinding | polishing by a magnetic cluster. It is an image figure which shows the result of the scratch processing which concerns on this invention, and uses an atomic force microscope (AFM). It is a graph which shows the cross-sectional shape of the scratch shown in FIG.

Explanation of symbols

1 Processing object (sample)
2 Support table 3 Polishing tool 4 Magnetic polishing solution 5 Spring screw 6 Traverse device 7 Base 8 Motor table 9 Load cell 10 Drive motor 11 Chuck part 12 Magnetic cluster 13 α cellulose 14 Abrasive grain 30 Cylindrical body 31 Permanent magnet (magnetic field source)

Claims (4)

It is a scratch processing method for forming a fine groove pattern by facing a polishing bite against a processing object and performing fluid polishing in the presence of a magnetic polishing liquid around these,
The polishing tool is provided with a magnetic field generation source that generates a magnetic field on the opposite side of the processing object, and the magnetic polishing liquid is present between the polishing tool and the processing object, so that the magnetic polishing liquid has a nonmagnetic abrasive. The particles are mixed, and a driving unit that performs a driving operation of a predetermined trajectory on a plane causes the polishing tool or the workpiece to perform a moving operation, and at this time, the magnetic field generation source A scratch processing method, wherein a fine groove pattern is formed by fluid polishing by applying a temporally steady or fluctuating magnetic field to a magnetic polishing liquid.   2. The scratch processing according to claim 1, wherein two of the driving means are linked to the polishing tool and the processing object, respectively, and both the polishing tool and the processing object are moved in opposite phases. Method. A polishing tool having a magnetic field generation source facing the object to be processed, a driving means for performing a motion operation of a predetermined locus on a plane, and a supply means for supplying a magnetic polishing liquid to a space between the polishing tool and the object to be processed And
The driving means is linked to either the polishing tool or the object to be processed, and nonmagnetic abrasive grains are mixed in the magnetic polishing liquid, and the supply means is activated to start the polishing tool and the object to be processed. The magnetic polishing liquid is present between the two and the driving means is activated to cause either the polishing tool or the object to be processed to move in a predetermined locus on a plane, and the magnetic field generation source causes the magnetic A scratch processing apparatus characterized by applying a stationary or fluctuating magnetic field in time to a polishing liquid.   4. The drive unit according to claim 3, wherein the number of driving means is two, the polishing tool and the workpiece are linked to each other, and both the polishing tool and the workpiece are moved in opposite phases. The scratch processing apparatus as described.

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