JP2013223817A - Brush roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the damage applied to an object to be washed in a washing process for applying scrub washing to the object to be washed from both face and back sides thereof at the same time.SOLUTION: A brush roller is configured to include a porous material having elasticity in a wet state and has an almost cylindrical roll body 3 and a plurality of projections 5. Each of the projections 5 is integrally projected from its base end part 5b on the outer peripheral surface 12 of the roll body 3 toward its top part 5a. The roll body 3 is fixedly supported on a rotary shaft 2 in a state that the rotary shaft 2 is inserted through the inner diameter part of the roll body 3. The brush roller rotates the roll body 3 centering around the rotary shaft 2 and brings each of the projections 5 into rotation contact with the surface 11 to be washed of a thin-walled flat object 10 to be washed to wash the surface 11 to be washed. The projecting direction of the projection 5 from the outer peripheral surface 12 of the roll body 3 is inclined with respect to the reference straight line 13 passing the center 17 of the rotary shaft 2 so as to allow the top part 5a of the projection 5 to offset to the rear side of the rotary direction 7 of the roll body 3 with respect to the base end part 5b of the projection 5.

Description

  The present invention relates to a brush roller used mainly for scrub cleaning in a cleaning process among manufacturing processes of electronic components such as a semiconductor electronic device wafer, a silicon wafer, and a hard disk.

  In the recent electronics industry, the precision of various parts has progressed dramatically, and the demand for cleanliness in the manufacturing environment has also increased. In particular, chemical contamination and adhering particles on the parts surface have a significant impact on product yield and operational reliability, so the importance of the cleaning process in the manufacturing process is extremely high, and various cleaning methods have been developed and implemented. Yes.

  For example, as a method for cleaning the surface (surface to be cleaned) of an object to be cleaned such as a semiconductor electronic device wafer, silicon wafer, hard disk, etc., for example, an elastic material composed of a polyvinyl acetal porous material and fixed to the outer periphery of a rotating shaft Scrub cleaning with a sponge roller (brush roller) having a substantially cylindrical roll body having a plurality of protrusions integrally formed on the outer peripheral surface of the roll body is known. Scrub cleaning refers to rubbing by bringing a plurality of protrusions on the outer peripheral portion of the roll body into contact with the surface to be cleaned and rotating a sponge roller through a rotating shaft while supplying water or other cleaning liquid to the contact portion between the two. It is something to wash.

Japanese Patent No. 3378015

  When the thin plate-shaped object to be cleaned for scrub cleaning has a first surface to be cleaned and a second surface to be cleaned on both sides, scrub cleaning using a pair of brush rollers is widely performed. ing. The pair of brush rollers are respectively fixed to two rotating shafts that rotate in opposite directions while being arranged substantially parallel to each other. The object to be cleaned is disposed between a pair of brush rollers in a posture substantially parallel to the two rotation shafts, and a protrusion of one brush roller is brought into rotational contact with the first surface to be cleaned, so that the second object to be cleaned By subjecting the projection of the other brush roller to rotational contact with the surface, the object to be cleaned can be scrub cleaned simultaneously from both the front and back sides. As device definition increases, scrub cleaning, which is a mechanism for contacting an object to be cleaned, is required to improve cleaning performance and reduce damage to device wafers.

  An object of the present invention is to reduce damage to a body to be cleaned in a cleaning process in which the body to be cleaned is scrubbed simultaneously from both the front and back sides.

  In order to achieve the above object, the brush roller of the present invention is made of a porous material having elasticity in a wet state, and has a substantially cylindrical roll body and a plurality of protrusions. The protrusion protrudes integrally from the base end portion on the outer peripheral surface of the roll body toward the top portion. The roll body is fixedly supported by the rotation shaft in a state where the rotation shaft is inserted into the inner diameter portion of the roll body. The brush roller cleans the surface to be cleaned by rotating the roll body around the rotation axis and rotating the protrusions in contact with the surface to be cleaned of the thin plate-shaped object to be cleaned.

  The protrusion direction of the protrusion from the outer peripheral surface of the roll body is inclined with respect to a reference straight line passing through the center of the rotation axis so that the top portion is offset to the rear side in the rotation direction of the roll body with respect to the base end portion.

  The protruding direction of the protrusion is a direction of an inclined straight line connecting the base end side reference point located at the center of the base end portion and the tip end side reference point located at the center of the top portion. An inclined straight line is inclined with respect to a reference straight line connecting the center.

  The protrusion direction of the protrusion is preferably inclined within a range of 5 to 60 degrees with respect to the reference straight line. That is, the angle between the reference straight line and the inclined straight line is preferably 5 degrees or more and 60 degrees or less.

  In order to ensure the strength and durability of the protrusion, it is preferable that the height of the protrusion along the reference line is not more than twice the width of the base end along the rotation direction of the roll body.

Further, in order to ensure a desired cleaning effect on the surface to be cleaned, the number of protrusions arranged on the same circumference in the rotation direction of the outer peripheral surface of the roll body is preferably 4 to 40, The number of protrusions arranged on the same straight line along the rotation axis direction of the outer peripheral surface of the outer periphery is preferably 2 or more and 60 or less. Further, the shape of the protrusion is preferably substantially cylindrical, and the area of the top of the protrusion is preferably 1πcm ² or less.

  The brush roller may be formed of a polyvinyl acetal resin porous material. In this case, the pore diameter of the porous material is preferably 50 μm or more and 200 μm or less, and the 30% compressive stress of the porous material is preferably 4 kPa or more and 20 kPa or less.

  In the above configuration, the protrusion direction of the protrusion from the outer peripheral surface of the roll body is inclined with respect to the reference straight line passing through the center of the rotation shaft so that the top portion is offset to the rear side in the rotation direction of the roll body with respect to the base end portion. Yes. For this reason, compared with the case where the protrusion direction of the protrusion is along the reference straight line, damage to the object to be cleaned is reduced when the protrusion is in rotational contact with the surface to be cleaned. Therefore, even when the object to be cleaned is scrubbed simultaneously from both the front and back sides, damage to the object to be cleaned can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the damage given to a to-be-cleaned body can be reduced in the washing | cleaning process of scrub-cleaning a to-be-cleaned body from both front and back simultaneously.

It is a perspective view which shows the state which wash | cleans a to-be-cleaned body with a pair of brush roller which concerns on one Embodiment of this invention. It is a side view of the brush roller of FIG. It is the schematic diagram which looked at the brush roller of FIG. 1 from the front. FIG. 4 is an enlarged view of the protrusion of FIG. 3. It is an expansion perspective view of the protrusion of FIG. It is a perspective view which shows the type | mold for shape | molding the brush roller of FIG. It is sectional drawing which shows the manufacturing method of the brush roller of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the protrusions are not shown.

  As shown in FIGS. 1 to 5, an object 10 to be cleaned is a thin disk-shaped wafer, and has a first surface 11 </ b> A and a second surface 11 </ b> B to be cleaned. .

  A pair of left and right brush rollers 1 (first brush roller 1A and second brush roller 1B) that perform scrub cleaning is a substantially cylindrical roll body 3 (first roll body 3A and second roll body 3B). And a plurality of protrusions 5 (first protrusions 5A and second protrusions 5B) integrally protruding from the outer peripheral surface 12 of the roll body 3 (3A, 3B) with a substantially uniform density. Each protrusion 5 has a cylindrical shape, and the protrusion 5 protrudes integrally from the base end portion 5b on the outer peripheral surface 12 of the roll body 3 toward the top portion (tip portion) 5a. Each roll body 3 is provided with a substantially cylindrical rotary shaft 2 (first rotary shaft 2A and second rotary shaft 2B) formed of a hard material such as metal or plastic. In addition, the shape of the protrusion 5 is not limited to the cylindrical shape.

  In scrub cleaning, the left and right rotating shafts 2 are separated by a predetermined distance and are arranged substantially in parallel, and the left and right roll bodies 3 ( The object to be cleaned 10 is sandwiched between the protrusion 5A of the first roll body 3A and the protrusion 5B of the second roll body 3B, and the surface to be cleaned 11 (the first surface to be cleaned 11A and the second surface to be cleaned 11B). ), The left and right rotating shafts 2 are rotated in opposite directions (the direction of rotation is indicated by an arrow 7), and the object to be cleaned 10 (the object to be cleaned is centered on the rotating shaft 6 substantially orthogonal to the rotating shaft 2). This is done by rotating the cleaning surface 11) (the direction of rotation is indicated by the arrow 8). When the protrusion 5A of the first roll body 3A is in rotational contact with the rotating first cleaned surface 11A, the first cleaned surface 11A is scrubbed, and the second cleaned surface 11B is rotated second. When the protrusion 5B of the roll body 3B is in rotational contact, the second surface 11B to be cleaned is scrubbed.

  The arrangement of the pair of brush rollers 1 is not limited to the left and right arrangements as described above. For example, the pair of brush rollers 1 is arranged vertically or obliquely. It can be arranged in various ways. Further, the rotation shaft 6 of the object to be cleaned 10 may be set so as to be substantially orthogonal to the rotation shaft 2 of the brush roller 1. For example, the pair of brush rollers 1 and the rotation shaft 2 are arranged in a substantially horizontal direction. In this case, the rotation shaft 6 of the object to be cleaned 10 may be set in a substantially vertical direction. Further, the first and second rotating shafts 2A and 2B may be rotated in synchronization with each other, or may be rotated independently (asynchronously).

  The brush roller 1 (roll body 3 and protrusion 5) is made of a polyvinyl acetal porous material (PVAt porous material) having elasticity in a water-containing state. The PVAt porous material is cured in a dry state and softened in a wet state. Further, the PVAt porous material is excellent in water absorption and water retention, exhibits favorable flexibility when wet and moderate rebound resilience, and is excellent in abrasion resistance. The rotating shaft 2 is inserted into the inner diameter portion of the roll body 3 and fixedly supports the roll body 3. For example, the outer peripheral surface of the rotating shaft 2 and the inner peripheral surface of the roll body 3 may be fixed by an adhesive, and the outer diameter of the rotating shaft 2 is formed larger than the inner diameter of the roll body 3. The roll body 3 may be fixedly supported on the rotary shaft 2 by the elastic force of the roll body 3 by press-fitting into the inner diameter portion of the roll body 3. Further, when the roll body 3 is manufactured, the roll body 3 may be fixed or supported on the rotary shaft 2 by using the rotary shaft 2 instead of the core rod 29 shown in FIG. In this case, the brush roller 1 (roll body 3) after the reaction is taken out of the mold 21 with the rotating shaft 2 and washed with water. By such fixed support, the roll body 3 rotates together with the rotating shaft 2.

  The two brush rollers 1A and 1B have substantially the same shape. That is, the first roll body 3A and the second roll body 3B have substantially the same shape, and the first protrusion 5A and the second protrusion 5B have substantially the same cylindrical shape. The plurality of first protrusions 5A and the plurality of second protrusions 5B are respectively arranged on the outer peripheral surface 12 of the roll bodies 3A and 3B according to a common pattern.

  During scrub cleaning, the first and second protrusions 5A and 5B abut against the first and second cleaned surfaces 11A and 11B, respectively, and elastically deform backward in the rotational direction 7. At this time, the first protrusion 5A presses the first surface to be cleaned 11A, and the second protrusion 5B presses the second surface to be cleaned 11B. As device definition increases, scrub cleaning, which is a mechanism for contacting an object to be cleaned, is required to improve the cleaning performance and reduce damage to the device wafer (object to be cleaned 10).

  In the present invention, the projection direction of the protrusion 5 from the outer peripheral surface 12 of the roll body 3 is such that the top portion 5a is offset to the rear side in the rotation direction 7 of the roll body 3 with respect to the base end portion 5b. Inclined with respect to the reference straight line 13 passing through the (axial center) 17. The protruding direction of the protrusion 5 is the direction of the inclined straight line 14 that connects the base end side reference point 15 located in the center of the base end portion 5b and the tip end side reference point 16 located in the center of the top portion 5a. An inclined straight line 14 is inclined with respect to a reference straight line 13 that connects the reference point 15 and the center 17 of the rotating shaft 2. Since the protrusion 5 of this embodiment has a cylindrical shape, the base end side reference point 15 is the center of the circular cross section of the protrusion 5 and the tip end reference point 16 is the center of the circular top surface 5a.

  It is preferable that the protrusion direction of the protrusion 5 is inclined in the range of 5 degrees to 60 degrees with respect to the reference straight line 13. That is, the angle θ between the reference straight line 13 and the inclined straight line 14 is preferably 5 degrees or more and 60 degrees or less.

  In order to ensure the strength and durability of the protrusion 5, the height H of the protrusion along the reference line 13 is not more than twice the width D of the base end portion 5 b along the rotation direction 7 of the roll body 3. Is preferred.

In order to secure a desired cleaning effect on the surface 11 to be cleaned, the number of the protrusions 5 arranged on the same circumference (on the same protrusion arrangement row) in the rotation direction of the outer peripheral surface 12 of the roll body 3 is four or more. 40 or less are preferable, and the number of protrusions 5 arranged on the same straight line along the axial direction of the outer peripheral surface 12 of the roll body 3 (axial center direction of the rotating shaft 2) is 2 or more and 60 or less. Is preferred. Further, the area of the top of the protrusion 5 is preferably 1πcm ² or less.

  The brush roller 1 made of a PVAt porous material is prepared by mixing, for example, one or more polyvinyl alcohols (raw materials) having an average polymerization degree of 500 to 3000 and a saponification degree of 80% or more to form an aqueous solution. Mineral acids as catalysts, starch and the like as pore-forming agents are added, and these mixed solutions are injected into a predetermined mold 21 as shown in FIGS. 6 and 7, and reacted at 40 to 80 ° C. After removing from 21, the pore-forming agent and the like are removed by washing with water.

  The mold 21 includes an outer mold 23, an inner mold 25, a bottom plate 27, a core rod 29, and a cap 31. Both the outer mold 23 and the inner mold 25 are formed in a cylindrical shape. The inner mold 25 has an outer diameter that is the same as or slightly smaller than the inner diameter of the outer mold 23, and is inserted into the outer mold 23. The core rod 29 is inserted approximately at the center of the inner mold 25. The bottom plate 27 closes the lower ends of the outer mold 23 and the inner mold 25 and supports the lower end of the core rod 29. The cap 31 is fitted to the inner peripheral surface at the upper end of the outer mold 23. The core rod 29 is positioned by the bottom plate 27 and the cap 31.

  A substantially cylindrical space 33 for forming the roll body 3 is defined between the inner peripheral surface of the inner mold 25 and the outer peripheral surface of the core rod 29. A plurality of through holes 35 for forming the protrusions 5 are formed in the inner mold 25, and each through hole 35 communicates with the space 33. The mixed liquid is injected into the space 33 from the casting nozzle 45 inserted between the outer mold 23 and the cap 31, and flows into the through holes 35 from the space 33. At the same time, the air in the through hole 35 moves to the space 33 and is released from the upper end of the space 33 to the atmosphere. Thereby, the liquid mixture is reliably filled up to the end of the through hole 35.

  Further, the 30% compressive stress (physical property value) of the brush roller 1 in an appropriate water-containing state is preferably 4 kPa or more and 20 kPa or less. The proper water content state refers to a water content state in which the PVAt porous material can exhibit an appropriate elasticity, and the water content (weight% of the water content state relative to the dry state) is obtained in a range of approximately 100% to 1500%. The 30% compressive stress means that the PVAT-based porous material with proper water content is cut so that the distance between both end faces (height in the longitudinal direction) is 30 mm, and a load is applied to the entire end face. It is set to a type load measuring instrument, and the load when it is crushed by 30% (9 mm) in the longitudinal direction is measured and obtained as a value obtained by dividing the load by the area of the end face.

  Moreover, as a PVAt type | system | group porous material, the porosity of the internal structure | tissue is 80% or more and 95% or less, and an average pore diameter is 50 micrometers or more and 200 micrometers or less.

  This is because if the porosity is less than 80%, the flexibility when wet is insufficient, and if the porosity is more than 95%, the practical strength is poor and none is suitable for cleaning applications. Further, if the average pore diameter is smaller than 50 μm, the elasticity at the time of wetting is insufficient and a sufficient brushing effect cannot be obtained, and if it exceeds 200 μm, the eyes are too coarse to be suitable for precision cleaning.

  The porosity is measured with a dry automatic dense watch on a dry rectangular parallelepiped PVAt sufficiently dried by a dryer, and from the apparent volume and true volume of the rectangular parallelepiped, the following equation (1) This is a calculated value.

  Porosity (%) = (apparent volume−true volume) / apparent volume × 100 (1)

  The average pore diameter is an average value of the diameters of a plurality of pores present in the internal structure of the PVAt porous material. In this embodiment, the average value of the long diameters (distances in the longitudinal direction of each pore) of a predetermined number of pores extracted from a plurality of pores on a predetermined basis is defined as the average pore diameter, and is obtained, for example, by the following measurement method Can do.

  The brush roller 1 is cut at a predetermined position, and the internal tissue exposed on the cut surface is photographed with an electron microscope. Next, a predetermined measurement range is set in the photographed photograph, and 20 pores are extracted in descending order of the longest diameter from a plurality of pores existing in the measurement range. Next, each major axis of the 20 extracted pores is measured. Finally, the average of the 11th to 20th measurement values counted from the larger of the 20 measurement values is calculated as the average pore diameter.

Furthermore, as the PVAt porous material, those having an apparent density of 0.06 g / cm ³ or more and a water retention of 600% or more are suitable.

  The apparent density is calculated by measuring the dry weight of the PVAt porous material of a predetermined shape (for example, rectangular shape) and the external dimensions under proper water content, and calculating the volume (wet volume) from the external dimensions. And obtained by dividing the dry weight by the wet volume.

  The water retention rate is a value calculated by the following equation (2) by measuring the dry weight of the PVAt porous material (dry weight) and the weight sufficiently wet (wet weight). is there.

  Water retention rate (%) = (wet weight−dry weight) / dry weight × 100 (2)

  As described above, according to this embodiment, the protrusion 5 from the outer peripheral surface 12 of the roll body 3 is offset so that the top portion 5a is offset to the rear side in the rotation direction 7 of the roll body 3 with respect to the base end portion 5b. The protruding direction is inclined with respect to the reference straight line 13 passing through the center 17 of the rotating shaft 2. For this reason, compared with the case where the protrusion direction of the protrusion 5 is along the reference straight line 13 (matches the reference straight line 13), the object to be cleaned 10 receives when the protrusion 5 rotates and contacts the surface 11 to be cleaned. Damage is reduced. Therefore, in the cleaning process of scrub cleaning the object to be cleaned 10 from both the front and back sides, damage to the object to be cleaned 10 can be reduced.

  In addition, this invention is not limited to the above-mentioned embodiment described as an example, and its modification, In the range which does not deviate from the technical idea which concerns on this invention even if it is other than the above-mentioned embodiment etc. If so, various changes can be made according to the design and the like.

  For example, the shape and basic pattern of the protrusion 5 are not limited to the above and are arbitrary. Further, the protrusions 5 may be arranged in different patterns on the two brush rollers 1A and 1B, and the first protrusion 5A and the second protrusion 5B may be set to different shapes and sizes. Further, the first roll body 2A and the second roll body 2B may be set to different sizes.

  Moreover, although the said embodiment demonstrated the case where the to-be-cleaned surface 11A, 11B of the to-be-cleaned body was scrub-cleaned by one pair of brush rollers 1A and 1B, 1 of the to-be-cleaned body 10 was carried out with one brush roller 1. FIG. Even when scrub cleaning is performed on two surfaces 11 to be cleaned, damage to the object to be cleaned 10 can be reduced.

  DESCRIPTION OF SYMBOLS 1,1A, 1B ... Brush roller, 2, 2A, 2B ... Rotating shaft, 3, 3A, 3B ... Roll body, 5, 5A, 5B ... Projection, 5a ... Base end part, 5b ... Top part, 10 ... Object to be cleaned 11, 11A, 11B: surface to be cleaned, 12: outer peripheral surface, 13: reference straight line, 14: inclined straight line, 15: base end side reference point, 16: distal end side reference point, 17 ... center of rotation axis

Claims (3)

It is composed of a porous material having elasticity in a wet state, and has a substantially cylindrical roll body and a plurality of protrusions, and the protrusions are integrated from the base end portion on the outer peripheral surface of the roll body toward the top. The roll body is fixedly supported by the rotary shaft in a state where the rotary shaft is inserted into the inner diameter portion of the roll body, the roll body is rotated around the rotary shaft, and the protrusion is formed into a thin flat plate. A brush roller for cleaning the surface to be cleaned by rotating the surface to be cleaned of the object to be cleaned,
The protrusion direction of the protrusion from the outer peripheral surface of the roll body is relative to a reference straight line passing through the center of the rotation shaft so that the top portion is offset to the rear side in the rotation direction of the roll body with respect to the base end portion. A brush roller that is inclined. The brush roller according to claim 1,
The protrusion direction of the protrusion is inclined within a range of 5 degrees to 60 degrees with respect to the reference straight line. The brush roller according to claim 1 or 2,
The height of the said protrusion along the said reference line is 2 times or less of the width | variety of the said base end part along the rotation direction of the said roll body. The brush roller characterized by the above-mentioned.

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