JP2006198701A - Double-disc plane polishing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate removal work of a body to be polished by preventing the sticking of the body to be polished to the surface of a solid grinding wheel of the upper grinding wheel unit without requiring a large control mechanism and a large peeling mechanism in a double-disc plane polishing device. <P>SOLUTION: The solid grinding wheels 2, 2 held by lapping surface plates 1, 1 of the upper/lower grinding wheel units 100, 200 are divided into grinding wheel segments 21 by a first groove part 31. A second groove part 32 is formed to the surface of each grinding wheel segment 21. The total number of the second groove parts 32, 32a of the grinding wheel segments 21 of the upper grinding wheel unit 100 is increased compared with that of the second groove parts 32 of the grinding wheel segments 21 of the lower grinding wheel unit 200. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a double-sided planar polishing apparatus, and in particular, when the upper grindstone unit of each grindstone unit separately provided on both upper and lower sides sandwiching the object to be polished is lifted after completion of the polishing process, The present invention relates to a double-sided planar polishing apparatus that has taken measures to prevent a situation where it is lifted while stuck to a unit.

By placing the grindstone unit that holds the solid grindstone on the lapping surface plate separately on the upper and lower sides sandwiching the object to be polished, the surface of the fixed grindstone of each grindstone unit is brought into contact with the upper and lower surfaces of the object to be polished A double-sided flat polishing apparatus that performs grinding or polishing by relatively rotating them while feeding a polishing liquid such as water has been conventionally known. A grindstone unit used in such a double-sided flat polishing apparatus is shown in FIG. It is shown in plan view.
The grindstone unit of FIG. 4 has a circular or ring-shaped lapping surface plate 1 holding circular or ring-shaped solid grindstones 2, and the solid grindstones 2 extend in radial directions formed at a plurality of equiangular positions. The groove 31 is divided into a plurality of grindstone segments 21 having the same shape. More specifically, as shown in a perspective view in FIG. 5, each grindstone segment 21 is mounted and held on an attachment plate 22 having substantially the same shape as that using an adhesive or the like. It is superimposed on the lapping platen 1 and bolted. 4 and 5, reference numeral 23 denotes a hole into which a bolt for fastening the mounting plate 22 to the lapping surface plate 1 is inserted.

  When performing a double-sided surface polishing process using the grindstone unit described with reference to FIG. 4, a high degree of surface flatness such as a substrate for an aluminum memory disk, a silicon wafer, and a glass wafer, and a high degree of parallelism on both sides are required. The required number of objects to be polished W are held on a plurality of locations of the carrier 9 shown in FIG. 6 and placed on a lower grindstone unit (not shown) installed upward, and on the object to be polished W. Place the upper whetstone unit installed downward. The carrier 9 is rotationally driven by the action of a sun gear 91, a planetary gear 92 provided on the carrier 9, a rotation drive mechanism 90 including an internal gear 93 and the like. And after arrange | positioning a grindstone unit separately on the upper and lower sides which pinch | interpose the to-be-polished body W as mentioned above, the surface of the fixed grindstone 2 in each upper and lower grindstone unit is made to contact with the upper surface and lower surface of the to-be-polished body W, respectively. The upper and lower surfaces of the object to be polished W are polished by relatively rotating them while feeding the polishing liquid.

  In this double-sided planar polishing apparatus, two grindstone units having the same configuration and the same size are arranged on both upper and lower sides of the object to be polished W. In addition, in the grindstone unit of the illustrated example, the first groove 31 is formed between the grindstone segments 21 and 21 adjacent to each other, and as shown in FIG. 4 or FIG. The second groove portion 32 that crosses diagonally is formed in the same pattern, and each of the first and second groove portions 31 and 32 functions as a drainage path for waste liquid containing polishing debris generated in the polishing process. It is like that.

  At the end of the polishing process using the double-sided flat polishing apparatus, a process of lifting the upper grindstone unit and taking out the object to be polished W from the polishing apparatus is performed. At that time, the object to be polished W is affected by the polishing liquid. May be lifted while adhering to the surface of the grindstone segment 21 of the upper grindstone unit. When such a situation occurs, the object to be polished W is slid so as to come to the outer peripheral portion of the first groove 31 or the grindstone segment 21, and then the object to be polished W is peeled off from the surface of the grindstone segment 21. In this case, not only is the troublesome task of collecting the object to be recovered, but also the object to be polished W may be damaged. In addition, the user may not notice that the workpiece W has adhered, and may enter the next operation as it is and cause an unexpected failure. Further, the object to be polished W adhered to the surface of the grindstone segment 21 of the upper grindstone unit falls in the middle of raising the upper grindstone unit, and the dropped object W is damaged or the lower grindstone unit. There is also a risk of hitting or damaging the object to be polished W on the surface.

  Therefore, conventionally, when the upper grindstone unit is lifted in the step of taking out the workpiece W from the polishing apparatus, the grindstone W does not remain attached to the surface of the grindstone segment 21 of the upper grindstone unit. Researches have been made to make it (see, for example, Patent Document 1).

  What is described in Patent Document 1 is a method in which a through hole that opens at the surface and side surface of the grindstone segment 21 is drilled in the grindstone segment 21 of the upper grindstone unit. When the unit is lifted, air naturally passes through the through-hole, and the object to be polished W is easily peeled off from the grindstone segment 21 without sticking to the grindstone segment 21. Scratches and breakage of the battery will be prevented. In addition, this Patent Document 1 also refers to a technique in which compressed air, pressurized water, or the like is sent using the through hole, and the object to be polished W is reliably peeled off from the surface of the grindstone segment 21 by the pressurizing action. By doing so, it is said that the diameter of the opening of the through hole can be kept small.

Utility Model Registration No. 2558864

  However, according to the technique described in Patent Document 1, the rotation drive mechanism 90 (see FIG. 7) is controlled so that the upper surface of the object to be polished W is positioned at the opening of the through hole at the end of the polishing process. Therefore, there is a problem that a large-scale control mechanism for controlling the rotational drive mechanism 90 is required separately, and the entire apparatus becomes expensive. In addition, when compressed air, pressurized water, or the like is sent using the through-hole, a large-scale mechanism for that purpose is required separately, which also causes a problem that the entire apparatus becomes expensive.

  The inventor of the present application has conducted extensive research under the above circumstances, and as a result, has completed the present invention. That is, according to the present invention, there is a situation in which an object to be polished is lifted while being attached to the surface of the grindstone segment of the upper grindstone unit due to the influence of the polishing liquid without using an expensive and large-scale apparatus separately. It is an object of the present invention to provide a double-sided planar polishing apparatus that can greatly improve the workability of recovery of an object to be polished and reduce the occurrence of quality defects due to dropping of the object to be polished.

  The double-sided flat polishing apparatus according to the present invention has a grindstone unit having the same configuration and the same size, each having a solid grindstone held on a lapping surface plate, on both upper and lower sides sandwiching the object to be polished, and fixed on each upper and lower grindstone unit. The polishing process is completed in a double-sided planar polishing apparatus that polishes both the upper and lower surfaces of the object by rotating the surface of the grindstone in contact with the upper and lower surfaces of the object and feeding the polishing liquid. At this time, the adhesion force between the surface of the fixed grindstone of the upper grindstone unit and the upper surface of the object to be polished is smaller than the adhesion force between the surface of the fixed grindstone of the lower grindstone unit and the lower surface of the object to be polished at the same time. Thus, the surface shapes of the fixed grindstones of the upper and lower grindstone units are made different.

  With this configuration, due to the difference in the surface shape of the fixed grindstones of the upper and lower grindstone units, at the end of the polishing process, the adhesion between the surface of the fixed grindstone of the upper grindstone unit and the upper surface of the object to be polished is Since the contact strength between the surface of the fixed whetstone of the lower whetstone unit and the lower surface of the object to be polished is smaller, the object to be polished is placed on the surface of the fixed whetstone of the lower whetstone unit when the upper whetstone unit is lifted. It will remain, and it will become difficult to stick to the surface of the fixed grindstone of the upper grindstone unit and lift. Therefore, it is not necessary to perform the troublesome work of peeling off and recovering the polishing body from the surface of the solid grindstone of the upper grindstone unit, and it becomes easy to prevent the object to be polished from being damaged. In addition, it is difficult to notice that the object to be polished W has adhered, and to enter the next operation as it is and cause an unexpected failure. In addition, the object to be polished attached to the surface of the solid grindstone of the upper grindstone unit may fall and be damaged, or the object to be polished on the lower grindstone unit may be damaged or damaged. Is less likely to occur.

  In the double-sided planar polishing apparatus according to the present invention, a grindstone unit having the same configuration and size having a solid grindstone held on a lapping surface plate is separately provided on both the upper and lower sides sandwiching the object to be polished, and fixed on the upper and lower grindstone units. In a double-sided planar polishing apparatus that polishes both the upper and lower surfaces of a polished object by bringing the surface of the grindstone into contact with the upper and lower surfaces of the object to be polished and feeding them with a polishing liquid, when polishing is completed. The surface tension of the polishing liquid fed to the contact portion between the surface of the upper grindstone unit of the upper grindstone unit and the upper surface of the object to be polished is the same as that of the lower grindstone unit of the lower grindstone unit and the surface to be polished. Adopt a configuration in which the surface shapes of the fixed whetstones of the upper and lower whetstone units are made different so as to be smaller than the surface tension of the polishing liquid fed to the contact portion with the lower surface of the body. The is also possible.

  Even with this configuration, due to the difference in the surface shape of the fixed grindstones of the upper and lower grindstone units, at the end of the polishing step, the polishing that is fed to the contact portion between the surface of the fixed grindstone of the upper grindstone unit and the upper surface of the object to be polished Since the surface tension of the liquid is smaller than the surface tension of the polishing liquid fed to the contact portion between the surface of the fixed whetstone of the lower whetstone unit and the lower surface of the object to be polished at the time of completion, the upper whetstone unit The adhesion force between the surface of the fixed grindstone and the upper surface of the object to be polished is smaller than the adhesion force between the surface of the fixed grindstone of the lower grindstone unit and the lower surface of the object to be polished at the end of the above and The same effect is exhibited.

  In the present invention, the circular or ring-shaped solid grindstones held by the circular or ring-shaped lapping surface plates in the upper and lower grindstone units are the same by the first groove portions extending in the radial direction formed at a plurality of equiangular positions. The grindstone segments are divided into a plurality of shapes, and the second grooves are formed in the same pattern on the surfaces of the grindstone segments, and the total number of the second grooves of each grindstone segment of the upper grindstone unit is It is possible to adopt a configuration in which the surface shapes of the fixed grindstones of the upper and lower grindstone units are made different by increasing the total number of the second groove portions of the grindstone segments of the side grindstone unit.

  With this configuration, the surface area of each grindstone segment of the upper grindstone unit with a large total number of second groove portions is smaller than the surface area of each grindstone segment of the lower grindstone unit with a small total number of second groove portions. At the end of the process, the adhesion to the object to be polished or the surface tension of the polishing liquid is smaller on the grindstone segment side of the upper grindstone unit than on the lower grindstone segment side, and the same effect as described above is exhibited.

  In the present invention, it is desirable that the first groove portion and the second groove portion are formed as a drainage path for waste liquid containing polishing debris and the like, so that the object to be polished becomes the grindstone segment of the upper grindstone unit. The first groove and the second groove for suppressing sticking are quickly discharged from the upper and lower grindstone units so that the waste liquid containing polishing debris generated in the polishing step is polished. An excellent effect is achieved in that the process is carried out smoothly and is useful for increasing the polishing accuracy.

  In the present invention, it is possible to adopt a configuration in which each of the grindstone segments has a shape substantially the same as that of the grindstone segment and is held in an overlapping manner on a mounting plate bolted to the lapping surface plate. This makes it easy to replace and replace the grindstone segments.

  In the present invention, the number ratio (m + 1) / when the total number of the second groove portions of each grindstone segment of the upper grindstone unit is m and the total number of the second groove portions of each grindstone segment of the lower grindstone unit is n. It is desirable that (n + 1) is set in the range of 1.2 to 6.0. Hereinafter, (m + 1) / (n + 1) is expressed as a number ratio. If the number ratio is less than 1.2, a sufficiently large surface area difference between the grindstone segment of the upper grindstone unit and the grindstone segment of the lower grindstone unit cannot be secured. It is possible that the effects of the adhesion force to the surface and the surface tension of the polishing liquid are balanced on the top and bottom, and sticking of the object to be polished to the grindstone segment of the upper grindstone unit cannot be reliably prevented. On the other hand, if the number ratio is more than 6.0, the number of irregularities on the surface of the grindstone segment of the upper grindstone unit will increase too much, and the finish accuracy will be lowered, and the finish accuracy between the upper and lower surfaces of the object to be polished will be reduced. It is easy to make a difference. And if the said number ratio is defined in the range of 1.2-6.0, the to-be-polished body with respect to the grindstone segment of an upper grindstone unit can be prevented, and also the upper surface and lower surface of a to-be-polished body The difference in finish accuracy is unlikely to occur.

  As described above, according to the double-sided flat polishing apparatus according to the present invention, an upper grindstone can be used without spending cost without requiring a large-scale control mechanism or peeling mechanism represented by some conventional double-sided flat polishing apparatuses. It becomes easy to prevent the object to be polished from sticking to the surface of the unit's solid grindstone (grindstone segment). Therefore, not only does it become difficult to perform the troublesome work of peeling and recovering the polishing body from the surface of the solid grindstone of the upper grindstone unit, it is easy to prevent the object to be polished from being damaged, but also the object to be polished If you do not notice that it has stuck, you can enter the next operation as it is and cause an unexpected failure, or the object to be polished that has adhered to the surface of the solid grindstone of the upper grindstone unit will fall and the object to be polished will It is difficult to cause damage or damage to the object to be polished on the lower grindstone unit. For these reasons, according to the double-sided planar polishing apparatus according to the present invention, a high degree of surface flatness such as a substrate for an aluminum memory disk, a silicon wafer, and a glass wafer and a high degree of parallelism on both front and back surfaces are required. The body can be manufactured at low cost without using a large-scale device.

  FIG. 1 is a schematic external view showing a positional relationship between an upper grindstone unit 100 and a lower grindstone unit 200 of a double-sided planar polishing apparatus according to the present invention, and FIGS. 2 (a) to 2 (f) are grindstone segments ( FIG. 3A is an explanatory diagram illustrating the surface shape of the grindstone segment (B) of the lower grindstone unit 200, and FIGS. 3A and 3B are explanatory diagrams illustrating the surface shape of the grindstone segment according to a modification.

  The lower grindstone unit 200 shown in FIG. 1 has the same structure as the grindstone unit described with reference to FIG. That is, a circular or ring-shaped lapping surface plate 1 holds a circular or ring-shaped solid grindstone 2, and the solid grindstone 2 extends in a radial direction formed at a plurality of equiangular positions and opens at the outer peripheral end surface. The first groove portion 31 is divided into a plurality of grindstone segments 21 having the same shape (hereinafter referred to as “lower grindstone segment 21”), and each lower grindstone segment 21 is bonded to a mounting plate 22 having substantially the same shape as that. The mounting plate 22 is superposed on the lapping surface plate 1 and bolted to the lower lapping stone segment 21. Further, each lower grindstone segment 21 is obliquely crossed on both side end faces. The second groove portions 32 opened in the same pattern are formed in the same pattern, and the first and second groove portions 31 and 32 are wastes including polishing dust generated in the polishing process. Is adapted to act as a discharge path for. In FIG. 1, it is not shown a bolt insertion hole which is provided in the grindstone segment 21.

  Although the upper whetstone unit 100 shown in FIG. 1 has the same basic configuration and size as the lower whetstone unit 200, the upper whetstone unit 100 differs from the lower whetstone unit 200 in that each whetstone segment 21 (hereinafter referred to as “upper whetstone unit 200”). The second groove portion 32a that obliquely crosses it is added to the “grindstone segment” one by one. Therefore, in the upper grindstone unit 100 and the lower grindstone unit 200, the same reference numerals are assigned to the same portions to avoid duplication of explanation.

  When performing the double-sided planar polishing process using the upper and lower grindstone units 100 and 200 shown in FIG. 1, as is apparent from the description with reference to FIG. 6, the substrate for the aluminum memory disk, the silicon wafer, and the glass wafer. The required number of objects to be polished W, which requires a high degree of surface flatness and a high degree of parallelism on both the front and back sides, are placed on the lower grindstone unit 200 that is placed upward while being held at a plurality of locations on the carrier 9, By placing the upper grindstone unit 100 placed downward on the object to be polished W, the grindstone units 100 and 200 are separately provided on both the upper and lower sides sandwiching the object to be polished W, and then in each of the upper and lower grindstone units 100 and 200. The surfaces of the fixed grindstones 2 and 2 are respectively brought into contact with the upper and lower surfaces of the object to be polished W, and they are rotated relatively while feeding the polishing liquid. Polishing the upper and lower surfaces of the object to be polished W by. At that time, the first groove portion 31 and the second groove portion 32 of each of the upper and lower grindstone segments 21 act as a drainage path for waste liquid containing polishing debris generated in the polishing process, and are added to the upper grindstone segment 21. Similarly, the two-groove portion 32a also functions as a drainage path for waste liquid containing polishing debris generated in the polishing process. Therefore, it is possible to prevent a situation in which waste liquid or polishing waste stays around the upper and lower solid grindstones 2 and impairs polishing accuracy and performance.

  In this embodiment, the second grindstone segment 32a is additionally formed in the upper grindstone segment 21, so the total number of the second groove portions 32, 32a formed in the upper grindstone segment 21 is the lower grindstone segment. The total number of second groove portions 32 formed in 21 is larger. Therefore, the surface shape of the upper solid grindstone 2 composed of the set of the upper grindstone segments 21 and the surface shape of the lower solid grindstone 2 composed of the set of the lower grindstone segments 21 are different, and their surface areas are The solid grindstone 2 is smaller than the lower solid grindstone 2. Therefore, when comparing the adhesion between the surface of the upper and lower solid grindstones 2 and 2 and the object to be polished at the end of the polishing process, the adhesion between the surface of the upper solid grindstone 2 having a small surface area and the object to be polished is It can be suppressed to be smaller than the adhesion force between the surface of the large lower solid grindstone 2 and the object to be polished. More specifically, the adhesion force between the surface of the upper grindstone segment 21 and the object to be polished is suppressed to be smaller than the adhesion force between the surface of the lower grindstone segment 21 and the object to be polished. In other words, the surface of the upper fixed whetstone 2 and the surface to be coated are higher than the surface tension of the polishing liquid fed to the contact portion between the surface of the lower fixed whetstone 2 and the lower surface of the object to be polished at the end of the polishing process. The surface tension of the polishing liquid fed to the contact portion with the upper surface of the polishing body is small.

  Thus, when the upper grindstone unit 100 is lifted at the end of the polishing process, the object to be polished is stuck on the surface of the lower solid grindstone 2 and remains on the lower solid grindstone 2; It is difficult for a situation where the upper grindstone 2 sticks to the surface of the upper grindstone 2 and is lifted by the upper grindstone unit 100. As a result, the work of taking out the object to be polished from the polishing apparatus only needs to be performed on the lower grindstone unit 200. Therefore, the troublesome work of removing the grinded body from the surface of the upper solid grindstone 2 and collecting it. It is not only necessary or unnecessary to be performed, but also it is difficult to move to the next operation while the object to be polished W is adhered to the upper solid grindstone 2. Furthermore, a situation where the object to be polished adhered to the surface of the upper solid grindstone 2 falls and the object to be polished is damaged, or the object to be polished on the lower grindstone unit 200 hits or is damaged. Is less likely to occur.

  In this embodiment, the lower grindstone 2 and the upper solid grindstone 2 are provided with the first groove portion 31 in the same pattern, and the lower grindstone segment 21 and the upper grindstone segment 21 are provided with the second groove portion 32 in the same pattern. In addition to being provided, by adding the second groove portion 32 a to the upper grindstone segment 21, the total number of the second groove portions 32, 32 a of the upper grindstone segment 21 can be set to the second groove portion 32 of the lower grindstone segment 21. Although the surface shapes of the fixed grindstones 2 and 2 of the upper and lower grindstone units 100 and 200 are made different from each other by increasing the total number of these, this point is different from the groove shape such as the added second groove portion 32a. Instead of providing the upper grindstone segment 21, a recess having an appropriate size and shape reaching the side surface or outer peripheral end surface of the upper grindstone segment 21 is provided. It is possible to make the surface shapes of the fixed grindstones 2 and 2 of the upper and lower grindstone units 100 and 200 different by providing them on the surface, so that the recesses of the upper and lower grindstone units 100 and 200 of the upper and lower grindstone units 100 and 200 can be made different. It is useful for making the surface shapes of the fixed grindstones 2 and 2 different, and the recess does not exhibit an adsorption action similar to a suction cup and does not exert an adsorption action on the object to be polished. However, in order to maintain an appropriate balance between the polishing accuracy for the upper surface of the object to be polished and the polishing accuracy for the lower surface, a groove shape such as the second groove portion 32a is formed on the surface of the upper grindstone segment 21 as in the embodiment. It is preferable to have it.

  Some specific examples in the case where the upper solid grindstone 2 and the lower solid grindstone 2 are made to have different surface shapes by providing a groove shape like the second groove portion 32a on the surface of the upper grindstone segment 21. It is shown in FIG. In the same figure, the surface shape of the lower grindstone segment 21 is illustrated in (a) to (f) of the row (A), and the surface shape of the upper grindstone segment 21 corresponding to the surface shape of the lower grindstone segment 21 is shown. (B) It is shown in (a) to (f) of the column. That is, in the combination shown in FIG. 5A, a second groove 32a that obliquely crosses the upper grindstone segment 21 is added, and in the combination shown in FIG. 5B and FIG. A second groove portion 32a is added, and in the combination of FIGS. 3C, 3D, 2E, and 2F, the second groove portion 32a that crosses the upper grindstone segment 21 diagonally and the second groove portion 32a that passes vertically inward and outward. And have been added. In addition, in the same figure (e) (f), the case where the 2nd groove part 32 is not formed in the lower grindstone segment 21 is shown.

  Moreover, the (C) row | line | column of FIG. 2 shows the number ratio of the 2nd groove parts 32 and 32a of the upper grindstone segment 21 with respect to the total number of the 2nd groove parts 32 of the lower grindstone segment 21, and it understands with these numerical values. Thus, in the combinations of the illustrated examples, the number ratio is in the range of 1.2 to 6.0. Here, when the number ratio is less than 1.2, in the actual polishing step, the influence of the adhesion force to the object to be polished and the surface tension of the polishing liquid is balanced up and down, and the object to be polished is stuck to the upper grindstone segment 21. It can be difficult to prevent. On the other hand, if the number ratio is more than 6.0 times, a difference in the finish tends to occur in the finish accuracy between the upper surface and the lower surface of the object to be polished. If the number ratio is set in the range of 1.2 to 6.0, it is possible to prevent the object to be polished from sticking to the upper grindstone segment 21 and to finish the upper and lower surfaces of the object to be polished. Differences in accuracy are unlikely to occur.

  In addition, the notation of the left side of the numerical formula of FIG.2 (C) row | line | column sets m as the total number of the 2nd groove parts 32 and 32a of the upper grindstone segment 21, and sets the total number of the 2nd groove parts 32 of the lower grindstone segment 21 to n. It is described as (m + 1) / (n + 1). This avoids that the ratio of the right side becomes infinite in consideration of the case where the total number of the second groove portions 32 is 0 like the lower grindstone segment 21 shown in FIGS. This is because.

  In the upper grindstone segment 21 described above, the second groove portions 32, 32a have been described as being open at both ends in the longitudinal direction on the side surfaces of the upper grindstone segment 21 and on the inner and outer end surfaces. As shown in 3 (a) and 3 (b), only one end in the longitudinal direction of the second groove portions 32 and 32a may be opened at the side surface of the upper grindstone segment 21 or the inner and outer end surfaces. In this way, when the surface of the upper grindstone segment 21 is in close contact with the object to be polished, air is discharged from the second grooves 32 and 32a, and the upper grindstone segment 21 is firmly attached to the object to be polished by the sucker action. The situation of adsorbing and sticking to the battery does not occur.

2 (a), (b), (c), (d), (e), and (f) in FIG. 2 as an example of the present invention, which is an elastic grindstone using silicon carbide GC4000 as abrasive grains and a binder of polyvinyl formal resin and phenol resin. And the grindstone unit corresponding to the comparative example with the same upper and lower surface shape was produced, and it attached to speed fam Co., Ltd. polisher 16B-4SSG-4, and implemented the grinding | polishing test. Thirty-two 3.5 inch aluminum substrates were polished at a processing pressure of 7.84 kPa, a processing rotation speed of 60 rpm, and a processing time of 180 seconds. This was performed 6 times, and the number of substrates adhered to the upper grindstone unit out of a total of 192 substrates was compared with the surface roughness of the polished aluminum substrate.
As shown in Table 1, in the present invention example, the substrate attached to the upper grindstone unit was reduced to ¼ or less compared to the comparative example. The surface roughness became rougher as the number of grooves increased.

(Table 1)
┌───────┬───────────┬──────────┬─────┐
│ │ Number ratio │ To upper grinding wheel │ On top of board │
│ │ (m + 1) / (n + 1) │ Number of sticking (rate) │Surface roughness ratio│
│ │ │ │ (Ra) │
├───────┼───────────┼──────────┼─────│
│Comparison example │ 1.0 │58 sheets (30.2%) │ 100 │
├───────┼───────────┼──────────┼─────│
│Invention example (a) │ 1.5 │14 sheets (7.3%) │ 102 │
├───────┼───────────┼──────────┼─────│
│Invention Example (b) │ 1.5 │13 sheets (6.8%) │ 98 │
├───────┼───────────┼──────────┼─────│
│Invention Example (c) │ 2.0 │ 8 sheets (4.2%) │ 104 │
├───────┼───────────┼──────────┼─────│
│Invention Example (d) │ 2.5 │ 6 sheets (3.1%) │ 106 │
├───────┼───────────┼──────────┼─────│
│Invention Example (e) │ 6.0 │ 2 sheets (1.0%) │ 110 │
├───────┼───────────┼──────────┼─────│
│Invention Example (f) │ 7.0 │ 2 sheets (1.0%) │ 131 │
└───────┴───────────┴──────────┴─────┘
The surface roughness ratio in Table 1 indicates the ratio of each Ra of the present invention example when the Ra of the comparative example is 100.

It is the outline external view which showed the positional relationship of each upper and lower grindstone of the double-sided plane polishing apparatus which concerns on this invention. (A)-(f) is explanatory drawing which illustrated the surface shape of each upper and lower grindstone segment. (A) (b) is explanatory drawing which illustrated the surface shape of the grindstone segment by a modification. It is a top view of the grindstone unit used for the conventional double-sided plane polishing apparatus. It is a perspective view of a grindstone segment. It is a bottom view of the state which mounted the upper grindstone unit on the to-be-polished body hold | maintained at the carrier.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lapping surface plate 2 Solid grindstone 21 Grinding wheel segment 22 Mounting plate 31 1st groove part 32 2nd groove part 100,200 Grinding wheel unit W To-be-polished body

Claims (6)

A grindstone unit of the same configuration and size having a solid grindstone held on a lapping surface plate is separately provided on both upper and lower sides sandwiching the object to be polished, and the surface of the fixed grindstone in each of the upper and lower grindstone units is the upper surface of the object to be polished In a double-sided flat polishing apparatus that polishes the upper and lower surfaces of the object to be polished by rotating them relative to each other while feeding the polishing liquid in contact with the lower surface,
At the end of the polishing process, the adhesion between the surface of the fixed grinding wheel of the upper grinding wheel unit and the upper surface of the object to be polished is the adhesion between the surface of the fixed grinding wheel of the lower grinding wheel unit and the lower surface of the object to be polished at the end of the polishing process. A double-sided planar polishing apparatus characterized in that the surface shapes of the fixed grindstones of the upper and lower grindstone units are made different so as to be smaller. A grindstone unit of the same configuration and size having a solid grindstone held on a lapping surface plate is separately provided on both upper and lower sides sandwiching the object to be polished, and the surface of the fixed grindstone in each of the upper and lower grindstone units is the upper surface of the object to be polished In a double-sided flat polishing apparatus that polishes the upper and lower surfaces of the object to be polished by rotating them relative to each other while feeding the polishing liquid in contact with the lower surface,
When the polishing is finished, the surface tension of the polishing liquid supplied to the contact portion between the surface of the fixed grinding wheel of the upper grinding wheel unit and the upper surface of the object to be polished is the surface of the fixed grinding stone of the lower grinding wheel unit at the end of the polishing. The surface shapes of the fixed grindstones of the upper and lower grindstone units are made different from each other so that the surface tension of the polishing liquid fed to the contact portion between the surface and the lower surface of the object to be polished is smaller. Flat polishing equipment. The circular or ring-shaped solid grindstones held by the circular or ring-shaped lapping surface plates in the upper and lower grindstone units have a plurality of same shapes by first grooves extending in the radial direction at a plurality of positions at equal angles. The grindstone segments are divided and the second grooves are formed in the same pattern on the surface of each grindstone segment, and the total number of the second grooves of each grindstone segment of the upper grindstone unit is determined by the lower grindstone unit. The double-sided planar polishing apparatus according to claim 1 or 2, wherein the surface shapes of the fixed grindstones of the upper and lower grindstone units are made different by increasing the total number of the second groove portions of each grindstone segment. 4. The double-sided planar polishing apparatus according to claim 1, wherein the first groove portion and the second groove portion are formed as a discharge path for waste liquid containing polishing waste and the like. 5. 5. The double-sided planar polishing apparatus according to claim 3, wherein each of the grindstone segments has a shape substantially the same as that of the grindstone segment and is held in an overlapping manner on a mounting plate bolted to the lapping surface plate. . The number ratio (m + 1) / (n + 1) where m is the total number of the second groove portions of each grindstone segment of the upper grindstone unit and n is the total number of the second groove portions of each grindstone segment of the lower grindstone unit. The double-sided planar polishing apparatus according to any one of claims 3 to 5, which is defined in a range of 1.2 to 6.0.

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