JP6266414B2 - Grinding equipment - Google Patents

Description

  The present invention relates to a grinding apparatus, and more particularly, to a grinding apparatus that performs grinding with a grinding wheel on a work surface of a plate-like workpiece to be ground.

  2. Description of the Related Art Conventionally, as a grinding apparatus that grinds a workpiece, one in which a part of a grinding wheel arranged in a ring on a grinding wheel is brought into contact with the workpiece is known (for example, see Patent Document 1). In this grinding apparatus, in order to avoid the phenomenon that grinding debris generated in the grinding process is clogged in the grinding wheel, cleaning water is supplied to the grinding wheel in a portion not in contact with the workpiece to perform grinding. The grinding stone is cooled and cleaned.

In addition, a grinding apparatus that performs grinding while performing dressing processing to sharpen the blade of a grinding wheel has been proposed in order to ensure grinding accuracy for a workpiece having high hardness such as sapphire and silicon carbide (SiC). (For example, refer to Patent Document 2). In this grinding apparatus, dressing is performed by bringing a dressing grindstone into contact with a portion of the grindstone that is not in contact with the workpiece. However, the number of rotations of the grinding wheel suitable for grinding (for example, 2000 to 4000 min ⁻¹ ) and the number of rotations of the grinding wheel suitable for dressing (for example, 1000 to 1500 min ⁻¹ ) are not necessarily the same. For this reason, when rotating a grinding wheel with the rotation speed suitable for grinding, the situation which cannot dress a grinding wheel appropriately is also assumed.

  On the other hand, in order to improve the efficiency of grinding using a grinding wheel, grinding is performed by heating the contact surface of the grinding wheel to the workpiece and performing a combination of thermal processing and machining by the heated grinding wheel. An apparatus has been proposed (see, for example, Patent Document 3). In this grinding apparatus, the grinding wheel is irradiated with a laser beam having a wavelength that is transmissive to the workpiece from the opposite side of the holding surface that holds the workpiece (the opposite side of the workpiece across the holding surface). In this way, the contact surface of the grinding wheel is heated.

JP 2010-149222 A JP 2012-135851 A JP 2011-171451 A

  However, in the above-described grinding apparatus described in Patent Document 3, it is necessary to configure the holding table (chuck table) that holds the workpiece with a transparent member so that the laser beam can pass through, and the cost required for manufacturing the holding table is high. To rise. As a result, the manufacturing cost of the grinding device increases.

  The present invention has been made in view of such circumstances, and a grinding apparatus capable of efficiently grinding a workpiece having high hardness while suppressing an increase in manufacturing cost of the grinding apparatus. The purpose is to provide.

  A grinding apparatus according to the present invention includes a chuck table for holding a plate-like workpiece, a grinding means for rotatably mounting a grinding wheel in which grinding wheels for grinding the plate-like workpiece held by the chuck table are annularly arranged, and grinding A grinding apparatus comprising: grinding feed means for approaching and moving away from the chuck table; and laser irradiation means for irradiating a laser on a contact surface of the grinding wheel where the grinding wheel comes into contact with the plate-like workpiece, wherein the laser irradiation means is A light emitting unit that emits a laser beam having a wavelength that is transmissive to the plate-like workpiece from the processing surface side of the plate-like workpiece held by the chuck table, and a condenser lens that collects the laser beam emitted from the light emitting unit And a laser beam emitted from the laser irradiating means and transmitted through the plate-like workpiece is a holding surface for holding the held surface of the plate-like workpiece. In is reflected, which comprises carrying out the machining of the workpiece plate with the grinding wheel with laser machining the contact surface by irradiating the contact surfaces of the grinding wheel.

  In the grinding apparatus, a laser irradiation unit that emits a laser beam is disposed on the processing surface side of the plate-shaped workpiece, and the laser beam is reflected by a part of the holding surface that holds the surface to be held of the plate-shaped workpiece to be applied to the grinding wheel. Irradiating. For this reason, it is not necessary to comprise the chuck table which hold | maintains a plate-shaped workpiece with a transparent material etc., and a laser beam can be irradiated to a grinding wheel. Thereby, an increase in the manufacturing cost of the chuck table can be suppressed, and as a result, an increase in the manufacturing cost of the grinding apparatus can be suppressed. Further, the contact surface of the grinding wheel is laser processed by irradiating the grinding wheel with a laser beam, and the plate-like workpiece is machined with the laser-grinding grinding wheel. Thereby, the complex grinding process of a heat processing and machining can be implemented, and even if it is a workpiece with high hardness, it can grind efficiently. As a result, it is possible to efficiently grind the workpiece having high hardness while suppressing an increase in manufacturing cost of the grinding apparatus.

  For example, in the above grinding apparatus, the laser irradiation means includes a cylindrical lens that condenses the laser beam emitted from the light emitting portion into a linear shape as a condensing lens. According to this configuration, since the laser beam emitted from the light emitting unit is condensed into a linear shape, the focal length of the laser beam can be easily adjusted. Thereby, the focus of a laser beam can be appropriately adjusted to the contact surface of the grinding wheel with respect to a plate-shaped workpiece | work, and it becomes possible to heat a contact surface effectively.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to perform an efficient grinding process with respect to a workpiece with high hardness, suppressing the raise of the manufacturing cost of a grinding device.

It is a schematic diagram which shows the principal part structure of the grinding apparatus which concerns on 1st Embodiment. It is a schematic diagram which shows the principal part structure of the grinding apparatus which concerns on 1st Embodiment. It is explanatory drawing of the structure of the condensing lens which the grinding apparatus which concerns on 1st Embodiment has, and the focal distance by a laser irradiation means. It is explanatory drawing of the focal length by the structure of the condensing lens which the grinding apparatus which concerns on the modification of 1st Embodiment has, and a laser irradiation means. It is a schematic diagram which shows the principal part structure of the grinding apparatus which concerns on the modification of 1st Embodiment. It is a schematic diagram which shows the principal part structure of the grinding apparatus which concerns on the modification of 1st Embodiment. It is explanatory drawing of the plate-shaped workpiece | work used with the grinding device which concerns on 2nd Embodiment. It is an enlarged view of the periphery of the reflection location of the laser beam in the grinding apparatus according to the third embodiment. It is explanatory drawing of the focal length by the structure of the condensing lens which the grinding apparatus which concerns on the modification of 1st Embodiment has, and a laser irradiation means.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In the following, a grinding apparatus that grinds a plate-shaped workpiece (semiconductor wafer) as a workpiece having high hardness such as sapphire or silicon carbide (SiC) to a predetermined thickness will be described. However, the material of the workpiece in the grinding apparatus according to the present invention is not limited to these and can be appropriately changed.

(First embodiment)
FIG.1 and FIG.2 is a schematic diagram which shows the principal part structure of the grinding apparatus 1 which concerns on 1st Embodiment. In FIG. 1, the grinding device 1 is shown from the side, and in FIG. 2, the grinding device 1 is shown from above. In FIGS. 1 and 2, only components related to grinding in the grinding apparatus 1 are shown for convenience of explanation. In FIG. 2, some of the constituent elements shown in FIG. 1 (the grinding feed means 4 and the light emitting portion 51 of the laser irradiation means 5 described later) are omitted.

  As shown in FIGS. 1 and 2, the grinding apparatus 1 according to the present embodiment includes a chuck table 2, a grinding means 3, a grinding feed means 4, and a laser irradiation means 5. Although omitted in FIGS. 1 and 2, the grinding apparatus 1 is an ordinary grinding apparatus such as a conveying means for conveying the plate-like workpiece W before or after grinding in addition to these components. It shall be provided with the component with which.

  The chuck table 2 has a holding surface 21 that holds the plate-like workpiece W (more specifically, the surface to be held of the plate-like workpiece W). The holding surface 21 has a circular shape in plan view (see FIG. 2), and is made of, for example, a porous ceramic material. The holding surface 21 is connected to a suction source (not shown) and configured to suck and hold the plate-like workpiece W. Further, the chuck table 2 is connected to a rotation drive mechanism (not shown), and is rotated while the plate-like workpiece W is held on the holding surface 21 by the rotation drive mechanism.

  In the vicinity of the center of the holding surface 21, a reflecting surface 22 constituting a part of the holding surface 21 is provided. The reflecting surface 22 has a circular shape in plan view (see FIG. 2). For example, the upper surface of the holding surface 21 is coated with a dielectric multilayer film such as gold (Au) or aluminum (Al). It is formed. For example, the reflecting surface 22 is disposed so as to be exposed on the upper surface of the holding surface 21 and plays a role of reflecting a laser beam emitted from the laser irradiation means 5 to a grinding wheel 311 described later. The reflective surface 22 may be formed by embedding a thin metal plate such as gold (Au) or aluminum (Al) on the upper surface of the holding surface 21. The details of the manner of reflection of the laser beam by the reflecting surface 22 will be described later.

  The grinding means 3 has a grinding wheel 31 for grinding the plate-like workpiece W held by the chuck table 2 and a rotating spindle 32 on which the grinding wheel 31 is rotatably mounted at the lower end. The grinding wheel 31 has a circular shape in plan view (see FIG. 2), and a plurality of grinding wheels 311 are provided on the lower surface thereof. These grinding wheels 311 are annularly arranged on the outer peripheral edge of the grinding wheel 31. For example, the grinding wheel 311 is composed of a diamond wheel obtained by solidifying diamond abrasive grains with a binder such as a metal bond or a resin bond. The rotary spindle 32 is connected to a rotary drive mechanism (not shown), and is configured so that the grinding wheel 31 can be rotated by this rotary drive mechanism.

  The grinding feed means 4 is attached to a part of the rotary spindle 32 of the grinding means 3 and moves the grinding means 3 (more specifically, the grinding wheel 31) toward and away from the chuck table 2. More specifically, the grinding feed means 4 uses the chuck table 2 (more specifically, the plate-like workpiece W held by the chuck table 2 when the plate-like workpiece W is ground to a predetermined thickness with the grinding wheel 311. ) To bring the grinding means 3 closer. On the other hand, the grinding means 3 is separated from the chuck table 2 when the plate-like workpiece W is carried in or out of the chuck table 2.

  The laser irradiation unit 5 includes a light emitting unit 51 and a condensing lens 52, and is disposed in a region above the chuck table 2 (on the grinding unit 3 side). The light emitting unit 51 is disposed obliquely above the grinding position by the grinding wheel 311, and the optical axis direction (left and right direction shown in FIG. 2) is parallel to the radial direction of the grinding wheel 31. The light emitting unit 51 is transmissive to the plate-like workpiece W from the processed surface (upper surface shown in FIG. 1) side of the plate-like workpiece W held on the chuck table 2, and is reflected at the reflection surface 22. The laser beam is emitted. For example, the laser beam emitted from the light emitting unit 51 is set to have a wavelength of 515 nm, a power of about 20 W, a pulse width of about 8 ps, and a repetition frequency of 200 kHz.

  The condenser lens 52 is disposed between the light emitting unit 51 and the plate-like workpiece W and condenses the laser beam emitted from the light emitting unit 51. For example, the condensing lens 52 includes a cylindrical lens that condenses the laser beam emitted from the light emitting unit 51 into a linear shape. In the first embodiment, a case where the condensing lens 52 is configured by a cylindrical lens will be described. However, the condensing lens 52 applied to the laser irradiation unit 5 is not limited to the cylindrical lens, and can be appropriately changed. For example, a convex lens or a toric lens can be used as the condenser lens 52.

  The laser beam emitted from the light emitting unit 51 is collected by the condenser lens 52 and then passes through the plate-like workpiece W to reach the chuck table 2 (holding surface 21). The laser beam that has reached the chuck table 2 is reflected by the reflecting surface 22 and is applied to the contact surface 311a of the grinding wheel 311 with the plate-like workpiece W. By this laser beam irradiation, the contact surface 311a of the grinding wheel 311 is laser-processed, and a combination of thermal processing and machining by the laser-processed grinding wheel 311 is performed.

  The condensing lens 52 condenses the laser beam emitted from the light emitting unit 51 on the reflection surface 22 provided in the center of the holding surface 21. In this case, the condensing lens 52 adjusts the focal length of the laser beam emitted from the light emitting unit 51 so that the entire contact surface 311a of the grinding wheel 311 is irradiated. More specifically, the condensing lens 52 increases the focal length of the laser beam applied to the inner portion of the contact surface 311a of the grinding wheel 311 while the focal length of the laser beam applied to the outer portion of the contact surface 311a. shorten.

  In order to adjust the focal length of the laser beam, the condenser lens 52 is disposed so as to extend in a direction perpendicular to the optical axis of the laser beam from the light emitting unit 51, as shown in FIG. For example, the condensing lens 52 has an arc shape on the light emitting portion 51 side as viewed from the extending direction of the condensing lens 52, and a planar shape on the plate-like workpiece W side (see FIG. 3A). Further, the condensing lens 52 is configured such that the R shape of the cross section near the upper end portion (end portion on the grinding means 3 side) in the side view is small and the R shape of the cross section near the lower end portion is large.

  Here, the structure of the condensing lens 52 with which the grinding apparatus 1 which concerns on this Embodiment is provided, and the focal distance by the laser irradiation means 5 are demonstrated. FIG. 3A is an explanatory diagram of the configuration of the condensing lens 52 included in the grinding apparatus 1 according to the present embodiment and the focal length by the laser irradiation means 5. In FIG. 3B, the laser irradiation means 5 ′ according to the reference example is shown for convenience of explanation.

  As shown in FIG. 3A, the condensing lens 52 is provided with a flat surface 52a on the plate-like workpiece W side and an arc-shaped surface 52b on the light emitting unit 51 side. Further, the condensing lens 52 is provided with a first R-shaped portion 521 at the upper end portion, and a second R-shaped portion 522 having an R shape larger than the first R-shaped portion 521 at the lower end portion. The condensing lens 52 is configured such that the R shape gradually increases from the first R shape portion 521 toward the second R shape portion 522.

In the condensing lens 52 having such a configuration, the focal length of the laser beam emitted from the light emitting unit 51 changes according to the position where the condensing lens 52 is incident. For example, the laser beam incident on the upper end portion of the condensing lens 52 is condensed by the first R-shaped portion 521 and the focal point is determined from the first R-shaped portion 521 at a position of length a ₁ . Meanwhile, the laser beam incident on the lower portion of the condenser lens 52 is condensed by the 2R-shaped portion 522, the focus is determined by the position of the length b ₁ from the 2R-shaped portion 522. Here, the length a ₁ is larger than the length b ₁ . For this reason, the laser beam incident on the upper end portion of the condenser lens 52 is focused at a position farther than the laser beam incident on the lower end portion.

  By using the condensing lens 52 having such a configuration, it is possible to adjust the position where the laser beam emitted from the light emitting unit 51 is irradiated on the contact surface 311a. More specifically, the laser beam incident on the first R-shaped portion 521 of the condensing lens 52 can be applied to the inner portion of the contact surface 311a (that is, the portion far from the condensing lens 52), and the second R-shaped portion. The laser beam incident on 522 can be applied to the outer portion of the contact surface 311a (ie, the portion close to the condenser lens 52). As a result, the entire contact surface 311a (the entire radial direction of the grinding wheel 31) can be laser processed uniformly.

FIG. 3B shows a case where third R-shaped portions 523a and 523b having the same R shape are provided on the upper end portion and the lower end portion of the condenser lens 52 ′. In the condensing lens 52 ′ having such a configuration, the focal length of the laser beam emitted from the light emitting unit 51 ′ is the same regardless of the position incident on the condensing lens 52 ′. For example, the laser beam is incident on the upper portion of the condenser lens 52 'is focused by the 3R-shaped portion 523a, the focus is determined by the position of the length _{a 2} of the 3R-shaped portion 523a. Meanwhile, the laser beam incident on the lower portion of the condenser lens 52 'is focused by the 3R-shaped portion 523b, the focus is determined by the position of the length _{b 2} from the 3R-shaped portion 523b. Here, the length a ₂ and the length b ₂ are the same length. For this reason, the focal point of the laser beam incident on the condensing lens 52 'is determined at a position of the same length regardless of the incident position.

  When the condensing lens 52 ′ having such a configuration is used, since the focal length of the laser beam emitted from the light emitting portion 51 ′ is the same, it is irradiated to substantially the same position on the contact surface 311 a of the grinding wheel 311. . For this reason, only a specific portion of the contact surface 311a of the grinding wheel 311 is locally laser processed.

  In the above description, the condensing lens 52 increases the focal length of the laser beam applied to the inner portion of the contact surface 311a of the grinding wheel 311 while the focal length of the laser beam applied to the outer portion of the contact surface 311a. In this case, the R shape of the upper end (end on the grinding means 3 side) is small and the R shape of the lower end is large (see FIG. 3A). However, on the premise that the focal length can be adjusted as described above, the shape of the condenser lens 52 can be changed as appropriate.

For example, as shown in FIG. 9, a rectangular portion 524 (hatched portion shown for convenience in FIG. 9) whose cross-sectional area continuously changes may be provided on the plate-like workpiece W side of the condenser lens 52. Note that the cross-sectional area of the rectangular portion 524 decreases from the upper end portion (first R-shaped portion 521) of the condenser lens 52 toward the lower end portion (second R-shaped portion 522). Even in the case of having the rectangular portion 524 as described above, the focal length of the laser beam applied to the inner portion of the contact surface 311a of the grinding wheel 311 is increased while the contact surface is similar to the condenser lens 52 shown in FIG. 3A. it is possible to shorten the focal length of the laser beam applied to the outer portion of the 311a (i.e., the length a ₄ is greater than the length b _1).

  Hereinafter, the operation | movement at the time of the grinding process in the grinding device 1 which concerns on this Embodiment is demonstrated. At the time of grinding, first, the grinding means 3 is separated from the chuck table 2 by the grinding feed means 4, and the plate-like workpiece W is carried into the chuck table 2 by a conveying means (not shown). Then, after the plate-like workpiece W is placed on the holding surface 21, the grinding means 3 is brought closer to the chuck table 2 by the grinding feed means 4. At that time, a driving force is supplied from the rotational drive mechanism to the chuck table 2 and the grinding means 3, and the chuck table 2 and the grinding wheel 31 are rotationally driven in the same direction (clockwise direction in FIG. 2).

  At the timing when the grinding wheel 311 provided on the grinding wheel 31 comes into contact with the plate-like workpiece W (or at a timing before a certain time before contact), a laser beam is emitted from the light emitting portion 51 of the laser emitting means 5. The laser beam emitted from the light emitting unit 51 is collected by the condenser lens 52, passes through the plate-like workpiece W, and reaches the reflecting surface 22 of the chuck table 2. Then, the laser beam reflected by the reflecting surface 22 is applied to the contact surface 311 a of the grinding wheel 311. The contact surface 311a of the grinding wheel 311 is laser processed by such laser beam irradiation. And the grinding process with respect to the plate-shaped workpiece | work W is implemented in the state in which the contact surface 311a was heated with laser processing in this way.

  In this grinding process, the contact surface 311a of the grinding wheel 311 is laser-processed, and the plate-like workpiece W is machined by the grinding wheel 311 heated with the laser processing. In other words, the plate-like workpiece W is subjected to a combined grinding process of thermal processing and machining. When the plate-like workpiece W reaches a predetermined thickness by such grinding, the grinding is stopped. Then, after the grinding means 3 is separated from the chuck table 2 by the grinding feed means 4, the plate-like workpiece W is unloaded from the chuck table 2 by a conveying means (not shown).

  As described above, in the grinding apparatus 1 according to the present embodiment, the laser irradiation means 5 (the light emitting unit 51 and the condenser lens 52) is disposed on the processed surface side of the plate-like workpiece W, and the laser beam is plate-like. The grinding wheel 311 is irradiated with the light reflected by the reflecting surface 22 which is a part of the holding surface 21 of the chuck table 2 of the workpiece W. For this reason, it becomes unnecessary to comprise the chuck table 2 holding the plate-like workpiece W with a transparent material or the like as in the conventional grinding apparatus, and an increase in the manufacturing cost of the grinding apparatus 1 can be suppressed.

  Further, in the grinding apparatus 1 according to the present embodiment, the contact surface 311a of the grinding wheel 311 is laser-processed by irradiating the grinding wheel 311 with a laser beam, and the plate-like workpiece is heated by the grinding wheel 311 heated with the laser processing. Machining can be applied to W. Thereby, the composite grinding of heat processing and machining can be performed. For this reason, the processing surface of the plate-like workpiece W can also be heated, and machining can be performed in a state in which the plate-like workpiece W is easily processed, and even a hard workpiece can be efficiently ground. Can be applied.

  Further, in the grinding apparatus 1 according to the present embodiment, the laser irradiation means 5 (the light emitting unit 51 and the condensing lens 52) is disposed on the processed surface side of the plate-like workpiece W. It can be arranged at any position around the chuck table 2. Thereby, compared with the structure which arrange | positions the laser irradiation means 5 inside the chuck | zipper table 2, for example, the freedom degree of design of the grinding device 1 can be ensured.

  Furthermore, the grinding apparatus 1 according to the present embodiment includes a cylindrical lens as the condenser lens 52. By using a cylindrical lens as the condenser lens 52, the laser beam emitted from the light emitting unit 51 can be condensed into a linear shape. Thereby, it is possible to easily adjust the focal length of the laser beam. For this reason, it is possible to appropriately focus the laser beam on the contact surface 311a of the grinding wheel 311 with respect to the plate-like workpiece W, and it is possible to effectively heat the contact surface 311a.

  In particular, in the grinding apparatus 1 according to the present embodiment, the cylindrical lens is disposed so as to extend perpendicular to the optical axis direction, and the R shape of one end (upper end) is more than the other end (lower end). It is small. As a result, the focal length can be adjusted according to the position of the laser beam incident on the cylindrical lens, and the entire contact surface 311a of the grinding wheel 311 can be laser processed.

In the above embodiment, the case where the tops of the arc-shaped surfaces 52b of the condenser lens 52 (cylindrical lens) are arranged at the center in the width direction of the first R-shaped portion 521 and the second R-shaped portion 522 is shown. (See FIG. 3A). However, the configuration of the condenser lens 52 is not limited to this, and can be changed as appropriate. For example, as shown in FIG. 4, the top of the arc-shaped surface 52 b may be arranged close to one side in the width direction of the first R-shaped portion 521 and the second R-shaped portion 522. Even in this case, the length a ₃ to the focal point determined by the first R-shaped portion 521 is longer than the length b ₃ to the focal point determined by the second R-shaped portion 522, as in the above embodiment. large. In this case, the focal position of the laser beam emitted from the light emitting unit 51 can be adjusted in the width direction of the condenser lens 52. For this reason, the position of the light emission part 51 and / or the condensing lens 52 can be selected flexibly by adjusting the position of the top part of the circular arc-shaped surface 52b.

  Further, in the above-described embodiment, the laser beam is positioned at a position obliquely above the grinding position by the grinding wheel 311 and whose optical axis direction (left-right direction shown in FIG. 2) is parallel to the radial direction of the grinding wheel 31. Irradiation means 5 (light emitting unit 51 and condenser lens 52) is arranged. In this case, a difference (optical path difference) occurs in the optical path from the reflection surface 22 to the contact surface 311a of the grinding wheel 311. For this reason, in order to absorb this optical path difference, the R shape of the upper end portion (end portion on the grinding means 3 side) of the condenser lens 52 is small, and the R shape of the lower end portion is large. However, the configuration and arrangement of the laser irradiation means 5 are not limited to this and can be changed as appropriate.

  For example, as shown in FIG. 5 and FIG. 6, a position that is obliquely above the grinding position by the grinding wheel 311 and whose optical axis direction (left-right direction shown in FIG. 6) is orthogonal to the radial direction of the grinding wheel 31. The laser irradiation means 5 (light emitting part 51 and condensing lens 52) may be arranged on the surface. Then, a laser beam is irradiated so as to be orthogonal to the radial direction of the grinding wheel 31, and the linear condensing portion L condensed by the condensing lens 52 in the radial direction of the grinding wheel 31 is positioned on the contact surface 311a. Good (see FIG. 6). In this case, there is no optical path difference until the reflection surface 22 is reflected and reaches the contact surface 311a of the grinding wheel 311. For this reason, it is not necessary to provide a difference in the R shape of the upper and lower end portions of the condenser lens 52 as in the above embodiment. For example, as shown in FIG. 5, the condensing lens 52 can be configured by a plano-convex lens in which the plate-like workpiece W side is a flat surface and the light emitting unit 51 side is a convex shape.

(Second Embodiment)
In the grinding apparatus 1 according to the first embodiment, the laser beam from the laser irradiation means 5 is reflected by the reflecting surface 22 that constitutes a part of the holding surface 21 of the chuck table 2, and the contact surface 311 a of the grinding wheel 311 is reflected. Irradiated. In the grinding apparatus according to the second embodiment, the laser beam from the laser irradiation means 5 is reflected by a part of the holding surface of the protective member that protects the plate-like workpiece W, and is irradiated onto the contact surface 311a of the grinding wheel 311. This is different from the grinding apparatus 1 according to the first embodiment.

  Hereinafter, the configuration of the grinding apparatus according to the second embodiment will be described focusing on differences from the grinding apparatus 1 according to the first embodiment. In the following description, “1” is given to the head of the same reference numeral for the configuration common to the grinding apparatus 1 according to the first embodiment, and the description and illustration thereof are omitted as appropriate.

  FIG. 7 shows a perspective view of a plate-like workpiece W to be ground by the grinding apparatus 11 according to the present embodiment. FIG. 7 shows a plate-like workpiece W having a notch indicating a crystal orientation. As shown in FIG. 7, the plate-like workpiece W to be ground by the grinding apparatus 11 according to the present embodiment has its front surface W1 adhered to the front surface P1 of the protective member P via an adhesive, and the rear surface W2 is exposed. Placed in the state. In this case, the surface P1 of the protection member P constitutes a holding surface that holds the surface W1 that is the surface to be held of the plate-like workpiece W.

  The protection member P is formed in a disk shape by a transparent member such as glass, for example, and prevents the plate-like workpiece W from being damaged or deformed during conveyance. In the grinding apparatus 11 according to the present embodiment, a circular reflecting surface 122 is provided on a part of the surface P1 of the protective member P. The reflection surface 122 is formed of, for example, a dielectric multilayer film such as gold (Au) or aluminum (Al) or a metal thin plate, like the reflection surface 22 according to the first embodiment. In a state where the plate-like workpiece W is bonded to the protection member P, the reflecting surface 122 is disposed at a position corresponding to the center of the plate-like workpiece W.

  The grinding apparatus 11 according to the present embodiment is different from the grinding apparatus 1 according to the first embodiment in that the reflecting surface 22 is not formed on the holding surface 21 of the chuck table 2. Other components (grinding means 3, grinding feed means 4 and laser irradiation means 5) are the same as those of the grinding apparatus 1 according to the first embodiment. Further, the operation at the time of grinding in the grinding apparatus 11 according to the present embodiment is also common to the operation of the grinding apparatus 1 according to the first embodiment.

  When grinding is performed by the grinding apparatus 11 according to the present embodiment, the plate-like workpiece W adhered to the protective member P is disposed on the chuck table 2. In this case, the plate-like workpiece W is held on the chuck table 2 via the protective member P. In a state of being held on the holding surface 21 of the chuck table 2, the reflecting surface 122 of the protection member P is disposed at a position equivalent to the reflecting surface 22 according to the first embodiment in plan view. For this reason, the laser beam radiated from the light emitting portion 51 of the laser irradiation means 5 during the grinding process and transmitted through the plate-like workpiece W is reflected by the reflecting surface 122 and irradiated onto the contact surface 311a of the grinding wheel 311. Grinding is performed on the plate-like workpiece W by the contact surface 311a heated in accordance with the laser processing by the laser beam irradiation. For this reason, also in the grinding apparatus 11 which concerns on this Embodiment, the effect similar to the grinding apparatus 1 which concerns on 1st Embodiment can be acquired.

  Here, the case where the protection member P is formed of a transparent member such as glass is described. However, the configuration of the protection member P is not limited to this, and can be changed as appropriate. For example, a protective tape that protects a device or the like provided on the surface of the plate-like workpiece W may be used as the protective member P. In this case, it is conceivable to use part or all of the sticking surface (holding surface) to the plate-like workpiece W as the reflecting surface 122. For example, a metal thin film can be coated on the sticking surface (holding surface) of the protective tape stuck on the surface W1 of the plate-like workpiece W. In this case, as in the case where the protective member P is formed of a transparent member such as glass, the laser beam emitted during grinding can be reflected by the reflecting surface 122 and irradiated onto the contact surface 311a of the grinding wheel 311. For this reason, also in the grinding apparatus 11 which concerns on this Embodiment, the effect similar to the grinding apparatus 1 which concerns on 1st Embodiment can be acquired.

(Third embodiment)
In the grinding apparatus 11 according to the second embodiment, the laser beam from the laser irradiation means 5 is reflected by the reflecting surface 122 that constitutes a part of the protective member P, and is irradiated onto the contact surface 311a of the grinding wheel 311. . In the grinding apparatus according to the third embodiment, the laser beam is reflected at the boundary portion between the plate-like workpiece W and the protection member P without providing such a reflection surface 122, and the contact surface 311 a of the grinding wheel 311 is reflected. It differs from the grinding device according to the second embodiment in that it is irradiated.

  Hereinafter, the configuration of the grinding apparatus according to the third embodiment will be described focusing on differences from the grinding apparatus 11 according to the second embodiment. In the following description, the same reference numerals are given to components common to the grinding apparatus 11 according to the second embodiment, and the description and illustration thereof are omitted as appropriate.

  FIG. 8 is an enlarged view of the vicinity of a laser beam reflection spot in the grinding apparatus according to the present embodiment. 8 shows a case where the laser irradiation means 5 (the light emitting portion 51 and the condensing lens 52) is arranged at a position where the optical axis direction is orthogonal to the radial direction of the grinding wheel 31, as shown in FIG. ing.

  The grinding apparatus according to the present embodiment is that the reflecting surface 122 is not formed on the protective member P and that the laser irradiation means 5 (the light emitting unit 51 and the condensing lens 52) is disposed on the plate-like workpiece W side. This is different from the grinding device 11 according to the second embodiment. Other components (grinding means 3 and grinding feed means 4) are the same as those of the grinding apparatus 11 according to the second embodiment. Further, the operation at the time of grinding in the grinding apparatus according to the present embodiment is also common to the operation of the grinding apparatus 11 according to the second embodiment.

  As shown in FIG. 8, in the grinding apparatus according to the present embodiment, the laser irradiation means 5 is arranged so that the laser beam is incident at an incident angle θ2 larger than the critical angle θ1 of the plate-like workpiece W. The laser beam is totally reflected by a part of the surface P1 of the protective member P having a refractive index smaller than that of the workpiece W (that is, a part of the holding surface that holds the held surface of the plate-like workpiece W). That is, when light travels from a medium having a high refractive index to a medium having a low refractive index, when the incident angle of light is larger than the critical angle, the light is not refracted and the light is totally reflected. That is, all incident light is reflected without passing through the boundary surface of these media. In the grinding apparatus according to the present embodiment, the laser beam from the laser irradiating means 5 is reflected by using such a light phenomenon, and is irradiated onto the contact surface 311a of the grinding wheel 311.

  For example, when the plate-like workpiece W is composed of a silicon wafer, the protective member P is composed of a protective tape made of polyolefin or polyethylene terephthalate (PET) as a base material. The laser beam from the means 5 can be reflected. The refractive index of the silicon wafer is about 3.5, and the refractive index of the protective tape of the base material is 1.5 to 1.7. Further, when the plate-like workpiece W is composed of a silicon wafer, it is conceivable to use a transparent resin plate or a glass plate as the other protective member P of the protective tape.

  As shown in FIG. 8, when a laser beam is incident at an incident angle θ2 exceeding the critical angle θ1, the laser beam does not pass through the boundary surface between the plate-like workpiece W and the protective member P (the surface P1 of the protective member P). Total reflection. By placing the grinding wheel 311 on the condensing part of the laser beam that totally reflects, the contact surface 311a can be irradiated. For this reason, also in the grinding apparatus which concerns on this Embodiment, the effect similar to the grinding apparatus which concerns on 1st, 2nd embodiment can be acquired. In particular, in the grinding apparatus according to the third embodiment, the laser beam is contacted with the grinding wheel 31 without separately providing the reflecting surface 22 provided on the chuck table 2 or the reflecting surface 122 provided on the protection member P. 311a can be irradiated.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, the above embodiment has been described on the premise of the laser irradiation means 5 in which the focal position by the condenser lens 52 is fixed. However, the configuration of the laser irradiation means 5 is not limited to this and can be changed as appropriate. For example, it is preferable as an embodiment that the focal position by the condensing lens 52 can be adjusted in accordance with the wear condition of the grinding wheel 311. For example, such adjustment of the focal position can be realized by changing the inclination angle of the light emitting unit 51 and / or the condenser lens 52. More specifically, the focal length of the laser irradiation means 5 is adjusted by detecting the degree of wear of the grinding wheel 311 and changing the inclination angle of the light emitting unit 51 and / or the condenser lens 52 according to the detection result. can do. Alternatively, a reflective mirror may be interposed between the light emitting unit 51 and the condenser lens 52, and the focal position may be adjusted by changing the angle of the reflective mirror. When the focal position by the condenser lens 52 can be adjusted as described above, the focal position of the laser beam can be adjusted according to the wear condition of the grinding wheel 311, so that even when the grinding wheel 311 is worn, The contact surface 311a can be appropriately heated.

  Moreover, in the said embodiment, it demonstrates using the plate-shaped workpiece | work W in which the surface processed by the grinding means 3 has a flat shape. However, the configuration of the plate-like workpiece W to be ground is not limited to this and can be changed as appropriate. For example, in order to ensure the strength of the plate-like workpiece W, the plate-like workpiece W provided with a circular reinforcing portion on the outer peripheral edge portion of the surface to be processed may be set as a grinding object.

  As described above, according to the present invention, while suppressing an increase in the manufacturing cost of the grinding device, it has an effect that it is possible to perform an efficient grinding process on a workpiece having high hardness, The present invention is useful for a grinding apparatus for grinding a plate-like workpiece made of sapphire, silicon carbide (SiC), or the like.

DESCRIPTION OF SYMBOLS 1,11 Grinding device 2 Chuck table 21 Holding surface 22, 122 Reflecting surface 3 Grinding means 31 Grinding wheel 311 Grinding wheel 311a Contact surface 32 Rotating spindle 4 Grinding feed means 5 Laser irradiation means 51 Light emitting part 52 Condensing lens W Plate-shaped workpiece P Protective member

Claims (2)

A chuck table for holding a plate-like work, a grinding means for rotatably mounting a grinding wheel in which grinding wheels for grinding the plate-like work held by the chuck table are arranged in an annular shape, and the grinding means on the chuck table A grinding apparatus comprising: a grinding feed unit that approaches and separates; and a laser irradiation unit that irradiates a laser on a contact surface of the grinding wheel where the grinding wheel comes into contact with a plate-shaped workpiece,
The laser irradiation means includes: a light emitting unit that emits a laser beam having a wavelength that is transmissive to the plate-like workpiece from the processing surface side of the plate-like workpiece held by the chuck table; and a laser beam emitted from the light emitting unit. A condensing lens for condensing
The laser beam emitted from the laser irradiating means and transmitted through the plate-like workpiece is reflected by a part of the holding surface that holds the holding surface of the plate-like workpiece, and irradiated to the contact surface of the grinding wheel to laser the contact surface. A grinding apparatus characterized by processing and machining a plate-like workpiece with the grinding wheel.   The grinding apparatus according to claim 1, wherein the laser irradiating means includes a cylindrical lens that condenses the laser beam emitted from the light emitting portion into a linear shape as the condensing lens.

Images