JP2016127108A - Chuck table mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chuck table mechanism which can easily fix a sheet-like member therein.SOLUTION: A chuck table mechanism 10 comprises a holding part 12 which has a holding surface 12a for holding a wafer; and a frame body 13 which surrounds the holding part 12. The chuck table mechanism 10 comprises a disk-like table body 11 which has the holding surface 12a and the frame body 13; a sheet-like member 20 which has a size of covering the holding surface 12a and extending to the frame body 13; and an annular fixing part 15 which fits with the outer periphery of the table body 11 to push down and fix a periphery part 24 projecting from the table body 11 of the sheet-like member 20 covering the holding surface 12a to the area lower than the holding surface 12a. When the annular fixing part 15 fitted with the outer periphery of the table body 11 is rotated in the circumferential direction and positioned at the predetermined position, the table body 11 and the annular fixing part 15 are fixed to each other by engagement means 40, 50 formed in the outer periphery of the table body 11 and the annular fixing part 15.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a chuck table mechanism of a laser processing apparatus used for laser processing.

  A technique is known in which a modified layer is formed inside a semiconductor wafer or an optical device wafer, and the wafer is divided into device chips using the modified layer as a breakage starting point. At this time, the laser beam forming the modified layer is permeable to the wafer, but is not permeable to the film formed on the surface of the wafer in many cases. A laser beam may be incident from the back side of a non-wafer.

  The wafer is usually processed by fixing and exposing the surface on which the device is formed on the annular frame via an adhesive tape. This is because the device is used for alignment or the like, and for the same reason after laser processing, it is more efficient to expose and fix the device.

  When a laser beam is incident from the back side of the wafer, a processing method is proposed in which the surface on which the device is formed is held by the holding surface of the chuck table and laser processing is performed from the back side of the wafer while allowing the adhesive tape to pass through. Yes. In order to prevent the device from directly contacting the holding surface and being damaged, a processing method for holding the device via the sheet-like member is also proposed, and a chuck table mechanism including means for fixing the sheet-like member is also proposed. (Patent Document 1).

JP 2013-229403 A

  However, in the chuck table mechanism disclosed in Patent Document 1, it is difficult to fix the sheet-like member due to an increase in flexibility due to the thinning of the sheet-like member.

  The present invention has been made in view of the above, and an object thereof is to provide a chuck table mechanism capable of easily fixing a sheet-like member.

  In order to solve the above-described problems and achieve the object, the chuck table mechanism of the present invention includes a holding portion having a holding surface for holding a wafer having a device formed on the surface, and a frame body surrounding the holding portion. A disk-like table main body having the holding surface and the frame, a sheet-like member that covers the holding surface and reaches the frame, and the table main body An annular fixing portion that fits to the outer periphery of the portion and covers the holding surface, and fixes the outer peripheral portion protruding from the table main body portion of the sheet-like member downward from the holding surface. When the annular fixing portion fitted to the outer periphery of the portion is rotated in the circumferential direction and positioned at a predetermined position, the table main body portion is engaged with the table main body portion by the engaging means formed on the outer periphery of the table main body portion and the annular fixing portion. The annular fixing parts are fixed to each other. Is the fact characterized.

  In the chuck table mechanism, the engaging means includes a concave portion formed on one of the outer periphery of the table main body and the annular fixing portion and a convex portion formed on the other, and the convex portion is formed in the concave portion. The annular fixing portion can be fixed to the table main body portion by fitting the portions.

  In the chuck table mechanism, the sheet-like member is formed of a material having flexibility and air permeability, covers the holding surface, and reaches a size of a main body portion reaching the frame body, and a peripheral edge of the frame body. And a plurality of intermittent hole portions that are intermittently formed in the main body portion and divide the holding region corresponding to the holding surface and the outer peripheral portion of the outer periphery of the holding region.

  In the chuck table mechanism of the present invention, the flexible sheet-like member can be reliably fixed by fixing the outer periphery of the sheet-like member while being pushed down from the holding surface by the annular fixing portion. . Further, since the table main body and the annular fixing portion are fitted by rotation, the sheet-like member can be reliably fixed and the attachment / detachment work can be facilitated.

FIG. 1 is a diagram illustrating a sheet-like member according to the embodiment. FIG. 2 is an exploded perspective view showing the chuck table mechanism on which the sheet-like member according to the embodiment is installed. FIG. 3 is a cross-sectional view of the main parts of the table main body portion and the annular fixing portion of the chuck table mechanism according to the embodiment. FIG. 4 is a cross-sectional view of the chuck table mechanism according to the embodiment. FIG. 5 is a perspective view showing a state in which the chuck table mechanism shown in FIG. 2 holds a wafer or the like. FIG. 6 is a side sectional view showing a state in which laser processing is performed on the wafer held by the chuck table mechanism shown in FIG.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

Embodiment
A chuck table mechanism according to an embodiment will be described with reference to the drawings. FIG. 1A is a plan view of a sheet-like member of the chuck table mechanism according to the embodiment. FIG.1 (b) is sectional drawing which follows the IB-IB line | wire in Fig.1 (a). FIG. 2 is an exploded perspective view illustrating the chuck table mechanism according to the embodiment. Fig.3 (a) is sectional drawing of the principal part before fixation of the table main-body part and annular fixing | fixed part of the chuck table mechanism which concerns on embodiment. FIG. 3B is a cross-sectional view of a main part after the table main body portion and the annular fixing portion of the chuck table mechanism according to the embodiment are fixed. FIG. 4 is a cross-sectional view of the chuck table mechanism according to the embodiment. FIG. 5 is a perspective view showing a state in which the chuck table mechanism shown in FIG. 2 holds a wafer or the like. FIG. 6 is a side sectional view showing a state in which laser processing is performed on the wafer held by the chuck table mechanism shown in FIG.

  The chuck table mechanism 10 according to the present embodiment constitutes the laser processing apparatus 1 shown in FIG. The laser processing apparatus 1 irradiates a wafer W with a laser beam L. A wafer W to be processed by the laser processing apparatus 1 shown in FIG. 6 is a disk-shaped semiconductor wafer or optical device wafer using silicon, sapphire, gallium or the like as a base material in this embodiment. .

  As shown in FIG. 5, the wafer W is formed with devices D in respective regions defined by the division lines S provided in a lattice pattern on the surface WS. As shown in FIGS. 5 and 6, the wafer W has a back surface WR on the back side of the surface WS in which a plurality of devices D are formed on the adhesive surface Ta of the adhesive tape T whose outer peripheral edge is attached to the annular frame F. By being attached, it is fixed to the annular frame F. For this reason, the wafer W is fixed to the annular frame F in a state where the surface WS on which a plurality of devices D are formed is exposed. Note that an epi layer (not shown) is formed on the surface WS of the wafer W. The epi layer is made of a material that attenuates or blocks the laser beam L. The adhesive tape T and the adhesive surface Ta are made of a material that transmits the laser beam L.

  The laser processing apparatus 1 is an apparatus that forms a modified layer K (shown in FIG. 6) inside the wafer W. The modified layer K means a region where the density, refractive index, mechanical strength and other physical characteristics are different from those of the surroundings, and includes a melt-treated region, a crack region, and a dielectric breakdown region. , A refractive index change region, a region where these regions are mixed, and the like.

  As shown in FIG. 6, the laser processing apparatus 1 irradiates a chuck table mechanism 10 that holds a wafer W, and a laser beam L having a wavelength of 1064 nm, for example, that passes through the wafer W that is held by the chuck table mechanism 10. Laser beam irradiating means 30, X-axis moving means and Y-axis moving means (not shown) for relatively moving the chuck table mechanism 10 and the laser beam irradiating means 30 in the X and Y axis directions parallel to the horizontal direction perpendicular to each other. Etc. at least.

  The chuck table mechanism 10 sucks and holds the wafer W by the holding surface 12a. As shown in FIGS. 2 and 5, the chuck table mechanism 10 includes a disk-shaped table main body 11 that sucks and holds the surface WS of the wafer W with a holding surface 12 a, a sheet-like member 20, and the table main body 11. And an annular fixing portion 15 that is detachably fastened.

  The table main body 11 holds the wafer W that has been bonded to the opening of the annular frame F by placing the wafer W before laser processing on the holding surface 12a. The table main body 11 includes a holding part 12 having a holding surface 12 a for sucking and holding the wafer W, and a frame body 13 surrounding the holding part 12. That is, the table main body 11 has a holding surface 12 a and a frame body 13. The holding unit 12 has a disk shape formed of a porous material such as porous ceramic, and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown) to suck the wafer W placed on the holding surface 12a. Hold by. The frame 13 is made of a metal such as stainless steel and is formed in an annular shape.

  The table body 11 is processed and fed in the X-axis direction by the X-axis moving means, rotated around the central axis by a rotation drive source (not shown), and indexed and fed in the Y-axis direction by the Y-axis moving means. The In addition, a plurality of clamp portions 14 that are driven by an air actuator and sandwich the annular frame F around the wafer W are provided around the table main body portion 11.

  The sheet-like member 20 covers the holding surface 12a of the holding part 12 of the table main body part 11 shown in FIGS. The sheet-like member 20 protects the device D on the wafer W surface WS facing the holding surface 12a. The sheet-like member 20 is a porous film made of a synthetic resin such as ultrahigh molecular weight polyethylene, and is formed of a material having flexibility, air permeability, and releasability. The sheet-like member 20 has a circular shape with a diameter larger than that of the holding surface 12 a of the holding unit 12. In the present embodiment, the sheet-like member 20 has a diameter of 340 mm and a thickness of about 0.1 mm to 0.4 mm, for example, about 0.18 mm.

  As shown in FIGS. 1A and 1B, the sheet-like member 20 covers the holding surface 12 a of the holding portion 12 and has a main body portion 21 having a size reaching the frame body 13 and a plurality of intermittent hole portions. 22. The diameter of the main body 21 is formed larger than the outer diameter of the frame 13, that is, the outer diameter of the table main body 11. The intermittent hole portion 22 is formed intermittently on the main body portion 21 along the peripheral edge (outer edge) of the frame body 13, and the main body holding region 23 corresponding to the holding surface 12 a and the outer periphery of the outer periphery of the main body holding region 23. The main body 21 is separated from the part 24. The intermittent hole portion 22 is a hole opened in the main body portion 21, and the planar shape is formed in an arc shape with the center of the main body portion 21 as the center of curvature, and is spaced at equal intervals in the circumferential direction of the main body portion 21. Has been placed.

  When the sheet-like member 20 covers the table main body 11 of the chuck table mechanism 10, the main body holding region 23 of the main body 21 divided by the intermittent hole 22 overlaps the holding surface 12 a and the upper surface of the frame 13. When the sheet-like member 20 covers the table main body 11 of the chuck table mechanism 10, the outer peripheral portion 24 of the main body 21 overlaps the outer peripheral surface of the frame 13, and the annular fixing portion 15 is fitted to the outer periphery. 13 is sandwiched between the outer peripheral surface 13 and the annular fixing portion 15. For this reason, when the sheet-like member 20 covers the table main body 11 of the chuck table mechanism 10, the intermittent hole 22 overlaps the corner 13 a of the frame 13. In the present embodiment, the width of the outer peripheral portion 24 of the sheet-like member 20 is formed to be about 20 mm.

  The annular fixing portion 15 is made of a metal such as stainless steel and is formed in an annular shape. The annular fixing portion 15 is fitted to the outer periphery of the frame body 13 of the table main body portion 11, and the outer peripheral portion 24 protruding from the outer edge of the frame body 13 of the table main body portion 11 of the sheet-like member 20 covering the holding surface 12a is framed. It is sandwiched between the outer peripheral surface of the body 13 and pressed down below the holding surface 12a to be fixed.

  The chuck table mechanism 10 includes a table main body side engaging means 40 (corresponding to an engaging means) provided in the table main body part 11 for fixing the table main body part 11 and the annular fixing part 15 to each other, and the annular fixing part 15. And an annular fixing portion side engaging means 50 (corresponding to an engaging means) provided on the head.

  The table main body side engaging means 40 is formed on the outer periphery of the frame 13 of the table main body 11. The table main body side engaging means 40 is connected to the outer peripheral protrusion 41 that protrudes in the outer peripheral direction from the edge of the outer peripheral surface of the frame 13 that is away from the holding surface 12 a, and to the tip of the outer peripheral protrusion 41. It is provided with a circumferentially extending portion 42 extending in the circumferential direction of the main body 11 and is formed in a flat plate shape. The circumferentially extending portion 42 is provided with a recess 43 that penetrates the circumferentially extending portion 42. That is, the table main body side engaging means 40 is provided with a recess 43.

  The annular fixing portion side engaging means 50 is provided on the outer periphery of the annular fixing portion 15. The annular fixing portion side engaging means 50 includes an axially extending portion 51 protruding in a direction away from the holding surface 12 a in parallel with the central axis from the outer peripheral surface of the annular fixing portion 15, and an outer periphery from the tip of the axially extending portion 51. The outer peripheral protrusion part 52 protruded in the direction is provided, and it is formed in an L shape when viewed from the side. The outer peripheral protruding portion 52 includes a convex portion 53 that protrudes toward the holding surface 12a and a rod-shaped grip portion 54 that protrudes further in the outer peripheral direction. In the table main body side engaging means 40 and the annular fixing part side engaging means 50, the convex part 53 is fitted in the concave part 43, and the annular fixing part 15 is fixed to the table main body part 11. Thus, the engaging means 40, 50 is composed of the concave portion 43 formed on one of the outer periphery of the table main body 11 and the annular fixing portion 15 and the convex portion 53 formed on the other side. The convex portion 53 is fitted, and the annular fixing portion 15 is fixed to the table main body portion 11. In addition, it is desirable that a plurality of engaging means 40 and 50 are provided at intervals in the circumferential direction. In this embodiment, two engaging means 40 and 50 are provided at equal intervals in the circumferential direction, and a table is provided. The main body side engaging means 40 is provided at the center between the adjacent clamp parts 14. Further, the engaging means 40 and 50 are disposed at positions spaced from the holding surface 12a in the central axis direction than the clamp portion 14 in a state of being fitted to each other.

  Next, a method for assembling the chuck table mechanism 10 having the above-described configuration will be described. In a state where the annular fixing portion 15 is not fitted, the main body holding region 23 of the sheet-like member 20 is overlapped with the holding surface 12 a of the table main body 11, and the intermittent holes 22 are formed at the corners of the frame 13 of the table main body 11. It overlaps with the part 13a. Then, while pressing the outer peripheral portion 24 of the sheet-like member 20 against the outer peripheral surface of the frame body 13 of the table main body portion 11, the annular fixing portion 15 is fitted to the outer periphery of the frame body 13 of the table main body portion 11. As shown in FIG. 3A, the table main body side engaging means 40 and the annular fixing part side engaging means 50 are arranged in the circumferential direction, and the outer peripheral protrusion 52 of the annular fixing part side engaging means 50. Is positioned at a position farther from the holding surface 12a than the table main body side engaging means 40, and the annular fixing portion 15 is fitted to the outer periphery of the frame body 13 of the table main body portion 11.

  Then, an annular shape fitted to the outer periphery of the table body 11 while gripping the grip 54 in a direction in which the recess 43 of the table main body side engaging means 40 and the convex 53 of the annular fixing part side engaging means 50 approach each other. The fixing portion 15 is rotated in the circumferential direction. Then, the table main body part side engaging means 40 rides on the convex part 53, and the convex part 53 fits into the concave part 43 as shown in FIG. Thus, when the annular fixing portion 15 is positioned at a predetermined position where the convex portion 53 is fitted into the concave portion 43, the engaging means 40 and 50 cause the table main body portion 11 and the annular fixing portion to be positioned as shown in FIGS. 15 are fixed to each other. At this time, since the intermittent hole portion 22 of the sheet-like member 20 overlaps the corner portion 13a of the frame body 13 of the table main body portion 11, the sheet-like member 20 is surely secured at the corner portion 13a of the frame body 13 of the table main body portion 11. The main body holding region 23 can be brought into close contact with the holding surface 12a.

  The laser processing apparatus 1 provided with the chuck table mechanism 10 having the above-described configuration sucks and holds the surface WS of the wafer W via the sheet-like member 20 on the holding surface 12a of the holding part 12 of the table main body part 11, and The annular frame F is clamped by the clamp part 14. Then, the adhesive surface Ta of the adhesive tape T mainly faces the sheet-like member 20 on the corner 13 a of the frame 13. Then, the laser processing apparatus 1 relatively moves the wafer W held on the chuck table mechanism 10 and the laser beam irradiation means 30 along the scheduled division line S by the X-axis moving means, the Y-axis moving means, and the rotational drive source. The modified layer K is formed on the division line S by irradiating the laser beam L from the laser beam irradiation means 30 toward the back surface WR of the wafer W. When the modified layer K is formed on all the division lines S, the irradiation of the laser beam L from the laser beam irradiation means 30 is stopped. Then, the wafer W on which the modified layer K is formed is transported to the next process or the like and then divided into device chips with the modified layer K as a base point.

  As described above, according to the chuck table mechanism 10 according to the present embodiment, the outer peripheral portion 24 of the sheet-like member 20 is fixed by being pushed down from the holding surface 12a by the annular fixing portion 15 to be flexible. The sheet-like member 20 can be securely fixed. Further, the annular fixing portion 15 fitted to the outer periphery of the frame body 13 is rotated in the circumferential direction so that the table main body side engaging means 40 and the annular fixing portion side engaging means 50 are fitted to each other. 11 and the annular fixing portion 15 can be fixed. Thus, since the table main body part 11 and the annular fixing part 15 can be fixed by the rotation of the annular fixing part 15, the sheet-like member 20 can be reliably fixed and the sheet-like member 20 can be easily fixed.

  In the chuck table mechanism 10, the table main body side engaging means 40 includes a concave portion 43 and the annular fixing portion side engaging means 50 includes a convex portion 53. Can be easily fixed. Further, the chuck table mechanism 10 is disposed at a position farther from the holding surface 12a in the central axis direction than the clamp portion 14 in a state where the engaging means 40 and 50 are fitted to each other. For this reason, the chuck table mechanism 10 can suppress the interference between the adhesive tape T with the wafer W sucked and held and the engaging means 40 and 50 interfering with each other.

  Further, in the chuck table mechanism 10, the intermittent hole portion 22 in which the sheet-like member 20 is intermittently opened in the main body portion 21 along the peripheral edge of the frame body 13 overlaps the corner portion 13 a of the frame body 13. For this reason, as for the sheet-like member 20, the intermittent hole part 22 will reduce a contact area with the adhesive tape T. FIG. Therefore, the sheet-like member 20 can reduce the possibility that the adhesive tape T sticks, can prevent the adhesive tape T from being peeled off at the end of laser processing, and reliably carry out the wafer W after laser processing. be able to.

  Further, since the intermittent hole portion 22 that is intermittently opened in the main body portion 21 of the sheet-like member 20 overlaps the corner portion 13 a of the frame body 13, the chuck table mechanism 10 is reliably bent at the corner portion 13 a of the frame body 13. The main body holding region 23 can be brought into close contact with the holding surface 12a and can be made to follow along the outer peripheral part 24 in close contact with the outer peripheral surface of the frame 13. Therefore, the sheet-like member 20 minimizes the influence on the main body holding region 23 that covers the holding surface 12a when the outer peripheral portion 24 hangs down from the holding surface 12a and extends along the outer peripheral surface of the frame 13. The flat state can be maintained without the main body holding region 23 covering the holding surface 12a being swung. Therefore, the sheet-like member 20 can be easily fixed to the chuck table mechanism 10.

  In the embodiment described above, the concave portion 43 is provided in the table main body side engaging means 40 and the convex portion 53 is provided in the annular fixing portion side engaging means 50. The convex portion 53 may be provided, and the concave portion 43 may be provided in the annular fixing portion side engaging means 50. Moreover, in this invention, the recessed part 43 may be the dent provided in these, without penetrating the table main-body-part side engaging means 40 and the cyclic | annular fixing | fixed part side engaging means 50. FIG.

  The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Chuck table mechanism 11 Table main-body part 12 Holding part 12a Holding surface 13 Frame 15 Annular fixing part 20 Sheet-like member 21 Main-body part 22 Intermittent hole part 23 Main-body part holding | maintenance area | region 24 Outer peripheral part 40 Table main-body-side engaging means Combined means)
43 concave part 50 annular fixing part side engaging means (engaging means)
53 Convex W Wafer WS Surface D Device

Claims (3)

A chuck table mechanism comprising a holding portion having a holding surface for holding a wafer having a device formed on a surface, and a frame body surrounding the holding portion,
A disc-shaped table main body having the holding surface and the frame;
A sheet-like member that covers the holding surface and reaches the frame;
An annular fixing portion that fits to the outer periphery of the table main body portion and covers the holding surface and presses and fixes the outer peripheral portion protruding from the table main body portion of the sheet-like member downward from the holding surface;
When the annular fixing portion fitted to the outer periphery of the table main body portion is rotated in the circumferential direction and positioned at a predetermined position, the table is moved by the engagement means formed on the outer periphery of the table main body portion and the annular fixing portion. A chuck table mechanism characterized in that a main body portion and the annular fixing portion are fixed to each other.   The engaging means includes a concave portion formed on one of the outer periphery of the table main body and the annular fixed portion, and a convex portion formed on the other, and the convex portion is fitted into the concave portion. The chuck table mechanism according to claim 1, wherein the annular fixing portion is fixed to the table main body portion. The sheet-like member is
A main body portion formed of a material having flexibility and air permeability, covering the holding surface, and sized to reach the frame;
A plurality of intermittent hole portions that are intermittently formed in the main body portion along the periphery of the frame and divide the holding region corresponding to the holding surface and the outer peripheral portion of the outer periphery of the holding region. The chuck table mechanism according to claim 1.

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