processing device

Abstract

A processing device for planar processing a workpiece to a desired thickness is provided. A processing device (1) for planar processing a non-circular workpiece (W) using a grinding wheel (21) has an adsorption member (33) capable of adsorbing and holding the workpiece (W), and an attachment (37) provided on the outer peripheral side of the adsorption member (33), made of a material more difficult to grind than the adsorption member (33), and capable of contacting the grinding wheel (21) at the time of self-grinding of the adsorption member (33).

Description

TECHNICAL FIELD

[0001] The present application relates to a processing device for planar processing of a workpiece. BACKGROUND

[0002] In the field of semiconductor manufacturing, a processing device is known for planar processing of a semiconductor workpiece (hereinafter referred to as "workpiece") such as a silicon wafer into thin and flat.

[0003] Patent Document 1 discloses a grinding device for grinding a rectangular workpiece held on a chuck table into a predetermined thickness by bringing a rotating grinding wheel into contact with the upper surface of the rectangular workpiece.

[0004] PRIOR ART DOCUMENT

[0005] PATENT DOCUMENT

[0006] Patent Document 1: JP Patent No. 5230982 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, in the case of planar processing of a workpiece, due to the influence of the fixing surface accuracy of the workpiece and the installation accuracy of the processing tool such as a grinding wheel, the processed workpiece can have a thickness unevenness. In order to eliminate such thickness unevenness, it has been necessary to reassemble or adjust the fixing surface of the workpiece or the processing tool.

[0009] In addition, in the case of feed processing of a workpiece of a shape other than a circle or a workpiece provided with an orientation plane (hereinafter collectively referred to as "workpiece of a non-circular shape"), the contact area between the workpiece and the grinding wheel that rotates every time the chuck table is not constant, and in the area where the contact area is relatively large, the grinding amount of the workpiece is reduced, and in the area where the contact area is relatively small, the grinding amount of the workpiece tends to be large. That is, the thickness of the workpiece is uneven corresponding to the size of the contact area between the grinding wheel and the workpiece in processing, and there is a problem that the workpiece cannot be processed to the desired thickness.

[0010] Therefore, in order to planar process the workpiece to the desired thickness, a technical problem arises, and the purpose of the present application is to solve this technical problem.

[0011] TECHNICAL SOLUTION FOR SOLVING THE PROBLEM

[0012] To achieve the above object, the present application relates to a machining device which performs face machining of a workpiece by a grinding wheel, characterized by comprising: an adsorption member which is capable of adsorbing and holding the workpiece; and an accessory which is provided on an outer peripheral side of the adsorption member, is detachably provided on a chuck table which accommodates the adsorption member, is made of a material which is more difficult to grind than the adsorption member, and is capable of contacting the grinding wheel at the time of self-grinding of the adsorption member.

[0013] According to this structure, in order to offset unevenness in thickness of the workpiece after face machining, the thickness of the adsorption member after self-grinding in the region where the grinding wheel contacts the adsorption member and the accessory is thicker than the thickness of the adsorption member after self-grinding in the region where the grinding wheel contacts the adsorption member, whereby unevenness in thickness of the workpiece after face machining can be alleviated.

[0014] Effects of the Invention

[0015] The present application can alleviate unevenness in thickness of the workpiece after face machining due to accuracy of a fixing surface of the workpiece, accuracy of installation of a machining tool, or a shape of the workpiece. BRIEF DESCRIPTION OF DRAWINGS

[0016] [ Figure 1 ] is a schematic view of a machining device showing one embodiment of the present application.

[0017] [ Figure 2 ] is a perspective view of a chuck table.

[0018] [ Figure 3 ] is a view of the chuck table of Figure 2 (a) is a plan view, Figure 3 (b) is a sectional view in the A-A direction of (a). Figure 3 Figure 3

[0019] [ Figure 4 ] is a schematic view showing a case of self-grinding.

[0020] [ Figure 5 ] is a plan view for comparing contact areas of a workpiece and a grinding wheel at two positions in the workpiece.

[0021] [ Figure 6 ] is a schematic view of thickness of a workpiece after face machining at the two positions shown in Figure 5

[0022] [ Figure 7 ] is a plan view showing a positional relationship between an accessory and an adsorption member.

[0023] [ Figure 8 ] is a schematic view in which Figure 8 ​​​(a) is a schematic diagram showing the thickness after self-grinding at two locations within the adsorption component. Figure 8 (b) is a schematic diagram showing the thickness of the planes at two locations within the workpiece after machining.

[0024] [ Figure 9 This is a perspective view of a chuck table used in a processing apparatus related to a variation of the present invention.

[0025] [ Figure 10 To indicate Figure 9 Diagram of the chuck table. Figure 10 (a) is a top view. Figure 10 (b) is Figure 10 The BB direction section view in (a). Detailed Implementation

[0026] An embodiment of the present invention will be described with reference to the accompanying drawings. Furthermore, in the following text, when referring to the number, value, quantity, range, etc., of the constituent elements, the reference is not limited to that specific number, except where specifically indicated or where it is explicitly limited to a particular number in principle; it may be above or below that specific number.

[0027] Furthermore, when referring to the shape or positional relationship of constituent elements, etc., except for cases specifically indicated or cases that are considered obviously not so in principle, it includes cases that are substantially similar or analogous to that shape, etc.

[0028] Furthermore, the accompanying drawings may exaggerate features by magnifying them to make them easier to understand, and the dimensions and proportions of the constituent elements may not necessarily be the same as in reality. Also, in cross-sectional views, some of the shaded lines of the constituent elements may be omitted to make the cross-sectional structure of the constituent elements easier to understand.

[0029] Furthermore, in this embodiment, the way of expressing directions such as up and down, left and right is not absolute. It is appropriate when each component is in the posture depicted in the accompanying drawings, but if the posture changes, it should be interpreted according to the change in posture.

[0030] The processing device 1 performs grinding on the workpiece W. For example... Figure 1 As shown, the processing device 1 has a processing section 2 and a holding section 3.

[0031] The machining section 2 includes a grinding wheel 21, a grinding wheel spindle 22, and a feed mechanism 23.

[0032] The grinding wheel 21 is, for example, a cup-shaped grinding wheel, and is mounted at the lower end of the grinding wheel spindle 22.

[0033] The grinding wheel spindle 22 is configured to rotate around the rotation axis 2a, and the grinding wheel 21 and the grinding wheel spindle 22 can rotate as a whole.

[0034] The feed mechanism 23 raises and lowers the grinding wheel spindle 22 in the vertical direction. The feed mechanism 23 is a known structure including, for example, a plurality of linear guides that guide the moving direction of the grinding wheel spindle 22, and a ball screw slider mechanism that raises and lowers the grinding wheel spindle 22. The feed mechanism 23 is interposed between the grinding wheel spindle 22 and the column 24.

[0035] The holding portion 3 has a chuck table 31 and a chuck spindle 32.

[0036] The chuck table 31 has a suction member 33 made of a porous material such as alumina on its upper surface, and a dense body 34 in which the suction member 33 is embedded at substantially the center thereof.

[0037] The chuck table 31 has a pipe line that extends through the inside to the surface, which is not shown. The pipe line is connected to a vacuum source, a compressed air source, or a water supply source through a rotary joint, which is not shown. When the vacuum source is activated, a negative pressure is generated between the workpiece W placed on the suction member 33 and the upper surface (suction surface 33a) of the suction member 33, and the workpiece W is suction-held on the suction surface 33a. Also, when the compressed air or water supply source is activated, the suction between the workpiece W and the suction member 33 is released.

[0038] The suction member 33 is formed in a shape corresponding to the rectangular workpiece W when viewed from the planar surface.

[0039] The chuck spindle 32 is configured to rotate around the rotation axis 3a and drive the chuck table 31. The drive source of the chuck spindle 32 can be, for example, a servo motor or the like.

[0040] As shown in Figure 2 , the chuck table 31 is formed with an annular recess 35 to surround the suction member 33. The bottom of the annular recess 35 is formed with a plurality of bolt holes 36. Also, the annular recess 35 need not be formed on the entire outer periphery of the suction member 33, but can be formed locally in a range in which an accessory 37 described later can be installed.

[0041] The accessory 37 is installed on the annular recess 35. Specifically, as shown in Figure 3 (a), the accessory 37 is disposed in a manner to close the four corners of the suction member 33 and the outer edge of the chuck table 31 in the radial direction of the chuck table 31 when viewed from the planar surface. The accessory 37 can be made of a difficult-to-grind material having a higher hardness than the suction member 33, for example, the same material as the dense body 34. Also, as shown in Figure 3 (b), the suction surface 33a is substantially flush with the upper surface (contact surface 37a) of the accessory 37 when the accessory 37 is installed on the chuck table 31.

[0042] Attachment 37 has bolt holes 38 that extend through the top and bottom. Attachment 37 is easily tightened onto the chuck table 31 by bolts 39. Furthermore, the corners of the contact surface 37a are preferably chamfered to suppress chipping of the grinding wheel 21.

[0043] The operation of the processing apparatus 1 is controlled by a control unit (not shown). The control unit controls the constituent elements of the processing apparatus 1. The control unit may consist of, for example, a central processing unit and a memory. Furthermore, the function of the control unit can be implemented using software control or by hardware operation.

[0044] Next, the self-grinding of the processing device 1 will be described based on the accompanying drawings.

[0045] like Figure 4 As shown, self-grinding refers to the process of bringing the grinding wheel 21 close to the chuck table 31 via the feed mechanism 23 to grind the adsorption surface 33a of the adsorption component 33 using the grinding wheel 21. Self-grinding is performed to maintain the adsorption surface 33a in the desired shape, and is usually performed when changing the chuck table 31, before performing planar machining on the workpiece W.

[0046] When the machining apparatus 1 contacts the machining surface of the grinding wheel 21 parallel to the machined surface of a non-circular workpiece W to machine the workpiece W in a planar manner, the machining amount (grinding amount) of the workpiece W may be unstable within the plane. The following will be based on... Figure 5 The reasons for this will be explained. Furthermore, the following explanation will use a workpiece W viewed from above as a square as an example, but the shape of workpiece W is not limited to this.

[0047] like Figure 5 As shown, comparing contact area A1 and contact area A2, it can be seen that contact area A1 is approximately twice the width of contact area A2. Contact area A1 is the contact area between workpiece W and grinding wheel 21 when the machining surface of grinding wheel 21 contacts the rotation center O of chuck table 31 through the corner of workpiece W; contact area A2 is the contact area between workpiece W and grinding wheel 21 when the machining surface of grinding wheel 21 contacts the rotation center O through the center of the edge of workpiece W.

[0048] Furthermore, when the grinding wheel 21 and the workpiece W are in uniform contact across the entire surface, as the contact area between the workpiece W and the grinding wheel 21 increases, the grinding amount of the workpiece W decreases, and the processed workpiece W becomes thicker. That is, when comparing the thickness of the ground workpiece W in contact areas A1 and A2, such as... Figure 6 As shown, the workpiece W in contact area A2 is formed to be thicker than the workpiece W in contact area A1. For example, in the case of a workpiece W with a square diameter of 280 mm, the end P2 of contact area A2 is ground to be about 4 μm thinner than the end P1 of contact area A1.

[0049] Therefore, in the processing device 1, the amount of self-grinding is locally increased and decreased in the adsorption member 33 in a manner to offset the change in the thickness of the workpiece W corresponding to the change in the contact area of the workpiece W and the grinding wheel 21 at the time of flat processing.

[0050] Specifically, as shown in Figure 7 , at the time of flat processing, assuming a first processing region Rl in which the amount of grinding of the workpiece W is relatively small and a second processing region R2 in which the amount of grinding of the workpiece W is relatively large, the outer periphery of the adsorption member 33 in the first processing region Rl is provided with the attachment 37.

[0051] In the present embodiment, the first processing region Rl is set to a sector shape with the diagonal of the adsorption member 33 as the center and a central angle of ±15°, and the second processing region R2 is set to a substantially sector shape between the adjacent first processing regions Rl with a central angle of 60°. Also, the size of each processing region Rl and R2 can be appropriately changed depending on the processing conditions of the workpiece W and the like.

[0052] Further, the attachment 37 is made of a material that is more difficult to grind than the adsorption member 33, whereby, as shown in Figure 8 (a), the amount of grinding of the adsorption member 33 in the first processing region Rl at the time of self-grinding is smaller than the amount of grinding of the adsorption member 33 in the second processing region R2, and therefore, the adsorption member 33 in the first processing region Rl is ground locally thicker.

[0053] Further, when flat processing is performed on the workpiece W, as shown in Figure 8 (b), the amount of grinding of the workpiece W in the first processing region Rl at the time of flat processing is smaller than the amount of grinding of the workpiece W in the second processing region R2, and therefore, the workpiece W in the first processing region Rl is processed thicker than the workpiece W in the second processing region R2.

[0054] Thus, at the time of flat processing, the difference in the amount of grinding between the first processing region Rl and the second processing region R2 is offset by the difference in the thickness of the first processing region Rl and the second processing region R2 in the adsorption member 33, thereby reducing the thickness unevenness of the workpiece W after flat processing.

[0055] Also, the shapes of the adsorption member 33 and the attachment 37 are not limited to the above-described shapes, for example, in the case where the chuck table 31 adsorptively holds the workpiece W formed with the oriented flat surface OF, as shown in Figure 9 , Figure 10 (a) and (b), the adsorption member 33 can be formed in a shape that is circular when viewed from the plane, and the attachment 37 can be formed in a shape that is annular sector when viewed from the plane.

[0056] Therefore, the processing device 1 in the present embodiment is a processing device 1 for performing face processing of the workpiece W using the grinding wheel 21, and is configured to have the adsorption member 33 capable of adsorbing and holding the workpiece W, and the attachment 37 provided on the outer peripheral side of the adsorption member 33, made of a material more difficult to grind than the adsorption member 33, and capable of contacting the grinding wheel 21 at the time of self-grinding of the adsorption member 33.

[0057] According to this configuration, in the case where the grinding wheel 21 performs face processing of the workpiece W, in order to offset the thickness unevenness of the workpiece W after processing caused by the change in the contact area between the grinding wheel 21 and the workpiece W with the rotation angle of the chuck table 31, the thickness of the adsorption member 33 after self-grinding in the first processing region R1 where the grinding wheel 21 contacts the adsorption member 33 and the attachment 37 is thicker than the thickness of the adsorption member 33 after self-grinding in the second processing region R2 where the grinding wheel 21 contacts the adsorption member 33, and thus the thickness unevenness of the workpiece W after face processing can be alleviated.

[0058] Further, the processing device 1 in the present embodiment is configured such that the attachment 37 is detachably provided on the chuck table 31 that accommodates the adsorption member 33.

[0059] According to this configuration, the position of the attachment 37 with respect to the adsorption member 33 can be changed, and thus the shape of the adsorption member 33 after self-grinding can be changed in accordance with the shape of the workpiece W and the processing conditions.

[0060] Further, the processing device 1 in the present embodiment is configured such that the workpiece W is formed in a non-circular shape.

[0061] According to this configuration, the thickness unevenness of the workpiece W after face processing caused by the shape of the workpiece W can be alleviated.

[0062] Furthermore, the present application can be modified in various ways other than those described above without departing from the spirit of the present application, and the present application naturally also extends to such modifications. Further, the above-described embodiments and each modification example can be combined with each other.

[0063] Explanation of Symbols

[0064] 1: Processing device

[0065] 2: Processing portion

[0066] 21: Grinding wheel

[0067] 22: Grinding wheel spindle

[0068] 23: Feed mechanism

[0069] 24: Column

[0070] 3: Holding portion

[0071] 31: chuck table

[0072] 32: chuck spindle

[0073] 33: suction member

[0074] 33a: suction surface

[0075] 34: compact body

[0076] 35: annular recess

[0077] 36: bolt hole (of compact body)

[0078] 37: attachment

[0079] 37a: contact surface

[0080] 38: bolt hole (of attachment)

[0081] 39: bolt

[0082] R1: first machining region

[0083] R2: second machining region

[0084] W: workpiece

Claims

1. A processing apparatus that uses a grinding wheel to perform planar processing on a non-circular workpiece, characterized in that, The processing device has: an adsorption member formed in a shape corresponding to the workpiece, capable of adsorbing and holding the workpiece; and an accessory provided on the outer periphery side of the adsorption member, detachably provided in the chuck table accommodating the adsorption member at a position corresponding to the shape of the workpiece, made of a material more difficult to grind than the adsorption member, capable of contacting the grinding wheel during self-grinding of the adsorption member, the accessory locally increases and decreases the grinding amount of the self-grinding in the adsorption member in a manner corresponding to the change in the workpiece when planar processing of the workpiece.

2. The processing device according to claim 1, wherein the accessory is provided on the outer periphery side of the adsorption member in a region where the processing pressure of the workpiece ground by the grinding wheel is relatively low when planar processing of the workpiece.

3. The processing device according to claim 1, wherein the adsorption member is formed in a rectangular shape, the accessory is provided on the outer periphery side of the four corners of the adsorption member.

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