JP7152882B2 - How to hold the workpiece unit - Google Patents

Description

The present invention relates to a holding mechanism and holding method for a workpiece unit.

In the semiconductor device manufacturing process, a large number of electronic circuits such as ICs and LSIs are formed on the front surface of a semiconductor wafer, and then the rear surface of the wafer is ground to a predetermined thickness before the electronic circuits are formed. A large number of semiconductor chips are obtained as devices from one wafer by performing dicing for cutting the region along the dividing lines.

A grinding device and a cutting device are generally used for backside grinding and dicing of a wafer, respectively. These apparatuses are provided with a holding table for holding a wafer under vacuum to expose the surface to be processed of the wafer, and processing means for processing the surface to be processed of the wafer held by the holding table. things are known. The processing means is a grinding means having a grinding tool such as a grinding wheel in the case of a grinding device, and a cutting means having a cutting tool such as a cutting blade in the case of a cutting device.

By the way, in general, when a workpiece such as a semiconductor wafer is handled, the workpiece is positioned in an opening of an annular frame and supported by the annular frame via an adhesive tape attached to the workpiece. Workability is improved and damage to the workpiece is prevented by holding an annular frame as a workpiece unit (see, for example, Patent Document 1). When the work piece of the work piece unit is held by a holding table provided in a processing device such as the grinding device or the cutting device, the annular frame does not interfere with the processing means. A common method is to clamp and hold the annular frame with clamps.

Japanese Patent Application Laid-Open No. H08-69985

However, when the annular frame is held by the clamping method, the annular frame is clamped from the outside, so a device area larger than the diameter of the annular frame is required, resulting in an increase in the size of the device. In addition, in recent years, the diameter of wafers has been increasing, and there is a concern that holding the annular frame by a clamping method will increase the size of the apparatus.

Therefore, in the case of holding a workpiece unit in a processing apparatus, there is a problem of not requiring a device area larger than the diameter of the annular frame, unlike the clamp system.

In order to solve the above problems, the present invention provides a grinding apparatus for grinding a workpiece using a grinding wheel, wherein the workpiece is provided with an annular frame that supports the workpiece positioned in an opening via an adhesive tape. holding the unit by a holding table means comprising a workpiece holding table for holding the workpiece and an annular frame holding portion surrounding the workpiece holding table and holding the annular frame In the method, the annular frame holding part is formed with a bolt-shaped engaging protrusion consisting of a head and a neck, and the annular frame holding part is vertically movable with respect to the workpiece holding table. The annular frame has at least an insertion hole into which the head of the engaging projection is inserted and an engaged elongated hole extending in the circumferential direction from the insertion hole into which the neck of the engaging projection is engaged. a workpiece unit placing step of placing the workpiece unit on the holding table means so as to insert the engaging projection into the insertion hole; and the workpiece unit and the holding table means. to move the engaging projection from the insertion position where the engaging projection is inserted into the insertion hole to the engaging position where the neck of the engaging projection engages with the engaged elongated hole. and lowering the annular frame holding portion relative to the workpiece holding table to push the annular frame downward below the holding surface of the workpiece holding table; enabling the workpiece to be ground without the frame coming into contact with the grinding wheel .

In the method for holding a workpiece unit according to the present invention, the annular frame holding portion is formed with a bolt-shaped engaging projection having a head portion and a neck portion, and the annular frame is inserted with the head portion of the engaging projection. The holding table means is machined so as to include at least an insertion hole and an engaging elongated hole extending in the circumferential direction from the insertion hole and engaged by the neck of the engaging projection, and the engaging projection is inserted into the insertion hole. The workpiece unit placing step for placing the workpiece unit and the workpiece unit and the holding table means are relatively rotated to move the engaging projection from the insertion position where the engaging projection is inserted into the insertion hole. and a workpiece unit engaging step of moving the engaging projection to an engaging position where the neck of the workpiece engages with the engaged elongated hole. Since the unit is held by the holding table means, it is no longer necessary to hold and fix the annular frame with clamps located outside the annular frame as in the clamp system, and the device area exceeding the diameter of the annular frame can be reduced. no longer needed.

It is a perspective view which shows an example of a to-be-processed object unit. It is a top view which shows an example of a to-be-processed object unit. FIG. 4 is a plan view showing an example of a holding mechanism for a workpiece unit; FIG. 4 is a cross-sectional view showing an example of a holding mechanism for a workpiece unit; FIG. 5 is a plan view showing a state in which the workpiece unit is placed on the holding table means so that the engaging projections of the annular frame holding portion are inserted into the insertion holes of the annular frame; By rotating the workpiece unit and the holding table means relative to each other, from the insertion position where the engaging projection is inserted into the insertion hole, to the engaging position where the neck of the engaging projection engages the engaged long hole. FIG. 10 is a plan view for explaining a case where the engaging projection is moved to the right; FIG. 5 is a cross-sectional view showing a state in which the engaging protrusion is in the engaging position and the workpiece unit is held by the holding table means;

The workpiece W shown in FIGS. 1 and 2 is, for example, a circular semiconductor wafer (for example, a wafer with a diameter of 300 mm), and the surface Wa of the workpiece W facing upward in FIG. The lines S are set so as to cross each other at right angles. Devices D are formed in each of the lattice-shaped regions partitioned by the planned division lines S. As shown in FIG.
In addition, the structure of the workpiece W is not limited to the example shown in this embodiment. For example, the workpiece W may be a substrate having a rectangular outer shape, or may be a wafer before devices are formed on the surface Wa.

The adhesive tape T shown in FIGS. 1 and 2 is a circular tape having a diameter larger than that of the workpiece W. As shown in FIG. The annular frame F shown in FIG. 1 is made of SUS or the like and has an outer diameter larger than the diameter of the adhesive tape T, and has a circular opening Fc in the center.
For example, the annular frame F is positioned with respect to the workpiece W so that the center of the workpiece W placed on a bonding table (not shown) substantially coincides with the center of the opening Fc of the annular frame F. . Then, the adhesive tape T is pressed against the back surface Wb of the workpiece W by a press roller or the like on the attaching table to be attached. Further, by attaching the outer peripheral portion of the adhesive surface (upper surface) of the adhesive tape T to the lower surface Fb of the annular frame F, the workpiece W is supported by the annular frame F via the adhesive tape T. In other words, it is possible to form a workpiece unit WU including an annular frame F that supports the workpiece W positioned in the opening Fc via the adhesive tape T.
The workpiece unit WU shown in FIGS. 1 and 2 has its surface Wa exposed for cutting. The back surface Wb is exposed upward by sticking.

The holding mechanism 3 of the workpiece unit WU shown in FIGS. At least a holding table means 3A consisting of a portion 31 is provided.
The holding mechanism 3 is provided in, for example, a cutting device that cuts the workpiece W by cutting the workpiece W with a rotating cutting grindstone. The holding mechanism 3 includes a grinding device that grinds and thins the workpiece W with a rotating grinding wheel, a laser processing device that performs desired processing on the workpiece W by irradiating the workpiece W with a laser, It may be provided in a polishing apparatus that polishes the workpiece W with a polishing pad, an inspection apparatus that inspects the state of the workpiece W, or the like.

The work piece holding table 30 has, for example, a circular outer shape, and includes a suction portion 300 made of a porous member or the like for sucking the work piece W, and a frame body 301 surrounding and supporting the suction portion 300 . . The adsorption unit 300 communicates with a suction source (not shown) that is a vacuum generator such as a compressor or an ejector. When a suction source (not shown) operates, the suction force generated by the suction source is transmitted to the holding surface 300a, which is the exposed surface of the suction unit 300, and the workpiece holding table 30 moves the workpiece W on the holding surface 300a. can hold the suction.
As shown in FIG. 4 , a rotary shaft 32 whose axial direction is the Z-axis direction is connected to the bottom surface of the workpiece holding table 30 . A motor (not shown) is connected to the lower end of the rotating shaft 32 , and the workpiece holding table 30 rotates around the Z-axis direction as the motor rotates the rotating shaft 32 .

The annular frame holding part 31 surrounding the workpiece holding table 30 and holding the annular frame F has, for example, a cylindrical outer shape with a bottom. , and is rotatable about the axis in the Z-axis direction together with the workpiece holding table 30 by rotation of the rotating shaft 32 . In this embodiment, the annular frame holding part 31 and the workpiece holding table 30 are separate bodies, and between the inner peripheral surface of the annular frame holding part 31 and the outer side surface of the workpiece holding table 30, However, the annular frame holding portion 31 may be attached to the outer surface of the workpiece holding table 30 and integrated therewith. The upper surface 31a of the annular frame holding portion 31 and the holding surface 300a of the workpiece holding table 30 are flush with each other.

For example, when the holding mechanism 3 is arranged in a grinding apparatus, the annular frame holding portion 31 may be vertically movable on the side surface of the rotating shaft 32 . As a result, the annular frame F of the workpiece unit WU shown in FIG. Therefore, the workpiece W can be ground without the annular frame F coming into contact with the grinding wheel.

On the upper surface 31a of the annular frame holding portion 31, bolt-shaped engaging protrusions 310, for example, each having a circular head portion 310a and a neck portion 310b having a diameter smaller than that of the head portion 310a, are arranged at regular intervals (for example, 90 degrees) in the circumferential direction. are formed with . That is, the engaging projection 310 has a substantially T-shaped vertical cross section, and the side surface of the neck portion 310b is not threaded.
For example, if the length of the neck portion 310b is slightly larger than the sum of the thickness of the annular frame F and the thickness of the adhesive tape T, the workpiece unit WU is held by the holding table means 3A. This is preferable because the head portion 310a suppresses fluttering of the workpiece unit WU in the vertical direction. Also, the number of engaging projections 310 to be arranged is not limited to four.

As shown in FIGS. 1 and 2, the annular frame F has an insertion hole Fe into which the head 310a of the engaging protrusion 310 of the annular frame holding portion 31 shown in FIGS. , and a long hole Fg to be engaged with which the neck portion 310b of the engaging projection 310 engages is formed through the engaging projection 310 . Four insertion holes Fe and four engaged long holes Fg are formed at equal intervals (90 degrees) in the circumferential direction in accordance with the number of engaging projections 310 arranged on the annular frame holding portion 31 . A shape in which the insertion hole Fe and the engaged long hole Fg are combined is a so-called daruma hole. For example, the diameter of the circular head 310a is slightly smaller than the diameter of the insertion hole Fe and larger than the diameter of the engaged slot Fg.

1 and 2 by using the workpiece unit holding mechanism 3 shown in FIGS. 3 and 4 will be described below.

(1) Work piece unit placing step First, a work piece unit WU shown in FIG. A workpiece unit WU is positioned above the holding table means 3A. Further, the heads 310a of the engaging projections 310 of the annular frame holding portion 31 and the insertion holes Fe of the annular frame F of the workpiece unit WU are aligned so that they are substantially aligned, and the engaging projections 310 are aligned. is positioned at the insertion position where is inserted into the insertion hole Fe.

Next, the workpiece unit WU is lowered to insert the engaging protrusion 310 into the insertion hole Fe, place the annular frame F on the upper surface 31a of the annular frame holding portion 31 via the adhesive tape T, and , the workpiece W is placed on the holding surface 300 a of the workpiece holding table 30 with the adhesive tape T interposed therebetween.

(2) Workpiece Unit Engaging Step By performing the workpiece unit placing step as described above, as shown in FIG. is at the insertion position where is inserted into the insertion hole Fe. For example, the operator rotates the workpiece unit WU clockwise when viewed from the +Z direction with respect to the workpiece holding table 30 which is in a fixed state as shown in FIG. As a result, the engaging projection 310 is moved from the insertion position where the engaging projection 310 is inserted into the insertion hole Fe to the engaging projection 310 where the neck portion 310b (see FIG. 4) of the engaging projection 310 is engaged with the engaged long hole Fg. The neck portion 310b is engaged with the engaged long hole Fg. Therefore, the vertical movement of the annular frame F is restricted by the head portion 310a having a larger diameter than the neck portion 310b.
By rotating the holding table means 3A in the counterclockwise direction when viewed from the +Z direction with respect to the workpiece unit WU in the fixed state, the engaged long hole Fg is aligned with the engaging projection 310. The neck portion 310b may be engaged with the engaged slot Fg by moving to the engagement position where it engages with the neck portion 310b.

Next, when a suction source (not shown) operates, the suction force generated by the suction source is transmitted to the holding surface 300a, and the workpiece holding table 30 holds the workpiece W by suction on the holding surface 300a, as shown in FIG. As shown, the workpiece unit WU is held by the holding table means 3A.

As described above, in the holding mechanism 3 of the workpiece unit WU according to the present invention, the annular frame holding portion 31 is formed with the bolt-shaped engaging protrusion 310 composed of the head portion 310a and the neck portion 310b. is formed with an insertion hole Fe into which the head portion 310a of the engaging projection 310 is inserted, and an engaged long hole Fg extending in the circumferential direction from the insertion hole Fe and into which the neck portion 310b of the engaging projection 310 is engaged. , relative rotation between the workpiece unit WU and the holding table means 3A causes the insertion position where the engaging projection 310 is inserted into the insertion hole Fe and the neck portion 310b of the engaging projection 310 to be engaged elongated hole Fg. The engaging projection 310 moves back and forth between the engaging projection 310 and the engaged position, and the workpiece unit WU can be held by the holding table means 3A when the engaging projection 310 is in the engaged position. Since it is not necessary to clamp and fix the annular frame F with a clamp located outside the annular frame F, unlike the method, a device area larger than the diameter of the annular frame F is not required, contributing to downsizing of the device. .

In the method for holding the workpiece unit WU according to the present invention, the annular frame holding portion 31 is formed with the bolt-shaped engaging projection 310 composed of the head portion 310a and the neck portion 310b, and the annular frame F has the engaging projection 310 At least an insertion hole Fe into which the head 310a is inserted, and an engaged long hole Fg extending in the circumferential direction from the insertion hole Fe and engaged by the neck 310b of the engaging projection 310, and the engaging projection 310 A workpiece unit WU placing step of placing the workpiece unit WU on the holding table means 3A so as to be inserted into the insertion hole Fe, and rotating the workpiece unit WU and the holding table means 3A relatively. Then, the engaging projection 310 is moved from the insertion position where the engaging projection 310 is inserted into the insertion hole Fe to the engaging position where the neck portion 310b of the engaging projection 310 engages with the engaged long hole Fg. By providing the work unit WU engaging step, the work unit WU is held by the holding table means 3A when the engaging projection 310 is in the engaging position, so that the conventional clamping method can be used. It is no longer necessary to hold and fix the annular frame F with clamps located outside the annular frame F, and a device area larger than the diameter of the annular frame F is no longer required.

It should be noted that the method for holding a unit to be processed according to the present invention is not limited to the above example, nor is the configuration of the holding mechanism 3 shown in the accompanying drawings limited to this, and the present invention is not limited to this. It can be appropriately changed within the range where the effect of can be exhibited.

After the workpiece unit WU is held by the holding table means 3A, when cutting the workpiece W, for example, the division line S of the workpiece W shown in FIG. Alignment (parallelization) for aligning the lines in parallel with the feeding direction), determination of the coordinate position of the planned division line S based on the alignment of the planned division line S, and the like are performed.

When the workpiece W is to be ground after the workpiece unit WU is held by the holding table means 3A, for example, the annular frame holder 31 is lowered relative to the workpiece holding table 30. 7 is pushed downward from the holding surface 300a of the workpiece holding table 30. As shown in FIG. Then, the workpiece W can be ground without the annular frame F coming into contact with the grinding wheel.
When the workpiece W is ground (or polished), the rotation speed of the holding table means 3A is basically high. The counterclockwise direction as viewed from the direction prevents the head 310a of the engaging protrusion 310 from returning to the insertion position and coming out of the insertion hole Fe, which is preferable. By pressing the annular frame F of the workpiece unit WU downward from the holding surface 300a of the workpiece holding table 30, the head 310a of the engaging projection 310 presses the annular frame F downward. Therefore, even if the rotating direction of the holding table means 3A shown in FIG. It is possible to prevent the occurrence of a situation in which the wire is pulled out.

WU: work piece unit W: work piece Wa: surface of work piece Wb: back side of work piece T: adhesive tape
F: Annular frame Fc: Opening of annular frame Fe: Insertion hole Fg: Long hole to be engaged 3: Holding mechanism 3A: Holding table means 30: Workpiece holding table 300: Suction part 300a: Holding surface 301: Frame 31: Annular frame holding part 310: Engagement projection 310a: Head 310b: Neck 32: Rotating shaft

Claims (1)

In a grinding apparatus for grinding a work piece using a grinding wheel, a work piece unit having an annular frame that supports the work piece positioned in an opening via an adhesive tape is provided as a work piece holding the work piece. A method of holding a workpiece unit held by a holding table means comprising a workpiece holding table and an annular frame holding portion surrounding the workpiece holding table and holding the annular frame, comprising:
A bolt-shaped engaging protrusion consisting of a head and a neck is formed on the annular frame holding portion,
The annular frame holding portion is vertically movable with respect to the workpiece holding table,
The annular frame includes at least an insertion hole into which the head of the engaging projection is inserted, and an engaged elongated hole extending in the circumferential direction from the insertion hole and into which the neck of the engaging projection is engaged,
a workpiece unit placing step of placing the workpiece unit on the holding table means so as to insert the engaging protrusions into the insertion holes;
By rotating the workpiece unit and the holding table means relative to each other, the neck portion of the engaging projection is moved from the insertion position where the engaging projection is inserted into the insertion hole. a work piece unit engaging step of moving the engaging protrusion to an engaged engaging position;
The annular frame holding portion is lowered with respect to the workpiece holding table, the annular frame is pushed downward from the holding surface of the workpiece holding table, and the workpiece is processed without the annular frame coming into contact with the grinding wheel. enabling the object to be ground;
A method for holding a workpiece unit, comprising:

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