JP5338249B2 - Cutting method - Google Patents

Description

  The present invention relates to a cutting method for cutting an inner side of an adhesive layer of a workpiece in which a wafer and a protective member are bonded to each other via an adhesive layer formed on an outer peripheral portion.

  A cutting device for cutting or grooving a workpiece such as a wafer on which a semiconductor device or an electronic component is formed includes a thin disk-shaped blade formed by diamond abrasive grains rotated at high speed by a spindle. A work table for sucking and holding the work and X, Y, Z, and θ movement axes for changing the relative positions of the work table and the blade are provided. When machining a workpiece, a cutting fluid for cooling or lubrication is supplied from a nozzle to a rotating blade or a machining point where the workpiece and the blade are in contact with each other, and the blade and the workpiece are relatively moved by each moving axis. Cutting or grooving is performed on the workpiece by cutting the workpiece with the blade.

  FIG. 1 shows an example of a cutting apparatus. The cutting apparatus 1 includes a high-frequency motor built-in spindles 3 and 3 that are disposed to face each other and have a blade 2 and a wheel cover (not shown) attached to the tip, an imaging unit 4 that images the surface of the workpiece W, and a workpiece W Is provided with a work table 6 having a work table 5 that holds the work table 5 and a moving shaft that relatively moves the work table 5 and the blade 2.

  The cutting device 1 includes a wafer cleaning device 7 that spin-cleans a processed workpiece W in addition to the processing unit 6, a load port 8 that mounts a cassette that stores a large number of workpieces W mounted on the frame F, Conveying means 9 for conveying the workpiece W, display means 10 for displaying an image picked up by the image pickup means 4 and inputting an operation to each part, a controller (not shown) for controlling the operation of each part, and the like. .

  In recent years, wafers processed by such a cutting device have been processed thinner by grinding the backside with a grinding device before cutting, in order to reduce the size and weight of semiconductor devices and electronic components. Yes. Since the wafer thinned in this way is very thin with a thickness of 100μ or less and low rigidity, it is difficult to carry and perform various processing, and a method of processing with a support bonded to the surface of the wafer has been proposed. (For example, refer to Patent Document 1 or Patent Document 2).

  However, if the support is bonded to such a wafer surface, the support must be peeled off after processing, and the adhesive must be degraded by various methods to reduce the adhesive force and peel off. I had to. Further, it is necessary to remove the adhesive remaining on the wafer surface after peeling, and complete removal of the adhesive is a very difficult operation.

In order to deal with such problems, a protective member is attached to the outer peripheral area of the wafer via an adhesive, and the inner side of the adhesive layer of the protective member is cut into a circular shape by a cutting device after the back surface grinding. A wafer processing method for removing the protective member has been proposed (see, for example, Patent Document 3).
Japanese Patent Laid-Open No. 2004-22634 JP 2003-209083 A JP 2005-123568 A

  However, when only the protective member is cut as described in Patent Document 3, in order to ensure separation of the protective member, cutting is performed deeply so as to completely penetrate the protective member over the entire circumference. In such a case, there is a problem that the blade cuts into the device formed on the wafer surface and damages the device.

  The present invention has been made for such a problem, and an object of the present invention is to provide a cutting method capable of reliably separating a protective member without damaging a device formed on a wafer surface.

In order to achieve the above object, the present invention has bonded a wafer having a plurality of devices formed on the surface and a protective member for protecting the surface of the wafer through an adhesive layer formed on the outer periphery. A cutting method in which a work is placed on a work table, and the work table and a blade rotated by a spindle are moved relative to each other by a moving shaft to cut the inside of the adhesive layer on the protective member side of the work. In this embodiment, a half-cut machining groove that cuts the protective member of the bonded workpiece to the middle and a full-cut machining groove that cuts through the protective member are formed in the protective member of the workpiece. The inside of the adhesive layer of the protective member is cut.

According to this , a work in which a wafer having a plurality of devices formed on the surface and a protective member that protects the surface of the wafer are bonded together via an adhesive layer formed on the outer periphery includes a blade and a spindle that rotates the blade. And a cutting device provided with a work table and a moving shaft for relatively moving the work table and the blade, the inside of the adhesive layer is cut into a circular shape, a circular arc shape, a polygonal shape, or a circular arc shape and a straight line shape. Processed.

  At this time, the protective member of the bonded member is formed by alternately forming a processing groove by a half cut that cuts the protective member of the bonded workpiece to the middle and a processing groove by a full cut that cuts through the protective member. The inside of the adhesive layer is cut.

  As a result, the protective member is fully cut at a portion where the device formed on the wafer surface is not damaged even if the blade comes into contact, and the protective member is cut so that the protective member can be reliably separated. Furthermore, the device is half-cut at a portion that may damage the device, and is cut without penetrating the protective member. The protective member after processing is reliably cleaved and separated along the processing groove starting from a processing groove formed by a full cut that passes therethrough by applying an external force in the shear direction.

In the cutting method, a work in which a wafer having a plurality of devices formed on the surface and a protective member that protects the surface of the wafer are bonded to each other via an adhesive layer formed on the outer peripheral portion is placed on a work table, In the cutting method of cutting the inside of the adhesive layer on the protective member side of the workpiece by moving the work table and a blade rotated by a spindle relative to each other by a moving shaft, the protective member of the bonded workpieces The inside of the adhesive layer of the protective member is cut by a half cut in which a cutting groove is formed to form a machining groove.

According to this , a work in which a wafer having a plurality of devices formed on the surface and a protective member that protects the surface of the wafer are bonded together via an adhesive layer formed on the outer periphery includes a blade and a spindle that rotates the blade. And a cutting device provided with a work table and a moving shaft for relatively moving the work table and the blade, the inside of the adhesive layer is cut into a circular shape, a circular arc shape, a polygonal shape, or a circular arc shape and a straight line shape. Processed. In the cutting process, a process groove is formed by a half-cut that cuts the protective member of the bonded workpieces to the middle.

  Thereby, it cuts to the thickness which can cleave a protection member, without penetrating a protection member. The protective member after processing is surely cleaved and separated along the processing groove by applying an external force in the shear direction.

In the above-described cutting method, the location where the full cut is performed is a location where the distance between the inner peripheral surface of the adhesive layer and the plurality of devices formed on the wafer surface is wider than twice the thickness of the blade. It is characterized by being.

According to this , the distance between the inner peripheral surface of the adhesive layer formed in a circle on the outer peripheral portion of the wafer and the protective member and the device on the wafer surface is full at a position wider than double the thickness of the blade for cutting. Cut is possible, and full cut is performed at the place where full cut is possible.

  This ensures a sufficient distance between the device and the blade during full cut without damaging the device, even when the blade is misaligned by cutting into a circular or arcuate shape and the width of the machining groove increases. The protective member is cut so as to be surely separable.

In the above-described cutting method, by performing the full cut including a part of the processed groove formed by the half cut after the half cut, the processed groove formed by the half cut and the full cut The processed grooves to be formed are alternately formed in the protective member.

According to this , the protective member of the workpiece in which the wafer on which the device is formed and the protective member that protects the surface of the wafer are bonded together through the adhesive layer is cut by the full cut after the part that can be fully cut is half cut. Processed.

  As a result, the protective member is fully cut at a position where the device formed on the wafer surface is not damaged, and a half cut is performed at a position where the device may be damaged. And the cut groove by half-cutting are performed so as to be surely separable without damaging the device on the wafer surface.

In the above-described cutting method, by alternately performing the half cut and the full cut, a processing groove formed by the half cut and a processing groove formed by the full cut are alternately formed in the protective member. It is characterized by.

According to this , the full-cut and half-cut control the position of the blade in the Z direction on the workpiece protective member that is bonded to the wafer on which the device is formed and the protective member that protects the wafer surface via the adhesive layer. However, it is alternately performed so that a full cut machining groove and a half cut machining groove are alternately formed only by one rotation drive in the θ direction.

  As a result, the protective member is fully cut at a position where the device formed on the wafer surface is not damaged, and is half-cut at a position where the device may be damaged, so that the device on the wafer surface is not damaged. Cutting is performed so that the protective member can be separated.

In the above-mentioned cutting method, the processed groove formed by the half cut and the full cut by performing the half cut between the plurality of processed grooves formed by the full cut after partially performing the full cut. The processing grooves formed by the above are alternately formed in the protective member.

According to this, since it is possible to move in the machining groove formed by the full cut under the same conditions as the position control of the half cut in the Z direction, the accuracy of the position in the Z direction of the machining groove formed by the half cut is accurately determined. Molding is possible.

  As a result, the protective member is fully cut at a position where the device formed on the wafer surface is not damaged, and a half cut is performed at a position where the device may be damaged. And the cut groove by half-cutting are performed so as to be surely separable without damaging the device on the wafer surface.

  As described above, according to the cutting method of the present invention, the processing groove by half cut that cuts to the middle of the protective member of the bonded workpiece and the processing groove by full cut that cuts through the protective member are formed. By forming the protective member on the wafer surface, it is possible to perform cutting into a circular shape, a polygonal shape, or a shape based on an arc and a straight line so that the protective member can be reliably separated without damaging the device formed on the wafer surface.

  Hereinafter, preferred embodiments of a cutting method according to the present invention will be described in detail with reference to the accompanying drawings. First, a cutting apparatus in which a cutting method according to the present invention is performed will be described.

  FIG. 1 is a perspective view showing an appearance of a cutting apparatus. The cutting apparatus 1 includes a high-frequency motor built-in spindles 3 and 3 that are disposed to face each other and have a blade 2 and a wheel cover (not shown) attached to the tip, an imaging unit 4 that images the surface of the workpiece W, and a workpiece W Is provided with a work table 6 having a work table 5 that holds the work table 5 and a moving shaft that relatively moves the work table 5 and the blade 2.

  The cutting device 1 includes a wafer cleaning device 7 that spin-cleans a processed workpiece W in addition to the processing unit 6, a load port 8 that mounts a cassette that stores a large number of workpieces W mounted on the frame F, Conveying means 9 for conveying the workpiece W, display means 10 for displaying an image picked up by the image pickup means 4 and inputting an operation to each part, a controller (not shown) for controlling the operation of each part, and the like. .

  As shown in FIG. 2, the workpiece W is bonded to a wafer 11 having a plurality of devices D formed on the surface thereof and a plate-like protective member 12 made of glass, silicon or the like via an adhesive layer 13 made of polyimide resin or the like. As shown in FIG. At this time, the adhesive layer 13 is formed in a ring shape on the surplus region 14 on the outer peripheral portion of the wafer 11 where the device D shown in FIG. 2 is not formed. As a result, as shown in FIG. A gap 15 is formed between them.

  The workpiece W thus formed is ground from the back surface side of the wafer 11 by the back surface grinding device, and the wafer 11 is thinned. The workpiece W after back grinding is mounted on the frame F with the wafer 11 side attached to the tape T as shown in FIG. In this state, the work W sucked and placed on the work table 5 of the cutting apparatus 1 is cut by the blade 2 that rotates at high speed by the spindle 3.

  In the cutting process, the blade 2 rotating at a high speed by the spindle 3 is lowered in the direction of arrow Z to be cut inside the adhesive layer 13 formed in a ring shape of the work W, and the work W is moved by the work table 5 in the direction of arrow θ. And then cut into a plurality of arcs leaving a circular or unprocessed part. As a result, the protection member 12 of the workpiece W is cut into a plurality of circular arcs while leaving a circular cut or unprocessed portion as shown in FIG.

  In addition, the work W rotates the work table 5 and changes the angle by changing the angle by the arrangement of the device D, thereby leaving a cut or unprocessed portion in a polygonal shape as shown in FIG. It is cut. Alternatively, the workpiece W is cut in the shape of an arc and a straight line as shown in FIG. Cutting is performed leaving unprocessed parts.

  Next, the cutting method according to the present invention will be described. 9 is a cross-sectional view showing a state in which half-cutting is performed, FIG. 10 is a cross-sectional view showing a state in which full-cutting is being performed, and FIG. 11 is a top view showing locations of half-cutting and full-cutting of a protective member. It is.

  The workpiece W bonded through the adhesive layer 13 so as to provide a gap 15 between the wafer 11 and the protective member 12 is ground from the back side of the wafer 11 to thin the wafer 11, and the wafer 11 side becomes the tape T. Affixed and mounted on frame F. In this state, the workpiece W is rotated by θ, and the inner side of the adhesive layer 13 is cut by the blade 2 so that the protective member 12 is cut into a circular shape, a circular arc shape, a polygonal shape, or a circular arc shape and a straight line shape.

  At this time, the protection member 12 is formed with a half-cut machining groove that cuts to the middle of the protection member 12 and a full-cut machining groove that cuts through the protection member 12 to form the device D on the surface of the wafer 11. Cutting is performed to ensure separation without damage. An external force in the shear direction is applied to the central portion of the protective member 12 after the cutting process, and the central part that has been cleaved and cut along the processing groove is separated from the processing groove that has been penetrated by the full cut.

  In the half-cut, the position inside the adhesive layer 13 of the protection member 12 is cut as shown in FIG. At this time, the blade 2 cuts and cuts the protective member 12 to an intermediate position without penetrating the protective member 12. As a result, the processing groove formed by the blade 2 is formed only on the protective member 12, and the blade 2 does not contact the wafer 11, so that the device D formed on the surface of the wafer 11 is not damaged.

As shown in FIG. 10, the full cut is performed by penetrating a position on the inner side of the adhesive layer 13 of the protective member 12. At this time, the blade 2 cuts and cuts the gap 15. Thereby, the protection member 12 is cut so as to be surely separable.
In the present embodiment, the blade 2 is cut to the gap 15 at a position inside the adhesive layer 13, but the present invention is not limited to this, and can be implemented even when the blade 2 is cut to the wafer 11. It is.

  The machining groove by the full cut and the half cut is performed by lowering the blade 2 to the gap 15 at the full cut possible place 16A while rotating the workpiece W as in the machining groove 16 shown in FIG. By half-cutting the blade 2 by raising the blade 2 to the middle of the protection member 12 at the location 16B, a processing groove by half-cutting and a processing groove by full-cutting are alternately formed on the protection member 12. In addition, the cutting process by a full cut and a half cut performs the full cut to the part 16A which can be fully cut after half-cutting the protection member 12, or the half cut of the protection member 12 after performing the full cut to the part 16A which can be fully cut May be cut.

  At this time, as shown in FIG. 12, the fully cuttable portion 16 </ b> A is a portion where the distance A between the inner peripheral surface of the adhesive layer 13 and the device D formed on the surface of the wafer 11 is wider than twice the thickness of the blade 2. It is. As a result, even when the width of the machining groove 16 is increased when cutting into a circular shape as shown in FIG. 13, the distance between the device D and the blade 2 is sufficiently secured, and the blade 2 comes into contact with the wafer 11. In addition, the protective member 12 is cut so as to be surely separable without damaging the device D. In the present invention, it is not necessary to fully cut all the places where full cut is possible, and the necessary full cut places corresponding to individual workpieces W are fully cut.

  As described above, according to the cutting method according to the present invention, the machining groove by the half cut that cuts to the middle of the protective member of the bonded workpiece and the machining by the full cut that cuts through the protective member. By alternately forming the grooves on the workpiece, the protective member can be cut into a circle so as to be surely separable without damaging the device formed on the wafer surface.

  In the present embodiment, the cutting process to the protection member 12 by the blade 2 is performed only on the inner side of the adhesive layer 13, but the present invention is not limited to this, and the half-cut portion 23 is bonded as shown in FIG. The protective member 12 may be cut to the portion where the layer 13 is formed, and the protective member 12 where the adhesive layer 13 is formed is cut by half-cutting with a blade 2A thicker than usual as shown in FIG. It may be processed.

The perspective view which shows the external appearance of a cutting apparatus. The perspective view which showed the structure of the workpiece | work. The perspective view which shows the external appearance of a workpiece | work. Sectional drawing which shows the structure of a workpiece | work. The perspective view which showed the state of the workpiece | work in which cutting is performed. The perspective view which showed the state by which the protection member was cut circularly. The perspective view which showed the state by which the protection member was cut into polygonal shape. The perspective view which showed the state by which the protection member was cut by the shape by a circular arc and a straight line. Sectional drawing which showed the mode of the half cut. Sectional drawing which showed the mode of the full cut. The top view which showed the state of the processing groove formed in the protection member. The top view which showed the conditions of the part which can be cut fully. The upper surface enlarged view which showed the mode of the blade at the time of cutting into a circle. Sectional drawing which showed the mode of the cutting process of the protection member of the part in which the contact bonding layer was formed. Sectional drawing which showed another mode of cutting of the protection member of the part in which the contact bonding layer was formed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cutting processing device 2, 2A ... Blade, 3 ... Spindle, 4 ... Imaging device, 5 ... Work table, 6 ... Processing part, 7 ... Wafer cleaning device, 8 ... Load port, 9 ... Conveying means, 10 ... Display Means: 11 ... wafer, 12 ... protective member, 13 ... adhesive layer, 14 ... excess region, 15 ... gap, 16 ... machined groove, 16A ... full-cut location, 16B ... half-cut location, D ... device, F ... frame , T ... tape, work ... W

Claims (9)

A work having a wafer having a plurality of devices formed on the surface and a protective member for protecting the surface of the wafer bonded through an adhesive layer formed on the outer periphery is placed on the work table, and the work table and the spindle In the cutting method of cutting the inner side of the adhesive layer on the protective member side of the workpiece by relatively moving the blade rotated by the moving shaft,
The distance between the inner peripheral surface of the adhesive layer and the plurality of devices formed on the wafer surface is a half-cut machining groove that cuts the protective member of the bonded workpiece to the middle . The distance between the inner peripheral surface of the adhesive layer and the plurality of devices formed on the wafer surface is a cut groove formed by full cutting that is formed in a portion less than double and cuts through the protective member. A cutting method characterized in that the inside of the adhesive layer of the protective member is cut by forming it at a location wider than the thickness of the blade . A work having a wafer having a plurality of devices formed on the surface and a protective member for protecting the surface of the wafer bonded through an adhesive layer formed on the outer periphery is placed on the work table, and the work table and the spindle In the cutting method of cutting the inner side of the adhesive layer on the protective member side of the workpiece by relatively moving the blade rotated by the moving shaft,
A distance between the inner peripheral surface of the adhesive layer and the plurality of devices formed on the wafer surface is equal to or less than twice the thickness of the blade by cutting the protective member of the bonded workpiece to the middle A cutting method characterized in that the inside of the adhesive layer of the protective member is cut by a half-cut formed at the location . After performing the half cut, including the part of the processed groove formed by the half cut and performing the full cut, the processed groove formed by the half cut and the processed groove formed by the full cut are 2. The cutting method according to claim 1, wherein the protective members are alternately formed. 2. The processing groove formed by the half cut and the processing groove formed by the full cut are alternately formed in the protective member by alternately performing the half cut and the full cut. The cutting method described in 1. A machining groove formed by the half-cut and a machining groove formed by the full-cut by performing half-cutting between a plurality of machining grooves formed by the full-cut after partially performing the full-cut. The cutting method according to claim 1, wherein the protective members are alternately formed. The cutting method according to any one of claims 1 to 5, wherein an inner side of the adhesive layer on the protective member side of the workpiece is cut into a circular shape or an arc shape. The cutting method according to any one of claims 1 to 5, wherein an inner side of the adhesive layer on the protection member side of the workpiece is cut into a polygonal shape. The cutting method according to any one of claims 1 to 5, wherein an inner side of the adhesive layer on the protection member side of the workpiece is cut into a shape formed by an arc and a straight line. 9. The blade according to claim 6, wherein the blade is cut to a portion where the adhesive layer is formed when the inner side of the adhesive layer on the protective member side of the workpiece is cut by the half cut. The cutting method of any one of Claims 1.

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