JP2022032303A - Method for processing substrate - Google Patents

Abstract

To provide a rectangular substrate having a flattened copper film on a front surface without causing damage to a byte tool.SOLUTION: A method for processing substrate by a cutting device 2 processing a substrate 1 in which copper films 3 and 7 are provided on an upper surface comprises: a division step of diving the substrate 1 into a plurality of rectangular substrates by cutting the substrate 1 along a division schedule line by a cutting tool 68 having a cutting blade 14 including an abrasive grain; an abrasive grain removing step of bringing a saw blade into contact with a cutting surface of the copper films 3 and 7 of at least one rectangular substrate thereby removing the abrasive grain of the cutting tool 68 left on the cutting surface of each copper film; and a flatting step of performing a byte cutting with a byte tool, on an upper surface of the copper films 3 and 7 of the rectangular substrate in which the abrasive grain is removed from the copper films 3 and 7 after the abrasive grain removing step.SELECTED DRAWING: Figure 6

Description

The present invention relates to a method for processing a substrate in which a substrate having a copper film formed on the surface thereof is divided to obtain individual rectangular substrates on which the copper film is flattened.

A device chip used in an electronic device such as a mobile phone or a personal computer is formed by dividing a semiconductor wafer having a plurality of devices formed on its surface. In recent years, there has been a remarkable demand for miniaturization and thinning of device chips, and there is also a demand for a small mounting area of device chips.

Therefore, metal protrusions called bumps were formed directly on the surface of the wafer without internal wiring by bonding wires, the bumps were sealed with a sealing material together with the surface of the wafer, and the wafer was divided into individual packages. The technology for obtaining chips has been put into practical use. The device chip obtained by this technique is called WL-CSP (Wafer-level Chip Size Package) (see, for example, Patent Document 1).

When the device chip is mounted on the mounting substrate by directly bonding the bump on the surface of the device chip to the electrode formed of a copper film or the like formed on the mounting substrate as an electrode, the mounting area of the device chip can be reduced. However, since the heights of the plurality of bumps formed on the surface of the device chip are non-uniform, all the bumps cannot be uniformly bonded to the electrodes of the mounting substrate as they are.

Therefore, the surface of the device chip is cut with a tool cutting device (surface sprayer) equipped with a tool with a cutting edge made of diamond chips, and the upper end of the bump together with the encapsulant is cut with a tool. Then, the sealing material is thinned and the heights of the bumps are made uniform (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2001-7135 Japanese Patent No. 4249827

The flatness of the surface of the device chip is improved, and the mounting substrate on which each device chip is mounted is also required to have a high surface flatness. Therefore, it is also conceivable to cut the copper film formed on one surface or both surfaces of the mounting substrate with a tool in the same manner to flatten the surface of the copper film.

Here, the mounting substrate is formed by cutting out from a large-sized substrate to a predetermined size. A cutting tool (cutting blade) having an annular cutting edge composed of diamond abrasive grains, a binder for dispersing and fixing the diamond abrasive grains, and an annular cutting edge is used for cutting the substrate. Then, when cutting the substrate with a cutting tool, the cutting tool is rotated to cut the cutting edge into the substrate. At this time, some diamond abrasive grains contained in the cutting edge adhere to the cut surface of the copper film.

Therefore, diamond abrasive grains are attached to the cut surface of the formed copper film of the mounting substrate. Then, when the mounting substrate having the copper film to which the diamond abrasive grains are attached is cut with a tool tool, the tool tool hits the diamond abrasive grains and the tool tool is damaged. Therefore, it is necessary to replace the tool tool frequently, which causes a problem that the time cost and the financial cost for obtaining a mounting substrate having a flattened copper film on the surface are high.

The present invention has been made in view of the above problems, and an object of the present invention is to process a substrate that can obtain a rectangular substrate having a flattened copper film on the surface without causing damage to the tool tool. To provide a method.

According to one aspect of the present invention, it is a method of processing a substrate for processing a substrate having a copper film on the upper surface, the substrate is cut by a saw blade along a planned division line, and the substrate is cut into a plurality of rectangles. The substrate is characterized by comprising a dividing step for dividing into a substrate, and after the dividing step, a flattening step for flattening the upper surface of the copper film of at least one of the rectangular substrates by cutting the upper surface of the copper film with a tool. Processing method is provided.

According to another aspect of the present invention, it is a method of processing a substrate for processing a substrate having a copper film on the upper surface, and the substrate is processed by a saw blade along a planned division line to obtain the copper film. A cutting tool having a machined groove forming step for forming a machined groove to be divided and a cutting tool containing abrasive grains and having a cutting edge having a thickness smaller than the width of the machined groove is used to cut into the region below the machined groove of the substrate and cut into the substrate. Is divided into a plurality of rectangular substrates by cutting along the planned division line, and after the division step, the upper surface of the copper film of at least one of the rectangular substrates is cut with a tool. A method for processing a substrate is provided, which comprises a flattening step for flattening.

According to still another aspect of the present invention, it is a method of processing a substrate for processing a substrate having a copper film on the upper surface, and the substrate is divided into scheduled lines by a cutting tool provided with a cutting tool containing abrasive grains. A division step of dividing the substrate into a plurality of rectangular substrates by cutting along the line, and a saw blade contacting the cut surface of the copper film of at least one of the rectangular substrates and remaining on the cut surface of the copper film. After the abrasive grain removing step for removing the abrasive grains of the cutting tool and the abrasive grain removing step, the upper surface of the copper film of the rectangular substrate from which the abrasive grains have been removed from the copper film is cut with a tool. A method for processing a substrate is provided, which comprises a flattening step for flattening.

In the substrate processing method according to one aspect of the present invention, the copper film provided on the upper surface of the substrate is cut with a saw blade that does not contain abrasive grains. Alternatively, after cutting the copper film with a cutting tool containing abrasive grains, the saw blade is brought into contact with the cut surface of the copper film to remove the abrasive grains remaining on the cut surface. Therefore, when the copper film of the rectangular substrate divided and formed from the substrate is flattened, the abrasive grains do not adhere to the copper film, and the tool tool does not come into contact with the abrasive grains. That is, the tool tool is not damaged, and the frequency of replacement of the tool tool can be reduced.

Therefore, the present invention provides a method for processing a substrate that can obtain a rectangular substrate having a flattened copper film on the surface without causing damage to the tool tool.

FIG. 1A is a perspective view schematically showing a substrate to be processed, and FIG. 1B is a perspective view schematically showing a rectangular substrate formed by dividing the substrate. It is a perspective view which shows the division step schematically. 3 (A) and 3 (B) are side views schematically showing the division steps. It is a perspective view which shows typically the tool cutting apparatus. It is a side view schematically showing the state of flattening a rectangular substrate with a tool cutting device. FIG. 6A is a side view schematically showing a machined groove forming step, and FIG. 6B is a side view schematically showing a dividing step. FIG. 7A is a side view schematically showing the division step, and FIG. 7B is a side view schematically showing the abrasive grain removing step. FIG. 8A is a flowchart illustrating a flow chart for each step of the substrate processing method according to an example, and FIG. 8B is a flow chart for explaining the flow of each step of the substrate processing method according to another example. It is a flowchart, and FIG. 8C is a flowchart illustrating the flow of each step of the substrate processing method according to still another example.

An embodiment of the present invention will be described with reference to the accompanying drawings. First, a substrate processed by the substrate processing method according to the present embodiment will be described. FIG. 1A includes a perspective view schematically showing the substrate 1. The substrate 1 has a plate-shaped base material layer 5 and copper films 3 and 7 provided on the front and back surfaces of the base material layer 5.

As shown in FIG. 1A, a plurality of planned division lines 9 intersecting each other are set on the substrate 1. When the substrate 1 is finally divided along the planned division line 9, a rectangular substrate 11 (see FIG. 1B) to be a mounting substrate or the like on which the device chip is mounted is formed.

For example, the base material layer 5 has a laminated structure of flame-resistant paper, glass, metal, or the like and a resin such as a phenol resin or an epoxy resin. The base material layer 5 may include metal wiring or the like. Copper films 3 and 7 are provided on one or both of the front surface and the back surface of the base material layer 5. The copper films 3 and 7 are patterned in a predetermined shape. For example, when a device chip or the like is mounted on a rectangular substrate 11 formed from a substrate 1, the electrodes of the device chips come into contact with each other and are between the electrodes. Functions as a terminal that ensures continuity.

In order to uniformly join the bumps provided on the surface of the device chip to the rectangular substrate 11, the upper surface of each bump is flattened and heightened by cutting with a tool, for example, a tool cutting device (surface sprayer). Is unified. In recent years, the surfaces of the copper films 3 and 7 serving as terminals of the rectangular substrate 11 to which the bumps are bonded are also required to be flat, and the copper film 3 of the rectangular substrate 11 formed by dividing the substrate 1 is also required. 7 was cut with a bite.

However, when the substrate 1 is divided by an annular cutting tool along the planned division line 9, the diamond abrasive grains contained in the cutting edge of the cutting tool adhere to the cut surfaces of the copper films 3 and 7 of the substrate 1. It ends up. That is, diamond abrasive grains are attached to the cut surfaces of the copper films 3 and 7 of the rectangular substrate 11. In this state, if the copper films 3 and 7 of the rectangular substrate 11 are cut with a tool tool, the diamond abrasive grains come into contact with the tool tool, so that the tool tool is damaged and frequent replacement is required. Therefore, the production efficiency of the rectangular substrate 11 was low.

Therefore, in the substrate processing method according to the present embodiment, the diamond abrasive grains are prevented from coming into contact with the tool for flattening the copper films 3 and 7 by cutting the tool, and the tool is not damaged. That is, when the substrate 1 is divided into the rectangular substrate 11, the diamond abrasive grains are not adhered to the copper films 3 and 7. Alternatively, the diamond abrasive grains adhering to the copper films 3 and 7 are removed.

Next, a cutting device used in the substrate processing method according to the present embodiment and a tool cutting device (surface sprayer) will be described. FIG. 2 and the like include a perspective view schematically showing a part of the cutting device 2. FIG. 4 is a perspective view schematically showing the cutting tool 18.

First, a cutting device 2 for cutting the substrate 1 along the planned division line 9 will be described with reference to FIGS. 2, 3 (A), and 3 (B). The cutting device 2 is attached to the spindle 6 by means of a spindle 6 along the Y-axis direction, a spindle housing 4 that rotatably accommodates the proximal end side of the spindle 6, and a flange mechanism 8 provided at the tip of the spindle 6. A fixed cutting tool 10 is provided.

The flange mechanism 8 has a front flange 8a that can be fixed to the tip of the spindle 6 and a rear flange 8b that is fixed to the spindle 6 at a position closer to the spindle housing 6 than the front flange 8a. The cutting tool 10 is fixed to the tip of the spindle 6 by being sandwiched between the front flange 8a and the rear flange 8b.

The spindle housing 4 is supported by an elevating mechanism (not shown), and can be elevated by the elevating mechanism. Further, inside the spindle housing 4, a rotation drive source such as a motor (not shown) for rotating the spindle 6 is provided. When the rotary drive source is operated, the cutting tool 10 mounted on the tip of the spindle 6 rotates.

The cutting tool 10 includes an annular cutting edge 14. The cutting blade 14 of the cutting tool 10 mainly used for cutting the copper films 3 and 7 has a plurality of saw blades formed on the outer periphery thereof, and the cutting tool 10 is called a metal saw (super hard cutter). The cutting edge 14 is formed of, for example, an alloy in which a carbide such as tungsten carbide (WC) is sintered and bonded using an iron group metal such as cobalt or nickel as a binder.

Instead of the cutting tool 10, the cutting tool 68 may be equipped with the cutting tool 68 shown in FIG. 6B or the cutting tool 68a shown in FIG. 7A, which can suitably cut the base material layer 5. 6 (B) and 7 (A) include side views schematically showing a part of the cutting device 62 to which the cutting tools 68 and 68a are mounted.

The cutting blades 72, 72a of the cutting tools 68, 68a used when cutting and dividing the substrate 1 are formed of diamond abrasive grains and materials such as resin, metal, and ceramics that disperse and fix the diamond abrasive grains. It is provided with a binder. The cutting blades 72, 72a are fixed to the outer peripheral portion of the annular base 70, 70a made of aluminum or the like.

When the rotating cutting tools 68 and 68a are cut into the workpiece, the diamond abrasive grains exposed from the binder come into contact with the workpiece and the workpiece is cut. The diamond abrasive grains are consumed while the workpiece is being cut, but the binder is also consumed and new diamond abrasive grains are exposed, so that the cutting ability of the cutting tools 68 and 68a is maintained.

The cutting device 2 includes a chuck table 16 (see FIGS. 3A and 3B) that supports and sucks and holds the workpiece, and the cutting device 62 includes a chuck table 64 (FIG. 6B). And FIG. 7 (A)). To. The chuck tables 16, 64 and the cutting tools 10, 68, 68a can move relatively in a direction parallel to the upper surface of the chuck tables 16, 64 (for example, in the X-axis direction). Also, the chuck tables 16 and 64 are rotatable about an axis perpendicular to the top surface.

Next, the tool cutting device 18 will be described with reference to FIG. 4 and the like. The tool cutting device 18 includes a base 20 that supports each component, and a column 22 is erected at the rear end of the base 20. A pair of guide rails 24 along the vertical direction (Z-axis direction) are fixed to the column 22. A tool cutting unit 26 is mounted on the pair of guide rails 24 so as to be movable in the vertical direction.

The tool cutting unit 26 has a spindle housing 28 and a support portion 30 that supports the spindle housing 28, and the support portion 30 is attached to a moving base 32 that moves in the vertical direction along a pair of guide rails 24. ing.

The tool cutting unit 26 includes a spindle 34 rotatably housed in the spindle housing 28, a motor 36 for rotationally driving the spindle 34, and a wheel mount 38 fixed to the tip of the spindle 34. A bite wheel 40 is detachably attached to the wheel mount 38.

FIG. 5 includes a side view schematically showing a part of the cutting tool cutting unit 26. The bite wheel 40 has an annular or disc-shaped wheel base 42 made of stainless steel or the like, and a bite tool 44 mounted on the lower surface of the wheel base 42. A cutting edge 44a such as a diamond tip is fixed to the tip of the tool tool 44.

The tool cutting device 18 includes a Z-axis moving mechanism 50 including a ball screw 46 that moves the tool cutting unit 26 in the vertical direction along a pair of guide rails 24, and a pulse motor 48 that rotates the ball screw 46. ing. A nut portion (not shown) screwed onto the ball screw 46 is provided on the back surface (rear surface) of the moving base 32, and when the pulse motor 48 is driven to rotate the ball screw 46, a bite cutting unit is provided. 26 moves up and down.

A recess 20a is formed on the upper surface of the base 20, and a chuck table mechanism 52 is arranged in the recess 20a. The chuck table mechanism 52 includes a table base 54 and a chuck table 56 mounted on the table base 54. The chuck table 56 has a porous member having the same size and planar shape as the rectangular substrate 11 formed from the substrate 1 on the upper surface, and the upper surface serves as a holding surface 56a. The porous member is provided with, for example, a concave portion having a size capable of accommodating the porous member on the upper surface thereof, and the porous member is accommodated in the concave portion.

The chuck table mechanism 52 includes a suction path (not shown) to which the porous member is connected to one end and a suction source (not shown) composed of a pump, an aspirator, or the like is connected to the other end. When the substrate 1 is placed on the holding surface 56a and the suction source is operated, the chuck table mechanism 52 can suck and hold the substrate 1.

Below the table base 54, a Y-axis moving mechanism (not shown) such as a ball screw type that moves the table base 54 along the Y-axis direction is provided. When the Y-axis moving mechanism is operated, the chuck table mechanism 52 moves along the Y-axis direction.

The Y-axis moving mechanism (not shown) of the chuck table mechanism 52 is covered with a bellows 58 disposed between the table base 54 and the fixed portion of the base 20 of the tool cutting device 18. At the front end of the base 20, an operation panel 60 is provided as an interface for inputting processing conditions and the like.

Next, each step of the substrate processing method according to the present embodiment will be described. FIG. 8A is a flowchart illustrating a flow of each step of the substrate processing method according to the present embodiment. In the method of processing a substrate according to the present embodiment, the substrate 1 is cut along a scheduled division line 9 by a saw blade, the substrate 1 is divided into a plurality of rectangular substrates 11, and at least one of the formed rectangular substrates 11 is formed. The upper surfaces of the copper films 3 and 7 are flattened by cutting with a tool tool 44.

First, a cutting tool 10 having a saw blade cuts the substrate 1 along the planned division line 9, and a division step S10 for dividing the substrate 1 into a plurality of rectangular substrates 11 is performed. FIG. 2 is a perspective view schematically showing the division step S10, and FIGS. 3A and 3B are side views schematically showing the division step S10. In the division step S10, the cutting device 2 shown in each figure is used.

In the division step S10, first, the substrate 1 is placed on the chuck table 16, and the substrate 1 is sucked and held by the chuck table 16. Next, the cutting tool 10 and the chuck table 16 are relatively moved in a direction parallel to the upper surface of the chuck table 16, and the cutting tool 14 and the cutting edge 14 of the cutting tool 10 are moved along the machining feed direction (X-axis direction). Arrange one scheduled division line 9 and.

Then, by rotating the spindle 6, the cutting tool 10 is rotated at a rotation speed of about 30,000 rotations per minute. After that, the substrate 1 and the cutting tool 10 are relatively moved in the machining feed direction, and the cutting blade 14 having a saw blade is cut into the substrate 1. Then, the substrate 1 is cut to form a cutting groove along the planned division line 9.

After cutting the substrate 1 along one planned division line 9, the substrate 1 and the cutting tool 10 are relatively moved along the indexing feed direction (Y-axis direction) to move to the other planned division line 9. The substrate 1 is cut along the line. In this way, after cutting the substrate 1 along all the planned division lines 9 along the machining feed direction, the chuck table 16 is rotated around the axis perpendicular to the upper surface, and the planned division lines 9 along the other directions are rotated. Align the orientation with the machining feed direction. After that, the substrate 1 is cut along the planned division line 9 along the other direction.

In this way, when the substrate 1 is cut along all the planned division lines 9, the substrate 1 is divided by the cutting groove to form individual rectangular substrates 11. FIG. 1B shows a perspective view schematically showing the rectangular substrate 11. As described above, in the division step S10, the substrate 1 is cut by the cutting tool 10 provided with the cutting blade 14 having the saw blade without the abrasive grains. Therefore, the abrasive grains do not adhere to the cut surfaces of the copper films 3 and 7.

Next, a flattening step S20 is performed in which the upper surfaces of the copper films 3 and 7 of the rectangular substrate 11 which are partially or wholly formed by cutting the substrate 1 are cut with a tool tool 44. FIG. 4 is a perspective view schematically showing the cutting tool 18 and FIG. 5 is a side view schematically showing the flattening step S20.

In the flattening step S20, the rectangular substrate 11 is placed on the chuck table 56, and the chuck table mechanism 52 sucks and holds the rectangular substrate 11. Then, the spindle 34 of the tool cutting unit 26 is rotated at about 2000 rpm, and the height of the lower end of the cutting edge 44a of the tool tool 44 is set to a predetermined height position in contact with the copper film 3 exposed on the upper surface of the rectangular substrate 11. The Z-axis moving mechanism 50 is driven so as to be positioned.

Next, the Y-axis moving mechanism is operated to move the chuck table 56 in the Y-axis direction, and the rectangular substrate 11 is passed below the tool cutting unit 26. Then, the rotating cutting edge 44a comes into contact with the copper film 3 of the rectangular substrate 11, and the copper film 3 is tool-cut (swivel-cut) and flattened.

When the copper film 7 provided on the surface of the rectangular substrate 11 opposite to the copper film 3 is also flattened by the tool tool in the flattening step S20, the chuck table 56 is after the flattening of the copper film 3 is completed. Is moved to the front side of the base 20 of the tool cutting device 18. Then, the suction holding of the rectangular substrate 11 by the chuck table mechanism 52 is released, the rectangular substrate 11 is turned upside down to expose the copper film 7 side of the rectangular substrate 11, and the rectangular substrate 11 is sucked and held again by the chuck table mechanism 52. Let me.

Then, the spindle 34 of the tool cutting unit 26 is rotated, and the height of the tool cutting unit 26 is adjusted so that the copper film 7 can be cut with a tool so as to have a predetermined thickness. Then, the Y-axis moving mechanism is operated to move the chuck table 56 in the Y-axis direction, and the rectangular substrate 11 is passed below the tool cutting unit 26. Then, the rotating cutting edge 44a comes into contact with the copper film 7 of the rectangular substrate 11, and the copper film 7 is tool-cut (swivel-cut) and flattened.

In the flattening step S20, in order to protect the surface of the rectangular substrate 11 to be cut with a tool on the side opposite to the surface to be machined, a tape-shaped protective member may be attached to the surface on the opposite side. In this case, the rectangular substrate 11 is sucked and held by the chuck table mechanism 52 via the protective member. In the flattening step S20, after the cutting of the bite of one rectangular substrate 11 is completed, the cutting of the bite of the other rectangular substrate 11 may be continuously performed.

Of the plurality of rectangular substrates 11 formed from the substrate 1, when the flattening of the rectangular substrate 11 to be processed is completed, the flattening step S20 is completed. Copper films 3 and 7 flattened in the flattening step S20 are provided on the front and back surfaces of the base material layer 5 of the rectangular substrate 11. That is, in the substrate processing method according to the present embodiment, a rectangular substrate 11 provided with flattened copper films 3 and 7 can be obtained.

In the substrate processing method according to the present embodiment, when the substrate 1 is cut by the cutting tool 10 in the division step S10, the diamond abrasive grains do not adhere to the cut surfaces of the copper films 3 and 7. Therefore, even if the copper films 3 and 7 are cut with a tool in the flattening step S20, the tool tool 44 is not damaged by the diamond abrasive grains. Therefore, it is not necessary to replace the tool tool 44 frequently. Therefore, the processing efficiency of the substrate 1 can be improved.

However, when attempting to cut the substrate 1 with a cutting blade 14 having a saw blade that does not contain abrasive grains, the substrate 1 may not be properly cut by the cutting tool 10 depending on the material of the substrate layer 5 of the substrate 1. be. For example, the cutting tool 10 provided with the cutting blade 14 having a saw blade can be suitably used for cutting the substrate 1 including the base material layer 5 made of resin. On the other hand, when the cutting tool 10 is used, the substrate 1 including the base material layer 5 made of a material such as metal cannot be easily cut.

Therefore, in the method of processing a substrate according to another aspect of the present embodiment described below, a cutting tool that mainly has a cutting tool 10 having a saw blade cuts copper films 3 and 7 and mainly has diamond abrasive grains. The substrate layer 5 is cut at 68. FIG. 8B is a flowchart illustrating the flow of each step of the substrate processing method according to the modified example of the present embodiment.

In the substrate processing method shown in FIG. 8B, first, the substrate 1 is processed by a saw blade along the planned division line 9, and the depth corresponding to the thickness of the copper film 3 or the copper film is formed. A machined groove forming step S30 for forming a machined groove deeper than the thickness of 3 on the substrate 1 is carried out. That is, in the machined groove forming step S30, the machined groove that divides the copper film 3 is formed. FIG. 6A is a side view schematically showing the machined groove forming step S30.

In the machined groove forming step S30, the cutting device 2 is used in the same manner as in the above-mentioned dividing step S10. In the machined groove forming step S30, the height of the cutting tool 10 is positioned so that the lower end of the cutting edge 14 of the cutting tool 10 is positioned at the same position as the lower end of the copper film 3 of the substrate 1 or at a position lower than the lower end. Is carried out in the same manner as in the division step S10, and therefore a part of the description will be omitted. When the machined groove forming step S30 is carried out, the machined groove 9a along the planned division line 9 is formed. At this time, the base material layer 5 is exposed at the bottom of the processing groove 9a. In the machined groove forming step S30, a part of the substrate 1 may be removed, or the bottom portion of the machined groove 9a may be located at any height between the upper end and the lower end of the board 1.

When cutting both the copper films 3 and 7 formed on both surfaces of the base material layer 5 with a tool in the flattening step S50 described later, the copper film 3 was cut with a cutting tool 10 to form a machined groove 9a. After that, the substrate 1 is turned upside down, and the copper film 7 is similarly cut with the cutting tool 10 to form the machined groove 9a. In this case, the base material layer 5 is also exposed at the bottom of the processing groove 9a formed in the copper film 7.

Next, the division step S40 for cutting the base material layer 5 to divide the substrate 1 will be described. FIG. 6B is a side view schematically showing the division step S40. In the division step S40, a cutting tool 68 having a cutting edge 72 having a thickness smaller than the width of the processing groove 9a cuts into the region below the processing groove 9a of the substrate 1, and the substrate 1 is cut along the planned division line 9. do. At this time, the lower end of the cutting blade 72 is brought to the lower side of the base material layer 5, and the cutting blade 72 is exposed on the back surface side of the substrate 1. As a result, the substrate 1 is divided into a plurality of rectangular substrates 11.

Here, in the cutting tool 68 that cuts into the base material layer 5 in the dividing step S40, the cutting blade 72 having the diamond abrasive grains and the binder for dispersing and fixing the diamond abrasive grains on the outer peripheral portion of the annular base 70 is provided. It is fixed. The cutting tool 68 may be mounted on the cutting device 2 described above in place of the cutting tool 10.

Further, the cutting tool 68 may be mounted and used on another cutting device 62 configured in the same manner as the cutting device 2. The cutting device 62 includes a spindle 66 as a rotation axis, a flange mechanism 74 for fixing a cutting tool 68 to the tip of the spindle 66, and a cutting tool 68 fixed to the tip of the spindle 66 via the flange mechanism 74. A chuck table 64 for holding the substrate 1 is provided.

Here, the width of the cutting edge 72 of the cutting tool 68 is smaller than the width of the cutting edge 14 of the cutting tool 10 used when forming the machining groove 9a. In this case, in the dividing step S40, only the base material layer 5 exposed to the bottom of the machined groove 9a is formed without contacting the cutting edge 72 of the cutting tool 68 with the cut surface of the copper films 3 and 7 exposed to the machined groove 9a. It can be cut with the cutting tool 68. For example, in the division step S40, it is preferable to cut the cutting edge 72 of the cutting tool 68 into the center of the machining groove 9a.

When the substrate 1 is cut with the cutting tool 68 without contacting the cutting blades 72 with the copper films 3 and 7, the diamond abrasive grains contained in the cutting blade 72 of the cutting tool 68 adhere to the copper films 3 and 7. There is no. Therefore, in the flattening step S50 described below, the tool tool 44 does not come into contact with the diamond abrasive grains and cause damage to the tool tool 44.

If the copper films 3 and 7 are provided on both sides of the base material layer 5 and one copper film 3 is tool-cut while the other copper film 7 is not tool-cut, the copper film 7 has a machined groove. It is not necessary to form 9a, and the copper film 7 may be cut with the cutting tool 68. When the copper film 7 is not cut by a tool tool 44, it does not matter if diamond abrasive grains are attached to the copper film 7.

Next, the flattening step S50 performed after the division step S40 will be described. In the flattening step S50, the upper surfaces of the copper films 3 and 7 of at least one rectangular substrate 11 are flattened by cutting with a tool tool 44. Since the flattening step S50 is carried out in the same manner as the flattening step S20 described above, the description of the flattening step S50 will be omitted. Also in the substrate processing method according to the modification, since the tool tool 44 does not come into contact with the diamond abrasive grains, the tool tool 44 is not damaged and the frequency of replacement of the tool tool 44 can be reduced.

The cutting tool 68 having a cutting edge 72 including diamond abrasive grains is suitable for cutting not only the base material layer 5 but also the copper films 3 and 7, and can realize precise division of the substrate 1. Therefore, after cutting the substrate 1 with the cutting tool 68 and dividing the substrate 1 into the rectangular substrate 11, the copper films 3 and 7 of the rectangular substrate 11 are cut before the copper films 3 and 7 are cut with the tool tool 44. The diamond abrasive grains adhering to the surface may be removed. Next, a method for processing the substrate according to a further modification of the present embodiment will be described.

FIG. 8C is a flowchart illustrating the flow of each step of the substrate processing method according to the further modification. In the substrate processing method according to the modification, first, the division step S60 is carried out. FIG. 7A is a side view schematically showing the division step S60. Since the division step S60 is performed in the same manner as the division step S40, a part of the description thereof will be omitted.

The division step S60 is performed by the cutting device 62 in the same manner as the above-mentioned division step S40, for example. In the dividing step S60, a cutting tool 68a including an annular base 70a and a cutting edge 72a containing abrasive grains such as diamond abrasive grains fixed to the outer peripheral portion of the annular base 70a is used. In the dividing step S60, the substrate 1 is divided into a plurality of rectangular substrates 11 by cutting the substrate 1 along the planned division line 9 by a cutting tool 68a provided with a cutting blade 72a containing abrasive grains such as diamond abrasive grains.

When the dividing step S60 is performed, as shown in FIGS. 7A and 7B, a machined groove 9b along the planned division line 9 is formed on the substrate 1, and the board 1 is divided by the machined groove 9b. .. Here, the width of the machined groove 9b is a size corresponding to the thickness of the cutting edge 72a of the cutting tool 68a.

After the dividing step S60, the saw blade is brought into contact with the cut surface of the copper films 3 and 7 of at least one rectangular substrate 11 to remove the abrasive grains of the cutting tool 68a remaining on the cut surface of the copper films 3 and 7. The abrasive grain removing step S70 is carried out. FIG. 7B is a side view schematically showing the abrasive grain removing step S70. Since the abrasive grain removing step S70 is carried out in the same manner as the division step S10, a part of the description will be omitted.

In the abrasive grain removing step S70, the above-mentioned cutting device 2 used in the dividing step S10 can be used. In the abrasive grain removing step S70, a cutting tool 10a having a cutting blade 14a having a saw blade is attached to the cutting device 2 and used.

For example, in the abrasive grain removing step S70, a cutting tool 10a including a cutting edge 14a thicker than the cutting tool 72a of the cutting tool 68a used in the dividing step S60 is used. Preferably, the thickness of the cutting edge 14a is greater than 1 times and less than 2 times the thickness of the cutting edge 72a. In the abrasive grain removing step S70, the cutting edge 14a is cut into the processing groove 9b.

In this case, the region of the rectangular substrate 11 facing the machined groove 9b is cut by the cutting edge 14a and removed. At this time, the abrasive grains of the cutting edge 72a adhering to the cut surface of the copper films 3 and 7 are removed by the cutting edge 14a. Here, the cutting edge 14a also cuts into the base material layer 5, but since the area where the cutting edge 14a cuts and removes is smaller than that in the case where the processing groove 9b is not formed, the cutting edge 14a is used. The load is small.

Further, in the abrasive grain removing step S70, a cutting tool 10a having a cutting edge 14a having a thickness smaller than that of the cutting edge 72a may be used. In this case, the cutting edge 14a is individually cut into one side and the other side of the copper films 3 and 7 divided by the processing groove 9b, and the diamond attached to the cut surface of the copper films 3 and 7. Remove the abrasive grains.

After performing the abrasive grain removing step S70, a flattening step of cutting the upper surface of the copper film 3 and 7 of the rectangular substrate 11 from which the abrasive grains have been removed from the copper film 3 and 7 with a tool tool 44 to flatten the surface. Carry out S80. Since the flattening step S80 is carried out in the same manner as the flattening step S20 and the flattening step S50 described above, a part of the description will be omitted.

In the substrate processing method described in the flowchart of FIG. 8C, the abrasive grains such as diamond abrasive grains adhering to the cut surfaces of the copper films 3 and 7 are removed by the abrasive grain removing step S70. Therefore, in the flattening step S80, the diamond abrasive grains do not come into contact with the tool tool 44, and the tool tool 44 is not damaged. Therefore, the tool tool 44 needs to be replaced less frequently, and the machining efficiency of the substrate 1 can be improved.

The present invention is not limited to the description of the above embodiment, and can be modified in various ways. For example, in the above embodiment, the case where the copper films 3 and 7 are formed on both surfaces of the base material layer 5 has been mainly described, but one aspect of the present invention is not limited to this. That is, a copper film may be formed on one surface of the base material layer 5, and the copper film may be flattened.

Further, in the above embodiment, the case where both the copper films 3 and 7 provided on both sides of the base material layer 5 are flattened by the tool tool 44 has been described as an example, but the substrate according to one aspect of the present invention has been described. The processing method is not limited to this. That is, at least one of the copper films 3 and 7 may be flattened. Even in this case, the copper films 3 and 7 to which the diamond abrasive grains are attached are not cut by the tool tool 44.

Further, in the substrate 1 processed by the substrate processing method according to one aspect of the present invention, a metal film formed of a material other than copper may be provided on one surface or both surfaces of the substrate layer. Even in this case, in the substrate processing method according to one aspect of the present invention, the tool cutting by the tool tool 44 can be completed before the diamond abrasive grains adhere to the metal film.

The structure, method and the like according to the above embodiment can be appropriately modified and carried out as long as they do not deviate from the scope of the object of the present invention.

1 Substrate 3,7 Copper film 5 Substrate layer 9 Scheduled division line 9a, 9b Machined groove 11 Rectangular substrate 2,62 Cutting device 4 Spindle housing 6,66 Spindle 8,74 Flange mechanism 8a Front flange 8b Rear flange 10,10a, 68, 68a Cutting Tool 70, 70a Base 14, 14a, 72, 72a Cutting Blade 16, 64 Chuck Table 18 Tool Cutting Device 20 Base 20a Recess 22 Column 24 Guide Rail 26 Tool Cutting Unit 28 Spindle Housing 30 Support 32 Move Base 34 Spindle 36 Motor 38 Wheel Mount 40 Tool Wheel 42 Wheel Base 44 Tool Tool 44a Cutting Blade 46 Ball Screw 48 Pulse Motor 50 Z-Axis Movement Mechanism 52 Chuck Table Mechanism 54 Table Base 56 Chuck Table 56a Holding Surface 58 Bellows 60 Operation panel

Claims (3)

It is a method of processing a substrate that processes a substrate having a copper film on the upper surface.
A division step of cutting the substrate with a saw blade along the planned division line and dividing the substrate into a plurality of rectangular substrates.
After the division step, a flattening step of cutting the upper surface of the copper film of at least one rectangular substrate with a tool to flatten the copper film.
A method of processing a substrate, which comprises. It is a method of processing a substrate that processes a substrate having a copper film on the upper surface.
A machined groove forming step in which the substrate is machined along a planned division line with a saw blade to form a machined groove for dividing the copper film, and
By cutting into the area below the machined groove of the substrate with a cutting tool containing abrasive grains and having a cutting edge having a thickness smaller than the width of the machined groove, and cutting the substrate along the planned division line. A division step that divides the board into multiple rectangular boards,
After the division step, a flattening step of cutting the upper surface of the copper film of at least one rectangular substrate with a tool to flatten the copper film.
A method of processing a substrate, which comprises. It is a method of processing a substrate that processes a substrate having a copper film on the upper surface.
A division step of dividing the substrate into a plurality of rectangular substrates by cutting the substrate along the planned division line with a cutting tool equipped with a cutting blade containing abrasive grains.
An abrasive grain removing step of bringing a saw blade into contact with the cut surface of the copper film of the at least one rectangular substrate and removing the abrasive grains of the cutting tool remaining on the cut surface of the copper film.
After the abrasive grain removing step, a flattening step of cutting the upper surface of the copper film of the rectangular substrate from which the abrasive grains have been removed with a tool to flatten the copper film.
A method of processing a substrate, which comprises.

Images