JP6748523B2 - Board division method - Google Patents

Description

The present invention relates to a substrate dividing method for dividing a substrate in which a device is formed in each area defined by a plurality of intersecting dividing lines into individual devices.

A substrate such as a package substrate is divided into a plurality of regions by dividing lines whose surface is arranged in a grid pattern, and various devices are formed in the respective grid-shaped regions. .. In a cutting device that cuts these substrates with a rotating cutting blade, a rectangular device chip is manufactured by cutting the substrates held on a holding table vertically and horizontally along a dividing line.

When holding the substrate on the cutting device, there is a case where the substrate is sucked and held by using a jig type holding table (for example, refer to Patent Document 1) designed exclusively for the substrate. Then, in the jig type holding table, for example, a plurality of blades that extend in the vertical and horizontal directions on the plane and are orthogonal to each other are formed on the surface so that the cutting blade can be cut to a cutting position that is equal to or larger than the thickness of the substrate. The cutting blade clearance groove is formed, and a plurality of suction portions for individually suction-holding the chips produced by cutting are formed. The cutting blade clearance groove corresponds to the dividing line of the substrate, the suction part communicates with the suction path that passes through the inside of the holding table body, and the suction path communicates with the suction source that generates suction force. By sucking and holding the substrate using such a jig type holding table, it is possible to perform cutting while sucking and holding the substrate in the area corresponding to each chip after division, so that it is possible to perform cutting during cutting. The position of the tip will not shift.

JP, 2007-273546, A

However, when the substrate is held by the jig type holding table having the blade clearance groove and the suction portion as described above and the substrate is cut, the holding surface is composed of a porous member or the like having fine holes. Compared to the case where a holding table is used, the cutting water easily circulates around the cutting blade on the back side of the substrate, and the cutting water stays in the form of water droplets around the cutting blade on the back side of the substrate. As a result, there is a problem that dirt such as cutting chips and watermarks tend to remain on the back surface of the substrate. If the cutting device has a cleaning mechanism for cleaning the remaining dirt, the chips divided by the cleaning mechanism are collectively cleaned over a period of time, and the cutting device does not have the cleaning mechanism. In this case, it is necessary to convey the divided chips to a separate cleaning device and take time to clean them. In any case, it takes a lot of time to clean the chips manufactured by dividing the substrate. There was a problem.

Therefore, when the substrate is held by a holding table having a blade clearance groove and a suction unit, and the substrate is divided into device chips by a cutting blade, the back surface of the substrate after cutting is contaminated with cutting chips or watermarks. There is a problem in that it does not adhere or is not formed.

According to the present invention for solving the above-mentioned problems, a substrate on which a device is formed is formed in each region divided by a plurality of intersecting planned dividing lines, and a plurality of suction portions for holding each device of the substrate by suction are formed on the upper surface. A main body having a suction area, a suction path formed inside the main body for transmitting a suction force to the suction portion, and a relief groove for a cutting blade formed in the suction area corresponding to the plurality of planned dividing lines. , A cutting table for cutting the substrate, a cutting fluid supply nozzle for supplying the cutting fluid to the cutting blade, and a cutting table for dividing the substrate into individual devices by using a cutting device. A method of irradiating the back surface of the substrate with ultraviolet rays to enhance hydrophilicity, a step of holding the back surface side of the substrate by the holding table, and a dividing step of dividing the substrate along the dividing line. And a method of dividing a substrate to carry out step.

As one of the causes that dirt such as cutting chips and watermarks are attached or formed on the back surface of the substrate after cutting, cutting water wraps around the back surface of the substrate during cutting and stays in the form of water droplets. Therefore, it is considered that the cutting water does not flow continuously and integrally on the back surface of the substrate. Therefore, in the method of dividing a substrate according to the present invention, by performing an ultraviolet irradiation step of irradiating the back surface of the substrate with ultraviolet rays to enhance hydrophilicity, the cutting water that has spilled around on the back surface of the substrate during cutting becomes water droplets. Instead, it spreads out on the back surface to form a water film so that the cutting water enters between the dirt such as cutting chips and the contact area with the back surface of the substrate, and these dirts are entrained and flow integrally. By doing so, it becomes possible to prevent the back surface of the substrate after the cutting processing from being attached or formed with dirt such as cutting chips and watermarks.

It is a perspective view showing an example of a cutting device. It is a perspective view showing an example of structure of a substrate, a holding table, and a jig base. It is a longitudinal cross-sectional view showing a state where the back surface of the substrate is irradiated with ultraviolet rays. It is sectional drawing which shows the state which cut|disconnects the board|substrate hold|maintained at the holding table by the cutting blade, and is dividing it.

The cutting device 1 shown in FIG. 1 is a device that cuts a substrate W held on the upper surface 300a of the holding table 30 with a rotating cutting blade 63 included in the cutting means 6 to perform cutting work. At the center of the base 10 of the cutting device 1, a cutting feed means 11 for moving the holding table 30 back and forth in the cutting feed direction (X-axis direction) is arranged.

On the rear side (+X direction side) of the base 10, a gate-shaped column 14 is erected so as to straddle the cutting feed means 11. On the front surface of the gate-shaped column 14, index feeding means 12 for reciprocating the cutting means 6 in the Y-axis direction is arranged. The indexing and feeding means 12 includes a ball screw 120 having an axis in the Y-axis direction, a pair of guide rails 121 arranged in parallel with the ball screw 120, a motor 122 for rotating the ball screw 120, and an internal nut having a ball screw 120. And a movable plate 123 whose side portion is slidably contacted with the guide rail 121. When the motor 122 rotates the ball screw 120, the movable plate 123 is guided by the guide rail 121 to move in the Y-axis direction, and the cutting means 6 disposed on the movable plate 123 moves. Is indexed and fed in the Y-axis direction.

On the movable plate 123, a cutting feed means 16 for reciprocating the cutting means 6 in the Z-axis direction is arranged. The cutting feed means 16 includes a ball screw 160 having an axis in the Z-axis direction, a pair of guide rails 161 arranged parallel to the ball screw 160, a motor 162 for rotating the ball screw 160, and an internal nut having a ball screw 160. And a supporting member 163 whose side portion is screwed onto the guide rail 161 and is in sliding contact with the guide rail 161. Then, when the motor 162 rotates the ball screw 160, the support member 163 is guided by the guide rail 161 and moves in the Z-axis direction along with this, and the cutting means 6 supported by the support member 163 causes the support member 163 to move. Is moved in the Z-axis direction along with the movement of.

The upper surface of the housing 61 of the cutting means 6 described later is fixed to the lower end surface of the supporting member 163, and the planned dividing line S of the substrate W to be cut is imaged on the lower side surface of the supporting member 163 on the −X direction side. Alignment means 15 is provided for the detection. The alignment unit 15 includes an alignment camera 150 that captures an image of the front surface Wa of the substrate W, and based on an image acquired by the alignment camera 150, the planned dividing line S for cutting the substrate W by image processing such as pattern matching. Can be detected. Then, the cutting means 6 and the alignment means 15 move together in the Y-axis direction and the Z-axis direction.

The cutting means 6 has a spindle 60 whose axial direction is a direction (Y-axis direction) that is orthogonal to the moving direction (X-axis direction) of the holding table 30 in the horizontal direction, and a housing 61 which rotatably supports the spindle 60. A motor (not shown) for rotating the spindle 60 and a cutting blade 63 fixed to the spindle 60 are provided, and the cutting blade 63 also rotates at high speed as the motor (not shown) rotationally drives the spindle 60. The cutting blade 63 is, for example, a washer-type annular blade or a disk-shaped hub blade provided with a base metal.

In the vicinity of the cutting blade 63, a cutting liquid supply nozzle 17 that supplies the cutting liquid to a processing point where the cutting blade 63 contacts the substrate W is arranged. Two cutting fluid nozzles 17 are provided, for example, so as to sandwich the cutting blade 60 from both sides in the Y-axis direction, and have an injection port facing the side surface of the cutting blade 60, and communicate with a cutting fluid supply source (not shown). doing.

The holding table 30 for sucking and holding the substrate W is mounted on a jig base 32 arranged on the cutting device 1. The jig base 32 is surrounded from the periphery by a cover 39, is rotatable about an axis in the vertical direction, and can be reciprocally moved on the base 10 in the X axis direction by the cutting feed means 11. There is.

The substrate W shown in FIG. 2 is, for example, a rectangular package substrate made of a predetermined resin, silicon, or the like, and on the front surface Wa of the substrate W, a plurality of device regions Wa1 in which a plurality of devices D are formed (illustration is shown). In the example of 3), 3) are formed. Each device region Wa1 is surrounded by a surplus region Wa2 which is made into small pieces and is mainly waste material. The device area Wa1 is further divided into a plurality of rectangular areas by a plurality of dividing lines S that are orthogonal to each other on the front surface Wa. A device D such as an IC or an LED is arranged in each rectangular region via a bonding agent or the like, and the substrate W is cut along each planned dividing line S to be cut, whereby each rectangular region is a device. It becomes an individual chip with D. In the illustrated example, a total of 48 chips including the device D can be manufactured from one device region Wa1 by cutting. For example, the front surface Wa of the substrate W is covered with an epoxy resin J (not shown in FIG. 2) so as to cover the planned dividing line S and the device D. Note that the substrate W is not limited to that in the present embodiment, and may be, for example, a circular semiconductor wafer, an alloy substrate whose back surface is sealed with a polymer resin, or the like. The number of regions Wa1 and the like are not limited to the examples illustrated in the accompanying drawings.

The holding table 30 shown in FIG. 2 has a main body 300 having a suction region 300f formed on the upper surface 300a with a plurality of suction portions 300c for holding each device D of the substrate W, and a suction portion 300c formed inside the main body 300. A suction path 304 for transmitting a suction force, and an escape groove 300e of the cutting blade 63 formed in the suction region 300f corresponding to the plurality of planned dividing lines S are provided. The main body 300 is a rectangular flat plate made of a material such as general-purpose engineering plastic or alloy, and the upper surface 300a of the main body 300 can hold the substrate W by suction. On the upper surface 300a of the main body 300, three suction regions 300f are formed side by side at equal distances in the X-axis direction so as to correspond to the three device regions Wa1 of the substrate W, respectively. In addition, a plurality of cutting blade relief grooves 300e are formed on the upper surface 300a of the main body 300 so as to avoid contact with the cutting blade 63 shown in FIG. In the three suction regions 300f, a plurality of substantially square suction portions 300c are formed by being divided by the cutting blade relief grooves 300e. Each suction part 300c corresponds to each device D on the substrate W in a one-to-one correspondence, and a total of 48 devices are formed in one device region Wa1.

The cutting blade clearance groove 300e is formed so as to be located at a position corresponding to the planned dividing line S of the substrate W, that is, immediately below the planned dividing line S when the substrate W is held by the holding table 30. The upper end of the cutting blade clearance groove 300e is opened to the upper surface 300a, and both ends thereof are formed so as to pass through the outer circumference of the holding table 30, respectively. The width of the cutting blade clearance groove 300e is wider than the blade thickness of the cutting blade 63 shown in FIG. 1, and the depth of the cutting blade clearance groove 300e is the cutting height position at which the cutting blade 63 completely cuts the substrate W. When the cutting blade 63 is lowered, the bottom end of the cutting blade 63 has such a depth that it does not contact the bottom of the cutting blade clearance groove 300e. Therefore, the cutting blade 63 in the rotated state is lowered to the cutting height position for completely cutting the substrate W, the holding table 30 holding the substrate W is cut and fed toward the cutting blade 63, and the substrate W is moved to the outer peripheral end. Even if the cutting is performed from to the opposite outer peripheral end, the holding table 30 and the cutting blade 63 do not interfere with each other. The main body 300 of the holding table 30 is formed thicker than the depth of the cutting blade clearance groove 300e.

As shown in FIG. 2, each suction portion 300c is provided with, for example, one suction passage 304 that opens on the suction portion 300c, and each suction passage 304 is formed in the thickness direction (Z-axis direction) of the main body 300. ) Is formed inside the main body portion 300 so as to penetrate therethrough.

As shown in FIG. 2, the upper surface of the jig base 32 is a double annular mounting surface on which the holding table 30 is mounted. When the holding table 30 is placed on the upper surface of 32, a trough-shaped first suction space 321 that communicates with the lower ends of the suction paths 304 is formed. Further, in the outer peripheral portion of the upper surface of the jig base 32, when the holding table 30 is placed on the upper surface of the jig base 32, the second suction of a square annular shape facing the outer region of the back surface of the main body 300 of the holding table 30. The space 322 is formed independently of the first suction space 321.

As shown in FIG. 1, the cutting device 1 includes a flow path 34 that communicates with a suction source 340 and transmits a suction force for sucking the substrate W to each suction unit 300c via a suction path 304 shown in FIG. ing. For example, one end 34a of the flow path 34 is opened at the bottom of the first suction space 321 of the jig base 32, and the other end 34b of the flow path 34 is provided with a suction source 340 including a vacuum generator and a compressor. Are connected. A solenoid valve 341, for example, is disposed on the flow path 34, and the solenoid valve 341 has a state in which the path to the flow path 34, the first suction space 321, and the suction path 304 communicates with the suction source 340 and the atmosphere. It has the function of switching between the open state and the open state.

For example, a branch path 35 branches and extends from the flow path 34, and one end 35 a of the branch path 35 communicates with the second suction space 322 of the jig base 32. For example, a solenoid valve 351 is disposed on the branch passage 35. The solenoid valve 351 is open to the atmosphere and a state in which the path to the branch passage 35 and the second suction space 322 communicates with the suction source 340. It has a function to switch between states.

Hereinafter, each step of the dividing method and the operation of the cutting apparatus 1 when the method of dividing the substrate W according to the present invention is performed using the cutting apparatus 1 shown in FIG. 1 will be described.

(1) UV Irradiation Step A state in which the outer peripheral region of the back surface Wb corresponding to the surplus region Wa2 of the substrate W is brought into contact with the upper surface of the shelf 500 of the ultraviolet irradiation device 5 shown in FIG. And Instead of the shelf 500, a table or the like that is formed of a transparent member such as glass that transmits ultraviolet rays and supports the entire back surface Wb of the substrate W may be used. Further, the ultraviolet irradiation device 5 may be arranged in the cutting device 1.

A plurality of UV lamps 501 are arranged in an array below the substrate W supported by the shelf 500. The UV lamp 501 is, for example, a low-pressure UV mercury lamp, and is capable of irradiating upward with ultraviolet rays having a wavelength of around 185 nm and ultraviolet rays having a wavelength of around 254 nm, respectively.

Then, ultraviolet rays are emitted from the UV lamp 501 toward the back surface Wb of the substrate W. After irradiating the back surface Wb of the substrate W with ultraviolet rays of a predetermined wavelength (for example, 185 nm) from the UV lamp 501 for a certain period of time, the ultraviolet rays emitted from the UV lamp 501 are switched to the ultraviolet rays of the wavelength 254 nm and the ultraviolet rays of the wavelength 254 nm are maintained for a certain period of time. The back surface Wb of the substrate W is irradiated. The irradiation of ultraviolet rays having different wavelengths is performed, for example, a plurality of times.

By irradiating the back surface Wb of the substrate W with ultraviolet light having a wavelength of 185 nm, oxygen molecules in the air existing between the back surface Wb of the substrate W and the UV lamp 501 absorb the ultraviolet light, and oxygen atoms in the ground state are absorbed. To generate. The generated oxygen atoms combine with surrounding oxygen molecules to generate ozone. In addition, the ultraviolet ray having a wavelength of 185 nm emits an intermolecular bond and an interatomic bond (for example, a carbon-carbon bond and a carbon-hydrogen bond) of an organic substance (mainly a polymer such as oil) attached to the back surface Wb of the substrate W. By breaking the (bond) to an excited state, organic substances are decomposed. Further, also in the portion of the back surface Wb of the substrate W on which the organic matter is not attached, the molecular chain is similarly cut. Further, the generated ozone absorbs the ultraviolet ray having the wavelength of 254 nm, and thereby the active oxygen in the excited state is generated. Since the generated active oxygen and ozone have high oxidizing power, organic substances are decomposed and the back surface of the substrate W is chemically unstable because the molecular chains of the back surface Wb are cut. It bonds with carbon or hydrogen of Wb to form a highly polar hydrophilic group such as a hydroxyl group, an aldehyde group and a carboxyl group. Since the generated amount of active oxygen and ozone is much larger than the amount of organic substances attached to the back surface Wb of the substrate W, most of the organic substances such as operator's sebum attached to the back surface Wb are hydrophilic. Change to higher functional groups. In addition, since hydrophilic groups are similarly formed on the portion of the back surface Wb of the substrate W to which no organic substance is attached, the back surface Wb of the substrate W is modified and the hydrophilicity of the back surface Wb is increased.

(2) Holding Step In the cutting device 1 shown in FIG. 1, the holding table 30 is mounted on the jig base 32 so that their positions are aligned, and the second suction space 322 formed in the jig base 32 is branched. The holding table 30 is suction-held by the jig base 32 by communicating with the suction source 340 via the passage 35 and the solenoid valve 351 and operating the suction source 340 to transmit the suction force to the second suction space 322. Is set to the open state.

The substrate W having the back surface Wb irradiated with the ultraviolet rays is conveyed to the holding table 30, and is placed on the holding table 30 with the back surface Wb facing down, as shown in FIG. The substrate W is aligned so that the cutting blade clearance groove 300e corresponds to each planned dividing line S of the substrate W. Each suction path 304 of the holding table 30 is connected to the suction source 340 via the first suction space 321, the flow path 34, and the solenoid valve 341 formed in the jig base 32. Therefore, by switching the solenoid valve 341 to the communicating position, the suction force is transmitted to each suction unit 300c, and the substrate W is suction-held on the holding table 30.

(3) Dividing Step For example, the holding table 30 holding the substrate W rotates about the vertical axis so that the longitudinal direction of the substrate W becomes the Y-axis direction. Next, the holding table 30 holding the substrate W is sent in the +X direction, and the surface Wa of the substrate W is imaged by the alignment camera 150 shown in FIG. 1 to detect the position of the planned dividing line S to be cut. As the dividing line S is detected, the cutting means 6 is driven in the Y-axis direction, and the dividing line S to be cut and the cutting blade 63 are aligned in the Y-axis direction.

After the cutting blade 63 is aligned with the detected planned dividing line S in the Y-axis direction, the cutting means 6 is cut and fed in the −Z direction, and the cutting blade 63 shown in FIG. 4 completely cuts the substrate W. The cutting blade 63 is positioned at a cutting height position where the lowermost end of the cutting blade 63 reaches the inside of the cutting blade clearance groove 300e of the holding table 30. The holding table 30 holding the substrate W is further fed in the +X direction, a motor (not shown) rotates the spindle 60 at high speed, and the cutting blade 63 fixed to the spindle 60 rotates at high speed as the spindle 60 rotates. The substrate W is cut and the planned dividing line S is cut. Further, when the cutting blade 63 cuts into the substrate W, the cutting liquid supply nozzle 17 jets and supplies the cutting liquid to the processing points of the cutting blade 63 and the substrate W.

By performing the ultraviolet irradiation step of irradiating the back surface Wb of the substrate W with ultraviolet rays to enhance hydrophilicity, the cutting water that has flowed around the back surface Wb of the substrate W in the dividing step does not become water droplets, and the cutting blade on the back surface Wb side 63 spreads around the cut-out surrounding Wb1 to form a water film. As a result, the cutting water flows in between the contact portion of the back surface Wb of the substrate W and the cutting waste generated around the periphery Wb1 of the cutting blade 63 of the substrate W, and the dirt such as the cutting waste is caught in the cutting. It will flow integrally along the blade clearance groove 300e. Therefore, it is possible to prevent dirt such as cutting chips and watermarks from being attached or formed on the back surface Wb of the substrate W after the cutting process.

When the substrate W advances in the +X direction to a predetermined position in the X-axis direction where the cutting blade 63 finishes cutting the planned dividing line S, the cutting feed of the substrate W in the +X direction is once stopped, and the cutting blade 63 is moved from the substrate W. After separating, the holding table 30 is sent out in the -X direction and returned to the original position. Then, the cutting blades 63 are indexed and fed in the Y-axis direction at intervals of the adjacent planned dividing lines S, and the same cutting is sequentially performed to cut all the planned dividing lines S in the same direction. Further, when the holding table 30 is rotated 90 degrees and the same cutting is performed, all the planned dividing lines S are fully cut vertically and horizontally.

The substrate dividing method according to the present invention is not limited to the above embodiment, and the configurations of the cutting device 1 and the ultraviolet irradiation device 5 illustrated in the accompanying drawings are not limited to this. It is possible to make appropriate changes within a range in which the effects of the present invention can be exhibited. For example, when the cutting device 1 includes a substrate cassette that stores the substrate W, the UV lamp 501 may be arranged in the substrate cassette and the substrate cassette may be the ultraviolet irradiation device 5.

1: Cutting device 10: Base 14: Gate type column 11: Cutting feed means 12: Indexing feed means 120: Ball screw 121: A pair of guide rails 122: Motor 123: Movable plate 16: Cutting feed means 160: Ball screw 161: Pair Guide rail 162: motor 163: support member 15: alignment means 150: alignment camera 6: cutting means 60: spindle 60: housing 63: cutting blade 17: cutting fluid supply nozzle 30: holding table 300: body 300a: holding table 300e: Cutting blade clearance groove 300f: Suction area 300c: Suction part 304: Suction path 32: Jig base 321: First suction space 322: Second suction space 34: Flow path 340: Suction source 341: Solenoid Valve 35: Branch path 351: Solenoid valve 39: Cover 5: UV irradiation device 500: Shelf 501: UV lamp
W: Substrate Wa: Surface of Substrate Wa1: Device Area Wa2: Surplus Area S: Planned Division Line D: Device J: Engineering Plastic Resin

Claims (1)

A substrate with a device formed in each area divided by a plurality of planned dividing lines that intersect,
A main body having a suction area in which a plurality of suction portions for holding each device of the substrate by suction are formed on the upper surface, a suction path formed inside the main body for transmitting a suction force to the suction portion, and the plurality of planned dividing lines. A holding table provided with a relief groove of the cutting blade formed in the suction region corresponding to
A cutting blade for cutting the substrate,
A method of dividing a substrate using a cutting device having at least a substrate and a cutting liquid supply nozzle for supplying a cutting liquid to the cutting blade, the device being divided into individual devices,
An ultraviolet irradiation step that irradiates the back surface of the substrate with ultraviolet rays to increase hydrophilicity,
A holding step of holding the back side of the substrate by the holding table;
And a dividing step of dividing the substrate along the dividing line, the dividing method of the substrate.

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