TWI504470B - Laser processing method and laser processing device - Google Patents

Description

Laser processing method and laser processing device Field of invention

The present invention relates to a laser processing technique for irradiating a laser beam to a workpiece such as a semiconductor wafer, performing a groove processing or a cutting process, and the like, and particularly relates to a method of applying a water-soluble resin to a workpiece held on a rotary table. The processed surface, or the technique of removing the applied resin.

Background of the invention

In the process of the semiconductor device, a plurality of rectangular wafer regions are divided on the surface of the substantially disk-shaped semiconductor wafer by a predetermined dividing line arranged in a lattice shape, and an electronic circuit such as an IC or an LSI is formed in the wafer regions, and then the wafer is subjected to the wafer processing. After necessary processing such as back grinding, the wafer is cut and divided along the dividing line. That is, each wafer region is obtained as a semiconductor wafer by dicing. The semiconductor wafer thus obtained is sealed with a resin and is widely used in various electric appliances and electronic devices such as mobile phones and PCs (personal computers).

The method of cutting a wafer into a semiconductor wafer is generally a blade cutting in which a high-speed rotating thin disk-shaped cutter is cut into a wafer. On the other hand, in recent years, it has been attempted to irradiate a penetrating laser beam along a predetermined line, and to melt the wafer, and to perform a laser cutting by cutting or cutting. (Refer to Patent Document 1). In the case of laser cutting, when the laser beam is irradiated, the droplets of the transpiration component called debris adhere to the wafer processing surface, which causes a problem of lowering the quality. Therefore, the applicant of the present invention proposed to irradiate the processed surface with laser light while forming a protective film on the wafer processing surface with a water-soluble resin. The technique in which the chips adhere to the resin and does not directly adhere to the surface of the wafer to ensure quality (see Patent Document 2).

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei 10-305420

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-188475

Invention

In the technique described in the above Patent Document 2, it is possible to effectively prevent the adhesion of debris to the wafer during laser processing, and two new steps of forming a protective film and removing the protective film by resin coating before and after the laser processing. . In the field of semiconductor device manufacturing in recent years, in order to meet the demand for mass production, the speed of manufacture and the quality have been similarly emphasized. Therefore, the addition of the two steps before and after the laser processing is disadvantageous in speeding up the manufacturing speed, and improvement measures are required.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a protective film forming step before laser processing for preventing adverse effects caused by the above-mentioned debris and a time required for a protective film removing step after laser processing. A laser processing method and a laser processing apparatus that can ensure the quality and speed up the manufacturing speed.

The laser processing method of the present invention comprises: a resin coating step of applying a liquid water-soluble resin on a processing surface of the workpiece, a laser beam irradiating the processed surface of the workpiece, a laser processing step of performing laser processing, and a washing step of performing laser processing of the workpiece; the resin coating step has a spin coating step of applying a water-soluble resin to the processing surface of the workpiece by a spin coating method, and supplying the warm air to the applied water-soluble solution a resin drying step of drying the water-soluble resin; and a cleaning step of the resin removing step of supplying the warm water to the water-soluble resin coated on the working member to remove the water-soluble resin, and The warm air is supplied to the work piece drying step of the work piece from which the water-soluble resin has been removed.

According to the laser processing method of the present invention, in the resin coating step before the laser processing step, the warm air is supplied to the water-soluble resin which is applied to the processing surface of the workpiece by the spin coating method, and is placed at a normal temperature. In the case of natural hardening, the hardening of the water-soluble resin can be promoted, and the hardening can be accelerated more. The hardened water-soluble resin is formed on the processing surface of the workpiece by a protective film. In the laser processing step, even if the above-mentioned debris is generated, it adheres to the protective film and does not directly adhere to the processing surface of the workpiece, thereby ensuring quality. .

In the washing step after the laser processing step, the warm water is supplied to the water-soluble resin (protective film), and the water-soluble resin is washed away and removed, and by using warm water, compared with the case of using normal temperature water. It can promote the dissolution of the water-soluble resin and accelerate the washing off. In the subsequent drying step, since the working member is dried by supplying warm air, the work piece can be accelerated to be dried. Thus, in the present invention, the drying of the water-soluble resin applied to the workpiece or the drying of the workpiece after the resin is removed from the workpiece is performed by warm air, and the washing water is used when the resin is removed from the workpiece. Since water is used, the time spent in each step can be shortened compared to the use of water or air at normal temperature, which contributes to an increase in the speed of manufacture.

Secondly, the laser processing apparatus of the present invention can be adapted to the above-described laser processing method, and includes a holding mechanism for holding the workpiece, a laser beam for irradiating the workpiece held by the holding mechanism, and performing laser processing for laser processing. The mechanism and the rotating device are a rotary table that rotates while holding the workpiece, and a resin supply mechanism that supplies the liquid water-soluble resin to the processing surface of the workpiece held before the laser processing of the rotary table, and washes The purified water is supplied to the washing water supply mechanism that holds the processing surface of the workpiece after the laser processing of the rotary table, and the air supply mechanism that supplies air to the processing surface of the workpiece held by the rotary table; The mechanism includes a resin source that supplies a water-soluble resin, and a first nozzle that supplies the water-soluble resin that is transported from the resin source to a processing surface of the workpiece held on the rotary table; the washing water supply mechanism has a water source for supplying the washing water, a first heat source that heats the washing water sent from the water source to form warm water, and a second nozzle that supplies warm water to the workpiece held on the turntable; air supply Having a configuration of an air source for supplying air, heated air from the air source of the delivery of hot air to form a second heat source, and the temperature was held in the air supply to the working member of the third nozzle of the turntable.

In the laser processing apparatus of the present invention, the first heat source and the second heat source are in the same heat source. According to this aspect, it is possible to save space and low cost by sharing a heat source.

Moreover, the laser processing apparatus according to the present invention includes the second nozzle having a mixing mechanism that mixes the warm water and the gas. In this form, a spray of warm water and a gas is sprayed to remove the water-soluble resin supplied to the processing surface of the workpiece, thereby promoting the cleaning effect of the spray. When the warm water heated by the above-mentioned second heat source is used as the warm water gas mixed at this time, the structure can be simplified, which is preferable.

Moreover, in the laser processing apparatus of the present invention, the first heat source and the second heat source are covered with a heat insulating material to suppress heat from being radiated to the periphery of the apparatus and to prevent heat from affecting other parts of the apparatus. Further, it is advantageous in that heat loss of the first heat source and the second heat source can be suppressed, energy saving is achieved, and external temperature change is less likely to be affected, and accuracy of temperature setting can be ensured.

Further, the working member referred to in the present invention is not particularly limited, and includes a semiconductor wafer such as a germanium wafer, an adhesive member such as a DAE (Die Attach Film) provided on the back surface of the wafer for packaging a wafer, a package of a semiconductor product, and a ceramic. Various drivers such as glass, sapphire or lanthanide substrates, various electronic components, LCD drivers for controlling liquid crystal display devices, and various processing materials requiring precision of micron sequences.

According to the present invention, before the laser processing, a water-soluble resin is applied to the processed surface of the workpiece to form a protective film, and warm air is supplied to the resin to be cured, and after the laser is washed, the resin is washed. After dissolving the resin in warm water, the work piece is dried by the warm air, so that the time required for the steps can be shortened. As a result, the adhesion of the above-mentioned chips is prevented, the quality is ensured, and the manufacturing speed is increased. .

The best form for implementing the invention

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 shows the entire laser processing apparatus 10 of one embodiment, and Fig. 2 shows the back side. This device 10 is a laser cutting device in which a semiconductor wafer (hereinafter simply referred to as a wafer) shown in FIG. 3 is used as a workpiece 1 and is automatically controlled to cut a wafer.

(1) Wafer

First, the wafer 1 will be described with reference to Fig. 3, and the wafer 1 is a disk having a single crystal material such as tantalum, and an orientation flat 1a is formed in one of the outer peripheral portions as a mark indicating the crystal orientation. A plurality of rectangular wafers 3 are divided on the surface (machined surface) of the wafer 1 by a predetermined dividing line 2 which is formed in a lattice shape. An electronic circuit such as an IC or an LSI (not shown) is formed on the surface of each of the wafers 3. The wafer 1 is laser-processed by the laser processing apparatus 10 into all the wafers 3 by laser processing. Further, at this time, the cutting is cut in addition to the entire thickness direction, and the groove processing is formed to form a predetermined depth to the middle of the thickness. The wafer during the trench processing is cut into a plurality of wafers by cutting or depositing the remaining thickness portion of the trench by a later step.

When the wafer 1 is supplied to the laser processing apparatus 10, as shown in FIG. 3, it is supported by the adhesive tape 5 inside the annular frame 4. The frame 4 is made of a metal plate or the like and has rigidity. Since the single surface of the adhesive tape 5 serves as an adhesive surface, the frame 4 and the wafer 1 are attached to the adhesive surface. The frame 4 (hereinafter referred to as a frame 6 with a wafer) that supports the wafer 1 by the adhesive tape 5 is placed in the wafer storage cassette 9 shown in FIG. 1 in a state in which the wafer 1 is placed on the upper side. A plurality of wafer-attached frames 6 are stacked in a horizontal and vertical direction and housed in the cassette 9.

(2) Laser processing device (2-1) Overall structure

The reference numeral 11 in Figures 1 and 2 is a cabinet. A laser processing mechanism 19 is disposed inside the cabinet 11. The laser processing mechanism 19 uses a structure having a laser that oscillates with a laser oscillator such as a YAG laser oscillator or a YVO4 laser oscillator, and illuminates the lens. Further, in FIGS. 1 and 2, a portion of the laser processing mechanism 19 is shown, and the laser beam is irradiated to the laser head below.

A touch panel type operation display panel is provided on one end side of the cabinet 11 in the Y direction (the front side in FIG. 1), and various settings relating to the automatic operation of the laser processing are performed by using the operation display panel 12. A function indicating the internal operation state or the like is also attached to the operation display panel 12. A display lamp 13 that displays an operational state or issues a warning is mounted on the top plate of the cabinet 11 above the operation display panel 12.

A base 14 is attached to the side 11a side of the cabinet 11. The center of the base 14 is set at a wafer loading and unloading position for loading and unloading the wafer 1 with respect to the disk-shaped chuck table (holding mechanism) 20. The chuck table 20 moves back and forth in the X direction between the wafer loading and unloading position on the base 14 and the processing position of the laser processing mechanism 19 in the cabinet 11. The chuck table 20 shown in Fig. 2 is positioned at the processing position. The wafer loading and unloading position is provided with a cassette table 15 on the front side in the Y direction in Fig. 1, and the rotating device 60A of the present invention is disposed on the inner side in the Y direction on the opposite side.

The above-described cassette 9 in which a plurality of frames 6 with wafers are housed is placed on the cassette table 15. The cassette table 15 is a lift type that can be lifted and lowered, and the frame 6 with the wafer in the cassette is positioned at a pull-out position of a certain height.

The wafer-attached frame 6 provided in the cassette 9 of the cassette 15 is moved from the above-described pull-out position to the chuck table 20 for holding. The suction cup table 20 is generally known as a vacuum type, and is rotatably supported by a rectangular base 21 in a Z direction (up and down direction) as a rotation axis, and is disposed in a rotation drive (not shown) provided in the base 21 The mechanism rotates in one direction or in both directions.

From the wafer loading and unloading position on the base 14 to the processing position of the laser processing mechanism 19 in the cabinet 11, a rectangular recess 16 extending in the X direction is provided as a moving space of the base 21. The base 21 is disposed on the bottom surface of the recess 16 and the back and forth moving mechanism (not shown) moves back and forth in the X direction. Therefore, the chuck table 20 moves back and forth together with the base 21 in the X direction. A serpentine tubular cover 17 is attached to both ends of the base 21 in the X direction. These covers 17 prevent the dust from falling into the recess 16 and the like, and expand and contract with the movement of the base 21.

A vacuum device (not shown) is connected to the chuck table 20. When the vacuum device is operated, the air above the chuck table 20 is sucked, and the wafer 1 is adsorbed and held on the chuck table 20 by the air suction. The outer diameter of the chuck table 20 is almost equal to that of the wafer 1, and the wafer 1 is entirely adhered to the upper surface of the chuck table 20 and is kept concentric. Further, the frame 4 around the wafer 1 is held by a plurality of clips 22 attached to the outer peripheral surface of the chuck table 20. The clips 22 hold the frame 4 in a detachable state, and are disposed at four positions along the X direction and the Y direction.

The above-described rotating device 60A has a rotary table 70 that holds the frame 6 to which the wafer is attached. The rotary table 70 is of the same vacuum chuck type as the above-described chuck table 20, and adsorbs and holds the frame 6 with the wafer attached thereto by air suction. In the rotating device 60A, a resin coating step of applying a water-soluble resin to the surface of the processing surface of the wafer 1 and a cleaning step of cleaning the wafer 1 after the laser processing are performed before the laser processing. This rotary device 60A will be described in detail later.

Next, a transport system for transporting the frame 6 with the wafer attached will be described with reference to FIG.

The frame 6 with one wafer is positioned in the cassette 9 and positioned at the pull-out position by the lifting operation of the cassette table 15, and the grip mechanism 30 is horizontally pulled out in the Y direction to be disposed on the crystal. One of the upper positions of the round loading and unloading position receives the positioning bar 35 extending in the Y direction. The grip mechanism 30 is provided with a nip portion 33 of the grip frame 4 at the front end of the arm 32 which is moved back and forth in the Y direction by the linear guide 31 provided on the side surface 11a of the cabinet 11. A pair of positioning bars 35 are separated in the X direction. The pair of positioning bars 35 are actuated to be close to or separated from each other in the X direction, and the intermediate positions of the two are generally coincident with the center of the chuck table 20.

The frame 6 to which the wafer is attached is held by the nip portion 33 of the grip mechanism 30, and is placed in a state where the movement of the arm 32 is erected on the two positioning bars 35. The positioning strips 35 are brought close to each other to contact the outer periphery of the frame 4, and the positioning of the frame 6 with the wafer in the X direction is performed. Further, the positioning in the Y direction is performed by the movement of the arm 32. Thereby, the wafer 1 and the chuck table 20 are concentrically positioned (position in the X and Y directions).

Then, the frame 4 supported by the positioning bar 35 is sucked and held by the first transport mechanism 40 above, and then the positioning bar 35 is separated, and the frame 6 with the wafer is held only by the first transport mechanism 40, and the first transport mechanism 40 The front end of the telescopic arm 42 which moves back and forth along the linear guide 41 provided on the side surface 11a of the cabinet 11 in the Y direction is provided with a plurality of vacuum suction pads 43 which are adsorbed onto the frame 4 and hold the frame 4.

The telescopic arm 42 of the first transport mechanism 40 is operated to expand and contract in the Z direction, and the telescopic arm 42 extends downward. When the vacuum suction of the vacuum suction pad 43 is released, the wafer 1 is placed on the chuck table 20 positioned at the wafer loading and unloading position. on. Further, in the state in which the telescopic arm 42 is extended downward by the first transport mechanism 40, the frame 6 with the wafer attached to the chuck table 20 is sucked and held by the vacuum suction pad 43, and the telescopic arm 42 is contracted upward to make the wafer After the rise, the movement moves to the inner side in the Y direction, and then extends downward to release the vacuum suction of the vacuum suction pad 43, and the frame 6 with the wafer is placed concentrically on the rotary table 70 of the rotary device 60A.

The frame 6 on which the wafer is attached to the turntable 70 is returned to the positioning bar 35 by the second transport mechanism 50. The second transport mechanism 50 has the same configuration as the first transport mechanism 40, and is disposed along the side surface 11a of the 11 The front end of the telescopic arm 52 on which the linear guide 51 on the lower side of the linear guide 41 moves back and forth in the Y direction is provided with a plurality of vacuum suction pads 53 which are adsorbed to the upper surface of the frame 4 and hold the frame 4.

By the second transport mechanism 50, the telescopic arm 52 is stretched, and the frame 4 having the frame 6 of the wafer is sucked and held by the vacuum suction pad 53. Then, the telescopic arm 52 is contracted and moved to the front side in the Y direction, and the frame 6 with the wafer is attached. Placed on the positioning bar 35. The frame 6 on which the wafer is placed on the positioning bar 35 is held by the holding mechanism 30, and the arm 32 is moved to the front side in the Y direction, thereby being housed in the cassette 9.

Further, as shown in Fig. 2, the conveyance system or the wafer loading/unloading position and the space above the rotating device 60A are covered by the cover members 11b and 11c. In Fig. 1, the inside of the cover members 11b and 11c are shown, and the cover members 11b and 11c are not shown.

(2-2) Structure of the rotating device of the first embodiment

The above is the overall configuration of the laser processing apparatus 10. Next, the rotating apparatus 60A of the first embodiment will be described with reference to Fig. 4 . This rotating device 60A has a cylindrical casing 61 and a support base 62 that supports the casing 61. The support table 62 has a plate-like base 63 that is horizontally disposed, a plurality of leg portions 64 that are erected on the base 63, and a receiving portion 65 that is fixed to the upper ends of the leg portions 64. The receiving portion 65 is formed in a circular disk shape, and the housing 61 is fitted and supported by the receiving portion 65 from the upper side.

The case 61 supported by the receiving portion 65 has a state in which the axis is almost in the vertical direction, and the turntable 70 and the case 61 are disposed concentrically inside the case 61. The turntable 70 is formed by fitting a disk-shaped adsorption portion 72 made of a porous body to the disk-shaped housing 71. The adsorption unit 72 is concentric with the casing 71 and occupies a large portion of the upper surface of the rotating table 70. The upper surface of the adsorption unit 72 and the upper surface of the annular frame 71 around the adsorption unit 72 form the same plane.

A vacuum device (not shown) is connected to the rotary table 70. When the vacuum device is operated, the air on the rotary table 70 is sucked, and the air is sucked, and the wafers are placed concentrically on the rotary table 70. The frame 6 is adsorbed and held by the adsorption portion 72.

The outer diameter of the frame 71 of the rotary table 70 is almost equal to the outer diameter of the frame 4, and the outer diameter of the adsorption portion 72 is almost equal to the outer diameter of the wafer 1. Therefore, when the frame 6 to which the wafer is attached is placed concentrically on the turntable 70, the outer periphery of the frame 4 and the frame 71 are almost identical, and the entire wafer 1 is closely held by the adsorption portion 72.

Further, the frame 4 to which the frame 6 of the wafer is attached is held by the plurality of clips 73 attached to the outer peripheral surface of the turntable 70. The clips 73 hold the frame 4 in a detachable state, and have a lid portion 73a that covers the frame 4 from above. The clip 73 is disposed at a position corresponding to the vacuum suction pad 53 of the second transport mechanism 50, and the vacuum suction pad 53 can be adsorbed when the frame 4 is covered by the lid portion 73a.

A motor 74 that rotates the rotary table 70 is fixed to the base 63 of the support table 62. The drive shaft 74a of the motor 74 (shown in FIG. 6) extends upward and penetrates the receiving portion 65 to be inserted into the housing 61. The front end of the drive shaft 74a is coupled to the center of the frame 71 of the rotary table 70, and when the motor 74 is actuated, the rotary table 70 is rotated in one direction.

The rotating table 70 is lifted and lowered by a lifting mechanism (not shown). With the lifting mechanism, the rotating table 70 can be positioned at a wafer transfer position from the upper side of the housing 61 and lowered from the wafer transfer position to the housing 61. Processing location. Further, the drive shaft 74a of the motor 74 has a structure that is expandable and contractible, and can follow the elevation of the rotary table 70. The rotating device 60A is housed inside the base 14, and the rotating device 60A shown in Fig. 1 shows a state in which the rotary table 70 is raised to the wafer transfer position. The rotary table 70 that rises to the wafer transfer position is almost the same height as the upper surface of the base 14.

In the casing 61, three nozzles (the first nozzle 81, the second nozzle 82, and the third nozzle 83) that are bent downward at the front end and extend in the horizontal direction are provided. At this time, the first nozzle 81 is individually rotatably supported by the first pipe base portion 81A. In addition, the second nozzle 82 and the third nozzle 83 are arranged one above the other, and are arranged to be horizontally rotatable by the second pipe base 82A disposed at a position spaced apart from the center of the first pipe base 81A by 70. The directions in which the first nozzle 81 and the second and third nozzles 82 and 83 extend from the pipe base are different from each other.

Each of the pipe substrate portions 81A and 82A is disposed in the vicinity of the inner wall of the casing 61. Each of the nozzles 81, 82, 83 is closer to the outer peripheral side than the rotary table 70 at a general position close to the inner wall of the casing 61, and is retracted to the frame 6 with the wafer attached to the rotary table 70 without being disturbed by the rotary table 70. The position of the frame 4. When the rotary nozzles 70 are positioned at the processing position (the state shown in FIG. 4), the nozzles 81, 82, and 83 are actuated to be horizontally rotated above the rotary table 70 from the retracted position.

A pipe 84A connected to a resin source 84 for supplying a liquid water-soluble resin is connected to the first nozzle 81. The liquid water-soluble resin is transferred from the resin source 84 to the first nozzle 81 through the pipe 84A, and the resin is dropped from the tip end of the first nozzle 81. A water-soluble protective agent such as polyvinyl alcohol (PVA), polyethylene glycol (PEG) or polyethylene oxide (PEO) is preferably used as the water-soluble resin to be used.

A pipe 85A connected to the water source 85 for supplying the washing water is connected to the second nozzle 82. The washing water is sent from the water source 85 to the second nozzle 82 through the pipe 85A, and the washing water is discharged from the front end of the second nozzle 82. The washing water to be used should be pure water or pure water containing CO ₂ to prevent static electricity. The discharge pressure of the washing water discharged from the tip end of the second nozzle 82 is adjusted to about 0.4 MPa.

Further, a pipe 86A connected to the air source 86 supplied to the air is connected to the third nozzle 83. Air is sent from the air source 86 to the third nozzle 83 through the pipe 86A, and the air is ejected from the third nozzle 83. The air ejected from the tip end of the third nozzle 83 is preferably in a dry state, and the discharge pressure is adjusted to 0.4 MPa.

The washing water is sent to the pipe 85A of the second nozzle 82 to pass the first heat source 91, and the air is sent to the pipe 86A of the third nozzle 83 to pass the second heat source 92. The heat sources 91 and 92 are different members, but are disposed close to each other, and the heat sources 91 and 92 are housed in a heat-insulating housing 95.

The washing water sent from the water source 85 to the second nozzle 82 is heated by the first heat source, and the washing water which has become warm water is discharged from the tip end of the second nozzle 82. The air sent from the air source 86 to the third nozzle 83 is heated by the second heat source, and the heated air is heated to form a warm air, and is ejected from the tip end of the third nozzle 83. It is preferred that the washing water is heated to a temperature higher than a normal temperature (for example, 25 ° C) to a temperature of about 80 ° C, and it is preferred that the air is heated to a temperature higher than a normal temperature to a temperature of about 120 ° C or so. Regarding the temperature of the washing water or the air, depending on the difficulty of the heat affected by each device, or the coating state of the water-soluble resin varies depending on the surface shape of each device, it is considered that the temperature conditions are set according to the processing device. Each of the heat sources 91 and 92 appropriately selects an electric heater for industrial use or the like, and the type is not limited as long as it can appropriately heat the washing water or the air.

In the first embodiment, the resin source 84 and the first nozzle 81 constitute the resin supply mechanism 87. The water source 85, the first heat source 91, and the second nozzle 82 constitute a washing water supply mechanism 88. Further, the air source 86, the second heat source 92, and the third nozzle 83 constitute an air supply mechanism 89. Further, although not shown, the receiving portion 65 is provided with a liquid discharge port for discharging the washing water or the resin to the predetermined processing equipment, and the liquid discharge port is connected to the liquid discharge pipe.

(2-3) Action of the laser processing device

Next, an operation of performing laser processing on the planned dividing line 2 of the wafer 1 by the above-described laser processing apparatus 10 will be described. In addition, Figure 5 shows the process of this action. In Fig. 5, C/T refers to the suction cup table 20.

(2-3-1) Resin coating step

The frame 6 with the wafer positioned in the drawing position by the lifting operation of the cassette table 15 is pulled out by the holding mechanism 30 and placed on the positioning bar 35 for positioning in the XY direction. . Next, the frame 4 of the frame 6 with the wafer on the positioning bar 35 is conveyed above the rotating device 60A by the first transport mechanism 40. The vacuum device is operated first, and the frame 6 to which the wafer is attached to the rotary table 70 that is in standby to rise to the wafer transfer position is concentrically adsorbed and held. At the same time, the frame 4 is held by the clips 73.

When the frame 6 with the wafer is transferred from the vacuum suction pad 43 of the first transport mechanism 40 to the rotary table 70, the rotary table 70 is lowered to the processing position, and the surface of the wafer 1 is coated with a water-soluble liquid resin as follows. (Rotating coating step).

First, the first nozzle 81 is rotated inside the casing 61, and the tip end thereof is positioned directly above the center of the wafer 1 as shown in the sixth (a), and the liquid water-soluble resin P is from the front end of the first nozzle 81. Dropped to the center of the surface of the wafer 1. After the start of the dropping of the resin P, the motor 74 is actuated to rotate the rotary table 70 in one direction, and the rotation is stopped after the predetermined dropping time elapses. The resin P dropped onto the wafer 1 is expanded to the outer peripheral side by the centrifugal force generated by the rotation of the rotary table 70 as shown in FIGS. 6(b) to 6(c), and is applied to the wafer 1 by coating. The surface is comprehensive.

Further, the rotation speed and the rotation speed of the rotary table 70 at the time of spin coating are set so that the resin P sufficiently covers the surface of the wafer 1, the rotation speed is about 500 to 3000 rpm, the rotation time is about 30 to 120 seconds, and the resin P is The film thickness is about 0.1 to 10 μm.

After the spin coating of the resin P is completed, the first nozzle 81 is retracted while the rotation of the rotary table 70 is continued, and the integrated second nozzle 82 and the third nozzle 83 are rotated inside the casing 61. . The warm air is sprayed from the tip end of the third nozzle 83, and the warm air is sprayed onto the resin P applied on the surface of the wafer 1, and the resin P is dried (resin drying step). The third nozzle 8 is repeatedly rotated back and forth several times to cause the warm air to be sprayed over the entire surface of the wafer 1. The resin P is rapidly dried by the spray of warm air and hardened to form a protective film P1.

As described above, the formation of the protective film P1 for coating and drying the water-soluble resin of the wafer 1 is completed, the rotation of the rotary table 70 is stopped, and the rotary table 70 is further raised to the wafer transfer position. Then, the frame 4 of the frame 6 with the wafer on the turntable 70 is sucked and held by the vacuum suction pad 53 of the second transport mechanism 50, and transported to the chuck table 20 by the frame 6 with the wafer attached to the second transport mechanism 50. It is held at the suction table 20. Further, the vacuum suction pad 53 of the frame 4 is adsorbed at a place where the cover portion 73a of the clip 73 is covered. When the cover portion 73a is covered, even when the spin coating is applied, the resin P is scattered, the scattering resin is covered with the lid portion 73a, and the resin is not adhered. Therefore, the vacuum adsorption pad 53 is directly adsorbed to the surface of the frame 4, and the frame is surely held. 4.

(2-3-2) Laser processing steps

Then, it is moved to the laser processing of the wafer 1. First, the chuck table 20, which adsorbs and holds the frame 6 with the wafer attached, moves by the base 21 and moves to the processing position in the cabinet 11. Then, at this processing position, the laser beam 19 is irradiated with the laser beam by the laser processing mechanism 19, and the laser beam is irradiated to cut the wafer 1.

Here, when the wafer 1 is irradiated with the laser light, the aforementioned debris is generated, and the debris adheres to the surface of the protective film P1 without directly adhering to the surface of the wafer 1, whereby the wafer 3 can be secured. Quality.

The cutting system performs the feeding of the suction cup table 20 in the X direction by interaction, and the laser beam is irradiated toward the dividing line 2 and the laser processing mechanism 19 is moved to the Y direction to align the laser beam irradiation position with the dividing line 2 It is executed by the action of indexing feed. When the wafer 1 is completely cut by laser processing, the wafer 1 is divided into a plurality of wafers 3, and the wafer 3 is directly attached to the adhesive tape 5, and is held in the form of the wafer 1. Laser processing is performed on all the division planned lines 2, and after the cutting of the wafer 1 is completed, the chuck table 20 is returned to the wafer loading and unloading position, and then the frame 6 with the wafer is directly sent to the washing step.

(2-3-3) Washing step

The wafer-attached frame 6 of the wafer 1 is transported from the chuck table 20 at the wafer loading and unloading position to the rotating device 60A by the first transport mechanism 40, and is held by the rotary table 70 which is placed at the wafer transfer position. .

Next, the turntable 70 is lowered to the processing position, and the rotation is started. While the warm water is discharged from the front end of the second nozzle 82, the second and third nozzles 82 and 83 are rotated back and forth to allow the warm water to spread over the entire protective film 1. Thereby, the protective film P1 made of a water-soluble resin is rapidly dissolved, and the resin P is removed from the surface of the wafer 1 and removed (resin removal step).

After the protective film P1 on the surface of the wafer 1 is completely removed, the warm water discharge of the second nozzle 82 is stopped, and then the rotation of the rotary table 70 and the rotation of the second and third nozzles 82 and 83 are continued. The warm air is ejected from the front end of the third nozzle 83. The warm air is sprayed over the entire surface of the wafer 1, and further, the moisture can be quickly dried by the action of the centrifugal force (wafer drying step). Thereafter, the rotary table 70 is raised to the wafer transfer position.

(2-3-4) Storage in the box

As described above, the wafer-attached frame 6 is subjected to the steps of forming the protective film P1 on the surface of the wafer 1, cutting the laser-processed wafer 1, and cleaning the wafer 1 of the protective film P1. The second transport mechanism 50 is moved from the turntable 70 to the positioning bar 35, and then returned to the cassette 9 by the grip mechanism 30.

The above series of actions are performed on all of the wafers 1 in the cassette 9. Then, after the wafer 1 in the cassette 9 is completely cut, the cassette 9 is transported to the next wafer pickup step, and each wafer 3 is picked up from the adhesive tape 5 to obtain each wafer 3.

(2-4) The effect of the laser processing device

According to the laser processing apparatus 10 of the above-described embodiment, in the resin coating step before the laser processing, the water-soluble resin P is applied onto the surface of the wafer 1 by a spin coating method, and then the warm air is sprayed from the third nozzle 83 to the surface. The resin P is applied to cure the resin P to form a protective film P. When the resin P phase is placed at a normal temperature to naturally harden it, the warm air is sprayed in this manner, and the reaction from drying to hardening is greatly promoted, so that the resin P can be accelerated and hardened. That is, the time required for the resin coating step is greatly shortened.

Further, in the washing step after the laser processing, by supplying warm water to the protective film P1, the resin P can be washed away and removed, and by using warm water, the resin P is greatly promoted compared to the case of using normal temperature water. It dissolves and accelerates washing off. In the subsequent drying step, the wafer 1 is dried by the spraying of the warm air, and the wafer 1 can be further accelerated to be dried.

As described above, in the present embodiment, the drying of the resin P applied to the wafer 1 and the drying of the wafer 1 after removing the resin P from the wafer 1 are performed by warm air, and in the cleaning step, The washing water used when the resin is removed from the wafer 1 uses warm water. Therefore, the time required for the steps can be greatly shortened compared to the case of using water or air at a normal temperature, and as a result, the wafer 3 can be taken from the wafer 1 even if the resin is applied to the surface of the wafer 1. The manufacturing speed of the whole is accelerated as much as possible.

Further, since the first heat source 91 and the second heat source 92 are covered by the heat-insulating casing 95, it is possible to suppress the divergence of heat around the heat sources 91 and 92 and prevent the thunder from the heat sources 91 and 92. The effect of heat on other parts of the processing device 10. Moreover, the heat loss of each of the heat sources 91 and 92 is suppressed by the casing 95, and energy saving can be achieved. Furthermore, since each of the heat sources 91 and 92 has the casing 95 and is not susceptible to external temperature changes, it also has the advantage of ensuring the accuracy of the temperature setting.

(3) Apparatus of the second embodiment

Next, a rotating device 60B according to the second embodiment will be described with reference to Fig. 7 .

In this rotating device 60B, there is one heat source. In the heat source 91A, the pipe 85A on the water source 85 side and the pipe 86A on the air source 86 side pass, and both the washing water and the air are heated by one heat source 91A. In other words, the first heat source 91 that heats the washing water of the above embodiment and the second heat source 92 that heats the air are configured by the same heat source 91A. In this way, a total of one heat source can save space and low cost.

Further, in the rotating device 60B of the second embodiment, the warm air supplied to the third nozzle 83 is mixed with the second nozzle 82 that discharges the washing water, and the warm air is ejected from the tip end of the second nozzle 82 at a high speed by the pipe 85a. A spray that is sprayed by the warm water of the heated washing water. The second nozzle 82 is a two-fluid nozzle that discharges a spray of warm water and warm air. In the resin removal step of the cleaning step, the high-temperature spray is ejected from the second nozzle 82 to remove the protective film P1. Thus, when the spray is sprayed and washed, the amount of water used is preferably about 200 ml/min, and there is an advantage that a high washing effect can be obtained with a small amount of water. In the resin drying step of the resin coating step and the wafer drying step of the cleaning step, as in the above embodiment, warm air is ejected from the third nozzle 83 to dry the wafer 1.

As described above, when the high-temperature spray is ejected from the second nozzle 82 to remove the resin P, the effect of removing the resin P is particularly excellent as compared with the case where only warm water is discharged, and the washing time can be further shortened. Further, the warm air mixed to the second nozzle 82 is supplied from the air source 86, heated by the second heat source 92, and the warm air sent to the third nozzle 83 is used, so that the structure is not complicated.

(4) Rotating device of the third embodiment

Next, a rotating device 60C according to the third embodiment will be described with reference to Fig. 8.

In the rotating device 60C, the third nozzle 83 that discharges warm air is different from the first embodiment. In other words, the third nozzle 83 of the third embodiment is fixed to the inner wall of the upper portion of the opening close to the casing 61. The third nozzle 83 has a cylindrical shape and is connected to a pipe 86A connected to the air source 86. The air dryer 98 and the filter 99 are sequentially disposed between the second heat source 92 of the pipe 86A and the casing 61 from the upstream side. The air dryer 98 removes moisture in the air flowing through the pipe 86A, and when the air is dried, the filter 99 captures the dust present in the air flowing in the pipe 86A. A foreign body such as Ai, and the air is purified.

In the rotating device 60C, in the resin drying step of the resin coating step and the wafer drying step in the cleaning step, warm air is ejected from the third nozzle 83, and the entire interior of the casing 61 is dried at a high temperature to carry out the resin P. Or the operation of wafer 1 drying.

1‧‧‧ wafer

1a‧‧‧ Orientation plane

2‧‧‧ dividing line

3‧‧‧ wafer

4‧‧‧Frame

5‧‧‧Adhesive tape

6‧‧‧with wafer frame

9‧‧‧匣 box

10. . . Laser processing device

11. . . cabinet

11a. . . side

11b. . . Cover member

11c. . . Cover member

12. . . Operation display panel

13. . . Indicator

14. . . Abutment

15. . .匣 box

16. . . Recess

19. . . Laser processing mechanism

20. . . Suction table

twenty one. . . Abutment

twenty two. . . folder

30. . . Grip mechanism

32. . . arm

33. . . Clip

35. . . Positioning bar

40. . . First transport mechanism

41. . . Linear guide

42. . . Telescopic arm

43. . . Vacuum adsorption pad

50. . . Second transport mechanism

51. . . Linear guide

52. . . Telescopic arm

53. . . Vacuum adsorption pad

60A. . . Rotating device

60B. . . Rotating device

60C. . . Rotating device

61. . . case

62. . . Support table

63. . . Pedestal

64. . . Foot

65. . . Undertaking department

70. . . Rotary table

71. . . framework

72. . . Adsorption section

73. . . folder

73a. . . Cover

74. . . motor

74a. . . Drive shaft

81. . . First nozzle

81A. . . First piping base

82. . . Second nozzle

82A. . . Second piping base

83. . . Third nozzle

84. . . Resin source

84A. . . Piping

85. . . Water source

85A. . . Piping

85a. . . Piping

86. . . Air source

86A. . . Piping

91. . . First heat source

91A. . . Heat source

92. . . Second heat source

95. . . case

98. . . Air dryer

99. . . filter

P. . . Water soluble resin

P1. . . Protective film

Fig. 1 is a perspective view showing the entire laser processing apparatus according to an embodiment of the present invention.

Fig. 2 is an overall perspective view of the back side of the laser processing apparatus.

Fig. 3 is a perspective view showing a state in which a semiconductor wafer subjected to laser processing in an embodiment is held in a frame by an adhesive tape.

Fig. 4 is a perspective view showing the apparatus of the first embodiment of the laser processing apparatus.

Fig. 5 is a graph showing the operation process of the laser processing of the laser processing apparatus.

6(a) to 6(c) are side views showing the spin coating resin on the wafer surface in the order of (a) to (c).

Fig. 7 is a perspective view showing the rotary device of the second embodiment.

Fig. 8 is a perspective view showing the rotary device of the third embodiment.

60A. . . Rotating device

61. . . case

62. . . Support table

63. . . Pedestal

64. . . Foot

65. . . Undertaking department

70. . . Rotary table

71. . . framework

72. . . Adsorption section

73. . . folder

73a. . . Cover

74. . . motor

81. . . First nozzle

81A. . . First piping base

82. . . Second nozzle

82A. . . Second piping base

83. . . Third nozzle

84. . . Resin source

84A. . . Piping

85. . . Water source

85A. . . Piping

86. . . Air source

86A. . . Piping

87. . . Resin supply mechanism

88. . . Washing water supply mechanism

89. . . Air supply mechanism

91. . . First heat source

92. . . Second heat source

95. . . case

Claims (5)

A laser processing method comprising: a resin coating step of coating a liquid water-soluble resin on a processing surface of a workpiece; and a laser processing step of irradiating a laser beam to the processing surface of the workpiece to perform laser irradiation a processor; and a cleaning step of cleaning the workpiece by performing the laser processing; the laser processing method is characterized in that the resin coating step has a spin coating step, and the spin coating method is used to a water-soluble resin is applied to the processing surface of the workpiece; and a resin drying step is to supply warm air to the applied water-soluble resin to dry the water-soluble resin; and the washing step has a resin a removing step of supplying a spray of warm water and warm air to the water-soluble resin coated on the working piece to remove the water-soluble resin; and a drying step of the working part, supplying warm air to the water-soluble solvent The aforementioned working piece of the resin to make the work piece dry. A laser processing apparatus comprising: a holding mechanism for holding a workpiece; and a laser processing mechanism for irradiating a laser beam to the workpiece held by the holding mechanism to perform laser processing; and The rotating device includes a rotary table that rotates while holding the workpiece, and a resin supply mechanism that supplies the liquid water-soluble resin to the processing surface of the workpiece held before the laser processing of the rotary table, and supplies the washing water. a washing water supply mechanism that holds the processing surface of the workpiece after the laser processing of the rotary table, and an air supply mechanism that supplies air to a processing surface of the workpiece held by the rotary table; the laser In the processing apparatus, the resin supply means includes a resin source for supplying the water-soluble resin, and a first nozzle for supplying the water-soluble resin conveyed from the resin source to the operation of holding the rotary table. The washing water supply mechanism includes: a water source that supplies the washing water; and a first heat source that heats the washing water sent from the water source to form warm water; and the second nozzle Providing fluid to the aforementioned work piece held by the rotating table; further, the air supply mechanism has: an air source, which supplies air; and a second heat source And heating the air that is sent from the air source to form a warm air; and the third nozzle is configured to supply the warm air to the workpiece held by the rotating table; and the second nozzle has the warm water Mixer with warm air And spraying the warm water and the warm air from the second nozzle to the workpiece. The laser processing apparatus of claim 2, wherein the first heat source and the second heat source are the same heat source. The laser processing apparatus of claim 2, wherein the warm air is heated by the second heat source. The laser processing apparatus according to any one of claims 2 to 4, wherein the first heat source and the second heat source are covered with a heat insulating material.