TW202116460A - Laser machining apparatus - Google Patents

Abstract

Provided is a laser machining apparatus that can reduce tact time required for laser machining of a wafer. The laser machining apparatus includes: a first laser light source configured to emit a laser light with a condition corresponding to the edge trimming; a second laser light source configured to emit a laser light with a condition corresponding to the hollowing; a first light forming element configured to form two first laser lights from the laser light emitted from the first laser light source; a second light forming element configured to form a second laser light from the laser light emitted from the second laser light source; a first condenser lens; two second condenser lenses arranged in a row with the first condenser lens interposed between the two second condenser lenses; and a connecting optical system configured to guide the two first laser lights emitted from the first light forming element to the first condenser lens and guide the second laser light emitted from the second light forming element selectively to the two second condenser lenses.

Description

Laser processing device

The present invention relates to a laser processing device for laser processing of wafers.

In the field of semiconductor device (device) manufacturing in recent years, a wafer (semiconductor wafer) is known in which a low-dielectric constant insulator film (Low-K) made of glassy material is layered on the surface of a substrate such as silicon. k film) and a laminate of functional films forming circuits to form a plurality of devices. A plurality of devices of this kind of wafer system are divided into grids using grid-like streets, and the wafers are divided along the dicing streets to manufacture each device.

In terms of the method of dividing the wafer into a plurality of devices (wafers), there are known: a method of using a high-speed rotating knife; and forming a laser processing area along the dicing path inside the wafer to form the laser processing area , To apply external force along the cutting path with reduced strength. However, in the case of a wafer to which the Low-k film is applied, since the material of the Low-k film is different from the material of the wafer, it is difficult for the former method to simultaneously cut the insulating film and the substrate with a knife. In addition, the latter method may have a Low-k film on the cutting path, and it is not easy to divide it into various devices with good quality.

Here, Patent Document 1 discloses performing a trimming process for forming two trimming grooves (blocking grooves) along the dicing path of the wafer (see Patent Document 2), and forming a hollow groove (dividing groove) between the two trimming grooves. ) Laser processing device for hollow processing. This laser processing device is along the processing feed direction parallel to the dicing path of the wafer, and is equipped with a first laser beam irradiation unit corresponding to the trimming process and a second laser beam irradiation unit corresponding to the hollow processing (refer to Figure 15 of Patent Document 1). Next, with respect to the wafer, the first laser beam irradiation unit and the second laser beam irradiation unit are relatively moved to one side of the processing feed direction (for example, the outgoing direction side), and the two are moved along the same dicing path. The trim groove and the hollow groove are formed at the same time (formed in parallel), and the Low-k film and the like are removed.

Patent Document 3 discloses a laser that performs first groove processing in which a first groove (fuse part) is formed along the dicing path of a wafer, and a second groove processing in which a second groove (fuse part) is formed at the bottom of the first groove Processing device. This laser processing device is along the processing feed direction parallel to the dicing path of the wafer. It has a first laser head corresponding to the first groove processing and a second laser corresponding to the second groove processing. Ray head. Then, by moving the first laser beam head and the second laser beam head relative to the wafer to one side of the processing feed direction (for example, the outgoing direction side), along the same dicing path The first groove and the second groove are formed at the same time.

Patent Document 4 discloses a chuck that holds a wafer and a laser optical system arranged at a position opposite to the wafer are relatively moved to form a pair of grooves (two grooves parallel to each other along the dicing path). The first groove), and the deep groove (furrow) (second groove) formed between a pair of grooves, which is a concave part, is a laser processing device. The laser optical system of Patent Document 4 is equipped with a laser light emitting system that emits a laser beam corresponding to the processing of a pair of grooves (two first laser beams) and a laser beam corresponding to the processing of deep grooves (second Laser light); and condensing optics, so that each laser beam is condensed on the wafer. This concentrating optical system is not related to the processing feed direction (outgoing direction, circuit direction) of the laser optical system (concentrating optical system) for the wafer, but makes the laser beam ratio corresponding to the groove processing The laser beam corresponding to the processing of the deep groove is advanced. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2009-182019 [Patent Document 2] Specification of U.S. Patent No. 5,922,224 [Patent Document 3] Japanese Patent Application Laid-Open No. 58-143553 [Patent Document 4] JP 2016-208035 A

[The problem to be solved by the invention]

As described in Patent Document 1, when forming two trimming grooves and a hollow groove along the cutting channel, two trimming grooves must be formed first, and then the hollow grooves must be formed. Therefore, in the laser processing apparatus of Patent Document 1, only the first laser beam irradiation unit and the second laser beam irradiation unit are made on one side of the processing feed direction (for example, the outgoing direction) with respect to the wafer. Side), two trimming grooves and hollow grooves can be formed at the same time along the same cutting path. Therefore, in the laser processing apparatus of Patent Document 1, when the respective light irradiating units are relatively moved to the other side of the processing feed direction (for example, the return direction side) with respect to the wafer, they cannot follow the same dicing path. At the same time, two trim trenches and hollow trenches are formed. As a result, the time required for processing a wafer (tact time) is increased.

Therefore, in the laser processing apparatus of Patent Document 1, when each light irradiation unit is relatively moved to the other side of the processing feed direction with respect to the wafer, trimming processing is performed on the second laser light irradiation unit, and Hollow processing is performed in the first laser beam irradiation unit. However, because the optical system corresponding to the finishing process is different from the optical system corresponding to the hollow process, when each light irradiation unit is set to correspond to both the finishing process and the hollow process, the optical system of each light irradiation unit becomes very complicated.

Also in the laser processing apparatus of Patent Document 3, when the heads of each laser beam are relatively moved to the other side of the processing feed direction (for example, the return direction side) with respect to the wafer, they cannot follow the same dicing path. The first groove and the second groove are formed at the same time.

In the laser processing device of Patent Document 4, regardless of the machining feed direction (outward direction, circuit direction), the trimming process is preceded by the hollow process, so the tact time can be made longer than that described in the above-mentioned Patent Document 1 to Patent Document 3. The number of laser processing devices is even more reduced. However, in the laser processing device described in Patent Document 4, laser light emitted from a common laser light source is used to perform trim processing and hollow processing. At this time, the conditions (wavelength, pulse width, repetition frequency, etc.) of the laser light suitable for the finishing process and the hollow process are different. Therefore, when the conditions of the laser light deviate from the conditions suitable for either trimming processing or hollow processing, the processing speed of one of them must be slowed down, and consequently, the processing speed of the other must also be slowed down. Therefore, in the laser processing apparatus described in Patent Document 4, there is a limit to the reduction in the tact time required for the laser processing of the wafer.

The present invention was completed in view of this situation, and aims to provide a laser processing device that can reduce the cycle time required for laser processing of wafers. [Means to solve the problem]

The laser processing device used to achieve the purpose of the invention is to process and feed the work table holding the wafer and the laser optical system arranged at a position opposite to the work table along the dicing path of the wafer. The direction is relatively moved, while irradiating the laser light from the laser optical system to the wafer, the trimming process and the hollowing process are performed for each dicing lane. The trimming process system forms two first grooves parallel to each other along the dicing lane. The hollow processing system forms the second groove between the two first grooves, The laser optics system has: The first laser light source emits laser light under the conditions corresponding to the trimming process; The second laser light source emits laser light under conditions corresponding to hollow processing; The first light forming element forms two first laser lights from the laser light emitted from the first laser light source; The second light forming element forms the second laser light from the laser light emitted from the second laser light source; The first condenser lens; Two second condensing lenses, sandwiching the first condensing lens and arranged in a row along the processing feed direction together with the first condensing lens; and The connecting optical system introduces the two first laser beams emitted from the first light forming element to the first condenser lens, and selectively leads the second laser beams emitted from the second light forming element to the two second condensers lens; When the splicing optics system moves the laser optics system relative to the table to the outgoing direction of the processing feed direction, the second laser light is guided to the return direction side of the processing feed direction relative to the first condenser lens. The second condensing lens, and when the laser optical system is relatively moved to the return direction side relative to the table, the second laser light is guided into the second condensing lens that is located on the outgoing direction side relative to the first condensing lens .

According to this laser processing device, the processing speed of the wafer can be increased (reduced tact time).

The laser processing device used to achieve the purpose of the invention is to process and feed the work table holding the wafer and the laser optical system arranged at a position opposite to the work table along the dicing path of the wafer. The direction is relatively moved, while irradiating the laser light from the laser optical system to the wafer, the trimming process and the hollowing process are performed for each dicing lane. The trimming process system forms two first grooves parallel to each other along the dicing lane. The hollow processing system forms the second groove between the two first grooves, The laser optics system has: The first laser light source emits laser light under the conditions corresponding to the trimming process; The second laser light source emits laser light under conditions corresponding to hollow processing; The first light forming element forms two first laser lights from the laser light emitted from the first laser light source; The second light forming element forms the second laser light from the laser light emitted from the second laser light source; The two first condenser lenses are arranged in a row along the processing feed direction; The second condenser lens is arranged between the two first condenser lenses; and The connecting optical system selectively guides the two first laser lights emitted from the first light forming element to the two first condenser lenses, and the second laser light emitted from the second light forming element into the second condenser lens, When the splicing optical system moves relative to the forward direction side of the processing feed direction of the laser optical system relative to the worktable, the two first laser beams are guided to the second condensing lens that is located on the outward direction side of the second condensing lens. 1 Condenser lens, and when the laser optical system moves relative to the worktable to the return direction side of the processing feed direction, the two first laser beams are guided to the second condensing lens that is located on the return direction side relative to the second condensing lens. 1 Condenser lens.

According to this laser processing device, the processing speed of the wafer can be increased (reduced tact time).

In another aspect of the laser processing apparatus of the present invention, a first moving mechanism is provided to relatively move the first condenser lens with respect to the table in a first vertical direction parallel to the table and perpendicular to the processing feed direction ; And the second moving mechanism to make the second condensing lens move relative to the worktable in the first vertical direction. In this way, each processing point can be moved (tracked) with the most appropriate motion path regardless of the motion accuracy of the processing feed axis during laser processing.

In the laser processing apparatus of another aspect of the present invention, the first moving mechanism allows the first condensing lens to move relative to the worktable in a first vertical direction and a second vertical direction perpendicular to the worktable, The second moving mechanism allows the second condensing lens to move relative to the table in the first vertical direction and the second vertical direction. In this way, each processing point can be moved (tracked) with the most appropriate motion path regardless of the motion accuracy of the processing feed axis during laser processing.

In another aspect of the laser processing apparatus of the present invention, it is provided with: a first moving mechanism for relatively moving the first condenser lens with respect to the table in a first vertical direction parallel to the table and perpendicular to the processing feed direction ; And the second moving mechanism, so that the two second condensing lenses relative to the worktable in the first vertical direction integrally move relative to each other.

In another aspect of the laser processing apparatus of the present invention, the first moving mechanism enables the first condensing lens to move relative to the worktable in a first vertical direction and a second vertical direction perpendicular to the worktable; The 2 movement mechanism allows the two second condensing lenses to be integrally moved relative to the table in the first vertical direction and the second vertical direction.

In another aspect of the laser processing apparatus of the present invention, the laser processing device is provided with: a first moving mechanism that moves the two first condenser lenses relative to the table in a first vertical direction that is parallel to the table and perpendicular to the processing feed direction Integrally move relative to each other; and a second moving mechanism to move the second condensing lens relative to the table in the first vertical direction.

In another aspect of the laser processing apparatus of the present invention, the first moving mechanism allows the two first condensing lenses to be integrated with the table in the first vertical direction and the second vertical direction perpendicular to the table Relative movement; The second moving mechanism makes the second condenser lens move relative to the worktable in the first vertical direction and the second vertical direction

In the laser processing apparatus of another aspect of the present invention, the first moving machine moves the table in the first vertical direction.

In the laser processing apparatus of another aspect of the present invention, the second moving mechanism moves the table in the first vertical direction.

In the laser processing apparatus of another aspect of the present invention, the first moving mechanism moves the table in the first vertical direction and the second vertical direction.

In the laser processing apparatus of another aspect of the present invention, the second moving mechanism moves the table in the first vertical direction and the second vertical direction. [Effects of Invention]

The present invention can reduce the tact time required for laser processing of wafers with a simple structure.

[Form to implement the invention]

[Overall configuration of the laser processing device of the first embodiment] Fig. 1 is a schematic diagram of a laser processing apparatus 10 according to the first embodiment. As shown in FIG. 1, the laser processing apparatus 10 performs laser processing (ablation groove processing) on the wafer 12 in the pre-process before dividing the wafer 12 into a plurality of wafers 14 (refer to FIG. 2). ). In addition, the XYZ directions in the figure are orthogonal to each other, wherein the X direction and the Y direction are horizontal directions, and the Z direction is the vertical direction. Here, the X direction corresponds to the machining feed direction of the present invention.

FIG. 2 is a plan view of the wafer 12 to be processed by the laser processing device 10. As shown in FIG. 2, the wafer 12 is a laminate in which a Low-k film and a functional film forming a circuit are layered on the surface area of a substrate such as silicon. The wafer 12 is divided into a plurality of regions by a plurality of dicing lines C (planned dividing lines) arranged in a grid. In each of the divided areas, a device 16 constituting the wafer 14 is provided.

The laser processing device 10, as shown by the numbers (1)～(4), ... in parentheses in the figure, performs laser processing on the wafer 12 along the dicing path C for each dicing path C (abrasion groove Processing), thereby removing the Low-k film on the substrate.

At this time, in order to reduce the tact time required for laser processing of the wafer 12, the laser processing apparatus 10 moves the laser optical system 24 described later relative to the wafer 12 in the X direction. Press each cutting path C to switch alternately.

For example, when performing laser processing along odd-numbered dicing lines C shown by numbers (1) and (3) in parentheses in the figure, the laser optical system 24 described later is opposed to the wafer 12 It moves to the outbound direction side X1 (refer to FIG. 5), and the outbound direction side X1 is one direction side of the X direction. In addition, when laser processing is performed along the even-numbered dicing C shown by numbers (2) and (4) in parentheses in the figure, the laser optical system 24 is relatively moved in the return direction with respect to the wafer 12 The side X2 (refer to FIG. 6), the return direction side X2 is the other direction side of the X direction.

Fig. 3 is an explanatory diagram for explaining the laser processing along the odd-numbered cutting path C. Fig. 4 is an explanatory diagram for explaining the laser processing along the even-numbered cutting path C.

As shown in FIGS. 3 and 4, in the present embodiment, in the laser processing, trimming processing and hollow processing are performed at the same time (in parallel). The trimming process is laser processing using two first laser lights L1, and is the formation of two trimming grooves 18 parallel to each other along the cutting path C (equivalent to the erosion grooves of the two first grooves of the present invention). Shot processing. Hollow processing is laser processing using a second laser light L2 whose diameter is thicker than the two first laser lights L1, and a hollow groove 19 is formed between the two trimming grooves 18 formed by trimming processing. It is equivalent to the laser processing of the second groove of the present invention (the erosion groove). In addition, since the two trimming grooves 18 and the hollow groove 19 belonging to the denudation grooves are well-known technologies, a detailed description thereof is omitted (refer to Patent Document 1).

In this way, in the laser processing apparatus 10 of this embodiment, the laser optical system 24 described later is moved relative to the wafer 12 to the forward direction side X1 (refer to FIG. 5), or to the return direction side X2. (Refer to FIG. 6) In any case of relative movement, the trimming process is performed before the hollow process.

Returning to FIG. 1, the laser processing device 10 includes: a table 20; a laser light source 22; a laser optical system 24; a microscope 26; a relative movement mechanism 28; and a control device 30.

The table 20 holds the wafer 12. In addition, the table 20 is under the control of the control device 30. The relative movement mechanism 28 moves in the X direction, which is parallel to the cutting path C of the processing object, which belongs to the processing feed direction, and the table is parallel to the Z direction. The central axis (rotation axis) of 20 rotates around the center.

The laser light source 22 constitutes the laser optical system of the present invention together with the laser optical system 24 described later. This laser light source 22 always emits laser light L suitable for both trimming processing and hollow processing conditions (wavelength, pulse width, repetition frequency, etc.). The laser light L emitted from the laser light source 22 enters the laser optical system 24.

The details of the laser optical system 24 (also known as the laser unit) will be described later. The laser light L from the laser light source 22 is divided into two to form two first laser lights L1 for trimming and hollow processing. The second laser beam L2. The laser optical system 24 emits (irradiates) two first laser beams L1 from the first condenser lens 38 toward the dicing line C. In addition, the laser optical system 24 is controlled by the control device 30 to selectively emit (irradiate) the second laser light L2 from the two second condenser lenses 40A, 40B toward the dicing lane C.

In addition, the laser optical system 24 is moved in the Y direction and the Z direction by the relative movement mechanism 28 under the control of the control device 30.

The microscope 26 is fixed to the laser optical system 24 and moves integrally with the laser optical system 24. Before trimming and hollowing the wafer 12, the microscope 26 photographs an alignment datum (not shown) formed on the wafer 12. In addition, the microscope 26 photographs the two trimming grooves 18 and the hollow groove 19 formed along the cutting path C by trimming processing and hollow processing. The captured image (image data) captured by the microscope 26 is output to the control device 30, and is displayed on a screen (not shown) through the control device 30.

The relative movement mechanism 28 is composed of an XYZ actuator and a motor not shown in the figure. Under the control of the control device 30, the table 20 moves in the X direction and rotates around the axis of rotation. The movement of the optical system 24 in the Y direction and the Z direction. Thereby, the relative movement mechanism 28 can move the laser optical system 24 relative to the table 20 and the wafer 12 held on the table 20. In addition, instead of moving the table 20 in the X direction and moving the laser optical system 24 in the YZ direction, for example, the laser optical system 24 can be moved in the Z direction and the table 20 can be moved in the XY direction. What is necessary is just to move the laser optical system 24 relative to the table 20 (wafer 12) in each direction (including rotation), and the relative movement method is not specifically limited.

It can be performed repeatedly by driving the relative movement mechanism 28: the alignment (alignment) of the laser optical system 24 with respect to the processing start position; and the laser optical system 24 in the X direction along the cutting path C [outward direction side X1 (Refer to Fig. 5) or relative movement in the return direction side X2 (Refer to Fig. 6)], the processing start position is one end of the cutting path C of the processing object. Furthermore, by driving the relative movement mechanism 28 to rotate the table 20 by 90°, each dicing path C along the Y direction of the wafer 12 can be made parallel to the X direction, which is the processing feed direction.

The control device 30 is constituted by, for example, an arithmetic device such as a personal computer, and is provided with an arithmetic circuit constituted by various processors and memories. Various processor systems include CPU (Central Processing Unit), GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), and programmable logic elements (such as SPLD (Simple Programmable Logic Devices), CPLD (Complex Programmable Logic Device), And FPGA (Field Programmable Gate Arrays)] etc. In addition, various functions of the control device 30 can also be implemented by one processor, or multiple processors of the same or different types.

The control device 30 collectively controls the operations of the laser light source 22, the laser optical system 24, the microscope 26, and the relative movement mechanism 28.

[Laser Optics] FIG. 5 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 that moves relative to the wafer 12 to the side X1 in the forward direction. FIG. 6 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system 24 that is relatively moved to the side X2 in the return direction with respect to the wafer 12. Hereinafter, the odd-numbered dicing line C belonging to the processing target of the laser optical system 24 that moves relative to the wafer 12 to the forward direction side X1 is appropriately referred to as the "outward stroke", and will be referred to the wafer 12 to the return direction side The even-numbered cutting track C belonging to the processing object of the laser optical system 24 that X2 moves relative to is appropriately referred to as "return".

As shown in FIGS. 5 and 6, the laser optical system 24 includes a safety shutter 100, a safety shutter drive mechanism 102, a branching element 31, a first light forming element 32, a second light forming element 34, and a connection The switching element 36, the first condenser lens 38, the two second condenser lenses 40A, 40B, the first high-speed shutter 47A and the second high-speed shutter 47B, and the high-speed shutter drive mechanism 47C.

The safety shutter drive mechanism 102 is controlled by the control device 30 to enable the safety shutter 100 to insert a separate actuator into the optical path between the laser light source 22 and the branching element 31. The safety shutter driving mechanism 102 is used to insert the safety shutter 100 into the above-mentioned optical path except during laser processing, thereby stopping the emission of the two first laser light L1 and the second laser light L2 from the laser optical system 24. In addition, the safety shutter driving mechanism 102 retreats the safety shutter 100 from the above-mentioned optical path during laser processing, so that two first laser light L1 and second laser light L2 can be emitted from the laser optical system 24.

For the branching element 31, for example, a half mirror is used. The dividing element 31 divides the laser light L emitted from the laser light source 22 into two, emits one of the divided laser light L into two toward the first light forming element 32, and directs the other of the laser light L toward the first light forming element 32. The second light forming element 34 emits. In addition, the division ratio of "two divisions" in this manual is not limited to 50:50, and can be changed as appropriate.

The first light forming element 32 uses, for example, a diffractive optical element (DOE). This first light forming element 32 forms two first laser lights L1 corresponding to the trimming process from the laser light L incident from the branch element 31, and emits the two first laser lights L1 toward the first condenser lens 38. In this way, the two first laser beams L1 are condensed on the dicing lane C (outgoing and returning) by the first condensing lens 38, and two spots (spots) separated in the Y direction are formed on the dicing lane C. (Also known as concentrating point or processing point). In addition, the optical paths of the two first laser lights L1 from the first light forming element 32 to the first condenser lens 38 (including various optical elements provided on the optical path) constitute a part of the splicing optical system of the present invention, but Illustration is omitted.

For the second light forming element 34, for example, a diffractive optical element and a mask are used. The second light forming element 34 forms the second laser light L2 corresponding to the hollow processing from the laser light L incident from the branching element 31. The second laser light L2 forms a rectangular (circular shape or other shapes) on the wafer 12 between the two trimming grooves 18 (refer to FIGS. 10 and 11). The width of the light spot in the Y direction is adjusted in accordance with the interval between the two trimming grooves 18. The second light forming element 34 emits the second laser light L2 toward the connection switching element 36.

The connection switching element 36 constitutes the connection optical system of the present invention together with the aforementioned branching element 31 and the like. As the connection switching element 36, for example, a known optical switch or various optical elements (λ/2 plate 52 and polarization beam splitter 54, half mirror 58 and shutter 62A shown in FIGS. 15 to 17) described later are used. , 62B, mirror 66A, 66B, etc.). The connection switching element 36 is controlled by the control device 30 to selectively guide the second laser light L2 emitted from the second light forming element 34 to the second condenser lenses 40A and 40B.

The first condenser lens 38 and the second condenser lenses 40A, 40B are arranged in a row along the X direction (processing feed direction). The first condenser lens 38 is arranged between the second condenser lens 40A and the second condenser lens 40B. The second condenser lens 40A is arranged on the return direction side X2 with respect to the first condenser lens 38. The second condenser lens 40B is arranged on the forward direction side X1 with respect to the first condenser lens 38.

The first condensing lens 38 condenses the two first laser beams L1 incident from the first light forming element 32 on the dicing lane C (outgoing and returning). The second condensing lens 40A condenses the second laser light L2 incident from the connection switching element 36 on the scribe lane C (outward path). The second condensing lens 40B condenses the second laser light L2 incident from the connection switching element 36 on the scribe lane C (return).

When the relative movement mechanism 28 moves the laser optical system 24 relative to the wafer 12 to either the outbound direction side X1 and the return direction side X2, the connection switching element 36 is formed from the second light forming element The second laser light L2 emitted from 34 is guided into the second condenser lenses 40A and 40B to be a lens located on the other direction side of the outbound direction X1 and the return direction X2 with respect to the first condenser lens 38.

Specifically, as shown in FIG. 5, the connection switching element 36 moves the laser optical system 24 with respect to the wafer 12 to the outbound direction side X1 by the relative movement mechanism 28, from the second light The second laser light L2 emitted from the forming element 34 is guided to the second condenser lens 40A. Thereby, the second laser light L2 is condensed on the dicing lane C (outgoing path) by the second condensing lens 40A. As a result, by the relative movement of the laser optical system 24 toward the outbound direction side X1, the trimming process is performed along the cutting path C (outbound stroke) to form two trimming grooves 18, and then the hollow process is performed to form two trimming grooves 18 A hollow groove 19 is formed between the two trimming grooves 18.

Furthermore, as shown in FIG. 6, when the laser optical system 24 is relatively moved to the return direction side X2 with respect to the wafer 12 by the relative movement mechanism 28, the connection switching element 36 will be emitted from the second light forming element 34 The second laser light L2 is guided to the second condenser lens 40B. Thereby, the second laser light L2 is condensed on the dicing lane C (return) by the second condensing lens 40B. As a result, by the relative movement of the laser optical system 24 toward the return direction side X2, the trimming process is first performed along the cutting path C (the return stroke) to form two trimming grooves 18, and then the two trimming grooves 18 are formed by performing hollow processing. Hollow grooves 19 are formed between trimming grooves 18.

The first high-speed shutter 47A can be inserted into the optical path of the laser light L between the branching element 31 and the first light forming element 32 (the optical path between the first light forming element 32 and the first condenser lens 38 may also be inserted) Set up in a separate way. When the first high-speed shutter 47A is inserted into the optical path between the branching element 31 and the first light forming element 32, by blocking the laser light L incident on the first light forming element 32 from the branching element 31, the two The first laser light L1 is emitted from the first condenser lens 38.

The second high-speed shutter 47B can be inserted and separated freely in the optical path of the laser light L between the branching element 31 and the second light forming element 34 (the optical path between the second light forming element 34 and the connection switching element 36 may also be) Way to set. When the second high-speed shutter 47B is inserted into the optical path between the branching element 31 and the second light forming element 34, by blocking the laser light L incident from the branching element 31 to the second light forming element 34, the second light forming element 34 is stopped. 2The laser light L2 is emitted from the second condenser lenses 40A and 40B.

The high-speed shutter drive mechanism 47C is under the control of the control device 30, which allows the first high-speed shutter 47A and the second high-speed shutter 47B to insert and separate actuators into the aforementioned optical paths. The high-speed shutter drive mechanism 47C retracts the first high-speed shutter 47A from the optical path of the laser light L during the trimming process, and inserts the first high-speed shutter 47A into the optical path of the laser light L except during the trimming process. In addition, the high-speed shutter drive mechanism 47C retracts the second high-speed shutter 47B from the optical path of the laser light L during hollow processing, and inserts the second high-speed shutter 47B into the optical path of the laser light L except during hollow processing.

FIG. 7 is a flowchart showing the flow of laser processing for each scribe line C of the wafer 12 (control method of the laser processing device 10) performed by the laser processing device 10 of the first embodiment of the above-mentioned configuration . In addition, in the initial state, the first high-speed shutter 47A, the second high-speed shutter 47B, and the safety shutter 100 are inserted into the optical path of the laser light L, respectively. In addition, in conjunction with the activation of the laser processing apparatus 10, the laser light L starts to be emitted from the laser light source 22.

As shown in FIG. 7, when the wafer 12 to be processed by the laser is held on the table 20, the control device 30 first drives the safety shutter drive mechanism 102 to make the safety shutter 100 retreat from the optical path of the laser light L ( Step S0). Thereby, the laser optical system 24 can emit the two first laser light L1 and the second laser light L2. In addition, at this point, since the first high-speed shutter 47A and the second high-speed shutter 47B are respectively inserted into the optical path of the laser light L, the two first laser light L1 and the second laser light L2 are not separated from the laser optical system. 24 was shot.

Next, the control device 30 drives the relative movement mechanism 28 to move the microscope 26 relative to the wafer 12 to a position where the alignment reference (not shown) of the wafer 12 can be photographed, and then executes the alignment reference using the microscope 26 Shooting. Next, the control device 30 performs alignment inspection for detecting the position of each dicing lane C in the wafer 12 based on the photographed image of the alignment reference taken by the microscope 26. Next, the control device 30 drives the relative movement mechanism 28 to perform alignment between the optical axis of the first condenser lens 38 of the laser optical system 24 and the processing start position of the first cutting lane C (outward path) (step S1 ).

In addition, the control device 30 drives the connection switching element 36 to switch the lens that emits the second laser light L2 to the second condenser lens 40A (step S2). In addition, with regard to steps S0 to S3, the order may be appropriately changed, or these processes may be executed in parallel.

Upon completion of step S2, the control device 30 drives the high-speed shutter driving mechanism 47C to retract the first high-speed shutter 47A from the optical path of the laser light L (step S3). Thereby, two first laser lights L1 are emitted from the first condenser lens 38 through the branching element 31 and the first light forming element 32, and the two first laser lights L1 are condensed on the dicing lane C (outgoing path). Processing start position.

Next, the control device 30 drives the relative movement mechanism 28, and the laser optical system 24 moves relative to the wafer 12 to the forward direction side X1 (step S4). Then, once the optical axis of the second condensing lens 40A reaches the processing start position of the dicing path C (outward path), the control device 30 drives the high-speed shutter drive mechanism 47C so that the second high-speed shutter 47B is removed from the laser light L Retreat on the road (step S5). Thereby, the second laser light L2 is emitted from the second condenser lens 40A via the branching element 31, the second light forming element 34, and the connection switching element 36, and the second laser light L2 is condensed at the above-mentioned processing start position. In addition, by shifting the start time of the hollow processing, it is possible to prevent the outer side of the wafer 12 from being laser processed (hollow processing).

When the relative movement of the laser optical system 24 toward the forward direction side X1 continues, as shown in FIGS. 3 and 5, the light spots of the two first laser light L1 and the second laser light L2 are along the cutting path C (Outgoing trip) Move to the side X1 in the outgoing trip direction. As a result, the formation of the two trimming grooves 18 by the trimming process and the formation of the hollow trench 19 by the hollowing process are performed simultaneously with an interval along the cutting path C (outward stroke).

Next, the control device 30 drives the high-speed shutter drive mechanism 47C in accordance with the point in time when the light spots of the two first laser lights L1 emitted from the first condenser lens 38 reach the processing completion position of the dicing path C (outbound) The first high-speed shutter 47A is inserted into the optical path of the laser light L (steps S6 and S7). In addition, the control device 30 drives the high-speed shutter drive mechanism 47C to insert the second high-speed shutter 47B in accordance with the point in time when the light spot of the second laser light L2 emitted from the second condenser lens 40A reaches the above-mentioned processing completion position. On the optical path of the laser light L, the driving of the relative movement mechanism 28 is stopped (step S8). In this way, the laser processing of the first cutting lane C (outgoing pass) is completed. In addition, in the case where the outer side of the wafer 12 can also be laser processed (trimming processing), the time when the first high-speed shutter 47A is inserted into the optical path of the laser light L can also be matched with the second high-speed shutter 47B. The point in time on the optical path of the laser light L.

The control device 30 drives the relative movement mechanism 28 when the laser processing of the first cutting path C (outgoing) is completed to perform the optical axis of the first condenser lens 38 and the second cutting path C (returning) ) The alignment of the processing start position (Yes in step S9, step S10).

In addition, the control device 30 drives the connection switching element 36 to switch the lens that emits the second laser light L2 to the second condenser lens 40B (step S11). In addition, with regard to step S10 and step S11, they can also be executed in the reverse order or simultaneously.

Upon completion of step S11, the control device 30 drives the high-speed shutter drive mechanism 47C to retract the first high-speed shutter 47A from the optical path of the laser light L (step S12). Thereby, two first laser lights L1 are emitted from the first condenser lens 38 via the branching element 31 and the first light forming element 32, and the two first laser lights L1 are condensed on the dicing lane C (return). The processing starts position.

Next, the control device 30 drives the relative movement mechanism 28 to relatively move the laser optical system 24 to the return direction side X2 with respect to the wafer 12 (step S13). When the optical axis of the second condensing lens 40B normally reaches the processing start position of the cutting path C (return), the control device 30 drives the high-speed shutter drive mechanism 47C so that the second high-speed shutter 47B moves from the optical path of the laser light L Retreat (step S14). Thereby, the second laser light L2 is emitted from the second condenser lens 40B via the branching element 31, the second light forming element 34, and the connection switching element 36, and the second laser light L2 is condensed in the forward direction from the above-mentioned processing start position. The position of the X1 shift on the direction side. In addition, by shifting the start time of the hollow processing, it is possible to prevent the outer side of the wafer 12 from being laser processed (hollow processing).

When the relative movement of the laser optical system 24 toward the return direction side X2 continues, as shown in FIGS. 4 and 6, the spots of the first laser light L1 and the spots of the second laser light L2 are along the cutting lane C. (Return) Move to X2 in the direction of return. As a result, the formation of the two trimming grooves 18 by the trimming process and the formation of the hollow trench 19 by the hollowing process are performed simultaneously at intervals along the cutting path C (return).

Next, the control device 30 drives the high-speed shutter drive mechanism 47C in accordance with the point in time when the light spots of the two first laser lights L1 emitted from the first condenser lens 38 reach the processing completion position of the cutting lane C (return) The first high-speed shutter 47A is inserted into the optical path of the laser light L (steps S15, S16). In addition, the control device 30 drives the high-speed shutter drive mechanism 47C so that the second high-speed shutter 47B is inserted into the laser light in accordance with the point in time when the spot of the second laser light L2 emitted from the second condenser lens 40B reaches the processing completion position. On the optical path of L, the driving of the relative movement mechanism 28 is stopped (step S17). In this way, the laser processing of the second cutting pass C (return) is completed. In addition, as described above, the time when the first high-speed shutter 47A is inserted into the optical path of the laser light L may be matched with the time when the second high-speed shutter 47B is inserted into the optical path of the laser light L.

Hereinafter, similarly, laser processing (trimming processing and hollow processing) is repeatedly performed along all the dicing paths C parallel to the X direction (YES in step S9, YES in step S18). Next, the control device 30 rotates the table 20 by 90° by driving the relative movement mechanism 28 to make the remaining dicing lanes C parallel to the Y direction parallel to the X direction on the wafer 12. The control device 30 repeatedly executes the series of processes described above. In this way, laser processing is performed along each dicing path C in a grid pattern.

Once the laser processing of all the scribe lanes C in the grid is completed (No in step S9, no in step S18), the wafer 12 is sent to the subsequent process and is divided into a plurality of wafers 14 (device 16). In addition, in this embodiment, a laser processing action in one direction (outward: X1 direction, return: X2 direction) is completed for each cutting path C (outward and return) to form two trimming grooves 18 and hollows. The flow of the fastest condition of the groove 19 is taken as an example, and the present invention is not limited to this. For example, under consideration of the respective processing depths of the two trimming grooves 18 and the hollow groove 19, at least one of the trimming processing and the hollowing processing may be performed multiple times in accordance with each cutting pass C (outgoing and returning).

[Effects of the first embodiment] As described above, in the laser processing apparatus 10 of the first embodiment, the second condensing lens 40A, 40B can be selectively used for hollowing in accordance with the relative movement direction of the laser optical system 24 with respect to the wafer 12 Processing. In this way, it is possible to simultaneously perform trimming processing and hollowing processing along the same cutting path C regardless of the outgoing and return strokes. Therefore, by making the laser optical system 24 reciprocate once in the X direction to complete the laser processing of two dicing lanes C (outward and return), the tact time required for the laser processing of the wafer 12 can be reduced. In addition, according to the relative movement direction of the laser optical system 24, only the connection switching element 36 can be activated to switch between the hollow processing of the second condenser lens 40A and the hollow processing of the second condenser lens 40B, so lightning can be prevented. The optical system 24 (optical system) is complicated. As a result, the tact time required for the laser processing of the wafer 12 can be reduced with a simple configuration.

[Second Embodiment] Next, the laser processing apparatus 10 of the second embodiment will be described. The laser processing apparatus 10 of the second embodiment has a function of adjusting the interval between the two trimming grooves 18 in the Y direction and the width of the hollow groove 19 in the Y direction. In addition, the laser processing apparatus 10 of the second embodiment is different in that it includes a first rotation mechanism 44 (refer to FIGS. 8 and 9) and a second rotation mechanism 46 (refer to FIGS. 10 and 11), which will be described later. The rest is basically the same configuration as the laser processing apparatus 10 of the first embodiment described above. Therefore, those that are the same as those of the first embodiment described above in terms of function or configuration are denoted by the same reference numerals and their description is omitted.

FIGS. 8 and 9 are explanatory diagrams for explaining the adjustment of the interval between the two trimming grooves 18 in the Y direction by the first rotating mechanism 44. As shown in FIGS. 8 and 9, the first rotation mechanism 44 is composed of, for example, a motor and a drive transmission mechanism. Under the control of the control device 30, the first light forming element 32 is directed around its optical axis. The direction of the axis of rotation. With this, when the wafer 12 is viewed from the upper side in the Z direction, the light spots of the two first laser lights L1 on the scribe lane C can be condensed by the first condensing lens 38 to be condensed first. The optical axis of the optical lens 38 rotates at the center. As a result, the distance in the Y direction between the two spots of the first laser light L1 condensed on the scribe lane C can be expanded or narrowed, so the distance between the two trimming grooves 18 in the Y direction can be adjusted.

10 and 11 are explanatory diagrams for explaining the width adjustment of the hollow groove 19 in the Y direction by the second rotating mechanism 46. As shown in FIGS. 10 and 11, the second rotation mechanism 46 is composed of, for example, a motor and a drive transmission mechanism similarly to the first rotation mechanism 44. Under the control of the control device 30, the second light forming element 34 is directed to orbit It rotates in the direction of the axis centered on its optical axis. As a result, when the wafer 12 is viewed from the upper side in the Z direction, the spot of the second laser light L2 on the scribe lane C can be condensed by the second condensing lenses 40A, 40B, and the spot of the second laser light L2 can be condensed secondly. The optical axes of the optical lenses 40A and 40B rotate around the center. Here, the spot of the second laser light L2 formed on the dicing lane C is rectangular, that is, non-circular. Therefore, by rotating this rectangular light spot, adjustments such as expanding or narrowing the width of the hollow groove 19 formed in the scribe lane C in the Y direction can be performed. In addition, the shape of the spot of the second laser light L2 is not limited to a rectangular shape as long as it is a non-circular shape.

The control device 30 drives the first rotation mechanism 44 and the second rotation mechanism 46, respectively, according to an adjustment instruction input by an operator (not shown) from an operating unit, so that the first light forming element 32 and the second light forming element 34 is rotated respectively to adjust the interval between the two trimming grooves 18 and the width of the hollow groove 19.

[Third Embodiment] Fig. 12 is a schematic diagram of the laser processing apparatus 10 according to the third embodiment. In the laser processing apparatus 10 of each of the above-mentioned embodiments, trimming processing and hollow processing are performed along the dicing path C of the wafer 12. At this time, in the laser processing apparatus 10 of each of the above-mentioned embodiments, the processing points including the trimming processing (the light spots of the two first laser lights L1 on the dicing line C are condensed by the first condenser lens 38) , And the two processing points of hollow processing (the light spot of the second laser light L2 condensed by the second condenser lens 40A, 40B on the cutting lane C) is a total of three processing points independent of each other, so each processing point With an interval of tens of mm. Therefore, as shown in the above embodiments, when the positions of the first condenser lens 38 and the second condenser lenses 40A, 40B in the laser optical system 24 are fixed, the processing feed axis ( The movement accuracy of the X axis), between the processing points of the two trimming grooves 18 and the processing points of the hollow groove 19, there will be an offset in the horizontal direction (Y direction) and vertical direction (Z direction) (from the most suitable Processing point offset).

Therefore, the laser processing apparatus 10 of the third embodiment has a function of individually adjusting the positions of the two processing points of the finishing processing and the hollow processing in the Y direction and the Z direction. The laser processing apparatus 10 of the third embodiment is basically the same as the laser processing apparatus 10 of the above-mentioned embodiments except for the difference in that it includes three mirrors 37, 39A, 39B and three moving mechanisms 48, 49A, 49B. The same composition. Therefore, the same reference numerals are attached to the same functions or structures as those of the above-mentioned respective embodiments, and the description thereof will be omitted.

The mirror 37 (first reflecting element) is arranged above the Z direction of the first condenser lens 38, and the two first laser beams L1 incident from the laser light source 22 through the branching element 31 and the first light forming element 32 are directed toward the first The condenser lens 38 reflects.

The mirrors 39A and 39B correspond to the second reflecting element of the present invention. The mirror 39A is arranged above the second condenser lens 40A in the Z direction, and reflects the second laser light L2 incident from the laser light source 22 via the connection switching element 36 and the like toward the second condenser lens 40A. In addition, the mirror 39B is arranged above the second condenser lens 40B in the Z direction, and reflects the second laser light L2 incident from the laser light source 22 via the connection switching element 36 and the like toward the second condenser lens 40B.

The moving mechanism 48 corresponds to the first moving mechanism of the present invention, and the moving mechanisms 49A and 49B correspond to the second moving mechanism of the present invention. As the moving mechanisms 48, 49A, and 49B, for example, a well-known linear actuator is used. Under the control of the control device 30, the moving mechanism 48 moves the mirror 37 and the first condenser lens 38 integrally in the Y direction (corresponding to the first vertical direction of the present invention), and moves the first condenser lens 38 toward Z Direction (corresponding to the second vertical direction of the present invention). The moving mechanism 49A moves the mirror 39A and the second condenser lens 40A integrally in the Y direction, and moves the second condenser lens 40A in the Z direction under the control of the control device 30. In addition, under the control of the control device 30, the moving mechanism 49B moves the mirror 39B and the second condenser lens 40B integrally in the Y direction, and moves the second condenser lens 40B in the Z direction.

In addition, instead of moving the first condenser lens 38 and the second condenser lens 40A, 40B in the Y direction by the moving mechanisms 48, 49A, 49B, respectively, the first condenser lens 38 and the second condenser lens 38 and the second condenser lens can be moved. The optical lenses 40A, 40B are inclined.

In this way, in the third embodiment, the mirror 37 and the first condenser lens 38, the mirror 39A and the second condenser lens 40A, and the mirror 39B and the second condenser lens 40B can be individually directed in the Y direction and the Z direction. mobile. As a result, the positions of the spots of the two first laser beams L1 formed on the dicing line C and the spots of the second laser beam L2 of the second condenser lenses 40A and 40B in the Y direction and the Z direction can be adjusted Adjust individually. Thereby, for example, the Y-direction position and the Z-direction position of each light spot can be adjusted (adjustment of parallelism) by the manufacturer of the laser processing apparatus 10.

In the laser processing of the wafer 12, the dicing line C, the two trimming grooves 18 (the spots of the two first laser light L1), and the hollow groove 19 (the second laser light L2) taken by the microscope 26 The shot image of the light spot) can make the processing point (light spot) of the finishing process track the cutting path C and the processing point (light spot) of the hollow process can track the center of the two finishing grooves 18. In addition, based on the above-mentioned captured image, it is possible to adjust the offset in the Z direction of the spots of the two first laser beams L1 and the second laser beam L2 with respect to the surface of the wafer 12 (dicing lane C) The amount (the offset of the spotlight position).

In addition, in this case, it is also possible to install a camera capable of simultaneously photographing the processing groove (two trimming grooves 18, hollow groove 19) and the light spot according to each lens of the first condenser lens 38 and the second condenser lens 40A, 40B. (camera).

As mentioned above, in the third embodiment, since the positions of the three processing points including the finishing processing point and the two hollow processing points in the Y direction and the Z direction can be adjusted individually, it does not matter when laser processing is performed. The motion accuracy of the processing feed axis (X axis) makes each processing point move (track) with the most suitable motion path.

In the above-mentioned third embodiment, it is set to individually adjust the positions of the three processing points in the Y direction and the Z direction, including the finishing processing point and the two hollow processing points. However, it is also possible to adjust only the Y direction and the position of the three processing points. Any one of the Z direction.

In the third embodiment described above, the positions of the three processing points including the finishing processing point and the two hollow processing points in the Y direction and the Z direction can be adjusted individually by the moving mechanisms 48, 49A, 49B, However, it is also possible to adjust the positions of the finishing processing points by the moving mechanism 48, and adjust the positions of the two processing points for hollow processing by the relative moving mechanism 28. That is, by moving the table 20 to at least one of the Y direction and the Z direction through the relative movement mechanism 28, the positions of the two processing points of the hollow processing can be adjusted.

In addition, conversely, the position of the finishing processing point can be adjusted by moving the table 20 by the relative moving mechanism 28, and the position of the two processing points of the hollow processing can be adjusted by the moving mechanisms 49A and 49B.

Fig. 43 is an explanatory diagram for explaining a modification of the third embodiment. In addition, the first laser light source 22A and the second laser light source 22B in FIG. 43 will be described in the fourth embodiment. In the third embodiment described above, the positions of the two processing points of the hollow processing in the Y direction and the Z direction can be individually adjusted by the movement mechanisms 49A and 49B. On the other hand, as shown by the symbols 1000A and 1000B in FIG. 43, the second condenser lenses 40A, 40B, mirrors 39A, 39B, etc. corresponding to the two processing points of the hollow processing may be arranged in the same frame (illustration omitted) Above, the positions of the two processing points of the hollow processing can be adjusted integrally in at least one of the Y direction and the Z direction by one moving mechanism 49. Since the two processing points of the hollow processing are not processed at the same time, there is no problem even if the positions of the two processing points of the hollow processing are moved integrally.

Furthermore, in FIG. 43, by moving the table 20 by the relative movement mechanism 28, the position adjustment of the processing point of a dressing process can also be performed. Furthermore, it is also possible to adjust the positions of the two processing points of the hollow processing by moving the table 20 by the relative movement mechanism 28.

[Fourth Embodiment] Next, the laser processing apparatus 10 of the fourth embodiment will be described. In the laser processing apparatus 10 of each of the above embodiments, the laser light L emitted from the common laser light source 22 is formed with two first laser light L1 for trimming processing and a second laser light L2 for hollow processing. The conditions (wavelength, pulse width, repetition frequency, etc.) of the laser light L suitable for trimming processing and hollow processing are different. Therefore, when the conditions of the laser light L deviate from the conditions suitable for either the trimming process and the hollow process, the processing speed of one of them must be slowed down, and, with this, the processing speed of the other must also be slowed down.

That is, when a laser light source 22 is used for trimming groove processing and hollow groove processing, according to the laser light conditions, even if the speed of trimming groove processing increases, the speed of hollow groove processing cannot be increased, and the hollow groove processing speed must not be increased. The processing speed is processed. Also, depending on the laser light conditions, there may be the opposite. Therefore, the speed on the side of the low speed in each of them becomes the upper limit speed in processing. In this way, in the finishing process of forming two trimming grooves 18 (blocking grooves) along the dicing path C of the wafer 12, and the trenching process of forming a hollow trench 19 (dividing groove) between the two trimming grooves 18, due to There are laser light conditions suitable for processing speed and finishing, so it is difficult to satisfy both conditions with one laser light source 22.

Therefore, in the fourth embodiment, different light sources are used for the first laser light L1 and the second laser light L2.

FIG. 13 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 moved to the side X1 in the forward direction with respect to the wafer 12 in the fourth embodiment. FIG. 14 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 moved to the side X2 in the return direction with respect to the wafer 12 in the fourth embodiment.

As shown in FIGS. 13 and 14, the laser processing apparatus 10 of the fourth embodiment replaces the laser light source 22 and the bifurcation element 31, and instead includes a first laser light source 22A, a second laser light source 22B, and a first laser light source 22A. The safety shutter 100A, the second safety shutter 100B, and the safety shutter drive mechanism 102A are different in this point, and the rest are basically the same configuration as the laser processing apparatus 10 of each of the above-mentioned embodiments. Therefore, the same reference numerals are attached to the same functions or structures as those of the above-mentioned respective embodiments, and the description thereof will be omitted.

The first laser light source 22A always emits laser light LA suitable for the conditions (wavelength, pulse width, repetition frequency, etc.) of the trimming process toward the first light forming element 32. Thereby, in the same manner as in the above embodiments, the first light forming element 32 is used to form two first laser lights L1, and the first condensing lens 38 is used to condense the two first laser lights L1 toward the dicing lane C. Light.

The second laser light source 22B always emits laser light LB suitable for the hollow processing conditions (wavelength, pulse width, repetition frequency, etc.) toward the second light forming element 34. Thereby, as in the above-described embodiments, the second light forming element 34 is used to form the second laser light L2, the connection switching element 36 is used to switch the second condenser lenses 40A and 40B, and the second condenser lens 40A is used to make the second laser light L2. The laser light L2 is condensed toward the scribe lane C (outward journey), and the second laser light L2 is condensed toward the scribe lane C (return journey) by the second condenser lens 40B.

The first safety shield 100A is detachably installed on the optical path of the laser light LA between the first laser light source 22A and the first light forming element 32. In addition, the second safety shield 100B is detachably installed on the optical path of the laser light LB between the second laser light source 22B and the second light forming element 34.

The safety shutter drive mechanism 102A is controlled by the control device 30 to make the first safety shutter 100A insert and separate the optical path of the laser light LA, and cause the second safety shutter 100B to insert and separate the optical path of the laser light LB. Actuator. The safety shutter driving mechanism 102A inserts the first safety shutter 100A into the optical path of the laser light LA except during the trimming process, thereby stopping the two first laser lights L1 from being emitted from the laser optical system 24. In addition, the safety shutter driving mechanism 102A retracts the first safety shutter 100A from the optical path of the laser light LA during the finishing process, thereby causing the two first laser lights L1 to be emitted from the laser optical system 24.

Also, similarly, the safety shutter driving mechanism 102A inserts the second safety shutter 100B into the optical path of the laser light LB except during hollow processing, thereby stopping the emission of the second laser light L2 from the laser optical system 24. Furthermore, the safety shutter drive mechanism 102A retracts the second safety shutter 100B from the optical path of the laser light LB during hollow processing, thereby causing the second laser light L2 to be emitted from the laser optical system 24.

The flow of the laser processing for each dicing line C by the laser processing apparatus 10 of the fourth embodiment is basically the same as the flow of the laser processing of the first embodiment shown in FIG. 7 described above. However, in step S0 of the fourth embodiment, the control device 30 controls the safety shutter drive mechanism 102A so that the first safety shutter 100A is retracted from the optical path of the laser light LA, and the second safety shutter 100B is removed from the laser light LA. The light path of LB is backed off.

As shown above, in the fourth embodiment, by separately providing the first laser light source 22A corresponding to the trimming process and the second laser light source 22B corresponding to the hollow process, it is possible to prevent the trimming process and the hollow process from being processed separately. The speed is reduced. As a result, the aforementioned tact time can be further reduced. In addition, it is possible to optimize the processing quality of the trimming processing and the hollow processing.

Furthermore, in the trimming process and the hollow process, the laser light LA and LB of different wavelengths are used, and the processing speed can be increased by optimizing the processing conditions of the wavelength. As a result, compared to the laser processing device 10 using the single laser light source 22 of the first embodiment, the laser processing device 10 using the first laser light source 22A and the second laser light source 22B of the fourth embodiment, More capable of faster processing.

In addition, in the fourth embodiment, similar to the above-mentioned third embodiment, by individually adjusting the positions of the finishing processing point and the two processing points of the hollow processing in the Y direction and the Z direction, it is possible to obtain the same as the above-mentioned third embodiment. The same effect of the form. Furthermore, not only can the positions of the three machining points including the finishing machining point and the two hollow machining points in the Y direction and the Z direction be adjusted individually, but also only the Y direction and the Z direction can be adjusted. .

[Specific examples of the connection switching element of the fourth embodiment] Next, specific examples 1 to 3 of the connection switching element 36 of the fourth embodiment will be described. In addition, the configuration other than the connection switching element 36 is basically the same as the laser processing apparatus 10 of the fourth embodiment (the first embodiment to the third embodiment). Therefore, the same reference numerals are attached to the same functions or structures as those of the above-mentioned respective embodiments, and the description thereof is omitted. In addition, these specific examples 1 to 3 can also be applied to the connection switching element 36 of the first to third embodiments described above.

<Specific example 1 of the connection switching element 36> FIG. 15 is an explanatory diagram for explaining specific example 1 of the connection switching element 36 of the fourth embodiment. As shown in FIG. 15, the connection switching element 36 of Specific Example 1 includes a λ/2 plate 52, a plate rotation mechanism 53, and a polarization beam splitter 54.

The λ/2 plate 52 rotates the polarization direction of the second laser light L2 (linearly polarized light) emitted from the second light forming element 34 and then emits the second laser light L2 toward the polarization beam splitter 54.

The plate rotation mechanism 53 is controlled by the control device 30, and adjusts the polarization direction of the second laser light L2 by rotating the λ/2 plate 52 about its optical axis. Thereby, the plate rotation mechanism 53 adjusts λ so that the second laser light L2 becomes S-polarized light when the laser optical system 24 is moved to the forward direction side X1 with respect to the wafer 12 by the relative moving mechanism 28. /2 The rotation angle of the plate 52. In addition, the plate rotation mechanism 53 adjusts λ/2 so that the second laser light L2 becomes P-polarized when the laser optical system 24 is moved to the return direction side X2 relative to the wafer 12 by the relative movement mechanism 28 The rotation angle of the plate 52.

The polarizing beam splitter 54 reflects the S-polarized light toward the second condenser lens 40A, and transmits the P-polarized light as it is and emits it toward the second condenser lens 40B. Thereby, according to the relative movement direction of the laser optical system 24 with respect to the wafer 12 (outward direction side X1 or return direction side X2), the second condenser lenses 40A and 40B can be selectively used for hollow processing.

<Specific example 2 of the connection switching element 36> FIG. 16 is an explanatory diagram for explaining specific example 2 of the connection switching element 36 of the fourth embodiment. As shown in FIG. 16, the connection switching element 36 of the specific example 2 includes a half mirror 58, a mirror 60, shutters 62A and 62B, and a shutter drive mechanism 64.

The half mirror 58 is on the optical path of the second laser light L2 emitted from the second light forming element 34 and is arranged at a position facing the second condenser lens 40A. The half mirror 58 divides the second laser light L2 incident from the second light forming element 34 into two, and reflects one of the divided into two second laser light L2 toward the second condenser lens 40A while passing through it. The other of the second laser light L2 is also emitted toward the mirror 60.

The mirror 60 is on the optical path of the second laser light L2 passing through the half mirror 58 and is arranged at a position facing the second condenser lens 40B. This mirror 60 reflects the second laser light L2 that has passed through the half mirror 58 toward the second condenser lens 40B.

The shutter 62A is detachably provided on the optical path of the second laser light L2 between the half mirror 58 and the second condenser lens 40A. Thereby, when the shutter 62A is inserted in the optical path of the second laser light L2, the second laser light L2 reflected by the half mirror 58 is blocked by the shutter 62A. When the shutter 62A is retreated from the optical path of the second laser light L2, the second laser light L2 reflected by the half mirror 58 is incident on the second condenser lens 40A.

The shutter 62B is detachably provided on the optical path of the second laser light L2 between the mirror 60 and the second condenser lens 40B. Thereby, when the shutter 62B is inserted into the optical path of the second laser light L2, the second laser light L2 reflected by the mirror 60 is blocked by the shutter 62B. When the shutter 62B is retreated from the optical path of the second laser light L2, the second laser light L2 reflected by the mirror 60 is incident on the second condenser lens 40B.

The shutter drive mechanism 64 is a well-known actuator, and performs insertion and separation (opening and closing) of the shutters 62A and 62B in the optical path of the second laser light L2 under the control of the control device 30. The shutter drive mechanism 64 is to retract the shutter 62A from the optical path of the second laser light L2 when the laser optical system 24 is moved to the forward direction side X1 with respect to the wafer 12 by the relative movement mechanism 28, and The shutter 62B is inserted into the optical path of the second laser light L2.

On the contrary, when the shutter drive mechanism 64 moves the laser optical system 24 with respect to the wafer 12 in the return direction side X2 by the relative movement mechanism 28, the shutter 62A is inserted into the second laser beam L2. On the optical path, the shutter 62B is retracted from the optical path of the second laser light L2. Thereby, it is possible to selectively use two second condenser lenses 40A, 40B for hollow processing according to the relative movement direction of the laser optical system 24 with respect to the wafer 12 (outward direction side X1 or return direction side X2) .

<Specific example 3 of the connection switching element 36> FIG. 17 is an explanatory diagram for explaining specific example 3 of the connection switching element 36 of the fourth embodiment. As shown in FIG. 17, the connection switching element 36 of the specific example 3 includes a mirror 66A, a mirror 66B, and a mirror drive mechanism 68.

The mirror 66A is provided at a position facing the second condenser lens 40A so as to be freely inserted and separable on the optical path of the second laser light L2 emitted from the second light forming element 34. When the mirror 66A is inserted into the optical path of the second laser light L2, it reflects the second laser light L2 incident from the second light forming element 34 toward the second condenser lens 40A. When the mirror 66A is retreated from the optical path of the second laser light L2, the second laser light L2 emitted from the second light forming element 34 is incident on the mirror 66B.

The mirror 66B is provided on the optical path of the second laser light L2 emitted from the second light forming element 34 at a position facing the second condenser lens 40B. This mirror 66B reflects the second laser light L2 incident from the second light forming element 34 toward the second condenser lens 40B.

The mirror drive mechanism 68 is a well-known actuator, and under the control of the control device 30, the mirror 66A is inserted and separated on the optical path of the second laser light L2. The mirror drive mechanism 68 inserts the mirror 66A into the optical path of the second laser light L2 when the laser optical system 24 is moved to the forward direction side X1 with respect to the wafer 12 by the relative movement mechanism 28. Thereby, all the second laser light L2 emitted from the second light forming element 34 is reflected toward the second condenser lens 40A by the mirror 66A.

On the contrary, the mirror drive mechanism 68 moves the laser optical system 24 with respect to the wafer 12 to the return direction side X2 by the relative movement mechanism 28, so that the mirror 66A is retracted from the optical path of the second laser light L2 . Thereby, all the second laser light L2 emitted from the second light forming element 34 is reflected toward the second condenser lens 40B by the mirror 66B. As a result, depending on the relative movement direction of the laser optical system 24 with respect to the wafer 12 (outward direction side X1 or return direction side X2), two second condenser lenses 40A, 40B can be selectively used for hollow processing .

[Fifth Embodiment] Next, the laser processing apparatus 10 of the fifth embodiment will be described. The laser processing apparatus 10 of the fourth embodiment described above is provided with two types of first laser light source 22A and second laser light source 22B, but it is generated in any one of the first laser light source 22A and the second laser light source 22B In the event of a defect, the laser processing of the wafer 12 becomes impossible. Therefore, the laser processing apparatus 10 of the fifth embodiment has the function of continuing the laser processing of the wafer 12 even when a failure occurs in any one of the first laser light source 22A and the second laser light source 22B .

FIG. 18 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 moved to the forward direction side X1 with respect to the wafer 12 in the fifth embodiment. FIG. 19 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 moving to the return direction side X2 with respect to the wafer 12 in the fifth embodiment. In addition, FIGS. 18 and 19 show when the second laser light source 22B has a malfunction.

As shown in FIGS. 18 and 19, the laser processing apparatus 10 of the fifth embodiment is basically the same as the fourth embodiment (including specific examples) except for the difference in that it includes bypass optical systems 72 and 74. The laser processing device 10 of 1 to 3) has the same configuration. Therefore, the same reference numerals are given to the same components as those of the above-mentioned fourth embodiment in terms of function or structure, and the description thereof will be omitted.

The bypass optical system 72 is composed of one or a plurality of optical elements, and is provided on the optical path of the laser light LA between the first laser light source 22A and the first light forming element 32. This bypass optical system 72 is under the control of the control device 30 and emits all the laser light LA emitted from the first laser light source 22A toward the first light forming element 32 when the second laser light source 22B does not cause any failure. In addition, whether the second laser light source 22B is defective or not can be determined by monitoring the operation of the second laser light source 22B, the light quantity of the laser light LB, and the like.

On the other hand, under the control of the control device 30, the bypass optical system 72 divides the laser light LA emitted from the first laser light source 22A into two when there is a defect in the second laser light source 22B, and divides the divided into One of the two laser lights LA is emitted toward the first light forming element 32, and the other of the laser lights LA is emitted toward the second light forming element 34. Thereby, the second laser light L2 is formed by the laser light LA in the second light forming element 34. This second laser light L2 is selectively emitted from the second condensing lenses 40A, 40B through the connection switching element 36 in the same manner as the fourth embodiment described above in accordance with the relative movement direction of the laser optical system 24.

The bypass optical system 74 is composed of one or a plurality of optical elements similarly to the bypass optical system 72, and is provided on the optical path of the laser light LB between the second laser light source 22B and the second light forming element 34. Under the control of the control device 30, the bypass optical system 74 emits all the laser light LB emitted from the second laser light source 22B toward the second light forming element 34 when the first laser light source 22A is not defective. In addition, whether the first laser light source 22A is defective or not can be determined by monitoring the operation of the first laser light source 22A, the light quantity of the laser light LA, and the like.

On the other hand, under the control of the control device 30, the bypass optical system 74 divides the laser light LB emitted from the second laser light source 22B into two when there is a defect in the first laser light source 22A, and divides the divided into One of the second laser lights LB is emitted toward the second light forming element 34, and the other of the laser lights LB is emitted toward the first light forming element 32. Thereby, two first laser beams L1 are formed by the laser beam LB in the first light forming element 32. The two first laser beams L1 are emitted from the first condenser lens 38 in the same manner as in the fourth embodiment described above.

As described above, in the laser processing apparatus 10 of the fifth embodiment, by providing the bypass optical systems 72 and 74, even if the first laser light source 22A and the second laser light source 22B produce In the event of a bad condition, the laser processing of the wafer 12 can also be continued. As a result, the downtime of the laser processing apparatus 10 can be reduced.

[Sixth Embodiment] Next, the laser processing apparatus 10 of the sixth embodiment will be described. The laser processing apparatus 10 of each of the above embodiments is provided with a first condenser lens 38 for trimming processing, and second condenser lenses 40A, 40B for hollow processing with the first condenser lens 38 interposed therebetween. However, it is also possible to exchange the first condenser lens 38 and the second condenser lenses 40A and 40B.

FIG. 20 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 moved to the forward direction side X1 with respect to the wafer 12 in the sixth embodiment. FIG. 21 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 moved to the return direction side X2 with respect to the wafer 12 in the sixth embodiment.

As shown in FIGS. 20 and 21, in the laser processing apparatus 10 of the sixth embodiment, instead of the first condenser lens 38, a second condenser lens 40 for hollow processing is provided instead of the second condenser lens. The optical lenses 40A and 40B are replaced with two first condenser lenses 38A and 38B for finishing processing, and the arrangement of the first light forming element 32 and the second light forming element 34 is changed. In addition, the other configuration is basically the same as that of the laser processing apparatus 10 of the first to third embodiments described above, so a detailed description is omitted here.

The first condenser lenses 38A and 38B and the second condenser lens 40 are arranged in a row along the X direction (processing feed direction). The second condenser lens 40 is arranged between the two first condenser lenses 38A and 38B. The first condenser lens 38A is arranged on the forward direction side X1 with respect to the second condenser lens 40. The first condenser lens 38B is arranged on the return direction side X2 with respect to the second condenser lens 40.

The first condensing lens 38A condenses the two first laser beams L1 input from the connection switching element 36 via the first light forming element 32 on the dicing lane C (outgoing path). The first condensing lens 38B condenses the two first laser beams L1 input from the connection switching element 36 via the first light forming element 32 on the scribe lane C (return). The second condensing lens 40 condenses the second laser light L2 input from the second light forming element 34 on the dicing lane C (outgoing and returning).

The connection switching element 36 of the sixth embodiment is configured to move the laser optical system 24 relative to the wafer 12 in any one of the outbound direction side X1 and the return direction side X2 by the relative movement mechanism 28. The two first laser beams L1 emitted from the light forming element 32 are introduced into the two first condenser lenses 38A and 38B which are located on the one direction side with respect to the second condenser lens 40.

Specifically, as shown in FIG. 20, the connection switching element 36 is configured to move the laser optical system 24 relative to the wafer 12 to the outbound direction side X1 by the relative movement mechanism 28. Under control, the two first laser beams L1 emitted from the first light forming element 32 are guided to the first condenser lens 38A. Thereby, the two first laser beams L1 are condensed on the dicing lane C (outgoing path) by the first condenser lens 38A. In addition, the second laser light L2 is condensed by the second condensing lens 40. As a result, by the relative movement of the laser optical system 24 toward the forward direction side X1, the trimming process and the hollowing process are performed along the dicing path C (outward path).

As shown in FIG. 21, the connection switching element 36 is configured to move the laser optical system 24 relative to the wafer 12 to the return direction side X2 by the relative movement mechanism 28. Under the control of the control device 30, The two first laser beams L1 emitted from the first light forming element 32 are guided to the first condenser lens 38B. Thereby, the two first laser beams L1 are condensed on the dicing lane C (return) by the first condensing lens 38B. In addition, the second laser light L2 is condensed by the second condensing lens 40. As a result, by the relative movement of the laser optical system 24 toward the return direction side X2, trimming processing and hollow processing are performed along the cutting path C (returning).

In addition, the fourth embodiment (including specific examples 1 to 3) and the fifth embodiment are also the same as the sixth embodiment, and the arrangement of the first condenser lens 38 and the second condenser lenses 40A and 40B can be exchanged. In addition, the arrangement of the first light forming element 32 and the second light forming element 34 are exchanged.

In addition, it is also possible to adjust the position of the two processing points of the finishing process by moving the table 20 using the relative movement mechanism 28, or adjust the position of the processing points of the hollow processing by moving the table 20 using the relative movement mechanism 28 . Furthermore, as a modification of the embodiment shown in FIG. 43 described above, the first condenser lenses 38A, 38B, etc., corresponding to the two processing points of the finishing process may be arranged in the same frame (illustration omitted) Above, the positions of the two processing points of the finishing process can be adjusted in at least one of the Y direction and the Z direction by one moving mechanism 48.

[Seventh Embodiment] FIG. 22 is an explanatory diagram for explaining the problem when the intensity distribution (E) of the second laser light L2 becomes a Gaussian shape. FIG. 23 is an explanatory diagram showing an example of the ideal intensity distribution (E) of the second laser light L2. FIG. 24 is an explanatory diagram showing an example of the actual intensity distribution (E) of the second laser light L2.

As indicated by the symbol XXIIA in FIG. 22, the intensity distribution of the laser light L emitted from the laser light source 22 has a Gaussian shape. Therefore, when the hollow processing is performed with the second laser beam L2 having a Gaussian shape, the cross-sectional shape of the hollow groove 19 (two trimming grooves 18 are not shown) is also a Gaussian shape as indicated by the symbol XXIIB. In this case, in the cutting process of cutting the wafer 12 along the hollow groove 19 (cutting path C) by the knife 110 rotating at a high speed after laser processing, the position of the knife 110 relative to the hollow groove 19 may vary. The knife 110 may suffer from partial wear. Therefore, the bottom of the hollow groove 19 is required to be flat (including substantially flat).

As shown in FIG. 23, in order to flatten the bottom of the hollow groove 19, for example, it is conceivable to use DOE and a refractive beam shaper to form the intensity distribution of the second laser light L2 into an isotropic top hat. The method of shape. However, although the above-mentioned optical elements such as DOE and refractive beam shaper are manufactured on the premise of an ideally round (cross-sectional shape) laser light L (beam), the actual cross-sectional shape of the laser light L is not a true circle. , It becomes an ellipse (a state of anisotropy at the expansion angle) caused by the individual difference of the laser light source 22 and the like. In this case, as shown in FIG. 24, since the intensity distribution (E) of the second laser light L2 has a shape different from the top hat shape, it is difficult to make the bottom of the hollow groove 19 flat.

In addition, as described above, when the divergence angle of the laser light L is anisotropic, astigmatism (astigmatism) occurs, and the Z position of the top hat shape is different for each of the XY directions. Furthermore, when hollow processing is performed using the second laser light L2 having an intensity distribution (E) as shown in FIG. 23, the cross-sectional shape of the hollow groove 19 is such that the light spot of the second laser light L2 is in accordance with the processing feed direction ( The shape obtained by cumulative calculation of the overlap ratio in the X direction. As a result, it is difficult to estimate the cross-sectional shape of the hollow groove 19 from the shape of the single spot of the second laser light L2.

Therefore, in the laser processing apparatus 10 of the seventh embodiment, the intensity distribution (E) of the second laser light L2 becomes a stable top hat shape and the cross-sectional shape of the hollow groove 19 is easily estimated. The forming element 34 adjusts the intensity distribution (E) of the second laser light L2. In addition, the laser processing apparatus 10 of the seventh embodiment has basically the same configuration as the laser processing apparatus 10 of the above-mentioned respective embodiments except for the difference in the function of the second light forming element 34. Therefore, the same reference numerals are attached to the same functions or structures as those of the above-mentioned respective embodiments, and the description thereof will be omitted.

The symbol XXVA in FIG. 25 is an explanatory diagram showing an example of the intensity distribution (E) of the second laser light L2 in the Y direction of the seventh embodiment, and the symbol XXVB shows the second laser light L2 of the seventh embodiment in the X direction. An explanatory diagram of an example of the intensity distribution (E). FIG. 26 is an explanatory diagram showing an example of the intensity distribution of the second laser light L2 in the XY plane of the seventh embodiment.

As shown in FIGS. 25 and 26, the second laser light L2 formed by the second light forming element 34 of the seventh embodiment has a shape in the first direction (for example, the Y direction perpendicular to the processing feed direction). The intensity distribution of the top hat shape has a Gaussian intensity distribution in the second direction (the X direction parallel to the processing feed direction). For such a second light forming element 34, an optical element such as a DOE and a refractive beam shaper is used (a plurality of optical elements may also be combined).

As described above, forming the second laser light L2 with a high-hat-shaped intensity distribution in only one direction (here, the Y-direction) is the same as forming a high-hat-shaped intensity distribution in a plurality of directions as shown in FIG. 23 Compared with the second laser light L2, the adjustment difficulty of forming the second laser light L2 into a top hat shape is reduced. As a result, since the second laser light L2 can be formed into a stable top hat shape, the bottom of the hollow groove 19 can be made flat.

In addition, by forming the intensity distribution of the second laser light L2 in the X direction (processing feed direction) into a Gaussian shape, the contour shape of the light spot of the second laser light L2 in the Y direction (that is, the opposite top hat shape) ) Is directly reflected in the processed shape of the hollow groove 19. As a result, the processed shape of the hollow groove 19 can be easily estimated from the shape of the single spot of the second laser light L2.

In addition, in FIGS. 25 and 26, the first direction is the Y direction and the second direction is the X direction, and the second light is formed through the second rotation mechanism 46 of the second embodiment (see FIGS. 10 and 11). The element 34 rotates, and the first direction and the second direction can be set in any direction in the XY plane (in the horizontal plane). That is, when the directions parallel to the table 20 (perpendicular to the traveling direction of the second laser light L2 emitted from the second light forming element 34) and orthogonal to each other are set as the first direction and the second direction, the second The light forming element 34 forms the second laser light L2 having a top hat-shaped intensity distribution in the first direction and a Gaussian-shaped intensity distribution in the second direction.

In addition, in the seventh embodiment, the second light forming element 34 forms the second laser light L2 having a top hat-shaped intensity distribution in only one direction. However, the first light forming element 32 can also be formed in only one direction. Two first laser beams L1 for the intensity distribution of the top hat shape. Furthermore, the invention of the seventh embodiment can be applied to various laser processing of the wafer 12 other than trimming processing and hollow processing.

[Eighth Embodiment] FIG. 27 is a schematic diagram of the laser optical system 24 of the laser processing apparatus 10 according to the eighth embodiment. In each of the above-mentioned embodiments, any one of the first condenser lenses 38, 38A, and 38B is used for trimming processing, and any one of the second condenser lenses 40, 40A, and 40B is used for hollow processing. In contrast, as shown in FIG. 27, in the laser processing apparatus 10 of the eighth embodiment, the trimming process is performed using the first condenser lens group 120 and any one of the second condenser lens groups 122A and 122B is used. Hollow processing.

The laser processing apparatus 10 of the eighth embodiment is basically the same as the above-mentioned embodiments except for the first condenser lens group 120 and the second condenser lens groups 122A and 122B. (Here, except for the sixth The laser processing apparatus 10 other than the embodiment has the same configuration. Therefore, the same reference numerals are attached to the same functions or structures as those of the above-mentioned respective embodiments, and the description thereof will be omitted. In addition, the first condensing lens group 120 and the second condensing lens groups 122A and 122B constitute a condensing optical system together with the aforementioned connection switching element 36 and the like.

The first condensing lens group 120 is provided in place of the first condensing lens 38 of each of the above-mentioned embodiments. This first condenser lens group 120 includes a branching element 124 and three first condenser lenses 38.

The dividing element 124 divides the two first laser beams L1 incident from the first light forming element 32 into three and emits them toward the three first condenser lenses 38, respectively. The three first condensing lenses 38 are arranged in a row along the X direction (processing feed direction), so that the two first laser beams L1 incident from the branching element 124 are simultaneously focused on the cutting lane C (outgoing and returning). )on.

The second condensing lens group 122A is provided in place of the second condensing lens 40A of the above-mentioned respective embodiments. This second condenser lens group 120A includes a branching element 126A and three second condenser lenses 40A.

The dividing element 126A divides the second laser light L2 incident from the second light forming element 34 into three and emits it toward the three second condenser lenses 40A, respectively. The three second condensing lenses 40A are arranged in a row along the X direction (processing feed direction), and the second laser light L2 incident from the branching element 126A is simultaneously condensed on the dicing lane C (outward path).

The second condensing lens group 122B is provided in place of the second condensing lens 40B of the above-mentioned respective embodiments. This second condenser lens group 120B includes a branching element 126B and three second condenser lenses 40B.

The dividing element 126B divides the second laser light L2 incident from the second light forming element 34 into three and emits it toward the three second condenser lenses 40B, respectively. The three second condensing lenses 40B are arranged in a row along the X direction (processing feed direction), and the second laser light L2 incident from the branching element 126B is simultaneously condensed on the dicing lane C (return).

FIG. 28 is an explanatory diagram for explaining the effect of the laser processing apparatus 10 of the eighth embodiment. In addition, the symbol XXVIIIA in FIG. 28 indicates that each laser light (two first laser light L1, second laser light L1, and second laser light L1) is condensed on the dicing lane C during trimming processing and hollow processing using the laser processing apparatus 10 of each embodiment described above. 2 The movement of the spot SP of the laser light L2). In addition, the symbol XXVIIIB in FIG. 28 shows the movement of the spots SP1 to SP3 of each laser beam condensed on the dicing lane C when the laser processing apparatus 10 of the eighth embodiment is used for trimming processing and during hollow processing.

As shown by the symbol XXVIIIA in FIG. 28, the laser optical system 24 is formed in the cutting lane C by the relative movement of the laser optical system 24 to the forward direction side X1 or the return direction side X2 during the trimming process and the hollow process. The spot SP of the first laser light L1 and the spot SP of the second laser light L2 of the two (outbound and return journeys) move along the dicing path C. At this time, if the moving speed of the relative movement of the laser optical system 24 is increased, the distance between the light spots SP along the processing feed direction will be enlarged, so that the processing groove (two trimming grooves 18 and hollow groove The bottom surface of 19) is uneven. Therefore, in each of the above-mentioned embodiments, it is necessary to limit the relative movement speed of the laser optical system 24 in such a way that the light spots SP adjacent to each other in the processing feed direction overlap each other partially.

In contrast, in the laser processing apparatus 10 of the eighth embodiment, the first condenser lens 38 and the second condenser lens 40A, 40B are arranged in plural along the processing feed direction, as shown in FIG. 28 As shown by the symbol XXVIIIB, the two first laser lights L1 and the second laser lights L2 can be condensed on the cutting lane C (outgoing and returning) at a plurality of places at the same time. Therefore, in the eighth embodiment, due to the relative movement of the laser optical system 24 toward the forward direction side X1 or the return direction side X2, two first laser beams are formed on the cutting lane C (outward and return). The light spots SP1, SP2, SP3 at the 3 places of L1 and the light spots SP1, SP2, SP3 at the 3 places of the second laser light L2 move along the dicing path C.

In this way, in the eighth embodiment, by increasing the number of light points processed by each laser, even when the relative movement speed of the laser optical system 24 is increased, the laser optical system 24 can be moved in the processing feed direction. The upper mutually adjacent light spots SP1, SP2, SP3 partially overlap each other. Thereby, a processing groove of a stable shape can be formed. As a result, in the eighth embodiment, the tact time required for the laser processing of the wafer 12 can be further reduced compared with the above-mentioned respective embodiments.

In addition, in the eighth embodiment, the first condenser lens 38, the second condenser lens 40A, and the second condenser lens 40B are respectively arranged in three along the processing feed direction, but the number of arrangements may be two. Or 4 or more. Moreover, similarly to the above-mentioned sixth embodiment (refer to FIGS. 21 and 22), the first condenser lens group 120 and the second condenser lens groups 122A and 122B may be exchanged.

[Ninth Embodiment] FIG. 29 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system 24 of the laser processing apparatus 10 of the ninth embodiment relative to the wafer 12 in the forward direction side X1. FIG. 30 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system 24 of the laser processing apparatus 10 of the ninth embodiment relatively moving to the side X2 in the return direction with respect to the wafer 12.

In each of the above embodiments, three types of the first condenser lens 38 (38A, 38B) and the second condenser lens 40A, 40B (40A, 40B) are selectively used in accordance with the relative movement direction of the laser optical system 24 with respect to the wafer 12. ) To perform laser processing. In contrast, as shown in FIGS. 29 and 30, in the ninth embodiment, the first condenser lens 38 and the second condenser lens 40 are used for laser processing. In addition, in the ninth embodiment, in accordance with the relative movement direction of the laser optical system 24 with respect to the wafer 12, the trimming process using the first condenser lens 38, the hollow process using the second condenser lens 40, and the use of the second condenser lens 40 are switched in accordance with the relative movement direction of the laser optical system 24 with respect to the wafer 12. 2 Trimming processing of the condenser lens 40 and hollow processing by the first condenser lens 38.

The laser optical system 24 of the ninth embodiment is provided with a first condenser lens 38 and a second condenser lens 40 instead of the first condenser lens 38 and the second condenser lenses 40A, 40B, and is equipped with a connecting optical system 200. Except for the difference in that the connection switching element 36 is replaced, the rest is basically the same configuration as the laser processing apparatus 10 of the first embodiment described above. Therefore, the same reference numerals are given to the same components as those of the first embodiment described above in terms of function or structure, and the description thereof will be omitted.

The first condenser lens 38 and the second condenser lens 40 are arranged in a row along the X direction (processing feed direction). The first condenser lens 38 is arranged on the forward direction side X1 with respect to the second condenser lens 40. The first condensing lens 38 condenses the two first laser light L1 or the second laser light L2 incident from the connecting optical system 200 described later on the dicing lane C. In addition, the second condensing lens 40 condenses the two first laser light L1 or the second laser light L2 incident from the connecting optical system 200 on the dicing lane C.

In the splicing optical system 200, when the relative movement mechanism 28 moves the laser optical system 24 relative to the wafer 12 to the outbound direction side X1, the two first laser beams L1 emitted from the first light forming element 32 are guided into the second 1 condensing lens 38 and guides the second laser light L2 emitted from the second light forming element 34 to the second condensing lens 40 (see FIG. 29). On the contrary, when the splicing optical system 200 relatively moves the laser optical system 24 with respect to the wafer 12 to the return direction side X2 by the relative movement mechanism 28, the two first laser beams emitted from the first light forming element 32 The incident light L1 is guided to the second condenser lens 40 and the second laser light L2 emitted from the second light forming element 34 is guided to the first condenser lens 38 (see FIG. 30).

FIG. 31 is an explanatory diagram for explaining the function of the connecting optical system 200 when the laser optical system 24 is relatively moved to the forward direction side X1 with respect to the wafer 12 by the relative moving mechanism 28. FIG. 32 is an explanatory diagram for explaining the function of the connecting optical system 200 when the laser optical system 24 is relatively moved to the return direction side X2 with respect to the wafer 12 by the relative moving mechanism 28.

In addition, in Figure 31 and Figure 32, the symbol PP1 shows that the two first laser lights L1 are P-polarized light, the symbol SP1 shows that the two first laser lights L1 are S-polarized light, and the symbol PP2 shows that the second laser light L2 is P Polarized light, the symbol SP2 indicates that the second laser light L2 is S-polarized light. In addition, in the present embodiment, the description will be made assuming that the two first laser lights L1 emitted from the first light forming element 32 and the second laser lights L2 emitted from the second light forming element 34 are P-polarized lights, respectively.

As shown in FIGS. 31 and 32, the connecting optical system 200 includes a polarization beam splitter 202, a λ/2 plate 204, a polarization beam splitter 206, a λ/2 plate 208, a polarization beam splitter 210, 212, a λ/2 plate 214, And mirrors 220, 222.

The polarization beam splitter 202, the λ/2 plate 204 and the polarization beam splitter 206 are arranged along the optical path from the first light forming element 32 to the first condenser lens 38. The λ/2 plate 208, the polarization beam splitters 210 and 212, and the λ/2 plate 214 are arranged along the optical path from the second light forming element 34 to the second condenser lens 40. The mirror 220 is arranged on the optical path between the polarization beam splitter 202 and the polarization beam splitter 210. The mirror 222 is arranged on the optical path between the polarization beam splitter 206 and the polarization beam splitter 212.

Each of the polarization beam splitters 202, 206, 210, and 212 allows the P-polarized light to pass through and reflect the S-polarized light.

The λ/2 plates 204, 208, and 214 can be switched to a reference state in which P-polarized light and S-polarized light pass without changing their polarization state, and a rotating state in which the optical axis is rotated by 45 degrees from this reference state. The λ/2 plates 204, 208, and 214 convert the incident P-polarized light into S-polarized light and convert the incident S-polarized light into P-polarized light while rotating.

The mirror 220 guides the S-polarized light reflected by the polarization beam splitter 210 to the polarization beam splitter 202. In addition, the mirror 222 guides the S-polarized light reflected by the polarization beam splitter 206 to the polarization beam splitter 212. In addition, the mirror 220 may be omitted when the polarizing beam splitters 202 and 210 are arranged opposite to each other in the X direction, and the mirror 222 may be omitted when the polarizing beam splitters 206 and 212 are arranged opposite to each other in the X direction.

As shown in FIG. 31, the control device 30 of the ninth embodiment (refer to FIG. 1) is used for laser processing of the cutting path C (outward path), that is, the relative movement mechanism 28 moves the laser optical system 24 relative to When the wafer 12 is relatively moved to the forward direction side X1, the λ/2 plates 204, 208, and 214 are respectively set to the reference state.

The two first laser beams L1 (P polarized light) emitted from the first light forming element 32 pass through the polarizing beam splitter 202, the λ/2 plate 204, and the polarizing beam splitter 206 in order to be guided to the first condenser lens 38. As a result, the first condensing lens 38 condenses the two first laser beams L1 on the dicing lane C (outward path).

The second laser light L2 (P polarized light) emitted from the second light forming element 34 sequentially penetrates the λ/2 plate 208, the polarization beam splitters 210, 212, and the λ/2 plate 214 and is guided to the second condenser lens 40. As a result, the second laser light L2 is condensed on the dicing lane C (outward path) by the second condensing lens 40.

As in the above-mentioned embodiments, by the relative movement of the laser optical system 24 toward the forward direction side X1, the trimming process is performed along the dicing path C (the forward process), and then the hollow process is performed. In addition, the timing at which the emission of the first laser light L1 and the second laser light L2 and the stop of the emission of the two laser beams during the laser processing of the cutting lane C (outward path) are the same as in the above-mentioned first embodiment, here is A detailed description is omitted (the same applies to the tenth embodiment and the eleventh embodiment described later).

As shown in FIG. 32, the control device 30 of the ninth embodiment performs laser processing of the scribe line C (return), that is, the relative movement mechanism 28 moves the laser optical system 24 relative to the wafer 12 in the return stroke. In the case of the direction side X2, the λ/2 plates 204, 208, and 214 are respectively set in the rotating state.

The two first laser beams L1 (P polarized light) emitted from the first light forming element 32 are converted into S polarized light by the λ/2 plate 204 after passing through the polarization beam splitter 202. The two first laser lights L1 converted into S-polarized light are reflected by the polarizing beam splitter 206 toward the mirror 222, and then reflected by the mirror 222 to be incident on the polarizing beam splitter 212. The two first laser beams L1 (S-polarized light) incident on the polarizing beam splitter 212 are reflected by the polarizing beam splitter 212 toward the λ/2 plate 214, and the λ/2 plate 214 is converted into P-polarized light and then guided into the second focusing beam. Optical lens 40. As a result, the two first laser beams L1 are condensed on the dicing lane C (return) by the second condenser lens 40.

The second laser light L2 (P polarized light) emitted from the second light forming element 34 is converted into S-polarized light by the λ/2 plate 208, and then reflected by the polarizing beam splitter 210 toward the mirror 220, and then reflected by the mirror 220 and incident To the polarizing beam splitter 202. The second laser light L2 (S-polarized light) incident on the polarizing beam splitter 202 is reflected toward the λ/2 plate 204 by the polarizing beam splitter 202, whereby the λ/2 plate 204 is converted into P-polarized light and then penetrates the polarizing beam splitter 206 And the first condenser lens 38 is introduced. As a result, the second laser light L2 is condensed on the dicing lane C (return) by the first condensing lens 38.

As in the foregoing embodiments, by the relative movement of the laser optical system 24 toward the outbound direction side X2, the trimming process is performed along the dicing path C (return process), and then the hollow process is performed. In addition, the timing at which the two first laser beams L1 and the second laser beam L2 are emitted and when the emission stops during laser processing of the cutting line C (return) is the same as in the first embodiment described above, so the details are omitted here. (The same applies to the tenth embodiment and the eleventh embodiment described later).

In addition, in the ninth embodiment, in order to make the polarization state of the two first laser beams L1 for the trimming process of the scribe lane C (return) coincide with the same P polarization during the trimming process of the scribe lane C (outbound) A λ/2 plate 214 is provided, but if it is not necessary to conform to the P polarization, the λ/2 plate 214 can also be omitted.

As described above, in the ninth embodiment, according to the relative movement direction of the laser optical system 24 with respect to the wafer 12, it is possible to switch between the trimming process using the first condensing lens 38 and the hollow process using the second condensing lens 40. , And trimming processing using the second condenser lens 40 and hollow processing using the first condenser lens 38. As a result, the same effects as in the above-mentioned respective embodiments can be obtained.

[Modifications of the ninth embodiment] <Modification 1> FIG. 33 is an explanatory diagram for explaining the trimming process and the hollow process performed by the laser optical system 24 moved to the forward direction side X1 with respect to the wafer 12 in the modification 1 of the ninth embodiment. FIG. 34 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 moving to the return direction side X2 relative to the wafer 12 in the modification 1 of the ninth embodiment.

In the above-mentioned ninth embodiment, the laser light L emitted from the laser light source 22 is formed with two first laser lights L1 for trimming processing and a second laser light L2 for hollow processing. In this regard, as shown in FIGS. 33 and 34, in Modification 1 of the ninth embodiment, similarly to the above-mentioned fourth embodiment (refer to FIGS. 13 and 14), the first corresponding to the finishing process is separately provided. 1 laser light source 22A and second laser light source 22B corresponding to hollow processing. In addition, the same reference numerals are given to the same components as those of the above-mentioned fourth embodiment in terms of function or structure, and the description thereof will be omitted.

In this way, by separately providing the first laser light source 22A corresponding to the finishing process and the second laser light source 22B corresponding to the hollow process in the modification 1 of the ninth embodiment, it is the same as the fourth embodiment described above. , Can prevent the respective processing speed of trimming and hollow processing from being reduced, so the tact time can be further reduced.

<Modification 2> 35 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 moved to the forward direction side X1 with respect to the wafer 12 in the modification 2 of the ninth embodiment. 36 is an explanatory diagram for explaining the trimming process and the hollow process performed by the laser optical system 24 moved to the return direction side X2 with respect to the wafer 12 in the modification 2 of the ninth embodiment.

As shown in FIGS. 35 and 36, in Modification 2 of the ninth embodiment, even when a malfunction occurs in any one of the first laser light source 22A and the second laser light source 22B in the modification 1 described above, It also has the function of continuously laser processing the wafer 12. Specifically, in Modification 2 of the ninth embodiment, the bypass optical systems 72 and 74 are provided in the same manner as in the above-mentioned fifth embodiment (see FIGS. 18 and 19). In addition, the same reference numerals are given to the same components as those of the above-mentioned fifth embodiment in terms of function or structure, and the description thereof will be omitted.

In this way, in the modification 2 of the ninth embodiment, by providing the bypass optical systems 72 and 74, as in the above-mentioned fourth embodiment, even in any one of the first laser light source 22A and the second laser light source 22B In the event of a defect, the laser processing of the wafer 12 can also be continued.

＜Other＞ In the above-mentioned ninth embodiment, as in the above-mentioned second embodiment (refer to FIGS. 8 to 11), the width of the two trimming grooves 18 may be adjusted by the first rotation mechanism 44, or the width of the two trimming grooves 18 may be adjusted by the second rotation mechanism 46. The width of the second laser light L2.

Also, in the above-mentioned ninth embodiment, similar to the above-mentioned third embodiment (refer to FIG. 12), mirrors 37, 39B and moving mechanisms 48, 49B, etc. can also be used to combine the spots of the two first laser beams L1 and the second 2The Y-direction position of the laser light spot L2 is set to be adjustable.

Furthermore, it is also possible to appropriately combine the configurations of the seventh embodiment and the eighth embodiment described above in the ninth embodiment (including the modification examples 1 and 2).

[Tenth Embodiment] FIG. 37 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system 24 of the laser processing apparatus 10 of the tenth embodiment. In the above-mentioned ninth embodiment, in accordance with the relative movement direction of the laser optical system 24 with respect to the wafer 12, switching: trimming processing using the first condenser lens 38 and hollow processing using the second condenser lens 40; and using the second condenser lens 40 2 Trimming processing of the condenser lens 40 and hollow processing using the first condenser lens 38. On the other hand, in the tenth embodiment, the trimming process is performed similarly to the above-mentioned ninth embodiment, and the hollow process using both the first condenser lens 38 and the second condenser lens 40 is performed.

The laser optical system 24 of the tenth embodiment is basically the same configuration as the laser processing apparatus 10 of the ninth embodiment, except that the function of the λ/2 plate 208 is partially different. Those that are the same in function or structure are marked with the same symbols and their descriptions are omitted.

The λ/2 plate 208 of the tenth embodiment is set by the control device 30 described above to a half-rotation state rotated by 22.5 degrees from the reference angle state. The λ/2 plate 208 rotates the polarization direction of the second laser light L2 by 45 degrees when the second laser light L2 (P-polarized light) is incident from the second light forming element 34 in a half-rotated state.

The polarizing beam splitter 210 of the tenth embodiment allows the P polarized light component of the second laser light L2 passing through the semi-rotating λ/2 plate 208 to pass through and emit it toward the polarizing beam splitter 212, and at the same time direct the S polarized light component toward the mirror 220 reflection. Thereby, the second laser light L2 is divided into two parts by the polarization beam splitter 210. The second laser light L2 (P polarized light) that has passed through the polarization beam splitter 210 passes through the polarization beam splitter 212 and the λ/2 plate 214 and is guided to the second condenser lens 40.

On the other hand, the second laser light L2 (S-polarized light) reflected by the polarization beam splitter 210 is reflected by the mirror 220 and enters the polarization beam splitter 202. In addition, the second laser light L2 (S-polarized light) is reflected toward the λ/2 plate 204 by the polarization beam splitter 202, and is converted into P-polarized light by the λ/2 plate 204, and then penetrates the polarization beam splitter 206 and is guided to the first Condenser lens 38. As a result, the second laser light L2 is condensed on the dicing lane C (return) by both the first condenser lens 38 and the second condenser lens 40.

By the relative movement of the laser optical system 24 toward the return direction side X2, the second condensing lens 40 is used to perform trimming processing and hollow processing along the cutting path C (returning), thereby first performing two trimming grooves 18 and hollows. The groove 19 is then hollowed by the first condenser lens 38, thereby forming a hollow groove 19 on the previous hollow groove 19 again. Thereby, the overlap rate of the light spots of the second laser light L2 adjacent to each other in the processing feed direction can be improved.

In addition, when the laser optical system 24 is relatively moved to the outbound direction side X1, the second laser light L2 (S-polarized light) reflected by the polarization beam splitter 202 must be converted during the time it enters the polarization beam splitter 206. Into P polarized light. In this case, for example, the λ/2 plate is temporarily arranged (in a rotating state) only on the optical path of the second laser light L2 between the polarization beam splitter 202 and the polarization beam splitter 206. Thereby, by the relative movement of the laser optical system 24 toward the forward direction side X1, the trimming process and the hollowing process are first performed by the first condenser lens 38 along the cutting path C (outward journey), and then the second condensing process is performed. The optical lens 40 performs hollow processing.

As described above, in the tenth embodiment, according to the relative movement direction of the laser optical system 24 with respect to the wafer 12, the implementation including the use of either the first condenser lens 38 and the second condenser lens 40 can be performed. The trimming processing and hollow processing performed are simultaneously processed with virtual three points of the hollow processing performed by the other of the first condenser lens 38 and the second condenser lens 40. As a result, the overlap rate of the spots of the second laser light L2 on the dicing lane C can be increased.

In addition, in the case of increasing the overlap rate of the spots of the two first laser beams L1 on the cutting lane C, instead of setting the λ/2 plate 208 to a half-rotation state, the λ/2 plate 204 is set to a half-rotation state. Rotating state. Thereby, the λ/2 plate 204 divides the two first laser beams L1 (P-polarized light) incident from the polarization beam splitter 202 into both P-polarized light and S-polarized light and emits them toward the polarization beam splitter 206. As a result, the P-polarized light of the two first laser beams L1 is guided to the first condenser lens 38, and the S-polarized light is guided to the polarization beam splitter 212 (the second condenser lens 40).

Therefore, in accordance with the relative movement direction of the laser optical system 24 with respect to the wafer 12, it is possible to perform trimming processing including the use of either the first condenser lens 38 and the second condenser lens 40, and the use of the first condenser lens. The trimming processing and hollow processing performed by the other of the optical lens 38 and the second condenser lens 40 are virtual three-point simultaneous processing. As a result, the overlap rate of the spots of the two first laser beams L1 on the dicing lane C can be increased.

<Modifications> In the tenth embodiment described above, similarly to the ninth embodiment (including modifications 1 and 2), the configurations of the second embodiment to the eighth embodiment described above may be appropriately combined.

[Eleventh Embodiment] FIG. 38 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system 24 of the laser processing apparatus 10 of the eleventh embodiment relatively moved to the forward direction side X1 with respect to the wafer 12. Fig. 39 is an enlarged view of the dotted circle K1 in Fig. 38. 40 is an explanatory diagram for explaining the trimming processing and hollow processing performed by the laser optical system 24 of the laser processing apparatus 10 of the eleventh embodiment relatively moved to the side X2 in the return direction with respect to the wafer 12. Fig. 41 is an enlarged view of the dotted circle K2 in Fig. 40.

In each of the above-described embodiments, the laser optical system 24 is moved relative to the wafer 12 to the forward direction side X1 and the return direction side X2, while performing trimming processing and hollow processing using a plurality of various lenses. On the other hand, in the eleventh embodiment, while moving the laser optical system 24 relative to the wafer 12 to the outbound direction side X1 and the return direction side X2, only one first condenser lens 38 is used to perform trimming. Processing and hollow processing.

As shown in FIGS. 38 to 41, the laser optical system 24 of the eleventh embodiment includes the first condenser lens 38 and the connecting optical system 200A, and the first light forming element 32 generates two first laser lights L1 (S Polarized light) and the second light forming element 34 generates the second laser light L2 (P polarized light). The rest is basically the same configuration as the laser processing apparatus 10 of each of the above-mentioned embodiments, except that the second light forming element 34 generates the second laser light L2 (P polarized light). Therefore, the same reference numerals are attached to the same functions or structures as those of the above-mentioned respective embodiments, and the description thereof will be omitted.

The first condensing lens 38 of the eleventh embodiment condenses the two first laser light L1 and the second laser light L2 incident from the connecting optical system 200A described later on the dicing lane C. In addition, the symbol OP in FIGS. 39 and 41 indicates the optical axis of the first condenser lens 38, the symbol SPA indicates the spot of the two first laser light L1, and the symbol SPB indicates the spot of the second laser light L2.

The connecting optical system 200A guides the two first laser lights L1 emitted from the first light forming element 32 and the second laser lights L2 emitted from the second light forming element 34 to the first condenser lens 38. At this time, when the splicing optical system 200A relatively moves the laser optical system 24 with respect to the wafer 12 in the forward direction side X1 by the relative movement mechanism 28, the spot SPA of the two first laser beams L1 is relative to the second laser beam. The spot SPB of the laser light L2 is relatively shifted (shifted) on the outbound direction side X1. On the contrary, when the splicing optical system 200A relatively moves the laser optical system 24 with respect to the wafer 12 to the return direction side X2 by the relative movement mechanism 28, the spot SPA of the two first laser beams L1 is relative to the first laser beam L1. 2 The spot SPB of the laser light L2 is relatively displaced on the return direction side X2.

The connecting optical system 200A includes a displacement element 230, a mirror 232, and a polarization beam splitter 234.

The displacement element 230 and the mirror 232 are arranged on the optical path from the first light forming element 32 to the polarization beam splitter 234.

The shift element 230 is composed of, for example, a plurality of ridges (shift ridges) or a plurality of mirrors, etc., and shifts the two first laser beams L1 incident from the first light forming element 32 to the X direction After that, the two first laser beams L1 are emitted toward the mirror 232 located on the lower side in the Z direction. By rotating the displacement element 230 around the Z axis, the displacement directions of the two first laser beams L1 can be adjusted arbitrarily. The displacement element 230 is in the direction around the Z axis, and when set at the first angular position, the two first laser beams L1 are displaced toward the forward direction side X1, and are set to rotate from the first angular position. In the case of the second angular position rotated by 180 degrees, the two first laser beams L1 are displaced toward the return direction side X2.

The mirror 232 guides the two first laser beams L1 incident from the displacement element 230 to the polarization beam splitter 234.

The polarization beam splitter 234 is arranged on the optical path from the second light forming element 34 to the first condenser lens 38. This polarization beam splitter 234 reflects the two first laser lights L1 (S-polarized light) incident from the mirror 232 toward the first condenser lens 38, and supplies the second laser light L2 (P Polarized light) penetrates and is emitted toward the first condenser lens 38. Thereby, the two first laser light L1 and the second laser light L2 are condensed on the dicing lane C by the first condensing lens 38.

As shown in FIGS. 38 and 39, the control device 30 of the eleventh embodiment is used for laser processing of the dicing line C (outward path), that is, when the relative movement mechanism 28 moves the laser optical system 24 relative to the wafer When 12 is relatively moved to the forward direction side X1, the displacement element 230 is set at the first angular position. Thereby, on the dicing lane C (outward journey), the spot SPA of the two first laser beams L1 is displaced to the outward direction side X1 relative to the spot SPB of the second laser beam L2. As a result, similarly to the above-described embodiments, the relative movement of the laser optical system 24 toward the forward direction side X1 causes the trimming process to be performed along the dicing path C (outward process), and then the hollowing process is performed.

As shown in FIGS. 40 and 41, the control device 30 of the eleventh embodiment is used for laser processing of the scribe line C (return), that is, the relative movement mechanism 28 moves the laser optical system 24 relative to the wafer 12 When relatively moving to the return direction side X2, the displacement element 230 is set at the second angular position. Thereby, on the scribe lane C (return), the spot SPA of the two first laser lights L1 is displaced to the return direction side X2 relative to the spot SPB of the second laser light L2. As a result, similarly to the foregoing embodiments, the relative movement of the laser optical system 24 toward the forward direction side X2 causes the trimming process to be performed along the dicing path C (outward process), and then the hollow process is performed.

As shown above, in the eleventh embodiment, by using the displacement element 230 to relatively displace the two first laser beams L1 relative to the second laser beam L2 in the processing feed direction, one first condenser lens can be used 38 Perform trimming processing and hollow processing of cutting path C (outgoing and returning). As a result, the same effects as in the above-mentioned respective embodiments can be obtained.

<Modifications> In the above-mentioned eleventh embodiment, although the displacement element 230 is used to displace the two first laser beams L1 (spot SPA), the second laser beam L2 (spot SPB) can also be moved in the direction opposite to the processing feed direction. Lateral displacement.

Fig. 42 is an explanatory diagram for explaining a modification of the eleventh embodiment. As shown by the symbols XLIIA and XLIIB in FIG. 42, the 11th embodiment is also the same as the above-mentioned second embodiment (refer to FIGS. 8 to 11), and the two trimming grooves 18 can also be adjusted by the first rotation mechanism 44. The width of the second laser beam L2 can be adjusted by the second rotating mechanism 46.

In addition, in the above-mentioned eleventh embodiment, the configurations of the above-mentioned fourth embodiment, fifth embodiment, seventh embodiment, and eighth embodiment may be appropriately combined.

[other] In each of the above embodiments, by inserting and separating the safety shields 100, 100A, and 100B in the optical path, the trimming process and the hollowing process are switched off-on. However, the laser light source 22 can also be switched off-on. (The first laser light source 22A and the second laser light source 22B) switch (on-off) to switch between trimming processing and hollow processing.

[Supplement] As understood from the description of the embodiments detailed above, this specification includes disclosures of various technical ideas including the inventions shown below.

(Additional item 1) A laser processing device that relatively moves a work table holding a wafer and a laser optical system arranged at a position opposite to the work table in the processing feed direction along the dicing path of the wafer. The laser light is irradiated on the wafer from the laser optical system, thereby performing trimming and hollowing processing for each of the dicing lanes. The trimming processing system forms two first grooves parallel to each other along the dicing lanes. The hollowing processing The second groove is formed between the two first grooves mentioned above, The aforementioned laser optics system has: The laser light emission system emits the two first laser lights corresponding to the aforementioned trimming process and the second laser light corresponding to the aforementioned hollow process; and The condensing optical system condenses the two first laser beams and the second laser beams on the cutting lane of the processing object, The condensing optical system moves the laser optical system relative to the worktable toward the outgoing direction side of the processing feed direction, so that the two first laser beams are in the same direction as the second laser beam. The position relatively displaced in the forward direction is focused on the cutting path, and when the laser optical system is relatively moved to the return direction side of the processing feed direction with respect to the table, the two first laser beams The light is condensed on the scribe lane at a position relatively displaced to the return direction side with respect to the second laser light.

(Additional item 2) Such as the laser processing device in appendix 1, where The aforementioned concentrating optical system has: The first condensing lens condenses the two first laser beams on the wafer; Two second condensing lenses sandwich the first condensing lens and arrange them in a row along the processing feed direction together with the first condensing lens. Each second condensing lens makes the second condensing lens. Concentrate light on the aforementioned wafer; and In the optical system, the two first laser lights emitted from the laser light emitting system are guided into the first condenser lens, and the second laser light emitted from the laser light emitting system is selectively guided into the two The second condenser lens, In the splicing optical system, when the laser optical system is relatively moved to the outbound direction side with respect to the table, the second laser light is guided to the first condensing lens that is located on the return direction side with respect to the first condenser lens. 2 Condenser lens, and when the laser optical system is relatively moved to the return direction side relative to the table, the second laser light is guided to the first condensing lens that is located on the outbound direction side with respect to the first condensing lens The second condenser lens.

(Additional item 3) Such as the laser processing device in appendix 1, where The aforementioned concentrating optical system has: Two first condensing lenses are arranged in a row along the aforementioned processing and feeding direction, and the two first laser beams are condensed on the aforementioned wafer according to each of the first condensing lenses; The second condensing lens is arranged between the two first condensing lenses to condense the second laser light on the wafer; and The optical system is connected, the two first laser lights emitted from the laser light emitting system are selectively guided into the two first condenser lenses, and the second laser light emitted from the laser light emitting system is guided into the The second condenser lens, When the connecting optical system moves relative to the outbound direction of the laser optical system relative to the worktable, the two first laser beams are guided in the outbound direction relative to the second condenser lens. The first condenser lens on the side, and when the laser optical system is relatively moved to the return direction side with respect to the worktable, the two first laser lights are guided to be positioned relative to the second condenser lens The first condenser lens on the side in the return direction.

(Additional item 4) Such as the laser processing device in appendix 1, where The aforementioned concentrating optical system has: Two condenser lenses are arranged in a row along the aforementioned processing feed direction; and Following the optical system, the two first laser beams and the second laser beams emitted from the laser beam emitting system are guided into the condenser lens, When the connecting optical system relatively moves the laser optical system to the outbound direction side with respect to the table, the two first laser lights are guided to the condenser lens on the outbound direction side, and the first laser light is introduced into the condenser lens on the outbound direction side. 2 When the laser light is guided to the condenser lens on the return direction side, and when the laser optical system is relatively moved to the return direction side with respect to the table, the two first laser lights are guided to the return direction side. The condenser lens guides the second laser light into the condenser lens on the outbound direction side.

(Additional item 5) Such as the laser processing device in appendix 4, where The connecting optical system divides one of the two first laser beams and the second laser beam into two parts, and guides the one to both of the two condenser lenses.

(Additional item 6) Such as the laser processing device in appendix 1, where The aforementioned concentrating optical system has: Condenser lens; and Following the optical system, the two first laser beams and the second laser beams emitted from the laser beam emitting system are guided into the condenser lens, The splicing optical system is equipped with a displacement element that moves the second laser light in the return direction relative to the two first laser lights when the laser optical system is relatively moved to the outbound direction side with respect to the worktable. Side relative displacement, and when the laser optical system is relatively moved to the return direction side with respect to the worktable, the second laser light is positioned relative to the two first laser lights to the outgoing direction side shift.

(Additional item 7) Such as the laser processing device of item 2 or 3, which is equipped with: The first moving mechanism moves the first condenser lens in a vertical direction parallel to the table and perpendicular to the processing feed direction, The second moving mechanism moves the second condenser lens in the vertical direction.

(Additional item 8) Such as the laser processing device of item 4 or 5, which is equipped with: A moving mechanism that moves the condenser lens in a vertical direction parallel to the worktable and perpendicular to the processing feed direction.

(Additional item 9) Such as the laser processing device of any one of items 1 to 8, in which The aforementioned laser light emitting system has: Laser light source, emitting laser light; The branching element makes the aforementioned laser light emitted from the aforementioned laser light source branch into two; The first light forming element forms the two first laser lights from one of the laser lights branched into two by the branching element; and The second light forming element forms the second laser light from the other of the laser light branched into two by the branching element.

(Additional item 10) Such as the laser processing device of any one of items 1 to 8, in which The aforementioned laser light emitting system has: The first laser light source emits laser light under the conditions corresponding to the aforementioned trimming process; The second laser light source emits laser light under the conditions corresponding to the aforementioned hollow processing; The first light forming element forms the two first laser lights from the laser light emitted from the first laser light source; and The second light forming element forms the second laser light from the laser light emitted from the second laser light source.

(Additional item 11) For example, the laser processing device of appendix 10, which is equipped with a bypass optical system, is used to divide the laser light emitted from the second laser light source into two when the first laser light source has a malfunction. 1 The light forming element and the second light forming element emit, and when the second laser light source has a defect, the laser light emitted from the first laser light source is divided into two and directed toward the first light forming element And the aforementioned second light forming element emits.

(Additional item 12) Such as the laser processing device of any one of items 9 to 11, which has: The first rotation mechanism rotates the first light forming element in a direction around an axis centered on the optical axis of the first light forming element.

(Additional item 13) Such as the laser processing device of any one of items 9 to 12, where The second light forming element forms the second laser light, and the second laser light forms a non-circular light spot on the wafer, It also includes a second rotation mechanism that rotates the second light forming element in the direction of an axis centered on the optical axis of the second light forming element.

(Additional item 14) Such as the laser processing device of any one of items 9 to 13, where When the directions parallel to and orthogonal to the table are set as the first direction and the second direction, the second light forming element is formed in the first direction and has a hat-shaped intensity distribution in the second direction. The aforementioned second laser light having a Gaussian intensity distribution.

(Additional item 15) Such as the laser processing device in appendix 1, where The aforementioned concentrating optical system has: The first condensing lens group is formed by arranging a plurality of first condensing lenses along the processing feed direction, and the first condensing lens condenses the two first laser lights on the wafer; The second condenser lens group is two sets of second condenser lens groups, which sandwich the first condenser lens group and are arranged in a row along the processing feed direction together with the first condenser lens group. , And according to each second condensing lens group, the second condensing lens that condenses the second laser light on the wafer is formed by arranging plural second condensing lenses along the processing feed direction; and The optical system is connected, the two first laser lights emitted from the laser light emission system are guided into the first condenser lens group, and the second laser light emitted from the laser light emission system is selectively introduced into the two groups of the The second condenser lens group, In the splicing optical system, when the laser optical system is relatively moved to the outbound direction side with respect to the table, the second laser light is guided to be located on the return direction side with respect to the first condenser lens group The second condensing lens group, and when the laser optical system is relatively moved to the return direction side with respect to the table, the second laser light is guided to be positioned relative to the first condensing lens group The second condenser lens group on the forward direction side.

10: Laser processing device 12: Wafer 14: chip 16: device 18: trim the ditch 19: Hollow groove 20: Workbench 22: Laser light source 22A: 1st laser light source 22B: 2nd laser light source 24: Laser optics 26: Microscope 28: Relative movement mechanism 30: control device 31: Bifurcation element 32: The first light forming element 34: The second light forming element 36: Connect the switching element 37: Mirror 38, 38A, 38B: the first condenser lens 39A, 39B: mirror 40, 40A, 40B: 2nd condenser lens 44: The first rotating mechanism 46: The second rotating mechanism 47A: 1st speed shutter 47B: 2nd high speed shutter 47C: High-speed shutter drive mechanism 48, 49A, 49B: mobile mechanism 52: λ/2 plate 53: plate rotating mechanism 54: Polarizing beam splitter 58: half mirror 60: mirror 62A, 62B: Shutter 64: Shutter drive mechanism 66A, 66B: mirror 68: Mirror drive mechanism 72, 74: Bypass optics 100: safety shutter 100A: The first safety shield 100B: 2nd safety shield 102, 102A: Safety shutter drive mechanism 110: Knife 120: The first condenser lens group 120A, 120B, 122A, 122B: 2nd condenser lens group 124, 126A, 126B: bifurcation element 200, 200A: Connected to optical system 202: Polarizing beam splitter 204:λ/2 plate 206 polarizing beam splitter 208:λ/2 plate 210, 212: Polarizing beam splitter 214:λ/2 plate 220,222: Mirror 230: displacement element 232: Mirror 234: Polarizing beam splitter C: Cutting road L: Laser light L1: 1st laser light L2: 2nd laser light LA, LB: Laser light SP, SP1, SP2, SP3, SPA, SPB: light spot X1: Outward direction side X2: Return direction side

Fig. 1 is a schematic diagram of the laser processing apparatus of the first embodiment. Fig. 2 is a plan view of a wafer to be processed using a laser processing device. Fig. 3 is an explanatory diagram for explaining laser processing along odd-numbered cutting lanes. Fig. 4 is an explanatory diagram for explaining laser processing along even-numbered cutting lanes. FIG. 5 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system that moves relative to the wafer in the forward direction side. FIG. 6 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system that moves relative to the wafer in the return direction side. FIG. 7 is a flowchart showing the flow of laser processing for each dicing lane of a wafer performed by the laser processing apparatus of the first embodiment. Fig. 8 is an explanatory diagram for explaining the adjustment of the interval between the two trimming grooves in the Y direction performed by the first rotating mechanism. Fig. 9 is an explanatory diagram for explaining the adjustment of the interval between the two trimming grooves in the Y direction by the first rotating mechanism. Fig. 10 is an explanatory diagram for explaining the width adjustment of the hollow groove in the Y direction by the second rotation mechanism. 11 is an explanatory diagram for explaining the width adjustment of the hollow groove in the Y direction by the second rotation mechanism. Fig. 12 is a schematic diagram of the laser processing apparatus of the third embodiment. FIG. 13 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system that moves relative to the wafer in the forward direction side in the fourth embodiment. 14 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system that moves relative to the wafer in the return direction side in the fourth embodiment. 15 is an explanatory diagram for explaining specific example 1 of the connection switching element of the fourth embodiment. Fig. 16 is an explanatory diagram for explaining specific example 2 of the connection switching element of the fourth embodiment. Fig. 17 is an explanatory diagram for explaining specific example 3 of the connection switching element of the fourth embodiment. FIG. 18 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system that moves relative to the wafer in the forward direction side in the fifth embodiment. FIG. 19 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 that moves relative to the wafer in the return direction side in the fifth embodiment. 20 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system that moves relative to the wafer in the forward direction side in the sixth embodiment. FIG. 21 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system 24 that moves relative to the wafer in the return direction side in the sixth embodiment. FIG. 22 is an explanatory diagram for explaining the problem when the intensity distribution of the second laser light becomes a Gaussian shape. FIG. 23 is an explanatory diagram showing an example of the ideal intensity distribution of the second laser light. FIG. 24 is an explanatory diagram showing an example of the actual intensity distribution of the second laser light. The symbol XXVA in FIG. 25 is an explanatory diagram showing an example of the intensity distribution (E) of the second laser light in the Y direction, and the symbol XXVB is an explanatory diagram showing an example of the intensity distribution (E) of the second laser light in the X direction. FIG. 26 is an explanatory diagram showing an example of the intensity distribution of the second laser light L2 in the XY plane of the seventh embodiment. Fig. 27 is a schematic diagram of the laser optical system of the laser processing apparatus according to the eighth embodiment. Fig. 28 is an explanatory diagram for explaining the effect of the laser processing apparatus of the eighth embodiment. 29 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system of the laser processing apparatus of the ninth embodiment relative to the wafer in the forward direction side. FIG. 30 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system of the laser processing apparatus of the ninth embodiment relative to the wafer in the return direction side. FIG. 31 is an explanatory diagram for explaining the function of the connecting optical system when the laser optical system is relatively moved with respect to the wafer in the forward direction side by the relative moving mechanism. FIG. 32 is an explanatory diagram for explaining the function of the connecting optical system when the laser optical system is relatively moved relative to the wafer in the return direction side by the relative moving mechanism. FIG. 33 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system relatively moving in the forward direction side of the wafer in Modification 1 of the ninth embodiment. FIG. 34 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system that moves relative to the wafer in the return direction side in Modification 1 of the ninth embodiment. 35 is an explanatory diagram for explaining the trimming process and the hollowing process performed by the laser optical system relatively moving in the forward direction side of the wafer in Modification 2 of the ninth embodiment. 36 is an explanatory diagram for explaining the trimming process and the hollow process performed by the laser optical system that moves relative to the wafer in the return direction side in the modification 2 of the ninth embodiment. Fig. 37 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system of the laser processing apparatus of the tenth embodiment. 38 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system of the laser processing apparatus of the eleventh embodiment relative to the wafer in the forward direction side. Fig. 39 is an enlarged view of the dotted circle K1 in Fig. 38. 40 is an explanatory diagram for explaining trimming processing and hollow processing performed by the laser optical system of the laser processing apparatus of the eleventh embodiment relative to the wafer in the return direction side. FIG. 41 is an enlarged view of the dotted circle K2 in FIG. 40. Fig. 42 is an explanatory diagram for explaining a modification of the eleventh embodiment. Fig. 43 is an explanatory diagram for explaining a modification of the third embodiment.

12: Wafer

14: chip

18: trim the ditch

19: Hollow groove

22A: 1st laser light source

22B: 2nd laser light source

24: Laser optics

32: The first light forming element

34: The second light forming element

36: Connect the switching element

38: The first condenser lens

40A: 2nd condenser lens

40B: 2nd condenser lens

47A: 1st speed shutter

47B: 2nd high speed shutter

47C: High-speed shutter drive mechanism

100A: The first safety shield

100B: 2nd safety shield

102A: Safety shutter drive mechanism

C: Cutting road

L1: 1st laser light

L2: 2nd laser light

LA, LB: Laser light

X1: Outward direction side

Claims (12)

A laser processing device that relatively moves a work table holding a wafer and a laser optical system arranged at a position opposite to the work table in the processing feed direction along the dicing path of the wafer. The laser light is irradiated on the wafer from the laser optical system, thereby performing trimming and hollowing processing for each of the dicing lanes. The trimming processing system forms two first grooves parallel to each other along the dicing lanes. The hollowing processing The second groove is formed between the two first grooves mentioned above, The aforementioned laser optics system has: The first laser light source emits laser light under the conditions corresponding to the aforementioned trimming process; The second laser light source emits laser light under the conditions corresponding to the aforementioned hollow processing; The first light forming element forms two first laser lights from the laser light emitted from the first laser light source; A second light forming element that forms second laser light from the laser light emitted from the second laser light source; The first condenser lens; Two second condensing lenses, sandwiching the first condensing lens and arranged in a row along the processing feed direction together with the first condensing lens; and The connecting optical system introduces the two first laser lights emitted from the first light forming element into the first condenser lens, and selectively introduces the second laser light emitted from the second light forming element into the two The aforementioned second condenser lens, The splicing optical system introduces the second laser light into the processing position relative to the first condenser lens when the laser optical system is relatively moved to the forward direction side of the processing feed direction with respect to the table. The second condensing lens on the return direction side of the feed direction, and when the laser optical system is relatively moved to the return direction side relative to the table, the second laser light is guided relative to the first condensing light The lens is the second condensing lens located on the side in the forward direction. A laser processing device that relatively moves a work table holding a wafer and a laser optical system arranged at a position opposite to the work table in the processing feed direction along the dicing path of the wafer. The laser light is irradiated on the wafer from the laser optical system, thereby performing trimming and hollowing processing for each of the dicing lanes. The trimming processing system forms two first grooves parallel to each other along the dicing lanes. The hollowing processing The second groove is formed between the two first grooves mentioned above, The aforementioned laser optics system has: The first laser light source emits laser light under the conditions corresponding to the aforementioned trimming process; The second laser light source emits laser light under the conditions corresponding to the aforementioned hollow processing; The first light forming element forms two first laser lights from the laser light emitted from the first laser light source; A second light forming element that forms second laser light from the laser light emitted from the second laser light source; The two first condenser lenses are arranged in a row along the aforementioned processing feed direction; The second condenser lens is arranged between the two aforementioned first condenser lenses; and The connecting optical system selectively guides the two first laser lights emitted from the first light forming element to the two first condenser lenses, and the second laser light emitted from the second light forming element Introduce the aforementioned second condenser lens, The splicing optical system guides the two first laser beams to be positioned relative to the second condenser lens when the laser optical system is relatively moved to the forward direction side of the processing feed direction with respect to the table The first condensing lens on the outgoing direction side, and when the laser optical system moves relative to the worktable to the return direction side of the processing feed direction, the two first laser beams are guided relative to The second condensing lens is the first condensing lens located on the side in the return direction. For example, the laser processing device of claim 1 or 2, which is equipped with: a first moving mechanism to make the first condensing lens be parallel to the worktable and perpendicular to the processing feed direction relative to the worktable. Relative movement; and The second moving mechanism relatively moves the second condensing lens with respect to the table in the first vertical direction. Such as the laser processing device of claim 3, where The first moving mechanism allows the first condensing lens to move relative to the worktable in the first vertical direction and the second vertical direction perpendicular to the worktable, The second moving mechanism allows the second condensing lens to move relative to the table in the first vertical direction and the second vertical direction. Such as the laser processing device of claim 1, which has: A first moving mechanism for relatively moving the first condensing lens relative to the worktable in a first vertical direction parallel to the worktable and perpendicular to the processing feed direction; and The second moving mechanism integrally moves the two second condenser lenses relative to the table in the first vertical direction. Such as the laser processing device of claim 5, where The first moving mechanism allows the first condensing lens to move relative to the worktable in the first vertical direction and a second vertical direction perpendicular to the worktable. The second moving mechanism allows the two second condensing lenses to be integrally moved relative to the table in the first vertical direction and the second vertical direction. Such as the laser processing device of claim 2, which has: A first moving mechanism for integrally moving the two first condenser lenses relative to the worktable in a first vertical direction parallel to the worktable and perpendicular to the processing feed direction; and The second moving mechanism relatively moves the second condensing lens with respect to the table in the first vertical direction. Such as the laser processing device of claim 7, where The first moving mechanism allows the two first condensing lenses to be integrally moved relative to the worktable in the first vertical direction and the second vertical direction perpendicular to the worktable, The second moving mechanism allows the second condensing lens to move relative to the table in the first vertical direction and the second vertical direction. Such as the laser processing device of claim 3, where The first moving mechanism moves the table in the first vertical direction. For example, the laser processing device of claim 3, wherein the second moving mechanism moves the worktable in the first vertical direction. Such as the laser processing device of claim 4, where The first moving mechanism moves the table in the first vertical direction and the second vertical direction. Such as the laser processing device of claim 4, where The second moving mechanism moves the table in the first vertical direction and the second vertical direction.

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