Laser light irradiation device

Abstract

To provide a laser beam emitting device that is able to efficiently emit a laser beam, emitted from a laser beam source, to an object.SOLUTION: A laser beam emitting device 1 comprises: a laser beam source 23 that emits a laser beam 21; a first polarization beam splitter 24-1 that splits the laser beam 21 into a first laser beam 21-1 of s-polarized light 211 and a second laser beam 21-2 of p-polarized light 212; a first spatial light modulator 25-1 that modulates and outputs the first laser beam 21-1 in accordance with a phase pattern; a second spatial light modulator 25-2 that modulates and outputs a second laser beam 21-2 in accordance with a phase pattern: a second polarizing beam splitter 24-2 that combines the first laser beam 21-1 output from the first spatial light modulator 25-1 and the second laser beam 21-2 output from the second spatial light modulator 25-2; and an image forming unit 27 that forms an image of the combined laser beams 21 and emits the laser beam to an object 200.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a laser light irradiation device.

Background Art

[0002] A laser light irradiation device that irradiates an object with laser light (see, for example, Patent Documents 1 and 2) is known. In such a laser light irradiation device, the laser light generated by a laser light source is modulated by a spatial light modulator and then condensed onto an object by an objective lens.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described laser light irradiation device, by increasing the energy of the laser light irradiated onto the object, it is possible to increase the number of branches of the laser light and perform processing efficiently, or to increase the irradiated area while maintaining the energy density. Therefore, a higher output of the laser light source is strongly desired.

[0005] By the way, a high-output laser light source is usually provided with random polarization. Also, the laser light incident on the spatial light modulator needs to be linearly polarized.

[0006] Therefore, when applying a high-output laser light source to the above-described laser light irradiation device, the laser light emitted from the laser light source is incident on a polarizing beam splitter (PBS) to be separated into p-polarized light and s-polarized light, and the laser light of one of the polarization components is guided to the spatial light modulator, modulated, and then irradiated onto the object.

[0007] In this case, the laser irradiation device wasted the laser light from the other polarized component, resulting in a halving of the energy of the laser light irradiated onto the target object. This presented a problem in that the laser light was not being used efficiently.

[0008] The present invention has been made in view of the above facts, and aims to provide a laser light irradiation device that can efficiently irradiate an object with laser light emitted from a laser light source. [Means for solving the problem]

[0009] To solve the above-mentioned problems and achieve the objective, the present invention provides a laser light irradiation device for irradiating an object with laser light, comprising: a laser light source that emits the laser light; a first polarization beam splitter that separates the polarization component of the laser light emitted from the laser light source into p-polarized and s-polarized components; a first spatial light modulator that receives one of the polarization components separated by the first polarization beam splitter, modulates the incident laser light according to the phase pattern, and emits it; and the first polarization beam splitter... A second spatial light modulator that receives the other polarized component and modulates the incident laser light according to the phase pattern before emitting it; a second polarized beam splitter that transmits the laser light emitted from the first spatial light modulator and reflects the laser light emitted from the second spatial light modulator, thereby combining the laser light emitted from the first spatial light modulator and the laser light emitted from the second spatial light modulator; and an imaging unit that images the laser light combined by the second polarized beam splitter and irradiates the object. The system includes a pressing member that presses the object toward the holding surface of a chuck table moved by a moving unit when irradiating it with laser light, and the pressing member is raised and lowered by a lifting unit. It is characterized by the following: In the laser beam irradiation device, The pressing member may be raised and lowered by a lifting unit attached to an arm portion on which a laser light irradiation unit comprising the laser light source, the first polarizing beam splitter, the first spatial light modulator, the second spatial light modulator, the second polarizing beam splitter, and the imaging unit is arranged. The laser beam irradiation device may be equipped with a temperature detector that detects the temperature of the object, and the temperature detector may output information indicating the temperature of the object to the control unit. In the laser beam irradiation device, The control unit may change the power density of the laser beam based on the detection result of the temperature detector. In the laser beam irradiation device described above, the pressing member is made of a material that transmits the laser beam, and the laser beam may be irradiated onto the object through the pressing member. The laser light irradiation device of the present invention is a laser light irradiation device for irradiating an object with laser light, comprising: a laser light source that emits the laser light; a first polarization beam splitter that separates the polarization component of the laser light emitted from the laser light source into p-polarized and s-polarized components; a first spatial light modulator that receives one of the polarization components separated by the first polarization beam splitter, modulates the incident laser light according to a phase pattern, and emits it; a second spatial light modulator that receives the other polarization component separated by the first polarization beam splitter, modulates the incident laser light according to a phase pattern, and emits it; and a second polarization beam splitter that transmits the laser light emitted from the first spatial light modulator and reflects the laser light emitted from the second spatial light modulator, thereby combining the laser light emitted from the first spatial light modulator and the laser light emitted from the second spatial light modulator. , applicable When irradiating the object with laser light, Moved by a mobile unit It comprises a pressing member that presses toward the holding surface of the chuck table. The imaging function of the first spatial light modulator and the imaging function of the second spatial light modulator image the laser light synthesized by the second polarizing beam splitter and irradiates the object, while the pressing member is raised and lowered by the lifting unit. It is characterized by the following: In the laser beam irradiation device, the pressing member is The laser beam irradiation unit, which comprises the laser light source, the first polarizing beam splitter, the first spatial light modulator, the second spatial light modulator, and the second polarizing beam splitter, is raised and lowered by the lifting unit attached to the arm portion where the laser beam irradiation unit is arranged. You can. The laser beam irradiation device may be equipped with a temperature detector that detects the temperature of the object, and the temperature detector may output information indicating the temperature of the object to the control unit.

[0010] The laser light irradiation apparatus may further include a first half-wave plate disposed between the first polarizing beam splitter and the first spatial light modulator, and a second half-wave plate disposed between the first polarizing beam splitter and the second spatial light modulator.

[0012] The laser light irradiation device of the present invention is a laser light irradiation device for irradiating an object with laser light, comprising: a laser light source that emits the laser light; a polarizing beam splitter that separates the polarization component of the laser light emitted from the laser light source into p-polarized and s-polarized components; a first spatial light modulator that receives one of the polarization components separated by the polarizing beam splitter, modulates the incident laser light according to a phase pattern, and emits it; a second spatial light modulator that receives the other polarization component separated by the polarizing beam splitter, modulates the incident laser light according to a phase pattern, and emits it; a first imaging unit that images the laser light emitted from the first spatial light modulator and irradiates the object; and a second imaging unit that images the laser light emitted from the second spatial light modulator and irradiates the object. When irradiating the object with the laser light, a pressing member presses the object toward the holding surface of the chuck table which is moved by the moving unit, The device is equipped with such that the conjugate plane of the laser light of one polarization component coincides with the conjugate plane of the laser light of the other polarization component. At the same time, the pressing member is raised and lowered by the lifting unit. It is characterized by the following: In the laser light irradiation device described above, the pressing member may be raised and lowered by a lifting unit attached to an arm portion on which a laser light irradiation unit comprising the laser light source, the polarizing beam splitter, the first spatial light modulator, the second spatial light modulator, the first imaging unit, and the second imaging unit is arranged. The laser light irradiation device includes a first relay optical system that emits laser light of one polarization component modulated by the first spatial light modulator toward the first imaging unit, and a second relay optical system that emits laser light of the other polarization component modulated by the second spatial light modulator toward the second imaging unit, wherein a half-wave plate may be placed between the first relay optical system and the first imaging unit, and between the second relay optical system and the second imaging unit.

[0013] The laser light irradiation device of the present invention is a laser light irradiation device for irradiating an object with laser light, comprising: a laser light source that emits the laser light; a polarizing beam splitter that separates the polarization component of the laser light emitted from the laser light source into p-polarized and s-polarized components; a first spatial light modulator that receives one of the polarization components separated by the polarizing beam splitter, modulates the incident laser light according to a phase pattern, and emits it; a second spatial light modulator that receives the other polarization component separated by the polarizing beam splitter, modulates the incident laser light according to a phase pattern, and emits it; a first imaging unit that images the laser light emitted from the first spatial light modulator and irradiates the object; and a second imaging unit that images the laser light emitted from the second spatial light modulator and irradiates the object. The first imaging unit is the imaging function of the first spatial light modulator, and the second imaging unit is the imaging function of the second spatial light modulator. It is characterized by the following. [Effects of the Invention]

[0014] This invention has the effect of efficiently irradiating an object with laser light emitted from a laser light source. [Brief explanation of the drawing]

[0015] [Figure 1] FIG. 1 is a perspective view showing a configuration example of a laser light irradiation device according to Embodiment 1. [Figure 2] FIG. 2 is a diagram schematically showing the configuration of a laser light irradiation unit and the like of the laser light irradiation device shown in FIG. 1. [Figure 3] FIG. 3 is a diagram schematically showing the configuration of a laser light irradiation unit and the like of the laser light irradiation device according to Embodiment 2. [Figure 4] FIG. 4 is a diagram schematically showing the configuration of a laser light irradiation unit and the like of the laser light irradiation device according to Embodiment 3. [Figure 5] FIG. 5 is a diagram schematically showing the configuration of a laser light irradiation unit and the like of the laser light irradiation device according to a modification of Embodiment 1. [Figure 6] FIG. 6 is a diagram schematically showing the configuration of a laser light irradiation unit and the like of the laser light irradiation device according to a modification of Embodiment 2. [Figure 7] FIG. 7 is a diagram schematically showing the configuration of a laser light irradiation unit and the like of the laser light irradiation device according to a modification of Embodiment 3. DETAILED DESCRIPTION OF THE INVENTION

[0016] Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the content described in the following embodiments. Further, the constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Also, various omissions, substitutions, or changes in the configuration can be made without departing from the gist of the present invention.

[0017] [Embodiment 1] The laser light irradiation device 1 according to Embodiment 1 of the present invention will be described based on the drawings. FIG. 1 is a perspective view showing a configuration example of the laser light irradiation device according to Embodiment 1. FIG. 2 is a diagram schematically showing the configuration of a laser light irradiation unit and the like of the laser light irradiation device shown in FIG. 1.

[0018] (Object) The laser beam irradiation device 1 shown in Figure 1 according to Embodiment 1 is a processing device that irradiates a target object 200 with laser light 21. The target object 200 of the laser beam irradiation device 1 according to Embodiment 1 comprises, for example, a rectangular substrate 201 and a plurality of semiconductor chips 202 arranged on the substrate 201. The target object 200 is flip-chip mounted on the substrate 201 by reflowing the connection bumps 203 (shown in Figure 2) of the semiconductor chips 202 with laser light 21. In Embodiment 1, the substrate 201 is, for example, a PCB (Printed Circuit Board) or a device wafer before it is divided into chips.

[0019] In Embodiment 1, the object 200 has multiple semiconductor chips 202 arranged on a substrate 201 via bumps 203. However, in the present invention, multiple semiconductor chips 202 may be stacked and bumps 203 may be provided between each semiconductor chip 202, or multiple device wafers may be stacked and joined together by bumps in a wafer-on-wafer configuration.

[0020] (Laser light irradiation device) The laser irradiation apparatus 1 shown in Figure 1 is a processing apparatus that holds the substrate 201 of the object 200 on a chuck table 10, irradiates the semiconductor chip 202 on the substrate 201 of the object 200 held on the chuck table 10 with laser light 21 to reflow the bumps 203 and mount the semiconductor chip 202 on the substrate 201. As shown in Figure 1, the laser irradiation apparatus 1 includes a chuck table 10 for holding the object 200, a laser irradiation unit 20 for irradiating the object 200 held on the chuck table 10 with laser light 21, a moving unit 30, an imaging unit 40, and a control unit 100.

[0021] The chuck table 10 holds the object 200 with a holding surface 11 parallel to the horizontal direction. The chuck table 10 is rotated by the rotational movement unit 33 of the movement unit 30 around an axis perpendicular to the holding surface 11 and parallel to the Z-axis direction which is also parallel to the vertical direction. The chuck table 10 is moved in the X-axis direction parallel to the horizontal direction by the X-axis movement unit 31 of the movement unit 30 together with the rotational movement unit 33, and moved in the Y-axis direction parallel to the horizontal direction and perpendicular to the X-axis direction by the Y-axis movement unit 32. The chuck table 10 is moved by the movement unit 30 between the processing area below the laser beam irradiation unit 20 and the loading / unloading area away from below the laser beam irradiation unit 20 where the object 200 is loaded and unloaded.

[0022] The laser beam irradiation unit 20 is a laser beam irradiation means that irradiates an object 200 held on the holding surface 11 of the chuck table 10 with laser light 21 that is absorbable by at least the semiconductor chip 202 (i.e., the object 200). In Embodiment 1, the processing head 22 of the laser beam irradiation unit 20 is located at the tip of an arm portion 4 whose base end is supported by an upright wall 3 erected from the main body of the apparatus 2, as shown in Figure 1.

[0023] As shown in Figure 2, the laser light irradiation unit 20 includes a laser light source 23 that emits laser light 21, a first polarizing beam splitter 24-1, a first spatial light modulator 25-1, a second spatial light modulator 25-2, a second polarizing beam splitter 24-2, a relay optical system 26, and an imaging unit 27.

[0024] Furthermore, the laser light source 23 emits laser light 21 whose polarization components include s-polarization 211 and p-polarization 212. Figure 2 shows the polarization components at various positions in the optical path of the laser light 21 as appropriate.

[0025] The first polarizing beam splitter 24-1 separates the polarization components of the laser light 21 emitted from the laser light source 23 into p-polarized 212 and s-polarized 211. The first polarizing beam splitter 24-1 is a polarizing beam splitter that separates the polarization components of the laser light 21. In Embodiment 1, the first polarizing beam splitter 24-1 reflects the laser light 21 of the laser light 21 emitted from the laser light source 23 that has s-polarized 211 polarization, and transmits the laser light 21 of the laser light 21 emitted from the laser light source 23 that has p-polarized 212 polarization, thereby separating the laser light 21 emitted from the laser light source 23 into s-polarized 211 laser light 21 and p-polarized 212 laser light 21. Hereafter, the laser light 21 reflected by the first polarizing beam splitter 24-1 will be referred to as the first laser light 21-1, and the laser light 21 transmitted through the first polarizing beam splitter 24-1 will be referred to as the second laser light 21-2.

[0026] In Embodiment 1, the first laser beam 21-1 of s-polarized light 211 reflected by the first polarizing beam splitter 24-1 passes through the first half-wave plate 28-1, where its polarization direction is rotated and its polarization component is changed to p-polarized light 212. Also in Embodiment 1, the second laser beam 21-2 of p-polarized light 212 that passes through the first polarizing beam splitter 24-1 is reflected by the mirror 29 and then passes through the second half-wave plate 28-2, where its polarization component is changed to s-polarized light 211.

[0027] The half-wave plates 28-1 and 28-2 change the polarization component of the laser light 21-1 and 21-2 from s-polarized 211 to p-polarized 212, and from p-polarized 212 to s-polarized 211. That is, in Embodiment 1, the laser light irradiation unit 20 further comprises a first half-wave plate 28-1 disposed between a first polarizing beam splitter 24-1 and a first spatial light modulator 25-1, and a first half-wave plate 28-1 disposed between a first polarizing beam splitter 24-1 and a second spatial light modulator 25-2. However, in the present invention, the laser light irradiation unit 20 does not need to include both half-wave plates 28-1 and 28-2.

[0028] The first spatial light modulator 25-1 receives the first laser beam 21-1, which is p-polarized 212, one of the polarization components separated by the first polarizing beam splitter 24-1 and whose polarization component has been changed by the first half-wave plate 28-1. The first spatial light modulator 25-1 modulates the incident first laser beam 21-1 according to the phase pattern and emits it. In Embodiment 1, the first spatial light modulator 25-1 is a so-called LCOS-SLM (Liquid Crystal On Silicon-Spatial Light Modulator) that modulates the optical characteristics of the first laser beam 21-1 before emitting it.

[0029] In Embodiment 1, the first spatial light modulator 25-1 has a display surface 251 that displays a phase pattern for modulating the optical properties of the first laser beam 21-1, and modulates the optical properties of the first laser beam 21-1 by reflecting the first laser beam 21-1 off the display surface 251 displaying the phase pattern. The display surface 251 is made of a liquid crystal display (LCD).

[0030] In Embodiment 1, the first spatial light modulator 25-1 is positioned such that the light distribution direction of the liquid crystal display device constituting the display surface 251 corresponds to the p-polarization 212, which is the polarization component of the incident first laser beam 21-1. The first spatial light modulator 25-1 reflects the first laser beam 21-1 off the display surface 251 and emits it toward the second polarizing beam splitter 24-2.

[0031] The second spatial light modulator 25-2 receives the second laser beam 21-2, which is the other polarization component, s-polarized 211, that has been separated by the first polarizing beam splitter 24-1 and whose polarization component has been changed by the second half-wave plate 28-2. The second spatial light modulator 25-2 modulates the incident second laser beam 21-2 according to the phase pattern and emits it. In Embodiment 1, the second spatial light modulator 25-2 is a so-called LCOS-SLM (Liquid Crystal On Silicon-Spatial Light Modulator) that modulates the optical characteristics of the first laser beam 21-1 and emits it.

[0032] In Embodiment 1, the second spatial light modulator 25-2 has a display surface 252 that displays a phase pattern for modulating the optical properties of the second laser beam 21-2, and modulates the optical properties of the second laser beam 21-2 by reflecting the second laser beam 21-2 off the display surface 252 displaying the phase pattern. The display surface 252 is made of a liquid crystal display (LCD).

[0033] In Embodiment 1, the second spatial light modulator 25-2 is positioned such that the light distribution direction of the liquid crystal display device constituting the display surface 252 corresponds to the s-polarization 211, which is the polarization component of the incident second laser beam 21-2. The second spatial light modulator 25-2 reflects the second laser beam 21-2 off the display surface 252 and emits it toward the second polarizing beam splitter 24-2.

[0034] The second polarizing beam splitter 24-2 transmits the first laser beam 21-1 emitted from the first spatial light modulator 25-1 and reflects the second laser beam 21-2 emitted from the second spatial light modulator 25-2, thereby combining the first laser beam 21-1 emitted from the first spatial light modulator 25-1 and the second laser beam 21-2 emitted from the second spatial light modulator 25-2 to emit laser beam 21 whose polarization components include p-polarization 212 and s-polarization 211. The laser beam 21 is a laser beam whose optical properties are modulated by the spatial light modulators 25-1 and 25-2 to be suitable for irradiating the object 200.

[0035] In Embodiment 1, the second polarizing beam splitter 24-2 emits the combined laser light 21 toward the relay optical system 26.

[0036] The relay optical system 26 comprises at least one well-known optical component such as a lens, and emits the laser light 21 emitted by the second polarizing beam splitter 24-2 toward the imaging unit 27.

[0037] The imaging unit 27 images the laser beam 21 synthesized by the second polarizing beam splitter 24-2 and irradiates it onto the object 200 held on the holding surface 11 of the chuck table 10. The imaging unit 27 includes an imaging lens 271 that images the laser beam 21 onto the semiconductor chip 202 of the object 200 held on the holding surface 11 of the chuck table 10, and a lens movement unit (not shown).

[0038] The imaging lens 271 is, for example, located within the processing head 22 and positioned along the Z-axis parallel to the vertical direction, facing the holding surface 11 of the chuck table 10. The imaging lens 271 is an imaging element that focuses and irradiates the object 200 held by the chuck table 10 with laser light 21.

[0039] The lens movement unit changes the distance in the Z-axis direction between the imaging lens 271 and the object 200 held on the chuck table 10. In Embodiment 1, the lens movement unit moves the imaging lens 271 along the optical axis of the laser beam 21, which is parallel to the Z-axis direction, thereby relatively changing the distance between the imaging lens 271 and the object 200 held on the chuck table 10 along the optical axis of the laser beam 21. In Embodiment 1, the lens movement unit includes a well-known ball screw that is rotatable around its axis and parallel to the Z-axis direction, a well-known pulse motor that rotates the ball screw around its axis, and a well-known guide rail that supports the imaging lens 271 so that it can move in the Z-axis direction.

[0040] Furthermore, in Embodiment 1, the laser beam irradiation unit 20 is adjusted so that the conjugate surface 301 of the first laser beam 21-1 and the conjugate surface 302 of the second laser beam 21-2 coincide. Alternatively, in order to make the conjugate surfaces 301 and 302 of the first laser beam 21-1 and the second laser beam 21-2 coincide, the optical system may be configured so that the optical path length of the first laser beam 21-1 and the optical path length of the second laser beam 21-2 are the same length, or the conjugate surfaces 301 and 302 may be made to coincide by controlling the phase patterns displayed by the first spatial light modulator 25-1 and the second spatial light modulator 25-2. In Embodiment 1, the conjugate surfaces 301 and 302 are formed between the second polarizing beam splitter 24-2 and the relay optical system 26.

[0041] The laser irradiation unit 20 irradiates the object 200 held on the chuck table 10 with laser light 21 of a wavelength absorbed by at least the semiconductor chip 202 of the object 200, heating the semiconductor chip 202, reflowing the bumps 203, and mounting (bonding and fixing) the semiconductor chip 202 onto the substrate 201.

[0042] The moving unit 30 moves the chuck table 10 and the machining head 22 of the laser beam irradiation unit 20 relative to each other around axes parallel to the X-axis, Y-axis, and Z-axis directions. The X-axis and Y-axis directions are mutually orthogonal and parallel to the holding surface 11 (i.e., the horizontal direction). The moving unit 30 includes an X-axis moving unit 31, which is a machining feed unit that moves the chuck table 10 in the X-axis direction; a Y-axis moving unit 32, which is an indexing feed unit that moves the chuck table 10 in the Y-axis direction; and a rotational moving unit 33 that rotates the chuck table 10 around an axis parallel to the Z-axis direction.

[0043] The Y-axis movement unit 32 is an indexing feed unit that moves the chuck table 10 and the processing head 22 of the laser beam irradiation unit 20 relative to each other in the Y-axis direction. In Embodiment 1, the Y-axis movement unit 32 is installed on the main body 2 of the laser beam irradiation device 1. The Y-axis movement unit 32 supports the movable plate 5 that supports the X-axis movement unit 31 so as to be movable in the Y-axis direction.

[0044] The X-axis movement unit 31 is a machining feed unit that moves the chuck table 10 and the machining head 22 of the laser beam irradiation unit 20 relative to each other in the X-axis direction. The X-axis movement unit 31 is installed on a moving plate 5. The X-axis movement unit 31 supports a second moving plate 6 that is movable in the X-axis direction, and the second moving plate 6 supports a rotary movement unit 33 that rotates the chuck table 10 around an axis parallel to the Z-axis direction. The second moving plate 6 supports the rotary movement unit 33 and the chuck table 10. The rotary movement unit 33 supports the chuck table 10.

[0045] The X-axis movement unit 31 and the Y-axis movement unit 32 are equipped with a well-known ball screw rotatably mounted around its axis, a well-known pulse motor for rotating the ball screw around its axis, and a well-known guide rail for supporting the movement plates 5 and 6 so that they can move in the X-axis direction or the Y-axis direction. The rotational movement unit 33 is equipped with a motor for rotating the chuck table 10 around its axis, etc.

[0046] Furthermore, the laser beam irradiation device 1 includes an X-axis position detection unit (not shown) for detecting the X-axis position of the chuck table 10, a Y-axis position detection unit (not shown) for detecting the Y-axis position of the chuck table 10, and a Z-axis position detection unit (not shown) for detecting the Z-axis position of the laser beam irradiation unit 20. Each position detection unit outputs its detection result to the control unit 100.

[0047] Furthermore, the laser beam irradiation device 1 includes a lens position detection unit (not shown) for detecting the Z-axis position of the imaging lens 271 of the laser beam irradiation unit 20. The lens position detection unit outputs the detection result to the control unit 100.

[0048] The imaging unit 40 images the object 200 held on the chuck table 10. The imaging unit 40 is equipped with an image sensor such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary MOS) image sensor whose objective lens is facing in the Z-axis direction. In Embodiment 1, the imaging unit 40 is located at the tip of the arm portion 4, as shown in Figure 1.

[0049] The imaging unit 40 acquires the image captured by the image sensor and outputs the acquired image to the control unit 100. The imaging unit 40 also images the object 200 held on the holding surface 11 of the chuck table 10 and acquires an image for performing alignment, which involves aligning the object 200 with the imaging lens 271 of the laser beam irradiation unit 20.

[0050] Furthermore, the laser beam irradiation device 1 is equipped with a temperature detector 50 and a pressing member 60, etc. The temperature detector 50 detects the temperature of the object 200 held on the holding surface 11 of the chuck table 10. The temperature detector 50 is configured, for example, to have an infrared camera. The temperature detector 50 outputs information indicating the temperature of the detected object 200 to the control unit 100. In Embodiment 1, the temperature detector 50 is positioned in the X-axis direction, aligned with the imaging unit 40 at the tip of the arm portion 4.

[0051] The pressing member 60 presses the semiconductor chip 202 of the object 200 held by the chuck table 10 toward the holding surface 11 of the chuck table 10 with its lower surface 61. The pressing member 60 is positioned between the arm portion 4 and the chuck table 10, and its lower surface 61 is formed flat along the horizontal direction. The pressing member 60 is made of a material that transmits laser light 21 (for example, quartz glass). The pressing member 60 is raised and lowered along the Z-axis direction by a lifting unit 62 attached to the arm portion 4.

[0052] The control unit 100 controls each of the above-mentioned components of the laser beam irradiation device 1 to cause the laser beam irradiation device 1 to perform processing operations on the target object 200. The control unit 100 is a computer having an arithmetic processing unit with a microprocessor such as a CPU (central processing unit), a storage device with memory such as ROM (read-only memory) or RAM (random access memory), and an input / output interface device. The arithmetic processing unit of the control unit 100 performs calculations according to the computer program stored in the storage device and outputs control signals for controlling the laser beam irradiation device 1 to the above-mentioned components of the laser beam irradiation device 1 via the input / output interface device, thereby realizing the function of the control unit 100.

[0053] Furthermore, the laser beam irradiation device 1 includes a display unit, which is a display means consisting of a liquid crystal display device that displays the status of processing operations and images, and an input unit, which is an input means used by the operator to input processing conditions, etc. The display unit and the input unit are connected to the control unit 100. The input unit consists of at least one of a touch panel provided on the display unit and an external input device such as a keyboard.

[0054] Next, the processing operation of the laser irradiation device 1 with the configuration described above will be explained. In the laser irradiation device 1, the control unit 100 receives and registers the processing conditions input by the operator, and the object 200 is placed on the holding surface 11 of the chuck table 10 positioned in the loading / unloading area. When the control unit 100 receives a processing start instruction from the operator, the laser irradiation device 1 starts the processing operation.

[0055] During the processing operation, the laser irradiation device 1 uses a control unit 100 to control the movement unit 30 to move the chuck table 10 to the processing area, and the imaging unit 40 captures an image of the object 200 held by suction on the chuck table 10 to acquire an image and perform alignment. During the processing operation, the laser irradiation device 1 uses a control unit 100 to control the movement unit 30 and the laser irradiation unit 20 to move the processing head 22 of the laser irradiation unit 20 and the chuck table 10 relatively according to the processing conditions, while irradiating the semiconductor chip 202 of the object 200 with laser light 21 to reflow the bumps 203 and bond the semiconductor chip 202 to the substrate 201.

[0056] In Embodiment 1, during the processing operation, when the laser irradiation device 1 irradiates the semiconductor chip 202 with laser light 21, the lifting unit 62 lowers the pressing member 60, and the lower surface 61 of the pressing member 60 presses the semiconductor chip 202 of the object 200 on the chuck table 10 toward the holding surface 11 of the chuck table 10, thereby irradiating the object 200 with laser light 21 through the pressing member 60. In Embodiment 1, during the processing operation, the control unit 100 may change the laser power density of the laser light 21, etc., based on the detection result of the temperature detector 50, in order to suppress damage to the semiconductor chip 202, etc.

[0057] Furthermore, in Embodiment 1, during the processing operation, the laser irradiation device 1 irradiates one semiconductor chip 202 at a time with laser light 21, but in the present invention, multiple semiconductor chips 202 may be irradiated with laser light 21 at a time. The laser irradiation device 1 terminates the processing operation when it has irradiated all the semiconductor chips 202 of the object 200 held on the chuck table 10 with laser light 21 and bonded them to the substrate 201.

[0058] As described above, the laser light irradiation device 1 according to Embodiment 1 separates the laser light 21 into a first laser light 21-1 with s polarization 211 and a second laser light 21-2 with p polarization 212 using a first polarizing beam splitter 24-1. Then, the laser lights 21-1 and 21-2 with their respective polarization components are incident on different spatial light modulators 25-1 and 25-2. The laser lights 21-1 and 21-2 modulated by the spatial light modulators 25-1 and 25-2 are combined by the second polarizing beam splitter 24-2 and irradiated onto the target object 200. As a result, the laser light irradiation device 1 according to Embodiment 1 can suppress the halving of the energy of the laser light 21 irradiated onto the target object 200, and has the effect of efficiently irradiating the target object 200 with the laser light 21 emitted from the laser light source 23.

[0059] [Embodiment 2] A laser light irradiation device 1 according to Embodiment 2 will be described based on the drawings. Figure 3 is a schematic diagram showing the configuration of the laser light irradiation unit and other components of the laser light irradiation device according to Embodiment 2. In Figure 3, the same reference numerals are used for the same parts as in Embodiment 1, and their descriptions are omitted. As with Figure 2, the polarization components at each position in the optical path of the laser light 21 are indicated as appropriate. The laser light irradiation device 1 according to Embodiment 2 is the same as in Embodiment 1 except for the configuration of the laser light irradiation unit 20.

[0060] As shown in Figure 3, the laser light irradiation unit 20-1 of the laser light irradiation device 1 according to Embodiment 2 comprises a laser light source 23 that emits laser light 21, a polarizing beam splitter 24, a first spatial light modulator 25-1, a second spatial light modulator 25-2, a first relay optical system 26-1, a second relay optical system 26-2, a first imaging unit 27-1, and a second imaging unit 27-2.

[0061] In Embodiment 2, the polarizing beam splitter 24 has the same configuration as the first polarizing beam splitter 24-1 in Embodiment 1. In Embodiment 2, the polarizing beam splitter 24 reflects the laser light 21 emitted from the laser light source 23, specifically the laser light 21 with the s-polarized component 211 toward the first spatial light modulator 25-1, and transmits the second laser light 21-2 with the p-polarized component 212, thereby separating the laser light 21 into the first laser light 21-1 with the s-polarized component 211 and the second laser light 21-2 with the p-polarized component 212.

[0062] In Embodiment 2, the first laser beam 21-1 of s-polarization 211 reflected by the polarizing beam splitter 24 is irradiated onto the display surface 251 of the first spatial light modulator 25-1. Also in Embodiment 2, the second laser beam 21-2 of p-polarization 212 transmitted through the polarizing beam splitter 24 is reflected by the mirror 29 and then irradiated onto the display surface 252 of the second spatial light modulator 25-2.

[0063] The first spatial light modulator 25-1 is a so-called LCOS-SLM that receives the first laser beam 21-1 of s-polarization 211, which is one of the polarization components separated by the polarizing beam splitter 24, modulates the incident first laser beam 21-1 according to the phase pattern, and emits it. In Embodiment 2, the first spatial light modulator 25-1 reflects the first laser beam 21-1 at the display surface 251, modulates the optical characteristics of the first laser beam 21-1, and emits it toward the first relay optical system 26-1.

[0064] The second spatial light modulator 25-2 is a so-called LCOS-SLM that receives the second laser beam 21-2, which is the other polarization component separated by the polarizing beam splitter 24 (p-polarized 212), modulates the incident second laser beam 21-2 according to the phase pattern, and emits it. In Embodiment 2, the second spatial light modulator 25-2 reflects the second laser beam 21-2 off the display surface 252 to modulate the optical characteristics of the second laser beam 21-2 before emission. In Embodiment 2, the second laser beam 21-2, whose optical characteristics have been modified by the second spatial light modulator 25-2, is reflected by the mirror 29-1 towards the second relay optical system 26-2.

[0065] The first relay optical system 26-1 emits a first laser beam 21-1, whose optical properties have been modulated by the first spatial light modulator 25-1, toward the first imaging unit 27-1. The second relay optical system 26-2 emits a second laser beam 21-2, whose optical properties have been modulated by the second spatial light modulator 25-2, toward the second imaging unit 27-2. Similar to the relay optical system 26 of Embodiment 1, the relay optical systems 26-1 and 26-2 include at least one well-known optical component such as a lens.

[0066] The first imaging unit 27-1 images the first laser beam 21-1 emitted from the first spatial light modulator 25-1 and irradiates the object 200 held on the holding surface 11 of the chuck table 10. The second imaging unit 27-2 images the second laser beam 21-2 emitted from the second spatial light modulator 25-2 and irradiates the object 200 held on the holding surface 11 of the chuck table 10. The imaging units 27-1 and 27-2 image the mutually independent laser beams 21-1 and 21-2, separated from the laser beam 21 by the polarizing beam splitter 24, onto the object 200 held on the holding surface 11 of the chuck table 10. In other words, in Embodiment 2, the laser beam irradiation unit 20 irradiates the object 200 with two laser beams 21-1 and 21-2 at once.

[0067] Each imaging unit 27-1, 27-2, similar to the imaging unit 27 of Embodiment 1, includes an imaging lens 271 that focuses laser light 21-1, 21-2 onto a semiconductor chip 202 of an object 200 held on the holding surface 11 of the chuck table 10, and a lens moving unit (not shown).

[0068] The imaging lens 271 is, for example, located within the processing head 22 and positioned along the Z-axis parallel to the vertical direction, facing the holding surface 11 of the chuck table 10. The imaging lens 271 is an imaging element that focuses and irradiates the object 200 held by the chuck table 10 with laser beams 21-1 and 21-2.

[0069] The lens movement unit changes the distance in the Z-axis direction between the imaging lens 271 and the object 200 held on the chuck table 10. In Embodiment 1, the lens movement unit moves the imaging lens 271 along the optical axes of laser beams 21-1 and 21-2, which are parallel to the Z-axis direction, thereby relatively changing the distance between the imaging lens 271 and the object 200 held on the chuck table 10 along the optical axes of laser beams 21-1 and 21-2.

[0070] Furthermore, in Embodiment 2, the laser beam irradiation unit 20 is adjusted so that the conjugate surface 301 of the first laser beam 21-1 and the conjugate surface 302 of the second laser beam 21-2 coincide. Alternatively, in order to make the conjugate surface 301 of the first laser beam 21-1 and the conjugate surface 302 of the second laser beam 21-2 coincide, the optical system may be configured so that the optical path length of the first laser beam 21-1 and the optical path length of the second laser beam 21-2 are the same length, or the conjugate surfaces 301 and 302 may be made to coincide by controlling the phase patterns displayed on the first spatial light modulator 25-1 and the second spatial light modulator 25-2. In Embodiment 2, the conjugate surface 301 is formed between the first spatial light modulator 25-1 and the first relay optical system 26-1, and the conjugate surface 302 is formed between the mirror 29-1 and the second relay optical system 26-2. Furthermore, in Embodiment 2 of the present invention, the conjugate surfaces 301 and 302 do not need to coincide, and the positions of the conjugate surfaces 301 and 302 may be adjusted to match the irradiated areas of the object to be irradiated with the first laser beam 21-1 and the object to be irradiated with the second laser beam 21-2, respectively.

[0071] In Embodiment 2, the laser irradiation unit 20 irradiates the object 200 held on the chuck table 10 with two laser beams 21-1 and 21-2 of wavelengths absorbed by at least the semiconductor chip 202 of the object 200, thereby heating the semiconductor chip 202, reflowing the bumps 203, and mounting (bonding and fixing) the semiconductor chip 202 onto the substrate 201.

[0072] The laser light irradiation device 1 according to Embodiment 2 separates the laser light 21 into a first laser light 21-1 with s polarization 211 and a second laser light 21-2 with p polarization 212 using a polarizing beam splitter 24. Then, the laser lights 21-1 and 21-2 of each polarization component are incident on different spatial light modulators 25-1 and 25-2, and the laser lights 21-1 and 21-2 modulated by the spatial light modulators 25-1 and 25-2 are irradiated onto the target object 200, respectively. As a result, the laser light irradiation device 1 according to Embodiment 2 can suppress the halving of the energy of the laser light 21 irradiated onto the target object 200, and has the effect of efficiently irradiating the target object 200 with the laser light 21 emitted from the laser light source 23.

[0073] [Embodiment 3] A laser beam irradiation device 1 according to Embodiment 3 will be described based on the drawings. Figure 4 is a schematic diagram showing the configuration of the laser beam irradiation unit and other components of the laser beam irradiation device according to Embodiment 3. In Figure 4, the same reference numerals are used for the same parts as in Embodiment 2, and their descriptions are omitted. As with Figure 2, the polarization components at each position in the optical path of the laser beam 21 are indicated as appropriate.

[0074] The laser light irradiation unit 20-2 of the laser light irradiation device 1 according to Embodiment 3 is the same as Embodiment 2, except that a half-wave plate 28 is placed between the first relay optical system 26-1 and the first imaging unit 27-1, and between the second relay optical system 26-2 and the second imaging unit 27-2. The configuration of the half-wave plate 28 is the same as the configuration of the half-wave plates 28-1 and 28-2 of Embodiment 1.

[0075] In the laser irradiation unit 20-2 of the laser light irradiation device 1 according to Embodiment 3, a half-wave plate 28 is placed between the second relay optical system 26-2 and the second imaging unit 27-2. The half-wave plate 28 changes the polarization component of the second laser light 21-2 from p-polarization 212 to s-polarization 211. The laser light irradiation unit 20 of the laser light irradiation device 1 according to Embodiment 3 irradiates the object 200 with two s-polarized laser beams 21-1 and 21-2 at once.

[0076] The laser beam irradiation device 1 according to Embodiment 3 separates the laser beam 21 into a first laser beam 21-1 with s polarization 211 and a second laser beam 21-2 with p polarization 212 using a polarizing beam splitter 24, and then irradiates the target object 200 with the modulated laser beams 21-1 and 21-2, respectively, using spatial light modulators 25-1 and 25-2. Therefore, similar to Embodiment 2, it has the effect of efficiently irradiating the target object 200 with the laser beam 21 emitted from the laser light source 23.

[0077] Furthermore, the laser light irradiation apparatus 1 according to Embodiment 3 can suitably perform processing even in cases where the polarization direction affects the processing result, such as SD (Stealth Dicing) processing for forming a modified layer, because the polarization directions of the two laser beams 21-1 and 21-2 are aligned.

[0078] Furthermore, the laser light irradiation device 1 according to Embodiments 1, 2, and 3 may be used for SD (Stealth Dicing) processing, which involves focusing laser light of a wavelength that the object can transmit into the object, and forming a modified layer or the like inside the object.

[0079] [Variation] A modified example of the laser light irradiation device 1 will be described based on the drawings. Figure 5 is a schematic diagram showing the configuration of the laser light irradiation unit, etc., of the modified example of the laser light irradiation device of Embodiment 1. Figure 6 is a schematic diagram showing the configuration of the laser light irradiation unit, etc., of the modified example of the laser light irradiation device of Embodiment 2. Figure 7 is a schematic diagram showing the configuration of the laser light irradiation unit, etc., of the modified example of the laser light irradiation device of Embodiment 3. In addition, in Figures 5, 6 and 7, the same reference numerals are used for the same parts as in Embodiments 1, 2 and 3, and their descriptions are omitted. As with Figure 2, the polarization components at each position in the optical path of the laser light 21 are indicated as appropriate.

[0080] Furthermore, the modified laser beam irradiation device 1 shown in Figures 5, 6, and 7 does not include imaging units 27, 27-1, and 27-2. Instead, it displays an imaging-enabled phase pattern on the display surface 251 of spatial light modulators 25-1 and 25-2, which modulate the optical properties of the laser beams 21-1 and 21-2 before emission, thereby imaging the laser beams 21-1 and 21-2 and irradiating them onto the target object 200. For this reason, in the modified example shown in Figure 5, the imaging unit that images the laser beam 21 synthesized by the second polarizing beam splitter 24-2 and irradiates it onto the target object 200 consists of the imaging function of the first spatial light modulator 25-1 and the imaging function of the second spatial light modulator 25-2. Furthermore, in the modified examples shown in Figures 6 and 7, the first imaging unit that images the first laser beam 21-1 emitted from the first spatial light modulator 25-1 and irradiates it onto the object 200 is the imaging function of the first spatial light modulator 25-1, and the second imaging unit that images the second laser beam 21-2 emitted from the second spatial light modulator 25-2 and irradiates it onto the object 200 is the imaging function of the second spatial light modulator 25-2. In addition, in the modified examples shown in Figures 5, 6 and 7, imaging units 27, 27-1 and 27-2 may be provided, similar to Embodiments 1, 2 and 3. That is, in the present invention, at least one of the imaging units 27, 27-1 and 27-2 and the spatial light modulators 25-1 and 25-2 only needs to image the laser beams 21, 21-1 and 21-2.

[0081] It should be noted that the present invention is not limited to the embodiments described above. That is, it can be implemented with various modifications without departing from the core principles of the present invention. [Explanation of symbols]

[0082] 1. Laser beam irradiation device 21 Laser light 21-1 First laser beam (laser light) 21-2 Second laser beam (laser light) 23 Laser light source 24 Polarizing Beam Splitter 24-1 First Polarizing Beam Splitter 24-2 Second Polarizing Beam Splitter 25-1 First spatial light modulator (imaging unit, first imaging unit) 25-2 Second spatial light modulator (imaging unit, second imaging unit) 27 Imaging Unit 27-1 First imaging unit 27-2 Second imaging unit 28-1 First half-wave plate 28-2 Second half-wave plate 200 Objects 211 s polarization 212p polarized light

Claims

1. A laser beam irradiation device that irradiates an object with laser light, A laser light source that emits the laser light, A first polarization beam splitter separates the polarization components of the laser light emitted from the laser light source into p-polarized and s-polarized components, A first spatial light modulator receives one of the polarization components separated by the first polarization beam splitter, modulates the incident laser light according to the phase pattern, and emits it. A second spatial light modulator receives the other polarization component separated by the first polarization beam splitter, modulates the incident laser light according to the phase pattern, and emits it. A second polarizing beam splitter transmits the laser light emitted from the first spatial light modulator and reflects the laser light emitted from the second spatial light modulator, thereby combining the laser light emitted from the first spatial light modulator and the laser light emitted from the second spatial light modulator. An imaging unit that images the laser light synthesized by the second polarizing beam splitter and irradiates it onto the target object, When irradiating the object with the laser light, a pressing member presses the object toward the holding surface of the chuck table which is moved by the moving unit, Equipped with, A laser beam irradiation device characterized in that the pressing member is raised and lowered by a lifting unit.

2. The laser light irradiation device according to Claim 1, characterized in that the pressing member is raised and lowered by a lifting unit attached to an arm portion on which a laser light irradiation unit comprising the laser light source, the first polarizing beam splitter, the first spatial light modulator, the second spatial light modulator, the second polarizing beam splitter, and the imaging unit is arranged.

3. A temperature detector is provided to detect the temperature of the object, The laser light irradiation device according to claim 1, characterized in that the temperature detector outputs information indicating the temperature of the object to the control unit.

4. The laser beam irradiation device according to claim 3, characterized in that the control unit changes the power density of the laser beam based on the detection result of the temperature detector.

5. The laser beam irradiation device according to claim 1, characterized in that the pressing member is made of a material that transmits the laser beam, and the laser beam is irradiated onto the object through the pressing member.

6. A laser beam irradiation device that irradiates an object with laser light, A laser light source that emits the laser light, A first polarization beam splitter separates the polarization components of the laser light emitted from the laser light source into p-polarized and s-polarized components, A first spatial light modulator receives one of the polarization components separated by the first polarization beam splitter, modulates the incident laser light according to the phase pattern, and emits it. A second spatial light modulator receives the other polarization component separated by the first polarization beam splitter, modulates the incident laser light according to the phase pattern, and emits it. A second polarizing beam splitter transmits the laser light emitted from the first spatial light modulator and reflects the laser light emitted from the second spatial light modulator, thereby combining the laser light emitted from the first spatial light modulator and the laser light emitted from the second spatial light modulator. The device includes a pressing member that presses the object toward the holding surface of a chuck table moved by a moving unit when irradiating it with laser light, The imaging function of the first spatial light modulator and the imaging function of the second spatial light modulator are used to image the laser light synthesized by the second polarizing beam splitter and irradiate the target object, A laser beam irradiation device characterized in that the pressing member is raised and lowered by a lifting unit.

7. The laser beam irradiation device according to claim 6, characterized in that the pressing member is raised and lowered by a lifting unit attached to an arm portion on which a laser beam irradiation unit comprising the laser light source, the first polarizing beam splitter, the first spatial light modulator, the second spatial light modulator, and the second polarizing beam splitter is arranged.

8. It is equipped with a temperature detector that detects the temperature of the object, The laser light irradiation device according to claim 6, characterized in that the temperature detector outputs information indicating the temperature of the object to the control unit.

9. A first half-wave plate is disposed between the first polarizing beam splitter and the first spatial light modulator, The system further comprises a second half-wave plate disposed between the first polarizing beam splitter and the second spatial light modulator. A laser light irradiation device according to any one of claims 1 to 8.

10. A laser beam irradiation device that irradiates an object with laser light, A laser light source that emits the laser light, A polarization beam splitter that separates the polarization component of the laser light emitted from the laser light source into p-polarized and s-polarized components, A first spatial light modulator receives one of the polarization components separated by the polarization beam splitter, modulates the incident laser light according to the phase pattern, and emits it. A second spatial light modulator receives the other polarization component separated by the polarization beam splitter, modulates the incident laser light according to the phase pattern, and emits it. A first imaging unit that images the laser light emitted from the first spatial light modulator and irradiates it onto the target object, A second imaging unit that images the laser light emitted from the second spatial light modulator and irradiates it onto the target object, When irradiating the object with the laser light, a pressing member presses the object toward the holding surface of the chuck table which is moved by the moving unit, Equipped with, The conjugate plane of the laser light of one polarization component coincides with the conjugate plane of the laser light of the other polarization component, A laser beam irradiation device characterized in that the pressing member is raised and lowered by a lifting unit.

11. The laser light irradiation device according to claim 10, characterized in that the pressing member is raised and lowered by a lifting unit attached to an arm portion on which a laser light irradiation unit comprising the laser light source, the polarizing beam splitter, the first spatial light modulator, the second spatial light modulator, the first imaging unit, and the second imaging unit is arranged.

12. A first relay optical system that emits laser light of one polarization component modulated by the first spatial light modulator toward the first imaging unit, The system comprises a second relay optical system that emits laser light of the other polarization component, modulated by the second spatial light modulator, toward the second imaging unit, The laser light irradiation apparatus according to claim 10, characterized in that a half-wave plate is placed between the first relay optical system and the first imaging unit, and between the second relay optical system and the second imaging unit.

13. A laser beam irradiation device that irradiates an object with laser light, A laser light source that emits the laser light, A polarization beam splitter that separates the polarization component of the laser light emitted from the laser light source into p-polarized and s-polarized components, A first spatial light modulator receives one of the polarization components separated by the polarization beam splitter, modulates the incident laser light according to the phase pattern, and emits it. A second spatial light modulator receives the other polarization component separated by the polarization beam splitter, modulates the incident laser light according to the phase pattern, and emits it. A first imaging unit that images the laser light emitted from the first spatial light modulator and irradiates it onto the target object, A second imaging unit that images the laser light emitted from the second spatial light modulator and irradiates it onto the target object, Equipped with, A laser light irradiation device characterized in that the first imaging unit is the imaging function of the first spatial light modulator, and the second imaging unit is the imaging function of the second spatial light modulator.

Images