Laser processing apparatus, method for controlling laser processing apparatus, and method for manufacturing electronic device

Abstract

A laser processing apparatus according to one aspect of the present disclosure comprises: a first actuator that moves a light-shielding plate in a direction orthogonal to an optical axis of a condensing optical system; a second actuator that can generate a high-density pattern with high-density light-condensing spots by moving a multi-spot pattern at a moving pitch shorter than a grid interval; and a third actuator that moves a workpiece in a direction orthogonal to the optical axis. At each of a plurality of step positions in a processing area that is changed by controlling the third actuator so that hole processing is performed only in a processing area requiring hole processing on a surface of the workpiece, the first actuator is controlled to select one of at least four high-density patterns which are different from each other in the number of rows or the number of columns, and the second actuator and a laser device are controlled so that the selected pattern is irradiated.

Description

Laser processing apparatus, control method for laser processing apparatus, and method for manufacturing electronic device

[0001] The present disclosure relates to a laser processing apparatus, a control method for a laser processing apparatus, and a manufacturing method for an electronic device.

[0002] In recent years, semiconductor exposure apparatuses have been required to improve their resolution in response to the miniaturization and high integration of semiconductor integrated circuits. To this end, the wavelength of light emitted from exposure light sources has been shortened. For example, KrF excimer laser devices that output laser light with a wavelength of approximately 248.4 nm and ArF excimer laser devices that output laser light with a wavelength of approximately 193.4 nm are used as gas laser devices for exposure.

[0003] Furthermore, excimer laser light has a pulse width of approximately several tens of nanoseconds and a short wavelength, and is therefore sometimes used for direct processing of polymeric materials, glass materials, and the like.

[0004] Chemical bonds in polymeric materials can be cut by excimer laser light, which has a photon energy higher than the bond energy. Therefore, it is known that excimer laser light enables non-heating processing of polymeric materials, resulting in clean processed shapes.

[0005] Furthermore, it is known that glass, ceramics, and the like have a high absorptivity for excimer laser light, so that even materials that are difficult to process with visible or infrared laser light can be processed with excimer laser light.

[0006] The spectral linewidth of the spontaneously oscillating light of KrF excimer laser devices and ArF excimer laser devices is wide, ranging from 350 pm to 400 pm. Therefore, constructing a projection lens using a material that transmits ultraviolet light, such as KrF and ArF laser light, can result in chromatic aberration. This can result in a decrease in resolution. Therefore, it is necessary to narrow the spectral linewidth of the laser light output from a gas laser device to a level where chromatic aberration is negligible. Therefore, a line narrowing module (LNM) containing a line narrowing element (e.g., an etalon or grating) may be installed within the laser resonator of the gas laser device to narrow the spectral linewidth. Hereinafter, a gas laser device with a narrowed spectral linewidth is referred to as a line narrowing gas laser device.

[0007] US Patent Application Publication No. 2006 / 0289412 JP 2007-268600 A JP 2011-161454 A US Patent Application Publication No. 2003 / 201578 A overview

[0008] a focusing optical system that focuses the plurality of second laser beams to generate a grid-like multi-point pattern in which a plurality of focused spots are arranged in row and column directions; a light blocking plate that can block at least a portion of the multi-point pattern; a first actuator that moves the light blocking plate in a direction perpendicular to the optical axis of the focusing optical system; a second actuator that can generate a high-density pattern in which the focused spots are densified by moving the multi-point pattern at a movement pitch shorter than the grid spacing; a third actuator that moves the workpiece in a direction perpendicular to the optical axis; and a laser processing processor that controls the first actuator to select one of at least four high-density patterns having different numbers of rows or columns at each of a plurality of step positions in a processing area that are changed by controlling the third actuator so that hole processing is performed only in processing areas that require hole processing on the surface of the workpiece, and controls the second actuator and the laser device so that the selected pattern is irradiated.

[0009] a focusing optical system that focuses the plurality of second laser beams to generate a grid-like multi-point pattern in which a plurality of focused spots are arranged in row and column directions; a light blocking plate that can block at least a portion of the multi-point pattern; a first actuator that moves the light blocking plate in a direction perpendicular to the optical axis of the focusing optical system; a second actuator that can move the multi-point pattern at a movement pitch shorter than the grid spacing to generate a high-density pattern in which the focused spots are densified; and a third actuator that moves the workpiece in a direction perpendicular to the optical axis, the method comprising: a laser processing processor that controls the third actuator to change a plurality of step positions in a processing area so that hole processing is performed only in processing areas requiring hole processing on the surface of the workpiece, and a laser processing processor that controls the first actuator to select one of at least four high-density patterns having different numbers of rows or columns, and controls the second actuator and the laser device so that the selected pattern is irradiated.

[0010] A method for manufacturing an electronic device according to one aspect of the present disclosure is a method for manufacturing an electronic device, comprising: a diffractive optical element that splits a first laser beam output from a laser device into a plurality of second laser beams and emits the split laser beams; a focusing optical system that focuses the plurality of second laser beams to generate a grid-like multi-point pattern in which a plurality of focused spots are arranged in row and column directions; a light-blocking plate that can block at least a portion of the multi-point pattern; a first actuator that moves the light-blocking plate in a direction perpendicular to the optical axis of the focusing optical system; a second actuator that can generate a high-density pattern in which the focused spots are densified by moving the multi-point pattern at a movement pitch shorter than the grid interval; a third actuator that moves a workpiece in a direction perpendicular to the optical axis; and a laser processing processor that controls a second actuator and a laser device to irradiate the selected pattern by controlling a first actuator to select one of at least four high-density patterns having different numbers of rows or columns at each of a plurality of step positions in a processing area that are changed by controlling a third actuator so that hole processing is performed only in the processing area that requires hole processing; forming a plurality of through holes in a glass substrate as a workpiece by a laser processing device that includes the laser processing processor; bonding an interposer having a glass substrate and conductors provided in each of the plurality of through holes to an integrated circuit chip to electrically connect them to each other; and bonding the interposer to a circuit board to electrically connect them to each other.

[0011] Some embodiments of the present disclosure are described below, by way of example only, with reference to the accompanying drawings. FIG. 1 is a diagram schematically illustrating the configuration of a laser processing system 1 according to a comparative example. FIG. 2 is a diagram schematically illustrating the configuration of a laser apparatus 2. FIG. 3 is a diagram schematically illustrating the operation flow of the laser processing system 1 according to the comparative example. FIG. 4 is a diagram illustrating details of a processing condition reading process. FIG. 5 is a diagram illustrating details of a fluence adjustment process. FIG. 6 is a diagram illustrating details of a simultaneous multi-point hole drilling process. FIG. 7 is a diagram illustrating an example of a multi-point pattern MP generated by a DOE 50 and a focusing optical system 51. FIG. 8 is a diagram illustrating an example of a first table A. FIG. 9 is a diagram illustrating an example of multiple step positions of the multi-point pattern MP on a surface 45a of a workpiece 45. FIG. 10 is a diagram schematically illustrating the operation flow of a laser processing system according to a densification technique. FIG. 11 is a diagram illustrating details of a high-density hole drilling process. FIG. 12 is a diagram illustrating details of a high-density pattern HP irradiation process. FIG. 13 is a diagram illustrating an example of a high-density pattern HP. FIG. 14 is a diagram illustrating an example of a second table B. FIG. 15 is a diagram showing an example of multiple step positions of a high-density pattern HP on the surface 45a of a workpiece 45. FIG. 16 is a diagram showing a schematic configuration of a laser processing system 1a according to the first embodiment. FIG. 17 is a diagram showing a schematic flow of the operation of the laser processing system 1a. FIG. 18 is a diagram showing details of the generation and storage process of the first table A. FIG. 19 is a diagram showing an example of a high-density pattern HP(1). FIG. 20 is a diagram showing an example of a high-density pattern HP(2). FIG. 21 is a diagram showing an example of a high-density pattern HP(3). FIG. 22 is a diagram showing an example of a high-density pattern HP(4). FIG. 23 is a diagram showing examples of the first to fourth areas R1 to R4. FIG. 24 is a diagram showing an example of the first table A. FIG. 25 is a diagram showing details of the generation and storage process of the second table B(s). FIG. 26 is a diagram showing an example of the second table B(1). FIG. 27 is a diagram showing an example of the position of the light-shielding plate 60 associated with the second table B(1). FIG. 28 is a diagram showing an example of the second table B(2). FIG. 29 is a diagram showing an example of the position of the light blocking plate 60 associated with the second table B(2).FIG. 30 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(2). FIG. 31 is a diagram showing an example of the second table B(3). FIG. 32 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(3). FIG. 33 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(3). FIG. 34 is a diagram showing an example of the second table B(4). FIG. 35 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(4). FIG. 36 is a diagram showing details of the high-density hole drilling process according to the first embodiment. FIG. 37 is a diagram showing details of the irradiation process of the high-density pattern HP(s) according to the first embodiment. FIG. 38 is a diagram schematically showing the configuration of a laser processing system 1b according to the second embodiment. FIG. 39 is a diagram showing an example of the second table B(1). FIG. 40 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(1). FIG. 41 is a diagram showing an example of the second table B(2). FIG. 42 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(2). FIG. 43 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(2). FIG. 44 is a diagram showing an example of the second table B(3). FIG. 45 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(3). FIG. 46 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(3). FIG. 47 is a diagram showing an example of the second table B(4). FIG. 48 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(4). FIG. 49 is a diagram schematically showing the configuration of a laser processing system 1c according to the third embodiment. FIG. 50 is a diagram showing an example of the second table B(1). FIG. 51 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(1). FIG. 52 is a diagram showing an example of the second table B(2). FIG. 53 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(2). Fig. 54 is a diagram showing an example of second table B(3). Fig. 55 is a diagram showing an example of the position of the light blocking plate 60 associated with second table B(3). Fig. 56 is a diagram showing an example of second table B(4).Fig. 57 is a diagram showing an example of the position of the light shielding plate 60 associated with the second table B(4). Fig. 58 shows details of the irradiation process of the high-density pattern HP(s) according to the third embodiment. Fig. 59 is a diagram showing a schematic configuration of the electronic device 100. Fig. 60 is a diagram showing a method for manufacturing the electronic device 100. Embodiment

[0012] <Contents> 1. Explanation of terms 1.1 Diffractive optical element 2. Comparative example 2.1 Configuration 2.2 Operation 2.3 Multi-point pattern 2.4 First table 2.5 Step position 2.6 Issues 3. First embodiment 3.1 High-density technology 3.2 High-density technology and technology for controlling the number of drilled holes 3.2.1 Configuration 3.2.2 Operation 3.3 Effects 4. Second embodiment 4.1 Configuration 4.2 Operation 4.3 Effects 5. Third embodiment 5.1 Configuration 5.2 Operation 5.3 Effects 6. Method for manufacturing electronic device 7. Example of configuration of laser processing processor

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure and do not limit the content of the present disclosure. Furthermore, not all of the configurations and operations described in each embodiment are necessarily essential to the configurations and operations of the present disclosure. Note that the same components are given the same reference symbols, and redundant explanations will be omitted.

[0014] 1. Explanation of Terms 1.1 Diffractive Optical Element A diffractive optical element (DOE) is an optical element that utilizes the diffraction phenomenon of light. For example, a DOE is fabricated by processing a fine structure designed through simulation onto a substrate using microfabrication technology. A DOE can convert laser light into various patterns. In this disclosure, a DOE converts laser light into a multi-point pattern MP.

[0015] 1 shows a schematic configuration of a laser processing system 1 according to a comparative example. Note that the comparative example is a configuration that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges.

[0016] The laser processing system 1 mainly includes a laser device 2 and a laser processing device 4. The laser processing system 1 is used for hole processing to form holes such as via holes in a glass substrate for an interposer.

[0017] The laser device 2 is a laser device that outputs ultraviolet pulsed laser light. For example, the laser device 2 is an F ２ , ArF, KrF, XeCl, XeF, or the like as a laser medium and outputs ultraviolet pulsed laser light. In this disclosure, the laser device 2 is a KrF excimer laser device that outputs ultraviolet pulsed laser light with a center wavelength of 248.4 nm. Hereinafter, the ultraviolet pulsed laser light output by the laser device 2 will be simply referred to as laser light Lb.

[0018] The laser device 2 and the laser processing device 4 are connected by an optical path 5. The optical path 5 is disposed on the optical path of the laser light Lb between the emission port of the laser device 2 and the incidence port of the laser processing device 4.

[0019] The laser processing apparatus 4 includes a laser processing processor 40, an optical device 41, a frame 42, an XYZ stage 43, and a table 44. The optical device 41 and the XYZ stage 43 are fixed to the frame 42.

[0020] The table 44 supports a workpiece 45. The workpiece 45 is a processing target for hole drilling. The workpiece 45 is a glass substrate for an interposer, for example, an alkali-free glass substrate. The workpiece 45 may also be a substrate made of quartz glass, an organic material, silicon single crystal, ceramics, or the like. A plurality of holes H are formed in the workpiece 45 by so-called multi-point drilling.

[0021] The XYZ stage 43 supports a table 44. A workpiece 45 is fixed on the table 44. The XYZ stage 43 allows the table 44 to move in the X, Y, and Z directions, and by moving the table 44, the position of the workpiece 45 is changed. The X, Y, and Z directions are perpendicular to one another. The X and Y directions are parallel to the surface 45a of the workpiece 45. The Z direction is perpendicular to the surface 45a. The XYZ stage 43 is a moving stage that allows the workpiece 45 to move in a direction perpendicular to the optical axis of the focusing optical system 51.

[0022] The optical device 41 includes a housing 41a, high-reflection mirrors 47a, 47b, and 47c, an attenuator 49, a DOE 50, and a focusing optical system 51. Each component in the optical device 41 is fixed to a holder (not shown), and is disposed at a predetermined position within the housing 41a.

[0023] The high-reflection mirror 47a is arranged to reflect the laser beam Lb that has passed through the optical path tube 5, and the reflected laser beam Lb passes through the attenuator 49 and is incident on the high-reflection mirror 47b. The optical path tube 5 and the housing 41a are purged with, for example, a purge gas. The purge gas is a gas such as nitrogen gas or an inert gas that hardly absorbs the laser beam Lb.

[0024] The attenuator 49 is disposed in the housing 41a on the optical path between the high-reflection mirror 47a and the high-reflection mirror 47b. The attenuator 49 includes, for example, two partial reflection mirrors 49a and 49b and rotation stages 49c and 49d for these partial reflection mirrors. The partial reflection mirrors 49a and 49b are optical elements whose transmittance changes depending on the angle of incidence of the laser beam Lb. The angle of incidence of the laser beam Lb on the partial reflection mirrors 49a and 49b is adjusted by the rotation stages 49c and 49d.

[0025] The high-reflection mirrors 47 b and 47 c are arranged to reflect the laser light Lb that has passed through the attenuator 49 , and the reflected laser light Lb enters the DOE 50 .

[0026] The DOE 50 is disposed on the optical path of the laser beam Lb reflected by the high-reflection mirror 47c. The DOE 50 diffracts the laser beam Lb incident from the high-reflection mirror 47c, splits it into multiple laser beams Lv, and outputs the split laser beams. The DOE 50 splits the laser beam Lb in the X and Y directions, thereby converting it into a lattice-like multi-point pattern MP. The laser beam Lb corresponds to the "first laser beam" according to the technology of the present disclosure. The laser beam Lv corresponds to the "second laser beam" according to the technology of the present disclosure.

[0027] The focusing optical system 51 is disposed so that the plurality of laser beams Lv emitted from the DOE 50 are incident thereon and that its focal plane is located on the surface 45a of the workpiece 45. The focusing optical system 51 is, for example, an Fθ lens, and focuses the plurality of laser beams Lv incident thereon from the DOE 50 to generate a multi-point pattern MP in which a plurality of focused spots P are arranged in a grid pattern.

[0028] The laser processing processor 40 transmits a target pulse energy Et and a light emission trigger Tr to the laser device 2. The target pulse energy Et is a target value of the pulse energy of the laser light Lb. The light emission trigger Tr is a trigger signal that causes the laser device 2 to output one pulse of laser light Lb.

[0029] The laser processing processor 40 controls the laser device 2 and the XYZ stage 43 so that a multi-point pattern MP is irradiated at each step position in a step-and-repeat manner in the processing area where hole processing is required on the surface 45a of the workpiece 45.

[0030] 2 shows a schematic configuration of the laser device 2. The laser device 2 includes an oscillator 20, a monitor module 30, a shutter 35, and a laser processor 38. The oscillator 20 includes a chamber 21, an optical resonator consisting of a rear mirror 25a and an output coupling mirror 25b, a charger 23, and a power supply unit (PPM: Pulsed Power Module) 22.

[0031] Windows 21a and 21b are provided in the chamber 21. The chamber 21 is filled with a laser gas as a laser medium.

[0032] An opening is formed in the chamber 21, and an electrically insulating plate 26 with a plurality of feedthroughs 26a embedded therein is provided to close the opening. The PPM 22 is disposed on the electrically insulating plate 26. A pair of discharge electrodes 27a, 27b serving as main electrodes, and a ground plate 28 are disposed within the chamber 21. The discharge surfaces of the discharge electrodes 27a, 27b are rectangular in shape.

[0033] The discharge electrodes 27a and 27b are arranged so that their discharge surfaces face each other in order to excite the laser medium by discharge. The surface of the discharge electrode 27a opposite the discharge surface is supported by an electrically insulating plate 26. The discharge electrode 27a is connected to a feedthrough 26a. The surface of the discharge electrode 27b opposite the discharge surface is supported by a ground plate 28.

[0034] The PPM 22 includes a switch 22a, a charging capacitor (not shown), a pulse transformer, a magnetic compression circuit, and a peaking capacitor. The peaking capacitor is connected to a feedthrough 26a via a connection (not shown). The charger 23 charges the charging capacitor under control of the laser processor 38.

[0035] The switch 22a is controlled to be turned on / off by the laser processor 38. The laser processor 38 turns on the switch 22a in response to a light emission trigger Tr transmitted from the laser processing processor 40.

[0036] When switch 22a is turned on, current flows from the charging capacitor to the primary side of the pulse transformer, and electromagnetic induction causes a reverse current to flow to the secondary side of the pulse transformer. A magnetic compression circuit is connected to the secondary side of the pulse transformer and compresses the pulse width of the current pulse. The peaking capacitor is charged by this current pulse. When the voltage of the peaking capacitor reaches the breakdown voltage of the laser gas, a dielectric breakdown occurs in the laser gas between discharge electrodes 27a and 27b, causing a discharge. This discharge generates one pulse of laser light Lb.

[0037] The rear mirror 25a is formed by coating a planar substrate with a highly reflective film. The output coupling mirror 25b is formed by coating a planar substrate with a partially reflective film. The chamber 21 is disposed between the rear mirror 25a and the output coupling mirror 25b. The laser light Lb generated in the chamber 21 is amplified by the optical resonator and output from the output coupling mirror 25b.

[0038] The monitor module 30 includes a beam splitter 31 and an optical sensor 32. The beam splitter 31 is disposed on the optical path of the laser light Lb output from the output coupling mirror 25b and reflects a portion of the laser light Lb. The optical sensor 32 is disposed at a position where the laser light Lb reflected by the beam splitter 31 is incident. The optical sensor 32 measures the pulse energy of the laser light Lb and transmits the measurement value to the laser processor 38.

[0039] The laser processor 38 controls the pulse energy of the laser light Lb output from the laser device 2 to the target pulse energy Et by changing the charging voltage of the charger 23 based on the pulse energy measured by the optical sensor 32.

[0040] The shutter 35 is disposed on the optical path of the laser light Lb that passes through the beam splitter 31. The shutter 35 opens and closes in response to a command from the laser processor 38. The laser processor 38 controls the shutter 35 to control the output of the laser light Lb from the laser device 2.

[0041] 2.2 Operation Next, the operation of the laser processing system 1 according to the comparative example will be described. FIG. 3 shows a schematic flow of the operation of the laser processing system 1 according to the comparative example. Before hole drilling, the workpiece 45 is set on the table 44 of the XYZ stage 43. First, the laser processing processor 40 reads the processing conditions (step S10). Next, the laser processing processor 40 adjusts the fluence on the surface 45a of the workpiece 45 (step S20). Then, the laser processing processor 40 controls the laser device 2 and the XYZ stage 43 to perform simultaneous multi-point hole drilling (step S30). Note that simultaneous multi-point hole drilling refers to simultaneously drilling multiple holes H in parallel using the laser light Lb output from the laser device 2.

[0042] 4 shows details of the processing condition reading process (step S10). The processing conditions read by the laser processing processor 40 in step S10 include, for example, the target fluence Fm, the number of holes to be simultaneously machined Q, the area S of the focused spot P, the number of irradiation pulses Nm, and the repetition frequency fm. These processing conditions may be read from an external device (not shown), via a network, or from an input device operated by an operator.

[0043] The target fluence Fm is the pulse energy density per pulse of one focused spot P on the surface 45a of the workpiece 45, and is a value greater than the processing threshold of the workpiece 45. When the workpiece 45 is an alkali-free glass substrate, the target fluence Fm is several tens of J / cm ２ is.

[0044] The number Q of simultaneously drilled holes is the number of holes H drilled simultaneously, and corresponds to the number of laser beams Lv generated by the DOE 50, i.e., the number of focused spots P included in the MP. The area S of one focused spot P is, for example, 1 / e of the peak intensity. ２ If the diameter of the distribution of light intensity where the difference is more than 2 times is D, then S = π(D / 2) ２ This is a value calculated using the following relational expression.

[0045] The number of irradiation pulses Nm is the number of pulses of the laser light Lb required to form a through hole that penetrates the workpiece 45 or a non-through hole having a target depth as the hole H. The repetition frequency fm is the repetition frequency of the laser light Lb output by the laser device 2, and is, for example, a rated value. The repetition frequency fm is, for example, 4 kHz to 6 kHz.

[0046] 5 shows details of the fluence adjustment process (step S20). In step S20, the laser processing processor 40 first transmits data of the target pulse energy Et required for hole drilling to the laser device 2 (step S200). After receiving the data, the laser device 2 controls the oscillator 20, and when it becomes possible to output laser light Lb with the target pulse energy Et, it transmits a preparation completion signal to the laser processing processor 40.

[0047] Next, the laser processing processor 40 determines whether or not it has received a preparation completion signal from the laser device 2 (step S201). If it determines that it has received a preparation completion signal (step S201: YES), the laser processing processor 40 calculates the transmittance Ta of the attenuator 49 to set the fluence on the surface 45a of the workpiece 45 to the target fluence Fm (step S202). For example, the laser processing processor 40 calculates the transmittance Ta using the following formula (1). Here, T ０ is the transmittance of the optical device 41 when the transmittance of the attenuator 49 is 100%. Ta=Fm×Q×S / (Et×T ０ ) ... (1)

[0048] Next, the laser processing processor 40 adjusts the attenuator 49 so that the transmittance becomes Ta (step S203). Specifically, the laser processing processor 40 controls the angles of incidence of the partial reflection mirrors 49 a and 49 b using the rotation stages 49 c and 49 d, thereby setting the transmittance of the attenuator 49 to Ta.

[0049] In addition, the laser processing processor 40 may adjust the target pulse energy Et instead of or in addition to the transmittance of the attenuator 49 to set the fluence at the surface 45a of the workpiece 45 to the target fluence Fm.

[0050] 6 shows the details of the simultaneous multi-point hole drilling process (step S30). In step S30, the laser processing processor 40 first sets a parameter n, which indicates the step position on the surface 45a of the workpiece 45, to 1 (step S300). Next, the laser processing processor 40 reads a position vector OS(n) from the first table A (step S301). The position vector OS(n) indicates the coordinates of the nth step position.

[0051] Next, the laser processing processor 40 positions the workpiece 45 in the X and Y directions by controlling the XYZ stage 43 based on the position vector OS(n) (step S302).The laser processing processor 40 also controls the XYZ stage 43 in the Z direction so that the focal plane of the focusing optical system 51 coincides with the surface 45a of the workpiece 45 (step S303).

[0052] Next, the laser processing processor 40 transmits a light emission trigger Tr to the laser device 2 based on the repetition frequency fm and the number of irradiation pulses Nm (step S304). As a result, laser light Lb is output from the laser device 2 in synchronization with the light emission trigger Tr and enters the laser processing device 4 via the optical path 5. This laser light Lb is reflected by the high-reflection mirror 47a, attenuated by the attenuator 49, and then reflected by the high-reflection mirrors 47b and 47c. The laser light Lb reflected by the high-reflection mirror 47c enters the DOE 50. The DOE 50 splits the incident laser light Lb into multiple laser beams Lv and emits them. The focusing optical system 51 focuses the multiple laser beams Lv to form a multi-point pattern MP on the surface 45a of the workpiece 45. As a result, holes H are formed by laser ablation at positions corresponding to each focused spot P included in the multi-point pattern MP.

[0053] Next, the laser processing processor 40 determines whether the currently set parameter n is the maximum value nmax, i.e., whether the current step position is the final step position (step S305). If the laser processing processor 40 determines that the parameter n is not the maximum value nmax (step S305: NO), it increments the parameter n, i.e., adds 1 to the parameter n (step S306), and returns the process to step S301.

[0054] The laser processing processor 40 repeatedly executes steps S301 to S306 until the parameter n reaches the maximum value nmax. If the laser processing processor 40 determines that the parameter n reaches the maximum value nmax (step S305: YES), the simultaneous multi-point hole machining process ends.

[0055] 2.3 Multi-Point Pattern In this disclosure, an arrangement of points in the X direction is defined as a "column," and an arrangement of points in the Y direction is defined as a "row." Furthermore, the number of rows arranged in the X direction is referred to as the "number of rows," and the number of columns arranged in the Y direction is referred to as the "number of columns." Here, a point refers to a hole H or a focused spot P. Furthermore, hereinafter, the X direction may also be referred to as the "column direction," and the Y direction may also be referred to as the "row direction."

[0056] 7 shows an example of a multi-point pattern MP generated by the DOE 50 and the focusing optical system 51. The multi-point pattern MP is a rectangular pattern in which a plurality of focusing spots P are arranged in a grid pattern in the row and column directions. In this comparative example, the number of rows and columns of focusing spots P included in the multi-point pattern MP is three. Here, the spacing Dx in the X direction and the spacing Dy in the Y direction of the multi-point pattern MP may be the same or different. The spacing Dx and the spacing Dy correspond to the "grating spacing" according to the technology of the present disclosure.

[0057] Furthermore, one of the plurality of focused spots P included in the multipoint pattern MP is referred to as a reference spot Pk. In this comparative example, one of the four focused spots P located at the four corners of the multipoint pattern MP is referred to as the reference spot Pk.

[0058] 2.4 First Table FIG. 8 shows an example of the first table A. In the first table A, the parameter n corresponds to the position vector OS(n). For example, the first table A is a data table stored in the memory of the laser processing processor 40. The position vector OS(n) represents the position of the reference spot Pk. Specifically, the position vector OS(n) is expressed by the X coordinate Xn and the Y coordinate Yn of the reference spot Pk. In this comparative example, nmax=12.

[0059] 2.5 Step Positions Figure 9 shows an example of multiple step positions of the multi-point pattern MP on the surface 45a of the workpiece 45. S(n) indicates the nth step position of the multi-point pattern MP. During simultaneous multi-point hole machining, the laser processing processor 40 controls the XYZ stage 43 to move the workpiece 45 so that the multi-point pattern MP is irradiated sequentially onto each step position S(n). The arrows in Figure 9 indicate the movement path of the step position S(n) onto which the multi-point pattern MP is irradiated. The step position S(n) is defined by the position of the reference spot Pk, i.e., the position vector OS(n).

[0060] 2.6 Issues Next, we will explain the issues with the laser processing device 4 according to the comparative example. As shown in Figure 9, by irradiating the multi-point pattern MP while changing the step position S(n), it is possible to process a large number of holes H in the surface 45a of the workpiece 45.

[0061] In recent years, there has been a demand for higher-density hole drilling. To achieve higher-density hole drilling, it is conceivable to shorten the intervals Dx and Dy of the multi-point pattern MP. However, shortening the intervals Dx and Dy requires reducing the diffraction angle of the laser light Lb by the DOE 50. However, reducing the diffraction angle makes the structure of the DOE 50 coarser, making it more difficult to diffract the laser light Lb. Therefore, there is a demand for higher-density hole drilling without shortening the intervals Dx and Dy of the multi-point pattern MP.

[0062] 9, reference numeral 46 denotes an example of a processing area, which is an area on the surface 45a of the workpiece 45 where hole processing is required. The processing area 46 is a rectangular area in which holes H arranged in a grid pattern are formed. If the number of rows and the number of columns of the holes H included in the processing area 46 are not divisible by the number of rows and the number of columns of the multi-point pattern MP, respectively, unnecessary holes H will be formed outside the processing area 46. In the example shown in FIG. 9, the number of columns of the holes H included in the processing area 46 is not divisible by the number of columns of the multi-point pattern MP, so one row of unnecessary holes H is formed outside the processing area 46. For this reason, it is desirable to be able to perform hole processing only in the processing area 46.

[0063] The present disclosure provides a laser processing apparatus that enables higher density hole processing only in the processing area 46, a control method for the laser processing apparatus, and a method for manufacturing an electronic device.

[0064] 3. First Embodiment A laser processing system 1a according to a first embodiment of the present disclosure will be described. Note that the same reference numerals will be used to designate components similar to those described above, and duplicated descriptions will be omitted unless otherwise specified.

[0065] 3.1 High Density Technology First, we will explain the high density technology that enables hole drilling at higher density. The configuration of the laser processing system related to this high density technology is similar to the configuration of the laser processing system 1 related to the comparative example.

[0066] 10 is a schematic diagram showing the operation flow of the laser processing system according to the densification technique. The operation of the laser processing system according to the present densification technique is the same as the operation flow of the laser processing system 1 according to the comparative example, except that a high-density hole processing (step S30A) is performed instead of the simultaneous multi-point hole processing (step S30).

[0067] 11 shows details of the high-density hole drilling process (step S30A). The high-density hole drilling process is the same as the simultaneous multi-point hole drilling process according to the comparative example, except that a high-density pattern HP irradiation process (step S304A) is performed instead of step S304 of the comparative example. As will be described in detail later, the high-density pattern HP is a pattern in which the focused light spots P are densified by moving the multi-point pattern PM at a movement pitch shorter than the grid spacing.

[0068] 12 shows details of the irradiation process for the high-density pattern HP (step S304A). In step S304A, the laser processing processor 40 first sets a parameter m, which indicates the position of the reference spot Pk, to 1 (step S3040). Next, the laser processing processor 40 reads a movement vector SM(m) from the second table B (step S3041). The movement vector SM(m) indicates the amount and direction of movement from the position of the first reference spot Pk to the position of the mth reference spot Pk. Note that the position of the first reference spot Pk is the position of the reference spot Pk when the densification of the focused spots P is not performed, as in the comparative example.

[0069] Next, the laser processing processor 40 calculates the position vector OM(m,n) based on the following equation (2) (step S3042). The position vector OM(m,n) indicates the position of the m-th reference spot Pk at the step position S(n). OM(m,n)=OS(n)+SM(m) (2)

[0070] Next, the laser processing processor 40 positions the workpiece 45 in the X and Y directions by controlling the XYZ stage 43 based on the position vector OM(m, n) (step S3043). Next, the laser processing processor 40 sends a light emission trigger Tr to the laser device 2 based on the repetition frequency fm and the number of irradiation pulses Nm (step S3044). As a result, holes H are formed by laser ablation at positions corresponding to each focused spot P on the workpiece 45.

[0071] Next, the laser processing processor 40 determines whether the currently set parameter m is the maximum value mmax, i.e., whether the current reference spot Pk is the final position (step S3045). If the laser processing processor 40 determines that the parameter m is not the maximum value mmax (step S3045: NO), it increments the parameter m (step S3046) and returns the process to step S3041.

[0072] The laser processing processor 40 repeatedly executes steps S3041 to S3046 until the parameter m reaches the maximum value mmax. If the laser processing processor 40 determines that the parameter m reaches the maximum value mmax (step S3045: YES), the laser processing processor 40 ends the irradiation process of the high-density pattern HP.

[0073] 13 shows an example of a high-density pattern HP. The high-density pattern HP is generated by irradiating a multi-point pattern MP while moving a workpiece 45 in the X and Y directions using an XYZ stage 43 at a movement pitch shorter than the intervals Dx and Dy. The numbers shown in FIG. 13 indicate the value of the parameter m, and the arrows indicate the movement order of the reference spot Pk.

[0074] The movement pitch of the reference spot Pk in the X direction is the value obtained by dividing the interval Dx by a positive integer. In the example shown in FIG. 13, the movement pitch of the reference spot Pk in the X direction is the value obtained by dividing the interval Dx by 4. The movement pitch of the reference spot Pk in the Y direction is the value obtained by dividing the interval Dy by a positive integer. In the example shown in FIG. 13, the movement pitch of the reference spot Pk in the Y direction is the value obtained by dividing the interval Dy by 4. As a result, the high-density pattern HP becomes a pattern in which a plurality of focused spots P are arranged in a grid pattern.

[0075] 13, mmax = 16. The movement order of the reference spots Pk is determined so that the total movement distance of the reference spots Pk for generating the high-density pattern HP is the shortest.

[0076] Fig. 14 shows an example of second table B. Second table B shown in Fig. 14 defines the relationship between parameter m and movement vector SM(m). Movement vector SM(m) is expressed by a movement amount xm in the X direction and a movement amount ym in the Y direction. In the examples shown in Figs. 13 and 14, a1 = 0, b1 = 0.

[0077] 15 shows an example of multiple step positions S(n) of the high-density pattern HP on the surface 45a of the workpiece 45. The step position S(n) of the high-density pattern HP is defined by the position of the reference spot Pk when m = 1. That is, the step position S(n) of the high-density pattern HP is expressed by the position vector OS(n) described in the comparative example.

[0078] The first table A stores position vectors OS(n) determined so that a plurality of focused spots P are arranged in a grid pattern by a plurality of high-density patterns HP, as shown in Fig. 15. The step positions S(n) of the high-density patterns HP may be the same as the step positions S(n) of the multi-point patterns MP described in the comparative example.

[0079] As described above, it is possible to irradiate each step position S(n) with the high-density pattern HP by irradiating the multi-point pattern MP while slightly moving the workpiece 45. However, as in the comparative example, unwanted holes H may be formed outside the processing area 46.

[0080] 3.2 High Density Technology and Technology for Controlling the Number of Drilled Holes Next, a first embodiment relating to a technology that enables drilling holes at a higher density and only in the drilling area 46 will be described.

[0081] 16 shows a schematic configuration of the laser processing system 1a according to the first embodiment. The laser processing system 1a differs from the laser processing system 1 according to the comparative example only in the configuration of the laser processing device 4a. The laser processing device 4a includes a light shielding plate 60 and an XY stage 61 in addition to the configuration of the laser processing device 4 according to the comparative example.

[0082] The light-shielding plate 60 is disposed near the surface 45a of the workpiece 45. The light-shielding plate 60 is held by a holder 62 that is movable in the X and Y directions on an XY stage 61. The XY stage 61 is fixed to the housing 41a via a bracket 63.

[0083] The XY stage 61 is a two-axis moving stage that moves the light blocking plate 60 in a direction perpendicular to the optical axis of the focusing optical system 51. Specifically, the XY stage 61 moves the light blocking plate 60 in the X and Y directions via a holder 62. The XY stage 61 is controlled by the laser processing processor 40. The laser processing processor 40 controls the XY stage 61 to change the relative position of the light blocking plate 60 with respect to the multi-point pattern MP. The XY stage 61 is an example of a "first actuator" according to the technology of the present disclosure.

[0084] The light-shielding plate 60 is capable of shielding at least a part of the multi-point pattern MP, and is therefore made of a material that is difficult to drill holes into with the focused spot P. The light-shielding plate 60 is made of metals such as W, Ta, and Mo, which have high melting points, or SiC and ZrO, which have a processing threshold higher than that of glass. ２ It is made of ceramics such as BN, silicon, diamond, or the like.

[0085] The light-shielding plate 60 is, for example, L-shaped with sides parallel to the X and Y directions, and is configured to be able to block at least one row and at least one column of the focused spots P included in the multi-point pattern MP.

[0086] In this embodiment, a high-density pattern HP(s) is generated by slightly moving the workpiece 45 using a step-and-repeat method with the XYZ stage 43 while a portion of the multi-point pattern MP is shielded by the light shielding plate 60. Here, the parameter s represents the type of high-density pattern HP(s). In this embodiment, the parameter s is an integer from 1 to 4. The high-density patterns HP(1) to HP(4) have different numbers of rows or columns of focused spots P because holes are drilled only in the processing area 46. The number of high-density patterns HP(s) may be four or more. In other words, the parameter s may be an integer greater than or equal to four. In this embodiment, the XYZ stage 43 corresponds to the "second actuator and third actuator" according to the technology disclosed herein.

[0087] 3.2.2 Operation Next, the operation of the laser processing system 1a according to the first embodiment will be described. Figure 17 shows an outline of the flow of operation of the laser processing system 1a. In this embodiment, steps S40 and S50 are added between steps S10 and S20.

[0088] After reading the processing conditions in step S10, the laser processing processor 40 generates and stores a first table A (step S40) and a second table B (step S50). The laser processing processor 40 then adjusts the fluence (step S20) and performs high-density hole processing (step S30A).

[0089] 18 shows details of the generation and storage process of first table A (step S40). In step S40, the laser processing processor 40 first determines high-density patterns HP(1) to HP(4) (step S400). For example, the laser processing processor 40 determines high-density patterns HP(1) to HP(4) based on drilling information including the number of rows and columns of holes H that need to be formed in the processing area 46. The drilling information may be read from an external device (not shown), via a network, or from an input device operated by the operator.

[0090] In the following steps, the first to fourth areas R1 to R4 onto which the high-density patterns HP(1) to HP(4) are irradiated are determined so that holes are drilled only in the processing area 46. The high-density patterns HP(1) to HP(4) are an example of "at least four high-density patterns" according to the technology of the present disclosure. The first to fourth areas R1 to R4 are also an example of "at least four areas" according to the technology of the present disclosure.

[0091] The laser processing processor 40 determines a first area R1 to be irradiated with one or more high-density patterns HP(1) and a movement path of the high-density patterns HP(1) within the first area R1 (step S401). Next, the laser processing processor 40 determines a second area R2 to be irradiated with one or more high-density patterns HP(2) and a movement path of the high-density patterns HP(2) within the second area R2 (step S402).

[0092] Next, the laser processing processor 40 determines a third area R3 onto which one or more high-density patterns HP(3) are irradiated and a movement path of the high-density patterns HP(3) within the third area R3 (step S403). Next, the laser processing processor 40 determines a fourth area R4 onto which one or more high-density patterns HP(4) are irradiated and a movement path of the high-density patterns HP(4) within the fourth area R4 (step S404).

[0093] Then, the laser processing processor 40 generates a first table A based on the information determined in steps S400 to S404 and stores it in memory (step S405).

[0094] 19 shows an example of a high-density pattern HP(1). The high-density pattern HP(1) is generated by not blocking the multi-point pattern MP with a light blocking plate 60. In other words, the high-density pattern HP(1) is the same as the high-density pattern HP shown in FIG.

[0095] 20 shows an example of a high-density pattern HP(2). The high-density pattern HP(2) is generated by blocking one or more rows of the multi-point pattern MP with a light blocking plate 60.

[0096] 21 shows an example of a high-density pattern HP(3). The high-density pattern HP(3) is generated by blocking one or more rows and columns of the multi-point pattern MP with a light blocking plate 60.

[0097] 22 shows an example of a high-density pattern HP(4). The high-density pattern HP(4) is generated by blocking one or more rows of the multi-point pattern MP with a light blocking plate 60.

[0098] The laser processing processor 40 can select one of the high-density patterns HP(1) to HP(4) by controlling the XY stage 61 that moves the light-shielding plate 60.

[0099] FIG. 23 shows an example of the first to fourth areas R1 to R4. The processing area 46 is divided into the first to fourth areas R1 to R4. In the example shown in FIG. 23, the first area R1 is an area made up of six high-density patterns HP(1). The second area R2 is an area made up of three high-density patterns HP(2). The third area R3 is an area made up of one high-density pattern HP(3). The fourth area R4 is an area made up of two high-density patterns HP(4). In this embodiment, the first to fourth areas R1 to R4 are each a single block area that is not divided into multiple areas.

[0100] 23, the movement paths of the high-density patterns HP(1) to HP(4) are indicated by arrows. The movement paths are continuous paths such that the step position S(n) of the irradiation target is changed to the adjacent step position S(n+1).

[0101] The number of rows in the high-density pattern HP(2) is equal to the remainder when the number of rows of holes H to be drilled in the processing area 46 is divided by the number of rows in the high-density pattern HP(1). The number of columns in the high-density pattern HP(2) is equal to the number of columns in the high-density pattern HP(1).

[0102] The number of rows in the high-density pattern HP(3) is equal to the remainder when the number of rows of holes H to be machined in the processing area 46 is divided by the number of rows in the high-density pattern HP(1). The number of columns in the high-density pattern HP(3) is equal to the remainder when the number of columns of holes H to be machined in the processing area 46 is divided by the number of columns in the high-density pattern HP(1).

[0103] The number of rows in the high-density pattern HP(4) is equal to the number of rows in the high-density pattern HP(1). The number of columns in the high-density pattern HP(4) is equal to the remainder when the number of columns of holes H to be drilled in the processing area 46 is divided by the number of columns in the high-density pattern HP(1).

[0104] 24 shows an example of the first table A. The parameter n is associated with the position vector OS(n). In the first table A, the position vector OS(n) is determined based on the movement path. The first table A also associates the parameter n with the second table B(s). The second table B(s) is a data table for generating the high-density pattern HP(s).

[0105] The step positions S(n) of 1≦n≦6 included in the first area R1 are associated with the second table B(1). The step positions S(n) of 7≦n≦9 included in the second area R2 are associated with the second table B(2). The step positions S(n) of n=10 included in the third area R3 are associated with the second table B(3). The step positions S(n) of 11≦n≦12 included in the fourth area R4 are associated with the second table B(4).

[0106] 25 shows details of the process of generating and storing second table B(s) (step S50). In step S50, the laser processing processor 40 first generates second table B(1) for generating high-density pattern HP(1) and stores it in memory (step S500). Next, the laser processing processor 40 generates second table B(2) for generating high-density pattern HP(2) and stores it in memory (step S501).

[0107] Next, the laser processing processor 40 generates a second table B(3) for generating a high-density pattern HP(3) and stores it in memory (step S502).Next, the laser processing processor 40 generates a second table B(4) for generating a high-density pattern HP(4) and stores it in memory (step S503).

[0108] In the second table B(s), a movement vector S M (m) and a position vector O B (m) indicating the position of the light shielding plate 60 are associated with the parameter m. For example, the position vector O B (m) is expressed by the X coordinate B xm and the Y coordinate Bym of the corner of the light shielding plate 60. The position vector O B (m) is an example of a "control value of the first actuator" according to the technology of the present disclosure. The movement vector S M (m) is an example of a "control value of the second actuator" according to the technology of the present disclosure. Therefore, the second table B (s) is an example of a "data table specifying the relationship between the control value of the first actuator and the control value of the second actuator" according to the technology of the present disclosure.

[0109] 26 shows an example of the second table B(1). In the second table B(1), the parameter m is associated with not only the movement vector SM(m) but also a position vector OB(m) indicating the position of the light blocking plate 60 for generating the high-density pattern HP(1). In the second table B(1), one position vector OB(m) = (C1, D1) is associated with 1≦m≦16.

[0110] Fig. 27 shows an example of the position of the light blocking plate 60 associated with the second table B(1). In the example shown in Fig. 27, the light blocking plate 60 is positioned at a position where it does not block the multi-point pattern MP.

[0111] 28 shows an example of the second table B(2). In the second table B(2), the parameter m is associated with not only the movement vector SM(m) but also a position vector OB(m) indicating the position of the light blocking plate 60 for generating the high-density pattern HP(2). In the second table B(2), the position vector OB(m) = (C1, D2) is associated with 1 ≤ m ≤ 3, 6 ≤ m ≤ 11, and 14 ≤ m ≤ 16. In addition, the position vector OB(m) = (C1, D3) is associated with 4 ≤ m ≤ 5 and 12 ≤ m ≤ 13.

[0112] Fig. 29 shows an example of the position of the light blocking plate 60 associated with the second table B(2). In the example shown in Fig. 29, the light blocking plate 60 is positioned so as to block one row of the multi-point pattern MP based on the position vector OB(m) = (C1, D2).

[0113] Fig. 30 shows an example of the position of the light blocking plate 60 associated with the second table B(2). In the example shown in Fig. 30, the light blocking plate 60 is positioned so as to block two rows of the multi-point pattern MP based on the position vector OB(m) = (C1, D3).

[0114] 31 shows an example of the second table B(3). In the second table B(3), the parameter m is associated with not only the movement vector SM(m) but also a position vector OB(m) indicating the position of the light blocking plate 60 for generating the high-density pattern HP(3). In the second table B(3), the position vector OB(m) = (C2, D2) is associated with 1 ≤ m ≤ 3, 6 ≤ m ≤ 11, and 14 ≤ m ≤ 16. In addition, the position vector OB(m) = (C2, D3) is associated with 4 ≤ m ≤ 5 and 12 ≤ m ≤ 13.

[0115] Fig. 32 shows an example of the position of the light blocking plate 60 associated with the second table B(3). In the example shown in Fig. 32, the light blocking plate 60 is positioned so as to block one row and one column of the multi-point pattern MP based on the position vector OB(m) = (C2, D2).

[0116] Fig. 33 shows an example of the position of the light blocking plate 60 associated with the second table B(3). In the example shown in Fig. 33, the light blocking plate 60 is positioned so as to block two rows and one column of the multi-point pattern MP based on the position vector OB(m) = (C2, D3).

[0117] 34 shows an example of the second table B(4). In the second table B(4), the parameter m is associated with not only the movement vector SM(m) but also a position vector OB(m) indicating the position of the light blocking plate 60 for generating the high-density pattern HP(4). In the second table B(4), the position vector OB(m) = (C2, D1) is associated with 1 ≤ m ≤ 16.

[0118] Fig. 35 shows an example of the position of the light blocking plate 60 associated with the second table B(4). In the example shown in Fig. 35, the light blocking plate 60 is positioned so as to block one column of the multi-point pattern MP based on the position vector OB(m) = (C2, D1).

[0119] 36 shows details of the high-density hole drilling process (step S30A) according to the first embodiment. Steps S301 and S304A of the first embodiment are changed to steps S301A and S304B, respectively, and the other steps are the same as the high-density hole drilling process described in FIG. 11. In this embodiment, in step S301A, the laser processing processor 40 reads the position vector OS(n) from the first table A and reads the second table B(s) corresponding to the position vector OS(n) defined in the first table A.

[0120] 37 shows details of the irradiation process (step S304B) of the high-density pattern HP(s) according to the first embodiment. The only differences from the irradiation process of the high-density pattern HP described in FIG. 12 are the content of step S3041 and the addition of step S3047. In this embodiment, in step S3041, the laser processing processor 40 reads the movement vector SM(m) and the position vector OB(m) from the second table B(s).

[0121] In this embodiment, after calculating the position vector OM(m, n) in step S3042, the laser processing processor 40 executes step S3047 in parallel with step S3043, which positions the workpiece 45 in the X and Y directions. In step S3047, the laser processing processor 40 positions the light blocking plate 60 by controlling the XY stage 61 based on the position vector OB(m).

[0122] After steps S3043 and S3047 are completed, the laser processing processor 40 executes step S3044.

[0123] As described above, in this embodiment, the laser processing processor 40 selects one of the high-density patterns HP(1) to HP(4) by controlling the XY stage 61 at each of the multiple step positions S(n) in the processing area 46 that are changed by controlling the XYZ stage 43, and controls the XYZ stage 43 and the laser device 2 so that the selected pattern is irradiated. As a result, in this embodiment, the first to fourth areas R1 to R4 are machined with the high-density patterns HP(1) to HP(4), respectively, with just the right amount of holes at high density.

[0124] 3.3 Effects The laser processing device 4a according to this embodiment generates high-density patterns HP(2) to HP(4) by using the light-shielding plate 60 to block light from part of the multi-point pattern MP, even if the number of rows and the number of columns of holes H included in the processing area 46 are not divisible by the number of rows and the number of columns of the high-density pattern HP(1), thereby enabling hole processing at a higher density and only in the processing area 46.

[0125] While it may be possible to replace the DOE 50 to generate the high-density patterns HP(1) to HP(4), replacing the DOE 50 would require time for alignment and fluence adjustments, resulting in a decrease in throughput. In this embodiment, the high-density patterns HP(1) to HP(4) are generated by using the light-shielding plate 60 to shield a portion of the multi-point pattern MP, thereby maintaining high throughput. Furthermore, in this embodiment, the movement path is set so as to change the step position S(n) of the irradiation target to the adjacent step position S(n+1), thereby reducing the number of times the light-shielding plate 60 is positioned, further improving throughput.

[0126] In this embodiment, the first to fourth areas R1 to R4 are each considered to be one block area, but one or more of the first to fourth areas R1 to R4 may be divided into blocks rather than being considered to be block areas.

[0127] Although the light-shielding plate 60 is L-shaped in this embodiment, the light-shielding plate 60 may have any shape as long as it can block a desired number of rows and columns of the multi-point pattern MP from the ends in the X and Y directions. For example, the light-shielding plate 60 may have a rectangular opening large enough to pass all of the multi-point pattern MP.

[0128] In this embodiment, the multi-point pattern MP is generated by the DOE 50 and the focusing optical system 51. However, the present invention is not limited to this example, and the DOE 50 may also function as the focusing optical system. In this case, the focusing optical system 51 can be omitted.

[0129] 4. Second Embodiment A laser processing system 1b according to a second embodiment of the present disclosure will be described. Note that the same reference numerals are used to designate components similar to those described above, and redundant descriptions will be omitted unless otherwise specified.

[0130] 38 schematically shows the configuration of a laser processing system 1b according to the second embodiment. The laser processing system 1b differs from the laser processing system 1a according to the first embodiment only in the configuration of the laser processing device 4b. The laser processing device 4b includes a transfer imaging optical system 52 in addition to the configuration of the laser processing device 4a according to the first embodiment.

[0131] The transfer imaging optical system 52 is disposed on the optical path of the plurality of laser beams Lv emitted from the focusing optical system 51. The transfer imaging optical system 52 is a reduction transfer imaging optical system that reduces the multi-point pattern MP formed on the focal plane 51 a of the focusing optical system 51 and transfers and images it onto the surface 45 a of the workpiece 45.

[0132] In this embodiment, the light blocking plate 60 is disposed on the focal plane 51a of the focusing optical system 51. The light blocking plate 60 is held by a holder 62 that is movable in the X and Y directions on an XY stage 61. The XY stage 61 is fixed to the housing 41a and is controlled by the laser processing processor 40.

[0133] Since the transfer imaging optical system 52 transfers and images an inverted image of the multi-point pattern MP onto the surface 45a of the workpiece 45, the planar shape of the light shielding plate 60 in this embodiment is a shape that is the inverse of the planar shape of the light shielding plate 60 in the first embodiment in the X and Y directions.

[0134] 4.2 Operation The operation of the laser processing system 1b according to the second embodiment is the same as the operation of the laser processing system 1a according to the first embodiment, except that the direction of movement of the light shielding plate 60 is opposite to that in the first embodiment.

[0135] In this embodiment, the second table B(s) is a data table in which a parameter m is associated with a movement vector S(m) and a position vector O(m) indicating the position of the light blocking plate 60 on the focal plane 51 a. For example, the position vector O(m) is expressed by the X coordinate Cxm and the Y coordinate Cym of the corner of the light blocking plate 60 on the focal plane 51 a.

[0136] 39 shows an example of second table B(1). In second table B(1), parameter m is associated with not only movement vector SM(m) but also position vector OC(m) indicating the position of light blocking plate 60 for generating high-density pattern HP(1). In second table B(1), one position vector OC(m) = (E1, F1) is associated with 1≦m≦16.

[0137] Fig. 40 shows an example of the position of the light blocking plate 60 associated with the second table B(1). In the example shown in Fig. 40, the light blocking plate 60 is positioned on the focal plane 51a at a position that does not block the multi-point pattern MP.

[0138] 41 shows an example of the second table B(2). In the second table B(2), the parameter m is associated with not only the movement vector SM(m) but also a position vector OC(m) indicating the position of the light blocking plate 60 for generating the high-density pattern HP(2). In the second table B(2), the position vector OC(m) = (E1, F2) is associated with 1 ≤ m ≤ 3, 6 ≤ m ≤ 11, and 14 ≤ m ≤ 16. In addition, the position vector OC(m) = (E1, F3) is associated with 4 ≤ m ≤ 5 and 12 ≤ m ≤ 13.

[0139] Fig. 42 shows an example of the position of the light blocking plate 60 associated with the second table B(2). In the example shown in Fig. 42, the light blocking plate 60 is positioned on the focal plane 51a based on the position vector OC(m) = (E1, F2) so as to block one row of the multi-point pattern MP.

[0140] Fig. 43 shows an example of the position of the light blocking plate 60 associated with the second table B(2). In the example shown in Fig. 43, the light blocking plate 60 is positioned on the focal plane 51a based on the position vector OC(m) = (E1, F3) so as to block two rows of the multi-point pattern MP.

[0141] 44 shows an example of the second table B(3). In the second table B(3), the parameter m is associated with not only the movement vector SM(m) but also a position vector OC(m) indicating the position of the light blocking plate 60 for generating the high-density pattern HP(3). In the second table B(3), the position vector OC(m) = (E2, F2) is associated with 1 ≤ m ≤ 3, 6 ≤ m ≤ 11, and 14 ≤ m ≤ 16. In addition, the position vector OC(m) = (E2, F3) is associated with 4 ≤ m ≤ 5 and 12 ≤ m ≤ 13.

[0142] Fig. 45 shows an example of the position of the light blocking plate 60 associated with the second table B(3). In the example shown in Fig. 45, the light blocking plate 60 is positioned on the focal plane 51a based on the position vector OC(m) = (E2, F2) so as to block one row and one column of the multi-point pattern MP.

[0143] Fig. 46 shows an example of the position of the light blocking plate 60 associated with the second table B(3). In the example shown in Fig. 46, the light blocking plate 60 is positioned on the focal plane 51a based on the position vector OC(m) = (E2, F3) so as to block two rows and one column of the multi-point pattern MP.

[0144] 47 shows an example of the second table B(4). In the second table B(4), the parameter m is associated with not only the movement vector SM(m) but also a position vector OC(m) indicating the position of the light blocking plate 60 for generating the high-density pattern HP(4). In the second table B(4), the position vector OC(m) = (E2, F1) is associated with 1 ≤ m ≤ 16.

[0145] Fig. 48 shows an example of the position of the light blocking plate 60 associated with the second table B(4). In the example shown in Fig. 48, the light blocking plate 60 is positioned on the focal plane 51a based on the position vector OC(m) = (E2, F1) so as to block one column of the multi-point pattern MP.

[0146] 4.3 Effects For example, when the workpiece 45 is a non-alkali glass substrate, the target fluence Fm on the surface 45a of the workpiece 45 is set to several tens of J / cm. ２ Therefore, if the light shielding plate 60 is disposed near the surface 45a of the workpiece 45 as in the first embodiment, there is a possibility that the light shielding plate 60 will be damaged. In contrast, in this embodiment, the light shielding plate 60 is disposed on the focal plane 51a of the condensing optical system 51, so that the fluence at the light shielding plate 60 is reduced and damage to the light shielding plate 60 is suppressed. Specifically, if the magnification of the transfer imaging optical system 52 is 1 / M, the fluence at the focal plane 51a is 1 / M of the target fluence Fm at the surface 45a of the workpiece 45. ２ Here, M>1.

[0147] Furthermore, it is preferable to use a thicker light-shielding plate 60 in order to prevent damage to the light-shielding plate 60. However, if the pitch of the holes H formed in the workpiece 45 is small or if the numerical aperture NA is large, it is difficult to place a thicker light-shielding plate 60 on the surface 45a of the workpiece 45. In contrast, in this embodiment, the light-shielding plate 60 is placed on the focal plane 51a where the focused spots P are arranged at a pitch larger than the pitch of the holes H, so it is possible to use a light-shielding plate 60 that is thicker than in the first embodiment.

[0148] In this embodiment, the transfer imaging optical system 52 is a reduced transfer imaging optical system, but the transfer imaging optical system 52 may be an equal-magnification transfer imaging optical system that transfers and images the multi-point pattern MP formed on the focal plane 51a at equal magnification onto the surface 45a of the workpiece 45. Also, this embodiment can be modified in the same way as the first embodiment.

[0149] 5. Third Embodiment A laser processing system 1c according to a third embodiment of the present disclosure will be described. Note that the same components as those described above will be assigned the same reference numerals, and duplicated descriptions will be omitted unless otherwise specified.

[0150] 49 schematically shows the configuration of a laser processing system 1c according to the third embodiment. The laser processing system 1c differs from the laser processing system 1b according to the second embodiment only in the configuration of the laser processing device 4c. The laser processing device 4c includes a beam steering device 53 and a pointing measurement device 70 in addition to the configuration of the laser processing device 4b according to the second embodiment.

[0151] The beam steering device 53 includes two actuators 53a and 53b that change the angle of the high-reflection mirror 47c. The actuators 53a and 53b are controlled by the laser processing processor 40 and change the angle of the high-reflection mirror 47c around two orthogonal axes.

[0152] The pointing measurement device 70 includes a beam splitter 71, a condenser lens 72, and a two-dimensional optical sensor 73. The beam splitter 71 is disposed on the optical path of the laser light Lb between the beam steering device 53 and the DOE 50. The beam splitter 71 reflects a portion of the laser light Lb reflected by the high-reflection mirror 47c and transmits the remaining laser light Lb. The laser light Lb that has transmitted through the beam splitter 71 enters the DOE 50.

[0153] The condenser lens 72 is disposed on the optical path of the laser beam Lb reflected by the beam splitter 71 and condenses the laser beam Lb. The two-dimensional optical sensor 73 is disposed at a position where it can detect the condensed image formed on the focal plane by the condenser lens 72. The two-dimensional optical sensor 73 may be a two-dimensional PSD (Position Sensitive Detector) or a two-dimensional photodiode array. The two-dimensional optical sensor 73 measures the position of the condensed image, i.e., the pointing of the laser beam Lb, and transmits the measurement value to the laser processing processor 40.

[0154] In this embodiment, the laser processing processor 40 changes the angle of the laser light Lb incident on the DOE 50 by controlling the angle of the high-reflection mirror 47c via the beam steering device 53. As the angle of the laser light Lb incident on the DOE 50 is changed, the multi-point pattern MP moves within the focal plane 51a. In other words, the beam steering device 53 is an example of a "second actuator" according to the technology of the present disclosure. The XYZ stage 43 is an example of a "third actuator" according to the technology of the present disclosure.

[0155] In this embodiment, the laser processing processor 40 performs feedback control based on the pointing measurement value transmitted from the pointing measurement device 70 so that the position of the multi-point pattern MP relative to the light-shielding plate 60 becomes a target position.

[0156] The planar shape of the light-shielding plate 60 according to this embodiment is the same as the planar shape of the light-shielding plate 60 according to the second embodiment. In this embodiment, the light-shielding plate 60 is fixed, and the beam steering device 53 is controlled to move the multi-point pattern MP, thereby changing the relative position of the light-shielding plate 60 with respect to the multi-point pattern MP. In this embodiment, the high-density pattern HP(s) can be generated by slightly moving the multi-point pattern MP in the X and Y directions in a step-and-repeat manner on the focal plane 51 a, while keeping the light-shielding plate 60 fixed.

[0157] 5.2 Operation In the operation of the laser processing system 1c according to the third embodiment, the laser processing processor 40 controls the beam steering device 53 instead of the XYZ stage 43 to slightly move the multi-point pattern MP during the irradiation process of the high-density pattern. The other operations are the same as those of the laser processing system 1b according to the second embodiment. The irradiation process of the high-density pattern of this embodiment will be described below.

[0158] In this embodiment, when the multi-point pattern MP is slightly moved on the focal plane 51a, the laser processing processor 40 controls the beam steering device 53 to change the angle of incidence of the laser light Lb incident on the DOE 50. Furthermore, the laser processing processor 40 calculates the angle of incidence of the laser light Lb incident on the DOE 50 based on the pointing measurement value transmitted from the pointing measurement device 70, and performs feedback control so that the angle of incidence becomes the target angle.

[0159] In this embodiment, the second table B(s) is a data table in which a parameter m is associated with a target angle Θ(m) and a position vector OC(s) indicating the position of the light blocking plate 60 on the focal plane 51a. The target angle Θ(m) is the angle of incidence of the laser light Lb incident on the DOE 50 when the reference spot Pk is at the mth position. For example, the position vector OC(s) is expressed by the X coordinate Cxs and the Y coordinate Cys of the corner of the light blocking plate 60 on the focal plane 51a. The position vector OC(s) is an example of a "control value of the first actuator" according to the technology of the present disclosure. The target angle Θ(m) is an example of a "control value of the second actuator" according to the technology of the present disclosure.

[0160] 50 shows an example of second table B(1). In second table B(1), parameter m is associated with not only target angle Θ(m) but also position vector OC(s) indicating the position of light blocking plate 60 for generating high-density pattern HP(1). In second table B(1), one position vector OC(s) = (E4, F4) is associated with 1≦m≦16.

[0161] Figure 51 shows an example of the position of the light-shielding plate 60 associated with the second table B(1). In the example shown in Figure 51, the light-shielding plate 60 is positioned at a position that does not block the high-density pattern HP generated on the focal plane 51a by slightly moving the multi-point pattern MP by controlling the beam steering device 53. In the example shown in Figure 51, the high-density pattern HP is not blocked by the light-shielding plate 60, and is therefore irradiated onto the surface 45a of the workpiece 45 as a high-density pattern HP(1).

[0162] 52 shows an example of the second table B(2). In the second table B(2), the parameter m is associated with not only the target angle Θ(m) but also a position vector OC(s) indicating the position of the light blocking plate 60 for generating the high-density pattern HP(2). In the second table B(2), one position vector OC(s) = (E4, F1) is associated with 1≦m≦16.

[0163] Fig. 53 shows an example of the position of the light shielding plate 60 associated with the second table B(2). In the example shown in Fig. 53, the light shielding plate 60 is positioned so as to shield five rows of the high-density pattern HP. In the example shown in Fig. 53, the five rows of the high-density pattern HP are shielded by the light shielding plate 60, thereby generating a high-density pattern HP(2) and irradiating it onto the surface 45a of the workpiece 45.

[0164] 54 shows an example of the second table B(3). In the second table B(3), the parameter m is associated with the target angle Θ(m) as well as a position vector OC(s) indicating the position of the light blocking plate 60 for generating the high-density pattern HP(3). In the second table B(3), one position vector OC(s) = (E2, F1) is associated with 1≦m≦16.

[0165] Figure 55 shows an example of the position of the light shielding plate 60 associated with the second table B(3). In the example shown in Figure 55, the light shielding plate 60 is positioned so as to shield five rows and four columns of the high-density pattern HP. In the example shown in Figure 55, the five rows and four columns of the high-density pattern HP are shielded by the light shielding plate 60, thereby generating a high-density pattern HP(3) and irradiating it onto the surface 45a of the workpiece 45.

[0166] 56 shows an example of the second table B(4). In the second table B(4), the parameter m is associated with the target angle Θ(m) as well as a position vector OC(s) indicating the position of the light blocking plate 60 for generating the high-density pattern HP(4). In the second table B(4), one position vector OC(s) = (E2, F4) is associated with 1≦m≦16.

[0167] Figure 57 shows an example of the position of the light shielding plate 60 associated with the second table B(4). In the example shown in Figure 57, the light shielding plate 60 is positioned so as to shield four rows of the high-density pattern HP. In the example shown in Figure 57, the four rows of the high-density pattern HP are shielded by the light shielding plate 60, thereby generating a high-density pattern HP(4) and irradiating it onto the surface 45a of the workpiece 45.

[0168] 58 shows details of the irradiation process (step S304B) of the high-density pattern HP(s) according to the third embodiment. In step S304B according to this embodiment, the laser processing processor 40 first reads the position vector OC(s) from the second table B(s) (step S3040A). Next, the laser processing processor 40 positions the light shielding plate 60 by controlling the XY stage 61 based on the position vector OC(s) (step S3041A).

[0169] The laser processing processor 40 sets the parameter m, which indicates the position of the reference spot Pk, to 1 (step S3042A). Next, the laser processing processor 40 reads the target angle Θ(m) from the second table B(s) (step S3043A). Then, the laser processing processor 40 controls the beam steering device 53 so that the angle of incidence of the laser light Lb incident on the DOE 50 becomes the target angle Θ(m) (step S3044A).

[0170] Next, the laser processing processor 40 transmits a light emission trigger Tr to the laser device 2 based on the repetition frequency fm and the number of irradiation pulses Nm (step S3045A). As a result, of the individual focused spots P included in the multi-point pattern MP, those that have passed through the focal plane 51a without being blocked by the light blocking plate 60 are irradiated onto the surface 45a of the workpiece 45 via the transfer imaging optical system 52.

[0171] Next, the laser processing processor 40 determines whether the currently set parameter m is the maximum value mmax (step S3046A). If the laser processing processor 40 determines that the parameter m is not the maximum value mmax (step S3046A: NO), it increments the parameter m (step S3047A) and returns the process to step S3043A.

[0172] The laser processing processor 40 repeatedly executes steps S3043A to S3047A until the parameter m reaches the maximum value mmax. If the laser processing processor 40 determines that the parameter m reaches the maximum value mmax (step S3046A: YES), it ends the irradiation process of the high-density pattern HP(s).

[0173] 5.3 Effects In this embodiment, when generating the high-density pattern HP(s), the multi-point pattern MP is slightly moved by the beam steering device 53. Therefore, unlike the second embodiment, there is no need to move the light-shielding plate 60, and it can be kept fixed. This further improves throughput.

[0174] Although the pointing measurement device 70 is not an essential component, by performing feedback control using the pointing measurement device 70, it is possible to move and position the multi-point pattern MP with high precision.

[0175] In the above embodiment, the beam steering device 53 is used to change the angle of incidence of the laser beam Lb incident on the DOE 50. However, the angle of incidence of the laser beam Lb may also be changed using an acousto-optic element. It is preferable to use a quartz acousto-optic element that can also be used for ultraviolet light as the acousto-optic element, and to control the angle of incidence of the laser beam Lb in two axial directions. This acousto-optic element is an example of a "second actuator" according to the technology of the present disclosure.

[0176] In addition, in this embodiment, the transfer imaging optical system 52 is a reduced transfer imaging optical system, but the transfer imaging optical system 52 may also be an equal-magnification transfer imaging optical system that transfers and images the multi-point pattern MP formed on the focal plane 51a onto the surface 45a of the workpiece 45 at equal magnification.

[0177] In this embodiment, the multi-point pattern MP generated by the DOE 50 is transferred and imaged onto the surface 45a of the workpiece 45 via the transfer imaging optical system 52, but this is not limiting. As in the first embodiment, the multi-point pattern MP generated by the DOE 50 may be irradiated onto the surface 45a of the workpiece 45 via the condensing optical system 51, and the light blocking plate 60 may be disposed near the surface 45a.

[0178] Furthermore, this embodiment can also be modified in the same manner as the first embodiment.

[0179] 6. Method for Manufacturing an Electronic Device The laser processing method according to each of the above-described embodiments can be applied to the formation of through holes in the glass substrate of the interposer 102 in the manufacture of the electronic device 100 described below.

[0180] Figure 59 schematically shows the configuration of an electronic device 100. The electronic device 100 shown in Figure 59 includes an integrated circuit chip 101, an interposer 102, and a circuit board 103. The integrated circuit chip 101 is, for example, a chip-shaped integrated circuit board in which an integrated circuit is formed on a silicon substrate. The integrated circuit chip 101 is provided with a plurality of bumps 101b that are electrically connected to the integrated circuit.

[0181] The interposer 102 comprises an insulating glass substrate with a plurality of through holes formed therein, and a conductor is provided in each through hole to electrically connect the front and back of the glass substrate. One surface of the interposer 102 is formed with a plurality of lands connected to bumps 101b provided on the integrated circuit chip 101, and each land is electrically connected to one of the conductors in the through holes. The other surface of the interposer 102 is provided with a plurality of bumps 102b, and each bump 102b is electrically connected to one of the conductors in the through holes.

[0182] A plurality of lands that connect to the respective bumps 102b are formed on one surface of the circuit board 103. The circuit board 103 also has a plurality of terminals that are electrically connected to these lands.

[0183] 60 shows a method for manufacturing the electronic device 100. As shown in FIG. 60, the method for manufacturing the electronic device 100 in this description includes a first bonding step SP1 and a second bonding step SP2. In the first bonding step SP1, the integrated circuit chip 101 and the interposer 102 are bonded together. Specifically, the bumps 101b of the integrated circuit chip 101 are placed on the lands of the interposer 102, and the bumps 101b and the lands are electrically connected together. In this way, the integrated circuit chip 101 and the interposer 102 are electrically connected together.

[0184] In the second bonding process SP2, the interposer 102 and the circuit board 103 are bonded together. Specifically, each bump 102b of the interposer 102 is placed on each land of the circuit board 103, and the bumps 102b and the lands are electrically connected. In this way, the integrated circuit chip 101 is electrically connected to the circuit board 103 via the interposer 102. Through the above processes, the electronic device 100 is manufactured.

[0185] 7. Example Configuration of Laser Processing Processor In the present disclosure, the laser processing processor 40 is configured, for example, by a CPU (Central Processing Unit). The laser processing processor 40 executes the various processes described above based on programs stored in memory. Some or all of the functions of the laser processing processor 40 may be realized using an integrated circuit, such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

[0186] The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to those skilled in the art that modifications may be made to the embodiments of the present disclosure without departing from the scope of the appended claims.

[0187] Terms used throughout this specification and the appended claims should be interpreted as "open-ended" terms. For example, the terms "include" or "including" should be interpreted as "not limited to what is stated as including." The term "having" should be interpreted as "not limited to what is stated as having." Additionally, the modifier "a" used in this specification and the appended claims should be interpreted as "at least one" or "one or more." Additionally, the term "at least one of A, B, and C" should be interpreted as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C," and should also be interpreted as including combinations other than "A," "B," and "C."

Claims

a focusing optical system that focuses the plurality of second laser beams to generate a lattice-like multi-point pattern in which a plurality of focused spots are arranged in row and column directions; a light-shielding plate that can block at least a portion of the multi-point pattern; a first actuator that moves the light-shielding plate in a direction perpendicular to an optical axis of the focusing optical system; a second actuator that can generate a high-density pattern in which the focused spots are densified by moving the multi-point pattern at a movement pitch shorter than a lattice spacing; a third actuator that moves a workpiece in a direction perpendicular to the optical axis; and a laser processing processor that controls the first actuator to select one of at least four of the high-density patterns having different numbers of rows or columns at each of a plurality of step positions in the processing area that are changed by controlling the third actuator so that hole processing is performed only in processing areas that require hole processing on the surface of the workpiece, and controls the second actuator and the laser device so that the selected pattern is irradiated.

2. A laser processing device according to claim 1, wherein the laser processing processor determines at least four areas to which at least four of the high-density patterns are irradiated so that holes are machined only in the processing areas.

3. A laser processing device according to claim 2, wherein each of the at least four areas is a single mass region.

4. A laser processing device as claimed in claim 2, wherein the laser processing processor controls the third actuator so as to change the step position of the irradiation target to an adjacent step position.

5. A laser processing device as claimed in claim 1, wherein the first actuator is a two-axis moving stage.

6. A laser processing apparatus as claimed in claim 1, wherein the second actuator and the third actuator are moving stages which move the workpiece in a direction perpendicular to the optical axis.

7. A laser processing apparatus as described in claim 1, wherein the second actuator is a beam steering device that changes the angle of incidence of the first laser light incident on the diffractive optical element, and the third actuator is a moving stage that moves the workpiece in a direction perpendicular to the optical axis.

8. A laser processing apparatus as described in claim 7, further comprising a pointing measurement device arranged on the optical path of the first laser light between the beam steering device and the diffractive optical element, for measuring the pointing of the first laser light.

9. A laser processing apparatus as described in claim 8, wherein the laser processing processor feedback controls the angle of incidence of the first laser light incident on the diffractive optical element based on the pointing measurement value obtained by the pointing measurement device.

10. A laser processing apparatus as claimed in claim 1, wherein the workpiece is arranged so that the surface coincides with the focal plane of the focusing optical system.

11. A laser processing apparatus according to claim 1, further comprising a transfer imaging optical system for transferring and imaging the multi-point pattern generated by the focusing optical system onto the surface.

12. A laser processing apparatus according to claim 11, wherein the transfer imaging optical system is a reduction transfer imaging optical system which reduces the multi-point pattern and transfers and images it onto the surface.

13. A laser processing apparatus as set forth in claim 12, wherein the light shielding plate is disposed on the focal plane of the focusing optical system.

14. A laser processing apparatus as described in claim 13, wherein the first actuator is a two-axis moving stage, the second actuator is a beam steering device that changes the angle of incidence of the first laser light incident on the diffractive optical element, and the third actuator is a moving stage that moves the workpiece in a direction perpendicular to the optical axis.

15. A laser processing apparatus as described in claim 1, wherein the laser processing processor controls the first actuator and the second actuator based on a data table that defines the relationship between the control value of the first actuator and the control value of the second actuator for generating at least four of the high-density patterns.

16. A control method for a laser processing device comprising: a diffractive optical element which splits a first laser beam output from a laser device into a plurality of second laser beams and emits the split laser beams; a focusing optical system which focuses the plurality of second laser beams to generate a lattice-like multi-point pattern in which a plurality of focused spots are arranged in row and column directions; a light-shielding plate capable of shading at least a part of the multi-point pattern; a first actuator which moves the light-shielding plate in a direction perpendicular to an optical axis of the focusing optical system; a second actuator which is capable of generating a high-density pattern in which the focused spots are densified by moving the multi-point pattern at a moving pitch shorter than the lattice interval; and a third actuator which moves a workpiece in a direction perpendicular to the optical axis, wherein a laser processing processor controls the first actuator to select one of at least four of the high-density patterns having different numbers of rows or columns at each of a plurality of step positions in the processing area which are changed by controlling the third actuator so that hole processing is performed only in a processing area on the surface of the workpiece where hole processing is required; controlling the second actuator and the laser device so that a selected pattern is irradiated.

17. A method for manufacturing an electronic device, comprising: a diffractive optical element which splits a first laser beam output from a laser device into a plurality of second laser beams and emits the split laser beams; a focusing optical system which focuses the plurality of second laser beams to generate a lattice-like multi-point pattern in which a plurality of focused spots are arranged in row and column directions; a light-shielding plate capable of shading at least a portion of the multi-point pattern; a first actuator which moves the light-shielding plate in a direction perpendicular to an optical axis of the focusing optical system; a second actuator which is capable of generating a high-density pattern in which the focused spots are densified by moving the multi-point pattern at a movement pitch shorter than a lattice interval; a third actuator which moves a workpiece in a direction perpendicular to the optical axis; and a laser processing processor which controls the first actuator to select one of at least four of the high-density patterns having different numbers of rows or columns at each of a plurality of step positions in the processing area which are changed by controlling the third actuator so that hole processing is performed only in processing areas requiring hole processing on the surface of the workpiece, and controls the second actuator and the laser device so that the selected pattern is irradiated. forming a plurality of through holes in a glass substrate as the workpiece by a laser processing apparatus including: bonding an interposer having the glass substrate and a conductor provided in each of the plurality of through holes to an integrated circuit chip to electrically connect them to each other; and bonding the interposer to a circuit board to electrically connect them to each other.

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