Laser processing apparatus and method for manufacturing electronic devices

Abstract

The present invention provides a laser processing apparatus and a method for manufacturing electronic devices that suppress fluctuations in the focusing position relative to the opening of the mask, thereby suppressing a decrease in transmittance and damage to the mask. [Solution] A laser processing apparatus according to one aspect of the present disclosure is a laser processing apparatus that performs laser processing by irradiating a workpiece with laser light output from a laser device, and comprises: a mask having an aperture and arranged in the optical path of the laser light; an illumination optical system that focuses the laser light to illuminate the aperture; a projection optical system that forms an image of the aperture on the surface of the workpiece; a beam splitter arranged between the illumination optical system and the mask and branches the laser light; an image sensor arranged in the optical path of the laser light branched by the beam splitter and generates an image including a focused image of the laser light on the mask; and a processor that corrects the focusing position of the laser light with respect to the aperture by controlling the illumination optical system based on the image.

Description

[Technical Field]

[0001] This disclosure relates to a laser processing apparatus and a method for manufacturing electronic devices. [Background technology]

[0002] In recent years, semiconductor lithography equipment has been required to improve resolution as semiconductor integrated circuits become smaller and more highly integrated. Therefore, efforts are being made to shorten the wavelength of light emitted from lithography light sources. For example, KrF excimer laser equipment that outputs laser light with a wavelength of approximately 248.4 nm, and ArF excimer laser equipment that outputs laser light with a wavelength of approximately 193.4 nm are used as gas laser equipment for lithography.

[0003] Furthermore, excimer laser light has a pulse width of approximately several tens of nanoseconds and a short wavelength, so it is sometimes used for direct processing of polymer materials, glass materials, and other materials.

[0004] Chemical bonds in polymer materials can be broken 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 polymer materials, resulting in cleaner processed shapes.

[0005] Furthermore, since materials such as glass and ceramics have a high absorption rate for excimer laser light, it is known that even materials that are difficult to process with visible and infrared laser light can be processed with excimer laser light. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Summary of U.S. Patent Application Publication No. 2024 / 0173796

[0007] A laser processing apparatus according to one aspect of the present disclosure is a laser processing apparatus that performs laser processing by irradiating a workpiece with laser light output from a laser device, and comprises: a mask having an aperture and arranged in the optical path of the laser light; an illumination optical system that focuses the laser light to illuminate the aperture; a projection optical system that forms an image of the aperture on the surface of the workpiece; a beam splitter arranged between the illumination optical system and the mask and splitting the laser light; an image sensor arranged in the optical path of the laser light split by the beam splitter and generating an image including a focused image of the laser light on the mask; and a processor that corrects the focusing position of the laser light relative to the aperture by controlling the illumination optical system based on the image.

[0008] A method for manufacturing an electronic device according to one aspect of the present disclosure is a laser processing apparatus that performs laser processing by irradiating a workpiece with laser light output from a laser device, comprising: a mask having an aperture and arranged in the optical path of the laser light; an illumination optical system that focuses the laser light to illuminate the aperture; a projection optical system that forms an image of the aperture onto the surface of the workpiece; a beam splitter arranged between the illumination optical system and the mask and branches the laser light; an image sensor arranged in the optical path of the laser light branched by the beam splitter and generating an image including a focused image of the laser light on the mask; and a processor that corrects the focusing position of the laser light relative to the aperture by controlling the illumination optical system based on the image; and a method for manufacturing an interposer by laser processing an interposer substrate with the laser processing apparatus to manufacture an interposer, coupling the interposer and an integrated circuit chip to electrically connect them to each other, and coupling the interposer and a circuit board to electrically connect them to each other. [Brief explanation of the drawing]

[0009] Some embodiments of this disclosure are described below, merely as examples, with reference to the accompanying drawings. [Figure 1] Figure 1 is a schematic diagram showing the configuration of a laser processing system related to a comparative example. [Figure 2] Figure 2 is a schematic diagram showing the configuration of the laser device. [Figure 3]FIG. 3 is a diagram schematically showing an image of laser light irradiated to a mask. [Figure 4] FIG. 4 is a diagram illustrating a cold state or a low load state. [Figure 5] FIG. 5 is a diagram illustrating how BD varies in a high load state. [Figure 6] FIG. 6 is a diagram illustrating how BP varies in a high load state. [Figure 7] FIG. 7 is a diagram schematically showing the configuration of a laser processing system according to the first embodiment. [Figure 8] FIG. 8 is a diagram schematically showing an image of laser light irradiated to a mask in the first embodiment. [Figure 9] FIG. 9 is a diagram illustrating a cold state or a low load state. [Figure 10] FIG. 10 is a diagram illustrating how BD varies in a high load state. [Figure 11] FIG. 11 is a diagram illustrating how BP varies in a high load state. [Figure 12] FIG. 12 is a diagram for explaining a process of calculating a change amount of a condensing position based on an image. [Figure 13] FIG. 13 is a diagram for explaining an irradiation period and a pause period. [Figure 14] FIG. 14 is a flowchart showing the overall flow of position control of a condenser lens. [Figure 15] FIG. 15 is a flowchart showing the flow of the first control. [Figure 16] FIG. 16 is a flowchart showing the flow of the second control. [Figure 17] FIG. 17 is a diagram schematically showing an image of laser light irradiated to a mask in a modified example. [Figure 18] FIG. 18 is a diagram for explaining a process of calculating a change amount of a condensing position based on an image in a modified example. [Figure 19] FIG. 19 is a diagram schematically showing the configuration of a laser processing system according to the second embodiment. [Figure 20]FIG. 20 is a diagram illustrating a cold state or a low load state. [Figure 21] FIG. 21 is a diagram illustrating the state in which BD fluctuates in a high load state. [Figure 22] FIG. 22 is a diagram illustrating the state in which BP fluctuates in a high load state. [Figure 23] FIG. 23 is a diagram schematically showing the configuration of the laser processing system according to the third embodiment. [Figure 24] FIG. 24 is a diagram illustrating a cold state or a low load state. [Figure 25] FIG. 25 is a diagram illustrating the state in which BP fluctuates in a high load state. [Figure 26] FIG. 26 is a diagram illustrating the state in which BP fluctuates in a high load state. [Figure 27] FIG. 27 is a flowchart showing the flow of the first control in the third embodiment. [Figure 28] FIG. 28 is a flowchart showing the flow of the second control in the third embodiment. [Figure 29] FIG. 29 is a diagram schematically showing the configuration of an electronic device. [Figure 30] FIG. 30 is a flowchart showing a method of manufacturing an electronic device. Embodiment

[0010] <Content> 1. Explanation of Terms 2. Comparative Example 2.1 Configuration 2.1.1 Laser Processing System 2.1.2 Laser Device 2.2 Operation 2.3 Problem 3. First Embodiment 3.1 Configuration 3.2 Operation 3.3 Effect 3.4 Variation 4. Second Embodiment 4.1 Configuration 4.2 Operation 4.3 Effect 4.4 Variations 5. Third Embodiment 5.1 Configuration 5.2 Operation 5.3 Effects 5.4 Variations 6. Methods for Manufacturing Electronic Devices 7. Processor Configuration

[0011] Each embodiment of this disclosure will be described in detail below with reference to the drawings. The embodiments described below are examples of the disclosure and do not limit the scope of this disclosure. Furthermore, not all configurations and operations described in each embodiment are necessarily essential to the configurations and operations of this disclosure. The same reference numerals are used for identical components, and redundant descriptions are omitted.

[0012] 1. Explanation of Terms In this disclosure, a converging lens refers to a lens capable of focusing light rays and having a positive optical power. A typical example of a converging lens is a convex lens. Optical power is defined as the reciprocal of the focal length of the lens, and the shorter the focal length, the greater the optical power.

[0013] Furthermore, in this disclosure, a divergent lens refers to a lens capable of diverging light rays and having a negative optical power. A typical example of a divergent lens is a concave lens.

[0014] Furthermore, the terms "converging lens" and "diverging lens" include, respectively, mirrors, lens sets that integrate multiple lenses, or combinations of mirrors and lenses, each performing substantially equivalent functions.

[0015] 2. Comparative Example 2.1 Configuration 2.1.1 Laser Processing System Figure 1 schematically shows the configuration of the laser processing system 1 according to the comparative example. Note that the comparative example is a form that the applicant recognizes as being known only to the applicant, and is not a prior art example that the applicant acknowledges.

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

[0017] Laser device 2 is a laser device that outputs ultraviolet pulsed laser light. For example, laser device 2 is a discharge-excited laser device that outputs ultraviolet pulsed laser light using F2, ArF, KrF, XeCl, XeF, etc. as the laser medium. In this disclosure, laser device 2 is a KrF excimer laser device that outputs ultraviolet pulsed laser light with a central wavelength of 248.4 nm. Hereinafter, the ultraviolet pulsed laser light output by laser device 2 will simply be referred to as laser light Lb.

[0018] The laser device 2 and the laser processing device 4 are connected by an optical path tube 5. The optical path tube 5 is positioned to surround the optical path of the laser beam Lb between the output port of the laser device 2 and the input port of the laser processing device 4.

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

[0020] The workpiece 45 is the object to be processed, specifically the part that will be drilled. The workpiece 45 is a glass substrate for an interposer, and is, for example, an alkali-free glass substrate. The workpiece 45 may also be a substrate made of quartz glass, organic material, silicon single crystal, ceramics, metal, etc. One or more holes H are formed in the workpiece 45.

[0021] The XYZ stage 43 supports the table 44. The workpiece 45 is fixed on the table 44. The XYZ stage 43 makes the table 44 movable 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 orthogonal to each other. 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 connected to the laser processing processor 40.

[0022] The optical system 41 comprises a housing 41a, high-reflection mirrors 47a and 47b, an attenuator 49, an illumination optical system 50, a mask 60, and a projection optical system 70.

[0023] Each component within the optical system 41 is fixed to a holder (not shown) and is positioned in a predetermined location within the housing 41a.

[0024] The high-reflection mirror 47a is positioned to reflect the laser light Lb that has passed through the optical path tube 5, and the reflected laser light Lb passes through the attenuator 49 and enters 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 an inert gas such as N2 gas, which hardly absorbs the laser light Lb.

[0025] The attenuator 49 is located within 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 incident angle of the laser light Lb. The incident angle of the laser light Lb is adjusted by the rotation stages 49c and 49d for the partial-reflection mirrors 49a and 49b.

[0026] The high-reflectivity mirror 47b is positioned to reflect the laser light Lb that has passed through the attenuator 49, and the reflected laser light Lb is incident on the illumination optical system 50.

[0027] The illumination optical system 50 includes a high-reflection mirror 51 and is arranged to equalize the light intensity distribution of the laser light Lb reflected by the high-reflection mirror 47b, thereby illuminating the mask 60 with a Köhler illuminator.

[0028] The mask 60 is positioned in the optical path between the illumination optical system 50 and the projection optical system 70. The mask 60 is, for example, a light-shielding plate that blocks laser light Lb, and has an opening 61 formed therein that has a shape corresponding to the processed shape of the hole H. In this comparative example, the processed shape is circular, and the opening 61 is a circular pinhole.

[0029] For example, when machining a via hole in a workpiece 45, the mask 60 has an opening 61 formed for machining a hole H having a diameter of 5 μm to 30 μm. If the projection magnification of the projection optical system 70 is M, the diameter of the opening 61 should be 1 / M times the diameter of the hole H to be machined.

[0030] Furthermore, the aperture 61 is not limited to a hole that physically penetrates the mask 60, but also includes a transparent portion that transmits the laser light Lb. The mask 60 may be, for example, a mask in which a pattern of a metal or dielectric multilayer film is formed on a synthetic quartz substrate that transmits ultraviolet light. In this case, the aperture 61 is formed by the pattern.

[0031] The projection optical system 70 is, for example, an imaging lens, and is arranged so that the laser light Lb transmitted through the aperture 61 of the mask 60 is imaged on the surface 45a of the workpiece 45. The imaging plane of the projection optical system 70 is a conjugate plane with the surface of the mask 60 and coincides with the surface 45a of the workpiece 45. In other words, the projection optical system 70 images the image of the aperture 61 of the mask 60 onto the surface 45a of the workpiece 45. Note that the projection optical system 70 may be a reduction projection optical system.

[0032] 2.1.2 Laser equipment Figure 2 schematically shows the 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.

[0033] Chamber 21 is provided with windows 21a and 21b. A laser gas, which serves as the laser medium, is sealed inside Chamber 21.

[0034] Furthermore, an opening is formed in the chamber 21, and an electrical insulating plate 26 with multiple feedthroughs 26a embedded in it is provided to close this opening. A PPM 22 is placed on the electrical insulating plate 26. Inside the chamber 21, a pair of discharge electrodes 27a and 27b as the main electrodes and a ground plate 28 are arranged. The discharge surfaces of the discharge electrodes 27a and 27b are rectangular in shape.

[0035] 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 discharge electrode 27a is supported on the side opposite to the discharge surface by an electrical insulating plate 26. The discharge electrode 27a is connected to a feedthrough 26a. The discharge electrode 27b is supported on the side opposite to the discharge surface by a ground plate 28.

[0036] The PPM22 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 connector (not shown). The charger 23 charges the charging capacitor based on control from the laser processor 38.

[0037] Switch 22a is controlled on / off by the laser processor 38. The laser processor 38 turns on switch 22a in response to the light emission trigger Tr transmitted from the laser processing processor 40.

[0038] 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. The 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, dielectric breakdown occurs in the laser gas between the discharge electrodes 27a and 27b, causing a discharge. This discharge generates one pulse of laser light Lb.

[0039] 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 positioned between the rear mirror 25a and the output coupling mirror 25b. The laser light Lb generated in the chamber 21 is amplified by an optical resonator and output from the output coupling mirror 25b.

[0040] The monitor module 30 includes a beam splitter 31 and an optical sensor 32. The beam splitter 31 is positioned on the optical path of the laser beam Lb output from the output coupling mirror 25b and reflects a portion of the laser beam Lb. The optical sensor 32 is positioned where the laser beam Lb reflected by the beam splitter 31 enters. The optical sensor 32 measures the pulse energy of the laser beam Lb and transmits the measured value to the laser processor 38.

[0041] 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 measurement value from the optical sensor 32.

[0042] The shutter 35 is positioned 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 commands from the laser processor 38. The laser processor 38 controls the output of the laser light Lb from the laser device 2 by controlling the shutter 35.

[0043] 2.2 Operation Next, the operation of the comparative example laser processing system 1 will be described. First, the laser processing processor 40 controls the XYZ stage 43 so that the imaging plane of the projection optical system 70 coincides with the surface 45a of the workpiece 45. Next, the laser processing processor 40 transmits a target pulse energy Et to the laser processor 38 and controls the transmittance of the attenuator 49 so that the fluence on the surface 45a becomes the target fluence Ft.

[0044] When the laser processor 38 receives the target pulse energy Et, it controls the charger 23 so that the pulse energy of the laser light Lb becomes the target pulse energy Et. Next, the laser processor 38 inputs a trigger to the switch 22a, causing the oscillator 20 to oscillate spontaneously. At this time, the shutter 35 is closed.

[0045] The laser light Lb output from the chamber 21 via the output coupling mirror 25b is partially sampled by the monitor module 30, and its pulse energy is measured. The laser processor 38 controls the charger 23 so that the difference ΔE between the pulse energy and the target pulse energy Et approaches zero. When the difference ΔE is within an acceptable range, the laser processor 38 sends a permission signal to the laser processing processor 40 and opens the shutter 35.

[0046] When the laser processing processor 40 receives a permission signal, it transmits a light emission trigger Tr with a predetermined repetition frequency and a predetermined number of pulses to the laser device 2. 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 tube 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 mirror 47b. The laser light Lb reflected by the high-reflection mirror 47b enters the illumination optical system 50.

[0047] The laser light Lb incident on the illumination optical system 50 is reflected by the high-reflectivity mirror 51 and illuminates the area of ​​the mask 60 including the aperture 61. The laser light Lb that passes through the aperture 61 is incident on the projection optical system 70.

[0048] The projection optical system 70 images the incident laser light Lb onto the surface 45a of the workpiece 45. When a predetermined number of laser pulses of laser light Lb are irradiated onto the surface 45a and the fluence exceeds the processing threshold, laser ablation occurs and a hole H is formed.

[0049] Next, the laser processing processor 40 controls the XYZ stage 43 and the laser device 2 to repeatedly change the irradiation position and irradiate in a step-and-repeat manner, thereby forming multiple holes H throughout the processing area where hole processing is required.

[0050] 2.3 Challenges Figure 3 schematically shows the image of the laser beam Lb irradiated onto the mask 60. At the position where the mask 60 is placed, the X direction corresponds to the discharge direction, and the Y direction corresponds to the direction perpendicular to the discharge direction. The laser beam Lb has the characteristic that the beam divergence angle differs in the discharge direction and the direction perpendicular to it due to the influence of the shape and arrangement of the discharge electrodes 27a and 27b. Therefore, the image of the laser beam Lb irradiated onto the mask 60 is size B0 in the X direction. X and size B0 in the Y direction Y They are different.

[0051] As shown in Figure 3, the laser light Lb irradiated onto the aperture 61 of the mask 60 by the illumination optical system 50 has a beam diameter larger than the size of the aperture 61, resulting in low transmittance of the laser light Lb passing through the aperture 61. Consequently, there is a large loss of pulse energy of the laser light Lb output from the laser device 2.

[0052] Therefore, as shown in Figure 4, it is conceivable to improve transmittance by adding a focusing lens 52 to the illumination optical system 50 to focus the laser light Lb incident from the high-reflectivity mirror 51 and irradiating it onto the aperture 61 of the mask 60.

[0053] However, if the operating load of the laser device 2 changes, the beam divergence (BD) and beam pointing (BP) of the laser light Lb output from the laser device 2 will fluctuate, and as a result, the focusing position F of the laser light Lb by the focusing lens 52 will change. In this disclosure, "operating load" refers to the physical effects such as changes in refractive index and deformation of the internal optical components caused by the heat generated during the operation of the laser device 2.

[0054] Figure 4 illustrates the cold or low-load state. Figure 5 illustrates how BD fluctuates under a high-load state. Figure 6 illustrates how BP fluctuates under a high-load state. The operating load of the laser device 2 is lowest in the cold state when pulse oscillation is stopped, and increases as the pulse oscillation frequency, elapsed time since the start of pulse oscillation, pulse energy, etc., increase. It is thought that BD and BP change due to the effects of heat generated during the operation of the laser device 2.

[0055] The term "cold state" refers to a state in which almost no heat has accumulated inside the laser device 2, such as before operation begins, and the physical effects of heat can be ignored. The term "low load state" refers to a state in which almost no heat has accumulated inside the laser device 2, such as immediately after operation begins or when the pulse oscillation frequency is low, and the physical effects of heat can be ignored.

[0056] As shown in Figure 4, under cold or low-load conditions, BD and BP are nearly stable, and the focusing position F coincides with the center of the aperture 61 of the mask 60, resulting in high transmittance of the laser light Lb. As shown in Figure 5, when BD fluctuates under high-load conditions, the focusing position F changes in the Z direction. Also, as shown in Figure 6, when BP fluctuates under high-load conditions, the focusing position F changes in the X or Y direction.

[0057] When the focusing position F changes in this way, a portion of the laser light Lb focused by the focusing lens 52 is blocked by the mask 60. As a result, the transmittance of the laser light Lb passing through the aperture 61 of the mask 60 decreases, and there is a risk that the mask 60 may be damaged by the high pulse energy of the laser light Lb.

[0058] In Figure 4, an example is shown where the aperture 61 of the mask 60 and the focusing position F are approximately coincident in the Z direction. However, in order to illuminate the aperture 61 of the mask 60 with a desired illuminance distribution, such as a uniform illuminance distribution, the system may be configured to focus the light at positions slightly forward or backward in the Z direction. Even in such cases, there is a risk of reduced transmittance or damage to the mask 60 due to fluctuations in BD and BP, as well as the potential for changing the conditions required to illuminate the aperture 61 with a desired illuminance distribution.

[0059] This disclosure provides a laser processing apparatus and a method for manufacturing an electronic device that suppresses a decrease in transmittance and damage to the mask 60 by suppressing fluctuations in the focusing position F relative to the aperture 61 of the mask 60.

[0060] 3. First Embodiment A laser processing system 1a according to the first embodiment of this disclosure will now be described. Components similar to those described above will be denoted by the same reference numerals, and redundant descriptions will be omitted unless otherwise specified.

[0061] 3.1 Configuration Figure 7 schematically shows the configuration of the laser processing system 1a according to the first embodiment. The laser processing system 1a has the same configuration as the laser processing system 1 according to the comparative example, except for the optical system 41.

[0062] In this embodiment, a focusing lens 52, a moving stage 53, a beam splitter 80, and an image sensor 81 are added to the optical system 41. The focusing lens 52 is positioned to focus the laser light Lb incident from the high-reflection mirror 51 and irradiate the aperture 61 of the mask 60. In this embodiment, the focusing lens 52 has optical power in the X and Y directions.

[0063] The moving stage 53 holds the converging lens 52 so that it can move in the X, Y, and Z directions, respectively. The moving stage 53 is connected to and controlled by the laser processing processor 40.

[0064] The beam splitter 80 is positioned in the optical path between the illumination optical system 50 and the mask 60, and splits the laser light Lb incident from the focusing lens 52. Specifically, the beam splitter 80 is a partial reflection mirror that reflects a portion of the laser light Lb that has passed through the focusing lens 52 and transmits the other portion. In this embodiment, the laser light Lb that has passed through the beam splitter 80 is incident on the mask 60.

[0065] Furthermore, the splitting of the laser beam Lb by the beam splitter 80 does not affect the projection onto the workpiece 45 via the projection optical system 70, thus maintaining processing accuracy.

[0066] The image sensor 81 is a sensor capable of capturing a two-dimensional image, and its imaging surface is positioned on the optical path of the laser beam Lb branched by the beam splitter 80, so as to be perpendicular to the optical axis of the laser beam Lb. In this embodiment, the image sensor 81 is positioned on the optical path of the laser beam Lb reflected by the beam splitter 80, and captures a focused image of the laser beam Lb in real time at a position optically conjugate to the mask 60. The image sensor 81 is connected to the laser processing processor 40 and outputs an image D including the focused image to the laser processing processor 40.

[0067] In this embodiment, the laser processing processor 40 measures the position of the focused image of the laser beam Lb on the mask 60 based on the image D, and corrects the focusing position F by adjusting the position of the focusing lens 52 based on the measured value.

[0068] 3.2 Operation The operation of the laser processing system 1a according to the first embodiment is the same as that of the laser processing system 1 according to the comparative example, except that the position adjustment control of the converging lens 52 is additionally performed. The position adjustment control of the converging lens 52 will be described below.

[0069] Figure 8 schematically shows the image of the laser beam Lb irradiated onto the mask 60 in the first embodiment. In this embodiment, since the focusing lens 52 focuses the laser beam Lb in the X and Y directions, the image of the laser beam Lb irradiated onto the mask 60 is smaller than in the comparative example. Specifically, the size of the image in the X direction B1 X and size B1 in the Y direction Y B1 X <B0 X and B1 Y <B0 Y It satisfies the relationship.

[0070] Figure 9 illustrates the cold or low-load state. Figure 10 illustrates how BD fluctuates under a high-load state. Figure 11 illustrates how BP fluctuates under a high-load state. As shown in Figure 9, under the cold or low-load state, the focusing position F coincides with the center of the aperture 61 of the mask 60.

[0071] As shown in Figure 10, if the focusing position F changes in the Z direction due to fluctuations in BD, the laser processing processor 40 controls the moving stage 53 to adjust the position of the focusing lens 52 in the Z direction. This corrects the focusing position F so that it coincides with the center of the aperture 61 of the mask 60. In Figure 10, the focusing lens 52, moving stage 53, and laser beam Lb before correction are shown by dashed lines. The same applies to the figures described below.

[0072] As shown in Figure 11, if the focusing position F changes in the X or Y direction due to fluctuations in BP, the laser processing processor 40 controls the moving stage 53 to adjust the position of the focusing lens 52 in the X or Y direction. This corrects the focusing position F so that it coincides with the center of the aperture 61 of the mask 60.

[0073] Figure 12 illustrates the process of calculating the change in the focusing position F based on image D. As shown in Figure 12, image D captures the focused image of the laser beam Lb. The center coordinates (xc,yc) of the focused image represent the positions of the focusing position F in the X and Y directions. The center coordinates (xc,yc) are defined as the peak position of the light intensity or the centroid position of the light intensity.

[0074] The difference (xdiff, ydiff) between the central coordinates (x0, y0) of aperture 61 and the central coordinates (xc, yc) of the focused image corresponds to the change in the X and Y directions of the focusing position F due to the variation in BP. The difference (xdiff, ydiff) is expressed by the following equations (1A) and (1B).

[0075]

number

number

[0076] The laser processing processor 40 controls the moving stage 53 and moves the converging lens 52 in the X and Y directions by the correction amounts (Δx, Δy). The correction amounts (Δx, Δy) are represented by the following equations (2A) and (2B).

[0077]

Equation

Equation

[0078] Here, C1x and C1y are the proportionality coefficients in the X and Y directions, respectively, and represent the ratio of the movement amount of the converging lens 52 to the movement amount of the condensing position F.

[0079] Also, the width wx in the X direction and the width wy in the Y direction of the converging image are indirect indicators for specifying the position of the converging position F in the Z direction. Either of the widths wx and wy can be used for specification, but in this embodiment, for example, only the width wx is used for specification. Specifically, the light quantity threshold T X The width in the X direction of the converging image having the above light quantity is measured as the width wx. The light quantity threshold T X As, the full width at half maximum (FWHM) of the light quantity distribution of the converging image, or the value at which the light quantity becomes 1 / e 2 times the maximum value is generally used.

[0080] The difference zdiff between the reference width wx0 and the width wx corresponds to the change amount in the Z direction of the converging position F due to the variation of BD. The difference zdiff is represented by the following equation (3). The reference width wx0 is the width in the X direction of the converging image in the cold state.

[0081]

Equation

[0082] The laser processing processor 40 controls the moving stage 53 to move the focusing lens 52 in the Z direction by a correction amount Δz. The correction amount Δz is expressed by the following equation (4).

[0083]

number

[0084] Here, C1z is the proportionality constant in the Z direction, representing the ratio of the movement of the converging lens 52 to the movement of the focusing position F.

[0085] The position control of the focusing lens 52 described above is performed during the irradiation period after the laser device 2 starts operation. The irradiation period is the period during which the laser device 2 performs pulse oscillation and a predetermined number of laser pulses Lb are irradiated onto the workpiece 45. During the irradiation period, the center coordinates (xc, yc) of the focused image and the width wx of the focused image can be measured based on the image D each time the laser light Lb is irradiated. Therefore, during the irradiation period, the position of the focusing lens 52 can be adjusted in real time based on the measured values. As a result, during the irradiation period, the focusing position F is maintained to coincide with the center of the aperture 61 of the mask 60.

[0086] As shown in Figure 13, after the irradiation period ends, there is a pause period followed by the start of another irradiation period. The pause period is the period during which the laser device 2 stops pulse oscillation and does not irradiate the workpiece 45 with laser light Lb. For example, the pause period corresponds to the period during which the irradiation position is changed by the XYZ stage 43 after one hole H has been machined in the workpiece 45.

[0087] During the pause period, the laser beam Lb is not irradiated onto the mask 60, so it is not possible to measure the center coordinates (xc,yc) of the focused image and the width wx of the focused image. For this reason, during the pause period, the laser processing processor 40 corrects the position of the focusing lens 52 based on the attenuation curve G represented by equation (5) below.

[0088]

number

[0089] Here, P represents the corrected position of the focusing lens 52 during the pause period. Pc is the position of the focusing lens 52 in the cold state. Ph is the position of the focusing lens 52 at the end of the previous irradiation period. t is the elapsed time from the start of the pause period. τ i is the time constant. i is a positive integer between 1 and n. C i is the time constant τ i The coefficient of contribution is such that it satisfies the relationship shown in equation (6) below.

[0090]

number

[0091] Note that equation (5) above does not distinguish between the X, Y, and Z directions. However, in each direction, the position of the converging lens 52 is corrected based on the attenuation curve G represented by equation (5) above. The attenuation curve G represents the attenuation of the heat load received during the immediately preceding irradiation period.

[0092] If the position of the focusing lens 52 is not corrected during the pause period, the position at the end of the irradiation period will remain unchanged. Therefore, if the focusing position F changes due to load attenuation during the pause period, when the irradiation period is resumed, the laser beam Lb immediately after the restart will be focused at a focusing position F that is offset from the center of the aperture 61 of the mask 60. In this way, by correcting the position of the focusing lens 52 based on the attenuation curve G during the pause period, the focusing position F can be maintained at the center of the aperture 61 with high precision.

[0093] Hereinafter, the position control of the converging lens 52 during the irradiation period will be referred to as "first control," and the position control of the converging lens 52 during the rest period will be referred to as "second control."

[0094] Figure 14 shows the overall flow of position control of the focusing lens 52. First, after the laser device 2 starts operation, the laser processing processor 40 determines whether the current time is during the irradiation period (step S10). If the laser processing processor 40 is in the irradiation period (step S10: YES), it executes the first control (step S11). On the other hand, if the laser processing processor 40 is not in the irradiation period, i.e., in the idle period (step S10: NO), it executes the second control (step S12).

[0095] After executing the first or second control, the laser processing processor 40 determines whether or not the termination condition is met (step S13). For example, the termination condition is that the laser processing processor 40 has received a termination command from an external device. If the laser processing processor 40 determines that the termination condition is not met (step S13: NO), it returns to step S10. If the laser processing processor 40 determines that the termination condition is met (step S13: YES), it terminates the process.

[0096] Through the above process, the first control is executed during the irradiation period, and the second control is executed during the rest period.

[0097] Figure 15 shows the flow of the first control. In the first control, the laser processing processor 40 first acquires the image D output from the image sensor 81 (step S110). Based on the acquired image D, the laser processing processor 40 calculates the center coordinates (xc, yc) of the focused image (step S111). Furthermore, the laser processing processor 40 calculates the difference (xdiff, ydiff) between the calculated center coordinates (xc, yc) and the center coordinates (x0, y0) of the aperture 61 (step S112). Next, the laser processing processor 40 controls the moving stage 53 to move the focusing lens 52 in the X and Y directions by a correction amount (Δx, Δy) (step S113).

[0098] Next, the laser processing processor 40 calculates the width wx of the focused image based on image D (step S114). After calculating the difference zdiff between the calculated width wx and the reference width wx0 (step S115), the laser processing processor 40 controls the moving stage 53 to move the focusing lens 52 in the Z direction by a correction amount Δz (step S116).

[0099] Note that the first control flow shown in Figure 15 is merely an example, and the order of processing can be changed as appropriate. For example, steps S114 to S116 may be executed before steps S111 to S113. Alternatively, steps S111, S112, S114, and S115 may be executed first, followed by steps S113 and S116.

[0100] Figure 16 shows the flow of the second control. In the second control, the laser processing processor 40 first determines whether the current time is immediately after the start of the pause period (step S120). If the laser processing processor 40 determines that it is immediately after the start of the pause period (step S120: YES), it stores the position Ph of the focusing lens 52 at the end of the previous irradiation period in a memory not shown (step S121). On the other hand, if it is not immediately after the start of the pause period (step S120: NO), step S121 is not executed.

[0101] Subsequently, the laser processing processor 40 obtains the elapsed time t from the start of the pause period (step S122) and calculates the correction position P of the focusing lens 52 using the above equation (5) (step S123). At this time, the laser processing processor 40 uses the position Ph of the focusing lens 52 stored in step S121 and the elapsed time t obtained in step S122. Then, the laser processing processor 40 controls the moving stage 53 to change the position of the focusing lens 52 to the correction position P (step S124).

[0102] As described above, the laser processing processor 40 changes the focusing position F at regular intervals by executing the first control or the second control at regular intervals. Here, for example, the regular interval is set as an integer multiple of the pulse oscillation period of the laser device 2.

[0103] 3.3 Effects According to this embodiment, the laser processing processor 40 corrects the position of the focusing lens 52 based on the image D during the irradiation period, thereby effectively suppressing fluctuations in the focusing position F relative to the aperture 61 of the mask 60. As a result, the stability of the focusing position F is improved, preventing a decrease in transmittance and suppressing damage to the mask 60.

[0104] Furthermore, since the laser processing processor 40 adjusts the position of the focusing lens 52 during the pause period, the focusing position F can be maintained with high precision at the center of the aperture 61 of the mask 60 immediately after the irradiation period resumes.

[0105] 3.4 Variations Next, a modified version of the first embodiment will be described. In this modified version, the opening 61 of the mask 60 described in the first embodiment is made into a slit shape, and the converging lens 52 is configured as a cylindrical lens.

[0106] In this modified example, the aperture 61 of the mask 60 is a slit shape extended in the X direction. The focusing lens 52 is a cylindrical lens having optical power in the Y direction, which is the width direction of the slit shape, and focuses the laser beam Lb in the Y direction.

[0107] Figure 17 schematically shows the image of the laser beam Lb irradiated onto the mask 60 in a modified example. In this modified example, since the focusing lens 52 focuses the laser beam Lb only in the Y direction, the image of the laser beam Lb irradiated onto the mask 60 is elongated in the X direction compared to the first embodiment. Specifically, since the focusing lens 52 does not have optical power in the X direction, the size of the image in the X direction is the size B0 before focusing. X It is maintained identically to the above.

[0108] Furthermore, since the converging lens 52 does not possess optical power in the X direction, control of the converging lens 52 in the X direction is unnecessary in this modified example. As a result, the X-direction movement mechanism in the moving stage 53 can be omitted. Specifically, even when the converging lens 52 is moved in the X direction, the focusing position F of the laser beam Lb does not change in the X direction, and this does not affect the focusing accuracy of the aperture 61 of the mask 60. Therefore, there is no need to adjust the position of the converging lens 52 in the X direction.

[0109] Figure 18 illustrates the process of calculating the change in the focusing position F based on image D in a modified example. As shown in Figure 18, image D captures the focused image of the laser beam Lb. In this modified example, the laser processing processor 40 only needs to calculate the center coordinate yc in the Y direction and the width wy in the Y direction of the focused image based on image D. The first and second controls in this modified example are the same as in the first embodiment, except that the focusing lens 52 is not moved in the X direction.

[0110] 4. Second Embodiment A laser processing system 1b according to a second embodiment of this disclosure will now be described. Components similar to those described above will be denoted by the same reference numerals, and redundant descriptions will be omitted unless otherwise specified.

[0111] 4.1 Configuration Figure 19 schematically shows the configuration of the laser processing system 1b according to the second embodiment. The laser processing system 1b has the same configuration as the laser processing system 1a according to the first embodiment, except for the illumination optical system 50.

[0112] In this embodiment, the illumination optical system 50 includes a high-reflection mirror 51, a converging lens 52, a diverging lens 54 positioned upstream of the converging lens 52, and a moving stage 55 that holds the diverging lens 54. The diverging lens 54 has the role of adjusting the divergence angle of the laser light Lb and is configured to be movable in the X, Y, and Z directions by the moving stage 55. In this embodiment, the converging lens 52 is fixed. In this embodiment, the converging lens 52 and the diverging lens 54 have optical power in the X and Y directions, respectively.

[0113] The moving stage 55 is connected to and controlled by the laser processing processor 40. In this embodiment, the laser processing processor 40 adjusts the focusing position F of the laser beam Lb by moving the diverging lens 54 instead of moving the converging lens 52 as in the first embodiment.

[0114] 4.2 Operation The operation of the laser processing system 1b according to the second embodiment is the same as that of the laser processing system 1a according to the first embodiment, except for the position adjustment control of the diverging lens 54. The position adjustment control of the diverging lens 54 will be described below.

[0115] Figure 20 illustrates the cold or low-load state. Figure 21 illustrates how BD fluctuates under a high-load state. Figure 22 illustrates how BP fluctuates under a high-load state. As shown in Figure 20, under the cold or low-load state, the focusing position F coincides with the center of the aperture 61 of the mask 60.

[0116] As shown in Figure 21, if the focusing position F changes in the Z direction due to fluctuations in BD, the laser processing processor 40 controls the moving stage 55 to adjust the position of the diverging lens 54 in the Z direction. This corrects the focusing position F so that it coincides with the center of the aperture 61 of the mask 60.

[0117] As shown in Figure 22, if the focusing position F changes in the X or Y direction due to fluctuations in BP, the laser processing processor 40 controls the moving stage 55 to adjust the position of the diverging lens 54 in the X or Y direction. This corrects the focusing position F to coincide with the center of the aperture 61 of the mask 60.

[0118] The position adjustment control of the diverging lens 54 in this embodiment is basically the same as the position control of the converging lens 52 in the first embodiment, except that the position of the diverging lens 54 is controlled instead of the converging lens 52. Specifically, the first control in this embodiment is performed in the same procedure as the first control in the first embodiment, except that the position of the diverging lens 54 is controlled instead of the converging lens 52.

[0119] In the second control of this embodiment, if it is immediately after a pause period, instead of the converging lens 52, control is performed to store the position Ph of the diverging lens 54 at the end of the previous irradiation period. Also, in the second control of this embodiment, instead of the converging lens 52, a correction position P of the diverging lens 54 is calculated, and the position of the diverging lens 54 is changed to the correction position P. The correction position P is calculated based on the attenuation curve G represented by equation (5) above, as in the first embodiment. In this embodiment, Pc is the position of the diverging lens 54 in the cold state.

[0120] 4.3 Effects According to this embodiment, the laser processing processor 40 corrects the position of the divergent lens 54 based on the image D during the irradiation period, so, similar to the first embodiment, fluctuations in the focusing position F relative to the aperture 61 of the mask 60 can be effectively suppressed. As a result, the stability of the focusing position F is improved, preventing a decrease in transmittance and suppressing damage to the mask 60.

[0121] Furthermore, since the laser processing processor 40 adjusts the position of the divergent lens 54 during the pause period, the focusing position F can be maintained with high precision at the center of the aperture 61 of the mask 60, even immediately after the irradiation period is resumed, similar to the first embodiment.

[0122] 4.4 Variations Next, a modified example of the second embodiment will be described. In this modified example, similar to the modified example of the first embodiment, the opening 61 of the mask 60 is made into a slit shape, and the converging lens 52 and the diverging lens 54 are each configured as cylindrical lenses.

[0123] In this modified example, the converging lens 52 is a cylindrical lens having optical power in the Y direction and focuses the laser beam Lb in the Y direction. The diverging lens 54 is a cylindrical lens having optical power in the Y direction and has the function of adjusting the divergence angle of the laser beam Lb in the Y direction.

[0124] In this modified version, since the diverging lens 54 does not have optical power in the X direction, control of the diverging lens 54 in the X direction is unnecessary. As a result, the X-direction movement mechanism in the moving stage 55 can be omitted. Specifically, even if the diverging lens 54 is moved in the X direction, the focusing position F of the laser beam Lb does not change in the X direction and does not affect the focusing accuracy of the aperture 61 of the mask 60. Therefore, there is no need to adjust the position of the diverging lens 54 in the X direction.

[0125] In this modified example, the laser processing processor 40 only needs to calculate the center coordinate yc and the width wy in the Y direction of the focused image based on the image D. The first and second controls in this modified example are the same as in the second embodiment, except that the divergent lens 54 is not moved in the X direction.

[0126] 5. Third Embodiment A laser processing system 1c according to the third embodiment of this disclosure will now be described. Components similar to those described above will be denoted by the same reference numerals, and redundant descriptions will be omitted unless otherwise specified.

[0127] 5.1 Configuration Figure 23 schematically shows the configuration of the laser processing system 1c according to the third embodiment. The laser processing system 1c has the same configuration as the laser processing system 1a according to the first embodiment, except for the illumination optical system 50.

[0128] In this embodiment, the illumination optical system 50 includes a high-reflection mirror 51, a converging lens 52, and a tilting stage 56 that holds the high-reflection mirror 51. The high-reflection mirror 51 has the role of adjusting the BP of the laser light Lb, and is configured so that its angle can be changed in the θx direction and θy direction by the tilting stage 56. Here, the θx direction is the direction of rotation with an axis parallel to the Y direction as the axis of rotation. The θy direction is the direction of rotation with an axis parallel to the X direction as the axis of rotation. In this embodiment, the converging lens 52 is fixed and has optical power in the X direction and Y direction. The high-reflection mirror 51 is an example of a "mirror" according to the technology of this disclosure.

[0129] The tilting stage 56 is connected to and controlled by the laser processing processor 40. In this embodiment, instead of moving the focusing lens 52 as in the first embodiment, the laser processing processor 40 controls the tilting stage 56 to adjust the angle of the high-reflection mirror 51, thereby adjusting the focusing position F of the laser beam Lb. In this embodiment, the focusing position F can be adjusted in the X direction or the Y direction.

[0130] 5.2 Operation The operation of the laser processing system 1c according to the third embodiment is the same as that of the laser processing system 1a according to the first embodiment, except for the angle adjustment control of the high-reflection mirror 51. The angle adjustment control of the high-reflection mirror 51 will be described below.

[0131] Figure 24 illustrates the cold or low-load state. Figures 25 and 26 illustrate how BP fluctuates under a high-load state. As shown in Figure 24, under the cold or low-load state, the focusing position F coincides with the center of the aperture 61 of the mask 60.

[0132] As shown in Figure 25, if the focusing position F changes in the X direction due to fluctuations in BP, the laser processing processor 40 controls the tilting stage 56 to adjust the angle of the high-reflectivity mirror 51 in the θx direction. This corrects the focusing position F so that it coincides with the center of the aperture 61 of the mask 60.

[0133] As shown in Figure 26, even when the focusing position F changes in the opposite direction to that shown in Figure 25 due to fluctuations in BP, the laser processing processor 40 controls the tilting stage 56 to adjust the angle of the high-reflectivity mirror 51 in the θx direction. This corrects the focusing position F to coincide with the center of the aperture 61 of the mask 60.

[0134] If the focusing position F changes in the Y direction due to fluctuations in BP, the laser processing processor 40 controls the tilting stage 56 to adjust the angle of the high-reflectivity mirror 51 in the θy direction.

[0135] Figure 27 shows the flow of the first control in the third embodiment. Steps S110A to S112A shown in Figure 27 are the same as steps S110 to S112 described in the first embodiment. In this embodiment, after step S112A, the laser processing processor 40 controls the tilting stage 56 and changes the angle of the high-reflection mirror 51 by a correction amount (Δθx, Δθy) (step S113). The correction amount (Δθx, Δθy) is expressed by the following equations (7A) and (7B).

[0136]

number

number

[0137] Here, C2x and C2y are proportionality constants in the θx and θy directions, respectively, and represent the ratio of the change in the angle of the high-reflectivity mirror 51 to the amount of movement of the focusing position F.

[0138] Figure 28 shows the flow of the second control in the third embodiment. In the second control, the laser processing processor 40 first determines whether the current time is immediately after the start of the pause period (step S120A). If the laser processing processor 40 determines that it is immediately after the start of the pause period (step S120A: YES), it stores the angle Nh of the high-reflectivity mirror 51 at the end of the previous irradiation period in memory (step S121A). On the other hand, if it is not immediately after the start of the pause period (step S120A: NO), step S121A is not executed.

[0139] Subsequently, the laser processing processor 40 obtains the elapsed time t from the start of the pause period (step S122A) and calculates the correction angle N of the high-reflection mirror 51 using the following formula (8) (step S123A). At this time, the laser processing processor 40 uses the angle Nh of the high-reflection mirror 51 stored in step S121A and the elapsed time t obtained in step S122A. Then, the laser processing processor 40 controls the tilting stage 56 and changes the angle of the high-reflection mirror 51 to the correction angle N (step S124A).

[0140]

number

[0141] Here, Nc is the angle of the high-reflectivity mirror 51 in the cold state. i is the time constant τ i The coefficient of contribution is such that it satisfies the relationship in equation (6) above.

[0142] Note that equation (8) above does not distinguish between the θx direction and the θy direction. However, in each direction, the angle of the high-reflection mirror 51 is corrected based on the damping curve represented by equation (8) above.

[0143] 5.3 Effects According to this embodiment, the laser processing processor 40 corrects the angle of the high-reflectivity mirror 51 based on the image D during the irradiation period, so, similar to the first embodiment, fluctuations in the focusing position F relative to the aperture 61 of the mask 60 can be effectively suppressed. As a result, the stability of the focusing position F is improved, a decrease in transmittance is prevented, and damage to the mask 60 is suppressed.

[0144] Furthermore, since the laser processing processor 40 adjusts the angle of the high-reflection mirror 51 during the pause period, the focusing position F can be maintained with high precision at the center of the aperture 61 of the mask 60, even immediately after the irradiation period is resumed, similar to the first embodiment.

[0145] 5.4 Variations Next, a modification of the third embodiment will be described. In this modification, similar to the modification of the first embodiment, the opening 61 of the mask 60 is made into a slit shape, and the converging lens 52 is further configured as a cylindrical lens.

[0146] In this modified example, the converging lens 52 is a cylindrical lens having optical power in the Y direction, and focuses the laser beam Lb in the Y direction.

[0147] In this modified configuration, since the converging lens 52 does not have optical power in the X direction, the angle adjustment mechanism in the θx direction of the tilting stage 56 can be omitted. As a result, control of the high-reflection mirror 51 in the θx direction becomes unnecessary. Specifically, even if the angle of the high-reflection mirror 51 is changed in the θx direction, the focusing position F of the laser beam Lb does not change in the X direction, and the focusing accuracy of the aperture 61 of the mask 60 is not affected. Therefore, there is no need to adjust the angle of the high-reflection mirror 51 in the θx direction.

[0148] In this modified example, since only the angle of the high-reflection mirror 51 in the θy direction is adjusted, the laser processing processor 40 only needs to calculate the center coordinate yc of the focused image in the Y direction based on the image D. The first and second controls in this modified example are the same as in the third embodiment, except that the angle of the high-reflection mirror 51 is not changed in the θx direction.

[0149] Furthermore, the angle adjustment of the high-reflection mirror 51 in the third embodiment can also be applied to the first or second embodiment and performed in combination with the position adjustment of the converging lens 52 or the diverging lens 54.

[0150] 6. Methods for Manufacturing Electronic Devices The laser processing methods according to each of the above embodiments can be applied to the formation of through-holes in the substrate of the interposer IP in the manufacturing of the following electronic device 100.

[0151] Figure 29 schematically shows the configuration of the electronic device 100. The electronic device 100 shown in Figure 29 includes an integrated circuit chip IC, an interposer IP, and a circuit board CS. The integrated circuit chip IC is, for example, a chip in which an integrated circuit (not shown) is formed on a silicon substrate. The integrated circuit chip IC is provided with a plurality of bump ICBs that are electrically connected to the integrated circuit.

[0152] The interposer IP comprises an insulating substrate with a plurality of through-holes (not shown) formed therein, and a conductor (not shown) is provided in each through-hole to electrically connect the front and back surfaces of the substrate. A plurality of lands (not shown) are formed on one side of the interposer IP, each connected to a bump ICB, and each land is electrically connected to one of the conductors in the through-holes. A plurality of bump IPBs are provided on the other side of the interposer IP, and each bump IPB is electrically connected to one of the conductors in the through-holes.

[0153] On one side of the circuit board CS, there are several lands (not shown) which are connected to bumps IPB. The circuit board CS is equipped with several terminals which are electrically connected to these lands.

[0154] Figure 30 shows the manufacturing method of the electronic device 100. First, in the first step SP1, laser processing and wiring formation are performed on the interposer substrate constituting the interposer IP. The laser processing of the interposer substrate includes the formation of through holes by irradiating the interposer substrate with pulsed laser light. The wiring formation includes the formation of a conductive film on the inner wall surface of the through holes formed in the interposer substrate. The interposer IP is manufactured by the first step SP1.

[0155] Next, in the second step SP2, the interposer IP and the integrated circuit chip IC are coupled. The second step SP2 includes, for example, placing the bump ICB of the integrated circuit chip IC on the land of the interposer IP and electrically connecting the bump ICB and the land.

[0156] Then, in the third step SP3, the interposer IP and the circuit board CS are coupled. The third step SP3 includes, for example, placing the bump IPB of the interposer IP on the land of the circuit board CS to electrically connect the bump IPB and the land.

[0157] 7. Processor Configuration The laser processing processor 40 and the laser processor 38 may be physically configured in hardware form to perform the various processes included in this disclosure. For example, the laser processing processor 40 and the laser processor 38 may be a computer including a memory storing a control program that defines the various processes, and a processing unit that executes the control program. The control program may be stored in a single memory, or it may be stored in multiple physically separate memories, and the various processes may be defined by the control program as a collection of these memories. The processing unit may be a general-purpose processing unit such as a CPU (Central Processing Unit), or a purpose-specific processing unit such as a GPU (Graphics Processing Unit).

[0158] Furthermore, the laser processing processor 40 and the laser processor 38 may be programmed in software form to perform the various processes included in this disclosure. For example, the laser processing processor 40 and the laser processor 38 may have the functions for performing the various processes implemented in a dedicated device such as an ASIC (Application Specific Integrated Circuit) or a programmable device such as an FPGA (Field Programmable Gate Array).

[0159] The various processes included in this disclosure may be performed by one computer, one dedicated device, or one programmable device, or by the cooperation of multiple computers, multiple dedicated devices, or multiple programmable devices located physically separately. The various processes may be performed by at least two combinations of one or more computers, one or more dedicated devices, and one or more programmable devices.

[0160] The above description is intended to be illustrative, not restrictive. It will be apparent to those skilled in the art that modifications can be made to the embodiments of this disclosure without departing from the claims. It will also be apparent to those skilled in the art that the embodiments of this disclosure can be used in combination. Terms used herein and throughout the claims should be construed as "non-restrictive" unless otherwise specified. For example, terms such as "includes," "has," "equips," and "possesses" should be construed as "not excluding the existence of components other than those described." The modifier "one" should be construed as meaning "at least one" or "one or more." The term "at least one of A, B, and C" should be construed as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C," and further construed as including combinations of these with anything other than "A," "B," and "C."

Claims

1. A laser processing apparatus that performs laser processing by irradiating a workpiece with laser light output from a laser device, A mask having an aperture is placed on the optical path of the laser beam, An illumination optical system that focuses the laser light to illuminate the aperture, A projection optical system that projects the image of the aperture onto the surface of the workpiece, A beam splitter is positioned between the illumination optical system and the mask and divides the laser light, An image sensor is positioned on the optical path of the laser beam split by the beam splitter and generates an image including a focused image of the laser beam on the mask, A processor that corrects the focusing position of the laser beam relative to the aperture by controlling the illumination optical system based on the aforementioned image, A laser processing device equipped with the following features.

2. A laser processing apparatus according to claim 1, The processor changes the light-gathering position at regular intervals.

3. A laser processing apparatus according to claim 1, The illumination optical system includes a focusing lens for focusing the laser light and a moving stage that movably holds the focusing lens. The processor corrects the focusing position by controlling the moving stage based on the image and adjusting the position of the focusing lens.

4. A laser processing apparatus according to claim 3, The aforementioned opening is slit-shaped, The converging lens is a cylindrical lens having optical power in the width direction of the slit shape.

5. A laser processing apparatus according to claim 3, The processor adjusts the position of the converging lens based on the light intensity peak position or the light intensity centroid position of the collected image.

6. A laser processing apparatus according to claim 3, The processor adjusts the position of the converging lens based on the width of the condensed image.

7. A laser processing apparatus according to claim 3, During the pause period when the output of the laser light from the laser device is suspended, the processor calculates a correction position based on an attenuation curve representing the change in the position of the converging lens, and changes the position of the converging lens to the correction position.

8. A laser processing apparatus according to claim 7, The aforementioned damping curve is expressed by equation (1), Here, P is the correction position, Pc is the position of the focusing lens in the cold state, Ph is the position of the focusing lens at the end of the previous irradiation period, t is the elapsed time from the start of the pause period, and τ ｉ C is the time constant. ｉ The time constant τ ｉ This is the coefficient of contribution. [Math 1]

9. A laser processing apparatus according to claim 1, The illumination optical system includes a focusing lens for focusing the laser light, a diverging lens positioned upstream of the focusing lens, and a moving stage that movably holds the diverging lens. The processor corrects the focusing position by controlling the moving stage based on the image and adjusting the position of the diverging lens.

10. A laser processing apparatus according to claim 9, The aforementioned opening is slit-shaped, The converging lens and the diverging lens are each cylindrical lenses having optical power in the width direction of the slit shape.

11. A laser processing apparatus according to claim 9, The processor adjusts the position of the diverging lens based on the light intensity peak position or light intensity centroid position of the focused image.

12. A laser processing apparatus according to claim 9, The processor adjusts the position of the diverging lens based on the width of the focused image.

13. A laser processing apparatus according to claim 9, During the pause period when the output of the laser light from the laser device is suspended, the processor calculates a correction position based on an attenuation curve representing the change in the position of the diverging lens, and changes the position of the diverging lens to the correction position.

14. A laser processing apparatus according to claim 13, The aforementioned damping curve is represented by equation (2), Here, P is the correction position, Pc is the position of the diverging lens in the cold state, Ph is the position of the diverging lens at the end of the previous irradiation period, t is the elapsed time from the start of the rest period, and τ ｉ C is the time constant. ｉ The time constant τ ｉ This is the coefficient of contribution. [Math 2]

15. A laser processing apparatus according to claim 1, The illumination optical system includes a mirror that reflects the laser light, a focusing lens that concentrates the laser light, and an inclined stage that holds the mirror so that its angle can be changed. The processor corrects the light-gathering position by controlling the tilting stage based on the image and adjusting the angle of the mirror.

16. A laser processing apparatus according to claim 15, The aforementioned opening is slit-shaped, The converging lens is a cylindrical lens having optical power in the width direction of the slit shape.

17. A laser processing apparatus according to claim 15, The processor adjusts the angle of the mirror based on the light intensity peak position or the light intensity centroid position of the focused image.

18. A laser processing apparatus according to claim 15, During the pause period when the output of the laser light from the laser device is suspended, the processor calculates a correction angle based on an attenuation curve representing the change in the angle of the mirror, and changes the angle of the mirror to the correction angle.

19. A laser processing apparatus according to claim 18, The aforementioned damping curve is represented by equation (3), Here, N is the correction angle, Nc is the angle of the mirror in the cold state, Nh is the angle of the mirror at the end of the immediately preceding irradiation period, t is the elapsed time since the start of the pause period, τ ｉ is the time constant, C ｉ is the time constant τ ｉ is the contribution coefficient of [Math 3]

20. A method for manufacturing electronic devices, A laser processing apparatus that performs laser processing by irradiating a workpiece with laser light output from a laser device, A mask having an aperture is placed on the optical path of the laser beam, An illumination optical system that focuses the laser light to illuminate the aperture, A projection optical system that projects the image of the aperture onto the surface of the workpiece, A beam splitter is positioned between the illumination optical system and the mask and divides the laser light, An image sensor is positioned on the optical path of the laser beam split by the beam splitter and generates an image including a focused image of the laser beam on the mask, A processor that corrects the focusing position of the laser beam relative to the aperture by controlling the illumination optical system based on the aforementioned image, An interposer is manufactured by laser processing an interposer substrate using a laser processing device equipped with the following: The interposer and the integrated circuit chip are coupled together and electrically connected to each other. The interposer and the circuit board are coupled together and electrically connected to each other. A method for manufacturing electronic devices, including the following.

Images