Laser processing apparatus and method of manufacturing electronic device

Abstract

The present application provides a laser processing apparatus and a method for manufacturing electronic devices, which is related to a laser processing apparatus that performs laser processing by irradiating laser light output from a laser device to a workpiece, the laser processing apparatus including: a mask disposed in an optical path of the laser light, having an opening; an illumination optical system that converges the laser light to illuminate the opening; a projection optical system that images an image of the opening on a surface of the workpiece; a beam splitter disposed between the illumination optical system and the mask, that branches the laser light; an image sensor disposed in an optical path of the laser light branched by the beam splitter, that generates an image containing a converged image of the laser light on the mask; and a processor that controls the illumination optical system based on the image, thereby correcting a converged position of the laser light with respect to the opening.

Description

Technical Field

[0001] This disclosure relates to laser processing apparatus and methods for manufacturing electronic devices. Background Technology

[0002] In recent years, with the miniaturization and high integration of semiconductor integrated circuits, there has been a growing demand for higher resolution in semiconductor exposure equipment. Therefore, efforts are underway to shorten the wavelength of light emitted from exposure light sources. For example, KrF excimer laser devices using lasers with an output wavelength of approximately 248.4 nm and ArF excimer laser devices using lasers with an output wavelength of approximately 193.4 nm are examples of gas laser devices used for exposure.

[0003] In addition, excimer lasers have a pulse width of about 10 ns and a short wavelength, so they are sometimes used for the direct processing of polymer materials, glass materials, etc.

[0004] Chemical bonds in polymer materials can be broken using excimer lasers, which have photon energies higher than bond energies. Therefore, it is known that excimer lasers can be used for non-thermal processing of polymer materials, resulting in aesthetically pleasing shapes.

[0005] In addition, it is known that glass, ceramics and other materials have high absorption rates for excimer lasers, so even materials that are difficult to process using visible light and infrared lasers can be processed using excimer lasers.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: U.S. Patent Application Publication No. 2024 / 0173796 Summary of the Invention

[0009] One aspect of this disclosure relates to a laser processing apparatus that performs laser processing by irradiating a workpiece with laser light output from a laser device. The laser processing apparatus comprises: a mask disposed in the optical path of the laser and having an opening; an illumination optics system that focuses the laser light to illuminate the opening; a projection optics system that images the opening onto the surface of the workpiece; a beam splitter disposed between the illumination optics system and the mask to branch the laser light; an image sensor disposed in the optical path of the laser light branched by the beam splitter, generating an image containing a converged image of the laser light on the mask; and a processor that controls the illumination optics system based on the image to correct the convergence position of the laser light relative to the opening.

[0010] One aspect of this disclosure relates to a method for manufacturing an electronic device, comprising: forming an interposer layer by laser processing an interposer substrate using a laser processing apparatus; bonding and electrically connecting the interposer layer to an integrated circuit chip, thereby bonding and electrically connecting the interposer layer to a circuit board, wherein the laser processing apparatus performs laser processing by irradiating a workpiece with laser light output from a laser device; the laser processing apparatus comprising: a mask disposed in the optical path of the laser light and having an opening; an illumination optics system that focuses the laser light to illuminate the opening; a projection optics system that images the opening onto the surface of the workpiece; a beam splitter disposed between the illumination optics system and the mask to branch the laser light; an image sensor disposed in the optical path of the laser light branched by the beam splitter to generate an image containing a converged image of the laser light on the mask; and a processor that controls the illumination optics system based on the image to correct the convergence position of the laser light relative to the opening. Attached Figure Description

[0011] The following description, by way of example only, refers to the accompanying drawings to illustrate several embodiments of the present disclosure.

[0012] Figure 1 This is a diagram that roughly illustrates the structure of the laser processing system involved in the comparative example.

[0013] Figure 2 It is a diagram that roughly represents the structure of a laser device.

[0014] Figure 3 It is a diagram that roughly represents the image of a laser beam illuminating a mask.

[0015] Figure 4 This is a diagram illustrating a cold or low-load condition.

[0016] Figure 5 This is a diagram illustrating the variation of BD under high load conditions.

[0017] Figure 6 This is a diagram illustrating the variation of BP under high load conditions.

[0018] Figure 7 This is a diagram that schematically illustrates the structure of the laser processing system according to the first embodiment.

[0019] Figure 8 It is a diagram that schematically represents the image of the laser beam irradiating the mask in the first embodiment.

[0020] Figure 9 This is a diagram illustrating a cold or low-load condition.

[0021] Figure 10 This is a diagram illustrating the variation of BD under high load conditions.

[0022] Figure 11 This is a diagram illustrating the variation of BP under high load conditions.

[0023] Figure 12 This diagram illustrates the process of calculating the change in convergence position based on an image.

[0024] Figure 13 This diagram illustrates the irradiation period and the rest period.

[0025] Figure 14 This is a flowchart illustrating the overall process of controlling the position of the converging lens.

[0026] Figure 15 This is a flowchart representing the flow of the first control.

[0027] Figure 16 This is a flowchart representing the process of the second control.

[0028] Figure 17 It is a diagram that roughly represents the image of the laser beam illuminating the mask in a modified example.

[0029] Figure 18 This diagram illustrates the process of calculating the change in convergence position based on the image in a modified example.

[0030] Figure 19 This is a diagram that roughly illustrates the structure of the laser processing system according to the second embodiment.

[0031] Figure 20 This is a diagram illustrating a cold or low-load condition.

[0032] Figure 21 This is a diagram illustrating the variation of BD under high load conditions.

[0033] Figure 22 This is a diagram illustrating the variation of BP under high load conditions.

[0034] Figure 23 This is a diagram that schematically illustrates the structure of the laser processing system according to the third embodiment.

[0035] Figure 24 This is a diagram illustrating a cold or low-load condition.

[0036] Figure 25 This is a diagram illustrating the variation of BP under high load conditions.

[0037] Figure 26 This is a diagram illustrating the variation of BP under high load conditions.

[0038] Figure 27 This is a flowchart illustrating the flow of the first control in the third embodiment.

[0039] Figure 28 This is a flowchart illustrating the flow of the second control in the third embodiment.

[0040] Figure 29 It is a diagram that schematically represents the structure of an electronic device.

[0041] Figure 30 It is a flowchart illustrating the manufacturing process of electronic devices. Detailed Implementation

[0042] <Content>

[0043] 1. Explanation of terminology

[0044] 2. Comparative Examples

[0045] 2.1 Structure

[0046] 2.1.1 Laser Processing System

[0047] 2.1.2 Laser Device

[0048] 2.2 Actions

[0049] 2.3 Research Topic

[0050] 3. First Implementation Method

[0051] 3.1 Structure

[0052] 3.2 Actions

[0053] 3.3 Effects

[0054] 3.4 Variations

[0055] 4. Second Implementation Method

[0056] 4.1 Structure

[0057] 4.2 Actions

[0058] 4.3 Effects

[0059] 4.4 Variations

[0060] 5. Third Implementation Method

[0061] 5.1 Structure

[0062] 5.2 Actions

[0063] 5.3 Effects

[0064] 5.4 Variations

[0065] 6. Manufacturing methods for electronic devices

[0066] 7. Processor Structure

[0067] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments described below represent several examples of the present disclosure and do not limit the content of the present disclosure. Furthermore, the structures and operations described in each embodiment are not necessarily all necessary for the structures and operations of the present disclosure. In addition, the same reference numerals are used to denote the same constituent elements, and repeated descriptions are omitted.

[0068] 1. Explanation of terminology

[0069] In this invention, a converging lens is a lens capable of converging light rays; it is a lens with 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; the shorter the focal length, the greater the optical power.

[0070] Furthermore, in this invention, a diverging lens refers to a lens that can diverge light rays; it is a lens with a negative optical power. A typical example of a diverging lens is a concave lens.

[0071] In addition, converging lenses and diverging lenses include mirrors that play essentially the same role, lens groups composed of multiple lenses integrated into one, or combinations of mirrors and lenses, etc.

[0072] 2. Comparative Examples

[0073] 2.1 Structure

[0074] 2.1.1 Laser Processing System

[0075] Figure 1 The structure of the laser processing system 1 involved in the comparative example is roughly shown. Furthermore, the term "comparative example" refers to a method known only to the applicant, not a publicly known example that the applicant himself acknowledges.

[0076] The laser processing system 1 includes a laser device 2 and a laser processing device 4 as its main structures. The laser processing system 1 is used for hole processing, such as forming through holes, on a glass substrate used as an interlayer.

[0077] 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 laser media. In this disclosure, 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 laser device 2 will be simply referred to as laser Lb.

[0078] The laser device 2 and the laser processing device 4 are connected by an optical path tube 5. The optical path tube 5 is configured to surround the laser Lb between the emission port of the laser device 2 and the inlet port of the laser processing device 4.

[0079] The laser processing apparatus 4 includes a laser processing processor 40, an optical system 41, a frame 42, an XYZ worktable 43, and a stage 44. The optical system 41 and the XYZ worktable 43 are fixed in the frame 42.

[0080] The workpiece 45 is the object to be processed for hole processing. The workpiece 45 is a glass substrate used for the interlayer, such as an alkali-free glass substrate. Alternatively, the workpiece 45 can also be a substrate formed of quartz glass, organic materials, monocrystalline silicon, ceramics, metals, etc. One or more holes H are formed on the workpiece 45.

[0081] The XYZ worktable 43 supports the workpiece 44. A workpiece 45 is fixed on the workpiece 44. The XYZ worktable 43 allows the workpiece 45 to move in the X, Y, and Z directions, thereby changing the position of the workpiece 45. The X, Y, and Z directions are perpendicular 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 worktable 43 is connected to the laser processing processor 40.

[0082] The optical system 41 includes a housing 41a, high-reflectivity mirrors 47a and 47b, an attenuator 49, an illumination optical system 50, a mask 60, and a projection optical system 70.

[0083] Each component in the optical system 41 is fixed to a retainer (not shown) and positioned within the housing 41a in a predetermined location.

[0084] The high-reflectivity mirror 47a is configured to reflect the laser Lb that has passed through the optical path tube 5, so that the reflected laser Lb passes through the attenuator 49 and is incident on the high-reflectivity mirror 47b. The optical path tube 5 and the housing 41a are, for example, purged with a purge gas. The purge gas is an inactive gas such as N2 gas, which hardly absorbs the laser Lb.

[0085] Attenuator 49 is disposed within housing 41a in the optical path between high-reflectivity mirrors 47a and 47b. Attenuator 49 includes, for example, two partial reflectors 49a and 49b and rotating stages 49c and 49d for these partial reflectors. Partial reflectors 49a and 49b are optical elements whose transmittance varies according to the incident angle of the laser Lb. The incident angle of the laser Lb is adjusted by the rotating stages 49c and 49d via partial reflectors 49a and 49b.

[0086] The high-reflectivity mirror 47b is configured to reflect the laser Lb that has passed through the attenuator 49 and to cause the reflected laser Lb to be incident on the illumination optics system 50.

[0087] The illumination optics system 50 includes a high-reflectivity mirror 51, configured to homogenize the intensity distribution of the laser Lb reflected by the high-reflectivity mirror 47b, and to provide Köhler illumination to the mask 60.

[0088] The mask 60 is disposed 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 the laser Lb, and has an opening 61 with a shape corresponding to the processing shape of the hole H. In this comparative example, the processing shape is circular, and the opening 61 is a circular pinhole.

[0089] For example, when machining a through hole on the workpiece 45, an opening 61 is formed on the mask 60 for machining a hole H with a diameter of 5 μm to 30 μm. When the projection magnification of the projection optical system 70 is M, the diameter of the opening 61 can be set to 1 / M times the diameter of the hole H to be machined.

[0090] Furthermore, the opening 61 is not limited to a hole that physically penetrates the mask 60, but also includes a transparent portion through which the laser Lb passes. The mask 60 may, for example, be a mask on which a pattern of a multilayer metal or dielectric film is formed on a synthetic quartz substrate that allows ultraviolet light to pass through. In this case, the opening 61 is formed through the pattern.

[0091] The projection optical system 70, for example, is an imaging lens, configured to image the laser Lb passing through the opening 61 of the mask 60 onto the surface 45a of the workpiece 45. The imaging surface of the projection optical system 70 is a conjugate surface conjugate to the surface of the mask 60, and coincides with the surface 45a of the workpiece 45. That is, the projection optical system 70 images the image of the opening 61 of the mask 60 onto the surface 45a of the workpiece 45. Furthermore, the projection optical system 70 can also be a reduction projection optical system.

[0092] 2.1.2 Laser Device

[0093] Figure 2 The structure of the laser device 2 is shown in general. The laser device 2 includes an oscillator 20, a monitoring module 30, an optical shutter 35, and a laser processor 38. The oscillator 20 includes a cavity 21, an optical resonator composed of a rear mirror 25a and an output coupling mirror 25b, a charger 23, and a power supply unit (PPM: Pulsed Power Module) 22.

[0094] Windows 21a and 21b are provided in chamber 21. Laser gas, which serves as the laser medium, is sealed inside chamber 21.

[0095] Additionally, an opening is formed in the chamber 21, and an electrically insulating plate 26 in which multiple feedthrough elements 26a are embedded is provided to block the opening. A PPM 22 is disposed on the electrically insulating plate 26. A pair of discharge electrodes 27a and 27b serving as main electrodes and a ground plane 28 are disposed within the chamber 21. The discharge surfaces of the discharge electrodes 27a and 27b are rectangular in shape.

[0096] Discharge electrodes 27a and 27b are configured with their discharge surfaces facing each other to excite the laser medium through discharge. The side of discharge electrode 27a opposite to its discharge surface is supported by an electrically insulating plate 26. Discharge electrode 27a is connected to a feedthrough 26a. The side of discharge electrode 27b opposite to its discharge surface is supported by a ground plane 28.

[0097] PPM22 includes a switch 22a, a charging capacitor (not shown), a pulse transformer, a magnetic compression circuit, and a peak capacitor. The peak capacitor is connected to the feedthrough 26a via a connection (not shown). Charger 23 charges the charging capacitor based on control from laser processor 38.

[0098] Switch 22a is controlled to be turned on / off by laser processor 38. Laser processor 38 turns on switch 22a according to the light emission trigger Tr sent from laser processing processor 40.

[0099] When switch 22a is turned on, current flows from the charging capacitor to the primary side of the pulse transformer, and due to electromagnetic induction, a reverse current flows to the secondary side of the pulse transformer. The magnetic compression circuit is connected to the secondary side of the pulse transformer, compressing the pulse width of the current pulse. The peak capacitor is charged by this current pulse. When the voltage of the peak capacitor reaches the breakdown voltage of the laser gas, the laser gas between the discharge electrodes 27a and 27b undergoes insulation breakdown, resulting in a discharge. This discharge generates a 1-pulse laser Lb.

[0100] The rear mirror 25a is formed by coating a high-reflectivity film onto a planar substrate. The output coupling mirror 25b is formed by coating a partially reflective film onto a planar substrate. A cavity 21 is disposed between the rear mirror 25a and the output coupling mirror 25b. The laser Lb generated in the cavity 21 is amplified by an optical resonator and output from the output coupling mirror 25b.

[0101] The monitoring module 30 includes a beam splitter 31 and an optical sensor 32. The beam splitter 31 is positioned in the optical path of the laser Lb output from the output coupling mirror 25b, causing a portion of the laser Lb to be reflected. The optical sensor 32 is positioned at the incident point of the laser Lb after reflection by the beam splitter 31. The optical sensor 32 measures the pulse energy of the laser Lb and sends the measured value to the laser processor 38.

[0102] The laser processor 38 changes the charging voltage of the charger 23 based on the measurement value of the pulse energy by the optical sensor 32, thereby controlling the pulse energy of the laser Lb output from the laser device 2 to become the target pulse energy Et.

[0103] Optical shutter 35 is positioned in the optical path of the laser Lb passing through beam splitter 31. Optical shutter 35 opens and closes according to instructions from laser processor 38. Laser processor 38 controls the output of laser Lb from laser device 2 by controlling optical shutter 35.

[0104] 2.2 Actions

[0105] Next, the operation of the laser processing system 1 involved in the comparative example will be described. First, the laser processing processor 40 controls the XYZ stage 43 to make the imaging plane of the projection optics system 70 coincide with the surface 45a of the workpiece 45. Next, the laser processing processor 40 sends the target pulse energy Et to the laser processor 38 and controls the transmittance of the attenuator 49 to make the flux on the surface 45a become the target flux Ft.

[0106] When the laser processor 38 receives the target pulse energy Et, it controls the charger 23 to make the pulse energy of the laser Lb the target pulse energy Et. Then, the laser processor 38 triggers the oscillator 20 to oscillate naturally by inputting a trigger to the switch 22a. At this time, the shutter 35 is in the closed state.

[0107] A portion of the laser Lb output from chamber 21 via output coupling mirror 25b is sampled by monitoring module 30, thereby measuring the pulse energy. Laser processor 38 controls charger 23 to bring the difference ΔE between the pulse energy and the target pulse energy Et close to zero. Furthermore, if the difference ΔE is within an acceptable range, laser processor 38 sends a permission signal to laser processing processor 40 and opens shutter 35.

[0108] Upon receiving a permission signal, the laser processing processor 40 sends a emission trigger Tr with a specified repetition frequency and a specified number of pulses to the laser device 2. As a result, a laser Lb is output from the laser device 2 synchronously with the emission trigger Tr and is incident on the laser processing device 4 via the optical path tube 5. This laser Lb is reflected by a high-reflectivity mirror 47a, reduced in intensity by an attenuator 49, and then reflected again by a high-reflectivity mirror 47b. The laser Lb reflected by the high-reflectivity mirror 47b is then incident on the illumination optical system 50.

[0109] The laser Lb incident on the illumination optics system 50 is reflected by the high-reflectivity mirror 51, illuminating the area of ​​the mask 60 including the opening 61. The laser Lb passing through the opening 61 is then incident on the projection optics system 70.

[0110] The projection optics system 70 images the incident laser Lb onto the surface 45a of the workpiece 45. When a laser Lb with a specified number of pulses irradiates the surface 45a and the flux exceeds the processing threshold, laser ablation occurs, forming a hole H.

[0111] Next, the laser processing processor 40 controls the XYZ stage 43 and the laser device 2 to repeatedly change and irradiate the position in a step-repeating manner, thereby forming multiple holes H in the entire processing area where hole processing is required.

[0112] 2.3 Research Topic

[0113] Figure 3 The image of the laser Lb irradiated by the mask 60 is roughly represented. At the location where the mask 60 is positioned, the X-direction corresponds to the discharge direction, and the Y-direction corresponds to the direction perpendicular to the discharge direction. The laser Lb has the characteristic that its beam divergence angle differs in the discharge direction and in its perpendicular direction due to the shape and arrangement of the discharge electrodes 27a and 27b. Therefore, the dimension B0 of the image of the laser Lb irradiated by the mask 60 in the X-direction is... X Dimension B0 in the Y direction Y different.

[0114] like Figure 3 As shown, the diameter of the laser beam Lb illuminating the opening 61 of the mask 60 by the illumination optics system 50 is larger than the size of the opening 61, resulting in low transmittance of the laser Lb passing through the opening 61. Consequently, the pulse energy loss of the laser Lb output from the laser device 2 is significant.

[0115] Therefore, as Figure 4 As shown, consider adding a converging lens 52 to the illumination optical system 50 so that the laser Lb incident from the high reflectivity mirror 51 is focused and illuminates the opening 61 of the mask 60, thereby improving the transmittance.

[0116] However, when the operating load of the laser device 2 changes, the beam divergence (BD) and beam direction (BP) of the laser Lb output from the laser device 2 change, resulting in a change in the focusing position F of the converging lens 52 on the laser Lb. 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.

[0117] Figure 4 Examples are shown for cold or low-load conditions. Figure 5 This illustrates the variation of BD under high load conditions. Figure 6The variation of BP under high load conditions is illustrated. The operating load of laser device 2 is lowest in the cold state after pulse oscillation stops, and increases with the frequency of pulse oscillation, the elapsed time since the start of pulse oscillation, and the pulse energy. It is assumed that BD and BP change due to the heat generated during the operation of laser device 2.

[0118] Furthermore, "cold state" refers to a state in which almost no heat accumulates inside the laser device 2 before operation begins, and the physical effects of heat can be ignored. "Low load state" refers to a state in which almost no heat accumulates inside the laser device 2 after operation begins and the pulse oscillation frequency is low, and the physical effects of heat can be ignored.

[0119] like Figure 4 As shown, under cold or low-load conditions, BD and BP are roughly stable, and the convergence position F coincides with the center of the opening 61 of the mask 60, thus resulting in high transmittance of laser Lb. Figure 5 As shown, when the load condition becomes high and BD changes, the convergence position F changes in the Z direction. Additionally, as... Figure 6 As shown, when the load condition becomes high and BP changes, the convergence position F changes in the X or Y direction.

[0120] When the convergence position F changes in this way, a portion of the laser Lb converged by the converging lens 52 is blocked by the mask 60. As a result, the transmittance of the laser Lb through the opening 61 of the mask 60 decreases, potentially causing damage to the mask 60 due to the high pulse energy of the laser Lb.

[0121] In addition, Figure 4 The diagram illustrates an example where the opening 61 of the mask 60 is approximately aligned with the converging position F in the Z direction. However, to illuminate the opening 61 of the mask 60 with a desired illuminance distribution, such as a uniform illuminance distribution, it can also be configured to converge at a position in the Z direction. Even in such a case, in addition to the risk of reduced transmittance and damage to the mask 60 due to variations in BD and BP, there is also the possibility of changes in the conditions required to illuminate the opening 61 with the desired illuminance distribution.

[0122] This disclosure provides a method for manufacturing a laser processing apparatus and an electronic device, which can suppress the decrease in transmittance and damage to the mask 60 by suppressing the variation of the convergence position F relative to the opening 61 of the mask 60.

[0123] 3. First Implementation Method

[0124] The laser processing system 1a according to the first embodiment of this disclosure will be described. Furthermore, structures identical to those described above will be labeled with the same reference numerals, and repeated descriptions will be omitted unless specifically stated otherwise.

[0125] 3.1 Structure

[0126] Figure 7 The structure of the laser processing system 1a according to the first embodiment is shown in a simplified manner. Except for the optical system 41, the laser processing system 1a has the same structure as the laser processing system 1 according to the comparative example.

[0127] In this embodiment, a converging lens 52, a moving stage 53, a beam splitter 80, and an image sensor 81 are added to the optical system 41. The converging lens 52 is configured to converge the laser Lb incident from the high-reflectivity mirror 51 and direct it toward the opening 61 of the mask 60. In this embodiment, the converging lens 52 has optical power in both the X and Y directions.

[0128] 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.

[0129] Beam splitter 80 is disposed in the optical path between illumination optics system 50 and mask 60 to branch the laser Lb incident from convergent lens 52. Specifically, beam splitter 80 is a partial reflector that reflects a portion of the laser Lb that has passed through convergent lens 52 while allowing another portion to pass through. In this embodiment, the laser Lb that has passed through beam splitter 80 is incident on mask 60.

[0130] In addition, the branching of the laser Lb by the beam splitter 80 does not affect the projection onto the workpiece 45 via the projection optics system 70, thus maintaining processing accuracy.

[0131] Image sensor 81 is a sensor capable of capturing two-dimensional images. It is configured with its imaging surface perpendicular to the optical axis of laser Lb on the optical path of laser Lb branched off by beam splitter 80. In this embodiment, image sensor 81 is configured on the optical path of laser Lb after reflection by beam splitter 80, and captures a converging image of laser Lb in real time at a position optically conjugate with mask 60. Image sensor 81 is connected to laser processing processor 40 and outputs an image D containing the converging image to laser processing processor 40.

[0132] In this embodiment, the laser processing processor 40 measures the position of the converging image of the laser Lb on the mask 60 based on the image D, and adjusts the position of the converging lens 52 based on the measurement value, thereby correcting the convergence position F.

[0133] 3.2 Actions

[0134] Except for the additional position adjustment control of the converging lens 52, the operation of the laser processing system 1a according to the first embodiment is the same as the operation of the laser processing system 1 according to the comparative example. Hereinafter, the position adjustment control of the converging lens 52 will be described.

[0135] Figure 8 This roughly represents the image of the laser Lb irradiating the mask 60 in the first embodiment. In this embodiment, the converging lens 52 focuses the laser Lb in both the X and Y directions, therefore the image of the laser Lb irradiating the mask 60 is smaller than in the comparative example. Specifically, the size B1 of the image in the X direction... X and the dimension B1 in the Y direction Y Satisfy B1 X <B0 X and B1 Y <B0 Y The relationship.

[0136] Figure 9 Examples are shown for cold or low-load conditions. Figure 10 This indicates the fluctuation of BD under high load conditions. Figure 11 This illustrates how BP varies under high load conditions. For example... Figure 9 As shown, in a cold or low-load state, the convergence position F coincides with the center of the opening 61 of the mask 60.

[0137] like Figure 10 As shown, when the convergence position F changes in the Z direction due to the variation of BD, the laser processing processor 40 controls the moving stage 53 to adjust the Z-direction position of the converging lens 52. Thus, the convergence position F is corrected to coincide with the center of the opening 61 of the mask 60. Figure 10 In the diagram, the converging lens 52, the moving stage 53, and the laser Lb before correction are represented by dashed lines. The following diagrams are the same.

[0138] like Figure 11 As shown, when the convergence position F changes in the X or Y direction due to the variation of BP, the laser processing processor 40 controls the moving stage 53 to adjust the position of the converging lens 52 in the X or Y direction. Thus, the convergence position F is corrected to coincide with the center of the opening 61 of the mask 60.

[0139] Figure 12 The processing of the change in convergence position F based on image D is explained. For example... Figure 12 As shown, a converging image of laser Lb is captured in image D. The center coordinates (xc, yc) of the converging image represent the position of the convergence point F in the X and Y directions. Furthermore, the center coordinates (xc, yc) are defined as the position of the light peak or the center of light centroid.

[0140] The difference (xdiff, ydiff) between the center coordinates (x0, y0) of the opening 61 and the center coordinates (xc, yc) of the converging image corresponds to the changes in the X and Y directions of the convergence position F caused by the variation of BP. The difference (xdiff, ydiff) is represented by the following equations (1A) and (1B).

[0141] [Mathematical Expression 1]

[0142]

[0143] [Mathematical Expression 2]

[0144]

[0145] The laser processing processor 40 controls the moving stage 53 to move the converging lens 52 by a correction amount (Δx, Δy) in the X and Y directions. The correction amount (Δx, Δy) is represented by the following equations (2A) and (2B).

[0146] [Mathematical Expression 3]

[0147]

[0148] [Mathematical Expression 4]

[0149]

[0150] Here, C1x and C1y are the scaling factors in the X and Y directions, respectively, representing the ratio of the movement of the converging lens 52 to the movement of the converging position F.

[0151] Furthermore, the width wx in the X direction and the width wy in the Y direction of the convergent image are indirect indicators used to determine the position of the convergence location F in the Z direction. Either width wx or wy can be used to determine this, but in this embodiment, for example, only width wx is used. Specifically, the image with a light intensity threshold T... X The width of the convergent image of the above light intensity in the X direction is measured as width wx. This width is used as the light intensity threshold T. X Generally, the full width at half maximum (FWHM) of the light intensity distribution in a convergent image is used, with the light intensity being 1 / e of the maximum value. 2 The value of a multiple.

[0152] The difference zdiff between the reference width wx0 and the width wx corresponds to the change in the convergence position F in the Z direction caused by the variation of BD. The difference zdiff is expressed by the following equation (3). The reference width wx0 is the width of the convergence image in the X direction under cold conditions.

[0153] [Mathematical Expression 5]

[0154]

[0155] The laser processing processor 40 controls the moving stage 53 to move the converging lens 52 in the Z direction by a correction amount Δz. The correction amount Δz is represented by the following formula (4).

[0156] [Mathematical Expression 6]

[0157]

[0158] Here, C1z is the scaling factor in the Z direction, representing the ratio of the movement of the converging lens 52 to the movement of the converging position F.

[0159] The position control of the converging lens 52 described above is performed during the irradiation period after the laser device 2 starts operating. The irradiation period refers to the period during which the laser device 2 pulses and irradiates the workpiece 45 with a specified number of laser pulses Lb. During the irradiation period, each time laser Lb is irradiated, the center coordinates (xc, yc) and the width wx of the converging image can be measured based on the image D. Therefore, during the irradiation period, the position of the converging lens 52 can be adjusted in real time based on the measured values. Thus, during the irradiation period, the converging position F is maintained aligned with the center of the opening 61 of the mask 60.

[0160] like Figure 13 As shown, after the irradiation period ends, the irradiation period begins again after a rest period. The rest period is the period during which the laser device 2 stops pulse oscillation and does not irradiate the workpiece 45 with laser Lb. For example, the period during which the irradiation position is changed by the XYZ stage 43 after machining a hole H on the workpiece 45 corresponds to the rest period.

[0161] During the pause, laser Lb is not irradiated onto mask 60, so the center coordinates (xc, yc) and width wx of the converging image cannot be measured. Therefore, during the pause, laser processing processor 40 corrects the position of convergent lens 52 based on the attenuation curve G represented by equation (5).

[0162] [Mathematical Expression 7]

[0163]

[0164] Here, P represents the corrected position of the converging lens 52 during the rest period. Pc is the position of the converging lens 52 in the cold state. Ph is the position of the converging lens 52 at the end of the previous irradiation period. t is the elapsed time since the start of the rest period. τ i It is the time constant. i is a positive integer between 1 and n. C i It is the time constant τ iThe contribution coefficients satisfy the following relationship (6).

[0165] [Mathematical Expression 8]

[0166]

[0167] Furthermore, 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 load caused by the heat received during the previous irradiation period.

[0168] Without correcting the position of the converging lens 52 during the rest period, the position at the end of the irradiation period is maintained as before. Therefore, if the convergence position F changes due to load attenuation during the rest period, and the irradiation period resumes, the laser Lb immediately after the restart will converge at a convergence position F that is offset from the center of the opening 61 of the mask 60. In this way, by correcting the position of the converging lens 52 based on the attenuation curve G during the rest period, the convergence position F can be maintained at the center of the opening 61 with high precision.

[0169] 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".

[0170] Figure 14 This describes the overall process of position control for the converging lens 52. First, after the laser device 2 starts operating, the laser processing processor 40 determines whether the current time point is within the irradiation period (step S10). If the laser processing processor 40 is within 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 within the irradiation period, i.e., within the rest period (step S10: No), it executes the second control (step S12).

[0171] After executing the first control or the second control, the laser processing processor 40 determines whether the termination condition is met (step S13). For example, the termination condition is that the laser processing processor 40 receives a termination command from an external device. If the laser processing processor 40 determines that the termination condition is not met (step S13: No), the processing returns to step S10. If the laser processing processor 40 determines that the termination condition is met (step S13: Yes), the processing ends.

[0172] Through the above process, the first control is implemented during irradiation and the second control is implemented during rest.

[0173] Figure 15The flow of the first control is described below. 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 converging image (step S111). Then, 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 opening 61 (step S112). Next, the laser processing processor 40 controls the moving stage 53 to move the converging lens 52 by correction amounts (Δx, Δy) in the X and Y directions (step S113).

[0174] Next, the laser processing processor 40 calculates the width wx of the convergent image based on the 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 converging lens 52 by a correction amount Δz in the Z direction (step S116).

[0175] also, Figure 15 The illustrated first control flow is merely an example, and the order of processing can be modified appropriately. For instance, steps S114-S116 can be executed before steps S111-S113. Alternatively, steps S111, S112, S114, and S115 can be executed first, followed by steps S113 and S116.

[0176] Figure 16 The flow of the second control is described. In the second control, the laser processing processor 40 first determines whether the current time point is after the start of a rest period (step S120). If the laser processing processor 40 determines that it is after the start of a rest period (step S120: Yes), the position Ph of the converging lens 52 at the end of the previous irradiation period is stored in a memory not shown (step S121). On the other hand, if it is not after the start of a rest period (step S120: No), step S121 is not executed.

[0177] Then, the laser processing processor 40 obtains the elapsed time t from the start of the rest period (step S122) and uses the above formula (5) to calculate the corrected position P of the converging lens 52 (step S123). At this time, the laser processing processor 40 uses the position Ph of the converging 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 converging lens 52 to the corrected position P (step S124).

[0178] As described above, the laser processing processor 40 changes the convergence position F at regular intervals by executing a first control or a second control at regular intervals. Here, for example, the regular interval is set to an integer multiple of the pulse oscillation period of the laser device 2.

[0179] 3.3 Effects

[0180] According to this embodiment, the laser processing processor 40 corrects the position of the converging lens 52 based on the image D during irradiation, thus effectively suppressing the variation of the convergence position F relative to the opening 61 of the mask 60. As a result, the stability of the convergence position F is improved, preventing a decrease in transmittance and suppressing damage to the mask 60.

[0181] Furthermore, the laser processing processor 40 adjusts the position of the converging lens 52 during the pause period, so that even after the irradiation period has just started again, the convergence position F can be maintained at the center of the opening 61 of the mask 60 with high precision.

[0182] 3.4 Variations

[0183] Next, a variation of the first embodiment will be described. In this variation, the opening 61 of the mask 60 described in the first embodiment is a slit shape, and the converging lens 52 is further configured as a cylindrical lens.

[0184] In this modified example, the opening 61 of the mask 60 is a slit shape extending along the X direction. Furthermore, the converging lens 52 is a cylindrical lens with optical power in the width direction of the slit shape, i.e., the Y direction, which causes the laser Lb to converge in the Y direction.

[0185] Figure 17 This roughly illustrates the image of the laser Lb irradiating the mask 60 in a modified example. In this modified example, the converging lens 52 converges the laser Lb only in the Y direction, therefore the image of the laser Lb irradiating the mask 60 is longer in the X direction compared to the first embodiment. Specifically, the converging lens 52 has no focal length in the X direction, so the size of the image in the X direction remains the same as the size B0 before convergence. X same.

[0186] Furthermore, since the converging lens 52 does not have optical power in the X direction, control of the converging lens 52 in the X direction is not required 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 Lb will not change in the X direction, and will not affect the focusing accuracy relative to the opening 61 of the mask 60. Therefore, it is not necessary to adjust the position of the converging lens 52 in the X direction.

[0187] Figure 18 This explains the processing of the change in convergence position F based on image D in the modified example. For example... Figure 18 As shown, a converging image of laser Lb is captured in image D. In this modified example, the laser processing processor 40 only needs to calculate the center coordinate yc of the converging image in the Y direction and the width wy in the Y direction based on image D. Furthermore, the first and second controls in this modified example are the same as in the first embodiment, except that the converging lens 52 is not moved in the X direction.

[0188] 4. Second Implementation Method

[0189] The laser processing system 1b according to the second embodiment of this disclosure will be described. Furthermore, structures identical to those described above will be labeled with the same reference numerals, and repeated descriptions will be omitted unless specifically stated otherwise.

[0190] 4.1 Structure

[0191] Figure 19 The structure of the laser processing system 1b according to the second embodiment is shown in a simplified manner. Except for the illumination optical system 50, the laser processing system 1b has the same structure as the laser processing system 1a according to the first embodiment.

[0192] In this embodiment, the illumination optical system 50 includes a high-reflectivity mirror 51, a converging lens 52, a diverging lens 54 disposed upstream of the converging lens 52, and a stage 55 for holding the diverging lens 54. The diverging lens 54 serves to adjust the divergence angle of the laser Lb, and is configured to be movable in the X, Y, and Z directions via the stage 55. In this embodiment, the converging lens 52 is fixed. Furthermore, in this embodiment, the converging lens 52 and the diverging lens 54 have optical power in the X and Y directions, respectively.

[0193] The moving stage 55 is connected to and controlled by the laser processing processor 40. In this embodiment, the laser processing processor 40 moves the diverging lens 54 instead of moving the converging lens 52 in the first embodiment, thereby adjusting the convergence position F of the laser Lb.

[0194] 4.2 Actions

[0195] 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.

[0196] Figure 20 Examples are shown for cold or low-load conditions. Figure 21This indicates how BD changes under high load conditions. Figure 22 This illustrates how BP varies under high load conditions. For example... Figure 20 As shown, in a cold or low-load state, the convergence position F coincides with the center of the opening 61 of the mask 60.

[0197] like Figure 21 As shown, when the convergence position F changes in the Z direction due to the variation of BD, the laser processing processor 40 controls the moving stage 55 to adjust the position of the diverging lens 54 in the Z direction. Thus, the convergence position F is corrected to coincide with the center of the opening 61 of the mask 60.

[0198] like Figure 22 As shown, when the convergence position F changes in the X or Y direction due to the variation of 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. Thus, the convergence position F is corrected to be aligned with the center of the opening 61 of the mask 60.

[0199] In this embodiment, the position adjustment control of the diverging lens 54 is basically the same as that of 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, in the first control of this embodiment, except that the position of the diverging lens 54 is controlled instead of the converging lens 52, the same procedures as those in the first control of the first embodiment are performed.

[0200] In the second control of this embodiment, when the period has just ended, instead of the converging lens 52, the control stores the position Ph of the diverging lens 54 at the end of the previous irradiation period. Furthermore, in the second control of this embodiment, instead of the converging lens 52, a corrected position P of the diverging lens 54 is calculated, and the position of the diverging lens 54 is changed to the corrected position P. Similar to the first embodiment, the corrected position P is calculated based on the attenuation curve G represented by the above equation (5). In this embodiment, Pc is the position of the diverging lens 54 in the cold state.

[0201] 4.3 Effects

[0202] According to this embodiment, the laser processing processor 40 corrects the position of the diverging lens 54 based on the image D during irradiation. Therefore, similarly to the first embodiment, it is possible to effectively suppress the variation of the convergence position F relative to the opening 61 of the mask 60. As a result, the stability of the convergence position F is improved, preventing a decrease in transmittance and suppressing damage to the mask 60.

[0203] Furthermore, the laser processing processor 40 adjusts the position of the diverging lens 54 during the pause period, so that, similar to the first embodiment, the convergence position F can be maintained at the center of the opening 61 of the mask 60 with high precision even after the irradiation period has just started again.

[0204] 4.4 Variations

[0205] Next, a variation of the second embodiment will be described. In this variation, similar to the variation of the first embodiment, the opening 61 of the mask 60 is slit-shaped, and the converging lens 52 and the diverging lens 54 are respectively configured as cylindrical lenses.

[0206] In this modified example, the converging lens 52 is a cylindrical lens with optical power in the Y direction, which converges the laser Lb in the Y direction. The diverging lens 54 is a cylindrical lens with optical power in the Y direction, which has the function of adjusting the divergence angle of the laser Lb in the Y direction.

[0207] In this modified example, the diverging lens 54 does not have optical power in the X direction, therefore, 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 when the diverging lens 54 is moved along the X direction, the convergence position F of the laser Lb will not change in the X direction, and the convergence accuracy relative to the opening 61 of the mask 60 will not be affected. Therefore, position adjustment of the diverging lens 54 in the X direction is not required.

[0208] In this modified example, the laser processing processor 40 only needs to calculate the center coordinates yc and the width wy in the Y direction of the converging image based on the image D. Furthermore, the first and second controls in this modified example are the same as in the second embodiment, except that they prevent the diverging lens 54 from moving in the X direction.

[0209] 5. Third Implementation Method

[0210] The laser processing system 1c according to the third embodiment of this disclosure will be described. Furthermore, structures identical to those described above will be labeled with the same reference numerals, and repeated descriptions will be omitted unless specifically stated otherwise.

[0211] 5.1 Structure

[0212] Figure 23 The structure of the laser processing system 1c according to the third embodiment is shown in a simplified manner. Except for the illumination optical system 50, the laser processing system 1c has the same structure as the laser processing system 1a according to the first embodiment.

[0213] In this embodiment, the illumination optical system 50 includes a high-reflectivity mirror 51, a converging lens 52, and a tilting stage 56 for holding the high-reflectivity mirror 51. The high-reflectivity mirror 51 serves to adjust the back pressure (BP) of the laser Lb, and is configured to be able to change its angle in the θx and θy directions via the tilting stage 56. Here, the θx direction is the direction of rotation about an axis parallel to the Y direction. The θy direction is the direction of rotation about an axis parallel to the X direction. In this embodiment, the converging lens 52 is fixed and has optical power in both the X and Y directions. Furthermore, the high-reflectivity mirror 51 is an example of a "reflector" according to the technology disclosed herein.

[0214] The tilting stage 56 is connected to and controlled by the laser processing processor 40. In this embodiment, the laser processing processor 40 replaces the movement of the converging lens 52 in the first embodiment, and adjusts the angle of the high-reflectivity mirror 51 by controlling the tilting stage 56, thereby adjusting the convergence position F of the laser Lb. In this embodiment, the convergence position F can be adjusted in either the X or Y direction.

[0215] 5.2 Actions

[0216] 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-reflectivity mirror 51. Hereinafter, the angle adjustment control of the high-reflectivity mirror 51 will be described.

[0217] Figure 24 Examples are shown for cold or low-load conditions. Figure 25 and Figure 26 This illustrates how BP varies under high load conditions. For example... Figure 24 As shown, in a cold or low-load state, the convergence position F coincides with the center of the opening 61 of the mask 60.

[0218] like Figure 25 As shown, when the convergence position F changes in the X direction due to the variation of BP, the laser processing processor 40 controls the tilt stage 56 to adjust the angle of the high-reflectivity mirror 51 in the θx direction. Thus, the convergence position F is corrected to coincide with the center of the opening 61 of the mask 60.

[0219] like Figure 26 As shown, at the convergence position F due to the change in BP, the direction is... Figure 25 In the opposite direction, the laser processing processor 40 also controls the tilting stage 56 to adjust the angle of the high-reflectivity mirror 51 in the θx direction. As a result, the convergence position F is corrected to coincide with the center of the opening 61 of the mask 60.

[0220] When the convergence position F changes in the Y direction due to the change of 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.

[0221] Figure 27 This indicates the flow of the first control in the third embodiment. Figure 27 Steps S110A to S112A shown 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 to change the angle of the high-reflectivity mirror 51 by a correction amount (Δθx, Δθy) (step S113). The correction amount (Δθx, Δθy) is represented by the following formulas (7A) and (7B).

[0222] [Mathematical Expression 9]

[0223]

[0224] [Mathematical Expression 10]

[0225]

[0226] Here, C2x and C2y are the scaling factors in the θx and θy directions, respectively, representing the ratio of the change in the angle of the high-reflectivity mirror 51 to the movement of the converging position F.

[0227] Figure 28 The flow of the second control in the third embodiment is described. In the second control, the laser processing processor 40 first determines whether the current time point is after the start of a rest period (step S120A). If the laser processing processor 40 determines that it is after the start of a rest period (step S120A: Yes), the angle Nh of the high reflectivity mirror 51 at the end of the previous irradiation period is stored in the memory (step S121A). On the other hand, if it is not after the start of a rest period (step S120A: No), step S121A is not executed.

[0228] Then, the laser processing processor 40 obtains the elapsed time t from the start of the rest period (step S122A) and uses the following formula (8) to calculate the correction angle N of the high-reflectivity mirror 51 (step S123A). At this time, the laser processing processor 40 uses the angle Nh of the high-reflectivity 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 to change the angle of the high-reflectivity mirror 51 to the correction angle N (step S124A).

[0229] [Mathematical Expression 11]

[0230]

[0231] Here, Nc is the angle of the high-reflectivity mirror 51 in the cold state. i It is the time constant τ i The contribution coefficient satisfies the relationship in equation (6) above.

[0232] Furthermore, Equation (8) above does not distinguish between the θx and θy directions. However, in each direction, the angle of the high-reflectivity mirror 51 is corrected based on the attenuation curve represented by Equation (8) above.

[0233] 5.3 Effects

[0234] According to this embodiment, the laser processing processor 40 corrects the angle of the high-reflectivity mirror 51 based on the image D during irradiation. Therefore, similarly to the first embodiment, it can effectively suppress the variation of the convergence position F relative to the opening 61 of the mask 60. As a result, the stability of the convergence position F is improved, preventing a decrease in transmittance and suppressing damage to the mask 60.

[0235] Furthermore, the laser processing processor 40 adjusts the angle of the high-reflectivity mirror 51 during the pause period, so that, similar to the first embodiment, the convergence position F can be maintained at the center of the opening 61 of the mask 60 with high precision even after the irradiation period has just started again.

[0236] 5.4 Variations

[0237] Next, a variation of the third embodiment will be described. In this variation, similar to the variation of the first embodiment, the opening 61 of the mask 60 is slit-shaped, and the converging lens 52 is further configured as a cylindrical lens.

[0238] In this modified example, the converging lens 52 is a cylindrical lens with optical power in the Y direction, which causes the laser Lb to converge in the Y direction.

[0239] In this modified example, the converging lens 52 has no optical power in the X direction, thus the angle-changing mechanism in the θx direction of the tilting stage 56 can be omitted. As a result, it is not necessary to control the high-reflectivity mirror 51 in the θx direction. Specifically, even if the angle of the high-reflectivity mirror 51 is changed in the θx direction, the convergence position F of the laser Lb will not change in the X direction, and the convergence accuracy relative to the opening 61 of the mask 60 will not be affected. Therefore, it is not necessary to adjust the angle of the high-reflectivity mirror 51 in the θx direction.

[0240] In this modified example, only the angle adjustment of the high-reflectivity mirror 51 in the θy direction is performed. Therefore, the laser processing processor 40 only needs to calculate the center coordinate yc of the converging image in the Y direction based on the image D. Furthermore, the first and second controls in this modified example are the same as those in the third embodiment, except that the angle of the high-reflectivity mirror 51 is not changed in the θx direction.

[0241] Furthermore, the angle adjustment of the high-reflectivity mirror 51 in the third embodiment can also be applied to the first embodiment or the second embodiment, and combined with the position adjustment of the converging lens 52 or the diverging lens 54 to perform the operation.

[0242] 6. Manufacturing methods for electronic devices

[0243] The laser processing methods described in the above embodiments can be applied to form through holes in a substrate having an interposer layer IP in the manufacture of the electronic device 100 described below.

[0244] Figure 29 The structure of electronic device 100 is shown schematically. Figure 29 The electronic device 100 shown includes an integrated circuit chip IC, an interposer IP, and a circuit substrate CS. The integrated circuit chip IC is, for example, a chip on a silicon substrate with an integrated circuit (not shown) formed thereon. Multiple bumps ICB, electrically connected to the integrated circuit, are provided on the integrated circuit chip IC.

[0245] The interposer IP comprises an insulating substrate having a plurality of through-holes (not shown), and a conductor (not shown) electrically connecting the front and back sides of the substrate is disposed within each through-hole. A plurality of connection pads (not shown) are formed on one surface of the interposer IP and are respectively connected to bumps ICB, each connection pad being electrically connected to any one of the conductors within the through-hole. A plurality of bumps IPB are disposed on the other surface of the interposer IP, and each bump IPB is electrically connected to any one of the conductors within the through-hole.

[0246] A plurality of connection pads (not shown) are formed on one side of the circuit board CS and are respectively connected to bumps IPB. The circuit board CS has a plurality of terminals that are electrically connected to these connection pads respectively.

[0247] Figure 30 This describes a method for manufacturing electronic device 100. First, in a 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 forming through-holes by irradiating the interposer substrate with a pulsed laser. The wiring formation includes forming a conductive film on the inner wall surface of the through-holes formed in the interposer substrate. The interposer IP is then fabricated through the first step SP1.

[0248] Next, in the second step SP2, the interposer IP and the integrated circuit chip IC are bonded together. The second step SP2 includes, for example, configuring the bumps ICB of the integrated circuit chip IC onto the connection pads of the interposer IP, and electrically connecting the bumps ICB to the connection pads.

[0249] Then, in the third process SP3, the interposer IP is bonded to the circuit substrate CS. The third process SP3 includes, for example, distributing the bumps IPB of the interposer IP onto the connection pads of the circuit substrate CS, and electrically connecting the bumps IPB to the connection pads.

[0250] 7. Processor Structure

[0251] Laser processing processor 40 and laser processor 38 may also be physically configured in hardware to execute the various processes included in this disclosure. For example, laser processing processor 40 and laser processor 38 may also be computers, including a memory storing control programs that define various processes and a processing device for executing the control programs. The control programs may be stored in a single memory or separately in multiple physically separate memories, defining various processes through the control programs as a collection of these memories. The processing device may be a general-purpose processing device such as a CPU (Central Processing Unit) or a purpose-specific processing device such as a GPU (Graphics Processing Unit).

[0252] Furthermore, the laser processing processor 40 and the laser processor 38 can also be programmed in software to perform the various processes included in this disclosure. For example, the functions of the laser processing processor 40 and the laser processor 38 in performing various processes can also be installed on a special-purpose device such as an ASIC (Application Specific Integrated Circuit) or a programmable device such as a FPGA (Field Programmable Gate Array).

[0253] The various processes included in this disclosure can be executed by a single computer, a single dedicated device, or a single programmable device, or by the cooperation of multiple physically separate computers, dedicated devices, or programmable devices. The various processes can also be executed by a combination of at least two of more than one computer, more than one dedicated device, and more than one programmable device.

[0254] The foregoing description is not limiting but merely illustrative. Therefore, 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. Furthermore, combinations of embodiments of this disclosure will also be apparent to those skilled in the art. Unless otherwise stated, the terms used throughout this specification and the claims should be interpreted as “non-limiting” terms. For example, terms such as “comprising,” “having,” “possessing,” and “comprise” should be interpreted as “not excluding the presence of constituent elements other than those described.” Furthermore, the modifier “a” should be interpreted as meaning “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 be interpreted as including combinations thereof with portions other than “A,” “B,” and “C.”

Claims

1. A laser processing apparatus that performs laser processing by irradiating a workpiece with a laser beam output from a laser device, wherein, The laser processing apparatus includes: A mask, which is disposed in the optical path of the laser and has an opening; An illumination optical system that focuses the laser light to illuminate the opening; A projection optical system that images the opening onto the surface of the workpiece; A beam splitter, disposed between the illumination optics system and the mask, branches the laser beam; An image sensor, configured in the optical path of the laser branched off by the beam splitter, generates an image containing a converged image of the laser on the mask; as well as A processor that controls the illumination optics system based on the image, thereby correcting the convergence position of the laser relative to the opening.

2. The laser processing apparatus according to claim 1, wherein, The processor changes the convergence position at regular intervals.

3. The laser processing apparatus according to claim 1, wherein, The illumination optical system includes a converging lens for focusing the laser and a moving stage for holding the converging lens in a movable position. The processor controls the moving stage based on the image to adjust the position of the converging lens, thereby correcting the convergence position.

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

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

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

7. The laser processing apparatus according to claim 3, wherein, During a pause when the laser output from the laser device is stopped, the processor calculates a corrected position based on an attenuation curve representing a change in the position of the converging lens, and changes the position of the converging lens to the corrected position.

8. The laser processing apparatus according to claim 7, wherein, The attenuation curve is represented by equation (1). [Mathematical Expression 1] Here, P is the correction position, Pc is the position of the converging lens in the cold state, Ph is the position of the converging lens at the end of the immediately preceding irradiation period, t is the elapsed time since the start of the rest period, τ i is the time constant, C i is the time constant τ i is the contribution coefficient of the correction position.

9. The laser processing apparatus according to claim 1, wherein, The illumination optical system includes: a converging lens that focuses the laser light; a diverging lens disposed upstream of the converging lens; and a stage that holds the diverging lens in a movable position. The processor controls the moving stage based on the image to adjust the position of the diverging lens, thereby correcting the converging position.

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

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

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

13. The laser processing apparatus according to claim 9, wherein, During a pause when the laser output from the laser device is stopped, the processor calculates a corrected position based on an attenuation curve representing a change in the position of the diverging lens, and changes the position of the diverging lens to the corrected position.

14. The laser processing apparatus according to claim 13, wherein, The attenuation curve is represented by equation (2). [Mathematical Expression 2] Here, P is the corrected 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 since the start of the rest period, and τ is the position of the diverging lens. i It is the time constant, C i It is the time constant τ i The contribution coefficient.

15. The laser processing apparatus according to claim 1, wherein, The illumination optical system includes: a reflector that reflects the laser light; a converging lens that focuses the laser light; and a tilting stage that holds the reflector at an angle that can be changed. The processor controls the tilting stage based on the image to adjust the angle of the reflector, thereby correcting the convergence position.

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

17. The laser processing apparatus according to claim 15, wherein, The processor adjusts the angle of the reflector based on the peak position or centroid position of the convergent image.

18. The laser processing apparatus according to claim 15, wherein, During a pause when the laser output from the laser device is stopped, the processor calculates a correction angle based on a decay curve representing the change in the angle of the reflector, and changes the angle of the reflector to the correction angle.

19. The laser processing apparatus according to claim 18, wherein, The attenuation curve is represented by equation (3). [Mathematical Expression 3] Here, N is the correction angle, Nc is the angle of the reflector in the cold state, Nh is the angle of the reflector at the end of the previous irradiation period, t is the elapsed time since the start of the rest period, and τ is the time τ has elapsed since the start of the rest period. i It is the time constant, C i It is the time constant τ i The contribution coefficient.

20. A method for manufacturing an electronic device, comprising: An intermediate layer is fabricated by laser processing of an intermediate layer substrate using a laser processing device. The interposer layer is combined with and electrically connected to the integrated circuit chip. The interposer layer is bonded to and electrically connected to the circuit board. The laser processing apparatus performs laser processing by irradiating the workpiece with laser light output from the laser device, and the laser processing apparatus includes: A mask, which is disposed in the optical path of the laser and has an opening; An illumination optical system that focuses the laser light to illuminate the opening; A projection optical system that images the opening onto the surface of the workpiece; A beam splitter, disposed between the illumination optics system and the mask, branches the laser beam; An image sensor, configured in the optical path of the laser beam branched by the beam splitter, generates an image containing a converged image of the laser beam on the mask; and A processor that controls the illumination optics system based on the image, thereby correcting the convergence position of the laser relative to the opening.

Images