Laser processing method, method for manufacturing substrate, laser processing apparatus, substrate and semiconductor package substrate

Abstract

The invention provides a laser processing method, a substrate manufacturing method, a laser processing apparatus, a substrate, and a semiconductor package substrate. In the laser processing method, a recess and / or a through hole is formed in a workpiece using a laser beam, and processing is performed in such a manner that the intensity distribution of the laser beam on a surface to be processed of the workpiece is in an irradiation shape in which the intensity of an outer portion of the intensity distribution is greater than the intensity of an inner portion of the intensity distribution. As a result, the laser processing method can suppress the formed recesses and / or through-holes from becoming a tapered shape even when the recesses and / or through-holes are formed with high resolution, and even can form highly fine and complicated patterns.

Description

Technical Field

[0001] The present invention relates to a laser processing method, a method for manufacturing a substrate, a laser processing apparatus, a substrate, and a semiconductor package substrate. Background Art

[0002] Semiconductor package substrates are shifting from the trend of "More Than More" to the trend of system-on-a-chip (SoC) that monolithizes systems, and are being actively developed along with this trend.

[0003] Moreover, the structure of semiconductor package substrates is becoming more complex and denser, and apparatuses using excimer lasers are gradually being applied in the manufacture of their base substrates.

[0004] For example, Patent Document 1 describes a laser processing method in which a workpiece is shaped by laser until a specified depth position, wherein the laser power of the laser and the relative movement speed between the workpiece and the laser are increased, and the number of irradiations required for laser processing is reduced, so that the energy per unit length of the laser optimally set according to the workpiece remains within the energy range that does not penetrate the workpiece even when the laser power increases due to power fluctuations in the laser oscillator.

[0005] Moreover, Patent Document 2 describes a laser processing method in which, for an excavation region of a workpiece, a laser having a small beam cross-section with respect to the excavation region is sequentially irradiated to process the excavation region. The laser processing method is characterized by including: a first processing step of sequentially irradiating the entire excavation region with a laser having a beam cross-section in a first shape and forming a first irradiation region having a beam cross-section corresponding to the first shape on the workpiece; and a second processing step of sequentially irradiating the excavation region with a laser having a beam cross-section in a second shape smaller than the first shape and forming a second irradiation region having a beam cross-section corresponding to the second shape on the workpiece. In the first processing step, the laser for forming the first irradiation region is sequentially irradiated in such a manner as to form an overlapping region where a part of the first irradiation regions overlap each other. In the second processing step, the laser for forming the second irradiation region is sequentially irradiated in such a manner that the second irradiation region is included in a region other than the overlapping region in the excavation region.

[0006] Moreover, Non-Patent Document 1 introduces the formation of high-quality and high aspect ratio Si through-holes using Bessel beams.

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: Japanese Patent Laid-Open No. 2009-22978

[0010] Patent Document 2: International Publication No. WO2013 / 094025 Specification

[0011] Non-Patent Document

[0012] Non-Patent Document 1: Koji Sugao, "Formation of High-Quality, High Aspect Ratio Si Through-Holes Using Optimized Ultrashort Pulse Bessel Beams", FORM TECH REVIEW 2016, VOL.26 Summary of the Invention

[0013] Problems to be Solved by the Invention

[0014] Conventionally, the recesses formed by laser processing have the following problems: the higher the resolution is, the smaller the width of the bottom of the recess is than the width of the opening of the recess on the initial processing surface, that is, the tip becomes thinner. For through-holes, there has also been the following problem: the higher the resolution is, the smaller the width of the lower end opening of the through-hole is than the width of the upper end of the through-hole, that is, the tip becomes thinner. Moreover, the formation of such tapered recesses and / or through-holes is not suitable for forming complex patterns (such as circuit patterns) with high precision.

[0015] In particular, in the application of substrates for semiconductor packages, metal wirings are sometimes embedded in the processed recesses. If it becomes a high-precision pattern, the wiring resistance will become high. Therefore, in order to prevent this phenomenon, processing with a deep depth and a large width up to the bottom is required. By performing such processing, a substrate for semiconductor packages with a low wiring resistance and high quality can be manufactured.

[0016] The present invention has been completed to solve the above problems, and an object thereof is to provide a laser processing method capable of suppressing the formed recesses and / or through-holes from becoming a tapered shape even when forming the recesses and / or through-holes with high resolution, and even capable of forming a high-precision and complex pattern, a manufacturing method of a substrate capable of manufacturing a substrate having a high-precision and complex wiring pattern, a laser processing apparatus capable of suppressing the formed recesses and / or through-holes from becoming a tapered shape even when forming the recesses and / or through-holes with high resolution, and further capable of providing a high-quality semiconductor package substrate with a low wiring resistance, and even capable of forming a high-precision and complex pattern, a substrate capable of realizing a high-precision and complex wiring pattern, a substrate capable of realizing a via electrode pattern with suppressed taper from the surface to the back surface, a semiconductor package substrate having a high-precision and complex metal wiring pattern, and a semiconductor package substrate having a via electrode pattern with suppressed taper from the surface to the back surface.

[0017] Means for Solving the Problems

[0018] In order to solve the above problems, the present invention provides a laser processing method for forming a recess and / or a through hole in a workpiece using a laser, wherein

[0019] The intensity distribution of the laser on the processed surface of the workpiece is set to an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than the intensity of the inner part for processing.

[0020] If such a laser processing method is used, even when forming a recess with high resolution, it is possible to suppress the width of the bottom of the recess from becoming smaller than the width of the opening of the recess on the initial processed surface. Moreover, if such a laser processing method is used, even when forming a through hole with high resolution, it is possible to suppress the width of the lower end opening of the through hole from becoming smaller than the width of the upper end of the through hole. That is, if the laser processing method of the present invention is used, even when forming a recess and / or a through hole with high resolution, it is possible to suppress the formed recess and / or through hole from becoming a tapered shape, and even possible to form a high-precision and complex pattern.

[0021] For example, as the processing progresses in the depth direction of the workpiece, it is possible to change the shape of the intensity distribution of the laser on the processed surface of the workpiece for processing.

[0022] In this way, it is also possible to change the intensity distribution of the laser as the processing progresses in the depth direction of the workpiece. However, in the present invention, it is only necessary to perform processing by setting the intensity distribution of the laser on at least one processed surface of the workpiece to an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than the intensity of the inner part, and it is not necessarily required to continuously change the laser intensity distribution.

[0023] At this time, it is also possible to change the shape of the intensity distribution of the laser in such a manner that the intensity of the outer part of the intensity distribution of the laser becomes greater than the intensity of the inner part as the processing progresses in the depth direction of the workpiece for processing.

[0024] By performing processing as described above, it is possible to more reliably suppress the formed recess and / or through hole from becoming a tapered shape, and even possible to more reliably form a high-precision and complex pattern.

[0025] For example, it is also possible to pass a laser having an intensity distribution with the maximum laser intensity at the center and a decreasing laser intensity at the periphery through a prism, and thereby change the shape of the intensity distribution of the laser in such a manner that the intensity of the outer part of the intensity distribution of the laser becomes greater than the intensity of the inner part as the processing progresses in the depth direction of the workpiece for processing.

[0026] The means for setting the irradiation shape of the laser to an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than the intensity of the inner part is not particularly limited. For example, the irradiation shape of the laser can be changed by a prism.

[0027] At this time, for example, as the prism, a prism including a roof prism or a conical prism can be used.

[0028] For example, a prism including a roof prism or a conical prism can also be used to set the irradiation shape of the laser to an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than the intensity of the inner part.

[0029] Moreover, in the present invention, a laser processing method is provided, in which a concave portion and / or a through hole are formed in a workpiece using a laser, wherein

[0030] an optical system is used, and the optical system shapes the irradiation shape of the laser having a shape in which the intensity of the outer part in the intensity distribution of the laser is greater than the intensity of the inner part into a top hat-shaped irradiation shape.

[0031] By using such an optical system to perform laser processing on the workpiece, it is possible to perform processing on at least a part of the workpiece that is away from the surface using the irradiation shape of the laser having a shape in which the intensity of the outer part is greater than the intensity of the inner part. If such a laser processing method is used, even when forming a concave portion with high resolution, it is possible to suppress the width of the bottom of the concave portion from becoming smaller than the width of the opening of the concave portion on the initial processing surface. Moreover, if such a laser processing method is used, even when forming a through hole with high resolution, it is possible to suppress the width of the lower end opening of the through hole from becoming smaller than the width of the upper end of the through hole. That is, if the laser processing method of the present invention is used, even when forming a concave portion and / or a through hole with high resolution, it is possible to suppress the formed concave portion and / or through hole from becoming a tapered shape, and furthermore, it is possible to form a high-precision and complex pattern.

[0032] For example, it can also be that the initial processed surface of the workpiece is processed using the laser having the top hat-shaped irradiation shape,

[0033] and for at least a part of the workpiece other than the initial processed surface, the laser having an irradiation shape in which the intensity of the outer part is greater than the intensity of the inner part is used for processing.

[0034] In this way, the initial processed surface of the workpiece can also be processed using the laser having the top hat-shaped irradiation shape.

[0035] For example, as the workpiece, a semiconductor package substrate can be processed to form a concave portion and / or a through hole in the semiconductor package substrate.

[0036] The workpiece is not particularly limited. For example, a semiconductor packaging substrate can be used as the workpiece.

[0037] Especially in the case of processing a semiconductor packaging substrate, there are processing patterns in which through-holes or recesses coexist, such as via processing or groove processing. At this time, the processes of via processing and groove processing do not need to be distinguished, and the processing can be carried out in the same process by the method of the present invention. Moreover, the semiconductor packaging substrate is being promoted towards high density. In the laser drilling method for via processing carried out in the past, the processing time becomes longer due to the increase in the number of hole processes accompanying high density. In contrast, in this method, the processing time does not increase due to the increase in the number of hole processes or the high refinement of the pattern.

[0038] For example, an excimer laser oscillator can also be used to oscillate and generate the laser.

[0039] The laser light source is not particularly limited. For example, an excimer laser oscillator can be used. By using an excimer laser, it is possible to efficiently process workpieces containing organic materials, such as Aromatic Benzocyclobutene Film (ABF) substrates, and high-productivity processing becomes possible. Moreover, since the excimer laser has low interferability, extremely uniform beam formation can be achieved by using the excimer laser.

[0040] The laser can also be irradiated onto the workpiece via a photomask.

[0041] The laser processing of the present invention can also be carried out using a photomask.

[0042] The processing can also be carried out while relatively scanning the laser with respect to the workpiece surface.

[0043] The laser processing of the present invention can also be set as scanning processing.

[0044] For example, ablation processing can be carried out.

[0045] According to the laser processing method of the present invention, ablation processing can be carried out, for example.

[0046] For example, the recess and / or through-hole having a width of 20 μm or less can be formed.

[0047] According to the laser processing method of the present invention, a high-precision pattern including a recess and / or through-hole having a width of 20 μm or less can be formed.

[0048] For example, the recess and / or through-hole having a depth of 20 μm or less can also be formed.

[0049] According to the laser processing method of the present invention, it is also possible to form a highly precise pattern including recesses and / or through holes having a depth of 20 μm or less.

[0050] As the recesses and / or through holes, it is possible to form recesses and / or through holes in which the ratio of the height of the processed portion to the width of the bottom of the recess or the width of the lower end opening of the through hole is 1.0 or more.

[0051] According to the laser processing method of the present invention, it is possible to form recesses and / or through holes having as high an aspect ratio as described above.

[0052] It is possible to form a recess in which the width of the bottom of the recess is 70% or more of the opening width of the recess on the initial processing surface of the workpiece, and / or

[0053] It is possible to form a through hole in which the width of the lower end opening of the through hole is 70% or more of the width of the upper end opening of the through hole on the initial processing surface of the workpiece.

[0054] According to the laser processing method of the present invention, for example, it is possible to form a recess in which the width of the bottom of the recess is 70% or more of the opening width of the recess on the initial processing surface of the workpiece, and / or a through hole in which the width of the lower end opening of the through hole is 70% or more of the width of the upper end opening of the through hole on the initial processing surface of the workpiece.

[0055] It is also possible to form a plurality of recesses and set the distance between the bottoms of adjacent recesses to 110% or less of the width of the bottom.

[0056] According to the laser processing method of the present invention, it is also possible to form a plurality of recesses at a high density.

[0057] Moreover, the present invention provides a method for manufacturing a substrate having recesses and / or through holes, including: forming the recesses and / or through holes in the substrate as the workpiece by the laser processing method of the present invention.

[0058] As described above, the laser processing method of the present invention can form a highly precise and complex pattern. Therefore, in the case of the method for manufacturing a substrate of the present invention including the laser processing method of the present invention, it is possible to manufacture a substrate having a highly precise and complex pattern.

[0059] Moreover, the present invention provides a laser processing apparatus that forms recesses and / or through holes in a workpiece using a laser, and the laser processing apparatus includes:

[0060] a laser light source that oscillates and generates the laser; and

[0061] An optical system is configured to form an irradiation shape of the laser such that the intensity of the outer portion of the intensity distribution of the laser on the processed surface of the workpiece is greater than that of the inner portion.

[0062] If such a laser processing apparatus is used, even when forming a concave portion with high resolution, it is possible to suppress the width of the bottom of the concave portion from becoming smaller than the width of the opening of the concave portion on the initial processed surface. Moreover, if such a laser processing apparatus is used, even when forming a through hole with high resolution, it is possible to suppress the width of the lower end opening of the through hole from becoming smaller than the width of the upper end portion of the through hole. That is, if it is the laser processing apparatus of the present invention, even when forming a concave portion and / or a through hole with high resolution, it is possible to suppress the formed concave portion and / or through hole from becoming a tapered shape, and even possible to form a highly precise and complex pattern.

[0063] As the optical system, it preferably includes:

[0064] A prism that converts a laser having an intensity distribution with the maximum laser intensity at the center and decreasing laser intensity toward the periphery into a laser having an irradiation shape in which the intensity of the outer portion of the intensity distribution of the laser is greater than that of the inner portion; and

[0065] A shaping optical system that converts the irradiation shape of the laser converted by the prism into a top-hat type irradiation shape.

[0066] As the optical system, for example, it may include an optical system including the prism and the shaping optical system.

[0067] At this time, for example, as the prism, it may include a prism including a roof prism or a conical prism.

[0068] For example, a prism including a roof prism or a conical prism may also be used to form an irradiation shape of the laser such that the intensity of the outer portion of the intensity distribution is greater than that of the inner portion.

[0069] As the laser light source, it is preferably a laser light source including an excimer laser oscillator.

[0070] The laser light source is not particularly limited. For example, an excimer laser oscillator can be used. By using an excimer laser, for example, it is possible to efficiently process a workpiece containing an organic material such as an ABF substrate, and high-productivity processing becomes possible. Moreover, since the excimer laser has low interferability, it is possible to achieve extremely uniform beam formation.

[0071] The laser processing apparatus of the present invention may also further include:

[0072] A stage for placing the workpiece; and

[0073] A photomask is disposed between the optical system and the stage.

[0074] The laser processing apparatus of the present invention may also include such a stage and a photomask.

[0075] At this time, the laser processing apparatus of the present invention may further include a controller configured to move the workpiece placed on the stage synchronously with the photomask.

[0076] The laser processing apparatus of the present invention may also include such a controller.

[0077] Moreover, as a substrate of the first aspect, the present invention provides a substrate for use in a semiconductor package substrate, wherein

[0078] On the surface of the substrate, there are at least two recesses adjacent to each other in a cross-section orthogonal to the surface.

[0079] The distance between the bottoms of the recesses in the cross-section is 110% or less of the width of the bottom of the recess.

[0080] The depth of the recess in the cross-section is 20 μm or less.

[0081] The ratio of the depth of the recess in the cross-section to the width of the bottom of the recess is 1.0 or more.

[0082] By loading wirings into the recesses, such a substrate can achieve a highly precise and complex wiring pattern.

[0083] Preferably, the width of the bottom of the recess is 70% or more of the opening width of the recess on the surface.

[0084] For such a substrate, when loading wirings into the recesses, a wiring pattern with a low wiring resistance can be achieved. Moreover, the contact area at the interface between the wiring and the substrate can be increased, so that defective conditions such as peeling of the wiring are difficult to occur.

[0085] Preferably, the opening width of the recess on the surface is 20 μm or less.

[0086] For such a substrate, a higher-precision wiring pattern can be achieved.

[0087] The ratio of the depth of the recess in the cross-section to the width of the bottom of the recess may also be 1.1 or more.

[0088] Alternatively, the ratio of the depth of the recess to the width of the bottom of the recess may also be 1.5 or more.

[0089] Alternatively, the ratio of the depth of the recess to the width of the bottom of the recess may also be 2.4 or more.

[0090] Alternatively, the ratio of the depth of the recess to the width of the bottom of the recess may also be 3.4 or more.

[0091] In the substrate of the first form, it is sufficient that the ratio of the depth of the recess to the width of the bottom of the recess is 1.0 or more. For example, it may also be 1.1 or more, 1.5 or more, 2.4 or more, or 3.4 or more.

[0092] For example, it may also be that the width of the bottom of the recess is 70% or more of the opening width of the recess, and

[0093] the substrate in which the ratio of the depth of the recess to the width of the bottom of the recess is 2.4 or more.

[0094] If it is such a substrate, a wiring pattern with high fineness and low resistance can be more reliably realized. Moreover, the contact area at the interface between the wiring and the substrate can be increased, so that defective conditions such as peeling of the wiring are less likely to occur.

[0095] The recess may also include a groove.

[0096] The plurality of recesses may, for example, also include grooves extending in a direction parallel to the surface of the substrate. Alternatively, the plurality of recesses may be blind holes having a circular or rectangular planar shape.

[0097] It may also be that the substrate has a back surface opposite to the surface,

[0098] and the substrate further has a through hole penetrating from the surface to the back surface.

[0099] If it is such a substrate, a packaging substrate further having a via electrode pattern can be realized.

[0100] For example, the width of the upper end opening of the through hole on the surface may be set to 20 μm or less.

[0101] If it is such a substrate, a via electrode pattern with high fineness and high density can be realized.

[0102] The ratio of the processing length of the through hole on the back surface to the width of the lower end opening of the through hole may be set to 1.0 or more.

[0103] The ratio of the processing length to the width of the lower end opening of the through hole is not particularly limited, but may be set to 1.0 or more, for example.

[0104] Preferably, the width of the lower end opening portion of the through hole on the back surface is 70% or more of the width of the upper end opening portion of the through hole on the front surface.

[0105] If such a substrate is used, a via electrode pattern with suppressed taper from the front surface to the back surface can be achieved.

[0106] Preferably, the ratio of the processing length of the through hole on the back surface to the width of the lower end opening portion of the through hole is 1.0 or more.

[0107] The width of the lower end opening portion of the through hole is 70% or more of the width of the upper end opening portion of the through hole on the front surface.

[0108] If such a substrate is used, a high-precision via electrode pattern with suppressed taper from the front surface to the back surface can be achieved.

[0109] For example, it may also be that the width of the bottom portion of the concave portion is 70% or more of the opening width of the concave portion.

[0110] The ratio of the depth of the concave portion to the width of the bottom portion of the concave portion is 2.4 or more.

[0111] The ratio of the processing length of the through hole on the back surface to the width of the lower end opening portion of the through hole is 1.0 or more.

[0112] The width of the lower end opening portion of the through hole is 70% or more of the width of the upper end opening portion of the through hole on the front surface.

[0113] If such a substrate is used, a wiring pattern and a via electrode pattern with high precision, suppressed taper from the front surface to the back surface can be more reliably achieved.

[0114] Moreover, as a semiconductor package substrate of the first form, the present invention provides a semiconductor package substrate including the substrate of the first form of the present invention, wherein metal wiring is embedded in the concave portion.

[0115] If such a semiconductor package substrate is used, a semiconductor package with a high-precision, high-density, and complex metal wiring pattern can be achieved.

[0116] Furthermore, in the present invention, as a substrate of the second form, a substrate for use in a semiconductor package substrate is provided, wherein

[0117] the substrate has a through hole penetrating from the front surface of the substrate to the back surface on the opposite side of the front surface.

[0118] The width of the lower end opening of the through hole on the back surface is 70% or more of the width of the upper end opening of the through hole on the front surface.

[0119] If it is a substrate of this second form, a semiconductor package having a via electrode pattern with suppressed taper from the front surface to the back surface can be achieved.

[0120] Preferably, the width of the upper end opening of the through hole on the front surface is 20 μm or less.

[0121] If it is such a substrate, a semiconductor package having a highly fine, high-density, complex, and via electrode pattern with suppressed taper from the front surface to the back surface can be achieved.

[0122] The ratio of the processing length of the through hole on the back surface to the width of the lower end opening of the through hole may also be 1.0 or more.

[0123] In the substrate of the second form, the ratio of the processing length of the through hole to the width of the lower end opening may be set to, for example, 1.0 or more.

[0124] Moreover, in the present invention, as a semiconductor package substrate of the second form, there is provided a semiconductor package substrate including a substrate having a through hole in the substrate of the first form or a substrate of the second form, wherein

[0125] The through hole is subjected to via processing.

[0126] If it is a semiconductor package substrate of the second form, it can have a highly fine, high-density, complex, and via electrode pattern with suppressed taper from the front surface to the back surface.

[0127] Effects of the Invention

[0128] As described above, if it is the laser processing method of the present invention, even when forming recesses and / or through holes with high resolution, it is possible to suppress the formed recesses and / or through holes from becoming tapered shapes, and furthermore, it is possible to form highly fine and complex patterns.

[0129] Moreover, if it is the manufacturing method of the substrate of the present invention, it is possible to manufacture a substrate having highly fine and complex patterns.

[0130] If it is the laser processing apparatus of the present invention, even when forming recesses and / or through holes with high resolution, it is possible to suppress the formed recesses and / or through holes from becoming tapered shapes, and further, it is possible to provide a high-quality semiconductor package substrate with low wiring resistance, and furthermore, it is possible to form highly fine and complex patterns.

[0131] In the case of the substrate of the first aspect of the present invention, by loading wirings into the concave portions, it is possible to realize a highly precise, high-density, and complex wiring pattern.

[0132] In the case of the semiconductor package substrate of the first aspect of the present invention, it is possible to realize a semiconductor package having a highly precise, high-density, and complex metal wiring pattern.

[0133] In the case of the substrate of the second aspect of the present invention, it is possible to realize a semiconductor package having a via electrode pattern in which the taper from the front surface to the back surface is suppressed.

[0134] In the case of the semiconductor package substrate of the second aspect of the present invention, it is possible to have a via electrode pattern in which the taper from the front surface to the back surface is suppressed.

[0135] To make the above features and advantages of the present invention more obvious and understandable, specific embodiments will be given below and described in detail with reference to the accompanying drawings. Description of the Drawings

[0136] Figure 1 is a schematic diagram showing an example of the laser processing apparatus of the present invention.

[0137] Figure 2 is a schematic diagram showing an example of laser irradiation in the laser processing method of the present invention.

[0138] Figure 3 is showing Figure 2 a schematic diagram of the defocus of the laser irradiation of.

[0139] Figure 4 is a schematic diagram showing an example of the laser processing method of the present invention.

[0140] Figure 5 is a schematic diagram showing another example of laser irradiation in the laser processing method of the present invention.

[0141] Figure 6 is a schematic cross-sectional view showing an example of the concave portion that can be formed by using the laser processing method of the present invention.

[0142] Figure 7 is an intensity distribution of an example of the laser that can be used in the laser processing method of the present invention.

[0143] Figure 8 is a schematic diagram showing an example of a conventional laser processing apparatus.

[0144] Figure 9 is a schematic diagram showing an example of laser irradiation in a conventional laser processing method.

[0145] Figure 10 is showing​​​​​​​​​​Figure 9 Schematic diagram of defocused laser irradiation.

[0146] Figure 11 is a schematic diagram showing an example of a conventional laser processing method.

[0147] Figure 12 is a schematic diagram showing another example of laser irradiation in a conventional laser processing method.

[0148] Figure 13 is a schematic cross-sectional view showing an example of a concave portion that can be formed by a conventional laser processing method.

[0149] Figure 14 is a schematic partial cross-sectional view of an example of a substrate according to the first embodiment of the present invention.

[0150] Figure 15 is a schematic partial perspective view of another example of a substrate according to the first embodiment of the present invention.

[0151] Figure 16 is a schematic partial cross-sectional view of another example of a substrate according to the first embodiment of the present invention.

[0152] Figure 17 is a schematic partial cross-sectional view of an example of a substrate according to the second embodiment of the present invention.

[0153] Figure 18 is a schematic partial cross-sectional view of an example of a semiconductor package substrate according to the first embodiment of the present invention.

[0154] Figure 19 is a schematic partial cross-sectional view of an example of a semiconductor package substrate according to the second embodiment of the present invention.

[0155] Figure 20 is a schematic partial cross-sectional view of another example of a semiconductor package substrate of the present invention.

[0156] Figure 21 is a schematic plan view of another example of a semiconductor package substrate of the present invention. Detailed Description

[0157] As described above, there is a need for: a laser processing method capable of suppressing the formed concave portions and / or through holes from becoming tapered shapes even when forming concave portions and / or through holes with high resolution, and even capable of forming highly precise and complex patterns; a substrate manufacturing method capable of manufacturing a substrate having highly precise and complex patterns; and the development of a laser processing apparatus capable of suppressing the formed concave portions and / or through holes from becoming tapered shapes even when forming concave portions and / or through holes with high resolution, and even capable of forming highly precise and complex patterns. ​​​​​​​​​​​

[0158] The inventors of the present invention repeatedly and intensively studied the above problems, and as a result, found a laser processing method for forming recesses and / or through holes in a workpiece by using a laser. In this method, processing is performed by setting the intensity distribution of the laser on the processed surface of the workpiece to an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than that of the inner part. Thus, even when forming recesses and / or through holes with high resolution, it is possible to suppress the formed recesses and / or through holes from becoming tapered shapes, and moreover, it is possible to form a highly precise and complex pattern, thereby completing the present invention.

[0159] That is, the present invention is a laser processing method for forming recesses and / or through holes in a workpiece by using a laser, wherein

[0160] processing is performed by setting the intensity distribution of the laser on the processed surface of the workpiece to an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than that of the inner part.

[0161] Moreover, the present invention is a laser processing method for forming recesses and / or through holes in a workpiece by using a laser, wherein

[0162] an optical system is used, and the optical system shapes the irradiation shape of the laser having a shape in which the intensity of the outer part of the intensity distribution of the laser is greater than that of the inner part into a top-hat type irradiation shape.

[0163] Moreover, the present invention is a method for manufacturing a substrate having the recesses and / or through holes, including: forming the recesses and / or through holes in the substrate as the workpiece by the laser processing method of the present invention.

[0164] Moreover, the present invention is a laser processing apparatus for forming recesses and / or through holes in a workpiece by using a laser, and the laser processing apparatus includes:

[0165] a laser light source that oscillates and generates the laser; and

[0166] an optical system that sets the irradiation shape of the laser to an irradiation shape in which the intensity distribution of the laser on the processed surface of the workpiece is such that the intensity of the outer part of the intensity distribution is greater than that of the inner part.

[0167] Moreover, the present invention is a substrate of a first form, which is used for a semiconductor package substrate, wherein

[0168] on the surface of the substrate, there are at least two adjacent recesses in a cross section orthogonal to the surface,

[0169] the distance between the bottoms of the recesses in the cross section is 110% or less of the width of the bottom of the recess,

[0170] The depth of the recess on the cross-section is 20 μm or less.

[0171] The ratio of the depth of the recess on the cross-section to the width of the bottom of the recess is 1.0 or more.

[0172] Moreover, the present invention is a semiconductor package substrate of the first form, which includes the substrate of the first form of the present invention, wherein a metal wiring is embedded in the recess.

[0173] Moreover, the present invention is a substrate of the second form, which is used for a semiconductor package substrate, wherein

[0174] the substrate has a through hole that penetrates from the surface of the substrate to the back surface opposite to the surface.

[0175] The width of the lower end opening of the through hole on the back surface is 70% or more of the width of the upper end opening of the through hole on the surface.

[0176] And, the present invention is a semiconductor package substrate of the second form, which includes the substrate including the through hole in the substrate of the first form or the substrate of the second form, wherein

[0177] the through hole is subjected to via processing.

[0178] Hereinafter, the present invention will be described in detail, but the present invention is not limited to these.

[0179] [Laser processing device]

[0180] Figure 1 is a schematic diagram showing an example of the laser processing device of the present invention. Figure 1 The shown laser processing device 100 is a laser processing device 100 that forms a recess and / or a through hole in a workpiece 70 using a laser. In addition, Figure 1 the shown laser processing device 100 is an example of the laser processing device of the present invention, but the laser processing device of the present invention is not limited to Figure 1 the shown device.

[0181] Figure 1 The shown laser processing device 100 includes: a laser light source 10 that oscillates and generates a laser 1; and an optical system 20 that converts the intensity distribution and irradiation shape of the laser 1 in the processing surface of the workpiece 70.

[0182] Figure 1In the laser processing apparatus 100 shown, the optical system 20 includes a prism 21 and a shaping optical system 22. Details will be described below, but the prism 21 is a prism that converts a laser having an intensity distribution with the maximum laser intensity at the center and a decreasing laser intensity at the periphery into a laser having an irradiation shape in which the intensity of the outer part in the intensity distribution of the laser becomes greater than the intensity of the inner part, and the shaping optical system 22 is a shaping optical system that converts the irradiation shape of the laser converted by the prism 21 into a top-hat type irradiation shape. Figure 1 In the laser processing apparatus 100 shown, the prism 21 includes a roof prism, but may also include a conical prism.

[0183] Figure 1 The laser processing apparatus 100 shown further includes, in order from the optical system 20 in the optical path of the laser processing apparatus 100 to the workpiece 70, a photomask 30, a folding mirror 40, and a reduction projection optical system 50.

[0184] The laser processing apparatus 100 further includes: a stage 60 for placing the workpiece 70; and a controller 80 electrically connected to the photomask 30 and the stage 60. On the other hand, the laser processing apparatus 100 further includes: a stage 60 for placing the workpiece 70; and a photomask 30 disposed between the optical system 20 and the stage 60.

[0185] In addition, the photomask 30, the folding mirror 40, the reduction projection optical system 50, the stage 60, and the controller 80 are optional components for the laser processing apparatus 100 of the present invention.

[0186] The light source 10 that oscillates and generates the laser 1 is, for example, a light source (laser oscillator) 10 that irradiates (emits) the laser 1 in a pulsed manner. More specifically, Figure 1 The laser light source 10 shown includes an excimer laser oscillator.

[0187] Moreover, Figure 1 The laser processing apparatus 100 shown includes: a mask alignment camera 31 as a photographing component for reading the characteristic part of the photomask 30; and a workpiece alignment camera 61 as a photographing component for reading the characteristic part of the workpiece 70. The mask alignment camera 31 is configured to send the position information of the characteristic part of the photomask 30 to the controller 80. The workpiece alignment camera 61 is configured to send the position information of the characteristic part of the workpiece 70 to the controller 80. The controller 80 is configured to align the relative positions of the workpiece 70 and the photomask 30 based on this position information. On the other hand, the controller 80 is configured to move the workpiece 70 placed on the stage 60 synchronously with the photomask 30.

[0188] [Laser Processing Method]

[0189] The laser processing method of the present invention can be carried out, for example, using the laser processing apparatus of the present invention, but can also be carried out using an apparatus other than the laser processing apparatus of the present invention.

[0190] Hereinafter, a specific example of the laser processing method of the present invention that can be carried out using Figure 1 the laser processing apparatus 100 shown will be described.

[0191] The laser processing method of the present invention is a laser processing method for forming a concave portion and / or a through hole in a workpiece 70 using a laser.

[0192] In the laser processing of the present invention, the intensity distribution of the laser on the processed surface of the workpiece 70 is set to an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than the intensity of the inner part, and processing is carried out. While referring to Figures 1 to 4 this, an example of such a laser processing method will be described.

[0193] First, as Figure 1 shown, laser 1 having Figure 1 (a) the irradiation shape shown is oscillated and generated from the laser light source 10. As Figure 2 shown, the irradiation shape of the laser 1 in this example is an irradiation shape of an intensity distribution in which the laser intensity of the inner part 1a is greater than the laser intensity of the outer part 1b. On the other hand, the irradiation shape of the laser 1 is an intensity distribution in which the laser intensity at the center (inner part) 1a is the maximum and the laser intensity at the periphery (outer part) 1b decreases.

[0194] Next, the laser 1 is incident on the prism 21 of the optical system 20. The prism 21 is a prism that converts the laser 1 into a laser 2 having an irradiation shape in which the intensity of the outer part in the intensity distribution becomes greater than the intensity of the inner part ( Figure 1 (b)). Figure 1 In Figure 2 this, as an example of the prism 21, a prism 21 including four (two pairs) roof prisms is shown. In addition,

[0195] the prism 21 is not limited to a roof prism, and for example, a prism including a conical prism can also be used.

[0196] In addition, Non-Patent Document 1 discloses the use of an axicon lens as a conical prism, but no mention is made of a prism for converting a laser into an irradiation shape in which the intensity of the outer part in the intensity distribution of the laser becomes greater than the intensity of the inner part.

[0197] Next, the laser that exits from the prism 21 and has Figure 1 (b) and Figure 2The laser beam 2 with the irradiation shape as shown is incident on the shaping optical system 22. As Figure 2 shown, the shaping optical system 22 focuses each component of the laser beam 2 toward the imaging point F1, and shapes the irradiation shape of the laser beam 2 into Figure 1 the top-hat type irradiation shape as shown in (c) to obtain the laser beam 3.

[0198] The laser beam 3 is incident on the photomask 30 located at the position of the imaging point F1. The photomask 30 has a mask pattern corresponding to the pattern to be processed on the workpiece 70. By scanning and irradiating the laser beam through the photomask 30 onto the workpiece 70, it is possible to form recesses and / or through-holes in the workpiece 70 in the desired pattern.

[0199] The laser beam 4 that exits the photomask 30 and has the Figure 1 irradiation shape (top-hat shape) as shown in (d) is redirected by the folding mirror 40 and incident on the reduction projection optical system (projection lens) 50. The effects of using an arbitrary reduction projection optical system 50 will be described later.

[0200] As Figure 2 shown, the laser beam 5 that exits the reduction projection optical system 50 reaches the surface (initial workpiece surface) 71 of the workpiece 70. Figure 2 Among them, an example is shown in which the imaging point F2 of the reduction projection optical system 50 is aligned with the surface 71 of the workpiece 70. However, the imaging point F2 of the reduction projection optical system 50 is not limited to the surface 71 of the workpiece 70.

[0201] As Figure 2 shown, the irradiation shape of the laser beam 5 irradiated onto the surface 71 of the workpiece 70 is a top-hat type as shown in Figure 1 (e) and Figure 2 shown. On the other hand, in the workpiece surface 72 that has been further processed from the imaging point F2, as Figure 2 shown, the intensity distribution of the laser beam 6 is set to an irradiation shape in which the intensity of the outer part 6b of the intensity distribution is greater than the intensity of the inner part 6a for processing.

[0202] Figure 1 and Figure 2 shown, in the examples as Figure 3 sketched in (a) to (e), as the distance from the imaging point F2 (under focus U) increases, the irradiation shape of the laser beam 6 becomes closer to the irradiation shape of the laser beam 2 before being shaped by the shaping optical system 22. This is the reason why the intensity distribution of the laser beam 6 becomes such that the intensity of the outer part 6b of the intensity distribution becomes greater than the intensity of the inner part 6a.

[0203] By the laser processing method of the present invention, in the surface 72 to be processed, the intensity distribution of the laser 6 is set to an irradiation shape in which the intensity of the outer part 6b of the intensity distribution is greater than the intensity of the inner part 6a, and thus, as Figure 4 sketched in, it is possible to suppress the formed recess 200 from becoming a tapered shape. By continuous processing, a through-hole with suppressed tapering can be formed. That is, according to the laser processing method of the present invention, deep digging can be carried out as the processing progresses without tapering occurring. Moreover, in the laser processing method of the present invention, it is possible to suppress the formed recess and / or through-hole from becoming a tapered shape as described above, and thus a highly precise and complex pattern can be formed. And, according to the laser processing method of the present invention, even when forming a recess and / or through-hole with high resolution, it is possible to suppress the formed recess 200 and / or through-hole from becoming a tapered shape.

[0204] On the other hand, as described below while referring to Figures 8 to 11 as follows, when the intensity distribution of the laser on the surface to be processed of the workpiece is not set to an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than the intensity of the inner part, it is impossible to prevent the formed recess and / or through-hole from becoming a tapered shape.

[0205] Figure 8 is a schematic diagram showing an example of a conventional laser processing apparatus. Figure 8 The shown laser processing apparatus 100' is the same as the Figure 1 shown laser processing apparatus 100 except that it does not include the prism 21.

[0206] Figure 8 In the shown laser processing apparatus 100', as Figure 8 and Figure 9 shown, the laser 1 oscillated and generated from the laser light source 10 and having the irradiation shape shown in Figure 8 (a) is incident on the shaping optical system 22 and becomes a laser 3' having a top-hat-shaped irradiation shape shown in Figure 8 (b). The laser 3' passes through the photomask 30 located at the imaging point F1 of the shaping optical system 22 and becomes a laser 4' having a top-hat-shaped irradiation shape shown in Fig. (c). The laser 4' is deflected by the folding mirror 40 and incident on the reduction projection optical system 50. The laser 5' that exits from the reduction projection optical system 50 and has the top-hat-shaped irradiation shape shown in Figure 8 (d) reaches the surface 71 of the workpiece 70 located at the imaging point F2 of the reduction projection optical system 50.

[0207] Next, as the surface 72 to be processed moves away from the surface 71 (front focus U) of the workpiece 70 as the processing progresses, the irradiation shape of the laser 6' is as Figure 10As shown in (a) to (e), it becomes closer to the irradiation shape of the laser beam 1 oscillated from the laser light source 10. Therefore, in the machining of the machining surface 72 located at a position far from the surface 71 of the workpiece 70, as Figure 10 shown, the intensity distribution of the laser beam 6' will not be an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than the intensity of the inner part.

[0208] When laser machining is performed using such a method, for example, as Figure 11 shown, the formed recess and / or through-hole becomes a tapered shape. Especially in the case of forming a recess and / or through-hole with high resolution, the occurrence of tapering becomes significant and high aspect ratio machining cannot be performed.

[0209] In the laser machining method of the present invention, it is only necessary to machine at least a part of the machining surface 72 of the workpiece 70 with a laser beam having an irradiation shape in which the intensity of the outer part 6b is greater than the intensity of the inner part 6a. For example, as in the examples shown in Figure 1 and Figure 2 the surface (initial machining surface) 71 of the workpiece 70 is machined with a laser beam 5 having a top-hat type irradiation shape.

[0210] In the present invention, for example, as Figure 4 shown, as the machining progresses in the depth direction of the workpiece 70, the shape of the intensity distribution of the laser beam 6 on the machining surface 72 of the workpiece 70 can be changed for machining.

[0211] On the other hand, Figure 4 the example of

[0212] can also be said to be an example in which, as the machining progresses in the depth direction of the workpiece 70, the shape of the intensity distribution of the laser beam 6 is changed so that the intensity of the outer part 6b in the intensity distribution of the laser beam 6 becomes greater than the intensity of the inner part 6a for machining.

[0213] By machining as described above, it is possible to more reliably suppress the formed recess and / or through-hole from becoming a tapered shape, and furthermore, it is possible to more reliably form a high-precision and complex pattern.

[0214] In the present invention, in order to form a pattern on a specified recess and / or through hole, a photomask 30 can also be used. Even when the photomask 30 is used, by setting the intensity distribution of the laser beam 6 on the processed surface 72 of the workpiece 70 to an irradiation shape in which the intensity of the outer part 6b of the intensity distribution is greater than that of the inner part 6a, processing can be performed, and it is possible to suppress the formed recess and / or through hole from becoming a tapered shape, and furthermore, it is possible to reliably form a high-precision and complex pattern. Or, as Figure 5 shown, in the present invention, the photomask 30 may not be used.

[0215] On the other hand, when the photomask 30 is not used, if the processing is not performed with an irradiation shape in which the intensity of the outer part 6b of the intensity distribution is greater than that of the inner part 6a, the formed recess and / or through hole will also become a tapered shape as in the example shown in Figure 11 . Similarly, when the photomask 30 is not used, if the processing is not performed with an irradiation shape in which the intensity of the outer part 6b of the intensity distribution is greater than that of the inner part 6a as shown in Figure 12 , the formed recess and / or through hole will also become a tapered shape as in the example shown in Figure 11 .

[0216] On the other hand, the example described with reference to Figures 1 to 4 can also be said to be a laser processing method for forming a recess and / or through hole in a workpiece 70 using a laser beam. In this method, an optical system 20 is used, and the optical system 20 converts the laser beam 1 into a laser beam 2 having an intensity distribution in which the intensity of the outer part is greater than that of the inner part, and further forms it into a top-hat-shaped irradiation shape of the laser beam 3.

[0217] By using such an optical system 20 to perform laser processing on the workpiece 70, it is possible to perform processing on at least a part of the workpiece 70 away from the surface using the irradiation shape of the laser beam 6 in which the intensity of the outer part 6b is greater than that of the inner part 6a. If such a laser processing method is used, even when forming a recess with high resolution, it is possible to suppress the width of the bottom of the recess from becoming smaller than the width of the opening of the recess on the initial processing surface 71. Moreover, if such a laser processing method is used, even when forming a through hole with high resolution, it is possible to suppress the width of the lower end opening of the through hole from becoming smaller than the width of the upper end of the through hole. That is, in the laser processing method of the present invention expressed in this aspect, even when forming a recess and / or through hole with high resolution, it is possible to suppress the formed recess and / or through hole from becoming a tapered shape, and furthermore, it is possible to form a high-precision and complex pattern.

[0218] The workpiece 70 that is the object of laser processing in the present invention is not particularly limited. For example, a semiconductor package substrate can be set as the workpiece 70.

[0219] Especially in the case of processing a semiconductor package substrate, there are processing patterns in which through-holes or recesses, such as via processing or groove processing, coexist. At this time, it is possible to perform processing in the same process by the method of the present invention without distinguishing between the processes of via processing and groove processing. Moreover, the semiconductor package substrate is advancing towards high density. In the conventional laser drilling method for via processing, as the number of hole processes increases with the increase in density, the processing time becomes longer. In contrast, in this method, the processing time does not increase due to an increase in the number of hole processes or high refinement of the pattern.

[0220] According to the present invention, for example, ablation processing can be performed on the workpiece 70. In the case of ablation processing, within the range where the energy of the lasers 5 and 6 is absorbed by the workpiece 70, the lasers can be freely set at wavelengths and energy densities at which ablation processing can be performed.

[0221] According to the present invention, as described above, it is possible to form a pattern of high-precision recesses and / or through-holes. Specifically, according to the present invention, for example, it is possible to form recesses and / or through-holes having a width of 20 μm or less and with taper suppression. In contrast, Figures 8 to 12 in the conventional laser processing apparatus 100', it is difficult to form recesses and / or through-holes having a width of 20 μm or less and with taper suppression.

[0222] Moreover, it can also be that the recesses and / or through-holes that can be formed by the present invention, for example, have a depth of 20 μm or less. In addition, as long as the processing depth is less than the thickness of the workpiece 70, it is possible to form a recess, and as long as the processing depth is set to be the same as the thickness of the workpiece 70, it is possible to form a through-hole.

[0223] On the other hand, according to the present invention, it is possible to form a pattern of recesses and / or through-holes with a high aspect ratio. According to the present invention, for example, it is possible to form a recess in which the ratio of the height of the processed portion to the width of the bottom of the recess is 1.0 or more. Moreover, according to the present invention, for example, it is possible to form a recess in which the ratio of the height of the processed portion to the width of the lower end opening of the through-hole is 1.0 or more. In contrast, in Figures 8 to 12 the conventional laser processing apparatus 100', it is difficult to form recesses and / or through-holes with an aspect ratio of 1.0 or more while suppressing taper.

[0224] Furthermore, on the other hand, according to the present invention, for example, a recess can be formed such that the width of the bottom of the recess is 70% or more of the opening width of the recess on the initial processing surface of the workpiece, and / or a through hole can be formed such that the width of the lower end opening of the through hole is 70% or more of the width of the upper end opening of the through hole on the initial processing surface of the workpiece.

[0225] Furthermore, in the present invention, a recess can be formed while suppressing tapering. Therefore, as Figure 6 shown, a plurality of recesses 200 can also be formed, and the distance 202 between the bottoms of adjacent recesses 200 can be set to 110% or less of the width 201 of the bottom. Therefore, in the present invention, a plurality of recesses 200 can be formed at a high density.

[0226] On the other hand, in the conventional laser processing method, for example, as Figure 13 shown, when forming a plurality of recesses 200', each recess 200' is formed in a tapered manner. Therefore, the distance 202' between the bottoms of adjacent recesses 200' exceeds 110% of the width 201' of the bottom, and thus a plurality of recesses 200' cannot be formed at a high density.

[0227] Hereinafter, any matters of the laser processing method and the laser processing apparatus of the present invention will be described, but the present invention is not limited to the specific examples described above and the modified examples described below.

[0228] <Laser and Laser Light Source>

[0229] The laser 1 is not particularly limited. For example, excimer laser can be used. By using excimer laser, for example, a workpiece containing an organic material such as an ABF substrate can be processed efficiently, and high-productivity processing becomes possible. Moreover, since excimer laser has low interferability, by using excimer laser, extremely uniform beam formation can be achieved.

[0230] Furthermore, by using excimer laser, compared with solid-state laser, high-precision adjustment of the processing depth and high-precision adjustment of the width of the recess and / or the through hole can be achieved. In particular, excimer laser is useful for forming recesses such as blind holes or grooves. Therefore, by using excimer laser, complex concavo-convex shape processing such as a circuit board can be performed with high precision.

[0231] In addition, the irradiation shape of the laser 1 oscillated and generated by the laser light source 1 is not limited to the shapes shown in Figure 1 , Figure 2 and Figure 5 . For example, it can also be an irradiation shape like the shape shown in Figure 7 , in which the laser intensity at the center (inside) 1a is the maximum and the laser intensity at the periphery (outside) 1b decreases.

[0232] <Scanning Irradiation>

[0233] In the present invention, processing may also be performed while relatively scanning the lasers 5 and 6 with respect to the work surface 71. That is, the laser processing of the present invention may also be set as scanning processing.

[0234] By performing scanning processing, even for a large-area workpiece 70, laser processing can be performed with high precision.

[0235] Moreover, by performing scanning processing, even if the number of recesses and / or through holes to be processed increases, an increase in processing time can be prevented.

[0236] Scanning processing is performed, for example, by synchronously moving the workpiece 70 placed on the stage 60 and the photomask 30.

[0237] Thereby, laser processing can be performed without moving the lasers 1 to 6 themselves.

[0238] Moreover, in this configuration, the processing area is not limited by the range of the lens, and thus an area (field angle) larger than the range of the lens can be processed.

[0239] And, according to this configuration, the reduction projection optical system 50 required for irradiation can be reduced, and the laser irradiation position accuracy or temperature controllability can also be performed well. Furthermore, the reduction projection optical system 50 described below can be reduced, and thus the distortion of the image caused by irradiation is also small.

[0240] Figure 1 In the shown laser processing apparatus 100, the controller 80 can be used to synchronously move the workpiece 70 placed on the stage 60 and the photomask 30.

[0241] More specifically, the controller 80 is configured to align the relative positions of the workpiece 70 and the photomask 30 based on the position information of the characteristic part of the photomask 30 obtained by using the mask alignment camera 31 and the position information of the characteristic part of the workpiece 70 obtained by using the workpiece alignment camera 61.

[0242] <Reduction Projection Optical System>

[0243] Figure 1 In the shown laser processing apparatus 100, by including the reduction projection optical system 50, the mask pattern formed on the photomask 30 can be magnified compared to the processing pattern actually desired to be formed on the workpiece.

[0244] By magnifying the mask pattern formed on the photomask 30 compared to the actual processing pattern, the energy of the laser 3 irradiated onto the photomask 30 can be made less than the actual processing energy. If the reduction magnification of the reduction projection optical system 50 is set to N, then compared to the processing energy on the surface of the workpiece 70, the energy of the laser irradiated onto the mask surface is 1 / (N 2 ). Thus, thermal drift caused by the energy of the laser 3 can be suppressed, and therefore thermal expansion of the photomask 30 can be suppressed, enabling high-precision processing even after a long processing operation.

[0245] Furthermore, deterioration of optical components (such as the optical system 20 and the photomask 30) caused by the heat of the laser can also be suppressed, thus extending the lifespan of the optical components.

[0246] The reduction projection optical system 50 may include a pair of reduction projection lenses. In the case where the reduction projection optical system 50 is an infinity optical system, the magnification of the reduction projection optical system 50 can be adjusted, for example, by the ratio of the focal lengths of the reduction projection lenses and the distance between the reduction projection lenses.

[0247] Preferably, the numerical aperture (NA) of the reduction projection lens is selected according to the energy density required for processing the workpiece 70 or the resolution of the processing. The NA of the reduction projection lens is preferably 0.12 or more. In the present invention, even when laser processing is performed with a high NA for high-resolution formation, it is possible to suppress the formed concave portions and / or through holes from becoming a tapered shape.

[0248] Preferably, the laser processing apparatus 100 of the present invention further includes a temperature adjustment component for adjusting the temperature of the reduction projection optical system 50.

[0249] By including the temperature adjustment component, the influence of heat caused by the laser energy in the reduction projection optical system 50 can be further suppressed. In the reduction projection optical system 50, the laser 4 that has passed through the photomask 30 is reduced-projected by 1 / N, so the energy of the laser on the lens part at the object front end becomes N2 times that of the laser irradiated onto the photomask 30, and this part is prone to heat influence. Therefore, in order to suppress this thermal energy, a temperature adjustment function is given to the reduction projection optical system 50, thereby suppressing thermal drift caused by the energy of the laser and enabling high-precision processing even after a long processing operation.

[0250] Moreover, in the laser processing method and the laser processing apparatus 100 of the present invention, a reduction projection lens with a very small aperture can be used. The temperature adjustment component for the reduction projection lens does not directly impart the temperature adjustment component to the lens itself, but cools the sheath portion that holds the lens. Therefore, if the lens aperture becomes larger, although temperature management can be performed on the peripheral portion of the lens, it is difficult for the temperature adjustment effect to reach the vicinity of the crucial central portion, making it difficult to perform thermal management. Thus, even for the minute energy absorption into the lens caused by long-term laser irradiation, thermal deformation is likely to occur. If the laser processing apparatus 100 has a temperature adjustment function for the reduction projection optical system 50, the lens aperture can be reduced, thereby suppressing such an adverse condition.

[0251] Furthermore, it is also possible to suppress the adverse effects caused by laser irradiation on the reduction projection optical system 50 and extend its lifespan.

[0252] [Method for manufacturing a substrate]

[0253] The method for manufacturing a substrate of the present invention is a method for manufacturing a substrate having recesses and / or through holes, and includes forming recesses and / or through holes in the substrate as the workpiece by the laser processing method of the present invention.

[0254] As described above, the laser processing method of the present invention can form a highly precise and complex pattern. Therefore, if it is a method for manufacturing a substrate of the present invention that includes the laser processing method of the present invention, a substrate having a highly precise and complex pattern can be manufactured.

[0255] [Substrate]

[0256] The substrate of the present invention is a substrate used for a semiconductor package substrate. The substrate of the present invention is roughly divided into two forms: a first-form substrate having at least two recesses and a second-form substrate having a through hole. A substrate having at least two recesses and a through hole may be included in either the first form or the second form.

[0257] Hereinafter, examples of the first-form substrate and the second-form substrate will be described in more detail with reference to the drawings.

[0258] <First form>

[0259] Figure 14 A schematic partial cross-sectional view showing an example of the first-form substrate of the present invention. Figure 14 The shown substrate 70 is a substrate used for a semiconductor package substrate.

[0260] The substrate 70 has at least two recesses 200 adjacent to each other on a cross-section 73 orthogonal to the surface 71 on its surface 71. Each recess 200 has an opening 200A on the surface 71 of the substrate 70 and a bottom 200B. The substrate 70 has a convex portion 74 between the adjacent recesses 200. The at least two recesses 200 may be of the same shape as each other or of different shapes. That is, the width of the opening portion 200A of the recess 200, i.e., the opening width W a and the width W of the bottom 200B b may be the same respectively or all different. Moreover, the processing depth D 200 (e.g., the depth of the recess 200 in the thickness direction of the substrate 70) may be different for each recess 200 or there may be recesses with the same processing depth D 200 .

[0261] The distance W between the bottoms 200B of the recesses 200 on the cross-section 73 of the substrate 70 c is 110% or less of the width W of the bottom 200B of the recess 200 b , preferably 100% or more and 110% or less, more preferably 100% or more and 105% or less. Here, the width W of the bottom 200B of the recess 200 b is the average of the widths W of the bottoms 200B of the adjacent recesses 200 b . Moreover, the distance W between the bottoms 200B of the recesses 200 c is the shortest distance between the bottoms 200B of the recesses 200. In addition, for the substrate 70 of the first aspect of the present invention, as long as the distance W c between the bottoms 200B of the recesses 200 is 110% or less of the width W of the bottom 200B of the recess 200 b , at least two recesses 200 are sufficient, and recesses not satisfying such a relationship may also be included.

[0262] Moreover, in the substrate 70, the depth D 200 of the recess 200 on the cross-section 73 is 20 μm or less. Moreover, in the substrate 70, the depth D 200 of the recess 200 on the cross-section 73 relative to the width W b of the bottom 200B of the recess 200 200 ratio (D b / W c ) is 1.0 or more.

[0263] In such a substrate 70, the distance W b between the bottoms 200B of the recesses 200 is 110% or less of the width W 200 of the bottom 200B of the recess 200, and the depth D200 The width W relative to the bottom 200B of the recess 200 b The ratio (D 200 / W b ) satisfies 1.0 or more, so the width W b can be set to a very small width. Therefore, such a substrate 70 can have a high-precision recess pattern. Also, by loading wiring such as metal wiring into such a recess 200 of the substrate 70, a high-precision and complex wiring pattern can be achieved.

[0264] Such a substrate of the first form can be manufactured, for example, by the laser processing method of the present invention or the manufacturing method of the substrate of the present invention described previously. Moreover, such a substrate of the first form can be manufactured, for example, using the laser processing apparatus of the present invention described previously.

[0265] Therefore, for example, the width W of the bottom 200B of the recess 200 b can be set to 70% or more of the opening width W of the recess 200 on the surface 71 a , preferably 80% or more, more preferably 90% or more.

[0266] In such a substrate 70, the recess 200 is not a tapered shape but is close to a so-called cylindrical tube shape. Therefore, when loading wiring into the recess 200, the wiring can exhibit low resistance. Thus, such a substrate 70 can achieve a wiring pattern with low wiring resistance. Also, since the contact area at the interface between the wiring and the substrate can be increased, it is difficult to cause defects such as peeling of the wiring.

[0267] Ideally, the width W of the bottom 200B of the recess 200 b is equal (100%) to the opening width W a .

[0268] Moreover, for example, preferably, the opening width W of the recess 200 on the surface 71 a is 20 μm or less.

[0269] If it is such a substrate 70, a higher-precision wiring pattern can be achieved. The lower limit is not particularly limited. For example, the opening width W of the recess 200 on the surface 71 a can be set to 1 μm or more and 20 μm or less.

[0270] In the substrate 70 of the first form, the ratio D 200 / W b only needs to be 1.0 or more. For example, it can also be 1.1 or more, 1.5 or more, 2.4 or more, or 3.4 or more. The ratio D 200 / W b has no particular upper limit. The ratio D 200 / W b For example, it can be set to be 10.0 or less.

[0271] The opening width W of the recess 200 on the surface 71 a can be set to be 20 μm or less.

[0272] For such a substrate, a higher-resolution wiring pattern can be achieved. The opening width W a has no particular limitation on its lower limit. For example, it can be set to be 1 μm or more.

[0273] For example, in the substrate 70 of the first form, the width W of the bottom 200B of the recess 200 b is the opening width W of the recess 200 a and is 70% or more of the opening width W of the recess 200, and the depth D of the recess 200 200 relative to the width W of the bottom 200B of the recess 200 b is a substrate with a ratio of 2.4 or more.

[0274] For such a substrate 70, a high-resolution, complex, and low-resistance wiring pattern can be more effectively achieved.

[0275] The recess 200 may also include, for example, Figure 15 the groove 200T as shown in the perspective view. The groove 200T extends in a direction parallel to the surface 71 of the substrate 70. A plurality of grooves 200T may also be as Figure 15 shown as an example, and the extending directions are different from each other.

[0276] The recess 200 is not limited to the groove 200T. For example, it may also be as Figure 15 shown in the example, and include a blind hole 200S having a rectangular surface shape or a blind hole 200U having a circular surface shape. It may also include a recess 200 having other surface shapes.

[0277] In the case where the recess 200 with D 200 / W b being 1.0 or more is the groove 200T, the width W b and the opening width W a are set to be the width of the groove 200T in the direction perpendicular to the extending direction of the groove. In the case where the recess 200 with D 200 / W b being 1.0 or more is the blind hole 200S having a rectangular surface shape, the smallest width in the surface shape is set as the width W b and the opening width W a . In the case where the recess 200 with D 200 / W bWhen the plurality of recesses 200 with a value of 1.0 or more have a blind hole 200U with a circular surface shape, the diameter of the circle is defined as the width W b and the opening width W a In the case where the surface shape is an ellipse, the minor axis is defined as the width W b and the opening width W a .

[0278] In addition, as described above, the substrate 70 of the first aspect of the present invention only needs to have at least two recesses 200 with a value of D 200 / W b of 1.0 or more, and it is not necessary for all recesses to satisfy a value of D 200 / W b of 1.0 or more.

[0279] The processing depth D of the recess 200 on the cross-section 73 200 (for example, the depth of the recess 200 in the thickness direction of the substrate 70) can be different for each recess 200, or there can be recesses with the same processing depth D 200 The processing depth D of the recess 200 200 can be set, for example, to 5 μm or more and 20 μm or less.

[0280] In a modified example, as Figure 16 shown, the substrate 70 of the first aspect may also have a back surface 71B on the side opposite to the surface 71 of the substrate 70, and further have a through hole 300 penetrating from the surface 71 to the back surface 71B.

[0281] If such a substrate 70 is used, a package substrate having a via electrode pattern can be realized.

[0282] For example, preferably, the width W of the upper end opening 300A of the through hole 300 on the surface 71 d is set to 20 μm or less.

[0283] If such a substrate 70 is used, a high-precision and high-density via electrode pattern can be realized.

[0284] The lower limit of the width W of the upper end opening 300A d is not particularly limited, and can be set to 1 μm or more, for example.

[0285] The processing length D of the through hole 300 on the back surface 71B 300 with respect to the width W of the lower end opening 300B of the through hole 300 e can be set to 1.0 or more.

[0286] The processing length D 300 with respect to the width W of the lower end opening 300B of the through hole 300e The upper limit of the ratio is not particularly limited, and can be set, for example, to 1.0 or more and 10.0 or less.

[0287] The substrate 70 having such a through hole 300 can also be formed, for example, by the laser processing method of the present invention or the manufacturing method of the substrate of the present invention described above. Moreover, the substrate 70 can be manufactured using the laser processing apparatus of the present invention described above.

[0288] Therefore, the width W of the lower end opening 300B of the through hole 300 on the back surface 71B e can be set to 70% or more of the width W of the upper end opening 300A of the through hole 300 on the surface 71. d Preferably, it has such a through hole 300. The substrate 70 having such a through hole 300 and at least two recesses 200 described above is a substrate of the first form and a substrate of the second form.

[0289] In such a substrate 70, the through hole 300 is not a tapered shape but is close to a so-called cylindrical tube shape. Therefore, when through-hole processing is performed on the through hole 300, the through-hole electrode formed in this way can exhibit low resistance. Moreover, since the contact area at the interface between the wiring and the substrate can be increased, it is difficult to cause defects such as peeling of the wiring. Thus, the substrate 70 of this modification can achieve a highly precise, complex, and low-resistance through-hole electrode pattern.

[0290] Ideally, the width W of the lower end opening 300B of the through hole 300 e is equal to (100%) the width W of the upper end opening 300A. The width W of the lower end opening 300B of the through hole 300 d can be set to 70% or more of the width W of the upper end opening 300A, preferably 80% or more, and more preferably 90% or more. e d

[0291] For example, in the substrate 70 of the first form, the processing length D of the through hole 300 on the back surface 71B 300 relative to the width W of the lower end opening 300B of the through hole 300 e is 1.0 or more, and the width W of the lower end opening 300B of the through hole 300 e is 70% or more of the width W of the upper end opening 300A of the through hole 300 on the surface 71. This form is preferred. d

[0292] ​​​In the case of such a substrate 70, a through-hole electrode pattern with high fineness and suppressed taper from the front surface to the back surface can be effectively realized. Moreover, since the contact area at the interface between the wiring and the substrate can be increased, it is difficult to cause defects such as peeling of the wiring.

[0293] Moreover, for example, the substrate 70 of the first form may also be a substrate as described below, that is, the width W of the bottom 200B of the recess 200 b is 70% or more of the opening width W of the recess 200, and the depth D of the recess 200 a is 2.4 or more with respect to the width W of the bottom 200B of the recess 200, and the processing length D of the through-hole 300 on the back surface 71B 200 is 1.0 or more with respect to the width W of the lower end opening 300B of the through-hole 300, and the width W of the lower end opening 300B of the through-hole 300 b is 70% or more of the width W of the upper end opening 300A of the through-hole 300 on the front surface 71. 300 e e d d e d e

[0294] In the case of such a substrate 70, a through-hole electrode pattern with high fineness and suppressed taper from the front surface to the back surface can be more effectively realized. Moreover, since the contact area at the interface between the wiring and the substrate can be increased, it is difficult to cause defects such as peeling of the wiring.

[0295] The planar shape of the through-hole 300 is not particularly limited. In the case where the through-hole 300 has a rectangular surface shape, the minimum width in the surface shape is set as the width W d and the width W e . In the case where the through-hole 300 has a circular surface shape, the diameter of the circle is set as the width W d and the width W e . In the case where the surface shape is an ellipse, the minor axis thereof is set as the width W d and the width W e .

[0296] <Second Form>

[0297] Figure 17 A schematic partial cross-sectional view showing an example of a substrate of the second form of the present invention. Figure 17 The substrate 70 shown is a substrate used for a semiconductor package substrate.

[0298] The substrate 70 has a through-hole 300 penetrating from the front surface 71 to the back surface 71B opposite to the front surface 71, and the width W of the lower end opening 300B of the through-hole 300 on the back surface 71B eis the width W of the upper end opening 300A of the through hole 300 on the surface 71 d More than 70%.

[0299] In this type of substrate 70, the through hole 300 is not a tapered shape but is close to a so-called cylindrical tube shape, so when the through hole 300 is processed, the through hole electrode formed in this way can present a low resistance. Therefore, this type of substrate 70 can realize a low-resistance through hole electrode pattern.

[0300] Furthermore, the through hole 300 is not in a tapered shape, so it is not necessary to ensure the width W of the lower end opening 300B of the through hole 300. e The width W of the upper opening 300A of the through hole 300 is d Therefore, the substrate 70 of this form can also realize a high-definition and complex through-hole pattern.

[0301] Ideally, the width W of the lower end opening 300B of the through hole 300 is e The width W of the upper opening 300A is d The width W of the lower opening 300B of the through hole 300 is equal to (100%). e The width W of the upper opening 300A can be set to d The content of the organic solvent is 70% or more, preferably 80% or more, and more preferably 90% or more.

[0302] The through hole 300 may be one or more. In the case where a plurality of through holes 300 are included, the width W of the plurality of through holes 300 is d and width W e It can be the same or different.

[0303] The planar shape of the through hole 300 is not particularly limited. When the through hole 300 has a rectangular surface shape, the smallest width in the surface shape is defined as the width W. d and width W e When the through hole 300 has a circular surface shape, the diameter of the circle is defined as the width W. d and width W e If the surface shape is an ellipse, its short diameter is set to width W. d and width W e .

[0304] Such a substrate 70 can be formed, for example, by the laser processing method of the present invention described above or the method for manufacturing a substrate of the present invention. In addition, the substrate 70 can be manufactured, for example, using the laser processing device of the present invention described above.

[0305] Preferably, the width W of the upper end opening portion 300A of the through hole 300 on the surface 71 d is 20 μm or less.

[0306] If such a substrate 70 is used, a semiconductor package having a highly precise via electrode pattern can be further realized.

[0307] The width W of the upper end opening portion 300A d has no particular limitation, and can be set to 1 μm or more, for example.

[0308] The processing length D of the through hole 300 on the back surface 71B 300 relative to the width W of the lower end opening portion 300B of the through hole 300 e can be set to 1.0 or more, for example. The processing length D 300 relative to the width W of the lower end opening portion 300B of the through hole 300 e has no particular limitation, and can be set to 1.0 or more and 10.0 or less, for example.

[0309] The substrate 70 of the second form may further include a recess that does not penetrate from the surface 71 to the back surface 71B. For example, the substrate 70 may also be the substrate 70 described below in the same manner as the case shown in Figure 16 , that is, it may include at least two recesses 200, and the depth D of the recess 200 on the cross section 73 200 is 20 μm or less, and the depth D of the recess 200 on the cross section 73 200 relative to the width W of the bottom 200B of the recess 200 b The ratio (D 200 / W b ) is 1.0 or more. Such a substrate 70 may also be called a substrate of the first form.

[0310] In addition, as described above, the substrate of the present invention can be formed, for example, by the laser processing method of the present invention or the manufacturing method of the substrate of the present invention, but can also be manufactured by other methods. Moreover, the substrate of the present invention can be manufactured using, for example, the laser processing apparatus of the present invention, but can also be manufactured using other apparatuses.

[0311] [Semiconductor Package Substrate]

[0312] The semiconductor packaging substrate of the present invention is a substrate used for semiconductor packaging. A semiconductor package is, for example, a component that serves the following functions: protecting a semiconductor element from the external environment and providing external connection wiring terminals when mounting the element on a printed wiring board or the like. That is, the semiconductor packaging substrate is a substrate used for semiconductor packaging, and it may or may not carry a semiconductor element. Moreover, it may or may not include a component for protecting the semiconductor element. Hereinafter, as an example, while referring to the drawings, a substrate that does not include a semiconductor element and a component for protecting the semiconductor element will be described.

[0313] Figure 18 A schematic partial cross-sectional view showing an example of the semiconductor packaging substrate according to the first aspect of the present invention.

[0314] Figure 18 The semiconductor packaging substrate 90 shown includes a substrate 70 which is an example of the first aspect of the present invention, as described while referring Figure 14 and explaining.

[0315] Moreover, Figure 18 in the semiconductor packaging substrate 90 shown, a metal wiring 91 is embedded in the recess 200 shown. On the other side surface, the semiconductor packaging substrate 90 may include a metal wiring 91 sandwiched by the convex portions 74 of the substrate 70. Figure 14 As described above, due to the presence of the recess 200 in the substrate 70, a highly fine and complex wiring pattern can be achieved. Therefore, for such a semiconductor packaging substrate 90, a semiconductor package having a pattern of a highly fine and complex metal wiring 91 can be realized. Moreover, since the contact area at the interface between the wiring and the substrate can be increased, defective conditions such as peeling of the wiring are less likely to occur.

[0316] As previously described, due to the presence of the recess 200 in the substrate 70, a highly fine and complex wiring pattern can be achieved. Therefore, for such a semiconductor packaging substrate 90, a semiconductor package having a pattern of a highly fine and complex metal wiring 91 can be realized. Moreover, since the contact area at the interface between the wiring and the substrate can be increased, defective conditions such as peeling of the wiring are less likely to occur.

[0317] Figure 19 A schematic partial cross-sectional view showing an example of the semiconductor packaging substrate according to the second aspect of the present invention.

[0318] Figure 19 The semiconductor packaging substrate 90 shown includes Figure 17 a substrate 70 which is an example of the second aspect of the present invention, as shown.

[0319] Figure 19 In the semiconductor packaging substrate 90 shown, via holes are formed in the through holes 300. More specifically, via electrodes 92 are formed on the surfaces of the specified through holes 300 in the substrate 70.

[0320] For the reasons described above, the substrate 70 of the second form can achieve a highly precise via electrode pattern with suppressed taper from the front surface to the back surface. Therefore, if it is a semiconductor packaging substrate 90 of the second form, it can have a highly precise via electrode pattern with suppressed taper from the front surface to the back surface.

[0321] In addition, Figure 19 in [the figure], the via electrode 92 includes a hollow portion (through hole 300), but the via electrode 92 may also not include a hollow portion.

[0322] For example, as Figure 20 shown, the semiconductor packaging substrate 90 of the second form may further include embedded metal wirings 91. The metal wirings 91 are embedded in the recesses 200 described in the substrate of the first form. Thus, Figure 20 the semiconductor packaging substrate 90 of the example shown may also be referred to as an example of the semiconductor packaging substrate of the first form.

[0323] In addition, the sizes of the metal wirings 91 may be different from each other as Figure 20 shown, or there may be metal wirings of the same size.

[0324] The semiconductor packaging substrate 90 of the present invention may, for example, also include a surface insulating film 93 as in Figure 21 the example showing a plan view. The surface insulating film 93 can cover the metal wirings 91 as shown by the dashed line. On the other hand, as Figure 21 shown, a part of the via electrode 92 may be exposed.

[0325] According to the present invention, for example, as Figure 21 shown, between the via electrodes 92, a plurality of metal wirings 91 may be formed as highly precise and complex patterns.

[0326] In addition, the substrate to be processed of the present invention may be provided with circuits such as metal wirings or resists, or may not be provided with these.

[0327] Moreover, the substrate to be processed of the laser processing method of the present invention, the substrate of the present invention, and the semiconductor packaging substrate of the present invention may each have a rectangular planar shape, or may have other shapes, such as a circular, elliptical, or polygonal planar shape.

[0328] This specification includes the following forms.

[0329] [1] A laser processing method for forming a recess and / or a through hole in a workpiece using a laser, wherein the intensity distribution of the laser on the processing surface of the workpiece is set to an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than the intensity of the inner part for processing.

[0330] [2] The laser processing method according to [1], wherein, as the processing advances in the depth direction of the workpiece, the shape of the intensity distribution of the laser on the processed surface of the workpiece is changed to perform the processing.

[0331] [3] The laser processing method according to [2], wherein the shape of the intensity distribution of the laser is changed such that the intensity of the outer portion in the intensity distribution of the laser becomes greater than the intensity of the inner portion as the processing advances in the depth direction of the workpiece to perform the processing.

[0332] [4] The laser processing method according to [3], wherein a laser having an intensity distribution with the maximum laser intensity at the center and a decreasing laser intensity at the periphery is passed through a prism, whereby the shape of the intensity distribution of the laser is changed such that the intensity of the outer portion in the intensity distribution of the laser becomes greater than the intensity of the inner portion as the processing advances in the depth direction of the workpiece to perform the processing.

[0333] [5] The laser processing method according to [4], wherein, as the prism, a prism including a roof prism or a conical prism is used.

[0334] [6] A laser processing method for forming a recess and / or a through hole in a workpiece using a laser, wherein an optical system is used to shape the irradiation shape of a laser having a shape in which the intensity of the outer portion in the intensity distribution of the laser is greater than the intensity of the inner portion into a top-hat type irradiation shape.

[0335] [7] The laser processing method according to [6], wherein the initial processed surface of the workpiece is processed using the laser with the top-hat type irradiation shape, and at least a part of the workpiece other than the initial processed surface is processed using the laser with an irradiation shape in which the intensity of the outer portion is greater than the intensity of the inner portion.

[0336] [8] The laser processing method according to any one of [1] to [7], wherein, as the workpiece, a substrate for semiconductor packaging is processed to form a recess and / or a through hole in the substrate for semiconductor packaging.

[0337] [9] The laser processing method according to any one of [1] to [8], wherein an excimer laser oscillator is used to oscillate and generate the laser.

[0338]

[10] The laser processing method according to any one of [1] to [9], wherein the laser is irradiated onto the workpiece via a photomask.

[0339]

[11] The laser processing method according to any one of [1] to

[10] , wherein the processing is performed while relatively scanning the laser with respect to the surface to be processed.

[0340]

[12] The laser processing method according to any one of [1] to

[11] , wherein ablation processing is performed.

[0341]

[13] The laser processing method according to any one of [1] to

[12] , wherein the recess and / or through-hole having a width of 20 μm or less is formed.

[0342]

[14] The laser processing method according to any one of [1] to

[13] , wherein the recess and / or through-hole having a depth of 20 μm or less is formed.

[0343]

[15] The laser processing method according to any one of [1] to

[14] , wherein, as the recess and / or through-hole, a recess and / or through-hole in which the ratio of the height of the processed portion to the width of the bottom of the recess or the width of the lower end opening of the through-hole is 1.0 or more is formed.

[0344]

[16] The laser processing method according to any one of [1] to

[15] , wherein a recess in which the width of the bottom of the recess is 70% or more of the opening width of the recess on the initial processing surface of the workpiece, and / or a through-hole in which the width of the lower end opening of the through-hole is 70% or more of the width of the upper end opening of the through-hole on the initial processing surface of the workpiece is formed.

[0345]

[17] The laser processing method according to any one of [1] to

[16] , wherein a plurality of the recesses are formed, and the distance between the bottoms of the adjacent recesses is set to 110% or less of the width of the bottom.

[0346]

[18] A method for manufacturing a substrate having a recess and / or through-hole, comprising: forming the recess and / or through-hole in the substrate as the workpiece by the laser processing method according to any one of [1] to

[17] .

[0347]

[19] A laser processing apparatus that forms a recess and / or through-hole in a workpiece using a laser, the laser processing apparatus including: a laser light source that oscillates and generates the laser; and an optical system that sets the irradiation shape of the laser to an irradiation shape in which the intensity of the outer portion of the intensity distribution of the laser on the surface to be processed of the workpiece is greater than the intensity of the inner portion.

[0348]

[20] The laser processing apparatus according to

[19] , wherein, as the optical system, it includes: a prism that converts a laser having an intensity distribution with the maximum laser intensity at the center and a decreasing laser intensity at the periphery into a laser having the irradiation shape in which the intensity of the outer portion in the intensity distribution of the laser becomes greater than the intensity of the inner portion; and a shaping optical system that converts the irradiation shape of the laser converted by the prism into a top-hat irradiation shape.

[0349]

[21] The laser processing apparatus according to

[20] , wherein, as the prism, it includes a prism including a roof prism or a conical prism.

[0350]

[22] The laser processing apparatus according to any one of

[19] to

[21] , wherein, as the laser light source, it includes an excimer laser oscillator.

[0351]

[23] The laser processing apparatus according to any one of

[19] to

[22] further includes: a stage for placing the workpiece; and a photomask disposed between the optical system and the stage.

[0352]

[24] The laser processing apparatus according to

[23] further includes a controller configured to move the workpiece placed on the stage synchronously with the photomask.

[0353]

[25] A substrate for use in a semiconductor package substrate, wherein on the surface of the substrate, there are at least two recesses adjacent to each other in a cross-section orthogonal to the surface, the distance between the bottoms of the recesses in the cross-section is 110% or less of the width of the bottom of the recess, the depth of the recess in the cross-section is 20 μm or less, and the ratio of the depth of the recess in the cross-section to the width of the bottom of the recess is 1.0 or more.

[0354]

[26] The substrate according to

[25] , wherein the width of the bottom of the recess is 70% or more of the opening width of the recess on the surface.

[0355]

[27] The substrate according to

[26] , wherein the opening width of the recess on the surface is 20 μm or less.

[0356]

[28] The substrate according to any one of

[25] to

[27] , wherein the ratio of the depth of the recess in the cross-section to the width of the bottom of the recess is 1.1 or more.

[0357]

[29] The substrate according to any one of

[25] to

[28] , wherein the ratio of the depth of the recess to the width of the bottom of the recess is 1.5 or more.

[0358]

[30] The substrate according to any one of

[25] to

[29] , wherein a ratio of the depth of the recess to a width of a bottom portion of the recess is 2.4 or more.

[0359]

[31] The substrate according to any one of

[25] to

[30] , wherein a ratio of the depth of the recess to a width of a bottom portion of the recess is 3.4 or more.

[0360]

[32] The substrate according to

[25] , wherein the width of the bottom portion of the recess is 70% or more of an opening width of the recess,

[0361] A ratio of the depth of the recess to a width of a bottom portion of the recess is 2.4 or more.

[0362]

[33] The substrate according to any one of

[25] to

[32] , wherein the recess includes a groove.

[0363]

[34] The substrate according to any one of

[25] to

[32] , wherein the substrate has a back surface opposite to the surface, and the substrate further has a through hole penetrating from the surface to the back surface.

[0364]

[35] The substrate according to

[34] , wherein a width of an upper end opening portion of the through hole on the surface is 20 μm or less.

[0365]

[36] The substrate according to

[34] or

[35] , wherein a ratio of a processing length of the through hole on the back surface to a width of a lower end opening portion of the through hole is 1.0 or more.

[0366]

[37] The substrate according to any one of

[34] to

[36] , wherein a width of a lower end opening portion of the through hole on the back surface is 70% or more of a width of an upper end opening portion of the through hole on the surface.

[0367]

[38] The substrate according to

[34] or

[35] , wherein a ratio of a processing length of the through hole on the back surface to a width of a lower end opening portion of the through hole is 1.0 or more,

[0368] A width of a lower end opening portion of the through hole is 70% or more of a width of an upper end opening portion of the through hole on the surface.

[0369]

[39] The substrate according to

[34] , wherein the width of the bottom portion of the recess is 70% or more of an opening width of the recess,

[0370] The ratio of the depth of the recess to the width of the bottom of the recess is 2.4 or more.

[0371] The ratio of the processing length of the through hole on the back surface to the width of the lower end opening of the through hole is 1.0 or more.

[0372] The width of the lower end opening of the through hole is 70% or more of the width of the upper end opening of the through hole on the surface.

[0373]

[40] A semiconductor packaging substrate, comprising the substrate according to any one of

[25] to

[39] , wherein a metal wiring is embedded in the recess.

[0374]

[41] A substrate for use in a semiconductor packaging substrate, wherein the substrate has a through hole that penetrates from the surface of the substrate to the back surface opposite to the surface, and the width of the lower end opening of the through hole on the back surface is 70% or more of the width of the upper end opening of the through hole on the surface.

[0375]

[42] The substrate according to

[41] , wherein the width of the upper end opening of the through hole on the surface is 20 μm or less.

[0376]

[43] The substrate according to

[41] or

[42] , wherein the ratio of the processing length of the through hole on the back surface to the width of the lower end opening of the through hole is 1.0 or more.

[0377]

[44] A semiconductor packaging substrate, comprising the substrate according to any one of

[34] to

[39] ,

[41] to

[43] , wherein the through hole is subjected to via processing.

[0378] In addition, the present invention is not limited to the above-described embodiments. The above-described embodiments are illustrative, and any content having a structure substantially the same as the technical idea described in the claims of the present invention and achieving the same effects is included in the technical scope of the present invention.

Claims

1. A laser processing method, which uses a laser to form a concave portion and / or a through hole in a workpiece, wherein, The intensity distribution of the laser on the processed surface of the workpiece to be processed is set to an irradiation shape in which the intensity of the outer part of the intensity distribution is greater than that of the inner part, and processing is performed.

2. The laser processing method according to claim 1, wherein, As processing progresses in the depth direction of the workpiece, the shape of the intensity distribution of the laser on the processed surface of the workpiece is changed for processing.

3. The laser processing method according to claim 2, wherein, The shape of the intensity distribution of the laser is changed so that as processing progresses in the depth direction of the workpiece, the intensity of the outer part in the intensity distribution of the laser becomes greater than that of the inner part, and processing is performed.

4. The laser processing method according to claim 3, wherein, Laser having an intensity distribution with the maximum laser intensity at the center and decreasing laser intensity toward the periphery is passed through a prism, whereby the shape of the intensity distribution of the laser is changed so that as processing progresses in the depth direction of the workpiece, the intensity of the outer part in the intensity distribution of the laser becomes greater than that of the inner part, and processing is performed.

5. The laser processing method according to claim 4, wherein, As the prism, a prism including a roof prism or a conical prism is used.

6. A laser processing method, which uses a laser to form a recess and / or a through hole in a workpiece, wherein, An optical system is used to shape the irradiation shape of the laser having a shape in which the intensity of the outer part in the intensity distribution of the laser is greater than that of the inner part into a top-hat type irradiation shape.

7. The laser processing method according to claim 6, wherein, The initial processed surface of the workpiece is processed using laser having the top-hat type irradiation shape, and for at least a part of the workpiece other than the initial processed surface, laser having an irradiation shape in which the intensity of the outer part is greater than that of the inner part is used for processing.

8. The laser processing method according to any one of claims 1 to 7, wherein, As the workpiece, a semiconductor package substrate is processed to form recesses and / or through holes in the semiconductor package substrate.

9. The laser processing method according to any one of claims 1 to 7, wherein, An excimer laser oscillator is used to oscillate and generate the laser.

10. The laser processing method according to any one of claims 1 to 7, wherein, The laser is irradiated onto the workpiece via a photomask.

11. The laser processing method according to any one of claims 1 to 7, wherein, Processing is performed while relatively scanning the laser with respect to the processed surface.

12. The laser processing method according to any one of claims 1 to 7, wherein, Ablation processing is performed.

13. The laser processing method according to any one of claims 1 to 7, wherein Recesses and / or through holes having a width of 20 μm or less are formed.

14. The laser processing method according to claim 13, wherein, Recesses and / or through holes having a depth of 20 μm or less are formed.

15. The laser processing method according to any one of claims 1 to 7, wherein, As the recesses and / or through holes, recesses and / or through holes are formed in which the ratio of the processing part height to the width of the bottom of the recess or the width of the lower end opening of the through hole is 1.0 or more.

16. The laser processing method according to any one of claims 1 to 7, wherein, Recesses are formed in which the width of the bottom of the recess is 70% or more of the opening width of the recess on the initial processed surface of the workpiece, and / or Through holes are formed in which the width of the lower end opening of the through hole is 70% or more of the width of the upper end opening of the through hole on the initial processed surface of the workpiece.

17. The laser processing method according to any one of claims 1 to 7, wherein, A plurality of the recesses are formed, and the distance between the bottoms of adjacent recesses is set to 110% or less of the width of the bottom.

18. A method for manufacturing a substrate having recesses and / or through holes, the method for manufacturing the substrate including: forming the recesses and / or through holes in the substrate as the workpiece by the laser processing method according to any one of claims 1 to 7.

19. A laser processing apparatus that forms recesses and / or through holes in a workpiece using a laser, the laser processing apparatus comprising: a laser light source that oscillates and generates the laser; and an optical system that sets the irradiation shape of the laser such that the intensity of the outer portion of the intensity distribution of the laser on the processed surface of the workpiece is greater than the intensity of the inner portion.

20. The laser processing apparatus according to claim 19, wherein, As the optical system, it includes: a prism that converts a laser having an intensity distribution with the maximum laser intensity at the center and decreasing laser intensity toward the periphery into a laser having an irradiation shape in which the intensity of the outer portion in the intensity distribution of the laser becomes greater than the intensity of the inner portion; and a shaping optical system that converts the irradiation shape of the laser converted by the prism into a top-hat type irradiation shape.

21. The laser processing apparatus according to claim 20, wherein, As the prism, it includes a prism including a roof prism or a conical prism.

22. The laser processing apparatus according to any one of claims 19 to 21, wherein, As the laser light source, it includes an excimer laser oscillator.

23. The laser processing apparatus according to any one of claims 19 to 21, further comprising: a stage for placing the workpiece; and a photomask disposed between the optical system and the stage.

24. The laser processing apparatus according to claim 23, further comprising a controller configured to move the workpiece placed on the stage synchronously with the photomask.

25. A substrate used for a semiconductor package substrate, characterized in that on the surface of the substrate, there are at least two recesses adjacent to each other in a cross-section orthogonal to the surface, the distance between the bottoms of the recesses in the cross-section is 110% or less of the width of the bottom of the recess, the depth of the recess in the cross-section is 20 μm or less, the ratio of the depth of the recess in the cross-section to the width of the bottom of the recess is 1.0 or more.

26. The substrate according to claim 25, characterized in that the width of the bottom of the recess is 70% or more of the opening width of the recess on the surface.

27. The substrate according to claim 26, characterized in that the opening width of the recess on the surface is 20 μm or less.

28. The substrate according to claim 25, characterized in that the ratio of the depth of the recess in the cross-section to the width of the bottom of the recess is 1.1 or more.

29. The substrate according to claim 25, characterized in that the ratio of the depth of the recess to the width of the bottom of the recess is 1.5 or more.

30. The substrate according to claim 25, characterized in that the ratio of the depth of the recess to the width of the bottom of the recess is 2.4 or more.

31. The substrate according to claim 25, characterized in that the ratio of the depth of the recess to the width of the bottom of the recess is 3.4 or more.

32. The substrate according to claim 25, characterized in that the width of the bottom of the recess is 70% or more of the opening width of the recess, The ratio of the depth of the recess to the width of the bottom of the recess is 2.4 or more.

33. The substrate according to claim 25, wherein the recess includes a groove.

34. The substrate according to claim 25, wherein the substrate has a back surface opposite to the surface, and the substrate further has a through hole penetrating from the surface to the back surface.

35. The substrate according to claim 34, wherein the width of the upper end opening of the through hole on the surface is 20 μm or less.

36. The substrate according to claim 34, wherein the ratio of the processing length of the through hole on the back surface to the width of the lower end opening of the through hole is 1.0 or more.

37. The substrate according to claim 34, wherein the width of the lower end opening of the through hole on the back surface is 70% or more of the width of the upper end opening of the through hole on the surface.

38. The substrate according to claim 34, wherein the ratio of the processing length of the through hole on the back surface to the width of the lower end opening of the through hole is 1.0 or more, and the width of the lower end opening of the through hole is 70% or more of the width of the upper end opening of the through hole on the surface.

39. The substrate according to claim 34, wherein the width of the bottom of the recess is 70% or more of the opening width of the recess, the ratio of the depth of the recess to the width of the bottom of the recess is 2.4 or more, the ratio of the processing length of the through hole on the back surface to the width of the lower end opening of the through hole is 1.0 or more, and the width of the lower end opening of the through hole is 70% or more of the width of the upper end opening of the through hole on the surface.

40. A semiconductor package substrate, comprising the substrate according to any one of claims 25 to 39, wherein a metal wiring is embedded in the recess.

41. A substrate for use in a semiconductor package substrate, wherein it has a rectangular planar shape and has a through hole penetrating from the surface of the substrate to the back surface opposite to the surface, and the width of the lower end opening of the through hole on the back surface is 70% or more of the width of the upper end opening of the through hole on the surface.

42. The substrate according to claim 41, wherein the width of the upper end opening of the through hole on the surface is 20 μm or less.

43. The substrate according to claim 41, wherein the ratio of the processing length of the through hole on the back surface to the width of the lower end opening of the through hole is 1.0 or more.

44. A semiconductor package substrate, comprising the substrate according to any one of claims 34 to 39, 41 to 43, wherein the through hole is subjected to via processing.

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