Laser drilling method, storage medium, laser drilling equipment and high-frequency high-speed substrate

Abstract

The invention relates to the technical field of circuit board processing, in particular to a laser drilling method, a storage medium, laser drilling equipment and a high-frequency high-speed substrate. The laser drilling method comprises the steps that hole machining information of a hole structure is obtained, wherein the hole machining information comprises the hole position, the hole outer contour and the hole depth; taking the hole position as a positioning reference, and performing at least one of laser winding and cutting treatment and laser etching treatment on the high-frequency high-speed substrate to form a hole structure; wherein the laser winding and cutting treatment comprises the steps that first laser is controlled to move along a first closed path matched with the outer contour of the hole, so that the side wall of the hole structure is formed; and the laser etching treatment comprises the steps of controlling a second laser to carry out punching processing on an enclosed area of the outer contour of the hole so as to remove a base material in the enclosed area and form a bottom wall of the hole structure, and the method can be used for manufacturing the high-quality hole structure on the high-frequency and high-speed substrate and also can be used for manufacturing the high-quality hole structure on the high-frequency and high-speed substrate. And the processing efficiency of manufacturing a high-quality hole structure on the high-frequency and high-speed substrate can be obviously improved.

Description

Technical Field

[0001] This application relates to the field of circuit board processing technology, and more specifically, to a laser drilling method, a storage medium, a laser drilling device, and a high-frequency, high-speed substrate. Background Technology

[0002] Laser drilling is a process that uses the high energy and high focus of lasers to ablate and vaporize the copper layer on the surface of the packaging substrate or the dielectric layer in the middle, forming blind holes or through holes with regular shapes and controllable sizes. It is widely used in the fabrication of hole structures on various packaging substrates.

[0003] With the rapid development of electronic information products, circuit systems in fields such as microwave devices, data communication, artificial intelligence, and 5G technology are evolving towards higher frequencies, higher speeds, greater integration, and greater multi-functionality. High-frequency and high-speed signal transmission and high-density interconnect packaging place higher demands on the materials used to manufacture packaging substrates. As a result, high-frequency and high-speed substrates made by laminating materials such as PTFE copper-clad laminates or M9-grade copper-clad laminates have emerged. However, the hole structure morphology obtained by directly processing high-frequency and high-speed substrates using current laser drilling methods is poor, with problems such as top copper overhang and uneven inner walls. Summary of the Invention

[0004] The inventors of this application have discovered that microvia structures are crucial for signal transmission channels in the fabrication of high-frequency, high-speed substrates, and the processing quality of the via walls directly affects signal transmission performance. However, laser drilling methods in related technologies produce hole structures with poor morphology directly on high-frequency, high-speed substrates, leading to decreased signal transmission performance. Therefore, the purpose of this application is to provide a laser drilling method, a storage medium, a laser drilling device, and a high-frequency, high-speed substrate, which can not only be used to fabricate high-quality hole structures on high-frequency, high-speed substrates but also significantly improve the processing efficiency of fabricating high-quality hole structures on high-frequency, high-speed substrates.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: This application provides a laser drilling method for processing hole structures on high-frequency, high-speed substrates. The laser drilling method includes: Obtain hole processing information for the hole structure, including hole location, hole outer contour, and hole depth; Using the hole position as a positioning reference, at least one of laser winding and laser etching processes is performed on the high-frequency high-speed substrate to form the hole structure; The laser cutting process includes: controlling a first laser to move along a first closed path that matches the outer contour of the hole, and making the penetration depth of the first laser at the outer contour of the hole consistent with the hole depth, so as to form the sidewall of the hole structure; The laser etching process includes: controlling a second laser to punch a hole in the enclosing area of ​​the outer contour of the hole, so as to remove the substrate of the enclosing area and form the bottom wall of the hole structure.

[0006] In some implementations, the laser etching process further includes: The third laser is controlled to move along at least one second closed path located within the enclosed area; wherein the second closed path is located inside the first closed path; The substrate of the enclosed area is removed by the second laser and the third laser together to form the bottom wall of the hole structure.

[0007] In some implementations, the hole location is subjected to laser bypass cutting and laser etching processes, including: First, the hole location is subjected to laser cutting, and then the hole location is subjected to laser etching. Alternatively, the hole location can be laser etched first, and then laser cut around the hole location.

[0008] In some implementations, the laser cutting process uses an ultrafast laser or a carbon dioxide laser, and the laser etching process uses an ultrafast laser or a carbon dioxide laser. The ultrafast laser has a wavelength of 340nm-1070nm and a pulse width of less than or equal to 15ps. The wavelength of the carbon dioxide laser is 9000nm~11000nm, and the pulse width of the carbon dioxide laser is 1μs~200μs.

[0009] In some implementations, the laser cutting process uses a pulsed laser with a Gaussian shape, and the laser etching process uses a pulsed laser with a flat-top shape.

[0010] In some implementations, the high-frequency, high-speed substrate includes at least one copper-clad laminate laminated along the thickness direction, wherein the light absorption rate of the dielectric layer of the copper-clad laminate is lower than a predetermined threshold.

[0011] In some implementations, the dielectric layer of the copper clad laminate contains at least one of quartz fiber cloth, PTFE, and spherical silica microparticles.

[0012] In some implementations, the number of hole structures is multiple, and each hole structure has corresponding hole processing information; The step of using the hole position as a positioning reference to perform at least one of laser winding and laser etching processes on the high-frequency high-speed substrate to form the hole structure includes: First, perform at least one of the laser circumferential cutting process and the laser etching process at one of the hole locations to form the hole structure; After one hole structure is formed, at least one of the laser circumferential cutting process and the laser etching process is sequentially performed on the next hole position to form the next hole structure, until at least one of the laser circumferential cutting process and the laser etching process is performed on all hole positions to form all hole structures.

[0013] In some implementations, the number of hole structures is multiple, and each hole structure has corresponding hole processing information; The step of using the hole position as a positioning reference to perform at least one of laser winding and laser etching processes on the high-frequency high-speed substrate to form the hole structure includes: First, perform either the laser wrapping process or the laser etching process sequentially on all the hole locations; Then, perform either the laser wrapping process or the laser etching process on all the hole locations to form all the hole structures.

[0014] In some implementations, the laser drilling method further includes: The laser cutting spot for the laser cutting process and the laser etching spot for the laser etching process are determined based on the hole processing information. The diameter of the cutting spot is greater than or equal to 10 μm and less than or equal to 30 μm; the diameter of the etching spot is greater than or equal to 30 μm and less than or equal to 100 μm.

[0015] This application provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the laser drilling method described in any of the above implementations.

[0016] This application provides a laser drilling device for laser drilling of high-frequency, high-speed substrates. The laser drilling device includes a laser, a beam control system, a processing platform, and a controller. The laser is used to emit pulsed laser under the control of the controller; The beam control system is used to provide a transmission optical path for the pulsed laser under the control of the controller, and to control the pulsed laser to form a light spot on the high-frequency high-speed substrate; The processing platform is used to carry and move the high-frequency, high-speed substrate under the control of the controller; The controller can be used to execute the laser drilling method described in any of the above implementations.

[0017] In some implementations, the laser includes at least one of an ultrafast laser and a carbon dioxide laser; The pulsed laser emitted by the ultrafast laser is an ultrafast laser with a wavelength of 340nm-1070nm and a pulse width of less than or equal to 15ps. The pulsed laser emitted by the carbon dioxide laser is a carbon dioxide laser with a wavelength of 9000nm~11000nm and a pulse width of 1μs~200μs.

[0018] In some implementations, the beam manipulation system includes: A shaping component, under the control of the controller, shapes the received pulsed laser from a Gaussian shape to a flat-top shape.

[0019] This application provides a high-frequency, high-speed substrate having a hole structure, which is obtained by using the laser drilling method described in any of the above implementations, or by using the laser drilling equipment described in any of the above implementations.

[0020] The main advantages of the laser drilling method, storage medium, laser drilling equipment, and high-frequency high-speed substrate provided in this application are as follows: By acquiring the hole processing information of the hole structure on the high-frequency and high-speed substrate, and using the hole position as a positioning reference, at least one of laser winding and laser etching processes is performed on the high-frequency and high-speed substrate to create the hole structure. The laser winding process involves moving a first laser along a first closed path to form the sidewall of the hole structure, while the laser etching process involves punching the enclosing area of ​​the hole's outer contour with a second laser to form the bottom wall of the hole structure. On the one hand, the laser winding and laser etching processes can use lasers with different parameters and different laser processing methods to ensure the smoothness of the sidewall and the flatness of the bottom wall of the hole structure, thereby improving the processing quality of the hole structure. On the other hand, by forming a sidewall with the same depth as the hole in the thickness direction of the high-frequency and high-speed substrate through laser winding, the physical connection between the substrate of the hole structure sidewall and the substrate of the enclosing area can be effectively cut off in a direction parallel to the thickness direction of the high-frequency and high-speed substrate, effectively reducing the adverse effects of laser heat during the punching process on the morphology of the hole structure sidewall. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic flowchart of the laser drilling method provided in the embodiments of this application; Figure 2 This is another schematic flowchart of the laser drilling method provided in the embodiments of this application; Figure 3 This is a schematic diagram of a high-frequency, high-speed substrate with a hole structure provided in an embodiment of this application; Figure 4 This is a schematic diagram illustrating the laser drilling method and laser etching process provided in the embodiments of this application. Figure 5 This is a schematic diagram of the blind via processing of a high-frequency, high-speed substrate provided in an embodiment of this application; Figure 6 This is a schematic diagram of another process for blind via fabrication on a high-frequency, high-speed substrate provided in this application embodiment; Figure 7 This is another schematic diagram of the laser drilling method and laser etching process provided in the embodiments of this application; Figure 8 This is a schematic diagram of another process for blind via fabrication on a high-frequency, high-speed substrate provided in this application embodiment; Figure 9 This is a schematic diagram of the process of processing through holes in a high-frequency, high-speed substrate provided in an embodiment of this application; Figure 10 This is a schematic diagram of another process for processing through holes in a high-frequency, high-speed substrate provided in an embodiment of this application; Figure 11 This is a schematic diagram of another process for processing through holes in a high-frequency, high-speed substrate provided in an embodiment of this application; Figure 12 This is a schematic diagram of another process for processing through holes in a high-frequency, high-speed substrate provided in an embodiment of this application; Figure 13 This is a partial structural schematic diagram of the laser drilling equipment provided in the embodiments of this application.

[0023] Explanation of key figure labels: 100. High-frequency high-speed substrate; 101. Hole structure; 103. Laser winding structure; 104. Laser etching structure; 105. Annular groove; 106. Pre-drilled hole; 107. Hole outer contour; 108. First closed path; 109. Second closed path; 110. Winding spot; 111. Punching spot; 112. Second winding spot; 113. Laser etching outer contour; 201. Processing platform; 202. Laser; 203. Shaping component; 204. Beam deflection assembly; 205. Controller; 206. Moving device; 207. Focusing assembly; 208. Beam control system. Detailed Implementation

[0024] Laser drilling is a process that uses the high energy and high focus of lasers to ablate and vaporize the copper layer on the surface of the packaging substrate or the dielectric layer in the middle, forming blind holes or through holes with regular shapes and controllable sizes. It is widely used in the fabrication of hole structures on various packaging substrates.

[0025] With the rapid development of electronic information products, circuit systems in fields such as microwave devices, data communication, artificial intelligence, and 5G technology are evolving towards higher frequencies, higher speeds, greater integration, and more multifunctionality. High-frequency, high-speed signal transmission and high-density interconnect packaging place higher demands on the materials used in circuit boards. Therefore, high-frequency, high-speed substrates made by laminating materials such as PTFE (Polytetrafluoro-Ethylene) copper clad laminate (CCL) or M9-grade copper clad laminate have emerged.

[0026] The inventors of this application have discovered that microvia structures are crucial for signal transmission channels in the fabrication of high-frequency, high-speed substrates. High-frequency, high-speed substrates can refer to packaged substrates used for signal transmission with operating frequencies in the gigahertz (GHz) range and / or transmission rates in the gigabits per second (Gbps) range and above. The processing quality of the microvia walls directly affects signal transmission performance. However, laser drilling methods in related technologies often result in poor hole morphology when directly processing high-frequency, high-speed substrates, exhibiting problems such as top copper overhang and uneven inner walls.

[0027] Therefore, this application provides a laser drilling method and laser drilling equipment. By using lasers with different parameters and different processing methods, the sidewalls of the hole structure fabricated on the high-frequency and high-speed substrate are made smooth and the bottom wall is flat, thereby improving the processing quality of the hole structure.

[0028] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are protected by this application.

[0029] Combination Figure 1 , Figure 3 , Figure 4 and Figure 5 As shown, Figure 1 This application illustrates a laser drilling method that can be used to fabricate a hole structure 101 on a high-frequency, high-speed substrate 100. It is understood that the hole structure 101 includes blind holes and / or through holes. Furthermore, the laser drilling method provided in this application can be applied to the laser drilling equipment provided in this application, and the laser drilling method can be executed by the controller 205 of the laser drilling equipment.

[0030] In this embodiment of the application, the packaging substrate of the high-frequency and high-speed substrate 100 is composed of multiple copper-clad laminates. The copper-clad laminate, also known as a copper-clad laminate, is a plate-shaped material made by impregnating fiberglass cloth and / or other reinforcing materials with resin to form a dielectric layer, covering one or both sides of the dielectric layer with copper foil, and hot pressing. The composition of the dielectric layer determines whether the packaging substrate can realize high-frequency and high-speed signal transmission.

[0031] The inventors of this application, through research and summarization of the processing technology of the hole structure 101 of the high-frequency and high-speed substrate 100, discovered that in order to achieve high-frequency and / or high-speed signal transmission, it is necessary to minimize the influence of the substrate outside the transmission channel on the transmitted signal. Given that the transmission speed of optical signals is much greater than that of electrical signals, the transmitted signals in the high-frequency and high-speed substrate 100 are usually transmitted mainly in the form of optical signals in the interconnection channel. Therefore, it is necessary to make the substrate of the packaging substrate have extremely low light interference capability or light absorption capability, that is, the substrate of the high-frequency and high-speed substrate 100 contains materials with light absorption rate below a certain threshold. According to the structure of the packaging substrate, compared with the substrate in the related technology, the dielectric layer of the copper clad laminate of the high-frequency and high-speed substrate 100 to be processed in this application is filled with materials with light absorption rate below a certain threshold, such as quartz fiber cloth with SiO2 purity exceeding 99.95%, spherical silicon micro powder with SiO2 purity exceeding 99.9%, or PEFT resin with light transmittance exceeding 95% and other reinforcing materials. Since the laser used in laser drilling is essentially a high-energy photon, when the laser drilling method in related technologies is directly applied to a high-frequency, high-speed substrate 100, it will face the problem of low laser energy absorption efficiency. If the effect of eliminating the substrate is achieved by directly extending the laser action time, it will lead to significant differences in volume change of different materials in the substrate due to different thermal stresses under the continuous action of high-density energy. For example, the volume change of the quartz fiber cloth or spherical silicon micropowder in the dielectric layer is small after heating, while the resin shrinks or melts rapidly after heating. As a result, the sidewalls of the hole structure 101 will have obvious burrs or uneven morphology due to the protrusion of the reinforcing materials such as fiber cloth or silicon micropowder.

[0032] Based on the above analysis and experimental tests, the laser drilling method and laser drilling equipment provided by the inventors of this application can solve the problem that the high-frequency high-speed substrate 100 filled with a material with a light absorption rate lower than a certain threshold has an extremely low laser energy absorption rate.

[0033] In some embodiments, the dielectric layer of the high-frequency high-speed substrate 100 may contain at least one of the following materials with extremely low light absorption: quartz fiber cloth, PTFE, or spherical silicon micropowder. Specifically, the high-frequency high-speed substrate 100 may include a packaging substrate made by laminating M9 grade copper-clad laminate and / or PTFE copper-clad laminate.

[0034] It should be noted that, depending on the type of constituent materials and the layered structure, the high-frequency high-speed substrate 100 can be a general board, a multilayer board, an HDI (High Density Interconnector), an FPC (Flexible Printed Circuit), or an IC substrate (Integrated Circuit Substrate) made of organic substrates, ceramic substrates, glass substrates, or other new substrates.

[0035] The laser drilling method provided in this application embodiment may include at least some or all of the following steps.

[0036] Step S100: Obtain hole processing information for hole structure 101. Hole processing information includes hole location, hole outer contour 107, and hole depth. Hole processing information can be extracted from processing drawing information or planned according to specific processing requirements. It includes, but is not limited to, the hole location, hole outer contour 107, and hole depth of the hole structure 101 to be processed. Hole location is used to locate the position coordinates of hole structure 101 on the orthographic projection plane. The orthographic projection plane can be the surface of the high-frequency high-speed substrate 100, or any plane perpendicular to the thickness direction of the high-frequency high-speed substrate 100. Hole outer contour 107 is used to locate the sidewall position of hole structure 101 together with hole location. Hole outer contour 107 can be the contour of the hole opening of hole structure 101. Hole depth is used to determine the depth to which the sidewall of hole structure 101 extends along the thickness direction of high-frequency high-speed substrate 100. It is understandable that when the hole structure 101 is a through hole, the hole structure 101 extends from the upper surface of the high-frequency high-speed substrate 100 to its lower surface, and the hole depth is the same as the thickness of the high-frequency high-speed substrate 100 to be processed.

[0037] Step S200: Using the hole position as a positioning reference, perform at least one of laser winding and laser etching on the high-frequency high-speed substrate 100 to form a hole structure 101; wherein, the laser winding includes: controlling a first laser to move along a first closed path 108 that matches the outer contour 107 of the hole, and making the penetration depth of the first laser outside the outer contour 107 of the hole consistent with the hole depth, so as to form the sidewall of the hole structure 101; the laser etching includes: controlling a second laser to punch a hole in the enclosing area of ​​the outer contour 107 of the hole, so as to remove the substrate in the enclosing area and form the bottom wall of the hole structure 101.

[0038] The hole position, as a positioning reference, refers to the location of the laser processing when at least one of laser winding and laser etching processes is performed on the high-frequency, high-speed substrate 100. The area enclosed by the outer contour 107 of the hole is the internal area enclosed by the outer contour 107 of the hole.

[0039] Laser wrapping can refer to a laser processing method that controls a laser beam (e.g., a first laser) to move continuously along a preset rotational or helical path, utilizing the interaction between the laser beam and the substrate along the moving path to modify or remove the substrate. In this embodiment, the laser spot (i.e., wrapping spot 110) formed by the first laser on the high-frequency high-speed substrate 100 is controlled to move along a first closed path 108 that matches the outer contour 107 of the hole. The substrate on the first closed path 108 is removed by the wrapping spot 110, thereby forming a sidewall of a hole structure 101 at the position of the outer contour 107 of the hole, extending from the upper surface of the processed high-frequency high-speed substrate 100 along the thickness direction with a penetration depth consistent with the hole depth. This can make the sidewall smooth, which is beneficial for forming a high-quality hole structure 101. It should be noted that the penetration depth being consistent with the hole depth can mean that the numerical value of the penetration depth is the same as the numerical value of the hole depth, or that the difference between the numerical value of the penetration depth and the numerical value of the hole depth is within the allowable error range of processing.

[0040] It is understandable that the slicing spot 110 formed by the first laser on the high-frequency, high-speed substrate 100 has a certain size. In order to make the position of the sidewall of the hole structure 101 correspond to the moving position of the outer edge of the slicing spot 110, therefore, see Figure 4 As shown, the first closed path 108 can be a path formed by equidistantly reducing the preset distance d1 to the inner side of the outer contour 107 of the hole. The shape of the first closed path 108 is the same as the shape of the outer contour 107 of the hole and the center positions of the two are the same, so that the first closed path 108 corresponds to the proportionally reduced contour of the outer contour 107 of the hole in the orthographic projection plane.

[0041] For example, the first closed path 108 is located inside the outer contour 107 of the hole, and the distance between the first closed path 108 and the outer contour 107 of the hole is 0.45-0.55 times the diameter of the laser cutting spot 110. After laser cutting, a sidewall of the hole structure 101 is formed. The orthographic projection of this sidewall in the orthographic projection plane coincides with the orthographic projection of the outer contour 107 of the hole in the orthographic projection plane. The distance between the first closed path 108 and the outer contour 107 of the hole can be 0.45 times, 0.5 times, or 0.55 times the diameter of the laser cutting spot 110. See also... Figure 5As shown, after laser winding, an annular groove 105 is formed between the outer contour 107 of the hole structure 101 and the center of the hole structure 101. The penetration depth of the annular groove 105 is consistent with the hole depth, and a physical cut is formed between the substrate of the side wall of the hole structure 101 and the substrate of the enclosing area.

[0042] Laser etching refers to controlling a laser beam (e.g., a second laser) to locally heat or photochemically react a designated area of ​​a substrate, causing the material to be removed through evaporation, decomposition, or peeling to form the desired micropore or micropattern structure. In this embodiment, the second laser is controlled to punch holes in the enclosing area of ​​the hole outline 107 on the high-frequency, high-speed substrate 100 to be processed. The punching location is continuously processed by the light spot (i.e., punching spot 111) formed by the second laser on the high-frequency, high-speed substrate 100, so that the substrate at the punching location is removed, thereby forming the bottom wall of the hole structure 101 in the enclosing area. The punching spot 111 is an etching spot.

[0043] In this embodiment, the laser winding process uses a first laser to penetrate from the upper surface of the high-frequency, high-speed substrate 100 to the depth of the hole, and uses an etching spot to cut the physical connection between the substrate of the sidewall of the hole structure 101 and the substrate of the enclosing area. This effectively reduces the adverse effects of laser heat during the laser processing of the substrate of the enclosing area on the sidewall morphology of the hole structure 101, so that the sidewall is smooth and without protrusions. The laser etching process uses a second laser to punch the enclosing area of ​​the outer contour 107 of the hole, which can remove the remaining substrate in the enclosing area of ​​the outer contour 107 of the hole, thereby forming the bottom wall of the hole structure 101. The laser winding process and the laser etching process use lasers with different parameters and different laser processing methods to ensure the smoothness of the sidewall and the flatness of the bottom wall of the hole structure 101, so as to improve the processing quality of the hole structure 101.

[0044] It is understood that the laser processing to form the hole structure 101 can include both laser cutting and laser etching, or it can include only laser cutting. In one embodiment, the hole structure 101 is a blind hole, which has sidewalls and a bottom wall. By performing laser cutting and laser etching in a certain order on the high-frequency, high-speed substrate, the sidewalls and bottom wall of the blind hole can be formed. In another embodiment, the hole structure 101 is a through hole, which only has sidewalls and no bottom wall. By performing laser cutting on the high-frequency, high-speed substrate, the sidewalls of the through hole can be formed.

[0045] See Figure 4As shown, in some embodiments, when using a first laser and a second laser, if the second laser is used to punch the enclosed area of ​​the outer contour 107 of the hole, and the orthographic projection of the material removed at the punching location within the enclosed area is substantially the same as the size of the punching spot 111, this situation can be applied to the processing of smaller hole structures 101.

[0046] See Figure 7 As shown, in some embodiments, to accommodate the processing of larger hole structures 101, the laser etching process further includes: controlling a third laser to move along at least one second closed path 109 within the enclosed area; wherein the second closed path 109 is located inside the first closed path 108; and removing the substrate of the enclosed area by the combined action of the second and third lasers to form the bottom wall of the hole structure 101. Exemplarily, the third laser moves along the second closed path 109, using the third laser to perform laser-cutting around the substrate on the second closed path 109 to remove the substrate on the second closed path 109. The laser spot formed by the third laser on the high-frequency, high-speed substrate 100 is the second cutting spot 112. To ensure that the second and third lasers completely remove the substrate within the enclosed area, the sum of the diameter of the second cutting spot 112 and the diameter of the cutting spot 110 should be greater than or equal to the radius of the enclosed area. When the sum of the diameters of the second etch spot 112 and the etch spot 110 is greater than the radius of the enclosed area, the orthographic projections of the second etch spot 112 and the punching spot 111 in the orthographic projection plane partially overlap. The substrate in the overlapping area can be removed by the second etch spot 112 and / or the punching spot 111. The second etch spot 112 is an etching spot.

[0047] It is understandable that the spot size of a pulsed laser is inversely proportional to its energy density. When processing the hole structure 101, the spot size and energy density can be rationally selected based on the type of substrate material to be removed and the processing depth. When the size of the hole structure 101 is large, multiple sequentially arranged second closed paths 109 can be set between the first closed path 108 and the punching position. Thus, through laser cutting around the hole, laser processing of the sequentially arranged second closed paths 109, and punching at the punching position, the substrate within the enclosed area can be completely removed to form the sidewalls and bottom wall of the hole structure 101.

[0048] In some embodiments, the laser drilling method can be used to process hole structures 101 with a diameter greater than or equal to 40 μm on a high-frequency, high-speed substrate 100. For example, when processing blind holes on the high-frequency, high-speed substrate 100 using the laser drilling method of this application, the diameter of the blind hole can be in the range of 40 μm to 250 μm; the diameter of the blind hole can be 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 125 μm, 150 μm, 175 μm, 200 μm, 225 μm, or 250 μm.

[0049] In some embodiments, laser winding and laser etching are performed on the hole location, including: first performing laser winding on the hole location, and then performing laser etching on the hole location; or, first performing laser etching on the hole location, and then performing laser winding on the hole location. When laser winding is performed first and then laser etching is performed, the laser winding can first sever the physical connection between the substrate of the hole structure sidewall and the substrate of the enclosing area, thereby avoiding fiber tension and thermal stress deformation on the hole structure sidewall during the subsequent laser etching process, which would cause fluctuations in the processing quality of the hole structure 101, and improve the surface quality of the hole wall while obtaining the target hole diameter. When laser etching is performed first and then laser winding is performed, the substrate in the center of the enclosing area can be removed first by laser etching, and then the edge contour can be trimmed by laser winding, which can more accurately correct the hole wall morphology so that the sidewall is smooth and without protrusions. It is understood that when processing the hole position, at least one laser winding process and at least one laser etching process can be performed. When using multiple laser winding processes and / or multiple laser etching processes, the appropriate sequence can be selected according to the actual processing conditions such as the specific structure of the substrate, the type of material, and the hole diameter requirements of the hole structure 101. This application does not impose any restrictions.

[0050] In some embodiments, the laser cutting process uses an ultrafast laser or a carbon dioxide laser, and the laser etching process uses an ultrafast laser or a carbon dioxide laser; wherein, the wavelength of the ultrafast laser is 340nm-1070nm, and the pulse width of the ultrafast laser is less than or equal to 15ps; the wavelength of the carbon dioxide laser is 9000nm-11000nm, and the pulse width of the carbon dioxide laser is 1μs-200μs. For example, the wavelength of the ultrafast laser can be 340nm, 375nm, 405nm, 450nm, 473nm, 488nm, 561nm, 635nm, 660nm, 694nm, 780nm, 808nm, 980nm, 1064nm, or 1070nm, and the pulse width of the ultrafast laser is less than or equal to 15ps. The wavelength of a carbon dioxide laser can be 9000nm, 9200nm, 9400nm, 9600nm, 10200nm, 10300nm, 10600nm, or 11000nm; the pulse width of a carbon dioxide laser can be 1μs, 5μs, 10μs, 50μs, 100μs, or 200μs.

[0051] In some embodiments, the laser wrap-around process uses an ultrafast laser, which refers to a laser beam with a pulse width of picoseconds or less (e.g., femtoseconds). The energy of an ultrafast laser is released in a concentrated manner within an extremely short time, resulting in extremely high peak power (up to GW to TW levels). This concentrates the laser energy within a very small temporal and spatial range, inducing multiphoton absorption and / or avalanche ionization at the material's processing location. This breaks the material's molecular chains, causing the material to vaporize and form smaller particles, thus achieving rapid material removal. Furthermore, the interaction time between the ultrafast laser pulse and the material is extremely short, resulting in minimal thermal impact on the surrounding material. No carbon slag is generated during processing, leading to better processed structural morphology, reduced need for structural correction, and improved processing efficiency. In addition, since the high-frequency, high-speed substrate 100 contains a copper foil layer, the energy density of the ultrafast laser is greater than the damage threshold of copper. Therefore, the ultrafast laser can directly break through the copper layer or interrupt copper-based circuitry without requiring additional pretreatment such as browning / blackening of the copper. In addition, due to the extremely high peak power and cold processing characteristics of ultrafast lasers, laser winding processing using ultrafast lasers can improve the laser absorption rate of the high-frequency and high-speed substrate 100 while reducing the accumulation of heat energy during laser processing. This avoids the formation of protrusions on the sidewalls of the hole structure 101 due to the different shrinkage rates of the reinforcing materials (such as quartz fiber cloth, spherical silicon powder, etc.) and resin after heating (such as the resin shrinking or melting when heated, while the reinforcing materials such as quartz fiber cloth or spherical silicon powder hardly deform when heated).

[0052] In other embodiments, the laser winding process can also use a carbon dioxide laser. When using a carbon dioxide laser to perform laser winding on the high-frequency, high-speed substrate 100, the peak power of the carbon dioxide laser is lower than that of an ultrafast laser, but the average power is higher. It removes the substrate through a direct thermal effect with the substrate. Because the average power of the carbon dioxide laser pulse is high and the duration is long, sufficient heat can be released rapidly at the processing location, causing the reinforcing material and resin of the dielectric layer to melt together in a very short time, thereby avoiding protrusions on the sidewalls of the hole structure 101 caused by differences in material thermal stress.

[0053] It is understandable that the first laser used in the laser winding process and the second (or third) laser used in the laser etching process can both be ultrafast lasers or carbon dioxide lasers. Alternatively, they can be combined with the material characteristics of the high-frequency and high-speed substrate 100 to be processed, taking advantage of the respective advantages of ultrafast lasers and carbon dioxide lasers in the processing of high-frequency and high-speed substrate 100.

[0054] In some embodiments, the laser winding process uses a Gaussian-shaped pulsed laser, and the laser etching process uses a flat-topped pulsed laser. The Gaussian-shaped pulsed laser has concentrated energy at the center and higher peak power, which is beneficial for increasing the laser pulse penetration depth and reducing the contact time with the substrate, thus reducing the thermal impact on the substrate. The flat-topped pulsed laser has a lower peak power than the Gaussian-shaped pulsed laser, but its spot energy density distribution is more uniform, making the bottom wall of the hole structure 101 flatter. For example, the first laser in the laser winding process is a Gaussian-shaped pulsed laser. The second laser in the laser etching process is a flat-topped pulsed laser, and / or the third laser in the laser etching process is a flat-topped pulsed laser. The Gaussian-shaped pulsed laser used in the laser winding process and the flat-topped pulsed laser used in the laser etching process can be emitted by the same laser 202, or they can be emitted by different lasers 202. When using the same laser 202, the Gaussian-shaped first laser can be shaped to obtain the flat-topped second or third laser.

[0055] It should be noted that in laser winding and laser etching processes, the method for moving a pulsed laser (e.g., a first laser, a second laser, or a third laser) relative to the high-frequency high-speed substrate 100 can be achieved by using a beam deflection component 204 to control the deflection angle of the pulsed laser relative to the high-frequency high-speed substrate 100. The beam deflection component 204 may include at least one of a galvanometer, a rotating mirror, an AOD, etc.

[0056] See Figure 2 As shown, in some embodiments, the laser drilling method further includes: Step S101: Determine at least one of the laser cutting spot 110 and the laser etching spot based on the hole processing information; wherein the diameter of the laser cutting spot 110 is greater than or equal to 10 μm and less than or equal to 30 μm; the diameter of the laser etching spot is greater than or equal to 30 μm and less than or equal to 100 μm. It is understood that step S101 is located after step S100 and before step S200.

[0057] For example, determining at least one of the laser cutting spot 110 in the laser cutting process and the etching spot in the laser etching process can be done by determining at least one of the diameters of the laser cutting spot 110 in the laser cutting process and the etching spot in the laser etching process. The cutting spot 110 is the spot where the first laser is incident on the hole position, and the diameter of the cutting spot 110 is the diameter of the spot where the first laser is incident on the hole position, i.e., the diameter of the first laser spot. The spot size of the same laser is inversely proportional to the spot energy density and also inversely proportional to the penetration depth of the laser in the substrate. Therefore, setting the diameter of the first laser spot to be small can ensure that the energy density is high enough to quickly penetrate the substrate and form a flat sidewall, minimize the contact time between the first laser and the sidewall, and reduce the thermal impact of laser heat accumulation on the dielectric layer. In laser etching, when only the second laser is used, the etching spot is the spot where the second laser is incident on the hole (punching spot 111), and the diameter of the etching spot is the diameter of the spot where the second laser is incident on the hole, i.e., the diameter of the second laser spot. The diameter of the second laser spot can be set to be larger than the diameter of the first laser spot, thus improving the removal efficiency of the substrate in the enclosed area. When both a second and a third laser are used in the laser etching process, the spot where the second laser is incident on the hole (punching spot 111) is an etching spot, and the spot where the third laser is incident on the hole (second wrap-around spot 112) is also an etching spot. Therefore, determining the diameter of the etching spot requires determining the diameter of the spot where the second laser irradiates the hole (i.e., the diameter of the second laser spot) and the diameter of the spot where the third laser irradiates the hole (i.e., the diameter of the third laser spot). Since both the second and second lasers are used for efficient removal of the substrate in the enclosed area, the diameter of the third laser spot can be set to be the same as the diameter of the second laser spot.

[0058] For example, the diameter of the etch spot 110 can be 10μm, 15μm, 20μm, 25μm, or 30μm; the diameter of the etching spot can be 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm. It is understood that the shape of the outer contour 107 of the hole can be circular, elliptical, or polygonal; a polygon can be triangular, quadrilateral, or pentagonal. When the shape of the outer contour 107 of the hole is elliptical or polygonal, the diameter of the hole structure 101 can be an equivalent diameter; for example, the equivalent diameter is the diameter of the circumcircle of the outer contour 107 of the hole.

[0059] The following description, in conjunction with the accompanying drawings, details the specific application of the laser drilling method according to the embodiments of this application when forming a hole structure 101 as a blind hole or a through hole on a high-frequency, high-speed substrate 100.

[0060] Combination Figure 4 and Figure 5 As shown, where, Figure 5 This is a schematic diagram of the blind via processing of a high-frequency, high-speed substrate 100 provided in an embodiment of this application; Figure 5 (a) represents the state of the high-frequency high-speed substrate 100 before processing; (b) represents the state after laser winding processing to form an annular groove 105 on the high-frequency high-speed substrate 100, where the annular groove 105 is the groove after removing the laser winding structure 103 in the enclosing area during laser winding processing, and the remaining structure in the enclosing area is the laser etched structure 104 that requires laser etching processing; (c) represents the state after laser etching processing to form a blind hole on the high-frequency high-speed substrate 100; according to the above... Figure 5 As can be seen from the description, blind vias can be formed by processing the high-frequency, high-speed substrate 100 with the first and second lasers. It should be noted that after the laser winding process, the laser-etched structure 104 has a laser-etched outer contour 113.

[0061] Combination Figure 4 and Figure 6 As shown, where, Figure 6 This is a schematic diagram of another process for blind via fabrication on a high-frequency, high-speed substrate 100 provided in this application embodiment; Figure 6 (a) shows the state of the high-frequency high-speed substrate 100 before processing; (b) shows the state after laser etching is used to remove the laser-etched structure 104, forming a pre-drilled hole 106 on the high-frequency high-speed substrate 100, with the laser-cut structure 103 to be removed subsequently shown as a dashed line in (b); (c) shows the state after the laser-cut structure 103 is removed by laser cutting, forming a blind hole on the high-frequency high-speed substrate 100; according to the above... Figure 6As can be seen from the description, blind holes can be formed by processing the high-frequency and high-speed substrate 100 with the first and second lasers.

[0062] Combination Figure 7 and Figure 8 As shown, where, Figure 8 This is a schematic diagram of another process for blind via fabrication on a high-frequency, high-speed substrate 100 provided in this application embodiment; Figure 8 (a) represents the state of the high-frequency high-speed substrate 100 before processing; (b) represents the state after laser winding processing is used to remove the laser winding structure 103, forming an annular groove 105 on the high-frequency high-speed substrate 100, and forming a laser etched structure 104 requiring laser etching processing within the enclosed area; (c) represents the state after the third laser in the laser etching process moves along a second closed path 109, removing part of the structure from the laser etched structure 104 to form a new laser etched structure 104; (d) represents the state after the second laser in the laser etching process punches a hole in the enclosed area, removing the remaining laser etched structure 104, and forming a blind hole on the high-frequency high-speed substrate 100. Based on the above... Figure 8 As can be seen from the description, blind vias can be formed by processing the high-frequency, high-speed substrate 100 with the first laser, the third laser, and the second laser. It should be noted that after the laser winding process, the laser-etched structure 104 has a laser-etched outer contour 113.

[0063] Figure 9 This is a schematic diagram of the process of processing through holes in a high-frequency, high-speed substrate 100 according to an embodiment of this application; Figure 9 (a) shows the state of the high-frequency high-speed substrate 100 before processing; (b) shows the state after laser winding processing is used to remove the laser winding structure 103, forming an annular groove 105 on the high-frequency high-speed substrate 100, at which point the laser-etched structure 104 is completely separated from the high-frequency high-speed substrate 100; (c) shows the state after the laser winding processing, when the laser-etched structure 104 falls off the high-frequency high-speed substrate 100, forming a through hole on the high-frequency high-speed substrate 100. Figure 9 As can be seen, when processing through holes in the high-frequency high-speed substrate 100, through holes can be formed after one laser winding process.

[0064] Figure 10 This is a schematic diagram of another process for processing through holes in a high-frequency, high-speed substrate 100 according to an embodiment of this application; Figure 10 (a) shows the state of the high-frequency, high-speed substrate 100 before processing; (b) shows the state after laser etching, with through-holes formed on the high-frequency, high-speed substrate 100. Figure 10 As can be seen, when processing through holes in the high-frequency high-speed substrate 100, through holes can be formed by a single laser etching process.

[0065] It should be noted that the laser drilling method provided in this application embodiment can also be used to process cross-layer hole structures on a high-frequency or high-speed substrate 100, further meeting the interconnection channel fabrication requirements of high-speed or high-frequency systems. A cross-layer hole structure refers to a hole structure 101 that penetrates multiple layers of copper-clad laminate from the upper surface of the high-frequency or high-speed substrate 100 to be processed. The cross-layer hole structure can be a through hole or a blind hole. For example, when processing the hole structure 101, the hole structure 101 can be processed by only one laser winding process and only one laser etching process; or the cross-layer hole structure can be processed by at least one of multiple laser winding processes and multiple laser etching processes.

[0066] The following description, in conjunction with the accompanying drawings, details the specific application of the laser drilling method according to the embodiments of this application when performing multiple processes on a high-frequency, high-speed substrate 100 to form a hole structure 101.

[0067] Figure 11 This is a schematic diagram of another process for processing through holes in a high-frequency, high-speed substrate 100 provided in this application embodiment; Figure 11 In the diagram, (a) represents the state of the high-frequency high-speed substrate 100 before processing; (b) represents the state after an annular groove 105 is formed on the high-frequency high-speed substrate 100, where the annular groove 105 is the groove after the laser winding structure 103 in the enclosing area is removed during laser winding processing, and the remaining structure in the enclosing area is the laser etched structure 104 that requires laser etching processing; (c) represents the state after a blind hole is formed on the high-frequency high-speed substrate 100 after laser etching processing; (d) represents the state after another laser winding process is performed on (c) and the laser winding structure 103 is removed; and (e) represents the state after a through hole is formed on the high-frequency high-speed substrate 100 after laser winding processing. Figure 11 As can be seen, when processing through holes in the high-frequency high-speed substrate 100, the process involves laser winding, laser etching, and laser winding in sequence to finally form through holes.

[0068] Figure 12 This is a schematic diagram of another process for processing through holes in a high-frequency, high-speed substrate 100 according to an embodiment of this application; Figure 12(a) shows the state of the high-frequency high-speed substrate 100 before processing; (b) shows the state after laser etching to remove the laser-etched structure 104, forming a pre-drilled hole 106 on the high-frequency high-speed substrate 100, with the laser-cut structure 103 to be removed subsequently shown as a dashed line in (b); (c) shows the state after the laser-cut structure 103 is removed by laser cutting, forming a blind hole on the high-frequency high-speed substrate 100; (d) shows the state after another laser cutting process is performed on top of (c), removing the laser-cut structure 103; (e) shows the state after laser cutting, forming a through hole on the high-frequency high-speed substrate 100. Figure 12 As can be seen, when processing through holes in the high-frequency high-speed substrate 100, the process involves laser etching, laser winding, and laser winding in sequence, ultimately forming through holes.

[0069] When there are multiple hole structures 101 on the high-frequency, high-speed substrate 100, each hole structure 101 has corresponding hole processing information. When laser cutting and laser etching are required at the hole locations, all hole locations can be processed using the same method first, followed by the other method; this processing mode can be called batch processing mode. Alternatively, a sequential processing operation can be performed, where each hole location undergoes both methods to form a hole structure 101 before processing another hole location; this processing mode can be called sequential processing mode. It is understandable that when the hole structure 101 is a through hole, if only laser cutting or laser etching is performed, all hole locations can be processed sequentially.

[0070] In some embodiments, for step S200, when there are multiple hole structures 101, each hole structure 101 has corresponding hole processing information. Using the hole position as a positioning reference, at least one of laser winding and laser etching processes is performed on the high-frequency, high-speed substrate to form the hole structure 101, including: Step S201: First, perform at least one of laser winding and laser etching on a hole location on the high-frequency high-speed substrate 100 to form a hole structure 101. After forming a hole structure 101, perform at least one of laser winding and laser etching on the next hole location in sequence to form the next hole structure 101, until all hole locations have undergone at least one of laser winding and laser etching to form all hole structures 101. This ensures consistent quality of individual holes, resulting in smooth sidewalls and minimal fiber or protrusion residue. In addition, this method reduces the difficulty of positioning and alignment, because when the hole structure 101 is a blind hole, misalignment between the central area and the outer contour of the blind hole can cause serious problems with the morphology of the processed structure (e.g., fiber or filler particles protruding, affecting subsequent conductive substrate filling and electroplating, and thus affecting the signal transmission of the substrate). Since each laser processing requires adjusting the alignment between the beam deflection component 204 and the processing position (e.g., the hole position), this process is time-consuming. Therefore, when the method of step S201 is used to add the hole structure 101 to the hole position, the processing efficiency can be greatly improved. If the beam deflection component 204 is a galvanometer scanning component, the processing efficiency can be improved by at least 40%. For example, the mode used in step S201 can be called the step-by-step processing mode. When the hole structure 101 is a blind hole, for a hole position on the high-frequency high-speed substrate 100, laser winding processing can be performed first, followed by laser etching processing to form the hole structure 101. After forming one hole structure 101, the next hole position is first laser winding processing, followed by laser etching processing to form the hole structure 101. When the hole structure 101 is a blind hole, for a hole position on the high-frequency high-speed substrate 100, laser etching processing can also be performed first, followed by laser winding processing to form the hole structure 101. After a hole structure 101 is formed, the next hole position is first laser etched and then laser cut around to form the hole structure 101.

[0071] In other embodiments, when there are multiple hole structures 101, each hole structure 101 has corresponding hole processing information. Using the hole position as a positioning reference, at least one of laser winding and laser etching processes is performed on the high-frequency, high-speed substrate to form the hole structure 101, including: Step S202: First, perform either laser winding or laser etching on all hole locations on the high-frequency, high-speed substrate 100; then, perform the other of laser winding and laser etching on all hole locations to form all hole structures 101. This is suitable for high-frequency, high-speed substrates 100 with large-scale, regular hole arrays. For example, the mode used in step S202 can be called a batch processing mode. For multiple hole locations on the high-frequency, high-speed substrate 100, laser winding can be performed on all hole locations first, followed by laser etching. Alternatively, laser etching can be performed on all hole locations first, followed by laser winding.

[0072] It is understandable that when there are multiple hole structures 101, the processing mode (batch processing mode or sequential processing mode) can be determined first, followed by the processing order (the execution order of laser cutting and laser etching processes); alternatively, the processing order can be determined first, followed by the processing mode. Furthermore, multiple hole locations can be divided into at least two groups as needed. For example, multiple hole locations are divided into two groups, and a processing mode and processing order are selected for each group. That is, the two groups can choose the same or different processing modes; and the processing orders can be the same or different.

[0073] It should be noted that steps S201 and S202 can be selectively executed as needed, for example, only step S201 can be executed, or only step S202 can be executed; when multiple hole positions are divided into at least two groups, the laser drilling method can execute steps S201 and / or step S202.

[0074] In some embodiments, after performing at least one of laser winding and laser etching processes on the high-frequency, high-speed substrate 100 to form the hole structure 101, the laser drilling method further includes: Step S300: Obtain the actual hole depth of the hole structure 101. Exemplarily, a method for obtaining the actual hole depth of the hole structure 101 includes: using a hole depth detection device to obtain the actual hole depth of the formed hole structure 101; the hole depth detection device includes one or more of a confocal displacement sensor, a white light interferometer, a laser triangulation thickness gauge, an ultrasonic thickness gauge, an eddy current thickness gauge, an X-ray fluorescence spectrometer (XRF), and an energy-dispersive X-ray spectrometer (EDS).

[0075] Step S301: Inspect the hole structure 101 to determine whether the actual hole depth of the hole structure 101 meets the requirements. If the actual hole depth of the hole structure 101 does not meet the requirements, mark the formed hole structure 101 to facilitate subsequent laser winding and / or laser etching, or other processing. For example, if the actual hole depth of the hole structure 101 is less than the hole depth (theoretical depth) in step S200, perform laser winding and / or laser etching on the hole structure 101; if the actual hole depth of the hole structure 101 is greater than the hole depth (theoretical depth) in step S200, perform a repair operation, such as filling the hole, and then performing at least one of laser winding and laser etching.

[0076] It is understood that in the laser drilling method provided in the embodiments of this application, when the depth of the processed hole structure 101 is less than the set value, it can be done by only one laser bypass cutting process and one laser etching process. Or when the depth of the processed hole structure 101 is greater than the set value, it can be done by at least one laser bypass cutting process and at least one laser etching process. For example, it can be two or three laser bypass cutting processes and one, two or three laser etching processes.

[0077] This application also provides a computer-readable storage medium storing a computer program. When the computer program is executed by the controller 205, it implements the various processes of the above-described laser drilling method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0078] Computer-readable storage media include: permanent and non-permanent, removable and non-removable media, which are tangible devices capable of retaining and storing instructions for use by an instruction execution device. Computer-readable storage media include: electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, and any suitable combination thereof. Computer-readable storage media include: phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, optical disc read-only memory (CD-ROM), digital versatile optical disc (DVD) or other optical storage, magnetic tape storage, magnetic disk storage or other magnetic storage devices, memory sticks, mechanical encoding devices (such as punched cards or raised structures in grooves on which instructions are recorded), or any other non-transfer medium that can be used to store information accessible by a computing device. As defined in the embodiments of this application, computer-readable storage media do not include temporary signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses passing through fiber optic cables), or electrical signals transmitted through wires.

[0079] All or part of the technical solutions of the embodiments of this application can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (including a personal computer, server, data center, or other network device) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code as listed above.

[0080] This application also provides a laser drilling apparatus, which uses the laser drilling method or computer storage medium in any of the above embodiments to process a hole structure 101 on a high-frequency, high-speed substrate 100. The laser drilling apparatus is used to perform at least one of laser winding and laser etching processes on the high-frequency, high-speed substrate 100 to form the hole structure 101.

[0081] See Figure 13As shown, in some embodiments, the laser drilling equipment includes: a laser 202, a beam control system 208, a processing platform 201, and a controller 205; wherein, the laser 202 is used to emit pulsed laser under the control of the controller 205; the beam control system 208 is used to provide a transmission optical path for the pulsed laser under the control of the controller 205, and to control the pulsed laser to form a light spot on the high-frequency high-speed substrate 100; the processing platform 201 is used to carry and move the high-frequency high-speed substrate 100 under the control of the controller 205; the controller 205 can execute the laser drilling method in any of the above embodiments or run a computer program stored in a computer storage medium. It should be noted that, in Figure 13 In the diagram, the dashed line with an arrow indicates the beam propagation path, and the solid line with an arrow indicates the electrical coupling path.

[0082] In some embodiments, the beam control system 208 further includes a shaping component 203, used to shape the received pulsed laser from a Gaussian pulse waveform to a flat-top waveform under the control of the controller 205. Exemplarily, the shaping component 203 is used to shape a first laser with a Gaussian pulse waveform into a second laser with a flat-top pulse waveform. The first laser is a pulsed laser with a Gaussian pulse waveform, which has a high energy peak, beneficial for increasing the penetration depth of the etched spot 110 and improving the flatness of the etched surface; while the second laser with a flat-top pulse waveform forms an etching spot with a more uniform energy density distribution on the high-frequency, high-speed substrate 100, which is beneficial for making the bottom wall of the blind hole flatter.

[0083] In some embodiments, the laser 202 includes at least one of an ultrafast laser and a carbon dioxide laser, wherein the ultrafast laser emits pulsed laser light with a wavelength range of 340 nm to 1070 nm and a pulse width of less than or equal to 15 ps; the carbon dioxide laser emits pulsed laser light with a wavelength of 9000 nm to 11000 nm and a pulse width of 1 μs to 200 μs. Exemplarily, the wavelength of the ultrafast laser can be 340 nm, 375 nm, 405 nm, 450 nm, 473 nm, 488 nm, 561 nm, 635 nm, 660 nm, 694 nm, 780 nm, 808 nm, 980 nm, 1064 nm, or 1070 nm, and the pulse width of the ultrafast laser is less than or equal to 15 ps. The wavelength of a carbon dioxide laser can be 9000nm, 9200nm, 9400nm, 9600nm, 10200nm, 10300nm, 10600nm, or 11000nm; the pulse width of a carbon dioxide laser can be 1μs, 5μs, 10μs, 50μs, 100μs, or 200μs.

[0084] In some embodiments, the beam control system 208 includes a beam deflection component 204 and a focusing component 207. The beam deflection component 204 can be used to adjust the beam spot formed on the high-frequency high-speed substrate 100 to deflect and move it, so that the pulsed laser emitted from the beam control system 208 can perform laser drilling on different hole positions on the high-frequency high-speed substrate 100. For example, the beam deflection component 204 can be a galvanometer scanning component.

[0085] In some embodiments, the laser drilling equipment may further include a moving device 206, which includes a first moving mechanism and a second moving mechanism; the high-frequency high-speed substrate 100 is placed on the processing platform 201; the first moving mechanism is used to drive the laser head composed of the beam deflection component 204 and the focusing component 207 to move, so as to control the up and down movement of the laser head (movement on the Z-axis) and the deflection angle of the laser head output beam. For example, the beam deflection component 204 may be a galvanometer, a rotating mirror, or other optical control components that can control the beam deflection angle; the processing platform 201 is disposed on the second moving mechanism, and the second moving mechanism is used to realize the movement of the processing platform 201 in the horizontal plane, that is, it can move or rotate along the X-axis and / or Y-axis; the X-axis, Y-axis and Z-axis are perpendicular to each other.

[0086] This application also provides a high-frequency high-speed substrate 100, which has a hole structure 101. The hole structure 101 is obtained by using the laser drilling method provided in any of the above embodiments, or by using the laser drilling equipment provided in any of the above embodiments.

[0087] It should be understood that, in the embodiments of this application, unless otherwise expressly specified and limited, the terms "connection," "fixed connection," "contact," etc., should be interpreted broadly. Those skilled in the art can understand the specific meanings of the various terms in the embodiments of this application according to the specific circumstances.

[0088] For example, the "connection" can be a fixed connection, a rotating connection, a flexible connection, a sliding connection, a one-piece molding, an electrical connection, a contact connection, or other connection methods; it can be a direct connection, or an indirect connection through an intermediate medium, or a connection within two components or an interaction between two components.

[0089] For example, a "fixed connection" can be a component that can be directly or indirectly fixedly connected to another component; a fixed connection can include mechanical connection, welding, bonding or integral molding, etc., wherein mechanical connection can include riveting, bolting, threaded connection, keying, snap-fit ​​connection, locking connection, plugging, etc., and bonding can include adhesive bonding and solvent bonding, etc.

[0090] It should also be understood that the “parallel” or “perpendicular” described in the embodiments of this application can be understood as “approximately parallel” or “approximately perpendicular”.

[0091] It should also be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0092] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature and the second feature are in direct contact, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0093] It should also be understood that the terms “length,” “width,” “up,” “down,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship (if any) based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0094] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims. In conclusion, the above description is merely a preferred embodiment of the technical solution of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A laser drilling method, characterized in that, The laser drilling method, applied to the fabrication of hole structures on high-frequency, high-speed substrates, includes: Obtain hole processing information for the hole structure, including hole location, hole outer contour, and hole depth; Using the hole position as a positioning reference, at least one of laser winding and laser etching processes is performed on the high-frequency high-speed substrate to form the hole structure; The laser cutting process includes: controlling a first laser to move along a first closed path that matches the outer contour of the hole, and making the penetration depth of the first laser at the outer contour of the hole consistent with the hole depth, so as to form the sidewall of the hole structure; The laser etching process includes: controlling a second laser to punch a hole in the enclosing area of ​​the outer contour of the hole, so as to remove the substrate of the enclosing area and form the bottom wall of the hole structure.

2. The laser drilling method as described in claim 1, characterized in that, The laser etching process further includes: The third laser is controlled to move along at least one second closed path located within the enclosed area; wherein the second closed path is located inside the first closed path; The substrate of the enclosed area is removed by the second laser and the third laser together to form the bottom wall of the hole structure.

3. The laser drilling method as described in claim 1, characterized in that, The hole location is subjected to laser bypass cutting and laser etching processes, including: First, the hole location is subjected to laser cutting, and then the hole location is subjected to laser etching. Alternatively, the hole location can be laser etched first, and then laser cut around the hole location.

4. The laser drilling method as described in claim 1, characterized in that, The laser cutting process uses an ultrafast laser or a carbon dioxide laser, and the laser etching process uses an ultrafast laser or a carbon dioxide laser. The ultrafast laser has a wavelength of 340nm-1070nm and a pulse width of less than or equal to 15ps. The wavelength of the carbon dioxide laser is 9000nm~11000nm, and the pulse width of the carbon dioxide laser is 1μs~200μs.

5. The laser drilling method as described in claim 1, characterized in that, The laser cutting process uses a pulsed laser with a Gaussian shape, and the laser etching process uses a pulsed laser with a flat-top shape.

6. The laser drilling method as described in claim 1, characterized in that, The high-frequency high-speed substrate includes at least one copper-clad laminate laminated along the thickness direction, wherein the light absorption rate of the dielectric layer of the copper-clad laminate is lower than a predetermined threshold.

7. The laser drilling method as described in claim 6, characterized in that, The dielectric layer of the copper clad laminate contains at least one of quartz fiber cloth, PTFE, and spherical silica microparticles.

8. The laser drilling method according to any one of claims 1-7, characterized in that, The number of hole structures is multiple, and each hole structure has corresponding hole processing information; The step of using the hole position as a positioning reference to perform at least one of laser winding and laser etching processes on the high-frequency high-speed substrate to form the hole structure includes: First, perform at least one of the laser circumferential cutting process and the laser etching process at one of the hole locations to form the hole structure; After one hole structure is formed, at least one of the laser circumferential cutting process and the laser etching process is sequentially performed on the next hole position to form the next hole structure, until at least one of the laser circumferential cutting process and the laser etching process is performed on all hole positions to form all hole structures.

9. The laser drilling method according to any one of claims 1-7, characterized in that, The number of hole structures is multiple, and each hole structure has corresponding hole processing information; The step of using the hole position as a positioning reference to perform at least one of laser winding and laser etching processes on the high-frequency high-speed substrate to form the hole structure includes: First, perform either the laser wrapping process or the laser etching process sequentially on all the hole locations; Then, perform either the laser wrapping process or the laser etching process on all the hole locations to form all the hole structures.

10. The laser drilling method according to any one of claims 1-7, characterized in that, The laser drilling method further includes: The laser cutting spot for the laser cutting process and the laser etching spot for the laser etching process are determined based on the hole processing information. The diameter of the cutting spot is greater than or equal to 10 μm and less than or equal to 30 μm; the diameter of the etching spot is greater than or equal to 30 μm and less than or equal to 100 μm.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the laser drilling method as described in any one of claims 1-10.

12. A laser drilling device, characterized in that, Laser drilling equipment is used for laser drilling of high-frequency, high-speed substrates. The laser drilling equipment includes a laser, a beam control system, a processing platform, and a controller. The laser is used to emit pulsed laser under the control of the controller; The beam control system is used to provide a transmission optical path for the pulsed laser under the control of the controller, and to control the pulsed laser to form a light spot on the high-frequency high-speed substrate; The processing platform is used to carry and move the high-frequency, high-speed substrate under the control of the controller; The controller can be used to perform the laser drilling method according to any one of claims 1-10.

13. The laser drilling equipment as described in claim 12, characterized in that, The laser includes at least one of an ultrafast laser and a carbon dioxide laser; The pulsed laser emitted by the ultrafast laser is an ultrafast laser with a wavelength of 340nm-1070nm and a pulse width of less than or equal to 15ps. The pulsed laser emitted by the carbon dioxide laser is a carbon dioxide laser with a wavelength of 9000nm~11000nm and a pulse width of 1μs~200μs.

14. The laser drilling equipment as described in claim 12, characterized in that, The beam manipulation system includes: A shaping component, under the control of the controller, shapes the received pulsed laser from a Gaussian shape to a flat-top shape.

15. A high-frequency, high-speed substrate, characterized in that, The high-frequency, high-speed substrate has a hole structure, which is obtained by laser drilling as described in any one of claims 1 to 10, or by laser drilling equipment as described in any one of claims 12 to 14.

Images