A method of forming an inner channel and an inner channel manufacturing system

Abstract

This application provides a method and system for forming internal channels. A Bessel beam is used to irradiate a workpiece to form multiple first modification lines and multiple second modification lines within the workpiece. These lines are distributed along a preset processing path. The first modification lines completely or partially penetrate the workpiece from a first side to allow the etchant to flow into the workpiece. The multiple second modification lines are located inside the workpiece. The workpiece is then placed in the etchant for etching, forming an internal channel within the workpiece that extends along the preset processing path and covers the locations of the multiple second modification lines. During etching, multiple first etching zones centered on the locations of the first modification lines are used to transfer the etchant to the multiple second etching zones centered on the locations of the second modification lines after etching. This improves the quality and morphology of the internal channels and enhances product quality.

Description

Technical Field

[0001] This application relates to the field of laser micromachining, and in particular to a method for forming an inner channel and an inner channel fabrication system. Background Technology

[0002] Micro-vias, as a common structure, are widely used in medical nebulization, biological detection, and chemical engineering. Currently, micro-via channels are generally processed using objective lenses, assisted by XY modules to fabricate specific areas of the sample, and supplemented by chemical etching to obtain the desired channel path. This requires repeated laser motion processing using the XY module and a Z-axis system, demanding high levels of automation and graphical path representation, while lacking flexibility in adjusting channel morphology, aperture size, and aperture shape. Therefore, providing a method to improve the morphology of internal channels has become an urgent technical problem to be solved. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a method for forming an inner channel and an inner channel manufacturing system, which can improve the quality and morphology of the inner channel and thus improve product quality. The specific solution is as follows:

[0004] In a first aspect, this application provides a method for forming an inner channel, comprising:

[0005] A Bessel beam is used to irradiate a workpiece to form a plurality of first modification lines and a plurality of second modification lines within the workpiece. These first and second modification lines are distributed along a predetermined processing path. The first modification lines completely or partially penetrate the workpiece from a first side, while the plurality of second modification lines are located inside the workpiece. When the first modification line partially penetrates the workpiece from its first side, its length is greater than or equal to the distance between the second modification line and the surface of the first side of the workpiece.

[0006] The device to be processed is placed in an etching solution for etching to form an inner channel within the device along the preset processing path and covering the locations of the plurality of second modification lines; during the etching process, a plurality of first etching zones centered on the locations of the first modification lines are used to transfer the etching solution to a plurality of second etching zones centered on the locations of the second modification lines after being etched.

[0007] Optionally, the extension direction of the first modified line and the plurality of second modified lines is perpendicular to the surface of the first side of the device to be processed.

[0008] Optionally, the spacing between two adjacent second modification lines in the plurality of second modification lines is greater than or equal to half the width of the inner channel and less than or equal to 0.9 times the width of the inner channel.

[0009] Optionally, the spacing between two adjacent first modification lines among the plurality of first modification lines is greater than or equal to twice the width of the inner channel and less than or equal to four times the width of the inner channel.

[0010] Optionally, the distance between the plurality of second modification lines and the surface of the first side of the device to be processed is equal, and the extension direction of the inner channel is parallel to the surface of the first side of the device to be processed.

[0011] Optionally, the plurality of second modification lines include a first group of modification lines and a second group of modification lines. The inner channel covering the location of the first group of modification lines is a first inner channel, and the inner channel covering the location of the second group of modification lines is a second inner channel. The first inner channel is located between the surface of the first side of the device to be processed and the second inner channel. The first modification lines corresponding to the first group of modification lines and the first group of modification lines are distributed along a first processing path, and the first modification lines corresponding to the second group of modification lines and the second group of modification lines are distributed along a second processing path.

[0012] Optionally, when the plurality of first modification lines penetrate the first side of the workpiece, the length of the first modification line is greater than the distance between the second set of modification lines and the surface of the first side of the workpiece; or,

[0013] The plurality of first modification lines include a third set of modification lines and a fourth set of modification lines. The third set of modification lines penetrates the device from a first side portion of the device to be processed, and the fourth set of modification lines penetrates the device from a second side portion of the device to be processed opposite to the first side surface. The length of the third set of modification lines is greater than the distance between the first set of modification lines and the first side surface of the device to be processed, and the length of the fourth set of modification lines is greater than the distance between the second set of modification lines and the second side surface of the device to be processed.

[0014] Optionally, the length of the first modification line is greater than or equal to 1 mm and less than or equal to 2 mm, and the length of the plurality of second modification lines is greater than or equal to 0.1 mm and less than 1 mm.

[0015] Optionally, the device to be processed includes opposing first and second side surfaces, and the step of irradiating the device to be processed with a Bezier beam to form a plurality of first modification lines and a plurality of second modification lines in the device to be processed includes:

[0016] An optical focusing module is used to focus a first laser beam emitted by a laser into a first Bessel focal line with a first depth of focus. The first Bessel focal line is controlled to be guided to the device to be processed for laser modification. The first Bessel focal line is moved according to the preset processing path to form the plurality of first modification lines. The position of the first Bessel focal line entering the device to be processed and the movement trajectory of the plurality of first Bessel focal lines are determined by controlling the relative position of the optical focusing module and the device to be processed.

[0017] The optical focusing module focuses the second laser beam emitted by the laser into a second Bessel focal line with a second depth of focus. The second Bessel focal line is controlled to perform laser modification inside the device to be processed. The second Bessel focal line is moved according to the preset processing path to form the plurality of second modification lines. The distance between the endpoint of the second Bessel focal line and the first side surface of the device to be processed, as well as the movement trajectory of the plurality of second Bessel focal lines, are determined by controlling the relative position of the optical focusing module and the device to be processed.

[0018] Optionally, at least one of the laser sources of the first laser beam and the second laser beam is a femtosecond laser or a picosecond laser.

[0019] Optionally, the optical focusing module includes: a diffractive optical element type Bessel module, a depth-of-focus type Bessel module, or a beam expander type Bessel module.

[0020] Optionally, placing the device to be processed in an etching solution for etching further forms a first micropore centered on the location of the first modified line, the first micropore communicating with the inner channel; the method further includes:

[0021] At least a portion of the first micropores are filled.

[0022] Secondly, this application provides an etching system, comprising:

[0023] A laser is used to emit a laser beam;

[0024] An optical focusing module is used to focus the laser beam to obtain a Bessel beam;

[0025] Stage module, used to place the device to be processed;

[0026] A movable module, which is connected to the optical focusing module or the stage module, so that the optical focusing module can move relative to the device to be processed;

[0027] The control module is used to control the execution of the inner channel forming method.

[0028] This application provides a method and system for forming an internal channel. A Bessel beam is used to irradiate a device to be processed, forming multiple first modification lines and multiple second modification lines within the device. These lines are distributed along a preset processing path. The first modification lines completely or partially penetrate the device from a first side. When the device is placed in an etchant for etching, the etchant preferentially etches the first modification lines and a first etching zone centered on the location of the first modification lines. During etching, the multiple first etching zones centered on the locations of the first modification lines are used to transfer the etchant to multiple second etching zones centered on the locations of the second modification lines after etching. The etchant is then guided into the interior of the device through the first etching zones. The multiple second modification lines are located inside the device. Thus, after etching the device, an internal channel is formed inside the device, following a preset processing path and covering the locations of the multiple second modification lines. In this way, by forming multiple second modification lines inside the device to be processed, the inner channel modification can be formed in one go, avoiding the drawbacks of multiple movements in the Z-axis direction of the objective lens method, effectively improving processing efficiency. Using the Bessel beam of this application to make the inner channel can improve the quality and morphology of the inner channel. Moreover, compared with the laser forming a blast point under the objective lens method, which causes cracks to form inside the device to be processed, the method of forming modification lines in this embodiment can reduce the damage to the device to be processed and improve product quality. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A schematic flowchart of an internal channel formation method provided in an embodiment of this application is shown;

[0031] Figures 2-4 This is a schematic diagram of the structure of the device to be processed during the formation of the inner channel in the embodiments of this application;

[0032] Figure 5 A cross-sectional view of a workpiece after it has been etched, as provided in an embodiment of this application;

[0033] Figure 6 A laser optical path diagram provided for an embodiment of this application;

[0034] Figure 7A cross-sectional view of Bessel spots at different locations in a sample provided for an embodiment of this application;

[0035] Figure 8 A top view of a device to be processed with an internal channel, provided for an embodiment of this application;

[0036] Figure 9-10 A cross-sectional view of a device to be processed, provided in an embodiment of this application;

[0037] Figure 11 A cross-sectional view of a workpiece after it has been etched, as provided in an embodiment of this application;

[0038] Figure 12 A schematic diagram of a detection method for a double-layer inner channel provided in an embodiment of this application;

[0039] Figure 13 A schematic diagram of an internal channel fabrication system provided in an embodiment of this application is shown. Detailed Implementation

[0040] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0041] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0042] Secondly, this application provides a detailed description in conjunction with schematic diagrams. When detailing the embodiments of this application, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this application. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0043] For ease of understanding, the following detailed description, in conjunction with the accompanying drawings, provides an embodiment of an inner channel forming method and an inner channel fabrication system provided in this application.

[0044] refer to Figure 1 The diagram shown is a flowchart of an inner channel formation method provided in an embodiment of this application. The method may include the following steps.

[0045] S101, using a Bessel beam to irradiate the device to be processed, thereby forming multiple first modification lines and multiple second modification lines in the device to be processed, reference. Figure 2 and Figure 3The diagram shown is a structural schematic of the device to be processed during the formation of the inner channel in an embodiment of this application. Figure 3 for Figure 2 A cross-sectional view of the device to be processed along the AA direction. Figure 4 for Figure 2 Another cross-sectional view of the device to be processed in the AA direction.

[0046] S102, the device to be processed is placed in an etching solution for etching processing, so as to form an inner channel in the device to be processed along a preset processing path and covering the locations of multiple second modification lines.

[0047] In this embodiment, the material of the device to be processed can be a glass plate. The device to be processed can include a first side surface and a second side surface opposite to each other. The first side surface is the surface located on the first side of the device to be processed, and the second side surface is the surface located on the second side of the device to be processed. As an example, the first side surface can be the upper surface, and the second side surface can be the lower surface. After the device to be processed is flipped, the first side surface can become the lower surface, and the second side surface can become the upper surface accordingly. In the following description, the first side surface is taken as the upper surface of the device to be processed as an example.

[0048] Specifically, a laser beam can be used to irradiate the workpiece, forming modification lines within it. These modification lines are laser-damaged traces on the workpiece. The area around the modification lines and the surrounding region are easily corroded, thus forming a porous structure within the workpiece. The laser beam can be a Bessel beam, which induces absorption within the workpiece, thereby creating the modification lines.

[0049] Specifically, multiple first modification lines can be formed in the device to be processed. These first modification lines are distributed along a preset processing path. They can either completely penetrate the first side of the device or partially penetrate it. When the device is placed in an etchant for etching, the etchant preferentially etches the first modification lines and the first etching zone centered on the location of each modification line. During etching, the multiple first etching zones centered on the locations of the first modification lines are used to transfer the etchant to multiple second etching zones centered on the locations of the second modification lines after etching, thus guiding the etchant into the interior of the device. The preset processing path is a path for the movement of a Belsey beam pre-defined according to the shape of the target internal channel to form the desired internal channel.

[0050] Generally speaking, considering that the first modification line is mainly used to guide the etchant into the second modification line position of the device to be processed, and considering the process time and cost, the number of the first modification lines is less than the number of the second modification lines.

[0051] Specifically, the extension direction of the first modification line can be perpendicular to the surface of the first side of the device to be processed, or it can be not completely perpendicular. Its position and direction are mainly determined by the ability to guide the etching solution outside the device to the position of the first modification line. The length of the first modification line can be greater than or equal to 1 mm and less than or equal to 2 mm. (Reference) Figure 2 As shown, the device to be processed 101 has multiple first modification lines 102, and the circular region surrounding the first modification lines 102 is the first etched region 1021 of the first modification lines 102. (Refer to...) Figure 3 As shown, the extension direction of the plurality of first modification lines 102 can be perpendicular to the surface of the first side of the device to be processed 101, and the plurality of first modification lines 102 completely penetrate the device to be processed 101. (Reference) Figure 4 As shown, multiple first modification lines 102 can also penetrate the first side portion of the device to be processed 101.

[0052] Specifically, multiple second modification lines can be formed in the device to be processed. These multiple second modification lines are distributed along a preset processing path and can be located inside the device to be processed. After being etched, multiple first corrosion zones transfer the etchant to multiple second corrosion zones centered on the location of the second modification lines. Thus, after the device to be processed is placed in the etchant for etching, an inner channel is formed inside the device to be processed, which is along the preset processing path and covers the location of multiple second modification lines.

[0053] Specifically, the extension direction of the multiple second modification lines can be perpendicular to or not completely perpendicular to the surface of the first side of the device to be processed. Their position and direction are primarily determined by ensuring that the preset path can be completely etched and uniformly connected through the second modification lines after the device is placed in the etching solution. The second modification lines determine the size and structure of the final inner channel. The length of the multiple second modification lines can be greater than or equal to 0.1 mm and less than 1 mm. When the first modification line penetrates the device from the first side, its length can be greater than or equal to the distance between the second modification line and the surface of the first side of the device, so that the etching solution drawn by the first etching zone can contact the second etching zone centered on the location of the second modification line, thereby etching the second etching zone. Then, the remaining modification lines and the etching zone centered on the modification line are etched, forming an inner channel covering the locations of the multiple second modification lines.

[0054] refer to Figure 2As shown, the device to be processed 101 has multiple second modification lines 103, and the circular region surrounding the second modification lines 103 is the second etched region 1031 of the second modification lines 103. The area of ​​the second etched region 1031 is equal to that of the first etched region 1021. Figure 3 and Figure 4 As shown, a plurality of second modification lines 103 are located inside the device to be processed 101, and the extension direction of the plurality of second modification lines 103 is perpendicular to the surface of the first side of the device to be processed 101. Figure 4 In the process, multiple first modification lines 102 partially penetrate the device to be processed 101, and the length of the first modification line 102 is greater than the distance between the second modification line 103 and the surface of the first side of the device to be processed 101.

[0055] In S102, when the device to be processed is placed in the etchant for etching, the etchant preferentially etches multiple first modification lines longitudinally. Once the etchant contacts the second modification line's second etching zone, that is, after reaching the internal modification channel, the etchant begins to etch the internal channel laterally. (Refer to...) Figure 5 The image shown is a cross-sectional view of a device to be processed after being etched, according to an embodiment of this application. Multiple first modification lines 102 and multiple first etched areas 1021 of the first modification lines are etched into multiple first micropores 104. Multiple second modification lines 103 and multiple second etched areas 1031 of the second modification lines are etched to form inner channels 105. The multiple first micropores 104 and the inner channels 105 are connected.

[0056] In this way, an inner channel can be formed within the device to be processed, along a preset processing path and covering the locations of multiple second modification lines. The inner channel is connected to the first micropore. By forming multiple second modification lines inside the device to be processed, the inner channel modification can be formed in one step, avoiding the drawbacks of multiple movements in the Z-axis direction of the objective lens method. This effectively improves processing efficiency, the quality and morphology of the inner channel. Moreover, compared to the laser-induced explosion point under the objective lens method, which causes cracks to form inside the device to be processed, the method of forming modification lines in this embodiment can reduce damage to the device to be processed and improve product quality.

[0057] In this embodiment, the distances between the plurality of second modification lines and the surface of the first side of the device to be processed can be equal, so that the extension direction of the inner channel is parallel to the surface of the first side of the device to be processed. (Reference) Figure 3 and Figure 4As shown, the distances between the multiple second modification lines 103 and the surface of the first side of the device to be processed 101 are equal. Of course, the distances between the multiple second modification lines and the surface of the first side of the device to be processed can also be unequal, with some second modification lines having larger distances and some second modification lines having smaller distances. In this way, the shape of the inner channel can be designed according to actual needs, such as a horizontal S-shape.

[0058] In this embodiment, the length of the first modification line can be equal to the sum of the length of the second modification line and the distance between the second modification line and the surface of the first side of the device to be processed. That is, the endpoint of the first modification line away from the surface of the first side of the device to be processed and the endpoint of the second modification line away from the surface of the first side of the device to be processed can be at the same horizontal height. Figure 4 As shown, the endpoints of the plurality of first modification lines 102 on the surface away from the first side of the device to be processed 101 are level with the endpoints of the plurality of second modification lines 103 on the surface away from the first side of the device to be processed 101. Of course, the endpoints of the first modification lines on the surface away from the first side of the device to be processed can also be at different horizontal heights from the endpoints of the second modification lines on the surface away from the first side of the device to be processed; for example, the horizontal line where the endpoints of the first modification lines on the surface away from the first side of the device to be processed are located may be higher or lower.

[0059] In the embodiments of this application, reference is made to Figure 2-4 As shown, after the corrosive liquid corrodes multiple first modification lines 102 to form multiple first micropores, the corrosive liquid guided by the multiple first micropores can simultaneously flow to the second modification lines 103 on both sides of the first micropores for corrosion, which can accelerate the corrosion rate and accelerate the formation of internal channels.

[0060] In this embodiment, the first corrosion regions 1021 of the plurality of first modification lines and the second corrosion regions 1031 of the plurality of second modification lines have overlapping areas. (See reference...) Figure 2 As shown, this ensures that the corrosive liquid guided by the first micropore can contact the second corrosion zone 1031 outside the second modification line, and then continue to contact the corrosion zones outside other modification lines, forming a connected internal channel.

[0061] In the embodiments of this application, reference is made to Figure 2As shown, when the second etched region 1031 of the second modification line 103 is cylindrical, the width of the inner channel 105 is equal to the diameter of the second etched region 1031 of the second modification line. Furthermore, the spacing between two adjacent second modification lines 103 can be greater than or equal to half the width of the inner channel 105, and less than or equal to 0.9 times the width of the inner channel 105. Specifically, if the spacing between the laser points forming the second modification line is denoted as D1, and the width of the inner channel is denoted as d, then D1 can be 0.7 times d, or D1 can be 15 μm, so that multiple second etched regions can form a connected inner channel after etching.

[0062] In this embodiment, multiple first modification lines are provided so that the etching solution can simultaneously enter the interior of the device under test from multiple first micropores, accelerating the formation of the internal channel and shortening the process time. The spacing between two adjacent first modification lines can be greater than or equal to twice the width of the internal channel and less than or equal to four times the width of the internal channel. Specifically, the spacing between the laser points forming the first modification lines is denoted as D2, which can be three times d or 100 μm. This ensures the connectivity of the internal channel, guarantees the uniformity of etching throughout the channel, and avoids process waste. If the multiplier is too large, the uniformity of the internal channel will be insufficient, or the channel may be narrow or even unable to connect. If the multiplier is too small, too many guide holes will be made, resulting in process waste.

[0063] In practical implementation, an optical focusing module can be used to focus the first laser beam emitted by the laser into a first Bessel focal line with a first focal depth. The first Bessel focal line is then guided to the workpiece for laser modification. Multiple first modification lines are formed by moving the first Bessel focal line according to a preset processing path. The position of the first Bessel focal line entering the workpiece and the movement trajectory of the multiple first Bessel focal lines are determined by controlling the relative position of the optical focusing module and the workpiece. Specifically, the optical focusing module is adjusted to obtain a first Bessel focal line with a long focal depth, wherein the length of the first Bessel focal line is greater than the entire workpiece. The thickness of the workpiece (when the first modification line is perpendicular to the surface of the first side of the workpiece, it is greater than the thickness of the workpiece in the vertical direction); in addition, by controlling the relative movement of the optical focusing module and the workpiece, that is, controlling the relative movement of the first Bezier focal line to the workpiece, the first Bezier focal line passes through the entire workpiece in the Z-axis direction and moves in the horizontal direction to form multiple first modification lines distributed along a preset path; furthermore, when controlling the relative movement of the optical focusing module and the workpiece, it is possible to control only the movement of the optical module, or only the movement of the workpiece, or both of them.

[0064] The first laser beam can be obtained by converting a pulsed laser beam. The laser source of the first laser beam can be a femtosecond laser or a picosecond laser to improve the peak power density of the laser. The laser can be 1064nm or 1030nm. The energy of the first laser beam is 20-100μJ, which is suitable for different sizes of devices to be processed, such as 50μJ. The optical focusing module used to focus the first laser beam can be a diffractive optical element (DOE) Bessel module, a depth-of-focus Bessel module, or a beam expander Bessel module.

[0065] Specifically, when the first modification line completely penetrates the device to be processed, the first Bessel focal line can be guided from either the first side surface or the second side surface of the device to be processed. The length of the first Bessel focal line is greater than the distance between the first and second side surfaces of the device to be processed before etching, i.e., the length of the first Bessel focal line is greater than the original thickness of the device to be processed, so that the first and second side surfaces have light spots. In addition, the difference between the distance between the center of the first Bessel focal line and the first side surface and the distance between the center of the first Bessel focal line and the second side surface is less than a preset value. The standard for setting this preset value is that the first end of the first Bessel focal line is on or outside the first side surface, and the second end of the first Bessel focal line is on or outside the second side surface. For example, the distance between the center of the first Bessel focal line and the first side surface is equal to the distance between the center of the first Bessel focal line and the second side surface, so that the center of the first Bessel focal line is located at the center of the device to be processed.

[0066] refer to Figure 6 The diagram shown is a laser optical path diagram provided in an embodiment of this application, including a laser 1-1, a beam expander 1-2, a reflector 1-3, an optical focusing module 1-4, a sample 1-5, a stage module 1-6, a moving module, and a control module 1-7. The moving module can be connected to either the stage module 1-6 or the optical focusing module 1-4, and is used to control the relative movement between the optical focusing module and the workpiece, i.e., to control the movement of the Bessel beam relative to the workpiece. This embodiment takes the connection between the moving module and the stage module 1-6 as an example. The control module 1-7... Simultaneously controlling the laser 1-1 and the moving module connected to the stage module 1-6, laser engraving is performed according to the preset processing path to form material modification at specific locations, such as forming the first modification line or the second modification line. The laser engraved pattern can be a line, a dot matrix, etc. The moving module can not only drive the stage module 1-6 to move in the X and Y directions, but also move in the Z-axis direction to change the specific position of the formed focal line. The optical focusing module 1-4 can adjust the spacing of the internal lens groups by adjusting the electric adjustment to achieve different depths of focus, thereby changing the length of the formed focal line.

[0067] Specifically, the focal depth of the Bessel spot can be adjusted to 1mm, making the length of the first modification line 1mm, the laser single pulse energy 50μJ, and the optical focusing modules 1-4 adjusted. Combined with the Z-axis control of the moving module, the device to be processed is positioned in the middle of the longitudinal focal depth of the spot. (Refer to...) Figure 7 The image shown is a cross-sectional view of Bessel spots at different positions in a sample provided in an embodiment of this application. By using a Bessel spot 2-2 with a long focal depth to act on samples 1-5, through-processing of the sample can be achieved, thereby forming the first micropore, which is also the guide hole for the etchant. The focal depth of the Bessel spot is greater than the sample thickness.

[0068] When the first modified line penetrates the device to be processed, the first Bessel focal line can be guided from the surface of the first side or the surface of the second side of the device to be processed into the device. The depth of the first micro-hole can be determined by controlling the relative position of the center position of the first Bessel focal line and the first side surface.

[0069] In practical implementation, an optical focusing module can be used to focus the second laser beam emitted by the laser into a second Bessel focal line with a second depth of focus. This second Bessel focal line is then controlled to undergo laser modification within the device to be processed, forming a second modification line. Optical focusing modules 1-4 can be adjusted to obtain a linear focused spot with a short depth of focus, for example, 0.1 mm. The Z-axis can be used to control the position of the focused spot within sample 1-5, as referenced. Figure 7 As shown, a short depth-of-focus Bessel spot 2-1 is used to process the sample at different depths to form a second modification line inside the sample. The Bessel spot 2-1 operates within sample 1-5, achieving localized processing of the sample's interior. The stage module 1-6 can also be adjusted to move in the XY-axis 2D plane, further forming an inner channel by patterning according to a preset processing path. The optical focusing module used to focus the second laser beam can be a diffractive optical element (DOE) Bessel module, a depth-of-focus extended Bessel module, or a beam expander Bessel module.

[0070] Specifically, multiple second Bessel focal lines can be formed by moving the second Bessel focal line according to a preset processing path. The distance between the endpoint of the second Bessel focal line and the first side surface of the device to be processed, as well as the movement trajectory of the multiple second Bessel focal lines, are determined by controlling the relative position of the optical focusing module and the device to be processed. Specifically, the operation of controlling the second laser beam to focus into the second Bessel focal line and guide it from the first side surface to the device to be processed for laser refining is repeatedly executed. That is, laser refining is performed once for each movement of a certain distance, forming a second refining line. After multiple movements and multiple laser refinings, multiple second refining lines can be formed. Specifically, the optical focusing module is adjusted to obtain a second Bezier focal line with a relatively short depth of focus. The length of the second Bezier focal line is less than the thickness of the entire device to be processed (when the first modified line is perpendicular to the surface of the first side of the device to be processed, i.e., less than the thickness of the device to be processed in the vertical direction). In addition, by controlling the relative movement of the optical focusing module and the device to be processed, that is, controlling the relative movement of the second Bezier focal line to the device to be processed, the second Bezier focal line is positioned at the required position inside the device to be processed in the Z-axis direction, and moves in the horizontal direction to form multiple second modified lines distributed along a preset path. Furthermore, when controlling the relative movement of the optical focusing module and the device to be processed, it is possible to control only the movement of the optical module, only the movement of the device to be processed, or both of them to move.

[0071] The second laser beam can be obtained by converting a pulsed laser beam and has a linear focused spot of a certain length. The laser source of the second laser beam can be a femtosecond laser or a picosecond laser to improve the peak power density of the laser. The energy of the second laser beam is 20–100 μJ, for example, 25 μJ.

[0072] The aforementioned first modification line can be formed before or after the second modification line, without affecting the implementation of the embodiments of this application or the actual technical effect.

[0073] refer to Figure 8 The image shown is a top view of a device to be processed with an internal channel according to an embodiment of this application. The device to be processed has eight first micropores 104. The first micropores 104 are formed by etching eight first modification lines and the first etching zone of the first modification lines with an etching solution. The eight first micropores 104 are connected to an internal channel 105. The internal channel 105 is formed by etching multiple second modification lines distributed along a preset processing path. The internal channel 105 is represented by a filled method. The internal channel 105 includes three sub-channels in the horizontal direction and four sub-channels in the vertical direction. The second modification lines are located on the center line of each sub-channel. The internal channel 105 is located inside the device to be processed 101. The boundary of the internal channel 105 is represented by a dashed line. The internal channel 105 is connected to multiple first micropores 104.

[0074] In this embodiment, multiple first modification lines are formed inside the device to be processed. The device is placed in an etching solution for etching, which also forms first micropores centered on the locations of the first modification lines. The first micropores are connected to an internal channel. After forming multiple first micropores and an internal channel inside the device to be processed, at least some of the first micropores can be filled, for example, only one pair of micropores for liquid inlet and one pair for liquid outlet can be retained, so that the structure of the device to be processed meets the actual requirements.

[0075] In this embodiment, a single-layer inner channel or multiple-layer inner channels can be formed inside the device to be processed. When forming a double-layer inner channel, the multiple second modification lines may include a first group of modification lines and a second group of modification lines. The inner channel covering the location of the first group of modification lines is the first inner channel, and the inner channel covering the location of the second group of modification lines is the second inner channel. The first inner channel is located between the surface of the first side of the device to be processed and the second inner channel. The first modification lines corresponding to the first group of modification lines and the first group of modification lines are distributed along the first processing path, and the first modification lines corresponding to the second group of modification lines and the second group of modification lines are distributed along the second processing path.

[0076] refer to Figure 9 The image shown is a cross-sectional view of a device to be processed according to an embodiment of this application. The device to be processed 101 has a first modification line 102, a first group of modification lines 106, and a second group of modification lines 107. The second group of modification lines 107 is located between the first group of modification lines 106 and the surface of the first side of the device to be processed 101. The first modification line 102 completely penetrates the device to be processed 101. Thus, after the etching liquid etches the first modification line 102 to form the first micropore 104, it can simultaneously etch the first group of modification lines 106 and the second group of modification lines 107, thereby forming the first inner channel and the second inner channel, saving process costs.

[0077] In this embodiment of the application, when forming a double-layer inner channel, the first modification line can not only completely penetrate the device to be processed, but also partially penetrate the device to be processed. When the first modification line partially penetrates the device to be processed from the first side, the length of the first modification line can be greater than the distance between the second set of modification lines and the surface of the first side of the device to be processed. In this way, while ensuring that the etchant can corrode the first set of modification lines and the second set of modification lines, the length of the first modification line is minimized, which saves more process costs.

[0078] In this embodiment of the application, when forming a double-layer inner channel, the plurality of first modification lines may include a third set of modification lines and a fourth set of modification lines. The third set of modification lines penetrates the device from the first side portion of the device to be processed, and the fourth set of modification lines penetrates the device from the second side portion of the device to be processed opposite to the first side surface. The length of the third set of modification lines is greater than the distance between the first set of modification lines and the first side surface of the device to be processed, and the length of the fourth set of modification lines is greater than the distance between the second set of modification lines and the second side surface of the device to be processed, so that the etching solution drawn by the third set of modification lines can etch the first set of modification lines, and the etching solution drawn by the fourth set of modification lines can etch the second set of modification lines, thus forming a double-layer inner channel.

[0079] refer to Figure 10 The diagram shown is a cross-sectional view of another device to be processed according to an embodiment of this application. The third set of modification lines includes two first modification lines 110, and the fourth set of modification lines includes two first modification lines 111. The etching solution can etch the first set of modification lines 106 through the two first modification lines 110, and can etch the second set of modification lines 107 through the other two first modification lines 111, thereby forming a double-layered inner channel. (Reference) Figure 11 The image shown is a cross-sectional view of a device to be processed after being etched according to an embodiment of this application. After the device to be processed is etched with an etchant, a first inner channel 108 and a second inner channel 109 can be formed inside the device to be processed. The two inner channels are not connected.

[0080] In this embodiment, the double-layer inner channel can be either a vertical double-layer inner channel or two horizontal inner channels, as shown in the reference. Figure 12 The diagram shown is a detection schematic of a double-layer inner channel provided in an embodiment of this application. It includes two inner channels. The inner channel on the left has a horizontal dimension of 42.708 μm and a vertical dimension of 92.044 μm, which is close to the focal depth of the Bessel spot of 0.1 mm, that is, close to the length of the second modification line. The inner channel on the right has a horizontal dimension of 44.535 μm and a vertical dimension of 94.512 μm.

[0081] In this embodiment, the etching solution can be determined according to the material characteristics of the device to be processed. The etching solution includes acidic etching solution or alkaline etching solution. Acidic etching solution includes at least one of hydrofluoric acid (HF), hydrochloric acid (HCl), sulfuric acid (H2SO4), ammonium fluoride (NH4F), etc., while alkaline etching solution includes potassium hydroxide (KOH), sodium hydroxide (NaOH), tetramethylammonium hydroxide (C4H4F), etc. 13At least one of the following hydroxides: NO. When the material of the device to be processed is glass, the acidic etching solution is: HF etching solution with a concentration range of 5% to 30%, or buffered oxide etching solution (BOE) with an HF:NH4F ratio range of 1:0.1 to 1:10, and a temperature range of 5 to 30°C; the alkaline etching solution is: NaOH solution with a concentration range of 10% to 50%, or KOH solution with a concentration range of 10% to 50%, and a temperature range of 80 to 95°C. When the device to be processed is placed in the etching solution for etching, the etching solution can be supplemented by a circulation system to ensure the consistency of the etching solution concentration and temperature, and improve the uniformity of etching.

[0082] The higher the concentration of the etching solution and the longer the device to be processed is placed in the etching solution, the more of the device to be processed will be etched away. Therefore, by considering the composition and concentration of the etching solution and the time the device to be processed is placed in the etching solution, the thickness of the etched material can be controlled, i.e., the aperture of the inner channel can be controlled. When the aperture of the inner channel reaches a preset value, the device to be processed can be removed, and etching can be stopped, resulting in the interconnected first micropore and inner channel. The time the device to be processed is placed in the etching solution is usually several hours.

[0083] This application provides a method for forming an internal channel. A Bessel beam is used to irradiate a device to be processed, forming multiple first modification lines and multiple second modification lines within the device. These lines are distributed along a preset processing path. The first modification lines completely or partially penetrate the device from a first side. When the device is placed in an etchant for etching, the etchant preferentially etches the first modification lines and a first etching zone centered on the location of the first modification lines. During etching, the multiple first etching zones centered on the locations of the first modification lines are used to transfer the etchant to multiple second etching zones centered on the locations of the second modification lines after etching. The etchant is then guided into the interior of the device through the first etching zones. The multiple second modification lines are located inside the device. Thus, after etching the device, an internal channel is formed inside the device, following a preset processing path and covering the locations of the multiple second modification lines. In this way, by forming multiple second modification lines inside the device to be processed, the inner channel modification can be formed in one go, avoiding the drawbacks of multiple movements in the Z-axis direction of the objective lens method, effectively improving processing efficiency. Using the Bessel beam of this application to make the inner channel can improve the quality and morphology of the inner channel. Moreover, compared with the laser forming a blast point under the objective lens method, which causes cracks to form inside the device to be processed, the method of forming modification lines in this embodiment can reduce the damage to the device to be processed and improve product quality.

[0084] Based on the above methods for forming internal channels, this application also provides an internal channel fabrication system, as described above. Figure 13 The diagram shows a schematic of an inner channel fabrication system provided in an embodiment of this application. It includes a laser 1-1, an optical focusing module 1-4, a stage module 1-6, and a control module 1-7. The laser 1-1 emits a laser beam, the optical focusing module 1-4 focuses the laser beam to obtain a Bessel beam, the stage module 1-6 places the device to be processed, and a moving module (not shown) is connected to either the optical focusing module 1-4 or the stage module 1-6, allowing the optical focusing module 1-4 to move relative to the device to be processed, i.e., controlling the movement of the Bessel beam relative to the device. The control module 1-7 controls the execution of the inner channel formation method. Further, the moving module can be connected to either the stage module 1-6, the optical focusing module 1-4, or both. It can control only the movement of the optical module, only the movement of the device to be processed, or both, so that when the Bessel beam irradiates the device to be processed, multiple first modification lines and multiple second modification lines are formed along a preset path.

[0085] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0086] The above description is merely a preferred embodiment of this application. Although this application has disclosed preferred embodiments above, it is not intended to limit this application. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this application using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solutions of this application. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this application without departing from the content of the technical solutions of this application shall still fall within the protection scope of the technical solutions of this application.

Claims

1. A method for forming an internal channel, characterized in that, include: A Bessel beam is used to irradiate the workpiece to form a plurality of first modification lines and a plurality of second modification lines in the workpiece, which serve as channels for the flow of etchant. The plurality of first modification lines and the plurality of second modification lines are distributed along a predetermined processing path. The first modification lines completely or partially penetrate the workpiece from a first side. The plurality of second modification lines are located inside the workpiece to define the outline of the internal channels to be formed. When the first modification line partially penetrates the workpiece from the first side, the length of the first modification line is greater than or equal to the distance between the second modification line and the surface of the first side of the workpiece. The device to be processed is placed in an etching solution for etching to form an inner channel within the device that runs along the preset processing path and covers the locations of the plurality of second modification lines. During the etching process, a plurality of first etching zones centered on the locations of the first modification lines are used to transfer the etching solution to a plurality of second etching zones centered on the locations of the second modification lines after being etched. The first etching zones of the plurality of first modification lines and the second etching zones of the plurality of second modification lines have overlapping areas. The spacing between any two adjacent second modification lines in the plurality of second modification lines is greater than or equal to half the width of the inner channel and less than or equal to 0.9 times the width of the inner channel; the spacing between any two adjacent first modification lines in the plurality of first modification lines is greater than or equal to twice the width of the inner channel and less than or equal to four times the width of the inner channel. The method of irradiating the device under work with a Bessel beam to form a plurality of first modification lines and a plurality of second modification lines in the device under work includes: An optical focusing module is used to focus a first laser beam emitted by a laser into a first Bessel focal line with a first focal depth. The first Bessel focal line is controlled to be guided to the device to be processed for laser modification. The first Bessel focal line is moved according to the preset processing path to form the plurality of first modification lines. The optical focusing module is used to focus the second laser emitted by the laser into a second Bessel focal line with a second focal depth. The second Bessel focal line is controlled to perform laser modification inside the device to be processed. The second Bessel focal line is moved according to the preset processing path to form the plurality of second modification lines. The length of the focal line is changed by using an optical focusing module.

2. The method according to claim 1, characterized in that, The extension direction of the first modification line and the plurality of second modification lines is perpendicular to the surface of the first side of the device to be processed.

3. The method according to any one of claims 1-2, characterized in that, The distance between the plurality of second modification lines and the surface of the first side of the device to be processed is equal, and the extension direction of the inner channel is parallel to the surface of the first side of the device to be processed.

4. The method according to any one of claims 1-2, characterized in that, The plurality of second modification lines include a first group of modification lines and a second group of modification lines. The inner channel covering the location of the first group of modification lines is a first inner channel, and the inner channel covering the location of the second group of modification lines is a second inner channel. The first inner channel is located between the surface of the first side of the device to be processed and the second inner channel. The first modification lines corresponding to the first group of modification lines and the first group of modification lines are distributed along a first processing path, and the first modification lines corresponding to the second group of modification lines and the second group of modification lines are distributed along a second processing path.

5. The method according to claim 4, characterized in that, When the plurality of first modification lines penetrate the first side portion of the device to be processed, the length of the first modification line is greater than the distance between the second set of modification lines and the surface of the first side of the device to be processed; or... The plurality of first modification lines include a third set of modification lines and a fourth set of modification lines. The third set of modification lines penetrates the device from a first side portion of the device to be processed, and the fourth set of modification lines penetrates the device from a second side portion of the device to be processed opposite to the first side surface. The length of the third set of modification lines is greater than the distance between the first set of modification lines and the first side surface of the device to be processed, and the length of the fourth set of modification lines is greater than the distance between the second set of modification lines and the second side surface of the device to be processed.

6. The method according to any one of claims 1-2, characterized in that, The length of the first modification line is greater than or equal to 1 mm and less than or equal to 2 mm, and the length of the plurality of second modification lines is greater than or equal to 0.1 mm and less than 1 mm.

7. The method according to any one of claims 1-2, characterized in that, The device to be processed includes a first side surface and a second side surface that are opposite each other; The position where the first Bessel focal line penetrates the device to be processed and the movement trajectory of the multiple first Bessel focal lines are determined by controlling the relative position of the optical focusing module and the device to be processed. The distance between the endpoint of the second Bessel focal line and the first side surface of the device to be processed, as well as the movement trajectory of the plurality of second Bessel focal lines, are determined by controlling the relative position of the optical focusing module and the device to be processed.

8. The method according to claim 7, characterized in that, The laser source of at least one of the first laser beam and the second laser beam is a femtosecond laser or a picosecond laser.

9. The method according to claim 7, characterized in that, The optical focusing module includes: a diffractive optical element type Bessel module, a depth-of-focus type Bessel module, or a beam expander type Bessel module.

10. The method according to any one of claims 1-2, characterized in that, The device to be processed is placed in an etching solution for etching, and is also used to form a first micropore centered on the location of the first modified line, the first micropore being in communication with the inner channel; the method further includes: At least a portion of the first micropores are filled.

11. An internal channel fabrication system, characterized in that, include: A laser is used to emit a laser beam; An optical focusing module is used to focus the laser beam to obtain a Bessel beam; Stage module, used to place the device to be processed; A movable module, which is connected to the optical focusing module or the stage module, so that the optical focusing module can move relative to the device to be processed; A control module is used to control the execution of the inner channel forming method as described in any one of claims 1-10.

Images