Circuit board laser windowing method, equipment, device and system

Abstract

The invention relates to a circuit board laser windowing method, equipment, device and system, and the method comprises the steps: controlling the center of a contour thinning laser spot to carry out the scanning on an insulating layer along a contour thinning track, so as to form a steep groove wall at the edge of the inner side of a preset windowing contour; and controlling the center of the filling scanning laser spot to scan on the insulating layer along a filling scanning track surrounded in the outline thinning track, so as to quickly remove the insulating layer in the preset windowing outline and further expose the conductive layer. According to the method, contour thinning laser spots with small spot sizes and large light intensity distribution unevenness are used for machining the edge of the inner side of a preset windowing contour, and filling scanning laser spots with large spot sizes and small light intensity distribution unevenness are used for conducting filling scanning on an insulating layer in the preset windowing contour; high-quality and high-efficiency windowing of the circuit board can be realized, and the problem of contradiction between quality and efficiency in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of laser processing of circuit boards, and particularly relates to a method, device, apparatus and system for laser windowing of circuit boards. Background Art

[0002] With the gradual maturity of the manufacturing technology of printed circuit boards, for the solder mask printing process of printed circuit boards, a photosensitive solder mask ink is pressed on the copper surface after the circuit is formed for use in the subsequent image transfer process, and at the same time, it protects the board surface in the subsequent process, prevents circuit oxidation and has the function of solder masking. Solder mask windowing refers to the size of the part of the copper that is exposed at the position where welding is required, that is, the size of the part without ink coverage. However, for the production of each type of circuit board, a corresponding exposure film is required, and the exposure parameters need to be adjusted accordingly according to different circuit boards. Inaccurate control by the operator of the exposure machine, film wrinkles, film black spots, etc. will all affect the final solder mask effect. Among them, exposure deviation is one of the main defects of the solder mask. Due to the complexity of human factors and other related process factors, it brings great potential risks to the control of the exposure deviation problem in solder mask production. This is where the advantages of laser windowing come into play. Laser windowing refers to a processing technology that uses a laser to remove the insulating layer in a local area on a circuit board to expose the conductive layer and form a window. Its advantages are as follows: 1) High precision: The laser beam can be focused into an extremely small spot, enabling high-precision windowing operations to ensure that the size and shape of the window highly match the design requirements. For example, when performing laser windowing on a PCB board, the windowing position and size can be accurately controlled to meet the welding and testing requirements of electronic components. 2) Strong flexibility: By programming, it is easy to achieve windowing of various complex shapes and patterns, and can quickly adapt to different design requirements without making complex molds.

[0003] However, the disadvantages of laser windowing of circuit boards are also obvious, mainly reflected in two aspects: low laser windowing efficiency and residual glue at the bottom of the groove. In fact, it is a contradiction between quality and efficiency. Generally speaking, high quality means low efficiency. Whether a laser windowing method can be found that can achieve both high quality and high-efficiency laser windowing is an urgent problem to be solved in the industry. Summary of the Invention

[0004] The present invention provides a method, device, apparatus and system for laser windowing of circuit boards to solve the contradiction between the quality and efficiency of laser windowing of circuit boards.

[0005] In a first aspect, the present invention provides a method for laser windowing of a circuit board, which controls a profile thinning laser spot and a filling scan laser spot to perform windowing processing on the circuit board according to a preset windowing profile; the circuit board at least includes a conductive layer and an insulating layer attached to the conductive layer; the light intensity distribution of the profile thinning laser spot and the light intensity distribution of the filling scan laser spot are both stronger in the central region than in the edge region, the size of the profile thinning laser spot is smaller than the size of the filling scan laser spot, and the flatness non-uniformity of the light intensity distribution of the profile thinning laser spot is greater than the flatness non-uniformity of the light intensity distribution of the filling scan laser spot;

[0006] The method for laser windowing of the circuit board includes:

[0007] Controlling the center of the profile thinning laser spot to scan along a profile thinning trajectory on the insulating layer to form a steep groove wall on the inner edge of the preset windowing profile; wherein, the shape of the profile thinning trajectory is the same as the shape of the preset windowing profile, and the profile thinning trajectory is shrunk relative to the preset windowing profile, and the shrunk distance is equal to the radius of the profile thinning laser spot;

[0008] Controlling the center of the filling scan laser spot to scan along a filling scan trajectory surrounded by the profile thinning trajectory on the insulating layer to quickly remove the insulating layer within the preset windowing profile, thereby exposing the conductive layer;

[0009] Among them, the profile thinning laser spot and the filling scan laser spot are controlled to scan according to a preset timing sequence, so as to quickly form a window with a steep groove wall on the circuit board.

[0010] In a second aspect, the present invention provides a circuit board laser windowing device for performing windowing processing on a circuit board according to a preset windowing profile; the circuit board at least includes a conductive layer and an insulating layer attached to the conductive layer; the circuit board laser windowing device includes:

[0011] A laser for generating a profile thinning laser beam and a filling scan laser beam;

[0012] A galvanometer scanning and flat field focusing device connected to the laser for scanning and focusing the profile thinning laser beam and the filling scan laser beam to output a scanned profile thinning laser spot and a filling scan laser spot; wherein, the light intensity distribution of the profile thinning laser spot and the light intensity distribution of the filling scan laser spot are both stronger in the central region than in the edge region, the size of the profile thinning laser spot is smaller than the size of the filling scan laser spot, and the flatness non-uniformity of the light intensity distribution of the profile thinning laser spot is greater than the flatness non-uniformity of the light intensity distribution of the filling scan laser spot;

[0013] A controller, which is connected to the galvanometer scanning and flat-field focusing device, is used to control the center of the contour thinning laser spot to scan along the contour thinning trajectory on the insulating layer, so as to form a steep groove wall on the inner edge of the preset windowing contour; wherein, the shape of the contour thinning trajectory is the same as the shape of the preset windowing contour, and the contour thinning trajectory is shrunk relative to the preset windowing contour, and the shrunk distance is equal to the radius of the contour thinning laser spot; control the center of the filling scanning laser spot to scan along the filling scanning trajectory surrounded by the contour thinning trajectory on the insulating layer, so as to quickly remove the insulating layer within the preset windowing contour, thereby exposing the conductive layer; specifically used to control the scanning of the contour thinning laser spot and the filling scanning laser spot according to a preset time sequence, so as to quickly form a window with a steep groove wall on the circuit board.

[0014] In a third aspect, the present invention provides a circuit board laser windowing device, including a processor, a memory, and a computer program stored in the memory and running on the processor. When the computer program runs, it implements the circuit board laser windowing method as described above.

[0015] In a fourth aspect, the present invention provides a circuit board laser windowing system, including a machine platform, and further including the circuit board laser windowing device and the circuit board laser windowing equipment as described above. The circuit board laser windowing device is electrically connected to the circuit board laser windowing equipment;

[0016] The machine platform is used to carry the circuit board;

[0017] The circuit board laser windowing device controls the circuit board laser windowing equipment to execute the circuit board laser windowing method as described above, so as to perform circuit board laser windowing processing on the circuit board carried on the machine platform.

[0018] The beneficial effects of the present invention are as follows: For a circuit board laser windowing method, equipment, device and system of the present invention, a contour thinning laser spot with a smaller spot size and a larger non-uniformity of light intensity distribution is used to process the inner edge of the preset windowing contour, and a filling scanning laser spot with a larger spot size and a smaller non-uniformity of light intensity distribution is used to perform filling scanning on the insulating layer within the preset windowing contour; due to the larger non-uniformity of the contour thinning laser spot, a steep and smooth groove wall can be formed, so that a good edge effect can be obtained, and basically no insulating material remains on the conductive layer at the bottom edge of the window; at the same time, due to the larger size of the filling scanning laser spot, the insulating layer within the preset windowing contour can be quickly and efficiently removed; therefore, the present invention can realize high-quality and high-efficiency circuit board windowing by using the cooperation of the contour thinning laser spot and the filling scanning laser spot, and solves the contradiction problem between quality and efficiency in the prior art. Description of the Drawings

[0019] Figure 1 This is a flowchart of a method for laser window opening on a circuit board according to the present invention;

[0020] Figure 2 This is a schematic structural diagram of a circuit board;

[0021] Figure 3 This is a schematic diagram of a contour thinning laser spot and a filling scan laser spot;

[0022] Figure 4 This is a schematic cross-sectional view of the contour thinning laser spot scanning the circuit board once;

[0023] Figure 5 This is a schematic cross-sectional view of the state of the contour thinning laser spot filling and scanning the circuit board;

[0024] Figure 6 This is a schematic cross-sectional view of the effect of the contour thinning laser spot filling and scanning the circuit board;

[0025] Figure 7 This is a schematic cross-sectional view of the filling scan laser spot scanning the circuit board once;

[0026] Figure 8 This is a schematic cross-sectional view of the filling scan laser spot filling and scanning the circuit board;

[0027] Figure 9 This is a schematic cross-sectional view of the contour thinning laser spot and the filling scan laser spot cooperating to scan the circuit board once;

[0028] Figure 10 This is a schematic cross-sectional view of the contour thinning laser spot and the filling scan laser spot cooperating to fill and scan the circuit board;

[0029] Figure 11 This is a schematic diagram of the contour thinning laser spot and the filling scan laser spot cooperating to scan on the insulating layer in the first embodiment;

[0030] Figure 12 This is a schematic diagram of the contour thinning laser spot and the filling scan laser spot cooperating to scan on the insulating layer in the second embodiment. Specific embodiments

[0031] The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0032] First aspect:

[0033] A method for laser windowing of a circuit board, which controls the contour thinning laser spot and the filling scanning laser spot according to a preset windowing contour to perform windowing processing on the circuit board; the circuit board at least includes a conductive layer and an insulating layer attached to the conductive layer; the light intensity distribution of the contour thinning laser spot and the light intensity distribution of the filling scanning laser spot are both stronger in the central region than in the edge region, the size of the contour thinning laser spot is smaller than the size of the filling scanning laser spot, and the unevenness of the light intensity distribution of the contour thinning laser spot is greater than the unevenness of the light intensity distribution of the filling scanning laser spot;

[0034] As Figure 1 shown, the method for laser windowing of the circuit board includes:

[0035] Controlling the center of the contour thinning laser spot to scan along the contour thinning trajectory on the insulating layer to form a steep groove wall at the inner edge of the preset windowing contour; wherein, the shape of the contour thinning trajectory is the same as the shape of the preset windowing contour, and the contour thinning trajectory is shrunk relative to the preset windowing contour, and the shrunk distance is equal to the radius of the contour thinning laser spot;

[0036] Controlling the center of the filling scanning laser spot to scan along the filling scanning trajectory surrounded by the contour thinning trajectory on the insulating layer to quickly remove the insulating layer within the preset windowing contour, thereby exposing the conductive layer;

[0037] Among them, the contour thinning laser spot and the filling scanning laser spot are controlled to scan according to a preset timing sequence, so as to quickly form a window with a steep groove wall on the circuit board.

[0038] Specifically, the preset timing sequence means that the contour thinning processing of the contour thinning laser spot and the filling scanning processing of the filling scanning laser spot can be carried out successively or simultaneously.

[0039] In some embodiments, the contour thinning processing of the contour thinning laser spot can be controlled first, and then the filling scanning processing of the filling scanning laser spot can be controlled; that is, the contour thinning laser spot and the filling scanning laser spot are controlled to scan according to a preset timing sequence, specifically:

[0040] First, control the center of the contour thinning laser spot to scan along the contour thinning trajectory on the insulating layer to perform thinning processing on the insulating layer along the inner edge of the preset windowing contour, forming a contour thinning area with a steep groove wall, and the thinned thickness is less than or equal to the thickness of the insulating layer corresponding to the contour thinning trajectory;

[0041] Then, control the center of the filling scan laser spot to scan along the filling scan trajectory on the insulating layer, so as to quickly remove the insulating layer within the preset windowing contour to expose the conductive layer; wherein, when the center of the filling scan laser spot scans along the outermost trajectory of the filling scan trajectory, the edge of the filling scan laser spot covers the contour thinning area and is sufficient to remove the insulating layer in the contour thinning area to expose the conductive layer, thereby forming a window with steep sidewalls.

[0042] In some other embodiments, the filling scan processing of the filling scan laser spot can be controlled first, and then the contour thinning processing of the contour thinning laser spot can be controlled; that is, control the scanning of the contour thinning laser spot and the filling scan laser spot according to a preset time sequence, specifically:

[0043] First, control the center of the filling scan laser spot to scan along the filling scan trajectory on the insulating layer, so as to quickly remove the insulating layer within the preset windowing contour to expose the conductive layer, and form a window with gentle sidewalls along the inner edge line of the preset windowing contour;

[0044] Then, control the center of the contour thinning laser spot to scan along the contour thinning trajectory to thin the gentle sidewalls along the inner edge line of the preset windowing contour, thereby forming a window with steep sidewalls.

[0045] In some other embodiments, the filling scan processing of the filling scan laser spot can also be controlled while controlling the contour thinning processing of the contour thinning laser spot; that is, control the scanning of the contour thinning laser spot and the filling scan laser spot according to a preset time sequence, specifically:

[0046] Control the center of the contour thinning laser spot to scan along the contour thinning trajectory on the insulating layer to form steep sidewalls at the inner edge of the preset windowing contour;

[0047] At the same time, control the center of the filling scan laser spot to scan along the filling scan trajectory to quickly remove the insulating layer within the preset windowing contour, thereby exposing the conductive layer and forming a window with steep sidewalls.

[0048] Regardless of which of the above preset timings is used to control the scanning of the profile thinning laser spot and the filling scanning laser spot, the inner edge of the preset window profile is processed by the profile thinning laser spot with a relatively small spot size and a relatively large unevenness of the light intensity distribution, and the insulating layer within the preset window profile is filled and scanned by the filling scanning laser spot with a relatively large spot size and a relatively small unevenness of the light intensity distribution; due to the relatively large unevenness of the profile thinning laser spot, a steep and smooth groove wall can be formed, so that a good edge effect can be obtained, and basically no insulating material remains on the conductive layer at the bottom edge of the window; at the same time, due to the relatively large size of the filling scanning laser spot, the insulating layer within the preset window profile can be removed quickly and efficiently; thus, by using the cooperation of the profile thinning laser spot and the filling scanning laser spot, the present invention can achieve high-quality and high-efficiency window opening of the circuit board, and solve the contradiction problem between quality and efficiency in the prior art.

[0049] Figure 2 FIG. 4 is a schematic structural diagram of the circuit board of this embodiment, and the circuit board includes a conductive layer 2 and an insulating layer 1 attached to the conductive layer 2.

[0050] Figure 3 FIG. 5 is a schematic diagram of the profile thinning laser spot and the filling scanning laser spot; wherein:

[0051] The profile thinning laser spot 3 is as Figure 3 (a) shows, its light intensity distribution is strong in the center and weak at the edge, the transverse light intensity distribution of the spot presents a Gaussian distribution or an approximate Gaussian distribution, and the focused spot is relatively small, generally less than 50 microns, and the light intensity drops rapidly from the center of the spot to the edge of the spot.

[0052] The filling scanning laser spot 4 is as Figure 3 (b) shows, its light intensity distribution is also strong in the center and weak at the edge, generally the spot diameter is designed to be greater than 50 microns and less than 200 microns, and the light intensity drops slowly from the center of the spot to the edge of the spot, presenting a relatively flat spot light intensity distribution.

[0053] Therefore, the unevenness refers to the degree of light intensity reduction from the center of the laser spot to the edge of the spot in the transverse light intensity distribution of the laser spot on the surface of the insulating layer of the circuit board.

[0054] The combined laser spot formed by combining the profile thinning laser spot 3 and the filling scanning laser spot 4 is as Figure 3 (c) shows, and the profile thinning laser spot 3 and the filling scanning laser spot 4 can be respectively controlled to perform laser scanning in their respective scanning trajectories through a scanning galvanometer, wherein the profile thinning laser spot 3 scans the outer contour of the laser window, and the filling scanning laser spot 4 is responsible for filling and scanning the inner area of the laser window.

[0055] Figure 4 Schematic cross-section of a single scan of a contour-thinned laser spot on a circuit board; among which, Figure 4 (a) Schematic cross-section of the state when the contour-thinned laser spot scans the circuit board once; Figure 4 (b) Schematic cross-section of the effect after the contour-thinned laser spot scans the circuit board once. After the contour-thinned laser spot 3 scans on the insulating layer 1 of the circuit board, a first groove 32 is formed. The first groove 32 has a first groove left slope 31 and a first groove right slope 33; due to the small focused spot of the contour-thinned laser spot 3 and the steep light intensity distribution within the spot range, both the first groove left slope 31 and the first groove right slope 33 are relatively steep; for example, if the contour-thinned laser spot 3 uses a 30-micron ultraviolet laser focused spot and the thickness of the insulating layer 1 is 50 microns, the horizontal lengths of both the first groove left slope 31 and the first groove right slope 33 are generally less than 20 microns.

[0056] If the contour-thinned laser spot 3 is used to perform filling scans on the insulating layer 1 of the circuit board, its scanning state is as Figure 5 shown; the effect after the contour-thinned laser spot 3 performs filling scans on the insulating layer 1 of the circuit board is as Figure 6 shown. After the contour-thinned laser spot 3 performs filling scans on the insulating layer 1 of the circuit board, a first opening 35 is formed. The first opening 35 has a first opening left slope 34 and a first opening right slope 36. It can be seen that both the first opening left slope 34 and the first opening right slope 36 are relatively steep, meeting the application requirements. However, the first opening 35 requires a total of 12 filling scans by the contour-thinned laser spot 3, with a large filling density and low processing efficiency, unable to meet the requirements of high-efficiency laser windowing production.

[0057] Therefore, if only a small spot with a steep light intensity distribution (i.e., the contour-thinned laser spot 3) is used for laser windowing of the surface insulating layer, a good edge effect (steep and smooth) can be obtained, but the filling scan efficiency is low and it cannot meet the requirements of high-efficiency laser opening production.

[0058] In order to improve the laser filling scan efficiency of the insulating layer 1 on the surface of the circuit board, a large spot with a gentle light intensity distribution (i.e., the filling scan laser spot 4) can be used for filling scans, as Figure 7 shown; among which, Figure 7 (a) Schematic cross-section of the state when the filling scan spot scans the circuit board once; Figure 7(b) is a schematic cross-sectional view of the effect after a single scan of the filling scan laser spot on the circuit board. After the filling scan laser spot 4 scans on the insulating layer 1 of the circuit board, a second groove 42 is formed. The second groove 42 has a left slope 41 of the second groove and a right slope 43 of the second groove. Since the filling scan laser spot 4 has a large focused spot and the light intensity distribution within the spot range is gentle, both the left slope 41 of the second groove and the right slope 43 of the second groove are relatively gentle. For example, if the filling scan laser spot 4 uses a 100-micron ultraviolet laser focused spot and the thickness of the insulating layer 1 is 50 microns, the horizontal length of both the left slope 41 of the second groove and the right slope 43 of the second groove generally exceeds 50 microns.

[0059] If the filling scan laser spot 4 is used to perform filling scan on the insulating layer 1 of the circuit board, as Figure 8 shown. Among them, Figure 8 (a) is a cross-sectional view of the state when the filling scan laser spot 4 performs filling scan on the insulating layer 1 of the circuit board. With the same laser windowing size, 12 spot filling scans are required using the profile thinning laser spot 3 (please refer to Figure 5 ), while only two spot filling scans are sufficient using the filling scan laser spot 4 (please refer to Figure 8 (a)); it can be seen that using the filling scan laser spot 4 for filling scan can achieve extremely high laser windowing efficiency, which is very in line with the expectations of mass laser windowing production. Figure 8 (b) is a cross-sectional view of the effect after the filling scan laser spot 4 performs filling scan on the insulating layer 1 of the circuit board; after the filling scan laser spot 4 performs filling scan on the insulating layer 1 of the circuit board, a second opening 45 is formed. The second opening 45 has a left slope 44 of the second opening and a right slope 46 of the second opening. The left slope 44 of the second opening and the right slope 46 of the second opening are relatively gentle, resulting in residual glue at the bottom of the window and not meeting the application requirements.

[0060] Therefore, if a large spot with a gentle light intensity distribution (i.e., the filling scan laser spot 4) is simply used for laser windowing of the surface insulating layer, the filling scan efficiency is high, and an efficient laser windowing production effect can be obtained. However, the window edge is too gentle, and the conductive layer within the windowing area is blocked by the insulating material on the gentle edge slope, resulting in residual glue at the bottom of the window and not meeting the production technical requirements.

[0061] Based on the above statement, the profile thinning laser spot 3 and the filling scan laser spot 4 can be combined at an appropriate spot center distance and scanned once on the insulating layer 1, as Figure 9 shown. Among them, Figure 9 (a) is a cross-sectional view of the state of a single scan of the profile thinning laser spot and the filling scan laser spot on the insulating layer, Figure 9(b) is a cross-sectional view of the effect of a contour-thinning laser spot and a fill-scan laser spot during a single scan on the insulating layer; after the contour-thinning laser spot 3 and the fill-scan laser spot 4 perform a single scan on the insulating layer 1, a third groove 6 is formed. The third groove 6 has a left slope 5 and a right slope 7 of the third groove. It can be seen that on the same insulating layer 1, the left slope 5 of the third groove scribed by the laser spot with a steep light intensity distribution (contour-thinning laser spot 3) is steep; the right slope 7 of the third groove scribed by the laser spot with a gentle light intensity distribution (fill-scan laser spot 4) is gentle.

[0062] Figure 10 is a cross-sectional view of the contour-thinning laser spot and the fill-scan laser spot during the fill-scan on the insulating layer; among them, Figure 10 (a) is a cross-sectional view of the state of the contour-thinning laser spot and the fill-scan laser spot during the fill-scan on the insulating layer. The contour-thinning laser spot 3 performs a laser windowing contour scan, and its core function is to obtain relatively steep windowing groove walls; the insulation layer at the contour edge is thinned, which is convenient for the subsequent fill-scan laser spot 4 to further thin the area with weak light at the edge, exposing the conductive layer 2. The fill-scan laser spot 4 performs a laser windowing internal fill-scan. Its main feature is that the fill-scan spacing is large, and it can obtain a fill-scan within the high-efficiency laser windowing area, efficiently remove the insulating material in the corresponding area, and expose the conductive layer 2; another important function is that by using the peripheral light of the fill-scan laser spot 4, the remaining insulating material after the cleaning by the contour-thinning laser spot 3 can be further removed, exposing the conductive layer 2, and finally completing the laser windowing. During the laser windowing process, the cooperation between the fill-scan laser spot 4 and the contour-thinning laser spot 3 is crucial. If there is no thinning of the insulating material by the contour-thinning laser spot 3 in the processed area, the laser windowing will have too large an edge slope, or rather, there will be a residual insulating layer material in the form of a slope layer in the contour edge area of the laser windowing area, which is directly judged as unqualified.

[0063] Figure 10 (b) is a cross-sectional view of the effect after the contour-thinning laser spot and the fill-scan laser spot perform the fill-scan on the insulating layer. After the contour-thinning laser spot 3 and the fill-scan laser spot 4 perform a combined scan on the insulating layer 1, a third window 9 is formed. The third window 9 has a left slope 8 and a right slope 10 of the third window; since the fill-scan laser spot 4 is a large spot, the efficiency of removing the insulating layer material by the fill-scan is very high; without the cooperation of the contour-thinning laser spot 3, there will be residual insulating layer materials with large slopes on both the left and right sides of the third window 9 (please refer to Figure 8(The second left slope 44 and the second right slope 46 in (b)); if, in cooperation with the profile-thinning laser spot 3, a part of the insulating material is removed in advance in the two side regions of the third opening 9 due to the profile-thinning laser spot 3, then basically no insulating material remains on both sides of the third opening 9, thereby obtaining a steeper third left slope 8 and a steeper third right slope 10 of the opening. This cooperation relationship between the profile-thinning laser spot 3 and the fill-scan laser spot 4 simultaneously obtains steep opening groove walls and high laser opening efficiency, solves the pain points in the industry, and has unexpected effects.

[0064] A small spot with a steep light intensity distribution has the advantage of having a steep groove wall for scribing, but has the disadvantage of low fill-scan efficiency; while a large spot with a gentle light intensity distribution has the advantage of high fill-scan efficiency, but has the disadvantage of a gentle slope of the groove wall for scribing. The present invention gives play to the advantages of the two laser spots, uses the profile-thinning spot to perform a laser opening profile scan, thins the surface insulating layer inside the profile, and obtains a steep laser opening groove wall; while using the fill-scan laser spot to perform a high-efficiency fill scan of the surface insulating layer in the laser opening area, removes the insulating material, and uses the weak light at the edge of the spot to further remove the thinned insulating material in the scan area of the profile-thinning spot, exposing the conductive layer, and completing high-efficiency and high-quality laser opening. Using the laser at the edge of the fill-scan laser spot for processing the thinned material area also avoids the edge of the fill-scan laser spot being designed outside the opening profile, thereby damaging the insulating material outside the opening profile.

[0065] A preferred embodiment of the method for laser opening of a circuit board according to the present invention is as follows:

[0066] Preferably, the laser peak power density of the profile-thinning laser spot and / or the fill-scan laser spot is not sufficient to process the conductive layer; or,

[0067] The laser peak power density of the profile-thinning laser spot and / or the fill-scan laser spot is sufficient to process the conductive layer, and the profile-thinning laser spot and / or the fill-scan laser spot interact with the conductive layer to form a plasma spark, and the plasma spark scatters and shields the profile-thinning laser spot and / or the fill-scan laser spot to prevent the conductive layer from being further etched by the profile-thinning laser spot and / or the fill-scan laser spot.

[0068] Since the laser spot for contour thinning and the laser spot for filling and scanning both have a higher light intensity at the center than at the edges, both the laser spot for contour thinning and the laser spot for filling and scanning can process the insulating layer. However, the peak power density of the laser beam of the spot is not sufficient to process the conductive layer under the insulating layer; or, the peak power density of the laser beam of the spot is too high, which can not only process the insulating layer but also the conductive layer. However, due to the too high peak power of the laser, a strong plasma spark is formed at the moment of the interaction between the spot and the conductive layer material. This plasma spark scatters and shields the subsequent transmitted laser, thereby blocking to a certain extent the further etching of the conductive layer by the laser spot for contour thinning and the laser spot for filling and scanning.

[0069] Preferably, when the peak power density of the laser beam of the laser spot for contour thinning and / or the laser spot for filling and scanning is sufficient to process the conductive layer, by controlling the scanning speed, the number of scans, the scanning filling density, and the laser parameters of the laser spot for contour thinning and / or the laser spot for filling and scanning, the laser etching amount of the conductive layer within the preset window profile is made within 5 micrometers.

[0070] Preferably, when controlling the center of the laser spot for contour thinning to scan along the contour thinning trajectory on the insulating layer, stop the thinning process when the conductive layer is exposed, and form a contour thinning area with a steep groove wall.

[0071] When controlling the center of the laser spot for filling and scanning to scan along the filling and scanning trajectory on the insulating layer, control the scanning speed, the number of scans, the scanning filling density, and the laser parameters of the laser spot for filling and scanning, so that the insulating layer within the preset window profile is directly delaminated from the conductive layer.

[0072] Preferably, when controlling the center of the laser spot for contour thinning to scan along the contour thinning trajectory on the insulating layer, the laser spot for contour thinning is absorbed by the insulating layer to remove the insulating layer along the inner side line of the preset window profile.

[0073] When controlling the center of the laser spot for filling and scanning to scan along the filling and scanning trajectory on the insulating layer, the laser spot for filling and scanning transmits or partially transmits the insulating layer and interacts with the conductive layer to form a plasma spark. Furthermore, the explosion force of the plasma spark eruption directly delaminates the insulating layer within the preset window profile from the conductive layer.

[0074] The filled scanning laser spot has a large size and a relatively low peak power. By selecting an appropriate laser wavelength, it can transmit or partially transmit the insulating layer material and directly act on the surface of the conductive layer to generate plasma sparks. The explosion force of the eruption of these plasma sparks directly peels the insulating layer from the conductive layer. When the insulating layer is peeled off, the airflow blown or pumped on the surface of the circuit board will carry away the peeled insulating layer material. This laser windowing method has the highest laser windowing efficiency, the best flatness of the windowing groove bottom, and the lowest probability of residual glue.

[0075] Preferably, before controlling the center of the filled scanning laser spot to scan along the filled scanning trajectory on the insulating layer, it further includes: controlling the profile thinning laser spot to scan the insulating layer island surrounded by the profile thinning trajectory to divide the insulating layer island surrounded by the profile thinning trajectory into multiple sub-regions;

[0076] When controlling the center of the filled scanning laser spot to scan along the filled scanning trajectory on the insulating layer, control the scanning speed, scanning times, scanning filling density, and laser parameters of the filled scanning laser spot so that the insulating layer of all sub-regions within the insulating layer island surrounded by the profile thinning trajectory is directly delaminated from the conductive layer.

[0077] Dividing the area within the insulating layer island surrounded by the profile thinning trajectory into multiple sub-regions is to divide the large-area peeled material into small-area peeled materials, which is beneficial for the laser windowing equipment to pump or suck away the peeled insulating material by air extraction.

[0078] Preferably, within the processing range of one scanning area or one processing platform area, control the profile thinning laser spot to jump between different windowings, and first perform profile thinning processing on each windowing area. After the profile thinning processing of all windowing areas within the processing range exposes the conductive layer, then control the filled scanning laser spot to delaminate the insulating layer within the contour of each window within the processing range.

[0079] After the profile thinning processing of all windowing areas within the processing range exposes the conductive layer, then control the filled scanning laser spot to delaminate the insulating layer within the contour of each window within the processing range, which can prevent the insulating material peeled off by the previous windowing from covering the subsequent windowing areas to be opened and blocking the processing of the insulating layer by the profile thinning laser spot. And the delamination processing mechanism of the filled scanning laser spot is not afraid of being blocked by the peeled insulating material. As mentioned above, the peeled insulating material is transparent or semi-transparent to the filled scanning laser spot.

[0080] For clearer illustration, further description is provided. Within each scanning area or across the entire circuit board, the contour-thinning laser spot first completes scanning of all laser window contours until the conductive layer is exposed, and then the filling-scanning laser spot performs laser processing to delaminate the surface insulating layer of the laser window area from the conductive layer. This processing method will have better reliability. If the laser windowing is carried out by the method of laser delamination, the insulating layer in the delaminated window area may block the subsequent laser beam for laser windowing processing. For subsequent laser windowing of other windows, mainly the contour-thinning laser spot needs to reliably complete scanning of all laser window contours until the conductive layer is exposed. This is the laser etching process, and it is necessary to avoid blocking the laser as much as possible. The laser processing of delaminating the insulating layer of the laser window area from the conductive layer by the filling-scanning laser spot is a process of laser transmitting through the insulating layer and generating plasma sparks by impacting on the surface of the conductive layer. Even if some areas are blocked, it does not affect the delamination of the insulating layer within the entire laser window area. Moreover, the insulating layer is transmissive or partially transmissive to the filling-scanning laser spot (transmission means transparent or non-absorbing, indicating that the filling-scanning laser spot can pass through or partially pass through the insulating layer to reach the conductive layer). Therefore, it does not matter even if it is blocked.

[0081] Preferably, after the filling-scanning laser spot directly delaminates the insulating layer within the preset window contour from the conductive layer, it further includes: performing sandblasting on the circuit board.

[0082] Preferably, the contour-thinning laser spot is a circular spot with a diameter less than 50 microns, and the filling-scanning laser spot is a circular spot with a diameter less than 300 microns.

[0083] The smaller the contour-thinning laser spot, the steeper the sidewall of the scribed groove. However, it is more sensitive to the fitting error of the movement trajectory of the filling-scanning laser spot, and it is easier to generate residual glue at the junction between the two spots. The larger the filling-scanning laser spot, the higher the filling-scanning efficiency and the higher the laser windowing efficiency. However, the slope of the edge of the scribed groove is longer. At this time, one contour-thinning laser spot may not be enough to fill this scanning range. Sometimes two or three, preferably equally spaced outer contour similar-shaped contour-thinning laser spots are needed for filling to cover the slope of the edge of the groove scribed by the filling-scanning laser spot. This further tests the matching degree of the trajectories of the two spots. Therefore, there is a compromise choice for the sizes of the two spots.

[0084] Preferably, the contour-thinning laser spot is a Gaussian beam orthogonally focused spot, and the filling-scanning laser spot is a Gaussian beam defocused focused spot.

[0085] These two energy distribution spots, namely the Gaussian beam orthogonally focused spot and the Gaussian beam defocused focused spot, are the easiest to obtain and are the most preferred spot combinations used in the present invention.

[0086] Preferably, the contour thinning laser spot and the filling scan laser spot are obtained by two different laser beams passing through different external optical paths and different focusing systems, or by two different laser beams passing through different external optical paths and the same focusing system, or by dynamically adjusting the laser spot size of the same Gaussian beam through a dynamic focusing system.

[0087] Laser parameters include laser average power, laser pulse energy, laser pulse repetition frequency, laser pulse width, laser beam quality factor, etc. The dynamic focusing system, that is, the control system that controls the dynamic change of the laser focusing spot position, can dynamically change the laser spot size of the laser beam on the surface of the insulating layer of the circuit board.

[0088] Preferably, the contour thinning laser spot and / or the filling scan laser spot is a laser beam shaping spot.

[0089] Preferably, the contour thinning laser spot and the filling scan laser spot are respectively obtained by scanning and focusing the contour thinning laser beam and the filling scan laser beam through the same set of scanning galvanometers and flat-field focusing lenses; the distance between the centers of the contour thinning laser spot and the filling scan laser spot is less than 40 millimeters.

[0090] The flat-field focusing lens is installed behind the scanning galvanometer. The laser beam first passes through the galvanometer and then passes through the flat-field focusing lens and projects onto the insulating layer on the surface of the circuit board.

[0091] Preferably, the contour thinning laser spot and the filling scan laser spot are combined into a combined laser spot, and the center distance between the contour thinning laser spot and the filling scan laser spot is less than the sum of the radii of the contour thinning laser spot and the filling scan laser spot.

[0092] Among them, the combined laser spot is as shown in Figure 3 (c).

[0093] Preferably, the contour thinning laser spot is within the filling scan laser spot range.

[0094] Preferably, the contour thinning laser beam and the filling scan laser beam are obtained by switching the same laser through an optical switch to different optical paths; or,

[0095] The contour thinning laser beam and the filling scan laser beam are generated by two independent lasers.

[0096] Preferably, the contour thinning laser beam and / or the filling scan laser beam is a nanosecond laser beam or an ultrafast laser beam.

[0097] Ultrafast lasers include sub-nanosecond lasers, picosecond lasers, femtosecond lasers, etc. It is easier to obtain a clean laser window groove bottom morphology using ultrafast lasers.

[0098] Preferably, the profile thinning laser beam and the filling scanning laser beam may be laser beams of the same wavelength or laser beams of different wavelengths.

[0099] The same laser wavelength facilitates galvanometer control; different laser wavelengths enable laser microprocessing of different materials.

[0100] Preferably, the insulating layer is composed of a single insulating material, or a plurality of different single insulating materials stacked together, or a plurality of different insulating materials mixed together;

[0101] The material of the conductive layer is any one or more combinations of copper, aluminum, gold, silver, nickel, chromium, beryllium and titanium.

[0102] Generally, the conductive layer is a copper layer, and the insulating layer is composed of two layers, a layer of polyimide (PI) and a layer of adhesive, and the adhesive layer bonds the polyimide layer and the copper layer together.

[0103] Preferably, the shape of the filling scanning track is any one or more combinations of a U-shaped, an I-shaped, a field-shaped, a T-shaped and a dot-matrix filling track.

[0104] Preferably, the preset window opening profile is a combination of one or more of a triangle, a square, and a circle.

[0105] Preferably, the length or width of the preset window opening profile is greater than 50 microns and less than 10 millimeters.

[0106] The method of the present invention is described below with reference to specific examples.

[0107] Example 1:

[0108] Figure 11 It is a schematic diagram of the coordinated scanning of the contour thinning laser spot and the filling scanning laser spot on the insulating layer in the first embodiment.

[0109] In this embodiment, the insulating layer 1 in the circuit board is composed of two layers of materials, namely 25-micron polyimide (PI) and 25-micron epoxy adhesive, stacked on top of each other. The conductive layer 2 is a copper layer with a thickness of 18 microns. For the convenience of drawing in the figure, the thickness ratio of the insulating layer 1 and the conductive layer 2 is distorted, please ignore it. The contour thinning laser beam has a laser wavelength of 355 nm, a pulse width of 30 ns, a tabletop laser average power of 8 W, and a pulse repetition frequency of 100 kHz. The contour thinning laser beam enters the scanning galvanometer after passing through the laser beam combiner, and is focused on the insulating layer 1 of the circuit board through the flat-field focusing lens, forming a contour thinning laser spot 3 with a spot diameter of 30 microns. The contour thinning laser spot 3 is a circular Gaussian focused spot. The filling and scanning laser beam has a laser wavelength of 355 nm, a pulse width of 15 ps, a tabletop laser average power of 20 W, and a pulse repetition frequency of 300 kHz. The filling and scanning laser beam enters the scanning galvanometer after passing through the laser beam combiner, and is defocused on the insulating layer 1 of the circuit board through the flat-field focusing lens, forming a filling and scanning laser spot 4. The filling and scanning laser spot 4 is a circular Gaussian defocused spot with a spot diameter of 120 microns. The scanning galvanometer uses a scan lab ultraviolet galvanometer with a scanning speed of 1000 mm per second and a jump speed of 3000 mm per second. The flat-field focusing lens uses a sill flat-field focusing lens, which is a telecentric flat-field focusing lens with a focal length of 100 mm and a wavelength of 355 nm.

[0110] Specifically, Figure 11 (a) is a plan view of the contour thinning laser spot and the filling and scanning laser spot scanning in cooperation on the insulating layer in the first embodiment; among them, the center of the contour thinning laser spot 3 scans along the contour thinning trajectory 12 inside the preset windowing contour 11, and the center of the filling and scanning laser spot 4 scans along the filling and scanning trajectory 13. The width of the preset windowing contour 11 is 300 microns and the length is 600 microns. The width of the contour thinning trajectory 12 is 270 microns and the length is 570 microns. The distance of inward contraction relative to the preset windowing contour 11 is equal to the radius of the contour thinning laser spot 3. The filling pitch of the filling and scanning trajectory 13 is 60 microns, ensuring that when cleaning the periphery, the weak energy laser at the edge of the filling and scanning laser spot 4 can remove the remaining insulating material after the contour thinning by the contour thinning laser spot 3. The cross-section of the effect after the contour thinning laser spot and the filling and scanning laser spot scan in cooperation on the insulating layer is as Figure 11 (b) shows that the horizontal width of the slope at the inner edge of the preset windowing contour 11 is 15 microns, and the bottom of the windowing groove is clean without residual insulating material.

[0111] Example two:

[0112] Figure 12 It is a schematic diagram of the contour thinning laser spot and the filling and scanning laser spot scanning in cooperation on the insulating layer in the second embodiment.

[0113] In this embodiment, the contour thinning laser beam has a laser wavelength of 532 nm, a pulse width of 15 picoseconds, a tabletop laser average power of 15 W, and a pulse repetition frequency of 200 kHz. The contour thinning laser beam enters a scanning galvanometer (not shown in the figure) after passing through a laser beam combiner, and is focused on the surface of the insulating layer 1 of the circuit board through a flat-field focusing lens, forming a contour thinning laser spot 3 with a spot diameter of 40 μm. The contour thinning laser spot 3 is a circular Gaussian focused spot. The filling and scanning laser beam has a laser wavelength of 532 nm, a pulse width of 10 picoseconds, a tabletop laser average power of 5 W, and a pulse repetition frequency of 200 kHz. The filling and scanning laser beam enters a scanning galvanometer (not shown in the figure) after passing through a laser beam combiner, and is defocused on the surface of the insulating layer 1 of the circuit board through a flat-field focusing lens, forming a filling and scanning laser spot 4. The filling and scanning laser spot 4 is a circular Gaussian defocused spot with a spot diameter of 240 μm. The scanning galvanometer uses a scanlab green laser galvanometer with a scanning speed of 1500 mm per second and a jump speed of 3000 mm per second. The flat-field focusing lens uses a sill flat-field focusing lens, which is a telecentric flat-field focusing lens with a focal length of 100 mm and a wavelength of 532 nm.

[0114] Specifically, Figure 12 (a) is a plan view of the contour thinning laser spot and the filling and scanning laser spot cooperating and scanning on the insulating layer in Embodiment 2; wherein, the center of the contour thinning laser spot 3 scans along the contour thinning track 12 inside the preset windowing contour 11, and the center of the filling and scanning laser spot 4 scans along the filling and scanning track 13. The width of the preset windowing contour 11 is 300 μm, and the length is 600 μm. The width of the contour thinning track 12 is 260 μm, and the length is 560 μm. The distance of inward contraction relative to the preset windowing contour 11 is equal to the radius of the contour thinning laser spot 3.

[0115] After the center of the contour thinning laser spot 3 scans along the contour thinning track 12 inside the preset windowing contour 11, an annular groove 37 is formed, as Figure 12 (b) shows that the inside of the annular groove 37 is the insulating layer 101 to be removed.

[0116] The filling and scanning laser spot 4 transmits or partially transmits the insulating layer 101 to be removed, as Figure 12 (c) shows that when the filling and scanning laser spot 4 reaches the surface of the conductive layer 2, the conductive layer 2 absorbs the laser and forms a plasma spark 4a, which is equivalent to a violent expansion in a closed environment. This expansion explosion force follows the filling and scanning laser spot 4 along the filling and scanning track 13 to scan, generating a following plasma explosion track and space until the insulating layer 101 to be removed is completely peeled off from the surface of the conductive layer 2, as Figure 12 (d) shows, and the laser windowing profile effect is completed as Figure 12As shown in (e), the horizontal width of the inner edge slope of the preset windowing contour 11 is less than 20 microns, the bottom of the windowing groove is clean, and there is no residue of insulating material.

[0117] The filling scan laser spot 4 directly transmits the insulating layer 101 to be removed, exciting the conductive layer metal plasma spark 4a to complete the overall peeling of the insulating layer 101 to be removed. On the one hand, the mechanism is that the insulating layer material is partially transparent to the laser (that is, the insulating material does not absorb or partially absorbs the laser, and the laser directly transmits through the insulating layer to the surface of the conductive layer). On the other hand, the transmitted laser beam excites plasma sparks on the surface of the conductive layer, generating a plasma explosion in the closed space, thereby directly peeling the insulating material from the surface of the conductive layer.

[0118] In summary, in this embodiment, a contour-thinning laser spot is used to obtain a steep laser windowing groove wall, and the filling scan laser spot, on the one hand, removes the remaining insulating material in the scanning area of the contour-thinning spot, and at the same time peels the insulating layer in the filling scan area through laser scanning. This laser windowing method for insulating layer peeling further greatly improves the laser windowing efficiency.

[0119] Second aspect:

[0120] A laser windowing device for a circuit board, which is used to perform windowing processing on the circuit board according to a preset windowing contour; the circuit board at least includes a conductive layer and an insulating layer attached to the conductive layer; the laser windowing device for the circuit board includes:

[0121] A laser, which is used to generate a contour-thinning laser beam and a filling scan laser beam;

[0122] A galvanometer scanning and flat-field focusing device, which is connected to the laser and is used to scan and focus the contour-thinning laser beam and the filling scan laser beam to output a scanned contour-thinning laser spot and a filling scan laser spot; wherein, the light intensity distribution of the contour-thinning laser spot and the light intensity distribution of the filling scan laser spot are both stronger in the central region than in the edge region, the size of the contour-thinning laser spot is smaller than the size of the filling scan laser spot, and the unevenness of the light intensity distribution of the contour-thinning laser spot is greater than the unevenness of the light intensity distribution of the filling scan laser spot;

[0123] A controller, which is connected to the galvanometer scanning and flat-field focusing device, is used to control the center of the profile-thinning laser spot to scan along the profile-thinning trajectory on the insulating layer, so as to form a steep groove wall on the inner edge of the preset windowing profile; wherein, the shape of the profile-thinning trajectory is the same as the shape of the preset windowing profile, and the profile-thinning trajectory is shrunk relative to the preset windowing profile, and the shrinking distance is equal to the radius of the profile-thinning laser spot; control the center of the filling-scanning laser spot to scan along the filling-scanning trajectory enclosed within the profile-thinning trajectory on the insulating layer, so as to quickly remove the insulating layer within the preset windowing profile, thereby exposing the conductive layer; specifically used to control the scanning of the profile-thinning laser spot and the filling-scanning laser spot according to a preset timing sequence, so as to quickly form a window with a steep groove wall on the circuit board.

[0124] In addition, the controller can also be connected to a laser, and is used to control the laser or an external optical path active optical device, and further control the laser parameters of the profile-thinning laser spot and the filling-scanning laser spot.

[0125] A laser windowing device for a circuit board according to the present invention further has the following preferred solutions:

[0126] Preferably, the controller controls the flat-field focusing and galvanometer scanning device to scan the profile-thinning laser spot and the filling-scanning laser spot in the same coordinate system, or controls the flat-field focusing and galvanometer scanning device to scan the profile-thinning laser spot and the filling-scanning laser spot separately in different coordinate systems.

[0127] The same coordinate system means that for the scanning of the profile-thinning laser spot and the filling-scanning laser spot, the galvanometer shares a galvanometer calibration table. For example, the galvanometer is calibrated using the profile-thinning laser spot, and then when the filling-scanning laser spot is scanned, the galvanometer uses the above-mentioned galvanometer calibration table.

[0128] Different coordinate systems mean that the galvanometer is calibrated using the profile-thinning laser spot to obtain the galvanometer calibration table corresponding to the profile-thinning laser spot; the galvanometer is calibrated using the filling-scanning laser spot to obtain the galvanometer calibration table corresponding to the filling-scanning laser spot; in this way, when the profile-thinning laser spot and the filling-scanning laser spot are scanned, the corresponding galvanometer calibration tables are used for the scanning movement respectively.

[0129] The third aspect:

[0130] A laser windowing device for a circuit board includes a processor, a memory, and a computer program stored in the memory and running on the processor. When the computer program runs, it implements the laser windowing method for a circuit board as described above.

[0131] The fourth aspect:

[0132] A circuit board laser windowing system, including a machine table, further including the circuit board laser windowing equipment and the circuit board laser windowing device as described above, and the circuit board laser windowing device is electrically connected to the circuit board laser windowing equipment;

[0133] The machine table is used for carrying a circuit board;

[0134] The circuit board laser windowing device controls the circuit board laser windowing equipment to execute the circuit board laser windowing method as described above, so as to perform circuit board laser windowing processing on the circuit board carried on the machine table.

[0135] For a circuit board laser windowing method, equipment, device and system of the present invention, a traditional laser transmission and transformation optical path is adopted to obtain a small focused spot in the positive focus and a large-sized defocused spot in the defocus, and laser windowing is performed on a circuit board, especially a flexible board. The contour thinning laser spot at the positive focus position can scribe on the insulating layer to obtain a groove with a steep groove wall, but due to the very steep field strength distribution of the spot, there will be a small amount of insulating material residue at the bottom of the groove and in the area near the filling scan side; and for the contour thinning laser spot at the defocus position on the surface of the insulating layer, because the spot is relatively large, high-efficiency laser scanning can be obtained by scribing on the insulating layer, but due to the relatively gentle field strength distribution of the spot, there is a large amount of insulating material residue in the areas on both sides of the groove; the present invention combines the two spots for combined processing to obtain the following unexpected effects:

[0136] (1). The edge of the laser windowing contour is steep. If the slope of the windowing edge is too large, it will directly reduce the area of the conductive layer exposed at the bottom of the window, which will directly lead to the reliability of subsequent welding.

[0137] (2). The bottom of the laser windowing window is flat. Since the scanning filling laser spot is large, the surface of the conductive layer at the bottom of the scanning windowing will be relatively flat. After actual testing, the roughness is less than 1 micron.

[0138] (3). The laser windowing efficiency is greatly improved. The reason is also that the scanning filling laser spot is large, and high-efficiency laser processing can be obtained with a relatively small filling density.

[0139] (4). The insulating layer at the contour edge is thinned, eliminating the problem of too gentle slope outside the filling scan laser spot. In the windowing area, due to the filling scan, there is no problem that the insulating layer cannot be removed, but there must be a contour slope insulating layer on the outermost side. Since the contour thinning laser spot thins most of the insulating layer material inside the windowing contour while obtaining a steep groove wall in the scanning contour, this makes up for the problem of too gentle slope outside the filling scan laser spot.

[0140] (5). There is room for further improvement in the laser windowing efficiency. By using appropriate laser parameters and galvanometer scanning parameters, the filled scanning laser spot can have a sparser filling density to layer-by-layer strip the insulating layer material of the area to be processed, achieving more efficient laser windowing processing.

[0141] (6). Orthogonal and defocused laser spots are designed on the surface of the circuit board insulating layer, and the light fields of the spots are both Gaussian field strength distributions, with a simple, stable and reliable optical path.

[0142] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A circuit board laser windowing method, characterized in that: According to the preset window opening profile, the contour thinning laser spot and the filling scanning laser spot are controlled to perform window opening processing on the circuit board; the circuit board at least includes a conductive layer and an insulating layer attached to the conductive layer; the light intensity distribution of the contour thinning laser spot and the light intensity distribution of the filling scanning laser spot are both stronger in the central area than in the edge area, the size of the contour thinning laser spot is smaller than the size of the filling scanning laser spot, and the unevenness of the light intensity distribution of the contour thinning laser spot is greater than the unevenness of the light intensity distribution of the filling scanning laser spot; The circuit board laser window opening method comprises: Controlling the center of the profile thinning laser spot to scan along the profile thinning track on the insulating layer to form a steep groove wall at the inner edge of the preset window profile; wherein the shape of the profile thinning track is the same as the shape of the preset window profile, and the profile thinning track is inwardly contracted relative to the preset window profile, and the inwardly contracted distance is equal to the radius of the profile thinning laser spot; Controlling the center of the filling scanning laser spot to scan on the insulating layer along the filling scanning track enclosed in the contour thinning track, so as to quickly remove the insulating layer in the preset window opening contour, thereby exposing the conductive layer; The contour thinning laser spot and the filling scanning laser spot are controlled to scan according to a preset timing, so as to quickly form a window with a steep groove wall on the circuit board.

2. The circuit board laser window opening method according to claim 1, characterized in that: The contour thinning laser spot and the filling scanning laser spot are controlled to scan according to a preset timing, specifically: First, the center of the profile thinning laser spot is controlled to scan along the profile thinning track on the insulating layer, so as to thin the insulating layer along the inner side of the preset window profile to form a profile thinning area with a steep groove wall, and the thinned thickness is less than or equal to the thickness of the insulating layer corresponding to the profile thinning track; Then, the center of the filling scanning laser spot is controlled to scan on the insulating layer along the filling scanning trajectory, so as to quickly clear the insulating layer within the preset window opening contour to expose the conductive layer; wherein, when the center of the filling scanning laser spot is scanned along the outermost trajectory of the filling scanning trajectory, the edge of the filling scanning laser spot covers the contour thinning area, and is sufficient to clear the insulating layer in the contour thinning area to expose the conductive layer, thereby forming a window opening with a steep groove wall.

3. The circuit board laser window opening method according to claim 1, characterized in that: The contour thinning laser spot and the filling scanning laser spot are controlled to scan according to a preset timing, specifically: First, the center of the filling scanning laser spot is controlled to scan on the insulating layer along the filling scanning track, so as to quickly remove the insulating layer within the preset window opening profile to expose the conductive layer, and form a window with a gentle groove wall along the inner side of the preset window opening profile; Then, the center of the contour thinning laser spot is controlled to scan along the contour thinning trajectory to thin the gentle groove wall along the inner side of the preset window opening contour, thereby forming a window opening with a steep groove wall.

4. The circuit board laser window opening method according to claim 1, characterized in that: The contour thinning laser spot and the filling scanning laser spot are controlled to scan according to a preset timing, specifically: Controlling the center of the profile thinning laser spot to scan along the profile thinning track on the insulating layer to form a steep groove wall at the inner edge of the preset window profile; At the same time, the center of the filling scanning laser spot is controlled to scan along the filling scanning track to quickly remove the insulating layer within the preset window opening contour, thereby exposing the conductive layer and forming a window opening with a steep groove wall.

5. The circuit board laser window opening method according to claim 1, characterized in that: The laser peak power density of the profile thinning laser spot and / or the filling scanning laser spot is insufficient to process the conductive layer; or, The laser peak power density of the profile thinning laser spot and / or the filling scanning laser spot is sufficient to process the conductive layer, and the profile thinning laser spot and / or the filling scanning laser spot interact with the conductive layer to form a plasma spark, and the plasma spark scatters and shields the profile thinning laser spot and / or the filling scanning laser spot to prevent the conductive layer from being further etched by the profile thinning laser spot and / or the filling scanning laser spot.

6. The circuit board laser window opening method according to claim 5, characterized in that: When the laser peak power density of the contour thinning laser spot and / or the filling scanning laser spot is sufficient to process the conductive layer, the scanning speed, number of scans, scanning filling density and laser parameters of the contour thinning laser spot and / or the filling scanning laser spot are controlled so that the laser etching amount of the conductive layer within the preset window contour is within 5 microns.

7. The circuit board laser window opening method according to claim 2, characterized in that: When the center of the profile thinning laser spot is controlled to scan along the profile thinning track on the insulating layer, the thinning process is stopped when the conductive layer is exposed, thereby forming a profile thinning area with a steep groove wall; When controlling the center of the filling scanning laser spot to scan along the filling scanning trajectory on the insulating layer, the scanning speed, number of scans, scanning filling density and laser parameters of the filling scanning laser spot are controlled so that the insulating layer within the preset window opening contour is directly layered and peeled off from the conductive layer.

8. The circuit board laser window opening method according to claim 7, characterized in that: When the center of the contour thinning laser spot is controlled to scan along the contour thinning track on the insulating layer, the contour thinning laser spot is absorbed by the insulating layer to remove the insulating layer along the inner side of the preset window opening contour; When the center of the filling scanning laser spot is controlled to scan along the filling scanning trajectory on the insulating layer, the filling scanning laser spot transmits or partially transmits the insulating layer and reacts with the conductive layer to form a plasma spark, and then the explosive force of the plasma spark ejects the insulating layer within the preset window outline directly from the conductive layer in layers.

9. The circuit board laser window opening method according to claim 7 or 8, characterized in that: Before controlling the center of the filling scanning laser spot to scan along the filling scanning track on the insulating layer, the method further includes: controlling the profile thinning laser spot to scan the insulating layer island surrounded by the profile thinning track to divide the insulating layer island surrounded by the profile thinning track into a plurality of sub-areas; When controlling the center of the filling scanning laser spot to scan along the filling scanning track on the insulating layer, the scanning speed, scanning times, scanning filling density and laser parameters of the filling scanning laser spot are controlled so that the insulating layers of all sub-areas within the insulating layer island surrounded by the contour thinning track are directly layered and peeled off from the conductive layer.

10. The circuit board laser window opening method according to claim 7 or 8, characterized in that: Within the processing range of a scanning format or a processing platform format, the contour thinning laser spot is controlled to jump between different windows, and each window area is first subjected to contour thinning processing. After the contour thinning processing of all window areas within the processing range is completed to expose the conductive layer, the filling scanning laser spot is controlled to perform layered peeling of the insulating layer within each window contour within the processing range.

11. The circuit board laser window opening method according to claim 7 or 8, characterized in that: After the filling scanning laser spot causes the insulating layer within the preset window outline to be directly peeled off from the conductive layer in layers, the method further includes: sandblasting the circuit board.

12. The circuit board laser window opening method according to claim 1, characterized in that: The contour thinning laser spot is a circular spot with a diameter less than 50 microns, and the filling scanning laser spot is a circular spot with a diameter less than 300 microns.

13. The circuit board laser window opening method according to claim 1, characterized in that: The profile thinning laser spot is a Gaussian beam positive focus spot, and the filling scanning laser spot is a Gaussian beam defocused collection spot.

14. The circuit board laser window opening method according to claim 13, characterized in that: The contour thinning laser spot and the filling scanning laser spot are obtained by two different laser beams passing through different external optical paths and passing through different focusing systems, or by two different laser beams passing through different external optical paths and passing through the same focusing system, or by the same Gaussian beam passing through a dynamic focusing system to dynamically adjust the laser spot size.

15. The circuit board laser window opening method according to claim 1, characterized in that: The contour thinning laser spot and / or the filling scanning laser spot is a laser beam shaping spot.

16. The circuit board laser window opening method according to claim 1, characterized in that: The contour thinning laser spot and the filling scanning laser spot are respectively obtained by scanning and focusing the contour thinning laser beam and the filling scanning laser beam through the same set of scanning galvanometers and flat field focusing mirrors; the distance between the center of the contour thinning laser spot and the center of the filling scanning laser spot is less than 40 mm.

17. The circuit board laser window opening method according to claim 16, characterized in that: The contour thinning laser spot and the filling scanning laser spot are combined into a combined laser spot, and the center distance between the contour thinning laser spot and the filling scanning laser spot is smaller than the sum of the radii of the contour thinning laser spot and the filling scanning laser spot.

18. The circuit board laser window opening method according to claim 16, characterized in that: The contour thinning laser spot is within the range of the filling scanning laser spot.

19. The circuit board laser window opening method according to claim 16, characterized in that: The contour thinning laser beam and the filling scanning laser beam are obtained by switching the same laser to different optical paths through an optical switch; or, The profile thinning laser beam and the filling scanning laser beam are generated by two independent lasers.

20. The circuit board laser window opening method according to claim 16, characterized in that: The profile thinning laser beam and / or the filling scanning laser beam is a nanosecond laser beam or an ultrafast laser beam.

21. The circuit board laser window opening method according to claim 1, characterized in that: The insulating layer is composed of a single insulating material, or a plurality of different single insulating materials stacked in layers, or a plurality of different insulating materials mixed; The material of the conductive layer is any one or more combinations of copper, aluminum, gold, silver, nickel, chromium, beryllium and titanium.

22. The circuit board laser window opening method according to claim 1, characterized in that: The shape of the filling scanning track is any one or more combinations of a U-shaped, an I-shaped, a field-shaped, a three-shaped and a dot-matrix filling track.

23. A circuit board laser window opening device, characterized in that: Used to perform window opening processing on a circuit board according to a preset window opening profile; the circuit board at least includes a conductive layer and an insulating layer attached to the conductive layer; the circuit board laser window opening equipment includes: A laser for generating a profile thinning laser beam and a filling scanning laser beam; a galvanometer scanning and flat-field focusing device, connected to the laser, for scanning and focusing the profile thinning laser beam and the filling scanning laser beam to output scanned profile thinning laser spots and filling scanning laser spots; wherein the light intensity distribution of the profile thinning laser spot and the light intensity distribution of the filling scanning laser spot are both stronger in the central area than in the edge area, the size of the profile thinning laser spot is smaller than the size of the filling scanning laser spot, and the unevenness of the light intensity distribution of the profile thinning laser spot is greater than the unevenness of the light intensity distribution of the filling scanning laser spot; A controller connected to the galvanometer scanning and flat-field focusing device, used to control the center of the contour thinning laser spot to scan along the contour thinning trajectory on the insulating layer to form a steep groove wall on the inner edge of the preset window opening contour; wherein the shape of the contour thinning trajectory is the same as the shape of the preset window opening contour, and the contour thinning trajectory is inwardly contracted relative to the preset window opening contour, and the inwardly contracted distance is equal to the radius of the contour thinning laser spot; the center of the filling scanning laser spot is controlled to scan along the filling scanning trajectory enclosed in the contour thinning trajectory on the insulating layer to quickly remove the insulating layer within the preset window opening contour, thereby exposing the conductive layer; specifically used to control the scanning of the contour thinning laser spot and the filling scanning laser spot according to a preset timing, thereby quickly forming a window opening with a steep groove wall on the circuit board.

24. The circuit board laser window opening device according to claim 23, characterized in that: The controller controls the flat-field focusing and galvanometer scanning device to scan the contour thinning laser spot and the filling scanning laser spot in the same coordinate system, or controls the flat-field focusing and galvanometer scanning device to scan the contour thinning laser spot and the filling scanning laser spot respectively in different coordinate systems.

25. A circuit board laser window opening device, characterized in that: It comprises a processor, a memory, and a computer program stored in the memory and running on the processor, wherein when the computer program is running, the circuit board laser window opening method as described in any one of claims 1 to 22 is implemented.

26. A circuit board laser window opening system, characterized in that , including a machine, and also including the circuit board laser window opening equipment as claimed in claim 23 or 24 and the circuit board laser window opening device as claimed in claim 25, the circuit board laser window opening device is electrically connected to the circuit board laser window opening equipment; The machine is used to carry the circuit board; The circuit board laser window opening device controls the circuit board laser window opening equipment to execute the circuit board laser window opening method as described in any one of claims 1 to 22, so as to perform circuit board laser window opening processing on the circuit board carried on the machine.

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