A method for manufacturing a high-precision character flexible circuit board for smart cameras
By electroplating copper layers on flexible circuit boards, etching grooves and filling them with ink, combined with micro-etching and AOI inspection, the problem of high-precision character processing was solved, and reliable forming and clarity of high-precision characters were achieved.
Patent Information
- Application Number
- CN202511026438.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-24
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2045-07-24
AI Technical Summary
It is difficult to process high-precision character flexible circuit boards with existing technology, especially when the character length or width is less than 0.7mm or the line thickness is less than 0.1mm, the characters are blurred and difficult to identify.
By electroplating a copper layer on the surface of the flexible core board, etching to form grooves and filling them with character ink, combined with micro-etching, sandblasting and AOI inspection, high-precision character graphics are formed, and release film isolation and pre-baking lamination technology are used to ensure the accurate filling and clarity of the character ink.
It achieves reliable forming of high-precision characters, improves the clarity and processing efficiency of character graphics, and reduces scrap rate and cost.
Smart Images
Figure CN120529502B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of flexible circuit board manufacturing, and in particular to a method for manufacturing a high-precision character flexible circuit board for an intelligent camera. Background Art
[0002] For a type of miniature smart camera module used in robots, low-altitude aircraft, smart connected cars and other fields, high-precision flexible circuit boards are required. For the high-precision characters produced on the board surface, it is also required to improve the design and processing accuracy, so as to form the processing of high-reliability and high-precision character flexible circuit boards under the conditions of smaller space and higher density.
[0003] Currently, there are two common methods for processing characters:
[0004] (1) Processing by silk screen printing: First make a silk screen screen according to the design data of the characters, then use the screen to print the characters on the board surface, and finally form the characters through curing and baking.
[0005] (2) Processing using a character inkjet printer: Directly use the character inkjet printer to print characters on the board according to the character design data.
[0006] However, the above two processing methods are not enough to meet the processing requirements of high-precision characters:
[0007] Due to the processing methods and application requirements, the length or width of ordinary characters on ordinary circuit boards is generally larger, generally greater than 0.7mm, and the line width of the characters is also thicker, generally greater than 0.1mm.
[0008] For high-precision characters, if the length or width of the characters is required to be less than 0.7mm, or the line thickness of the characters is less than 0.1mm, it exceeds the process capabilities of the above two processing methods, making the characters difficult to process and forming, resulting in problems such as blurred characters and difficulty in identification.
[0009] Therefore, in order to solve the above-mentioned problems, it is necessary to provide a method for manufacturing a high-precision character flexible circuit board for a smart camera. Summary of the Invention
[0010] The present invention aims to solve the comprehensive problem of low processing accuracy of character graphics in flexible circuit boards in the prior art, and proposes a method for manufacturing a high-precision character flexible circuit board for smart cameras. The flexible circuit board is processed according to design data, and the design data includes character graphics and pad patterns. The manufacturing method includes the following steps:
[0011] S10: manufacturing a flexible core board according to the design data, taking two layers of covering films, attaching them to the surface of the flexible core board respectively, and then electroplating to form a surface copper layer, so that the whole board becomes an electroplated board;
[0012] S20: forming a circuit pattern on the surface copper layer, forming grooves on the surface copper layer corresponding to the character pattern, forming a grooved plate on the entire plate, then silk-screening character ink to fill the grooves, and baking and curing to form a character pattern plate;
[0013] S30: removing the surface copper layer, making the pad pattern, and then making the via hole, and forming the flexible circuit board through post-processing.
[0014] Furthermore, the thickness of the surface copper layer is greater than or equal to the thickness of the character pattern.
[0015] Furthermore, the silk-screen character ink is prepared by making a dot-blocking screen, which has windows corresponding to the character pattern to form a silk screen window pattern, and then using the dot-blocking screen to silk-screen the character ink.
[0016] Furthermore, the size of one side of the silk screen window pattern is larger than that of the character pattern.
[0017] Furthermore, the baking and curing is to perform pre-baking first, then cover with a release film, press with a laminator, remove the release film, and perform post-baking.
[0018] Furthermore, the pre-baking is performed at a temperature of 65° C. to 75° C. for 20 to 40 minutes, and the post-baking is performed at a temperature of 100° C. to 125° C. for 30 to 50 minutes.
[0019] Furthermore, forming the character graphic plate includes performing micro-etching and sandblasting in sequence after the baking and curing.
[0020] Furthermore, forming the character graphic plate includes, after the baking and curing, sequentially performing browning treatment and AOI inspection.
[0021] Furthermore, the pad pattern is produced by laser ablating the covering film at a position corresponding to the pad pattern to expose the surface copper layer to form the pad pattern; the via hole is produced by drilling a through hole corresponding to the designed position of the via hole, then laser ablating the covering film corresponding to the through hole to form a hole ring, and then performing pattern electroplating to form the via hole.
[0022] Furthermore, forming the electroplated board includes opening windows in the covering film corresponding to the pad pattern to form window positions, forming the covering film into window covering films, and then respectively adhering them to the surface of the flexible core board, making a blue glue layer on the window positions, and then electroplating to form the electroplated board; forming the flexible circuit board includes removing the surface copper layer, tearing off the blue glue layer, and exposing the pad pattern.
[0023] The technical solution of the present invention mainly has the following beneficial effects:
[0024] The production process involves electroplating a copper layer on the surface of the cover film, etching corresponding character patterns to form grooves, filling the grooves with character ink, baking and curing, and finally removing the copper layer to form high-quality, high-precision characters. This provides a reliable production method for character patterns with smaller line sizes, breaking through the limitations of traditional processes on character pattern size and solving problems such as low processing accuracy of small-sized character patterns.
[0025] By pre-baking the character ink and then covering it with a release film for lamination, the isolation and uniform pressure of the release film can be used to fully fill the tiny gaps caused by screen printing errors, effectively improving the surface flatness and vertical accuracy of the character ink. On the other hand, it can prevent the character ink from adhering to the roller and avoid overflow or shifting of the character ink.
[0026] A micro-etching process is used to remove part of the electroplated copper layer, and then sandblasting is used to remove residual ink. The non-contact "polishing" method not only trims the edges of the characters but also reduces damage to the character structure itself, significantly improving the clarity of the character outline.
[0027] The browning treatment makes the surface copper layer appear brown-black, forming a strong color contrast with the white character ink, providing a clear visual basis for AOI optical scanning. Then, using AOI inspection equipment to compare the optical scan of the entire board with the design data, it can quickly locate micron-level defects and detect defects before etching, avoiding scrapping of the entire board and reducing costs.
[0028] (5) The entire process has consistency and processing reliability. Each process is closely linked to form a systematic processing flow, ensuring the reliable filling and molding of high-precision character ink. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.
[0030] Figure 1 Schematic diagram of the process flow of an embodiment of the present invention;
[0031] Figure 2 A schematic plan view of a cover core plate according to an embodiment of the present invention;
[0032] Figure 3 for Figure 2 AA cross-section diagram;
[0033] Figure 4 is a schematic cross-sectional view of an electroplating plate according to an embodiment of the present invention;
[0034] Figure 5 Schematic cross-sectional view of a groove plate according to an embodiment of the present invention;
[0035] Figure 6 A schematic cross-sectional view of a character graphic plate according to an embodiment of the present invention;
[0036] Figure 7 Schematic diagram of a plan view of a character graphic plate with a browning layer according to an embodiment of the present invention;
[0037] Figure 8 is a schematic cross-sectional view of a character plate according to an embodiment of the present invention;
[0038] Figure 9 Schematic cross-sectional view of a via plate according to an embodiment of the present invention;
[0039] Figure 10 is a schematic cross-sectional view of a flexible circuit board according to an embodiment of the present invention;
[0040] Figure 11 To correspond Figure 10 A top-down plan view of
[0041] Figure 12 Schematic cross-sectional view of a multi-layer flexible circuit board according to an embodiment of the present invention.
[0042] Explanation of the accompanying numbers: 10, covering core board; 1010, character graphics; 1020, covering film; 1030, pad pattern; 20, electroplating board; 2010, surface copper layer; 30, groove board; 3010, groove; 40, character graphic board; 4010, character ink; 40A, character graphic board with browning layer; 4020, browning layer; 50, character board; 60, via board; 6010, surface covering film; 6020, via; 70, flexible circuit board; 4010A, high-precision characters; 70A, multi-layer flexible circuit board.
[0043] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION
[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.
[0045] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, inside, outside, etc.) are only used to explain the relative position relationship and movement status of the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0046] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referenced. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, such as two or three, unless otherwise specifically defined.
[0047] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
[0048] See also Figure 1 , Figure 1 Schematic diagram of the process flow of an embodiment of the present invention.
[0049] The flexible printed circuit board 70 of this embodiment is processed according to the design data, which includes the character pattern 1010 and the pad pattern 1030. The manufacturing method includes the following steps:
[0050] See also Figure 2 、 Figure 3 and Figure 4 , Figure 2 A schematic plan view of a cover core plate according to an embodiment of the present invention; Figure 3 for Figure 2 AA cross-section diagram; Figure 4 Schematic cross-sectional view of an electroplating plate according to an embodiment of the present invention.
[0051] Step S10: Make a flexible core board according to the design data, take two layers of covering films 1020, attach them to the surface of the flexible core board respectively to form a covering core board 10, and then electroplate to form a surface copper layer 2010, and the whole board becomes a plated board 20.
[0052] The design data is the layout and process design data for circuit board processing; the production of flexible core board is to take flexible copper clad board, produce circuit pattern according to the design data, and form a flexible core board with surface circuit pattern.
[0053] In this embodiment, the unwindowed covering film 1020 is directly attached to the two surfaces of the flexible core board to form a panel with a smooth surface, providing a uniform and stable basic surface for electroplating copper processing, ensuring the thickness consistency and surface quality of the surface copper layer 2010, and also providing a processing basis for the subsequent character graphics 1010; the complete surface copper layer 2010 is directly electroplated on the surface of the covering film 1020, providing a copper layer foundation for the subsequent graphic transfer through the surface copper layer 2010, thereby producing characters.
[0054] The surface copper layer can be electroplated, optionally, using a plating process similar to that of a traditional flexible circuit board, that is, copper deposition and electroplating of the entire board. This can activate the cover film 1020 first, deposit copper to provide a conductive basis, and then electroplate copper.
[0055] Furthermore, the thickness of the surface copper layer 2010 is greater than or equal to the thickness of the character pattern 1010 .
[0056] The thickness of the surface copper layer 2010 needs to match the thickness of the subsequent character graphics 1010. The surface copper layer 2010 should not be too thick. On the one hand, it ensures that the character ink 4010 can form a sufficient height after filling to meet the visual indication requirements of high-precision characters; on the other hand, it can avoid the problem of increased difficulty in subsequent etching, excessive material consumption and increased energy consumption caused by the surface copper layer 2010 being too thick.
[0057] Optionally, since the thickness of the character pattern 1010 is generally 5 μm to 20 μm, the thickness of the surface copper layer 2010 is 5 μm to 20 μm, preferably 8 μm, 10 μm or 15 μm.
[0058] See also Figure 5 and Figure 6 , Figure 5 Schematic cross-sectional view of a groove plate according to an embodiment of the present invention; Figure 6 Schematic cross-sectional view of a character graphic plate according to an embodiment of the present invention.
[0059] Step S20: a circuit pattern is made on the surface copper layer 2010, a groove 3010 is formed in the surface copper layer 2010 corresponding to the character pattern 1010, and the entire plate forms a groove plate 30, and then the character ink 4010 is silk-screened to fill the groove 3010, and baked and cured to form a character pattern plate 40.
[0060] Specifically, a dry film is applied to the surface copper layer 2010, and then the dry film is exposed and developed according to the design data of the character graphic 1010. The copper layer is then etched, and the dry film is then removed (i.e., a graphic transfer process of applying dry film → exposing → developing → etching → removing the film is performed). Thus, an etched groove 3010 is formed at the position corresponding to the character graphic 1010, providing a basis for making the character graphic 1010. The groove 3010 is filled with character ink 4010, and then baked and cured, so that the character ink 4010 is made to adhere to the surface of the covering film 1020, thereby forming a character production process that relies on the groove 3010 as a constraint range.
[0061] Furthermore, the silk screen character ink 4010 is made by making a dot-blocking screen, which opens windows corresponding to the character pattern 1010 to form a silk screen window pattern, and then uses the dot-blocking screen to silk screen the character ink 4010.
[0062] Specifically, a high-precision dot-blocking screen is first produced based on the design data of the character graphic plate 40, and a window area that precisely corresponds to the character graphic plate 40 is formed on the screen through a photosensitive plate-making process, thereby forming a silk screen window pattern. After the screen production is completed, the character graphic plate 40 is evenly scraped into the groove 3010 through the dot-blocking screen by the equipment.
[0063] The shielding layer design of the dot-blocking screen can accurately limit the printing area of the character ink 4010. The area where characters need to be silk-screened can realize the transfer of character ink 4010 through opening windows, and the area where characters do not need to be silk-screened is blocked by the photosensitive paste shielding layer, making the silk-screen character ink 4010 more precise and significantly reducing material costs.
[0064] Furthermore, the size of one side of the screen window pattern is larger than that of the character pattern 1010 .
[0065] Since the character graphics 1010 in this embodiment have high precision requirements, the length, width and size of the character lines of a single character are relatively small. In the silk screen processing of the circuit board, the mesh count of the screen is subject to an upper limit constraint. For example, the character silk screen screen usually adopts a specification of 100 mesh to 150 mesh. Within the range of this mesh count constraint, the screen itself has a tolerance limit, resulting in that it is difficult for the high-precision character graphics 1010 to be completely and accurately aligned with the position of the groove 3010 itself within the allowable error range, and thus it is difficult to completely align the character graphics 1010; therefore, in order to ensure that the character ink 4010 can be smoothly filled into the groove 3010 position within the error range, it is necessary to pre-enlarge the screen window pattern, and use the pre-enlargement of the size to compensate for the errors generated in the screen production, silk screen positioning and ink transfer processes, thereby ensuring that the character ink 4010 can be accurately filled into the groove 3010, thereby ensuring the processing quality of the character graphics 1010.
[0066] Optionally, the size of the screen window pattern is larger than the size of the character pattern 1010 by 0.03 mm to 0.1 mm on one side.
[0067] Furthermore, the baking and curing is performed by pre-baking first, then covering with a release film, laminating with a laminator, removing the release film, and performing post-baking.
[0068] Furthermore, the pre-baking is performed at a temperature of 65° C. to 75° C. for 20 to 40 minutes, and the post-baking is performed at a temperature of 100° C. to 125° C. for 30 to 50 minutes.
[0069] Specifically, the pre-baking is to place the groove plate 30 after the silk screen character ink 4010 is printed in an oven, and bake it at a temperature of 65°C to 75°C for 20 minutes to 40 minutes to make the silk screen character ink 4010 initially solidified, and the character ink 4010 changes from a high flow state to a low flow state, effectively avoiding overflow or shift problems caused by excessive fluidity of the character ink 4010 during the subsequent lamination process. After the pre-baking is completed, the plate surface is covered with a release film, and the lamination is performed by a laminating machine, and the isolation effect of the release film is utilized. This prevents the character ink 4010 from adhering to the roller of the laminator. At the same time, through uniform lamination, the character ink 4010 further fills the tiny gaps in the groove 3010 caused by screen printing errors, improving the surface smoothness of the character ink 4010. After lamination, the release film is removed and the plate is post-baked at a temperature of 100°C to 125°C for 30 to 50 minutes to thoroughly cure the character ink 4010, ensuring that the character ink 4010 will not fall off, deform, or be damaged during subsequent processing and use. This meets the processing requirements of high-precision character graphics 1010.
[0070] Furthermore, the reason for pre-baking and then covering with a release film for lamination is that the character ink 4010 has greater fluidity and viscosity after silk screen printing is completed. If it is directly laminated, too much character ink 4010 will adhere to the surface of the release film, resulting in missing or insufficient character ink 4010.
[0071] Optionally, lamination is performed at room temperature with a pressure of 2.5 kgf / cm² to 4.5 kgf / cm² and a lamination speed of 2.0 m / min to 3.5 m / min.
[0072] Optionally, the release film is a PE, PET or PP film.
[0073] It is worth noting that using smaller pressure and faster speed for lamination processing can improve processing efficiency and prevent excessive lamination that causes the character ink 4010 to be excessively adhered to the release film and cause gaps.
[0074] It is worth noting that the function of the release film used in this step is to serve as an isolation layer between the pressure roller and the surface of the character ink 4010, so as to prevent the character ink 4010 from adhering to the surface of the pressure roller due to its high viscosity during the lamination process, thereby causing the character ink 4010 to leak or the pressure roller to be contaminated. Therefore, based on functional requirements, the release film only needs to meet the basic conditions of surface flatness and stable release effect. There is no need to use new materials. Release films that have been scrapped due to non-functional defects can be selected and reused after cleaning, thereby achieving the effect of material recycling.
[0075] Optionally, forming the character pattern plate 40 includes, after forming the character pattern 1010 , performing plasma treatment on the entire plate.
[0076] Furthermore, forming the character graphic plate 40 includes, after baking and curing, micro-etching and sandblasting the entire plate in sequence.
[0077] Since in the previous process, when the character ink 4010 is screen-printed, or when the release film is covered and the lamination process is performed, the character ink 4010 may diffuse slightly outside the etched pattern, resulting in burrs or blurred outlines on the edges of the character ink 4010. Therefore, through the micro-etching process, part of the thickness of the uniform surface copper layer 2010 can be etched away first, and then sandblasting is performed. The impact force of high-speed particles is used to remove the residual diffused character ink 4010, and at the same time, the edge of the character ink 4010 is finely trimmed, which significantly improves the visual recognition and processing quality of the character pattern 1010.
[0078] Furthermore, if micro-etching and sandblasting are used, the thickness of the surface copper layer 2010 is preferably designed to be greater than the design thickness of the character graphic 1010. Taking the thickness design value of the character graphic 1010 as 10μm as an example, the thickness of the surface copper layer 2010 can be controlled within the range of 13μm to 20μm during electroplating processing. By reserving an additional thickness of 3μm to 10μm, a "polishing allowance" is provided for the subsequent sandblasting process.
[0079] As a non-contact processing technology, sandblasting uses airflow to drive sand particles to achieve a "polishing" effect, removing the character ink 4010 that has diffused outside the groove 3010. Compared with traditional brush polishing or belt polishing, it can significantly reduce the risk of damage to the main structure of the character graphic board 40. The reserved thickness of the surface copper layer 2010 can provide a copper thickness margin for micro-etching and sandblasting, avoiding excessive wear on the character graphic 1010 body that needs to be retained, and retaining the original contour accuracy of the character graphic 1010 to the greatest extent.
[0080] In practical applications, the parameters of sandblasting can be dynamically adjusted according to the strength of the plate material, the accuracy requirements of the character graphics 1010 and the subsequent process requirements to achieve a balance between processing quality and efficiency.
[0081] See also Figure 7 , Figure 7 Schematic diagram of a plan view of a character graphic plate with a browning layer according to an embodiment of the present invention.
[0082] Furthermore, forming the character graphic plate 40 includes baking and curing, and then sequentially performing browning treatment to form a browning layer 4020, forming the entire plate into a character graphic plate 40A having a browning layer, and performing AOI inspection.
[0083] On the one hand, the AOI system performs an optical scan of the entire board and identifies problem areas on the board surface through color difference differentiation. This allows accurate identification of defects such as incomplete or offset character graphics 1010 before etching the surface copper layer 2010. If defects are discovered at this time, they can be promptly repaired through reprinting or other methods. Conversely, if problems are discovered after the entire board is etched, they cannot be remedied because the copper layer has been removed, significantly reducing the scrap rate.
[0084] On the other hand, due to the high precision of character production, traditional manual visual inspection, magnifying glass inspection or ordinary lens inspection are limited by the resolution of the human eye and subjective judgment differences, and the missed detection rate is high. The AOI system uses a high-resolution camera to collect images and compare them with the character graphics 1010 in the design data, which can quickly locate micron-level defects.
[0085] Specifically, the board is first quickly put through a browning process, which can change the color of the electroplated copper layer on the board surface to brown-black, even if its color is deepened. The character ink 4010 is generally white, and the character ink 4010 after post-baking will not be affected by the rapid browning process. Therefore, the brown-black electroplated copper layer and the white characters form a stronger color difference contrast, providing AOI with a stronger color difference basis for optical scanning. Secondly, AOI can efficiently scan the entire board at one time through optical scanning, and then compare it with the character data in the computer data, which can quickly give the comparison abnormal points, greatly improving the efficiency and quality of character inspection.
[0086] It is worth noting that since the browning layer 4020 is relatively fragile, it is easy to be scratched or fall off due to friction during the transportation and stacking of the panels. Therefore, a smooth isolation layer must be placed between each layer of the panels to prevent the browning layer 4020 from direct contact with hard objects and ensure its integrity is not damaged, thus providing a reliable premise for the accuracy of AOI inspection.
[0087] See also Figure 8 、 Figure 9 、 Figure 10 and Figure 11 , Figure 8 is a schematic cross-sectional view of a character plate according to an embodiment of the present invention; Figure 9 Schematic cross-sectional view of a via plate according to an embodiment of the present invention; Figure 10is a schematic cross-sectional view of a flexible circuit board according to an embodiment of the present invention; Figure 11 To correspond Figure 10 Schematic top view of the plan.
[0088] Step S30: Remove the surface copper layer 2010 to form the character plate 50, and make the pad pattern 1030, and then make the via hole 6020 to form the via hole plate 60, and then process it through the post-processing to form the flexible circuit board 70, wherein the character ink 4010 forms high-precision characters 4010A.
[0089] Furthermore, the pad pattern 1030 is produced by laser ablating the surface covering film 6010 at a position corresponding to the pad pattern 1030 to expose the surface copper layer 2010 and form the pad pattern 1030; the via hole 6020 is produced by drilling a through hole corresponding to the designed position of the via hole 6020, and then laser ablating the surface covering film 6010 corresponding to the through hole to form a hole ring, and then performing pattern electroplating to form the via hole 6020.
[0090] Specifically, a through hole is first drilled according to the designed position of the through hole 6020, and then the covering film 1020 around the through hole is laser ablated to form a ring-shaped exposed area, and then electroplating is performed to form the through hole 6020, so that the circuit board can achieve electrical connection between layers, and then the laser ablation technology is used to accurately remove the local covering film 1020 at the position corresponding to the pad pattern 1030 of the covering film 1020, so that the copper layer underneath is exposed to form the pad pattern 1030; this method is suitable for the situation where the board pads are small and the precision is high, and there are no many connected pads. The laser ablation method is used for processing, which can achieve efficient and high-precision processing effects.
[0091] Graphic electroplating is a process of electroplating only the through holes and hole rings to form the conductive holes 6020. Optionally, ordinary graphic electroplating can be used, that is, dry film or blue glue is attached to the areas that do not need to be electroplated, and electroplating is performed, and then the dry film is removed or the blue glue is removed.
[0092] Furthermore, forming the electroplating board 20 includes opening windows in the surface covering film 6010 corresponding to the pad pattern 1030 to form window positions, the surface covering film 6010 forms a window covering film, and then is attached to the surface of the flexible core board respectively, a blue glue layer is made for the window positions, and then electroplating is performed to form the electroplating board 20; forming the flexible circuit board 70 includes removing the surface copper layer 2010, tearing off the blue glue layer, and then making the pad pattern 1030.
[0093] Optionally, the surface covering film 6010 may have windows opened in the pad patterns 1030 corresponding to the larger sizes, while the corresponding pad patterns 1030 having the smaller sizes may not have windows opened, and then blue glue may be applied to the window positions to cover them.
[0094] Specifically, for larger-sized pad graphics 1030 with a diameter ≥ 0.05mm or a length and width both ≥ 0.05mm, if the process of "attaching a covering film 1020 to the front and then laser ablation" is adopted, a larger area needs to be ablated and a longer ablation time is required, resulting in low processing efficiency and a large amount of carbon powder generated by ablation, which is difficult to clean. Therefore, by pre-opening a window for the large-sized pad graphics 1030 and covering it with a blue glue layer for protection, the laser ablation area can be reduced, the processing time can be significantly shortened, and energy consumption can be reduced. For small-sized pad graphics 1030 (diameter < 0.05mm), laser ablation is used for processing, and the laser ablation area is reduced.
[0095] See also Figure 12 , Figure 12 Schematic cross-sectional view of a multi-layer flexible circuit board according to an embodiment of the present invention.
[0096] This embodiment is also applicable to the processing of a multi-layer flexible circuit board 70A. The production of each layer of flexible core board is completed in sequence according to the design data. After post-processing such as lamination, the character graphic 1010 is produced to form a multi-layer flexible circuit board 70A with high-precision characters having a multi-layer structure, which meets the demand for high-precision character identification.
[0097] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.
Claims
1. A method for manufacturing a high-precision character flexible circuit board for a smart camera, wherein the flexible circuit board is processed according to design data, wherein the design data includes character patterns and pad patterns, and wherein: The production method comprises the following steps: S10: manufacturing a flexible core board according to the design data, taking two layers of covering films, attaching them to the surface of the flexible core board respectively, and then electroplating to form a surface copper layer, so that the whole board becomes an electroplated board; S20: forming a circuit pattern on the surface copper layer, forming grooves on the surface copper layer corresponding to the character pattern, forming a grooved plate on the entire plate, then silk-screening character ink to fill the grooves, and baking and curing to form a character pattern plate; The baking and curing is to first perform pre-baking, then cover with a release film, press with a laminator, then remove the release film, and perform post-baking; Forming the character graphic plate includes, after the baking and curing, sequentially performing micro-etching and sandblasting, and / or, sequentially performing browning and AOI inspection; S30: removing the surface copper layer, making the pad pattern, and then making the via hole, and then performing post-processing to form the flexible circuit board; The forming of the electroplated board includes: opening windows in the cover film corresponding to the pad pattern to form window positions, forming the cover film into windowed cover films, and then respectively attaching them to the surface of the flexible core board, forming a blue glue layer on the window positions, and then electroplating to form the electroplated board; The forming of the flexible circuit board includes removing the surface copper layer, tearing off the blue glue layer, and exposing the pad pattern.
2. The method for manufacturing a high-precision character flexible circuit board for a smart camera according to claim 1, wherein: The thickness of the surface copper layer is greater than or equal to the thickness of the character pattern.
3. The method for manufacturing a high-precision character flexible circuit board for a smart camera according to claim 1, wherein: The silk screen printing character ink is prepared by making a dot-blocking screen plate, which opens windows corresponding to the character pattern to form a silk screen window pattern, and then uses the dot-blocking screen plate to silk screen the character ink.
4. The method for manufacturing a high-precision character flexible circuit board for a smart camera according to claim 3, wherein: The size of the screen window pattern on one side is larger than that of the character pattern.
5. The method for manufacturing a high-precision character flexible circuit board for a smart camera according to claim 1, wherein: The pre-baking is performed at a temperature of 65° C. to 75° C. for 20 to 40 minutes, and the post-baking is performed at a temperature of 100° C. to 125° C. for 30 to 50 minutes.
6. The method for manufacturing a high-precision character flexible circuit board for a smart camera according to claim 1, wherein: To produce the pad pattern, the covering film is laser ablated at a position corresponding to the pad pattern to expose the surface copper layer to form the pad pattern; to produce the via hole, a through hole is drilled at a designed position corresponding to the via hole, and the covering film is laser ablated at the via hole to form a hole ring, and then pattern electroplating is performed to form the via hole.