A manufacturing method of aluminum substrate with high-reliability surface marking

Abstract

The present invention discloses a method for manufacturing an aluminum substrate with a highly reliable surface identification. A first blue glue layer is made on the circuit layer, a first dry film pattern is made on the aluminum plate layer, then the aluminum plate layer is subjected to acid etching, electroplating, and a second blue glue layer is made; the first blue glue layer is torn off, a second dry film pattern is made on the circuit layer, a surface circuit pattern is made, the second dry film pattern is removed, and then a solder mask pattern is made; the second blue glue layer is torn off, immersion nickel and gold are carried out, and the first dry film pattern is removed to form a circuit board; by adopting the method of forming a groove through chemical etching and then depositing an immersion nickel and gold layer, it replaces the processing methods of directly making ink characters or laser marking characters after aluminum surface oxidation in the prior art, and uses the corrosion resistance characteristics of the metal layer to form a persistent surface identification, greatly improving the reliability and recognition of the characters. The overall process can be achieved by using the processing process of traditional circuit boards, without the need for cross-field and cross-industry processing processes, greatly improving the processing efficiency and reducing the processing difficulty.

Description

Technical Field

[0001] The present invention relates to the field of aluminum substrate manufacturing, and particularly to a method for manufacturing an aluminum substrate with a highly reliable surface marking. Background Art

[0002] Aluminum substrates have good heat dissipation performance and high strength performance. With the development needs of fields such as LEDs and automobiles, the requirements for high-precision and high-reliability processing of their surface markings are also increasing.

[0003] Regarding the surface markings of such aluminum-based substrates, the existing manufacturing methods and main problems are as follows:

[0004] (1) Screen-printing black or white text ink on the surface of the aluminum substrate and then baking and curing it to form surface markings. However, due to the relatively smooth surface of the aluminum substrate and its easy oxidation, this method also has defects such as easy unclear characters, natural surface oxidation, and poor corrosion resistance.

[0005] (2) Adopting anodizing treatment on the surface of the aluminum substrate and then using a laser engraving and ablation method to make surface markings. However, due to the relatively complex anodizing process of the aluminum surface, the processing flow is relatively long, and it does not belong to the processing scope of the traditional aluminum substrate field and industry. Therefore, it will generate relatively high processing costs and increase environmental pollution. Further, during subsequent applications, the anodized aluminum surface is easily affected by environmental corrosion or factors such as collision and friction, and problems such as character shedding and character blurring are likely to occur.

[0006] Therefore, to solve the above-mentioned problems, a method for manufacturing an aluminum substrate with a highly reliable surface marking is needed. Summary of the Invention

[0007] The present invention aims to solve the comprehensive problems such as low processing accuracy and low reliability in manufacturing the surface markings of aluminum substrates in the prior art, and proposes a method for manufacturing an aluminum substrate with a highly reliable surface marking. The upper and lower surfaces of the aluminum substrate are a circuit layer and an aluminum plate layer respectively. The manufacturing method includes the following steps:

[0008] S10: Making a first blue glue layer on the circuit layer, pasting a first dry film on the aluminum plate layer, and making a first dry film pattern, so that the whole board forms a dry film pattern board.

[0009] S20: Etching the aluminum plate layer of the dry film pattern board to form an etched board, then electroplating, and making a second blue glue layer, so that the whole board forms a blue glue board.

[0010] S30: Tearing off the first blue glue layer, pasting a second dry film on the circuit layer, and making a second dry film pattern, making a surface circuit pattern, then removing the second dry film pattern, and then making a solder mask pattern, so that the whole board forms a solder mask board.

[0011] S40: Tear off the second blue glue layer, perform immersion nickel and gold plating, and remove the first dry film pattern to form the aluminum substrate.

[0012] Further, the method for making the first blue glue layer is: attaching a blue glue film or screen printing blue glue ink.

[0013] Further, the etching is acid etching.

[0014] Further, after performing the etching, the etched plate is baked for the first time.

[0015] Further, the temperature of the first baking is 60°C to 75°C, and the time of the first baking is 10 min to 30 min.

[0016] Further, the depth of the etching is 3 μm to 20 μm.

[0017] Further, the method for tearing off the second blue glue layer is: baking the blue glue layer for the second time and then tearing off the second blue glue layer.

[0018] Further, the temperature of the second baking is 60°C to 75°C, and the time of the second baking is 3 min to 10 min.

[0019] Further, the method for removing the first dry film pattern is: soaking in a NaOH solution or KOH solution with a mass fraction of 1.5% to 3% for 5 min to 10 min and then stripping the film with a stripping solution.

[0020] Further, the method for removing the first dry film pattern is: grinding off the first dry film pattern by means of grinding.

[0021] The technical solution of the present invention forms a groove electroplating by chemical etching and then deposits an immersion nickel and gold layer, replacing the existing method of directly making ink characters or laser marking characters after aluminum surface oxidation. By utilizing the corrosion resistance of the metal layer to form a persistent surface mark, the reliability and recognition of the characters are greatly improved. Moreover, in the processing process, the copper circuit on the surface of the aluminum substrate is made first, then the circuit pattern on the other side is made, and finally the immersion nickel and gold are carried out together, avoiding the secondary immersion nickel and gold method of "one side → one side" production. This can effectively shorten the processing flow, improve the processing accuracy of double-sided immersion nickel and gold, reduce the use of high-risk, harmful and toxic processes of immersion nickel and gold, and improve environmental protection. The overall process can be achieved by using the processing process of traditional aluminum substrates, without the need for processing processes across different fields and industries, greatly improving the processing efficiency, relatively reducing the processing difficulty, providing an efficient, environmentally friendly and cost-effective solution, enhancing the reliability, clarity and durability of the surface mark on the aluminum substrate, and reducing the risk of fading or wear of the surface mark during long-term use. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0023] Figure 1 It is a schematic process flow diagram of an embodiment of the present invention;

[0024] Figure 2 It is a schematic plan view of a dry film pattern board of an embodiment of the present invention;

[0025] Figure 3 It is a schematic plan view of an etched board of an embodiment of the present invention;

[0026] Figure 4 It is a schematic plan view of the planar structure of a blue glue board of an embodiment of the present invention;

[0027] Figure 5 It is a schematic plan view of the planar structure of a dry film board of an embodiment of the present invention;

[0028] Figure 6 It is a schematic plan view of the planar structure of a solder mask board of an embodiment of the present invention;

[0029] Figure 7 It is a schematic plan view of the planar structure of an aluminum substrate of an embodiment of the present invention.

[0030] Explanation of the reference numerals in the drawings:

[0031] 10 - dry film pattern board; 1010 - circuit layer; 1020 - aluminum plate layer; 1030 - insulating layer; 1040 - first blue glue layer; 1050 - first dry film pattern; 20 - etched board; 2010 - etched pattern; 30 - blue glue board; 3010 - second blue glue layer; 3020 - electroplated copper pattern; 40A - dry film board; 4010 - second dry film pattern; 40 - solder mask board; 4020 - surface circuit pattern; 4030 - solder mask pattern; 50 - aluminum substrate; 5010 - pad pattern; 5020 - surface marking.

[0032] The realization of the object, functional features and advantages of the present invention will be further described with reference to the embodiments and the drawings. Specific embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] It should be noted that all directional indications (such as up, down, left, right, front, back, inside, outside, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If this specific posture changes, the directional indications will also change accordingly.

[0035] In addition, the descriptions such as "first" and "second" in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0036] 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 ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0037] Please refer to Figure 1 , Figure 1 which is a schematic process flow diagram of the embodiment of the present invention.

[0038] The manufacturing process of the embodiment of the present invention includes the implementation of each step process in Figure 1 . The following will further illustrate each step process in Figure 1 step by step.

[0039] The upper and lower surfaces of the aluminum substrate in this embodiment are respectively a circuit layer 1010 and an aluminum plate layer 1020, and the intermediate layer is an insulating layer 1030.

[0040] Please refer to Figure 2 , Figure 2 which is a plan view of the dry film pattern board of the embodiment of the present invention.

[0041] S10: A first blue glue layer 1040 is made on the circuit layer 1010, a first dry film is pasted on the aluminum plate layer 1020 to make a first dry film pattern 1050, and the whole plate forms a dry film pattern board 10.

[0042] By fabricating the first blue glue layer 1040 on the circuit layer 1010, it is to provide temporary protection for the circuit layer 1010 in subsequent processing steps, making it unaffected by subsequent processing, and providing a processing basis for subsequent etching and electroplating processes. The aluminum plate layer 1020 fabricates the first dry film pattern 1050, forming the processing basis for the subsequent electroplated copper pattern 3020.

[0043] Optionally, the fabrication of the first blue glue layer 1040 is as follows: attaching a blue glue film or screen-printing blue glue ink. Screen-printing generally uses a screen plate with a mesh count of 71, 100, or 120 for processing, and preferably uses a 71-mesh screen. The thickness of the screen-printed blue glue ink can be selected from 20 μm to 50 μm, and preferably is 35 μm or 50 μm.

[0044] Please refer to Figure 3 and Figure 4 , Figure 3 which is a schematic plan view of the etched plate according to the embodiment of the present invention; Figure 4 which is a schematic plan view of the blue glue plate according to the embodiment of the present invention.

[0045] S20: Etch the aluminum plate layer 1020 of the dry film pattern plate 10 to form an etched pattern 2010, form an etched plate 20 for the whole plate, then electroplate, and fabricate the second blue glue layer 3010, forming a blue glue plate 30 for the whole plate.

[0046] Electroplating forms an electroplated copper pattern 3020, providing a copper layer pattern basis for subsequent further fabrication of immersion nickel and gold, improving the adhesion of immersion nickel and gold. The thickness of the electroplated copper pattern 3020 can be 5 μm to 20 μm, and there is no need to electroplate too thick, otherwise there will be a problem of the protrusion of the surface mark 5020.

[0047] By selectively removing the aluminum plate layer 1020 not covered by the first dry film pattern 1050 using an acidic chemical reagent, forming the pattern of the desired surface mark 5020, which is the graphic basis for subsequent processing steps. This is one of the key steps to achieve the surface mark 5020. This step requires precise control of the etching time and temperature to ensure an ideal etching effect.

[0048] Furthermore, the etching depth is 3 μm to 20 μm. An appropriate etching depth can ensure that the surface mark 5020 has sufficient visual contrast and will not cause structural damage to the aluminum substrate 50. At the same time, the concave and convex structure formed by etching helps to improve the adhesion of the metal layer material, cooperating with the subsequent electroplating before and after. By depositing a metal layer on the surface of the pattern of the surface mark 5020 formed by etching, the surface mark 5020 is not easily erased or worn, and can maintain a good state for a long time in a harsh environment, with high reliability.

[0049] It should be noted that for the etching of the aluminum plate layer 1020 of the dry film pattern board 10, acidic etching is preferably used. Generally, an acidic etching solution of the H2O2 and HCl mixture system is selected, and the acidic etching line of the aluminum substrate 50 can be used for processing to complete the acidic etching process. The concentration of the acidic etching solution is relatively low, and it is not easy to cause passivation on the surface of the aluminum plate layer 1020.

[0050] It is also possible to use a combination of acidic etching and alkaline etching, that is, first use acidic etching for processing. To prevent passivation on the surface during etching and remove possible passivation on the surface, then perform mild alkaline etching to better remove the surface passivation and oxide layer, providing conductive and credential surface conditions for subsequent copper electroplating; the alkaline etching can be processed using the alkaline etching line of the aluminum substrate 50. Generally, the chemical components of the solution are a mixed system of copper chloride, ammonium bicarbonate, ammonia water, water, etc.; for multiple etchings, it is necessary to control the etching amount and the impact of the etching process on the blue glue layer and the dry film layer.

[0051] Optionally, after etching, the etched board 20 is subjected to the first baking.

[0052] Furthermore, the temperature of the first baking is 60°C to 75°C, and the time of the first baking is 10 min to 30 min.

[0053] Through the first baking, excess moisture is removed and the oxide film layer is stabilized, so that the first dry film pattern 1050 is completely cured on the surface. On the one hand, it also provides a processing basis for subsequent electroplating processes. On the other hand, it provides a board surface basis for subsequently making the second blue glue layer 3010 on the first dry film pattern 1050 and then tearing off the second blue glue layer 3010, preventing the problem that the first dry film pattern 1050 is torn when tearing off the second blue glue layer 3010.

[0054] It should be noted that the second blue glue layer 3010 can also be made by sticking a dry film in this step, but it will cause subsequent processes such as multiple repeated exposures, developments, film removals, and re-sticking of dry films, resulting in a cumbersome process, high processing costs, and low processing accuracy; therefore, in this embodiment, the method of directly making the second blue glue layer 3010 on the first dry film pattern 1050 to cover and protect the first dry film pattern 1050, the aluminum plate layer 1020, and the electroplated copper pattern 3020 is adopted. On the one hand, the processing efficiency is effectively improved. On the other hand, it also avoids problems such as secondary film sticking, secondary exposure, and secondary development, and it is easy to have problems such as misalignment between the developed pattern and the electroplated copper pattern 3020, affecting the accuracy of subsequent processes such as immersion nickel and gold plating. That is, the first dry film pattern 1050 is used for the entire subsequent immersion nickel and gold plating process with the same layer of dry film, and there are no problems such as low processing accuracy easily caused by secondary pattern making.

[0055] The second blue glue layer 3010 can also be made by attaching a blue glue film or screen-printing blue glue ink. Screen-printing generally uses a screen plate with a mesh count of 71, 100, or 120, and preferably uses a 71-mesh screen plate. The thickness of the screen-printed blue glue ink can be selected from 20 μm to 50 μm, preferably 35 μm or 50 μm.

[0056] Please refer to Figure 5 and Figure 6 , Figure 5 , which is a schematic plan view of the dry film plate according to the embodiment of the present invention; Figure 6 , which is a schematic plan view of the solder mask plate according to the embodiment of the present invention.

[0057] S30: Tear off the first blue glue layer 1040, attach a second dry film to the circuit layer 1010 and make a second dry film pattern 4010. The whole board forms a dry film plate 40A, then make a surface circuit pattern 4020, and then remove the second dry film pattern 4010. After that, make a solder mask pattern 4030, and the whole board forms a solder mask plate 40.

[0058] Tear off the first blue glue layer 1040 to expose the underlying circuit layer 1010, and make the surface circuit pattern 4020 and the solder mask pattern 4030 according to the standards of the original design data, which provides an accurate position positioning for the finally formed pad pattern 5010.

[0059] Please refer to Figure 7 , Figure 7 , which is a schematic plan view of the aluminum substrate according to the embodiment of the present invention.

[0060] S40: Tear off the second blue glue layer 3010, perform immersion nickel and gold plating, and remove the first dry film pattern 1050 to form an aluminum substrate 50.

[0061] Tear off the second blue glue layer 3010 used as a temporary protective layer to expose the electroplated copper pattern 3020, and perform immersion nickel and gold plating on the whole board, so that the pad pattern 5010 and the electroplated copper pattern 3020 are simultaneously processed for immersion nickel and gold plating, avoiding the complex process of separate processing and the process of using double materials, and avoiding the problem of alignment deviation caused by separate immersion nickel and gold plating.

[0062] The immersion nickel and gold plating simultaneously forms a protective layer with good wear resistance and corrosion resistance on the surfaces of the pad pattern 5010 and the electroplated copper pattern 3020, protecting the copper surface from oxidation, ensuring the quality and long-term stability of the welding points, and enabling the electroplated copper pattern 3020 to achieve pattern metallization to form the required surface identification 5020.

[0063] Optionally, tearing off the second blue glue layer 3010 is as follows: Bake the second blue glue layer 3010 for the second time, and then tear off the second blue glue layer 3010. By reheating the second blue glue layer 3010, the physical properties of the material of the second blue glue layer 3010 can be changed, making the glue layer soften and easier to peel off, preventing the first dry film pattern 1050 from being pulled off when tearing the second blue glue layer 3010, and at the same time reducing the possibility of residues.

[0064] Furthermore, the temperature of the second baking is 60°C to 75°C, and the time of the second baking is 3 min to 10 min, ensuring that the second blue glue layer 3010 can be fully softened without affecting the underlying electroplated copper pattern 3020. The control of the baking temperature and time helps to avoid deformation or damage caused by too high temperature, and can effectively shorten the subsequent processing time.

[0065] It is worth noting that after baking the second blue glue layer 3010 for the second time, preferably, tear it off in time within 5 minutes or less; since the physical properties of the second blue glue layer 3010 change after heat treatment, making it easy to peel off. If the second blue glue layer 3010 is removed after cooling, the second blue glue layer 3010 may increase its viscosity again, resulting in a reverse effect, making it more difficult to completely remove from the surface of the aluminum substrate 50, and may leave residues or damage the marks. Therefore, tearing it off in time after baking can ensure that neither the aluminum substrate 50 and the electroplated copper pattern 3020 are damaged due to too high temperature, nor the second blue glue layer 3010 re-hardens due to too long waiting time.

[0066] Optionally, removing the first dry film pattern 1050 is as follows: Immerse it in a NaOH solution or KOH solution with a mass fraction of 1.5% to 3% for 5 min to 10 min, and then use a film stripping solution to strip the film.

[0067] Since the first dry film pattern 1050 was completely cured in the early stage, if the film is directly stripped using a film stripping solution, it may be difficult to strip the dry film. Therefore, the method of soaking it in a strong base dilution solution and then using a film stripping solution to strip the film can effectively strip the first dry film pattern 1050.

[0068] In this embodiment, the first dry film pattern 1050 is soaked in a NaOH or KOH solution with a mass fraction of 1.5% to 3% to form selective corrosion and dissolve the first dry film pattern 1050, but will not significantly affect the aluminum substrate 50 itself. After the alkaline solution treatment is completed, a film stripping solution is used for treatment to completely remove the remaining first dry film pattern 1050 material, ensure that the surface of the aluminum substrate 50 is clean and tidy, and at the same time will not damage the already formed surface marks 5020.

[0069] Optionally, the removal of the first dry film pattern 1050 is as follows: the first dry film pattern 1050 is polished off by polishing; preferably, it is polished by a sand belt grinding plate, and further preferably: it is polished once with an 800-mesh sand belt and then once with a 1200-mesh sand belt.

[0070] To avoid the influence of alkaline solution immersion and stripping solution stripping on the solder mask pattern 4030, the first dry film pattern 1050 can be removed by polishing. Since the hardness of the board itself is relatively high and the hardness of the first dry film pattern 1050 is relatively small, a sand belt with a larger mesh number can be selected for polishing.

[0071] In this embodiment, by adopting the method of forming a groove by chemical etching and then depositing a nickel-gold immersion layer, it replaces the existing method of directly making ink characters or laser marking characters after aluminum surface oxidation. By utilizing the corrosion resistance of the metal layer, a persistent surface mark 5020 is formed, greatly improving the reliability and recognition of the characters. Moreover, in the processing process, the surface copper circuit of the aluminum substrate 50 is first made, then the circuit pattern on the other side is made, and finally the nickel-gold immersion is carried out on both sides simultaneously, avoiding the method of secondary nickel-gold immersion of "one side → one side", which can effectively shorten the processing flow, reduce the use of high-risk, harmful and toxic processes of nickel-gold immersion, and improve environmental protection; the overall process can be achieved by using the processing process of the traditional aluminum substrate 50, without the need for cross-field and cross-industry processing processes, greatly improving the processing efficiency, relatively reducing the processing difficulty, providing an efficient, environmentally friendly and cost-effective solution, enhancing the reliability, clarity and durability of the surface mark 5020 of the aluminum substrate 50, and reducing the risk of fading or wear of the surface mark 5020 during long-term use.

[0072] It should be noted that since the design and processing process of the aluminum substrate 50 are relatively precise, the structure in the actual processing process and the dimensions such as the thickness between layers and the line width are all at the micron level. If the drawings are made according to the enlarged scale of the actual structure, the problem of unclear illustration will occur. Therefore, in order to more clearly and intuitively represent the implementation process of the manufacturing method of this embodiment, the drawings of this embodiment are all schematic diagrams of enlarged technical features, which do not represent the dimensions of the actual structure, nor are they enlarged diagrams of the actual structure in proportion.

[0073] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent structural transformations made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied to other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A manufacturing method of an aluminum substrate with a highly reliable surface marking, wherein the upper and lower surfaces of the aluminum substrate are a circuit layer and an aluminum plate layer respectively, characterized in that The manufacturing method includes the following steps: S10: Fabricate a first blue glue layer on the circuit layer, attach a first dry film to the aluminum plate layer and fabricate a first dry film pattern, and form a dry film pattern board for the whole board; S20: Etch the aluminum plate layer of the dry film pattern board to form an etched board, then electroplate the aluminum plate layer not covered by the first dry film pattern to form an electroplated copper pattern, and fabricate a second blue glue layer to cover the first dry film pattern, the aluminum plate layer, and the electroplated copper pattern entirely, and form a blue glue board for the whole board; S30: Tear off the first blue glue layer, attach a second dry film to the circuit layer and fabricate a second dry film pattern, fabricate a surface circuit pattern, including fabricating and forming a pad pattern, then remove the second dry film pattern, and then fabricate a solder mask pattern, and form a solder mask board for the whole board; S40: Tear off the second blue glue layer, perform immersion nickel and gold plating on the solder mask board to simultaneously complete the immersion nickel and gold plating process for the pad pattern and the electroplated copper pattern, and remove the first dry film pattern to form the aluminum substrate.

2. The manufacturing method of an aluminum substrate with a highly reliable surface marking according to claim 1, characterized in that The fabrication of the first blue glue layer is: attaching a blue glue film or screen printing blue glue ink.

3. The manufacturing method of an aluminum substrate with a highly reliable surface marking as claimed in claim 1, wherein, The etching is acid etching.

4. The manufacturing method of an aluminum substrate with a highly reliable surface marking as described in claim 1 or 3, characterized in that, After the etching, perform the first baking on the etched board.

5. The manufacturing method of an aluminum substrate with a highly reliable surface marking as described in claim 4, characterized in that, The temperature of the first baking is 60°C to 75°C, and the time of the first baking is 10 min to 30 min.

6. The manufacturing method of an aluminum substrate with a highly reliable surface marking according to claim 1, characterized in that, The depth of the etching is 3 μm to 20 μm.

7. The manufacturing method of an aluminum substrate with a highly reliable surface marking as described in claim 1, characterized in that, Tearing off the second blue glue layer is: performing the second baking on the blue glue layer and then tearing off the second blue glue layer.

8. The manufacturing method of an aluminum substrate with a highly reliable surface marking according to claim 7, characterized in that, The temperature of the second baking is 60°C to 75°C, and the time of the second baking is 3 min to 10 min.

9. The manufacturing method of an aluminum substrate with a highly reliable surface marking as described in claim 1, characterized in that, Removing the first dry film pattern is: soaking in a NaOH solution or KOH solution with a mass fraction of 1.5% to 3% for 5 min to 10 min and then stripping the film with a film stripping solution.

10. The manufacturing method of an aluminum substrate with a highly reliable surface marking as described in claim 1, characterized in that, Removing the first dry film pattern is: grinding off the first dry film pattern by means of grinding.

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