Method for forming deep holes in single-sided aluminum substrate

Abstract

The invention discloses a single-sided aluminum substrate depth-controlled hole forming method, which comprises the following steps of: A, drilling a hole with a certain depth in an aluminum plate, and accurately controlling the depth and the position of the hole according to design requirements; b, the drilled holes are filled with resin, curing treatment is carried out, and resin plug holes are formed; c, pressing copper foil on a single surface of the hole plugging surface of the aluminum plate with the resin hole plugging to form a single-surface aluminum substrate; d, a depth control hole smaller than the plugged hole is drilled in the position where the resin is plugged, and the depth and the position of the hole need to be accurately controlled according to design requirements; and E, pasting protection on one surface, which is not laminated with the copper foil, of the aluminum plate, and then performing hole formation through copper deposition electroplating.

Description

Technical Field

[0001] The invention relates to the technical field of PCB production, and in particular to a method for controlling deep holes in a single-sided aluminum substrate. Background Art

[0002] The most notable feature of aluminum substrates is their excellent heat dissipation performance. As a metal with high thermal conductivity, aluminum can effectively conduct and dissipate the heat generated on the PCB board. This is especially important for electronic components that require high power operation or dense packaging, such as LED lighting, power electronics, automotive electronics, etc. Aluminum substrates can significantly reduce the operating temperature of these components, improve the stability and reliability of the system, and extend the service life of the components.

[0003] The aluminum substrate consists of a circuit layer (copper foil), an insulating layer, and a metal aluminum base layer. The heat generated by the device during operation can be quickly transferred to the metal aluminum base layer through the insulating layer and efficiently dissipated by the base layer. This structure gives the aluminum substrate excellent thermal conductivity and can significantly reduce the operating temperature of the device. Compared with traditional FR-4 and other boards, the aluminum substrate can significantly reduce thermal resistance, allowing heat to be dissipated more quickly, thereby improving the heat dissipation efficiency of the entire circuit board. In addition, the thermal expansion coefficient of the aluminum substrate is relatively low, which is closer to the thermal expansion coefficient of materials such as copper foil, which helps to reduce dimensional changes and deformation problems caused by temperature changes, thereby ensuring the stability and reliability of the circuit board.

[0004] However, due to the excellent thermal conductivity of the aluminum substrate, the heat generated when the drill bit contacts the aluminum substrate during the drilling process is difficult to dissipate quickly, which can easily lead to increased wear of the drill bit and even affect the drilling quality. Directly drilling holes on the aluminum substrate may cause physical damage to the aluminum substrate, such as scratches and cracks, which will further affect the performance and service life of the aluminum substrate, and also affect the quality and stability of its wires and circuits. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method for controlling deep holes on a single-sided aluminum substrate, which solves the difficulty that the aluminum substrate cannot be electroplated with copper, satisfies the single-sided aluminum substrate through electroplating copper holes to achieve the conduction function and increase the soldering area of ​​the plug-in hole, improves the soldering stability, and solves the problem that the aluminum substrate cannot be electroplated with the copper layer.

[0006] A method for controlling deep hole formation on a single-sided aluminum substrate according to an embodiment of the present invention comprises: Step A: Drill a hole of a certain depth on the aluminum plate. The depth and position of the hole need to be precisely controlled according to the design requirements; Step B: Fill the drilled hole with resin and perform a curing process to form a resin plug hole; Step C: Press copper foil on one side of the aluminum plate with resin-filled holes to form a single-sided aluminum substrate; Step D: Drill a depth-controlled hole that is smaller than the plug hole at the location where the resin has been plugged. The depth and position of the hole need to be precisely controlled according to the design requirements. Step E: After applying a protective layer on the side of the aluminum plate that is not laminated with copper foil, perform hole formation through copper electroplating.

[0007] A method for controlling the depth of a single-sided aluminum substrate according to an embodiment of the present invention has at least the following beneficial effects: a hole of a certain depth is drilled on the aluminum plate, and the depth and position of the hole must be precisely controlled strictly according to the design requirements, providing an accurate hole position and depth basis for subsequent steps, and then filling the drilled hole with resin and curing it to form a resin plug hole. During the filling process, bubbles in the hole must be removed to ensure the quality of the resin plug hole. The hole wall is protected by the resin plug hole, providing support for subsequent processing and preventing the penetration of the electroplating solution. The plug hole surface of the aluminum plate with the resin plug hole is subjected to surface treatment (such as decontamination, removal of the oxide layer, etc.), and then the copper foil and the aluminum plate are pressed together to form a single-sided aluminum substrate. A conductive layer is formed on one side of the aluminum plate to provide a basis for subsequent electroplating. A controlled depth hole smaller than the plug hole is drilled at the position where the resin has been plugged. Similarly, the depth and position of the hole also need to be precisely controlled according to the design requirements. A more accurate controlled depth hole is formed on the basis of the resin plug hole to provide a channel for electroplating. After affixing a high temperature resistant protective film to the side of the aluminum plate that is not pressed with copper foil, copper plating is used to form holes so that a conductive layer is formed in the controlled depth holes to achieve electrical connection between the holes and the copper foil.

[0008] Through the precise control of drilling, resin plugging, copper foil lamination, re-drilling and hole-forming, the purpose of forming controlled depth holes and hole-forming on the single-sided aluminum substrate is achieved. Throughout the process, there are strict requirements on the depth, position, aspect ratio of the holes and the selection of protective films to ensure the quality and performance of the final product, solve the difficulty of copper plating on the aluminum substrate, meet the single-sided aluminum substrate through copper plating hole-forming to achieve the conduction function and increase the plug-in hole welding area, improve welding stability, and solve the problem that the aluminum substrate cannot be combined with the copper layer by electroplating.

[0009] According to a method for controlled deep hole formation on a single-sided aluminum substrate according to an embodiment of the present invention, the protective film is a high temperature resistant protective film.

[0010] According to a method for controlling deep holes in a single-sided aluminum substrate according to an embodiment of the present invention, the protective film is a PVC protective film. The PVC protective film has the characteristics of acid and alkali resistance, good weather resistance, and anti-aging, and is suitable for a variety of complex environments.

[0011] According to a method for controlling deep holes in a single-sided aluminum substrate according to an embodiment of the present invention, the protective film is a silicone protective film. The silicone protective film has excellent high temperature resistance, low temperature resistance, weather resistance and chemical resistance, and has good self-adhesion and peeling properties. It is particularly suitable for occasions that require high protective performance and easy peeling, such as the protection of aluminum substrates in high temperature environments. In addition, after the protective film has been electroplated with a solution for more than three times, the film is fragile and difficult to tear off after electroplating. When the copper plating thickness is required to be thicker, the requirements for the protective film are higher, and a silicone protective film is preferred.

[0012] According to a method for controlled deep hole formation on a single-sided aluminum substrate according to an embodiment of the present invention, the thickness of the protective film is not less than 50 um to ensure that the aluminum plate is protected from damage during the electroplating process.

[0013] According to an embodiment of the present invention, a method for controlled deep hole formation of a single-sided aluminum substrate, step B: filling the drilled holes with resin, removing bubbles in the holes after filling the resin, and then performing a curing process to form resin plugged holes.

[0014] According to an embodiment of the present invention, a method for controlled deep hole formation of a single-sided aluminum substrate is provided, step C: plugging the surface of the aluminum plate that has been plugged with resin, and performing surface treatment on the aluminum plate and copper foil, and then pressing the copper foil and the aluminum plate to form a single-sided aluminum substrate.

[0015] According to a method for controlling deep holes on a single-sided aluminum substrate according to an embodiment of the present invention, the aspect ratio of the deep holes is ≤1:1, so as to ensure that the electroplating solution can smoothly penetrate to the bottom of the holes to form a uniform conductive layer. When the aspect ratio is greater than 1:1, the depth capability of the electroplating equipment affects the copper plating at the bottom of the controlled deep holes.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 It is a schematic diagram of a method for controlled deep hole formation of a single-sided aluminum substrate according to an embodiment of the present invention.

[0018] Description of reference numerals: Electroplated copper layer 100; Copper foil layer 200; PP layer 300; Aluminum plate layer 400; Resin layer 500 The protective film layer 600 . DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0020] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0021] In the description of the invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of the first or the second, it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0022] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0023] The most notable feature of aluminum substrates is their excellent heat dissipation performance. As a metal with high thermal conductivity, aluminum can effectively conduct and dissipate the heat generated on the PCB board. This is especially important for electronic components that require high power operation or dense packaging, such as LED lighting, power electronics, automotive electronics, etc. Aluminum substrates can significantly reduce the operating temperature of these components, improve the stability and reliability of the system, and extend the service life of the components.

[0024] The aluminum substrate consists of a circuit layer (copper foil), an insulating layer, and a metal aluminum base layer. The heat generated by the device during operation can be quickly transferred to the metal aluminum base layer through the insulating layer and efficiently dissipated by the base layer. This structure gives the aluminum substrate excellent thermal conductivity and can significantly reduce the operating temperature of the device. Compared with traditional FR-4 and other boards, the aluminum substrate can significantly reduce thermal resistance, allowing heat to be dissipated more quickly, thereby improving the heat dissipation efficiency of the entire circuit board. In addition, the thermal expansion coefficient of the aluminum substrate is relatively low, which is closer to the thermal expansion coefficient of materials such as copper foil, which helps to reduce dimensional changes and deformation problems caused by temperature changes, thereby ensuring the stability and reliability of the circuit board.

[0025] However, due to the excellent thermal conductivity of the aluminum substrate, the heat generated when the drill bit contacts the aluminum substrate during the drilling process is difficult to dissipate quickly, which can easily lead to increased wear of the drill bit and even affect the drilling quality. Directly drilling holes on the aluminum substrate may cause physical damage to the aluminum substrate, such as scratches and cracks, which will further affect the performance and service life of the aluminum substrate, and also affect the quality and stability of its wires and circuits.

[0026] Therefore, the present application proposes a technical solution to solve the difficulty that aluminum substrates cannot be electroplated with copper, so as to meet the needs of single-sided aluminum substrates to achieve the conduction function and increase the welding area of ​​the plug-in holes through copper plating, improve welding stability, and solve the problem that the aluminum base cannot be electroplated with the copper layer.

[0027] Reference Figure 1 , an embodiment of the present invention provides a method for controlled deep hole formation on a single-sided aluminum substrate, comprising step A: drilling a hole of a certain depth on the aluminum plate, wherein the depth and position of the hole need to be precisely controlled according to design requirements; Step B: Fill the drilled hole with resin and perform a curing process to form a resin plug hole; Step C: Press copper foil on one side of the aluminum plate with resin-filled holes to form a single-sided aluminum substrate; Step D: Drill a depth-controlled hole that is smaller than the plug hole at the location where the resin has been plugged. The depth and position of the hole need to be precisely controlled according to the design requirements. Step E: After applying a protective layer on the side of the aluminum plate that is not laminated with copper foil, perform hole formation through copper electroplating.

[0028] A hole of a certain depth is drilled on the aluminum plate. The depth and position of the hole must be precisely controlled according to the design requirements to provide a precise hole position and depth basis for the subsequent steps. Subsequently, the drilled hole is filled with resin and cured to form a resin plug hole. During the filling process, bubbles in the hole must be removed to ensure the quality of the resin plug hole. The resin plug hole protects the hole wall, provides support for subsequent processing, and prevents the penetration of the electroplating solution. The plug hole surface of the aluminum plate with resin plug hole is subjected to surface treatment (such as decontamination, removal of oxide layer, etc.), and then the copper foil and the aluminum plate are pressed to form a single-sided aluminum substrate. A conductive layer is formed on one side of the aluminum plate to provide a basis for subsequent electroplating holes. A controlled depth hole smaller than the plug hole is drilled at the position where the resin has been plugged. Similarly, the depth and position of the hole also need to be precisely controlled according to the design requirements. A more precise controlled depth hole is formed on the basis of the resin plug hole to provide a channel for electroplating holes. After affixing a high temperature resistant protective film to the side of the aluminum plate that is not pressed with copper foil, copper plating is used to form holes so that a conductive layer is formed in the controlled depth holes to achieve electrical connection between the holes and the copper foil.

[0029] Through the precise control of drilling, resin plugging, copper foil lamination, re-drilling and hole-forming, the purpose of forming controlled depth holes and hole-forming on the single-sided aluminum substrate is achieved. Throughout the process, there are strict requirements on the depth, position, aspect ratio of the holes and the selection of protective films to ensure the quality and performance of the final product, solve the difficulty of copper plating on the aluminum substrate, meet the single-sided aluminum substrate through copper plating hole-forming to achieve the conduction function and increase the plug-in hole welding area, improve welding stability, and solve the problem that the aluminum substrate cannot be combined with the copper layer by electroplating.

[0030] According to some embodiments of the present application, the protective film is a high temperature resistant protective film. Specifically, a PVC protective film or a silicone protective film can be selected, and the thickness is not less than 50um to ensure that the aluminum plate is protected from damage during the electroplating process. Among them, the PVC protective film has the characteristics of acid and alkali resistance, good weather resistance, and anti-aging, and is suitable for a variety of complex environments. The silicone protective film has excellent high temperature resistance, low temperature resistance, weather resistance and chemical resistance, and has good self-adhesion and peeling properties. It is particularly suitable for occasions that require high protective performance and easy peeling, such as the protection of aluminum substrates in high temperature environments. However, since the protective film is fragile after more than 3 times of electroplating solution, and it is difficult to tear off after electroplating, when the copper plating thickness is required to be thicker, the requirements for the protective film are higher. The present application prefers silicone protective film.

[0031] According to some embodiments of the present application, in step B, resin is filled into the drilled hole, and bubbles in the hole are removed after filling the resin to avoid adverse effects in subsequent steps. After the bubbles are removed, curing treatment is performed to form a resin plugged hole.

[0032] According to some embodiments of the present application, in step C, after the aluminum plate with resin plugging is plugged, the aluminum plate and the copper foil need to be surface treated, and then the copper foil and the aluminum plate are pressed together to form a single-sided aluminum substrate. The surface treatment includes decontamination, deoxidation layer, etc., to improve the bonding strength between the aluminum plate and the copper foil.

[0033] According to some embodiments of the present application, the aspect ratio of the deep hole is ≤1:1 to ensure that the electroplating solution can penetrate smoothly to the bottom of the hole to form a uniform conductive layer. When the aspect ratio is greater than 1:1, the depth capability of the electroplating equipment affects the copper plating at the bottom of the controlled deep hole.

[0034] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0035] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for controlling deep holes in a single-sided aluminum substrate, characterized in that: include: Step A: Drill a hole of a certain depth on the aluminum plate. The depth and position of the hole need to be precisely controlled according to the design requirements; Step B: Fill the drilled hole with resin and perform a curing process to form a resin plug hole; Step C: Press copper foil on one side of the aluminum plate with resin-filled holes to form a single-sided aluminum substrate; Step D: Drill a depth-controlled hole that is smaller than the plug hole at the location where the resin has been plugged. The depth and position of the hole need to be precisely controlled according to the design requirements. Step E: After applying a protective layer on the side of the aluminum plate that is not laminated with copper foil, perform hole formation through copper electroplating.

2. The method for controlled deep hole formation of a single-sided aluminum substrate according to claim 1, characterized in that: The protective film is a high temperature resistant protective film.

3. The method for controlled deep hole formation of a single-sided aluminum substrate according to claim 2, characterized in that: The protective film is a PVC protective film.

4. The method for controlled deep hole formation of a single-sided aluminum substrate according to claim 2, characterized in that: The protective film is a silicone protective film.

5. The method for controlled deep hole formation of a single-sided aluminum substrate according to claim 2, characterized in that: The thickness of the protective film is not less than 50um.

6. The method for controlled deep hole formation of a single-sided aluminum substrate according to claim 1, characterized in that: Step B: Fill the drilled holes with resin, remove the bubbles in the holes after filling the resin, and then perform a curing process to form a resin plugged hole.

7. The method for controlled deep hole formation of a single-sided aluminum substrate according to claim 1, characterized in that: Step C: Plug the surface of the aluminum plate with resin plugging, and perform surface treatment on the aluminum plate and copper foil, and then press the copper foil and the aluminum plate to form a single-sided aluminum substrate.

8. The method for controlled deep hole formation of a single-sided aluminum substrate according to claim 1, characterized in that: The aspect ratio of the hole depth hole is ≤1:1.

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