Printed circuit board metallization half slot processing method

Abstract

The invention relates to the technical field of circuit board processing, in particular to a method for processing a metalized half slot of a printed circuit board. The method comprises the following steps: milling a groove in a preparation material to obtain a groove hole with a preset size; processing the hole wall of the slot hole to obtain a metalized slot hole containing a tin layer; milling off a tin layer in a to-be-milled area of the hole wall of the metalized slot hole; etching the copper layer in the to-be-milled area by adopting an alkaline etching mode, and manufacturing a solder resist ink enhancement layer on the upper surface of the etched to-be-milled area; and milling and breaking the solder resist ink enhancement layer and the to-be-milled and broken area to obtain the metalized half-slot hole with a smooth opening. According to the invention, compact mounting design can be carried out on some irregular electronic devices, the wiring space is reduced, the size of the device is reduced, the cost is reduced, the phenomenon of burrs in the peripheral area of the metalized half slot can be prevented, the short circuit risk of the electronic devices caused by the burrs is completely eradicated, and a good mounting effect is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of circuit board processing, and in particular to a method for processing metallized half-slot holes in a printed circuit board. Background Art

[0002] The rapid development of innovation in communication network electronic technology has led to demands for increased wiring density and diverse component shapes. When mounting electrical components on printed circuit boards, these components must meet the requirements of compactness, small footprint, and minimal wiring area. Traditionally, slots have been created to allow for mounting electrical components, allowing the components to contact the copper material of the slot walls for electrical continuity. However, for some irregularly shaped electrical components, slots cannot meet the compact mounting requirements, requiring additional wiring space and resulting in higher mounting costs.

[0003] In the existing related technologies, there are still some that use half-slot holes to adapt to irregular-shaped electrical devices, but burrs are prone to appear at the opening of the half-slot hole, resulting in poor mounting effect. Summary of the Invention

[0004] The embodiments of the present application provide a method for processing metallized half-slot holes in a printed circuit board to solve one or more technical problems existing in the prior art and at least provide a beneficial option or create conditions.

[0005] In one aspect of an embodiment of the present application, a method for processing a metallized half-slot hole in a printed circuit board is provided, the method comprising: Milling grooves on the prepared material for the printed circuit board to obtain slots of preset sizes; The hole wall of the slot is subjected to copper plating and then tin plating to obtain a metallized slot containing a tin layer; Milling off the tin layer in the area to be milled off of the hole wall of the metallized slot by milling, so as to expose the copper layer in the area to be milled off; The copper layer in the area to be milled is etched by alkaline etching, and then the tin is stripped, and a solder resist ink reinforcement layer is formed at the half-slot hole fracture on the upper surface of the etched area to be milled; At the position of the solder resist ink reinforcement layer, the solder resist ink reinforcement layer and the area to be milled are milled by milling a slot hole to remove the area to be milled and obtain a metallized half slot hole with a smooth opening; The half-slot hole is used to place a preset electrical component, so that the electrical component is embedded in the metallized half-slot hole and fills the opening.

[0006] Optionally, the step of first copper plating and then tin plating the wall of the slot to obtain a metallized slot containing a tin layer includes: Performing a chemical copper deposition treatment on the hole wall of the slot to obtain a metallized hole wall copper layer after the chemical copper deposition treatment, wherein the thickness of the metallized hole wall copper layer after the chemical copper deposition treatment is 1 μm-3 μm; Electroplating is performed on the metallized hole wall copper layer after the chemical copper deposition treatment to obtain a metallized groove wall copper layer after the electroplating treatment, wherein the thickness of the metallized groove wall copper layer is 25 μm-30 μm; Tin plating is performed on the basis of the metallized slot wall copper layer after the electroplating treatment to obtain the metallized slot hole containing the tin layer after the treatment.

[0007] Optionally, the milling of the tin layer in the area to be milled off of the hole wall of the metallized slot by milling includes: The tin layer on the outer surface of the area to be milled is removed by a milling cutter, so that the copper layer of the area to be milled is exposed to the air.

[0008] Optionally, etching the copper layer in the area to be milled by alkaline etching includes: An alkaline etching solution is used to perform alkaline etching treatment on the outer surface of the area to be milled, so that the alkaline etching solution etches the copper layer, thereby exposing the insulating plate of the prepared material located in the area to be milled to the air, and performing tin stripping treatment to obtain semi-metallized slots and semi-metallized exposed insulating plates.

[0009] Optionally, the step of forming a solder resist ink reinforcement layer at the half-slot hole fracture on the upper surface of the area to be milled after etching comprises: A layer of solder resist ink is screen printed on the upper and lower surfaces of the half-slot hole fracture on the upper surface of the area to be milled after etching to form a solder resist ink reinforcement layer.

[0010] Optionally, the solder resist ink reinforcement layer and the area to be milled are milled at the position of the solder resist ink reinforcement layer by milling a slot, including: The cutter body of the milling cutter passes through the solder resist ink reinforcement layer and contacts the upper surface of the area to be milled, and the area to be milled is milled from top to bottom by the cutter body of the milling cutter to form a metallized half slot hole with an opening.

[0011] Optionally, the prepared material is obtained by the following steps: Performing a lamination process on a preset substrate material to obtain a laminated substrate, wherein the laminated substrate is composed of an insulating material and copper; Drilling the laminated substrate to obtain a plurality of via holes located on the sidewall of the substrate to obtain the prepared material; Wherein, the via hole is used to be electrically connected to the electrical device.

[0012] The embodiments of the present application include at least the following beneficial effects: According to a method for processing a metallized half-slot hole of a printed circuit board provided by the present application, first, milling is performed on the preparation material for the printed circuit board to open a slot hole of a preset size, and then the hole wall of the slot hole is first copper-plated and then tin-plated, and then drilling and milling are used to remove the tin layer from the local hole wall position of the hole wall of the metallized slot hole containing the tin layer that has been first copper-plated and then tin-plated; that is, the tin layer in the milling area is milled off to expose the copper layer in the area to be milled, and the copper layer in the area to be milled is exposed to the air to facilitate etching of the copper layer in the area to be milled, and the copper layer is first removed by etching and then the tin is stripped.

[0013] Furthermore, the copper layer in the area to be milled is etched, and a solder resist ink reinforcement layer is formed at the half-slot hole fracture on the upper surface of the area to be milled after etching. The solder resist ink reinforcement layer is used to reduce the stress of the prepared material near the opening during the removal (milling) process of the area to be milled. In other words, the solder resist ink reinforcement layer is used to improve the strength of the opening and prevent the occurrence of burrs at the opening. In this way, when the solder resist ink reinforcement layer and the area to be milled are milled from the inside out at the location of the solder resist ink reinforcement layer, the opening formed will not have the problem of burrs, and the prepared material (sheet material) near the opening has higher strength.

[0014] In summary, the printed circuit board metallized half-slot hole processing method provided in the present application can not only perform compact mounting for some irregular electrical devices, reduce wiring space, and lower wiring costs, but also prevent the metallized half-slot hole from having burrs, thereby ensuring good mounting effect and electrical performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0016] Figure 1 A schematic diagram of a process for processing a metallized half-slot hole in a printed circuit board according to an embodiment of the present application; Figure 2 A schematic cross-sectional view of the preparation material (substrate) provided in an embodiment of the present application; Figure 3 A schematic diagram of a complete slot provided in an embodiment of the present application; Figure 4 A schematic diagram of the area to be milled in the slot provided in an embodiment of the present application; Figure 5 A schematic diagram of performing tin stripping on the hole wall in the area to be milled provided in an embodiment of the present application; Figure 6 A schematic diagram of milling the area to be milled provided in an embodiment of the present application; Figure 7 A schematic diagram of a metallized half-slot provided in an embodiment of the present application; Figure 8 A schematic diagram of mounting an irregular electrical component into a half-slot hole provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are merely examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the appended claims.

[0018] It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various concepts, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the words "if" and "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0019] The terms "at least one", "plurality", "each", "any", etc. used in this application include "at least one", "two" or more, "plurality" or "each", "any" or "any one", "each" or "any one" as used herein.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0021] The following is a detailed introduction to the embodiments of the present application: like Figure 1 As shown, Figure 1 The flowchart of the method for processing the metallized half-slot hole of the printed circuit board provided in the embodiment of the present application is shown in FIG. Figure 1 As shown, the harmonic suppression method based on optical phase shifting provided in the embodiment of the present application specifically includes but is not limited to steps S1 to S5: In step S1 , a slot is milled on a material to be prepared for a printed circuit board to obtain a slot with a preset size.

[0022] Specifically, the material for preparing the printed circuit board can be a substrate comprising an insulating material and a copper material, and its schematic diagram can be as follows: Figure 2 As shown, after the insulating material and the copper material are laminated, the resulting substrate is used as the preparation material described in this application. Figure 2 The green areas are all insulating materials, while the orange areas are all copper materials. The prepared materials are obtained through the following processes: Performing a lamination process on a preset substrate material to obtain a laminated substrate, wherein the laminated substrate is composed of an insulating material and copper; Drilling the laminated substrate to obtain a plurality of via holes located on the sidewall of the substrate to obtain the prepared material; Wherein, the via hole is used to be electrically connected to the electrical device.

[0023] Specifically, the laminated substrate is obtained by laminating the substrate material, and the substrate is drilled to obtain a prepared material including a plurality of vias located on the sidewalls of the substrate. Of course, before the lamination process, multiple processing steps are also included, and the specific processing steps are as follows: Cutting, inner layer pre-treatment, inner layer exposure, inner layer etching, AOI (Automated Optical Inspection), and browning. Cutting refers to obtaining materials of a certain size according to process requirements (i.e., printed circuit board requirements). Inner layer pre-treatment refers to cleaning the copper surface of the substrate (removing grease, oxidation, and dust from cutting and grinding). Inner layer pre-treatment includes the steps of cleaning, washing, micro-etching, washing, and drying. Inner layer exposure involves exposing the circuit diagram portion of the PCB board under the protection of a film substrate. After exposure, this portion undergoes a polymerization reaction. During the development process, the unexposed portion can be washed away with a developer, while the portion that has undergone polymerization after exposure cannot be washed away. In this way, the circuit on the PCB board is initially formed.

[0024] The circuit exposure process involves first applying a photosensitive film to the copper-clad laminate. This is then placed alongside a circuit pattern negative and exposed to ultraviolet light. The UV-exposed film undergoes a polymerization reaction, making it resistant to the erosion of the weakly alkaline Na2CO3 solution during development. The unexposed areas are washed away during development, effectively transferring the circuit pattern from the negative to the copper-clad laminate.

[0025] Inner layer etching principle: In the inner layer pattern transfer process, D / F or ink is used as an etchant, which has the function of resisting electroplating or etching. Therefore, most people choose acid etching (dry film / wet film covers the surface of the circuit pattern to prevent copper etching: other unwanted copper exposed on the substrate will be removed by chemical reaction to form the desired circuit pattern. After the circuit pattern etching is completed, the dry film / wet film is removed with sodium hydroxide solution). AOI uses optical principles to detect common defects encountered during soldering on printed circuit boards. The principle of browning is based on a chemical reaction on the copper surface. Under the action of the browning solution, an oxidation-reduction reaction occurs on the copper surface, forming a composite conversion film composed of copper oxide, cuprous oxide, and an organic polymer. This film is brown in color, and its thickness is usually controlled between 0.5 and 1.5 microns. A film layer with moderate and uniform thickness is the basis for ensuring interlayer bonding. A film layer that is too thin will not provide sufficient anchoring points, while a film layer that is too thick may increase the brittleness of the film layer and reduce the bonding strength. From a microstructural perspective, the conversion film formed by browning has a unique rough and porous structure. Therefore, copper layers or copper materials can be placed into this porous structure. After browning, the lamination process begins.

[0026] Furthermore, a milling cutter is used to mill grooves on the substrate to obtain the following Figure 3 The complete slot shown is also the slot of preset size described in this application, wherein the size of the slot can be set according to actual needs, and the shape of the slot can also be customized, such as rectangular, circular, elliptical, etc. Figure 3 The circular slot shown in FIG is only an example, and the shape of the slot is not limited here. Figure 3 The dimensions shown are a circular slot with a radius of 2 cm. Of course, 2 cm is only an exemplary value among the preset dimensions.

[0027] In step S2, the hole wall of the slot is first copper plated and then tin plated to obtain a metallized slot containing a tin layer.

[0028] Specifically, copper plating, electroplating, and tin plating can all be considered image plating processes. The copper plating followed by tin plating on the slot walls specifically involves copper plating on the slot walls, covering them with a copper layer. The copper-covered hole walls are then electroplated. Electroplating utilizes the principle of electrolysis to deposit a thin layer of metal on the surface of the copper layer. This electrolysis creates a metal film on the copper layer, preventing oxidation (e.g., rust) and improving the substrate's wear resistance, conductivity, reflectivity, and corrosion resistance.

[0029] Furthermore, after electroplating the hole walls, the hole walls are tin-plated so that the outer surface of the copper layer is covered with a tin layer. In this way, the substrate and the slots opened on the substrate can be patterned, thereby forming a desired pattern on the substrate. After copper deposition, electroplating, and tin plating, a metallized slot containing a tin layer is obtained. At this time, the outer surface of the hole wall of the slot is covered with a tin layer, a thin electroplated layer, and a copper layer.

[0030] In step S3, the tin layer in the area to be milled off of the hole wall of the metallized slot is milled off by milling, so as to expose the copper layer in the area to be milled off.

[0031] Specifically, the tin layer on the outer surface of the area to be milled is removed by a milling cutter, that is, Figure 4 As shown, Figure 4 For the top view of the slot, select a local area of ​​the slot as the area to be milled. This area to be milled is the location of the opening (can be combined with Figure 7 The size and area of ​​the area to be milled can be set according to the size of the special-shaped device to be mounted (i.e., the preset electrical device described in this application), so that the special-shaped device to be mounted can be just placed in the half-slot hole and fill the opening, thereby achieving the purpose of compact mounting.

[0032] like Figure 5 As shown, Figure 5 This is a cross-sectional view of the slot, i.e., a side view. The hole wall surface in the area to be milled is covered with copper and tin layers. The tin layer is milled off by stripping the tin, and the copper layer is retained, so that the copper layer is exposed to the air.

[0033] Furthermore, the tin layer on the outer surface of the area to be milled off is milled off, and the copper layer metal exposed in the local position can be removed after alkaline etching, which can prevent the appearance of burrs on the outer surface of the area to be milled off. Because after the tin is stripped off the outer surface of the area to be milled off, the copper layer is exposed to the air, and the burrs are generated by the milling cutter when milling the insulating material in the substrate, rather than by milling the copper layer, the copper layer is exposed to the air, which means that the outer surface of the area to be milled off is the copper layer. During the milling process, the milling cutter does not contact the insulating material of the substrate, so no burrs are generated.

[0034] In step S4, an alkaline etching solution is used to perform alkaline etching treatment on the outer surface of the area to be milled, so that the alkaline etching solution etches the copper layer, so as to expose the insulating plate of the prepared material located in the area to be milled to the air, and perform tin stripping treatment to obtain semi-metallized slots and semi-metallized exposed insulating plates.

[0035] Specifically, an alkaline etching solution is passed through the outer surface of the area to be milled, causing the alkaline etching solution to etch the copper layer, thereby forming the desired pattern on the substrate. Since the aforementioned step only strips the tin layer in the area to be milled, tin layers still exist in other areas. Therefore, these tin layers can protect the etched pattern when the alkaline etching solution etches the copper layer of the local slot wall. Furthermore, all tin layers are stripped, so that the electrical vias in the hole wall of the slot on the substrate (prepared material) become partially metallized half-slot holes in the slot wall, which can then be mounted with electrical devices to achieve the purpose of electrical connection.

[0036] Furthermore, in the area to be milled, the copper layer and the tin layer here have been removed, and the hole wall here (the hole wall corresponding to the area to be milled) only has the insulating material inside the substrate. The purpose is to prevent the electrical device from being electrically connected to the hole wall in the area to be milled when it is mounted, that is, to form insulation at the opening, and only electrically connect the hole walls at other positions in the half-slot hole except the opening, among which the via hole is located in the hole wall in the half-slot hole except the opening.

[0037] In step S5, the solder resist ink reinforcement layer and the area to be milled are milled at the position of the solder resist ink reinforcement layer by milling a slot hole to remove the area to be milled and obtain a metallized half slot hole with a smooth opening.

[0038] Specifically, a circle of solder resist ink is screen-printed on the upper surface of the etched area to be milled to form a solder resist ink reinforcement layer. The cutter body of the milling cutter passes through the solder resist ink reinforcement layer and contacts the upper surface of the area to be milled. The cutter body of the milling cutter cuts the area to be milled from the inside to the outside in the center of the slot to form a metallized half slot hole with a smooth opening, such as Figure 6 As shown, the milling cutter cuts from the center of the slot from the inside out, passing through the solder mask ink reinforcement layer and the area to be milled (the area to be milled is only the insulating material, and the copper layer and tin layer have been removed). After the area to be milled is cut, the hole wall formed at the opening is also made of insulating material, ensuring the insulation of the opening after mounting. Figure 6 As shown in the solder mask ink reinforcement layer, the milling cutter needs to cut from the center of the slot from the inside to the outside (or from top to bottom from a top-down perspective) through the upper and lower solder mask ink reinforcement layers to complete the milling of the area to be milled, so as to form a smooth and flat insulating opening. Finally, the printed circuit board formed is as follows Figure 7 As shown, Figure 7 The half-slot hole shown is a half-slot hole processed by the printed circuit board metallization half-slot hole processing method of this application. Figure 8As shown, irregularly shaped electrical components are placed in half-slot holes so that the irregular parts can fill the openings. Due to the insulation of the openings and the absence of burrs, the risk of copper wire short circuits can be eliminated and the precision of mounting can be improved.

[0039] The half-slot hole is used to place a predetermined electrical component, so that the electrical component is embedded in the half-slot hole and fills the opening. The predetermined electrical component mentioned here is, for example, an irregular electrical component, so that the irregular electrical component is compactly mounted with the half-slot hole, and the opening is insulated and the hole wall at the opening is free of burrs, thereby solving the copper wire short-circuiting problem existing in the related art.

[0040] Since the copper layer of the hole wall is easily subjected to uneven force due to the milling cutter and the copper layer during the milling process, the copper layer of the hole wall is not completely milled off, causing part of the copper material in the copper layer to curl abnormally. The copper wire and the burr will bring great safety hazards to the subsequent mounting of electrical components (for example, the copper layer is not completely milled off, resulting in a short circuit). Therefore, the present application proposes a method for processing metallized half-slot holes in a printed circuit board, which not only meets the mounting requirements of special structural parts (i.e., irregular special-shaped components) and solves the problem of space cost, but also can achieve a good mounting effect and solve the problem of burrs. On the one hand, the external dimensions become more compact and miniaturized; on the other hand, there is no need to increase the wiring area, shortening the signal transmission distance, ensuring that the electrical performance of the entire printed circuit board after mounting is better and the operation is more stable.

[0041] In the above description of this specification, reference to the terms "one embodiment / example," "another embodiment / example," or "certain embodiments / 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 application. 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 can be combined in any appropriate manner in any one or more embodiments or examples.

[0042] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

[0043] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present application, and these equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A method for processing metallized half-slot holes in a printed circuit board, characterized in that: The method comprises: Milling grooves on the prepared material for the printed circuit board to obtain slots of preset sizes; The hole wall of the slot is subjected to copper plating and then tin plating to obtain a metallized slot containing a tin layer; Milling off the tin layer in the area to be milled off of the hole wall of the metallized slot by milling, so as to expose the copper layer in the area to be milled off; Etching the copper layer in the area to be milled by alkaline etching, and forming a solder resist ink reinforcement layer at the half-slot hole fracture on the upper surface of the area to be milled after etching; At the position of the solder resist ink reinforcement layer, the solder resist ink reinforcement layer and the area to be milled are milled by milling a slot hole to remove the area to be milled and obtain a metallized half slot hole with a smooth opening; The half-slot hole is used to place a preset electrical component, so that the electrical component is embedded in the metallized half-slot hole and fills the opening.

2. The method for processing metallized half-slot holes in a printed circuit board according to claim 1, characterized in that: The method of first copper plating and then tin plating the hole wall of the slot to obtain a metallized slot containing a tin layer after treatment includes: Performing a chemical copper deposition treatment on the hole wall of the slot to obtain a metallized hole wall copper layer after the chemical copper deposition treatment, wherein the thickness of the metallized hole wall copper layer after the chemical copper deposition treatment is 1 μm-3 μm; Electroplating is performed on the metallized hole wall copper layer after the chemical copper deposition treatment to obtain a metallized groove wall copper layer after the electroplating treatment, wherein the thickness of the metallized groove wall copper layer is 25 μm-30 μm; Tin plating is performed on the basis of the metallized slot wall copper layer after the electroplating treatment to obtain the metallized slot hole containing the tin layer after the treatment.

3. The method for processing metallized half-slot holes in a printed circuit board according to claim 2, characterized in that: The method of milling off the tin layer in the area to be milled off of the hole wall of the metallized slot by milling includes: The tin layer on the outer surface of the area to be milled is removed by a milling cutter, so that the copper layer of the area to be milled is exposed to the air.

4. The method for processing metallized half-slot holes in a printed circuit board according to claim 3, characterized in that: The etching of the copper layer in the area to be milled by alkaline etching comprises: An alkaline etching solution is used to perform alkaline etching treatment on the outer surface of the area to be milled, so that the alkaline etching solution etches the copper layer, thereby exposing the insulating plate of the prepared material located in the area to be milled to the air, and performing tin stripping treatment to obtain semi-metallized slots and semi-metallized exposed insulating plates.

5. The method for processing metallized half slot holes in a printed circuit board according to claim 4, characterized in that: The method of forming a solder resist ink reinforcement layer at the half-slot hole fracture on the upper surface of the area to be milled after etching comprises: A layer of solder resist ink is screen printed on the upper and lower surfaces of the half-slot hole fracture on the upper surface of the area to be milled after etching to form a solder resist ink reinforcement layer.

6. The method for processing metallized half-slot holes in a printed circuit board according to claim 5, characterized in that: The solder resist ink reinforcement layer and the area to be milled are milled at the position of the solder resist ink reinforcement layer by milling a slot, comprising: The cutter body of the milling cutter passes through the solder resist ink reinforcement layer and contacts the upper surface of the area to be milled, and the area to be milled is milled from top to bottom by the cutter body of the milling cutter to form a metallized half slot hole with an opening.

7. The method for processing metallized half-slot holes in a printed circuit board according to claim 1, characterized in that: The preparation material is obtained by the following steps: Performing a lamination process on a preset substrate material to obtain a laminated substrate, wherein the laminated substrate is composed of an insulating material and copper; Drilling the laminated substrate to obtain a plurality of via holes located on the sidewall of the substrate to obtain the prepared material; Wherein, the via hole is used to be electrically connected to the electrical device.

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