Printed circuit board

Abstract

This utility model discloses a printed circuit board, which includes: a circuit board body, the circuit board body including: a multilayer core board; a metal substrate, the metal substrate being sandwiched between two adjacent core boards, and through holes formed on the periphery of the metal substrate, with a first metal layer formed within the through holes. By processing through holes around the metal substrate, extending to the inner core board, the metal substrate can be connected to the inner core board, increasing the connection area between the metal substrate and the inner core board. This allows for the passage of larger currents, improves the flatness of the metal substrate, and the conductive paste filling the through holes can also form a heat conduction path, transferring heat from the inside to the outside, thus improving heat dissipation capacity.

Description

Technical Field

[0001] This utility model relates to the field of PCB technology, and in particular to a printed circuit board. Background Technology

[0002] In related technologies, heat dissipation of communication wireless PCB products is mainly achieved through metal substrate embedding. However, ordinary drilling processes cannot meet the heat dissipation requirements, and the heat dissipation capacity of PCB products needs to be further improved. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a printed circuit board that increases the connection area between the metal substrate and the inner core board by processing through holes around the metal substrate, extending the through holes to the inner core board. This allows for the passage of larger currents and improves the flatness and heat dissipation of the metal substrate.

[0004] The printed circuit board according to an embodiment of the present invention includes: a circuit board body, the circuit board body including: a multilayer core board; a metal base, the metal base being sandwiched between two adjacent core boards, a through hole being provided on the periphery of the metal base, and a first metal layer being formed in the through hole.

[0005] According to the printed circuit board of this utility model embodiment, by processing through holes around the metal base and extending the through holes to the inner core board, the metal base can be connected to the inner core board, increasing the connection area between the metal base and the inner core board, which can carry a larger current and improve the flatness of the metal base. Moreover, the conductive paste filling the through holes can also form a heat conduction path, transferring heat from the inside to the outside, thus improving the heat dissipation capacity.

[0006] According to some embodiments of the present invention, there are multiple through holes, which are arranged around the metal base and adjacent through holes are in contact with each other.

[0007] According to some embodiments of the present invention, the through hole extends to the inner core plate.

[0008] According to some embodiments of the present invention, the first metal layer is connected between the inner core plate and the metal base.

[0009] According to some embodiments of the present invention, the metal substrate penetrates the circuit board body.

[0010] According to some embodiments of the present invention, a conductive paste is disposed within the first metal layer.

[0011] According to some embodiments of this utility model, the conductive paste is one of silver conductive paste and copper conductive paste.

[0012] According to some embodiments of the present invention, a second metal layer is provided on the surface of the circuit board body.

[0013] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0014] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0015] Figure 1 This is a flowchart of a method for manufacturing a printed circuit board according to an embodiment of the present utility model;

[0016] Figure 2 This is a schematic diagram of a method for manufacturing a printed circuit board according to an embodiment of the present invention. Figure 1 ;

[0017] Figure 3 This is a schematic diagram of a method for manufacturing a printed circuit board according to an embodiment of the present invention. Figure 2 ;

[0018] Figure 4 This is a schematic diagram of a method for manufacturing a printed circuit board according to an embodiment of the present invention. Figure 3 ;

[0019] Figure 5 This is a schematic diagram of a method for manufacturing a printed circuit board according to an embodiment of the present invention. Figure 4 ;

[0020] Figure 6 This is a schematic diagram of a method for manufacturing a printed circuit board according to an embodiment of the present invention. Figure 5 ;

[0021] Figure 7 This is a schematic diagram of a method for manufacturing a printed circuit board according to an embodiment of the present invention. Figure 6 ;

[0022] Figure 8 This is a schematic diagram of a method for manufacturing a printed circuit board according to an embodiment of the present invention. Figure 7 .

[0023] Figure label:

[0024] 11. Metal base; 12. First through hole; 13. Second through hole. Detailed Implementation

[0025] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0026] The following is for reference. Figures 1-8 A printed circuit board according to an embodiment of the present invention is described.

[0027] The printed circuit board according to an embodiment of the present invention includes: a circuit board body, the circuit board body including: a multilayer core board and a metal base 11, the metal base 11 being sandwiched between two adjacent core boards, and a through hole being provided on the periphery of the metal base 11, and a first metal layer being formed in the through hole.

[0028] According to the printed circuit board of this utility model embodiment, by processing through holes around the metal base 11 and extending the through holes to the inner core board, the metal base 11 can be connected to the inner core board, increasing the connection area between the metal base 11 and the inner core board, which can carry a larger current and improve the flatness of the metal base 11. Moreover, the conductive paste filling the through holes can also form a heat conduction path, transferring heat from the inside to the outside, thus improving the heat dissipation capacity.

[0029] There are multiple through holes, which are arranged around the metal base 11, and two adjacent through holes are in contact with each other.

[0030] The through-holes extend to the inner core board. Thus, the inner core board and the metal substrate 11 can be electrically connected through the through-holes, thereby enabling current conduction on the printed circuit board. Furthermore, a first metal layer is connected between the inner core board and the metal substrate 11.

[0031] The metal substrate 11 penetrates the main body of the circuit board. In this embodiment, the metal substrate 11 is an embedded metal substrate, meaning that a metal with good thermal conductivity (such as aluminum or copper) is used as the core layer and embedded in the middle of the multilayer core board. It is isolated from the outer circuitry by an insulating layer, thereby improving the thermal management performance, mechanical strength, or electromagnetic shielding capability of electronic products.

[0032] Reference Figure 1 As shown, the method for manufacturing a printed circuit board according to this utility model embodiment includes: pressing a multilayer core board and a metal substrate 11 together to form a circuit board body. Specifically, the core board, prepreg, and metal substrate 11 are pressed together according to the designed structure to form a single circuit board body. A ring of through holes is processed around the metal substrate 11, located at the boundary where other parts of the circuit board body connect with the metal substrate 11. The through holes are electroplated and filled with conductive paste. Filling with conductive paste can establish vertical electrical connections, ensuring circuit conductivity between the layers of the circuit board body. The prepreg is a thin sheet material made by impregnating treated fiberglass cloth with resin and then heat-treating it. It softens under heat and pressure and solidifies upon cooling, and is a key material in PCB manufacturing.

[0033] The through-holes extend to the inner core board, allowing the metal base 11 to connect with it. This increases the connection area between the metal base 11 and the inner core board, enabling the passage of larger currents and improving the flatness of the metal base 11. Furthermore, the conductive paste connecting the inner core board creates a heat-conducting path, transferring heat from the inside to the outside, thus enhancing heat dissipation. The metal base 11 is a metal block embedded in the circuit board body, and it can be copper-based.

[0034] Therefore, by processing through holes around the metal base 11 and extending the through holes to the inner core board, the metal base 11 can be connected to the inner core board, increasing the connection area between the metal base 11 and the inner core board. This allows for the passage of a larger current and improves the flatness of the metal base 11. Furthermore, the conductive paste filling the through holes can form a heat conduction path, transferring heat from the inside to the outside, thus improving heat dissipation.

[0035] Reference Figure 2-5 As shown, the steps of machining a ring of through holes around the metal substrate 11, electroplating the through holes, and filling the through holes with conductive paste include: machining a ring of first through holes 12 around the metal substrate 11, with adjacent first through holes 12 spaced apart; electroplating the first through holes 12; and filling the first through holes 12 with conductive paste. Specifically, on the laminated circuit board body, a ring of first through holes 12 is machined around the metal substrate 11 using a mechanical drill to prepare for subsequent metallization. A gap of one through hole is left between adjacent first through holes 12, and then the first through holes 12 are filled with paste.

[0036] Furthermore, refer to Figure 6-8 As shown, after filling the first through hole 12 with conductive paste, the process further includes: machining a ring of second through holes 13 around the metal substrate 11, with the second through holes 13 positioned between two adjacent first through holes 12; electroplating the second through holes 13; and filling the second through holes 13 with conductive paste. That is, the second through holes 13 are drilled between two adjacent first through holes 12, and then plugged with conductive paste. In other words, drilling a ring of holes around the metal substrate 11 requires two operations: first, drilling the first through holes 12 with an interval; and second, drilling the second through holes 13 in the gap. This avoids uneven heating of the material caused by continuous drilling, which could lead to excessive stress or even deformation and cracking. By using intermittent drilling, drilling the first through holes 12 first to maintain material strength, and then drilling the second through holes 13 after the material has slightly released stress, effectively prevents crack propagation or deformation. Furthermore, the intermittently drilled first through holes 12 can also dissipate heat, reducing the localized high temperatures caused by continuous drilling. The material temperature is lower during the second drilling, thus improving the hole wall quality.

[0037] Furthermore, the electroplating step for the through-hole includes: descaling, copper plating, and electroplating the through-hole to form a first metal layer within the through-hole, the first metal layer being connected between the inner core board and the metal substrate 11. Alternatively, descaling, copper plating, and electroplating the circuit board body are performed to form a second metal layer on the surface of the circuit board body.

[0038] Specifically, drill smudge removal refers to the process where, due to the high-speed rotation of the drill bit, drill smudges may form on the hole walls. These smudges include melted epoxy resin, glass fiber fragments, dust residue, and impurities from drill bit wear. These contaminants can hinder subsequent metal layer deposition and affect the quality of conductive connections. Therefore, it is necessary to remove these contaminants after drilling to ensure good metal layer adhesion. Chemical or plasma treatments are typically used, employing alkaline or acidic chemical solutions (such as sulfuric acid or potassium permanganate) to remove organic contaminants from the hole walls. Plasma oxidation is particularly suitable for removing drill smudges, especially for high-density PCBs.

[0039] Copper plating refers to depositing a uniform layer of conductive copper on the inner walls of the first through-hole 12 and the second through-hole 13 on the main body of the circuit board, providing a foundation for subsequent electroplating. The hole walls after drilling are mainly composed of resin and glass fiber, which are non-conductive. A thin copper layer must first be formed before subsequent electroplating can thicken the surface. The copper plating process can use a palladium catalyst to deposit an activation layer on the hole walls, allowing subsequent electroless copper plating to adhere. Then, a chemical reduction reaction is used to form an extremely thin copper layer on the hole walls. This ensures uniform copper coverage during subsequent electroplating, provides initial conductivity, and guarantees that current can smoothly pass through the hole walls during electroplating.

[0040] Electroplating is the process of using electric current to thicken a copper layer, thereby improving its conductivity and mechanical strength. This provides sufficient conductivity and mechanical strength to ensure the reliability of the circuit board during soldering and use.

[0041] Furthermore, the copper thickness of the holes can be enhanced by plating through exposed holes.

[0042] Furthermore, a conductive paste is disposed within the first metal layer. The conductive paste is used to form conductive paths on a non-conductive substrate, that is, to form a conductive layer on the surface of a non-conductive material by coating or printing, for connecting different components in a circuit.

[0043] The conductive paste is either silver or copper. It consists of copper or silver particles and an organic solvent. Silver conductive paste exhibits excellent conductivity and high electron mobility, making it suitable for high-frequency and precision circuits. Silver does not form an oxide layer in air, exhibits strong oxidation resistance, and maintains good conductivity even after long-term use. It is suitable for humid and high-temperature environments and is not easily degraded by oxidation. Furthermore, it boasts high stability and good weather resistance, making it suitable for outdoor applications and high-end precision circuits. Copper conductive paste has a lower cost, significantly reducing production costs, making it suitable for mass production. It also offers good conductivity and higher mechanical strength.

[0044] Furthermore, the spacing of the holes drilled around the metal base 11 can be adjusted according to different designs, and the drilling, hole metallization and hole plugging steps can be repeated multiple times until the area around the metal base 11 is completely transformed into through holes that can connect the inner core board and other parts of the circuit board body.

[0045] The metal substrate 11 extends through the main body of the circuit board. In other words, the metal substrate 11 can be a through-type metal substrate 11. A through-type metal substrate 11 has a simple structure, no intermediate obstructions, and reduces energy loss. It also allows for rapid heat conduction and better heat dissipation performance.

[0046] In addition, a second metal layer is provided on the surface of the circuit board body. This second metal layer can be used to provide electrical connections, enhance conductivity, and protect the circuitry.

[0047] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0049] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A printed circuit board, characterized in that, include: The circuit board body includes: Multilayer core board; A metal substrate is sandwiched between two adjacent core plates, and a through hole is provided on the periphery of the metal substrate, and a first metal layer is formed in the through hole.

2. The printed circuit board according to claim 1, characterized in that, There are multiple through holes, which are arranged around the metal base, and adjacent through holes are in contact with each other.

3. The printed circuit board according to claim 1, characterized in that, The through-hole extends into the inner core plate.

4. The printed circuit board according to claim 3, characterized in that, The first metal layer is connected between the inner core plate and the metal base.

5. The printed circuit board according to claim 1, characterized in that, The metal substrate penetrates the main body of the circuit board.

6. The printed circuit board according to claim 1, characterized in that, The first metal layer contains a conductive paste.

7. The printed circuit board according to claim 6, characterized in that, The conductive paste is one of silver conductive paste and copper conductive paste.

8. The printed circuit board according to claim 1, characterized in that, A second metal layer is provided on the surface of the circuit board body.

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