Printed circuit board, electronic device and electromechanical equipment

Abstract

The invention relates to a printed circuit board, an electronic device and an electromechanical device. The printed circuit board is configured to have at least two electrically conductive layers and at least one dielectric layer, the electrically conductive layers and the dielectric layer are arranged in a stacked manner and the dielectric layer is arranged between two adjacent electrically conductive layers, at least one of the dielectric layers comprises a first dielectric material, and at least one of the dielectric layers comprises a second dielectric material. The first dielectric material is a plant fiber material obtained by at least partially removing lignin in a plant. According to the scheme, the plant fiber material made of raw materials such as natural bamboos can be used for replacing traditional materials such as glass fibers to manufacture the PCB, performance requirements can be met, reduction of carbon footprint and greenhouse gas emission can be promoted, and the purpose of environmental protection is achieved.

Description

Printed circuit boards, electronic devices and electromechanical equipment Technical Field

[0001] The present invention relates to the technical field of electronic devices, and more particularly, to printed circuit boards, electronic devices, and electromechanical equipment. Background Art

[0002] A printed circuit board (PCB) is a substrate used in electrical and electronic engineering to interconnect electronic devices in a controlled manner. It often adopts a stacked structure consisting of conductive layers and dielectric layers. Patterns of traces, planes and other features (similar to wires on a plane) that meet application requirements are usually designed on the conductive layers. For example, this can be achieved by etching one or more copper layers located above the dielectric layer and / or between different layers.

[0003] During use, electronic components are fixed to the conductive layers located on the outer layers of the PCB. These electronic components are designed for terminal devices or equipment and are generally soldered to electrically connect and mechanically secure them to the PCB. Another manufacturing process adds through-holes to allow electronic components to be interconnected through different layers. The dielectric layers in PCBs are typically made of dielectric composite materials. These composite materials consist of a matrix (usually epoxy resin) and a reinforcement (usually a woven fabric such as non-woven fabric, fiberglass, or sometimes even paper). In some cases, fillers such as ceramics may be added to the resin.

[0004] Currently, high-performance glass fibers with high strength, high modulus, and a large aspect ratio have been widely used in the manufacture of PCBs. For example, FR-4 grade epoxy resin is the most commonly used dielectric material. It is an epoxy resin in which glass fibers are used to increase properties such as toughness. The present application notes that the preparation process of synthetic glass fibers is complex, demanding, energy-intensive, and has a large carbon footprint. In particular, after the product is used, it is difficult to recycle and naturally degrade. Therefore, in the face of energy shortages and carbon emission constraints, how to fully utilize suitable materials such as natural materials that are renewable, low-cost, and have a low carbon footprint to manufacture PCBs is of great practical significance.

[0005] Summary of the Invention

[0006] In view of this, the present invention provides a printed circuit board, an electronic device and an electromechanical device, which can solve or at least alleviate one or more of the above-mentioned problems and other problems existing in the prior art, or can provide an alternative technical solution for the prior art.

[0007] According to one aspect of the present invention, a printed circuit board is first provided, which is constructed with at least two conductive layers and at least one dielectric layer, wherein the conductive layers and the dielectric layers are stacked and arranged, and the dielectric layer is arranged between two adjacent conductive layers. At least one of the dielectric layers contains a first dielectric material, which is a plant fiber material obtained by at least partially removing lignin from a plant.

[0008] In the printed circuit board according to the present invention, optionally, the plant comprises a herbaceous plant or a woody plant, lignin in the plant is removed through chemical treatment, and at least a partially collapsed cellulose-based tubular structure remains in the plant fiber material.

[0009] In the printed circuit board according to the present invention, optionally, the herb is natural bamboo, and the plant fiber material is a natural bamboo fiber material obtained by removing 5% to 95% of lignin from the natural bamboo.

[0010] In the printed circuit board according to the present invention, optionally, at least another dielectric layer among the dielectric layers comprises a second dielectric material, and the second dielectric material is different from the first dielectric material.

[0011] In the printed circuit board according to the present invention, optionally, the printed circuit board has a first conductive layer and a second conductive layer, the first conductive layer and the second conductive layer are stacked and arranged on the first side and the second side of the dielectric layer, respectively, and circuit traces for forming a circuit layer are provided on the first conductive layer and the second conductive layer.

[0012] According to another aspect of the present invention, there is further provided an electronic device, comprising the printed circuit board as described above, wherein the conductive layer is provided with circuit traces for forming a circuit layer.

[0013] In the electronic device according to the present invention, optionally, the electronic device has an electronic component and a heat sink, the electronic component is mounted on the conductive layer and is electrically connected to the circuit layer, and the heat sink is attached to the conductive layer to form a heat transfer path from the electronic component via the printed circuit board to the heat sink.

[0014] In the electronic device according to the present invention, optionally, the electronic device includes a QFP device, a FET device or an IGBT device, and / or the electronic device is mounted on the conductive layer by sintering, bonding or welding.

[0015] In the electronic device according to the present invention, optionally, an additional layer is provided between the heat sink and the conductive layer, and the additional layer is formed of a thermally conductive gap filling material.

[0016] In the electronic device according to the present invention, optionally, the thermally conductive gap filling material includes a silicone material with ceramic fillers.

[0017] In the electronic device according to the present invention, optionally, the electronic device is a power module, and / or the circuit layer is provided with a power interface, an input interface and an output interface, the electronic device is connected to the input power via the power interface, and receives an input signal via the input interface and forms an output signal after processing by the electronic device provided on the printed circuit board, and the output signal is output externally via the output interface.

[0018] According to yet another aspect of the present invention, there is further provided an electromechanical device, comprising:

[0019] An electronic device as described in any one of the above items; and

[0020] A working component is electrically connected to the output interface of the electronic device and is used to receive an output signal from the output interface to work. The working component includes a motor.

[0021] The solution of the present invention can use plant fiber materials made from natural bamboo and other raw materials to replace traditional materials such as glass fiber to manufacture PCB boards. This not only meets performance index requirements, but also can effectively reduce carbon footprint and greenhouse gas emissions, promote the easing of energy demand, and achieve green environmental protection goals. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic diagram showing the structure of a first embodiment of an electronic device according to the present invention.

[0023] FIG. 2 is a schematic diagram showing the structure of a second embodiment of an electronic device according to the present invention.

[0024] FIG3 is a schematic diagram showing the structure of an electromechanical device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] As an exemplary illustration, FIG1 first schematically shows the composition of an embodiment of an electronic device according to the present invention. In this embodiment, an example of a printed circuit board according to the present invention is configured and used. The following will specifically introduce the solution of the present invention in conjunction with the embodiment shown in FIG1.

[0026] As shown in FIG1 , a printed circuit board 10 is a support carrier used for connecting electronic circuits to electronic devices. It is configured with two conductive layers 11 and a dielectric layer 12 formed in a stacked arrangement, wherein the dielectric layer 12 is arranged between the two conductive layers 11 to provide insulation isolation, basic support, and other functions. Circuit traces can be set on the two conductive layers 11 as needed to form the desired circuit layer, thereby providing electronic circuits for electrically connecting electronic devices of the type and quantity required for a specific application, such as QFP (Quad Flat Package) devices, field effect transistors, insulated gate bipolar transistors, etc., such as QFP logic chips, MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), IGBTs (Insulated Gate Bipolar Transistors), etc. In FIG1 , the two electronic devices are simply exemplarily indicated by the reference numeral 20, one of which is schematically illustrated as a QFP device and the other as an electronic device that can be used to constitute a functional module such as an ECU (Electronic Control Unit).

[0027] Unlike the use of traditional materials such as glass fiber and non-woven fabrics that have long been commonly used in the industry in the matrix (such as epoxy resin, etc.), the dielectric layer 12 in the printed circuit board 10 uses a specific dielectric material. That is, the present invention innovatively proposes to use plant fiber materials as dielectric materials to replace traditional materials commonly used in the industry. Such plant fiber materials can be selected from plants such as herbaceous plants (such as bamboo, sugarcane, reed, palm, rattan, etc.) or woody plants (such as elm, fir, sandalwood, etc.), and then can be obtained by removing all or part of the lignin contained in the plants according to specific needs by using methods such as chemical processing.

[0028] For example, in one or some embodiments, one or more chemical solutions (such as alkaline solutions or acidic solutions, such as sodium hydroxide solution, potassium hydroxide solution, sodium sulfide solution, organic peracid solution, etc.) can be used to remove lignin contained in natural plants (such as natural bamboo, etc.). For example, 5% to 95% of the contained lignin can be removed as needed to make corresponding plant fiber materials (such as natural bamboo fiber materials, etc.). In the obtained plant fiber material, basically all or part of the collapsed cellulose-based tubular structure can be retained as needed, thereby obtaining a cellulose long fiber bundle structure with high performance. The prior art has provided some specific technical solutions on how to remove lignin from plants to obtain plant fiber materials. For example, some optional implementation plans are discussed in a paper entitled “Sustainable High-strength Microfibers Extracted From Natural Bamboo” published on pages 235–244 of Nature Sustainability 5 (2022). The present invention does not make specific limitations on such treatment processes and allows their implementation and application to obtain corresponding plant fiber materials.

[0029] For ease of understanding, natural bamboo will be used as the raw material for demonstration and explanation below, but it should be understood that the same or similar processing methods can be applied to other types of plants to obtain plant fiber materials derived from the plant type accordingly.

[0030] When selecting natural bamboo as raw material and removing lignin therein, the lignin in the corner area of ​​bamboo cells can be removed by using, for example, organic peroxides, etc., at this moment, colloid components and composite intercellular layers etc. can also be removed, and then the fiber bundle and adjacent parenchyma cells can be effectively separated by hydraulic shearing. Because the reactivity of organic peroxide to cellulose is relatively low, it is conducive to controlling or avoiding the serious depolymerization of cellulose molecular chains produced during the removal of lignin, so that cellulose can maintain a high degree of polymerization when the crystallinity increases. Subsequently, natural air drying can be carried out, and in this process, due to the removal of lignin components and the effect of capillary forces in the fiber cell wall, more hydrogen bonds and van der Waals forces can be formed between the neatly arranged microfibrils (such as nanometer size level) in the cell wall, promoting the self-densification of the fiber bundle to form a collapsed cellulose-based tubular structure, so that the microfibrils in the cell wall can be more closely combined and densely arranged in the cell wall, thereby significantly enhancing the bonding strength and crystallinity between the plant fibers, effectively reducing internal structural defects.

[0031] Mechanical test results show that the bamboo fiber material obtained after lignin removal has excellent mechanical properties, demonstrating a high tensile strength of 1.90±0.32GPa and a high Young's modulus of 91.3±29.7GPa. This means that the ultimate tensile strength and Young's modulus can reach 2.20GPa and 120GPa, respectively. Therefore, it is fully comparable to glass fiber materials and some carbon fiber materials, and may even exhibit better performance. Furthermore, compared with existing materials used to manufacture PCBs, plants such as natural bamboo not only grow naturally quickly and are easily available on a large scale and at low cost, but also have a significantly lower carbon footprint when producing materials such as bamboo fiber. According to tests, carbon emissions can be reduced by 25%-92%. This has considerable positive significance and beneficial impacts in replacing existing materials such as glass fiber and non-woven fabrics in the manufacture of PCBs, effectively alleviating energy demand, reducing greenhouse gas emissions, and protecting the natural environment.

[0032] Continuing with reference to the embodiment of FIG1 , a plant fiber material can be used in conjunction with a matrix (such as epoxy resin) to form the dielectric layer 12 of the printed circuit board 10. A conductive layer 11 can be stacked on both sides of the dielectric layer 12. Circuit traces are provided on the two conductive layers 11 to form an electronic circuit layout to provide a circuit layer so that one or more electronic devices required for the application can be mounted on the printed circuit board 10. Any feasible process such as sintering (such as silver sintering), bonding, or welding can be used to attach the electronic devices to the conductive layer 11 and form an electrical connection with the electronic circuits on the circuit layer. The conductive layer 11 can be made of a conductive material such as copper and processed through etching, laser burning, and other processes to form various possible circuit layers that meet actual needs.

[0033] The specific number and arrangement positions of the conductive layer 11 and the dielectric layer 12 on the printed circuit board 10 can be designed as needed to meet the requirements of different applications. For example, in another embodiment of an electronic device according to the present invention shown in FIG2 , it is shown that a greater number of conductive layers 11 and dielectric layers 12 can be arranged relative to the embodiment of FIG1 . This will be beneficial for providing any possible, even complex electronic circuit layout, and promoting the realization of more stable performance and more advanced and rich functional applications of the electronic device. In addition, it should be understood that in one or some optional embodiments, one or more dielectric layers 12 on the printed circuit board 10 can be made of the plant fiber material proposed in the present invention (which can be based on the same or different plant raw materials), while another one or some dielectric layers 12 on the printed circuit board 10 can be made of other suitable materials, such as glass fiber, non-woven fabric, paper, etc., so that it is possible to fully utilize the different material properties to meet various possible application requirements.

[0034] In the exemplary electronic devices 100 and 200 shown in Figures 1 and 2 , respectively, a heat sink 30 for cooling and dissipating heat is also shown. Depending on the application requirements, the heat sink 30 can be attached to the conductive layer 11 of the printed circuit board 10 using any feasible method, such as welding or bonding, thereby joining them together to form a heat transfer path from the electronic device 20 through the printed circuit board 10 to the heat sink 30. This is used to dissipate heat and cool the electronic device 20, the printed circuit board 10, etc., and promote stable and reliable operation of the electronic device.

[0035] In addition, as an optional situation, an additional layer 40 can be arranged between the heat sink 30 and the conductive layer 11. It can be formed using a thermally conductive filling material (such as a silicone material with ceramic filler, etc.). The additional layer 40 can help form a more sufficient contact between the heat sink 30 and the conductive layer 11, thereby promoting the heat sink 30 to achieve a more thorough and uniform heat dissipation effect.

[0036] It should be pointed out that the present invention does not impose any restrictions on the materials used, structural structure, number of settings, layout position, etc. of the radiator 30 itself. For example, the radiator 30 can be made of conventional thermally conductive materials such as copper, aluminum or aluminum alloy, and it can have structures such as heat dissipation fins (such as needle-shaped, corrugated, etc.), an internal cavity for filling with cooling medium (such as water, etc.), etc.

[0037] The electronic device according to the present invention can have a variety of application types, such as power modules, etc. According to actual application requirements, various possible interfaces such as power interfaces, input interfaces, and output interfaces can be set on the circuit layer of the printed circuit board 10 configured for the electronic device. For example, the input power and input signal from the outside of the electronic device can be introduced into the electronic device through the power interface and the input interface, respectively, so that the input signal can be processed by the corresponding electronic device 20 installed on the printed circuit board 10 to form an output signal, and then the output signal is output to the outside through the output interface to provide it to the required application. For example, when the electronic device 20 is set as a FET and / or IGBT and / or QFP device, the input power can be converted into a corresponding output voltage signal according to the input signal through such electronic devices and other electronic devices that may be set on the printed circuit board 10. Such an output voltage signal can be provided to the corresponding working component (such as a motor, etc.) to enable it to operate.

[0038] The present invention also provides an electromechanical device, which may include a working component (such as a motor) and an electronic device according to the present invention. By electrically connecting the working component to an output interface of the electronic device, the working component can be operated upon receiving an output signal from the output interface. The electromechanical device according to the present invention may be of a wide variety of types, including, but not limited to, compressors and hydraulic devices.

[0039] Referring to FIG3 , an embodiment of an electromechanical device according to the present invention is exemplarily shown. In the electromechanical device example of FIG3 , the electronic device 300 is embodied as an inverter, in which a printed circuit board of the present invention can be configured. In order to simplify the drawing, other parts of the inverter have been omitted in FIG3 except for the module part composed of IGBTs. Specifically, by grouping, for example, six electronic devices 20 (using IGBTs in this case) in pairs to form a three-phase bridge arm, they are electrically connected to form an IGBT power module to control the inverter to convert between AC and DC voltages (for example, converting DC voltage into AC voltage, or the opposite voltage conversion operation). The output voltage after the inverter conversion process can be provided to a working component 400 such as a motor to enable it to operate.

[0040] The printed circuit board, electronic device, and electromechanical equipment according to the present invention are described in detail above by way of example only. These examples are intended solely to illustrate the principles and implementation methods of the present invention and are not intended to limit the present invention. Various modifications and improvements may be made by those skilled in the art without departing from the scope of the present invention. Therefore, all equivalent technical solutions are intended to fall within the scope of the present invention and are defined by the claims of the present invention.

Claims

1. A printed circuit board (10), comprising at least two conductive layers (11) and at least one dielectric layer (12), wherein the conductive layers (11) and the dielectric layers (12) are stacked and arranged, and the dielectric layer (12) is arranged between two adjacent conductive layers (11), characterized in that: At least one of the dielectric layers (12) comprises a first dielectric material, wherein the first dielectric material is a plant fiber material obtained by at least partially removing lignin from plants.

2. The printed circuit board (10) according to claim 1, wherein: The plant comprises a herbaceous plant or a woody plant, lignin in the plant is removed by chemical treatment, and at least a partially collapsed cellulose-based luminal structure is retained in the plant fiber material.

3. The printed circuit board (10) according to claim 2, wherein: The herb is natural bamboo, and the plant fiber material is a natural bamboo fiber material obtained by removing 5% to 95% of lignin in the natural bamboo.

4. The printed circuit board (10) according to claim 1, wherein: At least one other of the dielectric layers (12) comprises a second dielectric material that is different from the first dielectric material.

5. The printed circuit board (10) according to claim 1, wherein: The printed circuit board (10) has a first conductive layer and a second conductive layer, the first conductive layer and the second conductive layer are stacked and arranged on a first side and a second side of the dielectric layer (12), respectively, and circuit traces for forming a circuit layer are arranged on the first conductive layer and the second conductive layer.

6. An electronic device (100, 200, 300), characterized in that: The electronic device (100, 200, 300) comprises a printed circuit board (10) according to any one of claims 1 to 5, wherein the conductive layer (11) is provided with circuit traces for forming a circuit layer.

7. The electronic device (100, 200, 300) according to claim 6, wherein: The electronic device (100, 200, 300) comprises an electronic component (20) and a heat sink (30), wherein the electronic component (20) is mounted on the conductive layer (11) and is electrically connected to the circuit layer, and the heat sink (30) is attached to the conductive layer (11) to form a heat transfer path from the electronic component (20) to the heat sink (30) via the printed circuit board (10).

8. The electronic device (100, 200, 300) according to claim 7, wherein: The electronic device (20) comprises a QFP device, a FET device or an IGBT device, and / or the electronic device (20) is mounted on the conductive layer (11) by sintering, bonding or welding.

9. The electronic device (100, 200, 300) according to claim 7, wherein: An additional layer (40) is provided between the heat sink (30) and the conductive layer (11), and the additional layer (40) is formed of a thermally conductive gap filling material.

10. The electronic device (100, 200, 300) according to claim 9, wherein: The thermal conductive gap filling material comprises a silica gel material with ceramic fillers.

11. The electronic device (100, 200, 300) according to claim 6, wherein: The electronic device (100, 200, 300) is a power module, and / or the circuit layer is provided with a power interface, an input interface and an output interface; the electronic device (100, 200, 300) is connected to an input power source via the power interface, and receives an input signal via the input interface and forms an output signal after processing by the electronic device (20) provided on the printed circuit board (10); the output signal is output to the outside via the output interface.

12. An electromechanical device, characterized in that: include: The electronic device (100, 200, 300) according to any one of claims 6 to 11; and A working component (400) is electrically connected to an output interface of the electronic device (100, 200, 300) and is used to receive an output signal from the output interface to work. The working component (400) includes a motor.

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