Composite circuit board and electronic equipment

Abstract

The utility model relates to a composite circuit board and electronic equipment. The composite circuit board comprises a substrate; the heat dissipation plate is fixedly connected with the substrate; the circuit board is electrically connected with the substrate and the heat dissipation plate; the circuit board comprises a conductive layer, a first protection layer and a second protection layer, the conductive layer is clamped between the first protection layer and the second protection layer, the second protection layer is connected with the substrate, and the first protection layer is connected with the heat dissipation plate; the first protection layer is provided with an avoiding area, the avoiding area is arranged to expose part of the structure of the conductive layer, and the first protection layer located in the avoiding area is provided with a plurality of bending parts. The avoiding area realizes the windowing design of the circuit board so as to expose the conducting layer, and the plurality of bending parts can avoid the problem of poor wire breakage caused by stress on the conducting layer at the soldering tin position. The intervention circuit board is electrically connected with the substrate and the heat dissipation plate without depending on direct electrical connection of the substrate and the heat dissipation plate, the overall stress bearing capacity of the composite circuit board is improved, and it is guaranteed that the composite circuit board does not lose efficacy.

Description

Technical Field

[0001] This application relates to the field of electronic equipment technology, and more particularly to a composite circuit board and electronic equipment. Background Technology

[0002] With the rapid development of LiDAR technology, its products have been widely used in various fields such as autonomous driving, robot navigation, and terrain mapping. LiDAR products generate significant heat during operation, requiring effective heat dissipation structures to ensure stable operation. Ceramic plates are often chosen as heat dissipation materials for LiDAR products due to their excellent thermal conductivity and mechanical strength. However, with the increasing trend towards miniaturization in electronic devices, simple ceramic plate heat dissipation structures are no longer sufficient to meet design requirements. Therefore, in practical applications, it is often necessary to stack ceramic plates with FR4 (Fiberglass Reinforced Epoxy) boards to form a composite structure that meets both heat dissipation and miniaturization requirements.

[0003] In related technologies, PCBA (Printed Circuit Board Assembly) stacked structure, for example, involves setting four pads on a ceramic plate, with the FR4 board and pads connected by SMT (Surface Mount Technology) soldering. This connection method not only achieves the physical connection between the ceramic plate and the FR4 board, but also undertakes the task of electrical signal transmission.

[0004] However, LiDAR products typically operate at high temperatures, and ceramic and FR4 boards have significantly different coefficients of thermal expansion due to their different materials. Under high-temperature operating conditions, the FR4 board, with its higher coefficient of thermal expansion, undergoes greater deformation, while the ceramic board, with its lower coefficient of thermal expansion, experiences less deformation. This difference in deformation causes the solder joints connecting the ceramic and FR4 boards to bear enormous stress under prolonged high-temperature operation, leading to solder cracking and ultimately causing the stacked board to fail.

[0005] Meanwhile, during the assembly process of PCBA stacked board structures, FR4 boards are susceptible to deformation due to their material properties. This deformation not only affects the alignment accuracy between pads but can also directly lead to solder cracking, thereby reducing the reliability and lifespan of the stacked board. This deformation problem caused by external forces is particularly prominent in automated production lines, posing a severe challenge to product quality control and production efficiency. Utility Model Content

[0006] This application provides a composite circuit board and electronic device that can avoid the problem of broken wires caused by stress at the solder joint, and ensure that the composite circuit board will not fail.

[0007] In a first aspect, this application provides a composite circuit board, comprising:

[0008] substrate;

[0009] A heat sink is fixedly connected to the substrate; and

[0010] A circuit board is electrically connected to the substrate and the heat sink, respectively. The circuit board includes a conductive layer, a first protective layer and a second protective layer. The conductive layer is sandwiched between the first protective layer and the second protective layer. The second protective layer is connected to the substrate and the first protective layer is connected to the heat sink.

[0011] The first protective layer has an avoidance area, which is configured to expose a portion of the conductive layer, and the first protective layer located in the avoidance area has multiple bends.

[0012] In one possible implementation, a plurality of the curved portions are arranged sequentially along a first direction of the composite circuit board, such that the plurality of curved portions are spliced ​​together in a sawtooth shape.

[0013] In one possible implementation, the curved portion includes a first curved edge and a second curved edge, with a chamfer between the first curved edge and the second curved edge;

[0014] Wherein, the first curved edge has a first angle relative to the second direction of the composite circuit board, and the second curved edge has a second angle relative to the second direction of the composite circuit board, wherein the first angle and the second angle are different.

[0015] In one possible implementation, a plurality of first pads are provided on the side of the first protective layer opposite to the conductive layer, and the circuit board is connected to the heat sink through the first pads.

[0016] In one possible implementation, a plurality of the pads are arranged sequentially along a first direction of the composite circuit board, and adjacent pads are staggered.

[0017] In one possible implementation, a plurality of second pads are provided on the side of the conductive layer near the first protective layer, and the plurality of second pads are arranged at intervals along a first direction of the composite circuit board.

[0018] A third pad is provided on the substrate, and the conductive layer is connected to the third pad of the substrate through the second pad.

[0019] In one possible implementation, the conductive portion located below the second pad is provided with a cutout; wherein the cutout is semi-circular in shape, and the diameter of the cutout is larger than the diameter of the third pad.

[0020] In one possible implementation, an adhesive portion is provided on the side of the second protective layer opposite to the conductive portion, and the second protective layer is bonded to the substrate through the adhesive portion;

[0021] The adhesive portion has a predetermined distance from the edge of the curved portion along the second direction of the composite circuit board.

[0022] In one possible implementation, a plurality of fourth welding pads are provided between the heat sink and the substrate, and the plurality of fourth welding pads are arranged along the circumference of the heat sink.

[0023] Secondly, this application provides a composite circuit board, comprising:

[0024] substrate;

[0025] A heat sink is fixedly connected to the substrate; and

[0026] Two circuit boards are symmetrically arranged along a first direction of the composite circuit board, and each circuit board is electrically connected to the substrate and the heat sink, respectively.

[0027] Each of the circuit boards includes a conductive layer, a first protective layer, and a second protective layer, with the conductive layer sandwiched between the first protective layer and the second protective layer. The first protective layer is connected to the substrate, and the second protective layer is connected to the heat sink.

[0028] The first protective layer has an avoidance area, which is configured to expose a portion of the conductive layer, and the first protective layer located in the avoidance area has multiple bends.

[0029] Thirdly, this application provides an electronic device, comprising:

[0030] The equipment itself; and

[0031] Composite circuit boards as described in the first aspect; and / or composite circuit boards as described in the second aspect.

[0032] The technical solutions provided in this application have the following advantages compared with the prior art:

[0033] The composite circuit board and electronic device provided in this application embodiment feature a windowed design in the avoidance area to expose the conductive layer. Multiple bends prevent stress on the conductive layer at the solder joints, thus avoiding wire breakage. The intervening circuit board achieves electrical connection with the substrate and heat sink, without relying on direct electrical connection between the substrate and heat sink, thereby improving the overall stress resistance of the composite circuit board and ensuring its continued operation. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0037] Figure 1 This is a schematic diagram of the structure of a composite circuit board provided in an embodiment of this application;

[0038] Figure 2 for Figure 1 The AA section view shown;

[0039] Figure 3 This is a schematic diagram of the circuit board structure provided in an embodiment of this application;

[0040] Figure 4 A schematic cross-sectional view of the circuit board provided in an embodiment of this application;

[0041] Figure 5 This is a schematic diagram of the structure of a composite circuit board provided in an embodiment of this application;

[0042] Figure 6 for Figure 5 The BB cross-sectional view shown.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. Substrate; 11. Third pad; 2. Heat sink; 3. Circuit board; 31. Conductive layer; 311. Second pad; 312. Cutout; 32. First protective layer; 321. Clearance area; 322. Bending portion; 3221. First curved edge; 3222. Second curved edge; 33. Second protective layer; 34. Glue; 35. Adhesive portion; 36. First pad; 4. Fourth pad. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0047] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0048] First Embodiment

[0049] like Figures 1-4As shown, a composite circuit board includes a substrate 1, a heat sink 2, and a circuit board 3. The substrate 1 is made of, for example, fiberglass reinforced epoxy (FR4) material, giving it good electrical, mechanical, thermal, corrosion resistance, and aging resistance, while also being easy to process and low in cost. The heat sink 2 is, for example, a ceramic plate, giving it good heat dissipation, insulation, high-temperature resistance, and corrosion resistance. Using a ceramic plate as the heat sink 2 can significantly improve the heat dissipation efficiency, stability, and safety of the composite circuit board. The circuit board 3 is, for example, a flexible printed circuit (FPC), which has a certain degree of bendability and adaptability when subjected to external forces.

[0050] The heat sink 2 is fixedly connected to the substrate 1 to improve the reliability of the connection. For example, a plurality of fourth pads 4 are provided between the heat sink 2 and the substrate 1. The plurality of fourth pads 4 are arranged along the circumference of the heat sink 2. The heat sink 2 and the substrate 1 are soldered together using SMT technology to further enhance the connection strength between the heat sink 2 and the substrate 1.

[0051] The number, shape, and size of the fourth pad 4 are determined according to actual requirements. For example, if the heat sink 2 is rectangular, it may have four fourth pads 4, located at the corners of the heat sink 2. This ensures the reliability of the connection between the heat sink 2 and the substrate 1 without taking up too much space.

[0052] The circuit board 3 is electrically connected to the substrate 1 and the heat sink 2 to transmit electrical signals. The circuit board 3 includes, for example, a conductive layer 31, a first protective layer 32 and a second protective layer 33. The first protective layer 32 and the second protective layer 33 are both made of polyimide (PI), which gives them excellent heat resistance, mechanical properties, chemical stability, radiation resistance and dielectric properties.

[0053] The conductive layer 31 is sandwiched between the first protective layer 32 and the second protective layer 33. For example, the conductive layer 31 is provided with colloid 34 on both sides along its thickness direction. The first protective layer 32 and the second protective layer 33 are bonded to the conductive layer 31 through the colloid 34, which improves the reliability of the connection.

[0054] The second protective layer 33 is connected to the substrate 1. Exemplarily, an adhesive portion 35 is provided on the side of the second protective layer 33 opposite to the conductive layer 31, through which it is bonded to the substrate 1. The adhesive portion 35 is, for example, 3M adhesive, which has high adhesion and good durability, and can maintain the bonding effect even in harsh environments, making it difficult to fall off.

[0055] The first protective layer 32 is connected to the heat sink 2. For example, a plurality of first solder pads 36 are provided on the side of the first protective layer 32 opposite to the conductive layer 31, and the circuit board 3 is soldered to the heat sink 2 through the first solder pads 36. The first solder pads 36 not only have a connection function, but also enable the transmission of electrical signals.

[0056] Multiple first pads 36 are arranged along the first direction of the composite circuit board (refer to) Figure 1 The first pads 36 are arranged sequentially along the X-axis as shown, and the two adjacent first pads 36 are staggered to ensure the stability and reliability of the connection. The first pads 36 are, for example, circular in shape, with a minimum diameter φ of 1mm, to ensure the reliability of the soldering between the circuit board 3 and the heat sink 2 and to prevent cold solder joints.

[0057] In this embodiment, as Figures 1-4 As shown, the first protective layer 32 has a clearance area 321, i.e., a coverlay design, which exposes part of the structure of the conductive layer 31 to facilitate soldering with the substrate 1. Within the clearance area 321, the first protective layer 32 has multiple bends 322. These bends 322 reduce the stress of the solder on the circuitry, preventing circuit breakage at the solder joint and effectively improving product yield. For example, the multiple bends 322 are sequentially arranged along the first direction of the composite circuit board, and are sequentially spliced ​​to form a serrated shape, enhancing stress resistance, strengthening the mechanical strength of the circuit board 3, and improving heat dissipation efficiency.

[0058] In this embodiment, as Figures 1-4 As shown, the curved portion 322 includes, for example, a first curved edge 3221 and a second curved edge 3222. The first curved edge 3221 and the second curved edge 3222 are connected, and the connection position is chamfered, making the shape between the first curved edge 3221 and the second curved edge 3222 resemble a parabola, further reducing the stress of the solder on the circuit. The radius R of the chamfer is, for example, 0.3 mm, to facilitate window opening operations.

[0059] The first curved edge 3221 is relative to the second direction of the composite circuit board (refer to) Figure 1 The Y-axis shown has a first angle, α, for example, 45°. The second curved edge 3222 has a second angle relative to the second direction of the composite circuit board. The first angle and the second angle are different. The second angle is, for example, 30°. This design allows the curved part 322 to better disperse stress when subjected to external force, improve the durability of the circuit board 3, minimize the stress of the solder on the circuit, and prevent the circuit from breaking at the solder point.

[0060] The edge of the curved portion 322 has a preset distance m with the adhesive portion 35 along the second direction of the composite circuit board. For example, when multiple curved portions 322 are spliced, the first curved edge 3221 of one curved portion 322 will also be connected with the second curved edge 3222 of another curved portion 322. The connection position is also chamfered. There is a preset distance m between the projection of the edges of the two curved portions 322 on the composite circuit board and the projection of the adhesive portion 35 on the composite circuit board. The preset distance m is, for example, 1mm-1.5mm, to prevent the stress on the circuit when the avoidance area 321 and the adhesive portion 35 are in the same position, and to prevent the circuit from breaking.

[0061] In this embodiment, as Figures 1-4 As shown, the conductive layer 31 has a plurality of second pads 311 on the side near the first protective layer 32. The plurality of second pads 311 are arranged sequentially at intervals along the first direction of the composite circuit board. The width d of the second pads 311 is greater than 0.6mm, and the spacing L between two adjacent second pads 311 is greater than 0.4mm, so as to ensure that there is no bridging or cold solder joints during SMT soldering operations and improve product yield.

[0062] A third pad 11 is provided on the substrate 1. The conductive layer 31 is soldered to the third pad 11 of the substrate 1 through the second pad 311, thereby realizing the electrical connection between the circuit board 3 and the substrate 1. To improve the reliability of the connection, a notch 312 is provided in the conductive part located below the second pad 311. The notch 312 is semi-circular, and its diameter D is greater than the width d of the third pad 11 and greater than 0.2mm. This ensures that when the circuit board 3 is attached, the semi-circular notch 312 will be aligned with the third pad 11 of the substrate 1, reducing the stress of the solder at the notch 312 of the circuit board 3, ensuring that there is no bridging or cold solder joints during the soldering operation, reducing stress concentration during the soldering process, and improving the soldering quality.

[0063] In this embodiment, the composite circuit board is connected to the heat sink 2 and the substrate 1 respectively. The circuit board 3 is a flexible circuit board, which can prevent the stacked boards from failing under high temperature and external force on the substrate 1. Furthermore, the four fourth pads 4 on the substrate 1 are non-functional pads, and solder cracking under high temperature and external force will not cause the composite circuit board to fail.

[0064] The circuit board 3 features a semi-circular cut to prevent cold solder joints, improve solder joint quality, and reduce stress on the solder joints at high temperatures. The circuit board 3 also has a bent portion 322, forming a serrated shape, which prevents stress on the conductive layer 31 at the solder joint from causing wire breakage. The bottom of the circuit board 3 has an adhesive portion 35, with the bent portion 322 offset to reduce stress on the traces in the avoidance area 321, thus reducing the likelihood of wire breakage.

[0065] Second Embodiment

[0066] like Figures 1-6 As shown, the second embodiment has a similar basic structure to the first embodiment, but the difference lies in the circuit board 3. In this embodiment, the composite circuit board includes two circuit boards 3, which are symmetrically arranged along the first direction of the composite circuit board. Each circuit board 3 is electrically connected to the substrate 1 and the heat sink 2, and the structure of each circuit board 3 is the same as that of the circuit board 3 in the first embodiment, which will not be repeated here.

[0067] The dual circuit board 3 design in this embodiment can further improve the reliability and heat dissipation efficiency of the circuit board 3 while ensuring circuit performance, and meet more line connection requirements. Especially in application scenarios that require processing a large amount of data or bearing a high load, the dual circuit board 3 design can significantly improve the overall performance of the composite circuit board.

[0068] Third Embodiment

[0069] An electronic device includes a device body and a composite circuit board as described in the first or second embodiment. The electronic device may be, for example, a LiDAR product, an autonomous driving system, or a robot navigation device. Due to the use of the composite circuit board in this application, the electronic device achieves improvements in heat dissipation, reliability, and stability.

[0070] The heat sink in the composite circuit board effectively dissipates the heat generated by the board, preventing high temperatures from damaging circuit components. At the same time, the special structural design of the circuit board improves its mechanical strength and durability, avoiding poor solder joints or weak connections, enabling electronic devices to maintain stable performance in harsh working environments.

[0071] Furthermore, the modular design of the composite circuit board makes the maintenance and upgrading of electronic devices much easier. When a circuit board fails, it can be quickly replaced without replacing the entire electronic device, thus reducing maintenance costs and time.

[0072] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0073] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0074] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A composite circuit board, characterized in that, include: substrate; The heat sink is fixedly connected to the substrate; as well as A circuit board is electrically connected to the substrate and the heat sink, respectively. The circuit board includes a conductive layer, a first protective layer and a second protective layer. The conductive layer is sandwiched between the first protective layer and the second protective layer. The second protective layer is connected to the substrate and the first protective layer is connected to the heat sink. The first protective layer has an avoidance area, which is configured to expose a portion of the conductive layer, and the first protective layer located in the avoidance area has multiple bends.

2. The composite circuit board according to claim 1, characterized in that, The multiple curved portions are arranged sequentially along the first direction of the composite circuit board, such that the multiple curved portions are spliced ​​together to form a sawtooth shape.

3. The composite circuit board according to claim 1, characterized in that, The curved portion includes a first curved edge and a second curved edge, and a chamfer is made between the first curved edge and the second curved edge; Wherein, the first curved edge has a first angle relative to the second direction of the composite circuit board, and the second curved edge has a second angle relative to the second direction of the composite circuit board, wherein the first angle and the second angle are different.

4. The composite circuit board according to claim 1, characterized in that, The first protective layer has a plurality of first pads on the side opposite to the conductive layer, and the circuit board is connected to the heat sink through the first pads.

5. The composite circuit board according to claim 4, characterized in that, The plurality of pads are arranged sequentially along the first direction of the composite circuit board, and adjacent pads are staggered.

6. The composite circuit board according to claim 1, characterized in that, The conductive layer has a plurality of second pads on the side near the first protective layer, and the plurality of second pads are arranged at intervals along the first direction of the composite circuit board. A third pad is provided on the substrate, and the conductive layer is connected to the third pad of the substrate through the second pad.

7. The composite circuit board according to claim 6, characterized in that, The conductive layer located below the second pad has a cutout; wherein the cutout is semi-circular and the diameter of the cutout is larger than the diameter of the third pad.

8. The composite circuit board according to claim 1, characterized in that, The second protective layer has an adhesive portion on the side opposite to the conductive layer, and the second protective layer is bonded to the substrate through the adhesive portion; The adhesive portion has a predetermined distance from the edge of the curved portion along the second direction of the composite circuit board.

9. The composite circuit board according to claim 1, characterized in that, A plurality of fourth welding pads are provided between the heat sink and the substrate, and the plurality of fourth welding pads are arranged along the circumference of the heat sink.

10. A composite circuit board, characterized in that, include: substrate; The heat sink is fixedly connected to the substrate; as well as Two circuit boards are symmetrically arranged along a first direction of the composite circuit board, and each circuit board is electrically connected to the substrate and the heat sink, respectively. Each of the circuit boards includes a conductive layer, a first protective layer, and a second protective layer, with the conductive layer sandwiched between the first protective layer and the second protective layer. The first protective layer is connected to the substrate, and the second protective layer is connected to the heat sink. The first protective layer has an avoidance area, which is configured to expose a portion of the conductive layer, and the first protective layer located in the avoidance area has multiple bends.

11. An electronic device, characterized in that, include: Equipment body; as well as The composite circuit board as described in any one of claims 1-9; And / or, the composite circuit board as described in claim 10.

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