Circuit board structure

Abstract

The embodiment of the utility model provides a circuit board structure, and relates to the field of circuit boards. The circuit board structure comprises a substrate, wherein the substrate comprises a first surface and a second surface which are oppositely arranged; the circuit board structure further comprises a first capacitor located on one side of the first surface and a second capacitor located on one side of the second surface. The first capacitor and the second capacitor are at least partially overlapped along the thickness direction of the circuit board structure; the first end of the first capacitor is connected with the power supply end of the wireless communication module, and the first end of the second capacitor is connected with the power supply end of the wireless communication module; the second end of the first capacitor is connected with the grounding end of the circuit board structure, and the second end of the second capacitor is connected with the grounding end of the circuit board structure. According to the circuit board structure provided by the embodiment of the utility model, at least parts of the first capacitor and the second capacitor are overlapped along the thickness direction of the circuit board structure, so that the phenomenon that the capacitors drive the circuit board to vibrate together is weakened, and the problem that the circuit board generates howling due to the capacitors is solved.

Description

Technical Field

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

[0002] In wireless communication circuits, capacitors are the most common components that cause howling.

[0003] When a periodic current passes through a capacitor in an electronic product circuit, the capacitor will produce a piezoelectric effect, causing the capacitor to stretch and contract in the stacking direction, generating high-frequency vibrations, resulting in a resonance effect, which in turn causes mechanical vibration of the component or circuit board itself; when the frequency of the amplitude reaches the frequency band that the human ear can hear, the electronic product will produce a howling sound, which seriously affects the user experience. Utility Model Content

[0004] This utility model provides a circuit board structure that solves the problem of circuit board vibration caused by the piezoelectric effect of capacitors, which in turn causes the circuit board to produce a whistling sound.

[0005] This utility model provides a circuit board structure, including a substrate, the substrate including a first surface and a second surface disposed opposite to each other;

[0006] The circuit board structure also includes a first capacitor located on one side of the first surface and a second capacitor located on one side of the second surface; along the thickness direction of the circuit board structure, the first capacitor and the second capacitor at least partially overlap;

[0007] The first terminal of the first capacitor is connected to the power supply terminal of the wireless communication module, and the first terminal of the second capacitor is also connected to the power supply terminal of the wireless communication module.

[0008] The second terminal of the first capacitor is connected to the ground terminal of the circuit board structure, and the second terminal of the second capacitor is also connected to the ground terminal of the circuit board structure.

[0009] Optionally, the first capacitor and the second capacitor are square capacitor patches;

[0010] The package dimensions of the first capacitor include a first length and a first width. The first length L1 satisfies 1.6mm≤L1≤3.2mm, and the first width D1 satisfies 0.8mm≤D1≤1.6mm.

[0011] The package dimensions of the second capacitor include a second length and a second width. The second length L2 satisfies 1.6mm≤L2≤3.2mm, and the second width D2 satisfies 0.8mm≤D2≤1.6mm.

[0012] Optionally, the first capacitor and the second capacitor completely overlap along the thickness direction of the circuit board structure;

[0013] The first terminal of the first capacitor and the first terminal of the second capacitor are symmetrical about the substrate, and the second terminal of the first capacitor and the second terminal of the second capacitor are symmetrical about the substrate.

[0014] Optionally, the circuit board structure may also include a first welding structure and a second welding structure;

[0015] The first welding structure is disposed between the substrate and the first capacitor, and the first capacitor is connected to the substrate through the first welding structure.

[0016] The second welding structure is disposed between the substrate and the second capacitor, and the second capacitor is connected to the substrate through the second welding structure.

[0017] Along the thickness direction of the circuit board structure, the thickness of the first welding structure is greater than the first preset thickness, and the thickness of the second welding structure is greater than the second preset thickness.

[0018] Optionally, the distance L3 between the edge of the first capacitor near the substrate edge and the substrate edge satisfies L3 < 2 mm;

[0019] The distance L4 between the edge of the second capacitor near the edge of the substrate and the edge of the substrate satisfies L4 < 2 mm.

[0020] Optionally, the circuit board structure may also include encapsulating adhesive covering the first capacitor and the second capacitor.

[0021] Optionally, the capacitance of the first capacitor is C1, and the capacitance of the second capacitor is C2;

[0022] Wherein, |C1-C2| / C1≤10%.

[0023] Optionally, the capacitance value C1 of the first capacitor satisfies 2.2μf≤C1≤10μf;

[0024] The capacitance value C2 of the first capacitor satisfies 2.2μf≤C2≤10μf.

[0025] Optionally, the area of ​​the first capacitor structure is S1, and the overlapping area of ​​the first capacitor and the second capacitor along the thickness direction of the circuit board structure is S2.

[0026] Among them, S2 / S1≥60%.

[0027] Optionally, the area S of the circuit board structure meets the requirement of 500 mm². 2 ≤S≤1200mm 2 .

[0028] The circuit board structure provided in this embodiment of the utility model, by symmetrically placing a first capacitor and a second capacitor about the substrate, makes the first capacitor and the second capacitor generate electric fields with opposite directions and the same magnitude. As a result, the vibrations generated by the first capacitor and the second capacitor due to the piezoelectric effect are in opposite directions and have the same amplitude. The vibrations generated by the first capacitor and the second capacitor due to the piezoelectric effect can cancel each other out, reducing the phenomenon of the capacitor causing the circuit board to vibrate together. This solves the problem of the circuit board vibrating due to the piezoelectric effect of the capacitor, which causes the circuit board to whistle.

[0029] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a circuit board structure provided in an embodiment of the present invention;

[0032] Figure 2 This is a circuit diagram of a circuit board structure provided in an embodiment of the present utility model;

[0033] Figure 3 This is a schematic diagram of another circuit board structure provided in an embodiment of the present utility model;

[0034] Figure 4 This is a schematic diagram of another circuit board structure provided in this embodiment of the utility model. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] Figure 1 This is a schematic diagram of a circuit board structure provided in an embodiment of the present invention. Figure 2 This is a circuit diagram of a circuit board structure provided in an embodiment of this utility model, combined with... Figure 1 and Figure 2 As shown, the circuit board structure of this utility model embodiment includes a substrate 1, which includes a first surface 2 and a second surface 3 disposed opposite to each other; the circuit board structure also includes a first capacitor 4 located on one side of the first surface 2 and a second capacitor 5 located on one side of the second surface 3; along the thickness direction of the circuit board structure, the first capacitor 4 and the second capacitor 5 at least partially overlap; the first end of the first capacitor 4 is connected to the power supply terminal 10 of the wireless communication module 9, and the first end of the second capacitor 5 is connected to the power supply terminal 10 of the wireless communication module 9; the second end of the first capacitor 4 is connected to the ground terminal of the circuit board structure, and the second end of the second capacitor 5 is connected to the ground terminal of the circuit board structure.

[0038] Optionally, the wireless communication module can be a Bluetooth communication module or a WIFI communication module, etc. Specifically, the Bluetooth communication module includes a Bluetooth chip, and the power supply pin of the Bluetooth chip is the power supply terminal of the wireless communication module; the WIFI communication module includes a WIFI chip, and the power supply pin of the WIFI chip is the power supply terminal of the wireless communication module.

[0039] like Figure 1As shown, the first capacitor 4 is located on the first surface 2 of the substrate 1, and the second capacitor 5 is located on the second surface 3 of the substrate 1. Positionally, the first capacitor 4 has a first projection on the first surface 2 of the substrate 1, and the second capacitor 5 has a second projection on the second surface 3 of the substrate 1. The first and second projections overlap in the thickness direction of the circuit board structure, meaning that the first capacitor 4 and the second capacitor 5 at least partially overlap along the thickness direction of the circuit board structure. Furthermore, the first capacitor 4 and the second capacitor 5 need to be soldered onto the substrate 1. Therefore, the side of the first capacitor 4 connected to the substrate 1 is closer to the first surface 2, and the side of the second capacitor 5 connected to the substrate 1 is closer to the second surface 3. The first capacitor 4 and the second capacitor 5 are placed opposite each other. Based on this placement, when the same power supply excitation is applied to the first capacitor 4 and the second capacitor 5 located on the first surface 2 and the second capacitor 5 located on the second surface 3, the components of the electric field generated inside the first capacitor 4 on the first surface 2 and the second capacitor 5 on the second surface 3 have the same magnitude and opposite direction in the thickness direction of the circuit board. The piezoelectric effect caused by opposite electric field directions is also opposite. Therefore, after applying alternating current to the circuit board, the expansion and contraction of the first capacitor 4 and the second capacitor 5 in the thickness direction (i.e., the stacking direction) of the circuit board due to the piezoelectric effect have the same amplitude but opposite directions. The vibration amplitude caused by this expansion and contraction is also the same and the vibration direction is opposite. At the same time, since the first capacitor 4 and the second capacitor 5 overlap at least partially along the thickness direction of the circuit board structure, when the first capacitor 4 and the second capacitor 5 vibrate, part of the force exerted by the first capacitor 4 and the second capacitor 5 on the substrate 1 can cancel each other out, thereby reducing the resultant force on the substrate 1, alleviating the vibration of the circuit board caused by the vibration of the first capacitor 4 and the second capacitor 5, and weakening the howling of the circuit board.

[0040] For example, if the first capacitor 4 and the second capacitor 5 completely overlap along the thickness direction of the circuit board structure, that is, the first projection and the second projection completely coincide in the thickness direction of the circuit board structure, then the first capacitor 4 and the second capacitor 5 apply force to the substrate 1 at the same point when they vibrate. At the same time, the amplitude of the vibration of the first capacitor 4 and the second capacitor 5 is the same and the direction is opposite. Therefore, the vibration of the first capacitor 4 and the second capacitor 5 can cancel each other out, eliminating the circuit board vibration caused by the expansion and contraction of the first capacitor 4 and the second capacitor 5 in the stacking direction.

[0041] Combination Figure 1 and Figure 2As shown, for the first capacitor 4 and the second capacitor 5, the upper interface is the first terminal of the first capacitor 4 and the lower interface is the second terminal of the first capacitor 4 and the second capacitor 5. The first terminals of the first capacitor 4 and the second capacitor 5 are connected to the power supply terminal 10 of the wireless communication module 9, and the second terminals of the first capacitor 4 and the second capacitor 5 are connected to the ground terminal of the circuit board structure. In the circuit, the function of the first capacitor 4 and the second capacitor 5 is to filter and stabilize the input voltage. Moreover, the connection of the first capacitor 4 and the second capacitor 5 in the above manner does not affect the function of the circuit, so different types of capacitors can be flexibly replaced according to the need to eliminate the PCB whistling. Connecting the first capacitor 4 and the second capacitor 5 to the circuit in the above manner can effectively solve the PCB whistling problem without affecting the main function of the circuit board.

[0042] The circuit board structure provided in this embodiment of the utility model, by placing the first capacitor and the second capacitor at least partially overlapping along the thickness direction of the circuit board structure, and placing the first capacitor and the second capacitor on opposite sides of the substrate, makes the components of the electric field generated by the first capacitor and the second capacitor in the thickness direction of the circuit board opposite in direction and the same in magnitude. As a result, the vibrations generated by the first capacitor and the second capacitor due to the piezoelectric effect are opposite in direction and the same in amplitude. The vibrations generated by the first capacitor and the second capacitor due to the piezoelectric effect can at least partially cancel each other out, weakening the phenomenon of the capacitor causing the circuit board to vibrate together, and solving the problem of the circuit board vibrating due to the piezoelectric effect of the capacitor, thus causing the circuit board to whistle.

[0043] Optionally, the first capacitor 4 and the second capacitor 5 are square capacitor patches; wherein, the package dimensions of the first capacitor 4 include a first length L1 and a first width D1, the first length L1 satisfying 1.6mm≤L1≤3.2mm, and the first width D1 satisfying 0.8mm≤D1≤1.6mm; the package dimensions of the second capacitor 5 include a second length L2 and a second width D2, the second length L2 satisfying 1.6mm≤L2≤3.2mm, and the second width D2 satisfying 0.8mm≤D2≤1.6mm.

[0044] In this embodiment, the surface containing the first length L1 and the first width D1 is the connection surface between the first capacitor 4 and the substrate 1, and the surface containing the second length L2 and the second width D2 is the connection surface between the second capacitor 5 and the substrate 1. The first length L1 of the first capacitor 4 satisfies 1.6mm ≤ L1 ≤ 3.2mm, and the first width D1 of the first capacitor 4 satisfies 0.8mm ≤ D1 ≤ 1.6mm; the second length L2 of the second capacitor 5 satisfies 1.6mm ≤ L2 ≤ 3.2mm, and the second width D2 of the second capacitor 5 satisfies 0.8mm ≤ D2 ≤ 1.6mm. That is, the length of the first capacitor 4 is between 1.6mm and 3.2mm, for example, it can be 1.6mm, 1.85mm, 2.01mm, 2.5mm, 2.8mm, 3.12mm, and 3.2mm. This embodiment of the invention does not limit the length of the first capacitor 4. The width of the first capacitor 4 can be between 0.8mm and 1.6mm, for example, 0.8mm, 0.98mm, 1.0mm, 1.12mm, and 1.6mm. This embodiment of the invention does not limit the width of the second capacitor 5. The length of the second capacitor 5 is between 1.6mm and 3.2mm, for example, 1.6mm, 1.4mm, 1.85mm, 2.01mm, 2.5mm, 2.8mm, 3.12mm, and 3.2mm. This embodiment of the invention does not limit the length of the second capacitor 5. The width of the second capacitor 5 can be between 0.8mm and 1.6mm, for example, 0.8mm, 0.98mm, 1.0mm, 1.12mm, and 1.6mm. This embodiment of the invention does not limit the width of the second capacitor 5. By limiting the length of the first capacitor 4 to between 1.6mm and 3.2mm and the width to between 0.8mm and 1.6mm, and the length of the second capacitor 5 to between 1.6mm and 3.2mm and the width to between 0.8mm and 1.6mm, both capacitors 4 and 5 can be ensured to have a relatively large volume. Since the contact area between a larger capacitor and the substrate 1 is larger than that between a smaller capacitor and the substrate 1, a larger voltage needs to be applied to the larger capacitor to cause it to vibrate during the piezoelectric effect. Therefore, a larger capacitor is less likely to cause the circuit board to vibrate due to the piezoelectric effect. Furthermore, for capacitors of the same type, a larger capacitor has a greater mass, resulting in greater inertia. To cause a capacitor with greater inertia to vibrate the circuit board due to the piezoelectric effect, a stronger excitation is required. Therefore, a larger capacitor is less likely to vibrate due to the piezoelectric effect.

[0045] In wireless communication chips, a capacitor is typically connected between the power supply and ground terminals to stabilize the input voltage to the circuit board. The circuit board structure provided in this invention replaces this single capacitor connection with two capacitors connected between the power supply and ground terminals: a first capacitor 4 and a second capacitor 5. These two capacitors are placed symmetrically to reduce vibration. The capacitance of the first capacitor 4 and the second capacitor 5 is between 2μF and 10μF. The power supply is the source of periodic voltage, which is the cause of circuit board vibration. Therefore, connecting the first capacitor 4 and the second capacitor 5 at the power supply terminal can significantly reduce circuit board vibration.

[0046] Optionally, the first capacitor 4 includes a 0603 packaged capacitor, a 0805 packaged capacitor, or a 1206 packaged capacitor, and the second capacitor 5 includes a 0603 packaged capacitor, a 0805 packaged capacitor, or a 1206 packaged capacitor.

[0047] Optionally, along the thickness direction of the circuit board structure, the first capacitor 4 and the second capacitor 5 completely overlap; the first end of the first capacitor 4 and the first end of the second capacitor 5 are symmetrical about the substrate, and the second end of the first capacitor 4 and the second end of the second capacitor 5 are symmetrical about the substrate.

[0048] For the first capacitor 4 located on the first surface 2, when the direction of the electric field inside the first capacitor 4 is from one plate to the other, this direction can be considered as the direction in which the capacitor stores energy. For the second capacitor 5 located on the second surface 3, the second capacitor 5 is symmetrically placed with respect to the first capacitor 4 about the substrate 1. Since the first terminals of the first capacitors 4 and 5 are connected to the same power supply, and the first capacitors 4 and 5 are symmetrically placed with respect to the substrate 1, opposite electric field distributions will be generated inside the first capacitors 4 and 5. This is because in a symmetrical circuit structure, the same external excitation will lead to opposite electric field distributions. Therefore, from the perspective of the electric field, the energy directions of the first capacitor 4 and the second capacitor 5 are opposite.

[0049] In summary, the first capacitor 4 and the second capacitor 5, symmetrically placed on the first surface 2 and the second surface 3 of the substrate 1, have the same energy magnitude but opposite energy direction. This symmetrical placement can provide better stability, balance, and anti-interference capability in circuit design.

[0050] Figure 3 This is a schematic diagram of another circuit board structure provided in an embodiment of the present invention, for reference. Figure 3Optionally, the circuit board structure further includes a first welding structure 6 and a second welding structure 7; the first welding structure 6 is disposed between the substrate 1 and the first capacitor 4, and the first capacitor 4 is connected to the substrate 1 through the first welding structure 6; the second welding structure 7 is disposed between the substrate 1 and the second capacitor 5, and the second capacitor 5 is connected to the substrate 1 through the second welding structure 7; along the thickness direction of the circuit board structure, the thickness of the first welding structure 6 is greater than the first preset thickness, and the thickness of the second welding structure 7 is greater than the second preset thickness.

[0051] The first preset thickness can be a specific thickness of the first welding structure 6 to meet the welding requirements between the first capacitor 4 and the substrate 1, and the second preset thickness can be a specific thickness of the second welding structure 7 to meet the welding requirements between the second capacitor 5 and the substrate 1. The first welding structure 6 is used to fix the first capacitor 4 to the substrate 1, and the second welding structure 7 is used to fix the second capacitor 5 to the substrate 1. When the first capacitor 4 and the second capacitor 5 exhibit piezoelectric effect, they vibrate. The first welding structure 6 can buffer the vibration of the first capacitor 4, and the second welding structure 7 can buffer the vibration of the second capacitor 5, thus reducing the vibration transmitted to the substrate 1, thereby reducing the overall vibration of the circuit board and decreasing the probability of product squealing. Therefore, the first welding structure 6 needs to be thick enough not only to fix the first capacitor 4 to the substrate 1 but also to effectively buffer the vibration of the first capacitor 4. The second welding structure 7 needs to be thick enough not only to fix the second capacitor 5 to the substrate 1 but also to effectively buffer the vibration of the second capacitor 5. Optionally, the thickness of the first welded structure 6 can be in the range of 0.12 mm to 0.15 mm, and the thickness of the second welded structure 7 can be in the range of 0.12 mm to 0.15 mm.

[0052] Optionally, the distance L3 between the edge of the first capacitor 4 near the edge of the substrate 1 and the edge of the substrate 1 satisfies L3 < 2mm; the distance L4 between the edge of the second capacitor 5 near the edge of the substrate 1 and the edge of the substrate 1 satisfies L4 < 2mm.

[0053] Specifically, the distance L3 between the first capacitor 4 and the edge of the substrate 1 satisfies L3 < 2mm, meaning the first capacitor 4 is relatively close to the edge of the substrate 1. Similarly, the distance L4 between the second capacitor 5 and the edge of the substrate 1 satisfies L4 < 2mm, meaning the second capacitor 5 is also relatively close to the edge of the substrate 1. When the first capacitor 4 and the second capacitor 5 are close to the edge of the substrate 1, the point of force exerted by the first capacitor 4 and the second capacitor 5 on the substrate 1 is located at the edge of the substrate 1. The vibration generated by the first capacitor 4 and the second capacitor 5 is unlikely to cause the entire substrate 1 to vibrate simultaneously, and the vibration of the substrate 1 will be mutually antagonistic, thus weakening the vibration of the substrate 1. However, when the first capacitor 4 and the second capacitor 5 are closer to the center of the substrate 1, the vibration generated by the first capacitor 4 and the second capacitor 5 is more easily transmitted to all parts of the circuit board. Therefore, the closer the first capacitor 4 and the second capacitor 5 are to the edge of the substrate 1, the smaller the impact of the vibration generated by the first capacitor 4 and the second capacitor 5 on the entire circuit board, and the lower the probability of the product experiencing a howling problem.

[0054] Optional, Figure 4 This is a schematic diagram of another circuit board structure provided in this embodiment of the present invention, for reference. Figure 4 The circuit board structure also includes encapsulating adhesive 8 covering the first capacitor 4 and the second capacitor 5.

[0055] For example, after the first capacitor 4 and the second capacitor 5 are soldered to the substrate 1, a layer of encapsulating adhesive 8, such as UV-curable adhesive, can be applied to cover the first capacitor 4 and the second capacitor 5. The encapsulating adhesive 8 can more firmly fix the first capacitor 4 and the second capacitor 5 to the substrate 1, making it more difficult for the first capacitor 4 and the second capacitor 5 to vibrate, thus reducing the whistling phenomenon of the circuit board.

[0056] Optionally, the capacitance of the first capacitor 4 is C1, and the capacitance of the second capacitor 5 is C2; wherein, |C1-C2| / C1≤10%.

[0057] For the same power supply excitation, the closer the magnitudes of the electric fields generated by the first capacitor 4 and the second capacitor 5 are, the better the effect of mutual cancellation of the vibrations generated by the first capacitor 4 and the second capacitor 5. Therefore, theoretically, the capacitance values ​​of the first capacitor 4 and the second capacitor 5 also need to be relatively close. Thus, the capacitance value C1 of the first capacitor 4 and the capacitance value C2 of the second capacitor 5 are set to satisfy |C1-C2| / C1≤10%, ensuring that the capacitance values ​​of the first capacitor 4 and the second capacitor 5 are close, ensuring that the vibrations generated by the first capacitor 4 and the second capacitor 5 cancel each other out or approximately cancel each other out, thus reducing the whistling phenomenon of the circuit board.

[0058] Optionally, the capacitance value C1 of the first capacitor satisfies 2.2μf ≤ C1 ≤ 10μf; the capacitance value C2 of the first capacitor satisfies 2.2μf ≤ C2 ≤ 10μf. Capacitors with a capacitance value of 2.2μf ≤ C2 ≤ 10μf can effectively filter ripple or noise from hundreds of hertz to thousands of hertz. For example, in a DC power supply after rectification of 50Hz or 60Hz industrial frequency AC power, capacitors with a capacitance value of 2.2μf ≤ C2 ≤ 10μf can effectively filter out ripple around 100Hz and 120Hz.

[0059] Optionally, the area of ​​the first capacitor 4 structure is S1, and the overlapping area of ​​the first capacitor 4 and the second capacitor 5 along the thickness direction of the circuit board structure is S2; wherein, S2 / S1≥60%.

[0060] Along the thickness direction of the circuit board structure, the higher the ratio of the overlap area S2 of the first capacitor 4 and the second capacitor 5 to the area S1 of the first capacitor 4 structure, the higher the degree of overlap between the first capacitor 4 and the second capacitor 5. This means a greater proportion of the vibrations generated by the first capacitor 4 and the second capacitor 5 can cancel each other out, resulting in a smaller resultant force on the substrate 1 and making it more difficult to induce vibrations in the circuit board. Optionally, the distance between the projections of the center points of the first capacitor 4 and the second capacitor 5 onto the substrate 1 should be less than 0.2 mm. The areas of the first capacitor 4 structure and the second capacitor 5 structure are equal, and S2 / S1 ≥ 99%.

[0061] Optionally, the first capacitor 4 includes a tantalum capacitor, and the second capacitor 5 includes a tantalum capacitor.

[0062] Tantalum capacitors have virtually no piezoelectric effect, so they hardly deform under an electric field and therefore do not vibrate due to changing electric fields, fundamentally reducing the possibility of circuit board vibration. At the same time, tantalum capacitors have a relatively large mass, increasing the inertia of the circuit board and making it even more difficult to induce vibration.

[0063] Optionally, the area S of the circuit board structure meets the requirement of 500 mm². 2 ≤S≤1200mm 2 .

[0064] Smaller electronic products are more prone to whistling due to capacitor vibration. Furthermore, the compact layout of small electronic products means that large-mass capacitors, with their relatively large package sizes, are not well-suited for the small circuit board area. Conversely, large-mass capacitors are needed to effectively suppress whistling on large circuit boards. For capacitors with a length of 1.2mm ≤ L2 ≤ 3.2mm and a width of 0.8mm ≤ D2 ≤ 1.2mm, the circuit board area can be as small as 500mm². 2 Up to 1200mm 2 .

[0065] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A circuit board structure, characterized in that, Includes a substrate, the substrate including a first surface and a second surface disposed opposite to each other; The circuit board structure also includes a first capacitor located on one side of the first surface and a second capacitor located on one side of the second surface; Along the thickness direction of the circuit board structure, the first capacitor and the second capacitor at least partially overlap; The first terminal of the first capacitor is connected to the power supply terminal of the wireless communication module, and the first terminal of the second capacitor is connected to the power supply terminal of the wireless communication module. The second terminal of the first capacitor is connected to the ground terminal of the circuit board structure, and the second terminal of the second capacitor is also connected to the ground terminal of the circuit board structure.

2. The circuit board structure according to claim 1, characterized in that, The first capacitor and the second capacitor are square capacitor patches; The first capacitor's package dimensions include a first length and a first width, wherein the first length L1 satisfies 1.6mm≤L1≤3.2mm, and the first width D1 satisfies 0.8mm≤D1≤1.6mm; The package dimensions of the second capacitor include a second length and a second width. The second length L2 satisfies 1.6mm≤L2≤3.2mm, and the second width D2 satisfies 0.8mm≤D2≤1.6mm.

3. The circuit board structure according to claim 1, characterized in that, Along the thickness direction of the circuit board structure, the first capacitor and the second capacitor completely overlap; The first terminal of the first capacitor and the first terminal of the second capacitor are symmetrical about the substrate, and the second terminal of the first capacitor and the second terminal of the second capacitor are symmetrical about the substrate.

4. The circuit board structure according to claim 1, characterized in that, The circuit board structure also includes a first welding structure and a second welding structure; The first welding structure is disposed between the substrate and the first capacitor, and the first capacitor is connected to the substrate through the first welding structure; The second welding structure is disposed between the substrate and the second capacitor, and the second capacitor is connected to the substrate through the second welding structure; Along the thickness direction of the circuit board structure, the thickness of the first welding structure is greater than the first preset thickness, and the thickness of the second welding structure is greater than the second preset thickness.

5. The circuit board structure according to claim 1, characterized in that, The distance L3 between the edge of the first capacitor near the edge of the substrate and the edge of the substrate satisfies L3 < 2 mm; The distance L4 between the edge of the second capacitor near the edge of the substrate and the edge of the substrate satisfies L4 < 2 mm.

6. The circuit board structure according to claim 1, characterized in that, The circuit board structure also includes encapsulating adhesive covering the first capacitor and the second capacitor.

7. The circuit board structure according to claim 1, characterized in that, The capacitance of the first capacitor is C1, and the capacitance of the second capacitor is C2; Wherein, |C1-C2| / C1≤10%.

8. The circuit board structure according to claim 6, characterized in that, The capacitance value C1 of the first capacitor satisfies 2.2μf≤C1≤10μf; The capacitance value C2 of the first capacitor satisfies 2.2μf≤C2≤10μf.

9. The circuit board structure according to claim 1, characterized in that, The area of ​​the first capacitor structure is S1, and the overlapping area of ​​the first capacitor and the second capacitor along the thickness direction of the circuit board structure is S2. Among them, S2 / S1≥60%.

10. The circuit board structure according to claim 1, characterized in that, The area S of the circuit board structure satisfies 500 mm². 2 ≤S≤1200mm 2 .

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