Patch capacitor assembly structure and vehicle-mounted iToF camera

Abstract

The utility model discloses an embodiment provides a kind of patch capacitor assembly structure and vehicle-mounted iTOF camera, the patch capacitor assembly structure includes: PCB substrate and patch capacitor, the opposite two side board surfaces of the PCB substrate are respectively symmetrically pasted with the patch capacitor, and the patch capacitor that is respectively symmetrically pasted on the opposite two side board surfaces of the PCB substrate is same in specification and is electrically connected by the metal via hole that is pre-formed on the PCB substrate. The utility model embodiment is pasted with patch capacitor by being mutually symmetric in the opposite two side board surfaces of PCB substrate respectively, and the patch capacitor that is respectively symmetrically pasted on the opposite two side board surfaces of the PCB substrate is same in specification and is electrically connected by the metal via hole that is pre-formed on the PCB substrate, and thus, the patch capacitor of two sides is synchronous when working, and the vibration frequency is same, amplitude is same, direction is opposite, and the mechanical stress that the two causes PCB substrate is mutually offset, and can effectively avoid the phenomenon of capacitor howling.

Description

Technical Field

[0001] This utility model relates to the field of automotive electronics technology, and in particular to a surface-mount capacitor assembly structure and an in-vehicle iToF camera. Background Technology

[0002] With the increasing number of electrified hardware components in automotive cabins, automotive electronic devices such as iTOF (Indirect Time-of-Flight) cameras are developing towards miniaturization and higher frequencies. In this process, MLCC (Multilayer Ceramic Capacitor) has become the mainstream choice for capacitors due to its small size and high capacitance. However, in high-frequency, high-current operating scenarios, the polarization-depolarization process of the dielectric layer inside the surface-mount capacitor can cause mechanical vibrations on the PCB substrate (frequency can reach above 10kHz), easily leading to howling noise problems. This not only affects the comfort of passengers but may also interfere with other automotive sensors (such as radar and microphones).

[0003] Traditional solutions to reduce howling noise include increasing the pad size of surface mount capacitors or using glue to fix them in place. However, these methods have drawbacks such as reduced electrical performance or high process complexity. Utility Model Content

[0004] The technical problem to be solved by this utility model embodiment is to provide a surface-mount capacitor assembly structure to effectively eliminate capacitor whistling.

[0005] The further technical problem to be solved by this utility model embodiment is to provide an in-vehicle iToF camera that can effectively eliminate capacitor howling.

[0006] To solve the above-mentioned technical problems, the present invention first provides the following technical solution: a surface mount capacitor assembly structure, comprising: a PCB substrate and surface mount capacitors attached to the surface of the PCB substrate, wherein the surface mount capacitors are respectively attached symmetrically on opposite sides of the PCB substrate, and the surface mount capacitors respectively attached symmetrically on opposite sides of the PCB substrate have the same specifications and are electrically connected through pre-formed metal vias on the PCB substrate.

[0007] Furthermore, each of the surface mount capacitors is attached to the surface of the PCB substrate via a pre-formed pad on the surface of the PCB substrate, and the PCB substrate has a vibration damping hole located inside the pad in the portion between two symmetrically arranged surface mount capacitors.

[0008] Furthermore, the walls of the vibration-damping holes are coated with a sound-absorbing layer made of a non-conductive material.

[0009] Furthermore, the sound-absorbing layer is made of resin, silicone, or porous ceramic.

[0010] Furthermore, the distance between the vibration damping hole and the edge of the pad is 10%-30% of the pad width.

[0011] To address the aforementioned technical problems, this utility model embodiment also provides the following technical solution: an in-vehicle iTOF camera, comprising a PCB substrate and a surface mount capacitor, wherein the surface mount capacitor is assembled on the PCB substrate using the surface mount capacitor assembly structure described in any of the preceding embodiments.

[0012] Furthermore, the PCB substrate is provided with multiple sets of surface mount capacitors, each set of surface mount capacitors consisting of two surface mount capacitors symmetrically arranged on opposite sides of the PCB substrate.

[0013] After adopting the above technical solution, the present utility model embodiment has at least the following beneficial effects: The surface mount capacitor assembly structure provided by the present utility model embodiment symmetrically mounts surface mount capacitors on opposite sides of the PCB substrate. The surface mount capacitors symmetrically mounted on opposite sides of the PCB substrate have the same specifications and are electrically connected through pre-formed metal vias on the PCB substrate. As a result, the surface mount capacitors on both sides have synchronized charging and discharging times, the same vibration frequency, the same amplitude, and opposite directions during operation. The mechanical stress generated by the two on the PCB substrate cancels each other out, thus effectively avoiding capacitor howling. Attached Figure Description

[0014] Figure 1 This is a cross-sectional structural diagram of an optional embodiment of the chip capacitor assembly structure of this utility model.

[0015] Figure 2 This is a noise test curve for an optional embodiment of the chip capacitor assembly structure of this utility model. Detailed Implementation

[0016] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the following illustrative embodiments and descriptions are only used to explain the present utility model and are not intended to limit the present utility model. Moreover, the embodiments and features in the embodiments of the present application can be combined with each other unless otherwise specified.

[0017] like Figure 1As shown, an optional embodiment of this utility model provides a surface mount capacitor assembly structure, including: a PCB substrate 1 and surface mount capacitors 3 attached to the surface of the PCB substrate 1. The surface mount capacitors 3 are symmetrically attached to opposite sides of the PCB substrate 1. The surface mount capacitors 3 attached to opposite sides of the PCB substrate 1 have the same specifications and are electrically connected through pre-formed metal vias 10 on the PCB substrate 1.

[0018] The surface mount capacitor assembly structure provided in this embodiment of the utility model involves symmetrically mounting surface mount capacitors 3 on opposite sides of a PCB substrate 1. These surface mount capacitors 3 are of the same specification and are electrically connected via pre-formed metal vias on the PCB substrate 1. Consequently, the surface mount capacitors 3 located on opposite sides of the PCB substrate 1 have synchronized charging and discharging times, the same vibration frequency, the same amplitude, and opposite directions during operation. This causes the mechanical stress generated on the PCB substrate 1 to cancel each other out, effectively preventing capacitor whistling.

[0019] like Figure 2 As shown, relevant noise tests revealed that the noise peak on the front of the product using the chip capacitor assembly structure provided by this utility model decreased from 27.7dB to 26.5dB, a reduction of 1.2dB, and the noise peak on the back of the product decreased from 29.8dB to 20.6dB, a reduction of 9.2dB, demonstrating a significant noise reduction effect.

[0020] In another optional embodiment of this utility model, each of the surface mount capacitors 3 is mounted on the surface of the PCB substrate 1 via a pre-formed pad 12. The PCB substrate 1 has a vibration-damping hole 14 located inside the pad 12 in the portion between two symmetrically arranged surface mount capacitors 3. This embodiment, by forming a vibration-damping hole 14 on the PCB substrate 1, prevents the non-soldered portion of the surface mount capacitor 3 from contacting the PCB substrate 1, creating a certain floating height and blocking the transmission path of vibrations generated during operation, effectively suppressing vibration transmission to the PCB substrate. In specific implementation, the surface mount capacitors 3 on both sides of the PCB substrate 1 are connected to the pad 12 via a layer of solder paste. The pad 12 is then connected to the metal via 10 through the circuit layer 11 on the PCB substrate 1, thus achieving communication between the surface mount capacitors 3 on both sides. It is understood that, for ease of clear representation of the relevant structures, Figure 1The dimensions of the metal vias 10, the circuit layer 11, and the pads 12, etc., have been adjusted proportionally. The solder paste and pads 12 are also treated as a whole in the figure and are not labeled separately. In addition, the cross-section of the vibration damping hole 14 can be designed as a rectangle with rounded corners or other shapes.

[0021] In another optional embodiment of this utility model, a sound-absorbing layer 16 made of non-conductive material is attached to the wall of the vibration-damping hole 14. This embodiment, by attaching the sound-absorbing layer 16 to the wall of the vibration-damping hole 14, can effectively absorb noise and reduce its outward transmission. Furthermore, since the sound-absorbing layer 16 is made of non-conductive material, it can effectively prevent a small amount of solder from flowing into the vibration-damping hole 14 during the high-temperature reflow soldering process after SMT soldering during the assembly of surface mount capacitors, thus preventing accidental electrical connections, short circuits, or signal interference.

[0022] In another embodiment of this invention, the sound-absorbing layer 16 is made of resin, silicone, or porous ceramic. This embodiment provides a variety of materials that can be used to form the sound-absorbing layer 16, which can be flexibly selected in specific implementations.

[0023] In another optional embodiment of this utility model, the distance between the vibration-damping hole 14 and the edge of the pad 12 is 10%-30% of the width of the pad 12. This embodiment, by limiting the size of the vibration-damping hole 14 relative to the pad 12, does not affect the soldering connection between the pad 12 and the surface mount capacitor 3, while obtaining a vibration-damping hole 14 as large as possible to better achieve vibration absorption and noise reduction. In specific implementations, the aperture of the vibration-damping hole 14 is closely related to the size of the surface mount capacitor 3. Generally, when the size of the surface mount capacitor 3 is larger, the aperture of the vibration-damping hole 14 will also be larger, thereby achieving a better vibration absorption and noise reduction effect.

[0024] On the other hand, this utility model also provides an in-vehicle iTOF camera, including a PCB substrate 1 and a surface mount capacitor 3, wherein the surface mount capacitor 3 is assembled on the PCB substrate 1 using the surface mount capacitor assembly structure described in any of the above embodiments. The in-vehicle iTOF camera provided by this utility model can effectively avoid capacitor howling.

[0025] In another optional embodiment of this utility model, the PCB substrate 1 is provided with multiple sets of surface-mount capacitors, each set of surface-mount capacitors consisting of two surface-mount capacitors 3 symmetrically arranged on opposite side surfaces of the PCB substrate 1. In this embodiment, when multiple sets of surface-mount capacitors are provided, they are all assembled on the PCB substrate using the surface-mount capacitor assembly structure described above, which prevents capacitor howling from occurring in the entire vehicle iTOF camera and gives it low-noise characteristics.

[0026] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many variations under the guidance of the present invention without departing from the inventive spirit and the scope of protection of the claims. These variations are all within the protection scope of the present invention.

Claims

1. A surface mount capacitor assembly structure, comprising: The PCB substrate and the surface mount capacitors mounted on the PCB substrate are characterized in that the surface mount capacitors are symmetrically mounted on opposite sides of the PCB substrate, and the surface mount capacitors symmetrically mounted on opposite sides of the PCB substrate have the same specifications and are electrically connected through pre-formed metal vias on the PCB substrate.

2. The surface mount capacitor assembly structure as described in claim 1, characterized in that, Each of the surface mount capacitors is attached to the surface of the PCB substrate via a pre-formed pad. The PCB substrate has vibration damping holes located inside the pads in the portion between two symmetrically arranged surface mount capacitors.

3. The surface mount capacitor assembly structure as described in claim 2, characterized in that, The walls of the vibration damping holes are covered with a sound-absorbing layer made of non-conductive material.

4. The surface mount capacitor assembly structure as described in claim 3, characterized in that, The sound-absorbing layer is made of resin, silicone, or porous ceramic.

5. The surface mount capacitor assembly structure as described in claim 2, characterized in that, The distance between the vibration damping hole and the edge of the pad is 10%-30% of the pad width.

6. A vehicle-mounted iTOF camera, comprising a PCB substrate and surface-mount capacitors, characterized in that, The surface mount capacitor is assembled on the PCB substrate using the surface mount capacitor assembly structure as described in any one of claims 1-5.

7. The vehicle-mounted iTOF camera as described in claim 6, characterized in that, The PCB substrate is provided with multiple sets of surface mount capacitors, each set of surface mount capacitors consisting of two surface mount capacitors symmetrically arranged on opposite sides of the PCB substrate.

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