Chip capacitor capable of reducing noise

Abstract

The utility model discloses a chip capacitor for reducing noise, which relates to the field of MLCC, and comprises an MLCC main body, the MLCC main body and a PCB are welded through a welding head, the MLCC main body comprises an electrode plate, a surface protection layer, a bottom protection layer and an external plating layer, the electrode plate is arranged between the bottom protection layer and the surface protection layer, and the external plating layer is arranged between the surface protection layer and the bottom protection layer. External plating layers are welded at the end parts of the electrode plate, the bottom protection layer and the surface protection layer through electroplating; according to the technical scheme of the utility model, the bottom protection layer is arranged, and the interior of the bottom protection layer is not provided with an electrode plate, so that the BaTiO3 ceramic does not deform, and when the height of soldering tin at the two ends does not exceed the thickness of the bottom protection layer, the generated deformation has small influence on the PCB, and the noise is effectively reduced, thereby avoiding the situation that howling may be perceived by a user. Therefore, the problems of influence on the evaluation and the use experience of the user on the equipment are solved, the performance of the equipment is improved, and meanwhile, the satisfaction degree of the user on the equipment evaluation and the comfort degree of the experience are improved.

Description

Technical Field

[0001] The utility model relates to the field of MLCC, in particular to a chip capacitor for reducing noise. Background Art

[0002] MLCC, short for chip capacitor, is made of ceramic dielectric diaphragms with printed electrodes (inner electrodes) stacked in a staggered manner, sintered at a high temperature once to form a ceramic chip, and then a metal layer (outer electrode) is sealed at both ends of the chip to form a monolithic structure, so it is also called a monolithic capacitor.

[0003] Among them, ferroelectric dielectrics have a strong electrostrictive characteristic - piezoelectric effect. Therefore, medium and high capacitance MLCCs made of ferroelectric dielectrics (Class II dielectrics), such as X7R / X5R characteristic products, will produce obvious noise howling under the action of a large AC electric field strength. The reason is that after a large voltage change is applied to both ends of the X7R-MLCC, the BaTiO3 ceramic produces an inverse piezoelectric effect, and the MLCC deforms and vibrates and is transmitted to the PCB board to resonate. Medium-voltage and high-capacity MLCC refers to a multilayer ceramic capacitor (MLCC) with a capacity of 1μF-10μF or more and a rated voltage of 100V-630V or more. When the frequency of the voltage signal is within the human hearing range of 20Hz to 20kHz, the capacitor can be heard howling. A large alternating voltage with a frequency between 20Hz and 20kHz will produce obvious howling when using X7R / X5R medium and high capacitance MLCCs, such as switching power supplies, high-frequency power supplies, etc.

[0004] Howling may cause current fluctuations in the circuit and affect the normal working performance of the equipment. If the howling is severe or lasts too long, it may cause the internal structure of the MLCC to rupture or deform, causing damage to the equipment. Even for some devices that require human-computer interaction (such as mobile phones, computers, etc.), howling may be perceived by users, thereby affecting users' evaluation of the device and usage experience.

[0005] To this end, we propose a noise-reducing chip capacitor. Utility Model Content

[0006] The utility model provides a chip capacitor for reducing noise.

[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a noise-reducing chip capacitor, comprising an MLCC body, wherein the MLCC body and a PCB board are welded via a welding head, wherein the MLCC body comprises an electrode sheet, a surface protective layer, a bottom protective layer and an external plating layer, wherein the electrode sheet is placed between the bottom protective layer and the surface protective layer, and the ends of the electrode sheet, the bottom protective layer and the surface protective layer are all welded with an external plating layer via electroplating, and the bottom electrode sheet is placed at one-half to two-thirds of the MLCC body from top to bottom.

[0008] Preferably, the plane at the top of the welding head is placed below the plane of the electrode sheet at the bottom.

[0009] Preferably, a groove is formed at the bottom end of the bottom protective layer.

[0010] Preferably, the inner wall of the groove is provided with raised portions and recessed portions, and the raised portions and recessed portions are evenly distributed on the inner wall of the groove.

[0011] Preferably, an arc-shaped portion is provided at the notch of the groove.

[0012] Preferably, the raised portion and the recessed portion are both arranged in an arc shape.

[0013] Compared with the prior art, the beneficial effects of the utility model are:

[0014] 1. The utility model sets up a bottom protective layer. Since there is no electrode sheet inside the bottom protective layer, this part of the BaTiO3 ceramic will not be deformed. When the solder height at both ends does not exceed the thickness of the bottom protective layer, the deformation generated at this time has little effect on the PCB, effectively reducing noise, thereby avoiding the problem that the howling may be perceived by the user, thereby affecting the user's evaluation and use experience of the device, improving the performance of the device, and at the same time improving the user's satisfaction with the device evaluation and the comfort of the experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0016] Figure 2 This is a schematic diagram of the cross-sectional structure of the utility model;

[0017] Figure 3 For this utility model Figure 2 Enlarged view of point A in the middle.

[0018] In the figure: 1. MLCC body; 101. electrode sheet; 102. bottom protective layer; 103. external plating layer; 104. groove; 105. raised part; 106. arc-shaped part; 107. surface protective layer; 108. recessed part; 2. PCB board; 3. welding head. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] Example 1

[0021] See also Figure 1-3 , a noise-reducing chip capacitor is shown in the figure, including an MLCC body 1, the MLCC body 1 and the PCB board 2 are welded by a welding head 3, wherein the MLCC body 1 includes an electrode sheet 101, a surface protection layer 107, a bottom protection layer 102 and an external plating layer 103, the electrode sheet 101 is placed between the bottom protection layer 102 and the surface protection layer 107, the ends of the electrode sheet 101, the bottom protection layer 102 and the surface protection layer 107 are all welded with the external plating layer 103 by electroplating, and the bottom electrode sheet 101 is placed at one-half to two-thirds of the MLCC body 1 from top to bottom;

[0022] The installation process of MLCC is as follows: ball milling of powder, stirring and degassing to form ceramic slurry; heating the slurry to solidify into a ceramic film tape; printing metal inner electrode slurry, reserving 1 / 3 to 1 / 2 of the overall height as the thickened base, and then brushing the inner electrode; stacking the printed metal inner electrode slurry according to the design to form a Bar block; isostatically pressing the Bar block into a uniform blank, and then cutting it into a single MLCC chip according to the design requirements; debonding the cut MLCC chip according to a specific curve and then sintering it; adding a certain proportion of auxiliary materials to chamfer the sintered MLCC chip; implanting the chamfered MLCC chip into a glue tray, coating it with end electrode slurry and then drying it; plating Ni and Sn in a plating tank at a certain current; testing the capacity, loss, insulation resistance, and withstand voltage of each product, and then using reflow soldering to solder the MLCC body 1 to the PCB board 2 through the soldering head 3, thereby realizing the production and installation of the MLCC body 1.

[0023] By setting the bottom protective layer 102, since there is no electrode sheet 101 inside the bottom protective layer 102, this part of the BaTiO3 ceramic will not be deformed. When the solder height at both ends does not exceed the thickness of the bottom protective layer 102, the deformation generated at this time will have little effect on the PCB, effectively reducing noise, thereby avoiding the problem that the howling may be perceived by the user, thereby affecting the user's evaluation and usage experience of the device, improving the performance of the device, and at the same time improving the user's satisfaction with the device evaluation and the comfort of the experience.

[0024] The plane at the top of the welding head 3 is placed below the plane of the bottommost electrode sheet 101;

[0025] The welding head 3 is lower than the electrode sheet 101, which means that the area of ​​heat input during welding is smaller, which helps to reduce thermal damage during welding and improve welding quality. At the same time, it can maintain an appropriate distance between the welding head 3 and the electrode sheet 101, which is conducive to more precise welding positioning and reduces the impact of welding stress on the electrode sheet 101, thereby improving welding efficiency. In addition, the position design of the MLCC body 1 can avoid the impact of spatter on the electrode sheet 101 during welding, thereby improving welding reliability.

[0026] Example 2

[0027] See also Figure 2-3 This embodiment further illustrates Example 1, and as shown in the figure, a groove 104 is provided at the bottom end of the bottom protection layer 102;

[0028] By setting the groove 104, the contact area between the bottom protective layer 102 and the external air can be increased, the air flow can be improved, and the heat transfer can be accelerated, which plays a role in indirect heat dissipation. Although the electric current will affect the howling, the howling will also be generated when the temperature is too high. Therefore, by setting the groove 104, the howling can be reduced to a certain extent. At the same time, since the core essence of the howling is vibration, it is easy to cause damage to the equipment, which can increase the service life of the equipment.

[0029] The inner wall of the groove 104 is provided with a raised portion 105 and a recessed portion 108 , and the raised portion 105 and the recessed portion 108 are evenly distributed on the inner wall of the groove 104 .

[0030] By setting the raised portion 105 and the recessed portion 108, the uneven design can increase the surface area of ​​the inner wall of the hole, thereby increasing the surface area in contact with the outside world, making the inner wall of the groove 104 stronger, and at the same time can improve the bending strength of the inner wall of the groove 104 to prevent the inner wall of the groove 104 from being deformed or broken when subjected to external force. In addition, the uneven design can increase the friction between the inner walls of the groove 104, thereby reducing the relative sliding between the inner walls of the groove 104 when subjected to external force, improving the stability of the inner wall of the groove 104, and avoiding the problem of insufficient strength of the inner wall 4 when howling, which easily leads to 4 cracking, thereby improving the reliability of the MLCC body 1 and at the same time improving the service life of the MLCC body 1.

[0031] An arc portion 106 is disposed at the notch of the groove 104 .

[0032] By providing the arc portion 106 , the overall strength of the product can be improved, making the product more sturdy and durable, thereby increasing the service life of the MLCC body 1 .

[0033] The raised portion 105 and the recessed portion 108 are both configured in an arc shape;

[0034] The entire groove 104 can be in an uneven state, and there are no edges and corners at the junction of the unevenness, thereby further improving the overall strength of the inner wall 4, thereby improving the strength of the MLCC body 1, avoiding the problem of insufficient inner wall strength 4 easily leading to 4 cracking when howling occurs, improving the reliability of the MLCC body 1, and at the same time increasing the service life of the MLCC body 1.

[0035] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include"-"comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process-method-article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process-method-article or device.

[0036] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A noise reducing chip capacitor, characterized by: The invention comprises an MLCC body (1), wherein the MLCC body (1) and a PCB board (2) are welded via a welding head (3), wherein the MLCC body (1) comprises an electrode sheet (101), a surface protection layer (107), a bottom protection layer (102) and an external plating layer (103), wherein the electrode sheet (101) is arranged between the bottom protection layer (102) and the surface protection layer (107), and the ends of the electrode sheet (101), the bottom protection layer (102) and the surface protection layer (107) are all welded with an external plating layer (103) via electroplating, and the bottom end of the electrode sheet (101) is arranged at a position between one-half and two-thirds of the MLCC body (1) from top to bottom.

2. A noise reducing chip capacitor according to claim 1, characterized in that: The plane at the top of the welding head (3) is placed below the plane of the electrode sheet (101) at the bottom.

3. The noise reducing chip capacitor according to claim 1, characterized in that: A groove (104) is formed at the bottom end of the bottom protection layer (102).

4. A noise reducing chip capacitor according to claim 3, characterized in that: The inner wall of the groove (104) is provided with a raised portion (105) and a recessed portion (108), and the raised portion (105) and the recessed portion (108) are evenly distributed on the inner wall of the groove (104).

5. A noise reducing chip capacitor according to claim 4, characterized in that: An arc-shaped portion (106) is provided at the notch of the groove (104).

6. A noise reducing chip capacitor according to claim 5, characterized in that: The convex portion (105) and the concave portion (108) are both configured to be arc-shaped.

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