A ceramic capacitor structure and a method of manufacturing the same

Abstract

This application discloses a ceramic capacitor structure and its fabrication method. The ceramic capacitor structure includes: a ceramic body, terminal electrodes, an electroplated metal layer, and a solder resist layer or a buffer layer. The terminal electrodes cover both end faces of the ceramic body and extend to the first surface of the ceramic body; the electroplated metal layer covers the second surface of the terminal electrodes. The solder resist layer covers the first surface of the ceramic body and overlaps with the projection of the terminal electrodes; or, the buffer layer covers the first surface of the ceramic body. By using the solder resist layer to shield part of the area of ​​the terminal electrodes, or by using the buffer layer to isolate the ends of the terminal electrodes from the ceramic body, the tensile stress on the ceramic body is reduced. In this way, when soldered to a circuit board, the solder separates from the ends of the terminal electrodes and the surface of the ceramic body. The tensile stress during the bending deformation of the circuit board cannot be directly applied to the joint between the terminal electrodes and the ceramic body through the solder, reducing the stress concentration effect and thus preventing the ceramic capacitor structure from being subjected to excessive concentrated stress and breaking.

Description

Technical Field

[0001] This application relates to the field of capacitor technology, and in particular to a ceramic capacitor structure and its preparation method. Background Technology

[0002] Electronic circuit boards integrate a large number of capacitors to perform functions such as storing charge, blocking direct current, filtering, coupling, distinguishing different frequencies, and tuning the circuit. These capacitors are typically made of ceramic.

[0003] As electronic devices become increasingly thinner and lighter, circuit boards also become thinner. During drops, squeezes, or impacts, the circuit board can deform, causing capacitors to experience concentrated stress and potentially fracture. Fractured capacitors can lead to leakage current, and in severe cases, prevent the electronic device from charging or turning on, significantly impacting the user experience. Summary of the Invention

[0004] This application provides a ceramic capacitor structure and its fabrication method to solve the problem that existing capacitors are prone to brittle fracture due to circuit board deformation.

[0005] In a first aspect, this application provides a ceramic capacitor structure, comprising: a ceramic body, two terminal electrodes, two electroplated metal layers, and a solder resist layer. The ceramic body includes a first surface and two end faces located at both ends of the first surface; the two terminal electrodes correspond one-to-one with the two end faces of the ceramic body and extend to the first surface of the ceramic body; the two electroplated metal layers correspond one-to-one with the two terminal electrodes and cover the second surfaces of the opposite terminal electrodes; the solder resist layer covers the first surface of the ceramic body and extends towards the electroplated metal layers, and the solder resist layer overlaps with the projection of the terminal electrodes.

[0006] The ceramic capacitor structure provided in this application embodiment covers a solder resist layer on the first surface of the ceramic body, using the solder resist layer to shield a portion of the terminal electrode area. During subsequent soldering onto the circuit board, this ensures that the solder avoids the bonding area between the terminal electrode and the ceramic body. Consequently, tensile stress generated during circuit board bending deformation cannot directly act on the bonding area between the terminal electrode and the ceramic body through the solder. This separation of the solder from the end of the terminal electrode and the surface of the ceramic body reduces stress concentration at the bonding point, thereby preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0007] In some implementations, the solder mask layer and the end electrode have a first overlap width; the first overlap width is greater than or equal to 0.1 mm. In this way, the solder mask layer covers the end electrode with a width of at least 0.1 mm, and the end of the end electrode can be shielded by the solder mask layer.

[0008] In some implementations, the ceramic body is rectangular; the first surface is the annular outer surface of the ceramic body. This allows the solder resist layer to be applied to the annular outer surface of the ceramic body.

[0009] In some implementations, the ceramic body is rectangular; the first surface is the surface of the ceramic body facing the circuit board. This allows a solder mask layer to be applied to the surface of the ceramic body facing the circuit board.

[0010] In some implementations, the ends of the electroplated metal layers coincide with the ends of the terminal electrodes and are connected to the first surface of the ceramic body; the two ends of the solder resist layer cover a portion of the third surface of the two electroplated metal layers. In this way, the solder resist layer can indirectly cover a portion of the surface of the terminal electrodes.

[0011] In some implementations, the end of the electroplated metal layer is located on the second surface of the opposite end electrode; both ends of the solder mask layer extend to the second surfaces of the two end electrodes and connect with the ends of the electroplated metal layer. This allows the solder mask layer to directly cover a portion of the surface of the end electrode.

[0012] In some implementations, the solder resist layer includes a first solder resist layer and a second solder resist layer spaced apart. One end of the first solder resist layer covers the third surface of one of the electroplated metal layers, and one end of the second solder resist layer covers the third surface of the other electroplated metal layer. The other ends of the first solder resist layer and the second solder resist layer are opposite each other. The first solder resist layer and one of the end electrodes have a first overlap width, and the second solder resist layer and the other end electrode have a first overlap width. This method of using the first and second solder resist layers to cover the ends of opposite end electrodes reduces costs.

[0013] In some implementations, both the first and second solder resist layers have a second overlap width with the first surface of the ceramic body; the second overlap width refers to the distance between the end of the electroplated metal layer and the other end of the first / second solder resist layer. This ensures that the first and second solder resist layers can cover the ends of the opposing electrodes.

[0014] In some implementations, the solder resist layer includes a first solder resist layer and a second solder resist layer spaced apart. One end of the first solder resist layer covers the second surface of one of the end electrodes and is connected to the end of one of the electroplated metal layers. One end of the second solder resist layer covers the second surface of the other end electrode and is connected to the end of the other electroplated metal layer. The other ends of the first solder resist layer and the other ends of the second solder resist layer are opposite each other. The first solder resist layer and one of the end electrodes have a first overlap width, and the second solder resist layer and the other end electrode have a first overlap width. This method of using the first and second solder resist layers to cover the ends of opposite end electrodes reduces costs.

[0015] In some implementations, both the first and second solder resist layers have a third overlap width with the first surface of the ceramic body; the third overlap width refers to the distance between the end of the terminal electrode and the other end of the first / second solder resist layer. This ensures that the first and second solder resist layers can cover the ends of the opposite terminal electrodes.

[0016] Secondly, this application provides a ceramic capacitor structure, including: a ceramic body, two terminal electrodes, two electroplated metal layers, and a solder resist layer. The ceramic body includes a first surface and two end faces located at both ends of the first surface; a buffer layer covers the first surface of the ceramic body; the two terminal electrodes correspond one-to-one to the two end faces of the ceramic body and extend to a fourth surface of the buffer layer; the two electroplated metal layers correspond one-to-one to the two terminal electrodes and cover the second surfaces of the opposite terminal electrodes.

[0017] The ceramic capacitor structure provided in this application embodiment covers a buffer layer on the first surface of the ceramic body. This buffer layer isolates the ends of the terminals from the surface of the ceramic body, reducing the tensile stress on the ceramic body. During subsequent soldering onto a circuit board, this ensures that the solder avoids the ceramic body, preventing tensile stress generated during circuit board bending from directly acting on the ceramic body through the solder. This separation of the solder from the surface of the ceramic body reduces stress concentration at the ceramic body, thus preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0018] In some implementations, the ceramic body is rectangular; the first surface is the annular outer surface of the ceramic body. This allows the solder resist layer to be applied to the annular outer surface of the ceramic body.

[0019] In some implementations, the ceramic body is rectangular; the first surface is the surface of the ceramic body facing the circuit board. This allows a solder mask layer to be applied to the surface of the ceramic body facing the circuit board.

[0020] In some implementations, the end of the buffer layer adjacent to the end face includes a first chamfer; the first chamfer is connected to the second chamfer of the ceramic body by a rounded transition; the second chamfer is located at the junction of the first surface and the end face. This allows the corners of the ceramic body to be sufficiently rounded, ensuring that the thickness of the end electrode meets requirements during subsequent coating.

[0021] Thirdly, this application provides a method for preparing a ceramic capacitor structure, which is used to prepare the ceramic capacitor structure as provided in the first aspect. The method includes: providing a ceramic body; coating both ends of the ceramic body with electrode paste to form end electrodes at both ends of the ceramic body, the two end electrodes extending to a first surface of the ceramic body; electroplating metal materials on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes to obtain an intermediate bonding member; and immersing a solder resist material on the surface of the intermediate bonding member to form a solder resist layer on the first surface of the ceramic body, the solder resist layer covering a portion of the electroplated metal layer so that the solder resist layer overlaps with the projection of the end electrodes.

[0022] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing processes such as dipping, sintering, electroplating, immersion coating, thermal curing, and partial removal on the ceramic body to form a solder resist layer on the first surface of the ceramic body. By indirectly shielding a portion of the terminal electrode area using the solder resist layer, it ensures that the solder avoids the bonding area between the terminal electrode and the ceramic body during subsequent soldering onto the circuit board. This prevents tensile stress generated during circuit board bending deformation from directly acting on the bonding area between the terminal electrode and the ceramic body through the solder. Thus, the separation of the solder from the end of the terminal electrode and the surface of the ceramic body reduces stress concentration at the bonding points, thereby preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0023] In some implementations, the solder mask layer and the end electrode have a first overlap width; the first overlap width is greater than or equal to 0.1 mm. In this way, the solder mask layer covers the end electrode with a width of at least 0.1 mm, and the end of the end electrode can be shielded by the solder mask layer.

[0024] In some implementations, the first surface is the annular outer surface of the ceramic body; and a solder resist material is dipped into the surface of the intermediate connector to form a solder resist layer on the first surface of the ceramic body, including: dipping the intermediate connector into all outer surfaces of the intermediate connector into the solder resist material; and after thermosetting, removing the solder resist material from the regions of the intermediate connector corresponding to the two end electrodes to form a solder resist layer on the annular outer surface of the ceramic body. Thus, based on the structure of the ceramic body, a solder resist layer is formed on the annular outer surface of the ceramic body by sequentially employing processes such as dipping, firing, electroplating, dip coating, thermosetting, and local removal.

[0025] In some implementations, the first surface is the surface of the ceramic body facing the circuit board; and, a solder resist material is dipped into the surface of the intermediate bonding member to form a solder resist layer on the first surface of the ceramic body, including: dipping the solder resist material into the region of the intermediate bonding member facing the circuit board; and after thermosetting, reducing the thickness of the solder resist coating to form a solder resist layer on the surface of the ceramic body facing the circuit board. Thus, based on the structure of the ceramic body, processes such as dipping, firing, electroplating, dip coating, thermosetting, and partial removal are sequentially employed to form a solder resist layer on the surface of the ceramic body facing the circuit board.

[0026] In some implementations, the first surface is the annular outer surface of the ceramic body; and a solder resist material is dipped into the surface of the intermediate connector to form a solder resist layer on the first surface of the ceramic body, including: dipping solder resist material into both ends of the intermediate connector respectively, the solder resist material covering two electroplated metal layers, and a portion of the annular outer surface adjacent to the two electroplated metal layers; after thermosetting, the solder resist material in the regions of the intermediate connector corresponding to the two end electrodes is removed to form a spaced first solder resist layer and a second solder resist layer on the annular outer surface of the ceramic body; one end of the first solder resist layer covers the third surface of one of the electroplated metal layers, and one end of the second solder resist layer covers the third surface of the other electroplated metal layer. Thus, based on the structure of the ceramic body, the processes of dipping, firing, electroplating, dipping, thermosetting, and partial removal are sequentially employed to form the first solder resist layer and the second solder resist layer on the annular outer surface of the ceramic body.

[0027] Fourthly, this application provides a method for preparing a ceramic capacitor structure, which is used to prepare the ceramic capacitor structure as provided in the first aspect. The method includes: providing a ceramic body; coating both ends of the ceramic body with electrode paste to form end electrodes at both ends of the ceramic body, the two end electrodes extending to a first surface of the ceramic body; immersing a solder resist material on the first surface of the ceramic body to form a solder resist layer on the first surface, the end of the solder resist layer covering a portion of the second surface of the end electrodes, so that the solder resist layer and the end electrodes have a first overlap width; electroplating a metal material on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surface of the end electrodes, the electroplated metal layer being connected to the solder resist layer.

[0028] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing processes such as dipping, sintering, immersion coating, thermosetting, partial removal, and electroplating on the ceramic body to form a solder resist layer on the first surface of the ceramic body. By directly shielding a portion of the terminal electrode area using the solder resist layer, it ensures that the solder avoids the bonding area between the terminal electrode and the ceramic body during subsequent soldering onto the circuit board. This prevents tensile stress generated during circuit board bending deformation from directly acting on the bonding area between the terminal electrode and the ceramic body through the solder. Thus, the separation of the solder from the end of the terminal electrode and the surface of the ceramic body reduces stress concentration at the bonding points, thereby preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0029] Fifthly, this application provides a method for preparing a ceramic capacitor structure, which is used to prepare the ceramic capacitor structure as provided in the second aspect. The method includes: providing a ceramic body; coating a buffer material on a first surface of the ceramic body to form a buffer layer on the first surface to obtain an intermediate bonding member; sputtering metal seed layers at both ends of the intermediate bonding member to form end electrodes at both ends of the intermediate bonding member, the two end electrodes extending to a fourth surface of the buffer layer; and electroplating metal materials on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes.

[0030] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing coating, chamfering, sputtering, and electroplating processes on the ceramic body to form a buffer layer on the first surface of the ceramic body. This buffer layer isolates the ends of the terminals from the surface of the ceramic body facing the circuit board, thereby reducing the tensile stress on the ceramic body. During subsequent soldering onto the circuit board, this ensures that the solder avoids the ceramic body, preventing tensile stress generated during circuit board bending from directly acting on the ceramic body through the solder. This separation of the solder from the ceramic body reduces stress concentration at the ceramic body, thus preventing the ceramic capacitor structure from breaking due to excessive stress concentration. Attached Figure Description

[0031] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application;

[0033] Figure 2 This is a schematic diagram of the first structure of a ceramic capacitor;

[0034] Figure 3This is a second structural schematic diagram of a ceramic capacitor;

[0035] Figure 4 This is a schematic diagram of a ceramic capacitor and its circuit board.

[0036] Figure 5 This is a schematic diagram of a ceramic capacitor that develops cracks.

[0037] Figure 6 This is a first structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application;

[0038] Figure 7 This is a flowchart of the first method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0039] Figure 8 This is the first process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0040] Figure 9 This is a second structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application;

[0041] Figure 10 This is the second process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0042] Figure 11 This is a third structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application;

[0043] Figure 12 This is the third process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0044] Figure 13 This is the fourth structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application;

[0045] Figure 14 This is a second method flowchart of the method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0046] Figure 15 This is the fourth process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0047] Figure 16 This is the fifth structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application;

[0048] Figure 17 This is the fifth process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0049] Figure 18This is the sixth structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application;

[0050] Figure 19 This is the sixth process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0051] Figure 20 This is a first structural schematic diagram of the ceramic capacitor structure and circuit board provided in the embodiments of this application;

[0052] Figure 21 This is a stress simulation diagram of the ceramic capacitor structure provided in the embodiments of this application during testing;

[0053] Figure 22 This is a graph showing the change in the first overlap width versus the transverse tensile stress, provided in an embodiment of this application.

[0054] Figure 23 This is the seventh structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application;

[0055] Figure 24 This is the third method flowchart of the method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0056] Figure 25 This is the seventh process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0057] Figure 26 This is the eighth structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application;

[0058] Figure 27 This is the eighth process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application;

[0059] Figure 28 This is a second structural schematic diagram of the ceramic capacitor structure and circuit board provided in the embodiments of this application;

[0060] Figure 29 This is a graph showing the change in thickness of the buffer layer versus transverse tensile stress according to an embodiment of this application.

[0061] Figure 30 This is a graph showing the change in elastic modulus versus transverse tensile stress of the buffer layer provided in the embodiments of this application.

[0062] Illustration:

[0063] Among them, 10-display screen, 20-middle frame, 30-ceramic capacitor, 30a-crack, 31-capacitor body, 32-outer electrode, 311-inner electrode, 312-dielectric layer, 313-ceramic cover plate, 40-circuit board, 50-solder;

[0064] 100-Ceramic body, 101-First surface, 102-End face, 103-First inner electrode, 104-Second inner electrode, 105-Ceramic dielectric, 106-Ceramic cover plate;

[0065] 200 - end electrode, 201 - second surface;

[0066] 300 - Electroplated metal layer, 301 - Third surface, 302 - Nickel layer, 303 - Tin layer;

[0067] 400 - Solder resist layer, 400a - Solder resist material, 401 - First solder resist layer, 402 - Second solder resist layer;

[0068] 500 - Buffer layer, 501 - Fourth surface, 502 - First chamfer. Detailed Implementation

[0069] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the protection scope of this application.

[0070] In the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0071] Furthermore, in this application, directional terms such as "upper" and "lower" are defined relative to the orientation of the components shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0072] The following explanations of the technical terms mentioned in the embodiments of this application are provided to facilitate understanding by those skilled in the art.

[0073] Surface Mount Technology (SMT), also known as surface mount technology, is a circuit assembly technology that mounts leadless or short-lead surface mount components onto the surface of a printed circuit board (PCB) or other substrates, and then assembles them using methods such as reflow soldering or dip soldering.

[0074] Multilayer ceramic capacitors (MLCCs) are the most widely used type of surface-mount components. They consist of multiple alternating parallel layers of internal electrode material and a ceramic substrate, co-fired into a single unit. Also known as monolithic surface-mount capacitors, they are characterized by small size, high specific capacitance, and high precision. They can be mounted on printed circuit boards and hybrid integrated circuit (HIC) substrates, effectively reducing the size and weight of electronic information terminal products (especially portable products) and improving product reliability. In electronic circuits, MLCCs can function as charge storage, DC blocking, filtering, coupling, distinguishing different frequencies, and tuning circuits.

[0075] The electronic devices described in this application include, but are not limited to, mobile phones, laptops, tablets, personal digital assistants, or wearable devices. The following description uses a mobile phone as an example.

[0076] Figure 1 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application.

[0077] like Figure 1 As shown, the electronic device may include a display screen 10, a mid-frame 20, and a rear cover. The display screen 10 and the rear cover are located on opposite sides of the mid-frame 20, and the display screen 10, mid-frame 20, and rear cover are sequentially fastened together to form a complete device cavity. The complete device cavity includes components such as a communication module, circuit board, battery, speaker assembly, and camera assembly, which are not listed here.

[0078] To facilitate the explanation of the positions of various components in the electronic device, this application embodiment exemplarily establishes a three-dimensional coordinate system based on the electronic device, wherein the x-axis direction is the width direction of the electronic device, the y-axis direction is the length direction of the electronic device, and the z-axis direction is the thickness direction of the electronic device.

[0079] Electronic devices integrate numerous ceramic capacitors, such as MLCCs, on their circuit boards. These ceramic capacitors are typically soldered onto the circuit board using surface mount technology (SMT). Ceramic capacitors come in various types and play different roles in electronic circuits. They are made of ceramic material.

[0080] Figure 2 This is a schematic diagram of the first structure of a ceramic capacitor; Figure 3 This is a second structural schematic diagram of a ceramic capacitor. Among them, Figure 3 Show Figure 2 The cross-sectional structure.

[0081] like Figure 2 and Figure 3As shown, the ceramic capacitor 30 includes a capacitor body 31 and an external electrode 32. The capacitor body 31 includes an internal electrode 311, a dielectric layer 312, and a ceramic cover plate 313, etc.

[0082] The capacitor body 31 has a cuboid structure. In the structure of the capacitor body 31, multiple internal electrodes 311 are staggered horizontally (x-axis direction) and arranged in the thickness direction (z-axis direction). A dielectric layer 312 is disposed between the multiple internal electrodes 311, and two ceramic cover plates 313 are located at the upper and lower ends of the dielectric layer 312 along the thickness direction. Both the dielectric layer 312 and the ceramic cover plates 313 are made of ceramic.

[0083] There are two external electrodes 32. The two external electrodes 32 cover the two end surfaces of the capacitor body 31 along the x-axis and are respectively connected to each internal electrode 311 on the adjacent side.

[0084] Figure 4 This is a schematic diagram of a ceramic capacitor and circuit board.

[0085] like Figure 4 As shown in Figure (a), when the ceramic capacitor 30 is soldered to the circuit board 40 using SMT technology, solder 50 is applied to both ends of the ceramic capacitor 30, and the ceramic capacitor 30 is soldered to the circuit board 40 using two sets of solder 50.

[0086] The two groups of solder 50 are spaced apart along the x-axis, and are bonded. Figure 3 As shown, solder 50 covers the external electrode 32 of the ceramic capacitor 30. There are two bonding points A1 and A2 on the bottom surface of the ceramic capacitor 30 with the two sets of solder 50. That is, bonding points A1 and A2 are the bonding positions of solder 50 with capacitor body 31 and external electrode 32.

[0087] like Figure 4 As shown in (b), with the development of thinner and lighter electronic devices, the circuit board 40 will deform during the process of the electronic device being dropped or subjected to pressure / impact. For example, the middle part of the circuit board 40 will bend upward (as shown by the hollow arrow in the figure).

[0088] The bending deformation of the circuit board 40 pulls the solder 50 to both sides, which is then transferred to the capacitor body 31 through the solder 50. This causes the outer electrodes 32 on both sides of the ceramic capacitor 30 to bear a large tensile stress F, with the direction of the tensile stress F on both sides being outward. As a result, a large stress concentration occurs at the junction of the capacitor body 31, the solder 50, and the outer electrodes 32 (junction points A1 and A2). Because the capacitor body 31 itself is made of brittle ceramic material, it causes the capacitor body 31 to fracture at this stress concentration point. Cracks 30a are generated in the capacitor body 31 at junction points A1 and A2 and propagate to both sides at a certain upward angle.

[0089] Figure 5 This is a schematic diagram of the structure of a ceramic capacitor that develops cracks.

[0090] like Figure 5 The stress simulation diagram of the ceramic capacitor 30 shown in Figure (a) illustrates that when the capacitor body 31 is subjected to an outward pulling force from the solder 50 on both sides, different areas experience different tensile stresses. Specifically, along the direction of the arrows, the tensile stress F increases sequentially, reaching its maximum at the junction points A1 and A2. Conversely, along the opposite direction of the arrows, the tensile stress F decreases sequentially in other areas. Junction points A1 and A2 are stress concentration areas and also points of tension.

[0091] like Figure 5 The microscopic diagram of the crack in the ceramic capacitor 30 shown in (b) illustrates the crack on the left side of the ceramic capacitor 30. Taking the left side structure of the ceramic capacitor 30 as an example, the ends of the solder 50 and the external electrode 32 are both located on the bottom surface of the capacitor body 31, forming a stress concentration area at the junction point A1. The tensile force F at the stress concentration point is the greatest, pulling the external electrodes 32 on both sides outward, causing crack 30a to form in the capacitor body 31 at junction point A1. Similarly, crack 30a also forms at junction point A2.

[0092] A breakage of the ceramic capacitor 30 can lead to mechanical failure, resulting in leakage risk. In severe cases, it can cause the product to fail to charge or turn on, greatly affecting the user experience.

[0093] To prevent the ceramic capacitor from brittle fracture due to deformation of the circuit board 40, this application provides a ceramic capacitor structure that separates the ends of the solder 50 and / or the external electrode 32 from the bottom surface of the capacitor body 31, thereby reducing the stress concentration effect at the joint of the three and preventing the ceramic capacitor structure from being subjected to excessive concentrated stress and breaking.

[0094] Figure 6 This is the first structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application.

[0095] like Figure 6 As shown, in some embodiments, the first type of ceramic capacitor structure provided in this application may include: a ceramic body 100, an end electrode 200, an electroplated metal layer 300, and a solder resist layer 400.

[0096] The ceramic body 100 includes an annular outer surface and two end faces 102 located at both ends of the annular outer surface. The extension direction of the annular outer surface is parallel to the x-axis direction, and the two end faces 102 are located at both ends of the annular outer surface along the x-axis direction. The two end faces 102 are connected to the annular outer surface, face each other, and are parallel to the z-axis direction.

[0097] The ceramic body 100 has a cuboid structure, and the eight corners of the ceramic body 100 include chamfers. That is to say, the annular outer surface of the ceramic body 100 is connected to the adjacent end face 102 with a rounded transition, which makes the corners of the ceramic body 100 sufficiently smooth, so that the thickness of the end electrode 200 can meet the requirements when it is coated later, and it is also easy to process.

[0098] The ceramic body 100 may include a first internal electrode 103, a second internal electrode 104, a ceramic dielectric 105, and a ceramic cover plate 106. The first internal electrode 103 and the second internal electrode 104 are offset along the x-axis, and the ceramic dielectric 105 is located between the first internal electrode 103 and the second internal electrode 104, forming an effective layer (not shown in the figure) of the ceramic capacitor structure. The effective layer helps to form the capacitor portion of the ceramic capacitor structure.

[0099] It should be noted that multiple first inner electrodes 103 and multiple second inner electrodes 104 can be repeatedly stacked to form an effective layer, that is, the first inner electrodes 103 and the second inner electrodes 104 are arranged along the z-axis direction, and the ceramic dielectric 105 is located between the multiple first inner electrodes 103 and the multiple second inner electrodes 104. The first inner electrodes 103 and the second inner electrodes 104 can be formed to alternately expose two end faces 102 in the stacking direction (z-axis direction) of the ceramic dielectric 105, and the first inner electrodes 103 and the second inner electrodes 104 can be electrically insulated from each other by the ceramic dielectric 105 disposed between them.

[0100] The ceramic cover plate 106 is located on the annular outer surface of the effective layer. The ceramic cover plate 106 does not cover the end face 102. The ceramic cover plate 106 is used to prevent the first inner electrode 103 and the plurality of second inner electrodes 104 from being damaged by physical or chemical stress. The ceramic cover plate 106 can serve as the edge of the ceramic body 100, that is, the outer surface of the ceramic cover plate 106 is the annular outer surface of the ceramic body 100.

[0101] For example, the ceramic dielectric 105 can be made of ceramic powder with a high dielectric constant, such as barium titanate (BaTiO3)-based powder or strontium titanate (SrTiO3)-based powder, to obtain high capacitance; the first inner electrode 103 and the second inner electrode 104 can be made of nickel. The ceramic cover plate 106 can have the same material and structure as the ceramic dielectric 105.

[0102] There are two end electrodes 200, which correspond one-to-one with the two end faces 102 of the ceramic body 100 and extend to the annular outer surface of the ceramic body 100. The two end electrodes 200 are electrically connected to the portions of their corresponding first inner electrode 103 and second inner electrode 104 exposed on the two end faces 102 of the ceramic body 100.

[0103] For example, the left end electrode 200 is located at the left end of the ceramic body 100, and the right end electrode 200 is located at the right end of the ceramic body 100. One end of the first inner electrode 103 is electrically connected to the left end electrode 200, and the other end is at a distance from the right end electrode 200; one end of the second inner electrode 104 is electrically connected to the right end electrode 200, and the other end is at a distance from the left end electrode 200.

[0104] When a voltage is applied to the two terminal electrodes 200, charge accumulates between the first inner electrode 103 and the second inner electrode 104, which face each other. In this case, the capacitance of the ceramic capacitor structure can be proportional to the area of ​​the overlapping region between the first inner electrode 103 and the second inner electrode 104.

[0105] For example, the terminal electrode 200 may be formed of a conductive paste containing a conductive metal, which may be nickel (Ni), tin (Sn), copper (Cu), palladium (Pd), gold (Au) or an alloy thereof, etc., and the embodiments of this application do not specifically limit this.

[0106] There are two electroplated metal layers 300, and each of the two electroplated metal layers 300 corresponds to one of the two end electrodes 200. The electroplated metal layers 300 cover the second surface 201 of the end electrode 200 opposite to them. The second surface 201 is the outer surface of the end electrode 200.

[0107] The end of the electroplated metal layer 300 coincides with the end of the terminal electrode 200 and is connected to the annular outer surface of the ceramic body 100, so that the electroplated metal layer 300 completely covers the second surface 201 of the terminal electrode 200. In this way, the terminal electrode 200 can be completely wrapped by the electroplated metal layer 300.

[0108] The electroplated metal layer 300 may include a nickel layer 302 and a tin layer 303. The nickel layer 302 is electroplated onto the second surface 201 of the terminal electrode 200, and the tin layer 303 is electroplated onto the outer surface of the nickel layer 302. For example, the thickness of both the nickel layer 302 and the tin layer 303 is approximately 10 μm. The nickel layer 302 is used to encapsulate the terminal electrode 200, preventing it from being exposed and protecting it from oxidation; the tin layer 303 is pre-applied solder to facilitate subsequent soldering.

[0109] In this way, a nickel layer 302 and a tin layer 303 can be electroplated sequentially on the terminal electrode 200 to form an electroplated metal layer 300 on the second surface 201 of the terminal electrode 200, thereby improving the solderability and solder resistance of the ceramic capacitor structure.

[0110] It should be noted that in some embodiments, the thickness of the electroplated metal layer 300 is very thin, and the end electrode 200 and the electroplated metal layer 300 covering its surface can be collectively referred to as the end electrode or the external electrode.

[0111] The solder resist layer 400 covers the first surface 101 of the ceramic body 100. For example, the solder resist layer 400 may be a polymer material with a resin system such as epoxy resin, acrylic, or polyimide.

[0112] Since the ceramic body 100 is rectangular, it can be referred to as Figure 2 The structure is shown. In one implementation, the first surface 101 is all the outer surfaces of the annular outer surface of the ceramic body 100 (hereinafter referred to as the first surface 101 being the annular outer surface of the ceramic body 100), or the first surface 101 is the upper and lower surfaces of the ceramic body 100. Thus, the solder resist layer 400 surrounds and covers the annular outer surface of the ceramic body 100, or covers the upper and lower surfaces of the ceramic body 100.

[0113] The solder resist layer 400 extends from both ends toward the electroplated metal layers 300 on the left and right sides, and the two ends of the solder resist layer 400 cover a portion of the third surface 301 of the two electroplated metal layers 300. The third surface 301 is the outer surface of the electroplated metal layers 300. In this way, the solder resist layer 400 indirectly covers a portion of the surface of the terminal electrode 200.

[0114] The projections of the solder mask layer 400 and the terminal electrode 200 overlap. Along the z-axis, the projections of the solder mask layer 400 and the terminal electrode 200 have a first overlap width L1; the first overlap width L1 is greater than or equal to 0.1 mm.

[0115] Thus, the solder mask layer 400 must cover the terminal electrode 200 with a width of at least 0.1 mm. The solder mask layer 400 can be used to shield the end of the terminal electrode 200, ensuring that the solder avoids the bonding area between the terminal electrode 200 and the ceramic body 100 during subsequent soldering onto the circuit board. Other areas of the terminal electrode 200 are not shielded by the solder mask layer 400 and are used for subsequent testing and soldering.

[0116] Meanwhile, to ensure welding quality and avoid the risk of tombstoning or incomplete welds, the length of the end electrode 200 can be increased. For example, Figure 6 The second surface 201 of the end electrode 200 is shown to be arc-shaped. The length of the end electrode 200 can be increased by increasing the curvature of the second surface 201. In this way, it can be ensured that the end electrode 200 still has a suitable welding area after the solder mask layer 400 covers part of the second surface 201 of the end electrode 200.

[0117] It should be noted that the thickness of the solder resist layer 400 along the z-axis is not limited in this embodiment of the application, as long as the solder resist layer 400 and the terminal electrode 200 have a first overlap width L1.

[0118] The ceramic capacitor structure provided in this application embodiment covers a solder resist layer 400 on the annular outer surface of the ceramic body 100, using the solder resist layer 400 to shield a portion of the terminal electrode 200. During subsequent soldering onto the circuit board, this ensures that the solder avoids the bonding area between the terminal electrode 200 and the ceramic body 100. Consequently, tensile stress generated during the bending deformation of the circuit board cannot directly act on the bonding area between the terminal electrode 200 and the ceramic body 100 through the solder. Thus, the solder separates from the end of the terminal electrode 200 and the surface of the ceramic body 100, reducing stress concentration at the bonding point and preventing the ceramic capacitor structure from breaking due to excessive concentrated stress.

[0119] Figure 7 This is a flowchart of the first method for preparing the ceramic capacitor structure provided in the embodiments of this application; Figure 8 This is the first process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application.

[0120] like Figure 7 and Figure 8 As shown, this application provides a method for preparing a first ceramic capacitor structure, which can include the following steps S101-S104:

[0121] Step S101: Provide a ceramic body.

[0122] In step S102, electrode paste is applied to both ends of the ceramic body to form end electrodes at both ends of the ceramic body, and the two end electrodes extend to the first surface of the ceramic body.

[0123] Step S103: Electroplating metal material on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes, thereby obtaining an intermediate bonding component.

[0124] Step S104: Dip and coat the surface of the intermediate bonding member with solder resist material to form a solder resist layer on the first surface of the ceramic body. The solder resist layer covers a portion of the electroplated metal layer so that the solder resist layer overlaps with the projection of the end electrode.

[0125] In step S101, as Figure 8 As shown in (a), when preparing the ceramic body 100, the first inner electrode 103 and the second inner electrode 104 are made of nickel, and the ceramic medium 105 and the ceramic cover plate 106 are made of barium titanate (BaTiO3) based powder.

[0126] The above raw materials are processed according to the following steps: ceramic film fabrication—electrode adhesive printing—stacking—uniform pressing—cutting—adhesive removal—sintering—beveling to obtain ceramic body 100. The structural characteristics of ceramic body 100 can be referred to the content of the first ceramic capacitor structure in the aforementioned embodiments, and will not be repeated here.

[0127] In step S102, as Figure 8 As shown in (b), the material of the terminal electrode 200 is copper, and the copper material is made into electrode paste.

[0128] Electrode slurry is applied to both ends of the ceramic body 100 using a coating process; and end electrodes 200 are formed at both ends of the ceramic body 100 by a firing process, with the two end electrodes 200 extending to the annular outer surface of the ceramic body 100.

[0129] In step S103, as Figure 8 As shown in (c), the metallic materials used are nickel (Ni) and tin (Sn) as conductive metals.

[0130] Using an electroplating process, nickel (Ni) is first electroplated onto the second surface 201 of the end electrode 200 to form a nickel layer 302; then tin (Sn) is electroplated onto the outer surface of the nickel layer 302 to form a tin layer 303. The nickel layer 302 and the tin layer 303 are used as the electroplated metal layer 300, with the end of the electroplated metal layer 300 coinciding with the end of the end electrode 200 and connected to the annular outer surface of the ceramic body 100, thus obtaining an intermediate bonding component.

[0131] In step S104, the first surface 101 is the annular outer surface of the ceramic body 100, and step S104 may include the following steps S1041-S1042:

[0132] Step S1041: Dip and coat all outer surfaces of the intermediate joint with solder resist material 400a.

[0133] In step S1042, after heat curing, the solder resist material 400a of the intermediate bonding member corresponding to the two end electrodes 200 is removed to form a solder resist layer 400 on the annular outer surface of the ceramic body 100.

[0134] In step S1041, as Figure 8 As shown in (d), the solder resist material 400a is made of epoxy resin.

[0135] The intermediate bonding component is immersed in a solder resist slurry made of solder resist material 400a using a dip coating process, so that the solder resist slurry completely covers all the outer surfaces of the intermediate bonding component.

[0136] To enhance the bonding force between the solder resist material 400a and the ceramic body 100, dirt on the surface of the intermediate bonding component can be removed by cutting methods such as isopropyl alcohol and Plasma cleaning before dip coating, thereby increasing the bonding force between the solder layer 400 and the ceramic body 100.

[0137] In step S1042, as Figure 8 As shown in (e), the intermediate bonding component, coated with solder resist slurry after the dip-coating process, undergoes thermosetting treatment. A local removal process is then used to remove the thermosetted solder resist 400a from the regions of the intermediate bonding component corresponding to the two end electrodes 200, exposing a portion of the end electrodes 200 for subsequent testing and welding. The solder resist 400a in the corresponding region of the annular outer surface of the ceramic body 100 is retained to form a solder resist layer 400 on the annular outer surface. The local removal process includes one or a combination of methods such as laser, plasma bombardment, or photolithography.

[0138] During subsequent soldering onto the circuit board, to ensure that the solder avoids the bonding area between the terminal electrode 200 and the ceramic body 100, the remaining solder mask layer 400 must cover a portion of the area of ​​the terminal electrode 200. The solder mask layer 400 covers a portion of the surface of the electroplated metal layer 300, thereby indirectly covering a portion of the surface of the terminal electrode 200, for bonding... Figure 6 Along the z-axis, the projection of the solder mask layer 400 and the projection of the terminal electrode 200 have a first overlap width L1; the first overlap width L1 is greater than or equal to 0.1 mm.

[0139] Finally, by testing and packaging the finished product, the first type of ceramic capacitor structure can be obtained.

[0140] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing processes such as dipping, sintering, electroplating, immersion coating, thermal curing, and partial removal on the ceramic body 100 to form a solder resist layer 400 on the annular outer surface of the ceramic body 100. By indirectly shielding a portion of the terminal electrode 200 using the solder resist layer 400, during subsequent soldering onto the circuit board, the solder can avoid the bonding area between the terminal electrode 200 and the ceramic body 100. This prevents tensile stress during the bending deformation of the circuit board from directly acting on the bonding area between the terminal electrode 200 and the ceramic body 100 through the solder. In this way, the solder separates from the end of the terminal electrode 200 and the surface of the ceramic body 100, reducing the stress concentration effect at the bonding point and thus preventing the ceramic capacitor structure from being subjected to excessive concentrated stress and breaking.

[0141] Figure 9 This is a second structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application.

[0142] like Figure 9As shown, in some embodiments, the second type of ceramic capacitor structure provided in this application may include: a ceramic body 100, an end electrode 200, an electroplated metal layer 300, and a solder resist layer 400.

[0143] It should be noted that the structural characteristics of the second type of ceramic capacitor structure differ from those of the first type in that the coverage area of ​​the solder resist layer 400 is different. Other details can be found in the corresponding content of the first type of ceramic capacitor structure, and will not be repeated here.

[0144] In this embodiment, the first surface 101 of the ceramic body 100 is the surface (lower surface) of the annular outer surface of the ceramic body 100 facing the circuit board (hereinafter referred to as the first surface 101 being the surface of the ceramic body 100 facing the circuit board). Thus, the solder resist layer 400 covers the surface of the ceramic body 100 facing the circuit board.

[0145] An electroplated metal layer 300 exists between the end of the solder resist layer 400 and the end electrode 200, and the solder resist layer 400 indirectly covers part of the surface of the end electrode 200. Along the z-axis direction, the projection of the solder resist layer 400 and the projection of the end electrode 200 have a first overlap width L1; the first overlap width L1 is greater than or equal to 0.1 mm.

[0146] The ceramic capacitor structure provided in this application embodiment covers the surface of the ceramic body 100 facing the circuit board with a solder resist layer 400, which shields a portion of the terminal electrode 200. During subsequent soldering onto the circuit board, this ensures that the solder avoids the bonding area between the terminal electrode 200 and the ceramic body 100. Consequently, tensile stress generated during circuit board bending deformation cannot directly act on the bonding area between the terminal electrode 200 and the ceramic body 100 through the solder. This separation of the solder from the end of the terminal electrode 200 and the surface of the ceramic body 100 reduces stress concentration at the bonding point, thus preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0147] Figure 10 This is the second process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application.

[0148] like Figure 10 As shown, this application provides a method for preparing a second ceramic capacitor structure. The method for preparing the ceramic capacitor structure may include the following steps S201-S204:

[0149] Step S201: Provide a ceramic body.

[0150] In step S202, electrode paste is applied to both ends of the ceramic body to form end electrodes at both ends of the ceramic body, and the two end electrodes extend to the first surface of the ceramic body.

[0151] Step S203: Electroplating metal material on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes, thereby obtaining an intermediate bonding component.

[0152] Step S204: Dip and coat the surface of the intermediate bonding member with solder resist material to form a solder resist layer on the first surface of the ceramic body. The solder resist layer covers a portion of the electroplated metal layer so that the solder resist layer overlaps with the projection of the end electrode.

[0153] like Figure 10 As shown in (a), (b) and (c), the contents of steps S201 to S203 can be referred to the contents of steps S101 to S103 in the previous embodiment, and will not be repeated here.

[0154] In step S204, the first surface 101 is the surface of the ceramic body 100 facing the circuit board, and step S204 may include the following steps S2041-S2042:

[0155] Step S2041: Dip solder resist material 400a into the area of ​​the intermediate bonding member facing the circuit board;

[0156] In step S2042, after heat curing, the thickness of the solder resist 400a is reduced to form a solder resist layer 400 on the surface of the ceramic body 100 facing the circuit board.

[0157] In step S2041, as Figure 10 As shown in (d), the solder resist material 400a is made of epoxy resin, and the coating method can be spraying, coating or printing.

[0158] A solder resist paste made of solder resist material 400a is sprayed onto the surface of the intermediate connector facing the circuit board using a spraying process, so that the solder resist paste covers the area of ​​the intermediate connector facing the circuit board, and the edge of the solder resist paste covers a portion of the area of ​​the electroplated metal layer 300.

[0159] The solder resist material 400a has a large coating thickness to ensure that the remaining thickness after subsequent local removal is sufficient to satisfy the first overlap width L1 between the projection of the solder resist layer 400 and the projection of the end electrode 200.

[0160] To enhance the bonding force between the solder resist material 400a and the ceramic body 100, dirt on the surface of the intermediate bonding component can be removed by cutting methods such as isopropyl alcohol and Plasma cleaning before dip coating, thereby increasing the bonding force between the solder layer 400 and the ceramic body 100.

[0161] In step S2042, as Figure 10 As shown in (e), the intermediate bonding component after the spraying process is subjected to thermosetting treatment, and a local removal process is used to reduce the spraying thickness of the solder resist material 400a so as to form a solder resist layer 400 on the surface of the ceramic body 100 facing the circuit board.

[0162] During subsequent soldering onto the circuit board, to ensure that the solder avoids the bonding area between the terminal electrode 200 and the ceramic body 100, the remaining solder mask layer 400 must cover a portion of the area of ​​the terminal electrode 200. The solder mask layer 400 covers a portion of the surface of the electroplated metal layer 300, thereby indirectly covering a portion of the surface of the terminal electrode 200. Figure 9 Along the z-axis, the projection of the solder mask layer 400 and the projection of the terminal electrode 200 have a first overlap width L1; the first overlap width L1 is greater than or equal to 0.1 mm.

[0163] Finally, by testing and packaging the finished product, a second type of ceramic capacitor structure can be obtained.

[0164] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing processes such as dipping, sintering, electroplating, spraying, thermal curing, and partial removal on the ceramic body 100 to form a solder resist layer 400 on the surface of the ceramic body 100 facing the circuit board. By indirectly shielding a portion of the terminal electrode 200 using the solder resist layer 400, during subsequent soldering onto the circuit board, the solder can avoid the bonding area between the terminal electrode 200 and the ceramic body 100. This prevents tensile stress during the bending deformation of the circuit board from directly acting on the bonding area between the terminal electrode 200 and the ceramic body 100 through the solder. In this way, the solder separates from the end of the terminal electrode 200 and the surface of the ceramic body 100, reducing stress concentration at the bonding point and preventing the ceramic capacitor structure from breaking due to excessive concentrated stress.

[0165] Figure 11 This is a third structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application.

[0166] like Figure 11 As shown, in some embodiments, the third ceramic capacitor structure provided in this application may include: a ceramic body 100, an end electrode 200, an electroplated metal layer 300, and a solder resist layer 400.

[0167] It should be noted that the structural characteristics of the third type of ceramic capacitor structure differ from those of the first type in that the structure of the solder mask layer 400 is different. Other details can be found in the corresponding content of the first type of ceramic capacitor structure, and will not be repeated here.

[0168] In this embodiment, the first surface 101 is taken as the annular outer surface of the ceramic body 100 for illustrative purposes.

[0169] The solder resist layer 400 may include a first solder resist layer 401 and a second solder resist layer 402 spaced apart, the first solder resist layer 401 and the second solder resist layer 402 being spaced apart along the x-axis and covering the first surface 101 of the ceramic body 100. That is, the first solder resist layer 401 surrounds and covers a portion of the annular outer surface of the ceramic body 100, and the second solder resist layer 402 surrounds and covers a portion of the annular outer surface of the ceramic body 100.

[0170] One end of the first solder resist layer 401 covers a portion of the area of ​​the third surface 301 of the electroplated metal layer 300 on the left, and one end of the second solder resist layer 402 covers a portion of the area of ​​the third surface 301 of the electroplated metal layer 300 on the right. The other end of the first solder resist layer 401 is opposite to the other end of the second solder resist layer 402.

[0171] The first solder mask layer 401 indirectly covers the left end electrode 200, and the first solder mask layer 401 and the left end electrode 200 have a first overlap width L1; the second solder mask layer 402 indirectly covers the right end electrode 200, and the second solder mask layer 402 and the right end electrode 200 have a first overlap width L1. Wherein, the first overlap width L1 is greater than or equal to 0.1 mm.

[0172] The first solder resist layer 401 and the first surface 101 of the ceramic body 100 have a second overlap width L2; the second solder resist layer 402 and the first surface 101 of the ceramic body 100 have a second overlap width L2. The second overlap width L2 refers to the distance between the end of the electroplated metal layer 300 on the left and the other end of the first solder resist layer 401, and also refers to the distance between the end of the electroplated metal layer 300 on the right and the other end of the second solder resist layer 402.

[0173] For example, the second overlap width L2 is greater than or equal to 0.03 mm. In other embodiments, the second overlap width L2 may also be less than 0.03 mm, provided that the widths of the first solder mask layer 401 and the second solder mask layer 402 are sufficient to cover the ends of the opposite end electrodes 200.

[0174] The ceramic capacitor structure provided in this application embodiment covers a first solder resist layer 401 and a second solder resist layer 402 on the annular outer surface of the ceramic body 100, using the first solder resist layer 401 and the second solder resist layer 402 to shield a portion of the area of ​​the opposing terminal electrodes 200. The first solder resist layer 401 and the second solder resist layer 402 are located in the vicinity of the terminal electrodes 200 to save costs. When subsequently soldered onto a circuit board, it can be ensured that the solder can avoid the bonding area between the terminal electrodes 200 and the ceramic body 100, thereby preventing tensile stress during the bending deformation of the circuit board from directly acting on the bonding area between the terminal electrodes 200 and the ceramic body 100 through the solder. In this way, the solder is separated from the end of the terminal electrode 200 and the surface of the ceramic body 100, which can reduce the stress concentration effect at the bonding location, thereby preventing the ceramic capacitor structure from being subjected to excessive concentrated stress and breaking.

[0175] It should be noted that the first solder resist layer 401 and the second solder resist layer 402 may only cover the surface of the ceramic body 100 facing the circuit board. Other details can be found in the foregoing embodiments and will not be repeated here.

[0176] Figure 12 This is the third process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application.

[0177] like Figure 12 As shown, this application provides a method for preparing a third type of ceramic capacitor structure. The method for preparing the ceramic capacitor structure may include the following steps S301-S304:

[0178] Step S301: Provide a ceramic body.

[0179] In step S302, electrode paste is applied to both ends of the ceramic body to form end electrodes at both ends of the ceramic body, and the two end electrodes extend to the first surface of the ceramic body.

[0180] Step S303: Electroplating metal material on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes, thereby obtaining an intermediate bonding component.

[0181] Step S304: Dip and coat the surface of the intermediate bonding member with solder resist material to form a solder resist layer on the first surface of the ceramic body. The solder resist layer covers a portion of the electroplated metal layer so that the solder resist layer overlaps with the projection of the end electrode.

[0182] like Figure 12 As shown in (a), (b) and (c), the contents of steps S301 to S303 can be referred to the contents of steps S101 to S103 in the previous embodiment, and will not be repeated here.

[0183] In step S304, the first surface 101 is the annular outer surface of the ceramic body 100, and step S304 may include the following steps S3041-S3042:

[0184] Step S3041: Solder resist material 400a is applied to both ends of the intermediate joint, and the solder resist material 400a covers the two electroplated metal layers 300 and a portion of the annular outer surface adjacent to the two electroplated metal layers 300.

[0185] In step S3042, after heat curing, the solder resist material 400a of the intermediate bonding member corresponding to the two end electrodes 200 is removed to form a first solder resist layer 401 and a second solder resist layer 402 spaced apart on the annular outer surface of the ceramic body 100.

[0186] In step S3041, as Figure 12 As shown in (d), the solder resist material 400a is made of epoxy resin, and the coating method can be dip coating.

[0187] A bonding process is used to bond the two ends of the intermediate joint with solder resist paste made of solder resist material 400a, so that the solder resist paste covers the opposite ends of the intermediate joint, thereby covering the two electroplated metal layers 300, as well as a portion of the annular outer surface adjacent to the two electroplated metal layers 300.

[0188] It should be noted that the width of the solder resist slurry covering the outer surface of the ring must meet the second overlap width L2.

[0189] In step S3042, as Figure 12 As shown in (e), the intermediate bonding component coated with solder resist slurry after the dip coating process is subjected to heat curing treatment, and a local removal process is used to remove the solder resist material 400a in the area of ​​the intermediate bonding component corresponding to the two end electrodes 200, exposing part of the end electrodes 200 for subsequent testing and welding. The solder resist material 400a in the corresponding area of ​​the annular outer surface of the ceramic body 100 is retained to form a first solder resist layer 401 and a second solder resist layer 402 spaced apart on the annular outer surface.

[0190] One end of the first solder resist layer 401 covers a portion of the third surface 301 of the electroplated metal layer 300 on the left side, thereby indirectly covering a portion of the surface of the left end electrode 200; one end of the second solder resist layer 402 covers a portion of the third surface 301 of the electroplated metal layer 300 on the right side, thereby indirectly covering a portion of the surface of the right end electrode 200. Combined Figure 11 The first solder mask layer 401 and the left end electrode 200 have a first overlap width L1; the second solder mask layer 402 and the right end electrode 200 have a first overlap width L1. The first overlap width L1 is greater than or equal to 0.1 mm.

[0191] Finally, by testing and packaging the finished product, a third type of ceramic capacitor structure can be obtained.

[0192] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing processes such as dipping, sintering, electroplating, immersion coating, thermal curing, and partial removal on the annular outer surface of the ceramic body 100 to form a first solder resist layer 401 and a second solder resist layer 402. By indirectly shielding a portion of the area of ​​the opposing terminal electrodes 200 using the first solder resist layer 401 and the second solder resist layer 402, it is ensured that the solder avoids the bonding area between the terminal electrodes 200 and the ceramic body 100 during subsequent soldering onto the circuit board. This prevents tensile stress during the bending deformation of the circuit board from directly acting on the bonding area between the terminal electrodes 200 and the ceramic body 100 through the solder. In this way, the solder separates from the end of the terminal electrode 200 and the surface of the ceramic body 100, reducing the stress concentration effect at the bonding point and thus preventing the ceramic capacitor structure from being subjected to excessive concentrated stress and breaking.

[0193] Figure 13 This is the fourth structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application.

[0194] like Figure 13 As shown, in some embodiments, the fourth ceramic capacitor structure provided in this application may include: a ceramic body 100, an end electrode 200, an electroplated metal layer 300, and a solder resist layer 400.

[0195] It should be noted that the structural characteristics of the fourth type of ceramic capacitor structure differ from those of the first type in that the coverage areas of the electroplated metal layer 300 and the solder resist layer 400 are different. Other details can be found in the corresponding content of the first type of ceramic capacitor structure, and will not be repeated here.

[0196] In this embodiment, the first surface 101 is taken as the annular outer surface of the ceramic body 100 for illustrative purposes.

[0197] When the electroplated metal layer 300 is formed on the second surface 201 of the end electrode 200, the end of the electroplated metal layer 300 is located on the second surface 201 of the end electrode 200 opposite to it. The end of the electroplated metal layer 300 on the left side is located on the second surface 201 of the left end electrode 200, and the end of the electroplated metal layer 300 on the right side is located on the second surface 201 of the right end electrode 200. That is, the end of the electroplated metal layer 300 terminates on the second surface 201 of the opposite end electrode 200 and does not extend to the annular outer surface of the ceramic body 100.

[0198] The solder resist layer 400 covers the annular outer surface of the ceramic body 100, and both ends of the solder resist layer 400 extend towards the left and right end electrodes 200, covering a portion of the second surface 201 of the two end electrodes 200. In this way, the solder resist layer 400 can directly cover a portion of the surface of the end electrodes 200.

[0199] The projections of the solder mask layer 400 and the terminal electrode 200 overlap. Along the z-axis, the projections of the solder mask layer 400 and the terminal electrode 200 have a first overlap width L1; the first overlap width L1 is greater than or equal to 0.1 mm.

[0200] Thus, the solder mask layer 400 must cover the terminal electrode 200 with a width of at least 0.1 mm. The solder mask layer 400 can be used to shield the end of the terminal electrode 200, ensuring that the solder avoids the bonding area between the terminal electrode 200 and the ceramic body 100 during subsequent soldering onto the circuit board. Other areas of the terminal electrode 200 are not shielded by the solder mask layer 400 and are used for subsequent testing and soldering.

[0201] The two ends of the solder mask layer 400 are connected to the ends of the electroplated metal layers 300 on the left and right sides, and the solder mask layer 400 and the electroplated metal layers 300 are seamlessly connected. In this way, the solder mask layer 400 and the electroplated metal layers 300 can completely cover the end electrode 200, avoiding exposure of the end electrode 200 and preventing oxidation of the end electrode 200.

[0202] The ceramic capacitor structure provided in this application embodiment covers a solder resist layer 400 on the annular outer surface of the ceramic body 100, using the solder resist layer 400 to shield a portion of the terminal electrode 200. During subsequent soldering onto the circuit board, this ensures that the solder avoids the bonding area between the terminal electrode 200 and the ceramic body 100. Consequently, tensile stress generated during the bending deformation of the circuit board cannot directly act on the bonding area between the terminal electrode 200 and the ceramic body 100 through the solder. Thus, the solder separates from the end of the terminal electrode 200 and the surface of the ceramic body 100, reducing stress concentration at the bonding point and preventing the ceramic capacitor structure from breaking due to excessive concentrated stress.

[0203] Figure 14 This is a second method flowchart of the method for preparing the ceramic capacitor structure provided in the embodiments of this application; Figure 15 This is the fourth process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application.

[0204] like Figure 14 and Figure 15 As shown, this application provides a method for preparing a fourth type of ceramic capacitor structure. The method for preparing the ceramic capacitor structure may include the following steps S401-S404:

[0205] Step S401: Provide a ceramic body.

[0206] In step S402, electrode paste is applied to both ends of the ceramic body to form end electrodes at both ends of the ceramic body, and the two end electrodes extend to the first surface of the ceramic body.

[0207] Step S403: Dip a solder resist material into the first surface of the ceramic body to form a solder resist layer on the first surface. The end of the solder resist layer covers a portion of the second surface of the end electrode so that the solder resist layer and the end electrode have a first overlap width.

[0208] In step S404, metal material is electroplated on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes, and the electroplated metal layer is connected to the solder resist layer.

[0209] like Figure 15 As shown in (a) and (b), the contents of steps S401 to S402 can be referred to the contents of steps S101 to S102 in the previous embodiment, and will not be repeated here.

[0210] In step S403, the first surface 101 is the annular outer surface of the ceramic body 100, and step S403 may include the following steps S4031-S4032:

[0211] Step S4031: Apply solder resist material 400a to the annular outer surface of the ceramic body 100 and the second surface 201 of the end electrode 200.

[0212] In step S4032, after heat curing, the solder resist material 400a in the corresponding areas of the two end electrodes 200 is removed to form a solder resist layer 400 on the annular outer surface of the ceramic body 100.

[0213] In step S4031, as Figure 15 As shown in (c), the solder resist material 400a is made of epoxy resin.

[0214] Using a dip coating process, Figure 15 The intermediate bonding component obtained in (b) is immersed in a solder resist slurry made of solder resist material 400a, such that the solder resist slurry fully covers the annular outer surface of the ceramic body 100 and the second surface 201 of the end electrode 200.

[0215] In step S4032, as Figure 15As shown in (d), the assembly coated with solder resist slurry after the dip coating process undergoes heat curing treatment, and a local removal process is used to remove the solder resist material 400a in the areas of the assembly corresponding to the two end electrodes 200, exposing part of the end electrodes 200 for subsequent testing and welding. The solder resist material 400a in the corresponding area of ​​the annular outer surface of the ceramic body 100 is retained to form a solder resist layer 400 on the annular outer surface.

[0216] During subsequent soldering onto the circuit board, to ensure that the solder avoids the bonding area between the terminal electrode 200 and the ceramic body 100, the remaining solder mask layer 400 must cover a portion of the terminal electrode 200. The solder mask layer 400 directly covers a portion of the surface of the terminal electrode 200, bonding... Figure 13 Along the z-axis, the projection of the solder mask layer 400 and the projection of the terminal electrode 200 have a first overlap width L1; the first overlap width L1 is greater than or equal to 0.1 mm.

[0217] In step S404, as Figure 15 As shown in (e), the metallic materials used are nickel (Ni) and tin (Sn) as conductive metals.

[0218] Using an electroplating process, nickel (Ni) is first electroplated onto the second surface 201 of the terminal electrode 200 to form a nickel layer 302; the end of the nickel layer 302 is bonded to the end of the solder resist layer 400. Then, tin (Sn) is electroplated onto the outer surface of the nickel layer 302 to form a tin layer 303; the tin layer 303 is bonded to the end of the solder resist layer 400. The nickel layer 302 and the tin layer 303 serve as the electroplated metal layer 300, which is connected to the solder resist layer 400.

[0219] Finally, by testing and packaging the finished products, a fourth type of ceramic capacitor structure can be obtained.

[0220] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing processes such as dipping, sintering, immersion coating, thermosetting, partial removal, and electroplating on the ceramic body 100 to form a solder resist layer 400 on the annular outer surface of the ceramic body 100. By directly shielding a portion of the terminal electrode 200 with the solder resist layer 400, during subsequent soldering onto the circuit board, the solder can avoid the bonding area between the terminal electrode 200 and the ceramic body 100. This prevents tensile stress during circuit board bending deformation from directly acting on the bonding area between the terminal electrode 200 and the ceramic body 100 through the solder. Thus, the solder separates from the end of the terminal electrode 200 and the surface of the ceramic body 100, reducing stress concentration at the bonding point and preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0221] Figure 16This is the fifth structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application.

[0222] like Figure 16 As shown, in some embodiments, the fifth ceramic capacitor structure provided in this application may include: a ceramic body 100, an end electrode 200, an electroplated metal layer 300, and a solder resist layer 400.

[0223] It should be noted that the structural characteristics of the fifth type of ceramic capacitor structure differ from those of the fourth type in that the coverage areas of the electroplated metal layer 300 and the solder resist layer 400 are different. Other details can be found in the corresponding content of the fourth type of ceramic capacitor structure, and will not be repeated here.

[0224] In this embodiment, the first surface 101 of the ceramic body 100 is the surface of the ceramic body 100 facing the circuit board. Thus, the solder resist layer 400 covers the surface of the ceramic body 100 facing the circuit board.

[0225] The end of the electroplated metal layer 300 facing the circuit board is located on the second surface 201 of the end electrode 200 and is connected to the end of the solder resist layer 400; the other ends of the electroplated metal layer 300 extend to other surfaces of the annular outer surface of the ceramic body 100.

[0226] The solder mask layer 400 directly covers a portion of the surface of the terminal electrode 200. Along the z-axis, the projection of the solder mask layer 400 and the projection of the terminal electrode 200 have a first overlap width L1; the first overlap width L1 is greater than or equal to 0.1 mm.

[0227] The ceramic capacitor structure provided in this application embodiment covers the surface of the ceramic body 100 facing the circuit board with a solder resist layer 400, which shields a portion of the terminal electrode 200. During subsequent soldering onto the circuit board, this ensures that the solder avoids the bonding area between the terminal electrode 200 and the ceramic body 100. Consequently, tensile stress generated during circuit board bending deformation cannot directly act on the bonding area between the terminal electrode 200 and the ceramic body 100 through the solder. This separation of the solder from the end of the terminal electrode 200 and the surface of the ceramic body 100 reduces stress concentration at the bonding point, thus preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0228] Figure 17 This is the fifth process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application.

[0229] like Figure 17 As shown, this application provides a method for preparing a fifth type of ceramic capacitor structure. The method for preparing the ceramic capacitor structure may include the following steps S501-S504:

[0230] Step S501: Provide a ceramic body.

[0231] In step S502, electrode paste is applied to both ends of the ceramic body to form end electrodes at both ends of the ceramic body. The two end electrodes extend to the first surface of the ceramic body to obtain an intermediate bonding member.

[0232] Step S503: Dip a solder resist material into the surface of the intermediate bonding member facing the circuit board to form a solder resist layer on the first surface of the ceramic body. The end of the solder resist layer covers a portion of the second surface of the end electrode so that the solder resist layer and the end electrode have a first overlap width.

[0233] Step S504: Electroplating metal material on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes, and the electroplated metal layer is connected to the solder resist layer.

[0234] like Figure 17 As shown in (a) and (b), the contents of steps S501 to S502 can be referred to the contents of steps S101 to S102 in the previous embodiment, and will not be repeated here.

[0235] In step S503, the first surface 101 is the surface of the ceramic body 100 facing the circuit board, and step S503 may include the following steps S5031-S5032:

[0236] Step S5031: Dip and coat the surface of the intermediate bonding member facing the circuit board with solder resist material 400a;

[0237] In step S5032, after thermal curing, the thickness of the solder resist 400a is reduced to form a solder resist layer 400 on a portion of the surface of the ceramic body 100 facing the circuit board and the second surface 201 of the terminal electrode 200.

[0238] In step S5031, as Figure 17 As shown in (c), the solder resist material 400a is made of epoxy resin, and the coating method can be spraying, coating or printing.

[0239] A solder resist paste made of solder resist material 400a is sprayed onto the side surface of the intermediate connector facing the circuit board using a spraying process, such that the solder resist paste covers the area of ​​the intermediate connector facing the circuit board, and the edge of the solder resist paste 400a covers a portion of the area of ​​the second surface 201 of the end electrode 200.

[0240] The solder resist material 400a has a large coating thickness to ensure that the remaining thickness after subsequent local removal is sufficient to satisfy the first overlap width L1 between the projection of the solder resist layer 400 and the projection of the end electrode 200.

[0241] In step S5032, as Figure 17 As shown in (d), the intermediate bonding component coated with solder resist slurry after the spraying process is subjected to heat curing treatment, and a local removal process is used to reduce the spraying thickness of the solder resist material 400a, so as to form a solder resist layer 400 on the surface of the ceramic body 100 facing the circuit board.

[0242] During subsequent soldering onto the circuit board, to ensure that the solder avoids the bonding area between the terminal electrode 200 and the ceramic body 100, the remaining solder mask layer 400 must cover a portion of the terminal electrode 200. The solder mask layer 400 directly covers a portion of the surface of the terminal electrode 200, bonding... Figure 16 Along the z-axis, the projection of the solder mask layer 400 and the projection of the terminal electrode 200 have a first overlap width L1; the first overlap width L1 is greater than or equal to 0.1 mm.

[0243] In step S504, as Figure 17 As shown in (e), the metallic materials used are nickel (Ni) and tin (Sn) as conductive metals.

[0244] Using an electroplating process, nickel (Ni) is first electroplated onto the second surface 201 of the end electrode 200 to form a nickel layer 302. The end of the nickel layer 302 facing the circuit board is located on the second surface 201 of the end electrode 200 and is bonded to the end of the solder resist layer 400; the other ends of the nickel layer 302 extend to other surfaces of the annular outer surface of the ceramic body 100.

[0245] Tin (Sn) is then electroplated onto the outer surface of the nickel layer 302 to form a tin layer 303. One end of the tin layer 303 facing the circuit board is located on the second surface 201 of the terminal electrode 200 and is bonded to the end of the solder resist layer 400; the other ends of the tin layer 303 extend to other surfaces of the annular outer surface of the ceramic body 100.

[0246] Nickel layer 302 and tin layer 303 are used as electroplated metal layer 300. The end of electroplated metal layer 300 facing the circuit board is located on the second surface 201 of the end electrode 200 and is connected to the end of solder resist layer 400. The other end of electroplated metal layer 300 extends to other surfaces of the annular outer surface of ceramic body 100.

[0247] Finally, by testing and packaging the finished products, a fifth type of ceramic capacitor structure can be obtained.

[0248] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing processes such as dipping, sintering, immersion coating, thermosetting, partial removal, and electroplating on the ceramic body 100 to form a solder resist layer 400 on the surface of the ceramic body 100 facing the circuit board. By directly shielding a portion of the terminal electrode 200 with the solder resist layer 400, during subsequent soldering onto the circuit board, the solder can avoid the bonding area between the terminal electrode 200 and the ceramic body 100. This prevents tensile stress generated during the bending deformation of the circuit board from directly acting on the bonding area between the terminal electrode 200 and the ceramic body 100 through the solder. Thus, the solder separates from the end of the terminal electrode 200 and the surface of the ceramic body 100, reducing stress concentration at the bonding point and preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0249] Figure 18 This is the sixth structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application.

[0250] like Figure 18 As shown, in some embodiments, the sixth ceramic capacitor structure provided in this application may include: a ceramic body 100, an end electrode 200, an electroplated metal layer 300, and a solder resist layer 400.

[0251] It should be noted that the structural characteristics of the sixth type of ceramic capacitor structure differ from those of the fourth type in that the structure of the solder mask layer 400 is different. Other details can be found in the corresponding content of the fourth type of ceramic capacitor structure, and will not be repeated here.

[0252] In this embodiment, the first surface 101 is taken as the annular outer surface of the ceramic body 100 for illustrative purposes.

[0253] The solder resist layer 400 may include a first solder resist layer 401 and a second solder resist layer 402 spaced apart, the first solder resist layer 401 and the second solder resist layer 402 being spaced apart along the x-axis and covering the first surface 101 of the ceramic body 100. That is, the first solder resist layer 401 surrounds and covers a portion of the annular outer surface of the ceramic body 100, and the second solder resist layer 402 surrounds and covers a portion of the annular outer surface of the ceramic body 100.

[0254] One end of the first solder resist layer 401 covers a portion of the area of ​​the second surface 201 of the left end electrode 200 and is connected to the end of the left electroplated metal layer 300; one end of the second solder resist layer 402 covers a portion of the area of ​​the second surface 201 of the right end electrode 200 and is connected to the end of the right electroplated metal layer 300; the other end of the first solder resist layer 401 is opposite to the other end of the second solder resist layer 402.

[0255] The first solder mask layer 401 directly covers the left end electrode 200, and the first solder mask layer 401 and the left end electrode 200 have a first overlap width L1; the second solder mask layer 402 directly covers the right end electrode 200, and the second solder mask layer 402 and the right end electrode 200 have a first overlap width L1. Wherein, the first overlap width L1 is greater than or equal to 0.1 mm.

[0256] The first solder resist layer 401 and the first surface 101 of the ceramic body 100 have a third overlap width L3; the second solder resist layer 402 and the first surface 101 of the ceramic body 100 have a third overlap width L3. The third overlap width L3 refers to the distance between the end of the left end electrode 200 and the other end of the first solder resist layer 401, and also refers to the distance between the end of the right end electrode 200 and the other end of the second solder resist layer 402.

[0257] For example, the third overlap width L3 is greater than or equal to 0.03 mm. In other embodiments, the third overlap width L3 may also be less than 0.03 mm, provided that the widths of the first solder mask layer 401 and the second solder mask layer 402 are sufficient to cover the ends of the opposite end electrodes 200.

[0258] The ceramic capacitor structure provided in this application embodiment covers a first solder resist layer 401 and a second solder resist layer 402 on the annular outer surface of the ceramic body 100, using the first solder resist layer 401 and the second solder resist layer 402 to shield a portion of the area of ​​the opposing terminal electrodes 200. The first solder resist layer 401 and the second solder resist layer 402 are located in the vicinity of the terminal electrodes 200 to save costs. When subsequently soldered onto a circuit board, it can be ensured that the solder can avoid the bonding area between the terminal electrodes 200 and the ceramic body 100, thereby preventing tensile stress during the bending deformation of the circuit board from directly acting on the bonding area between the terminal electrodes 200 and the ceramic body 100 through the solder. In this way, the solder is separated from the end of the terminal electrode 200 and the surface of the ceramic body 100, which can reduce the stress concentration effect at the bonding location, thereby preventing the ceramic capacitor structure from being subjected to excessive concentrated stress and breaking.

[0259] It should be noted that the first solder resist layer 401 and the second solder resist layer 402 may only cover the surface of the ceramic body 100 facing the circuit board. Other details can be found in the foregoing embodiments and will not be repeated here.

[0260] Figure 19 This is the sixth process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application.

[0261] like Figure 19 As shown, this application provides a method for preparing a sixth type of ceramic capacitor structure. The method for preparing the sixth type of ceramic capacitor structure may include the following steps S601-S604:

[0262] Step S601: Provide a ceramic body.

[0263] In step S602, electrode paste is applied to both ends of the ceramic body to form end electrodes at both ends of the ceramic body. The two end electrodes extend to the first surface of the ceramic body to obtain an intermediate bonding member.

[0264] Step S603: Apply solder resist material to both ends of the intermediate connector to form a solder resist layer on the first surface of the ceramic body. The end of the solder resist layer covers a portion of the second surface of the end electrode so that the solder resist layer and the end electrode have a first overlap width.

[0265] Step S604: Electroplating metal material on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes, the electroplated metal layer being connected to the solder resist layer.

[0266] like Figure 19 As shown in (a) and (b), the contents of steps S601 to S602 can be referred to the contents of steps S101 to S102 in the previous embodiment, and will not be repeated here.

[0267] In step S603, the first surface 101 is the annular outer surface of the ceramic body 100, and step S603 may include the following steps S6031-S6032:

[0268] Step S6031: Solder resist material 400a is applied to both ends of the intermediate joint, and the solder resist material 400a covers the two end electrodes 200 and a portion of the annular outer surface adjacent to the two end electrodes 200.

[0269] In step S6032, after heat curing, the solder resist material 400a of the intermediate bonding member corresponding to the two end electrodes 200 is removed to form a first solder resist layer 401 and a second solder resist layer 402 spaced apart on the annular outer surface of the ceramic body 100.

[0270] In step S6031, as Figure 19 As shown in (c), the solder resist material 400a is made of epoxy resin, and the coating method can be dip coating.

[0271] A coating process is used to coat the two ends of the intermediate joint with a solder resist paste made of solder resist material 400a, so that the solder resist paste covers the opposite ends of the intermediate joint, thereby covering the two end electrodes 200 and a portion of the annular outer surface adjacent to the two end electrodes 200.

[0272] It should be noted that the width of the solder resist slurry covering the outer surface of the ring must meet the third overlap width L3.

[0273] In step S6032, as Figure 19 As shown in (d), the intermediate bonding component coated with solder resist slurry after the dip coating process is subjected to heat curing treatment, and a local removal process is used to remove the solder resist material 400a in the area of ​​the intermediate bonding component corresponding to the two end electrodes 200, exposing part of the end electrodes 200 for subsequent testing and welding. The solder resist material 400a in the corresponding area of ​​the annular outer surface of the ceramic body 100 is retained to form a first solder resist layer 401 and a second solder resist layer 402 spaced apart on the annular outer surface.

[0274] One end of the first solder mask layer 401 covers a portion of the second surface 201 of the left end electrode 200, and one end of the second solder mask layer 402 covers a portion of the second surface 201 of the right end electrode 200. (Combined) Figure 18 The first solder mask layer 401 and the left end electrode 200 have a first overlap width L1; the second solder mask layer 402 and the right end electrode 200 have a first overlap width L1. The first overlap width L1 is greater than or equal to 0.1 mm.

[0275] In step S604, as Figure 19 As shown in (e), the metallic materials used are nickel (Ni) and tin (Sn) as conductive metals.

[0276] Using an electroplating process, nickel (Ni) is first electroplated onto the second surface 201 of the terminal electrode 200 to form a nickel layer 302. The end of the nickel layer 302 on the left side is bonded to the end of the first solder resist layer 401, and the end of the nickel layer 302 on the right side is bonded to the end of the second solder resist layer 402. Then, tin (Sn) is electroplated onto the outer surface of the nickel layer 302 to form a tin layer 303. The tin layer 303 on the left side is bonded to the end of the first solder resist layer 401, and the end of the tin layer 303 on the right side is bonded to the end of the second solder resist layer 402. The nickel layer 302 and the tin layer 303 serve as electroplated metal layers 300, and the electroplated metal layers 300 on both sides are connected to the first solder resist layer 401 and the second solder resist layer 402, respectively.

[0277] Finally, by testing and packaging the finished products, a sixth type of ceramic capacitor structure can be obtained.

[0278] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing processes such as dipping, sintering, immersion coating, thermosetting, partial removal, and electroplating on the annular outer surface of the ceramic body 100 to form a first solder resist layer 401 and a second solder resist layer 402. By directly shielding a portion of the terminal electrode 200 using the first and second solder resist layers 401 and 402, the solder can avoid the bonding area between the terminal electrode 200 and the ceramic body 100 during subsequent soldering onto the circuit board. This prevents tensile stress during circuit board bending deformation from directly acting on the bonding area between the terminal electrode 200 and the ceramic body 100 through the solder. In this way, the solder separates from the end of the terminal electrode 200 and the surface of the ceramic body 100, reducing stress concentration at the bonding points and preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0279] Figure 20 This is a first structural schematic diagram of the ceramic capacitor structure and circuit board provided in the embodiments of this application. The electroplated metal layer 300 is relatively thin. Figure 20 Not shown in the image.

[0280] like Figure 20 As shown, in the ceramic capacitor structures provided in the first to sixth embodiments, the junction position between the end of the terminal electrode 200 and the ceramic body 100 is B1. A solder resist layer 400 is provided in the ceramic capacitor structure, and the solder resist layer 400 and the terminal electrode 200 have a first overlap width L1; the first overlap width L1 is greater than or equal to 0.1 mm, such that the junction position between the end of the solder resist layer 400 and the terminal electrode 200 is B2.

[0281] Using SMT technology, the ceramic capacitor structure is soldered to the circuit board 40, with solder 50 covering the terminal electrode 200. Due to the presence of the solder mask layer 400, the junction point between the end of the solder 50 and the terminal electrode 200 is also B2, resulting in a first overlap width L1 between the end of the solder 50 (B2) and the junction point B1 between the terminal electrode 200 and the ceramic body 100. If a large amount of solder 50 is used, extending to the outer surface of the solder mask layer 400, the first overlap width L1 can still be maintained between the junction point B2 of the solder 50 and the terminal electrode 200 and the junction point B1 between the terminal electrode 200 and the ceramic body 100, since the solder mask layer 400 covers part of the area of ​​the terminal electrode 200.

[0282] In this way, the above embodiments allow the solder 50 to avoid the bonding position B1 between the terminal electrode 200 and the ceramic body 100 by using the solder resist layer 400. This reduces the angle of stress concentration effect at the bonding position of the ceramic body 100, the terminal electrode 200, and the solder 50, so that the tensile stress during the deformation process of the circuit board 40 cannot be directly applied to the bonding area between the ceramic body 100 and the terminal electrode 200 through the solder 50, thereby improving the risk of cracking of the ceramic capacitor structure when the circuit board 40 is bent and deformed.

[0283] Figure 21 These are stress simulation diagrams of the ceramic capacitor structure provided in the embodiments of this application during testing. In each set of stress simulation diagrams, the left side shows a stress table, and the right side shows the simulation diagram.

[0284] like Figure 21 As shown, the solder mask layer 400 and the terminal electrode 200 are set to have different first overlap widths L1. When the circuit board 40 is subjected to the same force and bent and deformed, the different tensile stresses on the ceramic body are tested to determine whether the ceramic capacitor structure meets the requirements, and thus the minimum value of the first overlap width L1 can be determined.

[0285] like Figure 21 As shown in (a), a comparative example is set, and the first overlap width L between the solder mask layer 400 and the terminal electrode 200 is... 11 =0, meaning a ceramic capacitor structure without a solder mask layer 400. When the circuit board 40 bends and deforms, the lateral tensile stress on the ceramic capacitor structure gradually increases along the direction of the arrow, reaching its maximum at position B1. The maximum lateral tensile stress S1 = 84.2 MPa was detected on the ceramic capacitor structure, causing it to fracture.

[0286] like Figure 21 As shown in (b), in the first test case, the first overlap width L between the solder mask layer 400 and the terminal electrode 200 is set. 12 =0.05mm. When the circuit board is bent at 40°, the lateral tensile stress on the ceramic capacitor structure gradually increases along the direction of the arrow, reaching its maximum at position B1. The maximum lateral tensile stress S2 on the ceramic capacitor structure was detected to be 66.8MPa.

[0287] like Figure 21 As shown in (c), in the second test case, the first overlap width L between the solder mask layer 400 and the terminal electrode 200 is set. 13 =0.1mm. When the circuit board is bent at 40°, the lateral tensile stress on the ceramic capacitor structure gradually increases along the direction of the arrow, reaching its maximum at position B1. The maximum lateral tensile stress S3 on the ceramic capacitor structure was detected to be 58.2MPa.

[0288] like Figure 21As shown in (d), in the third test case, the first overlap width L between the solder mask layer 400 and the terminal electrode 200 is set. 14 =0.15mm. When the circuit board is bent at 40°, the lateral tensile stress on the ceramic capacitor structure gradually increases along the direction of the arrow, reaching its maximum at position B1. The maximum lateral tensile stress S4 on the ceramic capacitor structure was detected to be 53.8 MPa.

[0289] Figure 22 This is a curve showing the change between the first overlap width and the transverse tensile stress provided in the embodiments of this application.

[0290] like Figure 22 As shown, the horizontal axis represents the first overlap width, the vertical axis represents the magnitude of the transverse tensile stress, and the percentage on the curve represents the reduction (percentage) of the transverse tensile stress of the test case compared to the transverse tensile stress of the comparative example.

[0291] First overlap width L 12 When the diameter is 0.05 mm, the maximum transverse tensile stress S2 of the first test case is reduced by 21% compared with the maximum transverse tensile stress S1 of the comparative example.

[0292] First overlap width L 13 When the diameter is 0.1 mm, the maximum transverse tensile stress S3 in the second test case is reduced by 31% compared with the maximum transverse tensile stress S1 in the comparative example.

[0293] First overlap width L 12 When the diameter is 0.15 mm, the maximum transverse tensile stress S4 in the third test case is reduced by 36% compared to the maximum transverse tensile stress S1 in the comparative example.

[0294] Combination Figure 21 and Figure 22 As can be seen from the test, as the first overlap width L1 increases, the transverse tensile stress on the ceramic capacitor structure gradually decreases, and the reduction in transverse tensile stress in the test case gradually increases compared to the transverse tensile stress in the comparative example.

[0295] If a ceramic capacitor structure does not break during testing and / or the reduction in lateral tensile stress meets the requirements, then the corresponding ceramic capacitor structure can be determined as meeting the requirements; and the minimum value in the corresponding first overlap width L1 can be determined as the minimum value.

[0296] For example, if the ceramic capacitor structure breaks when the first overlap width L1 is 0.05 mm, and does not break when the first overlap width L1 is 0.1 mm, and the reduction in lateral tensile stress meets the requirements, then the minimum value of the first overlap width L1 can be determined to be 0.1 mm.

[0297] It should be noted that during the testing process, when the first overlap width L1 is less than 0.1 mm, the ceramic capacitor structure may not necessarily break; however, the reduction in lateral tensile stress is too small and does not meet the requirements. Therefore, the minimum value of the first overlap width L1 can be dynamically adjusted according to whether the reduction in lateral tensile stress meets the requirements, and this application embodiment does not specifically limit it.

[0298] Figure 23 This is the seventh structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application.

[0299] like Figure 23 As shown, in some embodiments, the seventh ceramic capacitor structure provided in this application may include: a ceramic body 100, an end electrode 200, an electroplated metal layer 300, and a buffer layer 500.

[0300] It should be noted that the structural characteristics of the seventh type of ceramic capacitor structure differ from those of the first type in that it does not have a solder resist layer 400, but instead has a buffer layer 500. Other details can be found in the corresponding content of the first type of ceramic capacitor structure, and will not be repeated here.

[0301] In this embodiment, the first surface 101 of the ceramic body 100 is the surface of the ceramic body 100 facing the circuit board.

[0302] A buffer layer 500 covers the first surface 101 of the ceramic body 100, and the buffer layer 500 completely covers the surface of the ceramic body 100 facing the circuit board. The buffer layer 500 is used to isolate the end of the terminal electrode 200 and the first surface 101 of the ceramic body 100 to reduce the tensile stress on the ceramic body 100. The thickness h1 of the buffer layer 500 can be 10 μm to 20 μm, and the elastic modulus of the buffer layer 500 is less than or equal to 10 GPa.

[0303] For example, the material of the buffer layer 500 can be a high molecular polymer material with resin system such as epoxy, acrylic, polyimide, etc.; or it can be other insulating materials with similar buffering function and an elastic modulus of less than or equal to 10 GPa.

[0304] The end of the buffer layer 500 adjacent to the end face 102 of the ceramic body 100 includes a first chamfer 502, which is connected to a second chamfer (not shown in the figure) of the ceramic body 100 by a rounded transition. The second chamfer is located at the connection between the annular outer surface of the ceramic body 100 and the end face 102. It should be noted that the first chamfer 502 and the second chamfer can be collectively referred to as chamfers, which can be formed by uniformly rounded cutting after the buffer layer 500 is coated on the first surface 101. In this way, the corners of the ceramic body 100 can be made sufficiently smooth so that the thickness of the end electrode 200 can meet the requirements when the end electrode 200 is coated subsequently.

[0305] Two end electrodes 200 correspond one-to-one with the two end faces 102 of the ceramic body 100. The end of the end electrode 200 facing the circuit board extends to the fourth surface 501 of the buffer layer 500, and the other end of the end electrode 200 extends to other surfaces of the annular outer surface of the ceramic body 100. The fourth surface 501 is the outer surface of the buffer layer 500.

[0306] Two electroplated metal layers 300 correspond one-to-one with two end electrodes 200, and the electroplated metal layers 300 cover the second surface 201 of the end electrodes 200 opposite to them. The ends of the electroplated metal layers 300 may coincide with the ends of the end electrodes 200, or the end of the electroplated metal layers 300 facing the circuit board may extend to the fourth surface 501 of the buffer layer 500, and the other ends may extend to other surfaces of the annular outer surface of the ceramic body 100.

[0307] The ceramic capacitor structure provided in this application embodiment covers the surface of the ceramic body 100 facing the circuit board with a buffer layer 500. The buffer layer 500 isolates the ends of the terminal electrodes 200 from the surface of the ceramic body 100 facing the circuit board, thereby reducing the tensile stress on the ceramic body 100. During subsequent soldering onto the circuit board, this ensures that the solder avoids the ceramic body 100, preventing tensile stress generated during circuit board bending from directly acting on the ceramic body 100 through the solder. This separation of the solder from the surface of the ceramic body 100 reduces stress concentration at the ceramic body 100, thus preventing the ceramic capacitor structure from breaking due to excessive concentrated stress.

[0308] Figure 24 This is the third method flowchart of the method for preparing the ceramic capacitor structure provided in the embodiments of this application; Figure 25 This is the seventh process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application.

[0309] like Figure 24 and Figure 25 As shown, this application provides a method for preparing a seventh type of ceramic capacitor structure. The method for preparing the seventh type of ceramic capacitor structure may include the following steps S701-S704:

[0310] Step S701: Provide a ceramic body.

[0311] Step S702: A buffer material is coated on the first surface of the ceramic body to form a buffer layer on the first surface, thereby obtaining an intermediate bonding member.

[0312] In step S703, metal seed layers are sputtered onto both ends of the intermediate bonding member to form end electrodes at both ends of the intermediate bonding member, and the two end electrodes extend to the fourth surface of the buffer layer.

[0313] Step S704: Electroplating metal material on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes.

[0314] In step S701, as Figure 25 As shown in (a), the preparation process of the ceramic body 100 is as follows: fabrication of a ceramic film—printing of electrode adhesive—stacking—uniform pressing—cutting—removal of adhesive—sintering to form the ceramic body 100. The remaining contents of step S701 can refer to the contents of step S101 in the aforementioned embodiments, and will not be repeated here.

[0315] In step S702, as Figure 25 As shown in (b), the first surface 101 is the surface of the ceramic body 100 facing the circuit board.

[0316] After the ceramic body 100 is sintered, a buffer layer 500 is formed on the surface of the ceramic body 100 facing the circuit board to obtain an intermediate bonding component. The process of forming the buffer layer 500 may include coating, printing or spraying, etc. The thickness h1 of the buffer layer 500 is 10μm to 20μm, and the elastic modulus of the buffer layer 500 is less than or equal to 10GPa.

[0317] like Figure 25 As shown in (c), after step S702, the method for preparing the ceramic capacitor structure further includes: making arc cuts on the intermediate connector to form chamfers at each corner of the intermediate connector. Thus, the buffer layer 500 includes multiple first chamfers 502, and the ceramic body 100 includes multiple second chamfers. The first chamfers 502 and the second chamfers are connected by an arc transition to form a complete chamfer.

[0318] In step S703, as Figure 25 As shown in (d), after the chamfer is made, a sputtering-electroplating copper-annealing process is used to form end electrodes 200 at both ends of the intermediate joint.

[0319] A metal seed layer (not shown in the figure) is sputtered onto both ends of the ceramic body 100, and then copper is electroplated onto the outer surface of the metal seed layer at both ends to form end electrodes 200 with a certain thickness. The end of the end electrode 200 facing the circuit board extends to the fourth surface 501 of the buffer layer 500, and the other ends extend to other surfaces of the annular outer surface of the ceramic body 100.

[0320] For example, the metal seed layer can be a metallic material such as titanium (Ti), tungsten (W), or copper. The thickness of the electroplated copper can be 10 μm to 50 μm. The electroplated copper can be restructured through annealing or other methods to eliminate the internal stress of the electroplating. The advantage of using electroplated copper to fabricate the terminal electrode 200 is that it avoids the high-temperature sintering process of traditional ceramic capacitor terminal electrode fabrication, and prevents the polymer from carbonizing at extremely high sintering temperatures.

[0321] In step S704, as Figure 25 As shown in (e), the metallic materials used are nickel (Ni) and tin (Sn) as conductive metals.

[0322] Using an electroplating process, nickel (Ni) is first electroplated onto the second surface 201 of the terminal electrode 200 to form a nickel layer 302. The end of the nickel layer 302 facing the circuit board is located on the fourth surface 501 of the buffer layer 500, and the other ends of the nickel layer 302 extend to other surfaces of the annular outer surface of the ceramic body 100.

[0323] Tin (Sn) is then electroplated onto the outer surface of the nickel layer 302 to form a tin layer 303. One end of the tin layer 303 facing the circuit board is located on the fourth surface 501 of the buffer layer 500, and the other ends of the tin layer 303 extend to other surfaces of the annular outer surface of the ceramic body 100.

[0324] Nickel layer 302 and tin layer 303 are used as electroplated metal layers 300. Electroplated metal layers 300 fully cover the second surface 201 of the opposite end electrode 200. The ends of the two electroplated metal layers 300 facing the circuit board can extend to the fourth surface 501 of the buffer layer 500, and the remaining ends extend to other surfaces of the annular outer surface of the ceramic body 100.

[0325] Finally, by testing and packaging the finished products, the seventh type of ceramic capacitor structure can be obtained.

[0326] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing coating, chamfering, sputtering, and electroplating processes on the ceramic body 100 to form a buffer layer 500 on the surface of the ceramic body 100 facing the circuit board. The buffer layer 500 isolates the ends of the terminal electrodes 200 from the surface of the ceramic body 100 facing the circuit board, thereby reducing the tensile stress on the ceramic body 100. During subsequent soldering onto the circuit board, this ensures that the solder avoids the ceramic body 100, preventing tensile stress during circuit board bending from directly acting on the ceramic body 100 through the solder. This separation of the solder from the ceramic body 100 reduces stress concentration at the ceramic body 100, thus preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0327] Figure 26 This is the eighth structural schematic diagram of the ceramic capacitor structure provided in the embodiments of this application.

[0328] like Figure 26 As shown, in some embodiments, the eighth ceramic capacitor structure may include: a ceramic body 100, an end electrode 200, an electroplated metal layer 300, and a buffer layer 500.

[0329] It should be noted that the structural characteristics of the eighth ceramic capacitor structure differ from those of the seventh ceramic capacitor structure in that the coverage area of ​​the buffer layer 500 is different. Other details can be found in the corresponding content of the seventh ceramic capacitor structure, and will not be repeated here.

[0330] In this embodiment, the first surface 101 of the ceramic body 100 is the annular outer surface of the ceramic body 100. Thus, the buffer layer 500 surrounds and covers the annular outer surface of the ceramic body 100.

[0331] The ends of the two end electrodes 200 extend to the fourth surface 501 of the buffer layer 500. The fourth surface 501 is the annular outer surface of the buffer layer 500. The electroplated metal layer 300 covers the second surface 201 of the opposite end electrode 200, and the ends of the two electroplated metal layers 300 can also extend to the fourth surface 501 of the buffer layer 500.

[0332] The ceramic capacitor structure provided in this application embodiment covers a buffer layer 500 on the annular outer surface of the ceramic body 100. The buffer layer 500 isolates the end of the terminal electrode 200 from the annular outer surface of the ceramic body 100, thereby reducing the tensile stress on the ceramic body 100. When subsequently soldered onto a circuit board, this ensures that the solder avoids the ceramic body 100, preventing tensile stress generated during circuit board bending from directly acting on the ceramic body 100 through the solder. This separation of the solder from the surface of the ceramic body 100 reduces stress concentration at the ceramic body 100, thus preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0333] Figure 27 This is the eighth process flow diagram of the method for preparing the ceramic capacitor structure provided in the embodiments of this application.

[0334] like Figure 27 As shown, this application provides a method for preparing an eighth ceramic capacitor structure. The method for preparing the eighth ceramic capacitor structure may include the following steps S801-S804:

[0335] Step S801: Provide a ceramic body.

[0336] Step S802: A buffer material is coated on the first surface of the ceramic body to form a buffer layer on the first surface, thereby obtaining an intermediate bonding member.

[0337] In step S803, metal seed layers are sputtered onto both ends of the intermediate bonding member to form end electrodes at both ends of the intermediate bonding member, and the two end electrodes extend to the fourth surface of the buffer layer.

[0338] Step S804: Electroplating metal material on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes.

[0339] like Figure 27 As shown in (a), (b), (c), (d), and (e), the first surface 101 of the ceramic body 100 is the annular outer surface of the ceramic body 100, and the buffer layer 500 surrounds and covers the annular outer surface of the ceramic body 100. The contents of steps S801 to S804 can be referred to the contents of steps S701 to S704 in the foregoing embodiments, and will not be repeated here.

[0340] Finally, by testing and packaging the finished product made through steps S801 to S804, the eighth type of ceramic capacitor structure can be obtained.

[0341] The method for fabricating a ceramic capacitor structure provided in this application involves sequentially employing coating, chamfering, sputtering, and electroplating processes on the ceramic body 100 to form a buffer layer 500 on the annular outer surface of the ceramic body 100. The buffer layer 500 isolates the ends of the terminal electrodes 200 from the annular outer surface of the ceramic body 100, thereby reducing the tensile stress on the ceramic body 100. When subsequently soldered onto a circuit board, this ensures that the solder avoids the ceramic body 100, preventing tensile stress during circuit board bending from directly acting on the ceramic body 100 through the solder. This separation of the solder from the ceramic body 100 reduces stress concentration at the ceramic body 100, thus preventing the ceramic capacitor structure from breaking due to excessive stress concentration.

[0342] Figure 28 This is a second structural schematic diagram of the ceramic capacitor structure and circuit board provided in the embodiments of this application. The electroplated metal layer 300 is relatively thin. Figure 28 Not shown in the image.

[0343] like Figure 28 As shown, in the ceramic capacitor structures provided in the seventh and eighth embodiments, a buffer layer 500 is provided, and the junction position between the end of the terminal electrode 200 and the fourth surface 501 of the buffer layer 500 is B3. The thickness h1 of the buffer layer 500 is 10μm to 20μm, such that there is at least a distance h1 between the junction position B3 and the ceramic body 100.

[0344] Using SMT technology, the ceramic capacitor structure is soldered to the circuit board 40. Solder 50 covers the terminal electrode 200, and the junction of the end of solder 50 and the terminal electrode 200 is also B3, so that there is a distance h1 between the end of solder 50 (B3) and the ceramic body 100. If a large amount of solder 50 is used, so that the solder 50 extends to the fourth surface 501 of the buffer layer 500, since the buffer layer 500 fully covers the surface of the ceramic body 100, there can still be a distance h1 between the end of solder 50 (B3) and the ceramic body 100.

[0345] In this way, the above embodiments allow the soldering position of the solder 50 to avoid the ceramic body 100 through the buffer layer 500, reducing the angle of stress concentration effect on the ceramic body 100, so that the tensile stress during the deformation process of the circuit board 40 cannot be directly applied to the ceramic body 100 through the solder 50, thereby improving the risk of cracking of the ceramic capacitor structure when the circuit board 40 is bent and deformed.

[0346] Figure 29 This is a graph showing the change in thickness of the buffer layer versus lateral tensile stress provided in the embodiments of this application.

[0347] like Figure 29 As shown, the horizontal axis represents the thickness of the 500mm buffer layer, the vertical axis represents the magnitude of the transverse tensile stress, and the percentage on the curve represents the reduction in transverse tensile stress of the test case compared to the comparative example (percentage).

[0348] By setting the buffer layer 500 to have different thicknesses h1, when the circuit board 40 is subjected to the same force and bent and deformed, the different tensile stresses on the ceramic body are tested to determine whether the ceramic capacitor structure meets the requirements, and thus the minimum value of the thickness h1 of the buffer layer 500 can be determined.

[0349] Set a comparison scale, with a buffer layer thickness h of 500. 11 =0, meaning that the ceramic capacitor structure does not have a buffer layer 500. When the circuit board 40 is bent and deformed, the maximum lateral tensile stress S1 = 84.2 MPa was detected on the ceramic capacitor structure, and the ceramic capacitor structure broke.

[0350] The first test case is set with a buffer layer thickness h of 500. 12 =10μm. When the circuit board was bent at 40°, the maximum lateral tensile stress S2 on the ceramic capacitor structure was detected to be 66.8MPa. The lateral tensile stress S2 in the first test case was 20% lower than the lateral tensile stress S1 in the comparative example.

[0351] The second test case is set up with a buffer layer thickness h of 500. 13=15μm. When the circuit board was bent at 40°, the maximum lateral tensile stress S3 on the ceramic capacitor structure was detected to be 62.2MPa. The lateral tensile stress S3 in the second test example was 26% lower than the lateral tensile stress S1 in the comparative example.

[0352] The third test case is set up with a buffer layer thickness h of 500. 13 =20μm. When the circuit board was bent at 40°, the maximum lateral tensile stress S4 on the ceramic capacitor structure was detected to be 60.8MPa. The lateral tensile stress S4 in the third test case was 29.5% lower than the lateral tensile stress S1 in the comparative example.

[0353] Tests showed that as the thickness h1 of the buffer layer 500 increased, the lateral tensile stress on the ceramic capacitor structure gradually decreased, and the reduction in lateral tensile stress in the test case gradually increased compared to the comparative example.

[0354] If a ceramic capacitor structure does not break during testing and / or the reduction in lateral tensile stress meets the requirements, then the corresponding ceramic capacitor structure can be determined as meeting the requirements; and the minimum value of the thickness h1 of the corresponding buffer layer 500 can be determined as the minimum value, while the maximum value of the thickness h1 of the buffer layer 500 can be determined based on not excessively increasing the overall thickness requirement of the ceramic capacitor structure.

[0355] For example, if the ceramic capacitor structure does not break when the thickness h1 of the buffer layer 500 is 10 μm, and the reduction in lateral tensile stress meets the requirements, then the minimum value of the thickness h1 of the buffer layer 500 can be determined to be 10 μm, and the maximum value can be determined to be 20 μm.

[0356] It should be noted that during the testing process, when the thickness h1 of the buffer layer 500 is less than 10 μm, the ceramic capacitor structure may not necessarily break; however, the reduction in lateral tensile stress is too small and does not meet the requirements. Therefore, the minimum value of the thickness h1 of the buffer layer 500 can be dynamically adjusted according to whether the reduction in lateral tensile stress meets the requirements, and this application embodiment does not specifically limit it.

[0357] Figure 30 This is a graph showing the change in elastic modulus versus transverse tensile stress of the buffer layer provided in the embodiments of this application.

[0358] like Figure 30 As shown, the horizontal axis represents the elastic modulus of the buffer layer 500, the vertical axis represents the magnitude of the transverse tensile stress, and the percentage on the curve represents the reduction (percentage) of the transverse tensile stress of the test case compared to the transverse tensile stress of the comparative example.

[0359] By setting the buffer layer 500 to have different elastic moduli, when the circuit board 40 is subjected to the same force and bent and deformed, the different tensile stresses on the ceramic body are tested to determine whether the ceramic capacitor structure meets the requirements, and thus the maximum value of the elastic modulus of the buffer layer 500 can be determined.

[0360] In a comparative example, the ceramic capacitor structure does not include a buffer layer 500. When the circuit board 40 is bent and deformed, a transverse tensile stress S0 = 84.2 MPa is detected in the ceramic capacitor structure, causing it to fracture.

[0361] In the first test case, the elastic modulus E1 of the buffer layer 500 was set to 2.4 GPa. When the circuit board 40 bent, the maximum lateral tensile stress S1 on the ceramic capacitor structure was detected to be 67.8 MPa. The lateral tensile stress S1 in the first test case was 20% lower than the lateral tensile stress S0 in the comparative example.

[0362] In the second test case, the elastic modulus E2 of the buffer layer 500 was set to 5 GPa. When the circuit board 40 bent, the maximum lateral tensile stress S2 on the ceramic capacitor structure was detected to be 71.7 MPa. The lateral tensile stress S2 of the second test case was 15% lower than the lateral tensile stress S0 of the comparative example.

[0363] In the third test case, the elastic modulus E3 of the buffer layer 500 was set to 7.5 GPa. When the circuit board 40 bent, the maximum lateral tensile stress S3 on the ceramic capacitor structure was detected to be 72.08 MPa. The lateral tensile stress S3 in the third test case was 14.4% lower than the lateral tensile stress S0 in the comparative example.

[0364] In the fourth test case, the elastic modulus E4 of the buffer layer 500 was set to 10 GPa. When the circuit board 40 bent, the maximum lateral tensile stress S4 on the ceramic capacitor structure was detected to be 72.8 MPa. The lateral tensile stress S4 in the fourth test case was 13.7% lower than the lateral tensile stress S0 in the comparative example.

[0365] Tests showed that as the elastic modulus E of the buffer layer 500 decreased, the lateral tensile stress on the ceramic capacitor structure gradually decreased, and the reduction in lateral tensile stress in the test case gradually increased compared to the comparative example.

[0366] If a ceramic capacitor structure does not break during testing and / or the reduction in lateral tensile stress meets the requirements, then the corresponding ceramic capacitor structure can be determined as meeting the requirements; and the maximum value of the corresponding elastic modulus E can be determined as the maximum value.

[0367] For example, if the ceramic capacitor structure does not break when the elastic modulus E4 of the buffer layer 500 is 10 GPa, and the reduction in lateral tensile stress meets the requirements, then the maximum value of the elastic modulus E of the buffer layer 500 can be determined to be 10 GPa.

[0368] It should be noted that during the testing process, when the elastic modulus E of the buffer layer 500 is greater than 10 GPa, the ceramic capacitor structure may not necessarily fracture; however, the reduction in lateral tensile stress may be too small, failing to meet the requirements. Therefore, the maximum value of the elastic modulus E can be dynamically adjusted based on whether the reduction in lateral tensile stress meets the requirements, and this application does not specifically limit it.

[0369] The ceramic capacitor structure and its fabrication method provided in this application aim to mitigate the risk of cracking when the circuit board 40 is bent and deformed. Based on the mechanism of ceramic capacitor structure fracture failure under mechanical stress, and considering the stress concentration effect at the junction of the ceramic body 100, the terminal electrode 200, and the solder 50, two methods can be used to prevent cracking: First, by setting a solder resist layer 400, the soldering position of the solder 50 can avoid the junction of the terminal electrode 200 and the ceramic body 100, preventing the tensile stress during the deformation of the circuit board 40 from directly acting on the junction area of ​​the ceramic body 100 and the terminal electrode 200 through the solder 50. Second, by setting a buffer layer 500 at the junction of the solder 50, the terminal electrode 200, and the ceramic body 100, the tensile stress on the ceramic body 100 can be reduced. This prevents the formation of sharp stress concentration zones between the terminal electrode 200, the ceramic body 100, and the solder 50 during SMT soldering, thereby reducing the risk of failure of the ceramic capacitor structure under mechanical stress and improving the fracture resistance of the ceramic capacitor structure.

[0370] It should be noted that those skilled in the art, upon considering the specification and practicing the application disclosed herein, will readily conceive of other embodiments of this application. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope of this application is indicated by the following claims.

[0371] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A ceramic capacitor structure, characterized by, include: The ceramic body (100) includes a first surface (101) and two end faces (102) located at both ends of the first surface (101); Two end electrodes (200) are provided, each of which covers one of the two end faces (102) of the ceramic body (100) and extends to the first surface (101) of the ceramic body (100). Two electroplated metal layers (300) correspond one-to-one with the two terminal electrodes (200), and the electroplated metal layers (300) cover the second surface (201) of the terminal electrodes (200) opposite to them; A solder resist layer (400) covers the first surface (101) of the ceramic body (100) and extends toward the electroplated metal layer (300), the solder resist layer (400) overlapping the projection of the terminal electrode (200).

2. The ceramic capacitor structure according to claim 1, characterized in that, The solder resist layer (400) and the terminal electrode (200) have a first overlap width; The first overlap width is greater than or equal to 0.1 mm.

3. The ceramic capacitor structure according to claim 2, characterized in that, The ceramic body (100) is rectangular parallelepiped in shape; The first surface (101) is the annular outer surface of the ceramic body (100).

4. The ceramic capacitor structure according to claim 2, characterized in that, The ceramic body (100) is rectangular parallelepiped in shape; The first surface (101) is the surface of the ceramic body (100) facing the circuit board.

5. The ceramic capacitor structure according to claim 3 or 4, characterized in that, The end of the electroplated metal layer (300) coincides with the end of the terminal electrode (200) and is connected to the first surface (101) of the ceramic body (100). The solder resist layer (400) covers a portion of the third surface (301) of the two electroplated metal layers (300) at both ends.

6. The ceramic capacitor structure according to claim 3 or 4, characterized in that, The end of the electroplated metal layer (300) is located on the second surface (201) of the end electrode (200) opposite to it; The solder resist layer (400) extends to the second surface (201) of the two end electrodes (200) at both ends and is connected to the end of the electroplated metal layer (300).

7. The ceramic capacitor structure according to claim 5, characterized in that, The solder resist layer (400) includes a first solder resist layer (401) and a second solder resist layer (402) disposed at intervals; One end of the first solder resist layer (401) covers the third surface (301) of one of the electroplated metal layers (300), one end of the second solder resist layer (402) covers the third surface (301) of the other electroplated metal layer (300), and the other end of the first solder resist layer (401) is opposite to the other end of the second solder resist layer (402). The first solder mask layer (401) has the first overlap width with one of the end electrodes (200), and the second solder mask layer (402) has the first overlap width with the other end electrode (200).

8. The ceramic capacitor structure according to claim 7, characterized in that, The first solder resist layer (401) and the second solder resist layer (402) both have a second overlap width with the first surface (101) of the ceramic body (100); The second overlap width refers to the distance between the end of the electroplated metal layer (300) and the other end of the first solder resist layer (401) / the second solder resist layer (402).

9. The ceramic capacitor structure according to claim 6, characterized in that, The solder resist layer (400) includes a first solder resist layer (401) and a second solder resist layer (402) disposed at intervals; One end of the first solder mask layer (401) covers the second surface (201) of one of the terminal electrodes (200) and is connected to the end of one of the electroplated metal layers (300); one end of the second solder mask layer (402) covers the second surface (201) of the other terminal electrode (200) and is connected to the end of the other electroplated metal layer (300); the other end of the first solder mask layer (401) is opposite to the other end of the second solder mask layer (402); The first solder mask layer (401) has the first overlap width with one of the end electrodes (200), and the second solder mask layer (402) has the first overlap width with the other end electrode (200).

10. The ceramic capacitor structure according to claim 9, characterized in that, The first solder resist layer (401) and the second solder resist layer (402) both have a third overlap width with the first surface (101) of the ceramic body (100); The third overlap width refers to the distance between the end of the terminal electrode (200) and the other end of the first solder mask layer (401) / the second solder mask layer (402).

11. A ceramic capacitor structure, characterized by include: The ceramic body (100) includes a first surface (101) and two end faces (102) located at both ends of the first surface (101); A buffer layer (500) covers the first surface (101) of the ceramic body (100); Two end electrodes (200) are provided, each of which covers one of the two end faces (102) of the ceramic body (100) and extends to the fourth surface (501) of the buffer layer (500). Two electroplated metal layers (300) correspond one-to-one with the two terminal electrodes (200), and the electroplated metal layers (300) cover the second surface (201) of the terminal electrodes (200) opposite to them.

12. The ceramic capacitor structure according to claim 11, characterized in that, The ceramic body (100) is rectangular parallelepiped in shape; The first surface (101) is the annular outer surface of the ceramic body (100).

13. The ceramic capacitor structure according to claim 11, characterized in that, The ceramic body (100) is rectangular parallelepiped in shape; The first surface (101) is the surface of the ceramic body (100) facing the circuit board.

14. The ceramic capacitor structure according to claim 11, characterized in that, The end of the buffer layer (500) adjacent to the end face (102) includes a first chamfer (502); The first chamfer (502) is connected to the second chamfer of the ceramic body (100) by a rounded transition; The second chamfer is located at the connection point between the first surface (101) and the end face (102).

15. A method of fabricating a ceramic capacitor structure, characterized by, The method for preparing the ceramic capacitor structure according to any one of claims 1-10 includes: Provides ceramic body; Electrode slurry is applied to both ends of the ceramic body to form end electrodes at both ends of the ceramic body, and the two end electrodes extend to the first surface of the ceramic body. Metal materials are electroplated on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes, thereby obtaining an intermediate bonding member. A solder resist material is dipped onto the surface of the intermediate bonding member to form a solder resist layer on the first surface of the ceramic body. The solder resist layer covers a portion of the electroplated metal layer so that the solder resist layer overlaps with the projection of the end electrode.

16. The method according to claim 15, characterized in that, The solder resist layer and the end electrode have a first overlap width; The first overlap width is greater than or equal to 0.1 mm.

17. The method according to claim 16, characterized in that, The first surface is the annular outer surface of the ceramic body; as well as, The process of applying a solder resist material to the surface of the intermediate bonding member to form a solder resist layer on the first surface of the ceramic body includes: The solder resist material is applied to all outer surfaces of the intermediate joint. After thermosetting, the solder resist material in the region corresponding to the two end electrodes of the intermediate bonding member is removed to form a solder resist layer on the annular outer surface of the ceramic body.

18. The method according to claim 16, characterized in that, The first surface is the surface of the ceramic body facing the circuit board; and, The process of applying a solder resist material to the surface of the intermediate bonding member to form a solder resist layer on the first surface of the ceramic body includes: The solder resist material is applied to the area of ​​the intermediate connector facing the circuit board. After thermosetting, the thickness of the solder resist coating is reduced to form a solder resist layer on the surface of the ceramic body facing the circuit board.

19. The method according to claim 16, characterized in that, The first surface is the annular outer surface of the ceramic body; as well as, The process of applying a solder resist material to the surface of the intermediate bonding member to form a solder resist layer on the first surface of the ceramic body includes: The solder resist material is applied to both ends of the intermediate joint, and the solder resist material covers the two electroplated metal layers and a portion of the annular outer surface adjacent to the two electroplated metal layers. After thermosetting, the solder resist material in the region corresponding to the two end electrodes of the intermediate bonding member is removed to form a spaced first solder resist layer and a second solder resist layer on the annular outer surface of the ceramic body. One end of the first solder resist layer covers the third surface of one of the electroplated metal layers, and one end of the second solder resist layer covers the third surface of the other electroplated metal layer.

20. A method of fabricating a ceramic capacitor structure, characterized by, The method for preparing the ceramic capacitor structure according to any one of claims 1-10 includes: Provides ceramic body; Electrode slurry is applied to both ends of the ceramic body to form end electrodes at both ends of the ceramic body, and the two end electrodes extend to the first surface of the ceramic body. A solder resist material is dipped into the first surface of the ceramic body to form a solder resist layer on the first surface. The end of the solder resist layer covers a portion of the second surface of the end electrode so that the solder resist layer and the end electrode have a first overlap width. Metal materials are electroplated on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes, and the electroplated metal layer is connected to the solder resist layer.

21. A method of fabricating a ceramic capacitor structure, characterized by, The method for preparing the ceramic capacitor structure according to any one of claims 11-14 includes: Provides ceramic body; A buffer material is coated on the first surface of the ceramic body to form a buffer layer on the first surface, thereby obtaining an intermediate bonding member; Metal seed layers are sputtered at both ends of the intermediate connector to form end electrodes at both ends of the intermediate connector, and the two end electrodes extend to the fourth surface of the buffer layer. Metal materials are electroplated on the second surfaces of the two end electrodes to form an electroplated metal layer on the second surfaces of the end electrodes.

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