Chip multilayer ceramic capacitor

Abstract

The utility model relates to a chip multilayer ceramic capacitor, which comprises a laminated body and an external electrode, and is characterized in that the laminated body comprises laminated dielectric layers and staggered and opposite inner electrode layers; the inner electrode layer comprises an effective electrode pattern area and a lead-out part, and the long side direction of the effective electrode pattern area is consistent with the long side direction of the dielectric layer; the leading-out part is led out from any long edge or short edge of the effective electrode pattern area and extends to the edge of the dielectric layer along the width direction or the length direction of the effective electrode pattern area, and at least one side edge of the leading-out part is connected with the long edge of the adjacent effective electrode pattern area through a first obtuse angle transition part; the external electrode is formed on one side surface of the laminated body and covers the lead-out portion at the edge of the dielectric layer. The chip multilayer ceramic capacitor has the advantages that the effective mounting area of the PCB is increased, the stress of the inner electrodes is improved, the risk that the films at the right angles cannot be completely attached, gaps exist at the right angles of the dielectric films, and layering is prone to occurring is improved, and the product quality is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chip ceramic capacitors, and particularly to an internal structure design of a chip multilayer ceramic capacitor. BACKGROUND

[0002] A conventional chip multilayer ceramic capacitor (MLCC) is prepared by the following process: a prepared ceramic slurry is coated on a PET film by a casting head to form a thin dielectric film, the dielectric film is dried in an oven, a metal inner electrode is printed on the dried dielectric film, the dielectric film with the metal inner electrode is peeled off layer by layer by a laminator and stacked together to form a raw chip, the required product is obtained by lamination, cutting, degassing, sintering and chamfering, and a basic outer electrode is attached to both ends of the chip, and then a nickel layer and a tin layer are electroplated on the outer electrode, thereby obtaining the required chip multilayer ceramic capacitor product.

[0003] As shown in FIGS. Fig. 1 and Fig. 2 In a conventional example, a chip multilayer ceramic capacitor 100 is formed by stacking dielectric films 120 with metal inner electrodes 110 together to form a stack, and the inner electrodes 110 are led out from both ends of the stack in the length direction, and outer electrodes 130 are attached to both ends of the stack.

[0004] Problems of the conventional technology are as follows:

[0005] 1. The inner electrodes of the MLCC are staggered and stacked in the length direction, and the inner electrodes are led out from both ends of the MLCC in the length direction, so that the current path must pass through one end of the MLCC to the other end in the length direction, and the current path is the longest, thereby causing the ESR and ESL of the capacitor to be the largest, and affecting the high-frequency filtering performance of the capacitor.

[0006] 2. The basic outer electrodes are attached to both ends of the MLCC first, and then the nickel layer and the tin layer are electroplated on the basic outer electrodes. In order to ensure the welding stability of the outer electrodes and the pads, the width and thickness of the outer electrodes after being attached to the ceramic must be ensured to have a certain width and thickness, so as to ensure that the basic outer electrodes have sufficient adhesion on the surface of the ceramic. If the width or thickness of the basic outer electrodes after being attached is too wide or too thick, the attachment stress of the outer electrodes and the ceramic body will be increased, causing the MLCC to crack, and the material cost of the outer electrodes is also increased. In the application end of the MLCC, only the one face in contact with the pads is the welding face, and the other four faces are non-welding faces, and the material utilization rate of the outer electrodes on the four non-welding faces is very low, causing great waste of the outer electrode materials.

[0007] 3. If the external electrodes of the substrate after soldering are too narrow, too thin, or not dense enough, they are prone to detachment during chip application, or nickel may seep in during nickel plating, affecting product reliability. In severe cases, solder bursting may even occur, causing short circuits in the external electrodes due to solder layer connections between adjacent components.

[0008] 4. The chip mounting surface is random. If the mounting surface and the stack-up surface are on the same plane, due to the piezoelectric effect unique to the dielectric, the chip capacitor will cause a "whistling" problem due to electrostriction caused by the piezoelectric effect after the chip is powered on. Utility Model Content

[0009] Based on this, this application provides a chip multilayer ceramic capacitor that can solve the above-mentioned technical problems.

[0010] The above-mentioned objective of this application is achieved through the following technical solution:

[0011] This application provides a chip-type multilayer ceramic capacitor, including a laminate and external electrodes. The laminate includes laminated dielectric layers and internal electrode layers disposed alternately between the dielectric layers. The dielectric layers are rectangular in shape.

[0012] The inner electrode layer includes an effective electrode pattern area and a lead-out portion. The effective electrode pattern area is rectangular in shape, and its edge does not coincide with the outer edge of the dielectric layer. For each inner electrode layer, its lead-out portion is led out from the same side of its effective electrode pattern area and extends to the edge of the same side of the dielectric layer in a direction perpendicular to that side. The side of the effective electrode pattern area and at least one side of the lead-out portion are connected by a first obtuse angle transition portion.

[0013] The external electrode is formed on one side of the laminate that exposes the lead-out portion and covers the lead-out portion that extends to the edge of the dielectric layer.

[0014] In an exemplary embodiment, the portion of the lead-out portion that is in contact with the edge of the dielectric layer has a plurality of clearances for the external electrode to enter the laminate and contact the lead-out portion.

[0015] In one exemplary embodiment, a plurality of the clearance positions are evenly distributed at the edge where the lead-out portion meets the dielectric layer.

[0016] In one exemplary embodiment, the clearance is arc-shaped or semi-circular.

[0017] In one exemplary embodiment, the portion of the lead-out portion that connects to the edge of the dielectric layer and forms a clearance portion accounts for 30-50% of the total connecting portion.

[0018] In one exemplary embodiment, the lead-out portion includes a connecting portion connected to the effective electrode pattern area and an extending portion extending to the edge of the dielectric layer, and the width of the extending portion in a direction perpendicular to the extending direction of the lead-out portion is greater than the width of the connecting portion.

[0019] In one exemplary embodiment, at least one side of the extending portion is not in line with the side of the connecting portion, and a second obtuse angle transition portion is formed between the side and the side of the connecting portion.

[0020] In one exemplary embodiment, for two adjacent inner electrode layers, each extending portion extends to the outer edge of the adjacent other side of the dielectric layer in a direction away from the other, and the outer electrode extends from one side of the dielectric layer to the adjacent other side to cover the extending portion.

[0021] In one exemplary embodiment, the two sides of the lead-out portion form a first obtuse angle transition portion with the sides of the effective electrode pattern area led by the lead-out portion, respectively.

[0022] Alternatively,

[0023] One side of the lead-out portion forms a first obtuse angle transition portion with the side of the effective electrode pattern area led by the lead-out portion, and the other side of the lead-out portion is in line with the other side of the effective electrode pattern area.

[0024] In one exemplary embodiment, the structure of the outer electrode is selected from any one of the following:

[0025] One layer of outer electrode structure, two layers of outer electrode structure, three layers of outer electrode structure, four layers of outer electrode structure, five layers of outer electrode structure, six layers of outer electrode structure.

[0026] The present application has the following beneficial effects:

[0027] 1. The outer electrode is changed from covering the end entirely to being provided only on the side where the inner electrode is exposed, which can greatly save unnecessary waste of the outer electrode on the non-soldering side of the chip.

[0028] 2. The chip is changed from exposing the outer electrode on both ends in the length direction to exposing the outer electrode on only one side of the ceramic body, thereby saving the size space occupied by the original outer electrode, increasing the ceramic body space, and facilitating the development of larger capacity.

[0029] 3. Due to the cancellation of the end external electrode, the external electrode lead is adjusted from the length of the chip to the width direction of the chip, or one face in the length direction of the chip, improving the wiring on the PCB, reducing the distance between the pads and the space occupation and the consumption of the solder paste, and improving the effective mounting area of the PCB;

[0030] 4. The exposed internal electrode is changed from both ends of the chip end to only one end of one face, or one face in the length direction of the chip, and the other faces are ceramic bodies, which can greatly improve the risk of nickel penetration during the electroplating process of the chip. Since there is only one soldering face soldered to the pad, the other four faces are ceramic bodies, which greatly reduces the risk of tin explosion and the risk of short circuit caused by the tin layer connection of adjacent components due to tin explosion.

[0031] 5. The external electrode lead is adjusted from the length of the chip to the width direction of the chip, or one face in the length direction of the chip, greatly shortening the current path in the chip, which can greatly improve the ESR and ESL of the chip.

[0032] 6. The external electrode lead is adjusted from the length of the chip to the width direction of the chip, or one face in the length direction of the chip, and the chip mounting face and the lamination face are not in the same plane, which can greatly improve the "whistling" problem caused by the piezoelectric effect of the chip capacitor.

[0033] 7. Since the attached basic external electrode is only in one direction of the chip width, after burning, only one side of the chip appears burning stress, which can relieve the mechanical stress of the chip burning end and prevent short circuit caused by excessive stress cracking of the end.

[0034] 8. By changing the right angle between the effective electrode pattern area and the lead-out part to a first obtuse angle transition part, this design increases the contact width of the lead-out part and the effective electrode pattern area, and the contact surface electrode width gradient between the lead-out part and the effective electrode pattern area decreases, and the edge of the lead-out part smoothly transitions, which can improve the internal stress of the local electrode.

[0035] 9. The design of the first obtuse angle transition part can improve the problem that the diaphragm cannot completely adhere at the right angle, and there is a gap between the dielectric diaphragm at the right angle, which is prone to delamination. It can also improve the problem of charge concentration at the right angle and the phenomenon of sharp end discharge caused by charge concentration at the right angle. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figs. 1-2 is a schematic diagram of the structure of a traditional chip multilayer ceramic capacitor;

[0037] Figs. 3-4 is a schematic diagram of the structure of a chip multilayer ceramic capacitor in an exemplary embodiment;

[0038] Figs. 5-11 FIG. 1 is a schematic view of a structure of a dielectric layer and an internal electrode layer of a multilayer ceramic capacitor in an exemplary embodiment.

[0039] BRIEF DESCRIPTION OF DRAWINGS

[0040] 200: multilayer ceramic capacitor

[0041] 210: laminate; 220: dielectric layer; 230: internal electrode layer; 230a: first internal electrode layer; 230b: second internal electrode layer; 231: effective electrode pattern area; 232: lead-out portion; 232a: connection portion; 232b: extension portion; 233: first obtuse angle transition portion; 234: avoidance site; 240: external electrode DETAILED DESCRIPTION

[0042] In order to make the above objectives, features and advantages of the present application more clear and easily understood, the specific embodiments of the present application will be described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways without being limited to the specific embodiments described herein and it is to be understood that the present application is not limited in scope to the particular embodiments disclosed. It will be apparent to one skilled in the art that various modifications can be made and alternatives can be used without departing from the scope of the present application. Thus, other embodiments will be apparent to those skilled in the art from this disclosure.

[0043] In the description of the present application, it should be understood that, if there are terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0044] In addition, if there are terms such as "first", "second", these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can include at least one of the features explicitly or implicitly. In the description of the present application, if the term "plurality" appears, the meaning of "plurality" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0045] In the present application, unless specifically defined and limited otherwise, if there is any appearance of the terms "mount", "connect", "connection", "fix", and the like, these terms should be interpreted in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0046] In the present application, unless specifically defined and limited otherwise, if there is any appearance of the terms "mount", "connect", "connection", "fix", and the like, these terms should be interpreted in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0047] For the technical problems in the background art, the present application provides a chip multilayer ceramic capacitor, as shown in Figs. 3-5 In an embodiment, the chip multilayer ceramic capacitor 200 includes a laminated body 210 and an external electrode 240, wherein the laminated body 210 includes laminated dielectric layers 220 and internal electrode layers 230 arranged in an interleaved and opposite manner between the dielectric layers 220.

[0048] In the present embodiment, the dielectric layers 220 are rectangular in shape, and the laminated body 210 formed by the lamination thereof is a rectangular parallelepiped in shape. The dielectric layers 220 are usually ceramic materials and serve as insulators to ensure electrical insulation between the internal electrode layers 230. The internal electrode layers 230 are located between the dielectric layers 220 and are arranged in a specific pattern. Adjacent internal electrode layers 230 are opposite to each other but do not directly contact each other. The opposite internal electrode layers 230 are connected to the positive and negative poles of a circuit to form a capacitor structure.

[0049] As shown in Figs. 3-5 The internal electrode layers 230 include first internal electrode layers 230a and second internal electrode layers 230b interleaved and oppositely arranged between the dielectric layers 220, and the patterns of the first internal electrode layers 230a and the second internal electrode layers 230b are arranged in a symmetrical manner. Each internal electrode layer 230 includes an effective electrode pattern area 231 and a lead-out portion 232.

[0050] The effective electrode pattern area 231 is in a rectangular shape, and the effective electrode pattern area 232 is located on the inner side of the dielectric layer 220 as a whole, and has an area smaller than the dielectric layer 220, and the long side direction of the effective electrode pattern area 232 is consistent with the long side direction of the dielectric layer 220. In other embodiments, the two can also be opposite. The long side and short side edges of the effective electrode pattern area 231 do not coincide with the outer edge of the dielectric layer 220, and the projections of the effective electrode pattern areas 231 of the first inner electrode layer 230a and the second inner electrode layer 230b in the stacking direction of the inner electrode layer 230 overlap, that is, the shapes and sizes of the first inner electrode layer 230a and the second inner electrode layer 230b are also the same, and the lead-out portions 232 are symmetrically arranged left and right.

[0051] In Figs. 3-5 the embodiments, the lead-out portion 232 is led out from the long side of the effective electrode pattern area 231 and extends to the edge of the dielectric layer 220 along the width direction of the effective electrode pattern area 231. Specifically, the lead-out portions 232 of the first inner electrode layer 230a and the second inner electrode layer 230b are symmetrically arranged left and right, and are respectively led out at the left and right ends of the same side of the effective electrode pattern area 231, and the projections of the two in the stacking direction of the inner electrode layer 230 have no overlapping part.

[0052] In the present embodiment, one side or both sides of the lead-out portion 232 are not on the same straight line as the short side edge of the effective electrode pattern area 231, and the side is connected to the long side of the adjacent effective electrode pattern area 231 through the first obtuse angle transition portion 233.

[0053] The first obtuse angle transition portion 233 forms an obtuse angle with the long side of the effective electrode pattern area 231, and the side of the lead-out portion 232 also forms an obtuse angle with the first obtuse angle transition portion 233; or the first obtuse angle transition portion 233 forms an obtuse angle with the long side of the effective electrode pattern area 231, and directly extends to the edge of the dielectric layer 220, thereby forming the side of the lead-out portion 232.

[0054] The external electrode 240 includes two, which are respectively formed on the same side of the lead-out portion 232 exposed by the laminated body 210, and cover the two lead-out portions 232 extending to the edge of the dielectric layer 220.

[0055] Based on the same invention principle, as Fig. 11 shown in an embodiment, the lead-out portion 232 can be arranged at the short side edge of the effective electrode pattern area 231, and extend to coincide with the outer edge of the dielectric layer 220 along the long side direction of the effective electrode pattern area 231. Other design adjustments of the lead-out portion 232 can be referred to Figs. 5 to 10 Fig. 11 ​In the embodiment, the two sides of the lead-out portion 232 are not in the same straight line with the sides of the effective electrode pattern area 231, the two sides of the lead-out portion 232 are connected with the short sides of the effective electrode pattern area adjacent thereto through the first obtuse angle transition portion 233, and the external electrode 240 is formed on the side of the laminate 210 and covers the lead-out portion 232.

[0056] In the following embodiments of the present application, the lead-out portion 232 is exemplified to be led out from the long side of the effective electrode pattern area 231, and the following embodiments are also applicable to the scheme in which the lead-out portion 232 is led out from the short side of the effective electrode pattern area 231. Fig. 11

[0057] In the present embodiment, by adjusting the internal electrode lead-out portions from the opposite edges of the chip to the same side edge of the chip, the current path in the chip can be greatly reduced, and since the two external electrodes 240 are close to each other, the mounting area of the chip can be greatly reduced, the mounting capacity of the PCB is increased, and the mounting density is improved.

[0058] Compared with the prior art, the chip multilayer ceramic capacitor of the present embodiment has the following advantages:

[0059] 1. The external electrode is changed from covering the end to being provided only on the side with the exposed internal electrode, which greatly saves the unnecessary waste of the external electrode on the non-soldering side of the chip.

[0060] 2. The chip is changed from exposing the external electrode on both ends in the length direction to exposing the external electrode on only one side, thereby saving the size space occupied by the original external electrode, increasing the ceramic body space, and facilitating the development of larger capacity.

[0061] 3. Since the end external electrode is cancelled, the wiring on the PCB is improved, the distance and space occupation between the pads and the consumption of the solder paste are reduced, and the effective mounting area of the PCB is improved.

[0062] 4. The exposed internal electrode is changed from both ends of the chip to only one end of one side, and the other sides are ceramic bodies, which greatly improves the risk of nickel penetration in the electroplating process. Since there is only one soldering side to be soldered with the pad, the other four sides are ceramic bodies, which greatly reduces the risk of tin explosion and the risk of short circuit of the external electrode caused by the tin explosion of the adjacent components.

[0063] 5. The external electrode lead-out end is changed from the length of the chip to being led out in the width direction of the chip or on one side in the length direction of the chip, which greatly shortens the current path in the chip and greatly improves the ESR and ESL of the chip.​

[0064] 6. The external electrode leads are changed from being led out along the length of the chip to being led out along the width of the chip, or on one side along the length of the chip. Furthermore, the chip mounting surface and the stack-up surface are not on the same plane, which can greatly improve the squealing problem caused by electrostriction due to the piezoelectric effect of the chip capacitor.

[0065] 7. Since the external electrodes are only attached to the chip in one direction of the chip width, after burning, the burning stress only occurs on one side of the chip. This can alleviate the mechanical stress at the burning end of the chip and prevent short circuits caused by cracking due to excessive stress at the end.

[0066] 8. By changing the right angle between the effective electrode pattern area and the lead-out portion to a first obtuse angle transition portion, this design increases the contact width between the lead-out portion and the effective electrode pattern area, and the electrode width gradient of the contact surface between the lead-out portion and the effective electrode pattern area decreases, and the edge of the lead-out portion transitions smoothly, which can improve the internal stress of the local electrode.

[0067] 9. The design of the first obtuse angle transition section can improve the situation where the membrane cannot be fully adhered at the right angle, and the dielectric membrane has gaps at the right angle, which is prone to delamination.

[0068] In specific embodiments, such as Fig. 5 As shown, neither side of the lead-out portion 232 coincides with the short side of the effective electrode pattern area 231, and the two sides of the lead-out portion 232 are connected to the long side of the adjacent effective electrode pattern area 231 through the first obtuse angle transition portion 233.

[0069] like Fig. 6 As shown, in another embodiment, one side of the lead-out portion 232 coincides with the short side of the effective electrode pattern area 231, and the side and the short side of the effective electrode pattern area 231 are on the same straight line; the other side of the lead-out portion 232 is connected to the long side of the adjacent effective electrode pattern area 231 by a first obtuse angle transition portion 233.

[0070] exist Fig. 7 In the example, the first obtuse angle transition portion 233 directly forms the side of the lead-out portion 232 and extends to the edge of the effective electrode pattern area 231.

[0071] In the above embodiment, the width of the lead-out portion 232 gradually decreases as it moves away from the effective electrode pattern area 231. If the width of the lead-out portion 232 at the edge of the dielectric layer 220 is too small, its contact surface with the external electrode will also be small, which will cause the connection between the external electrode 240 and the inner electrode layer 230 to be unstable, or even the circuit transmission to be unstable.

[0072] To address this technical problem, such as Figs. 6-8As shown in the figure, in an embodiment, the part of the lead-out portion 232 where it meets the edge of the dielectric layer 220 is formed with a plurality of avoidance positions 234 for the external electrode 240 to enter the stack 210 and contact the lead-out portion 232. The avoidance position 234 refers to the electrode pattern of the lead-out portion 232 where there is a vacancy, i.e. the internal electrode pattern is not printed at the position of the avoidance position 234, and instead a gap is formed between the upper and lower dielectric layers 220 at the position of the avoidance position 234. When the paste of the external electrode 240 is applied, the paste of the external electrode 240 can enter the avoidance position 234, thereby increasing the contact area between the external electrode 240 and the lead-out portion 232, enhancing the welding strength between the internal electrode 230 and the external electrode 240 and the stability of the circuit transmission, and reducing the ESR / ESL.

[0073] In a preferred embodiment, as shown in the figure, Figs. 6-8 the avoidance positions 234 are uniformly distributed along the edge of the lead-out portion 232 where it meets the dielectric layer 220.

[0074] In a preferred embodiment, as shown in the figure, Figs. 6-8 the avoidance positions 234 are in the shape of an arc or a semicircle.

[0075] Optionally, the part of the lead-out portion 232 where it meets the edge of the dielectric layer 220 and forms the avoidance positions 234 accounts for 30-50% of the total meeting part.

[0076] In other embodiments, as shown in the figures, Fig. 9 and Fig. 10 the lead-out portion 232 includes a connecting portion 232a connected to the effective electrode pattern area 231 and an extension portion 232b extending to the edge of the dielectric layer, and the width of the extension portion 232b along the long side direction of the effective electrode pattern area 232a is greater than the width of the connecting portion, so that the contact area between the internal electrode layer 230 and the external electrode 240 is increased, the contact resistance between the internal electrode layer 230 and the external electrode 240 is improved, the ESR / ESL is reduced, and the welding strength of the external electrode 240 is increased.

[0077] In the embodiments shown in the figures, Fig. 9 and Fig. 10 the extension portion 232b extends in one direction from the connecting portion 232a, and in other embodiments, the extension portion 232b can extend in both left and right directions from the connecting portion 232a.

[0078] In the embodiments shown in the figures, Fig. 10 the extension portion 232b extends in the short side direction of the dielectric layer 220 and extends to the outer edge of the short side, and in this embodiment, the external electrode (not shown) extends from the outer edge of the long side of the dielectric layer 220 to the outer edge of the short side of the dielectric layer to cover the extension portion.

[0079] In some embodiments, at least one side edge of the extension 232b is not in line with a side edge of the connecting portion 232a, and a second obtuse transition (not shown) is formed between the side edge and the side edge of the connecting portion 232a.

[0080] Preferably, the above Figs. 3-11 The structure design, the first obtuse transition 233 and the avoiding position 234 can be combined in any way to achieve a better design and meet application requirements.

[0081] Preferably, on the basis of the above embodiments, the external electrode 240 can be a single-layer external electrode structure, and the external electrode is made of copper, silver, palladium or silver-palladium alloy and the like. After the chamfering, the MLCC is adhered with copper paste, silver paste, palladium paste, silver-palladium alloy paste and the like on both ends, and after the sintering, the copper, silver, palladium or silver-palladium alloy external electrode is formed.

[0082] Preferably, the external electrode 240 can be a double-layer external electrode structure, and the external electrode structure can be composed of nickel, copper (silver or gold). The nickel can be adhered with nickel paste on both ends of the capacitor green body after the sintering, and the basic external electrode is formed. Then, a layer of copper (silver or gold) is sintered or electroplated on the outside of the basic external electrode to form a nickel-copper (silver or gold) double-layer external electrode structure. Alternatively, the external electrode structure can be composed of copper, copper (silver or gold). The basic external electrode is adhered with copper paste on both ends of the MLCC after the chamfering, and the copper layer is sintered to form the basic external electrode. Then, a layer of copper, silver or gold is electroplated or sintered on the outside of the basic external electrode to form a copper-copper (silver or gold) double-layer external electrode structure. Alternatively, the external electrode structure can be composed of copper and high molecular resin. The basic external electrode is adhered with copper paste on both ends of the MLCC after the chamfering, and the copper layer is sintered to form the basic external electrode. Then, a layer of high molecular resin is adhered on the outside of the basic external electrode to form a two-layer structure composed of copper and high molecular resin.

[0083] Preferably, the external electrode 240 can be a three-layer external electrode structure, which can be formed by copper, nickel, tin (silver or gold): the base external electrode is adhered to the copper paste on both ends of the MLCC after chamfering, and after the copper layer is burned and adhered, the base external electrode is formed, and then a nickel layer and a tin (silver or gold) layer are electroplated outside the base external electrode, forming a copper-nickel-tin (silver or gold) three-layer external electrode structure. Alternatively, the external electrode structure can be formed by copper, copper, tin (silver or gold): the base external electrode is adhered to the copper paste on both ends of the MLCC after chamfering, and after the copper layer is burned and adhered, the base external electrode is formed, and then a copper layer and a tin (silver or gold) layer are electroplated outside the base external electrode, forming a copper-copper-tin (silver or gold) three-layer external electrode structure. Alternatively, the external electrode structure can be formed by copper, resin silver paste (copper paste), tin (or silver or gold): the base external electrode is adhered to the copper paste on both ends of the MLCC after chamfering, and after the copper layer is burned and adhered, the base external electrode is formed, and then a layer of resin silver paste (copper paste) is adhered outside the base external electrode and solidified, and then a tin (silver or gold) layer is electroplated outside the external electrode, forming a copper-resin silver paste-tin (or silver or gold) three-layer external electrode structure. Alternatively, the external electrode structure can be formed by copper, copper, high molecular resin: the base external electrode is adhered to the copper paste on both ends of the MLCC after chamfering, and after the copper layer is burned and adhered, the base external electrode is formed, and then a copper layer is burned or electroplated outside the base external electrode, and then a high molecular resin layer is adhered outside the copper layer, forming a copper-copper-high molecular resin three-layer external electrode structure.

[0084] Preferably, the external electrode 240 can be a four-layer external electrode structure, which can be formed by nickel, copper, nickel, tin: the base external electrode is adhered to the nickel paste on both ends of the MLCC green body, and then sintering is performed to form the base external electrode, and then a copper paste is adhered outside the base external electrode, and after the copper layer is burned and adhered, a nickel layer and a tin layer are electroplated on the copper layer, forming a nickel-copper-nickel-tin four-layer external electrode structure. Alternatively, the external electrode structure can be formed by copper, high molecular resin, nickel, tin: the base external electrode is adhered to the copper paste on both ends of the MLCC after chamfering, and after the copper layer is burned and adhered, the base external electrode is formed, and then a layer of high molecular resin is adhered outside the base external electrode, and then a nickel layer and a tin layer are electroplated, forming a copper-high molecular resin layer-nickel-tin three-layer external electrode structure. Alternatively, the external electrode structure can be formed by copper, resin silver paste (or copper paste), nickel, tin: the base external electrode is adhered to the copper paste on both ends of the MLCC after chamfering, and after the copper layer is burned and adhered, the base external electrode is formed, and then a layer of resin silver paste (or copper paste) is adhered outside the base external electrode and solidified, and then a nickel layer and a tin layer are electroplated on the surface of the resin silver paste (or copper paste), forming a copper-resin silver paste (or copper paste)-nickel-tin four-layer external electrode structure. Alternatively, the external electrode structure can be formed by copper, tin, nickel, tin: the base external electrode is adhered to the copper paste on both ends of the MLCC after chamfering, and after the copper layer is burned and adhered, the base external electrode is formed, and then a tin layer, a nickel layer and a tin layer are electroplated in sequence outside the base external electrode, forming a copper-tin-nickel-tin four-layer external electrode structure.

[0085] Preferably, the external electrode 240 can be a five-layer external electrode structure, which can be formed by copper, soft copper, soft pad, nickel, tin; the base external electrode is formed after sintering after the copper paste is attached to the two ends of the MLCC green body, and then the soft copper and soft pad are attached to the outside of the base external electrode, and then the nickel layer and the tin layer are electroplated on the soft pad after solidification, thereby forming a copper-soft copper-soft pad-nickel-tin five-layer external electrode structure.

[0086] Preferably, the external electrode 240 can be a six-layer external electrode structure, which can be formed by copper, soft copper, soft pad, nickel, copper (tin), and a polymer layer; the base external electrode is formed after sintering after the copper paste is attached to the two ends of the MLCC green body, and then the soft copper and soft pad are attached to the outside of the base external electrode, and then the nickel layer and the copper (tin) layer are electroplated on the soft pad after solidification, and then a polymer layer is wrapped outside the electroplated copper layer, thereby forming a copper-soft copper-soft pad-nickel-copper (tin)-polymer six-layer external electrode structure.

[0087] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0088] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the utility model patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims, and the description can be used to explain the content of the claims.

Claims

1. A multilayer ceramic chip capacitor comprising a laminate and external electrodes, characterized in that: the laminate comprises laminated dielectric layers and internal electrode layers alternately arranged between the dielectric layers, the dielectric layers being rectangular in shape; the internal electrode layers comprise effective electrode pattern regions and lead-out portions, the effective electrode pattern regions being rectangular in shape, the edges of the effective electrode pattern regions not coinciding with the outer edges of the dielectric layers; for each of the internal electrode layers, the lead-out portion thereof is led out from a side edge of the effective electrode pattern region thereof and extends to the edge of the same side edge of the dielectric layer in a direction perpendicular to the side edge, and the side edge of the effective electrode pattern region and at least one side edge of the lead-out portion are connected by a first obtuse angle transition portion; and the external electrodes are formed on a side surface of the laminate exposing the lead-out portions and cover the lead-out portions extending to the edges of the dielectric layers.

2. The multilayer ceramic chip capacitor according to claim 1, characterized in that: the portions of the lead-out portions contacting the edges of the dielectric layers are formed with a plurality of avoidance sites for the external electrodes to enter the laminate and contact the lead-out portions.

3. The multilayer ceramic chip capacitor according to claim 2, characterized in that: the plurality of avoidance sites are uniformly distributed on the edges of the lead-out portions contacting the dielectric layers.

4. The multilayer ceramic chip capacitor according to claim 2, characterized in that: the avoidance sites are arc-shaped or semicircular.

5. The multilayer ceramic chip capacitor according to claim 2, characterized in that: the portions of the lead-out portions contacting the edges of the dielectric layers and formed with the avoidance sites account for 30-50% of the entire contacting portions.

6. The multilayer ceramic chip capacitor according to claim 2, characterized in that: the lead-out portions comprise connecting portions connected to the effective electrode pattern regions and extending portions extending to the edges of the dielectric layers, and the width of the extending portions in a direction perpendicular to the extending direction of the lead-out portions is greater than the width of the connecting portions.

7. The multilayer ceramic chip capacitor according to claim 6, characterized in that: at least one side edge of the extending portion is not in the same straight line as the side edge of the connecting portion, and a second obtuse angle transition portion is formed between the side edge and the side edge of the connecting portion.

8. The multilayer ceramic chip capacitor according to claim 6, characterized in that: for two adjacent internal electrode layers, each of the extending portions extends to the outer edge of the adjacent other side edge of the dielectric layer in a direction away from the other, and the external electrodes extend from one side surface of the dielectric layer to the adjacent other side surface thereof to cover the extending portions.

9. The multilayer ceramic chip capacitor according to claim 1, characterized in that: the two side edges of the lead-out portion form first obtuse angle transition portions with the side edges of the effective electrode pattern regions led out by the lead-out portion, respectively; or one side edge of the lead-out portion forms a first obtuse angle transition portion with the side edge of the effective electrode pattern region led out by the lead-out portion, and the other side edge of the lead-out portion is in the same straight line as the other side edge of the effective electrode pattern region. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10. The multilayer ceramic capacitor of any one of claims 1 to 9, wherein The structure of the outer electrode is selected from any one of: a one-layer outer electrode structure, a two-layer outer electrode structure, a three-layer outer electrode structure, a four-layer outer electrode structure, a five-layer outer electrode structure, and a six-layer outer electrode structure.

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