Multi-layer ceramic capacitor preparation method and multi-layer ceramic capacitor

Abstract

The invention relates to the technical field of capacitors, and discloses a multi-layer ceramic capacitor preparation method and a multi-layer ceramic capacitor. According to the scheme, a clamp is arranged, and the two side faces, in the Z direction, of a laminated body mother board are clamped and covered by the clamp, when external electrodes are prepared, the external electrodes are only distributed on two first cut-off faces; therefore, the width dimension and the thickness dimension of the multilayer ceramic capacitor can be saved, the number of the inner electrodes and the width of the inner electrodes can be increased, and the capacitance of the multilayer ceramic capacitor can be improved. In addition, when any side surface except the two first cut surfaces is used as the mounting surface of the multilayer ceramic capacitor, soldering tin can be prevented from being filled between the multilayer ceramic capacitor and the bonding pad, so that the mounting height of the multilayer ceramic capacitor can be prevented from being increased.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitors, and in particular to a method for preparing a multilayer ceramic capacitor and a multilayer ceramic capacitor. Background Art

[0002] With the high capacity of multilayer ceramic capacitors, it is necessary to reduce the thickness of the internal electrodes and ceramic dielectric layers of the multilayer ceramic capacitors and increase the number of stacked layers of the internal electrodes. The number of stacked layers of the internal electrodes is limited by the total thickness of the multilayer ceramic capacitor, while the thickness of the external electrodes formed by the dip coating process is relatively large, usually reaching tens of microns to hundreds of microns. Therefore, the external electrodes increase the width and thickness of the multilayer ceramic capacitor, which is not conducive to increasing the number of stacked layers of the internal electrodes and increasing the capacitance of the multilayer ceramic capacitor. In addition, the external electrodes formed by the dip coating process will cover the mounting surface (towards the circuit board) of the multilayer ceramic capacitor. Therefore, after the multilayer ceramic capacitor is soldered to the circuit board, the solder will fill between the multilayer ceramic capacitor and the pad, thereby increasing the installation height of the multilayer ceramic capacitor on the circuit board. Summary of the invention

[0003] The object of the present invention is to provide a method for preparing a multilayer ceramic capacitor and a multilayer ceramic capacitor, which are used to solve the problem that the thickness of the external electrode formed by the dip coating process in the prior art is large and the external electrode easily covers the mounting surface of the capacitor, resulting in the capacitance of the capacitor being limited and the mounting height of the capacitor being increased.

[0004] In order to achieve the above objectives, in a first aspect, an embodiment of the present application provides a method for preparing a multilayer ceramic capacitor, comprising:

[0005] preparing a laminate mother board having internal electrodes;

[0006] Cutting the laminate mother board in sequence along the X direction to obtain a plurality of laminate blocks, wherein the laminate blocks have two first cut surfaces along the X direction, a portion of the internal electrodes is exposed on one of the first cut surfaces, and a portion of the internal electrodes is exposed on the other of the first cut surfaces;

[0007] Using two clamps to respectively clamp and cover the two side surfaces of the stacked body block along the Z direction, and attaching external electrodes to the two first cut surfaces respectively;

[0008] The clamp is removed from the stacked body block, and the stacked body block with the external electrodes formed thereon is sequentially cut along the Y direction to obtain a plurality of stacked bodies; the stacked body has two second cut surfaces along the Y direction, the two second cut surfaces form the first side surface and the second side surface of the stacked body, and the internal electrodes do not expose the first side surface and the second side surface; the stacked body has a third side surface and a fourth side surface along the Z direction;

[0009] The laminate is debinded and sintered in sequence to obtain a multilayer ceramic capacitor.

[0010] In some embodiments of the present application, the preparation of the laminated motherboard includes the following steps:

[0011] Preparation of ceramic thin films;

[0012] Printing an internal electrode slurry on the ceramic film and drying it to form a ceramic film with internal electrodes, wherein the lengths of the multiple internal electrodes extend along the X direction, and the multiple internal electrodes are arranged at intervals along the X direction and the Y direction on the ceramic film;

[0013] Stacking a plurality of the ceramic films with the internal electrodes along the Z direction, with two adjacent ceramic films with the internal electrodes being staggered along the X direction, to obtain a stacked unit;

[0014] A plurality of the ceramic films are stacked on the two side surfaces of the stack unit along the Z direction to form two protection layers covering the two side surfaces of the stack unit along the Z direction, thereby obtaining a stack mother board with internal electrodes.

[0015] In some embodiments of the present application, the second cut surface is located in the middle of two inner electrodes adjacent to each other along the Y direction.

[0016] In some embodiments of the present application, two side edges of the clamp along the X direction respectively protrude from the two first cut surfaces; or two side edges of the clamp along the X direction are respectively flush with the two first cut surfaces.

[0017] In some embodiments of the present application, the external electrode includes a first nickel layer;

[0018] Nickel metal slurry is coated on the two first cut surfaces successively or simultaneously and dried to form the first nickel layer; or the first nickel layer is formed on the two first cut surfaces successively or simultaneously by a sputtering coating process.

[0019] In some embodiments of the present application, the fixture is removed from the stack block, and the stack is debinded and sintered in sequence, and a second nickel layer and a first tin layer are electroplated in sequence on the surface of the first nickel layer.

[0020] In some embodiments of the present application, a plurality of additional mother electrodes are provided on both sides of the stacked mother board along the Z direction, and the additional electrodes extend along the Y direction;

[0021] The plurality of additional mother electrodes are arranged correspondingly at the cutting lines of the stacked mother board along the X direction, so that the third side surface and the fourth side surface of the stacked body are respectively provided with two additional sub-electrodes arranged at intervals.

[0022] In some embodiments of the present application, the additional sub-electrode includes a third nickel layer;

[0023] A screen printing process is used to apply nickel metal paste, and the nickel metal paste is applied to corresponding positions on two side surfaces of the laminated motherboard along the Z direction to form the third nickel layer, or a sputtering coating process is used to form the third nickel layer at corresponding positions on two side surfaces of the laminated motherboard along the Z direction;

[0024] After the stacked body is debinded and sintered, a second tin layer is electroplated on the surface of the third nickel layer.

[0025] In a second aspect, an embodiment of the present application provides a multilayer ceramic capacitor, which adopts the method for preparing the multilayer ceramic capacitor described in the above embodiment, and is characterized by comprising:

[0026] A ceramic body, wherein the ceramic body has a first end surface and a second end surface that are oppositely disposed along the X direction;

[0027] A plurality of internal electrodes are provided, wherein the plurality of internal electrodes are spaced apart in the ceramic body along the Z direction, some of the internal electrodes extend to the first end surface, and some of the internal electrodes extend to the second end surface; and

[0028] External electrode, the first end surface and the second end surface are both covered with the external electrode.

[0029] In some embodiments of the present application, the ceramic body has a third side surface and a fourth side surface that are oppositely disposed along the Z direction; and the multilayer ceramic capacitor further includes:

[0030] Additional sub-electrodes: two additional sub-electrodes are respectively disposed on the third side surface and the fourth side surface, and the two additional sub-electrodes are spaced apart along the X direction.

[0031] Compared with the prior art, the method for preparing a multilayer ceramic capacitor and the multilayer ceramic capacitor of the embodiment of the present invention have the following beneficial effects: by setting a clamp and clamping and covering the two side surfaces of the laminate mother board along the Z direction with the clamp, when preparing the external electrode, the external electrode is only distributed on the two first cut surfaces and will not cover the other side surfaces of the ceramic capacitor. Therefore, the width dimension and thickness dimension of the multilayer ceramic capacitor can be saved, which can be used to increase the number of internal electrodes and the width of the internal electrodes, thereby improving the capacitance of the multilayer ceramic capacitor; and when any side surface other than the two first cut surfaces is used as the installation surface of the multilayer ceramic capacitor, solder can be avoided from being filled between the multilayer ceramic capacitor and the pad, thereby suppressing the increase in the installation height of the multilayer ceramic capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is an appearance diagram of a multilayer ceramic capacitor according to an embodiment of the present invention;

[0033] Figure 2 is an appearance diagram of a ceramic body in an embodiment of the present invention;

[0034] Figure 3 is a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention;

[0035] Figure 4 is another cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention;

[0036] Figure 5 is another cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention;

[0037] Figure 6 An appearance diagram of a multilayer ceramic capacitor according to another embodiment of the present invention;

[0038] Figure 7 is a cross-sectional view of a multilayer ceramic capacitor according to another embodiment of the present invention;

[0039] Figure 8 The inner electrode film printing pattern of the embodiment of the present invention;

[0040] Fig. 9 A schematic diagram of stacking a plurality of ceramic films having internal electrodes formed thereon in an embodiment of the present invention;

[0041] Fig.10 is a schematic diagram of cutting a laminated mother board into laminated blocks in an embodiment of the present invention;

[0042] Fig.11 A schematic diagram of clamping a stacked body block with a clamp in an embodiment of the present invention;

[0043] Fig.12 Another schematic diagram of clamping a stacked body block with a clamp in an embodiment of the present invention;

[0044] Fig.13 is a schematic diagram of a laminated body block having a nickel layer with an external electrode formed thereon in an embodiment of the present invention;

[0045] Fig.14 It is a schematic diagram of cutting a laminate block having a nickel layer with external electrodes into laminates in an embodiment of the present invention.

[0046] In the figure, 1, ceramic body; 11, first end face; 12, second end face; 13, first side face; 14, second side face; 15, third side face; 16, fourth side face; 17, first inner electrode; 18, second inner electrode; 2, outer electrode; 3, additional sub-electrode; 4, inner electrode; 5, ceramic film; 6, stacked body block; 7, fixture. DETAILED DESCRIPTION

[0047] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0048] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. It should be understood that the terms "first", "second", etc. are used in the present invention to describe various information, but such information should not be limited to these terms, which are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0049] like Figure 1-Figure 14 As shown, in the first aspect, an embodiment of the present application proposes a method for preparing a multilayer ceramic capacitor, including: preparing a laminate mother board having an internal electrode 4 .

[0050] The laminate mother board is cut in sequence along the X direction to obtain a plurality of laminate blocks 6, each of which has two first cut surfaces along the X direction; part of the internal electrode 4 is exposed on one of the first cut surfaces to form a first internal electrode 17, and part of the internal electrode 4 is exposed on the other first cut surface to form a second internal electrode 18.

[0051] Use two clamps 7 to clamp and cover the two side surfaces of the stacked body block 6 along the Z direction, and make the two clamps 7 fit tightly with the two side edges of the two first cut surfaces along the Z direction, and apply the external electrode slurry on the two first cut surfaces to form the external electrode 2; so that the external electrode 2 is connected to the first internal electrode 17 and the second internal electrode 18 respectively; since the two side surfaces of the stacked body block 6 along the Z direction are covered by the clamps 7, when preparing the external electrode 2 on the two first cut surfaces, the external electrode 2 will only be formed on the first cut surface and the second cut surface, and the external electrode 2 will not cover the two side surfaces of the stacked body block 6 along the Z direction.

[0052] The clamp 7 is removed from the stack block 6, and the stack block 6 formed with the external electrode 2 is cut in sequence along the Y direction to obtain a plurality of stacks; the stack has two second cut surfaces along the Y direction, and the internal electrodes are not exposed in the two second cut surfaces; the stack has two second cut surfaces along the Y direction, and the two second cut surfaces respectively form the first side 13 and the second side 14 of the stack, and the internal electrodes are not exposed in the first side 13 and the second side 14; the two first cut surfaces of the stack block 6 opposite to each other along the X direction respectively form the first end face 11 and the second end face 12 of the stack, and the two side faces of the stack block 6 along the Z direction (that is, the two side faces clamped and covered by the clamp 7) respectively form the third side face 15 and the fourth side face 16 of the stack opposite to each other along the Z direction.

[0053] The obtained laminate is debonded and sintered in sequence to obtain a ceramic body 1 (multilayer ceramic capacitor); the specific process is as follows: first, debonding is performed, which is to heat the laminate to 250°C-350°C in air and keep it warm for 0.5 hour-3 hours to remove the adhesive contained in the laminate; or, the laminate is heated to 350°C-600°C in nitrogen and kept warm for 2 hours-6 hours to remove the adhesive contained in the laminate. Then sintering is performed, which is to heat the laminate to 1100°C-1300°C and keep it warm for 0.5 hour-3 hours in a reducing atmosphere formed by a mixed gas of humidified nitrogen and hydrogen (the volume of hydrogen is 0.1%-3% of the volume of nitrogen), and the laminate is sintered to be dense to obtain a multilayer ceramic capacitor.

[0054] Since the preparation of the external electrode 2 is before the stack block 6 is sequentially cut along the Y direction, after the stack block 6 is sequentially cut along the Y direction, the two second cut surfaces of the obtained stack along the Y direction (i.e., the first side surface 13 and the second side surface 14) will not be attached with the external electrode 2; finally, the external electrode 2 only covers the first end surface 11 and the second end surface 12 of the ceramic body 1, and does not cover the first side surface 13 and the second side surface 14, the third side surface 15 and the fourth side surface 16, so that the width and thickness dimensions of the finally obtained multilayer ceramic capacitor can be saved, which is used to increase the number of internal electrodes and the width of the internal electrodes, and improve the capacitance of the multilayer ceramic capacitor; and when the first side surface 13, the second side surface 14, When any one of the third side surface 15 and the fourth side surface 16 is used as the mounting surface of the multilayer ceramic capacitor (that is, the side facing the circuit board), solder can be prevented from filling between the multilayer ceramic capacitor and the soldering pad (the metallized surface has a higher chemical activity and can form a chemical bond with the solder, thereby promoting the adhesion of the solder, while the non-metallized surface lacks this activity, resulting in difficulty in solder adhesion). Since the first side surface 13, the second side surface 14, the third side surface 15, and the fourth side surface 16 are not covered with the external electrode 2, it is possible to prevent solder from adhering to the above-mentioned sides (filling between the soldering pad and the multilayer ceramic capacitor) during the welding process, thereby effectively suppressing the increase in the installation height of the multilayer ceramic capacitor.

[0055] In some embodiments of the present application, the production of the laminated motherboard includes the following steps:

[0056] Ceramic powder, adhesive, and organic solvent are mixed to form ceramic slurry, and the ceramic slurry is cast into a ceramic film 5. The material of the ceramic powder can be barium titanate, calcium zirconate, etc. The thickness of the ceramic film 5 can be, for example, 1 μm to 20 μm. If the thickness of the ceramic film 5 is too small, the reliability of the multilayer ceramic capacitor will be poor. If the thickness of the ceramic film 5 is too large, it is not conducive to improving the capacitance of the multilayer ceramic capacitor.

[0057] The internal electrode paste (nickel) is printed on the ceramic film 5 and dried to form a ceramic film 5 having an internal electrode 4. Figure 8 As shown in FIG. 1 , it is an inner electrode film printing pattern, the length of the plurality of inner electrodes 4 extends along the X direction, and the plurality of inner electrodes 4 are arranged at intervals along the X direction and the Y direction on the ceramic film 5 (the inner electrode is a rectangular sheet extending in the XY plane, so as to maximize the opposing area between adjacent inner electrodes, thereby increasing the capacitance of the multilayer ceramic capacitor); Figure 7As shown, the inner electrode 4 is divided into two groups, namely the first inner electrode 17 and the second inner electrode 18. The first inner electrode 17 and the second inner electrode 18 are alternately arranged along the Z direction, and the adjacent first inner electrodes 17 and the second inner electrodes 18 are opposite to each other along the Z direction and separated by the ceramic film 5, so that the first inner electrode 17 and the second inner electrode 18 are insulated from each other; the thickness of the inner electrode can be 0.5μm~1μm. When the thickness of the inner electrode is too small, the continuity of the inner electrode is poor, which is not conducive to increasing the capacitance; when the thickness of the inner electrode is too large, it is not conducive to reducing the thickness of the multilayer ceramic capacitor.

[0058] like Fig. 9 As shown, L represents a virtual cutting line (a first cutting surface is formed after the laminate motherboard is cut along the virtual cutting line), a plurality of ceramic films 5 with internal electrodes 4 are stacked along the Z direction (for example, 100-900 ceramic films 5 with internal electrodes 4 to increase the capacitance of the multilayer ceramic capacitor), and two adjacent ceramic films 5 with internal electrodes 4 along the Z direction are staggered along the X direction so as to form a first internal electrode 17 and a second internal electrode 18 in the laminate unit after the laminate motherboard is cut along the X direction and at the virtual cutting line position.

[0059] A plurality of ceramic films 5 are stacked on the two sides of the stack unit along the Z direction to form two protective layers covering the two sides of the stack unit along the Z direction, forming a structure in which the protective layer, the stack unit, and the protective layer are stacked in sequence, thereby obtaining a stack mother board having an internal electrode 4. The protective layer is used to protect the internal electrode 4 from moisture intrusion and mechanical damage; in this embodiment, the plurality of internal electrodes 4 are arranged at intervals along the X direction and the Y direction on the ceramic film 5 and the protective layer is provided on the two sides of the stack unit along the Z direction, so that the first internal electrode 17 is spaced apart from the second end face 12, the first side face 13, the second side face 14, the fourth side face 16, and the fourth side face 16, respectively, and the second internal electrode 18 is spaced apart from the first end face 11, the first side face 13, the second side face 14, the third side face 15, and the fourth side face 16, respectively.

[0060] In some embodiments of the present application, the second cut surface is located in the middle position of two adjacent inner electrodes along the Y direction, so that the distance between the inner electrodes (the first inner electrode 17 and the second inner electrode 18) in the finally formed multilayer ceramic capacitor and the side edges along the Y direction and the first side surface 13 and the second side surface 14 remains balanced.

[0061] In some embodiments of the present application, Fig.12 As shown, the two sides of the fixture 7 along the X direction slightly protrude from the two first cut surfaces, which makes it easy to coat more external electrode slurry on the first cut surfaces, so that the external electrode 2 is formed thicker; Fig.11As shown, the two side edges of the fixture 7 along the X direction are kept flush with the two first cut surfaces, which makes it easy to reduce the amount of external electrode paste coated on the first cut surfaces, thereby making the external electrode 2 thinner.

[0062] In the existing conventional preparation method of multilayer ceramic capacitors, when the dip coating process is used to form the external electrode, it is necessary to use a fixture with a complex shape and high dimensional accuracy to position the small granular ceramic body, and then immerse the ceramic body in metal slurry to form the external electrode. It is difficult to avoid the metal slurry covering the first side, the second side, the third side and the fourth side, so that the external electrode occupies a larger size, which is not conducive to improving the capacitance of the multilayer ceramic capacitor (the size of the multilayer ceramic capacitor is fixed. If the external electrode occupies a larger size, the width and number of the internal electrodes in the multilayer ceramic capacitor will be reduced), and the solder will be filled between the multilayer ceramic capacitor and the pad, thereby increasing the installation height of the multilayer ceramic capacitor on the circuit board. In addition, it is difficult to operate the small granular ceramic body, making it difficult to mass produce and ensuring the consistency of the shape and size of the external electrode. In the embodiment of the present invention, it is only necessary to use a simple-structured clamp 7 to clamp the stacked body block 6 and cover the two opposite side surfaces of the stacked body block 6 in the z direction, so that the external electrode 2 can be formed only on the first end face 11 and the second end face 12, thereby saving the width and thickness dimensions of the multilayer ceramic capacitor and reducing the installation height of the multilayer ceramic capacitor on the circuit board. In addition, one stacked body block 6 corresponds to multiple ceramic bodies 1, and processing the stacked body block 6 is very convenient for mass production, and it is also easy to ensure the consistency of the shape and size of the external electrode 2.

[0063] In some embodiments of the present application, the external electrode 2 is a first nickel layer.

[0064] In some embodiments of the present application, nickel metal slurry is coated on the two first cut surfaces successively or simultaneously, and then the fixture 7 is removed from the stacked body block 6 to dry the nickel metal slurry on the stacked body block 6 to form a first nickel layer.

[0065] Alternatively, a sputtering coating process is used to form a first nickel layer on the two first cut surfaces successively or simultaneously. The thickness of the first nickel layer obtained by the preparation method is 0.1 μm to 2 μm.

[0066] In some embodiments of the present application, the clamp 7 is removed from the stack block 6, and the stack is debonded and sintered, and then a second nickel layer is electroplated on the surface of the first nickel layer. The provision of the second nickel layer can improve the continuity of the nickel layer on the first end face 11 and the second end face 12 of the ceramic body 1 (when the first nickel layer is formed by the sputtering coating process for the first time, it is not easy to form a relatively thick nickel layer, and it is necessary to electroplate on the first nickel layer to form a thicker nickel layer, thereby improving the continuity of the nickel layer), and then the first tin layer is electroplated on the second nickel layer, so that the first tin layer has good continuity and uniformity. The provision of the first tin layer can improve the solderability of the multilayer ceramic capacitor (the provision of the first tin layer can ensure that the solder can effectively wet the surface of the welding part during the welding process to form a firm welding joint).

[0067] In this embodiment, since the first nickel layer (metal substrate) has been formed on the first end face 11 and the second end face 12, when the second nickel layer and the first tin layer are electroplated by electroplating, the second nickel layer and the first tin layer will only be produced in the area where the metal substrate is formed, and other positions will not be covered.

[0068] In some embodiments of the present application, Figure 6 , Figure 7 As shown, when the multilayer ceramic capacitor does not have high requirements for the capacitor capacitance and installation height (when there are high requirements for the stability of the installation), multiple additional mother electrodes can be provided on both sides of the laminate mother board along the Z direction, and the additional mother electrodes extend along the Y direction; the multiple additional mother electrodes are correspondingly arranged at the cutting line of the laminate mother board along the X direction; so that the final laminated body has two spaced-apart additional sub-electrodes 3 on the two sides along the Z direction (that is, the third side 15 and the fourth side 16).

[0069] The additional sub-electrode 3 is provided so that when any one of the third side surface 15 and the fourth side surface 16 is used as the mounting surface of the multilayer ceramic capacitor, not only the first end surface 11 and the second end surface 12 provided with the external electrode 2 can be soldered, but also the third side surface 15 and the fourth side surface 16 provided with the additional sub-electrode 3 can be soldered, thereby increasing the soldering area and making the installation of the multilayer ceramic capacitor on the circuit board more stable. The additional sub-electrode 3 is not provided on the first side surface 13 and the second side surface 14, so the width dimension of the multilayer ceramic capacitor can be saved and used to increase the width of the internal electrode, thereby compensating to a certain extent for the situation that the number of internal electrodes in the multilayer ceramic capacitor is reduced and the capacitance is reduced due to the additional sub-electrode 3 being provided and occupying a certain height space of the multilayer ceramic capacitor.

[0070] In some embodiments of the present application, the additional sub-electrode 3 includes a third nickel layer and a second tin layer electroplated on the surface of the third nickel layer. The provision of the second tin layer can improve the solderability of the multilayer ceramic capacitor during welding.

[0071] In some embodiments of the present application, a screen printing process is used to apply nickel metal paste to the two side surfaces of the laminate motherboard along the Z direction to form a third nickel layer, or a sputtering coating process is used to form a third nickel layer on the two side surfaces of the laminate motherboard along the Z direction, and the thickness of the third nickel layer is 0.1μm to 1μm (this is greatly reduced compared to the thickness of the external electrode 2 formed by the dip coating process, which can save thickness dimensions for multilayer ceramic capacitors to increase the number of internal electrodes and improve the capacitance of multilayer ceramic capacitors); after the laminate is debonded and sintered, a second tin layer is electroplated on the surface of the third nickel layer, and the thickness of the second tin layer is 3μm to 10μm. In the case of Figure 6 , Figure 7 In the given diagram, there are four additional sub-electrodes 3 on each multilayer ceramic capacitor, two of which are located at the two ends of the third side 15 along the X direction, and the other two are located at the two ends of the fourth side 16 along the X direction; when the additional parent electrode is set in this scheme, the additional parent electrode can be continuously extended or intermittently extended along the Y direction. Preferably, the additional parent electrode can be set to extend continuously along the Y direction, so that the additional sub-electrodes 3 on the finally formed multilayer ceramic capacitor can extend along the Y direction to the edge positions of the first side 13 and the second side 14 respectively, so as to facilitate the multilayer ceramic capacitor to be firmly soldered on the circuit board.

[0072] In a second aspect, an embodiment of the present application provides a multilayer ceramic capacitor, which adopts the multilayer ceramic capacitor preparation method in the above embodiment, including a ceramic body 1, the ceramic body 1 having a first end face 11 and a second end face 12 arranged opposite to each other along the X direction; an internal electrode 2, a plurality of which are provided, and the plurality of internal electrodes 2 are arranged in the ceramic body 1 at intervals along the Z direction, such as Figure 3 As shown, the inner electrode 2 is divided into two groups, namely a first inner electrode 17 and a second inner electrode 18. One end of the first inner electrode 17 along the X direction extends to the first end surface 11, and one end of the second inner electrode 18 along the X direction extends to the second end surface 12; the outer electrode 2 is coated on the first end surface 11 and the second end surface 12, and is respectively connected to one end of the first inner electrode 17 extending to the first end surface 11 and one end of the second inner electrode 18 extending to the second end surface 12.

[0073] In some embodiments of the present application, the ceramic body 1 has a third side surface 15 and a fourth side surface 16 arranged opposite to each other along the Z direction, and the multilayer ceramic capacitor also includes two additional sub-electrodes 3 arranged on the third side surface 15 and the fourth side surface 16, and the two additional sub-electrodes 3 are arranged at intervals along the X direction.

[0074] The working process of the present invention is: ceramic powder, adhesive, and organic solvent are mixed to form ceramic slurry, and the ceramic slurry is cast into a ceramic film 5 .

[0075] Nickel metal paste is printed on the ceramic film 5 and dried to form a ceramic film 5 having an internal electrode.

[0076] A plurality of ceramic thin films 5 having internal electrodes are stacked in the Z direction, and both sides of the stacked structure in the Z direction are covered with the stacked ceramic thin films 5 to obtain a stacked mother board.

[0077] The laminated mother substrate is pressed in the Z direction, and is sequentially cut into a plurality of elongated rod-shaped laminated body blocks 6 in the X direction.

[0078] Use two clamps 7 to clamp the two side surfaces of the stacked body block 6 along the Z direction, so that the ends of the clamps 7 are flush with the first cut surface or slightly protrude relative to the first cut surface in the X direction, and the clamps 7 are tightly fitted to the two side edges of the first cut surface along the Z direction, and then the first nickel layer of the external electrode 2 is formed on the two first cut surfaces of the stacked body block 6.

[0079] The laminated body block 6 on which the first nickel layer is formed is sequentially cut into a plurality of laminated bodies along the Y direction.

[0080] The laminate is debinded and sintered in sequence, and a first tin layer is electroplated on the first nickel layer to obtain a ceramic body 1 (multilayer ceramic capacitor).

[0081] In summary, the embodiments of the present invention provide a method for preparing a multilayer ceramic capacitor and a multilayer ceramic capacitor. In this scheme, a clamp 7 is set and the two side surfaces of the laminate motherboard along the Z direction are clamped and covered by the clamp 7, so that the external electrode 2 is only distributed on the first end surface 11 and the second end surface 12, and will not cover the other sides of the multilayer ceramic capacitor. Therefore, the width dimension and thickness dimension of the multilayer ceramic capacitor can be saved, which can be used to increase the number of internal electrodes and the width of the internal electrodes, thereby improving the capacitance of the multilayer ceramic capacitor; and when any side surface other than the first end surface 11 and the second end surface 12 is used as the mounting surface of the multilayer ceramic capacitor, solder can be avoided from being filled between the multilayer ceramic capacitor and the pad, thereby suppressing the increase in the mounting height of the multilayer ceramic capacitor.

[0082] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a multilayer ceramic capacitor, characterized in that: include: preparing a laminate mother board having an internal electrode (4); The laminate mother plate is sequentially cut along the X direction to obtain a plurality of laminate blocks (6), wherein the laminate block (6) has two first cut surfaces along the X direction, a portion of the internal electrode (4) is exposed on one of the first cut surfaces, and a portion of the internal electrode (4) is exposed on the other of the first cut surfaces; Using two clamps (7) to respectively clamp and cover the two side surfaces of the stacked body block (6) along the Z direction, and attaching external electrodes (2) to the two first cut surfaces respectively; The clamp (7) is removed from the stacked body block (6), and the stacked body block (6) formed with the external electrode (2) is sequentially cut along the Y direction to obtain a plurality of stacked bodies; the stacked body has two second cut surfaces along the Y direction, the two second cut surfaces form the first side surface (13) and the second side surface (14) of the stacked body, and the internal electrode (4) does not expose the first side surface (13) and the second side surface (14); the stacked body has a third side surface (15) and a fourth side surface (16) along the Z direction; The laminate is debinded and sintered in sequence to obtain a multilayer ceramic capacitor.

2. The method for preparing a multilayer ceramic capacitor according to claim 1, characterized in that: The production of the laminated motherboard comprises the following steps: preparing a ceramic film (5); Printing an internal electrode slurry on the ceramic film (5) and drying it to form a ceramic film (5) having internal electrodes (4), wherein the lengths of the multiple internal electrodes (4) extend along the X direction, and the multiple internal electrodes (4) are arranged at intervals along the X direction and the Y direction on the ceramic film (5); A plurality of the ceramic films (5) having the internal electrodes (4) are stacked along the Z direction, and two adjacent ceramic films (5) having the internal electrodes (4) are staggered along the X direction to obtain a stacked unit; A plurality of the ceramic films (5) are stacked on the two side surfaces of the stack unit along the Z direction to form two protective layers covering the two side surfaces of the stack unit along the Z direction, thereby obtaining a stack mother board having internal electrodes (4).

3. The method for preparing a multilayer ceramic capacitor according to claim 2, characterized in that: The second cut surface is located in the middle of two inner electrodes (4) adjacent to each other along the Y direction.

4. The method for preparing a multilayer ceramic capacitor according to claim 1, characterized in that: The two side edges of the clamp (7) along the X direction respectively protrude from the two first cut surfaces; or the two side edges of the clamp (7) along the X direction are respectively flush with the two first cut surfaces.

5. The method for preparing a multilayer ceramic capacitor according to claim 1, characterized in that: The outer electrode (2) comprises a first nickel layer; Nickel metal slurry is coated on the two first cut surfaces successively or simultaneously and dried to form the first nickel layer; or the first nickel layer is formed on the two first cut surfaces successively or simultaneously by a sputtering coating process.

6. The method for preparing a multilayer ceramic capacitor according to claim 5, characterized in that: The clamp (7) is removed from the stacked body block (6), and the stacked body is sequentially debonded and sintered, and a second nickel layer and a first tin layer are sequentially electroplated on the surface of the first nickel layer.

7. The method for preparing a multilayer ceramic capacitor according to claim 2, characterized in that: A plurality of additional mother electrodes are provided on both sides of the stacked mother board along the Z direction, and the additional electrodes extend along the Y direction; The plurality of additional mother electrodes are arranged correspondingly at the cutting line of the stack mother board along the X direction, so that the third side surface (15) and the fourth side surface (16) of the stack are respectively provided with two additional sub-electrodes (3) arranged at intervals.

8. The method for preparing a multilayer ceramic capacitor according to claim 7, characterized in that: The additional sub-electrode (3) comprises a third nickel layer; A screen printing process is used to apply nickel metal paste, and the nickel metal paste is applied to corresponding positions on two side surfaces of the laminated motherboard along the Z direction to form the third nickel layer, or a sputtering coating process is used to form the third nickel layer at corresponding positions on two side surfaces of the laminated motherboard along the Z direction; After the stacked body is debinded and sintered, a second tin layer is electroplated on the surface of the third nickel layer.

9. A multilayer ceramic capacitor, produced by the method for producing a multilayer ceramic capacitor according to any one of claims 1 to 8, characterized in that: include: A ceramic body (1), wherein the ceramic body (1) has a first end surface (11) and a second end surface (12) arranged opposite to each other along the X direction; A plurality of internal electrodes (4) are provided, wherein the plurality of internal electrodes (4) are arranged in the ceramic body (1) at intervals along the Z direction, and some of the internal electrodes (4) extend to the first end surface (11), and some of the internal electrodes (4) extend to the second end surface (12); and An external electrode (2), wherein the first end surface (11) and the second end surface (12) are both covered with the external electrode (2).

10. The multilayer ceramic capacitor according to claim 9, wherein: The ceramic body (1) has a third side surface (15) and a fourth side surface (16) arranged opposite to each other along the Z direction; the multilayer ceramic capacitor further comprises: Additional sub-electrodes (3), two of the additional sub-electrodes (3) are respectively arranged on the third side surface (15) and the fourth side surface (16), and the two additional sub-electrodes (3) are arranged at intervals along the X direction.

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