Capacitor and method of manufacturing the same

Abstract

To provide a capacitor capable of reducing a mounting area and increasing the degree of mounting freedom, and to provide a method of manufacturing the same.SOLUTION: According to an aspect of the present invention, there is provided a capacitor including a capacitor body including a dielectric structure and a plurality of internal electrodes embedded in the dielectric structure and spaced apart from each other in a direction from a side surface of the dielectric structure toward an inside of the dielectric structure, and an external electrode disposed on the capacitor body and connected to the internal electrodes, wherein each of the plurality of internal electrodes circumferentially surrounds another internal electrode disposed inside the internal electrode.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a capacitor and a manufacturing method thereof, and more particularly to a capacitor and a manufacturing method thereof that can reduce the mounting area and increase the degree of freedom in mounting. [Background technology]

[0002] With the development of mobile and wearable devices, the size of electronic devices is decreasing and the performance of application processors (APs) is maximizing. Therefore, the capacitors mounted on the bottom of the AP package, which perform the power backup and AC noise bypass functions of the AP package, are required to be smaller, thinner, and have low ESL (equivalent series inductance) characteristics, which are becoming daily challenges.

[0003] Existing multi-layer ceramic capacitors (MLCCs) are manufactured by stacking dielectric sheets and internal electrode sheets vertically from the bottom and firing them to form a capacitor body, and then forming external electrodes on both sides of the capacitor body. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made in consideration of the above-mentioned problems with conventional capacitors, and an object of the present invention is to provide a capacitor that can reduce the mounting area and increase the degree of mounting flexibility, and a method for manufacturing the same. Another object of the present invention is to provide a capacitor that reduces the number of solder balls depopulated by a capacitor and has low equivalent series inductance (ESL) characteristics, and a method for manufacturing the same. [Means for solving the problem]

[0005] The capacitor according to the present invention, which has been made to achieve the above object, comprises a dielectric structure, a capacitor body including a plurality of internal electrodes each embedded in the dielectric structure and spaced apart from one another in a direction from a side of the dielectric structure toward the inside of the dielectric structure, and an external electrode disposed on the capacitor body and connected to the internal electrode, wherein each of the plurality of internal electrodes circumferentially surrounds another internal electrode disposed inside the internal electrode.

[0006] In addition, a capacitor according to the present invention, which has been made to achieve the above-mentioned object, is characterized by having a capacitor body including an axial core, a dielectric structure surrounding the axial core, a plurality of first internal electrodes embedded in the dielectric structure and each including a first terminal exposed on an upper surface of the dielectric structure, and a plurality of second internal electrodes embedded in the dielectric structure and electrically insulated from the first internal electrodes and each including a second terminal exposed on an upper surface of the dielectric structure, and external electrodes arranged on the capacitor body and including a first external electrode connected to the first terminal and a second external electrode connected to the second terminal.

[0007] In order to achieve the above object, a method for manufacturing a capacitor according to the present invention includes the steps of: forming a capacitor body by alternately winding a dielectric sheet and an internal electrode sheet including a terminal around a shaft core; and forming external electrodes connected to the terminals on the capacitor body, wherein the step of forming the capacitor body includes the steps of arranging the dielectric sheet and the internal electrode sheet on a base so that they are spaced apart in a first direction; and winding the dielectric sheet and the internal electrode sheet around the shaft core. [Effects of the Invention]

[0008] According to the capacitor and the manufacturing method thereof of the present invention, it is possible to provide a capacitor that can reduce the mounting area and increase the degree of freedom in mounting. In addition, the number of solder balls that is reduced by the capacitor can be reduced. Furthermore, it is possible to provide a capacitor with low ESL characteristics. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a schematic configuration of a capacitor according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic perspective view of the capacitor body of FIG. 1. [Figure 3] FIG. 2 is a top view of the capacitor shown in FIG. [Figure 4] 4 is a cross-sectional view of the capacitor shown in FIG. 3 taken along line 4-4. [Figure 5] FIG. 10 is a cross-sectional view of a capacitor according to another embodiment of the present invention. [Figure 6] FIG. 10 is a cross-sectional view of a capacitor according to yet another embodiment of the present invention. [Figure 7] 2A and 2B illustrate areas of a substrate on which capacitors are mounted according to an embodiment of the present invention. [Figure 8] FIG. 10 is a diagram showing an area of ​​a substrate on which a capacitor according to Comparative Example 1 is mounted. [Figure 9] FIG. 10 is a diagram showing an area of ​​a substrate on which a capacitor according to Comparative Example 2 is mounted. [Figure 10] 10 is a table for comparing a capacitor according to an embodiment of the present invention with a capacitor according to Comparative Example 2. [Figure 11] 2A and 2B illustrate areas of a substrate on which capacitors are mounted according to an embodiment of the present invention. [Figure 12] FIG. 10 is a diagram showing an area of ​​a substrate on which a capacitor according to Comparative Example 2 is mounted. [Figure 13] FIG. 2 illustrates an area of ​​a substrate on which capacitors are mounted with solder balls having a small pitch according to an embodiment of the present invention. [Figure 14] FIG. 10 shows an area of ​​a substrate on which capacitors according to Comparative Example 2 are mounted with solder balls having a small pitch. [Figure 15]1A to 1C are views illustrating a method for manufacturing a capacitor body according to an embodiment of the present invention. [Figure 16] 1A to 1C are perspective views of a capacitor body according to various manufacturing stages; [Figure 17] 1A to 1C are perspective views of a capacitor body according to various manufacturing stages; [Figure 18] 1A to 1C are perspective views of a capacitor body according to various manufacturing stages; [Figure 19] 1A to 1C are perspective views of a capacitor body according to various manufacturing stages; [Figure 20] 1A to 1C are perspective views of a capacitor body according to various manufacturing stages; [Figure 21] 1A to 1C are perspective views of a capacitor body according to various manufacturing stages; [Figure 22] 10A to 10C are diagrams illustrating a process of forming an external electrode on a capacitor body. [Figure 23] 10A-10C are cross-sectional views illustrating an exemplary method for forming a molding material on a capacitor body. [Figure 24] 10A-10C are cross-sectional views illustrating an exemplary method for forming a molding material on a capacitor body. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, specific examples of embodiments for carrying out the capacitor and the manufacturing method thereof according to the present invention will be described with reference to the drawings.

[0011] As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In order to clearly explain the present invention, parts that are not necessary for the explanation will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components. Furthermore, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown. In the drawings, the thickness of various layers and regions is exaggerated for clarity. In the drawings, the thicknesses of some layers and regions are exaggerated for ease of explanation.

[0012] Throughout this specification, when a part is said to be "connected" to another part, this includes not only "directly connected" but also "indirectly connected" via another member. From a similar perspective, this includes not only being "physically connected" but also being "electrically connected." Furthermore, when a layer, film, region, plate, or other part is said to be "on" or "above" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there are no other parts in between. Also, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "above" in the direction opposite to gravity. Also, throughout the specification, when a part is said to "comprise" a certain element, this does not mean that it may further include other elements, unless specifically stated to the contrary.

[0013] Also, throughout the specification, "on a plane" means when the subject part is viewed from above, and "on a cross section" means when the subject part is cut vertically and viewed from the side. Furthermore, throughout the specification, the terms "first," "second," etc. are used to distinguish a component from other components that are identical or similar to it, and are not necessarily used with the intention of referring to a specific component. Thus, what is referred to as a first component in one part of this specification may also be referred to as a second component in another part of this specification. Also, throughout this specification, "monolithic" means something that is a single, integral piece formed or constructed from material with no joints or seams. Also, throughout the specification, a singular reference to an element includes a plural reference to those elements unless specifically stated to the contrary. Likewise, plural references to an element may be implemented as a singular element.

[0014] A capacitor and a method for manufacturing the same according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a capacitor according to the present invention, FIG. 2 is a schematic perspective view of the capacitor body of FIG. 1, FIG. 3 is a top view of the capacitor shown in FIG. 1, and FIG. 4 is a cross-sectional view of the capacitor shown in FIG. 3 taken along line 4-4. 1 to 4, a capacitor 100A according to an embodiment of the present invention includes an axial core 110, a dielectric structure 120, internal electrodes (131, 132) and external electrodes (141, 142) each including a terminal (1311, 1321).

[0015] In the present invention, the structure in which the axial core 110 and the internal electrodes (131, 132) are embedded in the dielectric structure 120 in the capacitor 100A is called a capacitor body CB. The axial core 110 is at least partially embedded in the dielectric structure 120 and functions as a support structure for forming the dielectric structure 120 and the internal electrodes (131, 132) when forming the capacitor body CB. For example, referring to FIG. 15, the capacitor body CB is formed by alternately winding the dielectric sheet 120' constituting the dielectric structure 120 and the internal electrode sheets (131', 132') constituting the internal electrodes (131, 132) around the axial core 110, and in this case, the axial core 110 is a support structure for winding the dielectric sheet 120' and the internal electrode sheets (131', 132').

[0016] In order to support the entire area of ​​the dielectric sheet 120' and the internal electrode sheets (131', 132') when forming the capacitor body CB, the length of the axial core 110 in the Z direction Z is equal to or longer than the length of the dielectric structure 120 and the internal electrodes (131, 132) in the Z direction Z. Therefore, the axial core 110 is exposed to the upper surface 120u and the lower surface 120l of the dielectric structure 120. For example, the axial core 110 protrudes above the upper surface 120u and / or the lower surface 120l of the dielectric structure 120. However, from the viewpoint of thinning the capacitor 100A, it is preferable that the upper surface of the axial core 110 is / is coplanar with the upper surface 120u of the dielectric structure 120, or that the lower surface of the axial core 110 is / is coplanar with the lower surface 120l of the dielectric structure 120.

[0017] The axial core 110 is cylindrical. By using a cylindrical axial core 110, the dielectric sheet 120' and the internal electrode sheets (131', 132') can be wound cylindrically around the axial core 110, easily providing a cylindrical capacitor. The shaft core 110 is made of an insulating material. Additionally, the axial core 110 can be formed from a less reactive material to prevent reaction with adjacent structures. For example, the axial core 110 may include silicon. Depending on the manufacturing method of the capacitor, the axial core 110 may be omitted. As an example, the capacitor may have a structure in which the axial core 110 is replaced by a dielectric structure 120 that fills the interior of the capacitor. As another example, the capacitor may have a hollow cylindrical shape with the axial core 110 removed or omitted.

[0018] A dielectric structure 120 surrounds the axial core 110 and provides the appearance of a capacitor body CB. Therefore, the upper surface 120u, the side surface 120s, and the lower surface 120l of the dielectric structure 120 respectively constitute the upper surface, the side surface, and the lower surface of the capacitor body CB. The dielectric structure 120 is cylindrical. By forming the dielectric structure 120 that forms the exterior of the capacitor body CB in a cylindrical shape, it is possible to provide a capacitor with a small mounting area, as will be described later. The dielectric structure 120 fills the space between adjacent internal electrodes (131, 132), for example, the first internal electrode 131 and the second internal electrode 132, and separates them from each other. For example, the dielectric structure 120 fills the spaces between the first internal electrode 131A and the second internal electrode 132A, between the second internal electrode 132A and the first internal electrode 131B, between the first internal electrode 131B and the second internal electrode 132B, and between the second internal electrode 132B and the first internal electrode 131C, and separates adjacent internal electrodes (131, 132) from each other.

[0019] The areas filling the spaces between the adjacent internal electrodes (131, 132) of the dielectric structure 120 may be integrated and have no visible boundaries between them. For example, the area filling the gap between the first internal electrode 131A and the second internal electrode 132A of the dielectric structure 120, the area filling the gap between the second internal electrode 132A and the first internal electrode 131B, the area filling the gap between the first internal electrode 131B and the second internal electrode 132B, and the area filling the gap between the second internal electrode 132B and the first internal electrode 131C may not have boundaries with one another. Also, the dielectric structure 120 fills / fills the space between the innermost arranged inner electrode 131A among the inner electrodes (131, 132) and the axial core 110, or covers the outermost arranged inner electrode 131C. In one embodiment, the dielectric structure 120 may be monolithic. The dielectric structure 120 may be made of an insulating material, such as a ceramic, such as barium titanate (BaTiO3).

[0020] The internal electrodes (131, 132) are embedded in the dielectric structure 120. The internal electrodes (131, 132) surround the axial core 110, respectively, and are spaced apart from each other in a direction away from the axial core 110 (radial direction). When described with reference to the side 120s of the dielectric structure 120, the internal electrodes (131, 132) can be understood to be spaced apart from each other in a direction from the side 120s of the dielectric structure 120 toward the inside of the dielectric structure 120 (i.e., in a radial direction toward the axial core 110). As described above, by winding the internal electrode sheets (131', 132') together with the dielectric sheet 120' around the axial core 110 to form the internal electrodes (131, 132), a structure is formed in which the internal electrodes (131, 132) surround the axial core 110 and are spaced apart in a direction away from the axial core 110.

[0021] Each of the internal electrodes (131, 132) circumferentially surrounds one or more other internal electrodes (131, 132) disposed inside the internal electrode (131, 132). For example, referring to FIG. 2, the internal electrode 132A surrounds the internal electrode 131A, which is the innermost of the internal electrodes (131, 132), the internal electrode 131B surrounds the internal electrodes (131A, 132A) located inside it, the internal electrode 132B surrounds the internal electrodes (131A, 132A, 131B) located inside it, and the internal electrode 131C surrounds the internal electrodes (131A, 132A, 131B, 132B) located inside it. The internal electrodes (131, 132) include a first internal electrode 131 and a second internal electrode 132 that are electrically insulated from each other. The first internal electrode 131 and the second internal electrode 132 may be physically separated or electrically isolated from each other by the dielectric structure 120 .

[0022] In one embodiment, the first internal electrodes 131 and the second internal electrodes 132 are alternately arranged in a direction away from the axial core 110 . For example, the first internal electrode 131 and the second internal electrode 132 include a first internal electrode 131A, a second internal electrode 132A, a first internal electrode 131B, a second internal electrode 132B, and a first internal electrode 131C, which are arranged sequentially in a direction away from the axial core 110. However, the number of first internal electrodes 131 and second internal electrodes 132 shown in the figure is an example, and the number of first internal electrodes 131 and second internal electrodes 132 is not limited to that shown in the figure. Furthermore, the number of first internal electrodes 131 and second internal electrodes 132 may be the same or different. In some embodiments, the first internal electrodes 131 and the second internal electrodes 132 may be arranged in other ways. For example, a first internal electrode 131 may be arranged in an inner region of the dielectric structure 120 adjacent to the axial core 110, and a second internal electrode 132 may be arranged in an outer region including the side surface 120s of the dielectric structure 120.

[0023] The internal electrodes (131, 132) include terminals (1311, 1321) that provide electrical connection between the internal electrodes (131, 132) and the external electrodes (141, 142), respectively. The terminals (1311, 1321) are exposed on the upper surface 120u of the dielectric structure 120 and are connected to the external electrodes (141, 142). For example, each of the first internal electrodes 131 includes a first terminal 1311 exposed to or located on the upper surface 120u of the dielectric structure 120, and each of the second internal electrodes 132 includes a second terminal 1321 exposed to or located on the upper surface 120u of the dielectric structure 120. The terminals (1311, 1321) are structured to protrude upward compared to other regions of the internal electrodes (131, 132). By exposing the first terminal 1311 and the second terminal 1321 on the same surface (upper surface 120u) of the dielectric structure 120, the external electrodes (141, 142) connected to them can be formed on the same surface of the dielectric structure 120. Therefore, the increase in the size of the capacitor due to the arrangement of the external electrodes 141 and 142 can be minimized. In addition, since the distance between the external electrodes 141 and 142 is short, a capacitor having low ESL (equivalent series inductance) characteristics can be provided.

[0024] On the upper surface 120u of the dielectric structure 120, the first terminal 1311 and the second terminal 1321 may be arranged laterally or radially opposite each other with respect to the axial core 110, or may be arranged on opposite sides of the axial core 110. In other words, on the upper surface 120u of the dielectric structure 120, the axial core 110 is disposed between the first terminal 1311 and the second terminal 1321. For example, with reference to FIG. 3, the first terminal 1311 is disposed on the left side of the axial core 110, and the second terminal 1321 is disposed on the right side of the axial core 110. By arranging the first terminal 1311 and the second terminal 1321 in opposite directions relative to the axial core 110, easy connection between the terminals (1311, 1321) and the external electrodes (141, 142) can be provided, and electrical short circuits between components that require electrical insulation can be prevented. The internal electrodes (131, 132) are no longer exposed to the lower surface 120l of the dielectric structure 120 where the external electrodes (141, 142) are not arranged, and are therefore physically and chemically protected by the dielectric structure 120, preventing the occurrence of electrical short circuits. The internal electrodes (131, 132) are made of a conductive material. For example, each of the internal electrodes (131, 132) can be made of nickel (Ni), copper (Cu), silver (Ag), tin (Sn), palladium (Pd), gold (Au), platinum (Pt), or an alloy of two or more of these.

[0025] The external electrodes (141, 142) are disposed on the capacitor body CB and connected to the internal electrodes (131, 132), providing electrical connection between the capacitor 100A and an external structure (eg, an AP package substrate). The external electrodes (141, 142) are respectively disposed on the upper surface 120u of the dielectric structure 120 in the capacitor body CB, connected to the terminals (1311, 1321) exposed on the upper surface 120u of the dielectric structure 120, and connected to the internal electrodes (131, 132) through the terminals (1311, 1321). The external electrodes (141, 142) include a first external electrode 141 connected to the first internal electrode 131 and a second external electrode 142 connected to the second internal electrode 132. For example, the first external electrode 141 is connected to the first internal electrode 131 through a first terminal 1311 exposed on the upper surface 120u of the dielectric structure 120, and the second external electrode 142 is connected to the second internal electrode 132 through a second terminal 1321 exposed on the upper surface 120u of the dielectric structure 120. The first external electrode 141 is not connected to the second internal electrode 132 , and the second external electrode 142 is not connected to the first internal electrode 131 . By disposing the first external electrode 141 and the second external electrode 142 on the upper surface 120u of the dielectric structure 120, the distance between the external electrodes 141 and 142 can be minimized, thereby providing a capacitor with low ESL characteristics.

[0026] The external electrodes (141, 142) are disposed over their entire area on the upper surface 120u of the dielectric structure 120. In other words, the external electrodes (141, 142) are disposed only on the upper surface 120u of the dielectric structure 120, but not on the outer surface 120s and the lower surface 120l of the dielectric structure 120. By disposing the external electrodes (141, 142) only on the upper surface 120u of the dielectric structure 120, it is possible to minimize an increase in the size of the capacitor due to the disposition of the external electrodes (141, 142). The external electrodes (141, 142) may be made of a conductive material. For example, the material of each of the external electrodes (141, 142) may be nickel (Ni), copper (Cu), silver (Ag), tin (Sn), palladium (Pd), gold (Au), platinum (Pt), or an alloy of two or more of these. Each of the outer electrodes (141, 142) may be made up of multiple layers. For example, the external electrodes (141, 142) may include a copper (Cu) layer, a nickel (Ni) layer, and a tin (Sn) layer disposed in sequence on the upper surface 120u of the dielectric structure 120.

[0027] FIG. 5 is a cross-sectional view of a capacitor according to another embodiment of the present invention. Referring to FIG. 5, a capacitor 100B according to another embodiment of the present invention further includes a molding material 150 covering at least a portion of the capacitor body CB. Molding material 150 can improve the moisture resistance of capacitor 100B and prevent cracks.

[0028] In one embodiment, the molding material 150 covers at least a portion of each of the side surface 120s and the bottom surface 120l of the dielectric structure 120, and further covers the bottom surface of the axial core 110 exposed at the bottom surface 120l of the dielectric structure 120. Furthermore, the molding material 150 does not cover the upper surface 120u of the dielectric structure 120 and the upper surface of the axial core 110 exposed therethrough. The molding material 150 may be made of an insulating material, for example, an epoxy molding compound (EMC), a thermosetting resin such as an epoxy resin, or a thermoplastic resin such as a polyimide. The capacitor 100B is formed, for example, by forming the internal electrodes (131, 132) surrounding the axial core 110 and the dielectric structure 120 to manufacture the capacitor body CB, forming a molding material 150 to cover the entire capacitor body CB, and then removing the upper region of the molding material 150 to expose the terminals (1311, 1321).

[0029] FIG. 6 is a cross-sectional view of a capacitor according to yet another embodiment of the present invention. Compared with the capacitor shown in FIG. 5, in the capacitor 100C according to this embodiment, the molding material 150 extends onto the upper surface 120u of the dielectric structure 120. Therefore, the molding material 150 fills the space between the upper surface 120u of the dielectric structure 120 and the external electrodes (141, 142). In addition, the terminals (1311, 1321) exposed on the upper surface 120u of the dielectric structure 120 are embedded in the molding material 150 and extend through it. The molding material 150 also extends onto the upper surface of the axial core 110 exposed at the upper surface 120 u of the dielectric structure 120 . The capacitor 100C is formed, for example, by forming the capacitor body CB so that the terminals (1311, 1321) protrude above the upper surface 120u of the dielectric structure 120, forming a molding material 150 to cover the entire capacitor body CB, and then removing the upper region of the molding material 150 to expose the terminals (1311, 1321).

[0030] FIG. 7 is a diagram showing an area of ​​a substrate on which a capacitor according to an embodiment of the present invention is mounted, FIG. 8 is a diagram showing an area of ​​a substrate on which a capacitor according to comparative example 1 is mounted, and FIG. 9 is a diagram showing an area of ​​a substrate on which a capacitor according to comparative example 2 is mounted. The capacitor according to the embodiment of the present invention is a cylindrical capacitor with a diameter d1 of 610 μm and a thickness in the Z direction Z of 80 μm.

[0031] The capacitors according to Comparative Examples 1 and 2 are hexahedral two-terminal low inductance ceramic capacitors (LICCs) and four-terminal LICCs, respectively, having the same or similar volumes as the capacitors according to the embodiments of the present invention. The capacitor 101 according to the first comparative example includes a capacitor body 1011 and two external electrodes (1012A, 1012B), and the capacitor 102 according to the second comparative example includes a capacitor body 1021 and four external electrodes (1022A, 1022B, 1022C, 1022D). The capacitor according to Comparative Example 1 has a length d2 in the X direction of 0.50 mm and a length d3 in the Y direction of 1.00 mm. The length d4 of the capacitor according to Comparative Example 2 in the X and Y directions excluding the external electrodes (141, 142) is 580 μm, and the length d5 ​​in the X and Y directions including the external electrodes (141, 142) is 600 μm. The thickness of the capacitor in the Z direction according to Comparative Example 2 is 70 μm.

[0032] The capacitor is disposed on a substrate (eg, an AP package substrate) 11 with solder balls 12 . Since the capacitor is disposed between the solder balls 12, the extent of depopulation of the solder balls 12 is determined by the mounting area of ​​the capacitor. Since the number of solder balls can affect the signal integrity and power stability of electronic devices, it is important to reduce the number of solder balls that are reduced by the capacitor. 7 to 9, the capacitor according to this embodiment has a reduction of 9 solder balls, the capacitor according to Comparative Example 1 has a reduction of 12 solder balls, and the capacitor according to Comparative Example 2 has a reduction of 9 solder balls. That is, the capacitor according to this embodiment has less solder ball loss than the capacitor according to Comparative Example 1.

[0033] FIG. 10 is a table comparing a capacitor according to an embodiment of the present invention with a capacitor according to Comparative Example 2, FIG. 11 is a diagram showing an area of ​​a substrate on which a capacitor according to an embodiment of the present invention is mounted, FIG. 12 is a diagram showing an area of ​​a substrate on which a capacitor according to Comparative Example 2 is mounted, FIG. 13 is a diagram showing an area of ​​a substrate on which a capacitor according to an embodiment of the present invention is mounted with solder balls having a small pitch, and FIG. 14 is a diagram showing an area of ​​a substrate on which a capacitor according to Comparative Example 2 is mounted with solder balls having a small pitch.

[0034] Referring to FIG. 10, it can be seen that the mounting area of ​​the capacitor according to the embodiment of the present invention is approximately 81% of the mounting area of ​​the capacitor according to Comparative Example 2 (which has a similar volume to the capacitor according to the embodiment), and has a smaller mounting area relative to its volume compared to the hexahedral-shaped capacitor. 11 and 12, it can be seen that the capacitor according to the embodiment of the present invention is advantageous in terms of flexibility in mounting compared to the capacitor according to Comparative Example 2 due to its small mounting area. 13 and 14, when placed on a substrate with solder balls having a small pitch, the capacitor according to the embodiment of the present invention has a smaller reduction in the number of solder balls than the capacitor according to Comparative Example 2. That is, it can be seen that the use of the capacitor according to the embodiment of the present invention is advantageous in terms of reducing the number of solder balls as the pitch of the solder balls decreases.

[0035] Figure 15 is a diagram for explaining a method for manufacturing a capacitor body according to an embodiment of the present invention, Figures 16 to 21 are perspective views of the capacitor body at each manufacturing stage, and Figure 22 is a diagram for explaining a process of forming external electrodes on the capacitor body. A method for manufacturing a capacitor according to an embodiment of the present invention includes forming a capacitor body CB (see FIG. 2) and forming external electrodes 141 and 142 on the capacitor body CB.

[0036] First, referring to Figures 15 to 21, the step of forming the capacitor body CB is performed by alternately winding a dielectric sheet 120' that is wound around the axial core 110 to form the dielectric structure 120 of the capacitor 100A and internal electrode sheets (131', 132') that form the internal electrodes (131, 132). At steps (a), (b), (c), (d), (e), and (f) of Figure 15, the dielectric sheet 120' and the internal electrode sheets (131', 132') are wound around the axial core 110 to form the dielectric structure 120 and the internal electrodes (131, 132), as shown in Figures 16 to 21, respectively.

[0037] The internal electrode sheets (131', 132') include a first internal electrode sheet 131' constituting the first internal electrode 131 of the capacitor 100A and a second internal electrode sheet 132' constituting the second internal electrode 132. The first internal electrode sheet 131' and the second internal electrode sheet 132' include a first terminal 1311 and a second terminal 1321 disposed at one end of each. The first internal electrode sheet 131' and the second internal electrode sheet 132' are alternately wound around the dielectric sheet 120'. For example, the capacitor body CB is formed by sequentially winding a dielectric sheet 120', a first internal electrode sheet 131A', a dielectric sheet 120', a second internal electrode sheet 132A', a dielectric sheet 120', a first internal electrode sheet 131B', a dielectric sheet 120', a second internal electrode sheet 132B', a dielectric sheet 120', a first internal electrode sheet 131C', and a dielectric sheet 120' around the axial core 110.

[0038] In order to alternately wind the dielectric sheet 120' and the internal electrode sheets (131', 132') around the axial core 110, the step of forming the capacitor body CB according to this embodiment includes the steps of arranging the dielectric sheet 120' and the internal electrode sheets (131', 132') on the substrate 13 so that they are spaced apart in the X direction X, and winding the dielectric sheet 120' and the internal electrode sheets (131', 132') around the axial core 110. In the step of winding the dielectric sheet 120' and the internal electrode sheets (131', 132'), the dielectric sheet 120' and the internal electrode sheets (131', 132') arranged on a base (e.g., a conveyor belt) 13 are wound around the axial core 110 sequentially along the X direction X. As an example, the axial core 110, whose axes are arranged in the Z direction, is moved in the X direction X and rotated around the axis, whereby the dielectric sheet 120' and the internal electrode sheets (131', 132') are wound around the axial core 110.

[0039] As another example, the dielectric sheet 120' and the internal electrode sheets (131', 132') arranged on the base 13 are moved in the opposite direction of the X direction (towards the left in the drawing) while the axial core 110 is rotated around the axis (arranged in the Z direction), so that the dielectric sheet 120' and the internal electrode sheets (131', 132') are wound around the axial core 110. In the step of winding the dielectric sheet 120 ′ and the internal electrode sheets ( 131 ′, 132 ′), the dielectric sheet 120 ′ and the internal electrode sheets ( 131 ′, 132 ′) are separated from the substrate 13 and wound around the axial core 110 . If necessary, a film may be additionally disposed between the substrate 13 and the dielectric sheet 120' and the internal electrode sheets (131', 132') for easy separation.

[0040] In order to allow the first internal electrode sheet 131' and the second internal electrode sheet 132' to be alternately wound around the dielectric sheet 120', the first internal electrode sheet 131' and the second internal electrode sheet 132' are alternately arranged between the dielectric sheets 120' on the substrate 13. On the substrate 13, the lengths (D1, D2) of the dielectric sheet 120' and the internal electrode sheets (131', 132') in the X direction X gradually increase as they are disposed farther along the X direction X (as they are wound later). This is because the later the wire is wound around the shaft core 110, the larger the diameter after winding.

[0041] On the substrate 13, the distance D5 between the dielectric sheet 120' and the internal electrode sheets (131', 132') is appropriately adjusted so that the terminals (1311, 1321) of the capacitor 100A are positioned at their designed positions without affecting the winding of the adjacent dielectric sheet 120' and internal electrode sheets (131', 132') around the axial core 110. For example, on the substrate 13, the spacing between the dielectric sheet 120' and the internal electrode sheets (131', 132') may be equal to or greater than the diameter of one of these configurations (e.g., the configuration located on the left side of the drawing) after being wound. Therefore, on the substrate 13 of the axial core 110, the distance between the dielectric sheet 120' and the internal electrode sheets (131', 132') gradually increases as they are disposed farther apart in the X direction.

[0042] On the substrate 13, the terminals (1311, 1321) are arranged at the upper ends (ends in the Z direction) of the internal electrode sheets (131', 132') so that the terminals (1311, 1321) are exposed on the surface on which the external electrodes (141, 142) of the capacitor body CB are formed. For example, on the substrate 13, the first terminal 1311 is disposed at the upper end of the first internal electrode sheet 131', and the second terminal 1321 is disposed at the upper end of the second internal electrode sheet 132'. 15, the Z direction Z is set as the direction from the upper surface to the lower surface of the shaft core 110, consistent with FIG. In addition, the dielectric sheet 120' and the internal electrode sheets (131', 132') are aligned on the base 13 by arranging them so that the imaginary line VL connecting the upper end (end in the Z direction Z) of the terminals (1311, 1321) and the upper end (end in the Z direction Z) of the dielectric sheet 120' forms a straight line.

[0043] To realize a structure in which the internal electrodes (131, 132) are embedded in the dielectric structure 120, on the substrate 13, the length D3 of the dielectric sheet 120' in the Z direction Z is longer than the length D4 of the internal electrode sheets (131', 132') in the Z direction Z. On the substrate 13, the imaginary line VL connecting the upper ends of the terminals (1311, 1321) and the upper end of the dielectric sheet 120' is made straight, and the length D3 of the dielectric sheet 120' is made longer than the length D4 of the internal electrode sheets (131', 132') so that the first internal electrode 131 and the second internal electrode 132 are not exposed to the lower surface 120l of the dielectric structure 120 in the capacitor body CB.

[0044] The positions of the first terminal 1311 and the second terminal 1321 are appropriately adjusted taking into consideration the positions where they are exposed from the dielectric structure 120 . For example, after the internal electrode sheets (131', 132') are wound, the first terminal 1311 and the second terminal 1321 are arranged in opposite directions relative to the shaft core 110, so that on the substrate 13, the first terminal 1311 is disposed at the end of the first internal electrode sheet 131' in the X direction (the left end in the drawing), and the second terminal 1321 is disposed at the center of the second internal electrode sheet 132' in the X direction. If necessary, the step of forming the capacitor body CB may further include a step of alternately winding the dielectric sheet 120' and the internal electrode sheets (131', 132') around the axial core 110, and then firing the dielectric sheet 120' and the internal electrode sheets (131', 132'). The firing temperature is determined by the materials of the dielectric sheet 120' and the internal electrode sheets (131', 132') and can be, for example, within the range of about 1000°C to 1400°C.

[0045] Referring to FIG. 22, external electrodes 141 and 142 are formed on the capacitor body CB to be connected to the terminals 1311 and 1321, respectively. For example, the first external electrode 141 is formed on the first terminal 1311 and connected to the first terminal 1311 , and the second external electrode 142 is formed on the second terminal 1321 and connected to the second terminal 1321 .

[0046] 23 and 24 are cross-sectional views illustrating an exemplary method for forming a molding material on a capacitor body. 23 and 24, the method for manufacturing a capacitor according to an embodiment of the present invention may further include molding the capacitor body CB with a molding material 150 and removing a portion of the molding material 150 to expose the terminals (1311, 1321).

[0047] Molding with the molding material 150 is performed, for example, by compression molding the capacitor body CB, impregnating it with a molding liquid, and applying heat and / or pressure. During molding, the entire area of ​​the capacitor body CB is covered with the molding material 150 . Therefore, an additional step is performed to expose the terminals (1311, 1321) for connection with the external electrodes (141, 142). The molding material 150 is removed by, for example, grinding the molding material 150. After grinding the molding material 150, the capacitor 100B shown in FIG. 5 can be manufactured by forming the external electrodes (141, 142) on the capacitor body CB so as to be connected to the terminals (1311, 1321). When the capacitor body CB is formed such that the terminals (1311, 1321) protrude above the upper surface 120u of the dielectric structure 120, the capacitor 100C shown in FIG. 6 can be manufactured by molding the molding material 150 and removing the upper region.

[0048] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the technical scope of the present invention. [Explanation of symbols]

[0049] 100A, 100B, 100C capacitors 110 axis core 120 Dielectric Structure 131, 132 Internal electrode 131,131A, 131B, 131C 1st internal electrode 132, 132A, 132A 2nd internal electrode 141, 142 External electrode 150 Molding material 1311 1st terminal 1321 2nd terminal

Claims

1. a capacitor body including a dielectric structure and a plurality of internal electrodes embedded in the dielectric structure and spaced apart from each other in a direction from a side surface of the dielectric structure toward an interior of the dielectric structure; an external electrode disposed on the capacitor body and connected to the internal electrode; A capacitor, wherein each of the plurality of internal electrodes circumferentially surrounds another internal electrode disposed inside the internal electrode.

2. The capacitor of claim 1 , wherein the internal electrodes each include a terminal exposed on an upper surface of the dielectric structure and connected to the external electrode.

3. The capacitor of claim 1 , wherein the external electrode has an entire area disposed on the upper surface of the dielectric structure.

4. The capacitor of claim 1 , wherein the capacitor body further comprises an axial core circumferentially surrounded by the dielectric structure.

5. The capacitor of claim 4 , wherein the axial core comprises silicon.

6. The capacitor according to claim 1 , wherein the internal electrodes are not exposed on the bottom surface of the dielectric structure.

7. The capacitor according to claim 1 , further comprising a molding material covering at least a portion of each of the side and bottom surfaces of the dielectric structure.

8. The capacitor of claim 7 , wherein the molding material extends onto an upper surface of the dielectric structure.

9. 10. The capacitor of claim 1, wherein the dielectric structure is cylindrical.

10. a capacitor body including an axial core, a dielectric structure surrounding the axial core, a plurality of first internal electrodes embedded in the dielectric structure, each having a first terminal exposed on an upper surface of the dielectric structure, and a plurality of second internal electrodes embedded in the dielectric structure, electrically insulated from the first internal electrodes, each having a second terminal exposed on an upper surface of the dielectric structure; and external electrodes disposed on the capacitor body, the external electrodes including a first external electrode connected to the first terminal and a second external electrode connected to the second terminal.

11. The capacitor of claim 10 , wherein the first internal electrode and the second internal electrode surround the axial core and are spaced apart from each other in a direction away from the axial core.

12. The capacitor of claim 11 , wherein the first internal electrodes and the second internal electrodes are alternately arranged in a direction away from the axial core.

13. The capacitor of claim 10 , wherein the first terminal and the second terminal are arranged in opposite directions on the upper surface of the dielectric structure with respect to the axial core.

14. The capacitor of claim 10 , wherein the first external electrode and the second external electrode are disposed over their entire areas on the top surface of the dielectric structure.

15. forming a capacitor body by alternately winding a dielectric sheet and an internal electrode sheet including terminals around an axial core; forming an external electrode on the capacitor body, the external electrode being connected to the terminal; The step of forming the capacitor body comprises: disposing the dielectric sheet and the internal electrode sheet on a base so that they are spaced apart in a first direction; and winding the dielectric sheet and the internal electrode sheet around the axial core.

16. In the winding step, the dielectric sheet and the internal electrode sheet disposed on the substrate are wound around the axial core sequentially along the first direction, 16. The method of claim 15, wherein the lengths of the dielectric sheets and the internal electrode sheets in the first direction on the substrate gradually increase as they are disposed farther apart in the first direction.

17. 16. The method of claim 15, wherein the terminals are disposed on the substrate at ends of the internal electrode sheets in a second direction perpendicular to the first direction.

18. the internal electrode sheets include first internal electrode sheets and second internal electrode sheets alternately wound around the dielectric sheet, On the substrate, the terminal of the first internal electrode sheet is disposed at an end of the first internal electrode in the first direction, 18. The method of claim 17, wherein the terminal of the second internal electrode sheet is disposed at the center of the second internal electrode in the first direction.

19. 16. The method of claim 15, wherein a length of the dielectric sheet in a second direction perpendicular to the first direction on the substrate is longer than a length of the internal electrode sheet in the second direction.

20. molding the capacitor body with a molding material; 16. The method of claim 15, further comprising removing a portion of the molding material to expose the terminals.

Images