Tantalum capacitor

Abstract

The invention provides a tantalum capacitor. The tantalum capacitor includes: a tantalum body including a tantalum body, a conductive polymer layer disposed on the tantalum body, and a tantalum wire passing through a portion of each of the tantalum body and the conductive polymer layer in a first direction; a molding unit surrounding the tantalum body; an anode lead frame exposed to one surface of the molding unit and connected to the tantalum wire; a cathode lead frame spaced apart from the anode lead frame and exposed to the one surface of the molded unit; and a first coating layer disposed in at least a portion of at least one of a region between the molding unit and the anode lead frame and a region between the molding unit and the cathode lead frame.

Description

[0001] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0085779 filed on July 3, 2023, in the Korean Intellectual Property Office, and Korean Patent Application No. 10-2023-0097580 filed on July 26, 2023, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference. Technical Field

[0002] The present disclosure relates to a tantalum capacitor, and more particularly, to a tantalum capacitor having improved stress resistance reliability and moisture resistance reliability. Background Art

[0003] Tantalum (Ta) is a widely used metal throughout industries including electrical and electronics, machinery, chemical engineering, medicine, aerospace, and military industries due to its mechanical and physical properties, such as a high melting point and excellent ductility and corrosion resistance.

[0004] In particular, Ta is currently widely used as an anode material for small capacitors due to its property of forming the most stable anodic oxide film among all metals.

[0005] Furthermore, due to the recent rapid development of IT industries such as the electronics industry and the information communication industry, the use of tantalum materials is rapidly increasing every year.

[0006] Tantalum capacitors use a structure that uses an internal lead frame to connect the tantalum body and the electrode. In this case, if sufficient adhesion between the internal lead frame and the molded unit is not ensured, interface defects may occur and moisture may penetrate through the interface. This deteriorates the characteristics of tantalum capacitors in high temperature and high humidity environments and affects reliability. Summary of the invention

[0007] An aspect of the present disclosure is to provide a tantalum capacitor having excellent reliability by enhancing interface bonding force and reducing moisture absorption rate.

[0008] An aspect of the present disclosure is to provide a tantalum capacitor having enhanced stress resistance.

[0009] According to one aspect of the present disclosure, a tantalum capacitor includes: a tantalum body including a tantalum body, a conductive polymer layer and a tantalum wire, the conductive polymer layer being disposed on the tantalum body, the tantalum wire passing through a portion of each of the tantalum body and the conductive polymer layer in a first direction; a molding unit surrounding the tantalum body and including a fifth surface and a sixth surface opposite to each other in the first direction, a third surface and a fourth surface opposite to each other in a second direction, and a first surface and a second surface opposite to each other in a third direction; an anode lead frame exposed to the second surface of the molding unit and connected to the tantalum wire; a cathode lead frame spaced apart from the anode lead frame and exposed to the second surface of the molding unit; and a first coating disposed in at least a portion of at least one of an area between the molding unit and the anode lead frame and an area between the molding unit and the cathode lead frame.

[0010] According to another aspect of the present disclosure, a tantalum capacitor includes: a tantalum body, including a tantalum body, a conductive polymer layer and a tantalum wire, the conductive polymer layer being disposed on the tantalum body, the tantalum wire passing through a portion of each of the tantalum body and the conductive polymer layer in a first direction; a molding unit surrounding the tantalum body and including a fifth surface and a sixth surface opposite to each other in the first direction, a third surface and a fourth surface opposite to each other in a second direction, and a first surface and a second surface opposite to each other in a third direction; an anode lead frame exposed to the second surface of the molding unit and connected to the tantalum wire; a cathode lead frame spaced apart from the anode lead frame and exposed to the second surface of the molding unit; a first coating disposed in at least a portion of a region between the molding unit and the tantalum body; and a second coating disposed on the first to sixth surfaces of the molding unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other aspects, features and advantages of the present disclosure will be more clearly understood through the following detailed description in conjunction with the accompanying drawings, in which:

[0012] Figure 1 is a perspective view of a tantalum capacitor according to the present disclosure;

[0013] Figure 2 is a diagram showing a tantalum capacitor according to the present disclosure viewed in a second direction;

[0014] Figure 3 is along Figure 1 A cross-sectional view taken along line II' of FIG. 1 , wherein the coating is omitted; and

[0015] Figures 4 to 13 is along Figure 1The cross-sectional view taken along line II' schematically shows the arrangement of the coating of the present disclosure. DETAILED DESCRIPTION

[0016] Hereinafter, exemplary embodiments of the inventive concept will be described in detail with reference to the accompanying drawings. However, the inventive concept may be illustrated in many different forms and should not be construed as being limited to the specific exemplary embodiments set forth herein. More specifically, these exemplary embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. In the accompanying drawings, for the sake of clarity, the shapes and sizes of the elements may be exaggerated, and the same reference numerals will always be used to represent the same or similar elements.

[0017] Hereinafter, exemplary embodiments in the present disclosure will be described with reference to the accompanying drawings.

[0018] In the drawings, an X direction may be defined as a first direction or a length direction, a Y direction may be defined as a second direction or a width direction, and a Z direction may be defined as a third direction or a thickness direction.

[0019] Figure 1 is a perspective view of a tantalum capacitor according to the present disclosure.

[0020] Figure 2 is a diagram showing a tantalum capacitor according to the present disclosure viewed in a second direction.

[0021] Figure 3 is along Figure 1 The cross-sectional view taken along line II' of FIG. 1 is a cross-sectional view taken along line II' of FIG. 1 , in which the coating is omitted in the exemplary embodiment of the present disclosure. Optionally, Figure 3 is a cross-sectional view of a prior art tantalum capacitor without a coating and may be considered a comparative example.

[0022] Reference Figures 1 to 3 The tantalum capacitor 1000 of the present exemplary embodiment may include: a tantalum body 100 including a tantalum body 110, a conductive polymer layer 120, and a tantalum wire 150, the conductive polymer layer 120 being disposed on the tantalum body, the tantalum wire 150 passing through a portion of each of the tantalum body 110 and the conductive polymer layer 120 in a first direction; a molding unit 200 including a fifth surface 5 and a sixth surface 6 opposite to each other in a first direction (X direction), a third surface 3 and a fourth surface 4 opposite to each other in a second direction (Y direction), and a first surface 1 and a second surface 2 opposite to each other in a third direction (Z direction), and the molding unit 200 surrounds the tantalum body 100; an anode lead frame 300 exposed to the second surface 2 of the molding unit 200 and connected to the tantalum wire 150; a cathode lead frame 400 spaced apart from the anode lead frame 300 and exposed to the second surface 2 of the molding unit 200; and a first coating 510 (on the Figures 4 to 13 ), disposed at at least a portion of at least one of an interface (or region) between the molding unit 200 and the anode lead frame 300 and an interface (or region) between the molding unit 200 and the cathode lead frame 400.

[0023] The tantalum body 100 may have a tantalum wire 150 exposed in a first direction (X direction). Here, the tantalum wire 150 may pass through a portion of the tantalum body 110 in the first direction (X direction). The tantalum wire 150 may be inserted and installed in a mixture of tantalum powder and a binder so as to be offset from the center before the mixture of tantalum powder and a binder is pressed. The tantalum body 110 may be formed by inserting and installing the tantalum wire 150 in the mixture of tantalum powder and a binder, and then pressing the mixture under high temperature and high vacuum (10 -5 sintered in a 400-1000-torr (torr or lower) environment for about 30 minutes to form the desired size.

[0024] The molding unit 200 may cover the tantalum body 100 , and may be formed such that one surface of the first connection part 320 of the anode lead frame 300 and one surface of the cathode lead frame 400 are exposed.

[0025] The molding unit 200 of the tantalum capacitor according to the present disclosure may be formed by transfer molding a resin such as epoxy molding compound (EMC) to surround the tantalum body 100. The molding unit 200 serves to protect the tantalum wire 150 and the tantalum body 100 from external influences.

[0026] The anode lead frame 300 may be connected to the tantalum wire 150 and may be used as a terminal when the tantalum capacitor 1000 is mounted on a board. The anode lead frame 300 may include a first connection portion 320 and a first bent portion 310, and the first bent portion 310 may be inclined toward the tantalum body 100 based on the first connection portion 320. The first connection portion 320 of the anode lead frame 300 may be exposed to the second surface 2 of the molding unit 200. The first connection portion 320 may be exposed to the lower surface (second surface 2) of the molding unit 200 and may be used as a terminal when the tantalum capacitor 1000 is mounted on a board. Here, the first connection portion 320 may be spaced apart from the tantalum body 100 and may be used as an anode of the tantalum capacitor 1000 according to the present disclosure. To this end, the anode lead frame 300 may be formed using a conductive metal such as a nickel / iron alloy.

[0027] The cathode lead frame 400 may be connected to the tantalum body 100 and may be used as a terminal when the tantalum capacitor 1000 is mounted on a board. The cathode lead frame 400 may be disposed to be spaced apart from the anode lead frame 300 and extend in the first direction (X direction). The cathode lead frame 400 may be exposed to the second surface 2 of the molding unit 200. The cathode lead frame 400 may be exposed to the lower surface (second surface 2) of the molding unit 200 and may be used as a terminal when the tantalum capacitor 1000 is mounted on a board, and may be used as a cathode of the tantalum capacitor 1000 according to the present disclosure. To this end, the cathode lead frame 400 may be formed using a conductive metal such as a nickel / iron alloy.

[0028] In addition, although not shown in the drawings, the tantalum capacitor according to the exemplary embodiment in the present disclosure may further include a conductive adhesive layer to bond the cathode lead frame 400 to the tantalum body 100. For example, such a conductive adhesive layer may be formed by coating and curing a certain amount of a conductive adhesive including an epoxy-based thermosetting resin and a conductive metal such as silver (Ag) powder, but the present disclosure is not limited thereto.

[0029] Reference Figure 3 The tantalum body 100 of the tantalum capacitor 1000 according to the exemplary embodiment of the present disclosure may include a tantalum body 110 formed by sintering a molded body including a metal powder (e.g., tantalum (Ta) powder (or tantalum particles)), a conductive polymer layer 120 disposed on the tantalum body 110 (e.g., disposed at the periphery of the tantalum body 110), a carbon layer 130 disposed on the conductive polymer layer 120, and a silver (Ag) layer 140 disposed on the carbon layer 130.

[0030] The tantalum capacitor may further include a tantalum wire 150 having an insertion region located inside the tantalum body 110 and a non-insertion region located outside the tantalum body 110 .

[0031] The tantalum body 110 may be formed by sintering a molded body including metal powder and a binder.

[0032] Specifically, the tantalum body 110 may be manufactured by mixing metal powder, a binder, and a solvent in a certain ratio, stirring the mixture, pressing the mixture to form a rectangular parallelepiped, and then sintering at a high temperature and high vibration.

[0033] The metal powder is not limited as long as it can be used for the tantalum body 110 of the tantalum capacitor 1000 according to the exemplary embodiment of the present disclosure, for example, it can be tantalum (Ta) powder (or tantalum particles). However, the present disclosure is not limited thereto, and the metal powder can be one or more selected from the group consisting of aluminum (Al), niobium (Nb), vanadium (V), titanium (Ti) and zirconium (Zr), and therefore, an aluminum body, a niobium body, etc. can also be used instead of a tantalum body.

[0034] The binder is not limited, and may be, for example, a cellulose-based binder.

[0035] The cellulose-based binder may be one or more selected from the group consisting of nitrocellulose, methylcellulose, ethylcellulose, and hydroxypropylcellulose.

[0036] Furthermore, before pressing the mixture, the tantalum wire 150 may be inserted and mounted eccentrically with respect to the center.

[0037] According to an exemplary embodiment in the present disclosure, a dielectric oxide layer may be formed as an insulating layer on the tantalum body 110. That is, the dielectric oxide layer may be formed by growing an oxide film (Ta2O5) on the surface of the tantalum body 110 through a formation process using an electrochemical reaction. Here, the dielectric oxide layer turns the tantalum body 110 into a dielectric. In addition, a conductive polymer layer 120 having a negative polarity may be coated and formed on the dielectric oxide layer.

[0038] For example, the conductive polymer layer 120 may include, but is not limited to, a conductive polymer.

[0039] Specifically, the conductive polymer may be formed by chemical polymerization or electropolymerization using EDOT (3,4-ethylenedioxythiophene), pyrrole monomer, or polypyrrole, and then formed as a negative electrode layer having the conductive polymer on the outer surface (formed as an insulating layer) of the tantalum body 110 .

[0040] That is, the conductive polymer layer 120 may be formed using a polymer slurry, and the polymer slurry may include at least one of polypyrrole, polyaniline, and EDOT (3,4-ethylenedioxythiophene). In addition, the conductive polymer layer 120 may include PEDOT:PSS (poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate)). PEDOT:PSS may be generated by oxidatively polymerizing EDOT using poly (styrene sulfonate) (PSS) as a template to balance the charge.

[0041] In addition, the carbon layer 130 may be stacked on the conductive polymer layer 120, and may be stacked by dissolving carbon powder in an organic solvent including epoxy resin, immersing the tantalum body 110 in the solution in which the carbon powder is dissolved, and then drying at a predetermined temperature to volatilize the organic solvent.

[0042] In addition, the carbon layer 130 may play a role in preventing silver (Ag) ions from passing through.

[0043] Next, a silver (Ag) layer 140 formed using a silver (Ag) paste may be coated on the surface of the carbon layer 130 .

[0044] A silver (Ag) layer 140 may be stacked on the outer portion of the carbon layer 130 to improve electrical conductivity.

[0045] In addition, the silver (Ag) layer 140 may facilitate electrical connection for polarity transfer by improving conductivity of the polarity of the negative electrode layer.

[0046] Figures 4 to 13 is along Figure 1 The cross-sectional view taken along line II' schematically shows the arrangement of the coating of the present disclosure.

[0047] A tantalum capacitor according to the present disclosure includes a coating 500 .

[0048] The prior art tantalum capacitor without coating has a problem that sufficient adhesion between the lead frame and the molded unit cannot be ensured, resulting in interface defects. Moisture may penetrate into the capacitor through the open interface under high temperature and high humidity environment (hereinafter referred to as moisture absorption defect), thereby reducing the reliability of the component.

[0049] The tantalum capacitor according to the present disclosure can reduce moisture absorption rate by enhancing the interface bonding force between the lead frame and the molding unit, thereby ensuring reliability. In addition, by using a material with excellent elasticity, when the internal elements of the tantalum capacitor expand due to moisture penetration, the tantalum capacitor can have enhanced resistance to internal stress.

[0050] The first coating layer 510 is disposed at at least a portion of at least one of an interface between the molding unit 200 and the anode lead frame 300 and an interface between the molding unit 200 and the cathode lead frame 400 .

[0051] The first coating layer 510 may extend to the second surface 2 of the molding unit 200. When the lead frames 300 and 400 extend to the second surface 2 of the molding unit 200, the interface between the second surface of the molding unit and the lead frames may have a structure susceptible to external moisture penetration. As in the present disclosure, when the first coating layer 510 extends to the second surface 2 of the molding unit 200, the penetration of external moisture may be fundamentally blocked.

[0052] The first coating 510 may include an organosilicon compound. The organosilicon compound may be formed to include a material having a hydrophobic functional group, and may form crosslinks with the surface of the mold unit 200 and the surface of the lead frames 300 and 400. In this specification, "bonding" may refer to a state in which the surface of the adhesive and the surface of the adherend are bonded by the bonding force of the interface. The bonding force of the interface may be due to a chemical interaction between the surface molecules of the adhesive and the surface molecules of the adherend, or may be due to mechanical bonding. In this specification, "crosslinking" may refer to the formation of a network structure by chemical bonds / physical bonds (such as covalent bonds, ionic bonds, van der Waals bonds, or hydrogen bonds) between molecules.

[0053] It may be difficult to ensure sufficient adhesion of the resin (such as EMC) of the molding unit 200 forming the appearance of the tantalum capacitor and the lead frames 300 and 400, so interface defects may occur. In addition, there is a problem that it is difficult to effectively suppress moisture penetration due to poor waterproofing effect.

[0054] In contrast, the first coating layer 510 according to the present disclosure may be connected to the molding unit 200 and the lead frames 300 and 400 through the above-mentioned cross-linking, thereby providing better bonding strength.

[0055] The first coating layer 510 may include multifunctional alkoxysilane. Alkoxysilane has hydrophobicity, thus preventing moisture penetration and contamination, and improving mechanical strength against bending stress through a curing reaction.

[0056] In an example, the first coating layer 510 may include a silane coupling agent. In this case, one end of the silicon (Si) atom of the first coating layer 510 may be covalently bonded or hydrogen-bonded to the mold unit 200 and the lead frames 300 and 400, and the other end of the silicon (Si) atom may be bonded to the hydrophobic functional group.

[0057] Specifically, the silane coupling agent has two functional groups of different reactivity, ie, a hydrophilic group and a hydrophobic group, in one molecule, and the silane coupling agent may be represented by the following [Chemical Formula 1].

[0058] [Chemical formula 1]

[0059] X-Si-R3

[0060] Here, R3 refers to a hydrolyzable hydrophilic functional group, and X refers to a non-hydrolyzable hydrophobic functional group.

[0061] R3 is a substance chemically bonded to an inorganic material, and may be, for example, an alkoxy group (RO) of an alkyl group having 1 to 16 carbon atoms, such as a methoxy group (CH3O-) or an ethoxy group (C2H5O-).

[0062] X may include an epoxy group, a vinyl group (CH2CH-), an amino group (-NH2), an acrylic group, a methacrylic group, a mercapto group (SH-), etc., but is not limited thereto.

[0063] Specific examples of the silane coupling agent may include 3-glycidyloxypropyltrimethoxysilane (GPTMS), 3-glycidyloxypropyltriethoxysilane (GPTES), vinyltriethoxysilane, aminopropyltrimethoxysilane (APTMS), etc., but are not limited thereto. These silane coupling agents may be used alone, or two or more of these silane coupling agents may be used in combination.

[0064] The first coating layer 510 may be formed on the lead frames 300 and 400 of the semi-finished (i.e., semi-finished product state) tantalum capacitor by dipping, spraying or deposition, but is not limited thereto. Here, the semi-finished product state may refer to a state before forming the molding unit 200 (forming the appearance of the tantalum capacitor).

[0065] The first coating layer 510 may have a thickness greater than 0 μm and less than or equal to 30 μm.

[0066] If the first coating layer 510 is not provided between the mold unit 200 and the lead frames 300 and 400, sufficient adhesion between the mold unit 200 and the lead frames 300 and 400 may not be ensured, resulting in interface defects. In addition, since moisture penetrates into the tantalum capacitor through an open interface (i.e., a moisture absorption defect), reliability may be deteriorated.

[0067] If the thickness of the first coating layer 510 is greater than 30 μm, a separation phenomenon may occur at the EMC interface of the molding unit 200 , which may cause a moisture absorption defect, thereby reducing reliability.

[0068] Table 1 below shows moisture absorption defects and interface defects according to the thickness of the first coating layer 510. The comparative example can be considered as Figure 3 A conventional tantalum capacitor is shown without coating.

[0069] [Table 1]

[0070] serial number Thickness [μm] Hygroscopic defects Interface defects 1 (Comparative example) 0 Defective Defective 2 0.5 No defects No defects 3 1 No defects No defects 4 10 No defects No defects 5 20 No defects No defects 6 30 No defects No defects

[0071] In addition, a test was conducted when the thickness of the first coating layer 510 was greater than 30 μm and less than or equal to 100 μm, and it was found that there were moisture absorption defects and interface defects.

[0072] Figure 4 and Figure 5 A case where the first coating layer 510 is provided at the lead frames 300 and 400 is shown.

[0073] Reference Figure 4 , the first coating layer 510 is disposed at both the interface between the mold unit 200 and the anode lead frame 300 and the interface between the mold unit 200 and the cathode lead frame 400. In this manner, the first coating layer 510 may be preferentially formed on the lead frames 300 and 400, and then the lead frames 300 and 400 are combined with the tantalum body 100.

[0074] Alternatively, if Figure 5As shown, after the lead frames 300 and 400 are combined with the tantalum body 100, the first coating layer 510 may be formed only on the lower portion of the lead frame, that is, formed in a region located below the tantalum body 100 in the Z direction. Specifically, the first coating layer 510 may be formed only on the first connection portion 320 of the cathode lead frame 400 and the anode lead frame 300, and may not be formed on the first bent portion 310.

[0075] Reference Figures 6 to 10 , the first coating 510 may also be disposed on the tantalum body 100 .

[0076] That is, the first coating layer 510 may be disposed not only at the interface between the mold unit 200 and the lead frames 300 and 400, but also at the interface between the mold unit 200 and the tantalum body 100. Specifically, the first coating layer 510 may directly contact the conductive polymer layer 120 and the silver (Ag) layer 140.

[0077] As described above, the first coating layer 510 ensures sufficient interface bonding strength between the mold unit 200 and the lead frames 300 and 400 to prevent moisture absorption defects. In addition, the first coating layer 510 may be further directly disposed on the tantalum body 100, thereby further improving moisture resistance reliability. In addition, when the tantalum body 100 expands due to moisture penetration, internal stress may be generated. Here, the first coating layer 510 having an elastic force may be disposed between the mold unit 200 and the tantalum body 100, so that the tantalum capacitor has an enhanced characteristic of resisting internal stress.

[0078] Reference Figure 6 , after the lead frames 300 and 400 are combined with the tantalum body 100, the first coating layer 510 may be formed only on a half region of the combination in the vertical direction. Specifically, the first coating layer 510 may be provided only in a region of the tantalum capacitor that is closer to the second surface 2 relative to the first surface 1 of the first surface 1 and the second surface 2 of the molding unit 200.

[0079] Reference Figure 7 , the first coating layer 510 is not disposed on the upper surface of the tantalum body 100. Here, the upper surface of the tantalum body 100 refers to a surface of the tantalum body 100 facing the first surface 1 of the molding unit 200. That is, the first coating layer 510 may be disposed at an interface between the remaining surface of the tantalum body 100 except the upper surface of the tantalum body 100 and the molding unit 200 and at an interface between the molding unit 200 and the lead frames 300 and 400.

[0080] Reference Figure 8 and Fig. 9, after the lead frames 300 and 400 are combined with the tantalum body 100, the first coating 510 may be formed only on a half area of ​​the combination in the horizontal direction. Figure 8 As shown, the first coating 510 may be provided only in a region of the tantalum capacitor that is closer to the fifth surface 5 than to the sixth surface 6 of the fifth surface 5 and the sixth surface 6 of the mold unit 200. Fig. 9 As shown, the first coating layer 510 may be provided only in a region of the tantalum capacitor that is closer to the sixth surface 6 than the fifth surface 5 of the fifth surface 5 and the sixth surface 6 of the mold unit 200 .

[0081] That is to say, Figures 6 to 9 As shown, in a semi-finished tantalum capacitor, a coating may be selectively formed only on a portion susceptible to moisture penetration.

[0082] Alternatively, if Fig.10 As shown, the first coating layer 510 may be formed at the entire interface between the mold unit 200 and the lead frames 300 and 400 and at the entire interface between the mold unit 200 and the tantalum body 100 .

[0083] However, the present disclosure is not limited thereto, and as described above, the first coating layer 510 may be disposed only at the interface between the mold unit 200 and the lead frames 300 and 400 , and may not be disposed at the interface between the mold unit 200 and the tantalum body 100 .

[0084] Reference Fig.11 In another exemplary embodiment of the present disclosure, after the tantalum body 100 is coated, the tantalum body 100 is combined with the lead frames 300 and 400. Here, the first coating layer 510 may be provided only at the interface between the molding unit 200 and the tantalum body 100.

[0085] The thickness and arrangement of the first coating 510 can be checked in the following manner. A cross-sectional sample of the tantalum capacitor in the first direction (X direction)-third direction (Z direction) is obtained by polishing the tantalum capacitor to a depth of about 1 / 2 along the second direction (Y direction). The thickness and arrangement of the coating at the interface (region) between the relevant part in the tantalum capacitor and the molding unit can be checked in the following manner: the obtained cross-sectional sample is observed at a magnification of 500 to 20,000 by a scanning electron microscope (SEM).

[0086] Reference Fig.12 and Fig.13 The tantalum capacitor according to the present disclosure may further include a second coating layer 520. The second coating layer 520 may be provided on a surface (ie, an outer surface) of the molding unit 200 of the tantalum capacitor to prevent moisture penetration due to external liquid substances or the like.

[0087] The second coating layer 520 may be disposed on the first to sixth surfaces of the molding unit 200 and may include a fluorine (F)-containing compound.

[0088] Specific examples of the fluorine (F)-containing compound may include 1H,1H,2H,2H-perfluorodecyl acrylate (PFDA), perfluorodecyl methacrylate (PFDMA), dodecafluoroheptyl acrylate, pentafluorophenyl methacrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-pentadecafluorononyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-pentadecafluorononyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-pentadecafluorononyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluorooctyl acrylate, and 2-methyl-2-methoxy ... ,8,8-tridecafluorooctyl acrylate, 3,3,4,4,5,5,6,6,7,7,7-undecanefluoroheptyl acrylate, 3,3,4,4,5,5,6,6,7,7,7-undecanefluoroheptyl acrylate, 2-methyl-acrylate, 3,3,4,4,5,5,6,6,6-nonafluorohexyl acrylate, 2-methyl-acrylate, 3,3,4,4,5,5,6,6,6-nonafluorohexyl acrylate, 3,3,4,4,5,5,6,6,6-nonafluorohexyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-nonadecafluoroundecyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-nonadecafluoroundecyl acrylate, 2-methyl-acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,1 0,10,11,11,11-Nineteenfluoroundecyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heneicosyl acrylate, 2-methyl-acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heneicosyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,13-twenicosyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,13-tricosyl acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,14-pentafluorotetradecyl acrylate, 2-methyl-acrylic acid 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,14-pentafluorotetradecyl ester, and the like, but are not limited thereto.

[0089] Fluorine (F)-containing compounds can provide excellent water repellency and physical / chemical resistance to foreign substances.

[0090] The second coating layer 520 may be disposed on the second surface of the molding unit 200 and expose the anode lead frame 300 and the cathode lead frame 400. The first coating layer 510 may be selectively formed at the interface (or region) between the molding unit 200 and the anode lead frame 300 and the interface (or region) between the molding unit 200 and the cathode lead frame 400.

[0091] For example, refer to Fig.12 , the tantalum capacitor may include only the second coating layer 520. Since the fluorine (F)-containing compound can provide excellent water resistance and physical / chemical resistance to external substances, Fig.12 Tantalum capacitors can have improved reliability. Fig.13 , the tantalum capacitor may include both the first coating layer 510 and the second coating layer 520, and the first coating layer 510 and the second coating layer 520 may be bonded to each other, thereby further improving the reliability of the tantalum capacitor. However, the present disclosure is not limited thereto.

[0092] One effect of the present disclosure is to provide a tantalum capacitor having excellent reliability by enhancing the bonding force of an interface and reducing the moisture absorption rate.

[0093] Another effect of the present disclosure is to provide a tantalum capacitor having enhanced stress resistance characteristics.

[0094] While example embodiments have been shown and described above, it will be readily apparent to those skilled in the art that modifications and variations may be made without departing from the scope of the present disclosure as defined by the appended claims.

Claims

1. A tantalum capacitor, comprising: a tantalum body comprising a tantalum body, a conductive polymer layer, and a tantalum wire, the conductive polymer layer being disposed on the tantalum body, the tantalum wire passing through a portion of each of the tantalum body and the conductive polymer layer in a first direction; a molding unit surrounding the tantalum body and including a fifth surface and a sixth surface opposite to each other in the first direction, a third surface and a fourth surface opposite to each other in the second direction, and a first surface and a second surface opposite to each other in the third direction; an anode lead frame exposed to the second surface of the mold unit and connected to the tantalum wire; a cathode lead frame spaced apart from the anode lead frame and exposed to the second surface of the molding unit; as well as A first coating layer is provided in at least a portion of at least one of a region between the molding unit and the anode lead frame and a region between the molding unit and the cathode lead frame.

2. The tantalum capacitor according to claim 1, wherein: The first coating layer includes an organosilicon compound.

3. The tantalum capacitor according to claim 2, wherein: The first coating layer includes a multifunctional alkoxysilane.

4. The tantalum capacitor according to claim 1, wherein: The first coating layer has a thickness greater than 0 μm and less than or equal to 30 μm.

5. The tantalum capacitor according to claim 1, wherein The first coating extends to the second surface of the molding unit.

6. The tantalum capacitor according to claim 1, wherein: The anode lead frame includes a first connecting portion and a first bent portion, and The first coating is not disposed on the first bent portion.

7. The tantalum capacitor according to claim 1, wherein: The tantalum body further comprises: a carbon layer disposed on the conductive polymer layer; and A silver layer is disposed on the carbon layer.

8. The tantalum capacitor according to claim 1, wherein The first coating is also provided in a region between the molding unit and the tantalum body.

9. The tantalum capacitor according to claim 8, wherein: The first coating layer is provided in a region of the tantalum capacitor that is closer to the fifth surface than the sixth surface of the fifth surface and the sixth surface of the mold unit.

10. The tantalum capacitor according to claim 8, wherein: The first coating layer is provided in a region of the tantalum capacitor that is closer to the sixth surface relative to the fifth surface of the fifth surface and the sixth surface of the mold unit.

11. The tantalum capacitor according to claim 8, wherein: The first coating layer is provided in a region of the tantalum capacitor that is closer to the second surface relative to the first surface of the first surface and the second surface of the molding unit.

12. The tantalum capacitor according to claim 8, wherein: The first coating layer is not provided on an upper surface of the tantalum body facing the first surface of the molding unit. 13 . The tantalum capacitor of claim 1 , further comprising a second coating layer provided on the first to sixth surfaces of the molding unit and comprising a fluorine-containing compound.

14. The tantalum capacitor according to claim 13, wherein: The second coating exposes the anode lead frame and the cathode lead frame.

15. The tantalum capacitor according to claim 1, wherein The anode lead frame includes a first connecting portion and a first bent portion, and The first coating is disposed on the first connecting portion and the first bending portion.

16. The tantalum capacitor according to claim 1, wherein The first coating layer is provided in a region between a portion of the tantalum wire that is not inserted into the tantalum body and the molding unit.

17. The tantalum capacitor according to claim 1, wherein: The first coating is spaced apart from the tantalum wire.

18. A tantalum capacitor, comprising: a tantalum body comprising a tantalum body, a conductive polymer layer, and a tantalum wire, the conductive polymer layer being disposed on the tantalum body, the tantalum wire passing through a portion of each of the tantalum body and the conductive polymer layer in a first direction; a molding unit surrounding the tantalum body and including a fifth surface and a sixth surface opposite to each other in the first direction, a third surface and a fourth surface opposite to each other in the second direction, and a first surface and a second surface opposite to each other in the third direction; an anode lead frame exposed to the second surface of the mold unit and connected to the tantalum wire; a cathode lead frame spaced apart from the anode lead frame and exposed to the second surface of the molding unit; a first coating disposed in at least a portion of a region between the molding unit and the tantalum body; as well as A second coating layer is disposed on the first surface to the sixth surface of the molding unit.

19. The tantalum capacitor according to claim 18, wherein The first coating layer includes an organosilicon compound, and the second coating layer includes a fluorine-containing compound.

20. The tantalum capacitor according to claim 18, wherein The first coating layer is also provided in at least a portion of at least one of a region between the molding unit and the anode lead frame and a region between the molding unit and the cathode lead frame.

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