A SMD solid-state plastic-sealed capacitor

Abstract

The present invention discloses a chip-type solid-state plastic-sealed capacitor, comprising: an element, the element comprising a core package, two L-shaped connecting terminals, the core package comprising an anode foil, a cathode foil and electrolytic paper, the anode foil and the cathode foil are separated by the electrolytic paper roll and sintered into the core package, the anode foil and the cathode foil are respectively connected to the first arm of the L-shaped connecting terminal; two lead pins, the two lead pins are respectively connected to the second arm of the L-shaped connecting terminal through conductive glue; a plastic package body that wraps the element and the lead pins by injection molding, the plastic package body is a resin material, and the bottom and free end of the lead pin are exposed outside the plastic package body. The present invention aims to solve the problems of poor comprehensive performance and high production cost of the metal shell of the solid-state capacitor, provide higher strength protection for the solid-state capacitor, ensure the normal operation of the capacitor under different harsh conditions, and increase the service life of the capacitor.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitors, and in particular to a SMD solid-state plastic-sealed capacitor. Background Art

[0002] Capacitors are an indispensable and important component in the power supply circuit of a computer system. Various boards and chipsets on the motherboard require power supplies of various voltages. To ensure the stable operation of the motherboard and boards, capacitors are needed to filter the power supply and ensure voltage stability. Compared with ordinary liquid aluminum electrolytic capacitors, solid capacitors use conductive polymers as dielectric materials. This material will not react with aluminum oxide and will not explode after power is turned on. At the same time, it is a solid product and will not burst due to thermal expansion. Solid capacitors have superior characteristics such as environmental protection, low impedance, high and low temperature stability, high ripple resistance and high reliability. They are the most advanced products among the current electrolytic capacitor products. At present, solid capacitors are all made of aluminum shells, which are easily damaged in various harsh environments such as high temperature, low temperature, high pressure or ozone, affecting the normal operation of the capacitors. Not only does it cause a waste of data, but it also cannot be effectively guaranteed in terms of safety.

[0003] In view of this, it is necessary to propose a SMD solid-state plastic-sealed capacitor to solve the above problems. Summary of the invention

[0004] The main purpose of the present invention is to provide a chip-type solid-state plastic-sealed capacitor, which aims to solve the problems of poor comprehensive performance and high production cost of the metal shell of the solid-state capacitor, provide higher strength protection for the solid-state capacitor, ensure that the capacitor works normally under different harsh conditions, and increase the service life of the capacitor.

[0005] In order to achieve the above object, the present invention provides a SMD solid-state plastic-sealed capacitor, comprising:

[0006] An element, the element comprising a core package and two L-shaped connecting terminals, the core package comprising an anode foil, a cathode foil and electrolytic paper, the anode foil and the cathode foil are separated by the electrolytic paper roll to form the core package, and the anode foil and the cathode foil are respectively connected to the first arm of the L-shaped connecting terminal;

[0007] Two lead pins, the two lead pins are respectively connected to the second arm of the L-shaped connecting terminal through conductive glue;

[0008] The element and the lead pins are wrapped in a plastic package body by injection molding, wherein the plastic package body is made of resin material, and the bottom and free end of the lead pins are exposed outside the plastic package body.

[0009] Preferably, the plastic package body includes a cylindrical core package and a square seat body, the cylindrical body wraps the core package of the element, and the square seat body wraps the lead pin and the second arm of the L-shaped connecting terminal and the first arm extending outside the core package; the free ends of the lead pin extend respectively from two oppositely arranged side surfaces of the square seat body.

[0010] Preferably, the lead pins are formed by cutting from a lead frame connected to the element.

[0011] Preferably, positive and negative pole markings are formed at two corners on the side surface where one of the lead pins is located.

[0012] Preferably, the bottom surface of the lead pin is flush with the bottom surface of the square base body or extends out from the bottom surface of the square base body.

[0013] Preferably, the length of the free end of the lead pin extending from the side surface is 0.5-4 mm.

[0014] Preferably, the conductive glue is copper glue or silver glue.

[0015] Preferably, the anode foil and the cathode foil are both aluminum foil.

[0016] Preferably, the second arm of the L-shaped connecting terminal is parallel to the body of the element.

[0017] Preferably, it is characterized in that the resin material is one or more of epoxy resin, silicone resin and polytetrafluoroethylene.

[0018] In the scheme of the present application, the chip-type solid-state capacitor includes an element, two lead pins and a plastic package that wraps the element and the lead pins. The second arm of the connecting terminal is fixed to the two lead pins respectively by conductive glue, and the plastic package wraps them therein. This scheme provides a higher level of protection for the solid-state capacitor through the provision of the plastic package, ensures that the capacitor works normally under different harsh conditions, and increases the service life of the capacitor. It avoids the problem of poor comprehensive performance and high production cost of the metal shell of the solid-state capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0020] Figure 1A schematic diagram of a SMD solid-state plastic-encapsulated capacitor according to an embodiment of the present invention;

[0021] Figure 2 It is a structural schematic diagram of a SMD solid-state plastic-sealed capacitor according to an embodiment of the present invention;

[0022] Figure 3 It is a structural schematic diagram of a plastic package body according to an embodiment of the present invention;

[0023] Figure 4 is a schematic structural diagram of an element according to an embodiment of the present invention;

[0024] Figure 5 It is a structural schematic diagram of an injection mold according to an embodiment of the present invention;

[0025] Figure 6 A schematic diagram of the working state of a lead frame according to an embodiment of the present invention;

[0026] Figure 7 Schematic diagram of the structure of a lead frame according to an embodiment of the present invention.

[0027] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings.

[0028] Description of Figure Numbers:

[0029] 100-capacitor, 110-element, 111-core package, 112-connecting terminal, 1121-first arm, 1122-second arm, 120-plastic package, 121-cylindrical body, 122-square seat, 1221-positive and negative pole markings;

[0030] 200-lead frame, 210 frame body, 220-lead unit, 221-lead pin, 222-hollow portion;

[0031] 300 - injection mold, 310 - upper mold, 320 - lower mold, 330 - injection hole, 340 - first injection area, 350 - second injection area, 360 - lead pin positioning groove. DETAILED DESCRIPTION

[0032] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] Please refer to the attached Figure 1 To Attachment Figure 7 .

[0037] The present invention provides a method for manufacturing a chip-type solid-state plastic-sealed capacitor, comprising the following steps:

[0038] S1, provide a plurality of elements 110 having two L-shaped connecting terminals 112, the elements 110 include an anode foil (not shown in the figure) and a cathode foil (not shown in the figure), the first arm 1121 of the L-shaped connecting terminal 112 is respectively connected to the anode foil (not shown in the figure) and the cathode foil (not shown in the figure), and the second arm 1122 of the L-shaped connecting terminal 112 is parallel to the core package 111 of the element 110.

[0039] S1 also includes sintering the anode foil (not shown in the figure) and the cathode foil (not shown in the figure) with an electrolytic paper roll interposed therebetween to form a core package 111 , and performing a chemical treatment on the element 110 .

[0040] Among them, the element 110 includes a core package 111 and an L-shaped connecting terminal 112. The core package 111 includes an anode foil (not shown in the figure), a cathode foil (not shown in the figure) and an electrolytic paper (not shown in the figure). The anode foil (not shown in the figure) and the cathode foil (not shown in the figure) are separated by an electrolytic paper (not shown in the figure) and rolled into the core package 111. The anode foil (not shown in the figure) and the cathode foil (not shown in the figure) are respectively connected to the first arm 1121 of the L-shaped connecting terminal 112.

[0041] S2, providing a lead frame 220 having a plurality of pairs of lead pins 221 spaced apart from each other.

[0042] Please also include the attached Figure 6 and attached Figure 7, a lead frame 220, comprising:

[0043] Frame body 210;

[0044] A plurality of lead units 220 are arranged in an array on the frame body 210, each lead unit 220 includes a pair of lead pins 221 arranged at intervals and at least one hollow portion 222, each lead pin 221 includes a root portion 2211 and a pin portion 2212 extending from the root portion in the length direction of the lead pin 221, the lead pin 221 is connected to the frame body 210 via the root portion 2211, and the hollow portion 222 surrounds the pin portion 2212 so that the pin portion 2212 can be detachably arranged from the frame body 210.

[0045] S3, fixing the element 110 on the lead pins 221 of the lead frame 220 by using conductive adhesive.

[0046] Specifically, the captured elements can be positioned one by one on the lead frame with conductive glue by a special chip mounter or positioning glue mounting equipment, and then the lead frame 220 and the elements 110 thereon are cured. Specifically, the curing is thermal curing, the curing temperature is 120-180 degrees, and the curing time is 20 to 30 minutes.

[0047] S4, placing the lead frame 220 fixed with the element 110 in the injection mold 330 and performing injection molding; wherein, a plurality of cavities (330, 340, 350, 360) corresponding to the element 110 and wrapping the element 110 are arranged in the upper mold 310 of the injection mold 300, the lead frame 220 is positioned in the lower mold of the injection mold 330, and a plurality of connected or isolated injection cavities (330, 340, 350, 360) are formed between the upper mold 310 and the lower mold 310; wherein, the bottom of the lead pin 221 and the distal end of the extension portion of the lead pin 221 extending from the connection between the lead pin 221 and the second arm 1122 toward the outside of the element 110 are exposed outside the injection cavity (330, 340, 350, 360).

[0048] S5, electroplating the lead frame 220 after injection molding;

[0049] Specifically, the lead frame 220 and the connection terminals 112 of the elements 110 on the lead frame 220 are plated with tin.

[0050] S6, cutting the lead pins 221 to obtain a plurality of SMD solid-state plastic-encapsulated capacitors 100.

[0051] Specifically, the distal end of the extension portion of the lead pin 221 extending from the connection between the lead pin 221 and the second arm 1122 toward the outside of the element 110 is cut by a wire cutting or shearing machine.

[0052] Furthermore, the second arm 1122 of the L-shaped connection terminal 112 is parallel to the core package 111 of the element 110 .

[0053] Furthermore, the injection mold 300 includes an upper mold 310 and a lower mold 320, and the mold cavity is provided with two lead pin positioning grooves 360, a second injection molding area 350, a first injection molding area 340 and an injection hole 330 from bottom to top; the injection material wraps the element 110 and the lead pin 221. Among them, the first injection molding area 340 is used to wrap the core package 111 of the element 110, and the second injection molding area 350 is used to wrap the L-shaped connection terminal 112 and the lead pin 221; the lead pin positioning groove 360 ​​is set at the bottom of the second injection molding area 350 to fix the lead pin 221, and the injection hole 330 is set at the top of the first injection molding area 340 for injection molding.

[0054] Furthermore, the second injection molding area 350 is a rectangular parallelepiped structure, and the two adjacent corners of the second injection molding area 350 are provided with positive and negative electrode marks 1221, and the first injection molding area 340 is a cylindrical structure. The core package 111 is formed by burning an anode foil (not shown in the figure) and a cathode foil (not shown in the figure) with an electrolytic paper roll in between, and is cylindrical. The first injection molding area 340 that wraps the core package 111 is set to a cylindrical shape so that it can be wrapped with as little injection molding material as possible. The lead pin 221 is a rectangular parallelepiped structure, and the second injection molding area 350 that wraps the lead pin 221 is also set to a rectangular parallelepiped structure so that it can be wrapped with as little injection molding material as possible.

[0055] Furthermore, one end of the lead pin 221 connected to the lead frame 220 is outside the lead pin positioning groove 360. The second injection molding area 350 wraps the free end of the lead pin 221, and its fixed end is connected to the lead frame 220 and exposed outside the second injection molding area 350. The inner wall of the lead pin positioning groove 360 ​​is fitted with the outer wall of the lead pin 221 to form a closed cavity.

[0056] Furthermore, the lead frame 220 is a metal part. Specifically, the lead frame 220 is a copper part. Copper has good electrical conductivity.

[0057] Furthermore, the conductive glue is copper glue or silver glue. Both copper glue and silver glue have good conductivity. Specifically, in this embodiment, the conductive glue is copper glue. On the one hand, the lead pin 221 is a copper piece, and copper glue has better compatibility than silver glue. On the other hand, copper glue is lower in cost.

[0058] Furthermore, the injection molding material is a polymer, and the polymer is selected from one or more of alkyd resin, polyester resin, phenolic resin, amino resin, epoxy resin, and polyurethane resin. Alkyd resin, polyester resin, phenolic resin, amino resin, epoxy resin, and polyurethane resin all have good wear resistance, corrosion resistance, and insulation, and the above materials are common plastic raw materials and are easy to obtain during the production process.

[0059] Please attach Figure 6 and attached Figure 7 The present application also provides a lead frame 220 for manufacturing a SMD solid-state plastic-encapsulated capacitor, comprising:

[0060] Frame body 210;

[0061] A plurality of lead units 220 are arranged in an array on the frame body 210, each lead unit 220 includes a pair of lead pins 221 arranged at intervals and at least one hollow portion 222, each lead pin 221 includes a root portion 2211 and a pin portion 2212 extending from the root portion in the length direction of the lead pin 221, the lead pin 221 is connected to the frame body 210 via the root portion 2211, and the hollow portion 222 surrounds the pin portion 2212 so that the pin portion 2212 can be detachably arranged from the frame body 210.

[0062] Furthermore, the hollow portion 222 is a rectangular hole and is distributed on two opposite sides of the lead pin 221. The roots of the two lead pins 221 are respectively connected to the two oppositely arranged side walls of the rectangular hole, and the ends of the pin portions 2212 of the two lead pins 221 in each lead unit 220 are arranged oppositely in the length direction of the lead pin 221. The hollow portions 222 distributed on the opposite sides of the lead pin 221 are connected to the gap between the lead pins 221, and together form an "I"-shaped hole that penetrates the frame body 210. It can be understood that the shape of the hollow portion 222 is not limited to the rectangular hole given in this embodiment, and can also be in the form of a pinhole, etc., as long as the pin portion 2212 can be separated from the frame body 210. And the arrangement of the hollow portion 222 can also be in the form of three-sided surrounding, four-sided surrounding, etc.

[0063] Preferably, the ends of the pin portions 2212 of a pair of lead pins 221 are arranged opposite, adjacent or staggered along the length direction. The lead portions 2212 of the lead pins 221 have different arrangements according to different requirements of the capacitor 100. Specifically, in this embodiment, the ends of the pin portions 2212 of a pair of lead pins 221 are arranged opposite to each other along the length direction.

[0064] Specifically, the lead units 220 are arranged in a rectangular array. It is understandable that the arrangement of the lead units 220 is not limited to the rectangular array given in this embodiment, and the lead units 220 can be arranged in a circular array, a rectangular array, etc. In this embodiment, the most common rectangular array arrangement is adopted, which not only has a low manufacturing cost, but also facilitates the cutting of the lead pins 221.

[0065] Specifically, the lead pin 221 is a rectangular parallelepiped structure. The lead pin 221 is used to place the element 110, and the element 110 is connected to the lead pin 221 through the second arm 1122 of the connecting terminal 112. The lead pin 221 of the rectangular parallelepiped structure can fit the L-shaped connecting terminal 112 with the largest area.

[0066] Preferably, the lead pins 221 and the frame body 210 are arranged on the same plane. The lead frame 220 and the lead pins 221 are manufactured as one piece during the manufacturing process and are directly cast. The lead pins 221 and the frame body 210 are arranged on the same plane to facilitate the manufacture of the lead frame 220 and reduce production costs.

[0067] Preferably, the lead frame 220 is a metal piece. Specifically, the lead frame 220 is a copper piece. Copper has good electrical conductivity.

[0068] The present invention further provides a SMD solid-state plastic-sealed capacitor. Preferably, the SMD solid-state plastic-sealed capacitor is prepared by the manufacturing method of the SMD solid-state plastic-sealed capacitor described above; the SMD solid-state plastic-sealed capacitor comprises:

[0069] The element 110 includes a core package 111 and an L-shaped connecting terminal 112. The core package 111 includes an anode foil (not shown in the figure), a cathode foil (not shown in the figure) and an electrolytic paper (not shown in the figure). The anode foil (not shown in the figure) and the cathode foil (not shown in the figure) are interposed with an electrolytic paper (not shown in the figure) to form the core package 111. The anode foil (not shown in the figure) and the cathode foil (not shown in the figure) are respectively connected to the first arm 1121 of the L-shaped connecting terminal 112.

[0070] Two lead pins 221, the two lead pins 221 are respectively connected to the second arm 1122 of the connection terminal 112 through conductive glue;

[0071] The plastic package 120 encapsulates the element 110 and the lead pins 221 by injection molding. The plastic package 120 is made of resin material. The bottom and free end of the lead pins 221 are exposed outside the plastic package 120 .

[0072] The second arm 1122 of the L-shaped connecting terminal 112 is parallel to the core package 111 of the element 110 .

[0073] Furthermore, the plastic package body 120 includes a cylindrical body 121 and a square seat body 122, the cylindrical body 121 wraps the core package 111 of the element 110, and the square seat body 122 wraps the L-shaped connection terminal 112 and the lead pin 221; the free ends of the lead pin 221 extend from two opposite sides of the square seat body 122. The structure of the plastic package body 120 is the inner cavity structure of the injection mold 300, which is naturally formed after injection molding and is not repeated here. The free ends of the lead pin 221 extend from two opposite sides of the square seat body 122, which facilitates the cutting of the lead pin 221, so that the capacitor 100 is removed from the lead frame 220 to form an independent product.

[0074] Preferably, the lead pin 211 is formed by cutting a lead frame 220 connected to the element 110. Specifically, the distal end of the extension of the lead pin 221 extending from the connection between the lead pin 221 and the second arm 1122 toward the outside of the element 110 is cut by a wire cutter or shearing machine.

[0075] Specifically, positive and negative pole marks 1221 are formed at two corners on the side where one of the lead pins 221 is located. The arrangement of the positive and negative pole marks 1221 facilitates the identification of the positive and negative poles of the capacitor 100 during use. In this embodiment, the two corners on the side where the positive lead pin 221 is located are cut off to mark the positive pole, and the second injection molding area 350 with a corresponding structure is directly used in the manufacturing process for direct injection molding.

[0076] Preferably, the bottom surface of the lead pin 221 is flush with the bottom surface of the square base body 122 or extends beyond the bottom surface of the square base body 122. The square base is formed by the second injection molding area 350 of the injection mold 300 during the injection molding process. Since the lead pin 221 is connected to the frame body 210, the inner wall of the second injection molding area 350 is in contact with the other three surfaces of the lead pin 221 except the bottom surface. The bottom surface of the square base formed by the second injection molding area 350 is flush with the bottom surface of the lead pin 221 or slightly higher than the bottom surface of the lead pin 221.

[0077] Specifically, the length of the free end of the lead pin 221 extending from the side is 0.5-4 mm. The length of the free end of the lead pin 221 extending from the side is as short as possible while being easy to cut. In this embodiment, the length of the free end of the lead pin 221 extending from the side is 2 mm.

[0078] Furthermore, the conductive glue is copper glue or silver glue. Both copper glue and silver glue have good conductivity. Specifically, in this embodiment, the conductive glue is copper glue. On the one hand, the lead pin 221 is a copper piece, and copper glue has better compatibility than silver glue. On the other hand, copper glue is lower in cost.

[0079] Specifically, the anode foil (not shown in the figure) and the cathode foil (not shown in the figure) are both aluminum foil, which is a common electrode material of the capacitor 100 because of its good conductivity and low price.

[0080] Preferably, the resin material is one or more of alkyd resin, polyester resin, phenolic resin, amino resin, epoxy resin, and polyurethane resin. Alkyd resin, polyester resin, phenolic resin, amino resin, epoxy resin, and polyurethane resin all have good wear resistance, corrosion resistance, and insulation, and the above materials are common plastic raw materials and are easy to obtain during the production process.

[0081] The solution of the present application provides a layer of plastic package 120 for the SMD solid-state electrical appliance by injection molding, and the plastic package 120 encapsulates the element 110 and the lead pin 221, providing a higher strength protection for the solid-state capacitor, ensuring that the capacitor works normally under different harsh conditions, and increasing the service life of the capacitor. The problem of poor comprehensive performance and high production cost of the metal shell of the solid-state capacitor is avoided.

[0082] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A chip-type solid-state plastic-sealed capacitor, characterized in that: include: The element comprises a core package and two L-shaped connecting terminals. The core package comprises an anode foil, a cathode foil and electrolytic paper. The anode foil and the cathode foil are separated by the electrolytic paper roll to form the core package. The core package is cylindrical. The anode foil and the cathode foil are respectively connected to the first arm of the L-shaped connecting terminal. Two lead pins, the two lead pins are respectively connected to the second arm of the L-shaped connection terminal through conductive glue, and the pins are rectangular parallelepiped structures; A plastic package body is formed by wrapping the element and the lead pins by injection molding, wherein the plastic package body is made of resin material, and the bottom and free end of the lead pins are exposed outside the plastic package body; The plastic package body comprises a cylindrical core package and a square seat body, wherein the cylindrical body wraps the core package of the element, and the square seat body wraps the lead pins and the second arm of the L-shaped connecting terminal and the first arm extending outside the core package; the free ends of the lead pins extend from two oppositely disposed side surfaces of the square seat body respectively; The lead pins are formed by cutting from a lead frame connected to the element; The conductive glue is copper glue; Two corners of the side surface where one of the lead pins is located are formed with positive and negative pole marks; The bottom surface of the lead pin is flush with the bottom surface of the square base body or extends out from the bottom surface of the square base body.

2. The SMD solid-state plastic-sealed capacitor according to claim 1, characterized in that: The length of the free end of the lead pin extending from the side surface is 0.5-4 mm.

3. The SMD solid-state plastic-sealed capacitor according to claim 1, characterized in that: The anode foil and the cathode foil are both aluminum foils.

4. The SMD solid-state plastic-sealed capacitor according to claim 1, characterized in that: The second arm of the L-shaped connecting terminal is parallel to the body of the element.

5. The SMD solid-state plastic-sealed capacitor according to any one of claims 1 to 4, characterized in that: The resin material is one or more of epoxy resin, silicone resin and polytetrafluoroethylene.

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