CN118315197A

CN118315197A - Packaging structure of coiled solid electrolytic capacitor, mass production method thereof and intermediate assembly for mass production of packaging structure

Info

Publication number: CN118315197A
Application number: CN202311139478.8A
Authority: CN
Inventors: 钟宇鹏; 李家伟; 许文正; 陈恩明; 曹哲之
Original assignee: Zowie Technology Corp
Current assignee: Zowie Technology Corp
Priority date: 2023-01-09
Filing date: 2023-09-05
Publication date: 2024-07-09

Abstract

The invention discloses a packaging structure of a winding type solid electrolytic capacitor, a mass production method thereof and an intermediate assembly for mass production thereof. A wound capacitor core is surrounded by an insulating material and sandwiched between two protective substrates. The surface of the protective substrate is provided with an anode conductive pad and a cathode conductive pad, and the two conductive pads are separated from each other and are not conducted. The central axis of the capacitor core is perpendicular to the two protection substrates. The anode lead and the cathode lead of the capacitor core are respectively electrically connected with the anode conductive pad and the cathode conductive pad. The anode conductive pad is in turn electrically connected to the anode external terminal, and the cathode conductive pad is also electrically connected to the cathode external terminal, thereby connecting the anode external terminal to the anode lead, and the cathode external terminal to the cathode lead. The method for electrically connecting the leads of the capacitor core and the conductive pads is divided into the steps of connecting the leads to the conductive pads through the through holes and directly connecting the leads to the conductive pads. In another configuration, the package structure uses only one protective substrate.

Description

Packaging structure of coiled solid electrolytic capacitor, mass production method thereof and intermediate assembly for mass production of packaging structure

Technical Field

The invention relates to a packaging structure and a packaging method of a capacitor core, in particular to a packaging structure and a packaging method of a winding type capacitor core.

Background

The existing packaging method of the coiled solid electrolytic capacitor has defects in terms of element size and shock resistance, and therefore has limitations in specific application fields. FIG. 1 shows a typical roll-to-roll type (or wound-to-type) solid electrolytic capacitor core manufactured with existing commercial equipment and parts. Of these, 10F and 10G are the most typical types. A typical wound (winding type) solid electrolytic capacitor core includes a cylindrical capacitor core body 13, an anode lead 11 and a cathode lead 12. The capacitor core body is cylindrical by winding (rolling into) an etched (etched) aluminum foil tape together with a spacer layer (SPACER LAYER), followed by filling with a polymer-based solid electrolyte. The leads are typically three-segment structures of three material compositions: the root section (11D, 12D) is an aluminum sheet (tab) or wire directly welded to an anode or cathode aluminum foil strip in the capacitor core body, the end section (11 DC, 12 DC) is a copper-clad steel core lead, and the connection section (11W, 12W) welds the root section and the end section to each other. For ease of illustration, this is referred to as a standard lead (STANDARD LEAD). Alternatively, a capacitor core using only aluminum wires as leads can be obtained, as shown by 11D and 12D in the medium states 10D and 10E in fig. 1. The two leads of the patterns 10F and 10D are at the same end of the body, while the leads of the patterns 10G and 10E are at the two ends of the body, respectively. The existing packaging method of the coiled solid electrolytic capacitor is to use a can-type aluminum housing to accommodate the capacitor core body and seal the capacitor core body at one end or both ends in a manner that the aluminum housing clamps (clamped) a sealing material (such as plastic or rubber). The existing packaging methods involve multiple separate parts that must be manufactured separately on special machines and usually must be performed one by one, failing to be manufactured in parallel (parallel processing). In many packaged capacitors, the encapsulant occupies a substantial portion of the total volume of the device. In addition, the can-type package forms the capacitor core to be supported by aluminum leads at one or both ends, and the core body is free of any mechanical support (MECHANICAL SUPPORT). Accordingly, in applications in the automotive and transportation industries, reliability problems can occur due to fatigue of aluminum lead materials caused by frequent vibration.

Because solid electrolytic capacitor cores are fragile, some common electronic packaging Cheng Hennan applications. Conventional encapsulation processes, such as transfer molding (molding compound), are high viscosity materials that flow under high pressure. In order to manufacture a thin insulating layer to reduce the element size, the spacing between the mold wall and the capacitor core needs to be reduced, resulting in an increase in the viscous stress to which the capacitor core is subjected while the flow rate is to be kept the same. Compression molding (compression molding) can reduce the pressure flow but does not eliminate it entirely. The sheet molding compound press forming process (sheet molding compound) involves high pressures. Accordingly, an improved packaging structure and method would be beneficial.

Disclosure of Invention

A package structure for a roll-type or wound-type aluminum conductive polymer capacitor core (aluminum conductive polymer capacitor element) is described. A wound capacitor core is surrounded by an insulating material and sandwiched between two protective substrates. The surface of the protective substrate is provided with an anode conductive pad and a cathode conductive pad, and the two conductive pads are separated from each other and are not conducted. The central axis of the capacitor core is perpendicular to the two protection substrates. The anode lead and the cathode lead of the capacitor core are electrically connected (ELECTRICALLY CONNECTION) to the anode conductive pad and the cathode conductive pad, respectively. The anode conductive pad is in turn electrically connected to the anode external terminal, and the cathode conductive pad is also electrically connected to the cathode external terminal, thereby connecting the anode external terminal to the anode lead, and the cathode external terminal to the cathode lead. The methods of electrically connecting the leads of the capacitor core and the conductive pads are roughly classified into two types: the leads are connected to the conductive pads via the vias and the leads are directly connected to the conductive pads.

The lead wire is connected with the conductive pad through the through hole, after the anode lead wire and the cathode lead wire of the capacitor core are cut down, the lead wire passes through the through hole (through holes) to the outer side of the protection substrate and is connected with and electrically connected (ELECTRICALLY CONNECTED) to the external terminals of the anode and the cathode on the outer surface of the protection substrate. For capacitor cores with only aluminum leads, the external terminals and the electrical connection (electric connection) from the terminals to the aluminum leads of the capacitor core are typically accomplished through a multi-step electroplating process that includes a zinc substitution (zinc substitution) step to enable the aluminum leads to be electroplated (RECEIVE PLATING). For capacitor cores with standard leads, i.e., with the typical three-material three-segment structure and copper-clad lead end segments described above, the electrical continuity between the leads and the external terminals is accomplished essentially by electroplating after soldering. The aluminum sheet portion (root section) in the lead is bent to rotate the connection section by about 90 degrees, which enables the body of the capacitor core to be close to the surface of the protection substrate or the package, thereby reducing the overall element size. The copper-clad portion (end section) of the lead is also bent to facilitate connection with an external terminal. The electrical continuity between the external terminals and the copper-clad end sections from the terminals to the capacitor core leads is accomplished substantially by soldering, surface treatment and plating.

The filling of the insulating material may be performed by a capillary filling process (CAPILLARY FILLING process) or a simple back-flow process (pouring and flooding process). Low to medium viscosity liquid insulating materials are typically used and low flow rates are maintained so as not to damage the capacitor core. After filling, the insulating material hardens during the curing process and bonds the assembly (bond) into one piece.

The method for directly connecting the lead with the conductive pad can be welding, silver or copper glue, resistance welding, ultrasonic welding, wire bonding and other methods.

In one configuration, the anode and cathode leads are bent approximately 90 degrees to reduce the distance between the capacitor core and the protective substrate.

In another configuration, the anode lead and the cathode lead are bent approximately 90 degrees to be directed to both sides of the package structure. The external terminals are arranged on both sides of the package structure and are positioned on the surface of the insulating material.

In yet another configuration, the package structure uses only one protective substrate.

Further, an embodiment of the present invention discloses a packaging structure of a coiled solid electrolytic capacitor, which is characterized in that the packaging structure of the coiled solid electrolytic capacitor includes: the two protection substrates comprise a lower substrate and an upper substrate, wherein the substrate is provided with an anode conductive pad and a cathode conductive pad at preset positions on the surface of the substrate, and the two conductive pads are not conductive; a winding type solid electrolytic capacitor core having a winding axis perpendicular to the protective substrate and disposed between the upper and lower substrates, the capacitor core including an anode lead electrically connected to the anode conductive pad and a cathode lead electrically connected to the cathode conductive pad; an insulating material filling the space between the substrates and surrounding the capacitor core, such that the protective substrate, the capacitor core, and the insulating material form an integrated solid; an anode external terminal plated on the anode conductive pad and a cathode external terminal plated on the cathode conductive pad, wherein the anode external terminal is electrically connected with the anode conductive pad in a conductive manner, and the cathode external terminal is electrically connected with the cathode conductive pad in a conductive manner.

Preferably, the anode conductive pad includes a through hole passing through the protective substrate, and the cathode conductive pad also includes a through hole passing through the protective substrate; the anode lead passes through the through hole on the anode conductive pad, and the cathode lead also passes through the through hole on the cathode conductive pad.

Preferably, the external terminals are copper plated, the anode lead and the cathode lead are aluminum leads, and the leads are electrically connected to the corresponding external terminals through an internal nickel layer.

Preferably, the protection substrate further comprises an anode internal conductive pad and a cathode internal conductive pad, and the through holes are copper plated through holes respectively connected with the anode and cathode conductive pads and the internal conductive pad; the anode lead and the cathode lead are standard leads with copper-coated tail end sections, and the copper-coated tail end sections of the leads are electrically connected with the corresponding conductive pads through a solder; the external terminals are copper plated on the conductive pad and the solder.

Preferably, the anode lead and the cathode lead are bent to reduce a distance between the capacitor core and the protective substrate.

Preferably, the protective substrate is an all-conductor substrate including a thin copper sheet, and the conductive pad is a portion that separates the Bao Tongpian into mutual non-conduction by selective etching.

Preferably, the package structure further comprises at least one accompanying element located within the same package.

Preferably, the package structure, the accompanying element is another capacitor for voltage regulation application purposes.

Preferably, the protective substrate further comprises an anode internal conductive pad and a cathode internal conductive pad; the anode lead and the cathode lead are bent to reduce a distance between the capacitor core and the protective substrate.

Preferably, the anode lead and the cathode lead are standard leads having copper-clad end segments electrically connected to the corresponding anode inner conductive pad and cathode inner conductive pad by a solder.

Preferably, the anode internal conductive pad is in electrical conductive connection with the anode conductive pad with a copper plated through hole, and the cathode internal conductive pad is in electrical conductive connection with the cathode conductive pad with a copper plated through hole.

Preferably, the anode lead and the cathode lead are aluminum leads.

Preferably, the aluminum lead is electrically connected to the corresponding anode inner conductive pad and the corresponding cathode inner conductive pad by using a wire bonding process, the anode inner conductive pad is electrically connected to the anode conductive pad by a copper plated through hole, and the cathode inner conductive pad is electrically connected to the cathode conductive pad by a copper plated through hole.

Preferably, the aluminum lead is electrically connected to the corresponding anode inner conductive pad and the cathode inner conductive pad by using conductive paste, the anode inner conductive pad is also electrically connected to the anode conductive pad by using conductive paste, and the cathode inner conductive pad is also electrically connected to the cathode conductive pad by using conductive paste.

Preferably, the aluminum leads are electrically connected to the external terminals through an internal nickel layer on the side surface of the package structure.

In addition, the embodiment of the invention also discloses a mass production method of the packaging structure of the coiled solid electrolytic capacitor, which is characterized by comprising the following steps of: (a) Providing a first substrate as an upper substrate, wherein the surface of the first substrate comprises a plurality of conductive pads and a plurality of through holes at preset positions; (b) Arranging a plurality of winding type solid electrolytic capacitor cores on the lower surface of the upper substrate, wherein electrode leads of the capacitor cores penetrate through the through holes; (c) Providing a second substrate as a lower substrate, clamping the plurality of capacitor cores between the lower substrate and the upper substrate, filling a liquid insulating material in a space between the two substrates, and hardening the insulating material to combine the upper substrate, the lower substrate and the plurality of capacitor cores into an integrated structure; (d) Copper is plated on the plurality of conductive pads to form a plurality of external terminals, and the electrode leads connecting the plurality of external terminals to the plurality of capacitor cores are electrically conducted.

Preferably, the electrically conductive connection of the plurality of external terminals and the electrode leads adopts aluminum wires as the electrode leads, and a nickel layer is plated at the tips of the aluminum wires by a zinc substitution process, and then copper is plated to the external terminals.

Preferably, the electrically conductive connection of the plurality of external terminals and the electrode leads includes: copper is plated on the plurality of through holes to form a plurality of copper plated through holes; taking a lead with a copper-coated end section as the electrode lead; the copper-clad end sections of the electrode leads are soldered to the conductive pads and the copper plated through holes.

The embodiment of the invention also discloses a double-substrate intermediate assembly for the mass production of the packaging structure of the coiled solid electrolytic capacitor, namely a structure combined into a whole in the mass production method. The dual substrate intermediate assembly includes: an upper substrate, the surface of which comprises a plurality of conductive pads at predetermined positions; a plurality of winding type solid electrolytic capacitor cores are arranged on the lower surface of the upper substrate; a lower substrate clamping the plurality of capacitor cores between the lower substrate and the upper substrate, filling a liquid insulating material in a space between the two substrates, and hardening the insulating material to combine the upper substrate, the lower substrate and the plurality of capacitor cores into an integrated structure; copper is plated on the plurality of conductive pads to form a plurality of external terminals, and the electrode leads connecting the plurality of external terminals to the plurality of capacitor cores are electrically conducted.

In addition, the embodiment of the invention also discloses a mass production method of the packaging structure of the coiled solid electrolytic capacitor, which is characterized by comprising the following steps of: (a) Providing a substrate, wherein the surface of the substrate comprises a plurality of conductive pads at preset positions; (b) Setting a plurality of winding type solid electrolytic capacitor cores on the surface of the substrate; (c) Providing a mold having a grid structure separating the plurality of wound solid electrolytic capacitor cores into a plurality of independent compartments; (d) Filling a liquid insulating material in the plurality of independent compartments, hardening the insulating material, and taking out the die with the grid structure to combine the substrate, the insulating material and the plurality of capacitor cores into an integral structure comprising a plurality of independent packaging structures; (e) The unitary structure is cut to separate it into a plurality of individual elements.

Furthermore, the embodiment of the invention also discloses a packaging structure of the coiled solid electrolytic capacitor, which comprises: a protective substrate having an anode conductive pad and a cathode conductive pad at predetermined positions on a surface thereof, the two conductive pads being non-conductive with each other; a wound solid electrolytic capacitor core having a winding axis perpendicular to the protective substrate, the capacitor core comprising an anode lead electrically connected to the anode conductive pad and a cathode lead electrically connected to the cathode conductive pad; an insulating material surrounding the capacitor core such that the protective substrate, the capacitor core, and the insulating material form an integral solid; an anode external terminal plated on the anode conductive pad and a cathode external terminal plated on the cathode conductive pad, wherein the anode external terminal is electrically connected with the anode conductive pad in a conductive manner, and the cathode external terminal is electrically connected with the cathode conductive pad in a conductive manner.

Preferably, the anode lead and the cathode lead are aluminum leads.

Preferably, the through holes are copper plated through holes respectively connecting the anode and cathode conductive pads and the internal conductive pad; the anode lead and the cathode lead are standard leads with copper-coated tail end sections, and the copper-coated tail end sections of the leads are electrically connected with the corresponding conductive pads through a solder; the external terminals are copper plated on the conductive pad and the solder.

In addition, the embodiment of the invention also discloses a single-substrate intermediate assembly for mass production of the packaging structure of the coiled solid electrolytic capacitor, namely a structure combined into a whole in the mass production method. The single-substrate intermediate assembly includes: a protective substrate having a surface including a plurality of conductive pads at predetermined positions; a plurality of winding type solid electrolytic capacitor cores are arranged on the surface of the substrate; each winding type solid electrolytic capacitor core is divided and coated in a plurality of small independent packaging structures separated from each other by an insulating material; each winding type solid electrolytic capacitor core, the winding axis of which is perpendicular to the protective substrate, comprises an anode lead and a cathode lead, the anode lead is electrically connected with the anode conductive pad in a conductive way, and the cathode lead is electrically connected with the cathode conductive pad in a conductive way; an anode external terminal plated on the anode conductive pad and a cathode external terminal plated on the cathode conductive pad, wherein the anode external terminal is electrically connected with the anode conductive pad in a conductive manner, and the cathode external terminal is electrically connected with the cathode conductive pad in a conductive manner.

Drawings

FIG. 1 illustrates several conventional wound solid electrolytic capacitor cores fabricated with existing commercial equipment and parts.

FIGS. 2 (a), (b) and (c) show one of the package structure and the package process of the wound solid electrolytic capacitor core according to the present invention, wherein the aluminum leads are located at the same end of the capacitor core body.

Fig. 3 is a cross-sectional view of the package structure of fig. 2.

FIGS. 4 (a) and (b) show an exemplary package structure according to the present invention, which includes a coiled solid electrolytic capacitor core and a small capacitor.

Fig. 5 is a cross-sectional view of the package structure of fig. 4.

Fig. 6 (a) and (b) show the package of the wound solid electrolytic capacitor core with aluminum leads at both ends of the capacitor core body, respectively, according to the present invention.

Fig. 7 (a) and (b) illustrate a method of mass-producing (batch manufacturing) a plurality of capacitor elements according to the present invention.

Fig. 8 (a), (b), (c), (d) and (e) show one of the package structure and the package process of the wound solid electrolytic capacitor core according to the present invention, wherein the standard leads are located at the same end of the capacitor core body.

Fig. 9 is a cross-sectional view of the package structure of fig. 8.

Fig. 10 is a cross-sectional view of a package structure based on an all-conductor (all-conductor) protection substrate according to the present invention.

Fig. 11 shows a wound capacitor core with a plurality of leads bent approximately 90 degrees to point to both sides.

Fig. 12 (a), (b), (c) and (d) show another package structure of the wound solid electrolytic capacitor core and a corresponding package process according to the present invention, in which standard leads are bent approximately 90 degrees and electrically conductive connection is achieved by soldering.

FIG. 13 is a schematic diagram showing another package structure of a wound solid electrolytic capacitor core according to the present invention, in which the aluminum leads are bent by about 90 degrees and electrically connected by wire bonding.

FIG. 14 shows another package structure of a wound solid electrolytic capacitor core according to the present invention, in which the aluminum leads are bent approximately 90 degrees and electrically conductive connection is achieved by conductive paste.

FIG. 15 shows another package structure of a wound solid electrolytic capacitor core according to the present invention, in which aluminum leads are bent approximately 90 degrees and electrically connected to the surface of the package structure.

Fig. 16 shows a batch fabrication (batch manufacturing) of a plurality of capacitor elements according to the present invention, in which the insulating material on the protective substrate is divided into a plurality of individual packages.

Detailed Description

The details of the invention will be described by way of the following examples:

example 1

A wound capacitor core package with aluminum leads at the same end of the core body uses a protective substrate with conductive pads on the non-conductive surface.

Fig. 2 (a) is an exploded view of a package structure of a wound capacitor core in which an anode lead and a cathode lead are located at the same end, showing major components. The capacitor core 10D is interposed between the upper protective substrate 20U and the lower protective substrate 20L in such a manner that the substrates are vertically protected in an axial direction (axis). The leads on the capacitor core have been cut in advance so that the remaining anode lead 11D and cathode lead 12D are both aluminum wires. The upper protective substrate 20U is composed of an electrically insulating substrate body 21 and conductive pads (22A, 22C) on the outer surface thereof. Two through holes (28A, 28C) penetrate the substrate body and the conductive pads. When assembled, anode lead 11D passes through hole 28A and cathode lead 12D passes through hole 28C, as shown in the cross-sectional views of fig. 2 (b) and 3. When assembled, the capacitor core is fixed on the upper protective substrate by an adhesive 52. The lower protective substrate 20L has a metal pad 22T on the inner side thereof, which serves as an anti-moisture barrier (anti-moisture barrier) during packaging.

The protective substrate may be fabricated using a copper-clad printed circuit board (PCB copper clad board). Copper-clad printed circuit boards are typically made of an electrically insulating substrate body 21 made of glass fiber reinforced epoxy, and a copper-clad layer on one or both sides. The copper conductive pad may be made by printing a copper-clad layer through standard circuit board printing processes. The through-hole plating may also be performed by standard circuit board printing processes.

Fig. 2 (b) shows the assembled state of the main components. The space 60S between the two protective substrates surrounding the capacitor core is filled with an insulating material 60, as shown in the perspective view of the packaged capacitor core of fig. 2 (c). An insulating material fills the through holes and encapsulates the leads and the entire capacitor core as shown in the cross-sectional view of fig. 3. The protruding portions of the two leads on the upper surface are cut, and then a conductive material is coated or plated to form external terminals. The packaged capacitor core perspective view of fig. 2 (C) shows external terminals 40A (anode) and 40C (cathode) on top of insulator 42. The outer conductive pads (22A, 22C) are covered with an electroplated conductive material. This causes the external anode terminal 40A and cathode terminal 40C to conduct with the anode lead 11D and cathode lead 12D of the capacitor core.

The manner in which the external terminals are formed, and their electrical conductive connection (ELECTRICAL CONNECTION) to the conductive pads on the protective substrate, is further explained below. After the insulating material 60 is filled and cured, and before the external terminals 40A and 40C are plated, tips of the leads (11D, 12D) slightly protruding from the conductive pads (22A, 22C) are processed so that surfaces are flattened and tip surfaces (11 DA, 12 DA) of the leads are exposed. A layer of a first conductive material is then deposited (first conductive material) on the tip face. For example, a layer of nickel is deposited on the tip surface by a zinc substitution process zinc substitution process and an electroless nickel strike process NICKEL STRIKE. In this example, electroless nickel (electroless NICKEL STRIKE) typically does not plate onto the exposed surface of the electrically insulating substrate body 21 or the insulating material 60, nor onto the copper pads (22A, 22C), since copper is not catalytic for electroless nickel. Further, an electroless copper plating process electroless copper plating and an electrolytic plating process electrolytic plating are performed to increase the thickness to form the external terminals 40A and 40C. An appropriate shield (masks) is used during the process to protect the areas where non-conduction needs to be maintained. The zinc substitution process zinc substitution process (or zinc activation process zincate process) or zinc-nickel process (zinc-nickel process) is an electroplating process for electroplating overlay aluminum. An exemplary description of this process can be found in K.Murakami et al, "Effect of Zincate Treatment on Adhesion of Electroless Nickel-Phosphorus Coating for Commercial Pure Aluminum",Materials Transactions,Vol.47,No.10(2006)pp.2518-2523,, or S.Court, "Monitoring of zincate pre-treatment of aluminium prior to electroless nickel plating",Transactions of the Institute of Metal Finishing 95(2):97-105, which are incorporated herein by reference in their entirety.

Example 2

A wound capacitor core having the anode lead and the cathode lead at the same end, and an accompanying element.

It may be convenient in some applications to package one or more of the accompanying components and the wound capacitor core in the same package, i.e., after combining the two into a circuit.

For example, a power supply system for a circuit board may require a set of capacitors containing various capacitance specifications in order to stabilize the supply voltage at the power supply connections of the components. The main capacitor (bulk capacitors) including the power connection near the circuit board varies in size from a few microfarads to hundreds of microfarads, and the local filtering and bypass (bypass-pass) capacitors typically range in size from 0.01 to 0.1 microfarads. The conventional method is to assemble individual capacitors with different types and capacity specifications onto a circuit board one by one. For mass production of circuit boards, the combination of a plurality of capacitors is packaged in one package, so that the total occupied area (bootprint) and the assembly time can be reduced, and the circuit board is convenient. For example, aluminum solid state electrolytic capacitors (aluminum solid electrolytic capacitors) of hundreds of microfarads are commonly used in close proximity to power connectors along with tantalum capacitors of hundreds to tens of microfarads. While the local sites use smaller capacitors such as thin film or laminated ceramic capacitors (MLCCs). Thus, for a tighter layout design, the capacitors can be packaged together. Since aluminum solid electrolytic capacitors are the largest volume, it is reasonable to package a coiled aluminum solid electrolytic capacitor with one or more smaller capacitors.

Fig. 4 (a) shows an exemplary package structure explosion diagram including a wound solid electrolytic capacitor core 10D and a small capacitor 70. Wherein the winding type solid electrolytic capacitor package and the connection method and parts are substantially the same as in the case of fig. 2 (a). However, the upper substrate additionally adds the second set of external conductive pads 23C and 23A and the internal conductive pads 23CI and 23AI.20UL shows the inside configuration of the upper substrate at a lower viewing angle. The inner and outer conductive pads are conducted through via holes (vias) 29C and 29A, i.e., plated through holes (plated through holes). The small capacitors are electrically conductively connected from the inside to the second set of conductive pads through solder or conductive paste 54. The via and its connection to the small capacitor may be done in advance in a separate process. Next, after the parts are assembled, an insulating material is filled to wrap the two capacitors, as shown in fig. 4 (b). Fig. 5 is a cross-sectional view of fig. 4 (b) at section A-A, showing the connection of a small capacitor. Thus, the package contains two separate capacitors with separate external terminals (40C, 40A and 41C, 41A) plated on the respective conductive pads (22C, 22A and 23C, 23A). In use, the two capacitors can be used as separate two components and the external terminals connected to the power/ground planes/nodes of the circuit board as desired.

EXAMPLE 3

The wound capacitor core (10E) with anode and cathode leads at both ends is packaged.

The packaging structure and process is substantially similar to that of fig. 2, with the only difference being that via 28A, anode conductive pad 22A and terminal 40A will be located on upper substrate 20U, and via 29A and cathode conductive pad 22C and terminal 40C will be located on lower substrate 20L. Fig. 6 shows a capacitor packaged in this case. Fig. 6 (a) shows the anode face of the package, while fig. 6 (b) shows the cathode face. 28A and 28C indicate where the leads are connected to the terminals.

EXAMPLE 4

Batch fabrication using parallel fabrication (parallel processing).

One of the advantages of this new package structure and process is that a large number of capacitor cores can be mass-fabricated simultaneously by parallel fabrication. Although fig. 2-5 show the construction construction as a single package, the construction may be extended to a two-dimensional matrix. Fig. 7 (a) (b) depicts this concept. The protective substrate is initially two large full-size (20 UF, 20 LF) substrates and the pre-processing of the conductive pads and holes has been completed at corresponding locations on the plurality of components. Several capacitor cores are then placed (glued) to these locations and assembled onto the substrate.

The insulating material 60 may be filled together as a whole between two full-sized substrates. The filling of the insulating material may be performed by a capillary filling process (CAPILLARY FILLING process) or a simple back-flow process (pouring and flooding process). Low to medium viscosity insulating materials are typically used and low flow rates are maintained so as not to damage the capacitor core. After filling, the insulating material hardens during curing and bonds the components (bond) together into a single piece, forming a two-substrate intermediate assembly. The curing/hardening process inevitably causes uneven expansion and contraction between the insulating material and the protective substrate. By sandwiching the insulating material between the two protective substrates, bending deformation of the intermediate assembly after hardening can be minimized.

Plating (e.g., 40A, 40C) of all the external terminals of the element may also be performed simultaneously. Finally, cutting is performed along the cutting lines CLH and CLV, separating the individual (differential) elements.

EXAMPLE 5

A wound capacitor core (10F) package with standard leads at the same end of the capacitor core body uses a protective substrate with conductive pads on the non-conductive surface.

The extension of the standard lead is covered with a copper layer to facilitate connection with external terminals. Because it can be welded directly, no zinc substitution is required. Fig. 8 illustrates a package structure and flow. Fig. 8 (a) and 8 (b) illustrate the assembly process of the main parts. The process is similar to fig. 2 (a) and 2 (b) except that the leads of the capacitor core are bent or folded. The aluminum sheet portions (11D, 12D) (root sections) in the leads are bent so that the connection sections (11W, 12W) are rotated by 90 degrees. This allows the body of the capacitor core to be brought close to the protective substrate when assembled, thereby reducing the overall element size. The copper-clad portions (11 DC, 12 DC) (end sections) of the leads are also bent so as to be directed upward toward the corresponding holes in the protective substrate 20U. The bending of the leads may be accomplished prior to assembly with the protective substrate using a forming die prior to an independent separation process.

The protective substrate may be fabricated using a copper-clad printed circuit board (PCB copper clad board). In fig. 8 (b), the capacitor core is attached to the bottom surface of the upper protective substrate 20U, and its leads pass through two via holes (vias) or plated through holes (29A, 29C) (plated through-holes). The plated through holes (plated through-holes) connect the outer conductive pads (22A, 22C) and the inner conductive pads (22 AI, 22 CI) of the anode and cathode, respectively. In other words, the via interior surface, the top and bottom outsides, and the wire passing through the hole are all copper. A spot welder may be used to weld the leads to the conductive pads on the upper side of the upper substrate. With proper use of the flux, solder 55 can flow into the plated through holes and bond the leads to the through holes and conductive pads, as shown in fig. 8 (c).

The insulating material 60 is then filled and cured, hardening the assembly into a complete solid. And combining the upper substrate, the lower substrate, the insulating material and the plurality of capacitor cores into an integrated structure. The protruding leads are then cut and the residue is ground. Fig. 8 (d) depicts this concept. A layer of copper is then electroplated onto the copper pads (22A, 22C) and the solder 55 remaining on the copper pads to form external terminals (40A, 40C), as shown in fig. 8 (e). Fig. 9 shows a cross-sectional view of the completed structure.

High temperature solder is preferably used to ensure that the packaged capacitor external terminals do not melt during the reflow process.

EXAMPLE 6

A coiled capacitor core (10F) package with standard leads at the same end of the capacitor core body uses an all-conductor (all-conductor) to protect the substrate.

The protective substrate may also have only conductive substrates and pads (pads) without insulating substrate bodies (insulating substrate body). For example, the all-conductor substrate (all-conductor substrate) may be made of a thin copper sheet. Such packaging may further reduce the overall component thickness. Taking the construction of a Printed Circuit Board (PCB) as an example, a typical Printed Circuit Board (PCB) may comprise an insulating core material made of glass fiber reinforced epoxy resin having a thickness of 4 to 8 filament (or 0.1 to 0.2 mm), and 1 ounce, even half ounce, copper clad layers (coppers clad) covered on both sides thereof, which correspond to a thickness of 1.4 to 0.7 filament (or 0.035 to 0.018 mm). The total thickness of the two protective substrates, which are made of Printed Circuit Boards (PCBs), is about 0.27 to 0.54 mm. On the other hand, if a copper foil (copper foil) of 0.1 mm is used, the total thickness of the two substrates can be reduced to 0.2 mm. If only copper clad sheets (coppers CLAD SHEETS) are used, the total thickness of the two substrates can be further reduced to 0.035 to 0.07 mm.

Fig. 10 shows a cross-sectional view of a package structure based on an all-conductor (all-conductor) protection substrate. This structure is substantially similar to that of fig. 9, with the only difference that the copper-clad printed circuit board (PCB copper clad board) is replaced by an upper metal (copper) substrate 20UM and a lower copper substrate 20 LM. The through holes (28A, 28C) may be through holes (direct through holes). The packaging process is also similar to that of fig. 8, except that copper pads 22A and 22C are required to be made by an etching process after wire bonding and curing of the insulating material, and a gap 20G is provided to separate the two electrodes.

EXAMPLE 7

The standard leads are respectively located at the winding type capacitor core (10G) packages at both ends of the capacitor core body.

This example is similar to example 5 or example 6, except that the anode lead and the cathode lead are connected to external terminals on opposite sides of the package element, the upper substrate and the lower substrate, respectively. The final element looks similar to the element shown in fig. 6.

The invention disclosed herein has been described above with respect to a number of specific embodiments and a number of process steps. However, many modifications, variations and improvements may be made thereto by those skilled in the art without departing from the spirit and scope of the disclosure, which is set forth in the claims.

In another alternative, the anode and cathode leads are bent approximately 90 degrees so as to be directed to both sides of the package structure. These leads and their corresponding internal conductive pads form an electrically conductive connection therebetween. This can be accomplished by a number of methods:

Soldering, for example, between standard leads (which have copper-clad layers) and copper pads or copper-clad pads;

Silver paste or copper paste for any standard lead or aluminum lead;

resistance welding for either standard or aluminum leads;

ultrasonic welding for either standard or aluminum leads;

Wire bonding, which uses extra thin wires to connect the two ends to the leads and copper pads, respectively, is typically performed by ultrasonic welding.

The inner conductive pads and their corresponding outer conductive pads are electrically connected by plating through holes (plated through holes) or by coating around the edge of the substrate with conductive paste. Or if the full-conductor substrate is used, the corresponding inner conductive pad and outer conductive pad are the same conductive pad. By the above method, the electrical connection between the electrode lead and the external conductive pad is completed before filling the insulating material.

In fig. 11, a winding type capacitor core shown in fig. 10D2, in which a plurality of aluminum leads are bent approximately 90 degrees to be directed to both sides; 10F2, the plurality of standard leads of which are bent approximately 90 degrees to be directed to both sides.

Example 8: as shown in fig. 12.

The standard lead is bent approximately 90 degrees 10F2 and directed to the two-sided wound capacitor core package, which electrically connects the lead to the corresponding inner conductive pad by soldering.

Fig. 12 (a) shows that the capacitor core is first fixed to the upper protective substrate 20U by the adhesive 52. In the prefabricated substrate, the inner conductive pads and their corresponding outer conductive pads are electrically connected by plated through holes (29A, 29C), as shown in fig. 12 (C). These leads are then connected to the internal conductive pads (22 AI, 22 CI) by a soldering process and solder 55, as shown in fig. 12 (b). The insulating material 60 is then filled and cured, and a plurality of external terminals (40A, 40C) are made by an electroplating process, as shown in fig. 12 (d).

Example 9: as shown in fig. 13.

The aluminum leads are bent approximately 90 degrees 10D2 and directed to the two-sided wound capacitor core package, which electrically connects the leads to corresponding internal conductive pads by a wire bonding connection process.

This example is similar to example 8, the only difference being that a wire bonding process is used to connect the leads to the conductive pads. The wire bond connection is typically used to connect aluminum leads to copper pads, but it may also be used to connect copper clad leads to copper pads.

Example 10: as shown in fig. 14.

The leads are bent approximately 90 degrees 10D2 and directed to the two-sided wound capacitor core package, which is electrically connected to the leads to the corresponding internal conductive pads by means of conductive glue 56.

This example is similar to example 8, the only difference being that conductive glue is used to connect the leads to the conductive pads. When the substrate is fabricated with a copper-clad printed circuit board, a conductive paste can be applied to wrap around the edges of the board, thereby connecting the inner conductive pads (22 AI, 22 CI) and the outer conductive pads (22A, 22C). In this example, no plated through holes are required.

In another variant, the anode and cathode leads are bent approximately 90 degrees so as to be directed to both sides of the package structure, and the electrical connection between the leads and the external terminals is arranged on the surface of the filled insulating material on both sides of the package structure. The substrate is not fabricated or without any vias.

Example 11: as shown in fig. 15.

The electrical conductive connection of the external terminals (40A, 40C) of this example is located at the package structure side surface. The capacitor core 10D2 with aluminum leads is first fixed to the upper protective substrate 20U by the adhesive 52. The core is then filled with an insulating material 60. After the insulating material 60 is filled and hardened, the side surfaces of the above-described package structure are processed, thereby exposing and planarizing the tips of the electrode leads 11DA, 12 DA. Thereafter, a first conductive material is deposited on the tip surface of the aluminum material. For example, a nickel layer is deposited on the tip surface by performing a zinc substitution step followed by an electroless strike nickel process. Copper can then be electroplated to the nickel layer to make the external terminal. For example, 30C indicates the location where the cathode lead is connected to the cathode external terminal.

The package structure of the present invention may use only one protective substrate, as in the example shown in fig. 12 and 15. However, in a batch manufacturing process using a large substrate to carry multiple components, only one substrate is used on one side of the package structure, because shrinkage after curing of the insulating material may result in warpage of such a single substrate intermediate assembly (i.e., a unitary structure). Warpage can present difficulties in subsequent processes. For example, such an intermediate assembly needs to be very flat during the cutting or dicing (cutting into individual elements) process. Fig. 16 presents a solution to this problem. During filling or pouring of the insulating material, the insulating material 60 is divided into a plurality of individual compartments D1, D2 … D5 …, etc., each individual compartment containing a capacitor element. One way of achieving this is to use a mould with a grid structure to form the grooves GV, GH that delimit the individual compartments. For example, silicone resin (silicone) can be used to make the above-described mold having a lattice structure, and then the above-described mold can be placed in a liquid filled insulating material and baked together therewith. Because silicone typically does not adhere to the epoxy-based insulating material, the silicone mold is then removed after the insulating material is cured and hardened. Because the insulating material is divided to form a plurality of small individual packages separated from each other, the shrinkage effect is limited to the extent of each individual package, and deformation does not accumulate across the entire intermediate assembly. Thereafter, the intermediate assembly is cut along the grooves to separate it into a plurality of individual elements.

Claims

1. A package structure of a coiled solid electrolytic capacitor, characterized in that the package structure of the coiled solid electrolytic capacitor comprises:

The two protection substrates comprise a lower substrate and an upper substrate, wherein the substrate is provided with an anode conductive pad and a cathode conductive pad at preset positions on the surface of the substrate, and the two conductive pads are not conductive;

a winding type solid electrolytic capacitor core having a winding axis perpendicular to the protective substrate and disposed between the upper and lower substrates, the capacitor core including an anode lead electrically connected to the anode conductive pad and a cathode lead electrically connected to the cathode conductive pad;

an insulating material filling the space between the substrates and surrounding the capacitor core, such that the protective substrate, the capacitor core, and the insulating material form an integrated solid;

An anode external terminal plated on the anode conductive pad and a cathode external terminal plated on the cathode conductive pad, wherein the anode external terminal is electrically connected with the anode conductive pad in a conductive manner, and the cathode external terminal is electrically connected with the cathode conductive pad in a conductive manner.

2. The package structure of claim 1, wherein,

The anode conductive pad comprises a through hole penetrating through the protection substrate, and the cathode conductive pad also comprises a through hole penetrating through the protection substrate;

The anode lead passes through the through hole on the anode conductive pad, and the cathode lead also passes through the through hole on the cathode conductive pad.

3. The package structure of claim 2, wherein the external terminals are copper plated, the anode lead and the cathode lead are aluminum leads, and the leads are electrically connected to the corresponding external terminals by an internal nickel layer.

4. The package structure of claim 2, wherein,

The protection substrate further comprises an anode internal conductive pad and a cathode internal conductive pad, and the through holes are copper plated through holes respectively connected with the anode and cathode conductive pads and the internal conductive pad;

The anode lead and the cathode lead are standard leads with copper-coated tail end sections, and the copper-coated tail end sections of the leads are electrically connected with the corresponding conductive pads through a solder;

the external terminals are copper plated on the conductive pad and the solder.

5. The package structure of claim 4, wherein the anode lead and the cathode lead are bent to reduce a distance between the capacitor core and the protective substrate.

6. The package structure of claim 2, wherein the protective substrate is an all-conductor substrate comprising a thin copper sheet, and the conductive pad is a portion that separates the Bao Tongpian into the mutually non-conductive portions by selective etching.

7. The package structure of claim 2, further comprising at least one accompanying element within the same package.

8. The package of claim 7, wherein the accompanying component is another capacitor for voltage regulation applications.

9. The package structure of claim 1, wherein,

The protective substrate comprises an anode inner conductive pad and a cathode inner conductive pad;

The anode lead and the cathode lead are bent to reduce a distance between the capacitor core and the protective substrate.

10. The package structure of claim 9, wherein the anode lead and the cathode lead are standard leads having copper-clad end segments electrically connected to the corresponding anode inner conductive pad and cathode inner conductive pad by a solder.

11. The package structure of claim 10, wherein the anode inner conductive pad is in electrical conductive connection with the anode conductive pad with a copper plated via and the cathode inner conductive pad is in electrical conductive connection with the cathode conductive pad with a copper plated via.

12. The package structure of claim 10, wherein the protective substrate is an all-conductor substrate comprising a thin copper sheet and the conductive pad is a portion that separates the Bao Tongpian into the mutually non-conductive portions by selective etching.

13. The package structure of claim 9, wherein the anode lead and the cathode lead are aluminum leads.

14. The package structure of claim 13, wherein the aluminum leads are electrically connected to the corresponding anode inner conductive pads and cathode inner conductive pads using a wire bonding process, the anode inner conductive pads are electrically connected to the anode conductive pads with copper plated through holes, and the cathode inner conductive pads are electrically connected to the cathode conductive pads with copper plated through holes.

15. The package structure of claim 13, wherein the aluminum leads are electrically connected to the corresponding anode inner conductive pads and cathode inner conductive pads using conductive paste, the anode inner conductive pads are also electrically connected to the anode conductive pads with conductive paste, and the cathode inner conductive pads are also electrically connected to the cathode conductive pads with conductive paste.

16. The package structure of claim 13, wherein the aluminum leads are electrically connected to the external terminals on the side surfaces of the package structure by an internal nickel layer.

17. A mass production method of a package structure of a coiled solid electrolytic capacitor, characterized in that the mass production method of the package structure of the coiled solid electrolytic capacitor comprises the following steps:

(a) Providing a first substrate as an upper substrate, wherein the surface of the first substrate comprises a plurality of conductive pads and a plurality of through holes at preset positions;

(b) Arranging a plurality of winding type solid electrolytic capacitor cores on the lower surface of the upper substrate, wherein electrode leads of the capacitor cores penetrate through the through holes;

(c) Providing a second substrate as a lower substrate, clamping the plurality of capacitor cores between the lower substrate and the upper substrate, filling a liquid insulating material in a space between the two substrates, and hardening the insulating material to combine the upper substrate, the lower substrate and the plurality of capacitor cores into an integrated structure;

(d) Copper is plated on the plurality of conductive pads to form a plurality of external terminals, and the electrode leads connecting the plurality of external terminals to the plurality of capacitor cores are electrically conducted.

18. The method of claim 17, wherein the electrically conductive connection of the plurality of external terminals and the electrode leads is performed by using aluminum wires as the electrode leads, and plating nickel layer on tips of the aluminum wires and then copper plating the external terminals by a zinc substitution process.

19. The method of claim 17, wherein the electrically conductive connecting the plurality of external terminals with the electrode leads comprises:

copper is plated on the plurality of through holes to form a plurality of copper plated through holes;

taking a lead with a copper-coated end section as the electrode lead;

the copper-clad end sections of the electrode leads are soldered to the conductive pads and the copper plated through holes.

20. A mass production method of a package structure of a coiled solid electrolytic capacitor, characterized in that the mass production method of the package structure of the coiled solid electrolytic capacitor comprises the following steps:

(a) Providing a substrate, wherein the surface of the substrate comprises a plurality of conductive pads at preset positions;

(b) Setting a plurality of winding type solid electrolytic capacitor cores on the surface of the substrate;

(c) Providing a mold having a grid structure separating the plurality of wound solid electrolytic capacitor cores into a plurality of independent compartments;

(d) Filling a liquid insulating material in the plurality of independent compartments, hardening the insulating material, and taking out the die with the grid structure to combine the substrate, the insulating material and the plurality of capacitor cores into an integral structure comprising a plurality of independent packaging structures;

(e) The unitary structure is cut to separate it into a plurality of individual elements.

21. A package structure of a coiled solid electrolytic capacitor, characterized in that the package structure of the coiled solid electrolytic capacitor comprises:

A protective substrate having an anode conductive pad and a cathode conductive pad at predetermined positions on a surface thereof, the two conductive pads being non-conductive with each other;

A wound solid electrolytic capacitor core having a winding axis perpendicular to the protective substrate, the capacitor core comprising an anode lead electrically connected to the anode conductive pad and a cathode lead electrically connected to the cathode conductive pad;

An insulating material surrounding the capacitor core such that the protective substrate, the capacitor core, and the insulating material form an integral solid;

22. The package structure of claim 21, wherein,

23. The package structure of claim 22, wherein the anode lead and the cathode lead are standard leads having copper-clad end segments electrically connected to the corresponding anode inner conductive pad and cathode inner conductive pad by a solder.

24. The package structure of claim 23, wherein the anode inner conductive pad is in electrical conductive connection with the anode conductive pad with a copper plated via and the cathode inner conductive pad is in electrical conductive connection with the cathode conductive pad with a copper plated via.

25. The package structure of claim 23, wherein the protective substrate is an all-conductor substrate comprising a thin copper sheet and the conductive pad is a portion that separates the Bao Tongpian into the mutually non-conductive portions by selective etching.

26. The package structure of claim 22, wherein the anode lead and the cathode lead are aluminum leads.

27. The package structure of claim 26, wherein the aluminum leads are electrically connected to the corresponding anode inner conductive pads and cathode inner conductive pads using a wire bonding process, the anode inner conductive pads are electrically connected to the anode conductive pads with copper plated through holes, and the cathode inner conductive pads are electrically connected to the cathode conductive pads with copper plated through holes.

28. The package structure of claim 26, wherein the aluminum leads are electrically connected to the corresponding anode inner conductive pads and cathode inner conductive pads using conductive paste, the anode inner conductive pads are also electrically connected to the anode conductive pads with conductive paste, and the cathode inner conductive pads are also electrically connected to the cathode conductive pads with conductive paste.

29. The package structure of claim 26, wherein the aluminum leads are electrically connected to the external terminals on the side surfaces of the package structure by an internal nickel layer.

30. The package structure of claim 22, wherein,

31. The package structure of claim 30, wherein the external terminals are copper plated, the anode leads and the cathode leads are aluminum leads, and the leads are electrically connected to the corresponding external terminals by an internal nickel layer.

32. The package as claimed in claim 30, wherein,

The through holes are copper plated through holes respectively connected with the anode and cathode conductive pads and the internal conductive pad;

the external terminals are copper plated on the conductive pad and the solder.

33. A single-substrate intermediate assembly for mass production of packaging structures for coiled solid state electrolytic capacitors, the single-substrate intermediate assembly comprising:

a protective substrate having a surface including a plurality of conductive pads at predetermined positions;

A plurality of winding type solid electrolytic capacitor cores are arranged on the surface of the substrate;

Each winding type solid electrolytic capacitor core is divided and coated in a plurality of small independent packaging structures separated from each other by an insulating material;

Each winding type solid electrolytic capacitor core, the winding axis of which is perpendicular to the protective substrate, comprises an anode lead and a cathode lead, the anode lead is electrically connected with the anode conductive pad in a conductive way, and the cathode lead is electrically connected with the cathode conductive pad in a conductive way;

34. A dual substrate intermediate assembly for mass production of a package structure for a coiled solid state electrolytic capacitor, the dual substrate intermediate assembly comprising:

An upper substrate, the surface of which comprises a plurality of conductive pads at predetermined positions;

a plurality of winding type solid electrolytic capacitor cores are arranged on the lower surface of the upper substrate;

a lower substrate clamping the plurality of capacitor cores between the lower substrate and the upper substrate, filling a liquid insulating material in a space between the two substrates, and hardening the insulating material to combine the upper substrate, the lower substrate and the plurality of capacitor cores into an integrated structure;

Copper is plated on the plurality of conductive pads to form a plurality of external terminals, and the electrode leads connecting the plurality of external terminals to the plurality of capacitor cores are electrically conducted.