Low-inductance electrolyte capacitor

Abstract

A capacitor is provided that can exhibit good electrical characteristics under a wide range of conditions. The capacitor includes a capacitor element comprising a sintered porous anode body, a dielectric layer over the anode body, and a solid electrolyte layer over the dielectric and containing a conductive polymer. The capacitor also includes a plurality of anode lead portions extending from the ends of the capacitor element. The capacitor further comprises a housing that defines an internal cavity in which the capacitor element is positioned and sealed.

Description

[Technical Field]

[0001] [Related applications] This application claims priority to U.S. Provisional Patent Application No. 63 / 491551, filed March 22, 2023, which is incorporated herein by reference. The present invention relates to a low-inductance electrolyte capacitor. [Background technology]

[0002] Decoupling capacitors are often used to manage noise problems that arise in circuit applications. They provide a stable local charge source required for switching and refreshing logic gates used in various digital circuits. However, decoupling capacitors must now be able to function at lower voltages and higher currents, and to function at the levels required in diverse applications in current technology, such capacitors require performance characteristics such as lower equivalent series resistance (ESR), higher capacitance, and lower inductance (or ESL (Equivalent Series Inductance)) within them. In particular, as switching speeds increase in electronic circuit applications, the need to reduce inductance becomes a serious limitation regarding improved system performance. Solid electrolyte capacitors (e.g., tantalum capacitors) are typically manufactured by pressurizing metal powder (e.g., tantalum) around metal leads, sintering the pressurized portion, anodizing the sintered anode, and then adding a solid electrolyte. Conductive polymers are often used as solid electrolytes due to their preferred low equivalent series resistance and "non-flammable / non-igniting" failure mode (see, for example, Patent Documents 1-12 and Non-Patent Documents 1-3). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2014 / 199480 [Patent Document 2] U.S. Patent No. 4,960,471 Specification [Patent Document 3] U.S. Patent No. 6,197,252 Specification [Patent Document 4] U.S. Patent No. 5,111,327 Specification [Patent Document 5] U.S. Patent No. 6,635,729 Specification [Patent Document 6] U.S. Patent No. 9,718,905 Specification [Patent Document 7] U.S. Patent Application Publication No. 2007 / 0064376 Specification [Patent Document 8] U.S. Patent No. 6,674,635 [Patent Document 9] U.S. Patent Application Publication No. 2006 / 0038304 Specification [Patent Document 10] U.S. Patent Application Publication No. 2003 / 0105207 Specification [Patent Document 11] U.S. Patent Application Publication No. 2010 / 0234517 Specification [Patent Document 12] U.S. Patent No. 7,554,793 [Non-Patent Document]

[0004] [Non-Patent Document 1] ASTM E337-02, Method A (2007) [Non-Patent Document 2] Y. POZDEEV-FREEMAN, Y. ROZENBERG, A. GLADKIKH, M. KARPOVSKI, A. PALEVSKI; “Critical oxygen content in porous anodes of solid tantalum capacitors”, Journal of Materials Science: Materials in Electronics, Vol. 9, pp. 309-311 (1998) [Non-Patent Document 3] O.Stephan,P.Schottland,PY.L.Gall,C.Chevrot,C.Mariet,M.Carrier;“Electrochemical behavior of 3,4-ethylenedioxythiophene functionalized by a sulphonate group. Application to the preparation of poly(3,4-ethylenedioxythiophene) having permanent cation-exchange properties”,Journal of Electroanalytical Chemistry,Vol.443,Issue 2, pp.217-226(1998) [Overview of the project] [Problems that the invention aims to solve]

[0005] However, while solid electrolyte capacitors offer clear advantages in terms of ESR, they are unable to withstand high-frequency applications or exhibit the low inductance required for decoupling and high-speed switching. Therefore, there is currently a need for solid electrolyte capacitors with improved performance. [Means for solving the problem]

[0006] According to one embodiment of the present invention, a solid electrolyte capacitor is disclosed, comprising a capacitor element including a sintered anode body, a dielectric layer overlapping the anode body, and a solid electrolyte layer overlapping the dielectric, wherein the solid electrolyte includes a conductive polymer. The capacitor element defines opposing first and second ends, an upper surface, and an opposing lower surface. A first exposed anode lead portion extends laterally from the first end of the capacitor element, and a second exposed anode lead portion extends laterally from the second end of the capacitor element. The capacitor further includes a housing defining an internal cavity, within which the capacitor element is positioned and sealed, and the first and second exposed anode lead portions are positioned within the internal cavity. A first anode terminal is electrically connected to the first exposed anode lead portion, a second anode terminal is electrically connected to the second exposed anode lead portion, and a cathode terminal is electrically connected to the solid electrolyte.

[0007] Other features and embodiments of the present invention will be described in further detail below.

[0008] A complete and effective disclosure of the present invention, including the best mode of the invention, is described more specifically and in detail in the remainder of this specification with reference to the accompanying drawings, for those skilled in the art. [Brief explanation of the drawing]

[0009] [Figure 1A] This is a side view of one embodiment of an anode body that can be used to form the capacitor of the present invention. [Figure 1B] This is a side view of another embodiment of the anode body that can be used to form the capacitor of the present invention. [Figure 1C] This is a side view of yet another embodiment of the anode body, which may be used to form the capacitor of the present invention. [Figure 2] This is a cross-sectional view of one embodiment of the capacitor of the present invention. [Figure 3] Figure 2 is a bottom view of the capacitor. [Figure 4] Regarding Example 1, this is a graphical representation of the S11 and S21 parameters modeled and measured over a wide frequency range. [Figure 5] This is an exemplary equivalent circuit used in Example 1. [Modes for carrying out the invention]

[0010] This discussion is merely a description of exemplary embodiments and does not limit broader embodiments of the present invention. It will be understood by those skilled in the art that broader embodiments are embodied in this exemplary configuration.

[0011] In general, the present invention relates to a capacitor capable of exhibiting good electrical properties under a wide variety of conditions. The capacitor includes a capacitor element comprising a sintered porous anode body, a dielectric layer over the anode body, and a solid electrolyte layer over the dielectric and containing a conductive polymer. The capacitor element includes opposing first and second ends and opposing upper and lower surfaces. The capacitor also includes a plurality of anode lead portions extending from the ends of the capacitor element. The capacitor further includes a housing that defines an internal cavity in which the capacitor element is positioned and sealed.

[0012] Through selective control of the particular configuration, the resulting capacitor may exhibit low ESL values, e.g., about 1 nanohenry or less, in some embodiments about 750 picohrenry or less, in some embodiments about 350 picohrenry or less, in some embodiments about 1 femtohenry to about 100 picohrenry, and in some embodiments about 50 femtohenry to about 10 picohrenry. Low ESL values ​​may also be characterized by low impedance values ​​that reflect parasitic inductance. The impedance may be, for example, about 1 ohm or less, in some embodiments about 0.8 ohms or less, in some embodiments about 0.6 ohms or less, and in some embodiments about 1 milliohm to about 0.3 ohms. Such low ESL (e.g., impedance) may also exhibit broadband frequencies, e.g., 1 kHz to about 100 MHz, in some embodiments about 100 kHz to about 100 MHz, and in some embodiments about 1 MHz to about 100 MHz. Minimizing parasitic inductance across a wide frequency range can contribute to good performance, particularly good decoupling performance, especially under fast transient conditions. In addition to exhibiting low ESL values, the capacitor may also exhibit low ESR values, for example, about 800 milliohms or less, in some embodiments about 600 milliohms or less, in some embodiments about 500 milliohms or less, in some embodiments about 350 milliohms or less, in some embodiments about 0.01 milliohms to about 250 milliohms, and in some embodiments about 0.1 milliohms to about 150 milliohms, when measured at an operating frequency of 100 kHz and a temperature of 23°C.

[0013] In particular, low ESR and ESL values ​​can remain stable even at high temperatures and / or high humidity levels. The ability to perform under such conditions is achieved in part by enclosing and sealing the capacitor element within a housing to limit the amount of oxygen and moisture supplied to the solid electrolyte of the capacitor element. In this regard, the resulting capacitor may exhibit ESR and / or ESL values ​​within the above range even after being exposed for a considerable period of time as described above to temperatures of about 80°C or higher, in some embodiments about 85°C to about 180°C, in some embodiments about 85°C to about 150°C (e.g., about 85°C, 105°C, 125°C, or 150°C) and / or relative humidity levels of about 40% or higher, in some embodiments about 45% or higher, in some embodiments about 50% or higher, in some embodiments about 70% or higher (e.g., about 85% to 100%). The relative humidity may be determined, for example, according to ASTM E337-02, Method A (2007) (see Non-Patent Document 1 above). The period of exposure to high temperature and / or humidity levels may be about 100 hours or longer, and in some embodiments, about 150 hours to about 3000 hours, and in some embodiments, about 200 hours to about 2500 hours (e.g., 250, 500, 750, or 1000 hours). For example, the ESR of a capacitor after 500 hours of exposure to a high temperature (e.g., about 85°C) and / or a humidity level (e.g., about 85%) may be about 1500 milliohms or less, in some embodiments about 1000 milliohms or less, in some embodiments about 800 milliohms or less, in some embodiments about 600 milliohms or less, in some embodiments about 0.01 milliohms to about 500 milliohms, and in some embodiments about 0.1 milliohms to about 200 milliohms.Furthermore, the ratio of the ESR of the capacitor after 500 hours of exposure to a high temperature (e.g., about 85°C) and / or humidity level (e.g., about 85%) to the capacitor's initial DCL (e.g., at about 23°C) may be about 10 or less, in some embodiments about 5 or less, in some embodiments about 3 or less, in some embodiments about 2 or less, and in some embodiments about 0.9 to about 1.5.

[0014] Due to its ability to provide a combination of low ESL and ESR values, the resulting capacitor may be uniquely positioned to provide robust broadband decoupling and high-speed switching. For example, a single capacitor according to the present invention may be used to replace multiple downcapacitance or limited-frequency decoupling capacitors, making the capacitor usable in confined spaces such as having a smaller height, further improving miniaturization.

[0015] A capacitor may exhibit excellent DC power filtering, as exemplified by excellent attenuation over a wide frequency range. As is known in the art, insertion loss measures power transmission between terminals, with gain indicating an increase in power and attenuation indicating a decrease in power across terminals. Therefore, a capacitor may exhibit high attenuation over a wide frequency range, ensuring that a wide frequency range is adequately filtered. For example, a capacitor may exhibit approximate attenuation (S) of about 15 dB or greater, about 25 dB or greater in some embodiments, about 30 dB or greater in some embodiments, about 35 dB to about 70 dB in some embodiments, and about 50 dB to about 70 dB in some embodiments. 21 The parameters may be shown. Such attenuation may be shown over a wide frequency band. For example, at low frequencies ranging from about 0.1 MHz to about 500 MHz, and in some cases from about 1 MHz to about 100 MHz, the capacitor exhibits attenuation (S) of about 40 dB or more, about 50 dB or more in some embodiments, about 55 dB or more in some embodiments, and about 60 dB to about 70 dB in some embodiments. 21The parameters may also be shown. Furthermore, at high frequencies ranging from about 500 MHz to about 10 GHz, and in some cases from about 1 GHz to about 5 GHz, the capacitor exhibits attenuation of about 20 dB or more, about 25 dB or more in some embodiments, about 30 dB or more in some embodiments, and about 30 dB to about 60 dB in some embodiments (S 21 The parameters may be shown. In particular, such attenuation makes it easy to use the capacitor in applications of DC power filtering. Furthermore, the capacitor can function consistently over a wide range of temperatures. For example, in one embodiment, the capacitor may vary by about 5 dB or less over a wide temperature range, for example, at temperatures of about 25°C or higher, in some embodiments about 50°C or higher, and in some embodiments about 70°C or higher.

[0016] Capacitors can exhibit other beneficial electrical properties. For example, capacitors can exhibit low leakage current (“DCL”) over a wide variety of conditions. Further, after being subjected to an applied voltage (e.g., 16 volts) at a temperature of about 23° C. for a period of time (e.g., from about 30 minutes to about 20 hours, in some embodiments from about 1 hour to about 18 hours, in some embodiments from about 4 hours to about 16 hours), the capacitor can exhibit a DCL of about 10 microamperes (“μA”) or less, in some embodiments about 5 μA or less, in some embodiments about 1 μA or less, in some embodiments from about 0.01 μA to about 5 μA. In one embodiment, the DCL of the capacitor after being exposed to a high temperature (e.g., about 85° C.) and / or humidity level (e.g., about 85%) for 500 hours can be about 10 μA or less, in some embodiments about 8 μA or less, in some embodiments about 6 μA or less, in some embodiments from about 0.1 μA to about 5 μA. Also, the ratio of the DCL of the capacitor after being exposed to a high temperature (e.g., about 85° C.) and / or humidity level (e.g., about 85%) for 500 hours to the initial DCL of the capacitor (e.g., at about 23° C.) can be about 20 or less, in some embodiments about 15 or less, in some embodiments about 10 or less, in some embodiments about 5 or less, in some embodiments from about 0.9 to about 4. The capacitor, when measured at a frequency of 120 Hz and a temperature of 23° C., can be about 30 nanofarads per square centimeter (“nF / cm 2 ”) or greater, in some embodiments about 100 nF / cm 2 or greater, in some embodiments about 200 nF / cm 2 to about 3000 nF / cm 2 in some embodiments about 400 nF / cm 2 to about 2000 nF / cm 2The dry capacitance may be shown. The actual capacitance may vary, for example, within the range of about 10 μF to about 1000 μF, in some embodiments from about 50 μF to about 500 μF, and in some embodiments from about 60 μF to about 250 μF. Similar to the DCL and ESR values, the capacitance can remain stable within the above-described high temperature and / or humidity level ranges. In one embodiment, for example, the ratio of the capacitance value of the capacitor after being exposed to a high temperature (e.g., about 85°C) and / or humidity level (e.g., about 85%) for 500 hours to the initial capacitance value of the capacitor (e.g., at about 23°C) is about 3.0 or less, in some embodiments about 2.0 or less, in some embodiments about 1.8 or less, in some embodiments about 1.6 or less, and in some embodiments may be from about 0.9 to about 1.3.

[0017] It is also conceivable that the dissipation factor of the capacitor can be maintained at a relatively low level. The dissipation factor generally refers to the losses occurring in the capacitor and is usually expressed as a percentage of the ideal capacitor performance. For example, if the dissipation factor of the capacitor is determined at a frequency of 120 Hz, it is typically about 250% or less, in some embodiments about 200% or less, and in some embodiments from about 1% to about 180%.

[0018] Next, various embodiments of the present invention will be described in more detail.

[0019] [I. Capacitor Element] [A. Anode Body] The anode body is formed from a powder containing valve metal (i.e., an oxidizable metal) or valve metal-based compounds, such as tantalum, niobium, aluminum, hafnium, titanium, their alloys, their oxides, their nitrides, etc. The specific charge of the powder typically ranges from about 5,000 to about 800,000 microfarad-volts per gram ("μF·V / g"), depending on the desired application. For example, in certain embodiments, high-charge powders with specific charge values ​​of about 100,000 μF·V / g to about 600,000 μF·V / g may be used, in some embodiments about 120,000 μF·V / g to about 500,000 μF·V / g, and in some embodiments about 150,000 μF·V / g to about 400,000 μF·V / g may be used. In other embodiments, low-charge powders having a charge-to-specific ratio of about 5,000 μF·V / g to about 100,000 μF·V / g, in some embodiments about 8,000 to about 90,000 μF·V / g, and in some embodiments about 10,000 μF·V / g to about 80,000 μF·V / g may be used. As is known in the art, the charge-to-specific ratio can be determined by multiplying the capacitance by the anodizing voltage used, and then dividing this product by the mass of the anodizing electrode body.

[0020] In one embodiment, for example, the powder is formed from tantalum. Optionally, a reduction process may be used in which a tantalum salt (e.g., potassium fluorotantalate (K2TaF7), sodium fluorotantalate (Na2TaF7), tantalum pentachloride (TaCl5), etc.) is reacted with a reducing agent. The reducing agent may be provided in the form of a liquid, a gas (e.g., hydrogen), or a solid, metal alloy, or metal salt, such as a metal (e.g., sodium). In one embodiment, for example, a tantalum salt (e.g., TaCl5) may be heated to a temperature of about 900°C to about 2000°C, in some embodiments about 1000°C to about 1800°C, and in some embodiments about 1100°C to about 1600°C to form a vapor that can be reduced in the presence of a gaseous reducing agent (e.g., hydrogen). Further details of such a reduction reaction can be described in the aforementioned Patent Document 1. After reduction, the product may be cooled, crushed, and washed to form a powder.

[0021] The powder may be a finely flowing powder containing primary particles. The primary particles of the powder generally have a median diameter (D50) of about 5 to about 250 nanometers, in some embodiments about 10 to about 200 nanometers, and in some embodiments about 20 to about 150 nanometers, determined by using a laser particle size distribution analyzer (e.g., LS-230) manufactured by BECKMAN COULTER, for example, after subjecting the particles to ultrasonic vibration for 70 seconds, if necessary. The primary particles typically have a three-dimensional granular shape (e.g., nodular or angular). Such particles typically have a relatively low "aspect ratio," which is the average diameter or width of the particle divided by the average thickness ("D / T"). For example, the aspect ratio of the particles may be about 4 or less, in some embodiments about 3 or less, and in some embodiments about 1 to about 2. In addition to primary particles, the powder may contain other types of particles, such as secondary particles formed by the agglomeration (or aggregation) of primary particles. Such secondary particles may have a median diameter (D50) of about 1 micrometer to about 500 micrometers, and in some embodiments, about 10 micrometers to about 250 micrometers.

[0022] Particle aggregation can occur by heating the particles and / or through the use of a binder. For example, aggregation can occur at temperatures from about 0°C to about 40°C, in some embodiments from about 5°C to about 35°C, and in some embodiments from about 15°C to about 30°C. Suitable binders include, for example, poly(vinyl butyral); poly(vinyl acetate); poly(vinyl alcohol); poly(vinylpyrrolidone); cellulose polymers such as carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, and methylhydroxyethylcellulose; atactic polypropylene, polyethylene; polyethylene glycol (e.g., Carbowax from Dow Chemical); polystyrene, poly(butadiene / styrene); polyamides, polyimides, and polyacrylamides, high molecular weight polyethers; copolymers of ethylene oxide and propylene oxide; fluoropolymers such as polytetrafluoroethylene, polyvinylidene fluoride, and fluoroolefin copolymers; acrylic polymers such as sodium polyacrylate, poly(lower alkyl acrylate), poly(lower alkyl methacrylate), and copolymers of lower alkyl acrylate and methacrylate; and fatty acids and waxes such as stearic acid and other soapy fatty acids, plant waxes, and microwaxes (purified paraffin). If desired, the powder may also be doped with a sintering retarder, such as an aqueous acid (e.g., phosphoric acid), in the presence of a dopant. The amount of dopant added depends in part on the surface area of ​​the powder, but is typically present in amounts of about 200 parts per million ("ppm") or less. The dopant may be added before, during, and / or after agglomeration. The powder may be subjected to one or more deoxidation treatments. For example, the powder may be exposed to a getter material (e.g., magnesium) as described in Patent Document 2 above. The temperature at which deoxidation of the powder occurs may vary, but is typically from about 700°C to about 1600°C, in some embodiments from about 750°C to about 1200°C, and in some embodiments from about 800°C to about 1000°C. The total time for the deoxidation treatment may range from about 20 minutes to about 3 hours.

[0023] The resulting powder has certain characteristics that enhance its ability to form on the capacitor anode. For example, the powder is typically about 0.5 m 2 From / g to approximately 10.0m 2 / g, approximately 0.7m in some embodiments 2 From / g to approximately 5.0m 2 / g, approximately 2.0m in some embodiments 2 From / g to approximately 4.0m 2 It has a specific surface area of ​​0.1 g / cm³. The bulk density of the powder is approximately 0.1 grams per cubic centimeter (g / cm³). 3 ) approximately 0.8 grams (g / cm³) 3 ), in some embodiments, about 0.2 g / cm³ 3 Approximately 0.6 g / cm³ 3 In some embodiments, the concentration is approximately 0.4 g / cm³. 3 Approximately 0.6 g / cm³ 3 That's fine.

[0024] Once the powder is formed, it is then generally compressed or pressurized using any conventional powder press device to form pellets. For example, the press die may be a single-station compression press containing a die and one or more punctures. Alternatively, an anvil-type compression press die using only a die and a single downward puncture may be used. Single-station compression press dies are available in several basic types, e.g., cam, toggle / knuckle press, and eccentric / crank press, with various capabilities such as single-acting, dual-acting, floating die, movable platen, opposing ram, screw, impact, hot press, coining, or sizing. The powder is typically about 0.5 to about 20 g / cm³. 3 In some embodiments, approximately 1 g / cm³ 3 Approximately 15g / cm³ 3 In some embodiments, approximately 2 g / cm³ 3 Approximately 10g / cm³ 3 It is pressurized to a density of [value].

[0025] Any binder may be removed after pressurization by heating the pellet under vacuum at a specific temperature (e.g., about 150°C to about 500°C) for several minutes. Alternatively, the binder may be removed by contacting the pellet with an aqueous solution, as described in Patent Document 3 above. After the removal of the binder, the anode body may be subjected to an optional deoxidation process. In one embodiment, for example, the deoxidation process includes exposing the anode body to a getter material (e.g., magnesium, titanium, etc.) capable of removing oxygen from the anode body by chemical reaction, adsorption, etc. More specifically, the anode body is first placed in an enclosure (e.g., a tantalum box) which also contains the getter material. The atmosphere inside the enclosure is typically an inert atmosphere (e.g., argon gas). To initiate deoxidation, the atmosphere inside the enclosure is heated to a temperature sufficient to melt and / or vaporize the getter material and to deoxidize the anode body. The temperature may vary depending on the specific charge of the anode powder, but is typically around 700°C to 1200°C, in some embodiments around 750°C to 1100°C, and in some embodiments around 800°C to 1000°C. The total deoxidation time may range from about 20 minutes to about 3 hours. This can occur in one or more steps. Upon completion of deoxidation, the getter material typically vaporizes and forms a precipitate on the enclosure walls. To ensure the removal of the getter material, the anode body may be subjected to one or more acid leaching steps with a solution such as nitric acid, hydrofluoric acid, hydrogen peroxide, sulfuric acid, water, or a combination thereof.

[0026] Therefore, the resulting anode body may have a relatively low oxygen content. For example, the anode body may have an oxygen content of about 5500 ppm or less, about 5000 ppm or less in some embodiments, and about 500 ppm to about 4500 ppm in some embodiments. The oxygen content may be measured by a LECO oxygen analyzer, and includes oxygen in the natural oxide on the tantalum surface and bulk oxygen in the tantalum particles. The bulk oxygen content is controlled by the period of the tantalum crystal lattice and increases linearly with increasing oxygen content of tantalum until the limit of solubility is reached. This method is described in Non-Patent Literature 2 above, in which the period of the tantalum crystal lattice was measured using X-ray diffraction analysis (XRDA). The oxygen in the sintered tantalum anode may be limited to a thin natural surface oxide, while the bulk tantalum does not actually contain oxygen.

[0027] After optional deoxidation, the anode body may be sintered to form a porous, integrated body. The anode body is typically sintered at a temperature of about 700°C to about 1600°C, in some embodiments about 800°C to about 1500°C, in some embodiments about 900°C to about 1200°C, for a period of about 5 minutes to about 100 minutes, in some embodiments about 8 minutes to about 15 minutes. This sintering may be carried out in one or more steps. If desired, sintering may occur in an atmosphere that restricts the movement of oxygen atoms to the anode. For example, sintering may occur in a reducing atmosphere such as a vacuum, an inert gas, or hydrogen. The reducing atmosphere may be at a pressure of about 10 Torr to about 2000 Torr, in some embodiments about 100 Torr to about 1000 Torr, and in some embodiments about 100 Torr to about 930 Torr. A mixture of hydrogen and other gases (e.g., argon or nitrogen) may be used. As described above, sintering of the anode body is generally carried out after deoxidation as needed. However, it should be understood that the anode body may be subjected to one or more pre-sintering steps before oxidation to help provide a desired degree of green intensity in the deoxidation process. Such pre-sintering steps may be carried out under the same or different conditions as the sintering process carried out after deoxidation. For example, pre-sintering may be carried out in one or more steps over a period of about 5 to 100 minutes, and in some embodiments about 8 to 15 minutes, at a temperature of about 700°C to about 1,600°C, about 800°C to about 1,500°C, and in some embodiments about 900°C to about 1,200°C. Pre-sintering may be carried out in a reducing atmosphere such as vacuum, inert gas, or hydrogen, as described above.

[0028] As described above, the capacitor also includes multiple anode lead portions electrically connected to each anode terminal. The anode lead portions may be formed as portions of a single anode lead (e.g., opposing ends) or as portions of individual anode leads. The anode leads may have any desired shape and size and may take the form of wires, sheets, etc. Typically, the anode leads extend longitudinally from the anode body and are formed from any conductive material such as tantalum, niobium, aluminum, hafnium, titanium, and their conductive oxides and / or nitrides. The connection of the leads to the anode body may be achieved using any known technique, such as welding one or more leads to the body or embedding one or more anode leads into the anode body during formation (e.g., before compression and / or sintering).

[0029] Referring to Figure 1A, one embodiment of an anode body 10 is shown, having a first anode lead 12 having an embedded portion 24 positioned within the anode body and an exposed first anode lead portion 26 extending from a first end 16 of the anode body 10. A second exposed anode lead portion 14 is similarly connected (e.g., by welding 20) to a second end 18 of the anode body 10. As shown in Figure 1A, the second exposed anode lead portion 14 is formed as a separate second anode lead portion extending from the second end 18 of the anode body. Naturally, as shown in Figure 1C, the first anode lead portion 26 and the second exposed anode lead portion 14 may be defined by opposing portions of a single continuous anode lead 22 extending through the first end 16 and second end 18 of the anode body 10. Regardless, the exposed anode lead portion is typically desired to extend from opposing ends of the anode body in generally the same plane. Referring again to Figure 1A, a gap may optionally exist between the embedded end of the first anode lead and the end of the anode body so that the electrical connection between the first and second anode leads is provided through the sintered anode body. For example in Figure 1A, this gap may be defined as the distance "t" between the second end 18 of the anode body and the embedded end (end of the embedded portion) 28 of the anode lead, typically ranging from about 0.2 mm to about 5 mm, in some embodiments from about 0.4 mm to about 4 mm, and in some embodiments from about 0.5 mm to about 2 mm. The length "l" of the anode may similarly range from about 1.5 mm to about 6 mm, and in some embodiments from about 2 mm to about 5 mm. In such embodiments, the ratio of distance "t" to length "l" may range from about 0.1 to about 0.8, in some embodiments from about 0.2 to about 0.7, and in some embodiments from about 0.3 to about 0.6.

[0030] Another embodiment is shown in FIG. 1B, in which the anode body 10 has a first anode lead 12 having an embedded portion 24 positioned within the anode body, and an exposed first anode lead portion 26 extending from the first end 16 of the anode body 10. The second exposed anode lead 14 has an embedded portion 32 positioned within the anode body, and an exposed second anode lead portion 34 extending from the second end 18 of the anode body 10. Thus, in this embodiment, the need for a welding portion for the second anode lead is not required. Similar to the above embodiment, a gap "t" may optionally exist between the embedded end of the first anode lead (the end of the embedded portion) and the embedded end of the second anode lead (the end of the embedded portion), and this gap may be within the above-described range.

[0031] <B. Dielectric> The anode body is coated with a dielectric. The dielectric may be formed by anodizing the sintered anode body with an anode ( "anodic oxidation") such that a dielectric layer is formed on and / or within the anode body. For example, a tantalum (Ta) anode may be anodized to tantalum pentoxide (Ta2O5). Typically, anodic oxidation is performed by first attaching a solution to the anode, for example, by immersing the anode in an electrolyte. The solvent is generally water (e.g., deionized water) or the like. To increase the ionic conductivity, a compound capable of dissociating in the solvent to form ions may be used. Examples of such compounds include acids as described below with respect to the electrolyte. For example, an acid (e.g., phosphoric acid) may constitute from about 0.01% to about 5% by mass of the anodic oxidation solution, from about 0.05% to about 0.8% by mass in some embodiments, and from about 0.1% to about 0.5% by mass in some embodiments. If desired, a blend of acids may be used.

[0032] An electric current may be passed through the anodic oxidation solution to form a dielectric layer. The value of the formation voltage controls the thickness of the dielectric layer. For example, the power supply may be initially set in galvanostat mode until the required voltage is reached. The power supply may then be switched to potentiostat mode to ensure that the desired dielectric thickness is formed over the entire surface of the anode. Of course, other known methods such as pulsed or step potentiostat methods may be used. The formation voltage used during the anodic oxidation process is generally about 20 volts or higher, about 30 volts or higher in some embodiments, about 35 volts or higher in some embodiments, and from about 35 volts to about 70 volts in some embodiments, and the temperature is about 10°C or higher, from about 20°C to about 200°C in some embodiments, and from about 30°C to about 100°C in some embodiments. The resulting dielectric layer may be formed on the surface of the anode and within its pores.

[0033] By selectively controlling a particular technique by which the anode body is formed, the resulting capacitor can exhibit a high dielectric strength and can improve the capacitance stability. "Dielectric strength" generally refers to the ratio of the "breakdown voltage" of a capacitor (the voltage at which the capacitor fails, measured in volts, "V") to the thickness of the dielectric (measured in nanometers, "nm"). The capacitor typically exhibits a dielectric strength of about 0.4 V / nm or higher, in some embodiments about 0.45 V / nm or higher, in some embodiments about 0.5 V / nm or higher, in some embodiments from about 0.55 V / nm to about 1 V / nm, in some embodiments from about 0.6 V / nm to about 0.9 V / nm. The capacitor is determined, for example, by increasing the applied voltage in 3-volt increments until the leakage current reaches 1 mA, and exhibits a relatively high breakdown voltage of, for example, about 30 volts or higher, in some embodiments about 35 volts or higher, in some embodiments about 50 volts or higher, in some embodiments about 65 volts or higher, in some embodiments about 85 volts or higher, in some embodiments about 90 volts or higher, in some embodiments about 95 volts or higher, in some embodiments from about 100 volts to about 300 volts. Its thickness can generally vary depending on a particular location of the anode body, but the "thickness of the dielectric" for the purpose of determining the dielectric strength is generally considered to be the maximum thickness of the dielectric and typically ranges from about 50 nm to about 500 nm, in some embodiments from about 80 nm to about 350 nm, in some embodiments from about 100 nm to about 300 nm. The thickness of the dielectric may be measured at a magnification of 20,000× to 50,000× using a Zeiss Sigma FESEM, and the sample is prepared by cutting the finished part in a plane perpendicular to the longest dimension of the finished part, and the thickness is measured at a site where the cut is perpendicular through the dielectric layer.

[0034] <C. Precoat Layer> Although not necessarily required, a precoat layer may be deposited, if desired, on a dielectric containing a metal-organic compound. The metal-organic compound has the following formula;

[0035] [ka]

[0036] It may have.

[0037] In the above formula, M is an organometallic atom such as silicon or titanium; R1, R2, and R3 are independently alkyl (e.g., methyl, ethyl, propyl, etc.) or hydroxyalkyl (e.g., hydroxymethyl, hydroxyethyl, hydroxypropyl, etc.), and at least one of R1, R2, and R3 is a hydroxyalkyl; n is an integer from 0 to 8, in some embodiments it is from 1 to 6, and in some embodiments it is from 2 to 4 (e.g., 3); X is an organic or inorganic functional group, such as glycidyl, glycidyloxy, mercapto, amino, vinyl, etc.

[0038] In certain embodiments, R1, R2, and R3 may be hydroxyalkyl groups (e.g., OCH3). However, in other embodiments, R1 may be an alkyl group (e.g., CH3), and R2 and R3 may be hydroxyalkyl groups (e.g., OCH3).

[0039] Furthermore, in certain embodiments, M may be silicon, so that the organometallic compound is an organosilane compound such as an alkoxysilane. Suitable alkoxysilanes include, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, and glycidoxymethyltrimethoxysilane. , glycidoxymethyltriethoxysilane, glycidoxymethyl-tripropoxysilane, glycidoxymethyltributoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, β-glycidoxyethyl-tripropoxysilane, β-glycidoxyethyl-tributoxysilane, β-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, α-glycidoxyethyltripropoxysilane, α-glycidoxyethyltributoxysilane, γ-Glycidoxypropyl-trimethoxysilane, γ-Glycidoxypropyltriethoxysilane, γ-Glycidoxypropyl-tripropoxysilane, γ-Glycidoxypropyltributoxysilane, β-Glycidoxypropyltrimethoxysilane, β-Glycidoxypropyl-triethoxysilane, β-Glycidoxypropyltripropoxysilane, α-Glycidoxypropyltributoxysilane, α-Glycidoxypropyltrimethoxysilane, α-Glycidoxypropyltriethoxysilane, α-Glycid Xyxypropyl-tripropoxysilane, α-glycidoxypropyltributoxysilane, γ-glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltripropoxysilane, δ-glycidoxybutyl-tributoxysilane, δ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltripropoxysilane, γ-propoxybutyltributoxysilane, δ-glycidoxybutyl-trimethoxysilane,δ-Glycidoxybutyltriethoxysilane, δ-Glycidoxybutyltripropoxysilane, α-Glycidoxybutyltrimethoxysilane, α-Glycidoxybutyltriethoxysilane, α-Glycidoxybutyl-tripropoxysilane, α-Glycidoxybutyltributoxysilane, (3,4-Epoxycyclohexyl)-methyl-trimethoxysilane, (3,4-Epoxycyclohexyl)methyl-triethoxysilane, (3,4-Epoxycyclohexyl)methyl-tripropoxysilane, (3,4-Epoxycyclohexyl)-methyl-tributoxysilane, (3,4-Epoxycyclohexyl)ethyl-trimethoxysilane, (3,4-Epoxycyclohexyl)ethyl-triethoxysilane This may include (3,4-epoxycyclohexyl)ethyl tripropoxysilane, (3,4-epoxycyclohexyl)ethyl triplotoxysilane, (3,4-epoxycyclohexyl)propyltrimethoxysilane, (3,4-epoxycyclohexyl)propyltriethoxysilane, (3,4-epoxycyclohexyl)propyl-tripropoxysilane, (3,4-epoxycyclohexyl)propyl triplotoxysilane, (3,4-epoxycyclohexyl)butyltrimethoxysilane, (3,4-epoxycyclohexyl)butyltriethoxysilane, (3,4-epoxycyclohexyl)butyl tripropoxysilane, (3,4-epoxycyclohexyl)butyl triplotoxysilane, etc.

[0040] The specific method of attaching the precoat layer to the capacitor body may vary as desired. In certain embodiments, the compound is dissolved in an organic solvent, and the portion is applied as a solution, for example, by screen printing, dipping, electrophoretic coating, spraying, etc. The organic solvent may vary, but is typically an alcohol such as methanol or ethanol. The organometallic compound may constitute from about 0.1% to about 10% by mass of the solution, in some embodiments from about 0.2% to about 8% by mass, and in some embodiments from about 0.5% to about 5% by mass. The solvent may also constitute from about 90% to about 99.9% by mass of the solution, in some embodiments from about 92% to about 99.8% by mass, and in some embodiments from about 95% to about 99.5% by mass. Once applied, the portion is then dried to remove the solvent therefrom and form a precoat layer containing the organometallic compound.

[0041] <D. Solid electrolyte> The solid electrolyte overlays the dielectric and an optional precoat. The total thickness of the solid electrolyte is typically from about 1 to about 50 μm, and in some embodiments from about 5 to about 20 μm. The solid electrolyte typically includes one or more layers of a conductive polymer (e.g., polypyrrole, polythiophene, polyaniline, etc., polyheterocycles such as polyacetylene, poly-p-phenylene, polyphenolate, etc.). Thiophene polymers are particularly suitable for use in solid electrolytes. In certain embodiments, for example, the following formula (I):

[0042] [Chemical formula]

[0043] A thiophene polymer having a repeating unit of may be used.

[0044] In formula (I), R7 is a straight-chain or branched C1-C 18Alkyl groups (e.g., methyl, ethyl, n- or iso-propyl, n-, iso-, sec-, or tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, etc.); C5~C 12 Cycloalkyl groups (e.g., cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, etc.); C6~C 14 Aryl group (e.g., phenyl, naphthyl); C7~C 18 It is an aralkyl group (e.g., benzyl, o-, m-, p-tolyl, 2,3-, 2,4-, 2,5-, 2-6, 3-4-, 3,5-xylyl, mesityl, etc.); q is an integer from 0 to 8, from 0 to 2 in some embodiments, and 0 in one embodiment.

[0045] In particular, suitable thiophene polymers are those in which "D" is a C2-C3 alkylene group substituted as needed. For example, the polymer is poly(3,4-ethylenedioxythiophene) or a derivative thereof substituted as needed, and is given by the following formula (II):

[0046] [ka]

[0047] It may include those that have repeating units.

[0048] In certain embodiments, "q" is 0. One commercially suitable example of 3,4-ethylenedioxythiophene is available from Heraeus under the name Clevios® M. Other suitable monomers are described in the above-mentioned Patent Documents 4 and 5. Derivatives of these monomers may be, for example, dimers or trimers of the above monomers. Higher molecular derivatives, i.e., tetramers, pentamers, etc. of monomers, are suitable for use in the present invention. Derivatives may consist of the same or different monomer units and may be used in pure form, as mixtures of each other and / or as mixtures with monomers. Oxidized or reduced forms of these precursors may be used.

[0049] To form a polymer, the precursor monomer may be polymerized in the presence of an oxidation catalyst (e.g., chemically polymerized). The oxidation catalyst typically includes transition metal cations such as iron(III), copper(II), chromium(VI), cerium(IV), manganese(IV), manganese(VII), or ruthenium(III) cations. Dopants may be used to provide excess charge to the conductive polymer and stabilize the polymer's conductivity. Dopants typically include inorganic or organic anions such as sulfonic acid ions (e.g., p-toluenesulfonate). In certain embodiments, the oxidation catalyst includes both cations (e.g., transition metals) and anions (e.g., sulfonic acid), thus possessing both catalytic and doping functionality. For example, the oxidation catalyst may be a transition metal salt containing an iron(III) cation, such as an iron(III) halide (e.g., FeCl3), or an iron(III) salt of another inorganic acid, such as Fe(ClO4)3 or Fe2(SO4)3, as well as an organic acid and an iron(III) salt of an inorganic acid containing an organic group. Examples of iron(III) salts of inorganic acids containing an organic group include, for example, C1-C 20 This includes iron(III) salts of monosulfate esters of alkanols (e.g., iron(III) salt of lauryl sulfate). Examples of iron(III) salts of organic acids include, for example, C1-C12. 20Iron(III) salts of alkanesulfonic acids (e.g., methane, ethane, propane, butane, or dodecanesulfonic acid); iron(III) salts of aliphatic perfluorosulfonic acids (e.g., trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, or perfluorooctanesulfonic acid); aliphatic C1-C 20 Iron(III) salts of carboxylic acids (e.g., 2-ethylhexylcarboxylic acid); iron(III) salts of aliphatic perfluorocarboxylic acids (e.g., trifluoroacetic acid or perfluorooctanoic acid); C1-C 20 These include iron(III) salts of aromatic sulfonic acids (e.g., benzenesulfonic acid, o-toluenesulfonic acid, p-toluenesulfonic acid, or dodecylbenzenesulfonic acid) optionally substituted with alkyl groups; iron(III) salts of cycloalkanesulfonic acids (e.g., camphorsulfonic acid), etc. Mixtures of these iron(III) salts may also be used. Iron(III)-p-toluenesulfonate, iron(III)-o-toluenesulfonate, and mixtures thereof are particularly suitable. One commercially suitable example of iron(III)-p-toluenesulfonate is available from Heraeus under the name Clevios® C.

[0050] The oxidation catalyst and precursor monomer may be applied sequentially or together to initiate the polymerization reaction. For example, the monomer may be first mixed with the oxidation catalyst to form a precursor solution. In certain embodiments, less than the stoichiometric amount of oxidation catalyst usually required may be used to help slow down the polymerization of the monomer, in which case shorter oligomers than those that would occur if fully polymerized into a polymer are created, allowing for good penetration into a high specific charge powder. For example, when the monomer contains a thiophene monomer (e.g., 3,4-ethylenedioxythiophene), the molar ratio typically required for polymerization of the monomer is about 1 mole of monomer to 18 moles of oxidation catalyst. However, less than 18 moles of oxidation polymerization catalyst can be present in the polymerization solution per mole of monomer (e.g., 3,4-ethylenedioxythiophene), for example, about 15 moles or less, in some embodiments about 4 to about 12 moles, and in some embodiments about 5 to about 10 moles.

[0051] In addition to monomers, oxidation catalysts, and optionally selected dopants, the polymerization solution may contain other components such as one or more solvents. Particularly suitable solvents may include, for example, water, alcohols (e.g., methanol, ethanol, n-propanol, iso-propanol, and butanol); glycols (e.g., propylene glycol, butylene glycol, triethylene glycol, hexylene glycol, polyethylene glycol, ethoxydiglycol, and dipropylene glycol); glycol ethers (e.g., methyl glycol ether, ethyl glycol ether, and isopropyl glycol ether); ethers (e.g., diethyl ether and tetrahydrofuran); triglycerides; ketones; esters (e.g., ethyl acetate, butyl acetate, diethylene glycol ether acetate, and methoxypropyl acetate); amides (e.g., dimethylformamide, dimethylacetamide, dimethylcapryl / caprin fatty acid amide, and N-alkylpyrrolidone); nitriles (e.g., acetonitrile, propionitrile, butyronitrile, and benzonitrile); sulfoxides or sulfones (e.g., dimethyl sulfoxide (DMSO) and sulfolane), etc.), as well as any mixture of the above (e.g., water and alcohol).

[0052] The polymerization solution is typically maintained at a relatively low temperature during the reaction, e.g., about -20°C to about 50°C, in some embodiments about -15°C to about 30°C, and in some embodiments about -10°C to about 10°C. The solution may be attached to the anode body using any suitable attachment technique known in the art, such as screen printing, dipping, electrophoretic coating, and spraying. Regardless of the attachment technique used, the monomers generally begin to react after being present on the anode body in order to form a polymer layer. The period during which the monomers react on the anode body is typically long enough to allow for good impregnation of the polymer into the small pores of the high specific charge powder. In most embodiments, for example, this period ("impregnation time") is about 1 minute or longer, in some embodiments about 1.5 minutes or longer, and in some embodiments about 2 minutes to about 5 minutes. After the reaction, the resulting conductive polymer layer may be contacted with a washing solution to remove various by-products, excess catalyst, etc. The period during which the cleaning solution is in contact with the conductive polymer layer ("cleaning time") is typically long enough to ensure that by-products, excess catalyst, etc., can be properly removed from the small pores of the high specific charge powder. The cleaning period may be, for example, about 25 minutes or longer, about 30 minutes or longer in some embodiments, and about 45 to 90 minutes in some embodiments. During this period, cleaning may be carried out in a single step or in multiple steps, the total time of each step being within the range described above. The cleaning solution may vary as desired, but is typically one or more solvents (e.g., water, alcohol, etc.) and, if necessary, dopants as described above.

[0053] After cleaning, the conductive polymer layer may be dried at a temperature typically about 15°C or higher, about 20°C or higher in some embodiments, and in some embodiments from about 20°C to about 80°C. The polymer layer may be repaired after formation. Repair may be performed after each adhesion of the conductive polymer layer, or after adhesion of the entire conductive polymer coating. In some embodiments, the conductive polymer may be repaired by immersing the anode body in an electrolyte solution and then applying a constant voltage to the solution until the current drops to a pre-selected level. If desired, such repair may be achieved in multiple steps. For example, the electrolyte solution may be a dilute solution of monomers, catalysts, and dopants dissolved in an alcohol solvent (e.g., ethanol).

[0054] In the process described above, the conductive polymer is generally formed "in situ" on the anode body. Naturally, this is not always necessary. In other embodiments, for example, the conductive polymer may be prepolymerized. In one embodiment, for example, the prepolymerized polymer is an intrinsically conductive polymer having a positive charge located on the main chain, at least partially compensated by anions covalently bonded to the polymer. Such polymers have relatively high specific conductivity, for example, in dry conditions of about 1 siemens per centimeter ("S / cm") or more, about 10 S / cm or more in some embodiments, about 25 S / cm or more in some embodiments, about 40 S / cm or more in some embodiments, and from about 50 S / cm to about 500 S / cm in some embodiments. An example of a suitable intrinsically conductive thiophene polymer is given by the following formula (III):

[0055] [ka]

[0056] It may have repeating units.

[0057] In equation (III), R is (CH2) a -O-(CH2) b -L, where L is a bond or HC([CH2] c H) and; a is between 0 and 10, and in some embodiments between 0 and 6, and in some embodiments between 1 and 4 (for example, 1); b is 1 to 18, and in some embodiments 1 to 10, and in some embodiments 2 to 6 (e.g., 2, 3, 4, or 5); c is between 0 and 10, and in some embodiments between 0 and 6, and in some embodiments between 1 and 4 (e.g., 1); Z is an anion, for example, SO3 - , C(O)O - BF4 - CF3SO3 - SbF6 - , N(SO2CF3)2 - C4H3O4 - ClO4 - etc; X is a cation, such as hydrogen, an alkali metal (e.g., lithium, sodium, rubidium, cesium, or potassium), or ammonium.

[0058] In a particular embodiment, Z in formula (III) is the intrinsically conductive polymer of the following formula (IV):

[0059] [ka]

[0060] It is a sulfonic acid ion that contains repeating units.

[0061] In formula (III), R and X are defined above. In formula (III) or formula (IV), a is preferably 1, and b is preferably 3 or 4. Also, X is preferably sodium or potassium.

[0062] If desired, the polymer may also be a copolymer containing other types of repeating units. In such embodiments, the repeating units of formula (III) constitute typically about 50 mol% or more of the total amount of repeating units in the copolymer, about 75 mol% to about 99 mol% in some embodiments, and about 85 mol% to about 95 mol% in some embodiments. Naturally, the polymer may also be a homopolymer up to a range of 100 mol% containing the repeating units of formula (III). Specific examples of such homopolymers include poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butanesulfonic acid, salt) and poly(4-(2,3-dihydrothieno-[3,4-b][l,4]dioxin-2-ylmethoxy)-l-propanesulfonic acid, salt).

[0063] In another embodiment, the intrinsically conductive polymer is given by the following formula (V):

[0064] [ka]

[0065] It has repeating thiophene units. In equation (V), a and b are as defined above; R5 is a C1-C6 linear or branched alkyl group (e.g., methyl) or halogen atom (e.g., fluorine) which may be substituted as needed; X is a hydrogen atom, an alkali metal (e.g., Li, Na, or K), or NH(R). 1 )3, or HNC5H5, however, R 1 Each of these is independently a hydrogen atom, or a C1-C6 alkyl group that is substituted as needed.

[0066] Specific examples of thiophene compounds used to form such repeats are described in the aforementioned Patent Document 6, for example, sodium 3-[(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-ethyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-propyl-1- Propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-butyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-pentyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-hexyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b] -[1,4]dioxin-2-yl)methoxy]-1-isopropyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isobutyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isopentyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-fluoro-1-propanesulfonate Propanesulfonate, potassium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonic acid, ammonium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, triethylammonium 3-[(2,3-dihydrothieno[3,4-b]-[1,4) Dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, etc., as well as combinations thereof and derivatives thereof, may be included. Each of the above-described thiophene monomers can be prepared from thieno[3,4-b]-1,4-dioxin-2-methanol and branched sultone compounds according to known methods (e.g., Non-Patent Document 3 above).

[0067] "External" conductive polymers may be used, generally requiring the presence of separate counterions not covalently bonded to the polymer. An example of such an external conductive polymer is poly(3,4-ethylenedioxythiophene). The counterions may be monomers or polymer anions that counteract the charge of the conductive polymer. Polymer anions may be, for example, polymer carboxylic acids (e.g., poly(meth)acrylic acids such as poly-2-sulfoethyl(meth)acrylate or poly-3-propylsulfo(meth)acrylate; polymaleic acid; etc.); polymer sulfonic acids (e.g., polystyrene sulfonic acid ("PSS"), polyvinyl sulfonic acid, etc.), and salts thereof, for example, anions derived from alkali metals, alkaline earth metals, transition metals, or ammonium salts thereof. Suitable monomer anions are C1-C 20 Alkanesulfonic acids (e.g., dodecanesulfonic acid); aliphatic fluorosulfonic acids (e.g., trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, perfluorooctanesulfonic acid, trifluoromethanesulfonimide, etc.); aliphatic C1-C 20 Carboxylic acids (e.g., 2-ethylhexylcarboxylic acid); aliphatic fluorocarboxylic acids (e.g., trifluoroacetic acid or perfluorooctanoic acid); C1-C as needed 20These can be derived from alkyl-substituted aromatic sulfonic acids (e.g., benzenesulfonic acid, o-toluenesulfonic acid, p-toluenesulfonic acid, or dodecylbenzenesulfonic acid); cycloalkanesulfonic acids (e.g., camphorsulfonic acid); boronic acid compounds (e.g., tetrafluoroboric acid); phosphoric acid compounds (e.g., hexafluorophosphate), etc., as well as salts thereof, e.g., from alkali metals, alkaline earth metals, transition metals, or ammonium salts. Particularly suitable counteranions are polymer anions, such as those derived from polymeric carboxylic acids or sulfonic acids (e.g., polystyrenesulfonic acid ("PSS")). The molecular weights of such compounds typically range from about 1,000 to about 2,000,000, and in some embodiments from about 2,000 to 500,000.

[0068] Whether the conductivity is intrinsic or external, the prepolymerized polymer layer can adhere to the anode body in various forms, such as a solution or dispersion. The intrinsic conductive polymer adheres, for example, preferably in the form of a solution, while the external conductive polymer adheres, preferably in the form of a dispersion.

[0069] When a solution is used, the concentration of the polymer may vary depending on the desired viscosity and the specific method by which the layer will adhere to the anode. However, typically, the polymer constitutes about 0.1% to about 10% by mass of the solution, about 0.4% to about 5% by mass in some embodiments, and about 0.5% to about 4% by mass in some embodiments. The solvent also constitutes about 90% to about 99.9% by mass of the solution, about 95% to about 99.6% by mass in some embodiments, and about 96% to about 99.5% by mass in some embodiments. Other solvents can certainly be used, but in the case of water, it is generally desirable that it be the primary solvent so that the solution is considered an "aqueous" solution. In most embodiments, for example, water constitutes at least about 50% by mass of the solvent used, at least about 75% by mass in some embodiments, and about 90% to 100% by mass in some embodiments. When used, the solution may be attached to the anode using any known technique, such as immersion, casting (e.g., curtain coating, spin coating, etc.), printing (e.g., gravure printing, offset printing, screen printing, etc.). The resulting conductive polymer layer may be dried and / or washed after being attached to the anode.

[0070] When a dispersion is used, the conductive polymer generally takes the form of prepolymerized conductive particles. Such particles typically have an average size (e.g., diameter) of about 1 to about 100 nanometers, about 2 to about 80 nanometers in some embodiments, and about 4 to about 50 nanometers in some embodiments. The particle diameter may be determined using known techniques such as ultracentrifugation or laser diffraction. The shape of the particles may also vary. In one particular embodiment, for example, the particle shape is spherical. However, it should be understood that other shapes such as plates, rods, discs, bars, tubes, and irregular shapes are also intended by the present invention. The concentration of particles in the dispersion may vary depending on the desired viscosity of the dispersion and the particular method by which the dispersion will be attached to the capacitor element. However, typically, the particles constitute about 0.1% to about 10% by mass of the dispersion, about 0.4% to about 5% by mass in some embodiments, and about 0.5% to about 4% by mass in some embodiments.

[0071] The dispersion may contain one or more binders that further enhance the adhesion of the polymer layer and increase the stability of the particles in the dispersion. The binder may have the properties of an organic substance and may be, for example, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl chloride, polyvinyl acetate, polyvinyl butyrate, polyacrylic acid ester, polyacrylamide, polymethacrylate, polymethacrylate, polyacrylonitrile, styrene / acrylic acid ester, vinyl acetate / acrylic acid ester, and ethylene / vinyl acetate copolymer, polybutadiene, polyisoprene, polystyrene, polyether, polyester, polycarbonate, polyurethane, polyamide, polyimide, polysulfone, melamine formaldehyde resin, epoxide resin, silicone resin, or cellulose. A crosslinking agent may be used to enhance the adhesive ability of the binder. Such crosslinking agents may include, for example, melamine compounds, masked isocyanates, or functional silanes such as 3-glycidoxypropyltrialkoxysilane, tetraethoxysilane, and tetraethoxysilane hydrolysates, or crosslinkable polymers such as polyurethanes, polyacrylates, or polyolefins, and subsequent crosslinking.

[0072] Dispersants may be used to facilitate the ability of the layer to adhere to the anode. Suitable dispersants include solvents, such as aliphatic alcohols (e.g., methanol, ethanol, i-propanol, and butanol), aliphatic ketones (e.g., acetone and methyl ethyl ketone), aliphatic carboxylic acid esters (e.g., ethyl acetate and butyl acetate), aromatic hydrocarbons (e.g., toluene and xylene), aliphatic hydrocarbons (e.g., hexane, heptane, and cyclohexane), chlorinated hydrocarbons (e.g., dichloromethane and dichloroethane), aliphatic nitriles (e.g., acetonitrile), aliphatic sulfoxides and sulfones (e.g., dimethyl sulfoxide and sulfolane), aliphatic carboxylic acid amides (e.g., methylacetamide, dimethylacetamide, and dimethylformamide), aliphatic and aromatic aliphatic ethers (e.g., diethyl ether and anisole), water, and mixtures of any of the aforementioned solvents. Water is a particularly suitable dispersant.

[0073] In addition to those described above, other components may also be used in the dispersion. For example, conventional fillers having a size of about 10 nanometers to about 100 micrometers, about 50 nanometers to about 50 micrometers in some embodiments, and about 100 nanometers to about 30 micrometers in some embodiments may be used. Examples of such fillers include calcium carbonate, silicate, silica, calcium sulfate or barium, aluminum hydroxide, glass fibers or valves, wood powder, cellulose powder, carbon black, conductive polymers, etc. The fillers may be introduced into the dispersion in powder form, but may also exist in other forms such as fibers.

[0074] Surface active substances such as ionic or nonionic surfactants may also be used in the dispersion. Furthermore, adhesives such as organic functional silanes or their hydrolysates, for example, 3-glycidoxypropyltrialkoxysilane, 3-aminopropyl-triethoxysilane, 3-mercaptopropyl-trimethoxysilane, 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, or octyltriethoxysilane may be used. The dispersion contains additives that increase conductivity, such as ether group-containing compounds (e.g., tetrahydrofuran), lactone group-containing compounds (e.g., γ-butyrolactone or γ-valerolactone), amide or lactam group-containing compounds (e.g., caprolactam, N-methylcaprolactam, N,N-dimethylacetamide, N-methylacetamide, N,N-dimethylformamide (DMF), N-methylformamide, N-methylformanilide, N-methylpyrrolidone (NMP), N It may also contain -octylpyrrolidone or pyrrolidone), sulfones and sulfoxides (e.g., sulfolane (tetramethylene sulfone) or dimethyl sulfoxide (DMSO)), sugars or sugar derivatives (e.g., saccharose, glucose, fructose, or lactose), sugar alcohols (e.g., sorbitol or mannitol), furan derivatives (e.g., 2-furanic acid or 3-furanic acid), or alcohols (e.g., ethylene glycol, glycerol, di- or triethylene glycol).

[0075] The dispersion may be applied using various known techniques, such as spin coating, impregnation, injection, drop-fitting, injection, spraying, doctor blade, brushing, printing (e.g., inkjet, screen, or pad printing), or dipping. The viscosity of the dispersion is typically from about 0.1 mPas to about 100,000 mPas (shear rate 100 sec). -1(measured in), in some embodiments from about 1 mPas to about 10,000 mPas, in some embodiments from about 10 mPas to about 1500 mPas, and in some embodiments from about 100 mPas to about 1000 mPas.

[0076] The solid electrolyte may be formed from multiple layers, such as an inner layer and / or an outer layer. The term "inner" in this context refers to one or more layers that overlap on the dielectric, whether directly or through another layer (e.g., a precoat layer). The inner layer typically contains, for example, a polymerized polymer in-situ and / or an intrinsically conductive polymer, such as those described above. One or more inner layers may be used. For example, the solid electrolyte typically contains from 2 to 30, in some embodiments from 4 to 20, and in some embodiments from about 5 to 15 inner layers (e.g., 10 layers). The solid electrolyte may contain only "inner layers" that are essentially formed from the same material, i.e., an intrinsically conductive polymer and / or a layer polymerized in-situ. However, in other embodiments, the solid electrolyte may contain one or more optional "outer" conductive polymer layers that are formed from a material different from the inner layer and overlap on the inner layer. For example, the outer layer may be formed from a dispersion of an extrinsically conductive polymer. In certain embodiments, the outer layer is mainly formed from such an extrinsically conductive polymer such that it constitutes about 50% by mass or more, in some embodiments about 70% by mass or more, and in some embodiments about 90% by mass or more (e.g., 100% by mass) of each outer layer. One or more layers may be used. For example, the solid electrolyte may contain from 2 to 30, in some embodiments from 4 to 20, and in some embodiments from about 5 to about 15 outer layers.

[0077] <E. External Polymer Coating> An external polymer coating superimposed on the solid electrolyte may also be used as needed. When used, the external polymer coating typically comprises one or more layers formed from prepolymerized conductive polymer particles as described above (e.g., a dispersion of external conductive polymer particles). The external coating may further penetrate into the edge region of the capacitor body to increase adhesion to the dielectric and provide a more mechanically robust portion, thereby reducing equivalent series resistance and leakage current. Generally, the goal is to improve edge coverage rather than impregnate the interior of the anode body, so the particles used in the external coating may be larger in size than those used in the outer layer of the solid electrolyte. For example, the ratio of the average size of particles used in the external polymer coating to the average size of particles used in any dispersion of the solid electrolyte is typically about 1.5 to about 30, about 2 to about 20 in some embodiments, and about 5 to about 15 in some embodiments. For example, the particles used in the dispersion of the external coating may have an average size of about 80 nanometers to about 500 nanometers, in some embodiments about 90 nanometers to about 250 nanometers, and in some embodiments about 100 nanometers to about 200 nanometers.

[0078] If desired, a crosslinking agent may also be used in the external polymer coating to enhance the degree of adhesion to the solid electrolyte. Typically, the crosslinking agent is applied before the dispersion used in the external coating is attached. Suitable crosslinking agents are, for example, those described in Patent Document 7 above and include, for example, amines (e.g., diamines, triamines, oligomeric amines, polyamines, etc.); salts or compounds of polyvalent metal cations, such as Mg, Al, Ca, Fe, Cr, Mn, Ba, Ti, Co, Ni, Cu, Ru, Ce, or Zn; phosphonium compounds; sulfonium compounds, etc. Particularly suitable examples include, for instance, 1,4-diaminocyclohexane, 1,4-bis(amino-methyl)cyclohexane, ethylenediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,12-dodecanediamine, N,N-dimethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyl-1,4-butanediamine, and mixtures thereof.

[0079] The crosslinking agent is typically applied from a solution or dispersion having a pH of 1 to 10, 2 to 7 in some embodiments, and 3 to 6 in some embodiments, as determined at 25°C. Acidic compounds may be used to help achieve the desired pH level. Examples of solvents or dispersants for the crosslinking agent include water or organic solvents such as alcohols, ketones, and carboxylic acid esters. The crosslinking agent may be attached to the capacitor body by spin coating, impregnation, casting, drop-fitting, spray coating, vapor deposition, sputtering, sublimation, knife coating, painting, or any known process such as inkjet, screen, or pad printing. Once attached, the crosslinking agent may be dried and then attached to the polymer dispersion. This process may then be repeated until the desired thickness is achieved. For example, the total thickness of the entire external polymer coating, including the crosslinking agent and dispersion layer, may range from about 1 μm to about 50 μm, from about 2 μm to about 40 μm in some embodiments, and from about 5 μm to about 20 μm in some embodiments.

[0080] <F. Moisture Barrier Layer> If desired, the moisture barrier layer may be used overlaid on the solid electrolyte and / or an optional external polymer coating. The moisture barrier layer may be formed from a variety of different materials such as, for example, hydrophobic elastomers such as silicone, fluoropolymers, etc. Silicone polymers are particularly suitable for use in the moisture barrier layer of the present invention. Such elastomers typically have the following formula:

[0081] [Chemical Formula]

[0082] and are derived from polyorganosiloxanes such as those having the following:

[0083] In the formula described immediately above, X is an integer greater than 1; and R1, R2, R3, R4, R5, R6, R7, and R8 are independently monovalent groups typically containing 1 to about 20 carbon atoms, such as alkyl groups (e.g., methyl, ethyl, propyl, pentyl, octyl, undecyl, octadecyl, etc.); alkoxy groups (e.g., methoxy, ethoxy, propoxy, etc.); carboxyalkyl groups (e.g., acetyl); cycloalkyl groups (e.g., cyclohexyl); alkenyl groups (e.g., vinyl, allyl, butenyl, hexenyl, etc.); aryl groups (e.g., phenyl, tolyl, xylyl, benzyl, 2-phenylethyl, etc.); and halogenated hydrocarbon groups (e.g., 3,3,3-trifluoropropyl, 3-chloropropyl, dichlorophenyl, etc.). Examples of such polyorganosiloxanes may include, for example, polydimethylsiloxane ("PDMS"), polymethylhydrogensiloxane, dimethyldiphenylpolysiloxane, dimethyl / methylphenylpolysiloxane, polymethylphenylsiloxane, methylphenyl / dimethylsiloxane, vinyldimethyl-terminated polydimethylsiloxane, vinylmethyl / dimethylpolysiloxane, vinyldimethyl-terminated vinylmethyl / dimethylpolysiloxane, divinylmethyl-terminated polydimethylsiloxane, vinylphenylmethyl-terminated polydimethylsiloxane, dimethylhydro-terminated polydimethylsiloxane, methylhydro / dimethylpolysiloxane, methylhydro-terminated methyloctylpolysiloxane, methylhydro / phenylmethylpolysiloxane, fluoromodified polysiloxane, and the like. To form an elastomer, the polyorganosiloxane may be crosslinked using any of the various known techniques, such as catalytic curing (e.g., platinum catalyst), room temperature vulcanization, or moisture curing. Crosslinking agents may include alkoxysilanes having the formula Si-OR (where R is H), alkyl groups (e.g., methyl), alkenyl groups, carboxyalkyl groups (e.g., acetyl), etc.

[0084] In addition to being hydrophobic, the material used to form the moisture barrier layer is generally desirable to have a relatively low modulus of elasticity and a certain degree of flexibility, which can help absorb some of the thermal stress caused by the expansion of the casing and also allow it to withstand compressive forces. The flexibility of the material may be characterized by the corresponding low modulus of elasticity ("Young's modulus"), for example, about 5,000 kilopascals ("kPa") or less, measured at a temperature of about 25°C, about 1 to about 2,000 kPa in some embodiments, and about 2 to about 500 kPa in some embodiments. The material also typically possesses a certain strength that allows it to maintain its shape even when subjected to compressive forces. For example, the material may possess a tensile strength of about 1 kPa to about 5,000 kPa, about 10 to about 2,000 kPa in some embodiments, and about 50 to about 1,000 kPa in some embodiments, measured at a temperature of about 25°C. Under the conditions described above, hydrophobic elastomers can further enhance the ability of capacitors to function under extreme conditions.

[0085] Nonconductive fillers may be used in the moisture barrier layer to help achieve desired flexibility and strength properties. When used, such additives typically constitute about 0.5% to about 30% by mass of the moisture barrier layer, about 1% to about 25% by mass in some embodiments, and about 2% to about 20% by mass in some embodiments. Silicone elastomers may constitute about 70% to about 99.5% by mass of the moisture barrier layer, about 75% to about 99% by mass in some embodiments, and about 80% to about 98% by mass in some embodiments. Certain examples of such fillers include silica, for example. Most forms of silica have a relatively hydrophilic surface due to the presence of silanol groups (Si-OH), but silica has a surface that is (CH3) nIt may be surface-treated as necessary to contain a -Si- group (where n is an integer from 1 to 3), further enhancing the hydrophobicity of the moisture barrier layer. The surface treatment agent may be, for example, an organosilicon compound monomer having a hydrolyzable group or a partial hydrolyzate thereof. Examples of such compounds may include organosilazanes, silane coupling agents as described above, etc.

[0086] The moisture barrier layer may be attached to any surface of the capacitor to provide desired properties. For example, the moisture barrier layer may be disposed on the upper surface, bottom surface, and / or side surface of the capacitor. The moisture barrier layer may also be disposed on the front surface and / or rear surface of the capacitor. The moisture barrier layer may cover only the entire region or a part of the region of the surface to which it is attached. In one embodiment, for example, the moisture barrier layer covers about 30% or more of the surface of the capacitor to which it is attached, in some embodiments about 40% or more, and in some embodiments about 50% or more.

[0087] <G. Other Optional Components> If desired, the capacitor element may contain other layers known in the art. For example, an adhesive layer may be formed as necessary between the dielectric and the solid electrolyte. The adhesive layer may be present, for example, between the dielectric and the precoat layer and / or between the precoat layer and the solid electrolyte. Irrespective of that, the adhesive layer is typically formed from a relatively insulating resinous material (natural or synthetic). Such materials have a resistivity greater than about 10 Ω·cm, in some embodiments greater than about 100, in some embodiments greater than about 1000 Ω·cm, in some embodiments greater than about 1×10 5 Ω·cm, and in some embodiments greater than about 1×10 10The resistivity may be greater than Ω·cm. Some resinous materials that can be used in the present invention include, but are not limited to, polyurethane, polystyrene, and esters of unsaturated or saturated fatty acids (e.g., glycerides). For example, suitable esters of fatty acids include, but are not limited to, esters of lauric acid, myristic acid, palmitic acid, stearic acid, eleostearic acid, oleic acid, linoleic acid, linolenic acid, aloylitic acid, and shellophosphate. These esters of fatty acids have been found to be particularly useful when used in relatively complex combinations to form a “drying oil,” which rapidly polymerizes the resulting film into a stable layer. Such drying oils may contain mono-, di-, and / or tri-glycerides having a glycerol backbone with 1, 2, and 3 esterified fatty acyl residues, respectively. For example, some suitable drying oils that can be used include, but are not limited to, olive oil, linseed oil, castor oil, tung oil, soybean oil, and shellac. These and other adhesive layer materials are described in more detail in Patent Document 8 mentioned above.

[0088] If desired, a carbon layer (e.g., graphite) and a silver layer may also be attached to that portion, respectively. The silver coating may act, for example, as a solderable conductor, contact layer, and / or charge collector for a capacitor, and the carbon coating may limit contact between the silver coating and the solid electrolyte. Such coatings may cover part or all of the solid electrolyte. Various techniques such as dipping, brushing, spraying, and printing may be used to attach the aforementioned layers.

[0089] [II. Housing] As described above, the capacitor element is sealed within a housing. Sealing may be carried out as necessary in the presence of a gaseous atmosphere containing air and / or at least one inert gas to inhibit oxidation of the solid electrolyte during use. When used, the inert gas may include, for example, nitrogen, helium, argon, xenon, neon, krypton, radon, etc., and mixtures thereof. Any of the various materials, such as metals, plastics, ceramics, etc., may be used to form the housing. In one embodiment, for example, the housing includes one or more layers of metals such as tantalum, niobium, aluminum, nickel, hafnium, titanium, copper, silver, steel (e.g., stainless steel), alloys thereof (e.g., conductive oxides), and composites thereof (e.g., metals coated with conductive oxides). In another embodiment, the housing may include one or more layers of ceramic materials such as aluminum nitride, aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, glass, etc., and combinations thereof.

[0090] The housing may have any desired shape, such as cylindrical, D-shaped, rectangular, triangular, or prism-shaped. Referring to Figures 2 and 3, one embodiment of a capacitor 100 having a housing 122 and a capacitor element 120 is shown. In this particular embodiment, the housing 122 is generally rectangular. Typically, the housing and the capacitor element have the same or similar shape so that the capacitor element can be easily housed in an internal cavity. In the exemplary embodiment, for example, both the capacitor element 120 and the housing 122 are substantially rectangular.

[0091] If desired, the capacitor of the present invention may exhibit relatively high volumetric efficiency. To facilitate such high efficiency, the capacitor element typically occupies a substantial portion of the volume of the internal cavity of the housing. For example, the capacitor element may occupy about 30 volume% or more of the internal cavity of the housing, about 50 volume% or more in some embodiments, about 60 volume% or more in some embodiments, about 70 volume% or more in some embodiments, about 80 to about 98 volume% in some embodiments, and about 85 to about 97 volume% in some embodiments. For this reason, the difference between the dimensions of the capacitor element and the dimensions of the internal cavity defined by the housing is typically relatively small.

[0092] Referring again to Figures 2 and 3, for example, the capacitor element 120 may have a length relatively similar to the length of the internal cavity 126 defined by the housing 122 (excluding the length of the anode lead 6). For example, the ratio of the anode length to the internal cavity length ranges from about 0.40 to 1.00, in some embodiments about 0.50 to 0.99, in some embodiments about 0.60 to 0.99, and in some embodiments about 0.70 to 0.98. The capacitor element 120 may have a length of about 5 millimeters to about 10 millimeters, and the internal cavity 126 may have a length of about 6 millimeters to about 15 millimeters. Furthermore, the ratio of the height of the capacitor element 120 (in the z direction) to the height of the internal cavity 126 may range from approximately 0.40 to 1.00, in some embodiments from approximately 0.50 to approximately 0.99, in some embodiments from approximately 0.60 to approximately 0.99, and in some embodiments from approximately 0.70 to approximately 0.98. The ratio of the width of the capacitor element 120 (in the x direction) to the width of the internal cavity 126 may range from approximately 0.50 to 1.00, in some embodiments from approximately 0.60 to approximately 0.99, in some embodiments from approximately 0.70 to approximately 0.99, in some embodiments from approximately 0.80 to approximately 0.98, and in some embodiments from approximately 0.85 to approximately 0.95. For example, the width of the capacitor element 120 may be approximately 2 mm to 7 mm, the width of the internal cavity 126 may be approximately 3 mm to 10 mm, the height of the capacitor element 120 may be approximately 0.5 mm to 2 mm, and the width of the internal cavity 126 may be approximately 0.7 mm to 6 mm.

[0093] Although not strictly required, the capacitor element may be mounted in a housing such that the anode and cathode terminals are formed on the outside of the housing, for later integration with the circuit. The specific configuration of the terminals may depend on the intended application. In one embodiment, for example, the capacitor may be formed to be surface-mountable and also mechanically robust. For example, the anode lead may be electrically connected to surface-mountable anode and cathode terminals (e.g., pads, sheets, plates, frames, etc.) on the outside. Such terminals may extend into the housing and be connected to the capacitor. The thickness or height of the terminals is generally selected to minimize the thickness of the capacitor. For example, the thickness of the terminals may range from about 0.05 mm to about 1 mm, in some embodiments from about 0.05 mm to about 0.5 mm, and from about 0.1 mm to about 0.2 mm. If desired, the surface of the terminals may be electroplated with nickel, silver, gold, tin, etc., as known in the art, to ensure that the final component is mountable to a circuit board. In one particular embodiment, the terminals are deposited with nickel and silver flash, respectively, and the mounting surface is plated with a tin solder layer. In another embodiment, the terminals have a thin outer metal layer (e.g., gold) deposited on a base metal layer (e.g., copper alloy) to further increase conductivity.

[0094] In certain embodiments, the anode lead connector may be located within the internal cavity of the housing to facilitate connection to the terminals in a mechanically stable manner. For example, referring again to Figures 2-3, the capacitor 100 may include a first anode lead connector 162a formed from a first portion 167a and a second portion 165a. The first anode lead connector 162a may be formed from a conductive material similar to the external terminals. The first portion 167a and the second portion 165a may be integral or separate pieces connected together directly or via an additional conductive element (e.g., metal). In the exemplary embodiment, the second portion 165a is located in a plane substantially parallel to the transverse direction (e.g., the y-direction) from which the first anode lead portion 26 extends. The first portion 167a is "upright" in the sense that it is located in a plane substantially perpendicular to the transverse direction from which the first anode lead portion 26 extends. Thus, the first portion 167a can restrict the movement of the first anode lead portion 26 in the horizontal direction, thereby enhancing surface contact and mechanical stability during use. If desired, an insulating material 7a (e.g., a Teflon® washer) may be used around the first anode lead portion 26. The first portion 167a may have a mounting area (not shown) connected to the first anode lead portion 26. The area may have a "U-shape" to further enhance surface contact and mechanical stability of the first anode lead portion 26. The connection between the area and the first anode lead portion 26 may be achieved using any of various known techniques, such as welding, laser welding, or conductive adhesive. In a particular embodiment, for example, the area is laser-welded to the first anode lead portion 26. However, regardless of the chosen technique, the first portion 167a can hold the anode lead in a substantially horizontal alignment to further enhance the dimensional stability of the capacitor element.

[0095] The capacitor 100 may include a second anode lead connector 162b. The second anode lead connector may be the same as or different from the first anode lead connector. In the exemplary embodiment, for example, the second anode lead connector 162b is formed from a first portion 167b and a second portion 165b, similar to the first anode lead connector 162a. In the exemplary embodiment, the second portion 165b is provided in a plane substantially parallel to the lateral direction (e.g., the y-direction) from which the second exposed anode lead portion 14 extends. The first portion 167b is "upright" in the sense that it is provided in a plane substantially perpendicular to the lateral direction from which the second exposed anode lead portion 14 extends. Thus, the first portion 167b can restrict the movement of the second exposed anode lead portion 14 in the horizontal direction to enhance surface contact and mechanical stability during use. If desired, an insulating material 7b (e.g., a Teflon® washer) may be used around the second exposed anode lead portion 14. The first portion 167b may have a mounting area (not shown) connected to the second exposed anode lead portion 14. The area may have a "U-shape" to further enhance surface contact and mechanical stability with respect to the second exposed anode lead portion 14. The connection between the area and the second exposed anode lead portion 14 may be achieved using any of the various known techniques, such as welding, laser welding, or conductive adhesive. However, regardless of the technique selected, the first portion 167b may hold the anode lead in a substantially horizontal alignment to further enhance the dimensional stability of the capacitor element.

[0096] The first anode lead connector 162a and the second anode lead connector 162b may be connected to the first anode terminal 127 and the second anode terminal 129, respectively, by various methods. In an exemplary embodiment, for example, the housing 122 includes an outer wall 123 and two opposing side walls 124, between which a cavity 126 containing a capacitor element 120 is formed. The outer wall 123 and the side walls 124 may be formed from one or more layers of metal, plastic, or ceramic material as described above. In this particular embodiment, the first anode terminal 127 includes a first region 127a located within the housing 122 and electrically connected to the first anode lead connector 162a, and a second region 127b located outside the housing 122 and providing a mounting surface 201. Furthermore, the second anode terminal 129 includes a first region 129a located within the housing 122 and electrically connected to the second anode lead connecting member 162b, and a second region 129b located outside the housing 122 and providing a mounting surface 203. It should be understood that the entirety of such a region does not necessarily have to be located inside or outside the housing.

[0097] In the exemplary embodiment, the first conductive trace 127c extends within the outer wall 123 of the housing to connect the first region 127a and the second region 127b. Similarly, the second conductive trace 129c extends within the outer wall 123 of the housing to connect the first region 129a and the second region 129b. The conductive traces and / or regions of the terminals may be separate or integrated. In addition to extending through the outer wall of the housing, the traces may be located elsewhere, such as outside the outer wall. Naturally, the present invention is by no means limited to the use of conductive traces to form a desired terminal. Regardless of the specific configuration used, the connection of the first anode terminal 127 and the second anode terminal 129 to the capacitor element 120 may be made using any known technique, such as welding, laser welding, or conductive adhesive. In a particular embodiment, for example, the first conductive adhesive 131a may be used to connect the second portion 165a of the first anode lead connector 162a to the first anode terminal 127. Alternatively, the second conductive adhesive 131b may be used to connect the second portion 165b of the second anode lead connector 162b to the second anode terminal 129. The conductive adhesive may be formed from conductive metal particles contained together with the resin composition. The metal particles may be silver, copper, gold, platinum, nickel, zinc, bismuth, etc. The resin composition may include a thermosetting resin (e.g., epoxy resin), a curing agent (e.g., acid anhydride), and a coupling agent (e.g., silane coupling agent). A suitable conductive adhesive is described, for example, in the aforementioned Patent Document 9.

[0098] The cathode of the capacitor element 120 is also connected to the cathode terminal 305, which provides the mounting surface 309. In one embodiment, for example, one or more conductive traces (e.g., conductive trace 307) may extend within the outer wall 123 of the housing to connect the bottom surface of the capacitor element 120 to the cathode terminal 305. In addition to extending through the outer wall of the housing, the traces may be positioned in other locations, such as outside the outer wall. Naturally, the present invention is by no means limited to the use of conductive traces to form a desired terminal. Regardless of the specific configuration used, the connection between the cathode terminal 305 and the capacitor element 120 may be made using any known technique, such as welding, laser welding, or conductive adhesive. In a particular embodiment, for example, a conductive adhesive 131c as described above may be used to connect the bottom surface of the capacitor element 120 to the cathode terminal 305. Naturally, it should also be understood that a cathode connecting member similar to the anode connecting member described above may be used to facilitate the connection between the capacitor element 120 and the cathode terminal 305, rather than being directly connected by the methods described above.

[0099] If necessary, the polymer restraint may be positioned in contact with one or more surfaces of the capacitor element, such as the rear, front, top, bottom, side, or any combination thereof. The polymer restraint can reduce the possibility of delamination of the capacitor element from the housing. In this regard, the polymer restraint may possess a certain strength that allows the capacitor element to be held in a relatively fixed position even when subjected to vibratory forces, but not so strong as to prevent cracking. For example, the restraint may possess a tensile strength of about 1 megapascal to about 150 megapascals ("MPa"), about 2 MPa to about 100 MPa in some embodiments, about 10 MPa to about 80 MPa in some embodiments, and about 20 MPa to about 70 MPa in some embodiments, measured at a temperature of about 25°C. Typically, it is desirable that the restraint is not conductive.

[0100] Any of the various materials may be used that have the desired strength characteristics described above, but curable thermosetting resins have been found to be particularly suitable for use in the present invention. Examples of such resins include epoxy resins, polyimides, melamine resins, urea-formaldehyde resins, polyurethanes, silicone polymers, phenolic resins, and the like. In certain embodiments, for example, one or more polyorganosiloxanes may be used as the restraining material. The silicon-bonded organic groups used in these polymers may contain monovalent hydrocarbons and / or monovalent halogenated hydrocarbon groups. Such monovalent groups typically have one to about 20 carbon atoms, preferably one to 10 carbon atoms, and are exemplified, but are not limited to, alkyl (e.g., methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl); cycloalkyl (e.g., cyclohexyl); alkenyl (e.g., vinyl, allyl, butenyl, and hexenyl); aryl (e.g., phenyl, tolyl, xylyl, benzyl, and 2-phenylethyl); and halogenated hydrocarbon groups (e.g., 3,3,3-trifluoropropyl, 3-chloropropyl, and dichlorophenyl). Typically, at least 50%, more preferably at least 80%, of the organic groups are methyl. Examples of such methylpolysiloxanes may include, for example, polydimethylsiloxane ("PDMS"), polymethylhydrogensiloxane, and the like. Other suitable methylpolysiloxanes may include dimethyldiphenylpolysiloxane, dimethyl / methylphenylpolysiloxane, polymethylphenylsiloxane, methylphenyl / dimethylsiloxane, vinyldimethyl-terminated polydimethylsiloxane, vinylmethyl / dimethylpolysiloxane, vinyldimethyl-terminated vinylmethyl / dimethylpolysiloxane, divinylmethyl-terminated polydimethylsiloxane, vinylphenylmethyl-terminated polydimethylsiloxane, dimethylhydro-terminated polydimethylsiloxane, methylhydro / dimethylpolysiloxane, methylhydro-terminated methyloctylpolysiloxane, methylhydro / phenylmethylpolysiloxane, and the like.

[0101] Organic polysiloxanes may contain one or more lateral and / or terminal polar functional groups, such as hydroxyl groups, epoxy groups, carboxyl groups, amino groups, alkoxy groups, methacrylic groups, or mercapto groups, which impart some degree of hydrophilicity to the polymer. For example, an organic polysiloxane may contain at least one hydroxyl group and, optionally, at least two silicon-bonded hydroxyl groups (silanol groups) per molecule. Examples of such organic polysiloxanes include, for example, dihydroxypolydimethylsiloxane and hydroxy-trimethylsiloxypolydimethylsiloxane. Other examples of hydroxy-modified organic polysiloxanes are described in the aforementioned Patent Document 10, which is incorporated herein in whole by reference for all purposes. Examples of alkoxy-modified organic polysiloxanes include, for example, dimethoxypolydimethylsiloxane, methoxy-trimethylsiloxypolydimethylsiloxane, diethoxypolydimethylsiloxane, and ethoxy-trimethylsiloxy-polydimethylsiloxane. Furthermore, other suitable organic polysiloxanes are those modified with at least one amino functional group. Examples of such amino-functional polysiloxanes include, for example, diamino-functional polydimethylsiloxane. Various other suitable polar functional groups relating to organic polysiloxanes are also described in the aforementioned Patent Document 11, which is incorporated herein in whole by reference for all purposes.

[0102] Epoxy resins are also particularly suitable for use as polymer restraints. Examples of suitable epoxy resins include, for example, bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenol novolac type epoxy resins, orthocresol novolac type epoxy resins, brominated epoxy resins and biphenyl type epoxy resins, cyclic aliphatic epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, cresol novolac type epoxy resins, naphthalene type epoxy resins, phenol aralkyl type epoxy resins, cyclopentadiene type epoxy resins, heterocyclic epoxy resins, and glycidyl ether type epoxy resins. Further other suitable conductive adhesive resins may also be described in the aforementioned Patent Document 12, which is incorporated herein in whole by reference for all purposes.

[0103] If desired, a curing agent may also be used in the polymer restraint to help accelerate curing. The curing agent typically constitutes about 0.1% to about 20% by mass of the restraint. Exemplary curing agents include, for example, amines, peroxides, anhydrides, phenolic compounds, silanes, acid anhydride compounds, and combinations thereof. Specific examples of suitable curing agents include dicyandiamide, 1-(2-cyanoethyl)2-ethyl-4-methylimidazole, 1-benzyl2-methylimidazole, ethylcyanopropylimidazole, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-methylimidazole, 2,4-dicyano-6,2-methylimidazolyl-(1)- These include ethyl-s-triazine and 2,4-dicyano-6,2-undecylimidazolyl-(1)-ethyl-s-triazine, imidazolium salts (for example, 1-cyanoethyl-2-undecylimidazolium trimellitate, 2-methylimidazolium isocyanurate, 2-ethyl-4-methylimidazolium tetraphenylborate, and 2-ethyl-1,4-dimethylimidazolium tetraphenylborate).Other useful curing agents include, for example, phosphine compounds such as tributylphosphine, triphenylphosphine, tris(dimethoxyphenyl)phosphine, tris(hydroxypropyl)phosphine, and tris(cyanoethyl)phosphine; phosphonium salts such as, for example, tetraphenylphosphonium-tetraphenylborate, methyltributylphosphonium-tetraphenylborate, and methyltricyanoethylphosphonium-tetraphenylborate; and, for example, 2,4,6-tris(dimethylaminomethyl)phenol and benzylmethylamine. This includes amines such as tetramethylbutylguanidine, N-methylpiperazine, and 2-dimethylamino-1-pyrroline; ammonium salts such as triethylammonium tetraphenylborate; diazabicyclo compounds such as 1,5-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3,0]-5-nonene, and 1,4-diazabicyclo[2,2,2]-octane; and salts of diazabicyclo compounds such as tetraphenylborate, phenol salts, phenol novolac salts, and 2-ethylhexanoate.

[0104] Further additives may include photoinitiators, viscosity modifiers, suspension aids, pigments, stress reducers, coupling agents (e.g., silane coupling agents), non-conductive fillers (e.g., clay, silica, alumina, etc.), stabilizers, etc. Suitable photoinitiators may include, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin n-propyl ether, benzoin isobutyl ether, 2,2-dihydroxy-2-phenylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, benzophenone, 4,4-bisdiallylaminobenzophenone, 4-dimethylaminobenzoic acid, alkyl 4-dimethylaminobenzoate, 2-ethylanthraquinone, xanthone, thioxanthone, 2-chlorothioxanthone, etc. When used, such additives typically constitute about 0.1% to about 20% by mass of the total composition.

[0105] In one embodiment, for example, a single polymer restraint may be positioned in contact with the top and rear surfaces of the capacitor element. It should also be understood that separate restraints may be used to achieve the same function. In fact, more generally, any number of polymer restraints may be used to contact any desired surface of the capacitor element. When multiple restraints are used, they may be in contact with each other or remain physically separated. For example, in one embodiment, a second polymer restraint may be used in contact with the top and front surfaces of the capacitor element. The first and second polymer restraints may or may not be in contact with each other. In yet another embodiment, the polymer restraint may be in contact with the bottom and / or sides of the capacitor element in conjunction with, or instead of, other surfaces. When used, it is also desirable that the polymer restraint be in contact with at least one surface of the housing to help further mechanically stabilize the capacitor element against possible delamination. For example, the restraint may be in contact with one or more inner surfaces of side walls, outer walls, lids, etc.

[0106] After connection by the desired method, the resulting package may be sealed as described above. Referring again to Figures 2 and 3, for example, the housing 122 may include a lid 125 positioned on the upper surface of the side wall 124 after the capacitor element 120 has been positioned within the housing 122. The lid 125 may be made of ceramic, metal (e.g., iron, copper, nickel, cobalt, etc., and alloys thereof), plastic, etc. If desired, a sealing member 187 may be placed between the lid 125 and the side wall 124 to help provide a good seal. In one embodiment, for example, the sealing member may include a glass-metal sealant, a Kovar® ring (Goodfellow Cambridge, Inc.), etc. The height of the side wall 124 is generally such that the lid 125 does not come into contact with or contaminate any surface of the capacitor element 120. When positioned in the desired location, the lid 125 is sealed to the side wall 124 using known techniques such as welding (e.g., resistance welding, laser welding, etc.) or soldering. Sealing may be carried out, if necessary, in the presence of the aforementioned gaseous atmosphere, so that the resulting condenser does not substantially contain reactive gases such as water vapor.

[0107] Naturally, the embodiments described above are merely examples of methods for incorporating capacitor elements within a housing. Further possible housing configurations may be used in the present invention. For example, a capacitor may be formed similarly to the embodiments described above, except that terminal pins are used as external terminals for the anode and cathode, respectively. In other words, the first terminal pin may extend through a trace formed on the outer wall and be connected to the first anode lead using a known technique (e.g., welding). Similarly, the second terminal pin may extend through a trace formed on the outer wall and be connected to the cathode via the conductive adhesive 133 described above. The embodiments shown in Figures 2 and 3 are discussed herein with respect to a single capacitor element only. However, it should be understood that multiple capacitor elements may be sealed within a housing. Multiple capacitor elements may be attached to the housing using any of a variety of different techniques.

[0108] The present invention can be better understood by referring to the following embodiments.

[0109] (Test Procedure) S-parameters S 11 and S 21 The parameters can be measured using a Vector Network Analyzer over various frequencies. The parameters may also be modeled using the equivalent circuit shown in Figure 5.

[0110] Equivalent series resistance (ESR) The equivalent series resistance may be measured using an HP4284A LCR meter with Kelvin Leads, under a 0-volt DC bias and a 10 mVAC signal. The operating frequency was 100 kHz, and the temperature was 23°C ± 2°C. The ESR may be measured through the cathode terminal and one or more anode terminals. When multiple anode terminals are used, the average ESR may be reported.

[0111] Dissipation coefficient The dissipation coefficient can be measured using an LCZHP4284A LCR meter with Kelvin Leads, under a 0-volt DC bias and a 10 mVAC signal. The operating frequency may be 120 Hz, and the temperature may be 23°C ± 2°C.

[0112] ·capacitance Capacitance may be measured using a Keithley 3330 Precision LCZ meter with Kelvin Leads, with a 2.2-volt DC bias and a 0.5-volt peak-to-peak sinusoidal signal. The operating frequency may be 120 Hz, and the temperature may be 23°C ± 2°C.

[0113] • Leakage current The leakage current may be measured using a leakage test meter (YHP4140B) at a temperature of 23°C ± 2°C, with a 1kΩ resistor to limit the charging current, and at the rated voltage (e.g., 2.5V) after a minimum of 5 minutes. [Examples]

[0114] Anode samples were formed using tantalum powder at 40,000 μFV / g. Each anode sample was measured at 6.0 g / cm³. 3 The material was pressurized to a density of 2.90 × 2.56 × 1.27 mm. 3The pellets had the following dimensions. The pellets were sintered at 1275°C, and then the first and second tantalum wires were attached to the opposing ends of the pellets by welding. After lead welding, the pellets were deoxidized at 860°C and sintered again at 1300°C. The pellets were anodized to 76 volts in a water / phosphate electrolyte at 40°C to form a dielectric layer. After anodizing, four precoat layers of organometallic compounds containing a solution of (3-aminopropyl)trimethoxysilane dissolved in ethanol (1.0%) were used. Next, a conductive polymer coating was formed by immersing the anode in a solution of poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butane-sulfonic acid) having a solid content of 2.0% (Clevios® K. Heraeus). After coating, the part was dried at 125°C for 15 minutes. This process was repeated twice. Subsequently, the part was immersed in dispersed poly(3,4-ethylenedioxythiophene) having a solid content of 1.1% and a viscosity of 20 mPa·s (Clevios® K. Heraeus). After coating, the part was dried at 125°C for 15 minutes. This process was repeated eight times. Subsequently, the part was immersed in a solution of poly(3,4-ethylenedioxythiophene) having a solid content of 2.0% The parts were immersed in dispersed poly(3,4-ethylenedioxythiophene) having a solid content of 2.0% and a viscosity of 20 mPa·s (Clevios® K. Heraeus). After coating, the parts were dried at 125°C for 20 minutes. This process was repeated three times. Subsequently, the parts were immersed in dispersed poly(3,4-ethylenedioxythiophene) having a solid content of 2.0% and a viscosity of 160 mPa·s (Clevios® K. Heraeus). After coating, the parts were dried at 125°C for 20 minutes. This process was repeated 14 times. Next, a graphite dispersion was applied to the parts and dried. Next, a silver dispersion was applied to the parts and dried. Finally, the parts were mounted on the substrate with terminals as described herein and shown in Figure 1A.

[0115] Multiple components (10) of a 22μF / 35V capacitor were fabricated in this manner and hermetically sealed in the ceramic package described herein. The resulting components were then tested for various electrical characteristics. The results are shown in the table below.

[0116] [Table 1]

[0117] Note that "ESR 1" in Table 1 represents the ESR of the measured component that contacts the first anode and cathode terminals. "ESR 2" in Table 1 represents the ESR of the measured component that contacts the second anode and cathode terminals.

[0118] These and other modifications and variations of the present invention can be practiced by those skilled in the art without departing from the spirit and scope of the invention. Furthermore, it should be understood that the various embodiments may be interchangeable, either in whole or in part. Furthermore, those skilled in the art will understand that the foregoing description is merely an example and is not limited to the invention further described in the appended claims. [Explanation of Symbols]

[0119] 7a Insulating material 7b Insulating materials 10 Anode Body 12. First anode lead 14. Second exposed anode lead portion 16 First end 18. Second end 22 consecutive anode reads 24 Embedded portion 26 First anode lead portion 28 Embedded end 32 Embedded portion 34 Second anode lead portion 100 Capacitors 120 Capacitor elements 122 Housing 123 Exterior Wall 124 Side wall 125 Lid 126 internal cavities 127 First anode terminal 127a First area 127b Second area 127c First conductive trace 129 Second anode terminal 129a First area 129b Second area 129c Second conductive trace 131a First conductive adhesive 131b Second conductive adhesive 131c conductive adhesive 133 Conductive adhesive 162 First anode connecting member 162a First anode lead connecting member 162b Second anode lead connecting member 165a Second part 165b Part 2 167a Part 1 167b Part 1 187 Sealing member 201 Implementation aspects 203 Implementation aspects 305 Cathode terminal 307 Conductive Trace 309 Implementation side

Claims

1. A capacitor element comprising a sintered anode body, a dielectric layer overlapping the anode body, and a solid electrolyte layer overlapping the dielectric, wherein the solid electrolyte comprises a conductive polymer, the capacitor element defines opposing first and second ends, an upper surface, and an opposing lower surface, the first exposed anode lead portion extending laterally from the first end of the capacitor element, and the second exposed anode lead portion extending laterally from the second end of the capacitor element, A housing defining an internal cavity, wherein the capacitor element is positioned and sealed within the internal cavity, and the first exposed anode lead portion and the second exposed anode lead portion are positioned within the internal cavity. The first anode terminal is electrically connected to the first exposed anode lead portion, The second anode terminal, which is electrically connected to the second exposed anode lead portion, The cathode terminal electrically connected to the solid electrolyte, A capacitor equipped with the following features.

2. The capacitor according to claim 1, wherein the anode body contains tantalum and the dielectric contains tantalum pentoxide.

3. The capacitor according to claim 1, wherein the solid electrolyte contains at least one layer formed from a dispersion of conductive polymer particles.

4. The capacitor according to claim 1, wherein the conductive polymer comprises poly(3,4-ethylenedioxythiophene) or a derivative thereof.

5. The capacitor according to claim 1, wherein the anode body is formed from valve metal powder having a specific charge ratio of approximately 5,000 to approximately 100,000 μF·V / g.

6. The capacitor according to claim 1, wherein the anode body is formed from valve metal powder having a specific charge ratio of about 100,000 to about 600,000 μF·V / g.

7. The capacitor according to claim 1, wherein the first anode lead is embedded in the anode body, which includes the first exposed anode lead portion and the embedded portion.

8. The capacitor according to claim 7, further comprising a second anode lead including the second exposed anode lead portion.

9. The capacitor according to claim 8, wherein the second anode lead is connected to the end of the anode body.

10. The capacitor according to claim 9, wherein the gap exists between the end of the embedded portion and the end of the anode body.

11. The capacitor according to claim 10, wherein the second anode lead is embedded in the anode body and includes an embedded portion.

12. The capacitor according to claim 11, wherein a gap exists between the end of the embedded portion of the first anode lead and the end of the embedded portion of the second anode lead.

13. The capacitor according to claim 1, wherein a continuous anode lead extends through the first end and the second end of the capacitor element, thereby defining the first exposed anode lead portion and the second exposed anode lead portion.

14. The capacitor according to claim 1, wherein the housing is formed from metal, plastic, ceramic, or a combination thereof.

15. The capacitor according to claim 1, further comprising a first anode lead connecting member, which includes a first portion positioned substantially perpendicular to the lateral direction of the first exposed anode lead portion and connected thereto.

16. The capacitor according to claim 15, wherein the first anode lead connecting member further includes a second portion substantially parallel to the transverse direction, which is the direction in which the first exposed anode lead portion extends.

17. The capacitor according to claim 16, wherein the second portion of the first anode lead connecting member is positioned within the housing.

18. The capacitor according to claim 15, wherein the first anode terminal includes a first region positioned within the housing and electrically connected to the first anode lead connecting member, and a second region positioned outside the housing and providing a mounting surface.

19. The capacitor according to claim 18, wherein the first conductive trace extends within the outer wall of the housing to connect the first region and the second region of the first anode terminal.

20. The capacitor according to claim 15, further comprising a second anode lead connecting member which includes a first portion positioned substantially perpendicular to the lateral direction of the second exposed anode lead portion and connected thereto.

21. The capacitor according to claim 20, wherein the second anode lead connecting member further includes a second portion substantially parallel to the transverse direction, which is the direction in which the second exposed anode lead portion extends.

22. The capacitor according to claim 21, wherein the second portion of the second anode lead connecting member is positioned within the housing.

23. The capacitor according to claim 20, wherein the second anode terminal includes a first region positioned within the housing and electrically connected to a second anode connecting member, and a second region positioned outside the housing and providing a mounting surface.

24. The capacitor according to claim 23, wherein a second conductive trace extends within the outer wall of the housing and connects the first region and the second region of the second anode terminal.

25. The capacitor according to claim 1, wherein the conductive trace extends within the outer wall of the housing to connect the lower surface of the capacitor element to the cathode terminal.

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