Low-inductance electrolytic capacitor

Abstract

Provided is a capacitor capable of exhibiting good electrical performance under a variety of different conditions. The capacitor includes a capacitor element including a sintered porous anode body, a dielectric overlying the anode body, and a solid electrolyte overlying the dielectric and including a conductive polymer. The capacitor also includes a plurality of anode lead portions extending from an end of the capacitor element. The capacitor also includes a housing defining an interior cavity in which the capacitor element is positioned and hermetically sealed.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 491,551, filed on March 22, 2023, which is incorporated herein by reference in its entirety. Background of the Invention

[0003] Decoupling capacitors are commonly used to manage noise issues that arise in circuit applications. They provide a stable local charge source required to switch and refresh logic gates used in various digital circuits. However, decoupling capacitors must now be able to operate at lower voltages and higher currents, requiring performance characteristics such as a lower Equivalent Series Resistance (ESR), a higher capacitance, and a lower inductance (or ESL - Equivalent Series Inductance) within such capacitors to function at the levels required for various applications in the current environment. In particular, as the switching speed increases in electronic circuit applications, the need to reduce inductance becomes a severe limitation for improving system performance. Solid electrolytic capacitors (e.g., tantalum capacitors) are typically made by pressing a metal powder (e.g., tantalum) around a metal lead, sintering the pressed component, anodizing the sintered anode, and then applying a solid electrolyte. Conductive polymers are commonly used as the solid electrolyte due to their advantages of low equivalent series resistance and a "non - burning / non - igniting" failure mode. However, despite the significant advantages of solid electrolytic capacitors in terms of ESR, solid electrolytic capacitors cannot withstand high - frequency applications and cannot exhibit the low inductance characteristics required for decoupling and high - speed switching. Therefore, there is a current need for a solid electrolytic capacitor with improved performance. Summary of the Invention

[0004] According to an embodiment of the present invention, a solid electrolytic capacitor is disclosed. The solid electrolytic capacitor includes a capacitor element, which includes a sintered anode body, a dielectric covering the anode body, and a solid electrolyte covering the dielectric. The solid electrolyte includes a conductive polymer. The capacitor element defines opposite first and second ends and an upper surface and an opposite lower surface. A first exposed anode lead portion extends in a lateral direction from the first end of the capacitor element, and a second exposed anode lead portion extends in a lateral direction from the second end of the capacitor element. The capacitor further includes a housing that defines an internal cavity, and the capacitor element is positioned and hermetically sealed within the internal cavity, wherein the first exposed anode lead portion and the second exposed anode lead portion 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.

[0005] Other features and aspects of the present invention are set forth in greater detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In the remainder of this specification, a complete and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth in more specific detail. This specification makes reference to the following drawings, in which:

[0007] Figure 1A is a side view of an embodiment of an anode body that can be used to form the capacitor of the present invention;

[0008] Figure 1B is a side view of another embodiment of an anode body that can be used to form the capacitor of the present invention;

[0009] Figure 1C is a side view of yet another embodiment of an anode body that can be used to form the capacitor of the present invention;

[0010] Figure 2 is a cross-sectional view of an embodiment of the capacitor of the present invention.

[0011] Figure 3 is for Figure 2 the bottom view of the capacitor;

[0012] Figure 4 is a graphical representation of the S 11 and S 21 parameters modeled and measured across a wide frequency range for Example 1.

[0013] Figure 5 is an exemplary equivalent circuit used in Example 1. Detailed implementation mode

[0014] Those of ordinary skill in the art should understand that this discussion is only a description of exemplary embodiments and is not intended to limit the broader aspects of the present invention, where the broader aspects are embodied in the exemplary construction.

[0015] Generally speaking, the present invention relates to a capacitor that can exhibit good electrical performance under a variety of different conditions. The capacitor includes a capacitor element, which includes a sintered porous anode body, a dielectric covering the anode body, and a solid electrolyte covering the dielectric and including a conductive polymer. The capacitor element includes opposite first and second ends and opposite 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, and the capacitor element is positioned within the internal cavity and sealed.

[0016] By selectively controlling its specific configuration, the resulting capacitor can exhibit a low ESL value, such as about 1 nanohenry or less, about 750 picohenries (picohenry) or less in some embodiments, about 350 picohenries or less in some embodiments, about 1 femtohenry to about 100 picohenries in some embodiments, and about 50 femtohenries to about 10 picohenries in some embodiments. The low ESL value can also be characterized by a low impedance value, which is a reflection of parasitic inductance. The impedance can be, for example, about 1 ohm or less, about 0.8 ohm or less in some embodiments, about 0.6 ohm or less in some embodiments, and about 1 milliohm to about 0.3 ohm in some embodiments. Such a low ESL (e.g., impedance) can be exhibited even over a wide frequency range (such as 1 kHz to about 100 MHz, about 100 kHz to about 100 MHz in some embodiments, and about 1 MHz to about 100 MHz in some embodiments). Minimizing parasitic inductance over a wide frequency range helps to obtain good performance, especially good decoupling performance, particularly under high-speed transient conditions. In addition to exhibiting a low ESL value, the capacitor can also exhibit a low ESR value, such as about 800 milliohms or less measured at an operating frequency of 100 kHz and a temperature of 23 °C, 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 to about 250 milliohms in some embodiments, and about 0.1 to about 150 milliohms in some embodiments.

[0017] Notably, even at high temperatures and / or high humidity levels, the low ESR and ESL values remain stable. The ability to operate 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, even after exposure to a temperature of about 80 °C or higher, in some embodiments about 85 °C to about 180 °C, and in some embodiments about 85 °C to about 150 °C (e.g., about 85 °C, 105 °C, 125 °C, or 150 °C) and / or a relative humidity level of about 40% or higher, in some embodiments about 45% or higher, in some embodiments about 50% or higher, and in some embodiments about 70% or higher (e.g., about 85% to 100%) for a relatively long period of time as described above, the resulting capacitor can still exhibit ESR and / or ESL values within the ranges described above. For example, the relative humidity can be determined according to Method A (2007) of ASTM E337-02. The period of time for exposure to high temperature and / or high humidity levels can be about 100 hours or longer, in some embodiments about 150 hours to about 3,000 hours, and in some embodiments about 200 hours to about 2,500 hours (e.g., 250 hours, 500 hours, 750 hours, or 1,000 hours). For example, measured at a working frequency of 100 kHz and a temperature of 23 °C, after exposure to high temperature (e.g., about 85 °C) and / or high humidity (e.g., about 85%) for 500 hours, the ESR of the capacitor can be about 1,500 milliohms or less, in some embodiments about 1,000 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 to about 500 milliohms, and in some embodiments about 0.1 to about 200 milliohms. Similarly, the ratio of the ESR of the capacitor after exposure to high temperature (e.g., about 85 °C) and / or high 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 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.

[0018] Due to its ability to provide a combination of low ESL and ESR values, the resulting capacitor can be uniquely positioned to provide robust broadband decoupling and high-speed switching. For example, a single capacitor according to the present invention can be used to replace multiple low-capacitance or limited-frequency decoupling capacitors, allowing the capacitor to utilize less space (such as having a smaller height), thereby further improving miniaturization.

[0019] Capacitors can exhibit excellent direct current (DC) power filtering performance, such as the excellent attenuation exhibited across a wide frequency range. As is known in the art, the power transfer between the insertion loss measurement terminals is measured. If the power increases, it exhibits gain, and if the power between the terminals decreases, it exhibits attenuation. Thus, capacitors can exhibit high attenuation across a wide frequency range, allowing for good filtering of a wide frequency range. For example, a capacitor can exhibit an attenuation (S 21 parameter) of about 15 dB or higher, about 25 dB or higher in some embodiments, about 30 dB or higher in some embodiments, about 35 dB to about 70 dB in some embodiments, and about 50 dB to about 70 dB in some embodiments. This attenuation can be exhibited across a wide frequency range. For example, in the low frequency range of about 0.1 MHz to about 500 MHz, and in some cases, in the low frequency range of about 1 MHz to about 100 MHz, a capacitor can exhibit an attenuation (S 21 parameter) of about 40 dB or higher, about 50 dB or higher in some embodiments, about 55 dB or higher in some embodiments, and about 60 dB to about 70 dB in some embodiments. Similarly, at high frequencies in the range of about 500 MHz to about 10 GHz, and in some cases at high frequencies in the range of about 1 GHz to about 5 GHz, a capacitor can exhibit an attenuation (S 21 parameter) of about 20 dB or higher, about 25 dB or higher in some embodiments, about 30 dB or higher in some embodiments, and about 30 dB to about 60 dB in some embodiments. Among other things, this attenuation can allow the capacitor to be easily used in DC power filtering applications. In addition, the capacitor can operate continuously across a wide temperature range. For example, in one embodiment, the capacitor can vary by about 5 dB or less over a large temperature range, such as a temperature change of about 25 °C or greater, about 50 °C or greater in some embodiments, and about 70 °C or greater in some embodiments.

[0020] Capacitors can also exhibit other beneficial electrical properties. For example, capacitors can exhibit low leakage current ("DCL") under various conditions. Additionally, after applying a voltage (e.g., 16 volts) at a temperature of about 23°C for a period of time (e.g., about 30 minutes to about 20 hours, in some embodiments about 1 hour to about 18 hours, in some embodiments 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, and in some embodiments about 0.01 to about 5 μA. In one embodiment, the DCL of the capacitor after being exposed to high temperature (e.g., about 85°C) and / or high humidity level (e.g., about 85%) for 500 hours can also be about 10 μA or less, in some embodiments about 8 μA or less, in some embodiments about 6 μA or less, and in some embodiments about 0.1 μA to about 5 μA. Similarly, the ratio of the DCL of the capacitor after being exposed to high temperature (e.g., about 85°C) and / or high 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, and in some embodiments about 0.9 to about 4. The capacitor can also exhibit a dry capacitance measured at a temperature of 23°C and a frequency of 120 Hz of about 30 nanofarads (nanoFarad) per square centimeter ("nF / cm 2 ") or greater, in some embodiments about 100 nF / cm 2 or greater, in some embodiments about 200 to about 3,000 nF / cm 2 and, in some embodiments, about 400 to about 2,000 nF / cm 2 . The actual capacitance value may vary, such as about 10 μF to about 1,000 μF, in some embodiments about 50 μF to about 500 μF, and in some embodiments about 60 μF to about 250 μF. Similar to the DCL and ESR values, the capacitance can also remain stable within the above high temperature and / or high humidity level ranges. For example, in one embodiment, the ratio of the capacitance value of the capacitor after being exposed to high temperature (e.g., about 85°C) and / or high humidity level (e.g., about 85%) for 500 hours to the initial capacitance value of the capacitor (e.g., at about 23°C) can be 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 about 0.9 to about 1.3.

[0021] It is also believed that the loss 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 typically expressed as a percentage of the performance of an ideal capacitor. For example, the dissipation factor of a capacitor measured at a frequency of 120 Hz is generally about 250% or less, about 200% or less in some embodiments, and about 1% to about 180% in some embodiments.

[0022] Various embodiments of the capacitor will now be described in more detail.

[0023] I. Capacitor element

[0024] A. Anode body

[0025] The anode body is formed from a powder comprising a valve metal (i.e., a metal capable of being oxidized) or a valve metal-based compound (such as tantalum, niobium, aluminum, hafnium, titanium, their alloys, their oxides, and their nitrides, etc.). Depending on the desired application, the specific charge of the powder typically varies between about 5,000 and about 800,000 microfarads * volts per gram ("μF*V / g"). For example, in certain embodiments, a high-charge powder having a specific charge of about 100,000 to about 600,000 μF*V / g, about 120,000 to about 500,000 μF*V / g in some embodiments, and about 150,000 to about 400,000 μF*V / g in some embodiments can be used. In other embodiments, a low-charge powder having a specific charge of about 5,000 to about 100,000 μF*V / g, about 8,000 to about 90,000 μF*V / g in some embodiments, and about 10,000 to about 80,000 μF*V / g in some embodiments can be employed. As is known in the art, the specific charge can be determined by multiplying the capacitance by the anodization voltage employed and then dividing the product by the weight of the anodized electrode body.

[0026] For example, in one embodiment, the powder is formed of tantalum. If desired, a reduction process can be employed in which a tantalum salt (e.g., potassium heptafluorotantalate (K2TaF7), sodium heptafluorotantalate (Na2TaF7), tantalum pentachloride (TaCl5), etc.) is reacted with a reducing agent. The reducing agent can be provided in the form of a liquid, a gas (e.g., hydrogen), or a solid (such as a metal (e.g., sodium), a metal alloy, or a metal salt). For example, in one embodiment, a tantalum salt (e.g., TaCl5) can be heated at a temperature of from about 900 °C to about 2,000 °C, in some embodiments from about 1,000 °C to about 1,800 °C, and in some embodiments from about 1,100 °C to about 1,600 °C to form a vapor that can be reduced in the presence of a gaseous reducing agent (e.g., hydrogen). Other details of such reduction reactions can be described in Maeshima et al. WO2014 / 199480. After reduction, the product can be cooled, pulverized, and washed to form the powder.

[0027] The powder can be a free-flowing, subdivided powder comprising primary particles. Optionally after subjecting the particles to 70 seconds of ultrasonic vibration, the median size (D 50 ) of the primary particles of the powder is typically from about 5 to about 250 nanometers, in some embodiments from about 10 to about 200 nanometers, and in some embodiments from about 20 to about 150 nanometers, such as measured using a laser particle size distribution analyzer (e.g., LS-230) manufactured by BECKMAN COULTER Corporation. 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 can be about 4 or less, in some embodiments about 3 or less, and in some embodiments from about 1 to about 2. In addition to the primary particles, the powder can also contain other types of particles, such as secondary particles formed by aggregating (or agglomerating) the primary particles. The median size (D50) of such secondary particles can be from about 1 to about 500 micrometers, and in some embodiments from about 10 to about 250 micrometers.

[0028] Agglomeration of the particles can occur by heating the particles and / or by using a binder. For example, agglomeration can occur at a temperature of 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 can likewise include, for example, poly(vinyl butyral); poly(vinyl acetate); poly(vinyl alcohol); poly(vinyl pyrrolidone); cellulose polymers such as carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose and methyl hydroxyethyl cellulose; atactic polypropylene, polyethylene; polyethylene glycol (e.g., Carbowax from Dow Chemical Co.); 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 fluorinated olefin copolymers; acrylic polymers such as sodium polyacrylate, poly(lower alkyl acrylate), poly(lower alkyl methacrylate), and copolymers of lower alkyl acrylate and lower alkyl methacrylate; and fatty acids and waxes such as stearic acid and other soapy fatty acids, vegetable waxes, microcrystalline wax (purified paraffin wax), etc. If desired, the powder can also be doped with a sintering flame retardant in the presence of a dopant such as an aqueous acid (e.g., phosphoric acid). The amount of dopant added depends in part on the surface area of the powder, but is typically present in an amount not exceeding about 200 parts per million (ppm). The dopant can be added before, during and / or after agglomeration. The powder can also be subjected to one or more deoxidation treatments. For example, the powder can be exposed to a getter material (e.g., magnesium) as described, for example, in U.S. Patent No. 4,960,471. The temperature at which deoxidation of the powder occurs can vary, but is typically in the range of from about 700 °C to about 1,600 °C, in some embodiments from about 750 °C to about 1,200 °C and in some embodiments from about 800 °C to about 1,000 °C. The total time of the deoxidation treatment can be in the range of from about 20 minutes to about 3 hours.

[0029] The resulting powder has certain properties that enhance its ability to form a capacitor anode. For example, the specific surface area of the powder is typically from about 0.5 to about 10.0 m 2 / g, in some embodiments from about 0.7 to about 5.0 m 2 / g, and in some embodiments from about 2.0 to about 4.0 m 2 / g. Likewise, the bulk density of the powder can be from about 0.1 to about 0.8 grams per cubic centimeter (g / cm 3)、In some embodiments, from about 0.2 to about 0.6 g / cm 3 、and in some embodiments, from about 0.4 to about 0.6 g / cm 3 .

[0030] Once the powder is formed, it is then typically pressed or compacted using any conventional powder pressing equipment to form pellets. For example, a die press can be employed, which is a single station compaction press that includes a die and one or more punches. Alternatively, an anvil-type compaction die that uses only a die and a single lower punch can be used. There are several basic types of single station compaction presses available, such as cam presses, toggle / knuckle presses, and eccentric / crank presses with different capabilities (such as single action, double action, floating die, moving platen, opposed ram, screw, impact, hot pressing, coining, or sizing). The powder is typically compacted to a density of about 0.5 to about 20 g / cm 3 、in some embodiments, from about 1 to about 15 g / cm 3 and in some embodiments, from about 2 to about 10 g / cm 3 .

[0031] After pressing, any binder can be removed by heating the pellets under vacuum at a certain temperature (e.g., from about 150 °C to about 500 °C) for a few minutes. Alternatively, the binder can also be removed by contacting the pellets with an aqueous solution, such as Bishop et al.As described in U.S. Patent No. 6,197,252. After removing the binder, the anode body can undergo an optional deoxidation process. For example, in one embodiment, the deoxidation process includes exposing the anode body to a getter material (e.g., magnesium, titanium, etc.), which can remove oxygen from the anode body through chemical reactions, adsorption, etc. More specifically, the anode body is first inserted into an encapsulation body (e.g., tantalum box) that also contains the getter material. The atmosphere inside the encapsulation body is typically an inert atmosphere (e.g., argon). To initiate deoxidation, the atmosphere inside the encapsulation body is heated to a temperature sufficient to melt and / or evaporate the getter material and deoxidize the anode body. The temperature can vary depending on the charge-to-mass ratio of the anode powder, but is typically in the range of about 700 °C to about 1200 °C, in some embodiments about 750 °C to about 1,100 °C, and in some embodiments about 800 °C to about 1,000 °C. The total deoxidation time can be in the range of about 20 minutes to about 3 hours. This can occur in one or more steps. When deoxidation is complete, the getter material typically evaporates and forms a precipitate on the walls of the encapsulation body. To ensure removal of the getter material, the anode body can also undergo one or more acid leaching steps, such as acid leaching with a solution of nitric acid, hydrofluoric acid, hydrogen peroxide, sulfuric acid, water, etc., or a combination thereof.

[0032] The resulting anode body can thus have a relatively low oxygen content. For example, the anode body can have no more than about 5,500 ppm of oxygen, in some embodiments no more than about 5,000 ppm of oxygen, and in some embodiments about 500 ppm to about 4,500 ppm of oxygen. The oxygen content can be measured by a LECO oxygen analyzer, and the oxygen content 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 lattice, and the bulk oxygen content increases linearly with the increase in the oxygen content in tantalum until the solubility limit is reached. This method is described in "Critical Oxygen Content In Porous Anodes Of Solid Tantalum Capacitors", Pozdeev-Freeman et al., Journal of Materials Science: Materials In Electronics 9, (1998) 309-311, where X-ray diffraction analysis (XRDA) is used to measure the period of the tantalum lattice. Oxygen in the sintered tantalum anode may be limited by the thin natural surface oxide, and there is almost no oxygen in the bulk of the tantalum.

[0033] After optional deoxidation, the anode body can be sintered to form a porous integral mass. The anode body is typically sintered at a temperature of from about 700 °C to about 1,600 °C, in some embodiments from about 800 °C to about 1,500 °C and in some embodiments from about 900 °C to about 1,200 °C for a time of from about 5 minutes to about 100 minutes and in some embodiments from about 8 minutes to about 15 minutes. This can occur in one or more steps. If desired, sintering can occur in an atmosphere that limits the transfer of oxygen atoms to the anode. For example, sintering can be carried out in a reducing atmosphere, such as in a vacuum, an inert gas, hydrogen, etc. The pressure of the reducing atmosphere can be from about 10 Torr to about 2,000 Torr, in some embodiments from about 100 Torr to about 1,000 Torr and in some embodiments from about 100 Torr to about 930 Torr. A mixture of hydrogen and other gases (e.g., argon or nitrogen) can also be employed. As described above, sintering of the anode body typically occurs after any optional deoxidation. However, it should be understood that the anode body can also be subjected to one or more pre-sintering steps prior to oxidation to help provide the desired level of green strength for the deoxidation process. Such pre-sintering steps can be carried out under the same or different conditions as the sintering process that occurs after deoxidation. For example, pre-sintering can occur in one or more steps at a temperature of from about 700 °C to about 1,600 °C, in some embodiments from about 800 °C to about 1,500 °C and in some embodiments from about 900 °C to about 1,200 °C for a time of from about 5 minutes to about 100 minutes and in some embodiments from about 8 minutes to about 15 minutes. Pre-sintering can also occur in a reducing atmosphere (such as in a vacuum, an inert gas, hydrogen, etc.), as described above.

[0034] As described above, the capacitor also includes a plurality of anode lead portions that are electrically connected to respective anode terminals. The anode lead portions can be formed as part of a single anode lead (e.g., opposite ends) or as part of separate anode leads. One or more anode leads can have any desired shape and size and can be in the form of a wire, a sheet, etc. Typically, one or more anode leads extend from the anode body in a longitudinal direction and are formed of any conductive material (such as tantalum, niobium, aluminum, hafnium, titanium, etc., and their conductive oxides and / or nitrides). The connection of one or more leads to the anode body can be achieved using any known technique, such as by welding one or more leads to the body during formation (e.g., before pressing and / or sintering), or by embedding one or more anode leads within the anode body.

[0035] Reference Figure 1A, shows an embodiment of the anode body 10 having a first anode lead 12 with an embedded portion 24 positioned within the anode body and a first exposed 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 solder joint 20) to a second end 18 of the anode body 10. As Figure 1A shown, the second exposed anode lead portion 14 is formed as part of a separate second anode lead extending from the second end 18 of the anode body. Of course, as Figure 1C shown, the first exposed anode lead portion 26 and the second exposed anode lead portion 14 can also be defined by opposite portions of a single continuous anode lead 22 extending through both ends 16 and 18 of the anode body 10. In any case, it is typically desirable for the exposed anode lead portions to extend from opposite ends of the anode body substantially in the same plane. Referring again to Figure 1A , an optional gap may exist between the embedded end of the first anode lead and the end of the anode body such that the electrical connection between the first and second anode leads is provided through the sintered anode body. For example, in Figure 1A , such a gap can be defined as the distance "t" between the anode body end 18 and the embedded end 28 of the anode lead, which is typically in the range of about 0.2 to about 5 millimeters, about 0.4 to about 4 millimeters in some embodiments, and about 0.5 to about 2 millimeters in some embodiments. The length "I" of the anode can similarly be in the range of about 1.5 to about 6 millimeters and about 2 to about 5 millimeters in some embodiments. In such an embodiment, the ratio of the distance "t" to the length "I" can be in the range of about 0.1 to about 0.8, about 0.2 to about 0.7 in some embodiments, and about 0.3 to about 0.6 in some embodiments.

[0036] Figure 1B shows another embodiment where the anode body 10 has a first anode lead 12 with an embedded portion 24 positioned within the anode body and a first exposed anode lead portion 26 extending from a first end 16 of the anode 10. A second anode lead 14 has an embedded portion 32 positioned within the anode body and a second exposed anode lead portion 34 extending from a second end 18 of the anode body 10. Thus, in this embodiment, a solder portion for the second anode lead is not required. Similar to the above embodiment, an optional gap "t" may exist between the embedded end of the first anode lead and the embedded end of the second anode lead, and this gap "t" can be within the above range.

[0037] B. Dielectric

[0038] The anode body is coated with a dielectric. The dielectric is formed by anodizing (anodic oxidation) the sintered anode body such that a dielectric layer is formed above and / or within the anode body. For example, a tantalum (Ta) anode can be anodized to tantalum pentoxide (Ta2O5). Typically, anodization is performed by first applying a solution to the anode (such as by dipping the anode into an electrolyte). A solvent is usually employed, such as water (e.g., deionized water). To enhance ionic conductivity, a compound capable of dissociating in the solvent to form ions can be used. Examples of such compounds include, for example, acids as described below with reference to the electrolyte section. For example, an acid (e.g., phosphoric acid) can be present in the anodization solution at about 0.01 wt% to about 5 wt%, in some embodiments about 0.05 wt% to about 0.8 wt% and in some embodiments about 0.1 wt% to about 0.5 wt%. If desired, blends of acids can also be used.

[0039] A current is passed through the anodization solution to form the dielectric layer. The value of the forming voltage controls the thickness of the dielectric layer. For example, the power supply is initially set to a constant current mode until the desired voltage is reached. Then, the power supply can be switched to a constant potential mode to ensure that the desired dielectric thickness is formed above the entire surface of the anode. Of course, other methods can also be used, such as pulse constant potential method or step constant potential method. The forming voltage employed during anodization is typically about 20 volts or higher, in some embodiments about 30 volts or higher, in some embodiments about 35 volts or higher and in some embodiments about 35 to about 70 volts, and the temperature ranges from about 10 °C or higher, in some embodiments about 20 °C to about 200 °C and in some embodiments about 30 °C to about 100 °C. The resulting dielectric layer can be formed on the surface of the anode and within the pores of the anode.

[0040] By selectively controlling the specific manner in which the anode body is formed, the resulting capacitor can exhibit a high level of dielectric strength, which can improve capacitance stability. "Dielectric strength" generally refers to the ratio of the "breakdown voltage" of the capacitor (the voltage at which the capacitor fails, in volts, "V") to the thickness of the dielectric (in nanometers, "nm"). Capacitors typically exhibit 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 about 0.55 to about 1 V / nm and in some embodiments about 0.6 to about 0.9 V / nm. For example, the capacitor can exhibit a relatively high breakdown voltage, such as 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 and in some embodiments about 100 volts to about 300 volts, such as determined by increasing the applied voltage in 3-volt increments until the leakage current reaches 1 mA. Although the thickness of the dielectric can typically vary depending on the specific location of the anode body, for purposes of determining the dielectric strength, the "dielectric thickness" is generally considered to be the maximum thickness of the dielectric, and the thickness of the dielectric typically ranges from about 50 to about 500 nm, in some embodiments about 80 to about 350 nm and in some embodiments about 100 to about 300 nm. The dielectric thickness can be measured using a Zeiss Sigma FESEM at a magnification of 20,000x to 50,000x, where the sample is prepared by cutting the finished component in a plane perpendicular to the longest dimension of the finished component, and the thickness is measured at a location perpendicular to the cut through the dielectric layer.

[0041] C. Pre-Coating

[0042] Although this is not required, a pre-coating can optionally be applied over the dielectric comprising the organometallic compound. The organometallic compound can have the following general formula:

[0043]

[0044] wherein,

[0045] M is an organometallic atom, such as silicon, titanium, etc.;

[0046] R1, R2, and R3 are independently an alkyl group (e.g., methyl, ethyl, propyl, etc.) or a hydroxyalkyl group (e.g., hydroxymethyl, hydroxyethyl, hydroxypropyl, etc.), wherein at least one of R1, R2, R3 is a hydroxyalkyl group;

[0047] n is an integer from 0 to 8, in some embodiments from 1 to 6 and in some embodiments from 2 to 4 (e.g., 3); and

[0048] X is an organic or inorganic functional group such as glycidyl, glycidyloxy, mercapto, amino, vinyl, etc.

[0049] In certain embodiments, R1, R2 and R3 can be hydroxyalkyl (e.g., OCH3). However, in other embodiments, R1 can be alkyl (e.g., CH3), while R2 and R3 can be hydroxyalkyl (e.g., OCH3).

[0050] Further, in certain embodiments, M can be silicon such that the organometallic compound is an organosilane compound, such as an alkoxysilane. Suitable alkoxysilanes can include, for example: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, glycidoxypropyltrimethoxysilane, glycidoxypropyltriethoxysilane, glycidoxypropyltripropoxysilane, glycidoxypropyltributoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, β-glycidoxyethyltripropoxysilane, β-glycidoxyethyltributoxysilane, β-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, α-glycidoxyethyltripropoxysilane, α-glycidoxyethyltributoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, β-glycidoxypropyltripropoxysilane, α-glycidoxypropyltributoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, α-glycidoxypropyltripropoxysilane, α-glycidoxypropyltributoxysilane, γ-glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltripropoxysilane, δ-glycidoxybutyltributoxysilane, δ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltripropoxysilane, γ-propoxybutyltributoxysilane, δ-glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltripropoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane, α-glycidoxybutyltripropoxysilane, α-glycidoxybutyltributoxysilane, (3,4-epoxycyclohexyl)methyltrimethoxysilane, (3,4-epoxycyclohexyl)methyltriethoxysilane, (3,4-epoxycyclohexyl)methyltripropoxysilane, (3,4-epoxycyclohexyl)methyltributoxysilane, (3,4-epoxycyclohexyl)ethyltrimethoxysilane, (3,4-epoxycyclohexyl)ethyltriethoxysilane, (3,4-epoxycyclohexyl)ethyltripropoxysilane, (3,4-epoxycyclohexyl)ethyltributoxysilane, (3,4-epoxycyclohexyl)propyltrimethoxysilane, (3,(3,4 - epoxycyclohexyl)propyltriethoxysilane, (3,4 - epoxycyclohexyl)propyltripropoxysilane, (3,4 - epoxycyclohexyl)propyltributoxysilane, (3,4 - epoxycyclohexyl)butyltrimethoxysilane, (3,4 - epoxycyclohexyl)butyltriethoxysilane, (3,4 - epoxycyclohexyl)butyltripropoxysilane, and (3,4 - epoxycyclohexyl)butyltributoxysilane, etc.,

[0051] The specific manner of applying the pre - coating to the capacitor body can vary as needed. In one particular embodiment, the compound is dissolved in an organic solvent and applied to the component in the form of a solution, such as by screen printing, dipping, electrophoretic coating, spraying, etc. The organic solvent can vary, but is typically an alcohol, such as methanol, ethanol, etc. The organometallic compound can be about 0.1 wt.% to about 10 wt.% of the solution, in some embodiments about 0.2 wt.% to about 8 wt.%, and in some embodiments about 0.5 wt.% to about 5 wt.%. The solvent can likewise be about 90 wt.% to about 99.9 wt.% of the solution, in some embodiments about 92 wt.% to about 99.8 wt.% and in some embodiments about 95 wt.% to about 99.5 wt.%. Once applied, the component can then be dried to remove the solvent therefrom and form a pre - coating containing the organometallic compound.

[0052] D. Solid electrolyte

[0053] The solid electrolyte is disposed over the dielectric and an optional pre - coating. The total thickness of the solid electrolyte is typically about 1 μm to about 50 μm and in some embodiments about 5 μm to about 20 μm. The solid electrolyte typically comprises one or more layers of conductive polymers (e.g., polyheterocyclic compounds (such as polypyrrole, polythiophene, polyaniline, etc.), polyacetylene, poly - p - phenylene, polyphenolate, etc.). Thiophene polymers are particularly suitable for the solid electrolyte. In certain embodiments, for example, a thiophene polymer having a repeating unit of formula (I) can be employed:

[0054]

[0055] wherein,

[0056] R7 is linear or branched C1 to C 18Alkyl (e.g., methyl, ethyl, n-propyl or isopropyl, n-butyl, isobutyl, sec-butyl 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 to C 12 Cycloalkyl (e.g., cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, etc.); C6 to C 14 Aryl (e.g., phenyl, naphthyl, etc.); C7 to C 18 Aralkyl (e.g., benzyl, o-tolyl, m-tolyl, p-tolyl, 2,3-xylenyl, 2,4-xylenyl, 2,5-xylenyl, 2-6-xylenyl, 3-4-xylenyl, 3,5-xylenyl, mesityl, etc.); and

[0057] q is an integer from 0 to 8, from 0 to 2 in some embodiments and 0 in one embodiment.

[0058] Particularly suitable thiophene polymers are thiophene polymers in which "D" is an optionally substituted C2 to C3 alkylene. For example, the polymer may include optionally substituted poly(3,4-ethylenedioxythiophene) or derivatives thereof, which have repeating units of the following general formula (II):

[0059]

[0060] In a particular embodiment, "q" is 0. A commercially suitable example of 3,4-ethylenedioxythiophene is Clevios TM M available from Heraeus. Other suitable monomers are also described in Of Blohm et al. U.S. Patent No. 5,111,327 and Groenendaal et al. U.S. Patent No. 6,635,729. Derivatives of these monomers may also be used, such as dimers or trimers of the above monomers. Higher molecular derivatives of the monomers, i.e., tetramers, pentamers, etc. of the monomers are suitable for the present invention. The derivatives may consist of the same or different monomer units and are used in pure form as well as in admixture with one another and / or with the monomers. Oxidized or reduced forms of these precursors may also be used.

[0061] To form a polymer, precursor monomers can be polymerized in the presence of an oxidation catalyst (e.g., chemical polymerization). Oxidation catalysts typically include transition metal cations such as iron(III), copper(II), chromium(VI), cerium(IV), manganese(IV), manganese(VII), or ruthenium(III) cations, etc. A dopant can also be used to provide an excess charge to the conductive polymer and stabilize its conductivity. Dopants typically include inorganic or organic anions such as sulfonic acid ions (e.g., p-toluenesulfonate). In certain embodiments, the oxidation catalyst has both catalytic and doping functions as it includes a cation (e.g., a transition metal) and an anion (e.g., sulfonic acid). For example, the oxidation catalyst can be a transition metal salt including: iron(III) cations such as iron(III) halides (e.g., FeCl3) or iron(III) salts of other inorganic acids such as Fe(ClO4)3 or Fe2(SO4)3; and, iron(III) salts of organic acids and inorganic acids containing organic radicals. Examples of iron(III) salts of inorganic acids with organic groups include, for example, iron(III) salts of monoesters of sulfuric acid of C1 to C 20 alkanol (e.g., iron(III) dodecyl sulfate). Similarly, examples of iron(III) salts of organic acids include, for example, iron(III) salts of C1 to C 20 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); iron(III) salts of aliphatic C1 to C 20 carboxylic acids (e.g., 2-ethylhexyl carboxylic acid); iron(III) salts of aliphatic perfluorocarboxylic acids (e.g., trifluoroacetic acid or perfluorooctanoic acid); optionally iron(III) salts of aromatic sulfonic acids substituted with C1 to C 20 alkyl groups (e.g., benzenesulfonic acid, o-toluenesulfonic acid, p-toluenesulfonic acid, or dodecylbenzenesulfonic acid); and iron(III) salts of naphthenesulfonic acids (e.g., camphorsulfonic acid), etc. Mixtures of the above iron(III) salts can also be used. Iron(III) p-toluenesulfonate, iron(III) o-toluenesulfonate, and their mixtures are particularly suitable. A commercially applicable example of iron(III) p-toluenesulfonate can be obtained from Heraeus under the trade name Clevios TM C.

[0062] The oxidation catalyst and precursor monomer can be applied sequentially or simultaneously to initiate the polymerization reaction. As an example, the monomer can first be mixed with the oxidation catalyst to form a precursor solution. In certain embodiments, a less than stoichiometric amount of the oxidation catalyst than normally required can be employed to help slow down the polymerization of the monomer, thereby producing oligomers that are shorter than the complete polymerization into a polymer to allow better penetration into the high charge-to-mass ratio powder. For example, when the monomer includes a thiophene monomer (e.g., 3,4-ethylenedioxythiophene), the molar ratio normally required for the polymerization monomer is about 1 mole of monomer to 18 moles of oxidation catalyst. However, in the polymerization solution, there can be less than 18 moles of the oxidation polymerization catalyst per mole of monomer (e.g., 3,4-ethylenedioxythiophene), such as about 15 moles or less, in some embodiments about 4 to about 12 moles and in some embodiments about 5 to about 10 moles.

[0063] In addition to the monomer, oxidation catalyst, and optional dopant, the polymerization solution can also contain other components, such as one or more solvents. Particularly suitable solvents can include, for example, water, alcohols (such as methanol, ethanol, n-propanol, isopropanol, butanol); glycols (such as propylene glycol, butylene glycol, triethylene glycol, hexylene glycol, polyethylene glycol, ethoxydiglycol, dipropylene glycol); glycol ethers (such as methyl glycol ether, ethyl glycol ether, isopropyl glycol ether); ethers (such as diethyl ether, tetrahydrofuran); triglycerides; ketones; esters (such as ethyl acetate, butyl acetate, diglycol ether acetate, methoxypropyl acetate); amides (such as dimethylformamide, dimethylacetamide, dimethyl caprylic / capric fatty acid amide, N-alkylpyrrolidone); nitriles (such as acetonitrile, propionitrile, butyronitrile, benzonitrile); sulfoxides or sulfones (such as dimethyl sulfoxide (DMSO), and sulfolane), etc., and mixtures of any of the foregoing (e.g., water and alcohol).

[0064] The polymerization solution is typically maintained at a relatively low temperature during the reaction, such as from about -20°C to about 50°C, in some embodiments from about -15°C to about 30°C and in some embodiments from about -10°C to about 10°C. Any suitable application technique known in the art can be used to apply the solution to the anode body, such as screen printing, dipping, electrophoretic coating, and spraying. Regardless of the application technique employed, the monomers typically begin to react once they appear on the anode body to form a polymer layer. The period of time during which the monomers react on the anode body is typically long enough for the polymer to be well impregnated into the small pores of the high charge-to-mass ratio powder. For example, in most embodiments, this period of time ("impregnation time") is about 1 minute or longer, in some embodiments about 1.5 minutes or longer and in some embodiments about 2 to about 5 minutes. After the reaction, the resulting conductive polymer layer can be contacted with a washing solution to remove various by-products, excess catalyst, etc. The period of time during which the washing solution contacts the conductive polymer layer ("washing time") is typically long enough to ensure that by-products and excess catalyst, etc. can be sufficiently removed from the small pores of the high charge-to-mass ratio powder. For example, the washing time can be about 25 minutes or longer, in some embodiments about 30 minutes or longer and in some embodiments about 45 minutes to about 90 minutes. During this period of time, the washing can be carried out in a single step or multiple steps, where the total time for each step is within the above range. The washing solution can vary as needed, but typically includes one or more solvents (e.g., water, ethanol, etc.) and optional dopants such as those described above.

[0065] Once washing is carried out, one or more conductive polymer layers can be dried, and the drying temperature is typically about 15°C or higher, in some embodiments about 20°C or higher and in some embodiments about 20°C to about 80°C. One or more polymer layers can also be repaired after formation. The repair can occur after each application of the conductive polymer layer, or it can occur after the entire conductive polymer coating is applied. In some embodiments, the conductive polymer can be repaired by dipping the anode body into an electrolyte solution and then applying a constant voltage to the solution until the current drops to a preselected level. If desired, such repair can be completed in multiple steps. For example, the electrolyte solution can be a dilute solution of monomers, catalyst, and dopant in an alcohol solvent (e.g., ethanol).

[0066] In the above process, the conductive polymer is typically formed "in-situ" on the anode body. Of course, this is not necessary. In other embodiments, for example, the conductive polymer can be pre-polymerized. For example, in one embodiment, the pre-polymerized polymer is an intrinsically conductive polymer having a positive charge on the main chain, which is at least partially compensated by an anion covalently bonded to the polymer. Such polymers can have, for example, a relatively high specific conductivity of about 1 siemens per centimeter ("S / cm") or higher in the dry state, about 10 S / cm or higher in some embodiments, about 25 S / cm or higher in some embodiments, about 40 S / cm or higher in some embodiments, and about 50 to about 500 S / cm in some embodiments. An example of a suitable intrinsically conductive thiophene polymer can have a repeating unit of formula (III):

[0067]

[0068] wherein,

[0069] R is (CH2)a - O - (CH2) b -L, where L is a bond or HC([CH2] c H);

[0070] a is from 0 to 10, from 0 to 6 in some embodiments, and from 1 to 4 in some embodiments (e.g., 1);

[0071] b is from 1 to 18, from 1 to 10 in some embodiments, and from 2 to 6 in some embodiments (e.g., 2, 3, 4, or 5);

[0072] c is from 0 to 10, from 0 to 6 in some embodiments, and from 1 to 4 in some embodiments (e.g., 1);

[0073] Z is an anion such as SO3 - 、C(O)O - 、BF4 - 、CF3SO3 - 、SbF6 - 、N(SO2CF3)2 - 、C4H3O4 - 、ClO4 - etc.;

[0074] X is a cation such as hydrogen, an alkali metal (e.g., lithium, sodium, rubidium, cesium, or potassium), ammonium, etc.

[0075] In a particular embodiment, Z in formula (III) is a sulfonate ion such that the intrinsically conductive polymer contains a repeating unit of formula (IV):

[0076]

[0077] wherein R and X are as defined above. In formula (III) or (IV), a is preferably 1, and b is preferably 3 or 4. Likewise, X is preferably sodium or potassium.

[0078] If desired, the polymer may be a copolymer containing other types of repeating units. In such embodiments, the repeating units of formula (III) typically comprise about 50 mol% or more of the total amount of repeating units in the copolymer, in some embodiments about 75 mol% to about 99 mol% and in some embodiments about 85 mol% to about 95 mol%. Of course, the polymer may also be a homopolymer containing 100 mol% of the repeating units of formula (III). Specific examples of such homopolymers include poly(4-(2,3-dihydrothieno[3,4-b][1,4] ... poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butane-sulphonic acid, salt)) and poly(4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butane-sulphonic acid, salt) (in-2-ylmethoxy)-1-propanesulfonic acid, salt).

[0079] In another embodiment, the intrinsically conductive polymer has repeating thiophene units of the following general formula (V):

[0080]

[0081] in,

[0082] a and b are as defined above;

[0083] R5 is an optionally substituted C1 to C6 linear or branched alkyl group (eg, methyl) or a halogen atom (eg, fluorine);

[0084] X is a hydrogen atom, an alkali metal (e.g., Li, Na, K, etc.), NH(R 1 )3, or HNC5H5, where R 1 Each is independently a hydrogen atom or an optionally substituted C1 to C6 alkyl group.

[0085] Specific examples of thiophene compounds used to form such repeats are described in U.S. Pat. No. 9,718,905 and may include, for example, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dihydrothiophene]- 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 Potassium 3-[(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy]-1-fluoro-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 Triethylammonium 3-[(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, etc., as well as their combinations and derivatives. Each of the above exemplary thiophene monomers can be prepared from thiophene[3,4-b]-1,4-dioxin-2-methanol and a branched sulfone lactone compound according to a known method (e.g., Journal of Electroanalytical Chemistry, 443, 217 to 226 (1998)).

[0086] "Extrinsically" conducting polymers can also be used, which typically require the presence of separate counterions that are not covalently bound to the polymer. An example of such an extrinsically conducting polymer is poly(3,4-ethylenedioxythiophene). The counterion can be a monomer or polymeric anion that neutralizes the charge of the conducting polymer. For example, the polymeric anion can be an anion derived from a polymeric carboxylic acid (e.g., poly(meth)acrylic acid, such as poly-2-sulfoethyl (meth)acrylate or poly-3-propylsulfonyl (meth)acrylate; polymaleic acid, etc.); polymeric sulfonic acid (e.g., polystyrenesulfonic acid ("PSS"), polyvinylsulfonic acid, etc.), and so on, as well as their salts, such as their alkali metal salts, alkaline earth metal salts, transition metal salts, or ammonium salts. Similarly, suitable monomer anions can be derived from C1 to C 20 alkanesulfonic acids (e.g., dodecanesulfonic acid); aliphatic fluorosulfonic acids (e.g., trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, perfluorooctanesulfonic acid, trifluoromethanesulfonimide, etc.); aliphatic C1 to C 20 carboxylic acids (e.g., 2-ethylhexylcarboxylic acid); aliphatic fluorocarboxylic acids (e.g., trifluoroacetic acid or perfluorooctanoic acid); aromatic sulfonic acids optionally substituted with C1 to C 20 alkyl groups (e.g., benzenesulfonic acid, o-toluenesulfonic acid, p-toluenesulfonic acid, or dodecylbenzenesulfonic acid); cycloalkanesulfonic acids (e.g., camphorsulfonic acid); boron compounds (e.g., tetrafluoroboric acid); phosphorus compounds (e.g., hexafluorophosphoric acid), and so on, as well as their salts, such as their alkali metal salts, alkaline earth metal salts, transition metal salts, or ammonium salts. Particularly suitable counterions are polymeric anions, such as those derived from polymeric carboxylic acids or sulfonic acids (e.g., polystyrenesulfonic acid ("PSS")). The molecular weight of such compounds is typically from about 1,000 to about 2,000,000, and in some embodiments from about 2,000 to about 500,000.

[0087] Whether intrinsically or extrinsically conducting, the prepolymer polymer layer can be applied to the anode body in various forms, such as solutions, dispersions, etc. For example, intrinsically conducting polymers are preferably applied in the form of solutions, while extrinsically conducting polymers are preferably applied in the form of dispersions.

[0088] When a solution is employed, the concentration of the polymer can vary depending on the desired viscosity and the specific manner of applying the layer to the anode. However, typically, the polymer comprises from about 0.1 wt.% to about 10 wt.% of the solution, from about 0.4 wt.% to about 5 wt.% in some embodiments, and from about 0.5 wt.% to about 4 wt.% in some embodiments. The solvent can similarly comprise from about 90 wt.% to about 99.9 wt.% of the solution, from about 95 wt.% to about 99.6 wt.% in some embodiments, and from about 96 wt.% to about 99.5 wt.% in some embodiments. Although other solvents can of course be used, it is generally desirable for water to be the primary solvent such that the solution is considered an "aqueous" solution. For example, in most embodiments, water comprises at least about 50 wt.% of the solvents used, at least about 75 wt.% in some embodiments, and from about 90 wt.% to 100 wt.% in some embodiments. When employed, the solution can be applied to the anode using any known technique, such as dipping, casting (e.g., curtain coating, spin coating, etc.), printing (e.g., gravure printing, offset printing, screen printing, etc.), and the like. The resulting conductive polymer layer can be dried and / or washed after being applied to the anode.

[0089] When a dispersion is employed, the conductive polymer is typically in the form of pre-polymerized conductive particles. Such particles typically have an average size (e.g., diameter) of from about 1 to about 100 nanometers, from about 2 to about 80 nanometers in some embodiments, and from about 4 to about 50 nanometers in some embodiments. The diameter of the particles can be determined using known techniques, such as by ultracentrifugation, laser diffraction, and the like. The shape of the particles can similarly vary. For example, in one particular embodiment, the particles are spherical. However, it should be understood that the present invention also encompasses other shapes, such as plate-like, rod-like, disc-like, strip-like, tubular, irregular shapes, and the like. The concentration of the particles in the dispersion can vary depending on the desired viscosity of the dispersion and the specific manner of applying the dispersion to the capacitor element. However, typically, the particles comprise from about 0.1 wt.% to about 10 wt.% of the dispersion, from about 0.4 wt.% to about 5 wt.% in some embodiments, and from about 0.5 wt.% to about 4 wt.% in some embodiments.

[0090] The dispersion may also contain one or more binders to further enhance the adhesion properties of the polymer layer and increase the stability of the particles in the dispersion. The binder may be of organic nature, such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl chloride, polyvinyl acetate, polyvinyl butyrate, polyacrylate, polyacrylamide, polymethacrylate, polymethacrylamide, polyacrylonitrile, styrene / acrylic ester, vinyl acetate / acrylic ester and ethylene / vinyl acetate copolymer, polybutadiene, polyisoprene, polystyrene, polyether, polyester, polycarbonate, polyurethane, polyamide, polyimide, polysulfone, melamine formaldehyde resin, epoxy resin, silicone resin or cellulose. Crosslinking agents can also be used to enhance the adhesion capacity of the binder. Such crosslinking agents can include, for example, melamine compounds, blocked isocyanates or functional silanes, such as 3-glycidoxypropyltrimethoxysilane, tetraethoxysilane and tetraethoxysilane hydrolysis products; or crosslinkable polymers, such as polyurethane, polyacrylate or polyolefin, and subsequent crosslinking.

[0091] Dispersants can also be used to facilitate the application of the layer to the anode. Suitable dispersants include solvents, such as aliphatic alcohols (e.g., methanol, ethanol, isopropanol 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., N-methylacetamide, dimethylacetamide and dimethylformamide), aliphatic and araliphatic ethers (e.g., diethyl ether and anisole), water, and mixtures of any of the above solvents. A particularly suitable dispersant is water.

[0092] In addition to those mentioned above, other components can also be used in the dispersion. For example, conventional fillers having a size of about 10 nanometers to about 100 micrometers, in some embodiments about 50 nanometers to about 50 micrometers and in some embodiments about 100 nanometers to about 30 micrometers can be used. Examples of such fillers include calcium carbonate, silicate, silica, calcium sulfate or barium sulfate, aluminum hydroxide, glass fiber or glass beads, wood powder, cellulose powder, carbon black, conductive polymers, etc. The filler can be introduced into the dispersion in powder form, but can also be present in another form, such as fiber.

[0093] Surfactants such as ionic or non-ionic surfactants can also be used in the dispersion. In addition, adhesives such as organofunctional silanes or their hydrolysis products can be used, for example 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane or octyltriethoxysilane. The dispersion can also contain additives that enhance 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-octylpyrrolidone or pyrrolidone), sulfones and sulfoxides (e.g., sulfolane (tetramethylene sulfone) or dimethyl sulfoxide (DMSO)), sugars or sugar derivatives (e.g., sucrose, glucose, fructose or lactose), sugar alcohols (e.g., sorbitol or mannitol), furan derivatives (e.g., 2-furoic acid or 3-furoic acid), alcohols (e.g., ethylene glycol, glycerol, diethylene glycol or triethylene glycol).

[0094] The dispersion can be applied using a variety of known techniques, such as by spin coating, dipping, pouring, drop coating, injection, spraying, knife coating, brush coating, printing (e.g., inkjet, screen printing or pad printing) or dipping. The viscosity of the dispersion is typically from about 0.1 to about 100,000 mPas, in some embodiments from about 1 to about 10,000 mPas, in some embodiments from about 10 to about 1,500 mPas and in some embodiments from about 100 to about 1000 mPas (measured at a shear rate of 100 s -1 -1).

[0095] The solid electrolyte can be formed of multiple layers, such as an inner layer and / or an outer layer. The term "inner" herein refers to one or more layers overlying the dielectric, whether directly or through another layer (e.g., a pre-coating). For example, the inner layer typically contains an in-situ polymerized polymer and / or an intrinsically conductive polymer as described above. One or more inner layers can be employed. For example, the solid electrolyte typically contains from 2 to 30, in some embodiments from 4 to 20, and in some embodiments about 5 to 15 (e.g., 10) inner layers. The solid electrolyte can consist only of "inner layers" such that it is formed substantially of the same material, i.e., an intrinsically conductive polymer and / or an in-situ polymerized layer. However, in other embodiments, the solid electrolyte can further contain one or more optional "outer" conductive polymer layers formed of a material different from that of the inner layer and overlying the inner layer. For example, the outer layer can be formed of a dispersion of a non-intrinsically conductive polymer. In a particular embodiment, the outer layer consists primarily of such non-intrinsically conductive polymers as they comprise about 50 wt.% or more, in some embodiments about 70 wt.% or more, and in some embodiments about 90 wt.% or more (e.g., 100 wt.%) of the corresponding outer layer. One or more outer layers can be employed. For example, the solid electrolyte can contain from 2 to 30, in some embodiments from 4 to 20, and in some embodiments about 5 to 15 outer layers.

[0096] E. External polymer coating

[0097] An external polymer coating can also be selectively applied over the solid electrolyte. When used, the external polymer coating typically contains one or more layers formed of pre-polymerized conductive polymer particles (e.g., a dispersion of non-intrinsically conductive polymer particles) as described above. The external coating can be capable of further penetrating into the edge region of the capacitor body to increase adhesion to the dielectric and form a mechanically stronger component, which can reduce the equivalent series resistance and leakage current. Since it is generally aimed at improving edge coverage rather than impregnating the interior of the anode body, the particles used in the external coating may have a larger size than the particles used in the outer layer of the solid electrolyte. For example, the ratio of the average size of the particles used in the external polymer coating to the average size of the particles used in any dispersion of the solid electrolyte is typically from about 1.5 to about 30, in some embodiments from about 2 to about 20, and in some embodiments from about 5 to about 15. For example, the average size of the particles used in the external coating dispersion can be from about 80 to about 500 nanometers, in some embodiments from about 90 to about 250 nanometers, and in some embodiments from about 100 to about 200 nanometers.

[0098] If desired, a crosslinking agent can also be used in the external polymer coating to enhance the adhesion to the solid electrolyte. Typically, the crosslinking agent is applied before the dispersion used to apply the external coating. Suitable crosslinking agents are described, for example, in To Merker et al. U.S. Patent Publication No. 2007 / 0064376, and include, for example, amines (e.g., diamines, triamines, oligomeric amines, polyamines, etc.); polyvalent metal cations such as salts or compounds of Mg, Al, Ca, Fe, Cr, Mn, Ba, Ti, Co, Ni, Cu, Ru, Ce or Zn, phosphorus compounds, sulfonium compounds, etc. Particularly suitable examples include, for example, 1,4-diaminocyclohexane, 1,4-bis(aminomethyl)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, etc., and mixtures thereof.

[0099] The crosslinking agent is typically applied in the form of a solution or dispersion having a pH value of 1 to 10, in some embodiments 2 to 7 and in some embodiments 3 to 6, as measured at 25 °C. Acidic compounds can be used to help achieve the desired pH value. Examples of solvents or dispersants for the crosslinking agent include water or organic solvents such as alcohols, ketones, carboxylic acid esters, etc. The crosslinking agent can be applied to the capacitor body by any known method such as spin coating, dipping, casting, drop coating, spraying, vapor deposition, sputtering, sublimation, knife coating, spraying or printing, such as inkjet, screen printing or pad printing. Once applied, the crosslinking agent can be dried before applying the polymer dispersion. Then the process is repeated until the desired thickness is achieved. For example, the total thickness of the entire external polymer coating (including the crosslinking agent and the dispersion layer) can be from about 1 μm to about 50 μm, in some embodiments from about 2 μm to about 40 μm and in some embodiments from about 5 μm to about 20 μm.

[0100] F. Moisture barrier layer

[0101] If desired, a moisture barrier layer can be applied over the solid electrolyte and / or the optional external polymer coating. The moisture barrier layer can be formed from a variety of different materials such as hydrophobic elastomers (e.g., silicone, fluoropolymer, etc.). Silicone polymers are particularly suitable for the moisture barrier layer of the present invention. These elastomers are typically derived from polyorganosiloxane, such as polyorganosiloxane having the following general formula:

[0102]

[0103] wherein,

[0104] wherein x is an integer greater than 1; and

[0105] R1, R2, R3, R4, R5, R6, R7 and R8 are independently monovalent groups usually containing from 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 can include, for example, polydimethylsiloxane ("PDMS"), polymethylhydrosiloxane, dimethyldiphenylpolysiloxane, dimethyl / methylphenylpolysiloxane, polymethylphenylsiloxane, methylphenyl / dimethylsiloxane, vinyl dimethyl endblocked polydimethylsiloxane, vinyl methyl / dimethylpolysiloxane, vinyl dimethyl endblocked vinyl methyl / dimethylpolysiloxane, divinyl methyl endblocked polydimethylsiloxane, vinyl phenyl methyl endblocked polydimethylsiloxane, dimethyl hydrogen endblocked polydimethylsiloxane, methyl hydrogen / dimethylpolysiloxane, methyl hydrogen endblocked methyloctylpolysiloxane, methyl hydrogen / phenylmethylpolysiloxane, fluorine-modified polysiloxane, etc. To form an elastomer, the polyorganosiloxane can be crosslinked using any known technique, such as catalytic curing (e.g., platinum catalyst), room temperature vulcanization, moisture curing, etc. The crosslinking agent can be an alkoxysilane such as having the formula Si-OR, where R is H, alkyl (e.g., methyl), hydrocarbon group, and carboxyalkyl (e.g., acetyl), etc.

[0106] In addition to hydrophobicity, it is generally desirable that the material used to form the moisture barrier layer has a relatively low modulus and a certain degree of flexibility, which can help absorb some of the thermal stress caused by the expansion of the housing and can also allow it to be subjected to compressive forces. The flexibility of the material is characterized by a corresponding low elastic modulus ("Young's modulus"), for example, measured at a temperature of about 25 °C to be about 5000 kilopascals ("kPa") or less, about 1 to about 2000 kPa in some embodiments and about 2 to about 500 kPa in some embodiments. The material also generally has a certain degree of strength such that it can maintain its shape even when subjected to compressive forces. For example, the tensile strength of the material measured at a temperature of about 25 °C can be about 1 to about 5000 kPa, about 10 to about 2000 kPa in some embodiments and about 50 to about 1000 kPa in some embodiments. Under the conditions mentioned above, the hydrophobic elastomer can even further enhance the ability of the capacitor to function under extreme conditions.

[0107] To help achieve the desired flexibility and strength properties, non-conductive fillers can be employed in the moisture barrier layer. When such additives are used, they typically comprise from about 0.5 wt.% to about 30 wt.%, in some embodiments from about 1 wt.% to about 25 wt.%, and in some embodiments from about 2 wt.% to about 20 wt.% of the moisture barrier layer. The silicone elastomer comprises from about 70 wt% to about 99.5 wt.%, in some embodiments from about 75 wt.% to about 99 wt.%, and in some embodiments from about 80 wt.% to about 98 wt.% of the moisture barrier layer. A specific example of such a filler includes, for example, silica. Although most forms of silica have a relatively hydrophilic surface due to the presence of silanol groups (Si-OH), the silica can optionally be surface-treated such that its surface contains (CH3) n -Si- groups (where n is an integer from 1 to 3), which further enhances the hydrophobicity of the moisture barrier layer. For example, the surface treatment agent can be a monomeric organosilicon compound having a hydrolyzable group or a partial hydrolyzate thereof. Examples of such compounds can include organosilazanes, silane coupling agents, etc., such as those described above.

[0108] The moisture barrier layer can be applied to any surface of the capacitor to provide the desired performance. For example, the moisture barrier layer can be located on the top surface, bottom surface, and / or side surface of the capacitor. The moisture barrier layer can also be located on the front surface and / or back surface of the capacitor. The moisture barrier layer can cover the entire area of the surface region to which it is applied, or only cover a portion of the surface region to which it is applied. In one embodiment, for example, the moisture barrier layer covers about 30% or more of the capacitor surface to which it is applied, in some embodiments about 40% or more, and in some embodiments about 50% or more.

[0109] G. Other optional components

[0110] If desired, the capacitor element can also include other layers known in the art. For example, an adhesive layer can optionally be formed between the dielectric and the solid electrolyte. For example, the adhesive layer can be present between the dielectric and the pre-coating and / or between the pre-coating and the solid electrolyte. In any case, the adhesive layer is typically formed from a relatively insulating resin material (natural or synthetic). The specific resistivity of such a material can be greater than about 10 Ω·cm, in some embodiments greater than about 100 Ω·cm, in some embodiments greater than about 1,000 Ω·cm, in some embodiments greater than about 1×10 5Ω·cm and in some embodiments greater than about 1×1010 Ω·cm. Some resin materials that can be used in the present invention include, but are not limited to, polyurethanes, polystyrenes, esters of unsaturated or saturated fatty acids (e.g., glycerol esters), etc. 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, aleuritic acid, shellolic acid, etc. It has been found that these esters of fatty acids are particularly useful when used in relatively complex combinations to form "drying oils", which allows the resulting film to rapidly polymerize into a stable layer. Such drying oils can include monoglycerides, diglycerides, and / or triglycerides, which have a glycerol backbone with one, two, and three 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.

[0111] These and other binder layer materials are described in more detail in Fife et al. U.S. Patent No. 6,674,635.

[0112] If desired, the component can also be separately applied with a carbon layer (e.g., graphite) and a silver layer. For example, the silver coating can act as a weldable conductor, contact layer, and / or charge collector of the capacitor, and the carbon coating can limit the contact of the silver coating with the solid electrolyte. These coatings can cover some or all of the solid electrolyte. Various techniques can be employed to apply such layers, such as dipping, brushing, spraying, printing, etc.

[0113] II. Housing

[0114] As described above, the capacitor element is hermetically sealed within a housing. The hermetic sealing can optionally be carried out in the presence of a gaseous atmosphere (such as an atmosphere containing air and / or at least one inert gas) to inhibit the oxidation of the solid electrolyte during use. When in use, the inert gas can include, for example, nitrogen, helium, argon, xenon, neon, krypton, radon, etc., and mixtures thereof. Any of a variety of different materials can be used to form the housing, such as metals, plastics, and ceramics, etc. For example, in one embodiment, the housing includes one or more metal layers, such metals as tantalum, niobium, aluminum, nickel, hafnium, titanium, copper, silver, steel (e.g., stainless steel), its alloys (e.g., conductive oxides), and its composite materials (e.g., metal coated with a conductive oxide), etc. In another embodiment, the housing can include one or more ceramic material layers, such as aluminum nitride, alumina, silica, magnesia, calcium oxide, glass, etc., and combinations thereof.

[0115] The housing can have any desired shape, such as cylindrical, D-shaped, rectangular, triangular, prismatic, etc. For example, referring to Figures 2 to 3, shows an embodiment of a capacitor 100 that includes a housing 122 and a capacitor element 120. In such a particular embodiment, the housing 122 is generally rectangular. Typically, the housing and the capacitor element have the same or similar shapes so that the capacitor element can be easily accommodated within the internal cavity. For example, in the illustrated embodiment, both the capacitor element 120 and the housing 122 have generally rectangular shapes.

[0116] If desired, the capacitors of the present invention can exhibit relatively high volumetric efficiency. To achieve such high efficiency, the capacitor element typically occupies a large portion of the volume of the internal cavity of the housing. For example, the capacitor element can occupy about 30 vol.% or more, in some embodiments about 50 vol.% or more, in some embodiments about 60 vol.% or more, in some embodiments about 70 vol.% or more, in some embodiments about 80 vol.% to about 98 vol.%, and in some embodiments about 85 vol.% to 97 vol.% of the internal cavity of the housing. To this end, the difference between the dimensions of the capacitor element and the dimensions of the internal cavity defined by the housing is typically relatively small.

[0117] Refer again to Figures 2 to 3, for example, the length of the capacitor element 120 (excluding the length of the anode lead 6) can be relatively approximate to the length of the internal cavity 126 defined by the housing 122. For example, the ratio of the length of the anode to the length of the internal cavity is in the range of about 0.40 to 1.00, in some embodiments about 0.50 to about 0.99, in some embodiments about 0.60 to about 0.99, and in some embodiments about 0.70 to about 0.98. The length of the capacitor element 120 can be about 5 to about 10 millimeters, and the length of the internal cavity 126 can be about 6 to about 15 millimeters. Similarly, the ratio of the height of the capacitor element 120 (in the -z direction) to the height of the internal cavity 126 can be in the range of about 0.40 to 1.00, in some embodiments about 0.50 to about 0.99, in some embodiments about 0.60 to about 0.99, and in some embodiments about 0.70 to about 0.98. The ratio of the width of the capacitor element 120 (in the -x direction) to the width of the internal cavity 126 can also be in the range of about 0.50 to 1.00, in some embodiments about 0.60 to about 0.99, in some embodiments about 0.70 to about 0.99, in some embodiments about 0.80 to about 0.98, and in some embodiments about 0.85 to about 0.95. For example, the width of the capacitor element 120 can be about 2 to about 7 millimeters, while the width of the internal cavity 126 can be about 3 to about 10 millimeters, and the height of the capacitor element 120 can be about 0.5 to about 2 millimeters, while the width of the internal cavity 126 can be about 0.7 millimeters to about 6 millimeters.

[0118] Although not necessary, the capacitor element can be attached to the housing in such a way that the anode terminal and the cathode terminal of the capacitor element are formed outside the housing for subsequent integration into a circuit. The specific configuration of the terminals may depend on the intended application. For example, in one embodiment, the capacitor can be shaped such that its surface is mountable while still having mechanical strength. For example, the anode lead can be electrically connected to an external, surface-mountable anode and cathode terminal (such as pads, sheets, plates, frames, etc.). Such terminals can extend through the housing to connect to the capacitor. The thickness or height of the terminals is typically selected to minimize the thickness of the capacitor. For example, the thickness of the terminals can be in the range of about 0.05 millimeters to about 1 millimeter, in some embodiments about 0.05 millimeters to about 0.5 millimeters, and about 0.1 millimeters to about 0.2 millimeters. If desired, the surface of the terminals can be electroplated with nickel, silver, gold, tin, etc. as known in the art to ensure that the finished component can be mounted on a circuit board. In a particular embodiment, the terminals are deposited with bright nickel and bright silver respectively, and the mounting surface is also plated with a solder layer. In another embodiment, one or more terminals are deposited with a thin external metal layer (such as gold) on a base metal layer (such as a copper alloy) to further improve conductivity.

[0119] In some embodiments, an anode lead connection member can be employed in the internal cavity of the housing to facilitate connection to the terminal in a mechanically stable manner. For example, referring again to Figures 2 to 3 , capacitor 100 can include a first anode lead connection member 162a formed by a first portion 167a and a second portion 165a. The first anode lead connection member 162a can be formed of a conductive material similar to the external terminal. The first portion 167a and the second portion 165a can be integral or separate pieces that are connected together either directly or through an additional conductive element (e.g., metal). In the illustrated embodiment, the second portion 165a is disposed in a plane generally parallel to the lateral direction (e.g., the -y direction) in which the first anode lead portion 26 extends. The first portion 167a is "upright", i.e., it is disposed in a plane generally perpendicular to the lateral direction in which the first anode lead portion 26 extends. In this way, the first portion 167a can limit the movement of the first anode lead portion 26 in the horizontal direction to enhance surface contact and mechanical stability during use. If desired, an insulating material 7a (e.g., Teflon TM washer) can be used around the first anode lead portion 26. The first portion 167a can have a mounting area (not shown) connected to the first anode lead portion 26. This area can have a "U-shape" to further enhance surface contact and mechanical stability of the first anode lead portion 26. The connection of this area to the first anode lead portion 26 can be achieved using any of a variety of known techniques, such as welding, laser welding, conductive adhesives, etc. In a particular embodiment, for example, this area is laser welded to the first anode lead portion 26. However, regardless of which technique is selected, the first portion 167a can keep the anode lead substantially horizontally aligned to further enhance the dimensional stability of the capacitor element.

[0120] Capacitor 100 can also include a second anode lead connection member 162b. The second anode lead connection member can be the same as or different from the first anode lead connection member. In the illustrated embodiment, for example, similar to the first anode lead connection member 162a, the second anode lead connection member 162b is formed by a first portion 167b and a second portion 165b. In the illustrated embodiment, the second portion 165b is disposed in a plane generally parallel to the lateral direction (e.g., the -y direction) in which the second anode lead portion 14 extends. The first portion 167b is "upright", i.e., it is disposed in a plane generally perpendicular to the lateral direction in which the second anode lead portion 14 extends. In this way, the first portion 167b can limit the movement of the second 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., TeflonTM washer). The first portion 167b may have a mounting area (not shown) connected to the second anode lead portion 14. This area may have a "U shape" to further enhance the surface contact and mechanical stability of the second anode lead portion 14. The connection of this area to the second anode lead portion 14 can be achieved by any one of a variety of known techniques, such as welding, laser welding, conductive adhesives, etc. However, regardless of which technique is chosen, the first portion 167b can keep the anode lead in a substantially horizontal alignment to further enhance the dimensional stability of the capacitor element.

[0121] The first connection member 162a and the second connection member 162b can be connected to their respective first anode terminal 127 and second anode terminal 129 in a variety of different ways. For example, in the illustrated embodiment, the housing 122 includes an outer wall 123 and two opposing side walls 124, and a cavity 126 including the capacitor element 120 is formed between the two side walls. The outer wall 123 and the side walls 124 can be formed by one or more layers of the metal, plastic, or ceramic materials as described above. In this particular embodiment, the first anode terminal 127 includes a first area 127a positioned inside the housing 122 and electrically connected to the first anode connection member 162a and a second area 127b positioned outside the housing 122 and providing a mounting surface 201. Similarly, the second anode terminal 129 includes a first area 129a positioned inside the housing 122 and electrically connected to the second anode connection member 162b and a second area 129b positioned outside the housing 122 and providing a mounting surface 203. It should be understood that the entire portions of these areas do not need to be located inside or outside the housing.

[0122] In the illustrated embodiment, a first conductive trace 127c extends in the outer wall 123 of the housing to connect a first region 127a and a second region 127b. Similarly, a second conductive trace 129c extends in the outer wall 123 of the housing to connect the first region 127a and the second region 127b. The conductive traces and / or regions of the terminals may be separate or integral. In addition to extending through the outer wall of the housing, the traces may be located at other positions, such as outside the outer wall. Of course, the present invention is not limited to using conductive traces to form the desired terminals. Regardless of the specific configuration used, the connection of the first terminal 127 and the second terminal 129 to the capacitor element 120 can be achieved using any known technique, such as soldering, laser soldering, conductive adhesives, etc. In one particular embodiment, for example, a first conductive adhesive 131a can be used to connect a second portion 165a of the first anode connection member 162 to the first anode terminal 127. Similarly, a second conductive adhesive 131b can be used to connect a second portion 165b of the second anode connection member 162b to the second anode terminal 129. The conductive adhesive can be formed from conductive metal particles contained in a resin composition. The metal particles can be silver, copper, gold, platinum, nickel, zinc, bismuth, etc. The resin composition can include a thermosetting resin (e.g., epoxy resin), a curing agent (e.g., acid anhydride), and a coupling agent (e.g., silane coupling agent). Osako et al. Suitable conductive adhesives are described in U.S. Patent Application Publication No. 2006 / 0038304, Osako .

[0123] The cathode of the capacitor element 120 is also connected to a cathode terminal 305 that provides a mounting surface 309. In one embodiment, for example, one or more conductive traces (e.g., conductive trace 307) can extend in 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 located at other positions, such as outside the outer wall. Of course, the present invention is not limited to using conductive traces to form the desired terminals. Regardless of the specific configuration used, the connection of the cathode terminal 305 to the capacitor element 120 can be achieved using any known technique, such as soldering, laser soldering, conductive adhesives, etc. In one particular embodiment, for example, the conductive adhesive 131c described above can be used to connect the bottom surface of the capacitor element 120 to the cathode terminal 305. Of course, in addition to the direct connection in the above manner, it should be understood that a cathode connection member similar to the above-described anode connection member can also be used to facilitate the connection of the capacitor element 120 to the cathode terminal 305.

[0124] Optionally, the polymer restraint may also be provided in contact with one or more surfaces of the capacitor element, such as the back surface, front surface, upper surface, lower surface, side surface, or any combination thereof. The polymer restraint can reduce the likelihood of the capacitor element separating from the housing. In this regard, the polymer restraint can have a certain strength such that it can hold the capacitor element in a relatively fixed position even when subjected to vibrational forces, but not so high as to cause it to break. For example, measured at a temperature of about 25 °C, the tensile strength of the restraint can be from about 1 to about 150 megapascals ("MPa"), from about 2 to about 100 MPa in some embodiments, from about 10 to about 80 MPa in some embodiments, and from about 20 to about 70 MPa in some embodiments. It is generally desirable for the restraint to be non-conductive.

[0125] Although various materials having the desired strength characteristics described above can be used, it has been found that curable thermosetting resins are particularly suitable for 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, the restraint can be one or more polyorganosiloxanes. The silicon-bonded organic groups used in these polymers can contain monovalent hydrocarbon groups and / or monovalent halogenated hydrocarbon groups. Such monovalent groups generally have from 1 to about 20 carbon atoms, preferably from 1 to 10 carbon atoms, and examples include but are not limited to alkyl groups (e.g., methyl, ethyl, propyl, pentyl, octyl, undecyl, and octadecyl); cycloalkyl groups (e.g., cyclohexyl); alkenyl groups (e.g., vinyl, allyl, butenyl, and hexenyl); aryl groups (e.g., phenyl, tolyl, xylyl, benzyl, and 2-phenylethyl); and halogenated hydrocarbon groups (e.g., 3,3,3-trifluoropropyl, 3-chloropropyl, and dichlorophenyl). Generally, at least 50%, more preferably at least 80%, of the organic groups are methyl. Examples of such methyl polysiloxanes can include, for example, polydimethylsiloxane ("PDMS"), polymethylhydrosiloxane, and the like. Other suitable methyl polysiloxanes can include dimethyldiphenyl polysiloxane, dimethyl / methylphenyl polysiloxane, polymethylphenylsiloxane, methylphenyl / dimethylsiloxane, vinyl dimethyl endblocked polydimethylsiloxane, vinyl methyl / dimethyl polysiloxane, vinyl dimethyl endblocked vinyl methyl / dimethyl polysiloxane, divinyl methyl endblocked polydimethylsiloxane, vinyl phenyl methyl endblocked polydimethylsiloxane, dimethyl hydrogen endblocked polydimethylsiloxane, methyl hydrogen / dimethyl polysiloxane, methyl hydrogen endblocked methyl octyl polysiloxane, methyl hydrogen / phenyl methyl polysiloxane, and the like.

[0126] The organopolysiloxane may also include one or more pendant and / or terminal polar functional groups, such as hydroxyl, epoxy, carboxyl, amino, alkoxy, methacrylic acid, or mercapto groups, which impart a degree of hydrophilicity to the polymer. For example, the organopolysiloxane may include at least one hydroxyl group and optionally an average of at least two silicon-bonded hydroxyl groups (silanol groups) per molecule. Examples of such organopolysiloxanes include, for example, dihydroxypolydimethylsiloxane, hydroxy-trimethylsiloxy polydimethylsiloxane, and the like. Kleyer et al. Other examples of hydroxy-modified organopolysiloxanes are described in U.S. Patent Application Publication No. 2003 / 0105207, the entire content of which is incorporated herein by reference. Alkoxy-modified organopolysiloxanes may also be used, such as dimethoxypolydimethylsiloxane, methoxy-trimethylsiloxy polydimethylsiloxane, diethoxypolydimethylsiloxane, ethoxy-trimethylsiloxy polydimethylsiloxane, and the like. Other suitable organopolysiloxanes are organopolysiloxanes modified with at least one amino functional group. Examples of such amino-functional polysiloxanes include, for example, diamino-functionalized polydimethylsiloxane. Plantenberg et al. U.S. Patent Application Publication No. 2010 / 00234517 also describes various other suitable polar functional groups for organopolysiloxanes, the entire content of which is incorporated herein by reference.

[0127] Epoxy resins are also particularly suitable as polymeric restraints. Examples of suitable epoxy resins include, for example, glycidyl ether type epoxy resins, such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenol novolac type epoxy resins, o-cresol novolac type epoxy resins, brominated epoxy resins, and biphenyl type epoxy resins, cycloaliphatic 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 the like. Other suitable electrically conductive adhesive resins may also be described in Osako et al. U.S. Patent Application Publication No. 2006 / 0038304 and Chacko U.S. Patent No. 7,554,793, the entire content of which is incorporated herein by reference.

[0128] If desired, a curing agent can also be used in the polymeric restraint to help promote curing. The curing agent typically comprises from about 0.1 to about 20 wt.% of the restraint. Exemplary curing agents include, for example, amines, peroxides, acid anhydrides, phenolic compounds, silanes, acid anhydride compounds, and combinations thereof. Specific examples of suitable curing agents are dicyandiamide, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, ethyl cyano propyl imidazole, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-methylimidazole, 2,4-dicyano-6,2-methylimidazolyl-(1)-ethyl-s-triazine, and 2,4-dicyano-6,2-undecylimidazolyl-(1)-ethyl-s-triazine, imidazolium salts (such as 1-cyanoethyl-2-undecylimidazole trimellitate, 2-methylimidazole isocyanurate, 2-ethyl-4-methylimidazole tetraphenylborate, 2-ethyl-1,4-dimethylimidazolium tetraphenylborate, etc.). Other useful curing agents include phosphine compounds such as tributylphosphine, triphenylphosphine, tris(dimethoxyphenyl)phosphine, tris(propylol)phosphine, and tris(cyanoethyl)phosphine; phosphonium salts such as tetraphenylphosphonium-tetraphenylborate, methyltributylphosphonium-tetraphenylborate, and methyltricyanoethylphosphonium-tetraphenylborate); amines such as 2,4,6-tris(dimethylaminomethyl)phenol, benzylmethylamine, tetramethylbutylguanidine, N-methylpiperazine, and 2-dimethylamino-1-pyrroline; ammonium salts such as triethylammonium tetraphenylborate; diazabicyclic 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; salts of diazabicyclic compounds such as tetraphenylborate, phenolate, novolac salt, and 2-ethylhexanoate, etc.

[0129] Other additives can also be used, such as 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 can 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-bis(diacrylamino)benzophenone, 4-dimethylaminobenzoic acid, 4-dimethylaminobenzoic acid alkyl ester, 2-ethylanthraquinone, xanthone, thioxanthone, 2-chlorothioxanthone, etc. When used, such additives typically comprise from about 0.1 to about 20 wt.% of the total composition.

[0130] For example, in one embodiment, a single polymer restraint can be arranged to contact the upper and rear surfaces of the capacitor element. It should also be understood that separate restraints can be employed to achieve the same function. In fact, more generally, any number of polymer restraints can be used to contact any desired surface of the capacitor element. When multiple restraints are used, they may contact each other or remain physically separated. For example, in one embodiment, a second polymer restraint can be used that contacts the upper and front surfaces of the capacitor element. The first polymer restraint and the second polymer restraint may or may not contact each other. In yet another embodiment, the polymer restraint can also contact the lower and / or side surfaces of the capacitor element, together with or in place of other surfaces. When used, it is typically desirable for the polymer restraint to also contact at least one surface of the housing to help further mechanically stabilize the capacitor element and prevent possible delamination. For example, the restraint can contact the inner surface of one or more sidewalls, outer walls, the lid, etc.

[0131] Once connected in the desired manner, the resulting package can be hermetically sealed as described above. Referring again to Figures 2 to 3 , for example, the housing 122 can also include a lid 125 that is placed on the upper surface of the sidewall 124 after the capacitor element 120 is positioned within the housing 122. The lid 125 can be formed of ceramic, metal (e.g., iron, copper, nickel, cobalt, etc., and their alloys), plastic, etc. If desired, a seal 187 can be provided between the lid 125 and the sidewall 124 to help provide a good seal. In one embodiment, for example, the seal can include a glass-to-metal seal, ring (Goodfellow Cambridge Ltd.) etc. The height of the sidewall 124 is typically such that the lid 125 does not contact any surface of the capacitor element 120 so as not to be contaminated. When placed in the desired position, the lid 125 is hermetically sealed to the sidewall 124 using known techniques (such as, welding (e.g., resistance welding, laser welding, etc.), brazing, etc.). The hermetic sealing can optionally be carried out in a gas atmosphere as described above so that the resulting capacitor is substantially free of reactive gases such as water vapor.

[0132] Of course, the above embodiments are merely examples of ways in which a capacitor element can be incorporated inside a housing. Other possible housing configurations can be used in the present invention. For example, a capacitor similar to the above embodiment can be formed, except that external terminals using terminal pins as the anode and cathode respectively are employed. In other words, the first terminal pin can extend through a trace formed in the outer wall and be connected to the first anode lead using known techniques (e.g., welding). Similarly, the second terminal pin can extend through a trace formed in the outer wall and be connected to the cathode as described above by the conductive adhesive 133. Only a single capacitor element is discussed hereinFigures 2 to 3 The embodiments shown. However, it should also be understood that multiple capacitor elements can also be hermetically sealed within the housing. The multiple capacitor elements can be attached to the housing using any of a variety of different techniques.

[0133] The present invention can be better understood by reference to the following examples.

[0134] Test procedure S-parameters

[0135] The S 11 and S 21 parameters can be measured at various frequencies using a vector network analyzer. This parameter can also be modeled using the equivalent circuit shown. Figure 5 shown.

[0136] Equivalent series resistance (ESR)

[0137] The equivalent series resistance can be measured using an HP4284A LCR meter with Kelvin leads, at 0 VDC bias and a 10 mVAC signal. The operating frequency is 100 kHz and the temperature is 23°C ± 2°C. The ESR can be measured through the cathode terminal and one or more anode terminals. When multiple anode terminals are used, the average ESR can be reported.

[0138] Dissipation factor

[0139] The dissipation factor can be measured using an HP4284A LCR meter with Kelvin leads, at 0 VDC bias and a 10 mVAC signal. The operating frequency can be 120 Hz and the temperature can be 23°C ± 2°C.

[0140] Capacitance

[0141] The capacitance can be measured using a Keithley 3330 Precision LCZ tester with Kelvin leads, at a 2.2 VDC bias and a 0.5 V peak-to-peak sinusoidal signal. The operating frequency can be 120 Hz and the temperature can be 23°C ± 2°C.

[0142] Leakage current

[0143] The leakage current can be measured using a leakage tester (YHP4140B) at a temperature of 23°C ± 2°C, with a 1 kΩ resistor limiting the charging current and at least 5 minutes after the rated voltage (e.g., 2.5 V).

[0144] Example

[0145] 40,000 μFV / g tantalum powder is used to form the anode samples. Each anode sample is compacted to 6.0 g / cm 3density. The resulting pellets were 2.90 × 2.56 × 1.27 mm in size. The pellets were sintered at 1275°C and then a first tantalum wire and a second tantalum wire were attached to opposite ends of the pellet by welding. For 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 / phosphoric acid electrolyte at 40°C to form the dielectric layer. During anodization, a four-layer pre-coat of an organometallic compound was used, which contained a 1.0% solution of (3-aminopropyl)trimethoxysilane in ethanol. The anode was then dipped into a 2.0% solid content of poly(4-(2,3-dihydrothieno[3,4-b][1,4]diol) (Clevios)-2-(2-aminobutanesulfonic acid)-1-butanesulfonic acid solution TM K, Heraeus) to form a conductive polymer coating. During coating, the component was dried at 125°C for 15 minutes. This process was repeated twice. Afterwards, the component was dipped into a dispersed poly(3,4-ethylenedioxythiophene) (Clevios) with a solid content of 1.1% and a viscosity of 20 mPa.s. TM K, Heraeus). During coating, the parts were dried at 125°C for 15 minutes. This process was repeated 8 times. Afterwards, the parts were dipped into a dispersed poly(3,4-ethylenedioxythiophene) (Clevios) with a solid content of 2.0% and a viscosity of 20 mPa.s. TM K, Heraeus). During coating, the parts were dried at 125°C for 20 minutes. This process was repeated 3 times. Afterwards, the parts were dipped into a dispersed poly(3,4-ethylenedioxythiophene) (Clevios) with a solid content of 2.0% and a viscosity of 160 mPa.s. TM K, Heraeus). When coating, the part was dried at 125°C for 20 minutes. This process was repeated 14 times. Then, a graphite dispersion was applied to the part and dried. Then, a silver dispersion was applied to the part and dried. Finally, the part was dried as described herein and Figure 1A The terminals are shown mounted on a base plate.

[0146] In this manner, a number of (10) 22 μF / 35 V capacitor components were fabricated and sealed into ceramic packages as described herein. The resulting components were then subjected to various electrical performance tests. The results are shown in the table below.

[0147]

[0148] Those skilled in the art can practice these and other modifications and variations of the present invention without departing from the spirit and scope of the present invention. In addition, it should be understood that aspects of various embodiments may be replaced in whole or in part with each other. Furthermore, those skilled in the art will understand that the foregoing description is merely exemplary and is not intended to limit the present invention, which will be further described in the claims.

Claims

1. A capacitor, the capacitor comprising: A capacitor element, the capacitor element comprising a sintered anode body, a dielectric covering the anode body, and a solid electrolyte covering the dielectric, wherein the solid electrolyte comprises a conductive polymer, wherein the capacitor element defines opposite first and second ends and an upper surface and an opposite lower surface, wherein a first exposed anode lead portion extends in a lateral direction from the first end of the capacitor element, and a second exposed anode lead portion extends in a lateral direction from the second end of the capacitor element; A housing, the housing defining an internal cavity, the capacitor element being positioned and hermetically sealed within the internal cavity, wherein the first exposed anode lead portion and the second exposed anode lead portion are positioned within the internal cavity; A first anode terminal, the first anode terminal being electrically connected to the first exposed anode lead portion; A second anode terminal, the second anode terminal being electrically connected to the second exposed anode lead portion; and A cathode terminal, the cathode terminal being electrically connected to the solid electrolyte.

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

3. The capacitor according to claim 1, wherein, The solid electrolyte comprises 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 a valve metal powder having a charge-to-mass ratio of about 5,000 to about 100,000 μF*V / g.

6. The capacitor according to claim 1, wherein The anode body is formed from a valve metal powder having a charge-to-mass 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, the anode body comprising the first exposed anode lead portion and an embedded portion.

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

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

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

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

12. The capacitor according to claim 11, wherein, There is a gap between an end of the embedded portion of the first anode lead and an 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, the capacitor further comprising a first anode lead connection member, the first anode lead connection member comprising a first portion positioned substantially perpendicular to the lateral direction of the first exposed anode lead portion and connected to the first exposed anode lead portion.

16. The capacitor according to claim 15, wherein, The first anode lead connection member further comprises a second portion extending substantially parallel to the lateral 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 connection member is positioned within the housing.

18. The capacitor according to claim 15, wherein, The first positive terminal includes a first region positioned within the housing and electrically connected to the first anode connection 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 in the outer wall of the housing to connect the first region and the second region of the first positive terminal.

20. The capacitor according to claim 15, further comprising a second anode lead connection member, the second anode lead connection member including a first portion positioned generally perpendicular to the lateral direction of the second exposed anode lead portion and connected to the second exposed anode lead portion.

21. The capacitor according to claim 20, wherein, The second anode lead connection member further includes a second portion extending generally parallel to the lateral direction of the second exposed anode lead portion.

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

23. The capacitor according to claim 20, wherein, The second positive terminal includes a first region positioned within the housing and electrically connected to the second anode connection 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 in the outer wall of the housing to connect the first region and the second region of the second positive terminal.

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

Images