Refractory metal paste for solid electrolytic capacitors

Abstract

A solid electrolytic capacitor that contains a capacitor element that includes an anode body, dielectric layer, and solid electrolyte is provided. The capacitor also contains an anode lead that is electrically connected to the anode body. Contrary to conventional capacitors in which the lead is welded or connected using a layer of seed particles, a refractory metal paste (e.g., tantalum paste) is employed in the present invention to electrically connect the anode lead to the anode body. The use of such a refractory metal paste allows the anode lead to be sinter bonded to a surface of the anode body after it is pressed. In this manner, a strong and reliable connection may be achieved without substantially decreasing the surface area of the lead that is available for connection to a termination. The paste of the present invention generally contains particles of a relatively small size. Due to in part to the relatively small size of the particles, the paste may have a relatively low viscosity, allowing it to be readily handled and applied to an anode lead and/or anode body during manufacture of the capacitor. Further, the thickness of the applied paste may also be relatively thin and still achieve the desired binding of the lead to the anode body.