Thermodynamic Analysis and Assembly Optimization of Large-Scale Solid Electrolyte Tantalum Capacitor welded on the LTCC substrate

LTCC multilayer substrate (LTCC, Low Temperature Co-fired Ceramic) is one of the most widely used substrate in the high performance MCM (MCM, multi-chip module). Many kinds of passive elements and active devices can be integrated on the surface of the substrate. As one kind of the passive element, solid tantalum electrolytic capacitor has many advantages such as the bigger capacity per unit volume and the lower resistivity impedance, which are benefit for the emission performance of the MCM modules. In this paper, two kinds of process are used for the assembly of large-scale solid tantalum electrolytic capacitor surface mounted on the LTCC multilayer substrate. Verified experiments are carried out on the basis of soldering and experimental process analysis. A new soldering method is creatively proposed to solve the reliable problem of the soldering of solid tantalum electrolytic capacitors on the LTCC substrate. After environment tests, the resistance between tantalum capacitor lead and soldering pad is less than 100 milliohm, the shear strength of tantalum capacitor joint is larger than 50N. And this method is successfully applied in the existing products.