the relevant development of solid electrolyte tantalum capacitors began some years after william shockley, john bardeen and walter houser brattain invented the transistor in 1947. it was invented by bell laboratories in the early 1950s as a miniaturized, more reliable low-voltage support capacitor to complement their newly invented transistor. the solution found by r. l. taylor and h. e. haring of the bell labs in early 1950 was based on experiences with ceramics. they ground tantalum to a powder, which they pressed into a cylindrical form and then sintered at high a temperature between 1500 and 2000 °c under vacuum conditions to produce a pellet ("slug").