ISSN:
1573-482X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The challenge recently demanded of electrolytic tantalum capacitors is to be able to operate above the frequency of 1 MHz which can be carried out insofar as their equivalent series resistance (ESR) is sufficiently small. Now, the mechanical quality of the oxide layers plays a determining part in the value of the ESR and the purpose of the present work is to detect in the oxide layer the areas most likely to be damaged but not yet cracked. It is shown that weaker zones exist in the oxide layer. These zones are revealed by chemical etching. The relative damaged area of one sample relative to another is correlated with the grain size ratio, by means of XPS, SEM and liquid capacitance measurements. It is established that the amorphous oxide is preferentially etched just above the grain boundaries of the tantalum substrate. These results lead to the conclusion that annealing at the greatest possible temperature has the best effect on the mechanical quality of the oxide layer.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00701091
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