Tape casting applications substrates

W R. Cannon, R. Becker, and K. R. Mikeska, Interactions Among Organic Additives Used for Tape Casting pp. 525-41 in Advances in Ceramics, Vol. 26, Ceramic Substrates and Packages for Electronic Applications. Edited by M. E Yan et al. The American Ceramic Society, Westerville, OH, 1989. 

Substrates made by the multilayer process from tape cast alumina have received considerable attention in recent years for multichip module (MCM) applications. An MCM consists of an array of closely packed chips on an interconnect board several inches on a side. Cofired ceramic is attractive relative to organic laminates because its thermal conductivity is almost 2 orders of magnitude higher, an important consideration in high-density circuitry. In addition both alumina and aluminum nitride ceramics are more closely matched to silicon in CTE than are organic boards. For similar reasons, alumina and AIN are attractive for ball grid array (EGA) mounting of chips. ... 

In general, doctor blades are used for casting thicker tapes, that is, those that are 25 microns or thicker in the dried state. All ceramic substrate casting machines use a doctor blade of some sort. For these applications, the green tape thickness is usually on the order of 250 to 1000 pm (0.010 to 0.040 in.). Some of the machines produced in Japan use the "comma coating head for these thick tapes. 

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