Robert Leighton Martin, JR
Respiratory Therapy at Archer Pl, Denver, CO

3978269, Aug 31, 1976

Dec 12, 1974

5/532270

Robert M. Martin - Golden CO

Coors Porcelain Company - Golden CO

B01J 3508, B32B 106

428403

In accordance with the invention, hollow pellets having outer surfaces of one material and inner surfaces of another material are manufactured by dropping drops of liquid into a bed of powder containing the material of which it is desired to make the outer surface portions of the hollow pellets and preferably also a binder, the liquid containing the material of which it is desired to make the inner surface portions of the hollow pellets. When the drops of liquid fall into the powder, the powder immediately forms a spherical shell around each drop so as to form the hollow pellets upon vaporization of the liquid. It is preferred that the powder additionally contain some sodium bicarbonate or the like and that the liquid be an aqueous acid solution such that, upon initial formation of the spherical shell of powder, the acid reacts with the sodium bicarbonate to generate carbon dioxide which causes the spherical shell to expand while yet additional powder coalesces onto the shell. This results in hollow pellets wherein the inner surfaces are formed from material included in the liquid and the outer surfaces are formed from material included in the bed. The method is particularly useful for the manufacture of pellets wherein at least the outer surfaces are of ceramic, there being a firing operation on the pellets after removal from the powder bed so as to sinter the ceramic to monolithic structure.

4786342, Nov 22, 1988

Nov 10, 1986

6/929386

James E. Zellner - Denver CO
Robert M. Martin - Golden CO

Coors Porcelain Company - Golden CO

B32B 1800, B32B 3120

156 89

A method is provided for producing a ceramic substrate with at least one surface having sufficient smoothness to allow for placement of fine line electrical circuitry. A ceramic powder is placed in a die. A ceramic tape is formed having one surface with a desired degree of smoothness. A portion of the tape is placed into the die with the surface opposite the smooth surface in contact with the ceramic powder. The powder and tape are dry pressed to form an integral ceramic green body with a smooth surface. The green body can be sintered to form a sintered smooth-surfaced ceramic substrate. The smooth-faced ceramic substrate can be formed with the smooth face countersunk or with edges pulled back. A ceramic substrate can be formed with a conductive material between the cast tape layer and the base layer. A ceramic tape cast on a smooth carrier such as polyvinyl butyral and a method for producing such cast tape is also disclosed.