Plasma Etching Of Chrome From Cermet Resistors
Original Publication Date: 1979-May-01
Included in the Prior Art Database: 2005-Feb-20
Cermet resistors can be fabricated on a ceramic substrate by first depositing layers of cermet chrome-copper-chrome material and then selectively depositing patterns of chrome-copper-chrome circuitry on top of the cermet in order to define the resistors. The last step in the process for fabricating such resistors is the removal of the layer of chrome from the top of the cermet where one wants the cermet to act as a resistor. Conventionally, this layer of chrome is removed by means of a wet chemical etching, such as by a mixture of glycerin and hydrochloric acid heated to a relatively high temperature. This technique is effective; however, the use of heated glycerin and hydrocloric acid presents relatively severe environmental and handling problems.