METHOD OF MANUFACTURE OF ELECTRIC RESISTORS FROM A METAL SHEET FIXED ON AN INSULATING SUPPORT

摘要

Disclosed is a method of manufacture of resistors from a sheet of metal or metal alloy fixed on an insulating support, in which an insulating mask having windows or grooves is applied against the sheet and the assembly is placed within an electrolytic cell in order to remove the metal or alloy opposite to the windows or grooves. The method comprises the following steps:(a) applying a layer of conductive material on an insulating support, the sheet of metal or alloy covered with the insulating mask being then applied on the said layer; (b) subjecting the sheet which is covered with the insulating mask and applied on the said layer of conductive material to a stream of electrolyte adjusted to a flow rate within the range of 70 to 100 cm per second in order to ensure that a viscous layer which introduces a high resistance at the contact surface between the sheet and the electrolyte is progressively removed as it is formed; (c) removing the layer of conductive material and the etched sheet metal or alloy from the insulating support; (d) applying the etched sheet of metal or alloy on a final insulating support by means of an electrical insulating coating; (e) removing the layer of conductive material by means of a suitable chemical or electrochemical treatment; (f) applying a second layer of insulating coating on the said sheet of metal or alloy.