Aluminum Etchant

Abstract

An aluminum etchant includes 3-30 wt % of hydrochloric acid, 4-20 wt % of sulfuric acid, 1-5 wt % of oxidizing agent, 0.5-2 wt % of surfactant, and water for the rest. The etchant can produce circuits of 200-25 μm wide on an aluminum foil or aluminum plate. The circuit has good quality. Therefore, the invention is suitable for miniaturized products that require higher precision.

1 . An etchant for aluminum with a thickness between 5 and 40 μm, comprising 3-20 wt % of hydrochloric acid, 4-20 wt % of sulfuric acid, 1-5 wt % of oxidizing agent, 0.5-2 wt % of the surfactant, and water for the rest, wherein the oxidizing agent enables the aluminum to rapidly for an oxide layer, the etchant removes the oxide layer, the surfactant functions to disallow hydrogen bubbles generated due to the chemical reactions to adhere onto the aluminum so that the etching path is not blocked by hydrogen bubbles, and the etching rate reaches 10-30 μm per minute while the etched lines have a line width within 200-25 μm wide. 
     
     
         2 . An etchant for aluminum with a thickness between 5 and 40 μm, comprising 1-20 wt % of hydrochloric acid, 10-50 wt % of phosphoric acid, 1-5 wt % of oxidizing agent, 0.5-2 wt % of the surfactant, and water for the rest, wherein the oxidizing agent enables the aluminum to rapidly for an oxide layer, the etchant removes the oxide layer, the surfactant functions to disallow hydrogen bubbles generated due to the chemical reactions to adhere onto the aluminum so that the etching path is not blocked by hydrogen bubbles, and the etching rate reaches 10-30 μm per minute while the etched lines have a line width within 200-25 μm wide.