Abstract: An apparatus for chemically etching the copper foil of a copper foil-clad substrate are disclosed. Significantly, this apparatus includes fluid jet injectors which serve to produce jets of chemical etchant. These fluid jet injectors are arranged so as to simultaneously achieve a relatively high etch rate and a relatively high etch uniformity.

Abstract: A fluid treatment apparatus and method for applying first and second fluids (e.g., etchant and water) to an article (e.g., circuit board) passing through the apparatus at a predetermined rate. The first fluid is impinged on a surface of the article and thereafter collected within the apparatus' common housing. The second fluid is impinged onto the surface of the article and collected within the same housing but at a location separate from the collected first fluid so as to at least partially prevent mixing thereof. The preferred means for effecting fluid impingement comprises separate fluid injecters, each including at least two rows of fluid jet injectors therein. The collected fluids are each returned to the respective impingement means. Replenishment of the second fluid is accomplished using a pump which supplies the second fluid, while the apparatus also includes means (e.g., a drain) to effectively remove the second fluid at a rate similar to the supply rate for the second fluid.