(under the class definition) Apparatus for treating a base with an etchant fluid the device having means causing the etchant fluid to contact the base in discontinuous or nonuniform manner.
(1) Note. In this subclass may be found, for example, devices which etch a taper on elongated workpieces by withdrawing at a controlled rate from an etching bath, devices etching through a mask, devices directing a thin jet of etchant at a particular spot on the workpiece to pierce the workpiece, etc..
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134, Cleaning and Liquid Contact With Solids, appropriate subclasses for devices there provided for even though the fluid may be disclosed and claimed as being an etchant. Devices peculiarly adapted to discontinuous or nonuniform etching are provided for in Class 156.
366, Agitating, appropriate subclasses for a mixing chamber with agitating means therefor, which may be disclosed for use with etching fluid.
