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-# ecthing
-Design files related to a photo-sensitive layering method etching machine everyone can build to produce prototypes quickly at home or in the lab. 
+# Embedded Etcher
+Design files related to a photo-sensitive layering method etching machine everyone can build to produce prototypes quickly at home or in the lab.
+## Architecture
+The etching machine consists basically out of two parts. The first part is a UV light, which is used to develop a photo-sensitive PCB. Once this has been done. The PCB has to be treated with sodium hydroxide (NaOH) dissolved in water. This removes the UV-sensitive plastic, where it has been tackeled by the light. 
+
+The second part is the actual etching machine, which is designed to be compatible to euro cards (and even bigger ones). The etching machine is either filled with sodium persulfate (Na<sub>2<\sub>S<sub>2<\sub>O<sub>8<\sub>) or iron(III) chloride.  
diff --git a/cad/.pcb_holder_lid.scad.swp b/cad/.pcb_holder_lid.scad.swp
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