Page 36 - PCMI Summer Journal 2021
P. 36

  An Overview of the Operation of Ferric Chloride Regeneration Systems in Photochemical Etching Machines
Presented by: Kirk Lauver, the Marketing Specialist, Chemcut Corporation, US
7/27/21
          mV=0.77+0.059log( ) - 0.222
𝐹𝐹𝑒𝑒+3
𝐹𝐹𝑒𝑒+ 2
 β€’ Avoid setpoints in the shaded area, >620mV
β€’ ORP values of 1000 are possible due to β€œover” regeneration
β€’ Redox setpoint may need to be changed as other metals accumulate
β€’ Affected by specific gravity, temperature and hydrochloric acid level
  10
    11
β€’ Easiest of the parameters to control and the slowest to change
β€’ Can be controlled manually or automatically
β€’ Affects: Etching rate, Surface finish, Viscosity, ORP
β€’ Required amount of water is different for each regeneration method. β€’ Water demand is highest for chlorine gas systems.
β€’ Demand is lowest with sodium chlorate regeneration.
β€’ Depends upon the specific gravity (Baume’) desired
   Issue 137 August 2021 PCMI Journal 36
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