The invention discloses a process for a 420-500 micron ultra-thick electrolytic
copper foil. The process comprises the following steps of 1, unreeling; 2, activating; 3,
pickling; 4, coarsening and curing; 5, carrying out
barrier layer treatment; 6, carrying out anti-oxidation treatment; 7, carrying out organic treatment; and 8,
drying and rolling. According to the process, the effect of radiatingheat generated by components outside a substrate can be achieved, so that the purpose of high-density
interconnection of high-power electric appliances is achieved, the original
power transmission forms such as cable wiring,
metal plate bars and the like are replaced, the production efficiency is improved, and the labor-hour cost, the cost of cables and accessories, the cost of
maintenance management and the like of wiring are reduced; the
copper foil high-current substrate can effectively reduce the
thermal load of a PCB and achieve quality homogenization, so that the reliability of a terminal complete
machine product using the high-current PCB is further improved; and by adopting the high-current substrate to replace the original cable wiring form, the design freedom degree of the wiring can be improved, so that the
miniaturization of the whole terminal product is achieved.