IMPROVED ELECTROLYTIC COPPER PLATING FOR FLEX PWBS

摘要

Today, the most common flexible printed circuit substrates are 12.5 - 25 μm thick, with the trend toward even thinner materials. Two primary types of copper foil are used for flex: electrolytic copper foil and rolled copper foil. Electrolytic copper foils typically come in thicknesses of 18 or 12 μm, while most rolled copper foils are 18 μm thick. As with polyimide substrates, both types of copper foils are moving to thinner dimensions. Generally, rolled copper foils demonstrate flexural properties superior to those of electrolytic copper foil. Applications that require very high degrees of flexibility and reliability, such as HDD read-write heads, are dominated by rolled copper foils.