Forming copper clad laminates

摘要

An improved method for preparing copper clad laminates from a copper substrate without a conventional or infrared oven. The method contains the steps of: (a) preparing a precursory coating composition which can be subsequently cured to become polyimide; (b) coating the precursory coating composition on a copper substrate; and (c) exposing the precursory coating composition to an infrared heater provided in an infrared curing apparatus. The infrared heater is selected such that it emits infrared rays of wavelengths correponding to the absorption spectrum of the precursory coating composition. A plurality of infrared heaters can be provided in the infrared curing apparatus, each can be designed to have a different effective heating length and/or operated at a uniquely predetermined surface temperature for optimum energy efficiency. Preferably, the precursory coating composition contains an upper layer consisting essentially of polyamic acid and a lower layer disposed between the upper layer and the copper substrate, the lower layer being a blended mixture of the polyamic acid and a modified bismaleimide.