Common Defects and Solutions of Adhesive Tape in Epoxy Plate

As one of the DMD insulation paper in the epoxy board, the quality of the adhesive sheet will directly affect the quality of CCL. For many production targets unqualified products, in the follow-up processing can also be adjusted to make up, but the subsequent production process will bring greater difficulty and inconvenience. Usually the surface of the adhesive film is smooth, no resin particles, bubbles, discount, fish eyes, exposed cloth pattern, yarn breakage yarn, yellow lines, impurities and other defects, and resin content, gel time, volatile content Technical indicators are to meet the requirements of the process requirements. In contrast, the poor quality of the adhesive sheet is much more, then what should we take remedial measures?
First, too much surface particles
The main reason for this defect is that the resin does not sufficiently penetrate into the cloth and forms a granular attachment on the surface. As the hardness of colloidal particles than the copper foil in the process of copper cladding in the corresponding point of the copper foil will be subject to extrusion extension thinning, may cause the printed circuit board is reflected in the appearance of copper foil surface highlights, As the bright spots on the copper foil surface of the antioxidant layer is destroyed, the product at the time of storage is easy to be oxidized or even the formation of corrosion points, greatly reducing the product storage cycle.
Second, glue marks
The main reason for the occurrence of glue marks is the resin content is too large, soaked glass fiber cloth through the measuring roller vertical into the oven, there is liquidity in the liquid due to the impact of gravity on the surface of the cloth to form strip marks. The presence of the marks will have a certain impact on the flatness and warpage of the CCL. In this case, the resin content of the adhesive sheet should be adjusted in time.
Three bubbles
There are two main reasons for the occurrence of bubbles, when the glue is not fully infiltrated into the gap, the air in the gap is not discharged, when the glue was covered with glue in the cloth. When the furnace into the oven due to heat, the residual air expansion in the mica tape for cable surface to form bubbles; dipping tank in the plastic bubble generated by the bubble floating on the surface of the glue, the measuring roller does not completely spread the bubble on the cloth.