STUB REMOVING TECHNOLOGY AND MANUFACTURING METHOD OF AN ULTRA-THIN MUTI-LAYERED PRINTED CIRCUIT BOARD THEREOF

摘要

PURPOSE: Stub removal technology and a manufacturing method of an ultra-thin multi-layer printed circuit board applying the same prevent inter-signal interference or disturbance by accurately removing a stub coated on the inner wall of a hole to a desired point with a chemical method. CONSTITUTION: A hole passing from an L1 layer to an L7 layer is formed. Copper foil is formed on the inner wall of the hole and the surfaces of the L1 layer and the L7 layer by performing copper plating. Insulating materials (30) are filled in the hole passing from the L1 layer to the L7 layer. A predetermined circuit pattern is transferred to the copper foil of the L1 layer and the L7 layer by selectively etching the copper foil of the L1 layer and the L7 layer. The upper surface of the hole is exposed by removing the copper foil covering the upper surface of the hole in the process of selectively etching the copper foil of the L1 layer. A stub coated on the inner wall of the hole from the L1 layer to the L7 layer is removed by spraying a chemical etching solution to the exposed upper surface of the hole.