| 摘要 |
<p>In a method for forming a resist pattern comprising exposing a photosensitive material which is a laminate of an insulating base plate, an electric conductive coating and a positive working photo resist coating, through a positive mask of circuit pattern placed on said photo resist, to an actinic radiation, developing the photo resist with an aqueous alkaline solution, thereby removing the exposed area and forming an etching resist, subjecting said resist to an etching with an acidic etching solution to remove the exposed conductive coating and finally removing the resist still remained on the unexposed area of the photosensitive material, an improvement which is characterized in that after said development and prior to the etching operation, the unexposed resist is further exposed to an actinic radiation. The present method is useful for giving a printed circuit board with excellent circuit pattern having no slender lines due to undesired side etching.</p> |
