LASER DRILLING METHOD AND ITS APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a laser drilling method and its apparatus without de-lamination of layers to secure an electrical connection between layers when drilling a plural numbers of layers sheet. SOLUTION: When drilling a sheet having a plural numbers of layers, before irradiating a pulse forming a hole-shape, a drilling is performed with a required shape and pierced hole without having a de-lamination of layers by making a hole with a pulse having a energy to generate an inter-laminar peeling power which is smaller than an inter-laminar coherent power and by irradiating a pulse having a bigger energy for forming the hole-shape.