Patent ID: 9168614
Filing Date: 2015-10-27
Classification: B23K,B26F,C03C,H03K,Y10T

Abstract:
1. A method of generating a hole, recess or well in a substrate, comprising: providing a substrate which is electrically insulating or semiconducting at room temperature and which has a first modulation layer on a first surface of the substrate and a second modulation layer on a second surface of the substrate such that the first and second modulation layers are in contact with a substrate region where the hole, recess or well is to be generated in the substrate; applying a focused laser beam having a spot size on the first modulation layer such that the first modulation layer is heated, that an opening smaller than the spot size is formed in the first modulation layer, that by exposing the substrate region directly to the focused laser beam through the opening, at least part of substrate material in the substrate region is molten, while the modulation layer and the opening modulate a heat profile generated by the focused laser beam such that an amount of heat reaching the substrate outside the substrate region is restricted; and applying to the substrate region of the substrate a DC electrical voltage sufficient to cause a dielectric breakdown across the substrate region such that the substrate material is ejected from the substrate and that the hole, recess or well is generated in the substrate region of the substrate, wherein the opening has a size defined by heat from the focused laser beam and at least one of a transformation/decomposition threshold of material of the first modulation layer and a thickness of the first modulation layer, and the opening is formed in the first modulation layer and the part of the substrate material is molten before the applying of the DC electrical voltage, and wherein each of the first and second modulation layers is made of a different material from each other.