A method of introducing a structure, preferably a hole or cavity or channel or well or recess, in a region of an electrically insulating substrate, said method comprising the steps: a) providing an electrically insulating substrate, characterized in that said method further comprises: b) storing electrical energy across said substrate using an energy storage element which is charged with said electrical energy, said energy storage element being electrically connected to said substrate, said electrical energy being sufficient to significantly heat, and/or melt and/or evaporate parts or all of a region of said substrate, c) applying additional energy, preferably heat, to said substrate or a region thereof to increase the electrical conductivity of said substrate or said region thereof, and thereby initiate a current flow and, subsequently, a dissipation of said stored electrical energy within the substrate, and d) dissipating said stored electrical energy, wherein the rate of dissipating said stored electrical energy is controlled by a current and power modulating element, said current and power modulating element being part of the electrical connection between said energy storage element and said substrate, wherein the amount of said electrical energy stored across said substrate and charged to said energy storage element is user-defined in relation to substrate parameters, such as substrate area, substrate thickness and process parameters, such as maximum temperature occurring during step d), wherein said energy storage element is an energy storage element having an impedance ≤10 kΩ, wherein furthermore said current and power modulating element is an ohmic resistor which is connected in series between said substrate and said energy storage element, said ohmic resistor being chosen such that it has a resistance in the range of from 0.1 - 100 kΩ if said substrate has a thickness ≥1 μm, and a resistance > 100 kΩ if said substrate has a thickness < 1 μm. a) providing an electrically insulating substrate, characterized in that said method further comprises: b) storing electrical energy across said substrate using an energy storage element which is charged with said electrical energy, said energy storage element being electrically connected to said substrate, said electrical energy being sufficient to significantly heat, and/or melt and/or evaporate parts or all of a region of said substrate, c) applying additional energy, preferably heat, to said substrate or a region thereof to increase the electrical conductivity of said substrate or said region thereof, and thereby initiate a current flow and, subsequently, a dissipation of said stored electrical energy within the substrate, and d) dissipating said stored electrical energy, wherein the rate of dissipating said stored electrical energy is controlled by a current and power modulating element, said current and power modulating element being part of the electrical connection between said energy storage element and said substrate, wherein the amount of said electrical energy stored across said substrate and charged to said energy storage element is user-defined in relation to substrate parameters, such as substrate area, substrate thickness and process parameters, such as maximum temperature occurring during step d), wherein said energy storage element is an energy storage element having an impedance ≤10 kΩ, wherein furthermore said current and power modulating element is an ohmic resistor which is connected in series between said substrate and said energy storage element, said ohmic resistor being chosen such that it has a resistance in the range of from 0.1 - 100 kΩ if said substrate has a thickness ≥1 μm, and a resistance > 100 kΩ if said substrate has a thickness < 1 μm.