Improved process and new laser source for spatter free welding of electronic copper components

Abstract

Today’s commonly used IR-lasers suffer from two limitations: Firstly the process reproducibility can be quite low as copper is highly reflective at the 1 µm wavelength, and secondly the process parameters used today typically result in splatters emerging from the welded region during the deep-penetration welding process, leading to short-circuits in electronic and electrical components.The most precise method to detect sputters is the recording of the welding process by means of a high-speed camera. With this technique, exactly which types of sputters are to be distinguished and which process phase is responsible for their formation can be determined.The time and the type of coupling of laser light into highly reflective materials can be determined as well.Pulsed and continuous welding processes, with both 1 µm and 0.5 µm wavelength, local power density distribution and temporal progression of the power have been examined and optimized.A newly developed laser source meets all the requirements of optimized process quality.Today’s commonly used IR-lasers suffer from two limitations: Firstly the process reproducibility can be quite low as copper is highly reflective at the 1 µm wavelength, and secondly the process parameters used today typically result in splatters emerging from the welded region during the deep-penetration welding process, leading to short-circuits in electronic and electrical components.The most precise method to detect sputters is the recording of the welding process by means of a high-speed camera. With this technique, exactly which types of sputters are to be distinguished and which process phase is responsible for their formation can be determined.The time and the type of coupling of laser light into highly reflective materials can be determined as well.Pulsed and continuous welding processes, with both 1 µm and 0.5 µm wavelength, local power density distribution and temporal progression of the power have been examined and optimized.A newly developed laser source meets all the requirements of optimized...