In the construction of hermetically sealed encapsulations, feedthroughs are commonly required as contacting interfaces. The so-called GTMS (glass-to-metal-seal) feedthroughs are often used in the field of sensor technology, acting as an interface between sensor unit and evaluation electronics. GTMS feedthroughs, consisting of a metal mount, a glass body and contacts, transfer electricity, electrical or optical signals through a glass-based barrier while protecting the inside of a sensor from the ingress of dust, moisture or gases. They are mainly used in humidity, temperature, pressure, flow and vacuum sensors and are actually produced in a furnace process in which the entire components are heated to the melting temperature (> 400 °C) of the glass body. Sufficient heat must be applied to reduce the viscosity of the glass body to ensure a reliable wetting of mount and contacts. If temperature-sensitive components are involved, a furnace process is not suitable as the high temperatures damage these components. In this case a technology with localised energy input is required. A laser-based process enables the reduction of the thermal load.


Therefore, investigations on the manufacture of compressed GTMS feedthroughs for multilayer LTCC (Low Temperature Cofired Ceramic) with a diode laser have been performed, which are described in the following paper. Results on the influence of the process parameters on the heat input and the thermal load of the components are discussed and quality-relevant properties such as helium tightness and burst pressure resistance are evaluated.