Low Temperature Cofired Ceramics (LTCC) technology offers a lot of advantages to sensor manufactures. It allows to produce heater and sensing element with very good properties in a single technology. The heater should fulfil the following requirements: uniform distribution of temperature over the sensitive material area, low power supply and cold ends at the place of wire connection.

At this time, Mentor Graphics supports two kinds of thermal simulation. AutoTherm is predominantly used for modeling heat transfer in MCMs and AutoFlow for performing three-dimensional system-level thermal analysis of electronic products. This paper describes the simulation, optimization and comparison of different models of heaters with AutoTherm in LTCC technology.

The first step in our process was to decide between several thick-film inks and to design the heater. During simulation, the number of layers and the place of the heater were modified. In addition a pattern of punched holes around the heating area permitted a changeable head gradient. Through the simulation, a concrete range could be defined. The arrangement of the hole-pattern is basic for a wide range of heat distribution. The simulation results were examined by measuring them with an infra-red camera. With this additional information, we could correct the boundary conditions without carrying out trials. The evaluation of similar temperature profiles in AutoTherm and with the camera software shows a good harmony, meaning we should be able to produce one sensor for different applications.

Bio:
Torsten Kirchner is a scientific assistant with the Technical University of Ilmenau, Germany. He has a Dipl.-Ing. degree in Electrical Engineering.