Thermal behaviour of front-end multi-chip modules

We report on a study of the thermal behaviour of a multi-chip module developed for the readout of GaAs microstrip detectors of the H1 experiment at DESY in Hamburg. The applicability of a low-cost laminated printed-circuit board technology will be demonstrated. From experiments using an air-cooled set-up (22°C and 17 cm/s) we determine a maximum thermal resistance of about 75 K/W. A comparison with modules realized in thin-film technique shows an improvement by a factor of at least 5. A hypothetical water-cooled set-up leads to maximum values for the laminated module of about 32 K/W, which corresponds to a threefold higher value than in case of the thin-film module. An analytical model is introduced, which can be used for simplified temperature profile calculations. Finite-element simulations confirm models accuracy better than 10%.