June 2008, Marseille, FranceInternational audienceBolometers cooled to very low temperature are currently the most sensitive detectors for low spectral resolution detection of millimetre and sub-millimetre wavelengths. The best performances of the state-of-the-art bolometers allow to reach sensitivities below the photon noise of the Cosmic Microwave Background for example. Since 2003, a french R&D effort called DCMB ("Developpement Concerte de Matrices de Bolometres") has been organised between different laboratories to develop large bolometers arrays for astrophysics observations. Funded by CNES and CNRS, it is intended to get a coherent set of competences and equipments to develop very cold bolometers arrays by microfabrication. Two paral...