Science and technology of large-mass bolometer arrays

After almost 20 years of R&D, cryogenic detectors are now officially inserted in the list of detectors for fundamental and applied physics. One of the main research fields where bolometers are conveniently exploitable is in the search of rare events, like Double Beta Decay, Dark Matter or Axions. The first requirement that had to be fulfilled for this application was to progress from the mg range of the first absorbers towards the kg range of nowadays detectors, together with the development of the array technique, that climbed from the first four detector style up to the present 60 and, possibly, the future 1000 channel array. The increase in mass and in number of channels must go on together with crucial scientific and technological achievements, some of which are discussed in this paper.