Since 1997, CEA/SAP and CEA/LETI/SLIR have been developing monolithic Si bolometer arrays sensitive in the far infrared and submillimeter range for space observations. Two focal planes, 32x64 and 16x32 pixel arrays, are designed and manufactured for the PACS (Photodetector Array Camera and Spectrometer) instrument of the Herschel observatory, to be launched in 2007. The two arrays cover respectively the 60-130 micrometer and 130-210 micrometer ranges. The goal of these large bolometer arrays is to achieve observations in a background limited NEP around 10(to the negative 16th power) W.Hz(to the negative 1/2 power). The detector physics and manufacture techniques of the different stages of these arrays are first presented. Then we describe the read-out and multiplexing cold electronics (300mK) that make possible several functional modes (temporal and fixed pattern noise reduction, etc.). The latest experimental measurements carried out with the complete detector system at the nominal temperature are presented and performances are discussed.