A two‐dimensional, time‐dependent analysis is made of array‐compatible bolometers directly deposited onto a single substrate. It applies both to antenna‐coupled and surface‐absorbing configurations. Unlike previous spherically symmetric treatments, it allows analysis of thermal crosstalk between closely neighboring detectors, and of the effects of finite substrate thickness. In a closely packed array of surface‐absorbing detectors, thermal crosstalk generally degrades the array’s resolution more severely than optical (diffractive) crosstalk. Diffraction‐limited resolution with surface‐absorbing detectors is possible only by sacrificing either thermal resistance, and therefore sensitivity, or filling factor. With a minimum substrate thickness ofLmin, a closely packed, diffraction‐limited array is limited to a thermal resistance ofZt≤0.08(&kgr;Lmin)−1, where &kgr; is the thermal conductivity of the substrate. An array of antenna‐coupled bolometers is not subject to this limitation since the thermally and optically sensitive areas need not be equal.