By using a novel method, the exposure time of the photosensitive paste layer
is
reduced and the exposure fineness of the layer is improved, thereby developing
a highly fine circuit substrate of high density having a thermal resistance at
a reasonable cost. A circuit substrate is manufactured as follows. A photosensitive
paste containing photoresist and a circuit material is applied onto a substrate
surface so as to form a photosensitive paste layer (4). This photosensitive
paste layer (4) is plotted by a laser beam (8) so as to form a plotted
area (7). The photosensitive paste layer (4) is developed and an
exposed area (4a) or an unexposed area (4b) is removed
so as to form a circuit pattern (17). This circuit pattern (17) is
sintered to form a circuit pattern (20) composed of the circuit material.
It is possible to form a highly fine circuit pattern of high density by laser beam
plotting. Moreover, when a greensheet (2) is used as the substrate, it is
possible to form a ceramic substrate (18) having a thermal resistance by
sintering. Furthermore, by using this method, it is possible to form an arbitrary
image on an arbitrary object.