<p>A P-conductivity type resistor layer 12a is formed in the main surface of the (511) or (811) face of a silicon substrate 11, and extends along a crystal axis shifted by 45 DEG from the [011] axis to allow a current to pass along its crystal axis. It has been found that the resistance value of a resistor layer of such orientation is less affected than other orientations in the same planes by the thermal stresses induced in the layer by the shrinkage of a plastics resin envelope 18 during the moulding thereof. <IMAGE></p>
