A gas delivery substrate for mounting gas supply components of a gas delivery system for a semiconductor processing apparatus. The substrate includes a plurality of layers having major surfaces thereof bonded together forming a laminate with openings for receiving and mounting first, second, third and fourth gas supply components on an outer major surface. The substrate includes a first gas channel extending into an interior major surface that at least partially overlaps a second gas channel extending into a different interior major surface. The substrate includes a first gas conduit including the first gas channel connecting the first gas supply component to the second gas supply component, and a second gas conduit including the second channel connecting the third gas supply component to the forth gas supply component.