Patent ID: 6120835
Filing Date: 2000-09-19
Classification: G01N

Abstract:
A thick film process to manufacture hydrogen sensors comprising:printing a palladium paste onto an essentially inert, electrically nonconductive substrate in a pattern to form at least two electrical networks;firing said substrate and palladium paste to firmly adhere said electrical networks to said substrate;printing a standard conductor paste onto said substrate at ends of said electrical networks to form pads;firing said substrate and standard conductor paste to firmly adhere said pads to said substrate;printing a barrier material over the pads to form a barrier layer on the pads;firing said substrate and barrier material to firmly adhere the barrier layer to the pads;printing a passivating material which is essentially inert, and hydrogen impermeable, onto at least one, but less than all said electrical networks; andfiring said substrate and passivating material to firmly adhere said passivating material to said electrical networks, without forming bubbles, voids or cracks.