Patent ID: 7451907

Claim:
A method of making a current collector plate of the type comprising two sheets of metallic material having a predetermined pattern of bonded facing surface portions and non-bonded facing surface portions, the current collector plate further comprising fluid flow channels formed in the non-facing surfaces of the sheets, said method comprising: applying a metallic bonding material to the facing surface of at least one of the sheets in the predetermined pattern, the metallic bonding material being softer than the metallic material of the sheets; pressing the sheets together between rollers to deform the metallic bonding material under roll bonding pressure so that facing portions are bonded by the deformed bonding material in the pre-determined pattern; placing the sheets with bonded facing portions between opposing forming surfaces, the opposing forming surfaces having (i) surface portions engaging locations of non-facing surfaces of the sheets for preventing expansion at the engaged sheet locations and (ii) relieved portions for expansion of non-engaged portions of the sheets into the fluid flow channels; and injecting fluid between the sheets to expand non-facing sides of non-bonded portions of the sheets into the relieved portions of the opposing forming surfaces to form the fluid flow channels.