초록 ▼

Wire bonds are made to palladium coated bonded pads on organic dielectric substrates at temperatures below 200° C. A layer of palladium thicker than 14 micro-inches is covered with a thin flash of gold. Palladium coated over copper pads is protected from copper diffusion by a thin nickel layer

Wire bonds are made to palladium coated bonded pads on organic dielectric substrates at temperatures below 200° C. A layer of palladium thicker than 14 micro-inches is covered with a thin flash of gold. Palladium coated over copper pads is protected from copper diffusion by a thin nickel layer positioned between the two. Subsequent baking for 1 hour at 185° C. drives off hydrogen molecules provided the gold is less than 200 Å thick. A bonding wire, preferably of gold is then successfully bonded to the pad using conventional bonding equipment at temperatures below 200° C.

대표청구항 ▼

1. An electrical card structure, comprising:a circuitized substrate having at least one wire bond pad located thereon;a layer of a first metal substantially free of hydrogen molecules located on said wire bond pad; anda thin layer of a second metal, different from said first metal, on said layer of

1. An electrical card structure, comprising:a circuitized substrate having at least one wire bond pad located thereon;a layer of a first metal substantially free of hydrogen molecules located on said wire bond pad; anda thin layer of a second metal, different from said first metal, on said layer of said first metal. 2. The electrical card structure of claim 1 in which said layer of said first metal is palladium having a thickness greater than about 5 micro-inches. 3. The electrical card structure of claim 2 in which said thin layer of said second metal is gold of about 50 Angstrom to about 200 Angstrom in thickness. 4. The electrical card structure of claim 1 in which said wire bond pad is comprised of copper and nickel. 5. The electrical card structure of claim 1 further comprising a wire bonded to said layer of first metal through said thin layer of said second metal. 6. The electrical card structure of claim 5 in which said wire is gold with a diameter of about 0.0008 to 0.00125 inches.