3D MID Plating Technology

Molded Interconnect Device Plating for Electronic Components

3D MID plating technology is used in the construction of circuits on a wide range of interconnect devices to achieve function and performance comparable to a circuit board.

Our molded interconnect device plating can be done in bulk (barrel) or individually (rack plating), depending on the application geometry & construction requirements.

For 3D-MIDs the common plating construction is electroless copper, electroless nickel, and immersion gold.

Electroless Copper

The copper deposit functions as the main conduit for electronic signals and current transmission.

The electroless copper process deposits a build of copper with the total thickness dependent on activity and time. Common thickness ranges are 150 micro-inches to 500 micro-inches.

The width, length, and thickness of the copper deposit are important factors contributing to transmission capability.

Electroless Nickel

Electroless nickel is the 2nd layer of plating on a 3D-MID.

The function of the electroless nickel is to act as a barrier coating protecting the copper trace from forming an oxide which would be detrimental to the electrical performance.

The thickness of the electroless nickel should be a minimum of 125 micro-inches to prevent copper oxidation and corrosion. Electroless nickel total thickness is also determined by activity and time; thicknesses up to 500 micro-inches are not uncommon.

While the electroless copper composition is 100% copper, electroless nickel deposits are alloys of nickel (90%) and phosphorus (10%).

Immersion Gold

The final layer to complete the circuit is immersion gold. This layer provides low-contact resistance & prevents oxidation of the nickel. The thin layer of gold also allows electrical contacts or subsequent bonding via solder or wire bonding to the trace.

Immersion gold can be deposited up to 8 micro-inches and is a displacement reaction so higher thicknesses are not possible. Build-up of gold can be achieved with an electroless gold process.

Other plating can be used as replacements for gold including palladium, ruthenium, and platinum.

All molded interconnect device plating is performed right here at SelectConnect Technologies.

Contact SelectConnect today & tell us about your 3D MID plating needs.