We are periodically asked about the acceptance criteria for cap plating of filled holes.
Today’s engineering tip gives the acceptance criteria per IPC A-600.
Target condition: Copper surface is planar with no protrusion (bump) and/or depression (dimple)
Acceptable condition – Class 1,2, and 3:
• Separation of copper cap to fill material
• No separation of the cap plating to underlying plating
• Cap protrusion (bump) and/or depression (dimple) meets the dimensional requirements in IPC 6012
• Fill material within the blind via shall be planar with the surface within +/- .076 mm (.003”) unless otherwise specified
• When cap plating is specified, fill material within the blind via shall meet the dimple/bump requirements of IPC 6012
• No voids in the cap plating over the resin fill
Please contact us if you have any questions!
Remember, designing and purchasing printed circuit boards should not be difficult!