Plating frame unit for holding a substrate in a chemical and/or electrolytic surface treatment of the substrate

A plating frame unit for holding a substrate in a chemical and/or electrolytic surface treatment of the substrate, comprising:

• a front plate,
• a back plate, and
• a vacuum unit,
• wherein the front plate comprises a front frame portion surrounding a front recess portion,
• wherein the back plate comprises a back frame portion,
• wherein the front frame portion and the back frame portion are connected to each other to hold the substrate between them, and
• wherein the vacuum unit is configured to reduce an inner pressure between the front frame portion and the back frame portion below a surrounding pressure to attach the front frame portion relative to the back frame portion,
• the plating frame unit further comprising electric contact portions provided at the front frame portion and the back frame portion,
• the electric contact portions being arranged at the front frame portion and the back frame portion to contact the substrate electrically,
• wherein the electric contact portions are finger-shaped,
• wherein the finger-shaped electric contact portions at the front frame portion have a first direction opposite to a second direction of the finger-shaped electric contact portions at the back frame portion, and
• wherein the first direction and the second direction intersect each other so that the finger-shaped electric contact portions at the front frame portion and the finger-shaped electric contact portions at the back frame portion cross each other when seen from a top view,
• the top view being across the front plate or the back plate, parallel to a longitudinal axis of the front plate and the back plate.