In a plating apparatus, a potential sensor capable of accurately confirming flatness in thickness of a plating film is provided. The plating apparatus includes a plating tank to store a plating solution, a substrate holder that holds the substrate, an anode disposed in the plating tank to oppose the substrate held by the substrate holder, a resistor disposed between the substrate held by the substrate holder and the anode and having a plurality of holes extending through sides of the resistor facing the anode and the substrate, and a potential sensor assembly disposed between the substrate held by the substrate holder and the resistor and configured to measure a potential of the plating solution, and the potential sensor assembly includes a base plate, a plurality of potential sensors arranged on the base plate, electrical wirings formed on the base plate for taking out signals from the plurality of potential sensors, and a protective film that protects the base plate and the electrical wirings.

After a chuck portion chucks a workpiece holding body which aligns and holds a plurality of workpieces on which components are to be placed, the posture of the workpieces held in the workpiece holding body is adjusted due to rotation mechanism by rotating the chuck portion around an axial line which extends in an aligning direction of the plurality of workpieces held in the workpiece holding body. Then, a placing head places the components on each of the plurality of workpieces which are subjected to posture adjustment.

A method of manufacturing a circuit board is described herein. The method may include adding a resin, forming first and second fiberglass fibers, and forming first and second signal line traces capable of transmitting electrical signals. In some examples, a ratio between fiberglass and resin material near the first signal line trace is similar to a ratio between fiberglass and resin material near the second signal line trace. In some examples, the first and second fiberglass fibers diagonally cross near the first and second signal line traces. In some examples, the first and second fiberglass fibers cross near the first and second signal line traces in a zig-zag pattern.

The present invention relates to a substrate edge etching apparatus including: a substrate support assembly having a horizontally rotatable chuck base, chuck pins disposed on top of the chuck base to support a substrate, a purge gas inlet hole extending from an underside center of the chuck base to an interior of the chuck base in an upward and downward direction thereof, and a purge gas outlet hole extending radially from the purge gas inlet hole and then extending upwardly to penetrate top of the chuck base; a purge gas supply assembly for supplying a purge gas to the purge gas inlet hole; a chemical liquid supply unit for supplying a chemical liquid to top of the substrate; a bowl assembly having bowls surrounding the periphery of the substrate support assembly and configured to be able to ascend and descend; and a fan filter unit spaced apart from top of the substrate support assembly.