The operation is analogous to the manufacture of printed circuit boards. Fritzing allows for easy creation of printed circuit boards. Wave soldering is a bulk soldering process used in the manufacture of printed circuit boards. This problem abstracts layout problems arising in the routing of multilayer printed circuit boards. It is also the same method used for printed circuit boards. Poor quality capacitors may leak electrolyte, which is harmful to printed circuit boards. Jumpers have been used since the beginning of printed circuit boards. The combination of these printed circuit boards forms two variable capacitors. It is used to connect traces on a printed circuit board. The layers beneath etched conductors in printed circuit boards (PCBs) also act as dielectrics. The method eliminates the design and fabrication of a printed circuit board. FPGAs originally began as competitors to CPLDs to implement glue logic for printed circuit boards. It is the de facto standard format used by printed circuit board or PCB software. Fuses designed for soldering to a printed circuit board have radial or axial wire leads. Etching is also used in the manufacturing of printed circuit boards and semiconductor devices.