An all-inclusive containment of electronic components attached on a board, and configured to function in a given way forms a circuit board. When the circuit boards are printed, they are referred to as printed circuit boards, and the process through which the boards are prepared is called the printed circuit board assembly process. Flawless execution of the process leads to full-functional boards that can be used for various electrical appliances. The critical stages in the assembly process are described below.
The setup phase – This is the first step, and involves a number of activities relating to the preparation of the materials, components and circuit-board specification and documentation details.
Patterning and etching phase – Once the materials and schematic representation of the circuit have been assembled, contact areas not required in the resulting circuit board are removed by etching. Small-scale PCB assemblers use etch-resist films to cover the unrequired areas, while mode advanced assemblers use plasma and laser techniques to trim the copper contacts to shape and size.
Multilayer pressing phase – Which involves the alignment of copper contacts with the insulating dielectric conductor ends into a solid board. This phase is essential in the assembly process as it yields the board used in the printed circuit board assembly process.
Drilling and masking phase – Drilling involves boring holes onto the circuit board. These holes should be matched with the size of the components to be attached on them. On the other hand, masking involves the creation of thin soldered layers masking the drilled holes and component edges.
Finishing and testing phase – The finishing phase involves coating padded areas with molten soldering material to protect the components from chipping off. The printed circuit board assembly process is completed by testing its functionality and usability on a given electrical appliance. It is common to use the following testing processes.
- Visual circuit board inspection
- Analogue signature analysis
- In-circuit testing technique
- Functional testing