In general, PCB assembly process involves preparation of the printed circuit board's surface, placing the components, soldering, and testing the completed item. Completed boards must pass through thorough testing before being released to a different part of a production line for attachment to a housing, such as a cell phone. This process is normally done through automated machines, but it is possible to make a homemade PCB with some modifications.
PCBs have specific points on their surface that can hold components; the first step in the PCB assembly process is applying solder paste across a screen. A machine places screens across the areas intended for the future components. Solder paste is spread across the screen to allow it to drip down onto the PCB's surface. This paste is meant to hold the future components to specific points on the PCB for a secure circuit connection.
Machines place components onto the solder paste in the next step of the PCB assembly process. A computer program controls the machine; it chooses particular components from a supply line and physically places them on the board. Solder paste provides the adhesion to hold the components in place before the soldering process.
