Author: Sherri Melton

Overview of the PCB Assembly Process

pcb-assembly Despite its diminutive appearance, a number of processes are actually involved in the assembly of printed circuit boards. These processes need tube accomplished in accordance with a prescribed sequence in order for them to result in a quality product that will play an integral role in numerous electronic products and devices. The PCB assembly sequence ensures that any issues and or glitches that occur at any of the stages can be quickly identified and appropriately addressed.

The first stage in the PCB assembly process is the application of solder paste using a solder screen. Even before any external components are integrated onto a printed circuit board, solder paste must be used to indicate the areas where solder is to be applied on the initially bare surface of the board.

The process of applying solder paste can be likened to the process of silkscreen printing –

The solder screen essentially functions in the same manner as a silkscreen since its primary purpose is to indicate the areas where the solder paste should be deposited in. The predetermined areas are also called solder pads and are based on the files of previously made printed circuit boards. The most vital step in this stage is consistency of the solder paste, since all solder pads must end up with the same deposited amount of solder.

The next stage in the PCB assembly process is known as the pick and place stage. This process is so called since the stage requires a machine to pick component parts and place them on their predetermined positions on the printed circuit board.

As long as the board is not subjected to sudden movements, the solder paste can sufficiently anchor the component parts on the surface. However, as a precautionary method, glue is also often added onto the printed circuit boards in order to further secure the component during the pick and place stage. The only disadvantage is that unless the glue is designed to eventually weaken, it will be hard to make subsequent repairs or changes.

Similar to solder screens, pick and place machines are also guided by pre made printed designs. The designs specify the positions of each individual component and thus serve to hasten and simplify the pick and place stage of printed circuit board assembly.

The third stage in the assembly process involves passing the printed circuit boards through a soldering machine. Due to the innovative and more efficient production afforded by the surface mount technology, soldering components onto the PCBs can now be completed at a much faster rate.

PCB-AssemblyAfter completing the soldering stage in quick turn pcb assembly, each individual printed circuit board will then have to undergo a thorough inspection. Since a manual inspection will prove too tedious and time-consuming, a specially programmed machine is instead used to inspect the hundred or so components on the printed circuit board. The optical inspection is meant to detect any wrongly positioned components and weakened joints.

Later on, those printed circuit boards which pass inspection are sent off for testing. It is a prerequisite for all electronic products and devices to undergo various testing methods in order to ensure that they are able to function as intended.

The final stage in PCB assembly is the generation of feedback – 

Although this is the last stage, it is by no means the least important one. In fact, this stage could determine the entire flow of the production line.

As soon as any defects are detected during the inspection stage, then feedback must be immediately provided in order to correct those problems. This will save manufacturers from producing and ending up with substandard boards thereby saving precious time and resources.

This efficient and optimized system ensures that only products of the highest quality ever leave the factory and end up inside your electronic devices.