Used by a Circuit Board Assembler
For every circuit board assembler who works to create functional electronic devices, ensuring the quality of each device is an integral part of their job. This is because defects or flaws in PCBs can have a wide variety of negative effects, including unusability, poor functionality, and even safety hazards. This is why leading PCB manufacturers in the US impose strict PCB assembly quality control measures.
One of the most critical steps in a PCB assembly is the bare board inspection stage. This involves examining the bare circuit boards for any issues that could compromise their function and performance. This is an important step because it is often easier to spot and fix problems in the bare board phase, before they are populated with components.
In order to conduct a bare board inspection, a team member will typically use a microscope to examine each connection in close detail. This allows them to see any flaws that may have been caused by the manufacturing process. In addition, they will also be checking for metalized vias, or plated holes, to ensure that they are complete and free from nodules or voids.
Once the bare boards have been thoroughly inspected, they will undergo the reflow soldering process. This is when the circuit board assembler is heated in order to melt the solder paste and create reliable electrical connections between the components and the bare boards. This is another crucial part of the bare board inspection, as it can be difficult to identify any faulty connections without heat.
What Quality Control Measures Are Used by a Circuit Board Assembler?
After the reflow soldering process, the bare boards will undergo another inspection for quality control. This is when the assembler will verify that all of the components have been placed correctly on the board, and that all of the connections are secure. This can be done by using an automatic optical inspection (AOI) machine, which uses a series of high-powered cameras to ‘see’ the circuit board. These cameras are positioned at different angles in order to view the solder connections from various perspectives.
For smaller batches of PCBs, a bare board assembler can also perform a manual visual inspection. However, this method becomes impractical as the number of bare boards being produced increases. In addition, looking at small, intricate components for an extended period of time can lead to optical fatigue, which can reduce a person’s accuracy and efficiency.
Another useful PCB assembly quality control measure is a SMT (surface mount technology) machine. These machines are able to quickly and accurately place surface-mount components on the board. This helps to streamline the assembly process and prevents errors that can occur when a human attempts to place these components by hand.
A final quality control measure that is used in the PCB assembly process is X-ray inspection. This is a powerful tool that can help to detect a wide range of issues, such as erroneous placement and hidden short circuits. This is an effective way to ensure that the populated circuit board is functioning as intended, and that it will be able to withstand the demands of its application.
