Automation has revolutionized the printed circuit board (PCB) industry with enhanced product reliability and faster assembly processes. There are several opportunities to improve the production yield by completely automating the PCB manufacturing process. However, there are certain process issues in achieving the maximum advantages of automation in PCB assembly. Also, using manual PCB assembly may be beneficial in low volume builds with simple circuitry. Since the assembly automation setup cost is high, it is necessary to understand the benefits and drawbacks of automating the assembly process.
Generally, automation is recommended in PCB assembly for multiple benefits, but there are a few applications where a manual assembly is considered a better choice. For example, prototype builds with unusual configurations, and PCBs using press-fit connectors or special components (tall or bulky parts). On the contrary, automation is ideal in SMT PCB assembly (Surface Mount Technology) and bulk production. Contract manufacturers can use either fixed or programmable, partial, or complete automation based on the available budget and build volume requirements.
Types of Automation
- Fixed automation is typically used in discrete mass production or continuous flow assembly setups by configuring equipment for a fixed and repeatable task. For instance, a conveyor belt is used to transfer material from one location to another in the PCB workshop.
- Flexible automation is used to accommodate adaptability in the production line. A computer program provides the required instructions to automate multiple processes with different product types. The trained staff members execute the computer programs to automate most of the production tasks with no downtime. Flexible automation is more suitable for performing batch processes in low-to-medium build volumes. For example, in material handling and flexible assembly lines.
- Integrated automation involves the complete automation of a production unit that is controlled by computers or industrial robots with minimal or no human intervention. It is a highly reliable and adaptable type of automation that can be used in both batch processes and continuous process manufacturing.
Benefits of Using PCB Assembly Automation
- Miniaturization: Automation drives excellent opportunities to build miniature devices with a reliable mounting of fine-pitch integrated circuits (ICs) (such as quad flat packages [QFPs], ball grid arrays [BGAs], etc.) or discrete components with small packages (0201, 01005). The increasing demand for wearable gadgets can be easily accomplished by an automated assembly process.
- Consistency: Using assembly automation, the reproducibility of the product increases. The accuracy of repeated tasks is quite high, and the product performance can be extremely reliable.
- Improved production speed: Using industrial robots can drastically reduce the chance of human error during the PCB assembly process. Also, automated machines can operate continuously without any fatigue. This can improve the assembly speed and production output.
- Efficient material handling: Tracking and supervising a huge amount of material movement can become a tedious and exhaustive job on the assembly shop floor. Automated material handling can optimize resource utilization and considerably reduce wastage.
- Better product quality: Automation can reduce PCB defects with exceptional repeatability of the assembly tasks. Regularly maintained assembly equipment and automated inspection machines ensure a better quality of the PCB assembly.
- Enhanced workplace safety: Automation can replace human intervention in a hazardous work environment. Operators can avoid exposure to chemicals or extreme temperatures that are common in solder reflow stations. Automated conveyor belts can handle safe material movement and eliminate the possibility of component damages due to electrostatic discharge (ESD).
- Drive mass production: Building large volume, robust products is made easy using automation. The reduced lead time and production costs are the major advantages driving mass PCB production.
- Adopts better cleanliness: Certain applications have stringent requirements on the cleanliness of PCBs post-assembly. There are certain cleanliness standards to be met, especially in medical PCBs. Automation avoids contamination that may happen due to manual handling of the PCB. Automatic washers are used in critical applications to clean the assembled boards.
Challenges in Using PCB Assembly Automation
- Large setup expenditures: The machinery and software required for automation are quite expensive and therefore involve a large initial investment. This can be a big obstacle for small-to-medium level assembly providers. It is necessary to evaluate the return on investment (ROI) before proceeding with the automation of the assembly unit.
- Possibility of adding multiple errors: Automating a task incorrectly enables repeated errors in the assembly line. This can reduce the process efficiency and increase material waste. There are chances of software corruption and other cyber threats that can cause bigger problems in the assembly line.
- Need for human intervention: There can be a requirement for manual intervention in the automated PCB assembly This can become a deterrent in the long run. For instance, in an automated SMT assembly process, it may be necessary to manually inspect small components for any displacement on the board after passing through the solder reflow oven.
- Impacts existing workforce to become redundant: Contract manufacturers may have to reduce the headcount once the assembly line is automated. There are also requirements to upskill the existing staff to understand and operate partial and programmable automation processes. This may lead to a redundant workforce.
There are several discrete automated processes used in the PCB assembly line. It can be pick-and-place machines for component placements, automatic soldering systems used in wave solder and reflow ovens, routing machines to detach PCBs from the panel, adding identification labels on PCB assembly, etc. These methods have certainly improved process efficiency.
Without the automation of the PCB manufacturing process, assembling high-speed, dense multi-layer circuit boards will be a big challenge. Contract manufacturers are depending on the latest automation techniques to build quick and high-performance PCB products. Evolving technologies demand reliable assembly and efficient testing of shrinking PCBs with fine-pitch components like BGAs. Automated assembly processes are mandatory to place tiny parts within tight tolerances. Even inspection and testing procedures are automated with overall developments in PCB manufacturing techniques.
To decide whether to implement automation in your assembly process, it is necessary to evaluate your build volumes and required capital investments. Industry 4.0 standards emphasize the importance of autonomous automation in the PCB manufacturing process to ensure high-quality product development. Automation is gaining wide acceptance in the manufacturing industry and PCB manufacturers are embracing the complete automation of PCB assembly to stay ahead of the competition.