How to increase the efficiency of SMT pick and place machines.

This chapter will discuss a unique topic: how to improve the efficiency of SMT placement machines. SMT placement machines not only need to be fast but also precise and stable. However, in actual operation, each SMT placement machine has different specifications for electronic components and varying speeds. For example, LED components have relatively lower precision requirements compared to SMT components, so LED products can be placed faster than SMT products. This is because SMT placement requires higher precision than LED placement, and when placing high-precision electronic components, the placement machine‘s processing speed slows down, naturally reducing placement efficiency. One issue with pick-and-place machine nozzles is insufficient vacuum pressure. Before picking up components, the mechanical valve on the placement head automatically switches from blowing air to vacuum suction, creating a certain level of negative pressure. When the negative pressure sensor detects a value within a certain range after picking up the component, the machine operates normally; otherwise, the suction is inadequate. On one hand, there may be pressure leaks in the air supply circuit, such as aging or rupture of rubber air tubes, aging or wear of seals, or wear of the nozzle after prolonged use. On the other hand, adhesives or dust in the external environment, especially the large number of debris generated after cutting paper tape-packaged components, can cause the pick-and-place machine nozzle to become blocked. Errors in the settings of the pick-and-place machine program can also reduce the machine’s placement efficiency. The solution is for the pick-and-place machine manufacturer to provide accurate and concise product operation information to the customer. Another factor is the quality of the electronic components themselves.

When the nozzle picks up and places electronic components, if the pins are not fully inserted, bent, or broken, this can only be controlled by ensuring the quality of the components purchased. This not only affects placement efficiency and product quality but also causes varying degrees of damage to the nozzle when it repeatedly picks up and places such components, eventually reducing the nozzle’s service life. An SMT assembly line typically includes a high-speed placement machine and a high-precision placement machine. The former primarily handles surface-mount components, while the latter focuses on ICs and irregularly shaped components. When both machines achieve equal and minimal placement times, the entire SMT assembly line achieves maximum production capacity. So, let‘s dive deep into the recommended order for mounting the chip components to achieve optimal efficiency in SMT pick and place machines.

First, load balancing. The general sequence and principle is to reasonably allocate the number of components to be mounted on each SMT machine, so that the mounting time of each machine is as equal as possible. When initially allocating the number of components to be mounted on each machine, there is often a large difference in mounting time. This requires adjusting the production load of all machines on the production line based on the mounting time of each machine, and transferring some of the components from machines with longer mounting times to other machines to achieve load balancing. 

Second, SMT equipment optimization. Optimizing the CNC programs for each piece of equipment involves ensuring that the pick-and-place machines operate as efficiently as possible during production, thereby achieving extremely high-speed placement and reducing equipment placement time. The principles of optimization depend on the structure of the equipment. Some principles may conflict during program optimization, requiring a compromise to select the optimal solution. Optimization software can be used for load distribution and equipment optimization, which includes equipment optimization programs and production line balancing software. Equipment optimization programs primarily focus on optimizing placement programs and feeder configurations. After obtaining the component BOM list and CAD data, placement programs and feeder configuration tables can be generated. The optimization program optimizes the movement paths of the placement heads and feeder configurations to minimize the movement distance of the placement heads, thereby saving placement time. Production line balancing software is an effective tool for optimizing the entire production line. Optimization software employs specific optimization algorithms, and current optimization software has achieved a certain level of intelligence, enabling it to complete the optimization process more quickly and effectively. 

Third, eliminate bottlenecks. An SMT assembly line consists of multiple automated machines. If one machine operates slower than the others, it becomes the bottleneck that limits the overall speed of the SMT production line. Bottlenecks often occur on the placement machines, and the only way to eliminate them is by adding more placement machines. In most cases, customers opt for a high-speed, multi-functional placement machine, as it combines the features of both high-speed and high-precision machines.

It can handle the range of components covered by both high-precision and high-speed placement machines, thereby resolving bottlenecks caused by either type of machine. The current trend in placement machine development also aligns with this direction to meet market demands. Adding a placement machine to the production line can resolve bottlenecks and accelerate production rates. This approach provides greater production capacity and more feeder positions, better balancing the production line without significantly increasing production line management complexity. This results in a much greater increase in production capacity than simply adding a single placement machine.

Fourth, implement strict and effective management measures. SMT equipment is precision machinery that integrates mechanical and electrical systems. Implementing strict and effective management measures during operation is an important method for improving the efficiency of SMT assembly line production. For example, we can pre-load components to be replenished onto spare feeders. While assembling the final few units of the previous batch on the production line, we can also prepare for the next batch of products. SMT assembly lines are large-scale production lines where output is calculated in seconds. The smoothness of production and product quality depend not only on equipment and environmental factors but also heavily on human factors. If operators are highly familiar with the equipment, they can resolve issues more quickly during production, thereby saving production time and improving efficiency. Therefore, employee training must also be prioritized. Regular inspections and maintenance of SMT equipment are also essential to ensure its optimal performance. Therefore, it is crucial to consistently conduct scientific inspections and maintenance of the equipment on a regular basis to keep it in good condition. 

To conclude, increasing the efficiency of SMT pick and place machines in a production line is crucial because it directly impacts productivity, cost-effectiveness, and product quality. Higher efficiency means faster component placement, reduced cycle times, and increased throughput, allowing manufacturers to meet growing demand and shorten lead times. It also minimizes errors, reduces material waste, and lowers operational costs by optimizing machine utilization and energy consumption. Additionally, improved efficiency enhances consistency in assembly, ensuring higher reliability and performance of electronic products. In a competitive industry, maximizing SMT machine efficiency is key to maintaining profitability and staying ahead in the market.