Nowadays, the market competition is more and more intense, how PCB assembly plant in such an environment can to be invincible. The first point is to reduce its production costs. To achieve this goal, the most important way is to improve the production efficiency of the production line. This paper discusses some measures and measures to improve the efficiency of SMT production line based on the author’s work practice.
一. Processing of chip mounting program
SMT production line consists of a number of equipment, including screen printing machine, chip mounter, reflow soldering and so on, but in fact the speed of the production line is determined by the chip mounter. A SMT production line usually consists of a high-speed machine and a high-precision chip mounter, the former mainly mounting chip components, while the latter mainly mounts IC and Odd-form components. The entire SMT production line has the maximum production capacity when the two patch machine completes an affixed time (hereinafter referred to as the mounting time) and the hourly hour. In order to achieve this goal, we can process the mounting procedure according to the following methods.
- Load distribution balance. Reasonable distribution of the number of mounting components of each device, so as to make the installation time of each device equal. When we first assign the number of mounting components for each equipment, there is a large gap in the mounting time. This requires the adjustment of the production load of all the equipment on the production line according to the mounting time of each equipment, and the part of the equipment on the equipment is moved one part to the other. The balance of current load distribution.
Equipment optimization. Each patch machine has a maximum value of the patch speed, for example, the YV100 of YAMAHA is called 0.25 seconds / slice, but in fact the speed value is realized under certain conditions. To optimize the numerical control program for each equipment, it is to make the chip mounter meet these conditions as much as possible in the production process, so as to achieve the highest speed mounting and reduce the installation time of the equipment. The principle of optimization depends on the structure of the equipment. The placement machine for X/Y structure is usually optimized according to the following principles.
- As far as possible, the mounting head can be picked up at the same time.
- When arranging the mounting program, the same type of components are arranged together to reduce the number of changing suction nozzles when the mounting head picks up the components and save mounting time.
- More supplies should be placed near the material station near the PCB.
- During the process of picking up and releasing, try to collect materials only from the front or rear material stations, so as to reduce the moving distance of the head.
- In every cycle of collection and circulation, the head should be loaded.
Notice: Some principles will conflict when optimizing the program, which requires compromise consideration to select the best optimization plan. Optimization software can be used in load distribution and equipment optimization. The optimization software includes equipment optimization program and production line balance software. The optimization procedure of the equipment is mainly to optimize the placement procedure and the configuration of the feeder. After the components BOM and CAD data are obtained, the mount program and the feeder configuration table can be generated. The optimization program will optimize the movement path of the mounting head and the configuration of the feeder, and reduce the moving distance of the mounting head as much as possible, thus saving the time of the mounting. The production line balancing software is an effective tool for the optimization of the whole production line. The optimization software adopts a certain optimization algorithm. The current optimization software has been intellectualized, and the optimization process can be completed faster and better.
二.Eliminating of bottlenecks
The SMT production line is made up of a number of automatic equipment. When a certain equipment is slower than other equipment, the device will be the bottleneck for the speed improvement of the whole SMT production line. According to a sample of 19 factories (Table 1), bottlenecks are often found in chip mounters, and only by adding chip mounters can they be eliminated. Of course, this requires a large amount of capital investment, but it can make full use of the production capacity of other equipment, far more than the investment of a SMT production line. What type of patch machine is added depends on the bottleneck of the production line. In general, it is best to buy a high speed, multi-functional chip mounter machine, because it has the features of both high speed and high precision machines. The range of mounting components covers the high precision machine and the high speed machine. It can solve the problem caused by the high speed machine or the high precision machine. Bottleneck problem. At present, the development trend of chip mounter is also developing in this direction to meet the needs of the market.
|Bottleneck of process steps||Percentage|
|High precision chip mounter||32|
|High Speed Chip Mounter||21|
|Online testing (ICT)||16|
Table 1 –Distribution of the most common bottlenecks in a factory
Adding a patch machine to the production line can solve the bottleneck problem and speed up the pace rate. This method provides more production capacity and more feeder position to better balance the production line without significantly increasing the complexity of production line management, which is much more than a single increase in the production capacity of a chip mounter machine. It’s much more powerful.
三.Implementing strict and effective management measures
1.SMT equipment is a precision equipment of mechatronics. Strict and effective management measures are an important way to improve the efficiency of SMT production line. If the components to be supplemented in advance are installed on the standby feeder, the production line will assemble the last few pieces of the batch number in front of the front, and do well the preparation of the next batch of products on the production line and so on.
2.The SMT production line is a large production line, and the output value is calculated in seconds. And the fluency of production and quality of products, besides equipment and environmental factors, human factors play a very important role. For example, if the operator is familiar with the equipment, it will take less time to eliminate problems in the production process, and it will also save production time and improve production efficiency. Therefore, we must attach great importance to the training of employees. In addition to regular professional training, some professional SMT books and periodicals should be used as teaching materials to organize the staff to learn, to cultivate the love of SMT and to improve the comprehensive business level of each person.
3.Regular inspection and maintenance of SMT equipment is also a powerful guarantee to ensure its full effect. Many companies often neglect this because of their heavy production tasks. Once the equipment fails to produce normally, the loss caused by the shutdown is far greater than the cost of regular shutdown inspection and maintenance of the equipment. Therefore, we must emphasize the regular inspection and maintenance of the equipment, so that the equipment is in good condition.
SMT production needs high investment, but if the management and use is appropriate, and pay attention to several aspects mentioned above by editor , It will fully tap the production potential of the SMT production line, improve production efficiency, in a few years will take back all of the investment, to achieve “high input, high output”.