1. Handling of mounting procedure
The SMT production line is composed of multiple equipment, including screen printing machine, mounting machine, reflow soldering, etc., but the speed of the production line is actually determined by the mounting machine. A SMT production line usually includes a high-speed machine and a high-precision mounter. The former is mainly used to mount chip like components, while the latter is mainly used to mount IC and special-shaped components. When the time for these two SMT mounters to complete a mounting process (hereinafter referred to as the mounting time) is equal and hours, the entire SMT production line will have a large production capacity. In order to achieve this goal, we can process the installer as follows.
Load distribution is balanced. Reasonably allocate the number of mounting elements of each equipment, and try to make the mounting time of each equipment equal. When we first allocate the number of mounting components of each equipment, there is often a large gap in mounting time. This requires adjusting the production load of all equipment on the production line according to the mounting time of each equipment, and moving some components on the equipment with a long mounting time to another equipment to achieve load distribution balance.
Equipment optimization. Each placement machine has a large placement speed value. For example, YAMAHA's YV100 boasts 0.25 seconds per patch, but in fact, this speed value must be achieved under certain conditions. To optimize the NC program of each equipment is to make the placement machine meet these conditions as much as possible in the production process, so as to achieve high-speed placement and reduce the installation time of the equipment. The principle of optimization depends on the structure of the equipment. The placement machine with X/Y structure is usually optimized according to the following principles.
2. Try to make the mounting head pick up the elements at the same time
When arranging the mounting procedures, the components of the same type are arranged together to reduce the number of nozzle changes when the mounting head picks up the components and save the mounting time. The feeder with more picking times shall be placed on the material station close to the printed board. In the process of a picking and placing cycle, try to take materials only from the front or rear material station to reduce the moving distance of the mounting head. During each picking cycle, the mounting head shall be fully loaded.
Some principles will conflict when optimizing the program, which requires compromise to select a good optimization plan. Optimization software can be used for load distribution and equipment optimization, which includes equipment optimization program and production line balancing software. The equipment optimization program is mainly aimed at the placement program and the configuration of the feeder. After obtaining the component BOM and CAD data, the mounting program and feeder configuration table can be generated. The optimization program will optimize the movement path of the mounting head and the configuration of the feeder, so as to minimize the moving distance of the mounting head and save the mounting time. The production line balancing software is an effective tool for optimizing the entire production line. The optimization software uses certain optimization algorithms. The current optimization software has a certain degree of intelligence and can quickly and well complete the optimization process.
SMT chip processing production line is composed of multiple automatic equipment. When the speed of one equipment is slower than that of other equipment, this equipment will become the bottleneck restricting the speed improvement of the whole SMT production line. According to the sampling of 19 factories, the general bottleneck often appears on the mounter, and the only way to eliminate the bottleneck is to increase the mounter. Of course, this requires a large amount of capital investment, but it can make full use of the overcapacity of other equipment, which is far more cost-effective than investing in another SMT production line. The type of mounting machine to be added depends on the bottleneck of the production line. Generally, it is better to purchase a high-speed, multi-functional mounting machine because it has the characteristics of both high-speed and high-precision machines. The range of mounting components covers high-precision machines and high-speed machines. It can solve the bottleneck problem caused by high-speed machines or high-precision machines. At present, the development trend of SMT is also developing in this direction to meet the needs of the market.