Nowadays printed board assembly is in an incredibly competition market. The first and foremost thing is to reduce its production cost. So, the most important way is to increase the production efficiency of the production line.
Placement program processing
The SMT production line consists of screen printers, placement machines, reflow soldering, etc., but the speed of the production line is determined by the placement machine. An SMT line usually consists of a high-speed machine and high-precision placement machine. The former mainly mounts chip components, while the latter mainly mounts ICs and shaped components. When the time for the two placement machines to complete a placement process (hereinafter referred to as the placement time) is equal and minimum, the entire SMT production line will have the maximum production capacity. In order to achieve this goal, we can handle the placement process as follows.
Load distribution balance. Reasonably allocate the number of components to be placed on each device, and try to make the placement time of each device equal. When we first allocate the number of components for each device, there is often a large gap in placement time. This requires adjustment of the production load of all devices on the production line according to the placement time of each device. Some components on the longer device are moved to another device to achieve load sharing balance.
Equipment optimization. Each placement machine has a maximum patch speed value, such as YAMAHA's YV100 0.25 sec/chip, but in fact this speed value is to be achieved under certain conditions. Optimizing the NC program for each device is to make the placement machine meet these conditions as much as possible during the production process, thus achieving the highest speed placement and reducing the mounting time of the device. The principle of optimization depends on the structure of the device. For X/Y-mounted placement machines, the following principles are usually optimized.
As far as possible, the placement head picks up the components at the same time.
When arranging the placement program, the same type of components are arranged together to reduce the number of times the nozzle is changed when the placement head picks up the component, thereby saving the mounting time.
Feeders with a high number of pick-ups should be placed close to the station on the printed board.
During a pick-and-place cycle, try to reclaim only from the front or back of the station to reduce the distance the placement head moves. • Make the placement head full load during each pick and place cycle.
Some principles conflict when optimizing the program, which requires a compromise to choose the best optimization. Optimized software is available for load sharing and equipment optimization, and the optimization software includes equipment optimization programs and line balancing software. The device optimization program is optimized for the placement program and feeder configuration. After obtaining the BOM and CAD data of the component, the placement program and the feeder configuration table can be generated. The optimization program optimizes the movement path of the placement head and the configuration of the feeder to minimize the placement head. Move the distance to save placement time. The production line balancing software is an effective tool for optimizing the entire production line. The optimization software adopts certain optimization algorithms. The current optimization software has certain intelligence, which can complete the optimization process faster and better.
The SMT production line is composed of multiple automation equipment. When the speed of one equipment is slower than other equipment, then this equipment will become the bottleneck restricting the speed of the entire SMT production line. According to the sampling of 19 factories (Table 1), the general bottleneck often appears on the placement machine. To eliminate the bottleneck, it can only be achieved by adding a placement machine. Of course, this requires a large capital investment, but this can make full use of the excess capacity of other equipment, far more cost-effective than investing in an SMT production line. What type of placement machine is added depends on the bottleneck of the production line. In general, it is best to purchase a high-speed, multi-functional placement machine because it combines the characteristics of high-speed machine and high-precision machine. The range covers high-precision machines and high-speed machines, which can solve bottleneck problems caused by high-speed machines or high-precision machines. At present, the development trend of the placement machine is also developing in this direction to meet the needs of the market.