Electronic manufacturing often exchanges terms of usage cycle and throughput. In fact, they are two different factors in the measurement of machine performance. Although the machine cycle is an important indicator of machine performance, it is still important to use total throughput as the primary metric when evaluating process equipment. The factors that affect the output of an SMT production line are various, and one factor often mentioned is the cycle time of solder paste printing equipment. In the past, the "machine cycle" was used as an important indicator of the throughput of major equipment, but for a stencil printer or other electronic manufacturing equipment, it was only a factor in measuring true output. Electronic manufacturing often exchanges terms of usage cycle and throughput. In fact, they are two different factors in the measurement of machine performance. The definition of the cycle period is the speed of the basic function tasks such as loading and unloading of the circuit board that the machine can complete. It generally includes the following: movement of the circuit board into and out of the machine, correction of the circuit board according to the set target (template reference mark), movement of the circuit board to its essential position, and time for the circuit board to be transferred to the next process. The actual completion of the main function of the machine (in this case the actual printing of the solder paste) generally depends on the various recognized elements that define the machine cycle. In most cases, the supplier of solder paste printing equipment only defines the cycle of the machine as the printed circuit board feeds into and out of the machine, and the process of correcting the printed circuit board according to a defined target (template reference mark). Many times the actual printing action is not included in the solder paste printing cycle. The printing action depends to a large extent on the solder paste used and the substrate size produced. Most modern solder paste printing equipment can move much faster than actual solder paste printing. Many customers are still using solder paste that must be printed slowly, which is often a major time factor in the solder paste printing process cycle. Because of the many variables that influence materials, equipment manufacturers reduce the definition of the cycle to those projects that they can control. We should consider the definition of the machine cycle more broadly to better understand machine throughput and equipment utilization. The broader definition includes all the above functions, plus all the "overhead" functions that the machine performs. The "indirect" function definition is: Not directly include all other machine functions in the actual operation of the circuit board to transfer and accurately print the solder paste. Most modern solder paste printers can perform many "indirect" functions such as stencil cleaning, two-dimensional (2D) post-print inspection, solder paste coating on stencils, etc. Some more advanced systems even provide solder paste printing. The three-dimensional (3D) post-print inspection, snap-off, positioning support needle installation, and statistical process control and other management and quality data acquisition functions are added to the machine. When this extended definition of the machine cycle is used, it is difficult to compare solder paste printer equipment because these functions typically replace manual and off-line process quality assurance functions. It takes time to thoroughly understand how each "indirect" function accomplishes its task before it can properly evaluate the performance of the machine. When proving the value of a function, the speed at which the machine performs indirect tasks is of course the main consideration. At the same time, it must also consider how accurately the machine will perform indirect operations with repeatability. Many printing devices can perform several "indirect" functions in parallel so that there is no actual loss of throughput due to increased functionality. If the machine can perform two or three "indirect" functions in parallel and still provide "best" accuracy and repeatability, the machine (according to the above extended definition method) has the fastest machine cycle. Throughput Throughput is defined as how many qualified printed circuit boards can be produced in a given time period. Although the machine cycle is an important indicator of machine performance, it is still important to use total throughput as the primary metric when evaluating process equipment. One of the important metrics for any electronics manufacturer is “How many of the boards that are manufactured today can be shipped to customers?†An excellent PCB assembly line should be 100% assembled at once through all board levels. And functional level tests without any supplements or repairs, ie 100% FPY (through rate). If the capacity of a printing press exceeds the throughput requirements of a manufacturing line, using some additional printing features will have a positive effect on the yield, such as increasing the stencil's scratch frequency, reducing the detachment rate, or increasing the inspection of key components. Wait. Electronic manufacturing jobs rely on the manufacturing of high-quality circuit boards to benefit, rather than relying on the speed of a machine. When considering throughput metrics, we must consider many influencing factors before the basic machine cycle.
Paste Printing Process Evaluation Throughput and Period (I)