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Editor's Note: This article originally appeared in the February 2012 issue of SMT Magazine.
In Metaphysica,Aristotle said, “The whole is greater than the sum of its parts.” In electronics manufacturing, this means that an integrated production can produce more than the simple collection of individual machines. Intelligent automated assembly systems are not only fast and accurate, but also highly flexible.
Small- and medium-size enterprises (SME) typically have highly-versatile electronics production with many changeovers. Setup costs, production errors, stock movements, and waiting times are main cost drivers. But, in recent times, cost and time pressure has become stronger, even for niche products. Therefore, small producers also must integrate, register quality data and control, and reduce manufacturing costs.
Produce Precise Quantities Using an Intelligent Feeder System
Old production machines and time-consuming feeder setup may be reasons for producing more than is actually ordered, so that setup costs can be divided by more PCBs. If the manufacturer is lucky, the overproduction can be sold with a later order.
However, overproduction can jeopardize a company and must be avoided. Even frame contracts are not true insurance. Automotive suppliers had to experience this painfully a few years ago when the required quantities suddenly shrank. Material and time were wasted on products that were no longer needed.
It is better to produce only the quantity that is ordered and paid for by the customer. Such just-in-time production is only feasible with modern production systems featuring a high feeder capacity and intelligent feeder setup plans. This type of plan must consider which components are installed on the machines in sufficient quantity so that they do not have to be reinstalled.
SMD pick-and-place machines such as the Cobra, Paraquda, or FLX, in combination with eMIS software, enable the organization of lean production. Production planning with eMIS can be simulated according to different parameters. For example, the production manager can decide on-screen if it would be better for the planned job to have an optimized, complete new feeder setup or to simply add the missing components to the machine.
Integrated Planning Reduces Material Stock
Flexible production often suffers from high material stock. The erratic demand and the risk of planning, purchasing and production errors lead to the purchase of more material rather than too little. However, the inventory is binded capital--it increases costs such as current assets, capital interests, management costs, and the price of warehouse space. If the material has not been used before its expiration date, depreciation and disposal costs must also be factored in.
Therefore, minimizing inventory brings two advantages: Reduced cost and logistical problems become visible and can then be solved. However, inventory reduction must be performed in a controlled environment. Such a reduction requires intelligent planning systems that know the current material consumption, as well as future needs as accurately as possible. ERP systems have such functionalities; however, few can model the complexity of highly-flexible electronics production.
eMIS is designed for such requirements because the software was developed based on practical experience. eMIS directly communicates with pick-and-place machines and knows the current component consumption in real-time. Additionally, the software tracks expiration dates and calculates the remaining floor lifetime of components with moisture sensitivity level (MSL) classification.
Quality from the Beginning
It is always better to produce quality from the beginning instead of controlling it later. Rework and repair is both expensive and time consuming. Quality assurance measures in electronics production include high levels of experience and motivation from all employees, continuous service on production machines, and setup checks before the start of production. An important principle to follow is “the easier the machine operation, the fewer errors that will occur.”
eeZ software technology has been developed to increase production quality and flexibility. eeZ is the base of the ePlace machine operation software and eMIS production management software suite. eeZ technology supports touch screens and simplifies the operation of complex systems. It supports operators with a multi-lingual help system, automatic command completion, input validation, and other features that are standard on modern software.
Intelligent feeders and barcode-based setup verification is the base for strict quality assurance. Furthermore, Essemtec’s pick-and-place machines feature “Virtual View,” a combination of a live PCB view with virtual components. This allows positioning and alignment to be verified before production start, similar to the combination of satellite images with virtual streets on Web-based map systems.
Even if a machine does not produce, it still creates costs in the form of capital interest, service, and space. Inline automated production lines with multiple pick-and-place machines often have standstill times. The reason is bad balancing of the placement work to the individual modules.
Such complex plans are not feasible without integrated computer assistance. The simulation tool must have all data of the current situation as well as all production details of each individual component. With eMIS it is possible to simulate, optimize, and test production in advance. The software even allows virtual assembly lines to be set up for more complex what-if analyses.
Store Components within Production
In the past, components were prepared for specific jobs, transported to production, and sent back to storage after job completion. This was reliable; however, it involved high material inventory as well as increased logistics and stock movement efforts.
Today, very compact automatic component storage systems, such as the Tower, offer new possibilities. The Tower can bring the required component reel directly to the pick-and-place system. After production, the machine operator can replace the reel in the stock. This simple system avoids feeder setup errors. The stock motion is registered, the inventory is automatically corrected and transport routes are eliminated.
A tower can even store MSL-classified components safely without any additional packing. Due to a temperature- and humidity-controlled environment, floor live time is kept constant after a reel has been stored inside the Tower. As such, the automatic storage system can save a great amount of expensive MSL packaging material.
Requirements for precision, quality assurance, and traceability of electronics production have risen in recent years. What used to be required only in aerospace and medical industries has become standard in “normal” production as well.
Cost and time pressure has also increased even for SME manufacturers. Product life cycles are becoming shorter and quality demands are on the rise. To withstand this pressure, electronics manufacturers must combine automation and flexibility. This is possible with integrated, intelligent and holistic automation concepts.
Adrian Schärli is a mechanical engineer with additional education in economics, marketing, sales, and journalism. He has several years of professional experience with various international companies. Since 2008, Schärli has owned Azular GmbH, an independent marketing and Web design consultancy company.