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66 SMT Magazine • May 2016 is not needed or cannot be justified. There will always be new goods with shapes, materials, or even in quantities, where automation will not be possible nor practical. The more equipment we put in place on our production lines, the more designers, technicians, programmers and integrators will be needed. Almost half of the world's global manufac- turing output came from Asia in 2013. Some- body once asked me if I thought that Asian electronics manufacturers are heading for full automation or partial automation. I think such considerations will be made by project rather than by geography. High-volume manufactur- ing of high-quality products will see more au- tomation than projects with lower volume re- quirements, higher mixes or lower quality re- quirements. Obstacles to Full automation What I know for certain is that full automa- tion is nearly impossible to achieve, and very seldom practical to implement. There are cur- rently too many obstacles to full automation, including: • Product designs • Component tolerances • Equipment availability • Packaging design and handling Many customer designs are variations of legacy products, or designs developed by engi- neers far removed from a high-volume manu- facturing environment. Often, they are not designed for fully automated handling and processing. Even with a thorough design for automated assembly (DFAA) exercise executed together with their manufacturing partner, it is very difficult to capture every requirement of every piece of assembly equipment, especially since the assembly equipment may not even have been designed yet at the time the design is being finalized. In addition, once an automo- tive electronics product has been tested and validated, it is nearly impossible to change it without incurring lengthy delays and repeating costly product and process validations. Components have to be selected for their ability to be unpacked and mounted automati- cally. A wide mechanical tolerance range, espe- cially between multiple manufacturers, have to be taken into account. Assembly technolo- gies have to be selected to balance the cost of the product with the cost and complexity of the equipment. Connection terminals have to be spaced far apart, with enough distance that allows them to be reached by automated welding or soldering equipment, and oriented in a symmetric manner to minimize handling time. Careful design techniques are necessary to avoid excessive tolerance stack-ups when multiple assemblies are connected together. Proper supports have to be provided under ar- eas to be pressfit. Sufficient clearances have to be provided for access by pressfit and screw- driving tools. Guide pins need to be added to plastic connectors for ease of assembly. Cham- fers and clips should be added to guide and hold smaller components. The use of adhesives should be minimized, and well controlled if its use is unavoidable. Gripping areas should ide- ally be symmetric and well balanced. Areas to be optically inspected should have a clutter-free background and easy to illuminate. The list of design guidelines goes on and on; a product de- sign engineer would be challenged to retain the collective know-how of the equipment manu- facturers, tool suppliers, component suppliers, system integrators and contract manufacturers. Many electronic components are very chal- lenging to pick and place automatically. Large electrolytic capacitors may have wide dimen- sional tolerance ranges. Small ceramic capaci- tors may be dip-coated and irregularly shaped, and therefore difficult and error-prone to grip. Large inductor coils may also have an irregular shape and be difficult to grip. Large variations in lead position or external dimensions greatly complicate handling. Many components may have been originally designed to be mounted in PCBs whereas many products today require them to be mounted in a lead frame of sorts; examples include power drivers and filter as- semblies. Many final assembly processes such as pick & place, printing and automated optical inspec- tion are relatively standard. However, the ma- jority of equipment available for standard pro- cesses are designed for front-end SMT processes, How FaR doES it MakE SEnSE to autoMatE?