Automating a system is necessary to remain competitive. Choosing to automate
brings many benefits such as, decreased downtime and improved quality. As products become smaller, automation
is needed to improve the accuracy that is required.
- Production automation is fundamental to Japan's competitiveness in terms of the cost and quality of its consumer electronic products. Since most fabrication activities have already been automated, the current focus of attention is on the automation of assembly lines, where labor content has been highest.
- There are several stages of assembly line automation, with varying impacts on flexibility and product design. The JTEC panel observed widespread automation during its plant tours.
- Key benefits cited for the use of automation include reducing factory set-up time, manufacturing defects, product lead time, and direct labor, and increasing the ability to rapidly deploy manufacturing operations around the world.
- It took three to four months to start up Sony's original production lines in Japan, but it required only two to three weeks to bring replicated lines up to speed in Singapore and France. The best defect rate using manual labor was 2000 parts per million (PPM), compared to 20 PPM after the first week of automation. Sony's personnel policy was to remove employees from manual labor jobs through automation so that "they could become more creative in solving problems and improving operations. Between 1987 and 1990 Sony increased sales by 121% with an increase of only 35 employees.
- Japanese electronics companies have made and continue to make large investments in production technologies and factory automation because of their commitment to miniaturization as well as to high product reliability and low product cost. As electronic components shrink to as small as 1.0 mm by 0.5 mm (called "1005" parts), and as component lead pitch approaches 0.2 mm, human assembly is no longer feasible.
- Miniaturization is forcing assembly technologies to become faster and more precise. Precision robots have improved repeatability from .05 to .01 mm over the past decade. Matsushita's latest SMT placement machine incorporates 11 placement heads with .01 mm placement repeatability. Sony's high-speed robots now work at .012 mm repeatability. These levels of precision are beyond human capabilities.
- In assembly operations, parts handling and feeding and line control are very complex; however, with the advances made in equipment, production control, and computers over the past decade, automated assembly lines are no longer unusual.
- Recent advances in production technology include robots and sensors, component feeding, line control, and production management techniques.
- Positioning is the most common problem for assembly automation. Different sizes and shapes of components make assembly difficult. A two-dimensional curving warp can be represented by three points, so the company had to come up with innovations in measurement point selection and interpolation techniques.
- Jigs are fundamental to positioning parts properly before assembly. Visual sensors can detect the positions of parts, allow for mixed-flow production operations, and detect parts' shapes. Toshiba's most recent application of CCD technology to visual sensors has allowed for 0.02 mm positioning accuracy.
- Flexible lines are required to cope with the demands of multiple-model, mixed-flow production. Movable jigs and visual sensors are used to adjust to changing parts shapes. Some companies have used memory cards on parts pallets to achieve this control. Integration of such parts flows with mixed-line assembly is based on sophisticated parts-feeding equipment, which may account for 80% of the automation success.
- Modular product designs are used to reduce equipment costs and to improve product reliability. It is then possible to simplify assembly and enhance operational reliability by orienting all the assembly steps in one direction or employing connection techniques amenable to automation. For complex assembly operations that could be handled by robots, Fujitsu developed special supplemental mechanisms that required changes in such details as screw shape.
- Product structures are divided into a number of modules for design purposes. Each module is assembled on a subline, and the assembly operations not amenable to automation are concentrated in the final assembly line. It is easy to achieve higher automation rates in the total assembly process because each module is designed to be compatible with automated assembly.
- Seiko Epson has designed its printers for the lowest total manufacturing cost and then constructed its assembly line accordingly. It has set about improving the automation rate while developing ways to handle multiple-module, mixed-flow production. Development of designs compatible with assembly automation is a new key concept that has great potential.