Infoscience

Thesis

Microfabrique: méthodologie de conception de systèmes de production miniaturisés et modulaires, disposant d'un environnement salles blanches

Since 1990 in Japan and the last years in Europe, the concept of small assembly lines called Microfactories is under investigation. The main goal of this thesis is to establish a methodology for a quick setup of a miniature and modular assembly line. This methodology assists the designer to choose the most appropriate configuration and size of microfactory. In order to achieve the design of the microfactory, it is necessary to create a "configuration database". The "configuration database" contains all the robots, machines and palettes useful for the product assembly. Following a control for the compatibility between product and process properties, the program compares the possible solutions, and proposes the higher throughput or the most economic one. This thesis proves the feasibility of such miniature assembly lines, operating in a clean mini environment, where the assembly process can be done out of a standard clean room. This feature reduces the development and the setup time and the cost of the system. In order to establish the clean room environment, compressed air or other inert gas with the appropriate filters, are used. The microfactory concept is modular, where each module is dedicated to specific assembly process. Each module includes: A system to transform compressed air to laminar flow. A robot to manipulate and to transfer components from the palette to the assembly post. After assembly, the robot transfers the sub-assembly to an adjacent position, which is accessible by the robot of the next assembly module. An entry port which is a system to input and output 50 mm x 50 mm palettes from non-clean environment into the clean one of a module. A clean air jet is purging both palette joins before opening. The palette is opened inside the microbox, without any contamination. The systems for the specific assembly processes (adhesive dispenser, pressing, vision assistance, cleaning, etc.) Measurements are demonstrating the efficiency and the feasibility of this system, using only compressed air and appropriate filters. A prototype is developed to demonstrate the feasibility and to confront directly the real problems of the concept. The working volume of this first prototype is a cubic decimeter. Its useful surface is equal to four times the surface of a palette of 2" (∼ 50 × 50 mm). The time to establish the clean room environment (class 10) is less than two minutes. It is demonstrated by measurement of the air velocity and visualization of the air stream, that compressed air may generate laminar flow using a special device called "homogeneisateur".

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