The Application Of Multi-level Module Division Method In PCB Exposure Machine Design

PCB exposure machine is a typical complex electromechanical product whose function is to complete the image information transfer of printing circuit diagram in the production process of printed circuit board.Optics,electrics,mechanics,vacuum,computer and some other professional and specialized technologies are involved in the exposure machine design.In order to enhance the market competitiveness,enterprises have to develop the products characterized by quick transformation to meet the diversified demands.Modular scheme is an important way to solve the problem of complex products design.By means of modular design method,the products are characterized by short manufacturing period,low cost,good quality and high reusability of parts,which wins the admiration of manufacturers and customer.Reasonable and effective module division is the key foundation of modular design,and it also directly affects the complexity of assembly,maintenance and recycle.Modules are divided into two categories: top-down functional decomposition and bottom-up structural clustering.Only functional decomposition,which is subjective,may result in poor flexibility of function tree or the separation between the underlying function and structure.Only structural clustering,which adds more complexity of products along with the increasing parts,the calculation is tremendous and hard to control.Therefore,the multi-level characteristics of modular division in product modularization design is discussed in the paper,the multi-level module division is put forward to solve the problems of complex electromechanical products.Combining functional decomposition with structural clustering effectively,the process of product module division can be divided into four levels,including system layer,machine layer,component layer and part layer.Research at different levels is respectively carried out on objects,purpose,methods,characteristics and effects on module division.The multi-level module division method of complex electromechanical products is applied into modular design of PCB exposure products.According to the design demand of PCB exposure machine,market needs and the modularization requirements of enterprise,the multi-level module division scheme of PCB exposure machine is made.And the modules of the product are divided at different levels.At the machine level,understanding and splitting of the PCB exposure machine function are conducted,and the module function is divided into basic function,the auxiliary function,special function and customization function.According to this method,the PCB exposure machine can be divided into several functional parts,such as functional modules of skeleton,frame,light source,motion control,position alignment,up-down transplant,shading and heat dissipation.These modules together compose the main function tree of product.This function module will be defined as the basic module,choose module or optional modules based on the requirements of configuration,and the main structure of PCB exposure machine is built up.At the components level,a module division method is proposed based on the minimum subset.Taking parts and components clustering of the light source functional module of the exposure machine for example,qualitative and quantitative methods are used to express geometry,function and physical correlation among different parts.The concept of minimal subset is introduced to intersect geometric,functional and physical correlation results,and then closely related minimal module group is obtained.Evaluation calculation of correlation degree and polymerization degree is done,and parts and components are assembled with the calculation results.By means of this method,the computational complexity of clustering algorithm can be effectively controlled,and also the clustering of product parts structure can be reasonably achieved.At the parts level,taking the exposure machine skeleton for example,the modular modeling process of product parts is explored.Analyzing and summarizing the geometrical configuration,structure and dimension of similar parts,the representative standard model of parts is extracted.The main model of standard parts module can be quickly reused to design the race parts by parameterized deformation and achieved standardization and generalization of the parts modes.In addition,taking the dimension series of light source module for example,the design of adaptive parameter is carried out under the constraints of product main function parameters.Through combination and reuse of parts,the serialization size of the parts,the machine and the race products is obtained.It is difficult to interpret the multiple attributes of functions and structural of complex electromechanical product modules with Single functional decomposition or structural clustering.A method of multi-level module division that respectively uses different ways to complete the module division of PCB exposure machine products is described at different levels.The module division results of each level is recursive and mutually proven,which provides a powerful model basis and data base for enterprises to adapt to market needs and design a series of modular products.