Complex low volume electronics simulation tool to improve yield and reliability

Assembly of Printed Circuit Boards (PCB) in low volumes and a high-mix requires a level of manual intervention during product manufacture, which leads to poor first time yield and increased production costs. Failures at the component-level and failures that stem from non-component causes (i.e. system-level), such as defects in design and manufacturing, can account for this poor yield. These factors have not been incorporated in prediction models due to the fact that systemfailure causes are not driven by well-characterised deterministic processes. A simulation and analysis support tool being developed that is based on a suite of interacting modular components with well defined functionalities and interfaces is presented in this paper. The CLOVES (Complex Low Volume Electronics Simulation) tool enables the characterisation and dynamic simulation of complete design; manufacturing and business processes (throughout the entire product life cycle) in terms of their propensity to create defects that could cause product failure. Details of this system and how it is being developed to fulfill changing business needs is presented in this paper. Using historical data and knowledge of previous printed circuit assemblies (PCA) design specifications and manufacturing experiences, defect and yield results can be effectively stored and re-applied for future problem solving. For example, past PCA design specifications can be used at design stage to amend designs or define process options to optimise the product yield and service reliability

Characterization of printed solder paste excess and bridge related defects

Surface Mount Technology (SMT) involves the printing of solder paste on to printed circuit board (PCB) interconnection pads prior to component placement and reflow soldering. This paper focuses on the solder paste deposition process. With an approximated cause ratio of 50 – 70% of post assembly defects, solder paste deposition represents the most significant cause initiator of the three sub-processes. Paradigmatic cause models, and associated design rules and effects data are extrapolated from academic and industrial literature and formulated into physical models that identify and integrate the process into three discrete solder paste deposition events - i.e. (i) stencil / PCB alignment, (ii) print stroke / aperture filling and (iii) stencil separation / paste transfer. The project’s industrial partners are producers of safety-critical products and have recognised the in-service reliability benefits of electro-mechanical interface elimination when multiple smaller circuit designs are assimilated into one larger Printed Circuit Assembly (PCA). However, increased solder paste deposition related defect rates have been reported with larger PCAs and therefore, print process physical models need to account for size related phenomena

A simulation module for supporting the manufacture of high value added electronics manufacturing

Given the global pressures and demanding requirements for high value added electronics manufacturing, it is vital to make the right decisions on the shop floor. One of the main shop floor level decisions in the domain is the selection of the most appropriate scheduling strategy for the available manufacturing system. Simulation has proved to be a powerful decision support tool. However, very few studies have used this potential to support the evaluation of scheduling strategies in a manufacturing context. A component-based simulation tool to evaluate the performance of scheduling strategies on a particular system is presented in this paper. The component based structure of the simulation tool allows the main problem requirements to be addressed. An example, based on a real company, illustrates the nature of the simulation results and the kind of support that can be obtaine

Complex Low Volume Electronics Simulation Tool to Improve Yield and Reliability

Assembly of Printed Circuit Boards (PCB) in low volumes and a high-mix requires a level of manual intervention during product manufacture, which leads to poor first time yield and increased production costs. Failures at the component-level and failures that stem from non-component causes (i.e. system-level), such as defects in design and manufacturing, can account for this poor yield. These factors have not been incorporated in prediction models due to the fact that systemfailure causes are not driven by well-characterised deterministic processes. A simulation and analysis support tool being developed that is based on a suite of interacting modular components with well defined functionalities and interfaces is presented in this paper. The CLOVES (Complex Low Volume Electronics Simulation) tool enables the characterisation and dynamic simulation of complete design; manufacturing and business processes (throughout the entire product life cycle) in terms of their propensity to create defects that could cause product failure. Details of this system and how it is being developed to fulfill changing business needs is presented in this paper. Using historical data and knowledge of previous printed circuit assemblies (PCA) design specifications and manufacturing experiences, defect and yield results can be effectively stored and re-applied for future problem solving. For example, past PCA design specifications can be used at design stage to amend designs or define process options to optimise the product yield and service reliability

A simulation module for supporting the manufacture of high value added electronics manufacturing

Given the global pressures and demanding requirements for high value added electronics manufacturing, it is vital to make the right decisions on the shop floor. One of the main shop floor level decisions in the domain is the selection of the most appropriate scheduling strategy for the available manufacturing system. Simulation has proved to be a powerful decision support tool. However, very few studies have used this potential to support the evaluation of scheduling strategies in a manufacturing context. A component-based simulation tool to evaluate the performance of scheduling strategies on a particular system is presented in this paper. The component based structure of the simulation tool allows the main problem requirements to be addressed. An example, based on a real company, illustrates the nature of the simulation results and the kind of support that can be obtaine

Characterization of printed solder paste excess and bridge related defects

Surface Mount Technology (SMT) involves the printing of solder paste on to printed circuit board (PCB) interconnection pads prior to component placement and reflow soldering. This paper focuses on the solder paste deposition process. With an approximated cause ratio of 50 – 70% of post assembly defects, solder paste deposition represents the most significant cause initiator of the three sub-processes. Paradigmatic cause models, and associated design rules and effects data are extrapolated from academic and industrial literature and formulated into physical models that identify and integrate the process into three discrete solder paste deposition events - i.e. (i) stencil / PCB alignment, (ii) print stroke / aperture filling and (iii) stencil separation / paste transfer. The project’s industrial partners are producers of safety-critical products and have recognised the in-service reliability benefits of electro-mechanical interface elimination when multiple smaller circuit designs are assimilated into one larger Printed Circuit Assembly (PCA). However, increased solder paste deposition related defect rates have been reported with larger PCAs and therefore, print process physical models need to account for size related phenomena

Novel modelling and simulation approaches to support electronics manufacturing in the UK

High value added products is the only segment of the electronics sector in which the UK is likely to remain competitive and where manufacturing will be retained within this country. Even though UK companies have a competitive advantage in this market, they also face a range of new challenges including demanding customer requirements, constantly changes conditions and highly complex products and technologies. Consequently, effective product and process (re-) design that encourages continuous improvement and innovation to satisfy highly demanding customers has become vital. Additionally, support to undertake design in an agile manner while managing complexity at the same time is required. The research described in this thesis addresses this problem by developing a software tool (i.e. INMOST – INtegrated MOdelling and Simulation Tool) that support agile design. This support is provided through modelling, simulation and root cause analysis (i.e. the functional modules within the tool. The functionality of the software is enabled through two novel concepts proposed. The first one is an integrated modelling framework that combines different modelling techniques in a single structure to enable more complete and realistic models. The second is a Hierarchical Object Oriented Simulation Structure (HOOSS) that unifies generalisation and customisation ideas to facilitate the utilisation of INMOST in an industrial context. The functionality of INMOST was tested wit three case studies. The case studies proves the capability of the software to be easily adopted in an industrial context, to provide predictive feedback to identify potential problems, and to complete the design cycle by providing decision support to solve identified problems. In this way, the compliance of the software with the domain requirements and needs is demonstrated. The research is completed by providing recommendations for the adoption of INMOST in industry and clear establishing clear directions for future work