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Electronic Manufacturing Technology Symposium, 1990 Proceedings, Competitive Manufacturing for the Next Decade. IEMT Symposium, Ninth IEEE/CHMT International

Date 12-17 Feb. 1989

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Displaying Results 1 - 25 of 65
  • Ninth IEEE/CHMT International Electronic Manufacturing Technology Symposium. Competitive Manufacturing for the Next Decade. Proceedings 1990 IEMT Symposium (Cat. No. 90CH2864-7)

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    Freely Available from IEEE
  • Statistical design techniques for high-speed circuit boards with correlated structure distributions

    Page(s): 185 - 191
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    New statistical design techniques have been developed for the line structures of high-speed circuit boards. These techniques account for dimensional distribution correlations caused by the fabrication process. Monte Carlo simulation is introduced into the finite-element method for calculating line parameters. The eye-pattern at the receiving end of transmission lines with parallel and stub parts is simulated, using distributed circuit models, for the calculated line parameter distributions. The simulator has an algorithm to save computer time. The calculated and experimental results are compared, and the accuracy of the simulation is discussed. Calculation results imply that the evaluation for the dimensional distribution of fabrication processes is very important. The timing and amplitude margins are found to depend strongly on fabrication deviations View full abstract»

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  • Automatic problem detection and documentation in a plasma etch reactor

    Page(s): 47 - 50
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    IC manufacturing involves a large number of complex process steps. There is a probability of a microprocessing error in each of these steps. The author describes two software tools, in a single-wafer plasma etcher, that have been developed to minimize the occurrence and maximize the efficiency of the diagnosis of such microprocessing. The first examines the endpoint trace of every wafer and determines whether that wafer has seen anomalous processing. If so, the software can terminate the processing of subsequent wafers. The second records the analog values of all the process control parameters during the entire etch process. When these two routines are linked appropriately, it is possible to record these analog values for only those wafers that have seen anomalous processing. This feature provides data for the analysis of the process problem. These procedures thus act to minimize the number of wafers that are microprocessed and provide pertinent diagnostic information for those that have been View full abstract»

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  • Statistical process characterization in advanced analog IC manufacturing

    Page(s): 135 - 140
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    The device parameter drift of a JFET operational amplifier is discussed in terms of yield loss and product quality of analog ICs. Planned statistical experimentation was used to identify process factors that were causing drift. The improvements obtained using statistical process characterization and the resultant analog IC yield enhancement are described. The scenario presented demonstrates the essential need for a statistical approach to solve complex IC manufacturing problems. The multidisciplinary approach involves statistics, device physics, process characterization, device characterization, and manufacturing View full abstract»

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  • Implementing SPC in a large manufacturing facility: an example

    Page(s): 200 - 203
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    The authors explain how statistical process control (SPC) was successfully implemented in a large manufacturing facility. The broad philosophies that resulted in the successful implementation incorporate the following ingredients that were necessary to make the program successful: top management commitment, SPC training, an organized approach to implementation, and an SPC career path. Each of these topics is discussed. Auditing SPC implementation is considered View full abstract»

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  • Modelling the epitaxial growth process of gallium arsenide

    Page(s): 61 - 65
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    A molecular dynamic model of epitaxial growth on gallium arsenide is presented. The results from the molecular dynamics model are used to obtain parametric growth data including layer thickness and doping concentration. Initially, it was necessary to check the potential, which was developed for bulk gallium arsenide, for its applicability to surface growth. The resultant continuum model, when integrated with Stanford University's SUPREM 3.5 code, can simulate gallium arsenide processing based on epitaxial material View full abstract»

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  • A model-based technique with a new indexing mechanism for industrial object recognition

    Page(s): 56 - 60
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    The authors address the problem of industrial scene object recognition for the purposes of sensor-based robot assembly. They propose a technique in which the representation of the models (training phase) is performed by using a finite set of primitives and relations between them (object elements), characterized by a proper set of parameters. They describe a new index building mechanism, using both the recognized object primitives and the relations between the primitives. They obtain the characteristic set of primitives and relations for each model of a given industrial object set by eliminating the common (similar) object primitives and relations. The characteristic set is referred to as the global index. The real scene object analysis (recognition phase) includes the recognition of scene primitives and relations between them, as well as their location in the global index. The proposed new index organization gives direct access to the particular object elements. significantly speeding up the hypothesis generation for the recognized scene object. The generated hypothesis is verified using the whole object representation obtained during the training phase View full abstract»

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  • Effect of system interactions on the removal of TOC from DI water polishing loops

    Page(s): 141 - 144
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    Ultrapure water systems in semiconductor plants consist of many components. The purpose is to explore the interactions of these units when they are placed in series and the effect of sequencing of these units and to establish conditions where these techniques can be used in combination. Two examples of these interactions are studied: UV interactions with membrane filters and UV interactions with the ion exchange units. An ultraviolet sterilization unit (Aquafine SL-1-TOC) generated radiation at both 185 nm and 254 nm wavelengths. The results indicate that the sequencing of UV and filter affects the TOC removal efficiency and that it is preferable to have a filter before UV. UV followed by ion exchange is an effective configuration for some impurities but can be undesirable for some contaminants and particles View full abstract»

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  • Automated statistical process control systems (ASPCS)

    Page(s): 204 - 207
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    Describes eight steps necessary to automate statistical quality control for a manufacturing facility. Successful implementation depends mainly on management support and the talent involved. The benefits of this system include improved productivity and self-sufficiency for the operator. The objective can be achieved through the implementation of automated statistical process control systems (ASPCSs) starting from the development through the manufacturing phases of the product. The underlying objective of ASPCSs is to ensure overall process optimization through the real-time identification and removal of causes of defects at the earliest point of the process. This is accomplished by integrating all of the following functions: data automation, database management, problem detection through statistical methods, problem definition through diagnostic methods, and corrective action feedback and follow-up. The author provides the step-by-step procedures for implementing an ASPCS workstation and describes the demonstration of these functions in manufacturing applications View full abstract»

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  • Group technology for high-mix printed circuit assembly

    Page(s): 264 - 269
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    The authors chronicle the successful application of the greedy board heuristic to the problem of assigning individual printed circuit board assemblies to product cells in a high-mix, capacity-constrained production environment. The specific case presented concerns the design of a high-speed surface mount line. The algorithm requires a list of boards, board volumes, and a bill of materials for each board. Temporal cells were designed to run at different times on the same set of equipment (two series Fuji CP-IIIs). The components in the first cell, comprising the highest-volume boards, were fixed on the entire first machine and half of the second. The remaining bank of the second machine was used to set up additional cells to run all remaining boards. Thus, high-volume boards could run at any time, while operators set up cells for low-volume work during high-volume board production. This approach improves machine utilization, accommodates changing mix, and permits simple operational alternatives View full abstract»

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  • Hierarchical real-time scheduling of a semiconductor fabrication facility

    Page(s): 312 - 317
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    A hierarchical framework for manufacturing system scheduling and planning and its experimental implementation in a semiconductor research laboratory are described. Its purpose is to aid the development of algorithms for real-time decision-making in a manufacturing enterprise in which such disruptive events as machine failures, material absences, expedited items, engineering changes, fluctuations of demand, and setups play a role. The hierarchy is divided into a set of levels that correspond to events that occur at very different frequencies. At each level, decisions are made in a way that satisfies the capacity constraints that are appropriate to that level and that meet objectives determined at higher levels. These decisions are either actions, such as the loading of a part of the initiation of a setup, or objectives to be issued to lower levels. The integration of the scheduler with the systemwide database, the structure of the scheduler as determined by the time constants and process flows in the system, and the use of the scheduler are described View full abstract»

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  • Template approach to design and manufacturing

    Page(s): 23 - 24
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    A key to successfully managing cost and scheduling while producing high-quality products is the template approach. The assumptions for the template effort are different from most government improvement efforts. First, the template approach recognizes that weapons systems acquisition is an industrial process and not a purchasing process. Secondly, the template advocates believe that both government and industry employees really want to do their best, but do not know how to proceed. Thirdly, the template approach provides employees with the needed background to understand the engineering and management discipline behind the standards and regulations. The templates as defined in DoD 4245.7-M are not the final word on disciplined engineering practices or reducing technical risks. Instead, the templates are a reference and a model that engineers and managers apply to their own industrial processes. The DoD template approach addresses the need for good engineering discipline in all aspects of systems acquisition. The disciplined approach is essential for success in both the military and commercial arenas View full abstract»

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  • Statistical control of VLSI fabrication processes

    Page(s): 174 - 183
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    The authors present a formal approach to statistical process control of VLSIC fabrication processes. The system, developed at Carnegie Mellon University (CMU), aims at integrating the design (process and layout), wafer processing, testing, diagnosis, and control into a set of strongly interacting procedures that will aim at maximizing the profit from the fabrication line. The authors describe an implementation of this approach within the CMU computer-aided-manufacturing (CAM) framework. The key feature of this methodology is the exploration of the multivariate distribution of parameters measured in the fabrication process. This allows for more accurate decision-making compared to the traditional statistical quality control (SQC) chart-based approaches. The statistical control system presented, while relying on more sophisticated algorithms, looks quite similar to the standard systems from the user standpoint. The system uses the in-process measurements available during manufacturing. The authors focus on the statistical quality control subsystem of the CAM framework View full abstract»

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  • CAFE-the MIT computer aided fabrication environment

    Page(s): 297 - 305
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    The computer-aided fabrication environment (CAFE) is a software system being developed at MIT for use in the manufacture of integrated circuits. CAFE is intended to be used in all phases of process design, development, planning, and manufacturing of integrated-circuit wafers. The CAFE architectural framework supports a wide variety of software modules, including both development tools and online applications. The key components of the CAFE architecture are the data model and database schema, the process flow and wafer representations, the user interface, and the application programming and database interfaces. All CAFE application modules store and retrieve persistent data through a common database interface layer. Interface wrappers provide seamless, transparent integration of external tools and packages which have their own internal data formats View full abstract»

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  • A precision vertical interconnect technology

    Page(s): 208 - 215
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    An interconnection technology is described that utilizes excimer laser drilled vias and computer controlled plating to provide vertical (Z-axis) electrical connections in high-performance flexible circuits. Specifically, solid vias and hemispherical microcontacts are created with a 1-μm nearest-neighbor height precision for the microcontacts. An architecture with a novel structure is employed to simplify the ground plane connections for impedance controlled flex circuits. The rationale for material and unit-process selection is described. The laser drilling of holes for the vertical interconnects is outlined. The deposition of the metal interconnects is considered. The performance of the resulting structures is characterized. This technology was implemented with a polyimide substrate and nickel contacts View full abstract»

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  • A rule based flow control plan for management of work-in-process

    Page(s): 270 - 276
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    The authors describe development of an integrated movement handling and work-in-process management system of an automated storage and retrieval system that is used as the material handling system for a highly automated electronic card assembly line. The line is designed for high-volume assembly of surface mount technology electronic boards. Use of an automated storage and retrieval system for work in process movement provides an opportunity for centralized management of work in process. This is a significant capability in light of the perishability of work in process, which is complicated by the highly stochastic nature of the robotic tools employed. The system developed is a rule-based system that seeks to smooth production, minimize spoilage problems, and reduce the burden of the material handling system under heavy traffic conditions View full abstract»

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  • Tailoring thermal profiles for the reflow of SMD assemblies

    Page(s): 77 - 81
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    The aim is to investigate the effects of various types of thermal components (also known as heat thieves/barriers) on the thermal profiles of a printed circuit board (PCB). It is demonstrated that it is practical to apply modeling techniques to the IR reflow soldering process. Results show that the thermal profiles of the PCB can be tailored. This is achieved by surrounding the PCB with different materials, such as copper, alumina, and graphite, in a strip or ring formation. This has the effect of altering the distribution of the thermal properties of the system. Results obtained using the model show that by attaching an alumina strip to the outer edge of the PCB can reduce the temperature differential of the PCB to less than 5°C View full abstract»

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  • SPC and setup analysis for screen printed thick films

    Page(s): 192 - 199
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    The authors describe some of the key process variables that affect the repeatability of the screen printing process for thick-film circuits and hence the quality of the final product. The discussion of major screen printing problem areas provides insight into the complexity of the overall process and the interrelationship of the process variables. The interrelationships of the key variables and their relative importance to process quality and performance are analyzed using a statistical process control technique, namely statistical design of experiments. The fractional factorial design is used as an example. The setting up of a screen printer is a manual operation. Some simple steps necessary to improve the learning process and record keeping are described based on S. Shingo's setup time analysis approach (1985) View full abstract»

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  • A process control methodology applied to sub-micron gate lithography in manufacturing GaAs MMICs

    Page(s): 128 - 134
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    A methodology for guiding the pursuit of process control at Hewlett-Packard's Microwave Technology Division is presented. The output of a given process or subprocess must reach four progressive levels of control. When the output can be reliably measured, it is considered measurable. The second level is reached when this output, viewed in aggregate and over time, is found to be predictable. When the distribution of outputs is centered within the spec limits and a sufficient fraction of the output lies within the spec limits, the process is considered acceptable. Finally, when the process, as it is currently operated, is fully documented and operator technique is passed on through training, the process reaches the fourth and final level of control, recoverable. An application of this methodology to the control of submicron gate lithography in a GaAs MMIC process is discussed. The unexpectedly broad organizational implications of developing and instituting this methodology are briefly described View full abstract»

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  • Technology development: focus on manufacturability

    Page(s): 334 - 339
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    The authors discuss the integration of manufacturability from the early stages of technology development based on the experiences of the leading-edge semiconductor development program at IBM's facility in Essex Junction, Vermont. An overview is presented of the methods used, the resultant line and information architectures developed, and experience and results to date. Major changes in the technology development cycle are required. The traditional laboratory role of design and process development has expanded to include a parallel responsibility for manufacturability. Design for manufacturability (DFM) and early manufacturing involvement (EMI) concepts are now major components of the development effort designed to maintain and enhance the rate of technology advancement and significantly improve the development-to-manufacturing transition View full abstract»

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  • Uncertainty management in process planning for PCB assembly

    Page(s): 290 - 296
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    Computer-aided process planning (CAPP) systems are an ideal application for expert system (ES) techniques in manufacturing. The design of a prototype CAPP system that can deal with the uncertainty that is an integral part of every manufacturing facility is described. The implementation of a nonmonotonic reasoning system (NMRS) and an educated-guess mechanism are discussed. In this case, the example is a printed circuit board (PCB) assembly. The uses of uncertainty management techniques in dealing with the dynamic and uncertain nature of a PCB manufacturing facility are considered View full abstract»

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  • Manufacturing host computer workstation

    Page(s): 325 - 328
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    The author focuses on the concepts and physical integration of electronic notebooks, manufacturing claiming, feedback to the manufacturing operator, expert systems, statistical process control (SPC), engineering analysis of data, and decision support systems at a host computer manufacturing workstation. Future activity on a PC workstation with multitasking is also addressed, with a discussion of neural networks, CD-ROM, and natural language systems. The concepts are looked at in the order of use by a manufacturing operator. A tool is optionally setup for a run. Next, the tool is run and measurements are taken for both tool and process control software. As a result, recommendations can be made to the operator for tool and process changes. Further in-depth analysis can then be performed by engineers at a later time View full abstract»

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  • Physiochemical stability of copper/polyphenylquinoxaline interfaces

    Page(s): 240 - 246
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    New results obtained with polyphenylquinoxaline (PPQ)/Cu multilayer structures are presented. Thermal stability at the Cu/polymer and polymer/Cu interfaces during the polymer curing process is very important to preserve good adhesion between the conductor and dielectric materials. The interfacial behavior is studied as a function of annealing temperature and of annealing atmosphere. In the case when copper is present, oxygen pollution, even at low levels, is shown to be detrimental for polymer integrity. Experimental results give a clear indication of catalytic degradation of the polymer in the presence of copper oxide. A thin chromium layer intervening between the Cu and polyphenylquinoxaline films is proven to be a very efficient oxygen diffusion barrier blocking any copper oxide formation and hence any enhanced polymer degradation View full abstract»

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  • Synchronizing manufacturing and materials flows

    Page(s): 252 - 255
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    The authors discuss a new logistics project being developed and implemented to synchronize materials flow with manufacturing. Called network management, the project is intended to satisfy the following requirements: recognize that not all parts should be ordered or controlled in the same manner; develop a system to classify parts to better determine what control mechanism to apply to which parts; define the material logistics business process and design the system to support it; forecast the use of selected items as the result of a timely outlook rather than a monthly requirements regeneration; generate pull signals to suppliers resulting from actual needs rather than a static plan; communicate information with suppliers via electronic data interchange (EDI); and associate a disbursement method with the characteristics of the item being replenished to the manufacturing line. The authors also address, as background, the thought process used in selecting the parts to which this concept was applied View full abstract»

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  • Design of experiment is the best way to optimize a process at minimal cost

    Page(s): 166 - 173
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    The authors deal with offline statistical control techniques which optimize a process and highlight the use of statistically designed experiments. The authors also describe the advantage of offline quality control over an online quality control mechanism. They define a systematic road map to carry out a designed experiment. The design of experiment (DOE) method not only defines the optimum window of operation but also the optimum parameters in those windows. In DOE the variables affecting the process are identified through a brain-storming session. Once the variables are identified, different levels of each variable are selected. The objective is to find the best possible way to optimize the manufacturing process, which is only possible if all variables with different levels are tested with each other in a controlled fashion. The inclusion of DOE in a corporate culture is discussed. A case study performed on a wire bond process where this process has been successfully implemented is described View full abstract»

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