Journal of Electronics Manufacturing最新文献

{"title":"The impacts of variability on scheduling approaches for a printed wiring board assembly operation","authors":"M. Pfund, Lian Yu, J. Fowler, M. Carlyle","doi":"10.1142/S0960313102000242","DOIUrl":"https://doi.org/10.1142/S0960313102000242","url":null,"abstract":"Unrelated parallel machine scheduling problems have been well-studied for several single objective cases under deterministic processing conditions. While these problems are adequate for some manufacturing environments, there are situations where multiple objectives need to be considered. We report on a case for a Japanese printed wiring board manufacturer's drilling operation, which is measured on five key performance objectives and which is subject to processing time variability and random equipment breakdowns (usually in the form of jams). This research presents and evaluates an optimization approach against three dispatching heuristics to determine how these different scheduling approaches are impacted by processing time variability and equipment breakdowns and to determine which perform best under various levels of uncertainty.","PeriodicalId":309904,"journal":{"name":"Journal of Electronics Manufacturing","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130117306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neural network open loop control system for wave soldering","authors":"D. Coit, B. T. Jackson, Alice E. Smith","doi":"10.1142/S0960313102000217","DOIUrl":"https://doi.org/10.1142/S0960313102000217","url":null,"abstract":"This paper describes the development of neural networks for the prediction of (1) printed circuit card surface temperature during a wave soldering process, and (2) the quality level of the circuit card assembly soldered connections. Using a combination of production data and design of experiment data, a set of hierarchically connected neural networks were developed and validated. These networks predict thermal behavior of a printed circuit card assembly at various points in the solder process based on process settings and circuit card design data. Then these predictions are used as inputs, together with other parameters, to estimate the quality of solder connections. The system can be used to decrease the number of solder connection defects, reduce set-up and preparation time between lots, and lead to consistent, repeatable process settings without trial production runs or operator tuning efforts. For the wave soldering process studied, this is especially important since the batch size is quite small, quality demands are stringent, and process settings are changed frequently.","PeriodicalId":309904,"journal":{"name":"Journal of Electronics Manufacturing","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129115538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ECONOMIC SENSITIVITY FOR END OF LIFE PLANNING AND PROCESSING OF PERSONAL COMPUTERS","authors":"J. Boon, J. Isaacs, S. Gupta","doi":"10.1142/S0960313102000254","DOIUrl":"https://doi.org/10.1142/S0960313102000254","url":null,"abstract":"As the use of personal computers (PCs) increases, their short life cycle and the fact that they contain many hazardous materials have a significant influence on finding economical and environmentally benign means for their retirement and disposal. Many communities are mandating the recycling of these PCs to recover parts and materials and to minimize the amount of waste landfilled or incinerated. An industry to process end-of-life PCs is evolving to take advantage of this stream of materials. At present, PC recycling is not profitable unless the recycler receives a processing fee. In this paper, the factors that most influence the profitability of end of life processing of PCs are investigated and reported so that PC manufacturers and legislators may better develop products and policies to ensure that there is a viable PCs recycling infrastructure.","PeriodicalId":309904,"journal":{"name":"Journal of Electronics Manufacturing","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132085376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating the Production Times in PCB Assembly","authors":"Tero Laakso, M. Johnsson, Tommi Johtela, J. Smed, O. Nevalainen","doi":"10.1142/S0960313102000400","DOIUrl":"https://doi.org/10.1142/S0960313102000400","url":null,"abstract":"Several control problems of PCB assembly industry involve the estimation of the component placement times for various different placement robots. A standard approach, widely used in scientic literature, is to let the time to be a linear function of the number of components. In this paper, we demonstrate that a more realistic model should include additional parameters (e.g., the number of different component types and the board size). Linear multiregression indicates that the coefficient of determination for the improved model is over 90 percent.","PeriodicalId":309904,"journal":{"name":"Journal of Electronics Manufacturing","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128320717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PARAMETRIC STUDIES OF MICROCHANNEL CONJUGATE LIQUID FLOWS WITH ZETA POTENTIAL EFFECTS","authors":"E. Ng, S. T. Poh","doi":"10.1142/S0960313100000290","DOIUrl":"https://doi.org/10.1142/S0960313100000290","url":null,"abstract":"This paper presents a computer model with the use of a finite-volume scheme on the liquid flow and heat transfer in microchannels, with streaming potential as the driving force. The concept of electric double layer (EDL) was introduced to explain the microscale deviation. Interfacial electrokinetic phenomena such as the EDL play important roles in various transport processes in microchannels. Conventional theories of fluid mechanics and heat transfer cannot explain these phenomena observed in microchannels. The presence of the EDL reduces the liquid velocity within the microchannel, which affects the heat transfer mechanism in the pressure-driven microchannels. In this paper, a source term in the form of the electrical body force was included in the governing momentum equations for microscale computation with the effects of the heat transfer through the channel wall. The numerical parametric studies performed allowed the conclusion that the flow and heat transfer characteristics in microchannels depend on the bulk ionic concentration, the Zeta potential and the aspect ratio of the channel, which is the reflection of the EDL effects. The existing of the EDL is more significant as aspect ratios decrease. Also, the friction coefficient increases as the ionic concentration of the aqueous KCL solution decreases and the Zeta potential of the system increases. However, one should be aware that the ionic concentration of 10-8 M is unlikely in reality.","PeriodicalId":309904,"journal":{"name":"Journal of Electronics Manufacturing","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124990680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DIRECT IMMERSION COOLED MICROELECTRONICS HEAT SINKS: EFFECTS OF TEST FLUID AND BONDING TECHNIQUE","authors":"S. Bhavnani, R. Jaeger","doi":"10.1142/S0960313100000319","DOIUrl":"https://doi.org/10.1142/S0960313100000319","url":null,"abstract":"There has been a great deal of interest in recent years relating to the use of direct liquid immersion cooling for heat dissipation from microelectronic components. The high levels of circuit integration place size constraints on any techniques used for heat removal. This paper presents results obtained using a novel heat sink which addresses the need for a mechanism to remove high heat fluxes, while at the same time dealing with space limitations. This heat sink consists of cavity structures etched into a silicon surface, utilizing manufacturing processes similar to those used in the production of the chips themselves. The enhanced surface features are in the form of pyramidal cavities with a mouth size as low as 12 μm, and cavity density as high as 420 cavities/cm2. Tests were conducted using thin film heaters deposited on a silicon surface as the heat source. Data obtained from a bonded heat source–heat sink combination indicated very low values of overshoot at boiling incipience. The cooling characteristics of these etched silicon heat sinks were studied in two dielectric fluids; R-113 and FC-72. The boiling performance of an epoxy bonded heat sink was compared with that of a direct bonded heat sink.","PeriodicalId":309904,"journal":{"name":"Journal of Electronics Manufacturing","volume":"291 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132215341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TURBULENT FLOW AND HEAT TRANSFER OVER HEATED MODULES FOR A WIDE RANGE OF REYNOLDS NUMBERS AND MODULE SIZE","authors":"P. Deb, P. Majumdar","doi":"10.1142/S0960313100000332","DOIUrl":"https://doi.org/10.1142/S0960313100000332","url":null,"abstract":"Computational prediction of turbulent fluid flow and heat transfer over heated modules of different sizes in a channel is presented. We assume that the channel is formed between two adjacent circuit boards with surface-mounted heat generating modules mounted on a single side of each board. The pressure drop and heat transfer coefficient over each module are calculated for wide range of Reynolds numbers. The standard k - e model has been used for Reynolds number of 7000 or higher while low Reynolds number model has been used for Reynolds range of 2000–6000. A computational study has been carried out in order to develop performance map for the flow and heat transfer characteristics over various sizes of heated modules (B/L = 0.375 ~ 0.625) and for a wide range of Reynolds number (ReH = 2000 ~ 10,000). The correlation of heat transfer coefficient and pressure drop with Reynolds number and dimension of modules has also been established from this study.","PeriodicalId":309904,"journal":{"name":"Journal of Electronics Manufacturing","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123748574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ANALYSIS AND EXPERIMENTS OF BALL DEFORMATION FOR ULTRA-FINE-PITCH WIRE BONDING","authors":"Z. Zhong, K. Goh","doi":"10.1142/S0960313100000204","DOIUrl":"https://doi.org/10.1142/S0960313100000204","url":null,"abstract":"This paper discusses ultra-fine-pitch bonding on a 50-μm bond-pad-pitch platform using ϕ23-μm gold wire. A technique for the bonding process and the bonding tool design was developed using the finite element method. It was possible to simulate and analyze the variation in the plastic deformation of ball bond when it was subjected to different loading conditions and capillary configurations. The analysis indicated that the critical bonding tool dimensions and bonding process parameters such as free air ball consistency and bonding force played critical roles in reliable bond deformation. A wire diameter of 23 μm with a capillary hole size of 28–30 μm would be robust for a mass production environment. A diameter of 32–33 μm is recommended as the average size of the free air balls for 50-μm bond-pad-pitch bonding using the ϕ23-μm gold wire. Based on the results obtained from the analysis, special bonding tool configurations were designed and fabricated. Actual bonding was performed to further validate the simulation results with experimental bonding responses. Comparison of the simulation results with the experimental data indicated that the actual ball size (38.5 μm) was approximately 3% larger than that (37.4 μm) obtained from the simulation.","PeriodicalId":309904,"journal":{"name":"Journal of Electronics Manufacturing","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126888339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"STUDY ON PROPERTY OF UNDERFILL BASED ON EPOXY CURED WITH ACID ANHYDRIDE FOR FLIP CHIP APPLICATION","authors":"S. Luo, T. Yamashita, C. Wong","doi":"10.1142/S0960313100000174","DOIUrl":"https://doi.org/10.1142/S0960313100000174","url":null,"abstract":"The adhesion and thermo-mechanical properties of epoxy underfills depend on the epoxy resin, the hardener, and the catalyst. In this study, three different epoxy resins, ERL4221 (cycloaliphatic type), EPON862 (bisphenol F type), and EPON 8281 (bisphenol A type), were cured with 4-methylhexahydrophthalic anhydride (MHHPA) as the hardener using different catalysts: cobalt acetylacetonate (CAA), imidazole derivatives, and tertiary amines. The flow behavior of the epoxy systems was studied with a rheometer. The curing profiles were recorded using a differential scanning calorimeter (DSC), revealing varying catalytic effect for the different catalysts. The curing peak temperature increased in the following order: tertiary amine < imidazole derivatives < cobalt acetylacetonate. The bulk properties of the systems were studied through a thermo-mechanical analyzer (TMA). Epoxy resins cured with different catalysts showed different glass transition temperatures (Tg) and coefficients of thermal expansion (CTE). Among them, the CAA catalyzed systems showed the highest Tg and low CTE. Due to the cycloaliphatic structure of the ERL4221 resin, the cured ERL4221 systems showed the highest Tg compared to the other systems with the same catalysts. EPON8281 systems generally had lower moisture absorption than the other epoxy systems. The surface tension of the underfills was measured. The adhesion strength was evaluated by a die shear test with SiO2 and Si3N4 (SiN) passivated silicon dies as substrates. Although there was no significant difference among the surface tension and contact angles of the underfill materials on the SiO2 or SiN, there were significant differences in the adhesion. For the ERL4221+MHHPA systems, the CAA catalyzed system exhibited excellent adhesion with SiO2 and SiN passivation. However, poor adhesion resulted with the catalysis by the imidazole derivatives and the tertiary amines. The bisphenol A and bisphenol F type epoxy resins showed excellent adhesion. Although the CAA catalyzed systems had higher Tg compared to the other systems, their adhesion was worse after aging in a high humidity environment at high temperatures.","PeriodicalId":309904,"journal":{"name":"Journal of Electronics Manufacturing","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121897967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"STATISTICAL OPTIMISATION OF THERMOPLASTIC INJECTION MOULDING PROCESS FOR THE ENCAPSULATION OF ELECTRONIC SUBASSEMBLY","authors":"N. Teh, P. Conway, P. J. Palmer, S. Prosser, A. Kioul","doi":"10.1142/S0960313100000150","DOIUrl":"https://doi.org/10.1142/S0960313100000150","url":null,"abstract":"This paper reports work from a major UK research project which seeks to develop a cost effective integrated production technology for the manufacture of plastic automotive components with embedded electronics and power distribution. The said electronics sub-systems are simultaneously packaged within the automotive structural thermoplastic (TP) component during the injection moulding process. Such innovative process and product integration represents an opportunity to significantly reduce component counts and wiring loom overhead for the vehicle. The assembly, weight and cost advantages envisaged from the proposed technology will satisfy the ever-increasing demand for automotive suppliers to manufacture complete, ready-to-assemble, reconfigurable component modules with superior reliability and as such may contribute to the increased incorporation of vehicle telematics. The paper addresses the technological and economic implications of the proposed overmoulding technology, presenting particular aspects of technological hurdles such as thermal, electrical and process requirements in the production of highly integrated polymer encapsulated electronics products. This paper highlights the findings derived from experiments undertaken to explore critical factors in the manufacture of such encapsulated electronics sub-systems, including such variables as electronics interconnection, materials selection and interactions and moulding process parameters.","PeriodicalId":309904,"journal":{"name":"Journal of Electronics Manufacturing","volume":"173 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121263324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}