Two test specimens are developed to measure interfacial fracture toughness in flip-chip assemblies. The specimens consist three layers of silicon chip, underfill and circuit board. Two symmetric edge cracks are embedded along the interface either between the chip and the underfill or between the underfill and the circuit board. The specimens are subjected to four-point-bend loading and critical loads are obtained. Analytical solutions for energy release rate have been derived for these two specimens and used to obtain the toughness from the measured critical loads. These specimens have been used to evaluate material combinations of chip passivation, underfill and solder mask for desired interfacial strength.
{"title":"Two Test Specimens for Determining the Interfacial Fracture Toughness in Flip-Chip Assemblies","authors":"Xiantao Yan, Rakesh K. Agarwal","doi":"10.1115/1.2792607","DOIUrl":"https://doi.org/10.1115/1.2792607","url":null,"abstract":"\u0000 Two test specimens are developed to measure interfacial fracture toughness in flip-chip assemblies. The specimens consist three layers of silicon chip, underfill and circuit board. Two symmetric edge cracks are embedded along the interface either between the chip and the underfill or between the underfill and the circuit board. The specimens are subjected to four-point-bend loading and critical loads are obtained. Analytical solutions for energy release rate have been derived for these two specimens and used to obtain the toughness from the measured critical loads. These specimens have been used to evaluate material combinations of chip passivation, underfill and solder mask for desired interfacial strength.","PeriodicalId":432053,"journal":{"name":"Manufacturing Science and Engineering: Volume 1","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123378187","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}
In Europe a consortium has been formed to develop a Sensor Fused Intelligent Monitoring System for Machining (SIMON). Starting from a generic module structure for process monitoring systems, the system architecture of a fully control integrated monitoring system for rough milling operations is presented based on digital drive signals. Machine integrated sensors are used for calibration and for wear monitoring. The potential of such a system is shown by previous work at WZL. Experimental results demonstrate successful tool overload and tool breakage monitoring for milling and drilling, based on drive current signals. Comprised only of software modules, directly linked into an industrial open system controller, the base system does not need any sensor or signal processing hardware to monitor 06mm drilling or 08mm end milling tools machining steel workpieces. Signal correction has been designed for monitoring during acceleration. Machine integrated sensors are presented to extend the range of reliable monitoring.
{"title":"Intelligent Process Monitoring for Rough Milling Operations Based on Digital Drive Currents and Machine Integrated Sensors","authors":"Michael Kaever, M. Weck","doi":"10.1115/imece1997-1081","DOIUrl":"https://doi.org/10.1115/imece1997-1081","url":null,"abstract":"\u0000 In Europe a consortium has been formed to develop a Sensor Fused Intelligent Monitoring System for Machining (SIMON). Starting from a generic module structure for process monitoring systems, the system architecture of a fully control integrated monitoring system for rough milling operations is presented based on digital drive signals. Machine integrated sensors are used for calibration and for wear monitoring. The potential of such a system is shown by previous work at WZL. Experimental results demonstrate successful tool overload and tool breakage monitoring for milling and drilling, based on drive current signals. Comprised only of software modules, directly linked into an industrial open system controller, the base system does not need any sensor or signal processing hardware to monitor 06mm drilling or 08mm end milling tools machining steel workpieces. Signal correction has been designed for monitoring during acceleration. Machine integrated sensors are presented to extend the range of reliable monitoring.","PeriodicalId":432053,"journal":{"name":"Manufacturing Science and Engineering: Volume 1","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131385408","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}
This paper deals with a sensor system based on the magnetostrictive effect, which is installed in a tool holder, for sensing cutting torque in order to monitor the milling process. Changes in the magnetic permeability of ferromagnetic alloy layers formed onto a rotating shaft due to torque are detected by coils as changes in impedance without contacting the rotating shaft. By mounting the magnetostrictive sensor on a tool holder, it became possible to detect cutting torque as close to the cutting point as possible. The accuracy of the proposed sensor system was confirmed through static and dynamic evaluation tests. In order to investigate the relationship between tool failure and cutting torque, side milling tests were performed, which bore out the possibility of estimating flank wear and tool fracture from the cutting torque detected by the proposed sensor system.
{"title":"Development of a Magnetostrictive Torque Sensor for Milling Process Monitoring","authors":"Hiro Ohzeki, A. Mashine, H. Aoyama, I. Inasaki","doi":"10.1115/1.2833078","DOIUrl":"https://doi.org/10.1115/1.2833078","url":null,"abstract":"This paper deals with a sensor system based on the magnetostrictive effect, which is installed in a tool holder, for sensing cutting torque in order to monitor the milling process. Changes in the magnetic permeability of ferromagnetic alloy layers formed onto a rotating shaft due to torque are detected by coils as changes in impedance without contacting the rotating shaft. By mounting the magnetostrictive sensor on a tool holder, it became possible to detect cutting torque as close to the cutting point as possible. The accuracy of the proposed sensor system was confirmed through static and dynamic evaluation tests. In order to investigate the relationship between tool failure and cutting torque, side milling tests were performed, which bore out the possibility of estimating flank wear and tool fracture from the cutting torque detected by the proposed sensor system.","PeriodicalId":432053,"journal":{"name":"Manufacturing Science and Engineering: Volume 1","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126824493","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}
Constraints of mechanical, thermal, and chemical properties are making ceramics the material choice for industrial and dental applications. The quality of a machined surface of ceramics is fundamentally dependent on the response of the material to the machining process. This paper presents a combined analytical and experimental study with focus on optimizing the machining performance of dental ceramics — DICOR/MGC — with three distinguished microstructures. The study starts from analyzing the microstructural characteristics to searching for the machining conditions that provide satisfactory performance in terms of acceptable flexural strength. Evidence gained from the cutting force measurements and evaluation of fracture strength degradation indicates that the control of micro-scale fracture formed on the machined surface, with microstructural characteristics being considered, is the key factor which dominates the machining performance.
{"title":"Microstructural Effects on the Machining Performance of Dental Ceramics","authors":"D. T. Le, L. Qi, G. Zhang","doi":"10.21236/ada605292","DOIUrl":"https://doi.org/10.21236/ada605292","url":null,"abstract":"\u0000 Constraints of mechanical, thermal, and chemical properties are making ceramics the material choice for industrial and dental applications. The quality of a machined surface of ceramics is fundamentally dependent on the response of the material to the machining process. This paper presents a combined analytical and experimental study with focus on optimizing the machining performance of dental ceramics — DICOR/MGC — with three distinguished microstructures. The study starts from analyzing the microstructural characteristics to searching for the machining conditions that provide satisfactory performance in terms of acceptable flexural strength. Evidence gained from the cutting force measurements and evaluation of fracture strength degradation indicates that the control of micro-scale fracture formed on the machined surface, with microstructural characteristics being considered, is the key factor which dominates the machining performance.","PeriodicalId":432053,"journal":{"name":"Manufacturing Science and Engineering: Volume 1","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133399378","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}
Frequently changing machining operations are a characteristic feature in one-off and small batch size production and require a high degree of flexibility in the production processes and facilities. Process monitoring systems applied in such a production environment have to be able to supply reliable process information under varying machining conditions. Therefore, generic and flexible monitoring solutions are needed, adaptable to the requirements of specific machining applications with minimum efforts. In this paper the requirements for such generic and flexible monitoring approaches are critically discussed. In the second part, monitoring strategies for a process state analysis in face milling, end milling and drilling operations is described, adaptable to varying machining conditions by combining several sensing and evaluation methods.
{"title":"Flexible Monitoring Strategies for Milling Operations","authors":"F. Klocke, M. Reuber, M. Rehse","doi":"10.1115/imece1997-1079","DOIUrl":"https://doi.org/10.1115/imece1997-1079","url":null,"abstract":"\u0000 Frequently changing machining operations are a characteristic feature in one-off and small batch size production and require a high degree of flexibility in the production processes and facilities. Process monitoring systems applied in such a production environment have to be able to supply reliable process information under varying machining conditions. Therefore, generic and flexible monitoring solutions are needed, adaptable to the requirements of specific machining applications with minimum efforts. In this paper the requirements for such generic and flexible monitoring approaches are critically discussed. In the second part, monitoring strategies for a process state analysis in face milling, end milling and drilling operations is described, adaptable to varying machining conditions by combining several sensing and evaluation methods.","PeriodicalId":432053,"journal":{"name":"Manufacturing Science and Engineering: Volume 1","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127817268","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}
It has been recently shown, [Liu and Mittal 1995, 1996] that it is feasible to eliminate the needs for grinding and superfinishing by turning, in selected conditions, directly on hardened steel up to a hardness of 64 RC, for a surface finish of Ra smaller than 8 μ in. Furthermore, it was shown that hard turning is capable of pre-stressing the machined surface so that it may partially “compensate” the surface load for improved fatigue life. A preliminary study has indicated a potential improvement of over 200% in fatigue life is possible. It also offers a prospect that it is possible to produce a component which will never fail due to fatigue. Therefore, it is desirable to explore the capability of pre-stressing by finish hard turning in broad machining condition, thus this study. The purpose of this study is to investigate the residual stress after finish machining of hardened AISI 52100 steel with hardness of 60–62 HRC using CBN inserts. The effect of tool, feed rate, and depth of cut on the residual stress distribution are studied. Surface finish better than 8 μ in. was produced comparable to that produced by grinding and superfinishing. The round tool (0.5 inch radius) was found to give more compressive stress than the 0.0623 inch nose radius diamond-shaped tool. The smaller feed rate gave more compressive residual stress.
{"title":"Experimental Study of the Pre-Stressing Capability Through Residual Stress Generation in Superfinish Machining of Hardened Steel","authors":"C. Liu, S. R. Agha","doi":"10.1115/imece1997-1093","DOIUrl":"https://doi.org/10.1115/imece1997-1093","url":null,"abstract":"\u0000 It has been recently shown, [Liu and Mittal 1995, 1996] that it is feasible to eliminate the needs for grinding and superfinishing by turning, in selected conditions, directly on hardened steel up to a hardness of 64 RC, for a surface finish of Ra smaller than 8 μ in. Furthermore, it was shown that hard turning is capable of pre-stressing the machined surface so that it may partially “compensate” the surface load for improved fatigue life. A preliminary study has indicated a potential improvement of over 200% in fatigue life is possible. It also offers a prospect that it is possible to produce a component which will never fail due to fatigue. Therefore, it is desirable to explore the capability of pre-stressing by finish hard turning in broad machining condition, thus this study. The purpose of this study is to investigate the residual stress after finish machining of hardened AISI 52100 steel with hardness of 60–62 HRC using CBN inserts. The effect of tool, feed rate, and depth of cut on the residual stress distribution are studied. Surface finish better than 8 μ in. was produced comparable to that produced by grinding and superfinishing. The round tool (0.5 inch radius) was found to give more compressive stress than the 0.0623 inch nose radius diamond-shaped tool. The smaller feed rate gave more compressive residual stress.","PeriodicalId":432053,"journal":{"name":"Manufacturing Science and Engineering: Volume 1","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117128110","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}
The failure of electrical devices associated with solder joints has become one of the most critical reliability issues for surface-mounted devices. Solder joint reliability performance has been found to be highly dependent on the solder joint configuration, which, in turn, is governed by bond pad size, alloy material, and leadframe structure, as well as solder reflow characteristics. To investigate Tombstone effect causing solder joint failure during leadless component reflow process, this work has focused on 1) developing numerical model for the simulations of the solder joint formation during the reflow process; 2) determining possibility that a tombstone effect for the leadless component may occur by analyzing the force and torque in the problem. Using this methodology, the Tombstone effect associated with different pad geometry configurations has been analyzed though the application of the software tool Surface Evolver. Simulations show that the tombstoning is very sensitive to pad / component geometry design, solder surface tension, paste volume, wetting area and wetting angle. This model simulation can be used to determine optimal solder paste volume, pad geometry configurations and solder material for avoiding Tombstone effect.
{"title":"Solder Joint Formation Simulation and Component Tombstoning Prediction During Reflow","authors":"X. Wu, X. Dou, C. Yeh, K. Waytt","doi":"10.1115/1.2792601","DOIUrl":"https://doi.org/10.1115/1.2792601","url":null,"abstract":"The failure of electrical devices associated with solder joints has become one of the most critical reliability issues for surface-mounted devices. Solder joint reliability performance has been found to be highly dependent on the solder joint configuration, which, in turn, is governed by bond pad size, alloy material, and leadframe structure, as well as solder reflow characteristics. To investigate Tombstone effect causing solder joint failure during leadless component reflow process, this work has focused on 1) developing numerical model for the simulations of the solder joint formation during the reflow process; 2) determining possibility that a tombstone effect for the leadless component may occur by analyzing the force and torque in the problem. Using this methodology, the Tombstone effect associated with different pad geometry configurations has been analyzed though the application of the software tool Surface Evolver. Simulations show that the tombstoning is very sensitive to pad / component geometry design, solder surface tension, paste volume, wetting area and wetting angle. This model simulation can be used to determine optimal solder paste volume, pad geometry configurations and solder material for avoiding Tombstone effect.","PeriodicalId":432053,"journal":{"name":"Manufacturing Science and Engineering: Volume 1","volume":"186 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114507921","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}
The Department of Mechanical Engineering at Lafayette College has implemented an innovative manufacturing laboratory course as part of its mechanical design sequence to give its students a basic understanding of engineering design and the influence of manufacturing in the design process. The course, which is required for all junior mechanical engineering students, teaches basic manufacturing skills and concepts, and design for manufacturability. The laboratory is co-taught by the mechanical engineering faculty and the engineering technicians. The course takes a hands-on approach to teaching these subjects and incorporates two interrelated projects; the manufacture of a pre-designed mechanical system, and the design, manufacture, evaluation, and competition of a semester long design project. This paper discusses the format of the course, the two projects, the role of the faculty and engineering technicians, and how these fit together to create an effective learning experience.
{"title":"Teaching Manufacturing and Design for Manufacturability to Mechanical Engineering Students","authors":"S. Nesbit, Jess J. Comer","doi":"10.1115/imece1997-1127","DOIUrl":"https://doi.org/10.1115/imece1997-1127","url":null,"abstract":"\u0000 The Department of Mechanical Engineering at Lafayette College has implemented an innovative manufacturing laboratory course as part of its mechanical design sequence to give its students a basic understanding of engineering design and the influence of manufacturing in the design process. The course, which is required for all junior mechanical engineering students, teaches basic manufacturing skills and concepts, and design for manufacturability. The laboratory is co-taught by the mechanical engineering faculty and the engineering technicians. The course takes a hands-on approach to teaching these subjects and incorporates two interrelated projects; the manufacture of a pre-designed mechanical system, and the design, manufacture, evaluation, and competition of a semester long design project. This paper discusses the format of the course, the two projects, the role of the faculty and engineering technicians, and how these fit together to create an effective learning experience.","PeriodicalId":432053,"journal":{"name":"Manufacturing Science and Engineering: Volume 1","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126749044","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}
The method of digital speckle correlation is introduced, so is the hardware system to implement the method. The advantages and the features of the technique are discussed and application examples are given. Owing to the high spatial resolution that this technique can achieve, the method is especially useful to measure small areas of an object, or a small component in an assembly, whether the surfaces under probing are planar or not. The applications have proved that the technique is a promising tool for the reliability study of microelectronic packages.
{"title":"Applications of Digital Correlation Method to Microscopic Strain Measurement and Materials’ Property Characterization","authors":"H. Lu","doi":"10.1115/imece1997-1119","DOIUrl":"https://doi.org/10.1115/imece1997-1119","url":null,"abstract":"The method of digital speckle correlation is introduced, so is the hardware system to implement the method. The advantages and the features of the technique are discussed and application examples are given. Owing to the high spatial resolution that this technique can achieve, the method is especially useful to measure small areas of an object, or a small component in an assembly, whether the surfaces under probing are planar or not. The applications have proved that the technique is a promising tool for the reliability study of microelectronic packages.","PeriodicalId":432053,"journal":{"name":"Manufacturing Science and Engineering: Volume 1","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133030619","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}
The current procedure followed to manufacture a new part by CNC machining is to write the part program, machine a test part and measure the test part for conformance to the required dimensions and tolerances. If the test part dimensions out of tolerance, the part program is modified and the process repeated until a successful part is machined. In many applications, such as the aerospace industry, where material cost and machining time are high, this iterative process becomes economically unacceptable. Research has been conducted to test the feasibility of using the Laser Ball Bar (LBB), a spatial coordinate measuring device, to measure dynamic continuous-path contours of CNC part programs to micrometer accuracy prior to machining. In this way, a virtual test part can be measured and compared to the design drawings to validate the CNC part program. This reduces or eliminates the costly and time-consuming steps involved in the machining of physical test parts.
{"title":"Dynamic Measurement of CNC Part Paths","authors":"T. Schmitz, J. Ziegert","doi":"10.1115/imece1997-1077","DOIUrl":"https://doi.org/10.1115/imece1997-1077","url":null,"abstract":"\u0000 The current procedure followed to manufacture a new part by CNC machining is to write the part program, machine a test part and measure the test part for conformance to the required dimensions and tolerances. If the test part dimensions out of tolerance, the part program is modified and the process repeated until a successful part is machined. In many applications, such as the aerospace industry, where material cost and machining time are high, this iterative process becomes economically unacceptable.\u0000 Research has been conducted to test the feasibility of using the Laser Ball Bar (LBB), a spatial coordinate measuring device, to measure dynamic continuous-path contours of CNC part programs to micrometer accuracy prior to machining. In this way, a virtual test part can be measured and compared to the design drawings to validate the CNC part program. This reduces or eliminates the costly and time-consuming steps involved in the machining of physical test parts.","PeriodicalId":432053,"journal":{"name":"Manufacturing Science and Engineering: Volume 1","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114147399","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}
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