Pub Date : 2007-08-01DOI: 10.1109/ICEPT.2007.4441422
F. Su, Jun Wei, J. Tew
Summary form only given. Lead free 80Au-20Sn solder was widely used in photonics packages and sometimes in electronic packages. As in other cases, mechanical properties of the solder materials is very critical for its reliability evaluation (e.g. fatigue life prediction). However, mechanical properties of this material is not well studied, part of the reason may be the cost. In this paper, steady-state creep behavior of lead free 80Au-20Sn solder was investigated at three different temperatures and a range of stress levels. Hyperbolic-sine model was employed to characterize the creep properties of the lead free solder, constants in the model (including the activation energy) were determined through data fitting and were compared with that of other lead free solders. Activation energy of the solder material was also experimentally investigated and compared with the fitted data.
{"title":"Creep Characterization of Lead Free 80Au-20Sn Solder","authors":"F. Su, Jun Wei, J. Tew","doi":"10.1109/ICEPT.2007.4441422","DOIUrl":"https://doi.org/10.1109/ICEPT.2007.4441422","url":null,"abstract":"Summary form only given. Lead free 80Au-20Sn solder was widely used in photonics packages and sometimes in electronic packages. As in other cases, mechanical properties of the solder materials is very critical for its reliability evaluation (e.g. fatigue life prediction). However, mechanical properties of this material is not well studied, part of the reason may be the cost. In this paper, steady-state creep behavior of lead free 80Au-20Sn solder was investigated at three different temperatures and a range of stress levels. Hyperbolic-sine model was employed to characterize the creep properties of the lead free solder, constants in the model (including the activation energy) were determined through data fitting and were compared with that of other lead free solders. Activation energy of the solder material was also experimentally investigated and compared with the fitted data.","PeriodicalId":325619,"journal":{"name":"2007 8th International Conference on Electronic Packaging Technology","volume":"184 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133981587","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}
Pub Date : 2007-08-01DOI: 10.1109/ICEPT.2007.4441374
Dongsheng Zhu, Changhong Wang, Xuan Zhou, S. Tu
An experimental facility of advanced packaging electroplating cell is developed to study the uniformity of the temperature and flow field in the high precision electroplating cell. Based on heat transfer and computational fluid dynamics, a 2D numerical model is founded to analyze the temperature field and flow field of the experimental electroplating cell enclosure. Combing with test and simulated results, the effects of the heat source intensity, ventilated mode and heat transfer coefficient on the thermal field of the cell are discussed. Under the condition of natural convection with temperature gradient driving, although heat/cold source intensity and ventilated mode both have effects on the temperature field and flow field of the electroplating enclosure, the heat/cold source is the more marked factor influencing the uniformity of temperature field and flow field. The experimental and simulated results can give a way to enhance the uniformity of the temperature field and flow field and to improve the quantity of the WL-CSP electroplating.
{"title":"Experimental and Numerical Simulation Study on Uniformity of Temperature and Flow Field in an Advanced Packaging Electroplating Cell","authors":"Dongsheng Zhu, Changhong Wang, Xuan Zhou, S. Tu","doi":"10.1109/ICEPT.2007.4441374","DOIUrl":"https://doi.org/10.1109/ICEPT.2007.4441374","url":null,"abstract":"An experimental facility of advanced packaging electroplating cell is developed to study the uniformity of the temperature and flow field in the high precision electroplating cell. Based on heat transfer and computational fluid dynamics, a 2D numerical model is founded to analyze the temperature field and flow field of the experimental electroplating cell enclosure. Combing with test and simulated results, the effects of the heat source intensity, ventilated mode and heat transfer coefficient on the thermal field of the cell are discussed. Under the condition of natural convection with temperature gradient driving, although heat/cold source intensity and ventilated mode both have effects on the temperature field and flow field of the electroplating enclosure, the heat/cold source is the more marked factor influencing the uniformity of temperature field and flow field. The experimental and simulated results can give a way to enhance the uniformity of the temperature field and flow field and to improve the quantity of the WL-CSP electroplating.","PeriodicalId":325619,"journal":{"name":"2007 8th International Conference on Electronic Packaging Technology","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123084396","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}
Pub Date : 2007-08-01DOI: 10.1109/ICEPT.2007.4441495
Kai Wang, Sheng Liu
As the LED's lumen efficiency increases rapidly in recent years, many new LED illumination applications are emerging. Based on the analysis of LED's characteristics, our optimization scheme and design methods for LED street lamps were proposed. A unique street lamp with ultra-long span and high total uniformity was designed as an example. The simulation results demonstrated that the road light utilization efficiency was 85% and the total uniformity was 0.52 for a 100times30 square meters test area at the height of 20 meters, which was much better than the current standard for the main road, proposing a challenging to the current standard with high pressure sodium lamps. Various sensors integrated with the LED street lamps were also discussed as the mainstream design concept for the next-generational LED street lamps.
{"title":"A Sensor Integrated Ultra-long Span LED Street Lamp System","authors":"Kai Wang, Sheng Liu","doi":"10.1109/ICEPT.2007.4441495","DOIUrl":"https://doi.org/10.1109/ICEPT.2007.4441495","url":null,"abstract":"As the LED's lumen efficiency increases rapidly in recent years, many new LED illumination applications are emerging. Based on the analysis of LED's characteristics, our optimization scheme and design methods for LED street lamps were proposed. A unique street lamp with ultra-long span and high total uniformity was designed as an example. The simulation results demonstrated that the road light utilization efficiency was 85% and the total uniformity was 0.52 for a 100times30 square meters test area at the height of 20 meters, which was much better than the current standard for the main road, proposing a challenging to the current standard with high pressure sodium lamps. Various sensors integrated with the LED street lamps were also discussed as the mainstream design concept for the next-generational LED street lamps.","PeriodicalId":325619,"journal":{"name":"2007 8th International Conference on Electronic Packaging Technology","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125284753","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}
Pub Date : 2007-08-01DOI: 10.1109/ICEPT.2007.4441444
Yaiiliong Tian, C. Hang, Chunqing Wang, Y. Zhou
Growth of Cu/Al intermetallic compounds (IMCs) at the interface between the copper bond and the Al metallization pad would increase the contact resistance and degrade the bond reliabilities. In this study, the thermosonic copper bump bonds were aged at 250degC for 1 to 196 hours. Then the evolution of Cu/Al IMCs was investigated. Three IMC layers with different colors were found at the Cu/Al interface using the optical microscopy on the xy plane cross-section of the ball bond. The main phases in the Cu/Al IMC are confirmed to be Cu9Al4, and CuAl2. CuAl is believed to be another phase in the copper bond. During the aging process, Cu/Al IMC grew from the periphery of the bond initially and propagated inward to the centre area later. Moreover, some cavities appeared between the IMC layer and bond bottom from the bond periphery and developed into the centre area.
{"title":"Evolution of Cu/Al Intermetallic Compounds in the Copper Bump bonds during Aging Process","authors":"Yaiiliong Tian, C. Hang, Chunqing Wang, Y. Zhou","doi":"10.1109/ICEPT.2007.4441444","DOIUrl":"https://doi.org/10.1109/ICEPT.2007.4441444","url":null,"abstract":"Growth of Cu/Al intermetallic compounds (IMCs) at the interface between the copper bond and the Al metallization pad would increase the contact resistance and degrade the bond reliabilities. In this study, the thermosonic copper bump bonds were aged at 250degC for 1 to 196 hours. Then the evolution of Cu/Al IMCs was investigated. Three IMC layers with different colors were found at the Cu/Al interface using the optical microscopy on the xy plane cross-section of the ball bond. The main phases in the Cu/Al IMC are confirmed to be Cu9Al4, and CuAl2. CuAl is believed to be another phase in the copper bond. During the aging process, Cu/Al IMC grew from the periphery of the bond initially and propagated inward to the centre area later. Moreover, some cavities appeared between the IMC layer and bond bottom from the bond periphery and developed into the centre area.","PeriodicalId":325619,"journal":{"name":"2007 8th International Conference on Electronic Packaging Technology","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126800729","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}
Pub Date : 2007-08-01DOI: 10.1109/ICEPT.2007.4441426
Guojun Hu, S. Chew, B. Singh
Finite element analysis (FEA) is widely used throughout the electronics industry to understand the thermal and thermo-mechanical behavior of electronic packages and interconnect during their manufacture and lifetime. After encapsulation, thermo-mechanical stress builds up within the package due to temperature coefficient of expansion mismatch between the respective materials within the package as it cools to room temperature. Due to the complexity and time consuming of the calculation, it is almost impossible for industry to carry out the numerical simulation using viscoelastic property which is the most close to the real material property of polymer material. However, FEA using temperature-dependent elastic property, temperature-dependent thermal expansion coefficient and accurate chemical cure shrinkage can help to improve the accuracy on the stress and warpage prediction. This study has developed an evaluation method for the chemical cure shrinkage based on the measurement of the warpage of bimaterial model. The results show that FEA simulations without chemical cure shrinkage fail to accurately predict the package warpage. On the other hand. FEA simulations with chemical cure shrinkage is outlined which show fair agreement with experimental measurements of package warpage over a range of temperatures.
{"title":"Cure Shrinkage Analysis of Green Epoxy Molding Compound with Application to Warpage Analysis in a Plastic IC Package","authors":"Guojun Hu, S. Chew, B. Singh","doi":"10.1109/ICEPT.2007.4441426","DOIUrl":"https://doi.org/10.1109/ICEPT.2007.4441426","url":null,"abstract":"Finite element analysis (FEA) is widely used throughout the electronics industry to understand the thermal and thermo-mechanical behavior of electronic packages and interconnect during their manufacture and lifetime. After encapsulation, thermo-mechanical stress builds up within the package due to temperature coefficient of expansion mismatch between the respective materials within the package as it cools to room temperature. Due to the complexity and time consuming of the calculation, it is almost impossible for industry to carry out the numerical simulation using viscoelastic property which is the most close to the real material property of polymer material. However, FEA using temperature-dependent elastic property, temperature-dependent thermal expansion coefficient and accurate chemical cure shrinkage can help to improve the accuracy on the stress and warpage prediction. This study has developed an evaluation method for the chemical cure shrinkage based on the measurement of the warpage of bimaterial model. The results show that FEA simulations without chemical cure shrinkage fail to accurately predict the package warpage. On the other hand. FEA simulations with chemical cure shrinkage is outlined which show fair agreement with experimental measurements of package warpage over a range of temperatures.","PeriodicalId":325619,"journal":{"name":"2007 8th International Conference on Electronic Packaging Technology","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127068077","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}
Pub Date : 2007-08-01DOI: 10.1109/ICEPT.2007.4441566
K. Tu
Summary form only given. The demand of flip chip technology in high density packaging for advanced electronic consumer products is growing rapidly. Due to the decrease in device size and increase in functionality, electromigration has now become the most serious reliability problem in flip chip solder joints, especially the Pb-free. Electromigration in flip chip solder joints has several unique features that are very different from the electromigration in Al and Cu interconnects. Solder alloy has a very small critical product of electromigration. thus it can fail at 103 A/cm2. Owing to the line-to-bump geometry in flip chip, current crowding occurs at the contact between the line and the bump and the failure mode of electromigration is a pancake-type void formation at the cathode. Eutectic solder composition has a constant chemical potential below the eutectic temperature, so it enables up-hill diffusion and a nearly complete phase separation to occur in electromigration without resistance. Joule heating due to Al or Cu interconnects can cause a very large temperature gradient in the solder joint, so thermomigration accompanies electromigration. In this talk, the reliability issues of flip chip solder joints when electrical force is combined with thermal force, chemical force or mechanical force will be discussed.
{"title":"Electromigration in Flip Chip Pb-Free Solder Joints","authors":"K. Tu","doi":"10.1109/ICEPT.2007.4441566","DOIUrl":"https://doi.org/10.1109/ICEPT.2007.4441566","url":null,"abstract":"Summary form only given. The demand of flip chip technology in high density packaging for advanced electronic consumer products is growing rapidly. Due to the decrease in device size and increase in functionality, electromigration has now become the most serious reliability problem in flip chip solder joints, especially the Pb-free. Electromigration in flip chip solder joints has several unique features that are very different from the electromigration in Al and Cu interconnects. Solder alloy has a very small critical product of electromigration. thus it can fail at 103 A/cm2. Owing to the line-to-bump geometry in flip chip, current crowding occurs at the contact between the line and the bump and the failure mode of electromigration is a pancake-type void formation at the cathode. Eutectic solder composition has a constant chemical potential below the eutectic temperature, so it enables up-hill diffusion and a nearly complete phase separation to occur in electromigration without resistance. Joule heating due to Al or Cu interconnects can cause a very large temperature gradient in the solder joint, so thermomigration accompanies electromigration. In this talk, the reliability issues of flip chip solder joints when electrical force is combined with thermal force, chemical force or mechanical force will be discussed.","PeriodicalId":325619,"journal":{"name":"2007 8th International Conference on Electronic Packaging Technology","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126246163","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}
Pub Date : 2007-08-01DOI: 10.1109/ICEPT.2007.4441434
J. Lee, P.C. Chen, Y. Lai
In the study, one 14x14 lead free CSP BGA with 0.3 mm/0.5 mm ball diameter/pitch was adopted as test vehicle. The intermetallic compounds morphology evolution which can be generated when using SnxAgCu and SnAgCuX solder ball in combination with electrolytic NiAu-plated substrates was investigated during 150degC thermal aging, such as single layer SnNi IMC and complex layer SnNi/SnNiCu IMC in the interface through top and X-section view, respectively. In addition, the intensity of plate-like Ag3Sn IMC formation in the SnxAgCu solder bulkfrom 1 to 4%Ag was observed by SEM as well. The CSP BGA package with above combination was assembled to PC boards with OSP finish using Sn3Ag0.5Cu solder paste under 245degC peak temperature reflow. The test vehicle assembled was subject to mechanical drop test following JESD22-B111 to evaluate the solder joint integrity after zero and 150degC/250 hrs thermal aging. The effect of interfacial IMC morphology evolution and Ag3Sn intensity in solder bulk by x (Ag percentage) and X (forth element addition) on the mechanical drop performance will be concluded. Furthermore, one approaching in IMC microstructure control to overcome SnAgCu drop concern will be presented.
{"title":"The Effect of SnxAgCu and SnAgCuX on the Mechanical Drop Performance in Lead Free CSP Package","authors":"J. Lee, P.C. Chen, Y. Lai","doi":"10.1109/ICEPT.2007.4441434","DOIUrl":"https://doi.org/10.1109/ICEPT.2007.4441434","url":null,"abstract":"In the study, one 14x14 lead free CSP BGA with 0.3 mm/0.5 mm ball diameter/pitch was adopted as test vehicle. The intermetallic compounds morphology evolution which can be generated when using SnxAgCu and SnAgCuX solder ball in combination with electrolytic NiAu-plated substrates was investigated during 150degC thermal aging, such as single layer SnNi IMC and complex layer SnNi/SnNiCu IMC in the interface through top and X-section view, respectively. In addition, the intensity of plate-like Ag3Sn IMC formation in the SnxAgCu solder bulkfrom 1 to 4%Ag was observed by SEM as well. The CSP BGA package with above combination was assembled to PC boards with OSP finish using Sn3Ag0.5Cu solder paste under 245degC peak temperature reflow. The test vehicle assembled was subject to mechanical drop test following JESD22-B111 to evaluate the solder joint integrity after zero and 150degC/250 hrs thermal aging. The effect of interfacial IMC morphology evolution and Ag3Sn intensity in solder bulk by x (Ag percentage) and X (forth element addition) on the mechanical drop performance will be concluded. Furthermore, one approaching in IMC microstructure control to overcome SnAgCu drop concern will be presented.","PeriodicalId":325619,"journal":{"name":"2007 8th International Conference on Electronic Packaging Technology","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124155321","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}
Pub Date : 2007-08-01DOI: 10.1109/ICEPT.2007.4441403
J. Auersperg, M. Klein, B. Michel
Recent studies show also how the evaluation of mixed mode interface delamination phenomena, classical strength hypotheses along with fracture mechanics approaches and thermal fatigue estimation of solder joints can simultaneously be taken into account. Here such an integrated approach is coupled with optimization algorithms towards a thermo-mechanical reliable design. At the same time, the attention is also turned to reach robustness against scattering model parameters-scattering of geometry as well as of materials properties, in particular. The assumption that some variables of the model are stochastic parameters leads directly to the consequence that all results show also scattering characteristics. The paper explains the methodology and results towards a robust design, to emphasize the potential of the utilized approach. Exemplarily, an underfilled flip-chip assembly based on reflow soldering and a non-underfilled Flip-Chip assembly with thermo-compression bonded metal-metal interconnections on low-k will be examined with regard to their board level reliability and robustness.
{"title":"Optimization of Electronics Assemblies towards Robust Design under Fracture, Delamination and Fatigue Aspects","authors":"J. Auersperg, M. Klein, B. Michel","doi":"10.1109/ICEPT.2007.4441403","DOIUrl":"https://doi.org/10.1109/ICEPT.2007.4441403","url":null,"abstract":"Recent studies show also how the evaluation of mixed mode interface delamination phenomena, classical strength hypotheses along with fracture mechanics approaches and thermal fatigue estimation of solder joints can simultaneously be taken into account. Here such an integrated approach is coupled with optimization algorithms towards a thermo-mechanical reliable design. At the same time, the attention is also turned to reach robustness against scattering model parameters-scattering of geometry as well as of materials properties, in particular. The assumption that some variables of the model are stochastic parameters leads directly to the consequence that all results show also scattering characteristics. The paper explains the methodology and results towards a robust design, to emphasize the potential of the utilized approach. Exemplarily, an underfilled flip-chip assembly based on reflow soldering and a non-underfilled Flip-Chip assembly with thermo-compression bonded metal-metal interconnections on low-k will be examined with regard to their board level reliability and robustness.","PeriodicalId":325619,"journal":{"name":"2007 8th International Conference on Electronic Packaging Technology","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122449276","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}
Pub Date : 2007-08-01DOI: 10.1109/ICEPT.2007.4441462
Weicheng Lin
During reflow soldering of BGA. voids are very easily produced in the solder joints. Void formation in solder joints is one of the many critical factors governing the solder joint reliability. Voids may degrade the mechanical robustness of the board level interconnection and consequently affect the reliability, the electrical and thermal conducting performance of the solder joint. In order to avoid void formation in the solder joints during the reflow soldering of BGA. we must reduce oxidation of solder, the metallization of the substrate, component or the solder powder surface, decrease gas production during soldering, make gas degassing from molten solder easily. Vacuum reflow soldering technology can greatly satisfy the three requests. It has been proved that vacuum reflow solder technology is a valid technology for the void-free and lead-free soldering of BGA. not only can we use it to reflow solder BGA. But also to rework BGA with voids in solder joints.
{"title":"The Void-free Reflow Soldering of BGA with Vacuum","authors":"Weicheng Lin","doi":"10.1109/ICEPT.2007.4441462","DOIUrl":"https://doi.org/10.1109/ICEPT.2007.4441462","url":null,"abstract":"During reflow soldering of BGA. voids are very easily produced in the solder joints. Void formation in solder joints is one of the many critical factors governing the solder joint reliability. Voids may degrade the mechanical robustness of the board level interconnection and consequently affect the reliability, the electrical and thermal conducting performance of the solder joint. In order to avoid void formation in the solder joints during the reflow soldering of BGA. we must reduce oxidation of solder, the metallization of the substrate, component or the solder powder surface, decrease gas production during soldering, make gas degassing from molten solder easily. Vacuum reflow soldering technology can greatly satisfy the three requests. It has been proved that vacuum reflow solder technology is a valid technology for the void-free and lead-free soldering of BGA. not only can we use it to reflow solder BGA. But also to rework BGA with voids in solder joints.","PeriodicalId":325619,"journal":{"name":"2007 8th International Conference on Electronic Packaging Technology","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122112412","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}
Pub Date : 2007-08-01DOI: 10.1109/ICEPT.2007.4441447
F. Yen, E. Chen, J. Lai, Yu Po Wang
The electronic package warpage is induced by the mismatch of coefficient of thermal expansion (CTE) between different materials that compose the package after specific temperature change process. To well control package warpage after assembly process is an important assignment for packaging engineer because those packages with excessive warpage will be rejected by customers due to board SMT process yield/quality concerns. The primary failure mechanism coming from excessive package warpage during SMT assembly process is ball shorting or opening to cause electrical connectivity failure, thus, package designers are being driven to improve package warpage during SMT temperature variation to ensure a robust board assembly performance at the earlier stage of package design development. From this study, we have studied for improvement of warpage performance of BGA. The PBGA with the low CTE mold compound can reduce the CTE mismatch effects on substrate, but there is no obvious evidence to show the thickness of mold compound and substrate effect on warpage. In addition, PKG with heat spreader design can get better warpage performance. EDHS-PBGA has smaller package warpage variation, compared with the PBGA due to drop-in mold compound heat spreader, so the EDHS-PBGA deformation depended on heat spreader and was controlled by heat spreader to achieve the improvable warpage at room and peak temperature.
{"title":"The Improvement Guidelines of BGA Warpage within SMT Temperature Profile Using Shadow Moiré Technique","authors":"F. Yen, E. Chen, J. Lai, Yu Po Wang","doi":"10.1109/ICEPT.2007.4441447","DOIUrl":"https://doi.org/10.1109/ICEPT.2007.4441447","url":null,"abstract":"The electronic package warpage is induced by the mismatch of coefficient of thermal expansion (CTE) between different materials that compose the package after specific temperature change process. To well control package warpage after assembly process is an important assignment for packaging engineer because those packages with excessive warpage will be rejected by customers due to board SMT process yield/quality concerns. The primary failure mechanism coming from excessive package warpage during SMT assembly process is ball shorting or opening to cause electrical connectivity failure, thus, package designers are being driven to improve package warpage during SMT temperature variation to ensure a robust board assembly performance at the earlier stage of package design development. From this study, we have studied for improvement of warpage performance of BGA. The PBGA with the low CTE mold compound can reduce the CTE mismatch effects on substrate, but there is no obvious evidence to show the thickness of mold compound and substrate effect on warpage. In addition, PKG with heat spreader design can get better warpage performance. EDHS-PBGA has smaller package warpage variation, compared with the PBGA due to drop-in mold compound heat spreader, so the EDHS-PBGA deformation depended on heat spreader and was controlled by heat spreader to achieve the improvable warpage at room and peak temperature.","PeriodicalId":325619,"journal":{"name":"2007 8th International Conference on Electronic Packaging Technology","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116591170","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：