Pub Date : 2022-05-11DOI: 10.23919/ICEP55381.2022.9795481
S. Kishida, Y. Takada, Z. Yinan, J. Song, K. Yasuda
The high thermal dissipation is one of the most urgent issues for the diverse utilization of advanced power electronic devices (SiC, GaN, GaO). Adoption of sub¬micrometer sized copper particles as die bonding materials could be a solution in terms of its high performance and material cost. In this study we investigated the copper-copper ultrasonic bonding using by porous pre-sintered copper layer with relatively low-power blue laser to apply as the bonding method. The results showed that rapid copper-copper bonding could be achieved by ultrasonic bonding with the homogenous layer by plastic deformation of porous sintered layer.
{"title":"Copper-Copper Ultrasonic Bonding by Using Blue Laser-Sintered Copper Nanoparticles","authors":"S. Kishida, Y. Takada, Z. Yinan, J. Song, K. Yasuda","doi":"10.23919/ICEP55381.2022.9795481","DOIUrl":"https://doi.org/10.23919/ICEP55381.2022.9795481","url":null,"abstract":"The high thermal dissipation is one of the most urgent issues for the diverse utilization of advanced power electronic devices (SiC, GaN, GaO). Adoption of sub¬micrometer sized copper particles as die bonding materials could be a solution in terms of its high performance and material cost. In this study we investigated the copper-copper ultrasonic bonding using by porous pre-sintered copper layer with relatively low-power blue laser to apply as the bonding method. The results showed that rapid copper-copper bonding could be achieved by ultrasonic bonding with the homogenous layer by plastic deformation of porous sintered layer.","PeriodicalId":413776,"journal":{"name":"2022 International Conference on Electronics Packaging (ICEP)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122079344","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 : 2022-05-11DOI: 10.23919/ICEP55381.2022.9795610
K. Nogita, J. Read, S. McDonald, Dong Xu, T. Nishimura
To make electronic packaging with minimal defects, during the wave soldering process, the fluidity of the solder alloy is an important parameter. In this research we measured the maximum fluidity length of 16 commercially available solders. We found alloy compositions including Ni have higher fluidity lengths (similar to eutectic Sn-37Pb solders) when compared to other Pb-free solder alloys. The effects of Ni and Co on the maximum fluidity length in Sn-0.7Cu alloys is discussed with respect to the solidification process and microstructures. The optimum concentrations of Ni and Co in Sn-0.7Cu alloys to achieve highest maximum fluidity length was investigated.
{"title":"Maximum Fluidity Length of Commercial Solder Alloys and the Effects of Ni and Co in Sn-0.7wt%Cu Solder Alloys","authors":"K. Nogita, J. Read, S. McDonald, Dong Xu, T. Nishimura","doi":"10.23919/ICEP55381.2022.9795610","DOIUrl":"https://doi.org/10.23919/ICEP55381.2022.9795610","url":null,"abstract":"To make electronic packaging with minimal defects, during the wave soldering process, the fluidity of the solder alloy is an important parameter. In this research we measured the maximum fluidity length of 16 commercially available solders. We found alloy compositions including Ni have higher fluidity lengths (similar to eutectic Sn-37Pb solders) when compared to other Pb-free solder alloys. The effects of Ni and Co on the maximum fluidity length in Sn-0.7Cu alloys is discussed with respect to the solidification process and microstructures. The optimum concentrations of Ni and Co in Sn-0.7Cu alloys to achieve highest maximum fluidity length was investigated.","PeriodicalId":413776,"journal":{"name":"2022 International Conference on Electronics Packaging (ICEP)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125792395","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 : 2022-05-11DOI: 10.23919/ICEP55381.2022.9795485
A. Schulz, K. Blau, J. Müller
A LTCC patch antenna array was designed and fabricated in Low Temperature Co-fired Ceramic (LTCC) multilayer technology using picosecond laser structuring for precise manufacturing of embedded air cavities and feeding structures, which are beneficial for the antenna RF performance. Moreover, free-standing feeding vias in the embedded air cavities were successfully implemented in LTCC technology that enable a very simple and low-loss feed at the antenna ports. The 2x2 dual-polarized patch antenna array with embedded air cavities and transitions was first characterized by reflection measurements. The measured center frequency of the antenna is about 29.5 GHz and a bandwidth of nearly 1 GHz was achieved.
{"title":"LTCC patch antenna array for 5G mobile applications featuring embedded air cavities","authors":"A. Schulz, K. Blau, J. Müller","doi":"10.23919/ICEP55381.2022.9795485","DOIUrl":"https://doi.org/10.23919/ICEP55381.2022.9795485","url":null,"abstract":"A LTCC patch antenna array was designed and fabricated in Low Temperature Co-fired Ceramic (LTCC) multilayer technology using picosecond laser structuring for precise manufacturing of embedded air cavities and feeding structures, which are beneficial for the antenna RF performance. Moreover, free-standing feeding vias in the embedded air cavities were successfully implemented in LTCC technology that enable a very simple and low-loss feed at the antenna ports. The 2x2 dual-polarized patch antenna array with embedded air cavities and transitions was first characterized by reflection measurements. The measured center frequency of the antenna is about 29.5 GHz and a bandwidth of nearly 1 GHz was achieved.","PeriodicalId":413776,"journal":{"name":"2022 International Conference on Electronics Packaging (ICEP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125818425","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 : 2022-05-11DOI: 10.23919/ICEP55381.2022.9795371
Chuantong Chen, Zheng Zhang, Yang Liu, K. Suganuma
In this study, Ag flake particles paste sinter joining on a bare DBA (Al/AlN/Al) substrate at temperature of 250 °C without pressure was achieved with a robust shear strength of 33.6 MPa in a SiC power module. The microstructure of sintered Ag and the bonded interface of Ag/Al indicated that the excellent sinter ability of the Ag paste. The Ag nanoparticles were in-situ-formed from the Ag flake particles, which tight bonding to the Al surface. High-temperature reliability of the SiC-DBA joint structure were investigated by high-temperature aging at 250 °C, and thermal shock test from -50 to 250 °C. The shear strength still larger than 30 MPa after 1000 h aging. Large deformation of Al layer occurred after thermal shock test, leading to the interface cracks generation and shear strength decrease.
{"title":"Micro-flake Ag paste sinter joining on bare DBA substrate for high temperature SiC power modules","authors":"Chuantong Chen, Zheng Zhang, Yang Liu, K. Suganuma","doi":"10.23919/ICEP55381.2022.9795371","DOIUrl":"https://doi.org/10.23919/ICEP55381.2022.9795371","url":null,"abstract":"In this study, Ag flake particles paste sinter joining on a bare DBA (Al/AlN/Al) substrate at temperature of 250 °C without pressure was achieved with a robust shear strength of 33.6 MPa in a SiC power module. The microstructure of sintered Ag and the bonded interface of Ag/Al indicated that the excellent sinter ability of the Ag paste. The Ag nanoparticles were in-situ-formed from the Ag flake particles, which tight bonding to the Al surface. High-temperature reliability of the SiC-DBA joint structure were investigated by high-temperature aging at 250 °C, and thermal shock test from -50 to 250 °C. The shear strength still larger than 30 MPa after 1000 h aging. Large deformation of Al layer occurred after thermal shock test, leading to the interface cracks generation and shear strength decrease.","PeriodicalId":413776,"journal":{"name":"2022 International Conference on Electronics Packaging (ICEP)","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129512648","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 : 2022-05-11DOI: 10.23919/ICEP55381.2022.9795483
Junsha Wang, K. Takeuchi, I. Kataoka, T. Suga
Gas cluster ion beam (GCIB) was employed to polish CVD diamond substrates for the direct bonding to power devices. After the coarse and fine polishing, the surface roughness Ra of diamond was reduced from 334 nm to 0.5 nm. The polished diamond substrate was successfully bonded to GaN at room temperature by surface activated bonding (SAB) method with a Si nano-layer.
{"title":"Polishing Diamond Substrates using Gas Cluster Ion Beam (GCIB) Irradiation for the Direct Bonding to Power Devices","authors":"Junsha Wang, K. Takeuchi, I. Kataoka, T. Suga","doi":"10.23919/ICEP55381.2022.9795483","DOIUrl":"https://doi.org/10.23919/ICEP55381.2022.9795483","url":null,"abstract":"Gas cluster ion beam (GCIB) was employed to polish CVD diamond substrates for the direct bonding to power devices. After the coarse and fine polishing, the surface roughness Ra of diamond was reduced from 334 nm to 0.5 nm. The polished diamond substrate was successfully bonded to GaN at room temperature by surface activated bonding (SAB) method with a Si nano-layer.","PeriodicalId":413776,"journal":{"name":"2022 International Conference on Electronics Packaging (ICEP)","volume":"123 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128215515","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 : 2022-05-11DOI: 10.23919/ICEP55381.2022.9795419
T. Hisada, S. Kohara, Chinami Marushima, T. Aoki
Increasing thermomechanical stress in complex and large flip-chip packages is a critical issue in maintaining mechanical integrity and reliability of the packages. Effects of varying mechanical properties of joining materials and organic substrate on stress mitigation in low-k dielectric layer under Cu pillar bump were studied using thermomechanical analysis. Lowering coefficient of thermal expansion (CTE) of organic substrate and lowering melting temperature of solder contribute to significant stress reduction. The effect of Cu pillar’s elastic modulus becomes relevant when its value is greatly reduced.
{"title":"Thermomechanical Analysis on Stress Mitigation of FCPBGA with Low Melting Temperature Solder and Low Elastic Modulus Cu Pillar","authors":"T. Hisada, S. Kohara, Chinami Marushima, T. Aoki","doi":"10.23919/ICEP55381.2022.9795419","DOIUrl":"https://doi.org/10.23919/ICEP55381.2022.9795419","url":null,"abstract":"Increasing thermomechanical stress in complex and large flip-chip packages is a critical issue in maintaining mechanical integrity and reliability of the packages. Effects of varying mechanical properties of joining materials and organic substrate on stress mitigation in low-k dielectric layer under Cu pillar bump were studied using thermomechanical analysis. Lowering coefficient of thermal expansion (CTE) of organic substrate and lowering melting temperature of solder contribute to significant stress reduction. The effect of Cu pillar’s elastic modulus becomes relevant when its value is greatly reduced.","PeriodicalId":413776,"journal":{"name":"2022 International Conference on Electronics Packaging (ICEP)","volume":"1055 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127841148","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 : 2022-05-11DOI: 10.23919/ICEP55381.2022.9795424
K. Fujimi, T. Hatakeyama, S. Nakagawa, R. Kibushi, M. Ishizuka
Thermal contact resistance (TCR) is an important parameter in the thermal management of electronics. However, the accuracy of the TCR prediction should be improved because the method for calculating the contact ratio between solids at low pressures has not yet been established. Therefore, we focus on the use of electric contact resistance (ECR) to calculate the contact ratio. In this study, the measured TCR are compared with the TCR calculated from the conventional prediction equation with the contact ratio from the measured ECR.
{"title":"Study on the Method for Predicting Surface Contact Ratio Using ECR","authors":"K. Fujimi, T. Hatakeyama, S. Nakagawa, R. Kibushi, M. Ishizuka","doi":"10.23919/ICEP55381.2022.9795424","DOIUrl":"https://doi.org/10.23919/ICEP55381.2022.9795424","url":null,"abstract":"Thermal contact resistance (TCR) is an important parameter in the thermal management of electronics. However, the accuracy of the TCR prediction should be improved because the method for calculating the contact ratio between solids at low pressures has not yet been established. Therefore, we focus on the use of electric contact resistance (ECR) to calculate the contact ratio. In this study, the measured TCR are compared with the TCR calculated from the conventional prediction equation with the contact ratio from the measured ECR.","PeriodicalId":413776,"journal":{"name":"2022 International Conference on Electronics Packaging (ICEP)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128816862","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 : 2022-05-11DOI: 10.23919/ICEP55381.2022.9795576
C. Arvin, S. Lim, David Locker, W. K. Loh, K. Sweatman, Francis Lee, M. Tsuriya
This paper reviews the materials and processes of 1st level interconnects and seeks to understand how utilization of low temperature materials can enable the future needs of 1st level packages. An industry survey was administered to understand the key drivers that necessitate the use of low temperature materials. These were incorporation of thermal sensitive components, utilization of advanced substrate materials, warpage control of thinned substrates / components and energy reduction. There were three approaches mentioned to incorporate these low temperature materials: 1) replace the interconnect materials completely with low temperature materials, 2) use traditional solders for attachment of certain items followed by second attachment steps using low temperature materials for thermal sensitive elements and 3) attach a component or die that has traditional SAC solder on it but has low temperature materials on the substrate side. Low melting point tin-bismuth alloys that have been introduced to board level assembly were highlighted as potential candidates for these 1st level interconnects. It had yet to be confirmed that properties of these alloys were consistent with the requirements of 1st level interconnects such as fine pitch connections near the processor. Concerns included alpha emissions, microstructural stability, susceptibility to electromigration, whisker growth, and possibility of polymorphic transformation of tin phase at cryogenic temperatures to which some processors might be exposed. For high frequency circuitry the inductance and capacitance properties of the interconnect materials also needed to be understood. Consideration was given to whether the low melting point indium alloys that have found application in the attachment of IR Focal Plane Arrays could be used for other devices. Where the properties of low melting point alloys might not be sufficient to cope with possible service conditions, post joining processes were discussed to convert the low melting point materials to a higher melting point final joint that were comprised substantially of intermetallic compounds.
{"title":"Low temperature interconnects in 1st level packaging and its challenges","authors":"C. Arvin, S. Lim, David Locker, W. K. Loh, K. Sweatman, Francis Lee, M. Tsuriya","doi":"10.23919/ICEP55381.2022.9795576","DOIUrl":"https://doi.org/10.23919/ICEP55381.2022.9795576","url":null,"abstract":"This paper reviews the materials and processes of 1st level interconnects and seeks to understand how utilization of low temperature materials can enable the future needs of 1st level packages. An industry survey was administered to understand the key drivers that necessitate the use of low temperature materials. These were incorporation of thermal sensitive components, utilization of advanced substrate materials, warpage control of thinned substrates / components and energy reduction. There were three approaches mentioned to incorporate these low temperature materials: 1) replace the interconnect materials completely with low temperature materials, 2) use traditional solders for attachment of certain items followed by second attachment steps using low temperature materials for thermal sensitive elements and 3) attach a component or die that has traditional SAC solder on it but has low temperature materials on the substrate side. Low melting point tin-bismuth alloys that have been introduced to board level assembly were highlighted as potential candidates for these 1st level interconnects. It had yet to be confirmed that properties of these alloys were consistent with the requirements of 1st level interconnects such as fine pitch connections near the processor. Concerns included alpha emissions, microstructural stability, susceptibility to electromigration, whisker growth, and possibility of polymorphic transformation of tin phase at cryogenic temperatures to which some processors might be exposed. For high frequency circuitry the inductance and capacitance properties of the interconnect materials also needed to be understood. Consideration was given to whether the low melting point indium alloys that have found application in the attachment of IR Focal Plane Arrays could be used for other devices. Where the properties of low melting point alloys might not be sufficient to cope with possible service conditions, post joining processes were discussed to convert the low melting point materials to a higher melting point final joint that were comprised substantially of intermetallic compounds.","PeriodicalId":413776,"journal":{"name":"2022 International Conference on Electronics Packaging (ICEP)","volume":"378 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114090128","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 : 2022-05-11DOI: 10.23919/ICEP55381.2022.9795550
K. Onishi, T. Iwata, Hitoshi Habuka, F. Nagano, F. Inoue
Low-temperature deposited PE-CVD SiCN has been comprehensively investigated towards the dielectric layer of Die-to-Wafer hybrid bonding. The PECVD SiCN was deposited at room temperature. The characterization of the deposited film and the impact of the plasma activation on the surface has been analyzed.
{"title":"Low-Temperature Chemical Vapor Deposition of SiCN for Hybrid Bonding","authors":"K. Onishi, T. Iwata, Hitoshi Habuka, F. Nagano, F. Inoue","doi":"10.23919/ICEP55381.2022.9795550","DOIUrl":"https://doi.org/10.23919/ICEP55381.2022.9795550","url":null,"abstract":"Low-temperature deposited PE-CVD SiCN has been comprehensively investigated towards the dielectric layer of Die-to-Wafer hybrid bonding. The PECVD SiCN was deposited at room temperature. The characterization of the deposited film and the impact of the plasma activation on the surface has been analyzed.","PeriodicalId":413776,"journal":{"name":"2022 International Conference on Electronics Packaging (ICEP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114202285","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 : 2022-05-11DOI: 10.23919/ICEP55381.2022.9795519
Wei Cheng, Cing-Wun Jheng, Ming-Tsang Lee, Jenn-Ming Song
In this study, cuprous oxide composite pastes were screen-printed on the plasma-modified polyimide substrates to form highly conductive copper films by means of laser sintering. The average resistivity of reduced and sintered copper films can be down to 4 μΩ-cm (theoretical resistivity of copper is 1.8 μΩ-cm). Cyclic bending test of the copper films on PI substrates (Rnom: 2.91 mm, and bending frequency: 1 Hz) were carried out to evaluate the fatigue reliability, and the variation of the electrical resistivity with the bending cycle number was also recorded. Experimental results show that O2 plasma caused a greater surface energy (especially polar component), higher surface roughness, and thereby exhibit superior bending fatigue resistance.
{"title":"Bending Fatigue of Laser-sintered Copper Films on Plasma Bombarded PI Substrate","authors":"Wei Cheng, Cing-Wun Jheng, Ming-Tsang Lee, Jenn-Ming Song","doi":"10.23919/ICEP55381.2022.9795519","DOIUrl":"https://doi.org/10.23919/ICEP55381.2022.9795519","url":null,"abstract":"In this study, cuprous oxide composite pastes were screen-printed on the plasma-modified polyimide substrates to form highly conductive copper films by means of laser sintering. The average resistivity of reduced and sintered copper films can be down to 4 μΩ-cm (theoretical resistivity of copper is 1.8 μΩ-cm). Cyclic bending test of the copper films on PI substrates (Rnom: 2.91 mm, and bending frequency: 1 Hz) were carried out to evaluate the fatigue reliability, and the variation of the electrical resistivity with the bending cycle number was also recorded. Experimental results show that O2 plasma caused a greater surface energy (especially polar component), higher surface roughness, and thereby exhibit superior bending fatigue resistance.","PeriodicalId":413776,"journal":{"name":"2022 International Conference on Electronics Packaging (ICEP)","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121338303","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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