2021 IEEE 71st Electronic Components and Technology Conference (ECTC)最新文献

{"title":"Extreme High Aspect Ratio RDL Patterning with Low Temperature Curable Polyimide using Double Patterning Technology","authors":"Atsushi Nakamura, T. Koizumi, Naoki Sato, Toshihide Aoshima, Michihiro Ogawa, Daisuke Asakawa, Yuki Sakamoto, H. Noguchi","doi":"10.1109/ECTC32696.2021.00254","DOIUrl":"https://doi.org/10.1109/ECTC32696.2021.00254","url":null,"abstract":"In this paper, extreme high aspect ratio RDL patterning technologies using double patterning technology and low temperature curable polyimide is demonstrated. The extreme high aspect ratio patterning is realized by combination of 1st and 2nd patterning before curing, and was used to successfully form both trench and via patterns, as well as combination of via and trench. The aspect ratio was measured by cross-sectional observation of the resulting pattern using an electron microscope, and was found to be over 8 after curing. Finally, a PI film was formed using the double patterning technology, and a single curing step was applied to obtain a permanent film, with reliability evaluation performed using biased HAST and HTS test. Furthermore, the elongation at break and modulus were measured through stress-strain curve. The results of biased HAST and HTS, as well as mechanical property measurements, are promising. The PI permanent film formed by double patterning and obtained by single curing is homogenized, passes the reliability evaluation, and can be applied to actual devices.","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116335522","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":"Extraordinarily enhanced sintering performance of pressureless sinterable Cu nanoparticle paste for achieving robust die-attach bonding by using reducing hybrid solvent","authors":"Hai-Jun Huang, Min-bo Zhou, Xin-Ping Zhang","doi":"10.1109/ECTC32696.2021.00104","DOIUrl":"https://doi.org/10.1109/ECTC32696.2021.00104","url":null,"abstract":"Hybrid solvents with reducing property, composed of diethylene glycol (DEG) and glycerol (G), are developed for use as carrier solvent of the Cu nanoparticle paste, which has been employed successfully to achieve die-attach bonding through a pressureless low-temperature sintering process, with sintered joints having shear strength of 72 MPa, the highest reported thus far. The amount of residual solvent in high temperature range (150–250 °C) determined by boiling point of carrier solvents is directly related to the ratio of unbonded areas in the sintered Cu paste matrix. Solvents with the reducing property, which is crucial to decomposition of Cu lactate during sintering process, are indispensable for forming highly dense Cu bulks as the reinforcing phase in the sintered matrix. Finite element simulations of the influence of unbonded areas (defects) in the sintered Cu paste matrix on thermal cycling performance of the joints show that equivalent total strain increases with unbonded area, but shear stress behaves in the opposite way. For sintered joints using DEG+G formulated Cu paste, the dwell time of high temperature storage (HTS) at 250°C has limited effect on joints' strength. The Cu NP paste stored in the fridge at −5°C and −40°C for 6 months still retains the capability of pressureless low-temperature sintering, which meets the requirement of the industry application, concerning with transportation, storage and handling of Cu paste.","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125442887","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 of the adhesion of a sintered Ag joint on a Cu substrate using laser shocks. Influence of aging","authors":"X. Milhet, T. de Rességuier, L. Signor, Etienne Barraud, Kokouvi Happy N'Tsouaglo, Hadi Bahsoum, J. Baillargeat","doi":"10.1109/ECTC32696.2021.00106","DOIUrl":"https://doi.org/10.1109/ECTC32696.2021.00106","url":null,"abstract":"Silver pastes sintering is a potential candidate for die bonding in power electronic modules which are built by stacking up layers of various materials having different coefficients of thermal expansion. Consequently, in operating conditions, thermal stresses (tensile or compressive) develop at the interfaces between the layers. Moreover, during aging, the initial interface is expected to evolve, mostly due to diffusion of atomic species between adjacent layers. In this study, original laser-shock experiments, involving tensile stresses near the interface, are performed to investigate the influence of aging on the adhesive strength of sintered silver joints onto copper.","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127951165","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":"Co-Design of Chip-Package-Antenna in Fan-out Package for Practical 77 GHz Automotive Radar","authors":"Chuanming Zhu, Yinglu Wan, Zongming Duan, Yuefei Dai","doi":"10.1109/ECTC32696.2021.00191","DOIUrl":"https://doi.org/10.1109/ECTC32696.2021.00191","url":null,"abstract":"This paper presents a co-design of chip-package-antenna in fan-out package for automotive radar. Many packaged chips are directly soldered onto the feeding network of planar antenna array. However, the interconnections and associated radiation interferences are seldom considered. Thus co-design of chip-package-antenna is necessary since the radiation pattern is seriously affected by the packaged chip and feeding network, especially at millimetre-wave frequency. In this work, the used antenna is a planar 12-element series-fed linear antenna array. Based on Dolph-Chebyshev magnitude distribution, the desired radiation pattern is firstly synthesized by tapering each patch width. Then the transition of chip-package-board is proposed and realized by properly designing redistribution layer (RDL) in fan-out package and the GCPW line on PCB. After chip is flip-chipped onto antenna, the side lobe level (SLL) of the whole chip-package-antenna gets worse. By redesigning the width and distances of between elements, the SLL can be improved. The results show that the proposed method of chip-package-antenna paves the way to practical automotive radar application.","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132352528","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":"Two-step fabrication process for die-to-die and die-to-wafer Cu-Cu bonds","authors":"J. Ong, K. Shie, K. Tu, Chih Chen","doi":"10.1109/ECTC32696.2021.00043","DOIUrl":"https://doi.org/10.1109/ECTC32696.2021.00043","url":null,"abstract":"The scale of joints shrinks continuously due to super small and extremely fast computing devices consent to Moore's Law. Copper-to-copper direct bonding appears to be one of a solution to the limitation of scaling down into sub-micron scale. Moreover, bonding quality such as mechanical strength and electrical properties in copper bonding becoming an important topic. In this study, we examine the relationship of the bonding time and temperature on the bonding strength and bump resistance in Cu-Cu bonds with highly <111> oriented nanotwinned copper. In addition, the Cu-Cu joints were subjected to a post annealing process at the bonding strength after the second step annealing at 300 °C under 47MPa for 1 hour in vacuum ambient. The bonding strength increases 3–4 folds after the post annealing. Some of the open Cu-Cu joints became connected after the post-annealing process.","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127577899","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":"The Study of Packaging Substrate Effect in FCBGA by Laser Assisted Bonding","authors":"Yu Lung Huang, Joe Huang, C. M. Huang, K. Yu, Tank Luo, W. Hong, Taishin Ren","doi":"10.1109/ECTC32696.2021.00110","DOIUrl":"https://doi.org/10.1109/ECTC32696.2021.00110","url":null,"abstract":"In order to support the high growth of Artificial Intelligence, Internet of Things, Industrial IOT, Cloud Service and 5G, the IC (Server/Router/Switch) needs higher/faster performance to collect, store, commute and transmit a mass of data. Therefore, the I/O (input/output) density of IC will increase with the silicon nodes < 5 nm, fine pitch $mutext{bump}$, and fine line width/space substrate. However, the solder reflow of IC faces two problems of the chip damages (silicon nodes: current leakage, highly electromigration; ELK (extremely low-k): current leakage, crack) and solder high stress (solder: wicking, IMC (intermetallic compound)) due to highly thermal budget of MR (mass reflow). In this paper, LAB (laser assisted bonding) will replace MR (mass reflow) to solve these problems. In this study, a test vehicle with the size of $55^{ast}55 text{mm}2$ FCBGA (flip chip ball grid array) was built. Two types (A and B) of substrate were applied to the FCBGA, with the differences between the solder mask (thickness, surface brightness/roughness) and substrate mass. LAB uses a semiconductor laser with wavelength of 980 nm, and the area of laser beam is 91.5% of the substrate area. The study is divided into three parts. For the first part, the surface temperature of die without substrate is higher than that of die with substrate at the same parameters about 187.2 °C. The result shows that the substrate has the function of heat storage. In addition, for the surface temperature of die with substrate, the result shows that all solders melt at 2.82 sec, and the surface temperature of the center of die is 22.8 °C lower than the four corners of it. Then the delta temperature between the surface temperature of the center of die and bump is 48.3 °C. The result shows that the overall temperature of die with substrate is not uniform. Next, for substrate effect, the surface temperature of die and B substrate is lower than that of die and A substrate based on the following reasons: for the solder mask, (a) the surface brightness of B substrate is 11% higher than that of A substrate result in an increase of the reflected light; (b) the roughness of B substrate is 26% lower than that of A substrate result in an increase of the reflected light; (c) the thickness of B substrate is 23% lower than that of A Substrate result in a reduction of Absorbed light; for substrate mass (d) the weight of B substrate is 10% higher than that of A substrate. Finally, the assembled FCBGA packages by LAB passed reliability tests: MSL4 pre-conditioning with uHAST 168 hours, TCT B 1000 thermal cycles and HTST 1000 hours. Details of the results are presented and discussed in the paper. In summary, we have developed the parameter set to solve it in different substrates and predicted the melting time of solder and temperature profile of die surface. Therefore, LAB (laser assisted bonding) can successfully solve the problems MR encounters. The full descriptions of the development results will ","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128922603","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":"FOWLP-Based Flexible Hybrid Electronics with 3D-IC Chiplets for Smart Skin Display","authors":"Y. Susumago, T. Odashima, M. Ichikawa, Hiroki Hanaoka, H. Kino, Tetsu Tanaka, T. Fukushima","doi":"10.1109/ECTC32696.2021.00017","DOIUrl":"https://doi.org/10.1109/ECTC32696.2021.00017","url":null,"abstract":"This paper deals with a flexible 3D-IC system fabrication methodology. Mini-LEDs and 3D-IC chiplets divided from a large 3D-IC with Cu-TSVs are embedded in an elastomer PDMS based on die-first FOWLP for heterogeneously integrating them into Smart Skin Display as a biomedical/wearable FHE (flexible hybrid electronics). We address a serious die-shift issue for the tiny chips in die-first FOWLP by using a new anchoring layer technique to drastically reduce the shift within $2.7 mumathrm{m}$ including assembly positioning errors. The mechanical/electrical properties of the flexible array of 3D-IC chiplets are characterized before and after repeated bending with a curvature radius of 10 mm. In addition, stress neutral axes are designed to stably endure bending cycle applicable to the biomedical/wearable FHE with multi-level metallization.","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124402014","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":"High-frequency electrical circuit model for integrated capacitors utilizing lossy nanostructures","authors":"S. Krause, R. Andersson, M. Bylund, V. Marknäs, A. Saleem, Elisa Passalaqua, Shafiq Kabir, V. Desmaris","doi":"10.1109/ECTC32696.2021.00197","DOIUrl":"https://doi.org/10.1109/ECTC32696.2021.00197","url":null,"abstract":"A physics-based model is presented that captures the electrical high-frequency behavior of low-dimensional nanostructures used in emerging technologies such as the ultra-high-density capacitor. Derived from transmission line theory the analytical expression provides a frequency-dependent admittance of a lossy nanostructure, which can be numerically integrated over arbitrary areas comprising the nanostructure. Edge effects, a distributed nature of resistivity or dimensions of the nanostructure comprising the device can be taken into consideration and make it a powerful tool for designing future integrated circuits. The model predictions show an excellent match with hardware measurements up to 3 GHz on state-of-the-art carbon nanofiber based MIM-capacitors with capacitance densities up to 500 nF/mm2 at $mathrm{6} mu mathrm{m}$ device height.","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114787531","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":"Impact of warpage on signal delivery with large size FC-PBGA package","authors":"Heeseok Lee, Jisoo Hwang, Henry H. Kwon, Junso Pak","doi":"10.1109/ECTC32696.2021.00274","DOIUrl":"https://doi.org/10.1109/ECTC32696.2021.00274","url":null,"abstract":"The impact of non-zero warpage on signal delivery characteristics is presented by analyzing transmission line on curved plane defined in cylindrical coordinate system. Authors will present a compact finite-difference frequency-domain method for quasi-TEM mode (C-FDFD-QT) with cylindrical coordinate system, which is a promising method to determine the characteristic impedance with efficiently reduced size of computational matrix by using quasi-TEM approximation. In summary, the non-zero warpage of large-size substrate constructing large size FC-BGA results in the increase of characteristic impedance, which has been quantitatively studied by using C-FDTD-QT. The characteristic impedance of stripline on curved plane is larger than that of stripline on the plane whose warpage is zero.","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114376221","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":"Thermal and electrical reliability analysis of TO-247 for bonding method, substrate structure and heat dissipation bonding material","authors":"Dong-hwan Kim, Aesun Oh, Eunyoung Park, Kyung-Hyun Kim, Sung-Jae Jeon, Hyun-Cheol Bae","doi":"10.1109/ECTC32696.2021.00308","DOIUrl":"https://doi.org/10.1109/ECTC32696.2021.00308","url":null,"abstract":"In this study, a 1700V/58A SiC MOSFET was used as the TO-247 module instead of the existing Si TO-247 module to analyze the thermal and electrical characteristics of a high-power module. The TO-247 module was manufactured to measure the electrical characteristics under thermal cycle testing (−40 to 125°C). The substrates used in the fabrication were standard TO-247 substrates, AlN DBC with high thermal conductivity, and Si3N4 AMB with high mechanical properties. The PbSn preform of the conventional solder base and a highly reliable Ag sintering paste were used as the bonding materials. For interconnection, wire bonding, which is most used in modules, and Cu clips attached using heterogeneous bonding materials were used in the TO-247 module. A total of 100 cycles were carried out, and Trr and RDS(on) were measured every 50 cycles to assess the electrical characteristics. The thermal analysis of the maximum temperature difference between the substrates, bonding materials, and interconnections was performed by adding a Cu clip bonding. The electrical properties were measured during the thermal cycling. all samples performed better than the 1700V/58A SiC MOSFET datasheet and operated normally after 100 cycles. Additionally, the maximum temperature difference between the Al wire and Cu clip bonding was not significant in the standard TO-247 module. However, using Cu clip bonding is more effective in reducing temperature when high heat is generated using substrates with low thermal conductivity.","PeriodicalId":351817,"journal":{"name":"2021 IEEE 71st Electronic Components and Technology Conference (ECTC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123554079","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}