Md Kabir - Academia.edu (original) (raw)
Papers by Md Kabir
Proceedings of the 2021 on Great Lakes Symposium on VLSI
With the popularity of 2.5D integration, an increasing number of chiplets are integrated into adv... more With the popularity of 2.5D integration, an increasing number of chiplets are integrated into advanced system-in-package designs. In such systems, redistribution layer (RDL) wires become longer and denser, with a growing impact on system performance. However, RDL inductive impacts in timing analysis are ignored by the traditional CAD tools. This paper presents our chiplet-package cooptimization flow, which can capture the RDL inductance impact on system performance and automatically adjust the IO drivers to compensate for the inductance overhead. We develop our extraction and timing analysis tool that models RDL wire inductive timing impact on 2.5D system performance within +/-1% error. Our study shows 35% signal paths through RDL violate the timing requirement because of the inductive impact, and remain undetected through only RC-based STA. CCS Concepts • Hardware → Physical design (EDA); Multi-chip modules; Modeling and parameter extraction; Package-level interconnect.
Journal of Nanoscience and Nanotechnology, 2020
A novel blend of membranes made of Nafion® and poly(vinylpyrrolidone) (PVP) was prepared and char... more A novel blend of membranes made of Nafion® and poly(vinylpyrrolidone) (PVP) was prepared and characterized to investigate its applicability in proton exchange membrane fuel cells (PEMFCs). In addition to being effectively proton conductive, the membranes exhibited better mechanical strength, chemical stability, and adequate water retention ability, as well as ion exchange capacity comparable to that of cast Nafion® membrane. The data obtained from an electrochemical impedance spectroscopy (EIS) fitting of the fuel cells revealed the membrane electrode assemblies (MEAs) made of 0.5 wt.% PVP/Nafion® had lower ohmic and charge transfer resistance compared with that of the Nafion® membrane. The intermolecular interactions and morphology of these membranes were assessed using Fourier-transform infrared spectroscopy and field-emission scanning electron microscopy. The results of the performance curve indicate that the introduction of PVP as a modifier played a vital role in improving memb...
2021 International Symposium on VLSI Design, Automation and Test (VLSI-DAT), 2021
In recent days, 2.5D package designs have gained popularity with an increasing number of heteroge... more In recent days, 2.5D package designs have gained popularity with an increasing number of heterogeneous chiplets integrated into advanced system-in-packages. RDL wires become longer and denser, presenting a growing impact on system performance, reliability, and integrity. At present, there exists no standard CAD flow that can design, analyze, and optimize a complete heterogeneous 2.5D system. The traditional die-by-die design approach processes each component independently during extraction and optimization and cannot be applied to heterogeneous systems without fundamental changes in standard CAD tools. Not only the chiplet-package extraction is inaccurate between the die-package interface ignoring all RDL capacitive and inductive impacts, but traditional CAD tools are also unable to perform cross-boundary design optimization. We present a complete chiplet-package co-optimization flow for both homogeneous and heterogeneous 2.5D designs. It encompasses 2.5Daware partitioning, chiplet-package co-planning, holistic and in-context extraction, package inductance consideration, and iterative optimization, along with design analysis and verification of the entire 2.5D system. In our previous work [1] targeting heterogeneous systems, we achieved an extraction error ranging between-2.10% and 24.0%. The in-context design flow proposed in this work achieves less than 1% extraction error on ground and coupling capacitance. This extraction result can be used to perform timing analysis with 99.8% accuracy and to generate timing context with 99.4% accuracy for iterative optimization.
Proceedings of the 39th International Conference on Computer-Aided Design, 2020
In recent years, 2.5D chiplet package designs have gained popularity in system integration of het... more In recent years, 2.5D chiplet package designs have gained popularity in system integration of heterogeneous technologies. Currently, there exists no standard CAD flow that can design, analyze, and optimize a complete heterogeneous 2.5D system. The traditional die-by-die design approach does not consider any package layers during extraction and optimization, and an accurate chiplet-package extraction can not be applied to heterogeneous designs without fundamental changes in standard CAD tools. In this paper, we present our Holistic and In-Context chiplet-package co-design flows for high-performance high-density 2.5D systems using standard ASIC CAD tools with zero overhead on IO pipeline depth. Our flow encompasses 2.5D-aware partitioning, chiplet-package co-planning, in-context extraction, iterative optimization, and post-design analysis and verification of the entire 2.5D system. We design our package planner with a routing and pin-planning strategy to minimize package routing congestion and timing overhead. An ARM Cortex-M0-based microcontroller system is designed as the benchmark. The performance gap to the reference 2D design reduces by 62.5% when chip-package interactions are taken into account in the holistic flow. Our in-context extraction achieves only 0.71% and 0.79% error on ground and coupling capacitance on a homogeneous system. Further, we implement a heterogeneous 2.5D system to demonstrate our novel in-context design and optimization methodology.
2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC), 2020
Chiplet integration using 2.5D packaging is gaining popularity nowadays which enables several int... more Chiplet integration using 2.5D packaging is gaining popularity nowadays which enables several interesting features like heterogeneous integration and drop-in design method. In the traditional die-by-die approach of designing a 2.5D system, each chiplet is designed independently without any knowledge of the package RDLs. In this paper, we propose a Chip-Package Co-Design flow for implementing 2.5D systems using existing commercial chip design tools. Our flow encompasses 2.5D-aware partitioning suitable for SoC design, Chip-Package Floorplanning, and post-design analysis and verification of the entire 2.5D system. We also designed our own package planners to route RDL layers on top of chiplet layers. We use an ARM Cortex-M0 SoC system to illustrate our flow and compare analysis results with a monolithic 2D implementation of the same system. We also compare two different 2.5D implementations of the same SoC system following the drop-in approach. Alongside the traditional dieby-die approach, our holistic flow enables design efficiency and flexibility with accurate cross-boundary parasitic extraction and design verification.
2020 IEEE 33rd International System-on-Chip Conference (SOCC), 2020
Traditionally, different components of a system are integrated through Printed Circuit Boards (PC... more Traditionally, different components of a system are integrated through Printed Circuit Boards (PCB). The long traces on PCB have severe power loss and limit the bandwidth of the interconnects between the components. Advanced packaging offers high-bandwidth, low power, and high-performance inter-die communications with compact sizes and dense pin arrays. 2.5D integration further provides better thermal dissipation, lower cost, and higher yield compared to 3D stacking. Novel CAD tool flows dedicated to 2.5D chiplet designs are essential to enable flexible and efficient 2.5D system designs. In this paper, we present our design, optimization, and analysis methodologies and a design case study implementing an ARM Cortex-M0 microcontroller system using a holistic 2.5D tool flow. We use TSMC 65nm as our chiplet implementation technology with a modified metal stack referring to 2.5D Fan-Out Wafer-Level Packaging (FOWLP) solutions. We also discuss design techniques for chiplet reuse and the Drop-in design approach to develop low-power, low-cost, and high-performance flavors of a 2.5D system. We compare the 2.5D system with its 2D counterpart to validate the holistic design flow.
Journal of Nanoscience and Nanotechnology, 2019
A successful polymer electrolyte membrane for fuel cell application must have efficient proton co... more A successful polymer electrolyte membrane for fuel cell application must have efficient proton conductivity as well as good water retention capability. The viability of using composite membranes prepared by blending 85% deacetylated chitosan (CS) and Nafion ® in proton exchange membrane fuel cells (PEMFCs) was investigated based on the concept of hydrophilicity and the water uptake characteristics of CS. These membranes were characterized by infrared spectroscopy and field-emission scanning electron microscopy to investigate their intermolecular interactions and morphology, respectively. Absorption studies were carried out to evaluate the interactions of the membranes with water. Titrimetric ion exchange capacity analysis indicated the availability of active sites in the membrane. The CS/Nafion ® blend was found to be suitable for PEMFC applications because of its relatively high proton conductivity compared to that of regular Nafion ®. Above all, the cost-effectiveness and simple fabrication of such composite membranes make their use in lowtemperature PEMFCs very attractive and economical.
Journal of nanoscience and nanotechnology, 2018
To increase the water retention and proton-conducting ability of Nafion®, we prepared a cross-lin... more To increase the water retention and proton-conducting ability of Nafion®, we prepared a cross-linked polymer consisting of poly(2-hydroxyethyl methacrylate) (pHEMA) and Nafion®. pHEMA was chosen as a cross-linking polymer because it produces a water-insoluble but water-swellable polymer. Although it is hydrophobic, its water-swellable characteristic means that water will not be excluded from the polymer. Introduction of pHEMA into Nafion® prevents polymer solubility and provides structural stability and rigidity, which should in turn reduce the methanol permeability. Moreover, convenient permeability of pHEMA to cations makes it a good candidate for a hydrocarbon proton-conducting polymer tuned with Nafion®.
Journal of nanoscience and nanotechnology, 2018
A novel blend of membranes made of cast Nafion® and poly(vinyl acetate) (PVAc) was prepared and i... more A novel blend of membranes made of cast Nafion® and poly(vinyl acetate) (PVAc) was prepared and its proton conductivity and ion exchange capacity (IEC) were characterized to investigate its applicability in proton exchange membrane fuel cells (PEMFCs). The intermolecular interactions and morphology of these membranes were assessed using Fourier-transform infrared spectroscopy (FT-IR) and field-emission scanning electron microscopy (FE-SEM). A twofold increase in the proton conductivity is observed for the PVAc/Nafion® composite membrane (2 × 10-2 Scm-1) compared to that of cast Nafion® (1.1 × 10-2 Scm-1). In addition to that, the composite membranes exhibited better mechanical strength and adequate water retention ability as well as IEC comparable to that of cast Nafion®. The thermal property and chemical degradation property were also investigated. The results indicate that the introduction of PVAc as a modifier played a vital role in improving the membrane performance. Accordingly...
Journal of Nanoscience and Nanotechnology, 2017
Acidic groups, which act as proton carriers, convert chitosan (CS) into a polyelectrolyte by prot... more Acidic groups, which act as proton carriers, convert chitosan (CS) into a polyelectrolyte by protonating its NH 2 groups. In this study, by employing this concept acidified CSs (CS acidified by phosphoric sulfuric, or acetic acid) were intentionally incorporated into a Nafion ® matrix to prepare composite membranes that exhibit improved proton conductivity for fuel cell applications. Using FT-IR measurements, we assessed the intermolecular interactions in the membranes. Additionally, these membranes showed excellent water retention abilities and ion exchange capacities (IEC), comparable to those of cast Nafion ®. Considering the excellent membrane performances, the low cost of the CS membrane material, and the facile synthetic approach, these novel membranes should be competent to apply in proton exchange membrane fuel cells (PEMFCs).
Science of Advanced Materials, 2018
Employing the concept of coordination networks, the conductivity of Nafion® was amplified by fabr... more Employing the concept of coordination networks, the conductivity of Nafion® was amplified by fabricating a composite based on Nafion® and an inexpensive and highly proton-conductive three-dimensional metal-organic framework (MOF), namely, {[(Me2NH2)3(SO4)]2[Zn2(ox)3]}n (1, Me = methyl, ox = oxalate). The proton conductivity increased by more than 18% for the MOF 1/Nafion® composite membrane, e in comparison to pristine cast Nafion® membrane. Such improvement in conductivity can be attributed to the interionic proton hopping through the extended hydrogen bonding networks, higher concentration of proton carriers, 3D hydrogen pathways (including nanopores on the surface of the MOF 1 crystals) and higher degree of crystallinity. Along with slightly higher thermal stability, increased ion exchange capacity (IEC) and optimum water uptake were observed, with the addition of 1 wt.% of MOF 1 to Nafion® appearing to be maximally efficient. This study offers a cost-effective and facile fabrica...
Proceedings of the 2021 on Great Lakes Symposium on VLSI
With the popularity of 2.5D integration, an increasing number of chiplets are integrated into adv... more With the popularity of 2.5D integration, an increasing number of chiplets are integrated into advanced system-in-package designs. In such systems, redistribution layer (RDL) wires become longer and denser, with a growing impact on system performance. However, RDL inductive impacts in timing analysis are ignored by the traditional CAD tools. This paper presents our chiplet-package cooptimization flow, which can capture the RDL inductance impact on system performance and automatically adjust the IO drivers to compensate for the inductance overhead. We develop our extraction and timing analysis tool that models RDL wire inductive timing impact on 2.5D system performance within +/-1% error. Our study shows 35% signal paths through RDL violate the timing requirement because of the inductive impact, and remain undetected through only RC-based STA. CCS Concepts • Hardware → Physical design (EDA); Multi-chip modules; Modeling and parameter extraction; Package-level interconnect.
Journal of Nanoscience and Nanotechnology, 2020
A novel blend of membranes made of Nafion® and poly(vinylpyrrolidone) (PVP) was prepared and char... more A novel blend of membranes made of Nafion® and poly(vinylpyrrolidone) (PVP) was prepared and characterized to investigate its applicability in proton exchange membrane fuel cells (PEMFCs). In addition to being effectively proton conductive, the membranes exhibited better mechanical strength, chemical stability, and adequate water retention ability, as well as ion exchange capacity comparable to that of cast Nafion® membrane. The data obtained from an electrochemical impedance spectroscopy (EIS) fitting of the fuel cells revealed the membrane electrode assemblies (MEAs) made of 0.5 wt.% PVP/Nafion® had lower ohmic and charge transfer resistance compared with that of the Nafion® membrane. The intermolecular interactions and morphology of these membranes were assessed using Fourier-transform infrared spectroscopy and field-emission scanning electron microscopy. The results of the performance curve indicate that the introduction of PVP as a modifier played a vital role in improving memb...
2021 International Symposium on VLSI Design, Automation and Test (VLSI-DAT), 2021
In recent days, 2.5D package designs have gained popularity with an increasing number of heteroge... more In recent days, 2.5D package designs have gained popularity with an increasing number of heterogeneous chiplets integrated into advanced system-in-packages. RDL wires become longer and denser, presenting a growing impact on system performance, reliability, and integrity. At present, there exists no standard CAD flow that can design, analyze, and optimize a complete heterogeneous 2.5D system. The traditional die-by-die design approach processes each component independently during extraction and optimization and cannot be applied to heterogeneous systems without fundamental changes in standard CAD tools. Not only the chiplet-package extraction is inaccurate between the die-package interface ignoring all RDL capacitive and inductive impacts, but traditional CAD tools are also unable to perform cross-boundary design optimization. We present a complete chiplet-package co-optimization flow for both homogeneous and heterogeneous 2.5D designs. It encompasses 2.5Daware partitioning, chiplet-package co-planning, holistic and in-context extraction, package inductance consideration, and iterative optimization, along with design analysis and verification of the entire 2.5D system. In our previous work [1] targeting heterogeneous systems, we achieved an extraction error ranging between-2.10% and 24.0%. The in-context design flow proposed in this work achieves less than 1% extraction error on ground and coupling capacitance. This extraction result can be used to perform timing analysis with 99.8% accuracy and to generate timing context with 99.4% accuracy for iterative optimization.
Proceedings of the 39th International Conference on Computer-Aided Design, 2020
In recent years, 2.5D chiplet package designs have gained popularity in system integration of het... more In recent years, 2.5D chiplet package designs have gained popularity in system integration of heterogeneous technologies. Currently, there exists no standard CAD flow that can design, analyze, and optimize a complete heterogeneous 2.5D system. The traditional die-by-die design approach does not consider any package layers during extraction and optimization, and an accurate chiplet-package extraction can not be applied to heterogeneous designs without fundamental changes in standard CAD tools. In this paper, we present our Holistic and In-Context chiplet-package co-design flows for high-performance high-density 2.5D systems using standard ASIC CAD tools with zero overhead on IO pipeline depth. Our flow encompasses 2.5D-aware partitioning, chiplet-package co-planning, in-context extraction, iterative optimization, and post-design analysis and verification of the entire 2.5D system. We design our package planner with a routing and pin-planning strategy to minimize package routing congestion and timing overhead. An ARM Cortex-M0-based microcontroller system is designed as the benchmark. The performance gap to the reference 2D design reduces by 62.5% when chip-package interactions are taken into account in the holistic flow. Our in-context extraction achieves only 0.71% and 0.79% error on ground and coupling capacitance on a homogeneous system. Further, we implement a heterogeneous 2.5D system to demonstrate our novel in-context design and optimization methodology.
2020 25th Asia and South Pacific Design Automation Conference (ASP-DAC), 2020
Chiplet integration using 2.5D packaging is gaining popularity nowadays which enables several int... more Chiplet integration using 2.5D packaging is gaining popularity nowadays which enables several interesting features like heterogeneous integration and drop-in design method. In the traditional die-by-die approach of designing a 2.5D system, each chiplet is designed independently without any knowledge of the package RDLs. In this paper, we propose a Chip-Package Co-Design flow for implementing 2.5D systems using existing commercial chip design tools. Our flow encompasses 2.5D-aware partitioning suitable for SoC design, Chip-Package Floorplanning, and post-design analysis and verification of the entire 2.5D system. We also designed our own package planners to route RDL layers on top of chiplet layers. We use an ARM Cortex-M0 SoC system to illustrate our flow and compare analysis results with a monolithic 2D implementation of the same system. We also compare two different 2.5D implementations of the same SoC system following the drop-in approach. Alongside the traditional dieby-die approach, our holistic flow enables design efficiency and flexibility with accurate cross-boundary parasitic extraction and design verification.
2020 IEEE 33rd International System-on-Chip Conference (SOCC), 2020
Traditionally, different components of a system are integrated through Printed Circuit Boards (PC... more Traditionally, different components of a system are integrated through Printed Circuit Boards (PCB). The long traces on PCB have severe power loss and limit the bandwidth of the interconnects between the components. Advanced packaging offers high-bandwidth, low power, and high-performance inter-die communications with compact sizes and dense pin arrays. 2.5D integration further provides better thermal dissipation, lower cost, and higher yield compared to 3D stacking. Novel CAD tool flows dedicated to 2.5D chiplet designs are essential to enable flexible and efficient 2.5D system designs. In this paper, we present our design, optimization, and analysis methodologies and a design case study implementing an ARM Cortex-M0 microcontroller system using a holistic 2.5D tool flow. We use TSMC 65nm as our chiplet implementation technology with a modified metal stack referring to 2.5D Fan-Out Wafer-Level Packaging (FOWLP) solutions. We also discuss design techniques for chiplet reuse and the Drop-in design approach to develop low-power, low-cost, and high-performance flavors of a 2.5D system. We compare the 2.5D system with its 2D counterpart to validate the holistic design flow.
Journal of Nanoscience and Nanotechnology, 2019
A successful polymer electrolyte membrane for fuel cell application must have efficient proton co... more A successful polymer electrolyte membrane for fuel cell application must have efficient proton conductivity as well as good water retention capability. The viability of using composite membranes prepared by blending 85% deacetylated chitosan (CS) and Nafion ® in proton exchange membrane fuel cells (PEMFCs) was investigated based on the concept of hydrophilicity and the water uptake characteristics of CS. These membranes were characterized by infrared spectroscopy and field-emission scanning electron microscopy to investigate their intermolecular interactions and morphology, respectively. Absorption studies were carried out to evaluate the interactions of the membranes with water. Titrimetric ion exchange capacity analysis indicated the availability of active sites in the membrane. The CS/Nafion ® blend was found to be suitable for PEMFC applications because of its relatively high proton conductivity compared to that of regular Nafion ®. Above all, the cost-effectiveness and simple fabrication of such composite membranes make their use in lowtemperature PEMFCs very attractive and economical.
Journal of nanoscience and nanotechnology, 2018
To increase the water retention and proton-conducting ability of Nafion®, we prepared a cross-lin... more To increase the water retention and proton-conducting ability of Nafion®, we prepared a cross-linked polymer consisting of poly(2-hydroxyethyl methacrylate) (pHEMA) and Nafion®. pHEMA was chosen as a cross-linking polymer because it produces a water-insoluble but water-swellable polymer. Although it is hydrophobic, its water-swellable characteristic means that water will not be excluded from the polymer. Introduction of pHEMA into Nafion® prevents polymer solubility and provides structural stability and rigidity, which should in turn reduce the methanol permeability. Moreover, convenient permeability of pHEMA to cations makes it a good candidate for a hydrocarbon proton-conducting polymer tuned with Nafion®.
Journal of nanoscience and nanotechnology, 2018
A novel blend of membranes made of cast Nafion® and poly(vinyl acetate) (PVAc) was prepared and i... more A novel blend of membranes made of cast Nafion® and poly(vinyl acetate) (PVAc) was prepared and its proton conductivity and ion exchange capacity (IEC) were characterized to investigate its applicability in proton exchange membrane fuel cells (PEMFCs). The intermolecular interactions and morphology of these membranes were assessed using Fourier-transform infrared spectroscopy (FT-IR) and field-emission scanning electron microscopy (FE-SEM). A twofold increase in the proton conductivity is observed for the PVAc/Nafion® composite membrane (2 × 10-2 Scm-1) compared to that of cast Nafion® (1.1 × 10-2 Scm-1). In addition to that, the composite membranes exhibited better mechanical strength and adequate water retention ability as well as IEC comparable to that of cast Nafion®. The thermal property and chemical degradation property were also investigated. The results indicate that the introduction of PVAc as a modifier played a vital role in improving the membrane performance. Accordingly...
Journal of Nanoscience and Nanotechnology, 2017
Acidic groups, which act as proton carriers, convert chitosan (CS) into a polyelectrolyte by prot... more Acidic groups, which act as proton carriers, convert chitosan (CS) into a polyelectrolyte by protonating its NH 2 groups. In this study, by employing this concept acidified CSs (CS acidified by phosphoric sulfuric, or acetic acid) were intentionally incorporated into a Nafion ® matrix to prepare composite membranes that exhibit improved proton conductivity for fuel cell applications. Using FT-IR measurements, we assessed the intermolecular interactions in the membranes. Additionally, these membranes showed excellent water retention abilities and ion exchange capacities (IEC), comparable to those of cast Nafion ®. Considering the excellent membrane performances, the low cost of the CS membrane material, and the facile synthetic approach, these novel membranes should be competent to apply in proton exchange membrane fuel cells (PEMFCs).
Science of Advanced Materials, 2018
Employing the concept of coordination networks, the conductivity of Nafion® was amplified by fabr... more Employing the concept of coordination networks, the conductivity of Nafion® was amplified by fabricating a composite based on Nafion® and an inexpensive and highly proton-conductive three-dimensional metal-organic framework (MOF), namely, {[(Me2NH2)3(SO4)]2[Zn2(ox)3]}n (1, Me = methyl, ox = oxalate). The proton conductivity increased by more than 18% for the MOF 1/Nafion® composite membrane, e in comparison to pristine cast Nafion® membrane. Such improvement in conductivity can be attributed to the interionic proton hopping through the extended hydrogen bonding networks, higher concentration of proton carriers, 3D hydrogen pathways (including nanopores on the surface of the MOF 1 crystals) and higher degree of crystallinity. Along with slightly higher thermal stability, increased ion exchange capacity (IEC) and optimum water uptake were observed, with the addition of 1 wt.% of MOF 1 to Nafion® appearing to be maximally efficient. This study offers a cost-effective and facile fabrica...