Design of Filled One Step Chip Attach Materials (OSCA) for Conventional Mass Reflow Processing: Curing Kinetics and Solder Reflow Aspects

2015 ◽  
Vol 2015 (DPC) ◽  
pp. 001502-001529 ◽  
Author(s):  
Daniel Duffy ◽  
Hemal Bhavsar ◽  
Lin Xin ◽  
Jean Liu ◽  
Bruno Tolla
Keyword(s):  
Flip Chip ◽  
Polymeric Materials ◽  
Cure Kinetics ◽  
Curing Kinetics ◽  
Filler Loading ◽  
Single Step ◽  
Die Attach ◽  
One Step ◽  
Organic Formulations ◽  
The Impact

One step chip attach materials (OSCA) are dispensable polymeric materials for flip chip assembly, which are designed to flux metallic interconnections and subsequently turn into an underfill upon curing. OSCA materials enable a drastic simplification of the assembly process by combining the reflow, flux residue cleaning and capillary underfilling steps used in traditional die attach processing into a single step. A key challenge when designing OSCA materials for conventional mass reflow processing (identified as OSCA-R) is timing the cure kinetics with the fluxing and soldering sequences during reflow processing. OSCA-R materials must also have a process-friendly rheological design that integrates seamlessly with standard dispensing equipment and enables the filler loading levels required for customized thermal conductivities. The consideration of the interactions between the filler particles and the organic portion of OSCA materials is critical for first achieving fluxing and interconnection during reflow and second curing the material to develop target thermo mechanical properties for reliability such as Tg, TC, CTE modulus and adhesion after reflow. This paper presents research focused on understanding the impact of filler loading, size, type and surface chemistry on curing, fluxing and interconnection kinetics during reflow processing measured by thermal and rheological methods. Preliminary results indicate the presence of chemical interactions between the filler and organic formulations, as well as complex physical interactions which need to be considered in the design of OSCA-R materials for a device assembly using conventional mass reflow processing.

Design of Filled One Step Chip Attach Materials (OSCA) for Conventional Mass Reflow Processing: Rheology Considerations for Jet Dispensing and Die Placement

2015 ◽  
Vol 2015 (1) ◽  
pp. 000856-000861
Author(s):  
Daniel Duffy ◽  
Hemal Bhavsar ◽  
Lin Xin ◽  
Jean Liu ◽  
Bruno Tolla
Keyword(s):  
Flip Chip ◽  
Polymeric Materials ◽  
Filler Loading ◽  
Single Step ◽  
Organic Substrates ◽  
Seamless Integration ◽  
Die Attach ◽  
One Step ◽  
Reliability Performance ◽  
The Impact

One step chip attach materials (OSCA) are dispensable polymeric materials for flip chip assembly, which are designed to flux metallic interconnections and subsequently turn into an underfill upon curing. OSCA materials enable a drastic simplification of the assembly process by combining the reflow, flux residue cleaning and capillary underfilling steps used in traditional die attach processing into a single step. A key challenge when designing filled OSCA materials for conventional mass reflow processing (OSCA-R) is to ensure that the materials have a process-friendly rheological design allowing seamless integration with jet dispensing equipment and allowing for accurate die placement. This paper presents research results and design concepts for OSCA-R materials focused on understanding the impact of filler loading, size, type and surface chemistry on rheology and the relationships with jet dispensing performance, die placement and reliability performance for test vehicles constructed with silicon and organic substrates.

One Step Chip Attach Materials (OSCA) for Conventional Mass Reflow Processing

2014 ◽  
Vol 2014 (1) ◽  
pp. 000262-000267
Author(s):  
Daniel J. Duffy ◽  
Lin Xin ◽  
Jean Liu ◽  
Bruno Tolla
Keyword(s):  
Flip Chip ◽  
Polymeric Materials ◽  
Cure Kinetics ◽  
Filler Loading ◽  
Single Step ◽  
Seamless Integration ◽  
Device Reliability ◽  
One Step ◽  
Traditional Processing

One step chip attach (OSCA) materials are dispensable polymeric materials for flip chip assembly, which are designed to flux metallic interconnections and subsequently turn into an underfill upon curing. OSCA materials enable a drastic simplification of the assembly process by combining the reflow (fluxing/soldering), defluxing and capillary underfilling steps used in traditional processing into a single step. One key challenge for the design of OSCA materials is timing the cure kinetics with fluxing activity and solder reflow during processing. A second key challenge is to factor a process-friendly rheological design into the formulation. The OSCA material rheology must allow for high filler loading levels, seamless integration with standard dispensing equipment, flow control during and after dispense (avoid keep out zones), flow during die placement (elimination of voids), after placement (fillet formation) and during reflow. The final key requirements for a functional device are defect-free interconnections combined with optimal thermo-mechanical and water resistant properties of the final underfill to guarantee the long-term reliability of the assembly in various environmental conditions. This paper presents the properties of materials designed by Kester for use in mass reflow processing (OSCA-R). The rheological design principles behind a seamless integration into customer-friendly processes will be presented In addition results illustrating the timing of cure kinetics with fluxing and soldering events during processing will be discussed. Preliminary device reliability results will also be presented for several types of test vehicles including; Si-Si and Si-FR4.

An Optimization of Two-Steps Curing Profile to Eliminate Voids Formation in Underfill Epoxy for Hi-CTE Flip Chip Packaging

2010 ◽  
Vol 97-101 ◽  
pp. 23-27 ◽  
Author(s):  
Zainudin Kornain ◽  
Azman Jalar ◽  
Rozaidi Rashid ◽  
Shahrum Abdullah
Keyword(s):  
Flip Chip ◽  
Coefficient Of Thermal Expansion ◽  
Ball Grid Array ◽  
Statistic Analysis ◽  
Curing Process ◽  
Ceramic Ball ◽  
Die Attach ◽  
Ball Grid Array Package ◽  
Flip Chip Packaging ◽  
The Impact

Underfilling is the preferred process to reduce the impact of the thermal stress that results from the mismatch in the coefficient of thermal expansion (CTE) between the silicon chip and the substrate in Flip Chip Packaging. Voids formation in underfill is considered as failure in flip chip manufacturing process. Voids formation possibly caused by several factors such as poor soldering and flux residue during die attach process, voids entrapment due moisture contamination, dispense pattern process and setting up the curing process. This paper presents the optimization of two steps curing profile in order to reduce voids formation in underfill for Hi-CTE Flip Chip Ceramic Ball Grid Array Package (FC-CBGA). A C-Mode Scanning Aqoustic Microscopy (C-SAM) was used to scan the total count of voids after curing process. Statistic analysis was conducted to analyze the suitable curing profile in order to minimize or eliminate the voids formation. It was shown that the two steps curing profile provided solution for void elimination.

An Assessment of the Impact of Interconnect Strategies on Thermal Performance of GaAs Power Amplifier IC Devices

2001 ◽  
Author(s):  
V. H. Adams ◽  
T.-Y. Tom Lee
Keyword(s):  
Thermal Resistance ◽  
Power Amplifier ◽  
Thermal Performance ◽  
Flip Chip ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Printed Circuit ◽  
Wire Bond ◽  
Die Attach ◽  
The Impact

Abstract Alternative interconnect strategies are being considered in place of the standard wire bond interconnect for GaAs power amplifier MMIC devices due to cost and electrical performance improvements. The package/die thermal performance consequences are potentially high-risk issue to these interconnect strategies and requires evaluation. Thermal simulations are conducted to compare and evaluate the thermal performances of three interconnect strategies: wire bond, gold post-flip chip, and through via interconnects. The test vehicle simulated is a three-stage, dual band power amplifier integrated circuit dissipating approximately 5 W steady-state power. Parametric studies are conducted to evaluate the impact of the printed circuit board, die thickness, solid gold vias, and design enhancements on package thermal performance. Best thermal performance is provided by a wire bonded, thin GaAs die attached with solder die attach to a printed circuit board that maximizes the number of plated-through-holes directly under the die. This configuration results in a best case junction-to-heat sink thermal resistance of 12 °C/W. Optimum flip chip and through via designs result in degraded thermal performance compared to the above described wire bond design but may have acceptable thermal performance. For these simulations, predicted junction-to-heatsink thermal resistance is in a range of 15–20 °C/W and is better than a comparable wire bonded design that uses a conductive epoxy die attach material.

scholarly journals Effects of drying pattern on aflatoxin in stored paddy rice

2018 ◽  
Vol 53 (4) ◽  
pp. 253-258
Author(s):  
S Masood ◽  
Alim Un Nisa ◽  
S Hina ◽  
I Ahmad
Keyword(s):  
Moisture Content ◽  
Single Step ◽  
Paddy Rice ◽  
Drying Pattern ◽  
Short Term ◽  
Study Results ◽  
Long Time ◽  
One Step ◽  
Rice Samples ◽  
The Impact

This study was done to evaluate the impact of drying pattern on the accumulation of aflatoxin in paddy rice during storage. Two drying pattern includes, 1) single step drying to reduced the moisture content of paddy rice 11-12 % within 6 hours and stored for long time; and 2) two steps drying to reduce the moisture up to 18%, in its first step and stored for short term (2 weeks) and in the second step, dried again to reduce the moisture content up to 11-12% and stored for longer time, with twenty five different paddy rice samples having moisture content ranging from 24-22 % were evaluated for the accumulation of aflatoxins in paddy rice during storage. In addition, this study also evaluated the best drying method that can control the accumulation of aflatoxin during prolong storage. The study results revealed that one step drying is safer than that of two steps drying in accumulating aflatoxins in paddy rice during 210 days of storage. The maximum total aflatoxins (B1, B2, G1,G2) was recorded as 27 ppb in paddy rice sample in two steps drying process, on the other hand, non-detectable level or <10 ppb level of aflatoxins was recorded in all the 25 paddy rice s amples analyzed.Bangladesh J. Sci. Ind. Res.53(4), 253-258, 2018

VLSI Design for Functional Failure Analysis in the < 90 nm and Flip-Chip Era

2003 ◽  
Author(s):  
Yoav Weizman ◽  
Ezra Baruch
Keyword(s):  
Failure Analysis ◽  
Flip Chip ◽  
Light Emission ◽  
Vlsi Design ◽  
Optical Resolution ◽  
Critical Issue ◽  
Acquisition Time ◽  
Resolution Limit ◽  
Design Rules ◽  
The Impact

Abstract In recent years, two new techniques were introduced for flip chip debug; the Laser Voltage Probing (LVP) technique and Time Resolved Light Emission Microscopy (TRLEM). Both techniques utilize the silicon’s relative transparency to wavelengths longer than the band gap. This inherent wavelength limitation, together with the shrinking dimensions of modern CMOS devices, limit the capabilities of these tools. It is known that the optical resolution limits of the LVP and TRLEM techniques are bounded by the diffraction limit which is ~1um for both tools using standard optics. This limitation was reduced with the addition of immersion lens optics. Nevertheless, even with this improvement, shrinking transistor geometry is leading to increased acquisition time, and the overlapping effect between adjacent nodes remains a critical issue. The resolution limit is an order of magnitude above the device feature densities in the &lt; 90nm era. The scaling down of transistor geometry is leading to the inevitable consequence where more than 50% of the transistors in 90nm process have widths smaller than 0.4um. The acquisition time of such nodes becomes unreasonably long. In order to examine nodes in a dense logic cuicuit, cross talk and convolution effects between neighboring signals also need to be considered. In this paper we will demonstrate the impact that these effects may have on modern design. In order to maintain the debug capability, with the currently available analytical tools for future technologies, conceptual modification of the FA process is required. This process should start on the IC design board where the VLSI designer should be familiar with FA constraints, and thus apply features that will enable enhanced FA capabilities to the circuit in hand during the electrical design or during the physical design stages. The necessity for reliable failure analysis in real-time should dictate that the designer of advanced VLSI blocks incorporates failure analysis constraints among other design rules. The purpose of this research is to supply the scientific basis for the optimal incorporation of design rules for optical probing in the &lt; 90nm gate era. Circuit designers are usually familiar with the nodes in the design which are critical for debug, and the type of measurement (logic or DC level) they require. The designer should enable the measurement of these signals by applying certain circuit and physical constraints. The implementation of these constraints may be done at the cell level, the block level or during the integration. We will discuss the solutions, which should be considered in order to mitigate tool limitations, and also to enable their use for next generation processes.

Surface Modification of Poly(Vinylchloride) for Manufacturing Advanced Catheters

2020 ◽  
Vol 27 (10) ◽  
pp. 1616-1633 ◽  
Author(s):  
Oana Cristina Duta ◽  
Aurel Mihail Ţîţu ◽  
Alexandru Marin ◽  
Anton Ficai ◽  
Denisa Ficai ◽  
...  
Keyword(s):  
Surface Modification ◽  
Chemical Modification ◽  
Medical Devices ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Modern Medicine ◽  
Structural Failure ◽  
Chemical Grafting ◽  
One Step

Polymeric materials, due to their excellent physicochemical properties and versatility found applicability in multiples areas, including biomaterials used in tissue regeneration, prosthetics (hip, artificial valves), medical devices, controlled drug delivery systems, etc. Medical devices and their applications are very important in modern medicine and the need to develop new materials with improved properties or to improve the existent materials is increasing every day. Numerous reasearches are activated in this domain in order to obtain materials/surfaces that does not have drawbacks such as structural failure, calcifications, infections or thrombosis. One of the most used material is poly(vinylchloride) (PVC) due to its unique properties, availability and low cost. The most common method used for obtaining tubular devices that meet the requirements of medical use is the surface modification of polymers without changing their physical and mechanical properties, in bulk. PVC is a hydrophobic polymer and therefore many research studies were conducted in order to increase the hydrophilicity of the surface by chemical modification in order to improve biocompatibility, to enhance wettability, reduce friction or to make lubricious or antimicrobial coatings. Surface modification of PVC can be achieved by several strategies, in only one step or, in some cases, in two or more steps by applying several techniques consecutively to obtain the desired modification / performances. The most common processes used for modifying the surface of PVC devices are: plasma treatment, corona discharge, chemical grafting, electric discharge, vapour deposition of metals, flame treatment, direct chemical modification (oxidation, hydrolysis, etc.) or even some physical modification of the roughness of the surface.

Development and Validation of an LC-MS/MS Method for Simultaneous Determination of Canagliflozin and Metformin HCl in Rat Plasma and its Application

2020 ◽  
Vol 16 (6) ◽  
pp. 752-762
Author(s):  
Vivek Nalawade ◽  
Vaibhav A. Dixit ◽  
Amisha Vora ◽  
Himashu Zade
Keyword(s):  
Internal Standard ◽  
Rat Plasma ◽  
Precipitation Method ◽  
Herbal Extracts ◽  
One Step ◽  
Precision And Accuracy ◽  
Development And Validation ◽  
The Impact ◽  
Metformin Hcl

Background: Food and herbal extracts rich in Quercetin (QRT) are often self-medicated by diabetics and can potentially alter the pharmacokinetics (PK) of Metformin HCl (MET) and Canagliflozin (CNG) leading to food or herb-drug interactions and reduced therapeutic efficacy. However, the impact of these flavonoids on the pharmacokinetic behaviour of MET and CNG is mostly unknown. Methods: A simple one-step protein precipitation method was developed for the determination of MET and CNG from rat plasma. The mobile phase chosen was MeOH 65% and 35% water containing 0.1% formic acid at a flow rate of 1mL/min. Results: The retention time of MET, internal standard (Valsartan) and CNG was 1.83, 6.2 and 8.2 min, respectively. The method was found to be linear in the range of 200 - 8000 ng/mL for CNG and 100 = 4000 ng/ml for MET. Precision and accuracy of the method were below 20% at LLOQ and below 15% for LQC, MQC, and HQC. Conclusion: The method was successfully applied for the determination of PK of MET and CNG by using 100 μL of rat plasma. QRT co-administration affects the PK parameters of MET and CNG. This alteration in PK parameters might be of significant use for clinicians and patients.

Synthesis of Polycycles and Oxacycles by Tandem Metathesis of endo–norbornene Derivatives

Synthesis ◽  
2021 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Sunil Pulletikurti ◽  
Ambareen Fatma ◽  
gopal dhangar ◽  
gonna somu Naidu
Keyword(s):  
Natural Products ◽  
Metal Complex ◽  
Carbonyl Group ◽  
Single Step ◽  
Time Dependent ◽  
Computational Studies ◽  
Nmr Studies ◽  
Tricyclic Compounds ◽  
One Step ◽  
Norbornene Derivatives

Here, we have demonstrated that the presence of a carbonyl group at C7 position is preventing the olefin metathesis of endo-norbornene derivatives due to the complexation of the metal alkylidene. Time-dependent NMR studies showed the presence of new proton signals in the metal alkylidene region, which indicate the formation of metal complex with the carbonyl group of the substrate. These observations were further proved by ESI-MS analysis. Whereas, computational studies provided that the catalyst was interacting with the C7 carbonyl group and aligned perpendicular to that of norbornene olefin. Later, these endo-keto norbornene derivatives were reduced to hydroxyl derivatives diastereoselectively. Ring-rearrangement metathesis (RRM) of these hydroxyl derivatives, produced the [6/5/6], and [5/6/5] carbo-tricyclic cores of the natural products in one step. Whereas the RRM of O-allyl derivatives, delivered the oxa-tricyclic compounds in a single step with excellent yields.

scholarly journals The Science of Ageism: Two Steps Forward, One Step Back

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 646-646
Author(s):  
Jerin Lee ◽  
Natalie Shook
Keyword(s):  
Psychological Health ◽  
Well Being ◽  
Census Bureau ◽  
Complex Nature ◽  
The Past ◽  
Growing Pains ◽  
Research Findings ◽  
One Step ◽  
Prejudicial Attitudes ◽  
The Impact

Abstract The past two decades have been marked by a rapidly aging population in the U.S. (U.S. Census Bureau, 2018), making prejudicial attitudes toward older adults (i.e., ageism) and the impact of such attitudes more relevant. As such, ageism researchers have worked tirelessly to not only understand this normalized and insidious form of bias, but also develop efforts to combat it. This symposium will feature four ageism researchers who will showcase both the growing pains and novel contributions of ageism research, ranging from the impact of ageism on psychological health to ageism interventions to issues related to the measurement of ageism. Specifically, Dr. Ayalon will present findings regarding difficulties with the assessment of exposure to ageism and the consequences of ageism for psychological well-being. Dr. Horhota will share research demonstrating challenges associated with confronting ageism. Dr. Levy will present a model showcasing factors associated with the reduction of ageism. Ms. Lee will discuss research findings examining the construct validity of several ageism measures. These talks highlight theoretical and real-world implications associated with the complex nature of ageism, providing important directions for enriching ageism research going forward.

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