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

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.

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

International Symposium on Microelectronics ◽

10.4071/isom-tp35 ◽

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.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.23 ◽

2010 ◽

Vol 97-101 ◽

pp. 23-27 ◽

Cited By ~ 5

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.

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

10.1115/imece2001/htd-24388 ◽

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.

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Thermal Cycling Reliability and Delamination of Anisotropic Conductive Adhesives Flip Chip on Organic Substrates With Emphasis on the Thermal Deformation

Journal of Electronic Packaging ◽

10.1115/1.1846062 ◽

2005 ◽

Vol 127 (2) ◽

pp. 86-90 ◽

Cited By ~ 37

Author(s):

Woon-Seong Kwon ◽

Myung-Jin Yim ◽

Kyung-Wook Paik ◽

Suk-Jin Ham ◽

Soon-Bok Lee

Keyword(s):

Thermal Cycling ◽

Thermal Deformation ◽

Flip Chip ◽

High Sensitivity ◽

Moiré Interferometry ◽

Acoustic Microscopy ◽

Moire Interferometry ◽

Organic Substrates ◽

Conductive Adhesives ◽

Reliability Performance

One of the most important issues whether anisotropic conductive film (ACF) interconnection technology is suitable to be used for flip chip on organic board applications is thermal cycling reliability. In this study, thermally induced deformations and warpages of ACF flip chip assemblies as a function of distance from neutral point (DNP) and ACF materials properties were investigated using in situ high sensitivity moire´ interferometry. For a nondestructive failure analysis, scanning acoustic microscopy investigation was performed for tested assemblies. To elucidate the effects of ACF material properties and DNP on the thermal cycling reliability of ACF assembly, Weibull analysis for the lifetime estimation of ACF joint was performed, and compared with thermal deformations of ACF flip chip assembly investigated by moire´ interferometry. Results indicate that the properties of ACF have a significant role in the thermal deformation and reliability performance during thermal cycling testing. Therefore, optimized ACF properties can enhance ACF package reliability during thermal cycling regime.

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Effects of drying pattern on aflatoxin in stored paddy rice

Bangladesh Journal of Scientific and Industrial Research ◽

10.3329/bjsir.v53i4.39188 ◽

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

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A REVIEW ON THE BENEFITS OF HORTICULTURAL THERAPY FOR RETIREMENT COMMUNITY IN MALAYSIA

Malaysian Journal of Sustainable Environment ◽

10.24191/myse.v2i1.5573 ◽

2017 ◽

Vol 2 (1) ◽

pp. 1

Author(s):

Amirul Amin Ismail ◽

Ismail Samsuddin ◽

Azman Zainonabidin ◽

Harlina Mohd Ali

Keyword(s):

Well Being ◽

The Elderly ◽

Retirement Community ◽

Analysis Method ◽

Horticultural Therapy ◽

Seamless Integration ◽

Ageing Society ◽

After Effects ◽

Malaysian Population ◽

The Impact

By the year 2030, Malaysian population will experience the after effects of the rapid growth of ageing society. This paper investigates the impact of seamless integration of horticultural activity in the new residential typology of retirement community. It is believed that horticultural therapy is not only beneficial for physical and psychological but also promotes socialisation opportunities among the elderly. Comparative analysis method on selected precedent studies has been carried out and analysed in accordance with Malaysian context. Initial findings indicate that a retirement community with horticultural activity gives therapy for healthier well-being. This therapeutic activity can be apositive change in elderly lifestyle and essential towards the establishment of retirement community in Malaysia.

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

ISTFA 2003: Conference Proceedings from the 29th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2003p0184 ◽

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 < 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 < 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.

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Surface Modification of Poly(Vinylchloride) for Manufacturing Advanced Catheters

Current Medicinal Chemistry ◽

10.2174/0929867327666200227152150 ◽

2020 ◽

Vol 27 (10) ◽

pp. 1616-1633 ◽

Cited By ~ 2

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.

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

Current Pharmaceutical Analysis ◽

10.2174/1573412915666190312161823 ◽

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.

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