Resin Selection Criteria for Molded Electronic Packages

1987 ◽  
Vol 108 ◽  
Author(s):  
S. B. Rimsa
Keyword(s):  
Thermal Stresses ◽  
Moisture Absorption ◽  
Initial Step ◽  
Electronic Packages ◽  
Application Process ◽  
Electronic Package ◽  
Wave Soldering ◽  
Multi Stage ◽  
End Use ◽  
The Cost

The selection of the proper resin system for a molded PWB or electronic package must take into account considerably more parameters than simply the cost of and the ability of the polymer to fill the tooling. Molding of an electronic package is only the initial step in a multi stage sequence to produce a functional PWB or interconnect device.It is of extreme importance that a manufacturer of molded electronic packages understand not only the fabrication properties of a resin, but also those mechanical, thermal, and chemical requirements of the circuit application and assembly operations.A specific circuitry application process will usually require a specific set of substrate characteristics. These performance characteristics may relate to platability, thermal stability, modulus, compressive strength, or even adhesive bondability for a given procedure. The substrate requirements for several popular circuit application methods is reviewed.Assembly presents perhaps the most demanding area of resin performance in electronic package or PWB fabrication. The thermal stresses encountered in wave soldering and vapor phase reflow will quickly differentiate among current engineering resin offerings. The importance of controlled moisture absorption and high temperature modulus retention is explored in addition to end use environmental factors which can be of special concern.

scholarly journals Exergoeconomic modeling and evaluation of a combined-cycle plant with MSF and MED desalination

2020 ◽  
Vol 10 (2) ◽  
pp. 158-172
Author(s):  
M. H. Khoshgoftar Manesh ◽  
S. Kabiri ◽  
M. Yazdi ◽  
F. Petrakopoulou
Keyword(s):  
Power Plant ◽  
Produced Water ◽  
Combined Cycle ◽  
Water Desalination ◽  
Simultaneous Generation ◽  
Multi Stage ◽  
Combined Cycle Plant ◽  
Industrial Use ◽  
End Use ◽  
The Cost

Abstract In the coming years, numerous regions are expected to suffer from water scarcity. One of the technologies of great interest in facing this challenge has been the generation of freshwater through water desalination, a process that reduces the amount of salt and minerals to a standard level, making the water suitable for drinking or agricultural/industrial use. The efficiency of each desalination process depends on the concentration of salts in the raw water and the end-use of the produced water. The present study presents the exergetic and exergoeconomic analyses of the coupling of a power plant with desalination units for the simultaneous generation of energy and water in Iran. The plant is integrated, first, with a multi-stage flash (MSF) unit and, then, with a multi-effect desalination (MED) unit. We find that the cost of exergy destruction of the MED and MSF integrated plants is lower when compared to the standalone power plant by about 0.1% and 9.2%, respectively. Lastly, the freshwater production in the plant using MED is significantly higher than that in the plant with MSF (1,000 versus 1,521 kg/s).

The Dependence of Moisture Induced Die Stresses Upon Moisture Properties of Polymer Materials in Electronic Packages

2017 ◽  
Author(s):  
Quang Nguyen ◽  
Jeffrey C. Suhling ◽  
Richard C. Jaeger ◽  
Pradeep Lall
Keyword(s):  
Flip Chip ◽  
Failure Modes ◽  
Moisture Absorption ◽  
Numerical Study ◽  
Polymer Materials ◽  
Electronic Packages ◽  
Major Drawback ◽  
Electronic Package ◽  
Plastic Ball ◽  
Moisture Property

Polymer materials have been widely used in electronic packaging with many advantages such as: lower cost, light weight and good performance. They however suffer a major drawback that results in a number of challenges for reliability engineers and researchers, in which polymer materials are quite sensitive to moisture absorption when exposed to humid environment, causing many failure modes in electronic packages such as: popcorn cracking, delamination or corrosion. It is well-known that finite element simulation is a powerful tool to evaluate the effects of moisture on electronic package reliability. In this study, three moisture properties (diffusivity, saturated concentration, and coefficient of moisture expansion) were experimentally characterized. The obtained results were then used to perform moisture diffusion simulations on various types of electronic package. Finally, a numerical study was conducted on the dependence of the moisture effects (weight gains, die stresses) upon each moisture property of polymeric components of three kinds of electronic packages (Quad Flat Package, Plastic Ball Grid Array, and Flip Chip on Laminate). The results of the study provided valuable insights into how moisture induced die stresses vary with each moisture property of polymeric components in the packages.

Organic Die Coat Materials for Plastic Packages

1989 ◽  
Vol 167 ◽  
Author(s):  
R. Padmanabhan
Keyword(s):  
Thermal Stresses ◽  
Moisture Absorption ◽  
Chemical Resistance ◽  
Dielectric Medium ◽  
Electronic Packages ◽  
Recent Application ◽  
Plastic Packages ◽  
High Lead ◽  
Selection Of

AbstractThe role of organic materials in electronic packages is constantly being expanded. A fairly recent application is the use of these materials for encapsulating high lead count IC dice, like TAB chips that are bonded directly to the board or housed in plastic packages. Since these packages are non-hermetic, some special constraints are placed in the selection of these die coat materials. Reliability issues that have to be addressed include compatibility with the underlying dielectric medium, chemical resistance, low moisture absorption, corrosion protection and resistance to thermal stresses. This paper discusses some of these concerns and reviews the suitability of different categories of die coat materials for this application.

scholarly journals Integration of a Solar Parabolic Dish Collector with a Small-Scale Multi-Stage Flash Desalination Unit: Experimental Evaluation, Exergy and Economic Analyses

2021 ◽  
Vol 13 (20) ◽  
pp. 11295
Author(s):  
Ali Babaeebazaz ◽  
Shiva Gorjian ◽  
Majid Amidpour
Keyword(s):  
Solar Radiation ◽  
Flow Rate ◽  
Quality Parameters ◽  
Small Scale ◽  
Conical Cavity ◽  
Multi Stage ◽  
Circulation Circuit ◽  
Parabolic Dish ◽  
Economic Analyses ◽  
The Cost

In this study, a small-scale two-stage multi-stage flash (MSF) desalination unit equipped with a vacuum pump and a solar parabolic collector (PDC) with a conical cavity receiver were integrated. To eliminate the need for heat exchangers, a water circulation circuit was designed in a way that the saline feedwater could directly flow through the receiver of the PDC. The system’s performance was examined during six days in July 2020, from 10:00 a.m. to 3:00 p.m., under two distinct scenarios of the MSF desalination operation under the vacuum (−10 kPa) and atmospheric pressure by considering three saline feedwater water flow rates of 0.7, 1 and 1.3 L/min. Furthermore, the performance of the solar PDC-MSF desalination plant was evaluated by conducting energy and exergy analyses. The results indicated that the intensity of solar radiation, which directly affects the top brine temperature (TBT), and the values of the saline feedwater flow rate have the most impact on productivity. The maximum productivity of 3.22 L per 5 h in a day was obtained when the temperature and saline feedwater flow rate were 94.25 °C (at the maximum solar radiation of 1015.3 W/m2) and 0.7 L/min, respectively, and the MSF was under vacuum pressure. Additionally, it was found that increasing the feedwater flow rate from 0.7 to 1.3 L/min reduces distillate production by 76.4% while applying the vacuum improves the productivity by about 34% at feedwater flow rate of 0.7 L/min. The exergy efficiency of the MSF unit was obtained as 0.07% with the highest share of exergy destruction in stages. The quality parameters of the produced distillate including pH, TDS, EC and DO were measured, ensuring they lie within the standard range for drinking water. Moreover, the cost of freshwater produced by the MSF plant varied from 37 US$/m3 to 1.5 US$/m3 when the treatment capacity increased to 8000 L/day.

scholarly journals PROFITABILITY ANALYSIS OF MARKETING OF FROZEN FISH IN KADUNA METROPOLIS, KADUNA STATE, NIGERIA

2020 ◽  
Vol 4 (2) ◽  
pp. 577-583
Author(s):  
M. B. Usman ◽  
O. S. Aaasa ◽  
O. S. Balogun ◽  
U. F. Yahaya
Keyword(s):  
Tertiary Education ◽  
Primary Data ◽  
Integrated Marketing ◽  
High Concentration ◽  
Profitability Analysis ◽  
Multi Stage ◽  
Return On Capital ◽  
Result Show ◽  
Frozen Fish ◽  
The Cost

This study investigated the marketing of frozen fish in Kaduna metropolis, Kaduna state. Ten (10) markets were purposively selected due to high concentration of frozen fish marketers and the volume of trading activities; Primary data were generated through the use of structured questionnaire administered to hundred (100) randomly selected retailers and fifteen (15) purposively selected wholesalers. The data were analyzed using descriptive statistic, budgeting technique, net marketing and rate of return on capital invested. The result show that majority 80 percent and 53 of the retailers and wholesalers were female, Majority (70prcent) of the retailers had primary education but most of the wholesaler’s attained tertiary education. The frozen fish marketing channels identified in the area are made up of zero and multi stage channels. Furthermore, the cost and return analysis revealed that the wholesalers realized about N121, 000.00 naira while the retailers got N56, 000.00 naira per month while return to per capital invested (RPCI) was 11 kobo and 22 kobo per Naira invested for the wholesalers and the retailers respectively. This implies that the enterprise is profitable. Transportation difficulties and marketing charges ranked were major constraints confronting frozen fish marketers. It is recommended that provision of good roads network and formidable integrated marketing system will further improve the profitability of the enterprise in the study area.

scholarly journals Integrated Offline and Online Decision Making under Uncertainty

2021 ◽  
Vol 70 ◽  
pp. 77-117
Author(s):  
Allegra De Filippo ◽  
Michele Lombardi ◽  
Michela Milano
Keyword(s):  
Optimization Problems ◽  
Greedy Heuristic ◽  
Management Problem ◽  
Quality Improvements ◽  
Solution Quality ◽  
Convex Optimization Problem ◽  
Routing Problem ◽  
Multi Stage ◽  
The Cost ◽  
Parametric Convex Optimization

This paper considers multi-stage optimization problems under uncertainty that involve distinct offline and online phases. In particular it addresses the issue of integrating these phases to show how the two are often interrelated in real-world applications. Our methods are applicable under two (fairly general) conditions: 1) the uncertainty is exogenous; 2) it is possible to define a greedy heuristic for the online phase that can be modeled as a parametric convex optimization problem. We start with a baseline composed by a two-stage offline approach paired with the online greedy heuristic. We then propose multiple methods to tighten the offline/online integration, leading to significant quality improvements, at the cost of an increased computation effort either in the offline or the online phase. Overall, our methods provide multiple options to balance the solution quality/time trade-off, suiting a variety of practical application scenarios. To test our methods, we ground our approaches on two real cases studies with both offline and online decisions: an energy management problem with uncertain renewable generation and demand, and a vehicle routing problem with uncertain travel times. The application domains feature respectively continuous and discrete decisions. An extensive analysis of the experimental results shows that indeed offline/online integration may lead to substantial benefits.

scholarly journals Pengaruh Sikap, Norma Subyektif dan Kontrol Perilaku yang Dirasakan Terhadap Niat Beli Pupuk Petroganik di Kabupaten Boyolali

2018 ◽  
Vol 14 (2) ◽  
pp. 95
Author(s):  
Novitasari Dika Kusuma Dewi ◽  
Eny Lestari ◽  
Heru [email protected] Irianto
Keyword(s):  
Structural Equation ◽  
Structural Equation Models ◽  
Environmental Awareness ◽  
Subjective Norms ◽  
Partial Least Square ◽  
Least Square ◽  
Product Attributes ◽  
Survey Techniques ◽  
Multi Stage ◽  
The Cost

<em>This   research   aims   to   find   out   the   effects   of   product   attributes, environmental awareness, the cost of fertilizer usage, subjective norms to the attitude of Petroganik fertilizer purchases also to find out the effects of attitude, subjective norms and cost of fertilizer usage to the intentions of purchasing Petroganik fertilizer. The method used in this research is explanatory methods by using survey techniques. Method taken to determine research location was conducted purposively and this research is done in Nogosari District and Musuk District. The method used for gathering samples with multi stage random sampling. Samples in this research were collected  from  64  respondents  split  from  4  villages  and  8  group  farmers.  The technique of collecting data was solved through observation, interviews, and logging. The analysis of the sample data used for this research is Structural Equation Models (SEM) method and also Partial Least Square (PLS) as an altiernative method. The research finds that (1) product attributes and  environmental awareness positively determinants of  purchase attitudes. (2) subjective norms, purchase attitudes, and cost of fertilizer usage affects the purchase intentions for Petroganik fertilizer.</em>

Design and Direct Assembly of 2.5D/3D Rigid Silicon Interposer on PCB

2014 ◽  
Vol 2014 (1) ◽  
pp. 000783-000786 ◽  
Author(s):  
Farhang Yazdani
Keyword(s):  
Flip Chip ◽  
Thermal Stresses ◽  
Stress Test ◽  
Temperature Cycle ◽  
3D Integration ◽  
Test Vehicle ◽  
Direct Assembly ◽  
Solder Balls ◽  
Present Design ◽  
The Cost

Silicon interposer is emerging as a vehicle for integrating dies with sub 50um bump pitch in 2.5D/3D configuration. Benefits of 2.5D/3D integration are well explained in the literature, however, cost and reliability is a major concern especially with the increase in interposer size. Among the challenges, reliability issues such as warpage, cracks and thermal-stresses must be managed, in addition, multi-layer build-up flip chip substrate cost and its impact on the overall yield must be considered. Because of these challenges, 2.5D/3D silicon interposer has developed a reputation as a costly process. To overcome the reliability challenges and cost associated with typical thin interposer manufacturing and assembly, a rigid silicon interposer type structure is disclosed. In this study, interposer with thickness of greater than 300um is referred to as rigid interposer. Rigid silicon interposer is directly assembled on PCB without the need for intermediary substrate. This eliminates the need for an intermediary substrate, thin wafer handling, wafer bonding/debonding procedures and Through Silicon Via (TSV) reveal processes, thus, substantially reducing the cost of 2.5D/3D integrated products while improving reliability. A 10X10mm2 rigid silicon interposer test vehicle with 310um thickness was designed and fabricated. BGA side of the interposer with 1mm ball pitch was bumped with eutectic solder balls through a reflow process. Interposer was then assembled on a 50X50mm2 FR-4 PCB. We present design and direct assembly of the rigid silicon interposer on PCB followed by temperature cycle results using CSAM images at 250, 500, 750 and 1000 cycles. It is shown that all samples successfully passed the temperature cycle stress test.

scholarly journals Critical Review of the Parameters Affecting the Effectiveness of Moisture Absorption Treatments Used for Natural Composites

2019 ◽  
Vol 3 (1) ◽  
pp. 27 ◽  
Author(s):  
Ahmad Al-Maharma ◽  
Naser Al-Huniti
Keyword(s):  
Moisture Absorption ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Complete Discussion ◽  
Natural Composites ◽  
Review Study ◽  
Fiber Matrix ◽  
Physical Treatments ◽  
The Cost ◽  
High Degree

Natural composites can be fabricated through reinforcing either synthetic or bio-based polymers with hydrophilic natural fibers. Ultimate moisture absorption resistance at the fiber–matrix interface can be achieved when hydrophilic natural fibers are used to reinforce biopolymers due to the high degree of compatibility between them. However, the cost of biopolymers is several times higher than that of their synthetic counterparts, which hinders their dissemination in various industries. In order to produce economically feasible natural composites, synthetic resins are frequently reinforced with hydrophilic fibers, which increases the incompatibility issues such as the creation of voids and delamination at fiber–matrix interfaces. Therefore, applying chemical and/or physical treatments to eliminate the aforementioned drawbacks is of primary importance. However, it is demonstrated through this review study that these treatments do not guarantee a sufficient improvement of the moisture absorption properties of natural composites, and the moisture treatments should be applied under the consideration of the following parameters: (i) type of hosting matrix; (ii) type of natural fiber; (iii) loading of natural fiber; (iv) the hybridization of natural fibers with mineral/synthetic counterparts; (v) implantation of nanofillers. Complete discussion about each of these parameters is developed through this study.

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