High Reliability No-Clean Solder Paste for Designs where Flux Cannot be Dried

2015 ◽  
Vol 2015 (1) ◽  
pp. 000434-000442
Author(s):  
Fen Chen ◽  
Ning-Cheng Lee

The miniaturization trend is driving industry to adopting low standoff components or components in cavity. The cost reduction pressure is pushing telecommunication industry to combine assembly of components and electromagnetic shield in one single reflow process. As a result, the flux outgassing/drying is getting very difficult for devices due to poor venting channel. This resulted in insufficiently dried/burnt-off flux residue. For a properly formulated flux, the remaining flux activity posed no issue in a dried flux residue for no-clean process. However, when venting channel is blocked, not only solvents remain, but also activators could not be burnt off. The presence of solvents allows mobility of active ingredients and the associated corrosion, thus poses a major threat to the reliability. In this work, a new halogen-free no-clean SnAgCu solder paste, 33-76-1, has been developed. This solder paste exhibited SIR value above the IPC spec 100 MΩ without any dendrite formation, even with a wet flux residue on the comb pattern. The wet flux residue was caused by covering the comb pattern with 10 mm × 10 mm glass slide during reflow and SIR testing in order to mimic the poorly vented low standoff components. Paste 33-76-1 also showed very good SMT assembly performance, including voiding of QFN and HIP resistance. The wetting ability of paste 33-76-1 was very good under nitrogen. For air reflow, 33-76-1 still matched paste C which is widely accepted by industry for air reflow process. The above good performance on both non-corrosion with wet flux residue and robust SMT process can only be accomplished through a breakthrough in flux technology.

2020 ◽  
Vol 39 (3) ◽  
pp. 3259-3273
Author(s):  
Nasser Shahsavari-Pour ◽  
Najmeh Bahram-Pour ◽  
Mojde Kazemi

The location-routing problem is a research area that simultaneously solves location-allocation and vehicle routing issues. It is critical to delivering emergency goods to customers with high reliability. In this paper, reliability in location and routing problems was considered as the probability of failure in depots, vehicles, and routs. The problem has two objectives, minimizing the cost and maximizing the reliability, the latter expressed by minimizing the expected cost of failure. First, a mathematical model of the problem was presented and due to its NP-hard nature, it was solved by a meta-heuristic approach using a NSGA-II algorithm and a discrete multi-objective firefly algorithm. The efficiency of these algorithms was studied through a complete set of examples and it was found that the multi-objective discrete firefly algorithm has a better Diversification Metric (DM) index; the Mean Ideal Distance (MID) and Spacing Metric (SM) indexes are only suitable for small to medium problems, losing their effectiveness for big problems.


2019 ◽  
Vol 10 (1) ◽  
pp. 1-27
Author(s):  
Aniek Wijayanti

Business Process Analysis can be used to eliminate or reduce a waste cost caused by non value added activities that exist in a process. This research aims at evaluating activities carried out in the natural material procurement process in the PT XYZ, calculating the effectiveness of the process cycle, finding a way to improve the process management, and calculating the cost reduction that can achieved by activity management. A case study was the approach of this research. The researcher obtained research data throughout deep interviews with the staff who directly involved in the process, observation, and documentation of natural material procurement. The result of this study show that the effectiveness of the process cycle of natural material procurement in the factory reached as much as 87,1% for the sand material and 72% for the crushed stone. This indicates that the process still carry activities with no added value and still contain ineffective costs. Through the Business Process Mechanism, these non value added activities can be managed so that the process cycle becomes more efficient and cost effectiveness is achieved. The result of the effective cycle calculation after the management activities implementation is 100%. This means that the cost of natural material procurement process has become effective. The result of calculation of the estimated cost reduction as a result of management activity is as much as Rp249.026.635,90 per year.


Author(s):  
Michael Woo ◽  
Marcos Campos ◽  
Luigi Aranda

Abstract A component failure has the potential to significantly impact the cost, manufacturing schedule, and/or the perceived reliability of a system, especially if the root cause of the failure is not known. A failure analysis is often key to mitigating the effects of a componentlevel failure to a customer or a system; minimizing schedule slips, minimizing related accrued costs to the customer, and allowing for the completion of the system with confidence that the reliability of the product had not been compromised. This case study will show how a detailed and systemic failure analysis was able to determine the exact cause of failure of a multiplexer in a high-reliability system, which allowed the manufacturer to confidently proceed with production knowing that the failure was not a systemic issue, but rather that it was a random “one time” event.


2017 ◽  
Vol 1 (2) ◽  
pp. 81-107
Author(s):  
Dheny Biantara

Summarized Indonesian airline executive views on the reason for the cost problem in mayor airline andon the potential areas and measures of cost reduction in airline operation. Present an introductionsurvey where 3 executives from 3 Indonesian airlines were respondent. In the executive opinion the costproblem in mayor Indonesian airline is primarily due to fuel and oil pricing and money currency. Of thevarious function in airline maintenance was seen as least cost efficiency, whereas flight operation wasseen as an area with most potential for cost reduction. Indonesian airline had made route and fleetchanges after the beginning of 2011 to reduce cost, concludes from the analisys result havingprivatization would be an important step towards more efficient airline operation. Flexibility fromIndonesian airline regulatory would be very much welcome and the value chain concept to improveIndonesian airline having competitive adventage and cost leadership differentiation.


2016 ◽  
Vol 857 ◽  
pp. 76-78
Author(s):  
Norliza Ismail ◽  
Roslina Ismail ◽  
Nur Izni Abd Aziz ◽  
Azman Jalar

Wettability for lead free solder 99.0Sn-0.3Ag-0.7Cu (SAC237) with addition of different weight percentage carbon nanotube after thermal treatment was investigated. SAC 237 solder powder with flux was mixed with 0.01%, 0.02%, 0.03% and 0.04% carbon nanotubes (CNTs) to form SAC-CNTs solder paste. Printed solder paste on test board with Cu surface finish was then reflow under 270°C temperature and isothermal aging at 150°C for 0,200 and 400 hours. Wettability of SAC-CNT solder was determined by measuring contact angle using optical microscope and image analyzer. As a result, from reflow process right through 400 hours of thermal aging, SAC237 with 0.04% CNT has the lowest contact angle as compared to other SAC-CNTs and SAC237 solder. As a conclusion, addition of carbon nanotubes into solder SAC237 improved their wettability on Cu substrate, especially at 0.04% of CNTs.


2016 ◽  
Vol 20 (3) ◽  
pp. 299-315
Author(s):  
Massimo Latour

In this work, a recently patented seismic damper to be applied to structures composed by systems of panels is presented. In particular, the article is devoted to characterize the behaviour of the proposed connector by means of an experimental and numerical analysis and to provide some information about the cost of the elements needed to realize the damper, accounting for the manufacturing process. The experimental analysis has regarded five specimens tested under different loading conditions, and it has been used as a term of comparison with the classical systems of connection currently employed in these structures. Afterwards, in the article, a design criterion able to control the capacity and ductility of the device by simply varying the shape of the damper is presented and its accuracy is evaluated by performing finite element analyses. The results of the experimental and finite element analyses are very promising in terms of cyclic behaviour and energy dissipation capacity and reveal that the design of the element can be accurately controlled by means of the proposed approach. Furthermore, the cost estimate has revealed that the proposed damper is also cheaper than the classical solutions with a cost reduction of about 40%.


2021 ◽  
pp. 1-48
Author(s):  
Robert M. Costrell

Abstract The ongoing crisis in teacher pension funding has led states to consider various reforms in plan design, to replace the traditional benefit formulas, based on years of service and final average salary (FAS). One such design is a cash balance (CB) plan, long deployed in the private sector, and increasingly considered, but rarely yet adopted for teachers. Such plans are structured with individual 401(k)-type retirement accounts, but with guaranteed returns. In this paper I examine how the nation's first CB plan for teachers, in Kansas, has played out for system costs, and the level and distribution of individual benefits, compared to the FAS plan it replaced. My key findings are: (1) employer-funded benefits were modestly reduced, despite the surface appearance of more generous employer contribution matches; (2) more importantly, the cost of the pension guarantee, which is off-the-books under standard actuarial accounting, was reduced quite substantially. In addition, benefits are more equitably distributed between short termers and career teachers than under the back-loaded structure of benefits characteristic of FAS plans. The key to the plan's cost reduction is that the guaranteed return approximates a low-risk market return, considerably lower than the assumed return on risky assets.


2014 ◽  
Vol 39 (1) ◽  
pp. 165-172
Author(s):  
Praveen Kumar Verma ◽  
SK Nag ◽  
SK Patil

The paper has studied the economic viability of improved technology (Introduced under NAIP component-3) for extraction of cashew kernel from cashew nut in Bastar region of Chhattisgarh, India. Cost concept has been used to calculate economics of cashew kernel. The technology (Boiling, steaming, cutting, drying, and peeling) has been found viable over conventional practices (Traditional manual separation by stone or hammer) on account of higher recovery of 40 percent and cost reduction by 29.71 percent. Overall net profit per unit (One unit includes one boiler, one steamer, two cutter, one dryer, six peelers and cost of land, depreciation and interest on working capital) in the case of improved technology has been estimated to be Rs 7.32 lakh. Cost of production in machine extraction practices was 202.80 Rupees per kilogram of cashew in spite of traditionally practiced 288.56 Rupees per kilogram. The cost benefit ratio was found higher in machine extraction (1.57) as compare to traditionally practiced (0.169). The mechanical decortications and separation could not only save time and money, also reduced women drudgery (due to manual breaking by stone or hammer to separate kernel). The technology has been found suitable for promotion of entrepreneurship on the processing of cashew kernel from cashew nut in the production catchments which otherwise is not properly utilized. DOI: http://dx.doi.org/10.3329/bjar.v39i1.20166 Bangladesh J. Agril. Res. 39(1): 165-172, March 2014


2009 ◽  
Vol 14 (37) ◽  
Author(s):  
L Brouwers ◽  
B Cakici ◽  
M Camitz ◽  
A Tegnell ◽  
M Boman

Experiments using a microsimulation platform show that vaccination against pandemic H1N1 influenza is highly cost-effective. Swedish society may reduce the costs of pandemic by about SEK 2.5 billion (approximately EUR 250 million) if at least 60 per cent of the population is vaccinated, even if costs related to death cases are excluded. The cost reduction primarily results from reduced absenteeism. These results are preliminary and based on comprehensive assumptions about the infectiousness and morbidity of the pandemic, which are uncertain in the current situation.


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