Reliability is defined as the ability of a system or component to perform its required functions under stated conditions for a specified period of time. The operation of any electronic device generates heat and with the increasing device density of the IC chips the amount of heat flux generated by the integrated circuit chips has gone to a level of 100-200 W/(cm^2 ) [2]. Each time a device is powered up, the individual components heat up and cool down. This heating and cooling leads to thermal cycling of the electronic components which causes many problems, such as shear deformation, due to the mismatch in coefficients of thermal expansion (CTE) of each material. Figure 2.1 shows the varying CTEs for a typical PBGA package in this research. …show more content…
A disadvantage of plastic moulding compounds is that they are hydrophilic and absorb moisture when exposed to a humid environment [4]. This popcorn-like explosion happens when moisture that is trapped inside the moulding compound becomes heated and vaporized during the solder joint reflow process and the only way for it to escape is to expand the moulding compound until it cracks and the vapor is released. After investigated the moisture sensitivity in several surface mount packages that included SOJ, PLCC, TQFP, and PQFP packages. A researcher studied the moisture induced failures of Ball Grid Array packages such as PBGA and TBGA. They showed that baking the chips at 115°C for sixteen hours essentially removes most of the moisture content from the package, and reduces the possibility of the interfacial delamination and popcorn cracking of the package. By encountering this popcorn cracking, it is used to propose a new lead frame design for improved reliability of these …show more content…
In this study, structural and thermal reliability of ball grid array packages, mainly the shear stresses and strains of critical solder balls, have been investigated using accelerated life testing. Many studies and failure analyses have been showing that interconnect failures due to mismatches of CTE during thermal cycling is the most critical mode of failure in leaded and SMT packages such as BGAs [5]. Figure 2.3 shows a schematic of what happens to the solder joints during thermal cycling due to mismatches in CTEs. It shows that at a stress-free temperature, the two components, silicon and the PCB, are relaxed. Then, as the temperature increases, the PCB wants to expand at a higher rate since the PCB’s CTE is 14.5 ppm/°C and the CTE of the silicon is 2.54 ppm/°C. As the temperature drops, the PCB wants to contract much quicker than the silicon. Looking at the schematic, one can see that the solder joints are having to flex and deform due to the mismatch in CTE between the two materials. Over time, these shear stresses and strains cause the solder joints to become fatigued, then cracks begin to propagate, and the package will ultimately fail once a certain number of thermal cycles have been
Nobody likes to get to the end of their popcorn bowl only to have most of the popcorn not popped. It is very frustrating to purchase popcorn and end up with a bowl of un-popped kernels. Well, this experiment is to determine which brand of popcorn yields the least amount of un-popped kernels?
Book Review: ‘Why does popcorn cost so much at the movies: and other pricing puzzles’ by Richard B. McKenzie
From pioneering in memory DRAM semicon to exiting the low-margin DRAM market – Intel was primarily a Memory semicon manufacturer before it entered microprocessors in 1980s. Its added value in the memory industry in 1970s was very high because of its advances in MOS process to produce DRAM. However, with increase in competition and the advancement of Japanese conglomerates in the memory industry Intel was forced to play a chasing game to improve performance and reduce costs. In the mid-1980s, Intel’s market share in the core memory business was <1%, however it was continuing to invest in this domain. They finally exited the DRAM market, which was more of a cash burner with low-margins.
First of all, the material cost element could be affected by the part weight driver under Design, material cost driver under Geography and scrap and defect driver under both Design and Operations. According to the data collected, Design will not cause any cost difference because each injection molded part is made with the exact same specifications in all regions. As a result, the material cost driver is the most important cost driver for the
Based on the 3 types of quality costs that have been discussed and reviewed above, I recommend that we look at doing more appraisals and inspections during the manufacturing process, this will limit the number of design changes that happen early in the process but it should help in cutting down our external failure costs and help limit
Have you ever wondered how popcorn kernels get left behind? Research by food scientist Bruce Hamaker from Perdue University suggests that it is lack of moisture. Moisture helps the corn kernel pop. You should store your popcorn in a cupboard where it is dry, never put your un-popped popcorn in the refrigerator because that will cause it to lose moisture. I am figuring out which brand of popcorn leaves least amount of kernels.
Mark Twain, although quite the comedian, makes a valid point in “Corn-Pone Opinions”. The observation of humanity and its tendencies to follow what society promotes is a relevant occurrence today. Twain leads on “. . . that it’s born of the human being’s natural yearning to stand well with his fellows and have their inspiring approval and praise . . .” (720). Humans are not equipped to stand their own ground; they prefer to follow the leader. Twain puts it simply, “we are creatures of outside influences; as a rule we do not think, we only imitate” (719). Twain clearly makes his point noticeable to his audience, holding back no opinion throughout the
The proliferation of packaging products and poor product education has caused confusion among end users. US consumers have traditionally viewed packaging supplies as a cost-saving resource. Consequently, packaging engineers are accorded high status and influence roughly 40% of material purchase decisions. The US market is experiencing strong growth, driven in part by the growth of the coated and uncoated bubbles segment. However, AirCap's market share remains stagnant (Appendix A).
Indium based solders have distinct features of low melting temperature and low temperature ductility. They have very rapid rate of recovery and recrystallization, which could be as fast as their work hardening rate. These characteristics make the indium joint seldom to fail under thermal cycling: usually they fail due to overload or unidirectional creep [1]. Therefore, indium solders could be a preferred choice to solder dissimilar materials to be used under thermal cyclic service condition [2].
Blockbuster was “the largest movie rental chain” in the Movies industry around the world (Biesada a). According to Rourke, Rothburd and Stansell (2006), Blockbuster mainly focused on “providing in-home rental, retail movie, and game entertainment”. It created 9,100 video stores and provided services to almost three million of customers in America and 24 other countries (p. 74). In 2010, the company filed for bankruptcy since it failed to adapt new technology in their strategies, and “was sold to satellite TV service provider DISH Network in 2011” (Biesada b).
Overall, there is an apparent disparity between the capacities of each of the operation processes. The output from the different stages ranges from 900 to as much as 1,800 boards. It is seen that the bottleneck in the whole manufacturing of circuit boards is in the part that has the lowest capacity, and incidentally, located in the earliest part of the production process the cleaning and coating machines. This means that the maximum number of circuit boards that will be finished by the end of the day is 900. From the finished boards, there is a historical defect rate of 20%, thereby leaving a total of only 720 boards that are ready for packing and shipping to the customer. It is therefore apparent that CBF is manufacturing very inefficiently, as they 280 circuit boards short of the required output per shift of 1,000 units.
As a global leader in the PC market, Lenovo’s success rests on its ability to deliver consumer centric innovations in products that deliver a blend of mobility, performance and price. Design is an infrastructural element that helps define every aspect of a company, including Web site, stores, customer support, packaging, and messaging as well as its products. Lenovo has a well-earned industry reputation for delivering superior quality products. Quality is a fundamental component and commitment to customer satisfaction by delivering products that are of superior quality to comparable offerings from their competitors is the key to Lenovo’s success. In recent years, Lenovo relies heavily on local manufacturing strategies to shorten
In the component market, integrated circuit technology is threat of new entrants. The growth of integrated circuit technology makes existing component market shrink. EPD has taken aggressive moves to protect its market share from competitors and new entrants. Therefore, in existing market, EPD needs a cost reduction effort more and change their business model into low-margin high-volume business. It means that they should change their evaluation system; the plant should maintain 40% of gross margin. Additionally, they need to introduce new products into market to acquire new source of revenue. EPD has not built the clear strategies and shared them with employees.
The cereal market is a booming industry. It has been around for over one hundred years and continues to attract millions of customers’ everyday. The market structure of the cereal industry is an Oligopoly. This is because there are four large firms, Kellogg, General Mills, Post, and Quaker Oats, which dominate the industry.
The evaluation of a film assigns some form of value to a film and the experience you encountered while watching the film. Evaluation can imply the criteria and standards that you can argue about to place value on a film. Thus, giving people a reason to question a film to develop reasons, make such standards are met and to understand the film. These standards can stem from the classical evaluation and pluralistic-category method which has given viewers a blueprint of how you should properly evaluate a film. There are certain ways that you can go about judging a films effectiveness. For instance, the classical evaluation method imposes the use of cinematicity within three concepts that all films should have. Like medium specificity, cinematicity allows film to distinguish itself from theatre with the use of close-ups, camera movement, etc.; thus, creates a universal structure for critics to judge a film. This is based on the creative style of the director and how much the viewers admire the way the has stuck with its cinematicity. However, the pluralistic-category does not base its evaluation on style and opinion. In all, these types of evaluations are used in different ways which will be further explained throughout this essay.