Technical Library | 2024-08-29 18:30:46.0
The mechanical experience of consumption (i.e., feel, softness, and texture) of many foods is intrinsic to their enjoyable consumption, one example being the habit of twisting a sandwich cookie to reveal the cream. Scientifically, sandwich cookies present a paradigmatic model of parallel plate rheometry in which a fluid sample, the cream, is held between two parallel plates, the wafers. When the wafers are counterrotated, the cream deforms, flows, and ultimately fractures, leading to separation of the cookie into two pieces. We introduce Oreology (/Oriːˈɒl@dʒi/), from the Nabisco Oreo for "cookie" and the Greek rheo logia for "flow study," as the study of the flow and fracture of sandwich cookies. Using a laboratory rheometer, we measure failure mechanics of the eponymous Oreo's "creme" and probe the influence of rotation rate, amount of creme, and flavor on the stress–strain curve and postmortem creme distribution. The results typically show adhesive failure, in which nearly all (95%) creme remains on one wafer after failure, and we ascribe this to the production process, as we confirm that the creme-heavy side is uniformly oriented within most of the boxes of Oreos. However, cookies in boxes stored under potentially adverse conditions (higher temperature and humidity) show cohesive failure resulting in the creme dividing between wafer halves after failure. Failure mechanics further classify the creme texture as "mushy." Finally, we introduce and validate the design of an open-source, three-dimensionally printed Oreometer powered by rubber bands and coins for encouraging higher precision home studies to contribute new discoveries to this incipient field of study
Technical Library | 2014-06-26 16:43:12.0
Edgebond adhesives have been widely used by the industry for improving the shock performance of area array packages. Most of the studies focus on the impact of material properties, such as coefficient of thermal expansion (CTE) and glass transition temperature (Tg), on reliability at room temperature. However, the operating temperature of a component on the printed circuit board bonded with edgebond adhesive can be close to or exceed Tg of the adhesive, where the material properties may be very different than at room temperature.
Technical Library | 2016-01-12 11:07:56.0
With the increasing demand of device miniaturization, high speed, more memory, more function, low cost, and more flexibility in device design and manufacturing chain, YINCAE has published a white paper on a first individual solder joint encapsulant which can eliminate underfilling process with at least five times solder joint increase and provide more flexibility for fine pitch and high density application. In order to meet the demand of manufacturing of high speed and low cost, YINCAE has invented a room temperature stable and jettable solder joint encapsulant adhesive – SMT 266. The invention of SMT 266 has allowed our customers to have more flexibility in their high-speed production line such as worry free on the work life of adhesive and workable jetting process.
Technical Library | 2019-05-21 00:21:26.0
Continue to talk about the dust removal from temperature humidity test chamber. Cleaning and maintenance: 1) Pls remove internal impurities inisde chamber before operation. 2) The power distribution room should be cleaned at least once a year, and the dust can be removed by vacuum cleaner. 3) The exterior chamber must also be cleaned more than once a year, which can be wiped with soapy water. Inspection and maintenance of humidifier: The water storage in humidifier should be replaced once a month to ensure clean water quality, humidifying water tray should be cleaned once a month to ensure smooth flow of water. The inspection of over-temperature protector:during the test: If the temperature is over 20 ℃ ~ 30 ℃ than the maximum value setted,the power supply of the heater will stop, the "OVERHEAT" overt-emperature warning light will automatically turn on but the fan is still in operation, if the equipment runs without operator around,the operator should check the over-temperature protector in advance to ensure wether it has been setted properly before start [wet ball over-temperature protector set to 120 ℃].
Technical Library | 2019-11-17 22:46:45.0
Overview of walk-in temperature and humidity chamber: It also belongs to environmental test equipment, it tests whether the product can resist high temperature, low temperature, humidity, or the physical and chemical changes produced under extreme conditions, the walk-in temperature and humidity chamber volume is large, the product is placed, or a large object can be placed, such as automobile, new energy, television and liquid crystal screen, etc. How to do the routine maintenance of the walk-in temperature and humidity chamber: 1. The wet gauze basically, if there is no special case, s/b usually changed once in 3 months 2. The water channel shall be regularly cleaned, including water cup, water tank, etc., so as to prevent the water from being blocked,affect the humidity test. 3. It is forbidden to test the flammable and explosive products inside working room. 4. Clean the chamber on a regular basis 2. How to operate walk-in temperature and humidity chamber: The operation method is same as standard temperature humidity test chamber,the controller is 7-inch LCD programmable color screen, you only need to setthe temperature point---test time--how many cycles need to be tested, This can be done automatically, and the machine will stop automatically when it is complete. If there is any problem during the operation, the corresponding problem point will be displayed on the machine control screen. Walk-in temperature and humidity chamber is a must equipment for reliability test of Automobile,Aerospace,Electronic parts,etc,the operation and maintenance are easy,it is teh tear down mahcine,Climatest engineers will be dispatched to do on-site support,for instance,we will finish commissioning,train customers how to operate,maintain,welcome to follow our company facebook page:https://www.facebook.com/Climatechambers
Technical Library | 2016-10-03 08:28:47.0
With the miniaturization of electronic device, Land Grid Array (LGA) or QFN has been widely used in consumer electronic products. However there is only 20-30 microns gap left between LGA and the substrate, it is very difficult for capillary underfill to flow into the large LGA component at room temperature. Insufficient underfilling will lead to the loss of quality control and the poor reliability issue. In order to resolve these issues, a room temperature fast flow reworkable underfill has been successfully developed with excellent flowability. The underfill can flow into 20 microns gap and complete the flow of 15mm distance for about 30 seconds at room temperature. The curing behavior, storage, thermal cycling performance and reworkability will be discussed in details in this paper.
Technical Library | 2008-03-13 13:02:50.0
Three full-field optical techniques, shadow moiré, fringe projection and digital image correlation (DIC), are used to measure temperature-dependent warpage for a PBGA package and a PCB component land site from room temperature to 250ºC. The results are qualitatively similar, but imaging resolution and noise properties create offsets between coplanarity values. The paper summarizes strengths and weaknesses for each technique.
Technical Library | 2016-01-08 11:56:03.0
Solder joint encapsulant adhesives have been successfully used to enhance the strength of solder joints and improve thermal cycling as well as drop performance in finished products. The use of solder joint encapsulant adhesives can eliminate the need for underfill materials and the underfill process altogether, thus simplifying rework, which results in a lower cost of ownership.Solder joint encapsulant adhesives include: low temperature and high temperature solder joint encapsulant adhesives, and their derivatives. Each solder joint encapsulant adhesive has: unfilled and filled solder joint encapsulant adhesives, and solder joint encapsulant paste. Each solder joint encapsulant product has been designed for different applications. In this paper, we are going to discuss the details and future of solder joint encapsulant adhesives.
Technical Library | 2011-12-22 16:45:49.0
This paper reports the feasibility of using surface mount adhesives to produce low temperature microchannel arrays in a wide variety of metals. Sheet metal embossing and chemical etching processes have been used to produce sealing bosses that eliminate ch
OSU School of Mechanical, Industrial, and Manufacturing Engineering (MIME)
Technical Library | 2022-01-26 15:22:33.0
Reliability of conformal coatings used to mitigate tin whisker growth depends on their ability to contain tin whiskers. Two key material properties required to assess the reliability of a polyurethane coating are documented experimentally: adhesion strength and puncture strength. A modified blister test using a predefined blister area is employed to assess the adhesion strength and a puncture test is employed to evaluate the puncture strength of the coating. After measuring the properties at time zero, the coatings are subjected to accelerated testing conditions (high temperature/humidity storage and temperature cycling) and the degradations of the coating properties are documented.
