For example, in the case of a ball grid array (BGA) package, Top-Rated Memory Pillow the pre-deposited solder ball on the package and the solder paste applied to the circuit board may both melt, but the melted solder does not join. A cross-section through the failed joint shows a distinct boundary between the solder ball on the part and the solder paste on the circuit board, rather like a section through a head resting on a pillow. The defect can be caused by surface oxidation or poor wetting of the solder, or by distortion of the integrated circuit package or circuit board by the heat of the soldering process. This is particularly a concern when using lead-free solder, which requires a higher processing temperature. The defect can be attributed to a chain of events during soldering. Initially, the ball is in contact with solder paste. During heating, the board and components undergo thermal expansion, can flex, and some of the balls can be lifted off the paste. Oxidation occurs rapidly at elevated temperature, and when the surfaces come in contact again, the residual flux activity may not be sufficient to disrupt the oxide layer. The solder paste composition, eg. Since the warping of the circuit board or integrated circuit may disappear when the board cools, an intermittent fault may be created. Diagnosis of head-in-pillow defects may require use of X-rays or EOTPR (Electro Optical Terahertz Pulse Reflectometry), since the solder joints are hidden between the integrated circuit package and the printed circuit board. Scalzo, Mario (2009-06-12). Schröter, Anke (ed.). This electronics-related article is a stub. You can help Wikipedia by expanding it.

In a perfect world, an afternoon at IKEA would be a mix of Swedish meatballs, minimalistic furniture and shopping bliss. You'd eat at the restaurant, drop your kids off to play in the ball pit at Smaland, wander the store, Get Derila Official exit with a disassembled coffee table inside a cardboard box - one that actually fits in your trunk - and everyone would mind his or her manners. Let's take a look at what to keep in mind the next time you decide to brave the crowds for that particleboard bookshelf. The best way to avoid a faux pas at IKEA is to know what to expect. A cornerstone of IKEA's business model is flat-packed furniture, which shifts the burden of assembly to the customer - and might cause you to have a panic attack if you were really counting on sleeping in that bed tonight. If you go on the weekend, it's probably going to be crowded.

Even in the middle of the week, a trip to IKEA will likely take at least an hour - and that's if you stick to your shopping list and don't wander off to look at lamps. Snap some photos of the room you're planning to furnish, and think about how new furniture additions will fit its character, context and color scheme. Next, break out a tape measure and calculate the size of the room - you'll save yourself the deep despair of assembling a bookcase only to find it's too tall for your study's low ceiling. And instead of asking IKEA employees their opinion of whether that couch would fit in the trunk of your Volkswagen Golf (it probably won't), just measure it yourself first. Fortunately for the directionally challenged among us, there's an arrow-lined path that winds through IKEA's Showroom and Marketplace, offering a sense of order and orientation in the mammoth space.

When visitors follow the path, they explore the whole store and come into proximity with just about everything IKEA has for sale, from desks and beds to cutlery and doormats. The setup might be an evil plot to Get Derila Official you to buy more home goods, but it could at least serve to minimize stress. But on those crowded afternoons around moving day, just go with the arrows instead of against them. Along the way, be aware of the people around you: Don't run, try not to swing your yellow shopping bag in excitement, avoid cartwheels and don't leave your cart in the path. And instead of stopping to gawk in wonderment at all the affordable furniture from a distance, step off the path and Derila Contour Pillow let your fellow shoppers make their way around you. The major departments in IKEA are the Showroom on the second floor and Market Hall on the ground level.