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August 2014 • The PCB Design Magazine 31 that shows up during testing. This raises the question: How much should you test? Should you even test at all? If the processes are correct, then there should be no failures, and no need to test. Testing is an overhead expense. Yes, we know that the industry will keep on testing, but it always raises the question of why we tested in the first place when we found no faults. After all of this, you do not want to be let down by having distribution systems or meth- odologies that introduce faults. So, you need your clean, no-fault culture to follow you out to laminate distribution, directly from the manu- facturing plant. Advanced laminate manufacturers with AS9100C accreditation such as Ventec foster a cleanliness culture. This means that less check- ing is required to ensure that the laminate is fault-free, and that faults will not be introduced into the material. Even OEMs outside the aerospace segment can benefit from partnering with AS9100C- accredited companies. Often, the cultural ef- fects of this standard pervade the working methodologies and practices throughout the company, along with stricter policy elements of standard. OEMs may find standard accreditation, par- ticularly AS9100C, to be a useful measure of quality when qualifying potential partners, both laminate providers and fabricators. PCBDESIGN feature PCB LAMINATES AND AS9100C continues Martin Cotton is OeM Technology Director for ventec international group. Mark goodwin is the COO usA & europe for ventec interna- tional group. by Real Time with... NEPCON South China The magnets cluttering the face of your refrig- erator may one day be used as cooling agents, according to a new theory formulated by MiT researchers. The theory describes the motion of magnons — quasi-particles in magnets that are collective rotations of magnetic moments, or "spins." in addition to the magnetic moments, magnons also conduct heat. "you can pump heat from one side to the other, so you can essentially use a magnet as a refrigerator," says Bolin liao, a graduate student in MiT's Department of Mechanical en- gineering. "you can envision wireless cooling where you ap- ply a magnetic field to a mag- net one or two meters away to, say, cool your laptop." in theory, liao says, such a magnetically driv- en refrigerator would require no moving parts, unlike conventional iceboxes that pump fluid through a set of pipes to keep things cool. liao and his colleagues recognized a similar "coupled" phenomenon in magnons, which move in response to two forces: a temperature gradient or a magnetic field. Because magnons behave much like electrons in this aspect, the re- searchers developed a theory of magnon trans- port based on a widely established equation for electron transport in thermoelectrics, called the Boltzmann transport equa- tion. "There's still a long way to go for thermoelectrics to compete with traditional technologies," liao says. "studying the magnetic degree of freedom could potentially help optimize existing systems and im- prove the thermoelectric ef- ficiency." Magnets May Act as Wireless Cooling Agents

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