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High-Throughput Vapor Phase Reflow

Continued from page 1

cluding vacuum before and during the soldering process, lowering the Galden boiling point for low- melting solders and gas ex- change during the process (vacuuming of contami- nants, flux-free soldering). The system uses independ- ent transport for the four chambers, which also helps with unloading. The cooling process is located at the rear of the system and is per- formed by convection at each chamber station. Effi- cient cooling, adopted from convection cooling soldering machines, ensures that the products arrive at the system outfeed at man- ageable temperatures. Loading and unloading of the

system’s goods carrier takes place in- ternally. The system offers the same advantage as convection flow sys- tems — products arrive on a convey- or belt and are then distributed with-

in the system to the goods carriers before being returned to a single track. According to the company, the CondensoX-Line Quad Core is the

July, 2020

CondensoX-Line Quad Core with four parallel process chambers.

only vapor phase soldering system to allow process gases and formic acid to be used, as well as continuous vac- uum processes, at high throughput. Contact: Rehm Thermal Sys-

tems, LLC, 3080 Northfield Place, Suite 109, Roswell, GA 30076 % 770-442-8913 fax: 770-442-8914 E-mail: Web: r

Continued from page 1

Self-Powered “Paper Chips” May Help Fight Wildfires To make paper-based thermo-

electric sensors, the researchers chose two ionic liquids that behaved differently when the temperature in- creased: One adsorbed to the surface of gold electrodes, while the other desorbed, producing opposite (posi- tive or negative) voltages. They deposited each ionic liquid

like an ink between two gold elec- trodes that were sputtered onto a piece of ordinary paper. When connected in series, the

two ionic liquids produced an electric signal when a large temperature dif-

ference occurred, as would happen in a fire. In a pilot test of the new sen- sor, the researchers attached one to a houseplant. When they placed a flaming cot-

ton ball close to the plant’s roots, the temperature at the bottom of the sen- sor quickly increased, producing a voltage that an attached microcom- puter chip transmitted to a receiver. Upon picking up the signal, the re- ceiver sounded an alarm and activat- ed a red light. The thermoelectric pa- per chips are cheap ($0.04), and the materials are eco-friendly. Web: r

The Optical Future of Computing

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covered. “What is remarkable about the

result is the full photonic integration and reproducibility with which fre- quency combs can be generated on demand,” adds Tobias J. Kippenberg, professor of physics at EPFL who leads the laboratory and photonics and quantum measurement (LPQM), and whose laboratory first observed microcombs more than a decade ago. The EPFL team has provided the

ultra-low-loss silicon nitride photonic chips, which were fabricated at the EPFL Center of MicroNanoTechnolo- gy (CMi) and serve as the key compo- nent for soliton comb generation. The low-loss silicon nitride photonics technology has been commercialized by the lab startup LIGENTEC.

Highly Coupled Behind all these improvements

lies in an interesting physical phe- nomenon. When the pump laser and resonator are integrated, their inter- action forms a highly coupled system that is self-injection-locking and si-

multaneously generates “solitons” — pulses that circulate indefinitely in- side the resonator and give rise to op- tical frequency combs. The new technology is expected

to have an extensive impact on pho- tonics. In addition to addressing the demands of multicolor light sources in communication-related products, it also opens new opportunities in many applications. One example is optical clocks, which provide the most accurate time standard in the world and are used in several appli- cations, from navigation to measur- ing physical constants. “Optical clocks used to be large,

heavy and expensive,” says Bowers. “There are only a few in the world. With integrated photonics, we can make something that could fit in a wristwatch, and you could afford it.” The future looks bright for pho-

tonics. “It is the key step to transfer the frequency comb technology from the laboratory to the real world,” says Bowers. “It will change photon- ics and our daily lives.” Web: r

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