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Researchers in the US present the first implementation of independent microfluidic cooling of different tiers in a heterogeneous 3D stack based on their power dissipation. Junction temperature difference between tiers with different power dissipation is decreased from 12 to 5 °C. Significant junction temperature reduction and thermal decoupling is achieved compared to air-cooling.
A sensitive age
The relevance of eddy current sensing in monitoring ageing state of electronic power modules is studied in work from France. An eddy current sensor is used to evaluate transistor chips on a direct copper bonded ceramic substrate of a power module. Analysis shows the sensor enables the chip and the substrate to be separately sensed and the ageing state of artificially aged chips can be clearly monitored.
In0.7Ga0.3As Π-gate junctionless transistors have been fabricated for the first time using a CMOS-compatible top-down approach in work from Singapore. The Π-gate structure effectively depletes the carriers in the channel and the 200 nm LG device exhibits good transfer and output characteristics.
A scheme that enhances both the efficiency and the lifetime of LED drivers has been proposed by researchers in Brazil. They have shown that a high-efficiency resonant conversion stage is capable of ripple reduction when working in conjunction with a power factor correction stage, thus allowing capacitance reduction without great penalties in efficiency.
Resonant intensity noise (RIN) is an important consideration when implementing QCLs in real world situations. This is difficult to evaluate in the mid-infrared range, so researchers in Japan have developed a new technique using a movable reflection mirror. The parameters relevant to the intensity noise characteristics were obtained by moving the mirror after the RIN measurements and by observing the self-mixing wave profile.