Analysis and experiment on multicarrier passive intermodulation in high power component

The ever-rising amount of data transferred between data centers and clients requires more computational power than ever. Temperature control requirements, such as set-point range and accuracy, during validation testing of high power components remain unchanged, creating a design challenge for thermal solutions. In addition, thermal solutions must remain within small footprints in order to fit the increasingly dense testing board. Thermal solutions based on Thermo-Electric Cooler (TEC) modules have been found to be a very flexible low cost solution with good thermal performance and easy temperature control. The cooling performance of a TEC is directly related to its size and number of Peltier elements. Therefore, high cooling capacities require a very large device foot-print which may not conform to design space constraints. This paper describes an empirical study which investigates the feasibility and performance of a TEC based thermal solution with auxiliary coolant channels embedded within the cold plate for additional cooling. This allows for an increase in cooling power without compromising the overall footprint. Experiments were performed on a mockup device simulating a very high power component with an internal heater producing up to 400W. A number of configurations were tested with a different number of coolant channels. The test configurations were chosen based on manufacturing constraints. Test results show a dramatic improvement in cooling performance in the high power range compared to the baseline configuration (solid cold plate). Temperature reductions of ∼40°C at 400W power load were observed. However, for low power loads, the addition of the coolant channels was found to interfere with the TEC cooling capabilities resulting in worse performance. Further testing of the channeled configuration without coolant flow showed very similar results to the baseline. Future implementation of flow control is expected to enable optimal performance in the whole power range.

The design of optical components for high average power lasers requires some additional and unique considerations not present in low power systems. Most common components simply cannot survive in the hostile environment of a high power laser beam. The most successful approaches are those which most constructively deal with the problem of the absorption of laser radiation and the removal of waste heat, while staying within an allowable beam distortion budget. This paper contains a discussion of the problems and promise of four high power components: solid windows, aerodynamic windows, high reflectance mirror coatings, and pulsed damage resistant mirrors. The state-of-the-art performance of these optical elements is discussed. Finally, some crucial issues which must be resolved if applications of high average power lasers are ever to become routine, are enumerated.

The design of optical components for high average power lasers requires some additional and unique considerations not present in low power systems. Most common components simply cannot survive in the hostile environment of a high power laser beam. The most successful approaches are those which most constructively deal with the problem of the absorption of laser radiation and the removal of waste heat, while staying within an allowable beam distortion budget. This paper contains a discussion of the problems and promise of four high power components: solid windows, aerodynamic windows, high reflectance mirror coatings, and pulsed damage resistant mirrors. The state of the art performance of these optical elements is discussed. Finally, some crucial issues which must be resolved if applications of high average power lasers are ever to become routine, are enumerated.

The overmoded rf transmission and pulsed power compression system for SLAC’s Next Linear Collider (NLC) program requires a high degree of transmission efficiency and mode purity to be economically feasible. To this end, a number of new, high power components and systems have been developed at X-band, which transmit rf power in the low loss, circular TE01 mode with negligible mode conversion. In addition, a highly efficient SLED-II [1] pulse compressor has been developed and successfully tested at high power at two accelerator test facilities at SLAC. The systems produced a 200 MW pulse with a near-perfect flat-top with pulse widths ranging from 150–245 ns. In this paper we describe the design and test results of a rectangular-to-circular mode converter and the components/transmission systems based on them, as well as the design and measurements of the high power pulse compression systems using SLED-II. We will also describe how these components are being used to efficiently provide high power rf in the NL...

RF & Optoelectronic packages continue to shrink in size with less space for die. Power densities are increasing as well. Packaging engineers are exploring a switch from conductive adhesive to eutectic solder attachments on high power components. Lower power components still allow adhesive attachment but have their own challenges due to tight spacing. This paper explores a range of case studies that demonstrate both eutectic and adhesive assembly and the results for closely spaced components. An overview of the technology and the placement accuracy and attachment method is presented for eutectic and adhesive based attachment for components ranging from 0.18mm [7.1mil] × 0.18mm [7.1mil] × 0.20mm [7.9mil] Si die to 1.7mm [67mil] × 1.4mm [55mil] × 0.16mm [6.3mil] GaAs die. Component spacing of 60μm or less create challenges in keeping epoxy or solder from squeezing between die. A review of tools, guidelines, and actual results will be shared in this paper.

Structural health monitoring of solder joints in QFN package

This study focuses on developing computational models for hybrid or liquid cooled data centers that may reutilize waste heat. A data center with 17 fully populated racks with IBM LS20 blade servers, which consumes 408 kW at the maximum load, is considered. The hybrid cooling system uses a liquid to remove the heat produced by high power components, while the remaining low power components are cooled by air. The paper presents three hybrid cooling scenarios. For the first two cases, air is cooled by direct expansion (DX) cooling system with air-side economizer. Unlike the cooling air, two different approaches for cooling water are investigated: air-cooled chiller and ground water through liquid-to-liquid heat exchanger. Waste heat re-use for pre-heating building water in co-located facilities is also investigated for the second scenario. In addition to the hybrid cooling models, a fully liquid cooling system is modeled as the third scenario for comparison with hybrid cooling systems. By linking the computational models, power usage effectiveness (PUE) for all scenarios can be calculated for selected geographical locations and data center parameters. The paper also presents detailed analyses of the cooling components considered and comparisons of the PUE results.

BackgroundChronic activation of the stress-response can contribute to cardiovascular disease risk, particularly in sedentary individuals. This study investigated the effect of a Bikram yoga intervention on the high frequency power component of heart rate variability (HRV) and associated cardiovascular disease (CVD) risk factors (i.e. additional domains of HRV, hemodynamic, hematologic, anthropometric and body composition outcome measures) in stressed and sedentary adults.MethodsEligible adults were randomized to an experimental group (n = 29) or a no treatment control group (n = 34). Experimental group participants were instructed to attend three to five supervised Bikram yoga classes per week for 16 weeks at local studios. Outcome measures were assessed at baseline (week 0) and completion (week 17).ResultsSixty-three adults (37.2 ± 10.8 years, 79% women) were included in the intention-to-treat analysis. The experimental group attended 27 ± 18 classes. Analyses of covariance revealed no significant change in the high-frequency component of HRV (p = 0.912, partial η2 = 0.000) or in any secondary outcome measure between groups over time. However, regression analyses revealed that higher attendance in the experimental group was associated with significant reductions in diastolic blood pressure (p = 0.039; partial η2 = 0.154), body fat percentage (p = 0.001, partial η2 = 0.379), fat mass (p = 0.003, partial η2 = 0.294) and body mass index (p = 0.05, partial η2 = 0.139).ConclusionsA 16-week Bikram yoga program did not increase the high frequency power component of HRV or any other CVD risk factors investigated. As revealed by post hoc analyses, low adherence likely contributed to the null effects. Future studies are required to address barriers to adherence to better elucidate the dose-response effects of Bikram yoga practice as a medium to lower stress-related CVD risk.Trial registrationRetrospectively registered with Australia New Zealand Clinical Trials Registry ACTRN12616000867493. Registered 04 July 2016.

The overmoded rf transmission and pulsed power compression system for SLAC's Next Linear Collider (NLC) program requires a high degree of transmission efficiency and mode purity to be economically feasible. To this end, a number of new, high power components and systems have been developed at X-band, which transmit rf power in the low loss, circular TE01 mode with negligible mode conversion. In addition, a highly efficient SLED-II* pulse compressor has been developed and successfully tested at high power. The system produced a 200 MW, 250 ns wide pulse with a near-perfect flat-top. In this paper we describe the design and test results of the high power pulse compression system using SLED-II.

With increasing power loss of electrical components, thermal performance of an assembled device becomes one of the most important quality factors in electronic packaging. Due to rapid advances in semiconductor technology, particularly in the field of high-power components, the temperature distribution inside of a component is a critical parameter of long-term reliability and must be carefully considered during the design phase. Two main drivers in the electronics industry are miniaturization and reliability. Whereas there is a continuous improvement concerning miniaturization of conductor tracks (i.e., lines and spaces have been reduced continuously over the past years), miniaturization of the circuit carrier itself, however, has mostly been limited to decreased layer counts and base material thickness. This can lead to significant component temperature increase and thence to accelerated system degradation. Enhancement of the system reliability is directly connected to an efficient thermal management on the PCB level. There are several approaches that can be used to address this issue: optimization of the board design, use of base materials with advanced thermal performance, and use of innovative buildup concepts. The paper provides a short overview about standard thermal solutions such as thick copper, thermal vias, plugged vias, or metal core based PCBs. Furthermore, attention will be focused on the development of copper filled thermal vias in thin board construction. In another approach, advanced thermal management solutions are presented at the board level, exploring different buildup concepts (e.g., cavities). Advantages of cavity solutions in the board are shown that not only decrease the thermal path leading from the high power component through the board to the heat sink, but also have an impact concerning the mechanical miniaturization of the entire system (reduction of z axis). Such buildups serve as a favorable packaging solution with promising thermal performance. Moreover, using thermal simulations different setups are compared and a deeper insight into the thermally relevant geometry and material parameters is provided, allowing production efforts to be reduced and to offering optimized designs and board buildups.

Currently, the vehicle manufacturers use the high power Li-ion technology to supply the electric and hybrid vehicles. This technology is able to ensure the power needed to propel the vehicle. Unfortunately, the lifetime of this technology is very low compared to that given by the energetic technology which can't ensure the needed power. So, to resolve the power limit of the energetic technology without decreasing its lifetime, this technology is associated with high power component (supercapacitor). This association (hybridization) requires the use of more power electronic components to ensure the good operating of these storage systems. This paper deals with the study of the hybrid supply sizing (weight, volume, autonomy and cost) including the size and cost of the DC/DC converter.

The thermal management of electronic products is always a headache to the high power electronics design engineer. Since all electronic components are assembled on the PCB, it's important to develop a good solution to dissipate the heat from PCB to the chassis with conduction method. There are many material and process used for PCB thermal dissipation in the industry now. Some of them like IMS (Insulated Metal Substrate), can be used only for simple circuits like LED substrate. Some like metal bonded PCB that is heavy and expensive. The standard thermal pad/via is not capable for high thermal density components like QFN. It is necessary to develop a simple PCB construction to solve the thermal problem. This paper introduces new design which embeds a small piece of metal coin inside PCB under the high power components. The attached component, like power transistor, sits on the exposed coin surface of the new developed PCB. During operation, the heat created from the components can be effectively dissipated through the coin to another side of the PCB. The heat can then be dissipated to the chassis of equipment or another heat sink. The system thermal problem can be solved for the low thermal resistance of the heat path. Since the coin is small and light weight, it has great advantage of lower cost and very goof performance. Even component with dimension as small as 3 mm long can be applied. Besides, the coin can be electrically connected to the PCB ground layer with different methods. Its electrical performance runs very well in power amplifier PCB for telecommunication industry. This paper will also simulate the thermal performance of different PCB thermal design, include four different coin insertion constructions and its comparison with thermal via PCB and IMS laminate. This technology has been used in the PCB of cell phone base station, point-to-point radio and military radar system. It is also under testing for IC substrate application now.

Thermal management is important for the performance and reliability of today's high power and high density electronics systems. The thermal architecture between the device and heat sink can quickly become very complex when designing for ideal operating temperatures. In order to predict the temperature rise, it is desirable to have a simple modeling technique which reduces the amount of time and effort required to obtain accurate results. Often, the heat flux of the device is based on either the die area or the case area. Complication occurs when simplifying the contact area of a given component. Detailed analyses have been performed for two different cases that show the importance of die-level modeling. In the first case, models of an insulated gate bipolar transistor (IGBT) attached to a cold plate are compared to determine the cold plate temperatures when assuming uniform heat flux, and when modeling from the device level. The different analyses results in a heat sink ?T that differs by 33%. In the second case, a heat spreader is used to cool several high power components. The heat generation areas of the components are significantly smaller than the case footprint. A detailed look at the device level spreading reveals a difference in maximum temperature of 14.5°C between the results of the different modeling techniques used.

This paper provides an overview of high power components for the application of Electron Cyclotron Heating transmission lines, and broadband devices for Electron Cyclotron Emission detection systems. The unique fabrication and assembly challenges are discussed, particularly in the context of ITER. The ITER ECH system will require robust, vacuum-compatible components such as polarizers, dummy loads, and switches that are sufficiently cooled to withstand 1 MW for 3,600 seconds. These elements, along with overmoded corrugated waveguide, are necessary to form transmission lines with efficiencies of 90%, and 90% transmitted HE11mode purity. Recent high power test results are summarized and scaled from the 63.5 mm internal diameter design to the 50 mm diameter version that will be used for ITER. Elements designed for Electron Cyclotron Emission detection and reflectometry systems are discussed, such as frequency filters and polarization rotators. The large frequency operating range of corrugated waveguide is exploited for such applications. The application of additive manufacturing technology towards both low and high power components is considered as a promising new area of development.

A working vessel for deploying and retrieving heavy loads in deep oceans is now operational. This is accomplished by lengthening or shortening a load-connected pipe string and by two pair of yoked, hydraulically powered cylinders that alternately support and transport the pipe string and load. This paper describes the deployment and retrieval system. The system, known as the Heavy Lift System, contains four 19-foot stroke hydraulic cylinders and their power units and 8500-ton capacity connecting yokes for each pair of cylinders. Ancillary hydraulic equipment includes a pipe string engaging latch on each yoke, a 450,000 ft-lb pipe string torquing/ detorquing device on one yoke, a stationary support for "parking" and rotating the load and the hydraulic power units for these elements. In addition, the system includes an instrumentation and control suit to automatically or manually operate the complete deployment and retrieval functions. The system has a stall load capacity of 8500 tons. It has been fully tested and successfully used to deploy and retrieve up to 7500 tons at 6 feet/minute in 17,000 foot depths. INTRODUCTION The GLOMAR EXPLORER is the surface support vessel for an operational system designed to work the ocean bottom. It transports the bottom equipment and provides the work platform from which the bottom equipment is operated, deployed and retrieved. Design parameters for deploying/retrieving were much greater than anything previously done from a vessel, and unique equipment had to be devised, tested, installed and operated. The resulting subsystem is called the Heavy Lift. The mechanical link between the Heavy Lift and the bottom equipment is a rigid pipe string. Deploying/retrieving is similar to current offshore riser and drill string operations, i.e., add/remove a pipe stand then lower/raise the pipe string to the next tool joint. Initial pipe string design payload and depth was up to 4,000 tons and 17,000 feet. To minimize pipe string stress and thereby its weight, the work platform for the Heavy Lift was gimballed and heave compensated1. Platform space was limited and any equipment on the platform added to the gimbal-heave compensator loads. Compact and light Heavy Lift components were needed. The design weather window for deploying/retrieving was' small and the necessary lowering/ raising rates could only be achieved by automation which, in turn, requires remotely controllable components. Finally, pipe stands weighed up to 40,000 lbs each, tool joint torque was up to 450,000 ft-lbs and, in spite of the gimbal-heave compensator refinement, the design payload for the Heavy Lift became 8,500 tons at 17,000 ft depths. High rates and high loads necessitated high powered Heavy Lift components. Compact, low weight, remotely controllable and high power components were achieved by designing hydraulically powered mechanical equipment. These were integrated with an electronic control system to meet the Heavy Lift subsystem functional requirements during automated operations.