Embedded heat pipes in cofired ceramic substrates for enhanced thermal management of electronics

A novel and new thermal management technology for advanced ceramic microelectronic packages has been developed incorporating miniature heat pipes embedded in the ceramic substrate. The heat pipes use an axially grooved wick structure and water as the working fluid. Prototype substrate/heat pipe systems were fabricated using high temperature co-fired ceramic (alumina). The heat pipes were nominally 81 mm in length, 10 mm in width, and 4 mm in height, and were charged with approximately 50–80 μL of water. Platinum thick film heaters were fabricated on the surface of the substrate to simulate heat dissipating electronic components. Several thermocouples were affixed to the substrate to monitor temperature. One end of the substrate was affixed to a heat sink maintained at constant temperature. The prototypes were tested and shown to successful and reliably operate with thermal loads over 20 Watts, with thermal input from single and multiple sources along the surface of the substrate. Temperature distributions are discussed for the various configurations and the effective thermal resistance of the substrate/heat pipe system is calculated. Finite element analysis was used to support the experimental findings and better understand the sources of the system's thermal resistance. ^

Technology professional development for principals: Impact on the integration of technology in elementary schools

The use of technology in schools is no longer the topic of educational debates, but how to ensure that technology is used effectively continues to be the focal point of discussions. The role of the principal in facilitating the successful integration of technology in the school is well established. To that end, the Florida Department of Education implemented the FloridaLeaders.net: a three-year professional development project in technology for school administrators. The purpose of this study was to investigate the effectiveness of this professional development project on integrating technology in elementary schools. ^ The study compared a group of schools whose principals have participated in the FloridaLeaders.net (FLN) program with schools whose principals have not participated in the program. The National Technology Standards for School Administrators and the National Technology Standards for Teachers were used as the framework to assess technology integration. ^ The sample consisted of three groups of educators: principals (n = 47), media specialists (n = 110), and teachers (n = 167). Three areas of technology utilization were investigated: (a) the use of technology in management and operations, (b) the use of technology in teaching and learning, and (c) the use of technology for assessment and evaluation. Analyses of variances were used to examine the differences in the perceptions and use of technology in each of the three areas, among the three groups of educators. ^ The findings indicated that the difference between FLN and non-FLN schools was not statistically significant in most of the technology indicators. The difference was however significant in two cases: (a) The use of technology for assessment and evaluation, and (b) The level of technology infrastructure in FLN schools. Additionally, all FLN and non-FLN groups reported the need for technology training for teachers to provide them with the necessary "know-how" to effectively integrate technology into the classrooms. ^ These findings would indicate that FloridaLeaders.net was not effective in integrating technology in schools over and above other current efforts. It is therefore concluded that the FLN project had some favorable impact but had not met all of its stated objectives. ^

Management of remote field instrumentation via the Internet

Supervisory Control & Data Acquisition (SCADA) systems are used by many industries because of their ability to manage sensors and control external hardware. The problem with commercially available systems is that they are restricted to a local network of users that use proprietary software. There was no Internet development guide to give remote users out of the network, control and access to SCADA data and external hardware through simple user interfaces. To solve this problem a server/client paradigm was implemented to make SCADAs available via the Internet. Two methods were applied and studied: polling of a text file as a low-end technology solution and implementing a Transmission Control Protocol (TCP/IP) socket connection. Users were allowed to login to a website and control remotely a network of pumps and valves interfaced to a SCADA. This enabled them to sample the water quality of different reservoir wells. The results were based on real time performance, stability and ease of use of the remote interface and its programming. These indicated that the most feasible server to implement is the TCP/IP connection. For the user interface, Java applets and Active X controls provide the same real time access.

Embedded Heat Pipes in Cofired Ceramic Substrates for Enhanced Thermal Management of Electronics

A novel and new thermal management technology for advanced ceramic microelectronic packages has been developed incorporating miniature heat pipes embedded in the ceramic substrate. The heat pipes use an axially grooved wick structure and water as the working fluid. Prototype substrate/heat pipe systems were fabricated using high temperature co-fired ceramic (alumina). The heat pipes were nominally 81 mm in length, 10 mm in width, and 4 mm in height, and were charged with approximately 50-80 mL of water. Platinum thick film heaters were fabricated on the surface of the substrate to simulate heat dissipating electronic components. Several thermocouples were affixed to the substrate to monitor temperature. One end of the substrate was affixed to a heat sink maintained at constant temperature. The prototypes were tested and shown to successful and reliably operate with thermal loads over 20 Watts, with thermal input from single and multiple sources along the surface of the substrate. Temperature distributions are discussed for the various configurations and the effective thermal resistance of the substrate/heat pipe system is calculated. Finite element analysis was used to support the experimental findings and better understand the sources of the system's thermal resistance.