Accelerated Thermal Degradation of Printed Circuit Board, Passive Components and Fiber Optic Cables for Single-Phase Immersion Cooled Data Centers

2021 ◽  
Author(s):  
Keerthivasan Padmanaban ◽  
Satyam Saini
Author(s):  
O. Crépel ◽  
Y. Bouttement ◽  
P. Descamps ◽  
C. Goupil ◽  
P. Perdu ◽  
...  

Abstract We developed a system and a method to characterize the magnetic field induced by circuit board and electronic component, especially integrated inductor, with magnetic sensors. The different magnetic sensors are presented and several applications using this method are discussed. Particularly, in several semiconductor applications (e.g. Mobile phone), active dies are integrated with passive components. To minimize magnetic disturbance, arbitrary margin distances are used. We present a system to characterize precisely the magnetic emission to insure that the margin is sufficient and to reduce the size of the printed circuit board.


Author(s):  
P. Singh ◽  
G.T. Galyon ◽  
J. Obrzut ◽  
W.A. Alpaugh

Abstract A time delayed dielectric breakdown in printed circuit boards, operating at temperatures below the epoxy resin insulation thermo-electrical limits, is reported. The safe temperature-voltage operating regime was estimated and related to the glass-rubber transition (To) of printed circuit board dielectric. The TG was measured using DSC and compared with that determined from electrical conductivity of the laminate in the glassy and rubbery state. A failure model was developed and fitted to the experimental data matching a localized thermal degradation of the dielectric and time dependency. The model is based on localized heating of an insulation resistance defect that under certain voltage bias can exceed the TG, thus, initiating thermal degradation of the resin. The model agrees well with the experimental data and indicates that the failure rate and truncation time beyond which the probability of failure becomes insignificant, decreases with increasing glass-rubber transition temperature.


2012 ◽  
Vol 2012 (DPC) ◽  
pp. 001096-001114
Author(s):  
Michael R. Whitley ◽  
Tracy D. Hudson

The increased usage of unmanned aerial vehicles has driven the desire for smaller and lighter missile bodies. The wiring harnesses required to connect the missile subsystems constitute a significant portion of the missile weight and cost. We have been exploring the development of flexible electronics substrates manufactured using ink jet technology on polyimide films. This technology has an advantage over traditional flex circuit manufacturing because in addition to creating traditional wiring patterns the ink jet technology enables the creation of passive components such as resistors and capacitors. The Dimatix DMP-2831 ink jet system uses individually controllable piezoelectric driven MEMS nozzles to precisely deposit nanoparticle inks. These inks are then annealed to form wiring patterns. We will present the process for converting traditional printed circuit board data formats to inkjet printable data, the process for depositing the ink, annealing and testing.


Author(s):  
Vasudivan Sunappan ◽  
Chee Wai Lu ◽  
Lai Lai Wai ◽  
Wei Fan ◽  
Boon Keng Lok

A novel process has been developed to embed discrete (surface mountable) passive components like capacitors, resistors and inductors using printed circuit board fabrication technology. The process comprises of mounting passive components on top surface of a core PCB (printed circuit board) material using surface mount technology. The passive components mounting were designed in multiple clusters within the PCB. Dielectric sheets are sandwiched between top surface of core PCB and second PCB material for lamination process. A direct interconnection of the passive components to one or more integrated circuits (IC) is further accomplished by mounting the ICs on the bottom surface of the core material in an area directly under the passive components. The close proximity of the embedded passive components such as capacitors to an IC improved electrical performance by providing impedance reduction and resonance suppression at high frequency range. The reliability of solder joints was evaluatedd by temperature cycling test.


Author(s):  
Jimil M. Shah ◽  
Keerthivasan Padmanaban ◽  
Hrishabh Singh ◽  
Surya Duraisamy Asokan ◽  
Satyam Saini ◽  
...  

Abstract The adoption of Single-phase Liquid Immersion Cooling (Sp-LIC) for Information Technology equipment provides an excellent cooling platform coupled with significant energy savings. There are, however, very limited studies related to the reliability of such cooling technology. The Accelerated Thermal Cycling (ATC) test given ATC JEDEC is relevant just for air cooling but there is no such standard for immersion cooling. The ASTM benchmark D3455 with some appropriate adjustments was adopted to test the material compatibility because of the air and dielectric fluid differences in the heat capacitance property and corresponding ramp rate during thermal cycling. For this study, accelerated thermal degradation of the printed circuit board (PCB), passive components, and fiber optic cables submerged in air, white mineral oil, and synthetic fluid at a hoisted temperature of 45C and 35% humidity is undertaken. This paper serves multiple purposes including designing experiments, testing and evaluating material compatibility of PCB, passive components, and optical fibers in different hydrocarbon oils for single-phase immersion cooling. Samples of different materials were immersed in different hydrocarbon oils and air and kept in an environmental chamber at 45C for a total of 288 hours. Samples were then evaluated for their mechanical and electrical properties using Dynamic Mechanical Analyzer (DMA) and a multimeter, respectively. The cross-sections of some samples were also investigated for their structural integrity using SEM. The literature gathered on the subject and quantifiable data gathered by the authors provide the primary basis for this research document.


Author(s):  
Mandar M. Chincholkar ◽  
Jeffrey W. Herrmann

With the miniaturization of electronic products, reducing the size of the printed circuit board that forms the backbone of the product is paramount. Embedding passive components, which otherwise occupy valuable “real estate” atop the printed circuit board, into the printed circuit board substrate itself is one way of achieving this objective. This first part of this paper examines the techniques and advantages of embedding passives. Embedding passives also affects manufacturing system performance, due to a change in the processing sequence and changes to the processing times at resources. The latter portion of this paper describes a design for production tool for understanding the impact of embedding passives on the performance of a manufacturing system.


2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
V.A. Vdovin ◽  
◽  
A.A. Geraskin ◽  
P.A. Gorbokonenko ◽  
S.A. Sapetskiy ◽  
...  

The effects arising in an integrated microchip (IC) of a microcontroller (MC) performing test logic operations under the action of powerful electrical impulses are investigated. The IC MC STM8S003 was chosen as a typical microcontroller. The exposure was carried out by electric pulses with an electric field strength of up to 20 kV/cm and a duration of 6 ns. It is shown that impulse influences can lead to logical failures when performing IC MC logical operations, the effectiveness of the influence depends not only on the parameters of the electromagnetic pulse, but also on the specific operation performed during which it occurred. The repetition rate of electromagnetic pulses up to 1 kHz does not significantly affect the type of failures of the IC MC. The supply voltage of the IC MC affects its stability; to create a failure, an increase in the amplitude of the electromagnetic pulse is required with an increase in the supply voltage. Passive components of a printed circuit board are more susceptible to electromagnetic influences than IC MC.


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