The Thermo-Gravimetric Characteristics of the Waste Game Printed Circuit Board under Different Atmosphere

2014 ◽  
Vol 1073-1076 ◽  
pp. 975-980
Author(s):  
Rong Feng ◽  
Bo Wang
Keyword(s):  
Weight Loss ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Volatile Components ◽  
Rapid Weight Loss ◽  
Kinetics Parameters ◽  
Loss Process ◽  
Printed Circuit ◽  
Air Atmosphere ◽  
Weight Loss Process

The printed circuit board (PCB) in the electronic waste contains a variety of metals and organic materials, including bromine, heavy metals and other pollutants. Thermal treatment is an effective method for harmless disposal of waste circuit boards with resources recycle. In this study, the composition of RF4 type waste game PCB was determined by elemental analysis and proximate analysis, followed by thermogravimetric analysis of the weight lost process in CO2、N2or air, at 10°C/min, 20°C/min or 30°C/min programmable heating rate, and the thermal decomposition reaction kinetics parameters were calculated with the Kissinger method. The results show that under the CO2atmosphere, the weight loss process of the sample consists of the 250°C～410°C and 750°C~960°C temperature intervals; under the N2atmosphere, the rapid weight loss stage is between 263°C and 420°C; under the air atmosphere, the weight loss process is from 178°C to 675°C, including three minor weight loss stages. The phenolic volatile components are mainly released around 260°C～360°C under three different atmospheres, while the residual carbon is further oxidized under the air atmosphere or gasified in CO2at temperatures above 800°C.

Influence of Na2CO3 on Thermal Degradation Process of Waste Printed Circuit Board in Air Atmosphere

2014 ◽  
Vol 1073-1076 ◽  
pp. 915-919
Author(s):  
Qiu Ping Zhou ◽  
Bo Wang
Keyword(s):  
Weight Loss ◽  
Printed Circuit Board ◽  
Initial Temperature ◽  
Degradation Process ◽  
Circuit Board ◽  
Printed Circuit ◽  
Air Atmosphere ◽  
Waste Printed Circuit Board ◽  
Thermal Degradation Process ◽  
Mechanism Function

The influence of Na2CO3on RF4-type waste printed circuit board (PCB) thermal degradation process in air atmosphere was studied with thermogravimetric analysis, and the reaction kinetics was calculated based on the Coats – Redfern method. It is shown that the weight loss process of WPCB in air atmosphere includes three stages. Addition of Na2CO3decreases the initial temperature of the first weight loss stage of WPCB, which indicates the enhancement effect on the decomposition of the flame retardant. Addition of Na2CO3increases the initial temperature of the second and third weight loss stage of WPCB, which indicates the obstruction effect on oxidation reaction. From the different mechanism function, the optimal mechanism function is f (α)=2/3(1-α)[-ln (1-α) ]3and the range of activation energy is 30~185 kJ /mol.

Influence of Na2CO3 on Thermal Decomposition of Waste Printed Circuit Board in Carbon Dioxide

2013 ◽  
Vol 864-867 ◽  
pp. 1954-1958 ◽  
Author(s):  
Bo Wang ◽  
Qiu Ping Zhou ◽  
Li Hong
Keyword(s):  
Carbon Dioxide ◽  
Weight Loss ◽  
Printed Circuit Board ◽  
Carbon Residue ◽  
Circuit Board ◽  
Enhancement Effect ◽  
Printed Circuit ◽  
Waste Printed Circuit Board ◽  
Mechanism Function ◽  
Gasification Reaction

The influence of Na2CO3on RF4-type waste printed circuit board (PCB) pyrolysis in carbon dioxide was studied with thermogravimetric analysis, and the reaction kinetics was calculated based on the Coats - Redfern method. It is shown that the weight loss process of waste PCB in carbon dioxide includes two stages. The first stage of weight loss is between 280 °C and 450 °C, at which the decomposition of epoxide resin leads to volatile materials release. The second stage of weight loss is the reaction between carbon residue and carbon dioxide between 600°C~960 °C, and carbon monoxide is formed. Addition of Na2CO3decreases the initial temperature of the second weight loss stage of waste PCB and increases the weight loss rate, which indicates the enhancement effect on gasification reaction between carbon residue and carbon dioxide. From the different mechanism function, the optimal mechanism function isf(a)=5(1-a)/4[-ln(1-a)]4and the range of activation energy is 75～135 kJ/mol.

Characteristics of Radiated Emission from a Printed Circuit Board with a Slit

2012 ◽  
Vol 132 (6) ◽  
pp. 404-410 ◽  
Author(s):  
Kenichi Nakayama ◽  
Kenichi Kagoshima ◽  
Shigeki Takeda
Keyword(s):  
Printed Circuit Board ◽  
Circuit Board ◽  
Printed Circuit ◽  
Radiated Emission

Confirming the Signal Integrity in Transmission of Digital Signals on Microstrip Straight Circuits via the Eye Diagrams

2014 ◽  
Vol 5 (1) ◽  
pp. 737-741
Author(s):  
Alejandro Dueñas Jiménez ◽  
Francisco Jiménez Hernández
Keyword(s):  
Integrated Circuits ◽  
Printed Circuit Board ◽  
Signal Integrity ◽  
High Volume ◽  
Information Storage ◽  
Circuit Board ◽  
Electromagnetic Simulation ◽  
Electronic Systems ◽  
Digital Signals ◽  
Printed Circuit

Because of the high volume of processing, transmission, and information storage, electronic systems presently requires faster clock speeds tosynchronizethe integrated circuits. Presently the “speeds” on the connections of a printed circuit board (PCB) are in the order of the GHz. At these frequencies the behavior of the interconnects are more like that of a transmission line, and hence distortion, delay, and phase shift- effects caused by phenomena like cross talk, ringing and over shot are present and may be undesirable for the performance of a circuit or system.Some of these phrases were extracted from the chapter eight of book “2-D Electromagnetic Simulation of Passive Microstrip Circuits” from the corresponding author of this paper.

Root Cause Analysis of a Connector Time-Delayed Fracture

2015 ◽  
Author(s):  
Prabjit Singh ◽  
Ying Yu ◽  
Robert E. Davis
Keyword(s):  
Printed Circuit Board ◽  
Ceramic Substrate ◽  
Circuit Board ◽  
Delayed Fracture ◽  
Ceramic Substrates ◽  
Printed Circuit ◽  
Root Cause ◽  
Chip Carrier ◽  
Electrical Connections ◽  
Grain Boundary Grooves

Abstract A land-grid array connector, electrically connecting an array of plated contact pads on a ceramic substrate chip carrier to plated contact pads on a printed circuit board (PCB), failed in a year after assembly due to time-delayed fracture of multiple C-shaped spring connectors. The land-grid-array connectors analyzed had arrays of connectors consisting of gold on nickel plated Be-Cu C-shaped springs in compression that made electrical connections between the pads on the ceramic substrates and the PCBs. Metallography, fractography and surface analyses revealed the root cause of the C-spring connector fracture to be plating solutions trapped in deep grain boundary grooves etched into the C-spring connectors during the pre-plating cleaning operation. The stress necessary for the stress corrosion cracking mechanism was provided by the C-spring connectors, in the land-grid array, being compressed between the ceramic substrate and the printed circuit board.

Application of Lock-in Thermography on PCB for Fault Localization and Validation of Failure Mechanism Due to External Discrete Component Variation

2010 ◽  
Author(s):  
William Ng ◽  
Kevin Weaver ◽  
Zachary Gemmill ◽  
Herve Deslandes ◽  
Rudolf Schlangen
Keyword(s):  
Failure Mechanism ◽  
Integrated Circuit ◽  
Printed Circuit Board ◽  
Hot Spot ◽  
Circuit Board ◽  
Discrete Component ◽  
Printed Circuit ◽  
Thermal Signature ◽  
Lock In

Abstract This paper demonstrates the use of a real time lock-in thermography (LIT) system to non-destructively characterize thermal events prior to the failing of an integrated circuit (IC) device. A case study using a packaged IC mounted on printed circuit board (PCB) is presented. The result validated the failing model by observing the thermal signature on the package. Subsequent analysis from the backside of the IC identified a hot spot in internal circuitry sensitive to varying value of external discrete component (inductor) on PCB.

Temperature and Humidity Dependent Reliability Analysis of RGB LED Chips

2006 ◽  
Author(s):  
Jun-Xian Fu ◽  
Shukri Souri ◽  
James S. Harris
Keyword(s):  
Reliability Analysis ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Light Emitting ◽  
Printed Circuit ◽  
Root Cause ◽  
Micro Cracks ◽  
Temperature And Humidity

Abstract Temperature and humidity dependent reliability analysis was performed based on a case study involving an indicator printed-circuit board with surface-mounted multiple-die red, green and blue light-emitting diode chips. Reported intermittent failures were investigated and the root cause was attributed to a non-optimized reflow process that resulted in micro-cracks and delaminations within the molding resin of the chips.

Materials Characterization of Lead Free Compositions for Minimum Temperature SMT Processes at the SLI-Second Level Interconnect Solder Joint

2004 ◽  
Author(s):  
Norman J. Armendariz ◽  
Prawin Paulraj
Keyword(s):  
Solder Joint ◽  
Printed Circuit Board ◽  
Gold Surface ◽  
Circuit Board ◽  
Lead Free ◽  
Processing Temperature ◽  
The European Union ◽  
Printed Circuit ◽  
Higher Temperature ◽  
Tin Silver Copper

Abstract The European Union is banning the use of Pb in electronic products starting July 1st, 2006. Printed circuit board assemblies or “motherboards” require that planned CPU sockets and BGA chipsets use lead-free solder ball compositions at the second level interconnections (SLI) to attach to a printed circuit board (PCB) and survive various assembly and reliability test conditions for end-use deployment. Intel is pro-actively preparing for this anticipated Pb ban, by evaluating a new lead free (LF) solder alloy in the ternary Tin- Silver-Copper (Sn4.0Ag0.5Cu) system and developing higher temperature board assembly processes. This will be pursued with a focus on achieving the lowest process temperature required to avoid deleterious higher temperature effects and still achieve a metallurgically compatible solder joint. One primary factor is the elevated peak reflow temperature required for surface mount technology (SMT) LF assembly, which is approximately 250 °C compared to present eutectic tin/lead (Sn37Pb) reflow temperatures of around 220 °C. In addition, extended SMT time-above-liquidus (TAL) and subsequent cooling rates are also a concern not only for the critical BGA chipsets and CPU BGA sockets but to other components similarly attached to the same PCB substrate. PCBs used were conventional FR-4 substrates with organic solder preservative on the copper pads and mechanical daisychanged FCBGA components with direct immersion gold surface finish on their copper pads. However, a materials analysis method and approach is also required to characterize and evaluate the effect of low peak temperature LF SMT processing on the PBA SLI to identify the absolute limits or “cliffs” and determine if the minimum processing temperature and TAL could be further lowered. The SLI system is characterized using various microanalytical techniques, such as, conventional optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and microhardness testing. In addition, the SLI is further characterized using macroanalytical techniques such as dye penetrant testing (DPT) with controlled tensile testing for mechanical strength in addition to disbond and crack area mapping to complete the analysis.

Magnetic Emission Mapping for Passive Integrated Components Characterisation

2003 ◽  
Author(s):  
O. Crépel ◽  
Y. Bouttement ◽  
P. Descamps ◽  
C. Goupil ◽  
P. Perdu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mobile Phone ◽  
Printed Circuit Board ◽  
Magnetic Sensors ◽  
Circuit Board ◽  
Magnetic Disturbance ◽  
Passive Components ◽  
Printed Circuit ◽  
Integrated Inductor ◽  
The Magnetic Field

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.

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