Conductive Adhesives for Electronic Assemblies

MRS Bulletin ◽  
2003 ◽  
Vol 28 (6) ◽  
pp. 449-454 ◽  
Author(s):  
C. T. Murray ◽  
R. L. Rudman ◽  
M. B. Sabade ◽  
A. V. Pocius
Keyword(s):  
Electronic Components ◽  
Conductive Adhesives ◽  
Electrically Conducting ◽  
Film Adhesive ◽  
Pressure Sensitive ◽  
Different Types ◽  
Judicious Choice ◽  
Thermally Conducting ◽  
Electronic Assemblies ◽  
Electrically Conducting Adhesives

AbstractA number of different types of adhesives are used in the assembly of electronic components and devices. This article provides an overview of such adhesives that also have another job–they work at conducting electricity or heat. The resins or binders in these adhesives range from thermosetting to pressure-sensitive. Conductivity is obtained by the judicious choice of filler. For electrically conducting adhesives, the fillers range from silver flake to silver-coated fibers. For thermally conducting adhesives, the fillers range from aluminum oxide to boron nitride. We also discuss a specific type of electrically conducting adhesive–the z-axis film adhesive. In these adhesives, particles are oriented in such a fashion that allows conduction in the direction perpendicular to the adhesive, but not in the plane of the adhesive.

Bejan’s Constructal Theory Analysis of Gas-Liquid Cooled Finned Modules

2011 ◽  
Vol 133 (7) ◽  
Author(s):  
Giulio Lorenzini ◽  
Simone Moretti
Keyword(s):  
Thermal Behavior ◽  
Heat Exchangers ◽  
High Performance ◽  
Numerical Study ◽  
Constructal Theory ◽  
Electronic Components ◽  
Theory Analysis ◽  
Pressure Losses ◽  
Different Types ◽  
Overall Performance

High performance heat exchangers represent nowadays the key of success to go on with the trend of miniaturizing electronic components as requested by the industry. This numerical study, based on Bejan’s Constructal theory, analyzes the thermal behavior of heat removing fin modules, comparing their performances when operating with different types of fluids. In particular, the simulations involve air and water (as representative of gases and liquids), to understand the actual benefits of employing a less heat conductive fluid involving smaller pressure losses or vice versa. The analysis parameters typical of a Constructal description (such as conductance or Overall Performance Coefficient) show that significantly improved performances may be achieved when using water, even if an unavoidable increase in pressure losses affects the liquid-refrigerated case. Considering the overall performance: if the parameter called Relevance tends to 0, air prevails; if it tends to 1, water prevails; if its value is about 0.5, water prevails in most of the case studies.

scholarly journals Dismantling of Waste Printed Circuit Boards with the Simultaneous Recovery of Copper: Experimental Study and Process Modeling

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5186
Author(s):  
Szabolcs Fogarasi ◽  
Árpád Imre-Lucaci ◽  
Florica Imre-Lucaci
Keyword(s):  
Environmental Performance ◽  
Printed Circuit Boards ◽  
Electrochemical Process ◽  
Circuit Boards ◽  
Electronic Components ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Different Types ◽  
Leaching Solution ◽  
The Impact

The study was carried out with the aim to demonstrate the applicability of a combined chemical–electrochemical process for the dismantling of waste printed circuit boards (WPCBs) created from different types of electronic equipment. The concept implies a simple and less polluting process that allows the chemical dismantling of WPCBs with the simultaneous recovery of copper from the leaching solution and the regeneration of the leaching agent. In order to assess the performance of the dismantling process, various tests were performed on different types of WPCBs using the 0.3 M FeCl3 in 0.5 M HCl leaching system. The experimental results show that, through the leaching process, the electronic components (EC) together with other fractions can be efficiently dismounted from the surface of WPCBs, with the parallel electrowinning of copper from the copper rich leaching solution. In addition, the process was scaled up for the dismantling of 100 kg/h WPCBs and modeled and simulated using process flow modelling software ChemCAD in order to assess the impact of all steps and equipment on the technical and environmental performance of the overall process. According to the results, the dismantling of 1 kg of WPCBs requires a total energy of 0.48 kWh, and the process can be performed with an overall low environmental impact based on the obtained general environmental indexes (GEIs) values.

Z-axis Interconnections for Next Generation Packaging

2011 ◽  
Vol 2011 (1) ◽  
pp. 000469-000475
Author(s):  
Rabindra N. Das ◽  
Frank D. Egitto ◽  
John M. Lauffer ◽  
Tim Antesberger ◽  
Voya R. Markovich
Keyword(s):  
Flip Chip ◽  
Electrical Performance ◽  
Next Generation ◽  
Low Loss ◽  
Electrically Conducting ◽  
S Parameter ◽  
Plastic Ball ◽  
Materials Used ◽  
Electrically Conducting Adhesives

In this paper, the use of electrically conducting adhesives (ECA) to form z-axis interconnections for next generation packaging is discussed. In particular, current efforts related to Z-axis interconnections for device level fabrication, integration, and electrical performance are highlighted. A few optimized ECAs were used for hole fill applications to fabricate Z-axis interconnections in laminates. Conductive joints were formed during composite lamination using the ECA. Around 5,000 to 200,000 through holes in the joining cores, formed by laser or mechanical drilling, and having diameters ranging from 50 μm to 750 μm, were filled with an optimized conducting adhesive. The adhesive-filled joining cores/layers were laminated with circuitized subcomposites to produce a composite structure. As a case study, a variety of z-axis interconnect constructions for a flip-chip plastic ball grid array package, rigid-flex, rigid-rigid, package-interposer-package (PIP), RF structures, and PWBs were fabricated and evaluated at both the subcomposite and composite levels to understand structural and electrical integrity. Electrically, S-parameter measurements showed very low loss at multi-gigahertz frequencies. The losses were low enough to support typical SERDES up to 15 Gbps over 750 mm. The present process allows fabrication of z-interconnect conductive joints having diameters in the range of 55 to 500 μm. The processes and materials used to achieve smaller feature dimensions, satisfy stringent registration requirements, and achieve robust electrical interconnections are discussed.

Understanding Nasal Emission During Speech Production: A Review of Types, Terminology, and Causality

2019 ◽  
Vol 57 (1) ◽  
pp. 123-126 ◽  
Author(s):  
Liran Oren ◽  
Ann Kummer ◽  
Suzanne Boyce
Keyword(s):  
Speech Production ◽  
Pressure Sensitive ◽  
Abnormal Structure ◽  
Different Types ◽  
Nasal Emission

There are several different types of nasal emission that can occur during speech due to either velopharyngeal dysfunction or abnormal articulation in the pharynx. Nasal emission can be inaudible or very loud and distracting, depending on the size of the velopharyngeal opening and the physics of the flow. Nasal emission can be obligatory and/or compensatory (due to abnormal structure) or it can be caused by a misarticulation that results in a substitution of a pharyngeal sound for an oral sound, despite normal velopharyngeal structure. Nasal emission can occur on all pressure-sensitive phonemes or it can be phoneme-specific. Although it is generally recognized that the loud and distracting form of nasal emission (called nasal turbulence or nasal rustle) is due to a small velopharyngeal opening, the causality of the distracted sound is debated. This article provides a brief review of the types of nasal emission, the terms used to describe it, and the potential causes. This article also stresses the need for further research to clarify the causality of the sound generated by a small velopharyngeal opening.

A Review of Shielding Performance for Anechoic Chamber

2015 ◽  
Vol 793 ◽  
pp. 600-604
Author(s):  
Hafizah Mustapha ◽  
K.H. Ismail ◽  
T.J. Daim ◽  
S.F. Jamil
Keyword(s):  
Random Noise ◽  
Operation Mode ◽  
Good Condition ◽  
Anechoic Chamber ◽  
Test Results ◽  
Electronic Components ◽  
Specific Test ◽  
Different Types ◽  
Anechoic Chambers ◽  
Typical Test

Anechoic chambers are widely used in performing EMC measurements according to the established EMC standards. As in space area, EMC measurement is critically important to ascertain all of electrical and electronic components in the satellite body will function correctly without fail during launching and operation mode. Recognizing the needs and importance of performing the EMC measurements, the shielding performance of the chamber should be prioritized to ensure the interference of electromagnetic wave from outside going to inside the constructed chamber does not exist. As to maintain the shielding element, periodic checking and inspection should be well planned by conducting a specific test. This paper outlines a series of procedures that are developed while running the test. The test will characterize the shielding performance at four (4) frequency ranges using different types of antenna set. Typical test results are gathered and presented at the measured frequencies. Based on the results, it is concluded that the shielding performance of anechoic chamber is standing in good condition at three (3) ranges of frequencies except for frequency of 10 kHz to 200MHz. Several steps are recommended to remove or eliminate the random noise.

Thermal Enhancement Coatings for Microelectronic Systems

1998 ◽  
Vol 120 (3) ◽  
pp. 229-237 ◽  
Author(s):  
L. S. Fletcher ◽  
M. A. Lambert ◽  
E. E. Marotta
Keyword(s):  
Heat Generation ◽  
Thermal Performance ◽  
Electronic Components ◽  
Thermally Induced ◽  
Thermal Enhancement ◽  
Thermally Conducting ◽  
Power Densities

The power densities and heat generation in microelectronic systems have increased dramatically as individual electronic components have been miniaturized. As a result of the growing number of thermally-induced failures in these systems, their thermal performance has become the focus of increasing concern. The use of thermally conducting interstitial coatings within and between electronic components has proven to be one technique suitable for thermal enhancement. This review will address both metallic and nonmetallic coatings suitable for thermal enhancement and discuss some of the major areas of application.

Thermal Management of Electronic Components by Using Computational Fluid Dynamic (CFD) Software, FLUENTTM in Several Material Applications (Epoxy, Composite Material & Nanosilver)

2013 ◽  
Vol 795 ◽  
pp. 141-147 ◽  
Author(s):  
M. Mazlan ◽  
A. Rahim ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
W. Razak ◽  
A.F. Zubair ◽  
...  
Keyword(s):  
Thermal Management ◽  
3D Model ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Junction Temperature ◽  
Electronic Components ◽  
Different Types ◽  
Fluent Software ◽  
Transfer Problems ◽  
Heat And Fluid Flow

This paper presents the thermal management of electronic components, microprocessor by using three dimensional numerical analysis of heat and fluid flow in computer. 3D model of microprocessors is built using GAMBIT and simulated using FLUENT software. The study was made for four microprocessors arranged in line under different types of materials, inlet velocities and package (chip) powers. The results are presented in terms of average junction temperature and thermal resistance of each package The junction temperature is been observed and it was found that the junction temperature of the microprocessors is not exceed 70o C. It also found that the (chip) powers and inlet velocities are the most important elements to control and manage the junction temperature. The strength of CFD software in handling heat transfer problems is proved to be excellent.

Preparation and Characterization of Purified Multi-Walled Carbon Nanotubes Filled Conductive Adhesive

2013 ◽  
Vol 341-342 ◽  
pp. 175-178
Author(s):  
Fan Zhang ◽  
Shu Hua Qi ◽  
Yi Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Conductive Adhesives ◽  
Pressure Sensitive Adhesive ◽  
Electrically Conductive ◽  
Oxidation Treatment ◽  
Pressure Sensitive ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Xrd And Tem

In this paper, purified multi-walled carbon nanotubes (MWNTs) were obtained by acid treatment and oxidation treatment using the crude MWNTs, then purified MWNTs were filled into acrylate pressure-sensitive adhesive (PSA) to produce electrically conductive adhesives (ECAs). XRD and TEM results showed that the impurities were greatly eliminated after purification treatment. The electrical conductivity of the ECAs increased gradually as the content of the purified MWNTs increased. When the content of the purified MWNTs is 4.0vol%, the properties of ECAs are optimum.

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