Electronics Manufacturing Technical Articles

Electronics Manufacturing Technical Articles

Papers and articles related to SMT, PCB & EMS industry.

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1752 SMT / PCB Assembly Related Technical Articles

Comparison of ROSE, C3/IC, and SIR as an effective cleanliness verification test for post soldered PCBA

Apr 17, 2023 | Kong Hui Lee, Rob Jukna, Jim Altpeter, Kantesh Doss

The purpose of this paper is to evaluate and compare the effectiveness and sensitivity of different cleanliness verification tests for post soldered printed circuit board assemblies (PCBAs) to provide an understanding of current industry practice for ionic contamination detection limits. Design/methodology/approach – PCBAs were subjected to different flux residue cleaning dwell times and cleanliness levels were verified with resistivity of solvent extract, critical cleanliness control (C3) test, and ion chromatography analyses to provide results capable of differentiating different sensitivity levels for each test. Findings – This study provides an understanding of current industry practice for ionic contamination detection using verification tests with different detection sensitivity levels. Some of the available cleanliness monitoring systems, particularly at critical areas of circuitry that are prone to product failure and residue entrapment, may have been overlooked. Research limitations/implications – Only Sn/Pb, clean type flux residue was evaluated. Thus, the current study was not an all encompassing project that is representative of other chemistry-based flux residues. Practical implications – The paper provides a reference that can be used to determine the most suitable and effective verification test for the detection of ionic contamination on PCBAs. Originality/value – Flux residue-related problems have long existed in the industry. The findings presented in this paper give a basic understanding to PCBA manufacturers when they are trying to choose the most suitable and effective verification test for the detection of ionic contamination on their products. Hence, the negative impact of flux residue on the respective product's long-term reliability and performance can be minimized and monitored effectively....

Publisher: Jabil Circuit, Inc.

Jabil Circuit, Inc.

An electronic product solutions company providing comprehensive electronics design, manufacturing and product management services.

St. Petersburg, Florida, USA

Consultant / Service Provider

Evaluation of No-Clean Flux Residues Remaining After Secondary Process Operations

Apr 17, 2023 | Phil Isaacs, Jennifer Bennett, Terry Munson

In an ideal world, manufacturing devices would work all of the time, however, every company receives customer returns for a variety of reasons. If these returned parts contributed to a fail, most companies will perform failure analysis (FA) on the returned parts to determine the root cause of the failure. Failure can occur for a multitude of reasons, for example: wear out, fatigue, design issues, manufacturing flaw or defect. This information is then used to improve the overall quality of the product and prevent reoccurrence. If no defect is found, it is possible that in fact the product has no defect. On the other hand, the defect could be elusive and the FA techniques insufficient to detect said deficiency. No-clean flux residues can cause intermittent or elusive, hard to find defects. In an attempt to understand the effects of no-clean flux residues from the secondary soldering and cleaning processes, a matrix of varying process and cleaning operation was investigated. Of special interest, traveling flux residues and entrapped residues were examined, as well as localized and batch cleaning processes. Various techniques were employed to test the remaining residues in order to assess their propensity to cause a latent failure. These techniques include Surface Insulation Resistance1 (SIR) testing at 40⁰C/90% RH, 5 VDC bias along with C32 testing and Ion Exchange Chromatography (IC). These techniques facilitate the assessment of the capillary effect the tight spacing these component structures have when flux residues are present. It is expected that dendritic shorting and measurable current leakage will occur, indicating a failing SIR test. However, since the residue resides under the discrete components, there will be no visual evidence of dendritic growth or metal migration....

Publisher: Foresite Inc.

Foresite Inc.

Foresite is a process consulting house and analytial laboratory dedicated to solving product reliability challenges for electronics manufacturers.

Kokomo, Indiana, USA

Consultant / Service Provider, Manufacturer

Characterizing of Emissions from Open Burning of Electronic Waste using TG-GC-MS System

Mar 27, 2023 | Jun Wang

Electronic waste (e-waste) is currently the fastest growing hazardous waste stream that continues to be a challenging concern for the global environment and public health. The average useful life of electronic products has continued to decline, and obsolete products are being stored or discarded with increasing frequency. E-waste is hazardous, complex and expensive to treat in an environmentally sound manner. As a result, new challenges related to the management of e-waste have become apparent. Most electronic products contain a combination of hazardous materials, toxic materials, and valuable elements such as precious metals and rare earth elements. There are risks to human health associated with the disposal of E-waste in landfills, or treatment by incineration. Americans discard 400+ million electronic items per year recycling less than 20 percent in safe and sustainable manner. E-waste is exported from developed countries and processed informally using unsafe conditions in many regions of developing countries. A mixture of pollutants is released from these informal rudimentary operations. Exposure to e-waste recycling includes the dismantling of used electronics and the use of hydrometallurgical and pyrometallurgical processes, which emit toxic chemicals, to retrieve valuable components. Thermal analysis integrated with chromatographic and spectroscopic techniques are used to determine dangerous chemicals emitted during the burning of e-waste. The information is used to assess the risk of exposure of workers at these semi-formal recycling centers....

Publisher: PerkinElmer Optoelectronics

PerkinElmer Optoelectronics

Manufacturer of Specialty Lighting and Medical Measurement Equipment

Salem, Massachusetts, USA

Manufacturer

Material & Process Influences on Conductive Anodic Filamentation (CAF)

Mar 16, 2023 | Alun Morgan and Doug Trobough

HISTORY: * In the late 1970s an abrupt unpredictable loss of insulation resistance was observed in PCBs, which were subject to hostile climatic conditions of high relative humidity and temperature while having an applied voltage. * The loss of resistance, even leading to a short circuit was observed to be due to the growth of a subsurface filament from the anode to the cathode. * The term "Conductive Anodic Filamentation" (CAF) was coined....

Publisher: Isola Group

Isola Group

Isola a global material sciences company focused on designing, developing, manufacturing and marketing copper-clad laminates and dielectric prepregs used to fabricate advanced multilayer PCBs.

Chandler, Arizona, USA

Manufacturer

Conductive Anodic Filament (CAF) Formation: A Potential Reliability Problem for Fine-Line Circuits

Mar 16, 2023 | Laura J. Turbini, W. Jud Ready & Brian A. Smith

Outline * Introduction & Background * Factors Affecting CAF Formation * CAF Formation ** Catastrophic Field Failure of Military Hardware ** Laboratory Experiments * Conclusion...

Publisher: Georgia Institute of Technology

Georgia Institute of Technology

Center for Board Assembly Research CBAR- advanced research on board assembly processes and systems

Atlanta, Georgia, USA

Research Institute / Laboratory / School

Conductive Anodic Filament Failure: A Materials Perspective

Mar 16, 2023 | Laura J. Turbini and W. Jud Ready

Conductive anodic filament (CAF) formation was first reported in 1976.1 This electrochemical failure mode of electronic substrates involves the growth of a copper containing filament subsurface along the epoxy-glass interface, from anode to cathode. Despite the projected lifetime reduction due to CAF, field failures were not identified in the 1980s. Recently, however, field failures of critical equipment have been reported.2 A thorough understanding of the nature of CAF is needed in order to prevent this catastrophic failure from affecting electronic assemblies in the future. Such an understanding requires a comprehensive evaluation of the factors that enhance CAF formation. These factors can be grouped into two types: (1) internal variables and (2) external influences. Internal variables include the composition of the circuit board material, and the conductor metallization and configuration (i.e. via to via, via to surface conductor or surface conductors to surface conductors). External influences can be due to (1) production and (2) storage and use. During production, the flux or hot air solder leveling (HASL) fluid choice, number and severity of temperature cycles, and the method of cleaning may influence CAF resistance. During storage and use, the principal concern is moisture uptake resulting from the ambient humidity. This paper will report on the relationship between these various factors and the formation of CAF. Specifically, we will explore the influences of printed wiring board (PWB) substrate choice as well as the influence of the soldering flux and HASL fluid choices. Due to the ever-increasing circuit density of electronic assemblies, CAF field failures are expected to increase unless careful attention is focused on material and processing choices....

Publisher: Georgia Institute of Technology

Georgia Institute of Technology

Center for Board Assembly Research CBAR- advanced research on board assembly processes and systems

Atlanta, Georgia, USA

Research Institute / Laboratory / School

Paper Substrates and Inks for Printed Electronics

Mar 13, 2023 | Laura K. Wood†, Erika Hrehorova, Thomas W. Joyce†, Paul D. Fleming, Margaret Joyce†, Alexandra Pekarovicova and Valery Bliznyuk

The present work explores the effects of paper properties on conventional silver-based conducting inks. The effects of smoothness, relative humidity, porosity, permeability and wettability on electrical properties of silver inks on different paper substrates were studied. Another objective of this work was to prepare and study polyaniline synthesized in the presence of different lignosulfonates....

Publisher: Western Michigan University

Western Michigan University

A national research university enrolling nearly 25,000 students from across the United States and more than 100 other countries.

Kalamazoo, Michigan, USA

Research Institute / Laboratory / School

Printed Electronics: Manufacturing Technologies and Applications

Mar 13, 2023 | Chuck Zhang

Translational Research in Additive Manufacturing at GTMI * Additive manufacturing/3D printing process and equipment development (e.g., metal, polymer and composites part manufacturing) * Computational modeling and simulation of additive manufacturing/printed electronics processes * Advanced materials development for additive manufacturing/printed electronics * Application development and demonstration of additive manufacturing/printed electronics...

Publisher: Georgia Institute of Technology

Georgia Institute of Technology

Center for Board Assembly Research CBAR- advanced research on board assembly processes and systems

Atlanta, Georgia, USA

Research Institute / Laboratory / School

Modeling Resistance Increase In A Composite Ink Under Cyclic Loading

Mar 13, 2023 | Q Li, E Chung, A Antoniou and O Pierron

The electrical performance of stretchable electronic inks degrades as they undergo cyclic deformation during use, posing a major challenge to their reliability. The experimental characterization of ink fatigue behavior can be a time-consuming process, and models allowing accurate resistance evolution and life estimates are needed. Here, a model is proposed for determining the electrical resistance evolution during cyclic loading of a screen-printed composite conductive ink. The model relies on two input specimen-characteristic curves, assumes a constant rate of normalized resistance increase for a given strain amplitude, and incorporates the effects of both mean strain and strain amplitude. The model predicts the normalized resistance evolution of a cyclic test with reasonable accuracy. The mean strain effects are secondary compared to strain amplitude, except for large strain amplitudes (>10%) and mean strains (>30%). A trace width effect is found for the fatigue behavior of 1 mm vs 2 mm wide specimens. The input specimen-characteristic curves are trace-width dependent, and the model predicts a decrease in Nf by a factor of up to 2 for the narrower trace width, in agreement with the experimental results. Two different methods are investigated to generate the rate of normalized resistance increase curves: uninterrupted fatigue tests (requiring ∼6–7 cyclic tests), and a single interrupted cyclic test (requiring only one specimen tested at progressively higher strain amplitude values). The results suggest that the initial decrease in normalized resistance rate only occurs for specimens with no prior loading. The minimum-rate curve is therefore recommended for more accurate fatigue estimates....

Publisher: Georgia Institute of Technology

Georgia Institute of Technology

Center for Board Assembly Research CBAR- advanced research on board assembly processes and systems

Atlanta, Georgia, USA

Research Institute / Laboratory / School

An Introduction To The Process Of Printed Electronics

Mar 13, 2023 | S.G.R. Avuthu, Ph.D., M. Gill, N Ghalib, M. Sussman, G. Wable, J. Richstein, Ph.D.

Printed electronics (PE) is impacting almost every branch of manufacturing. The printing of electronics on mechanically flexible substrates such as plastic, paper and textile, using traditional printing techniques, provides novel applications for wearable and stretchable electronics. Government sponsored consortiums, universities, contract printers, startups and global manufacturers are developing processes to bring this technology to market faster, more costeffectively and at scale. By increasing the speed of technology adoption while following industrialization best practices, industry researchers aim to create processes that ramp up the scale of production for simple circuits and integrated conductive structures....

Publisher: Jabil Circuit, Inc.

Jabil Circuit, Inc.

An electronic product solutions company providing comprehensive electronics design, manufacturing and product management services.

St. Petersburg, Florida, USA

Consultant / Service Provider

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