Electronics Manufacturing Technical Articles

Nanoelectromechanical Switches for Low-Power Digital Computing

Mar 02, 2017 | Alexis Peschot, Chuang Qian, Tsu-Jae King Liu

The need for more energy-efficient solid-state switches beyond complementary metal-oxide-semiconductor (CMOS) transistors has become a major concern as the power consumption of electronic integrated circuits (ICs) steadily increases with technology scaling. Nano-Electro-Mechanical (NEM) relays control current flow by nanometer-scale motion to make or break physical contact between electrodes, and offer advantages over transistors for low-power digital logic applications: virtually zero leakage current for negligible static power consumption; the ability to operate with very small voltage signals for low dynamic power consumption; and robustness against harsh environments such as extreme temperatures. Therefore, NEM logic switches (relays) have been investigated by several research groups during the past decade. Circuit simulations calibrated to experimental data indicate that scaled relay technology can overcome the energy-efficiency limit of CMOS technology.

This paper reviews recent progress toward this goal, providing an overview of the different relay designs and experimental results achieved by various research groups, as well as of relay-based IC design principles. Remaining challenges for realizing the promise of nano-mechanical computing, and ongoing efforts to address these, are discussed....

Publisher: EECS at University of California

The Evolution of Surface Finishes in Mobile Phone Applications

Feb 28, 2017 | Claus Würtz Nielsen Nokia Mobile Phones R&D

During the last 5 years mobile phones and other portable consumer electronics have been extremely popular and spread all over the world in different climate zones in very high volumes. At the same time the mobile phone terminal for many people has become a necessity that is brought with them in any activity they practice. These changes in user behavior have heavily changed the impact on handheld terminals from moisture, sweat, corrosive atmospheres and mechanical drop. As a result of this the requirement to solder joint reliability, corrosion stability and wear resistance are heavily increasing to keep a high reliability of the terminal.

Immersion Ni/Au has been the overall dominant surface finish on Printed Wiring Boards (PWB's) for the last 10 years, but a paradigm shift to avoid use of this thin and porous surface finish is ongoing nowadays because it can’t address these challenges in a satisfactory way.

In today's handheld terminals, Organic Solder Preservative (OSP) has replaced Immersion Ni/Au on solder pads. Carbon surface finish for Key- and spring contact-pads, combined with the right concept design can make use of Immersion Ni/Au unnecessary in the near future. The result will be higher reliability with less expensive and simpler processes.

This paper will discuss the various considerations for choice of surface finish and results from the feasibility studies performed....

Publisher: Nokia Corporation

Best Practices for Collecting Product Material and Compliance Data

Feb 23, 2017 | PTC

Managing the environmental performance of products is an increasingly complicated challenge for manufacturers today. These companies face a complex tangle of requirements and mandates from regulators, consumers and customers to manage the toxicity, recycleability and overall environmental impact of their products. Not only have governments, business-to-business customers and consumers demonstrated a clear preference for better environmentally performing and "greener" brands, but investors are now pressuring manufacturers, as well. For example, the Dow Jones Sustainability Index identifies and tracks leading sustainability-driven companies around the world.

This paper focuses on the challenges companies face and the best practices they can employ when collecting substance, material and compliance data from their suppliers and supply chain....

Publisher: PTC

Component Level Reliability For High Temperature Power Computing With SAC305 And Alternative High Reliability Solders

Feb 16, 2017 | Thomas Sanders, Sivasubramanian Thirugnanasambandam and John Evans, Ph.D., Michael Bozack, Ph.D., Jeff Suhling, Ph.D. - Auburn University, Wayne Johnson, Ph.D. - Tennessee Tech University

This experiment considers the reliability of a variety of different electronic components and evaluates them on 0.200” power computing printed circuit boards with OSP. Single-sided assemblies were built separately for the Top-side and Bottom-side of the boards. This data is for boards on the FR4-06 substrate.

This paper was originally published by SMTA in the Proceedings of SMTA International....

Publisher: Auburn University

Can Age and Storage Conditions Affect the SIR Performance of a No-Clean Solder Paste Flux Residue?

Feb 09, 2017 | Eric Bastow

The SMT assembly world, especially within the commercial electronics realm, is dominated by no-clean solder paste technology. A solder paste flux residue that does not require removal is very attractive in a competitive world where every penny of assembly cost counts. One important aspect of the reliability of assembled devices is the nature of the no-clean solder paste flux residue. Most people in this field understand the importance of having a process that renders the solder paste flux residue as benign and inert as possible, thereby ensuring electrical reliability.

But, of all the factors that play into the electrical reliability of the solder paste flux residue, is there any impact made by the age of the solder paste and how it was stored? This paper uses J-STD-004B SIR (Surface Insulation Resistance) testing to examine this question....

Publisher: Indium Corporation

BGA Rework Process

Feb 01, 2017 | Bob Wettermann

BGA Rework Course encompasses the skills necessary to perform rework of electronic printed circuit boards to include PBGA and CBGA technologies. There should be 'one-stop' solution, that offers a wide range of ball grid array rework and repair services....

Publisher: BEST Inc.

HOW MULTI-WAVELENGTH LED LIGHT IMPROVE CURING QUALITY

Jan 31, 2017 | DPL Industri A/S Denmark

Compared with general Mercury Lamp, normal LED can only provide a very narrow band. See the left side figure, which compare the output of a multi-wavelength( 365nm-410nm) LED lamp with traditional mercury lamp. At the same wavelength 365nm,LED lamp can output much more energy than traditional mercury lamp, means LED lamp can provide more high energy output in UV-A range. DPL eAsycure LED curing system use the latest LED technology on LED chip combination to reach high Joule Energy (DOSIS Energy), so it can easily cure UV ink in UVA range instead of single wavelength LED ink. According to our client’s ink performance, DPL LED Curing system can setup different output energy at different wavelength. If you have any question,please contact with our service team at dpl@dpl.dk or visit our website: www.dpl.dk...

what is LED UV curing?

Jan 31, 2017 | DPL Industri A/S Denmark

DPL LED Easycure LED system is base on the latest LED curing technology, which combine with a high effective and smart construction ensure a stable and perfect curing quality for different types of coating, printing, bonding application. DPL LED curing system series is build up with length from 82mm to 2240mm. We also provide customer design service. FEATURE : High UV curing energy output: with our special construction of LED Chips, DPL LED curing system can reach 146w/cm, output energy up to 650mj/cm2 by 100m/min printing speed, Peak energy up to 26w/cm2. Long lifetime: with high effective water chill construction, DPL LED curing system can reach more than 20.000 hours by 100% Radiation. Suitable for LED or mercury UV ink: DPL LED curing system provide high Joule energy (DOSIS ENERGY) with wave length from 365-395nm. “Plus & Play” smart system: DPL LED Curing system is smart system with “plus &play” design, easy to operation and suitable to install in existing machine....

What Type of PCB Substrate Material Is Right for Your PCB?

Jan 24, 2017 | Dora Yang

Basic performance of PCB (Printed Circuit Board) depends on the performance of substrate material. In order to improve the performance of PCB, you have to increase the performance of PCB substrate material first. This article introduces how to chose PCB substrate material for your custom PCB project from multiple perspectives....

Publisher: PCBCart

Environmentally sound: Aqueous cleaning with minimum water consumption

Jan 23, 2017 | Connie Miede

"Water is not a problem of the future, but a key issue of our time for businesses: In the future, urgent water risks will increase in many areas of the world. A growing population, a changing consumer behavior and climate change will have an immediate impact on the availability and quality of water and thus build further pressure on governments, businesses and societies." (Quote from the summary of the 2014 WWF study "The imported risk. Germany's water risk in the age of globalization.")...

Publisher: Kolb Cleaning Technology USA LLC

Rigid-Flex PCB Right the First Time - Without Paper Dolls

Jan 19, 2017 | Benjamin Jordan

The biggest problem with designing rigid-flex hybrid PCBs is making sure everything will fold in the right way, while maintaining good flex-circuit stability and lifespan. The next big problem to solve is the conveyance of the design to a fabricator who will clearly understand the design intent and therefore produce exactly what the designer/engineer intended.

Rigid-Flex circuit boards require additional cutting and lamination stages, and more exotic materials in manufacturing and therefore the cost of re-spins and failures are very much higher than traditional rigid boards. To reduce the risk and costs associated with rigid-flex design and prototyping, it is desirable to model the flexible parts of the circuit in 3D CAD to ensure correct form and fit. In addition it is necessary to provide absolutely clear documentation for manufacturing to the fabrication and assembly houses....

Publisher: Altium

Effect of Alloy and Flux System on High Reliability Automotive Applications

Jan 05, 2017 | Mitch Holtzer, Steve Brown - Alpha, Marcus Reichenberger - Technische Hochschule Nürnberg

The July 2006 implementation of ROHS exempted automotive applications from converting to lead free technology. Nine years later, all major OEM and Tier 1 automotive manufacturers have converted or are in the process of converting to lead free circuit assembly processing. Starting with SAC (SnAgCu) alloys as a baseline for lead free soldering, in the last years several specific alloys were developed in order to improve resistance to high temperature creep, vibration survival and the ability to withstand thermal cycling and thermal shock.

The paper compares three different solder alloys and two flux chemistries in terms of void formation and mechanical / thermal fatigue properties. Void content and reliability data of the alloys will be presented and discussed in relation to the acceptance criteria of a Tier 1 /OEM automotive supplier. As a result, a ranking list will be presented considering the combined performance of the alloys. In order to analyze the void formation and mechanical behavior of different solder alloys and flux chemistry combinations, statistical methods are used....

Publisher: MacDermid Alpha Electronics Solutions

Partially-Activated Flux Residue Impacts on Electronic Assembly Reliabilities

Dec 29, 2016 | Yanrong Shi, Ph.D., Kyle Loomis, Jennifer Allen, Bruno Tolla, Ph.D.

The reliabilities of the flux residue of electronic assemblies and semiconductor packages are attracting more and more attention with the adoption of no-clean fluxes by majority of the industry. In recent years, the concern of "partially activated" flux residue and their influence on reliability have been significantly raised due to the miniaturization along with high density design trend, selective soldering process adoption, and the expanded use of pallets in wave soldering process. When flux residue becomes trapped under low stand-off devices, pallets or unsoldered areas (e.g. selective process), it may contain unevaporated solvent, "live" activators and metal complex intermediates with different chemical composition and concentration levels depending on the thermal profiles. These partially-activated residues can directly impact the corrosion, surface insulation and electrochemical migration of the final assembly.

In this study, a few application tests were developed internally to understand this issue. Two traditional liquid flux and two newly developed fluxes were selected to build up the basic models. The preliminary results also provide a scientific approach to design highly reliable products with the goal to minimize the reliability risk for the complex PCB designs and assembly processes.

This paper was originally published by SMTA in the Proceedings of SMTA International

Publisher: Kester

Characterization, Prevention and Removal of Particulate Matter on Printed Circuit Boards

Dec 22, 2016 | Prabjit Singh, Patrick Ruch, Sarmenio Saliba - IBM Corporation, Christopher Muller - Purafil Inc.

Particulate matter contamination is known to become wet and therefore ionically conductive and corrosive if the humidity in the environment rises above the deliquescence relative humidity (DRH) of the particulate matter. In wet condition, particulate matter can electrically bridge closely spaced features on printed circuit boards (PCBs), leading to their electrical failure. (...)

The objective of this paper is to develop and describe a practical, routine means of measuring the DRH of minute quantities of particulate matter (1 mg or less) found on PCBs....

Publisher: IBM Corporation

Research on Decision-making of Green Reverse Logistics in Enterprises: A Case Study on Electronic Products Manufacturers from the Perspective of South Africa

Dec 21, 2016 | Syed Abdul Rehman Khan

Abstract: In recent years, the environmental problems caused by the traditional implementation of reverse logistics enterprises have become more and more serious. Especially for the enterprises of electronic products, the heavy metal pollution problems caused by the waste of electronic products have made more and more enterprises and researchers begin to seek a green approach of reverse logistics. Based on the idea of “Cradle to Cradle” industry model, by the use of relevant theory of activity-based costing and quality management theory, the conceptual model of decision-making of reverse logistics activities for the electronic products manufacturing enterprises will be established; to decrease the influence on environment when implementing reverse logistics activities....

A Comparison of Mulpin VS Embedded Passive Technology

Dec 15, 2016 | Mulpin

Why embed the components?

Embedded components have advantages over SMD because they are naturally screened from high frequency radio emissions (RFI or EMI). They can also be smaller than current SMD components. Both embedded and Mulpin components have these advantages, but Mulpin components have many more advantages and none of the disadvantages which can be seen below....

Publisher: Mulpin Research Laboratories

Understanding the Effect of Process Changes and Flux Chemistry on Mid-Chip Solder Balling

Nov 30, 2016 | Katherine Wilkerson, Ian J. Wilding, Michael Carter, Daniel Buckland

Mid-chip solder balling is a defect typically associated with solder paste exhibiting poor hot slump and/or insufficient wetting during the reflow soldering process, resulting in paste flowing under the component or onto the solder resist. Once molten, this solder is compressed and forced to the side of the component, causing mid-chip solder balling.

This paper documents the experimental work performed to further understand the impact on mid-chip solder balling from both the manufacturing process and the flux chemistry....

Publisher: Henkel Electronic Materials

Review of Interconnect Stress Testing Protocols and Their Effectiveness in Screening Microvias

Nov 30, 2016 | Edward Arthur; Raytheon Company, Charles Busa, Wade Goldman P.E., Alisa Grubbs; The Charles Stark Draper Laboratory, Inc.

The use of microvias in Printed Circuit Boards (PCBs) for military hardware is increasing as technology drives us toward smaller pitches and denser circuitry. Along with the changes in technology, the industry has changed and captive manufacturing lines are few and far between. As PCBs get more complicated, the testing we perform to verify the material was manufactured to our requirements before they are used in an assembly needs to be reviewed to ensure that it is sufficient for the technology and meets industry needs to better screen for long-term reliability. The Interconnect Stress Testing (IST) protocol currently used to identify manufacturing issues in plated through holes, blind, or buried vias are not necessarily sufficient to identify problems with microvias. There is a need to review the current IST protocol to determine if it is adequate for finding bad microvias or if there is a more reliable test that will screen out manufacturing inconsistencies.

The objective of this research is to analyze a large population of PCB IST coupons to determine if there is a more effective IST test to find less reliable microvias in electrically passing PCB product and to screen for manufacturing deficiencies. The proposed IST test procedure will be supported with visual inspection of corresponding microvia cross sections and Printed Wiring Assembly (PWA) acceptance test results. The proposed screening will be shown to only slightly affect PCB yield while showing a large benefit to screening before PCBs are used in an assembly....

Publisher: Raytheon

Miniaturizing IoT Designs

Nov 23, 2016 | Tom Nordman, Pasi Rahikkala

As we wirelessly connect more and more devices to the Internet, electronics engineers face several challenges, including how to package a radio transmitter into their existing device real estate and how to make increasingly smaller devices. They’re also striving to meet consumer demand for Internet of Things (IoT) products that are ergonomically easy to use and unobtrusive to the environment.

This whitepaper explores the challenges that come with designing connected devices into increasingly smaller products, specifically antenna integration, and how system-inpackage modules can help....

Publisher: Silicon Labs

How Mitigation Techniques Affect Reliability Results for BGAs

Nov 17, 2016 | Greg Caswell, Melissa Keener

Since 2006 RoHS requirements have required lead free solders to take the place of tin-lead solders in electronics. The problem is that in some environments the lead free solders are less reliable than the older tin-lead solders. One of the ways to solve this problem is to corner stake, edge bond or underfill the components. When considering what mitigation technique and material to use, the operating conditions must be characterized. The temperature range is important when selecting a material to use since the glass transition temperature (Tg) and coefficient of thermal expansion (CTE) are important properties. If improperly chosen, the mitigation material can cause more failures than an unmitigated component....

Publisher: DfR Solutions (acquired by ANSYS Inc)

A High Thermal Conductive Solderable Adhesive

Nov 17, 2016 | Dr. Mary Liu and Dr Wusheng Yin

With increasing LED development and production, thermal issues are becoming more and more important for LED devices, particularly true for high power LED and also for other high power devices. In order to dissipate the heat from the device efficiently, Au80Sn20 alloy is being used in the industry now. However there are a few drawbacks for Au80Sn20 process: (1) higher soldering temperature, usually higher than 320°C; (2) low process yield; (3) too expensive. In order to overcome the shortcomings of Au80Sn20 process, YINCAE Advanced Materials, LLC has invented a new solderable adhesive – TM 230. Solderable adhesives are epoxy based silver adhesives. During the die attach reflow process, the solder material on silver can solder silver together, and die with pad together. After soldering, epoxy can encapsulate the soldered interface, so that the thermal conductivity can be as high as 58 W/mk. In comparison to Au80Sn20 reflow process, the solderable adhesive has the following advantages: (1) low process temperature – reflow peak temperature of 230°C; (2) high process yield – mass reflow process instead of thermal compression bonding process; (3) low cost ownership. In this paper we are going to present the die attach process of solderable adhesive and the reliability test. After 1000 h lighting of LED, it has been found that there is almost no decay in the light intensity by using solderable adhesive – TM 230. ...

Publisher: YINCAE Advanced Materials, LLC.

Corrosion Resistant Servers for Free-Air Cooling Data Centers

Nov 10, 2016 | Qiujiang Liu; Baidu, Inc., Prabjit Singh; IBM

The demand for compute capability is growing rapidly fueling the ever rising consumption of power by data centers the worldwide. This growth in power consumption presents a challenge to data center total cost of ownership. Free-air cooling is one of the industrial trends in reducing power consumption, the power usage effectiveness (PUE) ratio, and the total cost of ownership (TCO). Free-air cooling is a viable approach in many parts of the world where the air is reasonably clean. In Eastern China, the poor quality of air, high in particle and gaseous contamination, is a major obstacle to free-air cooling. Servers exposed to outside air blowing in to data centers will corrode and fail at high rate. The poor reliability of hardware increase TCO dramatically.

This paper describes a corrosion resistant server design suitable for reliable operation in a free-air cooling data center located in Eastern China where the indoor air quality can be as poor as ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) severity level G3. An accelerated corrosion test method of verifying hardware reliability in the ASHRAE severity level G3 environment is also described....

Publisher: IBM Corporation

The Impact of LV 214-4 – The German Automotive OEM Connector Test Specification

Nov 10, 2016 | Rob Boyd, Senior Product Manager, Schleuniger, Inc.

It goes without saying that every manufacturer wants to ensure they are producing a quality product. Standards and specifications from various organizations provide a guideline from which manufacturers can measure different areas of quality, while also providing the end user with the reassurance that they are purchasing a trustworthy, long-lasting product. Within the wire processing industry there are many standards that manufacturers may choose or be required to adhere to. These standards and specifications are constantly evolving and increasing in detail, especially as monitoring technology improves. ...

Publisher: Schleuniger, Inc.

Is coating adhesion a problem?

Nov 09, 2016 | Dave Selestak, Alex Berlin, and Carla Loeffler

Nordson MARCH found a solution for a manufacturer of PCBAs used in ruggedized environments. Read how plasma prior to conformal coating reduced defects and virtually eliminated coating-related failures....

Publisher: MARCH Products | Nordson Electronics Solutions

How can you tell the differences between revisions of the same board?

Nov 08, 2016 | Simon Garrison

Over time most PCB designs need to change – a mistake is found, or a part becomes obsolete, etc. Typically once the changes are complete, a new set of manufacturing files (Gerbers, NC Drill files, BOM, Pick and Place, etc) are generated, and the updated design is stored as separate version within a version control system. Using a version control system makes it possible for design teams to go back later and compare differences between design versions. ****** http://www.numericalinnovations.com/blogs/news/gerber-comparisons-between-revisions-of-the-same-board *****...

Publisher: Numerical Innovations

A Novel Method for the Fabrication of a High-Density Carbon Nanotube Microelectrode Array

Nov 03, 2016 | Adam Khalifa, Zhaoli Gao, Amine Bermak, Yi Wang, Leanne Lai Hang Chan

We present a novel method for fabricating a high-density carbon nanotube microelectrode array (MEA) chip. Vertically aligned carbon nanotubes (VACNTs) were synthesized by microwave plasma-enhanced chemical vapor deposition and thermal chemical vapor deposition. The device was characterized using electrochemical experiments such as cyclic voltammetry, impedance spectroscopy and potential transient measurements. Through-silicon vias (TSVs) were fabricated and partially filled with polycrystalline silicon to allow electrical connection from the high-density electrodes to a stimulator microchip.

In response to the demand for higher resolution implants, we have developed a unique process to obtain a high-density electrode array by making the microelectrodes smaller in size and designing new ways of routing the electrodes to current sources....

Publisher: Hong Kong University of Science

Press Fit Technology Roadmap and Control Parameters for a High Performance Process

Oct 27, 2016 | Jose Becerra, Dennis Willie and Murad Kurwa

Press-fit technology is a proven and widely used and accepted interconnection method for joining electronics assemblies. Printed Circuit Board Assembly Systems and typical functional subassemblies are connected through press-fit connectors.

The Press-Fit Compliant Pin is a proven interconnect termination to reliably provide electrical and mechanical connections from a Printed Circuit Board to an Electrical Connector. Electrical Connectors are then interconnected together providing board to board electrical and mechanical inter-connection. Press-Fit Compliant Pins are housed within Connectors and used on Backplanes, Mid-planes and Daughter Card Printed Circuit Board Assemblies. High reliability OEM (Original Equipment Manufacturer) computer designs continue to use press-fit connections to overcome challenges associated with soldering, rework, thermal cycles, installation and repair.

This paper investigates the technical roadmap for press fit technology, putting special attention to main characteristics such, placement and insertion, inspection, repair, pin design trends, challenges and solutions. Critical process control parameters within an assembly manufacturing are highlighted....

Publisher: Flex (Flextronics International)

Focus on Biosensors

Oct 24, 2016 | Innovative Sensor Technology

Biosensors – a new Sensor Type from IST AG What are Biosensors? A biosensor is a device capable of detecting a certain substance or analyte with high specificity. Examples of such analytes are glucose, lactate, glutamine and glutamate. Most biosensors measure the concentration of an analyte in an aqueous solution, usually producing an electrical signal, which is proportional to the analyte’s concentration in its measuring range. An enzymatic biosensor comprises an enzyme, which recognizes and reacts with the target analyte generating a chemical signal, a transducer, which produces a physical signal out of that chemical one, and an electronic amplifier, which conditions and amplifies the signal. Biosensors allow the analysis in complex biological media. The detection of a large number of compounds is of great relevance not only for scientific research but also for process control in the chemical and food industry. It is also indispensable in the health care field for the diagnosis and treatment of diseases and monitoring of illnesses. The pharmaceutical and biotechnology industries greatly desire frequent to continuous analysis of biological media. Such analyses are conducted with the aid of analytical instruments like HPLC systems, which, although robust and reliable, are expensive and have a limited suitability for online operation. For this reason, the acquisition of Jobst Technologies GmbH positions IST AG as a key provider of high-performance and reliable online biosensors. ...

Publisher: Innovative Sensor Technology, USA Division

Focus on temperature and customized sensors

Oct 24, 2016 | IST AG

Temperature measurement is one of the most important physical parameters when determining quality, accuracy and reliability of processes not only in industrial use, but also in almost all human activities. Temperature sensors are produced with different technologies to fit specific application requirements. IST AG has concentrated one part of the development and manufacturing on high-end thin-film temperature sensors. This know-how is partially derived from the semiconductor industry and allows us to manufacture sensors with high accuracy, excellent long-term stability, high reliability and repeatability within a wide temperature range from -200 °C up to 1000 °C. Because of very small dimensions and low thermal mass, the thin-film temperature sensors exhibit a very short response time. ...

Publisher: Innovative Sensor Technology, USA Division

Analysis of Laminate Material Properties for Correlation to Pad Cratering

Oct 20, 2016 | Carlos Morillo, Yan Ning, Michael H. Azarian, Julie Silk, Michael Pecht.

Pad cratering failure has emerged due to the transition from traditional SnPb to SnAgCu alloys in soldering of printed circuit assemblies. Pb-free-compatible laminate materials in the printed circuit board tend to fracture under ball grid array pads when subjected to high strain mechanical loads. In this study, two Pb-free-compatible laminates were tested, plus one dicycure non-Pb-free-compatible as control. One set of these samples were as-received and another was subjected to five reflows. It is assumed that mechanical properties of different materials have an influence on the susceptibility of laminates to fracture. However, the pad cratering phenomenon occurs at the layer of resin between the exterior copper and the first glass in the weave. Bulk mechanical properties have not been a good indicator of pad crater susceptibility.

In this study, mechanical characterization of hardness and Young’s modulus was carried out in the critical area where pad cratering occurs using nano-indentation at the surface and in a cross-section. The measurements show higher modulus and hardness in the Pb-free compatible laminates than in the dicy-cured laminate. Few changes are seen after reflow – which is known to have an effect -- indicating that these properties do not provide a complete prediction. Measurements of the copper pad showed significant material property changes after reflow....

Publisher: CALCE Center for Advanced Life Cycle Engineering

Choosing An Oscilloscope

Oct 07, 2016 | Alan Lowne

15 points to consider when about to purchase a new oscilloscope...

Publisher: Saelig Co. Inc.

PCB Conformal Coatings Guide - II

Oct 07, 2016 | Sierra Assembly

In the previous post, we discussed the importance of conformal coatings, materials used for coatings, and methods of application. In this post, we shall look at various conformal coating curing methods, and analyze their immediate benefits. ...

Publisher: Sierra Assembly Technology LLC

PCB Laser Depanelizing Using a UV Laser

Oct 06, 2016 | Bob Wettermann

One of the methods gaining in popularity for singulating rigid/flex, rigid and flex circuit boards post assembly is through the use of laser routing. This method has the advantage of speed, positional accuracy, no tooling wear and lastly no induced mechanical stresses on components during the singulating process....

Publisher: BEST Inc.

Room Temperature Fast Flow Reworkable Underfill For LGA

Oct 03, 2016 | Dr. Mary Liu and Dr. Wusheng Yin

With the miniaturization of electronic device, Land Grid Array (LGA) or QFN has been widely used in consumer electronic products. However there is only 20-30 microns gap left between LGA and the substrate, it is very difficult for capillary underfill to flow into the large LGA component at room temperature. Insufficient underfilling will lead to the loss of quality control and the poor reliability issue. In order to resolve these issues, a room temperature fast flow reworkable underfill has been successfully developed with excellent flowability. The underfill can flow into 20 microns gap and complete the flow of 15mm distance for about 30 seconds at room temperature. The curing behavior, storage, thermal cycling performance and reworkability will be discussed in details in this paper....

Publisher: YINCAE Advanced Materials, LLC.

Re-Shoring or Near-Shoring Concepts Should be Strongly Considered when the OEM’s Goal is To Deliver Optimum Balance between Landed Cost and Time to Market

Sep 29, 2016 | Brian Graham

The old tactic of outsourcing to a low cost geography simply to deliver lowest cost direct and indirect labor was never a panacea supply chain solution. In fact, when evaluating solutions for lower volume and higher mix products typically found in the medical, industrial and public safety segments of the OEM market, IL & DL costs are only one subset of the total cost to land the product and service the ultimate customer.

In this paper, there will be examination of what actual cost components should be included in a landed cost analysis, the soft costs that an OEM should consider to deliver outstanding performance in quality, logistics and delivery management of the supply chain solution. A detailed comparison using a 'case study' will be presented to demonstrate a total landed cost option versus one that is focused on IL/DL cost....

Publisher: Kimball Electronics, Inc.

IPC-CC-830B Versus the 'Real World'

Sep 22, 2016 | Carolyn Taylor, Phil Kinner

Conformal Coatings are often used to increase the reliability of electronic assemblies operating in harsh or corrosive environments where the product would otherwise fail prematurely. Conformal coatings are often qualified to international standards, intended to enable users to better differentiate between suitable conformal coating chemistries, but always on a flat test coupon, which is not representative of real world use conditions.

In order to better correlate international standards with real world-use conditions, three-dimensional Surface Insulation Resistance (SIR) test boards have been manufactured with dummy components representative of those commonly used on printed circuit assemblies......

Publisher: Electrolube

Making Ovens Smarter

Sep 19, 2016 | Bjorn Dahle

This white paper seeks to set out the value of a ‘smarter’ approach to the reflow process and how a more intelligent oven can offer real added value and performance to the entire line. It also lays out some of the criteria that is important when selecting smart equipment for a smart process, that conforms to, and is ready for, IoM or Industry 4.0...

Publisher: KIC Thermal

Long Term Thermal Reliability of Printed Circuit Board Materials

Sep 15, 2016 | Eva McDermott, Ph.D., Bob McGrath, and Christine Harrington

This paper describes the purpose, methodology, and results to date of thermal endurance testing performed at the company. The intent of this thermal aging testing is to establish long term reliability data for printed wiring board (PWB) materials for use in applications that require 20+ years (100,000+ hours) of operational life under different thermal conditions. Underwriters Laboratory (UL) testing only addresses unclad laminate (resin and glass) and not a fabricated PWB that undergoes many processing steps, includes copper and plated through holes, and has a complex mechanical structure. UL testing is based on a 5000 hour expected operation life of the electronic product. Therefore, there is a need to determine the dielectric breakdown / degradation of the composite printed circuit board material and mechanical structure over time and temperature for mission critical applications....

Publisher: Amphenol Printed Circuit Board Technology

Making the Move from Machine Monitoring to SMART Manufacturing and the Implications on Profiling Systems

Sep 12, 2016 | Mark Stansfield

It is hard to open an Industry newsletter or visit an equipment manufacturer’s website without coming across a mention of the Internet of Things (IoT), Industry 4.0, SMART Manufacturing or ‘big data’. The accessibility to obtain data will only increase and this information and its real-time processing will become one of the most important resources for companies in the future. Production machinery will no longer simply processes the product, but the product will communicate with the machinery to tell it exactly what to do. Industry 4.0 has the vision to connects embedded system technologies and SMART production processes to drastically transform industry and production giving way to the SMART factory development. Future development in oven technology will allow machines to be controlled more intelligently and remotely resulting in the lowest cost model for manufacturing flow....

Publisher: Solderstar

How Clean is Clean Enough – At What Level Does Each of The Individual Contaminates Cause Leakage and Corrosion Failures in SIR?

Sep 08, 2016 | Terry Munson, Paco Solis, Nick Munson, Steve Ring, Evan Briscoe.

In this investigation a test matrix was completed utilizing 900 electrodes (small circuit board with parallel copper traces on FR-4 with LPI soldermask at 6, 10 and 50 mil spacing): 12 ionic contaminants were applied in five concentrations to three different spaced electrodes with five replicas each (three different bare copper trace spacing / five replications of each with five levels of ionic concentration). The investigation was to assess the electrical response under controlled heat and humidity conditions of the known applied contamination to electrodes, using the IPC SIR (surface insulation resistance) J-STD 001 limits and determine at what level of contamination and spacing the ionic / organic residue has a failing effect on SIR....

Publisher: Foresite Inc.

PCB-Conformal-Coatings-Guide-I

Sep 06, 2016 | Sierra Assembly

Printed circuit boards are the base of electronic products in a variety of consumer and industrial applications. New PCBs always perform well. However, their performance will deteriorate with time due to exposure to different environmental conditions like condensation, moisture, contamination of the iconic material on the surface, dust and dirt, mildew, alpha particles, etc. To avoid these problems, PCBs are protected with conformal coatings. Let’s see how this is done, and how they protect PCB components....

Publisher: Sierra Assembly Technology LLC

Reliability Study of Low Silver Alloy Solder Pastes

Sep 01, 2016 | Jennifer Nguyen, David Geiger and Murad Kurwa

Sn3.0Ag0.5Cu (SAC305) is currently the most popular near eutectic lead-free alloy used in the manufacturing processes. Over the last several years, the price of silver has dramatically increased driving a desire for lower silver alloy alternatives. As a result, there is a significant increase in the number of alternative low/no silver lead-free solder alloys available in the industry recently. Our previous study showed that many alternative low silver solder paste materials had good printing and wetting performance as compared to SAC305 solder pastes. However, there is lack of information on the reliability of alternative alloy solder joints assembled using alternative low silver alloy solder pastes.

In this paper, we will present the reliability study of lead-free solder joints reflowed using various lead-free alloy solder pastes after thermal cycling test (3000 cycles, 0°C to 100°C). Six different lead-free pastes were investigated. SAC305 solder joints were used as the control. Low and no silver solder pastes and a low temperature SnBiAg solder pastes were also included....

Publisher: Flex (Flextronics International)

Sustainable Product Design and Supplier Material Disclosure

Aug 25, 2016 | Tedie West, Kerri Doyle

Sustainable product design and the task of bringing new, earth friendly products to market is a top priority for corporate leaders in the manufacturing industry. By not reaching their compliance and sustainability goals, manufacturers risk loss of market share, fines for non-compliance against regulatory directives and possible damage to their brand. Managing material disclosure information from the supply chain is one of their biggest challenges....

Publisher: Siemens PLM Software

Mechanical stress test for component solder joints and bonding wires

Aug 24, 2016 | MINIMOTOR Benelux

From consumer electronics to systems control, automotive technology to aviation and aerospace – today, electronics are absolutely essential in many sectors. They increasingly replace mechanical components, eliminating wear and tear and thereby extending the service life. What is easily forgotten in this regard is that electronics are also subject to the laws of mechanics. Mechanical test equipment is crucial to test components for the secure hold of welded, soldered or adhesive bonds. A new, mechanically intricate test probe with universal clamping jaws, that can even grasp the individual bonding wires, is in line with the trend toward ever smaller components. Serving as an actuator for these is a micro drive that can be precisely controlled using a miniaturised motion controller to relieve the control unit in the test device....

Publisher: XYZTEC bv

Bond Test Measurement Accuracy

Aug 23, 2016 | Bob Sykes

While many things can affect the force measurement accuracy of a bond test, its ultimate limitation is that of the force sensor. With advances in technology, accuracy can be dramatically improved with no cost penalty and no need to select force measurement ranges. How is this accomplished? ...

Publisher: XYZTEC bv

Selective Reflow Rework Process

Aug 18, 2016 | Omar García, Enrique Avelar, C. Sanchez, M. Carrillo, O. Mendoza, J. Medina, Zhen (Jane) Feng,Ph.D., Murad Kurwa

The Selective Reflow Rework Process is an approach to improving the high volume rework process, increasing process capabilities and process repeatability by using a standard reflow oven of 12 zones, pick and place machinery, semi-automated printing gear and Solder Paste Inspection (SPI) implementations. This approach was able to reduce the amount of rework equipment by more than half. Our human resource requirements (indirect and direct labor) were cut by more than 50% and our rolled throughput yield increased from 68.9% to 84.14%. The Selective Reflow Rework Process is less reliant upon operators and has become a repeatable, stable rework process....

Publisher: Flex (Flextronics International)

Innovation ploughing into the automotive industry with the help of PCB’s

Aug 17, 2016 | Technotronix

To stake a claim in upcoming new technologies and increasing improved customer experience, it is now becoming a central point of consideration to bring out the new classy vehicle design, car manufacturing techniques, testing system in the global market. The current vehicle manufacturer’s also aim to maintain equilibrium between deep capital investment and long product cycle to make the car model a success story. With this, the type of printed circuit board to be used in the vehicle is decided with focusing more on the type of material used in the vehicle and the level of electronic manufacturing and design solution needed in the vehicle production. To go into the roots of the automotive industry, it is equally important to get insights into the PCB used in vehicles and the new innovations brought forward by researchers to create a dream vehicle of the series. The below paragraph drives you to the types of PCB used in the automotive sector....

Publisher: Technotronix

New Approaches to Develop a Scalable 3D IC Assembly Method

Aug 11, 2016 | Charles G. Woychik Ph.D. Sangil Lee, Ph.D., Scott McGrath, Eric Tosaya and Sitaram Arkalgud Ph.D.

The challenge for 3D IC assembly is how to manage warpage and thin wafer handling in order to achieve a high assembly yield and to ensure that the final structure can pass the specified reliability requirements. Our test vehicles have micro-bumped die having pitches ranging from 60um down to 30um. The high density of pads and the large die size, make it extremely challenging to ensure that all of the micro-bump interconnects are attached to a thin Si-interposer. In addition, the low standoff between the die and interposer make it difficult to underfill. A likely approach is to first attach the die to the interposer and then the die/interposer sub-assembly to the substrate. In this scenario, the die/interposer sub-assembly is comparable to a monolithic silicon die that can be flip chip attached to the substrate.

In this paper, we will discuss various assembly options and the challenges posed by each. In this investigation, we will propose the best method to do 2.5D assembly in an OSAT(Outsourced Assembly and Test) facility....

Publisher: Invensas Corporation

PCB Molding An Upward Curve Of Innovation In Building Protection Systems

Aug 11, 2016 | Technotronix

Be it a residential building, hospital, shopping mall, hotel, school, educational institution or any kind of a building, the security of the building is a prime facet to get a complete building solution. This also includes protecting the building, its assent and the human life from the airborne toxic industrial chemical, radiological and biological attacks or any accidental release apart from fire, water, earthquake and other security concerns. For these high value security solutions, the upgraded technology for the building safety system is now a top priority, especially in the commercial building sector and residential constructions. To introduce a completely new concept and a unique solution, it is necessary to focus on the dynamic electronic design and manufacturing solution in consultation with the custom PCB experts....

Publisher: Technotronix

Evaluation of Under-Stencil Cleaning Papers

Aug 04, 2016 | Lars Bruno

Solder paste screen printing is known to be one of the most difficult processes to quality assure in Printed Board Assembly (PBA) manufacturing. An important process step in solder paste screen printing is the under stencil cleaning process and one of the key materials in this process is the cleaning paper1. This, often neglected, material affects the cleaning process and thereby also the print quality. It is therefore important to perform tests of different cleaning papers before one could be chosen.

This article describes how cleaning papers can be tested and it also tells how big differences it can be between different materials....

Publisher: Ericsson AB