Electronics Manufacturing Technical Articles

Screen-Printing Fabrication and Characterization of Stretchable Electronics

Mar 09, 2017 | Jari Suikkola, Toni Björninen, Mahmoud Mosallaei, Timo Kankkunen, Pekka Iso-Ketola, Leena Ukkonen, Jukka Vanhala & Matti Mäntysalo

This article focuses on the fabrication and characterization of stretchable interconnects for wearable electronics applications. Interconnects were screen-printed with a stretchable silver-polymer composite ink on 50-μm thick thermoplastic polyurethane. The initial sheet resistances of the manufactured interconnects were an average of 36.2 mΩ/◽, and half the manufactured samples withstood single strains of up to 74%. The strain proportionality of resistance is discussed, and a regression model is introduced. Cycling strain increased resistance. However, the resistances here were almost fully reversible, and this recovery was time-dependent. Normalized resistances to 10%, 15%, and 20% cyclic strains stabilized at 1.3, 1.4, and 1.7. We also tested the validity of our model for radio-frequency applications through characterization of a stretchable radio-frequency identification tag....

Publisher: Tampere University of Technology

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