Electronics Manufacturing Technical Articles

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.