Electronics Manufacturing Technical Articles

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