Electronics Manufacturing Technical Articles

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