Electronics Manufacturing Technical Articles

Electronics Manufacturing Technical Articles

Papers and articles related to SMT, PCB & EMS industry.

  • Reflow Ovens
  • Precision, fluid dispensing systems for low volume, high mix, R&D, and high volume 24x7 production

Add Article »

1776 SMT / PCB Assembly Related Technical Articles

Avoidance of Ceramic-Substrate-Based LED Chip Cracking Induced by PCB Bending or Flexing

Sep 25, 2022 | Cree Lighting

Printed circuit board (PCB) bending and/or flexing is an unavoidable phenomenon that is known to exist and is easily encountered during electronic board assembly processes. PCB bending and/or flexing is the fundamental source of tensile stress induced on the electronic components on the board assembly. For more brittle components, like ceramic-based electronic components, micro-cracks can be induced, which can eventually lead to a fatal failure of the components. For this reason, many standards organizations throughout the world specify the methods under which electronic board assemblies must be tested to ensure their robustness, sometimes as a pre-condition to more rigorous environmental tests such as thermal cycling or thermal shock....

Publisher: Cree Lighting

Cree Lighting

Cree Lighting is a market-leading innovator of Indoor, Outdoor, and Consumer Bulb LED lighting.

Racine, Wisconsin, USA

Other

Cracking Problems in Low-Voltage Chip Ceramic Capacitors

Sep 25, 2022 | Alexander Teverovsky

Cracking remains the major reason of failures in multilayer ceramic capacitors (MLCCs) used in space electronics. Due to a tight quality control of space-grade components, the probability that as manufactured capacitors have cracks is relatively low, and cracking is often occurs during assembly, handling and the following testing of the systems. Majority of capacitors with cracks are revealed during the integration and testing period, but although extremely rarely, defective parts remain undetected and result in failures during the mission. Manual soldering and rework that are often used during low volume production of circuit boards for space aggravate this situation. Although failures of MLCCs are often attributed to the post-manufacturing stresses, in many cases they are due to a combination of certain deviations in the manufacturing processes that result in hidden defects in the parts and excessive stresses during assembly and use. This report gives an overview of design, manufacturing and testing processes of MLCCs focusing on elements related to cracking problems. The existing and new screening and qualification procedures and techniques are briefly described and assessed by their effectiveness in revealing cracks. The capability of different test methods to simulate stresses resulting in cracking, mechanisms of failures in capacitors with cracks, and possible methods of selecting capacitors the most robust to manual soldering stresses are discussed....

Publisher: NASA Office Of Safety And Mission Assurance

NASA Office Of Safety And Mission Assurance

The Office of Safety and Mission Assurance (OSMA) assures the safety and enhances the success of all NASA activities through the development, implementation and oversight of agencywide safety, reliability, maintainability and ...

Washington, District of Columbia, USA

Research Institute / Laboratory / School

Analysis of Interfacial Cracking in Flip Chip Packages With Viscoplastic Solder Deformation

Sep 25, 2022 | M. J. Heffes, H. F. Nied

This paper examines the modeling of viscoplastic solder behavior in the vicinity of interfacial cracking for flip chip semiconductor packages. Of particular interest is the relationship between viscoplastic deformation in the solder bumps and any possible interface cracking between the epoxy underfill layer and the silicon die. A 3-D finite element code, developed specifically for the study of interfacial fracture problems, was modified to study how viscoplastic solder material properties would affect fracture parameters such as strain energy release rate and phase angle for nearby interfacial cracks. Simplified twolayer periodic symmetry models were developed to investigate these interactions. Comparison of flip chip results using different solder material models showed that viscoplastic models yielded lower stress and fracture parameters than time independent elastic-plastic simulations. It was also found that adding second level attachment greatly increases the magnitude of the solder strain and fracture parameters. As expected, the viscoplastic and temperature dependent elastic-plastic results exhibited greater similarity to each other than results based solely on linear elastic properties. !DOI: 10.1115/1.1649242"

...

Publisher: Lehigh University

Lehigh University

Located in Pennsylvania's beautiful Lehigh Valley, Lehigh is one of the nation's most distinguished private research universities. Through academic rigor, an entrepreneurial mindset and collaborative opportunities we challenge our

Bethlehem, Pennsylvania, USA

Research Institute / Laboratory / School

ElectronicWaste, an Environmental Problem Exported to Developing Countries: The GOOD, the BAD and the UGLY

Sep 21, 2022 | Samuel Abalansa, Badr El Mahrad, John Icely and Alice Newton

Electronic waste (e-waste) is a rapidly developing environmental problem particularly for the most developed countries. There are technological solutions for processing it, but these are costly, and the cheaper option for most developed countries has been to export most of the waste to less developed countries. There are various laws and policies for regulating the processing of e-waste at different governance scales such as the international Basel Convention, the regional Bamoko Convention, and various national laws. However, many of the regulations are not fully implemented and there is substantial financial pressure to maintain the jobs created for processing e-waste. Mexico, Brazil, Ghana Nigeria, India, and China have been selected for a more detailed study of the transboundary movements of e-waste. This includes a systematic review of existing literature, the application of the Driver, Pressure, State, Impact, Response (DPSIR) framework for analysing complex problems associated with social ecological systems, and the application of the Life Cycle Assessment (LCA) for evaluating the environmental impact of electronic devices from their manufacture through to their final disposal. Japan, Italy, Switzerland, and Norway have been selected for the LCA to show how e-waste is diverted to developing countries, as there is not sufficient data available for the assessment from the selected developing countries. GOOD, BAD and UGLY outcomes have been identified from this study: the GOOD is the creation of jobs and the use of e-waste as a source of raw materials; the BAD is the exacerbation of the already poor environmental conditions in developing countries; the UGLY is the negative impact on the health of workers processing e-waste due to a wide range of toxic components in this waste. There are a number of management options that are available to reduce the impact of the BAD and the UGLY, such as adopting the concept of a circular economy, urban mining, reducing loopholes and improving existing policies and regulations, as well as reducing the disparity in income between the top and bottom of the management hierarchy for e-waste disposal. The overarching message is a request for developed countries to help developing countries in the fight against e-waste, rather than exporting their environmental problems to these poorer regions....

Publisher: Murray Foundation

Murray Foundation

The Murray Foundation's purpose is, for the public benefit, to advance education, to encourage and support dissemination of research and technical information in the area of environmental processes.

Liverpool, Lancashire, Ethiopia

Research Institute / Laboratory / School

Handling of Highly-Moisture Sensitive Components - An Analysis of Low-Humidity Containment and Baking Schedules

Sep 12, 2022 | R. L. Shook and J. P. Goodelle

Unique component handling issues can arise when an assembly factory uses highly-moisture sensitive surface mount devices (SMDs). This work describes how the distribution of moisture within the molded plastic body of a SMD is an important variable for survivability. JEDEC/IPC [1] moisture level rated packages classified as Levels 4-5a are shown to require additional handling constraints beyond the typical out-of-bag exposure time tracking. Nitrogen or desiccated cabinet containment is shown as a safe and effective means for long-term storage provided the effects of prior out-of-bag exposure conditions are taken into account. Moisture diffusion analyses coupled with experimental verification studies show that time in storage is as important a variable as floor-life exposure for highly-moisture sensitive devices. Improvements in floor-life survivability can be obtained by a handling procedure that includes cyclic storage in low humidity containment. SMDs that have exceeded their floor-life limits are analyzed for proper baking schedules. Optimized baking schedules can be adopted depending on a knowledge of the exposure conditions and the moisture sensitivity level of the device....

Publisher: Alcatel-Lucent

Alcatel-Lucent

Often referred to as "The Idea Factory" or "The Crown Jewel," Nokia Bell Labs has an unparalleled history of innovation output. Researchers at Nokia Bell Labs have been behind or involved in nearly every critical technological mil

New Providence, New Jersey, USA

Research Institute / Laboratory / School

Innovative process for sealing contours protects sensitive components

Sep 08, 2022 | Scheugenpflug

Liquid seals in the automotive industry have to meet high functional quality standards and have to be applied in the shortest possible time in view of the high volume of workpieces. This market environment gives rise to innovations that guarantee maximum speed and quality from initial design to final results....

Publisher: Scheugenpflug Inc.

Scheugenpflug Inc.

Producer of bonding, dispensing and potting solutions with outstanding expertise in automation. As part of the Atlas Copco Group, we have a worldwide sales & service network and access to the Group's extensive technology portfolio

Kennesaw, Georgia, USA

Manufacturer

Stencil Cleaning Handbook

Aug 17, 2022 | Mike Konrad

Back in the "good old days," stencil cleaning was effortless and effective. CFC-based solvents were sprayed or wiped onto a stencil with apertures hundreds of times larger than modern-day components. The stencil cleaning process was not considered a value-added procedure; instead it was the cleaning of a production tool. How times have changed. The late-1980s ushered in the end of most of the popular solvents, and the machines that consumed them. Assemblers turned to alternative cleaning agents, including IPAs and other solvents....

Publisher: Aqueous Technologies Corporation

Aqueous Technologies Corporation

Manufacturer of automated defluxing/cleaning equipment, cleanliness testing equipment, and stencil cleaning equipment.

Corona, California, USA

Manufacturer

Techniques for Selective Soldering High Thermal Mass and Fine-Pitch Components

Aug 08, 2022 | Reid Henry

Selective soldering has evolved to become a standard production process within the electronics assembly industry, and now accommodates a wide variety of through-hole component formats in numerous applications. Most through-hole components can be easily soldered with the selective soldering process without difficulty however some types of challenging components require additional attention to ensure that optimum quality is maintained. Several high thermal mass components can place demands on the selective soldering process, while the use of specialized solder fixtures, or solder pallets, often places additional thermal demand on the preheating process. Fine-pitch through-hole components and connectors place a different set of demands on the selective soldering process and typically require special attention to lead projection and traverse speed to minimize bridging between adjacent pins. Dual in-line memory module (DIMM) connectors, compact peripheral component interface (cPCI) connectors, coax connectors and other high thermal mass components as well as fine-pitch microconnectors, can present challenges when soldered into backplanes or multilayer printed circuit board assemblies. Adding to this challenge, compact peripheral component interface connectors can present additional solderability issues because of their beryllium copper base metal pins. Key Terms: Selective soldering, drop-jet fluxing, sustained preheating, flux migration, adjacent clearance, lead-to-hole aspect ratio, lead projection, thermal reliefs, gold embrittlement, solderability testing....

Publisher: Hentec Industries, Inc. (RPS Automation)

Hentec Industries, Inc. (RPS Automation)

Hentec Industries, Inc. designs and manufacturers high quality precision machines for use in selective soldering, lead tinning, and solderability testing applications.

Newman Lake, Washington, USA

Consultant / Service Provider, Manufacturer

Resource-efficient adhesion and potting technologies in electronics manufacturing

Aug 02, 2022 | Scheugenpflug

Saving resources in electronics manufacturing is not an end in itself. It is closely linked with reducing costs and gaining a competitive advantage. However, innovative adhesion and potting technologies in combination with highly functional adhesives and potting media make a significant contribution to the ideal union between economic performance and a reduced ecological footprint....

Publisher: Scheugenpflug Inc.

Scheugenpflug Inc.

Producer of bonding, dispensing and potting solutions with outstanding expertise in automation. As part of the Atlas Copco Group, we have a worldwide sales & service network and access to the Group's extensive technology portfolio

Kennesaw, Georgia, USA

Manufacturer

Fairstock hk limited: Authenticity Tests Electronic Components pdf

Jul 22, 2022 | Fairstock hk limited

Authenticity Tests Electronic Components...

Publisher: Fairstock hk limited

Fairstock hk limited

Fairstock hk limited is a leading certified stocking distributor and outsource procurement services provider specializing in the supply and material management of commercial level electronic components for OEMs.

Hong Kong, Greece

Distributor, Manufacturer

pcb fluid dispensers
Now Online
326
Visitors
2
Members

Who are SMTnet visitors?

Become a member now and receive the value and benefits of membership.

One stop service for all SMT and PCB needs
Void Free Reflow Soldering

Reflow Oven