Electronics Manufacturing Technical Articles

Electronics Manufacturing Technical Articles

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


  • Europlacer SMT Pick & Place Machines
  • Reflow Ovens
  • Precision, fluid dispensing systems for low volume, high mix, R&D, and high volume 24x7 production
  • Soldering Robots
  • Electronics manufacturing training materials - IPC, solder
  • PCB X-Ray Inspection
  • PCB Rework Tools
750 SMT / PCB Technical Articles

What is Kelvin Test?

Jul 14, 2015 | Rick Meraw, Todd Kolmodin, Manfred Ludwig, Holger Kern.

The PCB industry is ever changing and adapting to new technologies. OEM specifications and requirements have also advanced due to these technologies. In some cases the OEMs are asking for a low resistance test to be performed on some or all electrical test nets of the PCB or on the holes of the PCB. This requirement is typically not well defined on the fabrication drawing and that leads to misleading conclusions by the fabrication house (...)

This paper will use the data gathered by the company’s operations to outline what a 4-wire Kelvin test is and how it can be used. Several examples will be illustrated of what the 4 wire Kelvin test can and cannot do. A clear definition of what limitations are present during the testing operation will be defined. The paper will assist designers in understanding how the low resistance test can assist them and also identify causes that can identify unwanted concerns/issues....

Publisher: Gardien Services USA

Gardien Services USA

The Gardien Group is the world's largest provider of independent testing services to the PCB manufacturing industry.

Hillsboro, Oregon, USA

Test Services

Reliability Study of Bottom Terminated Components

Jul 14, 2015 | Jennifer Nguyen, Hector Marin, David Geiger, Anwar Mohammed, and Murad Kurwa

Bottom terminated components (BTC) are leadless components where terminations are protectively plated on the underside of the package. They are all slightly different and have different names, such as QFN (quad flat no lead), DFN (dual flat no lead), LGA (land grid array) and MLF (micro lead-frame. BTC assembly has increased rapidly in recent years. This type of package is attractive due to its low cost and good performance like improved signal speeds and enhanced thermal performance.

However, bottom terminated components do not have any leads to absorb the stress and strain on the solder joints. It relies on the correct amount of solder deposited during the assembly process for having a good solder joint quality and reliable reliability. Voiding is typically seen on the BTC solder joint, especially on the thermal pad of the component. Voiding creates a major concern on BTC component’s solder joint reliability. There is no current industry standard on the voiding criteria for bottom terminated component. The impact of voiding on solder joint reliability and the impact of voiding on the heat transfer characteristics at BTC component are not well understood. This paper will present some data to address these concerns....

Publisher: Flex (Flextronics International)

Flex (Flextronics International)

Flextronics is a global full-service supplier of a full spectrum of value-added Electronic Manufacturing Services.

Singapore, Singapore

Design, Service Provider

Predicting Fatigue of Solder Joints Subjected to High Number of Power Cycles

Jul 09, 2015 | Craig Hillman, Nathan Blattau, Matt Lacy

Solder joint reliability of SMT components connected to printed circuit boards is well documented. However, much of the testing and data is related to high-strain energy thermal cycling experiments relevant to product qualification testing (i.e., -55C to 125C). Relatively little information is available on low-strain, high-cycle fatigue behavior of solder joints, even though this is increasingly common in a number of applications due to energy savings sleep mode, high variation in bandwidth usage and computational requirements, and normal operational profiles in a number of power supply applications.

In this paper, 2512 chip resistors were subjected to a high (>50,000) number of short duration (<10 min) power cycles. Environmental conditions and relevant material properties were documented and the information was inputted into a number of published solder joint fatigue models. The requirements of each model, its approach (crack growth or damage accumulation) and its relevance to high cycle fatigue are discussed....

Publisher: DfR Solutions

DfR Solutions

DfR Solutions has world-renowned expertise in applying the science of Reliability Physics to electrical and electronics technologies, and is a leading provider of quality, reliability, and durability (QRD) research and consulting for the electronics industry.

College Park, Maryland, USA

Service Provider

Reliability Screening of Lower Melting Point Pb-Free Alloys Containing Bi

Jul 01, 2015 | Joseph M. Juarez, Michael Robinson, Joel Heebink; Honeywell, Polina Snugovsky, Eva Kosiba, Jeffrey Kennedy, Zohreh Bagheri, Subramaniam Suthakaran, Marianne Romansky; Celestica.

Aerospace and military companies continue to exercise RoHS exemptions and to intensively research the long term attachment reliability of RoHS compliant solders. Their products require higher vibration, drop/shock performance, and combined-environment reliability than the conventional SAC305 alloy provides. The NASA-DoD Lead-Free Electronics Project confirmed that pad cratering is one of the dominant failure modes that occur in various board level reliability tests, especially under dynamic loading.

One possible route to improvement of the mechanical and thermo-mechanical properties of solder joints is the use of Pb-free solders with lower process temperatures. Lower temperatures help reduce the possibility of damaging the boards and components, and also may allow for the use of lower Tg board materials which are less prone to pad cratering defects. There are several Sn-Ag-Bi and Sn-Ag-Cu-Bi alloys which melt about 10°C lower than SAC305. The bismuth in these solder compositions not only reduces the melting temperature, but also improves thermo-mechanical behavior. An additional benefit of using Bi-containing solder alloys is the possibility to reduce the propensity to whisker growth...

Publisher: Honeywell International

Honeywell International

Honeywell is a Fortune 100 company that invents and manufactures technologies to address tough challenges linked to global macrotrends such as safety, security, and energy.

Morristown, New Jersey, USA

Manufacturer of Components

Return on Investment of a Pre-Reflow AOI System

Jun 30, 2015 | CyberOptics Corporation

This paper describes the losses from defects at the placement process in the SMT line. Two case studies of European and Taiwanese SMT manufacturers illustrate the actual losses from their defects. An evaluation method to select a pre-reflow AOI system maximizing the return on investment (ROI) is introduced. In the end, ROIs of three commercial pre-reflow AOI systems are compared to demonstrate the importance of selecting an appropriate AOI system. This paper will increase the probability that anyone installing an AOI system during the pre-reflow process will obtain a successful gain with short payback period....

Publisher: CyberOptics Corporation

CyberOptics Corporation

CYBEROPTICS is a global leader in high-precision 3D sensors that significantly improve yields and productivity in the 3D scanning and metrology, Surface Mount Technology & Semiconductor Markets

Minneapolis, Minnesota, USA

Inspection

Automated Fluid Dispensing for Epoxy

Jun 30, 2015 | Eric Sari

Robotics for automated fluid dispensing have the ability to apply a variety of materials including epoxy, silicone, and acrylic coatings. These materials are extensively used in today’s high-speed fluid dispensers for the electronics industry.

Whether a dispenser is applying epoxy or another material, the central concept for applying any form of material remains the same. Specific points of an item being dispensed onto are programmed into the dispensing system. The automated fluid dispensers software interprets the programmed information and keeps the travel path in memory. A robotic arm moves fluid dispensing nozzles along this travel path and applies epoxy onto the surface of the item with precise accuracy. Machine speed can be adjusted to emit varying amounts of epoxy. The overall application process is auto-regulating and will not be disrupted....

Publisher: ETS - Energy Technology Systems, Inc.

ETS - Energy Technology Systems, Inc.

Manufacturer of Fluid Dispensing Equipment for Selective Conformal Coating, Potting, Encasulation & Underfill including Inspection, Conveying and Curing. Total Solution Fluid Dispensing & Conformal Cocating Process Lines.

Deer Park, Washington, USA

Adhesives/Dispensing, Inspection, Manufacturer of Assembly Equipment, Soldering, Turnkey

Reduce labor by automating your Selective Conformal Coating process

Jun 22, 2015 | Brian Stumm, Wes Noble

Applying conformal coatings to electronics has come a long way since the days of manually coating circuit boards. The extreme accuracy and highly repetitive process of automated conformal coatings is moving the electronics industry towards a more defect-free era for conformal coating. It enables new forms of electronics to become better protected, making it possible for electronics to withstand harsher environments than ever before. The following article is meant to aid in clarifying the advantages of specialty coating systems over manual applications for selective conformal coating. ...

Publisher: ETS - Energy Technology Systems, Inc.

ETS - Energy Technology Systems, Inc.

Manufacturer of Fluid Dispensing Equipment for Selective Conformal Coating, Potting, Encasulation & Underfill including Inspection, Conveying and Curing. Total Solution Fluid Dispensing & Conformal Cocating Process Lines.

Deer Park, Washington, USA

Adhesives/Dispensing, Inspection, Manufacturer of Assembly Equipment, Soldering, Turnkey

PCB Surface Finishes: A General Review

Jun 22, 2015 | Jun Nable, Ph.D., MacDermid Inc. Waterbury, CT

Surface finishing is an integral part of any PCB fabrication. It is generally applied to exposed Cu connectors and conductors on the board. Surface finishing has numerous important functions. It serves as a protective layer for the Cu connectors during storage. The surface finish helps minimize or reduce tarnish of the Cu substrate. Additionally, since it is the layer that comes into contact with other components during assembly, it ensures good solderability between the PCB and the component during assembly. Furthermore after assembly, the finish helps prolong the integrity of the solder joint during use.

A general review of common PCB surface finishes is presented. The advantages and disadvantages of each are discussed and compared. ...

Publisher: MacDermid Inc.

MacDermid Inc.

MacDermid is a global provider of specialty chemicals for the most complex printed circuit board designs. We specialize in the areas of final finishes, through-hole metallization, and circuit formation.

Waterbury , Connecticut, USA

Antistatic, Manufacturer of Assembly Material

The Use of an Available Color Sensor for Burn-In of LED Products

Jun 18, 2015 | Tom Melly Ph.D.

In the recent past, the Light Emitting Diode (LED) was hailed as the new energy efficient light source that would never have to be replaced. There were claims of 50,000+ hrs lifetime for the humble LED. That story has changed over the last few years as the number and diversity of the LED based products has increased. This is not to say that the original evidence was incorrect, but the initial enthusiastic estimates from the labs did not match the ultimate test, customers. As a result of poor quality products affecting the overall opinion of LED based products, it is critical that manufacturers can be confident in the quality of their product. In current times we want to have products certified, checked and ensure that we have the best quality.

For the purposes of this paper we will look at one aspect of LED product, and this is the Lumen maintenance and estimated lifetime. The method described here does not seek to replace using high quality rating labs, but hopefully will allow the manufacturer to know with confidence that their prototype product, upon going to certification labs will be of a high enough quality that no expensive re-designs are required....

Publisher: Feasa Enterprises Limited

Feasa Enterprises Limited

Feasa designs and manufactures a range of LED test products.

Limerick, Ireland

Other

Solder Paste Stencil Design for Optimal QFN Yield and Reliability

Jun 11, 2015 | B. Gumpert

The use of bottom terminated components (BTC) has become widespread, specifically the use of Quad Flat No-lead (QFN) packages. The small outline and low height of this package type, improved electrical and thermal performance relative to older packaging technology, and low cost make the QFN/BTC attractive for many applications.

Over the past 15 years, the implementation of the QFN/BTC package has garnered a great amount of attention due to the assembly and inspection process challenges associated with the package. The difference in solder application parameters between the center pad and the perimeter pads complicates stencil design, and must be given special attention to balance the dissimilar requirements...

Publisher: Lockheed Martin Corporation

Lockheed Martin Corporation

Lockheed Martin is a global security and aerospace company that employs about 112,000 people worldwide and is principally engaged in the research, design, development and manufacturing of advanced technology systems.

Bethesda, Maryland, USA

Other

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PCB Cleaning

Solder Paste Inspection