Electronics Manufacturing Technical Articles

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

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1798 SMT / PCB Assembly Related Technical Articles

How to Manage Material Outgassing in Reflow Oven

Nov 24, 2020 | Gerjan Diepstraten

In a lead-free reflow process, temperatures are higher, and materials use outgasses more than in a leaded reflow process. The trends toward higher density populated boards and more pin-in-paste technology also increase solder paste use. More components and more solder paste result in more outgassing of chemistry during the reflow process. Some assemblies report condensation of vapors when the cold printed circuit board enters the oven. Little is known about the interaction between these condensed materials in terms of the interaction between these condensed materials and the reliability of the assembly. Apart from the question of reliability, a printed circuit board contaminated with a small film of residues after reflow soldering is not desirable....

Publisher: Vitronics Soltec

Vitronics Soltec

Global manufacturer of XPM Reflow Ovens, ZEVA Selective Soldering and Delta Wave Soldering Equipment.

Camdenton, Missouri, USA

Manufacturer

The Risk And Solution For No-Clean Flux Not Fully Dried Under Component Terminations the Risk And Solution For No-Clean Flux Not Fully Dried Under Component Terminations

Nov 24, 2020 | Fen Chen and Ning Cheng Lee, Ph.D.

The miniaturization trend is driving industry to adopting low standoff components or components in cavity. The cost reduction pressure is pushing telecommunication industry to combine assembly of components and electromagnetic shield in one single reflow process. As a result, the flux outgassing/drying is getting very difficult for devices due to poor venting channel. This resulted in insufficiently dried/burnt-off flux residue. For a properly formulated flux, the remaining flux activity posed no issue in a dried flux residue for no-clean process. However, when venting channel is blocked, not only solvents remain, but also activators could not be burnt off. The presence of solvents allows mobility of active ingredients and the associated corrosion, thus poses a major threat to the reliability. In this work, a new halogen-free no-clean SnAgCu solder paste, 33-76-1, has been developed. This solder paste exhibited SIR value above the IPC spec 100 MΩ without any dendrite formation, even with a wet flux residue on the comb pattern. The wet flux residue was caused by covering the comb pattern with 10 mm × 10 mm glass slide during reflow and SIR testing in order to mimic the poorly vented low standoff components. The paste 33-76-1 also showed very good SMT assembly performance, including voiding of QFN and HIP resistance. The wetting ability of paste 33-76-1 was very good under nitrogen. For air reflow, 33-76-1 still matched paste C which is widely accepted by industry for air reflow process. The above good performance on both non-corrosivity with wet flux residue and robust SMT process can only be accomplished through a breakthrough in flux technology....

Publisher: Indium Corporation

Indium Corporation

Solder pastes, solder preforms, solder spheres, soldering fluxes, electrically-conductive adhesives. All alloys: tin-lead, lead-free, indium alloys, and more.

Utica, New York, USA

Manufacturer

What is an analog signature analyzer and how does it work?

Nov 19, 2020 | Irina Slobodyanyuk

Simultaneously with the first complex electronic circuits, the task of creating effective means of diagnosing and repairing them appeared. In previous decades, specialized programmable stands were used for diagnostics of serial electronic products, as well as various testers and probes for troubleshooting during their operation. But the dramatic increase in the density / cost factor, in parallel with the very rapid modification of electronic products, made programmable stands economically ineffective even in mass production. The use of traditional laboratory equipment (oscilloscopes, multimeters, etc.) requires power supply to the defective modules, which is often impossible and unsafe, since it can lead to failure of the working modules of the module. In addition, the use of this equipment requires documentation and highly qualified personnel. More automated and sophisticated signature analysis systems came to the rescue in solving this problem. A feature of these devices is that they allow you to test digital and analog assemblies without dismantling components and without supplying voltage....

Publisher: Engineering Physics Center of MSU

Engineering Physics Center of MSU

We're engaged in the development and sale of complex electronics, automation of experimental installations in laser physics, creation of automatic testing systems and diagnostics of printed circuit boards and electronic components

Moscow, Russia

Manufacturer

Troubleshooting the STM32F429 board and restoring its operation

Nov 19, 2020 | Igor Degtyarev

How to repair boards if they have been produced for a long time, and the documentation is lost? In this case, intelligent recognition systems can help, which will allow you to identify component pins without documentation for the board. In this article, we will find the STM32F429 board malfunctions without any documentation and in the least amount of time....

Publisher: Engineering Physics Center of MSU

Engineering Physics Center of MSU

Moscow, Russia

Manufacturer

Designing a High Performance Electroless Nickel and Immersion Gold to Maximize Highest Reliability

Nov 15, 2020 | Robert Spreemann, Rick Nichols, Sandra Nelle

The latest highest reliability requirements demand a high performance electroless nickel and immersion gold (HP ENIG). The new IPC specification 4552A has refocused the industry with reference to nickel corrosion. The interpretation of the existing specification, that judges corrosion on 3 levels, is complex and if misinterpreted can lead to phantom failures. An obvious way to avoid any potential misinterpretation is to eradicate any evidence of corrosion completely....

Publisher: Atotech

Atotech

One of the world's leading suppliers of integrated production systems, chemistry, equipment, know-how and service for electroplating, semiconductor and printed circuit board manufacturing.

Berlin, Germany

Manufacturer

Comparing Soldering Results of ENIG and EPIG Post Steam Exposure

Nov 15, 2020 | J. Bengston and R. DePoto Uyemura International

ENIG, electroless nickel immersion gold is now a well-regarded finish used to enhance and preserve the solder-ability of copper circuits. EPIG, electroless palladium immersion gold, is a new surface finish also for enhancing and preserving solder-ability but with the advantage of eliminating Electroless Nickel from the deposit layer. This feature has become increasingly important with the increasing use of high frequeny PWB designs whereby nickel's magnetic properties are detrimental. We examine these two finishes and their respective soldering characteristics as plated and after steam aging and offer an explanation for the performance deviation....

Publisher: Uyemura International Corporation

Uyemura International Corporation

Ontario, , California, USA

Printed Electronics for Medical Devices

Nov 10, 2020 | Jeff Grover

As is the case with many other markets where faster, highly capable technologies have resulted in more intelligent processes and products, the medical device sector is also undergoing a "smart" transformation. This has driven the development of medical devices that provide greater access to in-home care and monitoring and faster results for medical professionals, with the overarching benefit of better patient outcomes. Devices applied to the human body that commonly sense...

Publisher: Henkel Electronic Materials

Henkel Electronic Materials

Henkel is a manufacturer of materials for PCB and component assembly. The materials include Loctite adhesives, Multicore soldering products, Hysol encaps and underfills, and Power Devices thermal phase change pads.

Irvine, California, USA

Manufacturer

Reliability Challenges in Fabrication of Flexible Hybrid Electronics for Human Performance Monitors: A System Level Study

Nov 10, 2020 | Varun Soman, Student Member, IEEE, Yasser Khan, Madina Zabran, Mark Schadt, Member, IEEE, Paul Hart, Member, IEEE, Michael Shay, Member, IEEE, Frank Egitto, Member, IEEE, Konstantinos Papathomas, Member, IEEE, Natasha A. D. Yamamoto, Donggeon Han, Ana C.

Flexible hybrid electronics (FHE) interface rigid electronic components with flexible sensors, circuits, and substrates. This paper reports the reliability improvement of a FHE Human Performance Monitor (HPM), designed to monitor electrocardiography (ECG) signals....

Publisher: Stanford University

Stanford University

Life. Energy. Environment. This triad of engineering priorities is perhaps unmatched in its potential for improving the quality of life for all inhabitants of planet Earth. And at the heart of all three is chemical engineering.

Stanford, California, USA

Research Institute / Laboratory / School

Ball Grid Array (BGA) Voiding Affecting Functionality

Nov 09, 2020 | ACI Technologies, Inc.

A customer contacted ACI Technologies regarding a high failure rate of their assemblies. They provided assemblies to be X-rayed and inspected for the purpose of identifying any process related issues such as (but not limited to) solder and assembly workmanship and evidence of damage due to moisture related problems during reflow (a.k.a. "popcorning"). Moisture damage usually appears as physical damage to the component. The first indication of moisture damage would be externally observable changes to the package in the form of bulging or fractures to the outer surface of the component, an example of which is shown in Figure 1. Internally observable indicators of moisture damage typically include fractures to the die inside the package and lifted or fractured wire bonds. These conditions would be apparent during transmissive X-ray inspection. Another symptom of moisture related damage would be inconsistent solder joint sizes that result from package deformation during the liquidus phase of the reflow process. None of these indicators of moisture related damage were present on the customer samples....

Publisher: ACI Technologies, Inc.

ACI Technologies, Inc.

ACI, an authorized IPC Training Center operating the National Electronics Manufacturing Center of Excellence providing analytical testing, manufacturing and repair services to the electronics industry.

Philadelphia, Pennsylvania, USA

Consultant / Service Provider, Standards Setting / Certification, Training Provider

WHY CLEAN A NO-CLEAN FLUX

Nov 04, 2020 | Mike Bixenman, DBA [Kyzen Corporation] Mark McMeen, [STI Corporation] Bruno Tolla, Ph.D. [Kester Corporation]

Residues present on circuit boards can cause leakage currents if not controlled and monitored. How "Clean is Clean" is neither easy nor cheap to determine. Most OEMs use analytical methods to assess the risk of harmful residues. The levels that can be associated with clean or dirty are typically determined based on the exposed environment where the part will be deployed. What is acceptably clean for one segment of the industry may be unacceptable for more demanding segments. As circuit assemblies increase in density, understanding cleanliness data becomes more challenging. The risk of premature failure or improper function is typically site specific. The problem is that most do not know how to measure or define cleanliness nor can they recognize process problems related to residues. A new site specific method has been designed to run performance qualifications on boards built with specific soldering materials, reflow settings and cleaning methods. High impedance measurements are performed on break off coupons designed with components geometries used to build the assembly. The test method provides a gauge of potential contamination sources coming from the assembly process that can contribute to electrochemical migration....

Publisher: KYZEN Corporation

KYZEN Corporation

A leading supplier of precision cleaning chemistries to the worldwide electronics, metal finishing, medical, semiconductor, and optical industries.

Nashville, Tennessee, USA

Manufacturer

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