SMT Manufacturing: Why Soldering?

My last column—"Artificial Intelligence: Super-Exciting, Ultra-Competitive" (SMT007 Magazine, September 2018)—described compelling needs of the next generation of hardware in the artificial intelligence (AI) era. Upcoming AI hardware requires advanced semiconductors, packaging approaches, new architectures, increased speeds and capabilities of inference processing, and system design and manufacturing prowess continually developed to reach the interconnect density.

Against this backdrop, packaging and assembly levels—including surface-mount technology (SMT)—will continue to be critical technology and serve as the backbone of manufacturing electronic hardware to deliver desired products with enhanced miniaturization, functionality, and augmented intelligence promptly.

The SMT electronics manufacturing sector with OEMs and EMSs alike has overcome many challenges in the past. I do not doubt that we will tackle new challenges head-on to produce the required hardware in the AI era. Under the established infrastructure, will soldering (reflow, wave, selective, etc.) remain a necessary technique?

Soldering—the process to make solder joints—sounds like an ancient technique and is typically deemed unglamorous. However, substantial innovations and refinements in process and equipment have been made over the last three decades. Soldering offers an array of characteristics that bear both scientific and practical merits that will continue to maintain viability in the electronics industry. Here is my list of top five characteristics:

1. Application flexibility and agility: Solder can be readily made and applied in various physical forms, including bar, ingot, wire, powder, preform, solder sphere, solder column, paste, ink, and in a molten state.

2. Compatibility: Soft solder alloys fit into the process temperature range that electronic components—such as integrated circuits (ICs), passives, and optoelectronic devices—and the internal structure of the PCB are designed for and can withstand. Any other joining techniques (e.g., brazing, welding) need a much higher process temperature that is unsuitable for electronic components and PCBs.

3. Practicality: Solder alloys have the required environmental stability during manufacturing and in service (e.g., not prone to excessive oxidation, not corrosive, not unduly toxic).

4. Performance: A solder alloy—specifically a tin-based alloy with designed compositions—delivers the required physical properties (e.g., melting temperature, thermal and electrical conductivity, wetting ability, surface tension) and mechanical properties (e.g., strength, creep resistance, thermal fatigue resistance).

5. Cost and competitiveness: Solder alloys and soldering processes in the SMT infrastructure can be readily synchronized with intelligence-enabled manufacturing and automation, which is key to the future of electronic hardware manufacturing and producing reliable products economically.

Conclusion

Overall, the flexibility, agility, compatibility, practicality, performance, cost, and competitiveness offered by soldering are crucial to making both today’s electronic products and those anticipated in the future. This collective array of characteristics is unique. There is no better substitute in existence that delivers all of the necessary attributes previously listed.

For example, conductive adhesive and solder material have been studied in parallel when SMT was implemented for manufacturing PCB assemblies in the 1980s. Conductive adhesive worked in some selective applications but did not fill the interconnection role in a broad scope and or in mass production. This does not imply that new materials coupled with advanced techniques are not welcome. Instead, better methods, technologies, and materials should and will always be embraced by the industry.

The role of solder as the electrical, mechanical, and thermal linkage of circuitry is essential to electronic products. Soldering process know-how is closely linked with production defects, yields, and costs of electronic devices. An additional level of performance and reliability of solder joints is required mainly stemming from the confluence of three fronts: powerful chip designs, advanced IC packages, and higher density PCBs. Accordingly, SMT soldering is expected to deliver increased precision and heightened automation using solder materials that possess enhanced properties to make reliable solder interconnections for the new generation of electronic AI hardware.

Back

2018

SMT Manufacturing: Why Soldering?

11-15-2018

Upcoming AI hardware requires advanced semiconductors, packaging approaches, new architectures, increased speeds and capabilities of inference processing, and system design and manufacturing prowess continually developed to reach the interconnect density. Against this backdrop, packaging and assembly levels will continue to be critical technology and serve as the backbone of manufacturing electronic hardware to deliver desired products with enhanced miniaturization, functionality, and augmented intelligence promptly.

View Story

Artificial Intelligence: Super-Exciting, Ultra-Competitive

09-18-2018

Artificial intelligence (AI) and machine learning (ML) have become common everyday words, however, the present reality and future potential are yet to evolve. This article looks into the key considerations and strategies to better leverage these trends that are expected to transform the manufacturing world.

View Story

The Role of Bismuth (Bi) in Electronics, Part 3

08-08-2018

The third part of this column series aims to answer why SAC isn't able to become a universal interconnecting material for electronic circuits, and why a quaternary alloy system offer a more wholesome approach.

View Story

The Role of Bismuth (Bi) in Electronics, Part 4

06-04-2018

Dr. Jennie Hwang's column series continues in Part 4, which addresses two pivotal questions: Why SAC is not able to be a universal interconnecting material for electronic circuits, and why a quaternary alloy system offers a more wholesome approach.

View Story

New Year Resolutions and Best Wishes

03-12-2018

The New Year stands before us, like a chapter in a book, waiting to be written. We can help write that story by setting goals. But the true challenge is to keep these goals from falling into a wish list and to know how to stick to those goals and when. I hope that in this year to come, goals give us direction in whatever we do, be it on AI, 5G, mixed reality and quantum computing or the next chip design.

View Story
Back

2017

The Role of Bismuth (Bi) in Electronics, Part 2

12-08-2017

Part 2 of Dr. Jennie Hwang's article series outlines the Bi effects on 63Sn37Pb solder material, which have been substantiated by years of field performance prior to lead-free implementation. This should serve as the sound baseline for further discussion on the subject.

View Story

The Role of Bismuth (Bi) in Electronics, Part 1

10-17-2017

In this column series about bismuth, Dr. Jennie Hwang starts with its elemental properties: where it is usually mined, its safety data, and application areas—in the chemical world, the metals industry, and electronics. She also writes about how bismuth compounds improve the performance some electronics devices, such as varistors.

View Story

The Role of Bismuth (Bi) in Electronics: A Prelude

08-24-2017

When it comes to considering applications in electronics and microelectronics industry, over last three decades, the industry has shied away from using bismuth (Bi), at least not in standard practices in mass production. However, an interest has surfaced recently. This article series is tailored to electronics and microelectronics industry, to provide an overview in its entirety in the areas of importance to industry applications going forward.

View Story

Do Acquisitions Bear Fruit? A Pragmatic Perspective

05-02-2017

Acquisition is an effective tool for a company’s growth as a part of corporate growth strategy; and it is one of the top fiduciary duties of a company board’s governance oversight. However, statistically, the acquisition failure rate is quite high. In her column this month, Dr. Jennie Hwang reflects on her hands-on experience as well as observations on mergers and acquisitions in the corporate world.

View Story
Back

2016

The Theory Behind Tin Whisker Phenomena, Part 5

11-23-2016

In this installment of the series on the theory behind tin whisker phenomena, Dr. Jennie Hwang completes the discussion of key processes likely engaged in tin whisker growth—crystal structure and defects.

View Story

New Year Outlook: China’s Five Year Plan

01-25-2016

In this article, Dr. Jennie Hwang writes about the latest developments in the current global economic landscape, as well as mega-technological trends, which include: the highlights of macro-economy outlook, China factor, oil dynamics, cyber security, and grand challenges in technology and the path forward.

View Story
Back

2015

A Look at the Theory Behind Tin Whisker Phenomena, Part 3

11-05-2015

The third installation in Jennie Hwang's five-part series on tin whisker phenomena continues the discussion on key processes engaged in tin whisker growth. She discusses the energy of free surface, recrystallization, and the impact of solubility and external temperature on grain growth.

View Story

The Theory Behind Tin Whisker Phenomena, Part 2

08-06-2015

In the second part of this article series, Dr. Jennie Hwang writes that a plausible theory of tin whisker growth can be postulated through deliberating the combination and confluence of several key metallurgical processes.

View Story

The Theory Behind Tin Whisker Phenomena, Part 1

05-27-2015

In this first article of a five-part series, Dr. Jennie Hwang goes back to basics as she discusses the theory behind the tin whisker phenomena--the reasons and mechanisms behind its occurrence--as well as how tin whiskers can be mitigated in the plating process.

View Story

New Year Outlook: What Can We Expect in 2015?

03-04-2015

Dr. Jennie Hwang takes a long view on market thrusts in the anticipated global economic landscape, as well as mega-technological trends in selected areas deemed timely and relevant to the industry: macro-economy, oil dynamics, China factor, cybersecurity, and grand challenges in technology and the path forward.

View Story
Back

2014

2014: Year-end Review

12-31-2014

In her latest column, Dr. Jennie S. Hwang reviews how predictions in her January 2014 column actually panned out. She goes through the key sub-topics that directly or indirectly impact the industry in terms of macroeconomics, business environment, technology, and the global marketplace. By and large her 2014 outlook was on or close to target.

View Story

Tin Whiskers, Part 6, Preventive and Mitigating Measures: Strategy and Tactics

09-24-2014

In this installment of the tin whisker series, Dr. Jennie S. Hwang takes a look at the preventive and mitigating measures--the strategy and tactics. She says an effective strategy for prevention and mitigation starts with a good understanding of the causations of tin whiskers. A smorgasbord of material and technique options are offered as a guide to prevent or retard tin whiskers.

View Story

Capsulization

08-06-2014

Since lead-free implementation, concerns about tin whiskers have intensified. For the past 12 years, studies and research by various laboratories and organizations have delivered burgeoning reports and papers, and Dr. Hwang has devoted an entire series to this subject. This article aims to capsulize the important areas of the subject.

View Story

Tin Whiskers, Part 5: Impact of Testing Conditions

05-21-2014

Dr. Jennie S. Hwang says, "Real-life stresses may lead a different tin whisker behavior as in accelerated tests (temperature cycling, elevated temperature storage). The alloy-making process to achieve homogeneity needs to be taken into consideration. For an 'impurity' system, how the process that adds elements into tin could also affect the whisker propensity."

View Story

Tin Whiskers, Part 4: Causes and Contributing Factors

03-26-2014

According to Columnist Dr. Jennie S. Hwang, nucleation and growth can be encouraged by stresses introduced during and after the plating process. The sources of these stresses includes residual stresses caused by electroplatin, additional stresses imposed after plating, the induced stresses by foreign elements, and thermally-induced stresses.

View Story

New Year Outlook: What Can We Expect in 2014?

01-29-2014

In her latest column, Dr. Jennie Hwang takes a long view on market thrusts in the anticipated 2014 global economic landscape, as well as technological trends in selected areas important to the SMT industry. Readers, pay attention--her predictions for 2013 were extremely accurate.

View Story

2013, A Year-End Review

01-09-2014

For this year-in-review column, Dr. Jennie S. Hwang checks on whether her January 2013 column, "Outlook for the New Year," is on or off target. She addresses the key sub-topics that directly or indirectly impact the industry in terms of business environment, technology, and global marketplace to see how her predictions actually panned out.

View Story
Back

2013

Tin Whiskers: Concerns & Potential Impact

11-26-2013

What is the biggest concern about the growth of tin whiskers? A simple answer is "uncertainty." If or when tin whiskering occurs, what are likely sources of uncertainty or potential adverse impact? Dr. Jennie Hwang explains that concerns and impact concerning tin whiskers primarily fall into one of four categories.

View Story

Tin Whiskers: Phenomena and Observations

10-09-2013

Tin whisker reflects its coined name. It has long been recognized to be associated with electroplated tin coating and most likely occurs with pure tin. Its appearance resembles whiskers. However, whiskers can also form in a wide range of shapes and sizes, such as fibrous filament-like spiral, nodule, column, and mound.

View Story

Cyber Security: From Boardroom to Factory Floor

08-21-2013

Cyber attacks are and will continue to be a huge concern to U.S. corporations in the foreseeable future. It's a matter of when, not if. It is not industry-specific and every company will have to deal with this challenge. The earlier preparation is made, the better a company is positioned to fend off the attack.

View Story

SMT Perspectives and Prospects: Cyber Security - From Boardroom to Factory Floor

08-21-2013

Cyber attacks are and will continue to be a huge concern to U.S. corporations in the foreseeable future. It's a matter of when, not if. It is not industry-specific and every company will have to deal with this challenge. The earlier preparation is made, the better a company is positioned to fend off the attack.

View Story

Tin Whiskers: Clarity First

06-11-2013

Lead-free solder comprises a wide array of alloy systems and each system can be modified in numerous ways. A test scheme to represent lead-free is a daunting task with an astounding price tag. Dr. Jennie Hwang advises that any tin whisker propensity study be conducted with a specific alloy composition, as clarity is the name of the game.

View Story

SMT Perspectives and Prospects: Conflict Minerals: A Snapshot

04-03-2013

As the supply chain becomes increasingly complex and global, with an ever-increasing number of suppliers, full traceability of conflict minerals throughout the global supply chain is a daunting task. To comply with the SEC’s reporting and disclosure requirement, a company must formulate a comprehensive program to achieving traceability and transparency.

View Story

SMT Perspectives and Prospects: SAC System, A Revisit

03-13-2013

In compliance with the RoHS Directive initiated by the EU and later deployed globally, SAC305 of SnAgCu (SAC) system has been used as a lead-free solder interconnection alloy for both second- and third-level interconnection since the implementation of lead-free electronics. After a 10-year run, Dr. Jennie Hwang takes a look at SAC305 for IC packages and PCB assembly.

View Story

SMT Perspectives and Prospects: Outlook for the New Year

02-06-2013

After protracted high unemployment and lack of a speedy recovery in the U.S., and in the absence of clear solutions to the Eurozone's financial crisis and China's lower manufacturing activities in 2012, will the grim global economic outlook extend to 2013?

View Story

SMT Perspectives and Prospects: 2012 Year-End Review

01-16-2013

Dr. Jennie S. Hwang compares the past year to predictions made in her January 2012 column, "What Can We Expect in 2012?" including business, technology, and global marketplace issues. She feels that, overall, 2012 was another intriguing year filled with both wanted and unwanted events.

View Story
Back

2012

SMT Perspectives and Prospects: Can Microstructure Indicate a Good Solder Joint? Part IV

11-27-2012

How does one examine solder joint microstructure? Is the microstructure important? This month, Dr. Jennie S. Hwang continues a series that addresses the practical aspects of solder joint microstructure and what it can tell us about solder joint reliability. The focus of this offering is the role of the phase diagram in microstructure.

View Story

SMT Perspectives and Prospects: Can Microstructure Indicate a Good Solder Joint? Part III

11-06-2012

How does one examine solder joint microstructure? Is the microstructure important? This month, Dr. Jennie S. Hwang continues a series that addresses the practical aspects of solder joint microstructure and what it can tell us about solder joint reliability.

View Story

SMT Perspectives and Prospects: Can Microstructure Indicate a Good Solder Joint? Part I

09-11-2012

How does one examine solder joint microstructure? Is the microstructure important? This month, Dr. Jennie S. Hwang begins a series that addresses the practical aspects of solder joint microstructure and what it can tell us about solder joint reliability.

View Story

SMT Perspectives and Prospects: 100 Points on Lead-Free Performance and Reliability, Part 2

08-21-2012

In the final of a two-part series, Dr. Jennie S. Hwang takes a wide, sweeping look at the history, timeline, highlights, and future projections for lead-free manufacturing.

View Story
Back

2011

Reliability of Lead-Free System: Part II, The Role of Creep

10-26-2011

The degradation of a solder joint is inevitable. The solder joint intrinsic degradation process engages two scientific phenomena--fatigue and creep. In this article, industry expert Dr. Jennie S. Hwang continues her look at the reliability of the lead-free system with a closer examination of the latter.

View Story

Reliability of Lead-Free System: Part I, Solder Joint Fatigue

09-14-2011

Industry expert Dr. Jennie S. Hwang continues her look at the reliability of the lead-free system this month with a closer examination of solder joint fatigue. Fatigue is one of the most likely culprits for material failure--regardless of metals, polymers or ceramics.

View Story
Back

2002

Lead-free Symposium at APEX

04-15-2002

Amid a variety of programs, lead-free technology was "a conference in a conference" at APEX 2002, in San Diego. The program was designed with six focal themes covering components, printed wiring board (PWB) surface finishes, materials, assembly processes, test and rework, and reliability. Additionally, SMT Magazine developed an illuminative panel forum and NEMI discussed a summary report by NEMI

View Story
Copyright © 2018 I-Connect007. All rights reserved.