Creating the Perfect Solder Joint
From a visual standpoint, a good solder joint should be smooth, bright, shiny, clean, and have a nice concave solder fillet. But how do you ensure that inside those joints, good intermetallic bonds are formed? Solder joints play several different roles, and they represent several different opportunities to be a problem, a partial improvement, or a complete improvement. Since all solder joints aren’t created equal, the first step is to understand what is expected or required of that joint.
Rework and Reball Challenges for Wafer Level Packages
Amid the growing trend in package and PCB miniaturization, wafer-level packages (WLPs) have garnered recent popularity for their affordable cost, small footprint, and thin profile. Component suppliers must be prepared to support failure analysis for PCB-assembled WLPs, including fault isolation, nondestructive screening, as well as destructive analysis techniques.
Drying Boards after Rework Cleaning—To Do or Not to Do?
In cases where water soluble fluxes are being used in the rework process, in cases where the components need to have flux residues washed off, or in cases where the board needs to be cleaned with water for subsequent conformal coating touchup, proper drying and perhaps even bake out procedures need to be performed.
Rework and Reliability: Less is More!
Circuit boards are not always perfect after reflow or wave soldering. Scrapping boards with one or two defects is expensive, so rework happens. A good concept for rework is less is more, especially less flux. Use as little rework flux as possible, as in the old Brylcreem ads, "Just a little dab'll do ya."
A Look Into PCBA Rework and Repair
Despite the many technology advances in the SMT process, there will always be a need for rework and repair of PCB assemblies. Most especially as the industry trend continues towards finer pitch and spacing, smaller and smaller components, and increasing high-reliability requirements from customers.
Improving the Rework Process
An optimized SMT assembly process typically provides a yield of nearly 100%. Technology advancements—from the solder paste printing process, SPI, and parts placement, to reflow and wave soldering and AOI—have pushed the efficiency and accuracy of these steps in the SMT process such that a board assembly should be perfect at the end of the line. Still, EMS providers continually face the need to rework and repair PCBAs even after dialing in the perfect set-up.
Using Paste Flux for Rework
When using a hot air or IR rework system where the reflow cycle is mimicking the original SMT reflow profile, and when using flux for re-attachment, paste flux otherwise known as gel or tacky flux is the correct type of flux to use. Due to its high viscosity and tack properties, paste flux prevents components from being moved during hot-air reflow while being able to remain active for the complete time-temperature period.
Assembly Training and Education
Even if your PCB assembly process is optimized, there is always room for improvement. And no matter how successful your company has been in the past, you just can’t rest on your laurels. It is always in your best interest to strive towards a better operations model. We've created a survey to help us gauge the importance of training and education in your workforce, and the benefits that you get in ensuring that your operators and engineers have the most current knowledge and skill sets.
The Impact of Vias on PCB Assembly
Via technology has been one of the solutions to address the miniaturization and component density challenges in current electronic assemblies. However, vias are not without their own set of challenges. As per our recent survey, these include impedance matching, routing, placement of vias, minimum size limitations, aspect ratio, and the limitations for the PCB manufacturer.
The Industry Speaks
In the latest issue of SMT Magazine, we take a pause from covering the latest technology trends, challenges, and solutions in the electronics manufacturing and assembly industry. Instead, we are focusing on our readers—to give a voice to their thoughts on the industry, companies, jobs, interests, and even pain points when it comes to their respective specialties.
To Bake or Not to Bake (in Rework)—That is the Question
When performing rework on printed circuit boards, the issue of the moisture having to be baked out of the PCB is often debated. Whether it is localized mini-wave rework, hand-soldering or convection rework, the board, as well as neighboring components, needs to be taken into account in terms of moisture protection during the reflow cycle. This article details the baking requirements during PCB rework.
To Outsource or Not to Outsource PCB Rework
There is a case to be made that outsourcing certain rework projects makes a lot of sense, especially in large, complex or highly time-sensitive rework projects. However, careful review of the suppliers' knowledge of standards and adherence to processes needs to be taken in to consideration prior to making the outsourcing call.
Taking the Gremlins Out of Your Process
Every step in your assembly line is supposed to be designed to perform optimally for you to have an efficient, reliable, robust and reproducible process. However, and as isolated as they may seem, "gremlins" sometimes appear and mess up the results of a batch. The latest issue of SMT Magazine features strategies that can help you address these issues.
Medical EMS: Opportunities Abound
Megatrends such as the increasingly ageing population and growing demand in emerging economies worldwide bode well for the medical electronics assembly industry. However, challenges such as margin pressures, compliance costs and risks, supply chain instability, and new product introduction headaches are hindering a more aggressive prognosis of the industry. But, with innovation, medical manufacturers can churn out more.
Top 10 Factors to Consider When Selecting a Medical EMS Company
Once the decision has been made to use an EMS company, selecting the right one involves several steps. Although most EMS companies perform the same basic services, every EMS company is different. In this article, Mo Ohady and David Estes of Digicom Electronics write the 10 key factors to consider when selecting your medical EMS company.
Medical Electronics: Manufacturing Vitals
With the rapidly growing aging population, rising healthcare costs and increasing health awareness, opportunities abound in consumer medical devices, diagnostics, imaging, and instrumentation. However, the medical electronics industry is not without its own set of challenges. The January 2016 issue of SMT Magazine highlights the manufacturing challenges and opportunities in this growing sector.
The New Industrial Era
Key transformative technologies such as big data, analytics, and IoT are ushering in a new industrial era, where new technology forces and innovations are changing the dynamics, risks, and success factors for global manufacturing companies. To be successful in this environment, a mindset shift is required when it comes to deciding what to do and how to take your manufacturing operations to the next level.
Surface Mount Technology Association—a New Milestone
With a grand mission, SMTA is an international network of professionals who build skills, share practical experience and develop solutions in electronic assembly technologies, including microsystems, emerging technologies, and related business operations. The organization delivers the right information at the right time to empower the workforce, who collectively advances technology, innovates new products, and serves the global industry.
OK International Talks Trends Driving Product Innovation Strategies
Bryan Gass, vice president for global sales and marketing at OK International, discussed with I-Connect007's Stephen Las Marias how trends such as automation, wearables, and Industry 4.0 are driving his company's product innovation strategies.
NEPCON Shenzhen 2015 Puts Spotlight on China's EMS Industry
From ODM and OEM to EMS, the Chinese electronics manufacturing industry is transforming from single, passive processing to active, intelligent manufacturing—in line with the "Made in China 2025" plan, as well as the latest trends happening in the electronics industry.
BGA or CGA: When Is It Right for You?
In this interview with TopLine President and Founder Martin Hart, I-Connect007 Publisher Barry Matties focuses on column grid array (CGA) and how CGA can solve delamination problems. CGAs, also known as CCGA, are not necessarily new but are making a strong comeback in the high reliability market.
BEST, Inc.: Branching Out to Bare Board Rework
Bob Wetterman, president of BEST, Inc., joins Guest Editor Mark Thompson to discuss the company's move into reworking unpopulated boards, building products that facilitate faster rework and repair, and IPC certification and training.
From the Show: A Hands-on APEX Session
On the first day of APEX, IPC and three instructors from BEST decided to bring a more pragmatic approach to a PCB repair topic taught in the technical program. Along with 24 participants, the instructors from BEST led a hands-on reballing session. After a lively, highly participative 60-min. question and answer session on the fundamentals of reballing, the reballing process, and its various attributes, participants eagerly began the hands-on session.
STEP 10 Rework and Repair: The Complete BGA Rework Process
Robert Avila and Wade Gay, Finetech, describe the steps to BGA rework, aided by video clips of rework in action. There are at least five steps in successfully completing the cycle for BGA rework. These steps, which include component removal, site cleaning, reballing, and soldering, do not change, independent of whether or not the BGA is on a PCB that is large, small, thin, or thick, etc.