Mar 17, 2016 | Michael L. Cieslinski, Brent A. Fischthal
The rapid growth of electronic devices across the globe is driving manufacturers to enhance high-speed mass production techniques in the PCB assembly arena. As manufacturers drive to reduce costs while maximizing production by expanding facilities, updating automation equipment, or implementing lean six sigma techniques, the potential to build scrap product or rework printed circuit boards increases dramatically.
Manufacturers have two general paths to reduce the costs of high-speed printed circuit board assembly production. The first path is to reduce cost by focusing on high quality printing and mounting. The other, increasingly popular option is to utilize low-cost materials. In either case, the baseline must provide a consistent high-speed solder paste printing method, which considers the fill, snap-off, and cleaning processes.
Building on our expertise and testing, this paper will highlight the two trains of thought with specific focus on how low-cost materials affect print performance. It will also explore technologies, which can help provide stable, high-speed screen printing....
PFSA develops and supports innovative manufacturing automation equipment, processes and solutions around the core of electronic assembly, microelectronic, software and circuit manufacturing
Rolling Meadows, Illinois, USA
Mar 10, 2016 | Kris Troxel, Aileen Allen, Elizabeth Elias Benedetto, Rahul Joshi
Since the implementation of the European Union RoHS directive in 2006, the electronics industry has seen an expansion of available low-silver lead (Pb)-free1 alloys for wave soldering, miniwave rework, BGA and CSP solder balls, and, more recently, solder pastes for mass reflow. The risks associated with the higher processing temperatures of these low-silver (Ag between 0-3 wt%) solder alloys, such as potential laminate or component damage, increased copper dissolution, and reduced thermal process windows may present manufacturing challenges and possible field reliability risks for original equipment manufacturers (OEMs). In order to take advantage of potential cost reduction opportunities afforded by these new alloys, while mitigating manufacturing and reliability risks, the company has defined test protocols [1-4] that can be used for assessing new Sn-Ag-Cu(SAC), Sn-Ag, and Sn-Cu alloys for general use in electronics.
This paper describes initial test results for low-silver alloys using these solder paste alloy assessment protocols for BGAs and leaded components, and the impact of the alloys on printed circuit assembly process windows....
Publisher: HP Inc.
Mar 03, 2016 | David Ciufo, Sujatha Ramanujan, Janet Heyen, Michael Carmody; Intrinsiq Materials, Sunny Patel; Candor Industries.
This paper discusses a nano copper based paste for use in via filling. The company manufactures nano copper and disperses the coated nano copper into a paste in combination with micron copper. The resultant paste is injected or fills a via. The via is subsequently sintered by means of photonic sintering, or by heat in a reducing environment. The process will be accomplished in under an hour and results in filled solid copper vias....
Publisher: Intrinsiq Materials Inc.
Feb 25, 2016 | Umut Tosun, Jigar Patel, Kalyan Nukula, Fernando Gazcon, ZESTRON America
With regard to precision cleaning applications within electronics manufacturing, pH neutral product development was a major breakthrough in recent years. The impetus for this development resulted from changes with regard to solder paste formulations and resulting assembly processes.
The greater use of lead-free solder paste and the required higher reflow profiles have resulted in even more difficult to remove burnt-in flux residues. Coupled with increases in component density, larger component packages, higher lead counts, finer lead spacing, and lower standoff distances, effective cleaning is greatly challenged. The aqueous alkaline based cleaning agents can effectively remove these flux residues, however, the process often requires an increase in wash temperature and exposure time, chemical concentration, and mechanical energy. Although an efficient and effective cleaning process can be developed, oftentimes, the required operating parameters present a new set of challenges with regard to material compatibility.
Since their introduction, the newly developed pH neutral formulations have proven to be capable not only of removing these difficult post reflow residues from complex board geometries, but do so without affecting material compatibility of sensitive components. Additionally, they perform at low concentration levels. This study reviews the performance of pH neutral cleaning agents as compared to alkaline cleaning agent alternatives and includes field data demonstrating their effectiveness with regard to material compatibility and cleaning performance....
Publisher: ZESTRON Corporation
Feb 18, 2016 | Mehran Maalekian, Karl Seelig, Timothy O'Neill
As lead-free alloys shift into high reliability electronics, the issue of tin whisker growth remains a primary concern among those in the industry. Current research shows that there is no perfect alloy for all cases of electronic usage. Industry leaders and researchers continue to study and search for a lead free alloy that is able to withstand harsh environments while maintaining high reliability....
Publisher: AIM Solder
Feb 11, 2016 | Gerjan Diepstraten
Although reflow ovens may not have been dramatically changed during the last decade the reflow process changes step by step. With the introduction of lead-free soldering not only operation temperatures increased, but also the chemistry of the solder paste was modified to meet the higher thermal requirements. Miniaturization is a second factor that impacts the reflow process. The density on the assembly is increasing where solder paste deposit volumes decreases due to smaller pad and component dimensions. Pick and place machines can handle more components and to meet this high through put some SMD lines are equipped with dual lane conveyors, doubling solder paste consumption. With the introduction of pin in paste to solder through hole components contamination of the oven increased due to dripping of the paste....
Publisher: Vitronics Soltec
Feb 04, 2016 | Derek Ong, Lok Teng Kee, Chuah Rhun Chia
In a typical mechatronic manufacturing functional test setup, actual load simulations are usually done by connecting the DUT outputs to power or ground in order to establish either a high or low side driver. Each output is connected with different load and the test will either be sequential or concurrent. At lower power levels, these can usually be managed with general purpose switches. However, when it comes to higher power levels of currents more than 5 amps, such switching and loading might pose a greater challenge. Furthermore, critically in the manufacturing line, the tradeoff between cost and test time would have a great influence on the test strategy.
This paper will present some key points to design a cost effective high power switching and load management solution....
Publisher: Keysight Technologies
Jan 21, 2016 | Tony Lentz
Solder paste has long been viewed as "black magic". This "black magic" can easily be dispelled through a solder paste evaluation. Unfortunately, solder paste evaluation can be a challenge for electronic assemblers. Interrupting the production schedule to perform an evaluation is usually the first hurdle. Choosing the solder paste properties to test is simple, but testing for these properties can be difficult. Special equipment or materials may be required depending upon the tests that are chosen. Once the testing is complete, how does one make the decision to choose a solder paste? Is the decision based on gut feel or hard data?
This paper presents a process for evaluating solder pastes using a variety of methods. These methods are quick to run and are challenging, revealing the strengths and weaknesses of solder pastes. Methods detailed in this paper include: print volume, stencil life, response to pause, open time, tack force over time, wetting, solder balling, graping, voiding, accelerated aging, and others....
Publisher: FCT ASSEMBLY, INC.
Jan 12, 2016 | Dr. Mary Liu and Dr. Wusheng Yin
In order to meet the increasing demand of device miniaturization, high speed, more memory, more function, low cost, and more flexibility in device design and manufacturing chain, underfilling has increasingly become an essential process for the good reliability of electronic devices. Filled capillary underfill has been selected for used in package-level where there is large thermal stress caused by CTE mismatch issue, but the underfill is usually not reworkable. Unfilled capillary underfill has been used for board-level application such as BGA/CSP, POP, WL-CSP where there is need for mechanical shock resistance, the underfill is usually reworkable....
Publisher: YINCAE Advanced Materials, LLC.
Jan 12, 2016 | Dr. Mary Liu and Dr. Wusheng Yin
With the increasing demand of device miniaturization, high speed, more memory, more function, low cost, and more flexibility in device design and manufacturing chain, YINCAE has published a white paper on a first individual solder joint encapsulant which can eliminate underfilling process with at least five times solder joint increase and provide more flexibility for fine pitch and high density application. In order to meet the demand of manufacturing of high speed and low cost, YINCAE has invented a room temperature stable and jettable solder joint encapsulant adhesive – SMT 266. The invention of SMT 266 has allowed our customers to have more flexibility in their high-speed production line such as worry free on the work life of adhesive and workable jetting process....
Publisher: YINCAE Advanced Materials, LLC.