Technical Library | 2021-09-01 15:31:39.0
The long-standing trend in the electronics industry has been the miniaturization of electronic components. It is projected that this trend will continue as Original Equipment Manufacturers (OEMs) and Electronic Manufacturing Service (EMS) providers strive to reduce "real estate" on printed circuit boards. Typically, the miniaturization of components can be achieved by integration or size reduction. At present, size reduction is considered to be more cost effective and flexible than integration. Passive components, which are used in limiting current, terminating transmission lines and de-coupling switching noise, are the primary focus in size reduction due to their variety of uses.
Technical Library | 2007-08-09 12:23:10.0
Recent developments in No Flow-Fluxing Underfill (NFFUF) products have demonstrated their utility to enhance the reliability of flip chip assemblies with reduced processing steps over conventional capillary flow methods. This basic work considered processing conditions such as dispensed volume and placement force, speed and dwell time. Further evaluations of these new products on a variety of flip chip assembly configurations manufactured by various processes have been undertaken to provide further evidence of their suitability and potential in high volume electronic manufacturing. This paper summarizes the recent evaluations and discusses new studies of additional assembly configurations, which include higher input/output (l/O) counts up to full arrays in excess of 1200 l/Os.
Technical Library | 2013-04-18 16:46:42.0
Conformal coatings are considered a method of providing corrosion protection to electrical assemblies used in high-humidity or harsh environments. They are applied to PCBs for various reasons: to protect from moisture and contamination, to minimize dendritic growth, to provide stress relief, and for insulation resistance. These contribute to more durable handling, enhanced device reliability, and reduced warranty costs. Increased miniaturization of new circuit board designs requires flexible, low stress coating material to protect delicate components and fine-pitch leads. Silicone conformal coatings offer many advantages that address the general trend of ongoing PCBs designs, such as: high flexibility and low modulus to reduce stress on delicate or small components... First published in the 2012 IPC APEX EXPO technical conference proceedings.
Technical Library | 2013-06-20 14:33:12.0
With today's consumer technologies driving the need for denser and more compact devices, the assembly process for surface mounted devices has becoming increasingly more difficult. With the mixture of components requiring a broader range of print deposition volume, various techniques are in use in an attempt to ensure consistent and appropriate paste volume is achieved. Some of these techniques include step etching a stencil locally on a targeted device, promoting electroformed smooth wall nickel stencils, through to laser cutting newer grade stencil materials. This paper focuses on the relevant attributes that affect the properties of solder paste release and introduces the effects of surface free energy with respect to key elements that make up the stencil printing process.
Technical Library | 2014-10-02 20:10:07.0
Sn3.0Ag0.5Cu (SAC305) is the most popular near eutectic lead-free alloy used in the manufacturing processes. Over the last several years, the price of silver has dramatically increased driving a desire for lower silver alloy alternatives. As the results, there is a significant increase in the number of alternative low/no silver lead-free solder alloys available in the industry recently.In this paper, we'll present the performance and process capability of various low/no silver alloy solder pastes. Data from printability, wetting test, slump test, solder ball test, voiding, etc… will be discussed and compared with the control SAC305 solder paste. Benefits and concerns of using low/no silver alloy solder paste materials will also be addressed.
Technical Library | 2015-02-05 20:25:41.0
In the past 20 yrs the solvent industry has gone through a great deal of change. In the early 1990s, CFC-113 and 1,1,1-trichloroethane were the workhorses of the industry. The Montreal Protocol to phase-out substances that deplete the Earth's protective Ozone Layer was implemented in the mid 1990s. After phase-out of the CFC solvents, the solvent industry fragmented to a variety of cleaning solutions. The electronics industry was a large user of CFC solvents and many of these applications changed to aqueous based cleaners (...) But those alternatives are now facing various problems: e.g. aqueous based cleaners use a lot of energy, require long drying times, use equipment that requires frequent maintenance, and require a large footprint; no-clean fluxes leave flux residues; and trichloroethylene and n-propyl bromide have toxicity issues. In response to these serious issues newer solvents and blends are being introduced in the marketplace
Technical Library | 2016-07-07 15:37:18.0
How susceptible are the metals used in modern electronics manufacturing to corrosion by common beverages? This is a question of interest, especially to manufacturers, retailers and to a certain extent end customers. In this study the dissolution of aluminum, copper, gold, iron, lead, nickel, SAC305 solder, silver, tin and zinc was examined. Individual foils of these materials were fully immersed in one of sixteen chosen beverages and heated for 3 days at 40°C. The resulting solutions were analyzed using ICP-OES. The data were examined in light of the known pH, conductivity and ionic contents of the beverages, determined in previous work. Conclusions about the relative susceptibility to corrosion of the various metals and the corrosive power of the different beverages are made.
Technical Library | 2017-04-27 17:10:16.0
Using modern laser systems for the depanelization of circuit boards can create some challenges for the production engineer when it is compared to traditional mechanical singulation methods. Understanding the effects of the laser energy to the substrate material properly is essential in order to take advantage of the technology without creating unintended side effects. This paper presents an in-depth analysis of the various laser system operating parameters that were performed to determine the resulting substrate material temperature changes. A theoretical model was developed and compared to actual measurements. The investigation includes how the temperature increase resulting from laser energy during depaneling affects the properties of the PCB substrate, which varies from no measurable change to a lowering of the surface resistance of the cut wall depending on the cutting parameters.
Technical Library | 2017-08-02 20:18:21.0
In this rapidly moving electronics market, fast to market with new products is what separates top performing companies from average companies. A survey conducted by Arthur D. Little revealed that "New-Product Development (NPD) productivity in atop performing company is five times what it is in the average company. The top performer gets five times as much new product output for the same investment." What do they know that the rest of us do not? One winning factor is the use of the Robert Cooper process. (...)This paper will present a Lean Six Sigma approach to "right sizing" the Stage Gate process to be efficient, practical, and easy to manage. Various tools of Stage Gate, along with proven best practice, will be covered. In addition, a reduced Stage Gate model will be discussed for simple, low risk projects.
Technical Library | 2019-12-18 23:28:07.0
Electronic tongue systems equipped with cross-sensitive potentiometric sensors have been applied to pharmaceutical analysis, due to the possibility of various applications and developing new formulations. Many studies already proved the complementarity between the electronic tongue and classical analysis such as dissolution tests indicated by Pharmacopeias. However, as a new approach to study pharmaceuticals, electronic tongues lack strict testing protocols and specification limits; therefore, their results can be improperly interpreted and inconsistent with the reference studies. Therefore, all aspects of the development, measurement conditions, data analysis, and interpretation of electronic tongue results were discussed in this overview. The critical evaluation of the effectiveness and reliability of constructed devices may be helpful for a better understanding of electronic tongue systems development and for providing strict testing protocols.
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