Technical Library | 2022-08-17 01:21:54.0
Back in the "good old days," stencil cleaning was effortless and effective. CFC-based solvents were sprayed or wiped onto a stencil with apertures hundreds of times larger than modern-day components. The stencil cleaning process was not considered a value-added procedure; instead it was the cleaning of a production tool. How times have changed. The late-1980s ushered in the end of most of the popular solvents, and the machines that consumed them. Assemblers turned to alternative cleaning agents, including IPAs and other solvents.
Technical Library | 2007-09-27 16:18:15.0
Considerable interest exists in the process known as the pinin- paste, or the Alternative Assembly and Reflow Technology (AART) process. The AART process allows for the simultaneous reflow of both odd-form and through hole devices as well as surface mount components. This process has several advantages over the typical mixed technology process sequence that includes wave soldering and/or hand soldering, often in addition to reflow soldering.
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 | 2016-02-18 18:55:09.0
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.
Technical Library | 2024-05-16 16:06:24.0
Much like actual cities where streets and roads connect buildings together, ICs on a board are connected to each other with copper traces. And just like any metropolitan city, urban expansion tends to move vertically instead of horizontally, but instead of multi-story buildings, we get multilayer boards. Vias are copper-plated holes spanning through the different layers of a given board or panel. They are the entrance locations to the subway stations, if you will. Having those multilayer boards has enabled electronic design to minimize the size of boards immensely without compromising on the complexity.
Technical Library | 2014-08-14 17:58:41.0
High reliability applications for high performance computing, military, medical and industrial applications are driving electronics packaging advancements toward increased functionality with decreasing degrees of size, weight and power (SWaP) The substrate technology selected for the electronics package is a key enabling technology towards achieving SWaP. Standard printed circuit boards (PWBs) utilize dielectric materials containing glass cloth, which can limit circuit density and performance, as well as inhibit the ability to achieve reliable assemblies with bare semiconductor die components. Ceramic substrates often used in lieu of PWBs for chip packaging have disadvantages of weight, marginal electrical performance and reliability as compared to organic technologies. Alternative materials including thin, particle-containing organic substrates, liquid crystal polymer (LCP) and microflex enable SWaP, while overcoming the limitations of PWBs and ceramic. This paper will discuss the use of these alternative organic substrate materials to achieve extreme electronics miniaturization with outstanding electrical performance and high reliability. The effect of substrate type on chip-package interaction and resulting reliability will be discussed. Microflex assemblies to achieve extreme miniaturization and atypical form factors driven by implantable and in vivo medical applications are also shown.
Technical Library | 2007-12-20 16:28:08.0
Despite much research and discussion on the subject of reflow profiling, many questions and a good deal of confusion still exist. What is clear is that the pains often associated with profiling can be reduced if there is a strong understanding of the variables that can be encountered during the reflow process, as well as the metallurgical dynamics of the soldering process. This paper shall provide a brief outline of the reflow profile in general, with specific emphasis placed upon the suggested time spent above the melting temperature of the solder. The guidelines for soldering to various surfaces and with alternative solder alloys also are discussed.
Technical Library | 2012-11-27 14:06:48.0
Quality managers and line supervisors are routinely tasked with the responsibility of ensuring that the hand soldering process is under control. The method most commonly used is to measure the idle tip temperature of the soldering station and to use this reading as a benchmark of system compliance. This method, although popular is now being seriously questioned by many industry professionals as being irrelevant in qualifying true system process control. This document aims to present a practical view of what factors are important for successful hand soldering and to suggest an alternative procedure for qualification that is simple, repeatable and directly related to the effectiveness of the soldering station.
Technical Library | 2022-09-29 14:08:42.0
Electronic vehicles, devices and components must not overheat, otherwise they may fail to operate correctly. Thermal management is a major technical challenge as components are getting smaller, power densities are increasing and demands on robustness and reliability are becoming more stringent. To prevent power losses or defects resulting from overheating, liquid thermal interface materials (TIMs) are being increasingly used to dissipate their heat. This White Paper discusses the aspects that need to be taken into account when dispensing these mostly highly viscous, highly abrasive materials and why in many cases they are better alternatives to pads, tapes and foils.
Technical Library | 1999-05-07 10:04:13.0
Powerful desktop multiprocessor systems based on the Intel Architecture (iA) offer a formidable alternative to traditional scientific/engineering workstations for commercial application developers at an attractive costperformance ratio. However, the lack of adequate compiler and runtime library support for multithreading and parallel processing on Windows NT* makes it difficult or impossible to fully exploit the performance advantage of these multiprocessor systems. In this paper we describe the design, development, and initial performance results of the Illinois-Intel Multithreading Library (IML), which aims at providing an efficient and powerful (in terms of types of parallelism it supports) API for multithreaded application developers.
