Technical Library | 2008-01-24 16:19:43.0
The wave solder process is characterized by a large number of process parameters. To understand them all and their interactions is challenging, particularly when it comes to lead-free soldering. Wave soldering has a number of sub-processes, which include fluxing, preheating, soldering and cooling.
Technical Library | 2020-11-24 23:12:27.0
In a lead-free reflow process, temperatures are higher, and materials use outgasses more than in a leaded reflow process. The trends toward higher density populated boards and more pin-in-paste technology also increase solder paste use. More components and more solder paste result in more outgassing of chemistry during the reflow process. Some assemblies report condensation of vapors when the cold printed circuit board enters the oven. Little is known about the interaction between these condensed materials in terms of the interaction between these condensed materials and the reliability of the assembly. Apart from the question of reliability, a printed circuit board contaminated with a small film of residues after reflow soldering is not desirable.
Technical Library | 2020-04-22 23:50:30.0
Flexible bioelectronics, including wearable and implantable electronics, have revolutionized the way of human-machine interaction due to the fact that they can provide natural and seamless interactions with humans and keep stable and durable at strained states. As sensor elements or biomimetic actuators, flexible bioelectronics can dynamically sense and monitor physiological signals, reveal real-time physical health information and provide timely precise stimulations or treatments. Thus, the flexible bioelectronics are playing increasingly important roles in human-health monitoring and disease treatment, which will significantly change the future of healthcare as well as our relationships with electronics. This review summarizes recent major progress in the development of flexible substrates or encapsulation materials, sensors, circuits and energy-autonomous powers toward digital healthcare monitoring, emphasizing its role in biomedical applications in vivo and problems in practical applications. A future perspective into the challenges and opportunities in emerging flexible bioelectronics designs for the next-generation healthcare monitoring systems is also presented.
Technical Library | 1999-05-06 14:46:09.0
Semiconductor manufacturing is characterized by very complex process flows made up of individual process steps, many of which are built to very close tolerances. Furthermore, there are complex interactions in these process flows, whereby each process step can affect many other steps, and each final device parameter might be determined by the results from many inputs...
Technical Library | 2001-04-24 10:47:02.0
Board-level circuits today routinely run at speeds of 100 MHz or more and are composed of dozens of complex interacting VLSI components. To design such circuits in a timely and correct manner it is necessary to pay close attention to circuit timing early in the design cycle. At fast clock speeds, managing component and interconnect propagation delay becomes a key aspect of circuit design. It is imperative that the critical paths on a circuit and the slack available for interconnect delay consumption be identified early, and drive subsequent stages in the design flow.
Technical Library | 2007-06-13 13:44:10.0
Very high performance computer applications have created a demand for large organic substrates capable of interconnecting one or a few ASIC semiconductor devices with packaged memory devices. The electrical advantages offered by the use of a thin PTFE composite substrate were coupled with intrinsic mechanical advantages to create very high performance applications. The application development required interactions of design, fabrication, and new manufacturing technology to obtain rapid prototype production and allow a successful ensuing manufacturing ramp.
Technical Library | 2007-07-24 11:47:54.0
The rapid technical development of ultrashort laser systems is creating exciting possibilities for very precise localization of laser energy in time and space. These achievements have triggered novel laser applications based on nonlinear interaction processes. A promising three-dimensional microfabrication method that has recently attracted considerable attention is based on two-photon polymerization with ultrashort laser pulses.
Technical Library | 2018-02-01 00:31:48.0
This paper briefly summarizes the technologies underpinning the evolution in electrical system diagnosis and repair, which include schematic layout automation using prototypes and rule-based styling, instant language translation, 2D/3D view links with schematics, interactive diagnostic procedures, and dynamically-generated signal-tracing diagrams. These technologies empower after-sales service teams with state-of-the-art capabilities, which not only reduce costs but also improve brand quality in the eyes of its customers.
Technical Library | 2020-08-13 01:12:57.0
The solar industry has driven solutions that result in electronics systems that are required to perform in outside environments for over 25 years. This industry expectation has resulted in solutions to protect the electronics from failure that can result from interaction with moisture, and various chemicals leading to corrosion and shorting of the systems. Potting and encapsulation compounds can impart the very high level of protection from environmental, thermal, chemical, mechanical, and electrical conditions that the solar applications demand.
Technical Library | 2014-06-05 16:44:07.0
Stencil printing capability is becoming more important as the range of component sizes assembled on a single board increases. Coupled with increased component density, solder paste sticking to the aperture sidewalls and bottom of the stencil can cause insufficient solder paste deposits and solder bridging. Yield improvement requires increased focus on stencil technology, printer capability, solder paste functionality and understencil cleaning.(...) The purpose of this research is to study the wipe sequence, wipe frequency and wipe solvent(s) and how these factors interact to provide solder paste printing yield improvement.
