Technical Library | 2021-09-08 13:57:37.0
While the presence of silver in SAC solder provided excellent temperature cycling durability, the silver in high silver SAC alloy also made the solders susceptible to failures under drop/shock loading. To improve the drop/shock reliability, the silver content in SAC alloys was reduced from three percent, to as low as no silver. Solder dopants, also known as microalloy additions, are elements (typically 0.1% or lower) other than the main constituents of the alloy that have been shown to improve solder performance. Commonly used microalloy additions include nickel (Ni), bismuth (Bi), manganese (Mn), and antimony (Sb).
Technical Library | 2021-06-28 20:43:32.0
This book is a compilation of many articles I have published on the subjects of cleaning, reliability, and cleanliness testing. Throughout these articles, I promote a common mantra: Clean is better than dirty. Less contamination is better than more contamination. Some assemblies can tolerate more contamination; others, less.
Technical Library | 2008-11-20 00:46:10.0
The Sn/Ag/Cu family of alloys is the leading candidate for a lead-free alternative. The first part of this study was to determine if there is any significant difference between Sn/Ag/Cu alloys when used in automatic soldering equipment in terms of copper build-up in the system. The study compared two Sn/Ag/Cu alloys to determine if at processing temperatures one alloy would absorb less copper than the other alloy.
Technical Library | 2024-04-29 21:39:52.0
In this paper, we develop and put into practice an Automatic Optical Inspection (AOI) system based on machine vision to check the holes on a printed circuit board (PCB). We incorporate the hardware and software. For the hardware part, we combine a PC, the three-axis positioning system, a lighting device and CCD cameras. For the software part, we utilize image registration, image segmentation, drill numbering, drill contrast, and defect displays to achieve this system. Results indicated that an accuracy of 5µm could be achieved in errors of the PCB holes allowing comparisons to be made. This is significant in inspecting the missing, the multi-hole and the incorrect location of the holes. However, previous work only focusses on one or other feature of the holes. Our research is able to assess multiple features: missing holes, incorrectly located holes and excessive holes. Equally, our results could be displayed as a bar chart and target plot. This has not been achieved before. These displays help users analyze the causes of errors and immediately correct the problems. Additionally, this AOI system is valuable for checking a large number of holes and finding out the defective ones on a PCB. Meanwhile, we apply a 0.1mm image resolution which is better than others used in industry. We set a detecting standard based on 2mm diameter of circles to diagnose the quality of the holes within 10 seconds.
Technical Library | 2015-08-18 14:02:37.0
What is UV Curing? “Ultraviolet (UV) light is an electromagnetic radiation with a wavelength from 400 nm to 100 nm, shorter than that of visible light but longer than X-rays.” (Source: Wikipedia). Ultraviolet or UV curing is used to create a photochemical reaction using high intensity Ultraviolet (UV) energy or “light” to quickly dry inks, adhesives or conformal coatings. Most materials cure with a UV wavelength around 350 ~ 400nm although some materials require UVC energy near 255nm. There are many advantages to using UV curing over other traditional methods of curing. Not only will it increase production speed, it assists in creating a better bond, and improves scratch and solvent resistance. When compared to other methods of curing, UV curing generates a more reliable cured product at a much higher rate of production in a considerably shorter period of time.
Technical Library | 2023-05-02 18:54:30.0
Surface-mount PCB components are smaller than their lead-based counterparts and provide a radically higher component density. They are available in a variety of shapes and sizes designated by a series of standardized codes curated by the electronics industry. Of these PCB components, the 0201-sized are the smallest, measuring 0.024 x 0.012 in. (0.6 x 0.3 mm) – that's 70% smaller than the previous 0402 level! The 0201 components are designed to improve reliability in space-constrained applications such as portable electronics like smartphones, tablets, robotics and digital cameras, but require delicate handling during the assembly process.
Technical Library | 1999-05-07 10:23:43.0
Software decoding of Dolby Digital allows it to become a baseline capability on the PC, with greater flexibility than a hardware approach. Intel's MMX™ technology provides instructions that can significantly speed up the execution of the Dolby Digital decoder, freeing up the processor to perform other tasks such as video decoding and/or audio enhancement. Intel has worked closely with Dolby Laboratories to define an implementation of Dolby Digital based on MMX technology that has achieved Dolby's certification of quality.
Technical Library | 2014-03-27 14:50:01.0
Because of the phase out of CFC's and HCFC's, standard solder pastes and fluxes evolved from RA and RMA fluxes, to No-Clean, to low residue No-Clean, to very low residue No-Clean. Many companies came out with their cleaning solutions, aqueous and semi-aqueous, with each product release being more innovative than the previous one. Unfortunately for most of the suppliers of cleaners, two other trends appeared; lead-free soldering and the progressive miniaturization of electronic devices.
Technical Library | 2022-02-16 15:34:32.0
Because of the phase-out of CFCs and HCFCs, standard solder pastes and fluxes evolved from RA and RMA fluxes to No-Clean, to low residue No-Clean, to very low residue No-Clean. Many companies came out with their cleaning solutions, aqueous and semi-aqueous, with each product release being more innovative than the previous one. Unfortunately for most of the suppliers of cleaners, two other trends appeared; lead-free soldering and the progressive miniaturization of electronic devices
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.
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