Technical Library | 2014-05-15 14:26:27.0
350mA). Slotted surface showed good performance on both thermal and optical properties of the given 3W green LED.
Technical Library | 2013-08-15 13:12:11.0
An automated visual PCB inspection is an approach used to counter difficulties occurred in human’s manual inspection that can eliminates subjective aspects and then provides fast, quantitative, and dimensional assessments. In this study, referential approach has been implemented on template and defective PCB images to detect numerous defects on bare PCBs before etching process, since etching usually contributes most destructive defects found on PCBs. The PCB inspection system is then improved by incorporating a geometrical image registration, minimum thresholding technique and median filtering in order to solve alignment and uneven illumination problem. Finally, defect classification operation is employed in order to identify the source for six types of defects namely, missing hole, pin hole, underetch, short-circuit, mousebite, and open-circuit.
Technical Library | 2008-10-01 13:03:00.0
Many Original Equipment Manufacturers, (OEM’s), struggle to continue shipping aging or obsolete electronic products. Electronic products designed five to ten years ago are still relevant in the marketplace. Often these venerable old products have gained particular acceptance amongst a select group of customers. In many cases these old products fulfill a need in a unique manner. Examples include: designs that are grandfathered into an application due to regulatory considerations; designs having unique form-fit-and-function; designs running special software ; designs subject to contractual support and service requirements; designs in which a new contract stipulates delivery of older gear as part of a larger system offering. Any one or all of these reasons can lead an OEM to continue the production of electronic equipment well into its end of useful component life
Technical Library | 2010-05-06 18:46:29.0
Stencil printing technology has come a long way since the early 80’s when SMT process gained importance in the electronics packaging industry. In those early days, components were fairly large, making the board design and printing process relatively simple. The current trend in product miniaturization has led to smaller and more complex board designs. This has resulted into designs with maximum area utilization of the board space. It is not uncommon, especially for hand held devices, to find components only a few millimeters from the edge of the board. The board clamping systems used in the printing process have become a significant area of concern based on the current board design trend.
Technical Library | 2010-07-08 19:49:59.0
Aging characteristics of new lead free solder alloys are in question by many experts because of higher amount of tin’s effect on the diffusion of other metals, primarily copper, to create undesirable boundary intermetallics over long periods of time and even moderately elevated temperatures. A primary layer of intermetallics, Cu6Sn5 forms as the liquid solder makes contact with the solid copper substrate. This reaction however ceases as the solder temperature falls below that of liquidus. A secondary intermetallic Cu3Sn1, an undesirable weak and brittle layer, is thought to form over time and may be accelerated by even mildly elevated temperatures in electronic modules such as laptops under power. This project was designed to quantify the growth rate of Cu3Sn1 over an extended period of time in a thermal environment similar to a laptop in the power on mode.
Technical Library | 2011-09-26 13:53:30.0
On September 14, 2010, the late Shannon Wren, owner of VisionTech Components ("VisionTech"), and Stephanie McCloskey, VisionTech's Administrative Manager, were arrested during the execution of search and seizure warrants issued against the pair by the United States government after evidence connected them to the sale of counterfeit parts to the U.S. Navy, defense contractors and others. A ten-count indictment charged McCloskey with conspiracy, aiding and abetting in violation of Title 18 United States Code, Sections 371 and 2; trafficking in counterfeit goods, in violation of Title 18 United States Code, Section 2320; and mail fraud, in violation of Title 18 United States Code, Section 1341. McCloskey pled guilty to conspiracy and aiding and abetting for her role in the scheme.
Technical Library | 2012-03-08 20:08:57.0
You may have heard talk in the news lately regarding counterfeit electronic components making it into the US military supply chain. The U.S. Senate Armed Services Committee (SASC) recently reported in the Counterfeit Electronic Parts in the Defense Department Supply Chain hearing held on November 17, 2011, 1,800 cases of suspected counterfeit components that went into more than 1 million individual products. If you consider this number for the military, we can only imagine the number of counterfeits in our commercial yet high reliability products, such as life support or other critical systems. If you are the person within your electronics-based company who must perform risk analyses, counterfeiting is not a new concern, yet many do not realize just how good counterfeiters have become at their "trade".
Technical Library | 2013-08-13 09:49:53.0
One of the common issues I’ve noticed when visiting shops that use crimp force monitors (CFMs) is that the CFMs are usually turned off, regardless of the brand, because engineers and operators are not using them properly. Why, with all of their benefits, are CFMs not being used regularly by employees? One of the biggest problems is the lack of understanding of the variables affecting the CFM’s ability to detect variations. Crimp quality detection is similar to baking a cake. There are a lot of ingredients and if one ingredient is missing or of bad quality, you likely are not going to achieve your desired result. This article will go back through the basics of a crimp quality detection system and discuss what ingredients or variables you need to consider before switching off that CFM.
Technical Library | 2015-06-30 16:07:12.0
Robotics for automated fluid dispensing have the ability to apply a variety of materials including epoxy, silicone, and acrylic coatings. These materials are extensively used in today’s high-speed fluid dispensers for the electronics industry. Whether a dispenser is applying epoxy or another material, the central concept for applying any form of material remains the same. Specific points of an item being dispensed onto are programmed into the dispensing system. The automated fluid dispensers software interprets the programmed information and keeps the travel path in memory. A robotic arm moves fluid dispensing nozzles along this travel path and applies epoxy onto the surface of the item with precise accuracy. Machine speed can be adjusted to emit varying amounts of epoxy. The overall application process is auto-regulating and will not be disrupted.
Technical Library | 2015-07-14 21:32:04.0
The PCB industry is ever changing and adapting to new technologies. OEM specifications and requirements have also advanced due to these technologies. In some cases the OEMs are asking for a low resistance test to be performed on some or all electrical test nets of the PCB or on the holes of the PCB. This requirement is typically not well defined on the fabrication drawing and that leads to misleading conclusions by the fabrication house (...) This paper will use the data gathered by the company’s operations to outline what a 4-wire Kelvin test is and how it can be used. Several examples will be illustrated of what the 4 wire Kelvin test can and cannot do. A clear definition of what limitations are present during the testing operation will be defined. The paper will assist designers in understanding how the low resistance test can assist them and also identify causes that can identify unwanted concerns/issues.
