Technical Library | 2019-06-19 11:06:46.0
Tin (Sn) metal displays the characteristic of growing “tin whiskers” from pure tin coatings (most actively on relatively thin, electrodeposited or immersion tin coatings), usually months or years from the initial deposition of the tin. Tin whiskers are electrically conductive, filamentary, single crystals of white (beta phase) tin. These filaments of single crystal tin are usually one to five microns in diameter, and a few microns up to several tens of millimeters long, that grow spontaneously from the tin coatings. Alloying additions of several percent (by weight) of lead (Pb) prevents these electrically conductive tin whiskers from growing. Pb alloyed into the Sn was discovered to prevent the occurrence of tin whiskers in electronic assemblies in the 1950s as the Bell Laboratories solution to the problem of tin whiskers. The alloying of the tin with lead has thus quietly averted incalculable losses from short circuits in electronic equipment for the last 60 years.
Technical Library | 2009-05-14 13:57:43.0
Is screen printing technology able to keep pace with rising quality demands and increasingly complex board layouts? Or, is new jet printing technology ready to fill the gap? A comparison study between the two methods reveals some interesting differences. Screen printers offer some possibilities for optimizing solder paste deposits, but optimization is far easier and quicker with the jet printer. At the same time, the ability to print individualized deposits on every single pcb pad may be the ultimate answer to the growing quality challenge.
Technical Library | 2021-06-15 18:40:53.0
The jet printing of a dense mixed non-Newtonian suspension is based on the rapid displacement of fluid through a nozzle, the forming of a droplet and eventually the break-off of the filament. The ability to model this process would facilitate the development of future jetting devices. The purpose of this study is to propose a novel simulation framework and to show that it captures the main effects such as droplet shape, volume and speed. In the framework, the time dependent flow and the fluid-structure interaction between the suspension, the moving piston and the deflection of the jetting head is simulated. The system is modelled as a two phase system with the surrounding air being one phase and the dense suspension the other. Hence, the non-Newtonian suspension is modelled as a mixed single phase with properties determined from material testing. The simulations were performed with two coupled in-house solvers developed at Fraunhofer-Chalmers Centre; IBOFlow, a multiphase flow solver and LaStFEM, a large strain FEM solver. Jetting behaviour was shown to be affected not only by piston motion and fluid rheology, but also by the energy loss in the jetting head. The simulation results were compared to experimental data obtained from an industrial jetting head.
Fraunhofer-Chalmers Research Centre for Industustrial Mathematics
Technical Library | 2020-05-28 02:19:28.0
Properly functioning printed circuit boards are essential for both manufacturers of electronic devices and also the developers if the overall intent is for the electronic device to function at high capacity. From designing the schematics of the printed circuit boards to testing the products, there is no process of PCB manufacturing and/or assembly that can be taken for granted. While it's true that you can attempt this process on your own, especially if you are in possession of a large scale manufacturing facility, here are a few reasons why it would be a better option to opt for a professional company for PCB manufacturing and assembly. 1. Variety A professional printed circuit boards manufacturing company will be able to offer you a huge variety. You will be able to choose from rigid, flexible, or rigid-flex. What's more, the PCBs will be customized as per the need of the application. 2. Quality Professional and good printed circuit board manufacturing and assembling companies might cost you just a little bit extra but they also guarantee to produce the best results and offer very high quality products. In the end, it is quality that will make the difference between mediocre and a high functioning PCB. 3. Cost Efficiency Since you don't have to waste time or resources on buying equipment to produce the best PCBs or hiring staff to oversee the process, you can actually end up saving money. You can even save on PCB assembly cost by hiring this job out. All you have to do is to negotiate the quote and sit back, relax, and wait for the PCBs to be delivered to you. 4. Eliminate Design Flaws Design engineers hired by PCB manufacturing and assembling companies use the best graphic software to develop and test the schematics of PCBs. This increases the chances of eliminating flaws in the printed circuit boards during the initial design phase. 5. Multilayer PCB Manufacturing and Assembly The process of manufacturing and assembling multilayer PCBs is as intricate as it sounds. All processes of manufacturing and assembling multilayer PCBs require the best machines and trained technicians to pass the quality and functionality tests. Manufacturing and assembling multilayer printed circuit boards yourself is going to cost you a lot. Even the smallest of mistakes during the manufacturing and assembling process might render the entire PCB entirely useless. 6. Save Time PCBs are just a single part of the electronic device. To complete the device, many more pieces would be needed. The manufacturers of the electronic device can hire out the job of manufacturing or assembling the PCBs, which will mean they will have one less chore to do. This, in turn, will save you a lot of time which could be spent on elevating the quality of the product. 7. Experience Experience makes all the difference. It is what makes the name of any company reliable in the market. Long experience of manufacturing and assembling printed circuit boards makes the company well versed in the process and it also makes it an expert to identify design, manufacturing, assembling, and testing needs of certain applications We, at Asia Pacific Circuits, offer these benefits and so much more. For quick turn PCB assembly, PCB manufacturing and PCB designing, you can contact us anytime.
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