Technical Library | 2022-01-05 23:10:11.0
Waste electrical and electronic equipment or e-waste generation has been skyrocketing over the last decades. This poses waste management and value recovery challenges, especially in developing countries. Printed circuit boards (PCBs) are mainly employed in value recovery operations. Despite the high energy costs of generating crushed and milled particles of the order of several microns, those are employed in conventional hydrometallurgical techniques. Coarse PCB pieces (of order a few centimetres) based value recovery operations are not reported at the industrial scale as the complexities of the internal structure of PCBs limit efficient metal and non-metal separation.
Technical Library | 2011-03-30 21:14:33.0
The expression "multifunctional PCB", as a synonym for a PCB which is applicable with a variety of assembly techniques, is already established on the market. That means the PCB can be used for multiple reflow soldering and multiple assembly techniques lik
Technical Library | 2016-12-22 16:44:04.0
Particulate matter contamination is known to become wet and therefore ionically conductive and corrosive if the humidity in the environment rises above the deliquescence relative humidity (DRH) of the particulate matter. In wet condition, particulate matter can electrically bridge closely spaced features on printed circuit boards (PCBs), leading to their electrical failure. (...) The objective of this paper is to develop and describe a practical, routine means of measuring the DRH of minute quantities of particulate matter (1 mg or less) found on PCBs.
Technical Library | 2021-04-15 14:49:27.0
In this study, a predefined template-based image processing system is proposed to automatically detect of PCB soldering defects that negatively affect circuit operation. The proposed system consists of a scaled inspection structure, a camera, an image processing algorithm merged with Fuzzy and template guided inspection process. The prototype is produced using a plastic material, depending on the focal length of the camera and the PCB size. Image processing step comprises two steps. Firstly, solder joints are determined and boxed using Fuzzy C-means clustering algorithm.
Technical Library | 2013-12-05 17:09:03.0
The functionality of electronic devices continues to increase at an extraordinary rate. Simultaneously consumers are expecting even more and in ever smaller packages. One enabler for shrinking electronics has been the flexible circuit board that allows the circuit board to fit a wide variety of shapes. Flexible printed circuits (FPC) have the capability to be very thin and can have unpackaged components directly attached using surface mount technology (SMT) and flip chip on flex technologies. Bare die can also be thinned and attached very close to the circuit board. However one caveat of high density flexible circuit boards with thin die is that they can be very fragile. The use of back side films and underfill can protect the die making circuits more robust. For underfill to work well it requires good adhesion to the circuit board which can mean that flux residues under the die normally must be removed prior to underfilling.
Technical Library | 2022-09-12 14:07:47.0
Unique component handling issues can arise when an assembly factory uses highly-moisture sensitive surface mount devices (SMDs). This work describes how the distribution of moisture within the molded plastic body of a SMD is an important variable for survivability. JEDEC/IPC [1] moisture level rated packages classified as Levels 4-5a are shown to require additional handling constraints beyond the typical out-of-bag exposure time tracking. Nitrogen or desiccated cabinet containment is shown as a safe and effective means for long-term storage provided the effects of prior out-of-bag exposure conditions are taken into account. Moisture diffusion analyses coupled with experimental verification studies show that time in storage is as important a variable as floor-life exposure for highly-moisture sensitive devices. Improvements in floor-life survivability can be obtained by a handling procedure that includes cyclic storage in low humidity containment. SMDs that have exceeded their floor-life limits are analyzed for proper baking schedules. Optimized baking schedules can be adopted depending on a knowledge of the exposure conditions and the moisture sensitivity level of the device.
Technical Library | 2021-10-20 18:21:06.0
The solderability of the SAC305 alloy in contact with printed circuit boards (PCB) having different surface finishes was examined using the wetting balance method. The study was performed at a temperature of 260 _C on three types of PCBs covered with (1) hot air solder leveling (HASL LF), (2) electroless nickel immersion gold (ENIG), and (3) organic surface protectant (OSP), organic finish, all on Cu substrates and two types of fluxes (EF2202 and RF800). The results showed that the PCB substrate surface finish has a strong effect on the value of both the wetting time t0 and the contact angle h. The shortest wetting time was noted for the OSP finish (t0 = 0.6 s with EF2202 flux and t0 = 0.98 s with RF800 flux), while the ENIG finish showed the longest wetting time (t0 = 1.36 s with EF2202 flux and t0 = 1.55 s with RF800 flux). The h values calculated from the wetting balance tests were as follows: the lowest h of 45_ was formed on HASL LF (EF2202 flux), the highest h of 63_ was noted on the OSP finish, while on the ENIG finish, it was 58_ (EF2202 flux). After the solderability tests, the interface characterization of cross-sectional samples was performed by means of scanning electron microscopy coupled with energy dispersive spectroscopy.
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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