Technical Library | 2023-04-17 21:37:32.0
Ionic contamination is a leading cause in the degradation and corrosion of electronic assemblies, leading to lifetime limitation and field failure (Fig. 1). Ionic residue comes from a variety of sources shown in Fig. 2 opposite: Examples of ionic contaminants: * Anions * Cations * Weak Organic Acid
Technical Library | 2019-04-07 22:47:46.0
How to protect your PCB from moisture related damage? J-STD-033 put forward stricter regulation on the MSD exposure environment,when the exposure time exceed the tolerated,the moisture will penetrate into electronics,Moreover, the newest RoHS regulation will rise soldering temperature,the sudden high temperature will lead to expansion and cracking on electronic components. In order to decrease the moisture defect on PCB for the manufacturers in China,Climatest Symor® begin to concentrated on electronic dry cabinet R&D since early 1990s,we specialize in handling temperature and humidity for 20 years,and we provide best solution for PCB storage.
Technical Library | 2013-04-12 08:20:15.0
There is much to read about the shifting sands of electronics manufacturing, including current moves by OEMs to alter their EMS relationships to better mitigate risk and cost, while EMS companies look for additional ways in which to adjust their business models in an attempt to improve their profitability. Electronics outsourcing over time evolved from a means to buffer manufacturing demand fluctuations into a wide scale shift in capabilities, in part in order to deal with vastly shorter product life cycles. Following the global economic crash of 2000, aka “the internet bubble,” more and more EMS providers responded by transferring their manufacturing to low cost labour regions, and in particular China.
Technical Library | 2019-04-08 23:21:29.0
Climatest Symor® adopts molecular sieve to dry air, the whole system is controlled by microcomputer, when humidity is high, It will start to absorb moisture,when the humidity reach the pre-set value, it will stop absorbing, and then discharge the water to outside the cabinet by heating,again and again by automatic control. The most effective and environment-friendly moisture-absorbing desiccant is molecular sieve, molecular sieve is the microporous crystal material synthesized by silicon and aluminium oxide. In order to keep the crystal net discharge to be zero, atoms with cations are located in the crystal structure.and the cation used in these synthetic crystals is usually sodium. At present, there are two kinds of molecular sieves widely used in the dry box industry: Class A and Class X. Molecular sieves are synthesized, shaped and activated under strictly controlled production processes. The whole controlled sythesis process can ensure consistency of the three-dimensional pore size. 3A molecular sieve pore size is 3 angstroms, 4A molecular sieve pore size is 4 angstroms; 13X molecular sieve pore size is 8.5 angstroms. The working principle of molecular sieve: Molecular sieves adsorb molecules onto the crystal surface by physical attraction force. Since 95% surface area of the molecular sieve is within aperture,it needs to screen the adjacent molecules by different size. Only small size molecules can enter into the inner adsorption surface of the molecular sieve through the crystal aperture. This selective adsorption phenomenon is called molecular sieve effect. The molecular sieve adsorption capacity and charge density (polarity) are further related to the adsorbed molecules. The molecular sieves can further distinguish which of the mixed molecules can be adsorbed and determine to what extent the charge density can allow the molecules to be adsorbed onto the crystal. Water molecules are particularly small (2.6 angstroms), that belong to highly polar molecules (very strong positive and negative electron density), and are easily adsorbed by molecular sieves, even under very low moisture condition,once the water molecules are adsorbed,they will be firmly fixed on the crystal. The environment-friendly moisture absorption device is equipped with molecular sieve. When it’s absorbing, the memory alloy controller is in tensile state, and the spring is in contractive state,which just make the valve contact the outer baffle, this insulates the outside air from inside dry box air to achieve dehumidification purpose; and after molecular sieve absorbed moisture inside dry box and become saturated, the program will automatically control the memory alloy device to shrink it so that the valve reaches the inner baffle position. Meanwhile, due to the shrinkage of the memory alloy, the spring is stretched and the valve is pulled out of the outer baffle,so that the moisture in molecular sieve will be discharged into the outside. after the dehumidifying process finished, the program automatically control and reset the memory alloy and spring,to restart absorbing status.
Technical Library | 2010-05-27 22:12:10.0
The quad flat pack no lead or quad flat non-leaded (QFN) is one of the fastest growing package types in the electronics industry today. While the advantages of QFNs are well documented, concerns arise with its reliability and manufacturability. Acceptance of this package, especially in long-life, severe-environment, high-reliability applications, is currently limited. One of the most common drivers for reliability failures is inappropriate adoption of new technologies, such as the case with QFN. In this presentation, we will review and discuss QFN related reliability concerns and challenges, and propose Physics-of-Failure (PoF) based approaches to allow the confident introduction of QFN components into electronics products.
Technical Library | 2019-12-13 00:39:29.0
Salt spray corrosion chamber can test the ability of material and its protective layer to resist salt mist corrosion, or compare the process quality of similar protective layers, at the same time; this equipment is suitable for parts, electronic components, protective layer of metal material and other industrial products. Salt spray test is divided into neutral and acid test. What is the difference between neutral and acid in salt spray test? First, the temperature applied in the test method is different: Neutral test: a. Laboratory:35°C ±1°C, b. Saturated air drums:47°C ±1°C Acid test: a. Laboratory:50°C ±1°C, b. Saturated air drums:63°C ±1°C Second, the production material is different,neutral test chamber adoptes the traditional PVC plates, acid test chamber asopts PP sheet,which is more high temperature resistance and suits strong acid test. Third. Different test methods satisfied Neutral salt spray chamber according to GB/T 2423.17-2008, GB/T 2423.18-2000, salt spray test method and GB/T 10125-1997, GB/T 10587-2006, GB10593.2-1990, GB/T 1765-1979, GB/T 1771-2007, GB/T 12967.388, GB/T 1705.8-2008, etc. In addition to the test methods specified in the national standard, acid salt spray chamber also needs to expand the standard setting such as IEC,MIL,DIN,ASTM,IS,CNS. Last, Comparison of neutral test solutions China: NaCI distilled water solution NaCI mass concentration (50 ±5) g ≤ l pH value 6.5 ≤ 7.2 United States: distilled water solution NaCI mass concentration 5% ±1% pH value 6.5 ≤ 7.2 Germany: NaCI distilled water solution NaCI mass concentration (50 ±5) g ≤ l pH value 6.5 ≤ 7.2 Japan: NaCI distilled water solution NaCI mass concentration 5% ±1% pH pH value 6.5 ~ 7.2 France: NaCI distilled water solution NaCI mass concentration 5% pH 6.5 ≤ 7.2 https://climatechambers.com/articles&latestnews/difference-between-neutral-and-acid-salt-spray-corrosion-test.html
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Nordson Electronics Solutions makes reliable electronics an everyday reality. Our ASYMTEK, MARCH, and SELECT brands deliver precision fluid dispensing, conformal coating, plasma treatment and selective soldering equipment.
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