Technical Library | 2021-08-11 00:52:35.0
Formulators of multi-component adhesives, potting and encapsulation materials are careful not to supply products with entrapped air. They do this by manufacturing under vacuum or degassing them before supplying to the end user. Consequently, entrapped air in a mixed material is usually a processing issue.
Technical Library | 2022-10-31 18:35:40.0
Voids affect the thermal characteristics and mechanical properties of a solder joint, thereby affecting the reliability of the solder interconnect. The automotive sector in particular is requiring the mitigation of solder voids in various electronic control modules to the minimum possible level. Earlier research efforts performed to decrease voids involved varying the reflow profile, paste deposit, paste alloy composition, stencil aperture, and thickness. Due to the various advantages they offer, the use of Ball Grid Array packages is common across all industry sectors. They are also prone to process voiding issues. This study was performed to determine if vacuum assisted reflow process can help alleviate the voids in area array solder joints. Test parameters in this study largely focused on vacuum pressure level and vacuum dwell time.
Technical Library | 2018-09-10 08:44:08.0
Issue: Moisture and bubbles in your dispensing material with larger quantities Solution: Scheugenpflug’s 55-gal Barrel Agitator Station Barrel agitators for casting resins take their technology from the paint sector. They fall short of meeting the special demands of the auto, medical, aeronautics and electronics industries. They can’t guarantee a solid seal on the barrels – often containing expensive, moisture sensitive resins – allowing the humidity of the surrounding environment to damage the material. Also, conventional barrel agitators, as opposed to smaller units, cannot work in a vacuum to process materials directly.
Technical Library | 2020-12-29 20:55:46.0
Voiding in solder joints has been studied extensively, and the effects of many variables compared and contrasted with respect to voiding performance. Solder paste flux, solder powder size, stencil design, circuit board design, via-in-pad design, surface finish, component size, reflow profile, vacuum reflow, nitrogen reflow and other parameters have been varied and voiding quantified for each. The results show some differences in voiding performance with respect to most of these variables but these variables are not independent of each other. Voiding in solder joints is a complex issue that often requires multiple approaches to reduce voiding below required limits. This paper focuses on solutions to voiding for commonly used bottom terminated components (BTCs).
Technical Library | 2020-12-16 18:38:49.0
Fabrication of large structures using out-of-autoclave prepreg materials will lead to a great amount of savings in manufacturing costs. In the out-of-autoclave processing method, the presence of voids inside the laminate has been an issue due to the lack of high pressure during manufacturing. This study aims primarily to observe the moisture absorption response of composite samples containing different levels of void. By changing the vacuum level inside the bag during the manufacturing process, three different unidirectional laminates at three levels of void have been manufactured. After immersing the samples in warm water at 60°C for about one year, the moisture absorption level was monitored and then diffusion coefficients were calculated using Fick's law. Results show that the moisture absorption coefficient changes by %8 within the experimental range of void contents. The mechanical behaviour of these laminates has been studied at four different moisture levels by performing dynamic mechanical analysis (DMA) and short beam shear tests. Empirical results indicate that, in general, interlaminar shear strength and glass transition temperature decrease by moisture build-up inside the samples. DiBenedetto equation is proposed to make a correlation between the moisture content and glass transition temperature.
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