scholarly journals Reliability Study of Electronic Components on Board-Level Packages Encapsulated by Thermoset Injection Molding

2020 ◽  
Vol 4 (1) ◽  
pp. 26 ◽  
Author(s):  
Romit Kulkarni ◽  
Mahdi Soltani ◽  
Peter Wappler ◽  
Thomas Guenther ◽  
Karl-Peter Fritz ◽  
...  
Keyword(s):  
Injection Molding ◽  
Manufacturing Industry ◽  
Printed Circuit Boards ◽  
Thermal Loading ◽  
Operating Conditions ◽  
Raw Material ◽  
Electronic Components ◽  
Reliability Study ◽  
Encapsulation Process ◽  
Board Level

A drastically growing requirement of electronic packages with an increasing level of complexity poses newer challenges for the competitive manufacturing industry. Coupled with harsher operating conditions, these challenges affirm the need for encapsulated board-level (2nd level) packages. To reduce thermo-mechanical loads induced on the electronic components during operating cycles, a conformal type of encapsulation is gaining preference over conventional glob-tops or resin casting types. The availability of technology, the ease of automation, and the uncomplicated storage of raw material intensifies the implementation of thermoset injection molding for the encapsulation process of board-level packages. Reliability case studies of such encapsulated electronic components as a part of board-level packages become, thereupon, necessary. This paper presents the reliability study of exemplary electronic components, surface-mounted on printed circuit boards (PCBs), encapsulated by the means of thermoset injection molding, and subjected to cyclic thermal loading. The characteristic lifetime of the electronic components is statistically calculated after assessing the probability plots and presented consequently. A few points of conclusion are summarized, and the future scope is discussed at the end.

scholarly journals An Assessment of Thermoset Injection Molding for Thin-Walled Conformal Encapsulation of Board-Level Electronic Packages

2019 ◽  
Vol 3 (1) ◽  
pp. 18 ◽  
Author(s):  
Romit Kulkarni ◽  
Peter Wappler ◽  
Mahdi Soltani ◽  
Mehmet Haybat ◽  
Thomas Guenther ◽  
...  
Keyword(s):  
Injection Molding ◽  
Manufacturing Industry ◽  
Mechanical Stability ◽  
Flow Simulation ◽  
Dust Particles ◽  
Injection Molding Process ◽  
Market Demand ◽  
Molding Process ◽  
Thin Walled ◽  
Board Level

An ever-growing market demand for board (second) level packages (e.g., embedded systems, system-on-a-chip, etc.) poses newer challenges for its manufacturing industry in terms of competitive pricing, higher reliability, and overall dimensions. Such packages are encapsulated for various reasons including thermal management, protection from environmental conditions and dust particles, and enhancing the mechanical stability. In the due course of reducing overall sizes and material saving, an encapsulation as thin as possible imposes its own significance. Such a thin-walled conformal encapsulation serves as an added advantage by reducing the thermo-mechanical stresses occurring due to thermal-cyclic loading, compared to block-sized or thicker encapsulations. This paper assesses the encapsulation process of a board-level package by means of thermoset injection molding. Various aspects reviewed in this paper include the conception of a demonstrator, investigation of the flow simulation of the injection molding process, execution of molding trials with different encapsulation thicknesses, and characterization of the packages. The process shows a high dependence on the substrate properties, injection molding process parameters, device mounting tolerances, and device geometry tolerances. Nevertheless, the thermoset injection molding process is suitable for the encapsulation of board-level packages limiting itself only with respect to the thickness of the encapsulation material, which depends on other external aforementioned factors.

scholarly journals Tagasaste, leucaena and paulownia: three industrial crops for energy and hemicelluloses production

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Alberto Palma ◽  
Javier Mauricio Loaiza ◽  
Manuel J. Díaz ◽  
Juan Carlos García ◽  
Inmaculada Giráldez ◽  
...  
Keyword(s):  
Activation Energy ◽  
Acid Hydrolysis ◽  
Energy Production ◽  
Combustion Process ◽  
Operating Conditions ◽  
Raw Material ◽  
Energy Of Combustion ◽  
Increasing Temperature ◽  
Hydrolysis Of ◽  
Chamaecytisus Proliferus

Abstract Background Burning fast-growing trees for energy production can be an effective alternative to coal combustion. Thus, lignocellulosic material, which can be used to obtain chemicals with a high added value, is highly abundant, easily renewed and usually inexpensive. In this work, hemicellulose extraction by acid hydrolysis of plant biomass from three different crops (Chamaecytisus proliferus, Leucaena diversifolia and Paulownia trihybrid) was modelled and the resulting solid residues were used for energy production. Results The influence of the nature of the lignocellulosic raw material and the operating conditions used to extract the hemicellulose fraction on the heat capacity and activation energy of the subsequent combustion process was examined. The heat power and the activation energy of the combustion process were found to depend markedly on the hemicellulose content of the raw material. Thus, a low content in hemicelluloses resulted in a lower increased energy yield after acid hydrolysis stage. The process was also influenced by the operating conditions of the acid hydrolysis treatment, which increased the gross calorific value (GCV) of the solid residue by 0.6–9.7% relative to the starting material. In addition, the activation energy of combustion of the acid hydrolysis residues from Chamaecytisus proliferus (Tagasaste) and Paulownia trihybrid (Paulownia) was considerably lower than that for the starting materials, the difference increasing with increasing degree of conversion as well as with increasing temperature and acid concentration in the acid hydrolysis. The activation energy of combustion of the solid residues from acid hydrolysis of tagasaste and paulownia decreased markedly with increasing degree of conversion, and also with increasing temperature and acid concentration in the acid hydrolysis treatment. No similar trend was observed in Leucaena diversifolia (Leucaena) owing to its low content in hemicelluloses. Conclusions Acid hydrolysis of tagasaste, leucaena and paulownia provided a valorizable liquor containing a large amount of hemicelluloses and a solid residue with an increased heat power amenable to efficient valorization by combustion. There are many potential applications of the hemicelluloses-rich and lignin-rich fraction, for example as multi-components of bio-based feedstocks for 3D printing, for energy and other value-added chemicals.

MECHANICAL PROPERTIES OF ROTATIONALLY MOLDED PET MICROFIBRIL REINFORCED COMPOSITES

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4613-4618 ◽  
Author(s):  
R. J. T. LIN ◽  
D. BHATTACHARYYA ◽  
S. FAKIROV
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Industry ◽  
Polymer Processing ◽  
Raw Material ◽  
Medium Density ◽  
Reinforced Composites ◽  
Rotational Molding ◽  
Commercial Scale ◽  
Strength And Stiffness ◽  
Set Up

Being a fast growing plastic manufacturing industry, rotational molding has been using the linear polyethylenes extensively as the raw material. As these materials have shown insufficient mechanical properties for certain applications where strength and stiffness of the products are the main concerns, worldwide rotational molders have expressed a need for stronger and stiffer materials to be available for rotomolding. A possible attractive solution may be the recently developed microfibril reinforced composites (MFCs). Blends of linear medium density polyethylene/polyethylene terephthalate (LMDPE/PET) with an MFC structure are manufactured on a commercial-scale set-up and thereafter used in rotational molding. The samples are characterized morphologically and tested mechanically. The results obtained show that the MFC-concept has good application opportunities in the polymer processing including rotational molding.

Agglomeration Technologies of Processing Powder Wastes

2015 ◽  
Vol 244 ◽  
pp. 121-129
Author(s):  
Marian Peciar ◽  
Roman Fekete ◽  
Peter Peciar
Keyword(s):  
Research Work ◽  
Operating Conditions ◽  
Airborne Particles ◽  
Raw Material ◽  
Production Cycle ◽  
Shear Forces ◽  
Material Resources ◽  
New Type ◽  
Two Phases ◽  
High Technologies

This article deals with the presentation of modern applications for processing powdered, primarily hazardous, waste to an agglomeration form appropriate for subsequent processing by classical methods, for example in the construction, automotive and consumer goods industries. The aim of the research work was to set appropriate operating conditions in order to appreciate currently non-processable wastes resulting from the intensive production of often extremely expensive materials. Technologies which enable returning powder waste back into the primary production cycle were developed and experimentally tested, thus saving raw material resources. When necessary for the fixing of fine airborne particles with a problematic compacting curve (hard to compress, repulsive due to the surface charge) extrusion processes using a patented technology enabling controlled modification of shear forces in the extrusion zone were successfully applied. A new type of axial extruder allows the elimination of the liquid phase and as a result prevents the clogging of the extrusion chamber. In the case of need for granulation of sensitive materials (for example pharmaceuticals not allowing the addition of any kind of agglomerating fluid or reacting strongly in the contact of the two phases), a process of compaction between rolls with different profiled surface was successfully applied. The developed high technologies and the resulting products thus represent a major contribution to environmental protection in the context of not only the work but also the communal environment.

PHM Features for Large Circuit Boards to Be Implemented Into Electric Drivetrain Applications

2021 ◽  
Author(s):  
Alexander Otto ◽  
Eberhard Kaulfersch ◽  
Prashant Kumar Singh ◽  
Claudio Romano ◽  
Marcus Hildebrandt ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Experimental Methods ◽  
Accelerated Ageing ◽  
Deformation Analysis ◽  
Electronic Control ◽  
Circuit Boards ◽  
Electronic Components ◽  
Printed Circuit ◽  
Early Warning Indicators ◽  
Warning Indicators

Abstract Canary structures being used as early warning indicators represent an important tool for condition and health monitoring of electronic components and systems. In this paper, printed circuit boards with canary structures based on SMD 2512 ceramic chip resistors with reduced solder pad sizes were studied. Focus of these investigations was set on thermo-mechanical and mechanical stresses caused by passive thermal cycling as well as by vibrational loads. For this purpose, experimental methods such as deformation analysis and accelerated ageing tests as well as finite element based methods were applied. In addition, an outlook on the implementation of these canary structures into dual inverter electronic control boards for electrical powertrain applications will be given.

INCREASING THE RESOURCE OF DIESEL CYLINDER HEADS BY IMPROVING THE TECHNOLOGY OF THEIR RESTORATION

2020 ◽  
Vol 15 (7) ◽  
pp. 950-957
Author(s):  
G.D. Mezhetskiy ◽  
◽  
V.A. Strelnikov ◽  
Keyword(s):  
Diesel Engines ◽  
Thermal Loading ◽  
Theoretical Calculations ◽  
Operating Conditions ◽  
Advanced Technology ◽  
Temperature Fields ◽  
Cylinder Block ◽  
Diesel Cylinder ◽  
Thermal Intensity

The article presents the results of studies of the thermal fatigue strength of diesel cylinder heads and their resource under operating conditions, by using the most advanced technology for their restoration. Based on the results of theoretical calculations of durability and operational studies, a restoration technology has been proposed, which makes it possible to increase the resource of cylinder heads by 2 ÷ 2.5 times. For this purpose, the non-uniformity of the temperature field on the firing bottom of the cylinder heads of YaMZ-238NB diesel engines was theoretically determined and experimentally confirmed. On the basis of theoretical calculations, the most heatstressed sections of the plane of the cylinder heads of diesel engines bonded to the cylinder block were determined, and the appearance of cracks in them. When developing a method for calculating the temperature fields of the fire bottom, the universal finite element method (FEM) was used. This method makes it possible to take into account the geometry and conditions of thermal loading of the cylinder heads quite accurately. For the determination of temperature fields, a well-founded assignment of the boundary conditions is crucial. With this in mind, a number of surfaces were determined that characterize the durability of the entire part during operation. As a result of calculations carried out on a computer, temperature fields have been obtained that make it possible to analyze the distribution of temperatures and temperature gradients at any point of the fire bottom. The highest temperatures (620...635K) are localized in the central part of the fire bottom, which is two times higher in thermal intensity than the peripheral one and confirms the appearance of cracks in these places during the operation of diesel cylinder heads.

Border Trade between Regions of Russia and Provinces of China

2021 ◽  
Vol 20 (10) ◽  
pp. 103-116
Author(s):  
Natalya S. Epifanova ◽  
Vladimir N. Akulinin
Keyword(s):  
Manufacturing Industry ◽  
Raw Materials ◽  
Value Added ◽  
Raw Material ◽  
Structural Development ◽  
Regional Economies ◽  
Russian Regions ◽  
Goods And Services ◽  
Border Trade ◽  
Regions Of Russia

The purpose of this article is to study border trade in the regions of Russia and the provinces of China. It is shown that in recent years there have been negative trends in border trade, leading to its reduction. Therefore, Russian regions bordering with China should transform into separate objects of regional policy, while also forming a legislative framework for border interaction in all its main spheres: trade, humanitarian cooperation, science and education, and others. In border cooperation with China, special emphasis should be placed on cooperation in the innovation sphere, as well as on improving the quality of exported goods and services and promoting infrastructure projects. Border trade between the regions of Russia and China is built mainly on trade and export of labour resources from China to Russia, as well as China’s receipt of additional sales channels for the confidently growing sales markets for consumer goods and sources of raw materials and primary products. The interaction of Russian regions with neighbouring provinces on the border with China not only preserves the raw material orientation of these regions, but also hinders the development and strengthening of the manufacturing industry in the structure of their regional economies, since border interaction for Russian regions immobilizes those stages of value-added production observed in the very first stages. In general, for the Chinese provinces there is a similar problem associated with such exports to border regions that have common borders with Russia, which does not contribute to the diversification and structural development of the regional economies of the Chinese provinces. That is why building an effective mechanism for border interaction between Russia and China is a strategically important issue for both countries.

scholarly journals Effects of Injection Molding Screw Tips on Polymer Mixing

2018 ◽  
Vol 62 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Dániel Török ◽  
József Gábor Kovács
Keyword(s):  
Injection Molding ◽  
Processing Parameters ◽  
Raw Material ◽  
Molding Machine ◽  
Surface Color ◽  
Melt Temperature ◽  
Injection Molding Machine ◽  
Aesthetic Appearance ◽  
Molded Parts ◽  
Injection Molded

In all fields of industry it is important to produce parts with good quality. Injection molded parts usually have to meet strict requirements technically and aesthetically. The aim of the measurements presented in our paper is to investigate the aesthetic appearance, such as surface color homogeneity, of injection molded parts. It depends on several factors, the raw material, the colorants, the injection molding machine and the processing parameters. In this project we investigated the effects of the injection molding machine on surface color homogeneity. We focused on injection molding screw tips and investigated five screw tips with different geometries. We produced flat specimens colored with a masterbatch and investigated color homogeneity. To evaluate the color homogeneity of the specimens, we used digital image analysis software developed by us. After that we measured the plastication rate and the melt temperature of the polymer melt because mixing depends on these factors. Our results showed that the screw tips (dynamic mixers) can improve surface color homogeneity but they cause an increase in melt temperature and a decrease in the plastication rate.

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