Ceramic-Polyimide Systems for Electronic Packaging

1993 ◽  
Vol 304 ◽  
Author(s):  
Wayne E. Marsh ◽  
K. Kanakarajan ◽  
Garry D. Osborn

AbstractA family of new high performance thermoplastic polyimide adhesives have been developed that can be directly laminated to ceramic substrates, polyimide films, metals, and/or sputter metallized for eventual circuit fabrication. We have also developed new heat-sealable composite polyimide films that have improved CTE, that have good dimensional stability and that can also be directly bonded to ceramic and glass-ceramic substrates. With these new material sets various constructions of ceramic-polyimide rigid-flex systems can be conceived to meet the more demanding needs of the electronics industry. We have laminated these films to metals and various ceramic substrates such as alumina, aluminum nitride, glass, etc. and investigated the bond stabilities under thermal and humidity aging conditions.

Alloy Digest ◽  
2018 ◽  
Vol 67 (6) ◽  

Abstract Alloy CuSn6 (UNS C51900) is a high-performance copper alloy. Typical uses include components for the electronics industry such as connector springs, relays, leaf springs, and switches as well as machine parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming and joining. Filing Code: Cu-873. Producer or source: Gebr. Kemper GmbH + Company KG Metallwerke.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2400
Author(s):  
Leandra P. Santos ◽  
Douglas S. da Silva ◽  
Thais H. Morari ◽  
Fernando Galembeck

Many materials and additives perform well as fire retardants and suppressants, but there is an ever-growing list of unfulfilled demands requiring new developments. This work explores the outstanding dispersant and adhesive performances of cellulose to create a new effective fire-retardant: exfoliated and reassembled graphite (ERG). This is a new 2D polyfunctional material formed by drying aqueous dispersions of graphite and cellulose on wood, canvas, and other lignocellulosic materials, thus producing adherent layers that reduce the damage caused by a flame to the substrates. Visual observation, thermal images and surface temperature measurements reveal fast heat transfer away from the flamed spots, suppressing flare formation. Pinewood coated with ERG underwent standard flame resistance tests in an accredited laboratory, reaching the highest possible class for combustible substrates. The fire-retardant performance of ERG derives from its thermal stability in air and from its ability to transfer heat to the environment, by conduction and radiation. This new material may thus lead a new class of flame-retardant coatings based on a hitherto unexplored mechanism for fire retardation and showing several technical advantages: the precursor dispersions are water-based, the raw materials used are commodities, and the production process can be performed on commonly used equipment with minimal waste.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 567
Author(s):  
Hong Yang ◽  
Mingyu Gao ◽  
Jinxin Wang ◽  
Hongbo Mu ◽  
Dawei Qi

In the absence of high-quality hardwood timber resources, we have gradually turned our attention from natural forests to planted fast-growing forests. However, fast-growing tree timber in general has defects such as low wood density, loose texture, and poor mechanical properties. Therefore, improving the performance of wood through efficient and rapid technological processes and increasing the utilization of inferior wood is a good way to extend the use of wood. Densification of wood increases the strength of low-density wood and extends the range of applications for wood and wood-derived products. In this paper, the effects of ultrasonic and vacuum pretreatment on the properties of high-performance wood were explored by combining sonication, vacuum impregnation, chemical softening, and thermomechanical treatments to densify the wood; then, the changes in the chemical composition, microstructure, and mechanical properties of poplar wood before and after treatment were analyzed comparatively by FT-IR, XRD, SEM, and mechanical tests. The results showed that with ultrasonic pretreatment and vacuum impregnation, the compression ratio of high-performance wood reached its highest level and the MOR and MOE reached their maximums. With the help of this method, fast-growing softwoods can be easily prepared into dense wood materials, and it is hoped that this new material can be applied in the fields of construction, aviation, and automobile manufacturing.


2011 ◽  
Vol 1306 ◽  
Author(s):  
Wenting Dong ◽  
Wendell Rhine ◽  
Shannon White

ABSTRACTHigh performance polyimides have been widely investigated as materials with excellent thermal, mechanical, and electronic properties due to their highly rigid structures. Aspen has developed an approach to prepare polyimide aerogels which have applications as low dielectric constant materials, separation membranes, catalyst supports and insulation materials. In this paper, we will discuss the preparation of polyimide-silica hybrid aerogel materials with good mechanical strengths and low thermal conductivities. The polyimide-silica hybrid aerogels were made by a two-step process and the materials were characterized to determine thermal conductivity and compressive strength. Results show that compressive moduli of the polyimide-silica hybrid aerogels increase dramatically with density (power law relationship). Thermal conductivity of the aerogels is dependent on the aging conditions and density, with the lowest value achieved so far being ~12 mW/m-K at ambient conditions. The relationship between aerogel density and surface area, thermal stability, porosity and morphology of the nanostructure of the polyimide-silica hybrid aerogels are also described in this paper.


2011 ◽  
Vol 287-290 ◽  
pp. 858-861
Author(s):  
Hui Wang ◽  
Zhou Qing Zhao ◽  
Jian Zeng

Aiming at the characteristics of pavement rutting damage of test road under the condition of heavy load and abrupt slope, an overlay design scheme and a new overlay material with high performance was proposed. The new material is PG82 modified asphalt SMA-13 added polyester fibre which can significantly improve the high temperature performance of asphalt mixture under severe environment, and its strength and crack resistance are superior to normal SMA-13. Tracking survey of test road shows that the pavement performances keeps good and rutting is under good control. Therefore those measurements are successful and can be a reference to similar projects.


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