Properties Of A Photoimageable Thin Polyimide Film II.

1991 ◽  
Vol 227 ◽  
Author(s):  
Taishih Maw ◽  
Richard E. Hopla

ABSTRACTThe polylmide synthesized from benzophenonetetracarboxylic dianhydride and alkyl-substituted diamines is inherently photosensitive at ≤365 nm, and a solvent soluble, negative-acting system can be formulated from the fully-imidized resin. The lithographic, thermal, mechanical, and electrical properties of the polyimide films have been characterized. This polyimide film shows good thermal, mechanical, and electrical properties, and a 1:1 aspect ratio is consistently achieved on 10 μm thick films. The thermal properties of the films were determined using TGA and TMA methods. The decomposition temperature was 527°C, the weight loss of the cured film at 350°C in nitrogen was 0.04 %/hour and the thermal expansion coefficient was 37 ppm/°C. The dielectric constant and dissipation factor of the film were 3.0 and 0.003 respectively at 4% humidity. The effects of hard-bake time, hard-bake temperature, nitrogen purge rate during heat treatment, and humidity on the thermal and electrical properties of the thin film were also examined, and are presented here. The rate of weight loss of the cured film increases when the rate of nitrogen purge decreases or when the cure temperature increases. Longer heat treatments resulted in a slight decrease in the CTE and an Increase in the Tg. The electrical properties of the films are dependent both on the humidity during measurement and on the hard-bake temperature.

2001 ◽  
Vol 40 (Part 1, No. 9A) ◽  
pp. 5382-5388 ◽  
Author(s):  
Yongdong Liu ◽  
Seiichi Hata ◽  
Kouichi Wada ◽  
Akira Shimokohbe

2021 ◽  
pp. 009524432110604
Author(s):  
Ganesan J ◽  
Jeyadevi S ◽  
Siva Kaylasa Sundari S ◽  
Arunjunai Raj M ◽  
Pitchaimari G ◽  
...  

In the present study, the aim is to synthesize the particulate nanocomposites with difunctional and trifunctional epoxy blend as matrix and synthesized nanoporous materials as fillers. Organic/inorganic hybrid networks were prepared by the novel solvent free method. Viscoelastic, thermal, and electrical properties of di- and trifunctional epoxy and the effect of different nanoparticles in the particulate nanocomposites have been studied by dynamic mechanical analyzer, thermogravimetry (TGA), and dielectric strength. Epoxy mixed with different compositions of TGPAP and particulate nanocomposites by the addition of different types of nanomaterials shows higher storage modulus than the pure epoxy. The addition of TGPAP and nanofillers decreases the thermal stability of epoxy matrix. The evolved gas analysis (TG-FTIR) was also done in order to study the products formed during degradation. An increase in dielectric strength and impact strength (4%) was also observed in the particulate nanocomposites.


2006 ◽  
Vol 28 (1) ◽  
pp. 33-43 ◽  
Author(s):  
X. Zhang ◽  
H. Q. Xie ◽  
M. Fujii ◽  
H. Ago ◽  
K. Takahashi ◽  
...  

Author(s):  
Naokazu Murata ◽  
Naoki Saito ◽  
Kinji Tamakawa ◽  
Ken Suzuki ◽  
Hideo Miura

Both mechanical and electrical properties of electroplated copper thin films were investigated experimentally with respect to changes in their micro texture. Clear recrystallization was observed after the annealing even at low temperature of about 150°C. The fracture strain of the film annealed at 400°C increased from the initial value of about 3% to 15%, and at the same time, the yield stress of the annealed film decreased from about 270 MPa to 90 MPa. In addition, it was found that there were two fatigue fracture modes in the film annealed at the temperatures lower than 200°C. One was a typical ductile fracture mode with plastic deformation and the other was brittle one. When the brittle fracture occurred, the crack propagated along weak or porous grain boundaries which remained in the film after electroplating. The brittle fracture mode disappeared after the annealing at 400°C. These results clearly indicated that the mechanical properties of electroplated copper thin films vary drastically depending on their micro texture. Next, the electrical reliability of electroplated copper thin film interconnections was discussed. The interconnections used for electromigration (EM) tests were made by damascene process. The width of the interconnections was varied from 1 μm to 10 μm. An abrupt fracture mode due to local fusion appeared in the as-electroplated films within a few hours during the test. Since the fracture rate increased linearly with the increase of square of the applied current density, this fracture mode was dominated by local Joule heating. It seemed that the local resistance of the film increased due to the porous grain boundaries and thus, the local temperature around the porous grain boundaries increased drastically. On the other hand, the life of the interconnections annealed at 400°C was improved significantly. This was because of the increase of the average grain size and the improvement of the quality of grain boundaries in the annealed films. The electrical properties of the electroplated copper films were also dominated by their micro texture. However, the stress migration occurred in the interconnections after the annealing at 400°C. This was because of the high residual tensile stress caused by the constraint of the densification of the films by the surrounding oxide film in the interconnection structures during the annealing. Finally, electroplating condition was controlled to improve the electrical properties. Both the resistance of electromigration and electrical resistivity were improved significantly. However, electromigration of copper atoms still occurred at the interface between the electroplated copper and the thin tantalum (Ta) layer sputtered as base material. Therefore, it is very important to control the crystallographic quality of electroplated copper films and the interface between different materials for improving the reliability of thin film interconnections.


2019 ◽  
Vol 3 (2) ◽  
pp. 35
Author(s):  
Eunice Cunha ◽  
Maria Paiva

Graphene has excellent mechanical, thermal, and electrical properties. Graphene can serve as potential reinforcement in polymer-based nanocomposites. In order to achieve this goal, graphene has to be distributed homogeneously and dispersed throughout the polymer matrix, establishing a strong interface with the polymer. Solution mixing is an interesting method for the preparation of homogeneous nanocomposites, in particular when using environmentally friendly solvents such as water. The major difficulty met in the production of graphene/polymer composites concerns the preparation and stabilization of graphene in aqueous suspension. In the present work three different graphite-based materials, with different crystallinity and purity grades, were exfoliated in aqueous solution of an amphiphilic pyrene derivative, forming few-layer graphene (FLG). The FLG prepared was dispersed in waterborne polyurethane (WPU) to produce composite films. The composite films were produced by solvent casting and spray coating, forming free-standing films that were characterized in terms of its distribution of FLG through the composite, its permeability to water vapor, its electrical resistivity, and its mechanical properties. The studies demonstrated the influence of different factors on the composite film properties such as the use of graphite vs. FLG, the FLG lateral dimensions, and the FLG composition and composite preparation method.


2020 ◽  
Vol 29 ◽  
pp. 2633366X1989459 ◽  
Author(s):  
Aseel A Kareem

The silicon carbide/carbon fiber (SiC/CF) hybrid fillers were introduced to improve the electrical and thermal conductivities of the epoxy resin composites. Results of Fourier transform infrared spectroscopy revealed that the peaks at 3532 and 2850 cm−1 relate to carboxylic acid O–H stretching and aldehyde C–H stretching appearing deeper with an increased volume fraction of SiC. Scanning electron microscopic image shows a better interface bonding between the fiber and the matrix when the volume fraction of SiC particles are increased. As frequency increases from 102 Hz to 106 Hz, dielectric constants decrease slightly. Dissipation factor (tan δ) values keep low and almost constant from 102 Hz to 104 Hz, has a slight increase after 104 Hz, and obtain relaxation peaks approximately between 105 and 106 Hz. A sharp increase in dielectric constant and dissipation factors is observed in epoxy (Ep)/CF composites with 30 vol.% of SiC. The increase in electrical conductivity of composites may result from the increased chain ordering by annealing effect. The electrical conductivities of the Ep/CF composites are decreasing with the increasing volume fraction of SiC. It is attributed to the introduction of insulating SiC. The glass transition temperature ( T g) of the Ep/CF-30 vol.% SiC composite was 352 C, which was higher than other composites. The decomposition temperature at 5% weight loss, decomposition temperature at 10% weight loss, and maximum decomposition temperature of the Ep/CF-30 vol.% SiC composite were about 389.5°C, 410.7°C, and 591°C, respectively, and were higher than pure epoxy and other composites. A higher thermal conductivity of 1.86 W (m K)−1 could be achieved with 30 vol.% SiC/CF hybrid fillers, which is about nine times higher than that of native epoxy resin of 0.202 W (m.K)−1.


Polyimide film is widely used in different areas due to its brilliant chemical and electrical properties. This chapter discusses effect of direct fluorination on surface charge and surface partial discharge of polyimide films. The influences of different fluorination time and voltage frequency are studied. The trap properties of polyimide film are analyzed. It is clear that the fluorination has changed the micro structure of the sample so that the trap property and the dissipation time are different. Further research focuses on the effects of water absorption on surface charge and dielectric breakdown of nanocomposite. The polyimide/Al2O3 film is selected as sample and the relation between water absorption and surface charge and breakdown voltage is discussed.


Author(s):  
Christine Chan ◽  
Shannon Chang ◽  
Hani E. Naguib

This study involved the development and characterization of novel porous, non-permeable, and conductive hydrogels. The hydrogels were fabricated with HEMA and crosslinked with PEGDA through a complete parametric study of the synthesis parameters which included water content and crosslinking content. The hydrogels were fabricated using UV photopolymerization and in situ polymerization of PPy, and characterization was conducted with respect to their physical, thermal, mechanical, and electrical properties. The physical properties were analyzed with respect to their swelling ratio and equilibrium water content. The thermal properties were analyzed based on the decomposition temperature and residue weight. The mechanical properties examined the elastic modulus of the hydrogels, and the electrical properties investigated the conductivity of the hydrogels. The relationships observed between the processing, structure, and resulting properties provide the basis for further development and application of these porous, non-permeable, and conductive hydrogels.


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