Dielectric Resin Research Articles

Safety of fusion magnets: Model experiments to high current arcs at ITER busbars and feeder lines

Abstract Electric arcs moving along the power cables (the so-called busbars) of the toroidal field (TF) coils of ITER may reach and penetrate the cryostat wall. Model experiments with the VACARC (VACuum ARC) device were initiated to investigate the propagation and destruction mechanisms of busbar arcs in small scale. These experiments are intended to support the development and validation of a numerical model. The present setup simulates the fact that the busbar is contained by an inner and an outer feeder tube which absorb radiated energy and will be in contact with hot metal melt from the busbar. The tubes may also direct the hot plasma jet flow of the arc as long as they are intact. Experiments at scaled values for tube diameter, wall thickness and expected power density suggest serious damage to the inner feeder tube by the arc. This asks for further investigations that include the outer tube, too. The extent of damage to the tube samples depends on arc power, as expected. At high currents an additional luminous effect takes place, which is attributed to a reaction of oxygen and hydrogen probably set free from the dissociation of the insulation resin by the heat of the arc.

Effect of water addition on centrifugal treatment to remove lead compounds from polyvinylchloride in electric wires and cables

Recycling treatment of cable insulation resin generated from electric wires and cables was investigated. Here, PVC is the most common insulation resin and conventional insulation PVC contains a lead component, tribase, as a thermal stabilizer. To recycle this PVC as insulation resin, lead removal is necessary to be able to conform to RoHS. This paper proposes a solvent dissolution and centrifugation method and the effects of flocculants and water addition in the processes involved are described.

Study on Downsizing Techniques for Conventional Motor with Solid Insulation System

This paper describes a feasibility study of a solid insulation system applied downsized motor. A large amount of insulation resin was employed to replace structural metal materials used in conventional motors. The optimal heat design, mechanically stable structure, and proper insulation resin are proposed and discussed. A prototype motor was manufactured, and results of a basic insulation test, temperature rise test and noise test are presented.

Synthesis and optoelectronic properties of high transparent polymer based anode materials with good wetting abilities and their application in electroluminescent devices

Electroluminescent (EL) phenomenon has been widely used in the illumination industry such as light emitting diode (LED) and organic light emitting diode (OLED) nowadays. In this research, flexible EL devices were fabricated by using the flexible substrates and conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) dispersions as the anode materials. The PEDOT:PSS dispersion was firstly prepared by oxidative polymerization while PSS was served as a polymeric template. Via introducing poly(vinyl pyrrolidone) (PVP) ethanol solution into the PEDOT:PSS dispersion, viscosity and wetting ability of the mixed PEDOT:PSS/PVP solution were enhanced in the same time. The three formed PEDOT:PSS/PVP thin films on glass substrates presented good conductivity and high transmittance (transmittance >76%). The wetting abilities of these PEDOT:PSS/PVP dispersions on the PET films coated with the low dielectric resin were evaluated from the contact angle measurements. It showed that the contact angle was decreased with increasing the addition of PVP ethanol solution. The different PEDOT:PSS/PVP dispersions were further used as the anode material in the EL flat plates and EL wires by dip coating process. Uniform and smooth conductive thin films with high transmittance were formed on the low dielectric resin layer. The luminance of these EL devices was observed and photographed after connecting to 110V AC power.

Removal of lead compounds from polyvinylchloride in electric wires and cables using cation-exchange resin

Recycling treatment of cable insulation resin generated from electric wires and cables was investigated. Conventional insulation PVC contains a lead component, tribase, as a thermal stabilizer and lead removal is necessary to recycle this PVC as insulation resin. This paper describes a solid surface adsorption method using ion exchange resin to remove the fine lead containing particles from PVC dissolved solution. Low lead concentration in the recovered PVC, complying with the requirements of RoHS, was achieved.

应用低介电材料丙烯酸酯树脂作为TFT-LCD的钝化层材料

A low dielectric material, acrylate resin has been investigated as a passivationdielectric layer for thin-film transistor (TFT) arrays in this paper. Compared with the conventional nitride film (SiNx, e≈7), the acrylate resin passivation layer exhibits a flat surfaceand a low dielectric constant (e≈4.5) which lowers the RC delay in a device. The hightransmittance and good planarization characteristics of the low dielectric acrylate resin filmenhance the brightness and aperture ratio of thin film transistors liquid crystal displays (TFT-LCDs), and lower the manufacture cost.

Surface modification of an epoxy resin with polyamines via cyanuric chloride coupling

The presence of polyamine groups on the surface of dielectric resins potentially improves the adhesion with electrochemically deposited metals. In this article, first cyanuric chloride is covalently bound to the surface hydroxyl groups of the epoxy resin. The remaining reactive sites on the coupled cyanuric chloride molecule are then used to anchor polyamines. New data on the triazine coupling is presented. The surface reactions are monitored and characterized by means of ATR-IR, SEM-EDS, XPS and ToF-S-SIMS.

Introduction of amino groups on the surface of thin photo definable epoxy resin layers via chemical modification

The introduction of amine groups on the surface of dielectric resins improves the adhesion with electrochemically deposited metals. In this work, etched epoxy resin surfaces are modified with aliphatic amines via a two step wet chemical reaction approach. First, cyanuric chloride is introduced on the surface. Next, the remaining reactive sites of cyanuric chloride are used to couple an aliphatic polyamine. Both reaction steps are optimized by variation of reaction parameters such as concentration, chemicals, temperature and time. A detailed surface characterization after each reaction step is provided using following techniques: ATR-IR, SEM–EDS, XPS and AFM.

Study on properties of low dielectric loss resin matrix

AbstractAllyl phenyl compounds, allyl epoxy resins, and epoxy acrylate resins are adapted to copolymerize with bismaleimide (BMI) resins and to modify mechanical properties and processing properties. Reaction activity, physical properties, mechanical properties, dielectric properties, and thermal stability were investigated. Impact strength and flexural strength of modified BMI resin are increased about twice and 42% than that of pure BMI resin, respectively. Fracture elongation is from 1.6 to 2.3%. The fracture surfaces of the broken specimens are examined by scanning electron microscopy (SEM). As a result, modified BMI resins put up typical toughness rupture. The modified BMI resins possess excellent dielectric properties, and dielectric constant and dielectric loss almost hold the line with increasing epoxy concentration. When the test frequency scope is from 1 to 20 GHz, the dielectric constant and dielectric loss of modified BMI resins is 3.05–3.12 and 0.0089–0.012, respectively. The modified BMI resins still possess fine properties after hydrothermal aging. After 100 h in boiling water, the reservation ratios of both the impact strength and flexural strength of modified system exceeded 90%, and the water absorption and heat distortion temperature (HDT) is 2.6% and 235°C, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 315–319, 2006

Rapid curing of positive tone photosensitive polybenzoxazole based dielectric resin by variable frequency microwave processing

High performance polymer dielectrics such as polyimides and polybenzoxazoles are used for several applications in the semiconductor industry due to their excellent dielectric and thermomechanical properties. However, these materials require curing at high temperatures for long periods of time in order to achieve the desired properties. High temperature exposure for long periods of time can be detrimental to device characteristics and reliability. In this study, rapid low temperature curing of a positive tone photosensitive polybenzoxazole based dielectric resin by variable frequency microwave (VFM) processing was investigated. The chemical changes occurring in the film during the condensation reaction and the percent conversion achieved as a function of cure condition were monitored by Fourier transform infrared spectroscopy. The effectiveness of rapid VFM curing was studied by characterizing the optical, electrical, and thermomechanical properties of VFM cured films with thermally cured films. The thermal stability of cured films was investigated by thermal gravitational analysis (TGA) and mass spectrometry (MS) studies. The results showed that a higher percent conversion and higher thermal stability can be achieved by using VFM processing than can be obtained using conventional thermal curing at the same cure temperature. However, the complete removal of photopackage related residual products requires slow ramp rates and long cure times

Surface Modification of Insulation Resin for Build-up Process Using TiO2 as a Photocatalyst and Its Application to the Metallization

Surface Modification of Insulation Resin for Build-up Process Using TiO2 as a Photocatalyst and Its Application to the Metallization

Fabrication of a three-dimensional terahertz photonic crystal using monosized spherical particles

Three-dimensional artificial crystals with periodicity corresponding to terahertz wave lengths were fabricated by self-assembling monosized metal spherical particles. The metal crystals were weakly sintered to utilize them as templates. The metal templates were inverted to air spheres crystal embedded in dielectric resin though infiltration and etching. The resulting resin inverted crystals clearly presented the photonic stop gaps within terahertz wave region and the frequencies of the gaps were confirmed to agree well with calculation by plane wave expansion method.

Micro via filling plating technology for IC substrate applications

The trend of electronic products toward lighter, thinner, and faster transmission is challenging the printed circuit board industry to incorporate high density interconnection technology (such as build‐up and semi‐additive processes). Micro stacked via is one technology utilized to produce high‐density structures. Dielectric resin, conductive paste or via plating are usually applied for the filling process. As compared with other filling methods, via filling plating technology has advantages in offering a shorter process and higher reliability. This paper discusses the influence of different equipment design, operating conditions and additives on via filling plating technology.

Effects of ultraviolet/ozone treatment on benzocyclobutene films

Benzocyclobutene (BCB) is a dielectric polymer resin used in microelectronics for its physical properties and its chemical resistance. UV/ozone photochemical treatment modifies the chemical properties of BCB: It creates a near SiO2 composition oxidized surface layer and degrades the polymer structure of BCB. The oxidized surface layer can be etched with fluoride acid and the degraded layer underneath is soluble with acetone. These BCB chemical modifications may be useful for BCB reworking after polymerization. UV/ozone treatment also has an effect on surface characteristics improving the surface tension and decreasing surface roughness of BCB.

Development of porous SiLK™ Semiconductor Dielectric Resin for the 65 nm and 45 nm Nodes

AbstractPorous SiLK resin is an ultra-low-k interlayer dielectric (ILD) material designed to meet the needs of the 65 nm technology node and beyond. In early 2002, the porous SiLK resin formulation was defined and scaled up, facilitating the tight monitoring and control of key properties, including pore size distribution, over several lots of material. The film processing kinetics are now well understood and a wide process window exists which ensures optimum pore morphology and pore size distribution. Thermal cycling of films demonstrates no effect on pore morphology or dielectric constant. The material has been designed to minimize the impact of CTE mismatch at high temperature, which challenged the integration of some previous generations of SiLK and porous SiLK dielectric resins. The discrete, closed-cell pore geometry is well characterized and enables the extendibility of process module development from SiLK resin technology to porous SiLK resin. Concurrent with the scale up efforts, advancements in minimizing both cure time and temperature simultaneously, as well as significant improvements in pore size and pore size distribution, have been achieved. The cure and porogen burn out time has been reduced by 50% or greater, and the temperature has been reduced to 370°C. The pore size has been reduced by ∼35%, and the pore size distribution has been narrowed by ∼40%. These advancements have resulted in the introduction of porous SiLK T resin, with a dielectric constant of k = 2.4 and a recommended cure temperature of 370°C, and the introduction of porous SiLK U resin, with a mean pore diameter of ∼5 nm and a dielectric constant of k = 2.2.

Development and Application of On-Wafer Small Angle X-Rayscattering for the Quantification of Pore Morphology in Low Kporous Silk Semiconductor Dielectrics

AbstractThe continual drive for faster interconnects requires the development of new interlayer dielectricmaterials with k values less than 2.1. Porous SiLKTM semiconductor dielectric resin wasdeveloped to achieve these low dielectric constants by introducing nanometer-sized pores intothe dense SiLK resin matrix. A quantitative description of the nano-porous morphology in low-kinterlayer dielectrics can be difficult to achieve for many reasons, including: complexities in theporous structure (size range, geometry, pore/pore interaction), inadequate mathematicaldescriptors, limitations of existing metrology technology, and availability of “tailor-made” experimental samples with a wide range of pore morphologies. On-wafer quantification of poremorphology is even more difficult as data must be obtained from extremely limited samplevolumes (thin films of ∼100-500 nm) residing on thick silicon (Si) wafer substrates.This paper will focus on the design, development and successful application of on-wafer smallangle x-ray scattering (SAXS) technology to characterize the morphology of porous SiLK resin.It will be demonstrated, by example, that this technology is able to deliver rapid quantificationover the entire pore size range for these systems. Recently developed data acquisition, reductionand analysis tools will be described. Direct evaluation of the strengths and challenges of severalmodels used to generate average pore size and pore size distribution will be reviewed. Finally,additional capabilities offered by this technology (wafer mapping and detection of “killer” pores)will also be discussed.

Stabilization of carbon-fiber cold field-emission cathodes with a dielectric coating

A comprehensive investigation has been carried out to determine the source of an inherent temporal instability in the spatial distribution and the electron emission current obtained from field-emitting carbon fiber tips. These instability effects were successfully overcome by coating the tip with a sub-micron layer of dielectric epoxy resin coating. The influence of the coating thickness was studied and an optimum thickness of 0.2–0.3 μm that produced high emission stability was found. A large reduction in the intensity fluctuations of the emission image, at this coating thickness is demonstrated by using chart recorder traces in addition to slow scans of an optically monitored screen signal. The current–voltage ( I– V) characteristics were obtained at a threshold field that is a few times lower than that of the uncoated tip. At low emission current levels linear F– N plots were obtained with a slope value lower than that of the uncoated emitter. The spatial distribution consisted of a very bright spot without any internal structure. The total energy distribution of the emitted electrons demonstrated a non-metallic behavior. The spectra obtained consisted of a single peak for low currents and a double peak for higher currents. The electron energy was measured relative to the Fermi level of tungsten and a spectral shift was shown to be a function of the current. Experiments have shown that the coated tips are not affected by the variations of pressure conditions down to 10 −6 mbar. These results suggest that a resin coated fiber tip offers superior performance to tungsten as a cold field emission electron source. Numerous improvements in the performance are underway. This includes a variety of polymeric coatings and more emissive carbon fibers.

Quantitation of trimethyl amine by headspace gas chromatography-mass spectrometry using a base-modified column.

Headspace gas chromatography-mass spectrometry (GC-MS) has been successfully applied to the analysis of the highly volatile species trimethyl amine (TMA). TMA quantitation in fiberglass insulation resins (ultimately used by the automotive and building products industries) is of interest because of its highly odoriferous nature. The release of TMA from fiberglass insulation products is the principal component responsible for the "fishy" odor encountered in automobiles. Currently, the industry standard for the analysis of TMA involves injecting an aqueous insulation extract into the GC-MS equipped with a polyethylene glycol column. Several problems inherent in this analysis prohibit consistent performance and enhance the possibility for wide variations in the quantitative results. This article reports the development of a new approach to the quantitation of TMA from fiberglass insulation between the levels of 1 and 150 ppm.

Automation and optimization of multidimensional microcolumn size exclusion chromatography-liquid chromatography for the analysis of photocrosslinkers in Cyclotene 4000 series advanced electronic resins

Multidimensional chromatography using on-line, coupled, micro-column size exclusion chromatography and reversed-phase high performance liquid chromatography, has been successfully implemented for the quantitative determination of photoinitiator concentrations in photosensitive, interlayer dielectric resin formulations. The actual formulation consists of the prepolymer, aromatic solvent, antioxidant, and a variety of bis-azide photocrosslinkers. This paper describes the development of an automated system for Micro SEC-LC, as well as accuracy and precision data for the photoinitiator analysis. The technology is very effective for the analysis of small molecules (e.g. additives) in polymer products, and as such can have wide ranging applicability to other polymer and complex products. The use of microcolumns in the first dimension allows the introduction of the complete fraction containing the components of interest into a reversed-phase second dimension without deterioration of the separation when using a very strong mobile phase such as THF.

Mechanical prestressing improves electrical strength

There is a strong mechanical influence on the growth of electrical trees in electrical insulation resins. This is not to argue that electrical treeing is exclusively a mechanical phenomenon directly analogous to mechanical cracking. It is obviously an electrically driven process; no volts, no trees. Nevertheless, the mechanical dimension is of sufficient importance for its effects to be exploited to advantage using the prestressing technique. The effect that post-curing at 100/spl deg/C has on the development of prestress, and on the ability of the cured sample to retain its prestress as the temperature is raised, has both positive and negative aspects. On the down side, material cured at 100/spl deg/C requires a greater tension to be applied to the fibers during the casting process in order to achieve the same degree of prestress. On the other hand, the increase in the glass transition temperature from 65/spl deg/C to 113/spl deg/C permits the use of the composite at temperatures up to 80/spl deg/C before any significant loss of prestress occurs, as compared with 40/spl deg/C for material cured at room temperature. As an additional bonus, there is an enhancement of the mechanical strength resulting from the inclusion of cast-in fibers, which is important where the electrical insulation also acts as a structural member in the insulation system.