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Components, Packaging, and Manufacturing Technology, Part A, IEEE Transactions on

Issue 2 • Date Jun 1995

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Displaying Results 1 - 25 of 32
  • A correlation study between different types of CDM testers and “real” manufacturing in-line leakage failures

    Publication Year: 1995 , Page(s): 295 - 302
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB)  

    Charged device model (CDM) tests generated ESD failures that correlated closely to assembly/test manufacturing in-line leakage failures. Both the “field induced noncontact” and “socketed” CDM testers correctly identified the weakest pins in a 0.8-μm CMOS technology device. A correlation of the initial fail voltage was found between the different field-induced CDM testers and the eight weakest pins. Similar CDM-tests found a weak pin to pin correlation between the two different socketed CDM testers View full abstract»

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  • A new smart material-multilayer PTC thermistor

    Publication Year: 1995 , Page(s): 249 - 251
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (216 KB)  

    New multilayer PTC thermistors, barium titanate-based ceramics, and polymer V2O3-based composites, have been studied. These thermistors are also passively smart materials with a self-repair mechanism by nonlinear temperature dependent resistance (R(T)) and voltage dependent current (I(V)) behavior. The laminated ceramic and composite thermistors possess many good features, such as small size and new characteristics of lower resistivity and larger current. It is the first time that such multilayer PTC thermistors have been reported. The lamination technology and electrical behavior of a multilayer positive temperature coefficient (MLPTC) thermistor were investigated View full abstract»

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  • A sensitive device for the measurement of the force exerted by the arc on the electrodes

    Publication Year: 1995 , Page(s): 322 - 328
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (452 KB)  

    In this paper a very sensitive device allowing the measurement of the forces exerted on an electrode by an electric arc is presented. The device principle is based on the use of a piezoelectric transducer. The calibration of the device is explained and experimental results are presented concerning the force exerted on various electrode materials (Ag and AgSnO2) for cathodes and anodes. Force measurements have also been realized for various cover gases (air and argon) and for various arc current pulse durations View full abstract»

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  • Influence of tester, test method, and device type on CDM ESD testing

    Publication Year: 1995 , Page(s): 284 - 294
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (992 KB)  

    In this paper, the charged device model (CDM) electrostatic discharge (ESD) events emulated by different commercial concerns are studied. First, the characteristic waveforms, defined by the EOS/ESD CDM ESD draft standard (DS5.3-1993), are compared and some major problems related to the specification of socketed CDM testers are discussed. Second, the results of an extensive CDM ESD test program are reported. The influences of various test parameters, such as the charging method (direct or field), the discharge mode (contact or noncontact), the charge pin (substrate pin or pin to be discharged) and the device package are studied. Finally, correlations of CDM ESD test results (the voltage thresholds and electrical failure signatures) are investigated View full abstract»

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  • Polarity effect of unsymmetrical material combination on the arc erosion and contact resistance behavior

    Publication Year: 1995 , Page(s): 334 - 343
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1004 KB)  

    The arc duration, material transfer, contact morphology, surface composition, and contact resistance of dissimilar contact combinations of palladium to silver were experimentally examined with a breaking inductive load from 0.5 to 4.0 A for 6×104 operations in air at atmosphere pressure. The test results have led to the conclusion that polarity significantly affects are erosion and electrical contact resistance behavior. By utilizing results from a previous study, it is known that cathode materials have significant influence on are erosion, i.e., through material transfer, arc duration, and erosion patterns. Contact resistance, however, is dominated by the anode material due to surface contamination, specifically anode oxidation in the late gaseous phase. Also, evidence is found in this work that material transfer between two electrodes greatly influences are erosion and contact resistance behavior View full abstract»

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  • Constriction resistance of microcone-based contacts

    Publication Year: 1995 , Page(s): 385 - 389
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (408 KB)  

    Based on a recently developed semiconductor processing technique for field emitters, molybdenum cones are made on the surface of contact members to achieve low constriction resistance. A model was set up to calculate the constriction resistance of such a cone-based contact interface. The constriction resistance is obtained from the solution to a linear system of current flow equations for the contact structure. The effects of surface features such as number, size and distribution of microcontacts, and cluster area on the constriction resistance were evaluated by a computer simulation. The least-square optimization of numerical results led to an empirical expression which relates the constriction resistance to the cone radius, cone density and cluster area. The model predicts the reduction of constriction resistance as a function of cone density, and it agrees well with the experimental results View full abstract»

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  • Effective erosion rates for selected contact materials in low-voltage contactors

    Publication Year: 1995 , Page(s): 329 - 333
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (404 KB)  

    Effective and absolute erosion rates are reported for contact materials from vacuum interrupters used for low voltage contactors. The effective erosion rates were determined from the linear erosion of both contacts with 60 Hz half cycle currents (from 630 to 685 A peak) and maximum gaps of ~2.2 mm. The contacts were opened at a present time in a half cycle, and the drawn arc continued to the next and final current zero. The polarity of the current automatically changed for each operation to ensure uniform erosion history for both contacts during many thousands of operations. Afterwards, the contacts were removed and placed in a demountable arcing chamber for determination of the absolute dc erosion rate of the cathode material. The absolute cathodic erosion rates were determined with applied dc current pulses on the order of 100 A and maximum gaps of 8.5 mm. With ac operation at a gap of 2.2 mm, a significant fraction of the ions and neutral vapor leaving one contact deposits on the other contact, so the effective erosion rate is markedly smaller than the absolute erosion rate. The materials investigated were Ag-WC, Cu-Cr, and Cu-Cr-Bi View full abstract»

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  • ESD protection in a mixed-voltage interface and multirail disconnected power grid environment in 0.50- and 0.25-μm channel length CMOS technologies

    Publication Year: 1995 , Page(s): 303 - 313
    Cited by:  Papers (31)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (944 KB)  

    On-chip ESD protection for semiconductor chips with mixed-voltage interface applications and internal multiple power bus architecture is discussed. ESD robustness in shallow trench isolation 0.50- and 0.25-μm channel-length CMOS technologies is demonstrated using novel ESD structures View full abstract»

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  • Carbon contamination of contacts due to organic vapors

    Publication Year: 1995 , Page(s): 399 - 404
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (436 KB)  

    The formation of carbon on the contact surface of commercial relays by thermal decomposition of organic vapors emanating from various organic materials may cause an undesirable increase of the contact resistance of the order of several ohms. A model switch was developed to investigate the influence of outgassing vapors of any organic material on contact reliability. Carbon deposits on contact surfaces cause certain phenomena confirming that the observed characteristic contact resistance increase to a value of the order of several ohms is caused by elementary carbon. Investigations of various organic materials showed that their contact compatibility cannot be derived just from the qualitative knowledge of their emanating vapors, but that the problem is more complex and requires a quantitative approach View full abstract»

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  • The impact of technology scaling on ESD robustness and protection circuit design

    Publication Year: 1995 , Page(s): 314 - 320
    Cited by:  Papers (78)  |  Patents (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (636 KB)  

    The trends in ESD robustness as a function of technology scaling, for feature sizes down to 0.25 μm, have been experimentally determined using single finger nMOS transistors and full ESD protection circuits. It is shown that as feature sizes are reduced, good ESD performance can be obtained provided the negative effects of the shallower junctions are offset by the positive effects of the reduction in the effective channel lengths. Hence, processes and protection circuits with feature sizes as small as 0.25 μm can be developed without degrading ESD robustness View full abstract»

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  • Effect of oxide films and arc duration characteristics on Ag contact resistance behavior

    Publication Year: 1995 , Page(s): 409 - 416
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (596 KB)  

    In order to confirm that oxide films are the predominant reason for contact resistance degradation of Ag contacts operating in normal air conditions, experiments were performed in mixed nitrogen-oxygen gas with switching inductive load and in normal air condition without switching load. Even-though the failure rate of contact resistance in nonload conditions is quite low, the strong carbon peak exists in the AES spectra. While in load condition, the oxygen peak usually occurs in the AES spectra and the carbon-peak is not found in mixed oxygen-nitrogen gas, although, sometimes in normal air. It is very interesting to note that contact resistance degradation is not only dependent on oxygen density, but also on the difference of arc duration in both the metallic and gaseous phases. The tested results help verify that oxide films dominate the contact resistance behavior of Ag contacts in mixed oxygen-nitrogen gas, as well as in normal air condition View full abstract»

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  • Reliability of the asperity contact model in determining charge injection across interfaces

    Publication Year: 1995 , Page(s): 353 - 363
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1100 KB)  

    Current profiles across mechanically contacted materials usually differ from the ones obtained by corresponding evaporated contacts. The asperity contact model has been brought up to cover such discrepancies. However, there is a lack of experimental evidence concerning its applicability on electronic injection across the interfaces. The work presented in this paper uses I-V curves of a well-documented device, the metal-semiconductor contact, as a tool to examine the validity of the asperity contact model and the implications of the interfacial layer, the axial contact force, the interfacial field and the relative permittivity of the surrounding space, on the injection process. Namely, the influence of interfacial layers has been studied in ultra-high-vacuum (UHV) environment (10-10 mbar) using cleaved silicon samples, contacted by hemispherical metal electrodes (Au, Cu, In, Al) covered in situ by fresh overlayers. The applied axial forces were controlled by electromagnets which displaced stainless steel electrodes to contact chemically prepared and cleaved [110] Si samples in a UHV environment. The importance of the interfacial fields has been examined by using Si and GaAs samples having specific surface profiles, i.e., mesas with 10 μm diameter and 1 μm height, fabricated by plasma etching or wet chemistry processes. Finally, the effect of the relative permittivity of the surrounding space has been investigated by applying sinusoidal 50-Hz high current densities on metal-metal contacts in the laboratory and high vacuum (10-6 mbar) environments. Utilizing the framework of the theory of the asperity contact model, the obtained results are in good agreement with the expected implications of the examined factors View full abstract»

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  • Reliability of electrically conducting knife-edge bearings of switches

    Publication Year: 1995 , Page(s): 390 - 398
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (768 KB)  

    Knife-edge bearings are used as electrically conducting elements between the movable and fixed part of the current path in many kinds of switches, e.g., microswitches and snap-action rocker switches. The contact resistance of such bearings may rise to unacceptably high values and may diminish the reliability of the device. Experimental investigations showed that fretting corrosion is the cause of occasionally observed increase and fluctuation of the electrical resistance of nonbouncing knife-edge bearings. In the case of bouncing knife-edge bearings erosion and oxidation-caused by the arc during the repeatedly opening and closing bearing contacts (notch-cut)-diminishes the reliability of the bearings. Precautions have been specified in order to improve the reliability of knife-edge bearing in the current path of switches. A detailed description of the results of the investigations, a synopsis of the fundamentals (of fretting corrosion, dynamics of knife-edge bearings, friction, bouncing), and an indication of important correlations facilitate the understanding of the phenomenon occurring in electrically conducting knife-edge bearings View full abstract»

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  • Estimation of properties of contact materials used in vacuum interrupters based on investigations of the microdischarge phenomenon

    Publication Year: 1995 , Page(s): 344 - 347
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (308 KB)  

    The paper presents electroinsulating properties of the vacuum gap between chosen contact materials used in vacuum interrupters. Cu-Cr25, Cu-Cr50, W-Cu30 sinter materials were investigated. Microdischarges-typical phenomena in the pre-breakdown stage were analyzed using the arrangement for partial discharge measurements as well as the multichannel analyzer. It has been noted that there is a very strong relation between the breakdown voltage in the vacuum gap and parameters describing microdischarges View full abstract»

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  • Shock protection with a nonlinear spring

    Publication Year: 1995 , Page(s): 430 - 437
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (544 KB)  

    Using the simplest case of a nonlinear spring with a cubic restoring force, we show that a hard characteristic might be advisable for structural elements which are able to withstand high accelerations (decelerations), while the maximum displacement has to be made small by any means. Application of a spring with a soft characteristic can result in appreciably lower maximum accelerations (decelerations) than in a linear system; therefore, such application can be recommended in the case when the requirement for the lowest displacement possible is not very stringent. However, if the maximum drop height is not known with certainty (which is typically the case) the advantages of a soft spring cannot be utilized to a full extent, because of the possibility of a “rigid impact”. In such a case (which occurs if the initial potential energy of the element is too high and significantly exceeds the work of the restoring force within the actual “breaking distance”), a probabilistic approach can be effectively used to design a soft spring with a low enough probability of a rigid impact. The obtained results can be helpful when designing spring protectors for vulnerable structural elements in portable electronics. These results can be useful for a rather broad class of nonlinear springs, not necessarily with cubic restoring forces View full abstract»

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  • Development of gas sensors for environmental protection

    Publication Year: 1995 , Page(s): 252 - 256
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (436 KB)  

    Principles and materials for three types of ceramic sensors to detect gaseous components related to environmental problems are briefly reviewed. Newly developed sensors, based on solid electrolytes or semiconducting oxides, are demonstrated for detecting oxygenic gases (CO 2, NO, NO3, SOx, and O3) and offensive odorants (NH3 and H2S). Particularly emphasized is the importance of Type III solid electrolyte sensors for oxygenic gases View full abstract»

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  • Wear rate reductions in carbon brushes, conducting current, and sliding against wavy copper surfaces

    Publication Year: 1995 , Page(s): 375 - 381
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (644 KB)  

    Wear tests are presented in which a carbon brush, loaded by a constant force spring, conducts current and slides against smooth and wavy copper rotors. The wavy rotors possessed surface waves of tens to hundreds of microns. With brush current varying from 0 to 40 A, carbon brushes slid over the smooth and wavy rotors and wear rates (μg/s) were plotted versus rotor speed. Wear rates on the wavy rotor were generally less than wear rates on the smooth rotor, with and without current. Wear rates on the wavy rotor were considerably less than corresponding wear rates on the smooth rotor at certain rotor speeds. Evidence suggests that wear rates were most reduced at those rotor speeds where surface waves on the wavy rotor passing beneath the brush caused the brush-stiffness-rotor system to resonate. Studies of contact voltage drop suggest that under these resonant conditions, the brush and rotor stayed connected. Also, no evidence of arcing or micro-arcing was found on the copper track. This study shows appreciable reductions (up to 50%) in wear rate possible on brush rotor systems by prescribing tiny surface waves on the rotor and running the rotor at speeds such that the surface waves induce microvibrations and resonance View full abstract»

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  • Protective treatments for gold-flashed contact finishes with a nickel substrate

    Publication Year: 1995 , Page(s): 405 - 408
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (312 KB)  

    While precious metals such as gold or gold-flashed palladium are preferred contact materials for connectors, cost considerations dictate the actual thickness used and hence the corrosion resistance. A method of preventing corrosion on contacts and providing connectors with uniform performance at a minimal cost is desirable. We were successful in developing a post-plating surface treatment that provides 0.1-μm thick gold contact finishes sufficient protection against 24 h exposure to a standard mixed-gas accelerated test; the contact resistance of a 0.1-μm gold on a nickel substrate is below 50 mΩ, while the contact resistance of the same gold flash over a matte-finish nickel phosphorus alloy is below 5 mΩ View full abstract»

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  • A new type of linear piezoelectric stepper motor

    Publication Year: 1995 , Page(s): 257 - 260
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (352 KB)  

    A new type of linear piezoelectric stepper motor combining the piezoelectric effect with the electrorheological (ER) effect as studied. The ER effect occurred in fluids that can make a transition from the liquid state to a weak solid state reversibly controlled by an electric field. The driving device of a piezomotor consists of a bilayer piezoactuator using PMN-PNN-PZT ceramics, an ER fluid clamp, and a grid base. Compared with conventional piezoelectric motors, it has unique advantages: no vibration noise, zero wear, low power consumption, large travel range, high mechanical resolution, etc. It will be used widely in the field of precise micropositioners particularly, such as STM, alignment of optical fibers, biological cell operation, and semiconductor manufacture techniques, etc. A motor with an inchworm velocity of about 1.5 μm/s and pulse force of about 0.25 kgf was obtained View full abstract»

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  • Electrical characteristics of various contact contaminations

    Publication Year: 1995 , Page(s): 369 - 374
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (428 KB)  

    Contact reliability may be endangered by various types of contact contaminations as particles, corrosion products, polymers or carbon deposits. Often information about the type of contamination may be gained by easily applicable measurements of current and contact voltage only: i.e., contact resistance measurements after each operation of a routine life test (employing increasing voltage and current), and voltage oscillograms across opening contacts View full abstract»

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  • Field-induced ESD from CRT's: its cause and cure

    Publication Year: 1995 , Page(s): 280 - 283
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (392 KB)  

    Electrostatic discharges have been reported at business locations where individuals wearing headsets work in front of cathode ray tubes (CRT's). The cause has been elusive. We have investigated the problem and have demonstrated that an electric field coupling exists between the human body and the CRT's. This coupling can elevate the electrostatic potential of personnel working near the CRT by thousands of volts. The personnel voltage can then trigger a field-induced electrostatic discharge to a nearby grounded conductor, such as a metallic component in a headset. We have devised a protection strategy for this ESD event View full abstract»

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  • Intelligent materials in future electronics

    Publication Year: 1995 , Page(s): 245 - 248
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (336 KB)  

    With the increasing demand for higher speed and performance of computers, a new concept of electron devices is indispensable for future electronics. Devices with intelligent materials meet such a demand and can simplify electronics, so that a system made of the devices can perform more complex functions close to those for the human brain and organisms. Intelligent materials are distinct from conventional materials in their characteristics, and they have the potential to become a dominant electronic-material in the future because of their various built-in functions. In this paper an important concept in the design of intelligent materials, called k-space engineering, is introduced. The k-space engineering, which manipulates the band structure of an existing material, is promising for future electron devices View full abstract»

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  • Computer simulation for the constriction resistance depending on the form of conducting spots

    Publication Year: 1995 , Page(s): 382 - 384
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (184 KB)  

    The constriction resistance of conducting spots in a contact surface is one of the most fundamental problems of conduction on a steady current field. Although equations for the constriction resistance of conducting spots with simple circle and square shapes were derived, these are no equations for the constriction resistance of conducting spots with irregular shapes. While constriction resistance depends on the form of conducting spots, the problem has not been addressed; moreover, it is very difficult to pursue effective study in this matter. Computer simulation is a very suitable method for the above problem. In this paper, computer simulations, based upon the boundary element and Monte Carlo methods are carried out, and the constriction resistance of conducting spots of regular and irregular forms are analyzed. As a result, the behavior of the constriction resistance is clarified View full abstract»

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  • Approaches to electronic miniaturization

    Publication Year: 1995 , Page(s): 274 - 278
    Cited by:  Papers (6)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (588 KB)  

    Over the past few years, dramatic progress has been made in miniaturizing electronics products. This has been driven by many forces, the chief of which have been increasing integration at the integrated-circuit chip level and competitiveness in the consumer marketplace. This paper examines elements that lead to effective miniaturization, including components, materials, and manufacturing processes. Specific examples are presented, including the “smart card,” wireless headsets, and the PCMCIA modem View full abstract»

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  • Electrical properties of surfaces of unirradiated and irradiated polymers in humid environments

    Publication Year: 1995 , Page(s): 266 - 269
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (352 KB)  

    The behavior of surface charge decay of corona-charged polyether ether ketone (PEEK) and polypropylene (PP) for different charging potentials is reported in this work. The nature of the charge decay with PEEK shows a presence of two processes involving a fast decay which is followed by a slower process. The fast decay process may originate from a field-induced dielectric polarization while the slow process arises from a thermal hopping process. The charge decay with PP was found to be quite insignificant over an extended period of time. The adsorption of water of these two polymers with and without gamma irradiation (6 Mrad) have also been measured over a range of humidity (RH%). The adsorption was observed to be enhanced for PEEK with gamma irradiation, whereas for PP it was significantly reduced View full abstract»

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Aims & Scope

This Transaction ceased production in 1998. The current publication is titled IEEE Transactions on Components, Packaging, and Manufacturing Technology.

Full Aims & Scope