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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Microelectronics and Packaging Society
Journal Basic Information
Journal DOI :
The Korean Microelectronics and Packaging Society
Editor in Chief :
Volume & Issues
Volume 11, Issue 4 - Dec 2004
Volume 11, Issue 3 - Sep 2004
Volume 11, Issue 2 - Jun 2004
Volume 11, Issue 1 - Mar 2004
Selecting the target year
Characteristics of Joint Between Ag-Pd Thick Film Conductor and Solder Bump and Interfacial Reaction
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 1~6
The requirements for harsh environment electronic controllers in automotive applications have been steadily becoming more and more stringent. Electronic substrate technologists have been responding to this challenge effectively in an effort to meet the performance, reliability and cost requirements. An effect of the plasma cleaning at the ECM(Engine Control Module) alumina substrate and the intermetallic compound layer between Sn-37wt%Pb solder and pad joints after reflow soldering has been studied. Organic residual carbon layer was removed by the substrate plasma cleaning. So the interfacial adhesive strength was enhanced. As a result of AFM measurement, conductor pad roughness were increased from 304 nm to 330 nm.
formed during initial reflow process at the interface between TiWN/Cu pad and solder grew by the succeeding reflow process, so the grains became coarse. A cellular-shaped
was observed at the interface between Ag-Pd conductor pad and solder. The diameters of the
grains ranged from about 0.1∼0.6
. And a needle-shaped was also observed at the inside of the solder.
Broadband Microstrip Patch Antenna Design
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 7~11
In this paper, the wideband microstrip patch antennas for the Personal communications Service (PCS : 1750∼1870 MHz) and International Mobile Telecommunications-2000 (IMT-2000 : 1920∼2170 MHz) dual band are studied. Experimental and simulation results on the dual band antenna are presented. Simulation results are in good agreement with measurements. The experimental and simulation results confirm the wideband characteristics of the antenna. The studied antenna satisfied the wideband characteristics that are required characteristics for above 420 MHz impedance bandwidth for the PCS and IMT-2000 dual band antenna. In this paper, through the designing of a dual band antenna, we have presented the availability for PCS ＆ IMT-2000 base station antenna. An impedance bandwidth of 33% (VSWR<1.5, 650 GHz) and a maximum gain of 7dB can be achieved. The radiation pattern is stable across the passband.
Design of Wideband Microstrip Antenna using Multi-dimensional Pattern Technology
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 13~19
This paper demonstrates the detailed study of a microstrip Yagi-Uda antenna with and without PBG structure at wireless LAN(5725∼5825 MHz) frequency band. The impedance bandwidth of the antenna with the PBG holes is greater than (about 30 MHz) that of its counter part without PBG holes. The measured gains of the antenna at the frequency band are 7 dB and 6 dB respectively for antenna with and without PBG. The improvement of gain of about 1 dB is likely due to the suppression of surface wave.
Formation of Fine Pitch Solder Bumps on Polytetrafluoroethylene Printed Circuit Board using Dry Film Photoresist
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 21~28
We have demonstrated the applicability of dry film photoresist (DFR) in photolithography process for fine pitch solder bumping on the polytetrafluoroethylene (PTFE/Teflon ) printed circuit board (PCB). The copper lines were formed with 100
width and 18
thickness on the PTFE test board, and varying the gaps between two copper lines in a range of 100-200
. The DFRs of 15
thickness were laminated by hot roll laminator, by varying laminating temperature from
and laminating speed from 0.28-0.98cm/s. We have found the optimum process of DFR lamination on PTFE PCB and accomplished the formation of indium solder bumps. The optimum lamination condition was temperature of
and speed of about 0.63cm/s. And the smallest size of indium solder bump was diameter of 50
with pitch of 100
Flexible and Embedded Packaging of Thinned Silicon Chip
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 29~36
A flexible packaging scheme, which includes chip packaging, has been developed using a thinned silicon chip. Mechanical characteristics of thinned silicon chips are examined by bending tests and finite element analysis. Thinned silicon chips (t<30
) are fabricated by chemical etching process to avoid possible surface damages on them. And the chips are stacked directly on
film by thermal compressive bonding. The low height difference between the thinned silicon chip and
film allows electroplating for electrical interconnection method. Because the 'Chip' is embedded in the flexible substrate, higher packaging density and wearability can be achieved by maximized usable packaging area.
Effect of Annealing Conditions on Properties of Ni-Cr Thin Film Resistor
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 37~42
In the electronic components and devices fabrication, thin film resistors with low TCR (temperature coefficient of resistance) and high precision have been used over 3 ㎓ microwave in recent years. Ni-Cr alloys thin films resistors is one of the most commonly used resistive materials because they have low TCR and highly stable resistance. In this work, we fabricated thin film resistors using Evanohm alloys target(72Ni-20Cr-3Al-4Mn-Si) of S-type with excellent resistors properties by RF-sputtering. Also we reported the best annealing condition of thin film resistors for microwave to observe microstructure and electronic properties of thin film according to annealing conditions(
Mechanical Tenacity Analysis of Moisture Barrier Bags for Semiconductor Packages
Kim, Keun-Soo ; Kim, Tae-Seong ; Min Yoo ; Yoo, Hee-Yeoul ;
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 43~47
We have been using Moisture Barrier Bags for dry packing of semiconductor packages to prevent moisture from absorbing during shipping. Moisture barrier bag material is required to be waterproof, vapor proof and offer superior ESD (Electro-static discharge) and EMI shielding. Also, the bag should be formed easily to the shape of products for vacuum packing while providing excellent puncture resistance and offer very low gas ＆ moisture permeation. There are some problems like pinholes and punctured bags after sealing and before the surface mount process. This failure may easily result in package pop corn crack during board mounting. The bags should be developed to meet the requirements of excellent electrical and physical properties by means of optimization of their raw material composition and their thickness. This study investigates the performance of moisture barrier bags by characterization of their mechanical endurance, tensile strength and through thermal analysis. By this study, we arrived at a robust material composition (polyester/Aluminate) for better packing.
Resistive Polymeric Humidity Sensor Fabricated with Ink-Jet Printing Technique
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 49~57
The modified polyionene polyelectrolyte inks were newly prepared and applied to the humidity-sensitive membrane of humidity sensor. The films were fabricated on the alumina substrate with comb-type gold electrode using a ink-jet printing technique. The copolymers of methyl methacrylate, acrylic acid, 2-hydroxyethyl methacrylate and [(2-methacryloyloxy)ethyl]trimethylammonium chloride were also prepared for the humidity-sensing material. which was fabricated by dip-coating method. Electrical measurements under various relative humidity were performed. The humidity-sensitive characteristics of sensors obtained by ink-jet printing technique were compared with that of dip-coating method. Humidity sensors showed a decrease in resistance as an increase of relative humidity and their resistance characteristics are in a close agreement each other.
The Characteristic of Prepared Electrode Catalyst and MEA using CNF and CNT
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 59~64
The performance of fuel cell electrode depends on the characteristics of the catalyst support material. This paper deals with the use of CNF(carbon nanofibre) and CNT(carbon nanotube) as platinum catalyst support. The CNF and CNT were synthesized with catalyst treated by mechanochemical process and were prepared by chemical vapor deposition (CVD) method. The platinum supported on CNF and CNT for polymer electrolyte membrane fuel cell (PEMFC) application. In result, the best I-V characteristic was verified by the prepared MEA(membrane electrode assembly) from twisted CNF that had a diameter of 65 nm.
High Performance Electrode of Polymer Electrolyte Membrane Fuel Cells Prepared by Direct Screen Printing Process
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 65~69
Screen printing it one of the most popular methods for the fabrication of catalytic layer in electrode of polymer electrolyte membrane fuel cells (PEMFCs) due to its convenience and adaptability. This paper suggests an improved screen-printing method, which is rather simple suppressing the swelling trouble without additive process and competitive with very low Pt loading in comparison with the previous methods. Particularly, the gasket unified MEA made better performances than the other especially at high current area due to blocking effect on the gas leakage during the operation. These methods give us more simplified and faster fabrication chances.
Embedded Combline Band-Pass Filter using LTCC Technology
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 71~76
A compact embedded tapped-line combline filter with interdigital capacitors using low temperature co-fired ceramic (LTCC) technology for wireless application is proposed. Also, in-situ measurement using T-pattern microstrip resonator was performed to acquire exact knowledge of electrical properties of the LTCC substrate. The proposed filter makes it possible to realize a relatively small size, 2.7mm
2.03mm. by employing interdigital and combline structure. It shows 1.8 ㏈ insertion loss, 37.6㏈ return loss, and 280 MHz bandwidth at the center frequency of 5.09 GHz. Its small size and simple structure make it a good candidate as an integrated filter for various LTCC substrates.
Fluxless Plasma Soldering of Pb-free Solders on Si-wafer -Effect of Plasma Cleaning -
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 77~85
To evaluate the effect of plasma cleaning on the soldering reliability the plasma cleaning using Ar-10vol%
gas was applied on a UBM(Under Bump Metallization). The UBM consisted of Au/ Cu/ Ni/ Al layers which were deposited on a Si-wafer with 20 nm/ 4
thickness respectively. Sn-3.5%Ag, Sn-3.5%Ag-0.7%Cu and Sn-37%Pb solder balls sized of 500
in diameter were used. Solder balls on the UBM were plasma reflowed under Ar-10%
plasma (with or without plasma cleaning). They were compared with air reflowed solder balls with flux. The spreading ratios of plasma reflowed solder with plasma cleaning was 20-40% higher than that of plasma reflowed solder without plasma cleaning. The shear strength of plasma reflowed solder with plasma cleaning was about 58-65MPa. It showed 60-80% higher than that of plasma reflowed solder without plasma cleaning and 15-35% higher than that of air reflowed solder. Thus it was believed that plasma cleaning for the UBM using Ar-10vol%
gas was considerably effective for the improvement of the strength of solder ball.
Comparison of Experimental Values and Theoretical Predictions of the Dielectric Constant of Epoxy/BaTiO
Composite Embedded Capacitor Films
Journal of the Microelectronics and Packaging Society, volume 11, issue 1, 2004, Pages 87~96
Polymer/ceramic composites are the most promising embedded capacitor material for organic substrates application. Predicting the effective dielectric constant of polymer/ceramic composites is very important for design of composite materials. In this paper, we measured the dielectric constant of epoxy/
composite embedded capacitor films with various
particles loading for 5 different sizes
powders. Experimental data were fitted to several theoretical equations to find the equation useful for the prediction of the effective dielectric constant of polymer/ceramic composites and also to estimate the dielectric constant of
powders. The Lichtenecker equation and the Jayasundere-Smith equation were useful for the prediction of the effective dielectric constant of epoxy/
composites. And calculated dielectric constants of the
powders were in the range of 100 to 600, which were lower than those of