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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Microelectronics and Packaging Society
Journal Basic Information
Journal DOI :
The Korean Microelectronics and Packaging Society
Editor in Chief :
Volume & Issues
Volume 10, Issue 4 - Dec 2003
Volume 10, Issue 3 - Sep 2003
Volume 10, Issue 2 - Jun 2003
Volume 10, Issue 1 - Mar 2003
Selecting the target year
Non-linear Temperature Dependent Deformation Anaysis of CBGA Package Assembly Using Moir′e Interferometry
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 1~8
Thermo-mechanical behavior of a ceramic ball grid array (CBGA) package assembly are characterized by high sensitive moire interferometry. Moir fringe patterns are recorded and analyzed at various temperatures in a temperature cycle. Thermal-history dependent analyses of global and local deformations are presented, and bending deformation (warpage) of the package and shear strain in the rightmost solder ball are discussed. A significant non-linear global behavior is documented due to stress relaxation at high temperature. Analysis of the solder interconnections reveals that inelastic deformation accumulates on only eutectic solder fillet region at high temperatures.
Bipolar Integrated Optical Link Receiver with Low Supply Voltage
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 9~14
The new optical link receiver with data transfer rate higher than 10Mbps at the supply voltage of 1.8V was designed and fabricated using bipolar technology. The fabricated IC showed the dissipation current of 4.6mA under high level input voltage of 1.5V. The high level output voltage(
) and the low level output voltage(
) were 1.15V and 0V, respectively, for a given 10 Mbps signal which has duty ratio of 50%,
(low level input voltage) of 0.5V, and
(high level input voltage) of 1.5V, The duty ratio of output waveform was 52.6%. The rising time(t
) and the falling time(t
) were 9.5ns and 6.8ns, respectively. The propagation delay difference(
) and the jitter(
) were 11.7ns and 4.3ns, respectively.y.
Flying State Analysis of Head Slider with Ultra-Thin Spacing
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 15~20
A method that predicts the flying state of the head slider in an optical disk drive (ODD) or a hard disk drive(HDD) was investigated. The dual solver based on the Newton method and the quasi-Newton method have been developed to simulate the steady-state flying conditions. The numerical results show the effectiveness and reliability of this new solver.
Capacitive Humidity Sensor Using Reactive Methacrylate Copolymers
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 21~27
The copolymers with various composition of methyl methacrylate (MMA), ethyl methacrylate (EMA), methacrylic acid (MA) and hydroxyethyl methacrylate (HEMA) were synthesized for capacitive humidity sensitive materials. The capacitive humidity sensor consisted of a polymethacrylate film coated on both sides with gold electrode. Capacitance versus relative humidity increased with HEMA content in the copolymer. In the case of self-crosslinkable MMA/MA/HEHA= 40/10/10, the average capacitance at 30%RH, 60%RH and 90%RH are 102, 134 and 166 pF, respectively. And also, the hysteresis, temperature cycle and long-term stability were evaluated as a capacitance humidity sensor.
Copper Ohmic Contact on n-type SiC Semiconductor
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 29~33
Material and electrical properties of copper-based ohmic contacts on n-type 4H-SiC were investigated for the effects of the post-annealing and the metal covering conditions. The ohmic contacts were prepared by sequential sputtering of Cu and Si layers on SiC substrate. The post-annealing treatment was performed using RTP (rapid thermal process) in vacuum and reduction ambient. The specific contact resistivity (
), sheet resistance (
), contact resistance (
), transfer length (
), were calculated from resistance (RT) versus contact spacing (d) measurements obtained from TLM (transmission line method) structure. The best result of the specific contact resistivity was obtained for the sample annealed in the reduction ambient as
. The material properties of the copper contacts were also examined by using XRD. The results showed that copper silicide was formed on SiC as a result of intermixing Cu and Si layer.
Properties of Organic Light Emitting Diode with ITO/MEH-PPV/Al Structure on Heating Temperatures
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 35~38
Polymer light emitting diode (PLED) with an ITO/MEH-PPV/Al structure were prepared by spin coating method on the ITO (indium tin oxide)/glass substrates, using poly(2-methoxy-5-(2-ethylhexoxy)-1,4-phenylenevinylene (MEH-PPV) as the light emitting material. The dependence of heat treatment on the electrical and optical properties for the prepared PLED samples were investigated. The luminance decreased greatly from 630 cd/
to 280 cd/
at 10V input voltage as the heating temperature increased from
. In addition, the luminance efficiency was found to be about 2 lm/W for the sample heat treated at
. These results may be related to the interface roughness and/or the formation of an insulation layer, which is caused by the reaction between electrode and MEH-PPV organic luminescent film layer.
Formation of Sn-Cu Solder Bump by Electroplating for Flip Chip
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 39~46
Sn-Cu eutectic solder bump was fabricated by electroplating for flip chip and its characteristics were studied. A Si-wafer was used as a substrate and the UBM(Under Bump Metallization) of Al(400 nm)/Cu(300 nm)/Ni(400 nm)/Au(20 nm) was coated sequentially from the substrate to the top by an electron beam evaporator. The experimental results showed that the plating ratio of the Sn-Cu increased from 0.25 to 2.7
/min with the current density of 1 to 8 A/d
. In this range of current density the plated Sn-Cu maintains its composition nearly constant level as Sn-0.9∼1.4 wt%/Cu. The solder bump of typical mushroom shape with its stem diameter of 120
was formed through plating at 5 A/d
for 2 hrs. The mushroom bump changed its shape to the spherical type of 140
diameter by air reflow at
. The homogeneity of chemical composition for the solder bump was examined, and Sn content in the mushroom bump appears to be uneven. However, the Sn distributed more uniformly through an air reflow.
Preparation and Characterization of Bi based frit for Ag Electrode in PDP Application
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 47~52
A new type of Bi based glass frit was developed for Ag paste in PDP applications and its properties are compared with the commercially used Pb based glass frit. After optimization of the properties of Bi based frits for PDP application such as the softening temperature and the coefficient of thermal expansion (C.T.E), the screen printed electrodes prepared with the Bi based fit contained Ag paste were characterized. In
glass system with the more than 50% of
, the softening temperature, the thermal expansion coefficient and the line resistivity was 400∼
> and 4.1∼4.8
respectively. Properties of the Bi based frits are comparable with the Pb based frits. A printability and an uniformity of the Bi based frits were excellent in screen printed Ag eletrode. The Bi based frit system is an excellent candidate material for Pb free and Alkali free frit in PDP applications.
DI water Nozzle Design for Effective Removal of the Particles Generated during Wafer-sawing
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 53~60
CCD(Charge-Coupled Device) wafers, with a layer of micro lenses on top, usually are not passivated with dielectric films. Micro lenses, in general, are made of polymer material, which usually has a large affinity for particles generated in the various chip fabrication processes, most notably the wafer sawing for chip-dicing. The particles deposited on the micro lens layer either seriously attenuate or deflect the incoming light and often lead to CCD failure. In this study we introduce new type of saws which would significantly reduce the particle-related problems found in conventional type of saws. In the new saws, the positions and diverging angles of side and center nozzles have been optimized so as to flush the particles effectively. In addition, an independent nozzle is added for the sole purpose of flushing the generated particles. The test results show that, with the new saws. the ratio of the particle-related CCD chip failures has been dropped drastically from 9.1% to 0.63%.
Determination of Stress Profiles by Fractography in Single Ion-exchanged Glass
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 61~64
The fractography was used to observe the stress profile on a single ion-exchanged glass. In the processing, the temperature was varied during the ion exchange, and then the stress profile on the single ion-exchanged glass was shifted from glass surface to slightly below the glass surface. The hackle mark and mirror surface were varied according to process conditions, and the glass strength was increased with increasing the number of hackle markers. In case of breaking the stress profile by using indenter, the breaking property was similar to the annealed glass.
Ultrasonic Spray Nozzle System with Piezoelectric Device for Chemicals Dispersion
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 65~71
A new type of ultrasonic spray nozzle was fabricated employing a piezoelectric device. The spray nozzle was designed to disperse chemicals in a water treatment mixing tank. The piezoelectric properties in ultrasonic spray nozzles were optimized to improve the dispersion of chemicals. The piezoelectrics were packaged in an aluminum case with silicone resin for the aqueous solution proof packaging. Chemicals were dispersed with high efficiency and the chemicals consumption was reduced by the ultrasonic fine particle spraying. The concentration of Escherichia coli in mixing tank was decreased remarkably using ultrasonic spray nozzle dispersion compared to the conventional methods.
The Effect of Electroplating Parameters on the Compositions and Morphologies of Sn-Ag Bumps
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 73~79
With the variation of Ag concentration in bath, current density, duty cycle, additive and agitation for electroplating of Sn-Ag solder, the compositions and the morphologies of solder were studied. It was possible to controll Ag content in Sn-Ag solder by varying Ag concentration in bath and current density. The microstructure size of Sn-Ag solder decreased with increasing current density. Duty cycle of pulse electroplating and quantity of additive affected on Ag content of deposit and surface roughness. In this work eutectic Sn-Ag solder bumps with fine pitch of 30
and height of 15
was formed successfully. The Ag content of electrodeposited solder was confirmed by EDS and WDS analyses and the surface morphologies was analyzed by SEM and 3D surface analyzer.
Electromigration of Sn-3.5 Solder Bumps in Flip Chip Package
Journal of the Microelectronics and Packaging Society, volume 10, issue 4, 2003, Pages 81~86
Electromigration of Sn-3.5Ag solder bump was investigated using flip chip specimens which consisted of upper Si chip and lower Si substrate. While the resistance of the flip chip sample did not almost change until the time right before the failure, the resistivity increased abruptly at the moment when complete failure of the solder joint occurred in the flip chip sample. At current densities of
, the activation energy for electromigration of the Sn-3.5Ag solder bump was characterized as ∼0.7 eV. Failure of the Sn-3.5Ag solder bump occurred at the solder/UBM interface due to the formation and propagation of voids at cathode side of the solder bump.