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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 14, Issue 4 - Dec 2007
Volume 14, Issue 3 - Sep 2007
Volume 14, Issue 2 - Jun 2007
Volume 14, Issue 1 - Mar 2007
Selecting the target year
A Viscoelasitc Finite Element Analysis of Thermal Nanoimprint Lithography Process
Kim, Nam-Woong ; Kim, Kug-Weon ; Sin, Hyo-Chol ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 1~7
Nanoimprint lithography (NIL) is an emerging technology enabling cost-effective and high-throughput nanofabrication. To successfully imprint a nano-sized pattern, the process conditions such as temperature, pressure, and time should be appropriately selected. This starts with a clear understanding of polymer material behavior during the NIL process. In this work, the squeezing of thin polymer films into nanocavities during the thermal NIL has been investigated based upon a two-dimensional viscoelastic finite element analysis in order to understand how the process conditions affect a pattern quality. The simulations have been performed within the viscoelastic plateau region and the stress relaxation effect has been taken into account.
Characteristics of Reliability for Flip Chip Package with Non-conductive paste
Noh, Bo-In ; Lee, Jong-Bum ; Won, Sung-Ho ; Jung, Seung-Boo ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 9~14
In this study, the thermal reliability on flip chip package with non-conductive pastes (NCPs) was evaluated under accelerated conditions. As the number of thermal shock cycle and the dwell time of temperature and humidity condition increased, the electrical resistance of the flip chip package with NCPs increased. These phenomenon was occurred by the crack between Au bump and Au bump and the delamination between chip or substrate and NCPs during the thermal shock and temperature and humidity tests. And the variation of electrical resistance during temperature and humidity test was larger than that during thermal shock test. Therefore it was identified that the flip chip package with NCPs was sensitive to environment with moisture.
Effect of Thermal Aging on the Intermetallic compound Growth kinetics in the Cu pillar bump
Lim, Gi-Tae ; Lee, Jang-Hee ; Kim, Byoung-Joon ; Lee, Ki-Wook ; Lee, Min-Jae ; Joo, Young-Chang ; Park, Young-Bae ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 15~20
Growth kinetics of intermetallic compound (IMC) at various interface in Cu pillar bump during aging have been studied by thermal aging at 120, 150 and
for 300h. In result,
were observed in the Cu pillar/SnPb interface and IMC growth followed parabolic law with increasing aging temperatures and time. Also, growth kinetics of IMC layer was faster for higher aging temperature with time. Kirkendall void formed at interface between Cu pillar and
as well as within the
layer and propagated with increasing time.
formed at interface between SnPb and Ni(P) after reflow and thickness change of
didn't observe with aging time. The apparent activation energies for growth of total
intermetallics from measurement of the IMC thickness with thermal aging temperature and time were 1.53, 1.84 and 0.81 eV, respectively.
Study on Characteristics of Sn-0.7wt%Cu-Xwt%Re Solder
Noh, Bo-In ; Won, Sung-Ho ; Jung, Seung-Boo ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 21~25
In this study, the properties of Sn-0.7wt%Cu-Xwt%Re(X=
) older were investigated by using DSC(differential scanning calorimetry), wetting balance, victors hardness and tensile testers. The melting temperature of solder was increased with increasing the contents of rare earth element, and the melting temperature range of Sn-0.7Cu-(
)Re solder was
. The wettability with Sn-0.7Cu-0.1Re solder was higher than that of Sn-0.7Cu-0.01Re and Sn-0.7Cu-1.0Re solders, and the wettability of Sn-0.7Cu-0.1Re solder was higher than that of Sn-0.7wt%Cu-0.01w%P solder. Also, the hardness and tensile strength of solder were increased with increasing the contents of rare earth element.
A Study of the Interfacial Reactions between Various Sn-Ag-Cu Solder Balls and ENIG (Electroless Ni Immersion Gold) and Cu-OSP (Organic Solderability Preservative) Metal Pad Finish
Park, Yong-Sung ; Kwon, Yong-Min ; Son, Ho-Young ; Moon, Jeong-Tak ; Jeong, Byung-Wook ; Kang, Kyung-In ; Paik, Kyung-Wook ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 27~36
In this study, we investigated the interfacial reactions between various Sn-Ag-Cu(SAC) solder alloys and ENIG(Electroless Ni Immersion Gold) and Cu-OSP(Organic Solderability Preservative) pad finish. In the case of the interfacial reaction between Sb added SAC solder and ENlf thinner P-rich Ni layer was formed at the interface. In the case of the interfacial reaction between Ni added SAC solder and Cu-OSP, the uniform
, intermetallic compounds(IMCs) were formed and
grain did not grow after multiple reflows. Thinner
IMCs were farmed at the interface between
and Cu-OSP after
The Properties of Hole Injection and Transport Layers on Polymer Light Emitting Diode
Shin, Sang-Baie ; Chang, Ho-Jung ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 37~42
We fabricated the polymer light emitting diodes (PLEDs) with ITO/PEDOT:PSS/PVK/PFO:MEH-PPV/LiF/Al structures. The effect of the thickness of PEDOT:PSS hole injection layer(HIL) on the electrical and optical properties of PLEDs was investigated. In addition, PVK hole transport layer(HTL) was introduced in the PLED device, and compared the properties of the PLEDS with and without PVX layer. All organic film layers were prepared by the spin coating method on the plasma treated ITO/glass substrates. As the thickness of PEDOT:PSS film layer decreased from about 80 nm to 50 nm, the luminance of PLED device increased from
. This may be ascribed to the increased transportation efficiency of the holes into the emission layer of PLED. The maximum current density and luminance were obtained fir the PLED device with PVX hole transport layer, showing that the current density and luminance were
at 12V, respectively. This values were improved by about 14% and 22% in current density and luminance compared with the PLED device without PVK layer.
A Study of Post Electrode Formation by Microwave Sintering in LTCC Substrate
Kim, Yong-Suk ; Lee, Taek-Jung ; Yoo, Won-Hee ; Chang, Byeung-Gyu ; Park, Sung-Yeol ; Oh, Yong-Soo ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 43~48
This study is focused on the effect of the surface properties for the post electrode, which is used in pad formation consisted of SMT such as IC, passive component, combined with fired LTCC substrate, We carried out the surface microstructure of sintered electrode and the basic reliability evaluations with sample fired by microwave sintering to solve the problems occurred in post electrode by electric sintering. We evaluated surface densification status of post electrode according to various conditions of microwave sintering. In additions, it is obtained strong effect on blister improvement of post electrode because of over-sintering and the insufficient out gas in bum out process. As a result of adhesion strength, we confirmed
in microwave sintering and
in electric sintering, respectively. This result will be used for the basic reliability test. Finally, microwave sintering seems to be economic in process time with 30 min compared to electric sintering with 10 hr. In terms of Mass production and efficiency, microwave sintering are excepted to be higher than electric sintering.
Interfacial Adhesion between Electroless Plated Ni Film and Polyimide by Post-baking Treatment Conditions
Min, Kyoung-Jin ; Park, Sung-Cheol ; Lee, Jee-Jeong ; Lee, Kyu-Hwan ; Lee, Gun-Hwan ; Park, Young-Bae ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 49~56
Effects of post-baking treatment conditions on the interfacial adhesion between electroless plated Ni and polyimide film were evaluated using
peel test. Measured peel strength values monotonically decrease from
for the variations of post-baking treatment temperatures from
, respectively. Wet chemical treatment on the polyimide surface produces carboxyl and amide functional groups on the surface which is closely related to the change in interfacial adhesion between electroless Ni and polyimide films. It is speculated that interfacial adhesion seems to be controlled by carbonyl oxygen bonding near cohesive failure region during post-baking treatment.
Characterization of a Micro Power Generator using a Fabricated Square Coil of 4 Layers and Nd Magnet
Lee, Dong-Ho ; Kim, Seong-Il ; Lee, Yoon-Pyo ; Chang, Young-Soo ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 57~61
We designed and fabricated square coils of 4 layered structure on a PCB board. The size of the coils were
. The line width of the fabricated coils was
. By reciprocating a magnet on the surface of a fabricated square coil which is composed of 4 layers, an alternating output voltage was obtained. We changed the vibrational frequency from 0.5 to 7 Hz. The generated voltages were 62 mV at
and 245 mV at
when 5.5 Hz frequency. We rectified and stepped up the output voltage using a quadrupler circuit and
coil. Before using the step up circuit, the measured voltage was 320 mV at 7 Hz. After using the step up circuit, the measured voltage was 400 mV at 7 Hz.
Interconnection Processes Using Cu Vias for MEMS Sensor Packages
Park, S.H. ; Oh, T.S. ; Eum, Y.S. ; Moon, J.T. ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 63~69
We investigated interconnection processes using Cu vias for MEMS sensor packages. Ag paste layer was formed on a glass substrate and used as a seed layer for electrodeposition of Cu vias after bonding a Si substrate with through-via holes. With applying electrodeposition current densities of
at direct current mode to the Ag paste seed-layer, Cu vias of
depth were formed successfully without electrodeposition defects. Interconnection processes for MEMS sensor packages could be accomplished with Ti/Cu/Ti line formation, Au pad electrodeposition, Sn solder electrodeposition and reflow process on the Si substrate where Cu vias were formed by Cu electrodeposition into through-via holes.
Effect of Reflow Number on Mechanical and Electrical Properties of Ball Grid Array (BGA) Solder Joints
Koo, Ja-Myeong ; Lee, Chang-Yong ; Jung, Seung-Boo ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 71~77
In this study, the mechanical and electrical properties of three different ball grid array (BGA) solder joints, consisting of Sn-37Pb, Sn-3.5Ag and Sn-3.5Ag-0.75Cu (all wt.%), with organic solderability preservative (OSP)-finished Cu pads were investigated as a function of reflow number. Based on scanning electron microscopy (SEM) analysis results, a continuous
, intermetallic compound (IMC) layer was formed at the solder/substrate interface, which grew with increasing reflow number. The ball shear testing results showed that the shear force peaked after 3 reflows (in case of Sn-Ag solder, 4 reflows), and then decreased with increasing reflow number. The electrical property of the joint gradually decreased with increasing reflow number.
Ultrasonic Bonding of Au Stud Flip Chip Bump on Flexible Printed Circuit Board
Koo, Ja-Myeong ; Kim, Yu-Na ; Lee, Jong-Bum ; Kim, Jong-Woong ; Ha, Sang-Su ; Won, Sung-Ho ; Suh, Su-Jeong ; Shin, Mi-Seon ; Cheon, Pyoung-Woo ; Lee, Jong-Jin ; Jung, Seung-Boo ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 79~85
This study was focused on the feasibility of ultrasonic bonding of Au stud flip chip bumps on the flexible printed circuit board (FPCB) with three different surface finishes: organic solderability preservative (OSP), electroplated Au and electroless Ni/immersion Au (ENIG). The Au stud flip chip bumps were successfully bonded to the bonding pads of the FPCBs, irrespective of surface finish. The bonding time strongly affected the joint integrity. The shear force increased with increasing bonding time, but the 'bridge' problem between bumps occurred at a bonding time over 2 s. The optimum condition was the ultrasonic bonding on the OSP-finished FPCB for 0.5 s.
Fabrication of Red LED with Mn activated
phosphors on InGaN UV bare chip
Kang, Hyun-Goo ; Park, Joung-Kyu ; Kim, Chang-Hae ; Choi, Seung-Chul ;
Journal of the Microelectronics and Packaging Society, volume 14, issue 4, 2007, Pages 87~92
red phosphor showed the highest emission intensity at a concentration of 0.02mole
and the high crystallinity and luminescent properties were obtained at
firing temperature for 3hr. The synthesized phosphor showed a broad emission band at 658nm wavelength. Red light-emitting diodes(LEDs) were fabricated through the integration of on InGaN UV bare chip and a 1:3 ratio of
and epoxy resin in a single package. This coated LED can be applicable to make White LEDs under excitation energy of UV LED.