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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
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Volume & Issues
Volume 22, Issue 4 - Dec 2015
Volume 22, Issue 3 - Sep 2015
Volume 22, Issue 2 - Jun 2015
Volume 22, Issue 1 - Mar 2015
Selecting the target year
Aluminium Based Brazing Fillers for High Temperature Electronic Packaging Applications
Sharma, Ashutosh ; Jung, Jae-Pil ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 1~5
DOI : 10.6117/kmeps.2015.22.4.001
In high temperature aircraft electronics, aluminium based brazing filler is the prime choice today. Aluminium and its alloys have compatible properties like weight minimization, thermal conductivity, heat dissipation, high temperature precipitation hardening etc. suitable for the aerospace industry. However, the selection of brazing filler for high temperature electronics requires high temperature joint strength properties which is crucial for the aerospace. Thus the selection of proper brazing alloy material, the composition and brazing method play an important role in deciding the final reliability of aircraft electronic components. The composition of these aluminium alloys dependent on the addition of the various elements in the aluminium matrix. The complex shapes of aluminium structures like enclosures, heat dissipaters, chassis for electronic circuitry, in avionics are designed from numerous individual components and joined thereafter. In various aircraft applications, the poor strength caused by the casting and shrinkage defects is undesirable. In this report the effect of various additional elements on Al based alloys and brazing fillers have been discussed.
Cu Electroplating and Low Alpha Solder Bumping on TSV for 3-D Packaging
Jung, Do hyun ; Kumar, Santosh ; Jung, Jae pil ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 7~14
DOI : 10.6117/kmeps.2015.22.4.007
Research and application of three dimensional packaging technology in electronics have been increasing according to the trend of high density, high capacity and light weight in electronics. In this paper, TSV fabrication and research trend in three dimensional packaging are reported. Low alpha solder bumping which can solve the soft error problem in electronics is also introduced. In detail, this paper includes fabrication of TSV, functional layers deposition, Cu filling in TSV by electroplating using PPR (periodic pulse reverse) and 3 step PPR processes, and low alpha solder bumping on TSV by solder ball. TSV and low alpha solder bumping technologies need more studies and improvements, and the drawbacks of three dimensional packaging can be solved gradually through continuous attentions and researches.
A Review of Ag Paste Bonding for Automotive Power Device Packaging
Roh, Myong-Hoon ; Nishikawa, Hiroshi ; Jung, Jae-Pil ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 15~23
DOI : 10.6117/kmeps.2015.22.4.015
Lead-free bonding has attracted significant attention for automotive power device packaging due to the upcoming environmental regulations. Silver (Ag) is one of the prime candidates for alternative of high Pb soldering owing to its superior electrical and thermal conductivity, low temperature sinterability, and high melting temperature after bonding. In this paper, the bonding technology by Ag paste was introduced. We classified into two Ag paste bonding according to applied pressure, and each bonding described in detail including recent studies.
PLC Devices Fabricated on Flexible Plastic Substrate by Roll-to-Roll Imprint Lithography
Kang, Ho Ju ; Kim, Taehoon ; Jeong, Myung Yung ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 25~29
DOI : 10.6117/kmeps.2015.22.4.025
Demand for a low-cost, high-throughput, and high-resolution patterning method for fabricating devices continues to increase. The roll-to-roll (R2R) imprint lithography technique has received a great deal of attention as a means of fabricating next-generation devices. In this paper, we propose a fabrication method for polymeric planar lightwave circuit (PLC) devices that uses R2R imprint lithography. The proposed technique uses an elastomeric polydimethylsiloxane (PDMS) mold. A Si wafer with micro patterns is used as the Si master. The PDMS mold is then replicated from the Si master. By applying a precise web tension and at a given web speed, we fabricated a micro-patterned PLC device. The insertion losses were 4.0 dB for a
optical splitter. As such, the proposed method of fabricating a PLC device by the R2R process was shown to be an effective solution.
Study of On-chip Liquid Cooling in Relation to Micro-channel Design
Won, Yonghyun ; Kim, Sungdong ; Kim, Sarah Eunkyung ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 31~36
DOI : 10.6117/kmeps.2015.22.4.031
The demand for multi-functionality, high density, high performance, and miniaturization of IC devices has caused the technology paradigm shift for electronic packaging. So, thermal management of new packaged chips becomes a bottleneck for the performance of next generation devices. Among various thermal solutions such as heat sink, heat spreader, TIM, thermoelectric cooler, etc. on-chip liquid cooling module was investigated in this study. Micro-channel was fabricated on Si wafer using a deep reactive ion etching, and 3 different micro-channel designs (straight MC, serpentine MC, zigzag MC) were formed to evalute the effectiveness of liquid cooling. At the heating temperature of
and coolant flow rate of 150ml/min, straight MC showed the high temperature differential of
after liquid cooling. The shape of liquid flowing through micro-channel was observed by fluorescence microscope, and the temperarue differential of liquid cooling module was measuremd by IR microscope.
A Study on Heat Transfer Characteristics of PCBs with a Carbon CCL
Cho, Seunghyun ; Jang, Junyoung ; Kim, Jeong-Cheol ; Kang, Suk Won ; Seong, Il ; Bae, Kyung Yun ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 37~46
DOI : 10.6117/kmeps.2015.22.4.037
In this paper, the heat transfer characteristics of PCB (Printed Circuit Board) with cabon CCL (Copper Claded Layer) were studied through experiments and numerical analysis to compare of PCBs with conventional the FR-4 core and heavy copper cores. For study, samples are producted with HDI (High Density Interconnection) PCB of mobile phone with variations of thickness of core materials and grades of carbon material to evaluate heat transfer characteristics respectively. From this research results, heat transfer characteristics of the carbon core was rather low than heavy copper, but better than FR-4 core. In addition, even though the carbon and heavy copper core contributed on the heat transfer characteristics as their thickness increases, FR-4 cores disturbed heat transfer characteristics as it`s thickness increases. Therefore, carbon core is recommendable to improve the heat transfer characteristics of the PCB because heavy copper core has much disadvantages such as increasing of wear of drill, the weight of PCB, and manufacturing cost by additional insulation materials for electrical insulation.
A Study on Thermal Behavior and Reliability Characteristics of PCBs with a Carbon CCL
Cho, Seunghyun ; Kim, Jeong-Cheol ; Kang, Suk Won ; Seong, Il ; Bae, Kyung Yun ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 47~56
DOI : 10.6117/kmeps.2015.22.4.047
In this paper, the Thermal behavior and reliability characteristics of carbon CCL (Copper Claded Layer), which can be used as the core of HDI (High Density Interconnection) PCB (Printed Circuit Board) are evaluated through experiments and numerical analysis using CAE (Computer Aided Engineering) software. For the characterization of the carbon CCL, it is compared with the conventional FR-4 core and Heavy Cu core. From research results, the deformation amount of the flexure strength of PCB is the highest with pitch grade carbon and thermal behavior of PCB is lowest as temperature increases. In addition, TC (Thermal Cycling), LLTS (Liquid-to-Liquid Thermal Shock) and Humidity tests have been applied in the PCB with carbon core and the reliability of PCB with carbon core is confirmed through reliability tests. Also, possibility of uneven surface of the via hole and wear of the drill bit due to the carbon fibers are analyzed. surface of the via hole is uniform, the surface of the drill bit is smooth. Therefore, it is proved that the carbon CCL has the drilling workability of the same level as conventional core material.
A Method for Application of Ammonium-based Pretreatment Solution in Preparation of Copper Flakes Coated by Electroless Ag Plating
Kim, Ji Hwan ; Lee, Jong-Hyun ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 57~63
DOI : 10.6117/kmeps.2015.22.4.057
In order to prepare a low-cost conductive filler material possessing improved anti-oxidation property, Ag-coated Cu flakes were fabricated and the effects of an applying method of ammonium-based pretreatment solution on the Cu flakes were analyzed. The pretreatment solution was used to remove the surface oxide layer on Cu flake. During a single-stage pretreatment process, hole-shaped defects were formed on the flake surface during the pretreatment after 2 min, and the number and size increased in proportion to the pretreatment time. In the case that Ag plating solution was injected in the pretreatment solution after the pretreatment for 2 min, the defects were also formed during Ag plating. In contrast, the defects tremendous decreased in the case that the pretreatment solution was removed after the first pretreatment for 2 min and the Ag plating proceeded after the second pretratment using a low concentration pretreatment solution. As the final result, the 15 wt% Ag-coated Cu flake sample which was fabricated using the single-stage pretreatment oxidized at
, but the sample fabricated by the double-stage pretreatment oxidized at
, indicating definitely improved anti-oxidation property.
Evaluation of Thermal Conductivity for Screen-Printed AlN Layer on Al Substrate in Thickness Direction
Kim, Jong-Gu ; Park, Hong-Seok ; Kim, Hyun ; Hahn, Byung-Dong ; Cho, Young-Rae ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 65~70
DOI : 10.6117/kmeps.2015.22.4.065
A study on thermal properties for a single-layer metal and two-layer composites was investigated for the heat-sink application. For the single-layer metal, an aluminum alloy (Al6061) was selected. A screen printed aluminum nitride (AlN) layer on the Al6061 substrate was chosen for the two-layer composites. The thermal conductivity of the sample was determined from the thermal diffusivity measured by the light flash analysis (LFA), specific heat and density. Measured thermal property values were compared to calculated values using the data from the references. The thermal conductivity of composites with screen printed AlN layer on the Al6061 substrate decreased linearly with increasing the thickness of AlN layer. Measured values of the thermal conductivity for composites with
thick AlN layers were
, respectively. In particular, the thermal conductivity of the screen-printed AlN layer was demonstrated by appling the rule of mixture in view point of thermal resistivity. Measured values of the thermal conductivity for AlN layers with the thickness of
Study on the Electrode Design for an Advanced Structure of Vertical LED
Park, Jun-Beom ; Park, Hyung-Jo ; Jeong, Tak ; Kang, Sung-Ju ; Ha, Jun-Seok ; Leem, See-Jong ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 71~76
DOI : 10.6117/kmeps.2015.22.4.071
Recently, light emitting diodes (LEDs) have been studied to improve their efficiencies for the uses in various fields. Particularly in the aspect of chip structure, via hole type vertical LED chip is developed for improvement of light output power, and heat dissipations. However, current vertical type LEDs have still drawback, which is current concentration around the n-contact holes. In this research, to solve this phenomenon, we introduced isolation layer under n-contact electrodes. With this sub-electrode, even though the active area was decreased by about 2.7% compared with conventional via-hole type vertical LED, we could decrease the forward voltage by 0.2 V and wall-plug efficiency was improved approximately 4.2%. This is owing to uniform current flow through the area of n-contact.
Sol-gel Modification on La
Cathode for Intermediate Temperature Solid Oxide Fuel Cell
Lee, Seung Jin ; Kang, Choon-Hyoung ; Chung, Chang-Bock ; Yun, Jeong Woo ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 77~82
DOI : 10.6117/kmeps.2015.22.4.077
To increase the performance of solid oxide fuel cell operating at intermediate temperature (
(SDC) thin layer was applied to the
(LSMCu) cathode by sol-gel coating method. The SDC was employed as a diffusion barrier layer on the yttria-stabilized zirconia(YSZ) to prevent the interlayer by-product formation of
. The by-products were hardly formed at the electrolyte-cathode interlayer resulting to reduce the cathode polarization resistance. Moreover, SDC thin film was coated on the cathode pore wall surface to extend the triple phase boundary (TPB) area.
Hybrid Fabrication of Screen-printed Pb(Zr,Ti)O
Thick Films Using a Sol-infiltration and Photosensitive Direct-patterning Technique
Lee, J.-H. ; Kim, T.S. ; Park, H.-H. ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 83~89
DOI : 10.6117/kmeps.2015.22.4.083
In this paper, we propose a fabrication technique for enhanced electrical properties of piezoelectric thick films with excellent patterning property using sol-infiltration and a direct-patterning process. To achieve the needs of high-density and direct-patterning at a low sintering temperature (<
), a photosensitive lead zirconate titanate (PZT) solution was infiltrated into a screen-printed thick film. The direct-patterned PZT films were clearly formed on a locally screen-printed thick film, using a photomask and UV light. Because UV light is scattered in the screen-printed thick film of a porous powder-based structure, there are needs to optimize the photosensitive PZT sol infiltration process for obtaining the enhanced properties of PZT thick film. By optimizing the concentration of the photosensitive PZT sol, UV irradiation time, and solvent developing time, the hybrid films prepared with 0.35 M of PZT sol, 4 min of UV irradiation and 15 sec solvent developing time, showed a very dense with a large grain size at a low sintering temperature of
. It also illustrated enhanced electrical properties (remnant polarization,
, and coercive field,
value was over four times higher than those of the screen-printed films. These films integrated on silicon wafer substrate could give a potential of applications in micro-sensors and -actuators.
Elastic Modulus of Locally Stiffness-variant Polydimethylsiloxane Substrates for Stretchable Electronic Packaging Applications
Oh, Hyun-Ah ; Park, Donghyeun ; Han, Kee-Sun ; Oh, Tae Sung ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 91~98
DOI : 10.6117/kmeps.2015.22.4.091
In order to apply to stretchable electronics packaging, locally stiffness-variant stretchable substrates consisting of island structure were fabricated by combining two polydimethylsiloxane elastomers of different stiffnesses and their elastic moduli were characterized as a function of the width of the high-stiffness island. The low-stiffness substrate matrix and the embedded high-stiffness island of the stretchable substrate were formed by using Dragon Skin 10 of the elastic modulus of 0.09 MPa and Sylgard 184 of the elastic modulus of 2.15 MPa, respectively. A stretchable substrate was fabricated to be a configuration of 6.5-cm length, 0.4-cm thickness, and 2.5-cm width, in which a high-stiffness Sylgard 184 island, of 4-cm length, 0.2-cm thickness, and 0.5~1.5-cm width, was embedded. The elastic modulus of a stretchable substrate was increased from 0.09 MPa to 0.16 MPa by incorporating the Sylgard 184 island of 0.5-cm width to Dragon Skin 10 substrate matrix. The elastic modulus was further improved to 0.18 MPa and 0.2 MPa with increasing the Sylgard 184 island width to 1.0 cm and 1.5 cm, which were in good agreement with values estimated by combining the Voigt structure of isostrain and the Reuss structure of isostress.
Study on the Relationship between Concentration of JGB and Current Density in TSV Copper filling
Jang, Se-Hyun ; Choi, Kwang-Seong ; Lee, Jae-Ho ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 99~104
DOI : 10.6117/kmeps.2015.22.4.099
The requirement for success of via filling is its ability to fill via holes completely without producing voids or seams. Defect free via filling was obtained by optimizing plating conditions such as current mode, current density and additives. However, byproducts stemming from the breakdown of these organic additives reduce the lifetime of the devices and plating solutions. In this study, the relationship between JGB and current density on the copper via filling was investigated without the addition of other additives to minimize the contamination of copper via. AR 4 with
diameter via were used for this study. The pulse current was used for the electroplating of copper and the current densities were varied from 10 to
and the concentrations of JGB were varied from 0 to 25 ppm. The map for the JGB concentration and current density was developed. And the optimum conditions for the AR 4 via filling with
diameter were obtained.
Analyses on Airbag Sensor Signals by Different Packaging
Kim, Yeong K. ; Kang, Hyun Jin ; Kim, Joon Ki ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 105~109
DOI : 10.6117/kmeps.2015.22.4.105
In this study, a new airbag sensor packaging technique of directly attachment by adhesive to the automobile frame is introduced. To assess the feasibility for the packaging, a test instrument was manufactured to examine the impact sensibility by drop tests. The conventional sensor module attached mechanically by bolts with plastic housing and the new sensor packaging were installed to aluminum channel, and the results were compared with each other. Numerical analysis was also performed to investigate the signal characteristics created by the sensors. The preliminary results showed that the pattern of the MEMS sensor signal was strongly dependent on the structural behavior of the frame where the sensors were installed, which indicated the complexity of the packaging design for proper airbag deployments.
Study on the Passivation of Si Surface by Incorporation of Nitrogen in Al
Thin Films Grown by Atomic Layer Deposition
Hong, Hee Kyeung ; Heo, Jaeyeong ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 111~115
DOI : 10.6117/kmeps.2015.22.4.111
To improve the efficiency of the Si solar cell, high minority carrier life time is required. Therefore, the passivation technology is important to eliminate point defects on the silicon surface, causing the loss of minority carrier recombination. PECVD or post-annealing of thermally-grown
is commonly used to form the passivation layer, but a high-temperature process and low thermal stability is a critical factor of low minority carrier lifetime. In this study, atomic layer deposition was used to grow the
passivation layer at low temperature process.
was selected as a passivation layer which has a low surface recombination velocity because of the fixed charge density. For the high charge density, an improved minority carrier lifetime, and a low surface recombination, nitrogen was doped in the
thin film and the improvement of passivation was studied.
Deformation Behavior of Locally Stiffness-variant Stretchable Substrates Consisting of the Island Structure
Oh, Hyun-Ah ; Park, Donghyeun ; Shin, Soo Jin ; Oh, Tae Sung ;
Journal of the Microelectronics and Packaging Society, volume 22, issue 4, 2015, Pages 117~123
DOI : 10.6117/kmeps.2015.22.4.117
In order to develop stretchable substrate technology for stretchable devices, locally stiffness-variant stretchable substrates were processed with two polydimethylsiloxane elastomers of different stiffnesses and their deformation behavior was characterized. Low-stiffness substrate matrix and embedded high-stiffness island of the stretchable substrate were formed by using Dragon Skin 10 of the elastic modulus of 0.09 MPa and Sylgard 184 of the elastic modulus of 2.15 MPa, respectively. A stretchable substrate was fabricated to a configuration of 6.5 cm length, 0.4 cm thickness, and 2.5 cm width. The elastic modulus of a stretchable substrate was increased from 0.09 MPa to 0.13~0.33 MPa by embedding a Sylgard 184 island of 1 cm width and 1~6 cm length into the center part of the Dragon Skin 10 substrate matrix. The elastic modulus of a stretchable substrate was improved to 0.16~0.2 MPa by embedding a Sylgard 184 island of 4 cm length and 0.5~1.5 cm width and to 0.1421~0.154 MPa by embedding a Sylgard 184 island of 2 cm length and 0.5~1.5 cm width. With increasing the tensile strain of a stretchable substrate, deformation restriction of the locally stiffness-variant Sylgard 184 island was further enhanced due to substantial increase in the strength difference between Sylgard 184 and Dragon 10 at large strain.