• 한국정보디스플레이학회:학술대회논문집
• /
• 2000.01a
• /
• pp.219-220
• /
• 2000

We propose a new method for the formation of an aluminum parting layer in the fabrication of field emitter arrays, in which we used a reflow property of aluminum at a lower temperature than the deformation point of glass. After the sputtered aluminum layer on the gate metal was etched for the formation of gate holes, we carried out a rapid thermal annealing process, by which the aluminum slightly diffused into the gate hole. This reflowed aluminum could be used as a parting layer and emitter arrays were easily fabricated using this method.

• Proceedings of the KIEE Conference
• /
• 1987.07a
• /
• pp.561-564
• /
• 1987

The deposition and reflow properties or BPSG film deposited by APCVD was characterized by variation of each process parameter. As deposition temperature is increased higher, deposition rate is decreased. Maximum deposition rate of BPSG film is obtained in higher 02/Hyride ratio than CVD Oxide or PSG. BPSG film shows stable dielectric properties and we obtained good planarization effect at lower reflow temperature in case of BPSG film than PSG film.

• Proceedings of the KIEE Conference
• /
• 2003.07c
• /
• pp.1920-1922
• /
• 2003

We have fabricated the pyrex glass microlens using thermal reflow process. Fabricated microlens is the plano convex refractive type and was fabricated with pyrex glass-Si anodic bonding wafer. The etched circle or cylindrical pyrex glass pattern was melted in a furnace $800^{\circ}C$ to $900^{\circ}C$ for about 15min. The surface roughness of the microlenses was measured by the AFM and average surface roughness of the microlenses was below 15min. The radius of curvature of the microlens was measured with phase shift interferometer.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.6
• /
• pp.443-453
• /
• 2017

In flip chip technology, the conventional solder bump has been replaced with a copper (Cu) pillar bump owing to its higher input/output (I/O) density, finer pitch, and higher reliability. However, Cu pillar bump technology faces several issues, such as interconnect shorting and higher low-k stress due to stiffer Cu pillar structure when the conventional reflow process is used. Therefore, the thermal compression bonding (TCB) process has been adopted in the flip chip attachment process in order to reduce the package warpage and stress. In this study, we investigated the package warpage induced during the TCB process using a numerical analysis. The warpage of the TCB process was compared with that of the reflow process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2006.05a
• /
• pp.95-98
• /
• 2006

LCD-BLU (Back Light Unit) is one of kernel parts of LCD unit. The fabrication method of a 3-D micro mold patterned with micro-lenses for the LGP (Light Guiding Plate), one of the most important parts of LCD-BLU, was presented. Instead of dot pattern made by etching, 3-D optical pattern design with $50{\mu}m$ micro-lens was applied in the present study. The micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP. The positive micro-lens patterned injection mold with different aspect ratios (i.e. 0.3 and 0.4) was fabricated with modified LiGA with thermal reflow process. The brightness of LCD-BLU increased as aspect ratio of micro-lens increased.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2003.11a
• /
• pp.151-155
• /
• 2003

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 alumina substrate and the IMC layer between $Sn-37wt\%Pb$ solder and Ag-Pd thick film conductor 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, Ag-Pd conductor pad roughness were increased from 304nm to 330nm. $Cu_6Sn_5$ formed during initial ref]ow process at the interface between TiWN/Cu UBM and solder grew by the succeeding reflow process so the grains had a large diameter and dense interval. A cellular-shaped $Ag_3Sn$ was observed at the interface between Ag-Pd conductor pad and solder. The diameters of the $Ag_3Sn$ grains ranged from about $0.1\~0.6{\mu}m$. And a needle-shaped $Ag_3Sn$ was also observed at the inside of the solder.

• Proceedings of the KWS Conference
• /
• 2007.11a
• /
• pp.235-237
• /
• 2007

In this paper, fabrication of Sn-3.0Ag-0.5Cu solder bumping having accurate composition and behavior of intermetallic compounds(IMCs) growth at interface between Sn-Ag-Cu bumps and Cu substrate were studied. The ternary alloy of the Sn-3.0Ag-0.5Cu solder was made by two binary(Sn-Cu, Sn-Ag) electroplating on Cu pad. For the manufacturing of the micro-bumps, photo-lithography and reflow process were carried out. After reflow process, the micro-bumps were aged at $150^{\circ}C$ during 1 hr to 500 hrs to observe behavior of IMCs growth at interface. As a different of Cu contents(0.5 or 2wt%) at Sn-Cu layer, behavior of IMCs was estimated. The interface were observed by FE-SEM and TEM for estimating of their each IMCs volume ratio and crystallographic-structure, respectively. From the results, it was found that the thickness of $Cu_3Sn$ layer formed at Sn-2.0Cu was thinner than the thickness of that layer be formed Sn-0.5Cu. After aging treatment $Cu_3Sn$ was formed at Sn-0.5Cu layer far thinner.

• Journal of Welding and Joining
• /
• v.29 no.5
• /
• pp.95-98
• /
• 2011

Recently, there is a growing tendency that fine-pitch electronic devices are increased due to higher density and very large scale integration. Finer pitch printed circuit board(PCB) is to be decrease insulation resistance between circuit patterns and electrical components, which will induce to electrical short in electronic circuit by electrochemical migration when it exposes to long term in high temperature and high humidity. In this research, the effect of soldering flux acting as an electrical carrier between conductors on electrochemical migration was investigated. The PCB pad was coated with OSP finish. Sn3.0Ag0.5Cu solder paste was printed on the PCB circuit and then the coupon was treated by reflow process. Thereby, specimen for ion migration test was fabricated. Electrochemical migration test was conducted under the condition of DC 48 V, $85^{\circ}C$, and 85 % relative humidity. Their life time could be increased about 22% by means of removal of flux. The fundamentals and mechanism of electrochemical migration was discussed depending on the existence of flux residues after reflow process.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.4
• /
• pp.1347-1355
• /
• 1996

The purpose of this paper is to evaluate the delamination and fracture integrity of the IC plastic package under hygrothermal loading by stress analysis and fracture mechanics approaches. The plastic SOJ package with a dimpled diepad under the reflow slodering process of IR heating type is considered. On the package without a crack, the stress variation according to the change of the design variables such as the material and shape of the package is calculated and the possibility of delamination is considered. For the model fully delaminated between the chip and diepad, J-integrals are calculated for the various design variables and the fracture integrity is discussed. From the results, optimal design values of variables to prevent the delamination and fracture of IC package are obtained. In this study, FDM program to obtain the vapor pressure from the content of moisture absorbed into the package is developed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.6
• /
• pp.575-579
• /
• 2004

Package reliability test was conducted to investigate the effect of solder paste composition at BGA Package. It was found that the shape and size of the phase form are affected by the processing parameters. The material have used to fill in the via was Sn/36Pb/2Ag and Sn/0.75Cu type solder paste. Sn/36Pb/2Ag and Sn/0.75Cu paste were fabricated on Tape-BGA substrates by screen printing process, and via ball mount data were characterized with variations of dwell time of 85 seconds at reflow peak temperature at 22$0^{\circ}C$ or 24$0^{\circ}C$. The test condition was MRT 30 $^{\circ}C$/60 %RH/96 HR. Failures formed of a ball-off in solder paste process were observed by using a Optical Microscope and SEM(Scanning Electron Microscope). It was concluded that intermetallic layer growth played important roles in increasing solder fatigue strength for addition of Ag composition. The degradation of shear strength of solder composition is discussed.