• Journal of Welding and Joining
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• v.20 no.5
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• pp.106-112
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• 2002

In the present study, the wettability and interfacial tension between (bare Cu, electroless Ni/cu, immersion Au/Ni/Cu) substrates and indium solder were investigated as a function of soldering temperature, types of flux. The wettability of In solder increased with soldering temperature and solid content of flux. The wettability of In solder was affected by the substrate metal finish used, i.e., nickel, gold and copper. On the bare Cu substrate, In solder wet better than any of the substrate metal finishes tested. Intermetallic compound formation between liquid solder and substrate reduced the interfacial energy and improved wettability. For the identification of intermetallic compounds, X-Ray Diffraction(LRD) were employed. Experimental results showed that the intermetallic compounds, such as Cu11In9 and In27Ni10 are observed f3r different substrates respectively. The wetting kinetics is investigated by measuring wetting time with the wetting balance technique. The activation energy of wetting calculated for the In solder/cu substrate and In solder/electroless Au/Ni/Cu substrate are 36.13 and 27.36 kJ/mol, respectively.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.75-87
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• 2001

Three different kinds of substrate used in this study : bare Cu substrate, Ni-P/Cu substrate with a Ni-P layer thickness of $5\mu\textrm{m},$ and Au/Ni-P/Cu substrate with the Ni-P and Au layers of $0.15\mu\textrm{m}$ and $5\mu\textrm{m}$ thickness respectively. The wettability of various Sn-base solders was affected by the substrate metal finish used, i.e., nickel, gold and copper. On the Au/Ni-F/Cu substrate, Sn-base solders wet better than any of the other substrate metal finishes tested. The interfacial reaction between various substrate and Sn-base solder was investigated at $70^{\circ}C,$ $100^{\circ}C,$ $120^{\circ}C,$ $150^{\circ}C,$ $170^{\circ}C$ and $200^{\circ}C$ for reaction times ranging from 0 day to 60 day. Intermetallic phases was formed along a Sn-base solder/ various substrate interface during solid-state aging. The apparent activation energy for growth of Sn-Ag/Cu, Sn-Ag-Bi/Cu, and Sn-Bi/Cu couples were 65.4, 88.6, and 127.9 Kj/mol, respectively. After isothermal aging, the fracture surface shoved various characteristics depending on aging temperature and time, and the types of BGA pad.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.142-142
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• 2011

Epitaxial $CuCrO_2$ thin films have been grown on single crystal substrate of c-plane $Al_2O_3$, $SrTiO_3$, YSZ and Quarts by laser ablation of a $CuCrO_2$ target using 266nm radiation from a Nd:YAG laser. X-ray measurements indicate that the $CuCrO_2$ grows epitaxially on all substrate, with its orientation dependent on the kinds of substrates. Most of the layer were polycrystalline with (001), (015) and random as the dominant surface orientation on c-plane YSZ, $SrTiO_3$ and quarts substrate, respectively. (001) orientated $CuCrO_2$ grows on C-plane $Al_2O_3$ and YSZ substrate, (015) orientated $CuCrO_2$ films are found on c-plane $SrTiO_3$ substrate and random orientated $CuCrO_2$ films grows on quarts substrate. These data are compared with the in-plane orientation and the mismatch of the $CuCrO_2$ and each substrate lattices in an attempt to relate the preferred orientation to the plane of the sapphire on which it is grown. Further characterization show that the grain size of the films increases for a substrate temperature increase, whereas the electrical properties of $CuCrO_2$ thin films depend upon their crystalline orientation.

• The Korean Journal of Ceramics
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• v.4 no.3
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• pp.222-226
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• 1998

$Cu_3N$ film deposited on silicon oxide substrate by r.f. reactive sputtering technique. Synthesis and properties of copper nitride film were investigated for its possible application to Cu metallization as adhesive interlayer between copper and $SiO_2. Cu_3N$ film was synthesized at the substrate temperature ranging from $100^{\circ}C$ to $200^{\circ}C$ and at nitrogen gas ratio above $X_{N2}=0.4. Cu_3N, CuN_x$, and FGM-structured $Cu/CuN_x$ films prepared in this work passed Scotch-tape test and showed improved adhesion property to silicon oxide substrate compared with Cu film. Electrical resistivity of copper nitride film had a dependency on its lattice constant and was ranged from 10-7 to 10-1 $\Omega$cm. Copper nitride film was, however, unstable when it was annealed at the temperature above $400^{\circ}C$.

• Korean Journal of Materials Research
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• v.19 no.11
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• pp.625-630
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• 2009

Embedding of active devices in a printed circuit board has increasingly been adopted as a future electronic technology due to its promotion of high density, high speed and high performance. One responsible technology is to embedded active device into a dielectric substrate with a build-up process, for example a chipin-substrate (CiS) structure. In this study, desmear treatment was performed before Cu metallization on an FR-4 surface in order to improve interfacial adhesion between electroless-plated Cu and FR-4 substrate in Cu via structures in CiS systems. Surface analyses using atomic force microscopy and x-ray photoemission spectroscopy were systematically performed to understand the fundamental adhesion mechanism; results were correlated with peel strength measured by a 90o peel test. Interfacial bonding mechanism between electrolessplated Cu and FR-4 substrate seems to be dominated by a chemical bonding effect resulting from the selective activation of chemical bonding between carbon and oxygen through a rearrangement of C-C bonding rather than from a mechanical interlocking effect. In fact, desmear wet treatment could result in extensive degradation of FR-4 cohesive strength when compared to dry surface-treated Cu/FR-4 structures.

• Journal of the Korean Vacuum Society
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• v.14 no.1
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• pp.17-23
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• 2005

Glow discharge mass spectrometry(GDMS) was used to determine the impurity concentrations of the deposited Cu films and the 6N Cu target. Cu films were deposited on Si (100) substrates at zero substrate bias voltage and a substrate bias voltage of -50 V using a non-mass separated ion beam deposition method. Since do GDMS has a little difficulty to apply to thin films because of the accompanying non-conducting substrate, we have used an aluminum foil to cover the edge of the Cu film in order to make an electrical contact of the Cu film deposited on the non-conducting substrate. As a result, the Cu film deposited at the substrate bias voltage of -50 V showed lower impurity contents than the Cu film deposited without the substrate bias voltage although both the Cu films were contaminated during the deposition. It was found that the concentration change of each impurity in the Cu films by applying the negative substrate bias voltage is related to the difference in their ionization potentials. The purification effect by applying the negative substrate bias voltage might result from the following reasons: 1) Penning ionization and an ionization mechanism proposed in the present study, 2) difference in the kinetic energy of accelerated Cu+ ions toward the substrate with/without the negative substrate bias voltage.

• Journal of Fisheries and Marine Sciences Education
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• v.10 no.1
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• pp.69-78
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• 1998

Thermal sprayed Cu-Ni alloy coating on the carbon steel was carried out impingement erosion-corrosion test and electrochemical corrosion test in the marine environment. The impingement erosion-corrosion behavior and electrochemical corrosion characteristics of substrate(SS400) and thermal sprayed Cu-Ni coating was investigated, and the corrosion control efficiency of Cu-Ni coating to substrate was estimated quantitatively. Main results obtained are as follows : 1) The weight loss rate of Cu-Ni coating layer by the impingement erosion-corrosion compared with substrate was smaller in high specific resistance solution than in low specific resistance solution. 2) The corrosion potential of Cu-Ni coating layer spray coating in the marine environment became more noble than that of substrate. 3) With the lapse of time, corrosion current density of Cu-Ni coating layer became stable, but that of substrate was increased. 4) As the corrosion control efficiency of Cu-Ni coating layer in the marine environment was over 90%, its anti-corrosion characteristics was excellent.

• Electrical & Electronic Materials
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• v.8 no.1
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• pp.6-12
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• 1995

High Tc superconducting YBa$_{2}$Cu$_{3}$$O_{7-x}$ thin films were prepared on various substrates by off-axis rf magnetron sputtering method to examine the substrate effects on the film structure and its R-T characteristics. The SEM analysis showed that the surface morphology of the grown YBa$_{2}$Cu$_{3}$O.sub 7-x/, film has different characteristic structure with different substrate used. The film on (100) SrTiO$_{3}$ substrate has critical current density of 3*10$^{5}$ A/cm$^{2}$ at 77K under zero magnetic field. The X-ray diffraction measurements revealed that the films on (100) SrTiO$_{3}$ substrate have mixed a-axis and c-axis normal to the substrate surface and the films on (100) MgO and ZrO$_{2}$/sapphire substrates have c-axis normal orientation to the substrate surface. However, YBa$_{2}$Cu$_{3}$$O_{7-x}$ films on (100) sapphire substrates showed no preferential orientation.ion.

• Journal of the Korean Vacuum Society
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• v.8 no.3A
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• pp.249-255
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• 1999

Deposition characteristics of Cu thin films using Ar carrier gas and $H_2$ processing gas at various working pressures and substrate temperatures were investigated. Also, effects of $H_2$ pretreatment using plasma at $200^{\circ}C$ of substrate temperature and 0.6 Torr of chamber pressure were stdied. Cu thin films were deposited on TiN/Si substrate at working pressure of 0.5~1.5 Torr, substrate temperatures of 140~$240^{\circ}C$ with (hface)Cu(tmvs). Substrates were pretreated by $H_2$ plasma, and Cu films deposited in situ using twofold shower head. The purity, electrical resistivity, thickness, surface morphology, optical properties of the deposited Cu films were measured b the AES, four point probe, stylus profiler, SEM,. and the uv-visible spectrophotometer. This study suggests that $H_2$ plasma is an effective method for enhancing deposition rate and for producing high quality copper thin films.

• Journal of the Korean Ceramic Society
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• v.29 no.5
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• pp.383-390
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• 1992

We investigated the effect of substrate on the properties of the Ni-Zn-Cu ferrite thin films deposited on SiO2 (1000∼3000${\AA}$) / Si (100) substrate at various conditions by rf magnetron sputtering. A disktype Ni-Zn-Cu ferrite sintered by conventional ceramic process and argon gas were used as a target and a sputtering gas, repectively. The compositions of the thin films measured by EPMA were similar to target composition (Fe: 65.8 at%, Ni: 12.7 at%, Cu: 6.7 at%, Zn: 14.8 at%) irrespective of substrate temperature. Amorphous thin films were deposited when substrate was not intentionally heated, but the films came to crystallize with increasing substrate temperature, and crystalline thin films were deposited at substrate temperature above 200$^{\circ}C$. Below 250$^{\circ}C$ saturation magnetization (Ms), remanence (Mr) and coercivity (Hc) of the ferrite thin film increased with the substrate temperature due to the increase of grain size and the improvement of crystallinity. And above 250$^{\circ}C$, Ms, Mr increased slightly, but Hc of the amorphous thin films increased due to crystallization, whereas that of the crystalline thin films decreased because of grain growth and stress release.