• Journal of the Microelectronics and Packaging Society
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• v.27 no.3
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• pp.29-34
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• 2020

The behavior of brittle fracture of electroless nickel immersion gold (ENIG) /Sn-3.0wt.%Ag-0.5wt.%Cu (SAC305) solder joints was evaluated. The pH of the electroless nickel plating solution for ENIG surface treatment was changed from 4.0 to 5.5. As the pH of the Ni plating solution increased, pin hole in the Ni-P layer increased. The thickness of the interfacial intermetallic compound (IMC) of the solder joint increased with pH of Ni plating solution. The high speed shear strength of the SAC305 solder joint on ENIG surface finish decreased with the pH of the Ni plating solution. In addition, the brittle fracture rate of the solder joint was the highest when the pH of the Ni plating solution was 5.

• Journal of the Korean Electrochemical Society
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• v.2 no.3
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• pp.138-143
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• 1999

Recently, miniaturization of large scale integrated circuits (LSI) and printed circuit board (PCB) have become essential with the downsizing of electronic devices. Gold electroplating is applied of conductivity wiring or terminals for improvement of conductivity and corrosion resistance. However, electroplating is not applicable since the circuits are becoming finer and denser. Accordingly, electroless plating is recently highly attractive method because of the simplicity of the operation requiring no external source of current and no elaborate equipment. In this work, we tried to develop a plating technique on electroless Ni/Au plating. First, the electroless Ni plating was deposited on the PCB with agitation in the bath at $85^{\circ}C$. Then the Au layer was deposited on the Ni layer surface by same method at $90^{\circ}C$. The bonderability were tested in order to evaluate the stability of the electroless Ni/Au by gold wire or solder ball test.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.2
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• pp.125-136
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• 2006

Statement of problem. The success of the bonding between electroforming gold and resin is dependent on the surface-conditioning technique but its effective technique has net been studied widely. Purpose. The purpose of the study was to evaluate the bond strength between the electroforming gold and resin with varying the surface-conditioning technique. Materials and methods. Sixty rectangular shaped metal specimens were made and one side of each specimen were gold hard plated. The sand-blasted specimens were divided into four experimental groups with fifteen specimens in each group and were treated as follows. Group 1: Silicoating (Rocatec, 3M ESPE)+ Sinfony (3M ESPE), Group 2: SR Link+ SR Adoro (Ivoclar Vivadent), Group 3: Tin plating (Microtin, Danville Engineering)+ SR Link+ SR Adoro, Group 4: Tin plating (Micro tin, Danville Engineering)+ Silicoating (Rocatec)+ Sinfony. Shear bond strength at metal-resin interface were measured using universal testing machine. Energy Dispersive x-ray analysis was done and scanning electron microscope images were taken and observed. Results and Conclusion. The following conclusions were drawn. 1. The mean shear bond strength values in order were 11.69MPa (Group 2), 22.35MPa (Group 3), 22.40MPa (Group 1) and 27.71MPa (Group 4). There was no significant difference in Group 1, Group 3 and Group 4(P>0.05). 2. In the EDX line analysis, the Au was detected on the surface of all specimen. $SnO_2$ showed on the surface of Group 2 and $SiO_2$ was detected on the surface of Group 1. 3. Increasing of roughness by sandblasting(Group 2), formation of micro-irregularities and tin crystals by electrolytic tin plating(Group 3) and formation of surface irregularities and $SiO_2$ layer(Group 1,4) were observed in SEM photo. 4. Tin plating(Group 3) and Rocatec treatment(Group 1) showed clinically effective shear bond strength(>20MPa), but when the two surface conditioning method were used together higher bond strength were achieved.

• Restorative Dentistry and Endodontics
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• v.19 no.2
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• pp.473-484
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• 1994

To investigate the effect of resin cement, which had been known to increase the adhesive capacity of the cast gold inlay, on the gingival marginal fit and whether the tin-planting of the beveled area affects the marginal fit, Class II cast gold inlays were made on the 25 sound molars. Control group(ZPC goup) was cemented with the ZPC by conventional method. Experimental groups were cemented with the resin cement(Super-hond & $Panavia_{EX}$) and subdivided further by the existence or nonexistence of the tin-plating of the beveled area(ST & PT groups: with plating, SNT & PNT groups: without plating). So, each group was consisted of 5 teeth and the gingival margin of each specimen was mesiodistally sectioned by 3 times and the marginal and internal gap were evaluated by the Stereo Microscope (${\times}180$) and the Scanning Electron Micrascope(${\times}5,000$) was used for examining the adhesive relationship of the resin cement to the cavity wall and to the cast gold surface. The results were as follows : 1. Marginal gap was less than internal gap in all groups. 2. ZPC and SNT(bevel without tin-plating) groups showed the least gap and gap in PNT(bevel without tin-plating) group, ST(bevel with tin-plating) group, PT(bevel with tin-plating) group showed the greater value in order in evaluation of the both internal gap and marginal gap. 3. With the exception of the relationships between ZPC and SNT groups, ST and PNT groups, relationships between any other groups showed the statistical significance in the internal gap(p<0.05). 4. In the marginal gap, all relationships between groups showed the statistical significance (p<0.05) except the relationships between ZPC and SNT groups, ST and PNT groups, ZPC and PNT groups. 5. ZPC group showed more soluble phenamena than the resin groups(ST, SNT, PT, PNT). 6. Resin cement showed the void spaces in spite of good penetration into the micro-irregularities on both the tooth surface and the cast surface. The void was shown more in PT and PNT groups than in the ST and SNT groups. 7. After the treatment of heat and desiccation for SEM specimen, resin cements were detached more easily from the tooth surface than from the cast surface.

• Journal of the Korean institute of surface engineering
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• v.28 no.1
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• pp.23-33
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• 1995

AISI 304 stainless steel has high resistance to corrosion due to the presence of a self-healing chromium oxide film on the surface, which also accounts for the difficulty in plating. Surface cleaning of this alloy is of fundamental importance in gold plating since its effectiveness puts an upper limit on the quality of the final coating. The cleaning of AISI 304 stainless steel was investigated with elimination of artificial passive oxide film and degreasing of remaining buffing wax as stearic acid. The familiar cleaning methods i.e. ultrasonic cleaning, electro-cleaning and activation treatment were fabricated in this study. Activation treatment showed best cleaning efficiency for elimination of passive oxide film among these methods, which was also confirmed by AES (Auger electron spectrometer) analysis. However, the best condition of cleaning was obtained by combining these methods. Electrocleaning time, for degreasing the stearic acid layer, was decreased with increasing amount of added KCN.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.625-628
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• 1999

Recently. high-density printed circuit boards(PCB) become indispensable with the minaturization of components. Nickel is deposited on the copper patterns and followed by the gold deposition for improving connection reliability between the printed circuit boards and electronic components. Conventionally electrodeposition has been applied to metalization of copper patterns. However metalization by this method is not applicable for the isolated fine and concentrated patterns. Therefore, metalization technology of the fine patterns by electroless plating is required in place of electrodeposition. The application of electroless nickel plating for interconnection with solder strongly relies on the solderability and the interactions between nickel and solder. Factors such as phosphorus content of the deposit additive and bath temperature may influence solderability of the electroless nickel deposit. So solderability of electroless nickel/ gold deposits was investigated with substrates plated changing the condition of nickel solution.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.993-994
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• 2011

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.198.1-198
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• 2003

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.273-279
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• 2016

This paper deals with a control system with a concentration sensor for Ni-W alloy plating solutions. The printed circuit board market has increased with the development of the electronics industry. Gold consumption has also increased dramatically. Various studies of composite plating solutions have been conducted because of the expense of gold. In comparison, the development of sensors capable of measuring a composite plating solution in real-time is still insufficient. Furthermore, there are few systems that can measure and control the concentration of the solution precisely. This study developed a sensor and system to control the concentration of composite plating solution accurately. The sensors were developed based on a spectrophotometric method and a feedback control method was applied in this system.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.709-713
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• 1996

Mechanical solderless chip packaging with small gold bumps or metal balls has increased in the electronic devices. The preparation of conductive particles (5~7 $\mu\textrm{m}$ diamiter) by electroless nickel plating have been investigated. Generally, batch type electroless plating is applied to provide conductivity on the nonconductors. Since the surface areas of particles are much larger than the bulk substrate, accordingly the electroless plating bath becomes unstable. Thus, we applied the continuous dropping method for the preparation of conductive particles. The uniform coverage of deposited nickel on the particles was obtained by using ammonium acetate as a complexing agent, and surface coverage is further improved without coagulation of particles by the surface active agent treatment before enter the plating bath.