• Journal of the Microelectronics and Packaging Society
• /
• v.23 no.3
• /
• pp.63-67
• /
• 2016

In this paper, we present an indirect method of elastic modulus measurement for various lamination layers formed on polymer-based compliant substrates. Although the elastic modulus of every component is crucial for mechanically reliable microelectronic devices, it is difficult to accurately measure the film properties because the lamination layers are hardly detached from the substrate. In order to resolve the problem, 3-point bending test is conducted with a film-substrate specimen and area transformation rule is applied to the cross-sectional area of the film region. With known substrate modulus, a modulus ratio between the film and the substrate is calculated using bending stiffness of the multilayered specimen obtained from the 3-point bending test. This method is verified using electroplated copper specimens with two types of film-substrate structure; double-sided film and single sided film. Also, common dielectric layers, prepreg (PPG) and dry film solder resist (DF SR), are measured with the double-sided specimen type. The results of copper (110.3 GPa), PPG (22.3 GPa), DF SR (5.0 GPa) were measured with high precision.

• Korean Journal of Materials Research
• /
• v.19 no.11
• /
• pp.596-600
• /
• 2009

Electrochemical deposition characteristics of CdSe nanorods were investigated for hybrid solar cell applications. CdSe nanorods were fabricated by electrochemical method in $CdSO_4$ and $H_2SeO_3$ dissolved aqueous solution using an anodic aluminum oxide (AAO) template. Uniformity of CdSe nanorods was dependent on the diameter and the height of holes in AAO. The current density, current mode, bath composition and temperature were controlled to obtain a 1:1 atomic composition of CdSe. CdSe nanorods deposited by direct-current method showed better uniformity compared to those deposited by purse-current and/or purse-reverse current methods due to the bottom-up filling characteristics. $H_2SeO_3$ concentration showed more significant effects on pH of solution and stoichiometry of deposits compared to that of $CdSO_4$. A 1:1 stoichiometry of uniform CdSe nanorods was obtained from 0.25M $CdSO_4-5$ mM $H_2SeO_3$ electrolytes with a direct current of 10 $mA/cm^2$ at room temperature. X-ray diffraction and electron diffraction pattern investigations demonstrate that CdSe nanorods are a uniform cubic CdSe crystal.

• Journal of Advanced Marine Engineering and Technology
• /
• v.19 no.3
• /
• pp.50-61
• /
• 1995

In recent years, many ceramic researchers have discoved various methods of joining ceramic to metal. However, most of these joining methods are perfomed under vacuum and pressured circumstances. So, when we join ceramic to metal,the proceedings are very complicated and require a very high cost. The purpose of this study is to develop a new joining method of an alumina ceramic to an aluminum metal in air atmosphere. The joining condition, such as copper metallizing, nickel plating, brazing, etc. was investigated through the shear strength test of the trial joint. The results obtained from the above experimenta are summarized as follows : 1) In the case of the $Al_2O_3$/$Al_2O_3$joint, the shear strength of the joint was affected by the various foctor such as kaolin content, copper metallizing thickness, firing temperature, firing time. 2) The better shear strength of the $Al_2O_3$/Al joint was obtained when Ni plating was conducted under higher current density than existing plating condition. 3) The shear strength of the $Al_2O_3$/Al joint increases with the Ni plating thickness is confined to the range of this paper. 4) The shear strength of the thermal-shocked specimen($Al_2O_3$/Al joint) was far more deteriorated than that of the as-bonded specimen.

• Journal of the Microelectronics and Packaging Society
• /
• v.25 no.3
• /
• pp.67-74
• /
• 2018

Thermoelectric thin film devices of the in-plane configuration consisting of 8 pairs of n-type $Bi_2Te_3$ and p-type $Sb_2Te_3$ legs were processed on Si submounts by electrodeposition. The thermoelectric generation characteristics of the thin film devices were investigated with respect to the apparent temperature difference ${\Delta}T$ caused by LED lighting as well as the change of the leg thickness. When ${\Delta}T$ was 7.4 K, the open circuit voltages of 6.1 mV, 7.4 mV, and 11.8 mV and the maximum output powers of 6.6 nW, 12.8 nW, and 41.9 nW were measured for the devices with the thermoelectric legs of which thickness were $2.5{\mu}m$, $5{\mu}m$, and $10{\mu}m$, respectively.

• Proceedings of the KWS Conference
• /
• 2010.05a
• /
• pp.81-81
• /
• 2010

전자 패키징은 미세화, 경량화, 저가화를 지향하고 신뢰성의 향상을 위해 발전해 왔다. 이러한 경향은 전자부품 자체의 성능 향상 뿐 아니라 전자부품을 장착, 고정할 수 있게 하는 인쇄회로 기판(PCB : Printed Circuit Board)의 성능에 많은 관심을 가지게 되었다. 전기적 신호의 손실을 줄이기 위해 전기, 전자 산업체에서는 가볍고 굴곡성이 우수한 연성인쇄회로기판(FPCB : Flexible PCB)과 가격이 싸고 신뢰성이 입증된 경성인쇄회로기판(RPCB : Rigid PCB)이 그 대상이다. 본 논문에서는 이 PCB중에서도 RPCB와 FPCB간의 열압착 방식으로 접합 시 전극간의 접합 양상을 보았다. 이 열압착 방식은 기존에 PCB를 접합하는데 사용하고 있는 connector를 이용한 체결법을 대체하는 기술로써 솔더를 중간층(interlayer)로 이용하여 열과 압력으로 접합하는 방식이다. 이 방식을 connector를 사용하는 방식에 비해 그 부피가 작고 I/O개수에 크게 영향 받지 않으며 자동화 공정이 쉬운 장점을 가지고 있다. 접합의 대상 중 RPCB의 경우는 무전해 니켈 금도금(ENIG : Electroless Nickle Immersion Gold)로 제작하였으며 FPCB의 경우는 ENIG와 유기보호피막(OSP : Organic solderability preservation) 처리하였다. 실험에 사용한 PCB는 $300\;{\mu}m$ pitch의 미세피치이며 솔더의 조성은 Sn-3.0Ag-0.5Cu (in wt%)과 Sn-3.0Ag (in wt%)를 사용하였다. 접합 온도와 접합 시간 그리고 접합 압력에 따라 최적의 접합 조건을 도출하였다. 접합 강도는 $90^{\circ}$ Peel Test를 통해서 측정하였으며 접합면 및 파괴면은 SEM과 EDS를 통하여 분석하였다.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.20 no.1
• /
• pp.22-26
• /
• 1983

P+N and P+NN+ solar cells with the area of 3.36 $\textrm{cm}^2$ were fabricated by thermal diffusion. Under the light intensity of 100 mW/$\textrm{cm}^2$, total area(active area) conversion efficiency was 13.4%(14.7%) for P+N cell fabricated by 15 min boron predeposition at 94$0^{\circ}C$ and 20 min annealing at 80$0^{\circ}C$, and 14.3%(15.6%) for P+NN+ cell processed by 15 min boron predeposition at 94$0^{\circ}C$ and 50 min annealing at 80$0^{\circ}C$ after 20 min back phosphorus diffusion at 1,05$0^{\circ}C$. The minority carrier lifetime in bulk of P+NN+ cells was increased about 2~3 times comparing with P+N cells because of guttering and BSF effect due to back phosphorus doping. The methods used for efficiency improvement were AR coating, Ag electroplating, back doping and fine grid pattern as well as the control of front doping profile.

• Journal of Surface Science and Engineering
• /
• v.38 no.4
• /
• pp.163-166
• /
• 2005

Carbon nanotube-copper composite structures were fabricated using composite plating method and their field emission characteristics were investigated. Multi-walled carbon nanotubes (MWNTs) synthesized by chemical vapor deposition were used in the present study. It was revealed that turn-on field was about $3.0\;V/{\mu}m$ with the current density of $0.1\;{\mu}A/cm^2.$ We observed relatively uniform emission characteristics as well as stable emission current Carbon nanotube-copper composite plating method is efficient and it has no intrinsic limit on the deposition area. Moreover, it gives strong adhesion between emitters and an electrode. Therefore, we recommend that carbon nanotube-copper composite plating method can be applied to fabricate electron field emitters for large area FEDs and large area vacuum lighting sources.

• Journal of Surface Science and Engineering
• /
• v.1 no.1
• /
• pp.5-13
• /
• 1967

Up to this date, numerous methods of analysis of electropling solutions are published. Some, however, need lots of works before reaching final results, or require high technique and special instruments, and also some are unaccurate due to unclearnes of end point. Like our undevelop countries, technicians of electroplating shops are most high school graduates or under, and have not much knowledge on chemistry. Furthermore, those technicians have to control their plating solutions by themselves without having enough analytical laboratory equipment . Therefore, in this paper the simplest, besides accurate method is investigated after comparing numerous methods published. Among the methods of copper determinations from acid and alkaline copper plating baths, EDTA titration method are chosen, due to these methods are the simpest and fastest for the evaluation of metal content, without requirng any special instrument. For acid copper solutions, chelate titrations were accurate enough. Since the end point of titration of chelate method is variable according to the kind of indicators and other metal's coexisitence as well as solution component, many difficulties were encountered from cyanide copper, on the contrary of acid copper bath. PAN , PV, and MX indicators were tried , but it is found that MX is the best. In chyanide solution ,due to cyanide is the masking reagent , elimination of this component is essential , and finally found that elimination CN-by precipitation with AgNO$_3$ solution was the simplest and the most accurate way among others. This method was very accurate for the new plating solutions even coexistence with organic brightners. However used solutions for long months running have to be predetermined the accurate copper value by thiosulfate method form time to time, before chelate titration by means of AgNO$_3$ precipitation. Always some constant deviations will be seen according to the solutions nature. Therefore those deviation values have to be compensated each time.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2018.06a
• /
• pp.136-136
• /
• 2018

듀얼 페이즈(DP) 강철과 같은 고강도강(HSS), TRIP강, TWIP강은 무게를 줄이고 자동차의 안전을 향상시키기 위해서 자동차 산업에서 광범위하게 쓰이고 있다. HSS강의 내부식성을 향상시키기 위해서, 향상된 박막 재료와 기존의 아연도금 공정을 대체하는 공정 방법이 필요하다. Zn-Mg 박막은 강의 부식 방지에 대한 강력한 후보이며, 물리적 기상 증착 공정(PVD)은 강의 Zn-Mg 박막의 증착을 위한 유망한 공정이다. 그러나 이전 연구에서 보고 된 바와 같이 Zn-Mg 박막은 Zn-Mg 박막의 높은 취성으로 인하여 Zn 박막에 비하여 접착력이 매우 불충분하였다. 따라서 본 연구에서는 Zn-Mg 박막의 첩착력을 향상시키기 위해 TRIP강 기판 위에 증발 증착법을 활용하여 Zn-Mg/Zn 이중층 박막을 합성하고 진공에서 열처리를 실시하여 박막의 깊이에 따른 Mg의 함량 변화를 유도하였다. Zn-Mg/Zn 박막 합성 시 EMH-PVD를 활용하여 증착하였으며, Zn 중간층을 모재와 Zn-Mg 층 사이에 증착하고 진공중에서 열처리를 실시하여 박막 내에서 Mg 함량의 기울기 변화가 박막의 밀착력에 주는 영향을 평가하였다. 증착된 박막은 FE-SEM을 통하여 미세조직과 박막의 두께를 분석하였고 line-EDS를 통하여 깊이에 따른 Zn와 Mg의 변화를 분석하였으며 XRD를 사용하여 합금상을 분석하였다. Lap shear test를 활용하여 박막의 밀착력을 정략적으로 분석하였다. FE-SEM 및 EDS 분석 결과 Zn-Mg/Zn 박막을 진공에서 열처리를 실시한 후 FE-SEM으로 분석한 결과 미세조직의 큰 차이는 보이지 않았으나, line-EDS 결과 Mg이 확산되는 것을 확인 할 수 있었다. XRD 분석 결과 확산한 Mg에 의해서 Zn상은 감소하고 $Mg_2Zn_{11}$, $MgZn_2$와 같은 합금상은 증가하는 것을 확인하였다. Lap shear test 결과 $200^{\circ}C$에서 열처리한 Zn-15wt.%Mg/Zn 박막의 경우 밀착력이 19 MPa로 열처리를 하지 않았을 경우(11 MPa)보다 향상되는 것을 확인하였다. 이러한 결과는 통하여 Zn-Mg 박막의 두께의 Mg의 함량 변화에 의해서 박막의 밀착력이 변화되는 것을 알 수 있다.

• Korean Journal of Materials Research
• /
• v.17 no.9
• /
• pp.469-474
• /
• 2007

Electroless deposition(ELD) was applied to fabricate Cu interconnections on a TaN diffusion barrier with Pd seed layer. The Pd seed layer was obtained by self-assembled monolayer method(SAM) with PDDA and PSS as surfactants. We were able to obtain about 10nm Pd nano particles as seeds for electroless Cu deposition and the density of Pd seeds was much higher than that of Pd seeds fabricated by conventional Pd sensitization-activation method. Also we were able to obtain finer Cu interconnections by ELD. Therefore we concluded that the Pd seed layer by SAM was able to be applied to form Cu interconnection by ELD for under 30nm feature.