전기도금법을 이용한 FCCL용 구리박막 제조시 레벨러의 영향 연구

강인석,구연수,이재호,Kang, In-Seok,Koo, Yeon-Soo,Lee, Jae-Ho 한국마이크로전자및패키징학회 2012 마이크로전자 및 패키징학회지 Vol.19 No.2

최근에 전자 산업 분야에서 장치의 고용량을 구현 하기 위해 구동 drive IC의 선폭은 좁아지고 집적도는 증가하고 있다. 이러한 반도체, 전자 산업 분야의 초소형화, 고밀도화에 따라 FCCL(Flexible Copper Clad Laminate)의 표면 품질이 더욱 중요해 지고 있다. FCCL의 표면 결함으로는 돌기, 스크레치, 덴트 등이 있다. 특히 돌기가 표면에 존재할 경우 후속 공정에서 쇼트와 같은 불량을 유발할 수 있으며, 제품의 품질 저하를 야기 시킬 수 있다. 하지만 표면에 돌기가 존재한다 하더라도, 전해액의 레벨링 특성이 우수하다면 돌기의 성장을 막을 수 있다.평탄하고, 결함이 없는 도금표면을 얻기 위해서는 첨가제의 역할이 필수적이다. 평탄한 구리 표면을 형성하기 위해서 stock solution에 가속제, 억제제, 레벨러를 첨가하였다. 레벨러를 첨가하는 이유는 평탄한 표면을 얻고, 돌기의 형성을 억제하기 위함이다. 구리도금 표면 형상을 향상시키기 위한 레벨러로는 SO(Safranin O), MV(Methylene Violet), AB(Alcian Blue), JGB(Janus Green B), DB(Diazine Black) and PVP(Polyvinyl Pyrrolidone)가 사용되었다. 도금 첨가제와 도금 조건의 변화를 통해 도금시레벨링 특성을 향상시키고, 레벨링 특성 측정을 위해 니켈 인공돌기를 제작 한 후 레벨링 특성을 측정하였다. In recent days, the wire width of IC is narrowed and the degree of integration of IC is increased to obtain the higher capacity of the devices in electronic industry. And then the surface quality of FCCL(Flexible Copper Clad Laminate) became increasingly important. Surface defects on FCCL are bump, scratch, dent and so on. In particular, bumps cause low reliability of the products. Even though there are bumps on the surface, if leveling characteristic of plating solution is good, it does not develop significant bump. In this study, the leveling characteristics of additives are investigated. The objective of study is to improve the leveling characteristic and reduce the surface step through additives and plating conditions. The additives in the electrodeposition bath are critical to obtain flat surface and free of defects. In order to form flat copper surface, accelerator, suppressor and leveler are added to the stock solution. The reason for the addition of leveler is planarization surface and inhibition of the formation of micro-bump. Levelers (SO(Safranin O), MV(Methylene Violet), AB(Alcian Blue), JGB(Janus Green B), DB(Diazine Black) and PVP(Polyvinyl Pyrrolidone) are used in copper plating solution to enhance the morphology of electroplated copper. In this study, the nucleation and growth behavior of copper with variation of additives are studied. The leveling characteristics are analyzed on artificially fabricated Ni bumps.

동박과 접착력 향상을 위한 폴리이미드 합성 및 접착특성 평가

박재연(Jae Yun Park),박종현(Jong Hyun Park),박유민(Yu Min Park),박노균(No Kyun Park),김윤호(Yun Ho Kim),원종찬(Jong Chan Won) 한국고분자학회 2017 폴리머 Vol.41 No.5

차세대(5G) 디스플레이의 발전으로 인하여 데이터 전송량이 점차 증가하므로, 신호전송이 빠른 대역대인 고주파 대역을 사용한다. 신호전송을 위한 회로는 동박과 폴리이미드 필름으로 이뤄진 유연동박적층판(FCCL)이 사용되는데, 고주파는 표면으로 신호가 흐르므로 두 소재 사이의 계면 조도를 낮춰 경로를 최소화하여야 한다. 그러나 저조도 동박을 사용하면 동박과 폴리이미드 수지와의 접착 강도가 떨어지게 되므로 이러한 문제점을 보완해야 한다. 본 연구에서는 동박과 접착력 향상을 위해 다양한 폴리이미드 구조를 설계하고, 아민계 실란 기능기를 도입한 폴리아믹산을 합성하였다. 다양한 구조의 폴리아믹산은 pyromellitic dianhydride(PMDA), 3,3"4,4"-biphenyltetracarboxylicdianhydride(BPDA), 4,4"-(hexafluoroisopropylidene) diphthalic anhydride(6FDA)와 m-tolidine(mTB), 2,2"-bis(trifluoromethyl)-[1,1"-biphenyl]-4,4"-diamine(TFMB) 등의 조합으로 합성하여, 이를 동박에 코팅하고 이미드화하여 FCCL을 제조하였다. 접착력에 대한 특성은 다양한 폴리이미드 구조에 따른 박리 강도 시험과 분리된 계면에 대한 AFM, SEM, 접촉각 측정으로 상관관계를 비교 해석하여 확인하였다. Since the development in mobile display requires high data transmission speed, there is a growing need in the development of flexible copper clad laminate (FCCL) for flexible printed circuit board (FPCB) that has a high signal propagation at high frequency range. The circuit for signal transmission uses FCCL which is composed of copper foil and polyimide film. The surface roughness of copper foil has to be low to reduce the pathway of signal because the current flows near the surface at high frequency range. However, such low roughness of the copper foil results in poor adhesion to polyimide, which is a problem that should be addressed. In this study, the poly(amic acid)s (PAAs) having various structures were synthesized and the silane functional group was introduced as end group to investigate the enhancement in the adhesion with the copper metal. Various polyimide structures were synthesized with the combinations of pyromellitic dianhydride (PMDA), 4,4"-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), 3-aminopropyltriethoxysilane (TEOS), 3,3",4,4"-biphenyltetracarboxylic dianhydride (BPDA), m-tolidine (mTB) and 2,2"-bis(trifluoromethyl) biphenyl-4,4"-diamine (TFDB). The synthesized PAAs were casted on the copper foil and were imidized for the fabrication of polyimide for FCCL. The adhesion strength between the polyimide and the copper foil was investigated by peel strength test and interfacial characteristics was investigated with AFM, SEM, FTIR and contact angle measurement.

Cu/Ni-Mo-Nb/Polyimide FCCL (Flexible Copper Clad Laminate)의 개발 및 플렉시블 전자기기 응용을 위한 접착 특성

방성환,김경각,정호영,설재복 한국진공학회 2013 한국진공학회 학술발표회초록집 Vol.2013 No.2

2층 FCCL (연성회로기판, Flexible Copper Clad Laminate)에 있어서 폴리이미드 필름과 구리의 접착력을 향상 시키기 위해 기존에 사용되고 있는 Ni-Cr대신 박리강도가 높고 에칭성도 매우 뛰어난 Ni-Mo-Nb 박막을 Roll-to roll 스퍼터 장비를 이용하여 개발하였다. 새롭게 개발된 Ni-Mo-Nb 박막은 기존 연구되어진 Ni-Cr 물질 대비 고온 박리강도 약 1.5∼2.0배, 에칭성 8배 이상의 매우 우수한 특성을 보였다. Ni-Mo-Nb 접착층의 두께가 7∼40 nm로 증가함에 따라 상온 박리강도가 향상 되는 것을 확인하였다. Ni-Mo-Nb 박막을 증착 하기 전 폴리이미드 기판 표면을 RF 플라즈마 전처리 하였을 때 0.67 kg f/cm의 우수한 상온 박리강도를 나타내었으며 FCCL 샘플을 150oC에서 168시간동안 열처리 한 후 접착력을 측정하였을 때도 0.54 kg f/cm의 높은 고온 박리강도를 보였다. FCCL의 박리강도, 표면 거칠기, 원소들의 화학적 결합, 박막의 미세구조를 peel test, atomic force microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy를 이용하여 폴리이미드 기판 플라즈마 전처리 효과를 확인하였다. 그 결과 플라즈마 전처리를 한 폴리이미드 기판의 경우 처리하지 않은 기판보다 상온과 고온에서 더 우수한 접착력을 가지는 것을 확인 할 수 있었는데 이것은 폴리이미드 기판의 표면 거칠기 증가에 의한 mechanical interlocking effect가 아닌 전처리를 통한 폴리이미드 표면 개질로 C-0, C-N와 같은 chemical functional group이 증가했기 때문인 것으로 확인되었다.

임프린트 공정을 이용한 연성동박적층필름(FCCL)의 마이크로 패턴 제작

민철홍,김태선,Min, Chul Hong,Kim, Tae Seon 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.12

In this paper, we designed and fabricated low cost imprinting process for micro patterning on FCCL (flexible copper clad laminate). Compared to conventional imprinting process, developed fabrication method processing imprint and UV photolithography step simultaneously and it does not require resin etch process and it can also reduce the fabrication cost and processing time. Based on proposed method, patterns with $10{\mu}m$ linewidth are fabricated on $180mm{\times}180mm$ FCCL. Compared to conventional methods using LDI (laser direct imaging) equipment that showed minimum line with $10{\sim}20{\mu}m$, proposed method shows comparable pattern resolution with very competitive price and shorter processing time. In terms of mass production, it can be applied to fabrication of large-area low cost applications including FPCB.

The Electrochemical Migration Phenomenon of the Ni-Cr Seed Layer of Sputtered FCCL

Woo-young Ahn,Joong soon Jang 한국표면공학회 2014 한국표면공학회지 Vol.47 No.2

As the demand for fine-pitch FPCB (Flexible Printed Circuit Board) increases, so do the number of applications of sputtered FCCL (Flexible Copper Clad Laminate). Furthermore, as the width between the circuit patterns decreases, greater defects are observed in the migration phenomenon. In this study we observed changes in ion migration in real circuit-pattern width using sputtered FCCL. We found that as the applied voltage and residue thickness of the NiCr seeds increase, ion migration occurs faster. If the NiCr seed layer thickens due to a high cathode power and long deposition time while being sputtered, the NiCr will form a residue that quickly becomes a factor for incurring ion migration.

Sulfate 용액을 이용하여 전기도금 한 FCCL용 Cu 필름의 특성에 미치는 전류밀도와 pH의 영향

신동율(Dong-Yul Shin),박덕용(Doek-Yong Park),구본급(Bon-Keup Koo) 한국표면공학회 2009 한국표면공학회지 Vol.42 No.4

Nanocrystalline Cu thin films for FCCL were electrodeposited from sulfate baths to investigate systematically the influences of current density, solution pH on current efficiency, residual stress, surface morphology, and microstructure of thin Cu films. Current efficiencies were measured to be approximately 100%, irrespective of the applied current density and solution pH. But these influenced residual stress, surface morphology, XRD pattern, and grain size of electrodeposited Cu thin film. The residual stress decreased with decreasing the surface roughness, but increased with increasing the fcc(111) peak strength of XRD patterns.

열처리 환경 조건에 따른 FCCL의 tiecoat층과 폴리이미드 필름의 계면 분석 연구 (초)

김경록,허광수,김경각,안중규 대한금속재료학회 ( 구 대한금속학회 ) 2007 대한금속재료학회 학술대회 개요집 Vol.2007 No.1

황산염용액으로부터 전기도금 된 FCCL용 Cu 필름의 특성에 미치는 Cu 이온농도 및 첨가제의 영향

신동율(Dong-Yul Shin),박덕용(Doek-Yong Park),구본급(Bon-Keup Koo) 한국표면공학회 2009 한국표면공학회지 Vol.42 No.5

Nanocrystalline Cu thin films were electrodeposited from sulfate baths and investigated systematically the influences of Cu<SUP>2+</SUP> concentration and additives on current efficiency, residual stress, surface morphology, and XRD patterns of electrodeposited Cu film. Current efficiency was nearly 100% at from 0.2M to 1.0 M Cu<SUP>2+</SUP> concentration. but it was linearly increased with Cu<SUP>2+</SUP> concentration at less than 0.2M . The residual stress was observed in range of 7.9 to 18.4 ㎫ and tensile stress mode. Dendritic and powdered form was obtained at below 0.1 M. As increased with Cu<SUP>2+</SUP> concentration in solution, the main peak in the XRD pattern shifted (111) and (220) from (200). In the other hand, all about 100% current efficiency observed in all additive concentration systems, and residual stress observed in range of 20.4 to 26.3 MPa tensile stress. The condition 5(Ultra make-up - 10 ml/l, Ulta A - 0.5ml/l, Ultr B - 0.5 ml/l) was good surface morphology, and fcc(111) peak in XRD patterns increased with increasing additive concentration.

On-Line Electric Vehicle의 EMF 저감을 위한 FCCL 차폐효과 분석

심형욱(Hyung-Wook Shim),김종우(Jong-Woo Kim),조동호(Dong-Ho Cho) 대한전기학회 2014 전기학회논문지 Vol.63 No.6

According to ICNIRP guidelines for limiting exposure to time-varying electric, magnetic and electromagnetic fields up to 300GHz, magnetic flux density which range from 3Hz to 150kHz are regulated to lower than 6.25μT. In order to comply with its standard, OLEV(On-Line Electric Vehicle) have been designed considering EMF(Electro-Magnetic Field) reduction. However, if a current flowing in power line would be bigger for increasing power transfer efficiency, the established shield system no longer acts their role properly. In this paper, therefore, FCCL(Flexible Copper Clad Laminate) is applied to power line and pick-up devices to solve the problems. Though, the FCCL is normally utilized to insulator on circuit board, because of its high heat resistance characteristic, flexibility and thin properties, it makes effectiveness in the shielding device as well. 4 types of FCCL shielding structure are introduced to power line and pick-up devices. From the results, the FCCL which are placed in proposed positions shows maximum EMF reduction compared to the established shielding structure. Henceforth, if OLEV is applied FCCL shielding structure in practice, it will not only be more safe but also step forward to commercialization near future.

Effect of Cr Thickness on Adhesion Strength of Cu/Cr/Polyimide Flexible Copper Clad Laminate Fabricated by Roll-to-Roll Process

Noh, Bo-In,Yoon, Jeong-Won,Choi, Jung-Hyun,Jung, Seung-Boo The Japan Institute of Metals 2010 Materials Transactions Vol.51 No.1

<P>The adhesion strength of a Cu/Cr/polyimide (PI) flexible copper clad laminate (FCCL), which was manufactured by the roll-to-roll process, was evaluated according to the thickness of the Cr seed layer using the 90° peel test. The changes in the morphology, chemical bonding and adhesion properties were characterized by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. The peel strength of the FCCL decreased with increasing Cr layer thickness. The higher FCCL peel strength was attributed to the lower proportion of C-N bonds and higher proportion of C-O or carbonyl (C=O) bonds on the PI surface compared to the FCCL with the lower adhesion strength. The FCCL with the higher peel strength had a fractured PI surface with a higher surface roughness. The adhesion strength between the metal and PI was mostly attributed to the chemical interaction between the metal layer and the functional groups of the PI.</P>