스크린 인쇄의 부분 코팅을 활용한 도공지 포장 케이스의 폴드 크랙 보완에 관한 연구

노경환,하영백,유창준,오성상 한국인쇄학회 2022 한국인쇄학회지 Vol.37 No.1

패키지를 제작함에 있어서 괘선/구부림 가공은 판지 인쇄 후가공에서 가장 중요하게 생각되는 공정이다. 후가공 시 접지된 부분에 터짐 현상이 발생한다. 터짐 현상은 코팅 지가 괘선/구부림 과정을 거칠 때 발생하는 미관상의 결함이다. 주로 패키지가 구부러 졌을 때 발생하며 외관상 구부린 부분에서 코팅층의 소규모 분열로 특정 지어진다. 따 라서 도공지에서 발생하는 폴드 크랙을 종이를 만드는 제작 과정에서가 아니라 인쇄 적인 방법으로 보완할 수 있는 방법을 찾고자 한다. 또한 포장 패키지에 적용하고 있는 라미네이팅을 없애고 폴드 크랙을 보완하는 방안으로 스크린 인쇄 방식을 적용하여 폴 드 크랙 등의 문제를 해결하기 위해 본 연구를 진행하였다. 그 결과 다음과 같은 결론 을 얻었다. 용지 평량에 따른 폴드 크랙의 결과는 평량이 높을수록 두께가 두꺼워지므로 폴드 크랙의 발생이 더 많은 것을 알 수 있다. 포장 케이스의 경우 각 평량에 따라 괘선 넣 기 압력을 적절하게 수행되지 않으면 폴드 크랙의 발생률이 높아지는 것으로 나타났다. 용지의 두께에 따라 괘선 나이프의 높이를 조절하여 괘선 넣기 작업의 압력을 조절 한 결과 결 방향보다는 횡 방향에서 폴드 크랙이 많이 발생하지만 괘선 넣기 압력이 적절하게 수행되면 횡 방향에서 폴드 크랙이 개선이 되는 것으로 나타났다. 스크린 인쇄의 부분 코팅으로 폴드 크랙의 발생을 보완하는 결과는 코팅 용액 A보다 코팅 용액 B에서 더 좋은 결과가 나타났다. 코팅 용액의 성질은 A는 연질에 가깝고 B 는 강질이라고 하여 연질보다 강질의 품질이 더 좋은 것으로 나타났다. 따라서 첫 번째는 포장 케이스의 용도에 맞게 평량과 용지의 결 방향을 잘 맞출 필 요하다. 또한 스크린 인쇄의 부분적인 코팅을 통하여 폴드 크랙을 개선 확인할 수 있었 다. 추후 지속적인 연구를 통하여 스크린 인쇄방식이 아닌 오프셋 평판 인쇄방식으로 오버 코팅용 코팅 액을 개발한다면 환경적으로나 가격적인 측면에서 훨씬 더 나아질 것으로 기대된다. Ruled line/bend processing is the most important process in the processing after paperboard printing in manufacturing the package. During post-press, a cracking phenomenon occurs at the grounded part. The tearing phenomenon is an aesthetic defect that occurs when the coated paper goes through the creasing/bending process. It mainly occurs when the package is bent, and is characterized by small cleavage of the coating layer in the apparently bent part. Therefore, we want to find a way to compensate for fold cracks that occur in coated paper with a printing method, not during the paper production process. In addition, this study was conducted to solve problems such as folder cracks by using screen printing method as a way to eliminate laminating applied to packaging packages and to compensate for fold cracks. As a result, the following conclusions could be drawn. As a result of the fold crack according to the basis weight of the paper, the higher the basis weight, the thicker the paper, therefore, it can be seen that the occurrence of fold cracks is more. In the case of the packaging case, it was found that the incidence of fold cracks increased if the pressure to put the ruled line was not properly performed according to the basis weight of each. According to the thickness of the paper, by adjusting the height of the ruled line knife, the pressure of putting the ruled line was adjusted. As a result, fold cracks occur more in the transverse direction than in the grain direction. However, it was found that fold cracks were improved in the transverse direction when the corrugation pressure was properly performed. The result of compensating for the occurrence of fold cracks by partial coating of screen printing showed better results in coating solution B than in coating solution A. As for the properties of the coating solution, A was close to soft and B was hard, indicating that the quality of steel was better than that of soft. Therefore, first, it is necessary to properly match the basis weight and the grain direction of the paper according to the purpose of the packaging case. In addition, it was possible to confirm the improvement of fold cracks through partial coating using screen printing. In addition, if a coating solution for overcoating is developed using an offset lithographic printing method rather than a screen printing method through continuous research in the future, it is expected to be much better in terms of environment and price.

Post ionized defect engineering of the screen-printed Bi₂Te_2.7Se_0.3 thick film for high performance flexible thermoelectric generator

Kim, Sun Jin,Choi, Hyeongdo,Kim, Yongjun,We, Ju Hyung,Shin, Ji Seon,Lee, Han Eol,Oh, Min-Wook,Lee, Keon Jae,Cho, Byung Jin Elsevier 2017 Nano energy Vol.31 No.-

<P><B>Abstract</B></P> <P>Flexible thermoelectric generators (f-TEGs), fabricated by the screen printing technique, have been introduced as a semi-permanent power source for wearable and flexible electronic systems. However, the output power density of the f-TEG module is still limited due to the low ZT of the screen-printed thermoelectric (TE) film. We herein report a post ionized defect engineering process that effectively controls ionized defects and improves the ZT value of a screen-printed ternary TE film. It was found that post annealing in a forming gas ambient (4% H<SUB>2</SUB>+96% Ar) can reduce the nano- and micro-bismuth oxide particles in screen-printed n-type BiTeSe films, resulting in a bismuth rich condition and creation of bismuth antisite defects. We achieved a maximum ZT of 0.90 with the screen-printed n-type BiTeSe thick film at room temperature, which is almost comparable to that of the bulk Bi<SUB>2</SUB>Te<SUB>2.7</SUB>Se<SUB>0.3</SUB> and is a 2-fold increase over the same screen-printed film without the hydrogen ambient annealing. To demonstrate the applicability of this approach, a f-TEG device with 72 TE pairs (p-type Bi<SUB>0.5</SUB>Sb<SUB>1.5</SUB>Te<SUB>3</SUB>, forming gas annealed n-type Bi<SUB>2</SUB>Te<SUB>2.7</SUB>Se<SUB>0.3</SUB>) was fabricated by the screen printing technique. The device generated a high output power of 6.32mWcm<SUP>−2</SUP> at ΔT=25.6°C. These results demonstrate the feasibility of high performance and large-scale f-TEG fabrication using ionized-defect engineering.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A post ionized defect engineering process for improving ZT value of the screen-printed BiTeSe thick film is proposed. </LI> <LI> A post annealing in a forming gas ambient (4% H<SUB>2</SUB> + 96% Ar) can reduce the nano- and micro-bismuth oxide particles in screen-printed BiTeSe films, resulting in a bismuth rich condition and creation of bismuthantisite defects. </LI> <LI> A maximum ZT of 0.90 with the screen-printed BiTeSe film at room temperature, which isalmost comparable to that of the bulk Bi<SUB>2</SUB>Te<SUB>2.7</SUB>Se<SUB>0.3</SUB> and is a 2-fold increase over the same screen-printed film without the hydrogen ambient annealing. </LI> <LI> A f-TEG device with 72 TE pairs (p-type Bi<SUB>0.5</SUB>Sb<SUB>1.5</SUB>Te<SUB>3</SUB>, forming gas annealed n-type Bi<SUB>2</SUB>Te<SUB>2.7</SUB>Se<SUB>0.3</SUB>) generatesa high output power of 6.32 mWcm<SUP>-2</SUP> at ΔT = 25.6 °C. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

AI-Aided Printed Line Smearing Analysis of the Roll-to-Roll Screen Printing Process for Printed Electronics

Anton Nailevich Gafurov,Thanh Huy Phung,Beyong-Hwan Ryu,Inyoung Kim,Taik-Min Lee 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.2

Screen printing has been adopted for fabricating a wide variety of electronic devices. However, the printing defects and reliability have been an obstacle for industrialization of printed electronics. In this research, the artificial intelligence (AI) model was developed and integrated with the in-house roll-to-roll screen printing system to detect smearing defect, which is one of the main defects of screen printing. The U-Net architecture was adopted, and a total of 19 models were designed with model sizes ranging from 8E + 3 to 3E + 7 number of parameters. Their performances as validation mean Intersection over Union (IoU) were analyzed, and the optimal model was chosen with a validation mean IoU of 95.1% and a number of parameters of 8E + 6. The printed line images were evaluated by the AI model for various printing conditions, such as printed line widths, printing paste premixing, printing speeds, and printed line directions, which showed that the model could effectively detect the smearing defects. Also, the AI model capabilities were investigated for repeated printing, which demonstrated that it can be used for the reliability assessment of the screen printing process.

비정질 $MnO_2$ 전극의 전극두께에 따른 고출력 특성 변화

성우경,김은실,이하영,김선욱,Seong W. K.,Kim E. S.,Lee H. Y.,Kim S. W. 한국전기화학회 2000 한국전기화학회지 Vol.3 No.4

고출력 전기화학 캐패시터를 위한 전극제조공정으로 screen printing과 doctor blade법이 연구되었다. Screen printing에 의해서 제작된 비정질 $MnO_2$전극으로 측정된 CV (cyclic voltammogram)는 이상적인 캐패시터에 가까운 특성을 보여주었다. 50mV/s의 scan rate에서의 CV로부터 계산된 비용량은 $140{\mu}m,\;24{\mu}m,\; 3{\mu}m$의 전극두께에 대해서 각각 5.8F/g과, 81.8F/g, 172.0F/g의 값을 나타내었다. Screen printing전극에서의 $MnO_2$활물질의 이용율을 $100\%$로 하였을 때, paste와 doctor blade법의 이용율은 각각 $3.4\%$와 $47.6\%$이었다. Screen printing은 고출력 응용을 위한 얇은 전극의 코팅 방법으로 우수한 특성을 보였다. Screen-printing and doctor blade method were investigated and proposed as an electrode coating process for high power capacitor. CV measured from the amorphous $MnO_2$ electrode prepared by screen-printing shows closer to ideal capacitor characteristics. Specific capacitances calculated from CVs with potential scan rate of 50mV/s were 5.8, 81.8, and 172.0 F/g for electrode thickness of $140{\mu}m,\;24{\mu}m,\; 3{\mu}m$, respectively. Assumed that utilization of active $MnO_2$ in electrode of screen-printing is $100\%$, those were $3.4\%$ in one of paste method and $47.6\%$ in one of doctor blade method. The screen-printing can be good technique to coat thin film on current collector for high power application.

Enhancement of reproducibility and reliability in a high-performance flexible thermoelectric generator using screen-printed materials

Choi, Hyeongdo,Kim, Yong Jun,Kim, Choong Sun,Yang, Hyeong Man,Oh, Min-Wook,Cho, Byung Jin Elsevier 2018 Nano energy Vol.46 No.-

<P><B>Abstract</B></P> <P>Flexible thermoelectric generators (f-TEGs) have recently attracted significant attention because they can be applied to non-flat surfaces and used as semi-permanent power sources. The use of screen printing to fabricate f-TEGs would enable large-scale, mass production. To realize this aim, several hundred pairs of thermoelectric (TE) materials formed by screen printing must all exhibit uniform TE properties. However, parameter deviation commonly occurs in such batches because the materials formed by screen printing are usually crystallized in a large furnace or chamber. We report here a new crystallization process that avoids these problems while improving the output characteristics of the f-TEGs, using screen printed thermoelectric elements (sp-TEs). The sp-TEs were formed with a paste containing an excess of tellurium, which allowed a single-step crystallization process to be developed. The simplified process improved the low density associated with conventional sp-TE fabrication (to 6.23 g cm<SUP>−3</SUP> for Bi<SUB>.5</SUB>Sb<SUB>1.5</SUB>Te<SUB>3</SUB> and 6.43 g cm<SUP>−3</SUP> for Bi<SUB>2</SUB>Te<SUB>2.7</SUB>Se<SUB>.3</SUB>), and reduced the deviation in TE parameters (Seebeck coefficient, electrical and thermal conductivity) to less than half of the conventional range. As a result, the highest material figure of merit (ZT<SUB>MAT</SUB>) values among sp-TEs was achieved for both p-type sp-TE (0.93 ± 0.020) and n-type (0.64 ± 0.025) at room temperature. F-TEGs consisting of 200 couples of the improved sp-TEs produced an output power density of 5.23 ± 0.2 mW/cm<SUP>2</SUP> at a temperature difference (ΔT) of 25 K, demonstrating the feasibility of mass producing high-output f-TEGs with reliability and reproducibility.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new crystallization process for screen-printed TE materials (sp-TEs) is proposed. </LI> <LI> The reproducibility of f-TEG is greatly improved by reducing the deviation of sp-TE. </LI> <LI> The average ZT<SUB>M</SUB> <SUB>A</SUB> <SUB>T</SUB>s of p- and n-type sp-TEs through mass production are 0.93 and 0.64. </LI> <LI> Fabricated f-TEGs achieve a high power density of 5.23 ± 0.2mW/cm<SUP>2</SUP> with ΔT = 25K. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

스크린 인쇄법의 공정 조건이 전극 패턴 균일성에 미치는 영향

이나영,김동철,여동훈,이주성,윤상옥,신효순,이준형,Lee, Na-Young,Kim, Dong-Chul,Yeo, Dong-Hun,Lee, Joo-Sung,Yoon, Sang Ok,Shin, Hyo-Soon,Lee, Joon-Hyung 한국전기전자재료학회 2020 전기전자재료학회논문지 Vol.33 No.5

In this study, image analysis and surface roughness measurements using an optical microscope are presented as a method to quantitatively evaluate the results of screen printing. Using this method, the squeegee speed, which is the printing process condition, and the printability of the electrode according to the screen mesh were evaluated. Increasing the squeegee speed in the printing process acts as a process element that increases the line width precision of the printed electrode and lowers the surface roughness of the printed surface. Furthermore, the edge roughness, which indicates the clarity of printing, was not significantly affected by the speed of the squeegee during printing. The print thickness increases in proportion to the squeegee speed, but is largely dependent on the screen thickness.

스크린 프린팅법을 이용하여 제조된 고분자 전해질 연료전지에서 MEA(조합 막 전극)의 특성

임재욱,최대규,류호진 한국반도체디스플레이기술학회 2003 한국반도체장비학회지 Vol.2 No.4

The effect of fabrication method of catalytic layer on electrode performance has been investigated. Brush, spray gun and screen printer were used as fabrication tool and catalytic layers were formed by several methods in screen printing. Direct screen printing on polymer membrane, screen printing on carbon paper, and their combined method were applied. In the electrode fabricated by the screen printing method, Pt loading of Pt/C catalysts could be cut down to 50%, compared with results by the brushing and spraying methods. The best result of electrode was obtained as 0.6 V, at 1 A/$\textrm{cm}^2$ when catalytic layer was formed by the combined way.

결정질 실리콘 태양전지에 적용될 스크린 프린팅 기술 개발 동향 : 리뷰

전영우,장민규,김민제,이준신,박진주 한국태양광발전학회 2022 Current Photovoltaic Research Vol.10 No.3

The screen-printing method is the most mature solar cell fabrication technology, which has the advantage of being faster and simpler process than other printing technology. A front metallization printed through screen printing influences the efficiency and manufacturing cost of solar cell. Recent technology development of crystalline silicon solar cell is proceeding to reduce the manufacturing cost while improving the efficiency. Therefore, screen printing requires process development to reduce a line width of an electrode and decrease shading area. In this paper, we will discuss the development trend and prospects of screen-printing metallization using metal paste, which is currently used in manufacturing commercial crystalline silicon solar cells.

Screen Printing법을 이용한 PMN-PZT 후막의 제조 및 특성 연구

김상종,최형욱,백동수,최지원,김태송,윤석진,김현재 한국전기전자재료학회 2000 전기전자재료학회논문지 Vol.13 No.11

Characteristics of Pb(Mg, Nb)O$_3$-Pb(Zr, Ti)O$_3$system thick films fabricated by a screen printing method were investigated. The buffer layer were coated with various thickness of Ag-Pd by screen printing to investigate the effect as a diffusion barrier and deposited Pt as a electrode by sputtering on Ag-Pb layer. The printed thick films were burned out at 650$\^{C}$ and sintered at 950$\^{C}$ in O$_2$condition for each 20, 60min after printing with 350mesh screen. The thickness of piezoelectric thick film was 15∼20㎛ and Ag-Pb layer acted as a diffusion barrier above 3㎛ thickness. The PMN-PZT thick films were screen printed on Pt/Ag-Pb(6m) and sintered by 2nd step (650$\^{C}$/20min and 950$\^{C}$/1h) using paste mixed PMN-PZT and binder in the ratio of 70:30, and the remnant polarization of thick film was 9.1$\mu$C/㎠ in this conditions.

스크린 인쇄와 리버스 오프셋 인쇄를 혼합한 대면적 미세 전극용 인쇄공정

박지은,송정근,Park, Ji-Eun,Song, Chung-Kun 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.5

In this paper a printing process for patterning electrodes on large area substrate was developed by combining screen printing with reverse off-set printing. Ag ink was uniformly coated by screen printing. And then etching resist (ER) was patterned in the Ag film by reverse off-set printing, and then the non-desired Ag film was etched off by etchant. Finally, the ER was stripped-off to obtain the final Ag patterns. We extracted the suitable conditions of reverse Using the process we successfully fabricated gate electrodes and scan bus lines of OTFT-backplane used for e-paper, in which the diagonal size was 6 inch, the resolution $320{\times}240$, the minimum line width 30 um, and sheet resistance 1 ${\Omega}/{\Box}$.