High-performance printed electronics based on inorganic semiconducting nano to chip scale structures

Dahiya Abhishek Singh,Shakthivel Dhayalan,Kumaresan Yogeenth,Zumeit Ayoub,Christou Adamos,Dahiya Ravinder 나노기술연구협의회 2020 Nano Convergence Vol.7 No.33

The Printed Electronics (PE) is expected to revolutionise the way electronics will be manufactured in the future. Building on the achievements of the traditional printing industry, and the recent advances in flexible electronics and digital technologies, PE may even substitute the conventional silicon-based electronics if the performance of printed devices and circuits can be at par with silicon-based devices. In this regard, the inorganic semiconducting materials-based approaches have opened new avenues as printed nano (e.g. nanowires (NWs), nanoribbons (NRs) etc.), micro (e.g. microwires (MWs)) and chip (e.g. ultra-thin chips (UTCs)) scale structures from these materials have been shown to have performances at par with silicon-based electronics. This paper reviews the developments related to inorganic semiconducting materials based high-performance large area PE, particularly using the two routes i.e. Contact Printing (CP) and Transfer Printing (TP). The detailed survey of these technologies for large area PE onto various unconventional substrates (e.g. plastic, paper etc.) is presented along with some examples of electronic devices and circuit developed with printed NWs, NRs and UTCs. Finally, we discuss the opportunities offered by PE, and the technical challenges and viable solutions for the integration of inorganic functional materials into large areas, 3D layouts for high throughput, and industrial-scale manufacturing using printing technologies.

Control and Measurement of Doctoring Angle at Deformed State in Doctoring Apparatus for Printed Electronics

전성웅,김충환,김철 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.5

In printed electronics, the performance of printed devices depends on the quality of the printed patterns, or printability. It depends on the printing ink, the printing equipment, and printing conditions. Therefore, for reliable printed patterns with high printability, the printing conditions should be optimized and then maintained at constant values. Among the various printing conditions, parameters related to the doctoring process are important in gravure printing. In this study, the doctoring angle is redefined by the contact angle between the master plate and the doctor blade at the deformed state rather than the undeformed initial angle. The doctoring apparatus, capable of varying the angle of the doctor blade by controlling the position of the blade at the desired position, is developed. To estimate the doctoring angle in the deformed state without measurement from the photo image, mathematical model that calculates the doctoring angle in the deformed state using only geometric properties are derived. The doctoring angles based on the proposed mathematical model are compared with those measured from direct photo images for verifying the proposed method. In addition, the effect of the doctoring angle on the printability of the printed patterns is examined qualitatively through an experiment.

패턴 형상, 인쇄 및 건조 조건이 전도성 잉크를 이용한 그라비아 인쇄 결과물의 성능에 미치는 영향

안병준(Byoung Joon Ahn),한경준(Kyung Joon Han),고성림(Sung Lim Ko) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.3

e-Printing은 전통 인쇄 기술을 기반으로 하는 전자소자를 생산하기위한 새로운 기술이다. 이러한 인쇄 전자소자들은 가격을 낮추기 위하여 대면적 인쇄가 요구된다. 이렇듯 원가를 절감하며 전자 소자에 요구되는 정밀도를 충족하기 위하여 롤투롤(Roll to Roll) 방식의 그라비아(Gravure) 인쇄 시스템이 하나의 대안으로 제시된다. 그라비아 인쇄에는 인쇄 전자 소자의 성능에 영향을 미치는 요소들이 매우 많다 : 건조 방식, 건조 온도, 운전 장력, 인쇄 속도, 잉크 점도, 잉크의 전도성, 망점 및 패턴의 정밀도. 이상에서 언급한 요소들은 각각 매우 밀접한 관계를 가지고 있다. 따라서 인쇄 전자소자의 성능을 향상시키기 위해서는 반듯이 인쇄 적합조건을 찾아야만 한다. 본 논문에서는, 전도성 잉크 및 그라이아 인쇄기를 사용하여 다양한 요소의 조건을 변화하여 패턴(선 및 면)을 인쇄하였으며, 각 인쇄 요소의 변화가 인쇄 전자소자의 성능에 미치는 영향에 관하여 분석 및 연구를 수행하였다. e-Printing is a new manufacturing technology for electronic products and is based on traditional printing technology. The electronic products require a large area to facilitate printing and to be economical. A gravure printing system that supports a roll to roll (R2R) manufacturing process can be used to reduce the cost and to achieve the required accuracy. Many factors such as drying method, drying temperature, tension,-printing velocity, ink viscosity, ink conductivity, pattern accuracy, and dot geometry influence the performance of printed electronics. These factors are closely interrelated. The optimum condition for printing must be determined to enhance the performance of the printed electronics. In this study, lines and areas are printed using a gravure printer with conductive ink under different conditions of the above mentioned factors. The results are analyzed to investigate the influence of various factors on the performance of the printed electronics.

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.

3D Printed Electronics of Non-contact Ink Writing Techniques: Status and Promise

Haining Zhang,Seung Ki Moon,Teck Hui Ngo 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.2

Non-contact ink writing techniques are a newly developed three-dimensional printing technology to fabricate customized and flexible electronic devices, while dramatically reducing chemical waste and lowering manufacturing costs. However, the use of non-contact ink writing technologies for fabricating electronics is still limited due to printing quality. To develop an electronic device with high performance, conductive lines should be printed with high controllability and excellent uniformity. Under such circumstances, many traditional optimization methods have been proposed to improve the printing quality. However, as the non-contact ink writing process is very sensitive to the system drifts and random variations, in situ process monitoring and online optimization technologies to optimize the printed line quality are in demand for practical printing. In this paper, we describe the processes of non-contact ink writing techniques based on inkjet printing (IJP) and aerosol jet printing (AJP). The key influencing factors in the non-contact ink writing processes are also discussed based on the three main printing stages. Then we analyze the advantages and disadvantages of the IJP and AJP techniques and review the state of art in quality optimization and precise control techniques that can be adopted in non-contact ink writing process. Additionally, to further develop a non-contact ink writing system, the major challenges and limitations of the current printing quality optimization technologies are also highlighted in this paper.

Flexible 2-Layer Paper Printed Circuit Board Fabricated by Inkjet Printing for 3-D Origami Electronics

강민규,강경태 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.5 No.3

Inkjet printing has advantages to be easy to use, environmentally benign and adaptable for flexible electronics manufacturing. Also, paper is an emerging potential substrate due to extremely cheap price and its abundance. We used inkjet printing on a paper to make inexpensive flexible 3-D origami electronics. We printed two pads of 2 × 2mm2 and the metal lines between pads that had the width of 0.2 mm and the length of 5 mm on the paper. Repetitive printing methods reduced the resistance value of metal lines. The measured resistance values of metal lines printed on a chromatography paper ten times repeatedly were less than 10 ohms. We confirmed that the metal lines printed on both sides of the paper were not connected and could be connected through the ‘printed via without holes’. The inkjet-printed metal lines on paper were successfully used to construct the simple PCB with LED. We also tested bending test and confirmed lighting the LED. In order to prevent that metal lines were broken during folding the paper PCB, both sides of the folding point were additionally printed such as via. As a result, the metal line was not broken even when folded.

A study on the relationship between print-ability and flash light sinter-ability of Cu nano/micro-ink for printed electronics

Ryu, Chung-Hyeon,Moon, Chang-Jin,Kim, Hak-Sung Elsevier 2019 THIN SOLID FILMS - Vol.671 No.-

<P><B>Abstract</B></P> <P>In this study, the effect of rheological properties of Cu nano/micro (NP/MP)-inks with various amounts of dispersant on the print-ability and sinter-ability for flash light sintering was investigated. The rheological properties such as viscosity, viscoelasticity and thixotropic index of Cu NP/MP-inks were measured using a rheometer. The fabricated Cu NP/MP-inks were printed on polyimide substrate using a screen printing method. The 3D profile of printed Cu NP/MP-ink pattern was measured using surface profiler. In order to sinter the printed Cu NP/MP-inks, flash light sintering technique was employed. The flash light irradiation conditions (pulse power, pulse number, on-time, and off-time) were optimized to obtain the high sintering characteristic of Cu NP/MP-inks. In order to characterize the microstructures and transformation crystal phase of the sintered Cu NP/MP-inks, scanning electron microscopy, focused ion-beam and X-ray diffraction analysis were performed. From the results, the optimal sintered Cu NP/MP-ink film had a 6.16 μΩ·cm resistivity and 5B level of adhesion strength.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We investigated the effect of dispersant on print-ability and sinter-ability. </LI> <LI> 2.6 wt% of dispersant enhanced the printing uniformity and aspect ratio. </LI> <LI> Enhanced print-ability improved the flash light sinter-ability. </LI> <LI> The sintered Cu film showed the low resistivity and high adhesion strength. </LI> </UL> </P>

미세표면구조 위에서 전자인쇄를 위한 미세 라인 패터닝

김승환(Seung-hwan Kim),강현욱(Hyun Wook Kang),이경헌(Kyung Heon Lee),성형진(Hyung Jin Sung) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

The effect of micro surface structure on printing for printed electronics has been studied experimentally. The photolithography MEMS fabrication was used to make PDMS pillar microstructure on surface. In the aspect of printed electronics, we used silver paste conductive ink. We measured the surface energy variation on microstructure and flat PDMS surface. The microstructure was used to real printing experiment by a screen printing. We printed 1㎝ micro lines which have 30~250㎛ width, and checked the conductivity to sort out opened line pattern. Printability was defined by success probability of printed patterns and we found that the present microstructures improve the printability significantly.

그라비아 인쇄용 롤(roll)의 패턴 형상이 전도성 잉크를 이용한 인쇄 성능에 미치는 영향

안병준(Byoung Joon Ahn),한경준(Kyoung Joon Han),고성림(Sung Lim Ko) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

e-Printing is the new manufacturing technology compared to traditional printing technology for electronic products. And these products need wide area printing and to be very cheap. Therefore gravure printing system with roll to roll(R2R) system will be used to reduce cost and to keep the required accuracy. Engraved roll for gravure printing system will be used. On the surface of the roll, the structure to be printed is machined negatively, which will be filled by conductive ink and transferred to the web material. As one of the characteristics of gravure printing, the areas and lines are composed of a set of dots. In this paper, lines and areas will be printed using gravure printer with conductive ink. The engraved pattern of the gravure roll is composed of various geometry of dots like depth, angle are shape. The printing result, the ratio of ink transfer and accuracy of lines, will be analyzed to investigate the influence of the geometry of dots to the quality of printing.

롤투롤 그라비아 옵셋 인쇄전자장비의 특성

윤성식(Seong Shik Yoon),강은구(Eun Gu Kang),유세민(Se Min Yu),허성준(Seong Joon Heo),조정대(Jeong Dai Jo) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

Recently, printed electronics have been actively research for apply to electronic device manufacturing process to replace traditional manufacturing process. Roll to Roll printing technology can make it possible to produce electronic device such as display, RFID, solar cell, e-paper, etc. Gravure offset printing is typical method for Roll to Roll printing. In this study, Gravure offset printing is applied to the vertical structure of the printing module equipped with printing system, we found that ink and blanket, film's characteristics are very important element by printing test of the 20㎛, 30㎛, 40㎛, 50㎛ horizontal, vertical, bending, radial fine pattern.