Reverse-offset Printing Process and Equipment for Fine Patterning and Precision Overlay

Transcription

1 Reverse-offset Printing Process and Equipment for Fine Patterning and Precision Overlay Dongwoo Kang (Ph.D) June 22, 2017 (Monterey) Korea Institute of Machinery & Materials (KIMM)

2 Demand on FPE

3 What is bottleneck of FPE Complex process Long production time High cost equipment Photolithography Large material consumption Rigid substrates High Performance VS Printing process No vacuum deposition / No photolithography Simple process Applicable to various substrates Lower fabrication costs Mass production (R2R) Low Performance FHE (Flexible Hybrid electronics)

4 Alternative approach : Performance improvement Performance improvement (Process & Equipment) - Fine patterning - Dimensional accuracy (Overlay) - Material is out-of-scope in this presentation Target performance

5 Process & System Dimensional accuracy : R2R or R2P? Fine patterning : Process S. Khan et al., IEEE Sensors 15, (2014) W. Chen et al., Micromachines, 6, (2015) Coating Off process Patterning Set process

6 Fine patterning : Ink transfer & Patterning mechanism Printing window Critical dimensions The relation varies w.r.t the pattern dimension(w, l) and ink thickness(t) Y.-M. Choi et al., J. Micromech. Microeng. 25, (2014)

7 Fx (N) Fine patterning : Equipment (Synchronization) Large process margin in synchronization > ~1% - Fine patterning is possible even in large geometrical tolerances of equipment Delta position (mm) < Friction force at small relative displacement btw. roll and substrate > Off step PW > 1.4% Set step PW > 1.9% D. Kang et al.j. Appl. Phys. 115, (2014) < Friction force under rolling contact btw. roll and substrate (Pringing force 8kgf/20kgf) >

8 Fine patterning : 1μm line & TCF Y.-M. Choi et al., Microelectron. Eng. 134, 1-6 (2015) Y.-M. Choi et al., Journal of Information Display 16, (2015)

9 Dimensional accuracy Printing position error causes the position mismatch between printed sample and PCB (Example) KIMM T. Kamata, FLEX Japan 2017 presentation

10 Dimension accuracy of printing system : Repeatability Synchroniztion and printing pressure was controlled precisely Repeated printing under same process and equipment conditions Printing position repeatability : dx : 0.7 μm, dy : 0.9 μm - Air-bearing guide & Coreless linear motor : 0.013% RMS (100mm/s) - Printing force control : ±1N - DDR motor in rotary system : 0.015% RMS (100mm/s) Resolution : 100nm Repeatability : ±0.45 um/full stroke 10um 10um < Printing position error map> H. Kim et al.rev. Sci. Instrum. 87, (2016)

11 Precision position control of blanket roll Deformation control of substrate by tension control System concept of overlay correction

12 Printing equipment for overlay correction

13 Summary Roll-to-roll reverse-offset printing system is being developed - film width : 250mm - Overlay accuracy : 5 μm - Patterning resolution : 5 μm Printing module was developed - Printing position repeatability : ~2 μm in 2σ level Active correction method of overlay error was proposed - Control of relative position between the blanket roll and the plate during patterning step - Correction accuracy : X/Y (2σ) = 1.7/2.3 μm - Overlay accuracy on glass substrate : X/Y (mean+2σ) < 3.4/4.1 μm Roll-to-roll module is now under-construction (Developing control algorithm) - Result of overlay on the roll-to-roll film will be gathered at the end of this year

14 Dept. of Printed electronics. KIMM Ph.D. Jeongdai Jo (Principal researcher) / Mechanical Engineering Ph.D. Taikmin Lee (Head of a department of printed electronics) Ph.D. Kwangyoung Kim (Principal researcher) / Mechanical Engineering Ph.D. Inyoung Kim (Principal researcher) / Materials Science & Engineering Ph.D. Sin Kwon (Principal researcher) / Mechanical Engineering Ph.D. Yunseok Jang (Senior researcher) / Chemical Engineering Ph.D. Seunghyun Lee (Senior researcher) / Mechanical Engineering Ph.D. Dongwoo Kang (Senior researcher) / Mechanical Engineering Ph.D. Kyoohee Woo (Senior researcher) / Materials Science & Engineering Ph. D. Hyunchang Kim (Senior researcher) / Mechanical Enginerring THANK YOU