• 한국포장학회지
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• 제30권1호
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• pp.73-83
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• 2024

In this study, environmental evaluation of high barrier coated paper (coating layer/paper) packaging is conducted in comparison with conventional aluminum laminated (PET/VMPET/LLDPE) plastic packaging. The target product for this packaging is a KF94 mask, which requires a high barrier of water and oxygen to maintain the filtration ability of the mask filter. The functional unit of this study is 10,000 mask packaging materials based on a material capable of blocking oxygen (<1 g/m²day) and moisture (<3 g/m²day) for the preservation of KF94 masks. In order to understand the results easily, paper-based mask packaging system divided into 6 stages (pulp, pulping & paper making, calendaring & coating, printing, packing and waste management), while plastic-based mask packaging consists of 5 stages (material production, processing, printing, packing, waste management) In case of paper-based mask packaging, most contributing stage is calendaring & coating, resulting from heat and electricity production. On the other hand, plastic-based mask packaging is contributed more than 30% by material production, specifically due to linear low density polyethylene and purified terephthalic acid production. The comparison results show that global warming potential of paper-based mask packaging has 32% lower than that of plastic-based mask packaging. Most of other impact indicators revealed in similar trend.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2000년도 추계 기술심포지움 논문집
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• pp.31-34
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• 2000

• 마이크로전자및패키징학회지
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• 제23권4호
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• pp.7-10
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• 2016

The post cleaning method for clean the shadow mask using in OLED (organic light emitting diode) emitter layer is always reforming. The cleaning solution and analysis method of shadow mask is still lack and not optimized. We use the simple and useful analytical method to determine the quantity and quality of organic and inorganic residue on surface of shadow mask. Finally analyze the cleaning solution using Raman spectroscopy efficiently.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
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• pp.191-194
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• 2003

Low energy EPL용 마스크 구현을 위한 특성을 연구하였다. Monte Carlo 법을 이용하여 시뮬레이터를 제작하였고, pattern side wall의 slope와 membrane의 Thickness, 전자빔의 가속전압에 따른 전자빔의 거동을 확인함을 통하여 Low energy EPL용 마스크 제작을 위한 spec.을 도출하였다. 또한 실제 제작을 위한 기초단계로 Si etching을 수행하였으며, mask 제작법에 대한 가능성을 확인할 수 있었다.

• Safety and Health at Work
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• 제13권3호
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• pp.364-371
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• 2022

Background: Respiratory masks can provide healthcare workers with protection from biological hazards when they have good performance. There is a direct relationship between the visual specifications of a mask and its efficacy; thus, the aim of this study was to develop tools for qualitative assessment of the performance of masks used by healthcare workers. Methods: A mixed-methods design was used to develop a qualitative assessment tool for medical face masks (MFM) and particle filtering half masks (PFHM). The development of domains and items was undertaken using observation and interviews, the opinions of an expert panel, and a review of texts and international standards. The second phase evaluated the psychometric properties of tools. Finally, the validated Mask Qualitative Assessment Tools (MQAT) were used to assess six samples from 10 brands of the two types of masks. Results: MQAT-MFM and MQAT-PHFM shared 42 items across seven domains: "cleanliness," "design," "marking, labeling and packaging," "mask layers," "mask strap," "materials and construction," and "nose clip." MQAT-MFM included one additional item. MQAT-PHFM included another nine items associated with an eighth "Practical Performance" domain, and the valve version had another additional "Exhalation Valve" domain and six items. The evaluation indicated 80% compliance for MFM and 71% compliance for PFHM. "Marking, labeling and packaging" and "Layers" were associated with the least compliance in both types of masks and should be checked carefully for defining mask quality. Conclusion: MQAT can be used for immediate screening and initial assessment of MFM and PHFM through appearance, simple tools, and visual inspection.

• 마이크로전자및패키징학회지
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• 제6권3호
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• pp.65-71
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• 1999

광 패키징에서 광섬유와 광전자소자를 정확히 정렬하기 위한 V-groove의 치수 정밀도에 미치는 마스크 재료와 에칭용액의 영향을 연구하였다. PECVD nitride, LPCVD nitride, thermal oxide($SiO_2$)를 마스크재료로 사용하였고 실리콘을 이방성에칭하는 용액으로 KOH(40wt%)용액과 KOH(40wt%)용액에 IPA를 첨가한 용액을 이용하였다. 마스크재료로는 LPCVD nitride가 가장 좋은 선택적에칭특성을 나타내었으며 사용된 마스크재료 중 thermal oxide가 가장 빠른 속도로 에칭되었다. V-groove의 크기 증가는 마스크충 아래로의 undercutting에 의해 생겼는데 이는 주로 (111)면으로의 에칭 때문이었다. KOH(40wt%)용액에서 (111)면의 에칭속도는 0.034 - 0.037 $\mu\textrm{m}$/min로 마스크재료에 관계없이 거의 일정하였다. IPA를 KOH(40wt%)용액에 첨가하면 (100)면과 (111)면의 에칭속도는 모두 감소하지만 (111)면에 대한 (100)면의 에칭속도비는 증가하였다. 그러므로 이런 용액에서 (111)면으로의 에칭에 의한 undercutting현상은 줄어들었으며 V-groove의 크기를 더 정확하게 조절할 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.141-144
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• 2002

Computer code was developed to design waveguide gratings based on coupled-mode equations and the transfer matrix formalism. The experimental set-up has been constructed for inscribing Bragg gratings in planar waveguides with a phase mask and uv laser beam, which enables alignment and packaging of grating devices as well as in-situ performance measurements. Bragg grating has been fabricated on silica planar waveguides with 0.75% Germanium concentration and its transmittance spectrum was measured to have 95% reflectance at the peak wavelength. Optical losses as the function of the misalignment were measured and their usage is described.

• 한국생산제조학회지
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• 제21권3호
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• pp.408-414
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• 2012

Screen printing is a printing method that uses a woven mesh to support an ink-blocking stencil by transferring ink or other printable materials in order to form an image onto a substrate. Recently, the screen printing method has applied to micro-electronic packaging by using solder paste as a printable material. For the screen printing of solder paste, metal masks containing a number of micro-holes are used as a stencil material. The metal mask undergoes deformation when it is installed in the screen printing machine, which results in the deformation of micro-holes. In the present study, finite element (FE) analysis was performed to predict the amount of deformation of a metal mask. For an efficient calculation of the micro-holes of the metal mask, the sub-domain analysis method was applied to perform FE analyses connecting the global domain (the metal mask) and the local domain (micro-holes). The FE analyses were then performed to evaluate the effects of slot designs on the deformation characteristics, from which more uniform and adjustable deformation of the metal mask can be obtained.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2002년도 International Symposium
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• pp.79-94
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• 2002

Root cause -Thermal expansion coefficient mismatch -Tape warpage -Initial die crack (die roughness) Guideline for failure prevention -Optimized tape/Substrate design for minimizing the warpage -Fine surface of die backside Root cause -Thermal expansion coefficient mismatch - Repetitive bending of a signal trace during TC cycle - Solder mask damage Guideline for failure prevention - Increase of trace width - Don't make signal trace passing the die edge - Proper material selection with thick substrate core Root cause -Thermal expansion coefficient mismatch -Creep deformation of solder joint(shear/normal) -Material degradation Guideline for failure Prevention -Increase of solder ball size -Proper selection of the PCB/Substrate thickness -Optimal design of the ball array -Solder mask opening type : NSMD -In some case, LGA type is better

• 마이크로전자및패키징학회지
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• 제21권2호
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• pp.53-57
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• 2014

Thin glass (< 100 microns) is a promising material from which advanced interposers for high density electrical interconnects for 2.5D chip packaging can be produced. But thin glass is extremely brittle, so mechanical micromachining to create through glass vias (TGVs) is particularly challenging. In this article we show how laser processing using deep UV excimer lasers at a wavelength of 193 nm provides a viable solution capable of drilling dense patterns of TGVs with high hole counts. Based on mask illumination, this method supports parallel drilling of up over 1,000 through vias in 30 to $100{\mu}m$ thin glass sheets. (We also briefly discuss that ultrafast lasers are an excellent alternative for laser drilling of TGVs at lower pattern densities.) We present data showing that this process can deliver the requisite hole quality and can readily achieve future-proof TGV diameters as small $10{\mu}m$ together with a corresponding reduction in pitch size.