On-line surface inspection of roll-to-roll film processing

卷对卷薄膜加工的在线表面检测

• 批准号: EP/K007068/1
• 负责人: Feng Gao
• 金额: $ 11.94万
• 依托单位: University of Huddersfield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FK007068%2F1
• 关键词: line; surface; inspection; roll; film

The rapidly increasing use of nano scale and ultra-precision structured surfaces is widely spread in many applications ranges and covers photovoltaic thin film, optics, Si wafers, hard disks, MEMS/NEMS, micro fluidics and the micro moulding industries. These industries all critically rely on ultra precision surfaces. There is however a fundamental limiting factor to the manufacture of such surfaces, namely the ability to measure the product rapidly in the manufacturing environment. It has been reported that currently the quality of fabrication depends largely on the experience of process engineers backed up by an expensive trial-and-error approach. Consequently many of these manufactured items suffer from high scrap rates as high as 50-70%. In the industries those making high volume large area foil products such as paper and packaging products and emerging market sectors such as flexible electronics, the manufacturing processes often involve the deposition and patterning of multi-layer thin films on large area substrates and foils. For these types of product, increased product performance and functionality can come from an increase in the number of layers, or a decrease from micro- to nano-scale in the thickness of individual layers or size of pattern features. To achieve high yield in the coating and patterning processes the films must be uniform and largely perfect over most of the area of the foil. However there is an increased risk of defects forming as the number of interfaces increases in the multi-layer films, and the size and nature of those defects changes as the layer thicknesses shrink to the nano-scale. Coating defects can be caused by surface anomalies on the foil (e.g. scratches and surface spikes or holes), by contamination in the form of ambient particles or chemical stains only a few atoms thick, and by incorrect process conditions (e.g. particle generation or build-up of reaction by-products). Patterning defects arise from incorrect pattern transfer, e.g. scribing or moulding faults. In order to ensure high product yield the key challenge is to inspect the foil surface at production speed with sufficient resolution to detect i) the presence of problem defects on the starting foil surface and ii) defects as they appear during the coating and patterning processes. Due to the nature of these processes the inspection methods have to be in noncontact with the film surfaces. Effective inspection is the key for further process such as applying local repair techniques to remove the defects from the film surface. Currently there is no effective inspection methods that can be applied for the above applications. This project attempts to address shortcomings of the techniques that we currently employed for surfae inspections by investigating a high speed on-line surface profile optical measurement technique based on white light spectral interferometry and parallel signal processing using general purpose graphic processing unit (GPGPU). These techniques combined have the potential to be applied to real-time on-line measurement of high precision surfaces such as those resulting from roll-to-roll film processing, lithographic etching processing, doping, CVD/PVD coatings, lapping, and CMP processing on the production line. The proposed system is a key for mass production of high quality, high efficiency photovoltaic thin film and other roll-to-roll film productions. The success of this product will help us to convert solar power to electricity more efficiently and cost effectively.

纳米尺度和超精密结构化表面的使用迅速增加，广泛分布在许多应用领域，涵盖光伏薄膜、光学器件、硅晶片、硬盘、MEMS/NEMS、微流体和微成型行业。这些行业都严重依赖超精密表面。然而，对于这种表面的制造存在基本限制因素，即在制造环境中快速测量产品的能力。据报道，目前的制造质量在很大程度上取决于工艺工程师的经验，而工艺工程师的经验又是以昂贵的试错法为后盾的。因此，许多这些制造的物品遭受高达50- 70%的高废品率。在那些制造高容量大面积箔产品（例如纸和包装产品）的工业以及新兴市场部门（例如柔性电子产品）中，制造工艺通常涉及在大面积基板和箔上沉积和图案化多层薄膜。对于这些类型的产品，增加的产品性能和功能可以来自于层数量的增加，或者单个层的厚度或图案特征的尺寸从微米级减小到纳米级。为了在涂覆和图案化过程中实现高产量，薄膜必须在箔的大部分区域上均匀且基本上完美。然而，随着多层膜中界面数量的增加，缺陷形成的风险增加，并且随着层厚度收缩到纳米级，这些缺陷的尺寸和性质发生变化。涂层缺陷可能由箔上的表面异常（例如划痕和表面尖峰或孔洞）、环境颗粒或仅几个原子厚的化学污渍形式的污染以及不正确的工艺条件（例如颗粒生成或反应副产物积累）引起。图案缺陷是由不正确的图案转移引起的，例如划线或模制故障。为了确保高产品产量，关键的挑战是以足够的分辨率以生产速度检查箔表面，以检测i）起始箔表面上是否存在问题缺陷，以及ii）在涂覆和图案化过程中出现的缺陷。由于这些过程的性质，检查方法必须与薄膜表面不接触。有效的检测是进一步加工的关键，如应用局部修复技术来去除膜表面的缺陷。 目前还没有有效的检测方法可以应用于上述应用。本计画针对目前表面检测技术之不足，以白色光干涉法为基础，并以通用图形处理器（GPGPU）进行平行讯号处理，研究一种高速在线表面轮廓光学量测技术。这些技术相结合，有可能被应用到高精度表面的实时在线测量，如那些从辊到辊膜处理，光刻蚀刻处理，掺杂，CVD/PVD涂层，研磨，和CMP生产线上的处理。该系统是大规模生产高质量、高效率光伏薄膜和其他卷对卷薄膜产品的关键。该产品的成功将帮助我们更有效地将太阳能转化为电力，并具有成本效益。

项目成果

In-situ defect detection systems for R2R flexible PV barrier films

R2R 柔性光伏阻隔膜的原位缺陷检测系统

• 发表时间: 2015
• 作者: Gao, F.,

In-Situ Surface Inspection Using White Light Channelled Spectrum Interferometer

• 发表时间: 2015-03
• 作者: Xiang Jiang;Dawei Tang;F. Gao

White Light Spetral Interferometry for Real Time Surface Profile Measurement

用于实时表面轮廓测量的白光光谱干涉仪

• 发表时间: 2013
• 作者: Gao, F.

Implementation of line-scan dispersive interferometry for defect detection

• 发表时间: 2016-05
• 作者: Dawei Tang;F. Gao;Xiang Jiang

Verification of an in Process Optical System based on High Resolution Interferometry for Detecting Flexible PV Barrier Films Defects

基于高分辨率干涉测量的过程中光学系统的验证，用于检测柔性光伏阻隔膜的缺陷

• 发表时间: 2014
• 作者: Elrawemi. M