Stephanie Edwards, R. Persons, S. Feltham, Jeff Howerton, Geoffrey A. Lott, D. Macko
{"title":"Laser Etching of Gold Conductors for RF Applications","authors":"Stephanie Edwards, R. Persons, S. Feltham, Jeff Howerton, Geoffrey A. Lott, D. Macko","doi":"10.4071/2380-4505-2019.1.000373","DOIUrl":null,"url":null,"abstract":"\n Thick film customers who require fine line resolution for their circuitry typically utilize wet chemical etching as a means to reduce conductor's lines and spaces when fine line definition cannot be reliably attained with screen printing alone. Wet chemical etching typically has the means to reduce conductor line widths from a printed definition of 3 mil (75 μm) to as low as 1 mil (25 μm) lines and spaces. The process of performing this chemical etching is time consuming and costly when factoring in the necessary process limitations.\n With the issues presented by wet chemical etching, thick film customers are presented with a high process cost, yield loss due to the imaging process, and costly wastewater/environmental treatment regulations. Therefore, laser etching will be presented as an alternative method to wet chemical etching for various thick film conductor products.\n For many years, specialized gold formulations have been etched using typical wet chemical etching processes. Standard and less costly conductor alloys that typically would not be suitable for wet chemical etching will be explored, possibly opening the doors for a wide variety of different applications which would benefit from utilizing this laser etching method. By being able to utilize different conductor alloys (Ag, Cu, etc.), laser etching offers alternative solutions for some of these applications with the added benefit of improved cost and increased throughput. As an example, wet chemical processing of silver conductors has proven to be very challenging in some cases due to the metal form-factor and specialized glasses required. By having the option of laser ablating the silver, a potentially advantageous and cost-effective option would now be possible.\n Taking into account that laser etching of thick film conductors on ceramic is a relatively new method, this paper will concentrate on some of the opportunities/advantages it can offer. It will illustrate the boundaries of laser etching and how it compares to wet chemical etching while determining/comparing the impact on several properties including adhesion, signal propagation, line definition, and other important defining characteristics of the fired film in the final application.","PeriodicalId":14363,"journal":{"name":"International Symposium on Microelectronics","volume":"38 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Symposium on Microelectronics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4071/2380-4505-2019.1.000373","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Thick film customers who require fine line resolution for their circuitry typically utilize wet chemical etching as a means to reduce conductor's lines and spaces when fine line definition cannot be reliably attained with screen printing alone. Wet chemical etching typically has the means to reduce conductor line widths from a printed definition of 3 mil (75 μm) to as low as 1 mil (25 μm) lines and spaces. The process of performing this chemical etching is time consuming and costly when factoring in the necessary process limitations.
With the issues presented by wet chemical etching, thick film customers are presented with a high process cost, yield loss due to the imaging process, and costly wastewater/environmental treatment regulations. Therefore, laser etching will be presented as an alternative method to wet chemical etching for various thick film conductor products.
For many years, specialized gold formulations have been etched using typical wet chemical etching processes. Standard and less costly conductor alloys that typically would not be suitable for wet chemical etching will be explored, possibly opening the doors for a wide variety of different applications which would benefit from utilizing this laser etching method. By being able to utilize different conductor alloys (Ag, Cu, etc.), laser etching offers alternative solutions for some of these applications with the added benefit of improved cost and increased throughput. As an example, wet chemical processing of silver conductors has proven to be very challenging in some cases due to the metal form-factor and specialized glasses required. By having the option of laser ablating the silver, a potentially advantageous and cost-effective option would now be possible.
Taking into account that laser etching of thick film conductors on ceramic is a relatively new method, this paper will concentrate on some of the opportunities/advantages it can offer. It will illustrate the boundaries of laser etching and how it compares to wet chemical etching while determining/comparing the impact on several properties including adhesion, signal propagation, line definition, and other important defining characteristics of the fired film in the final application.
对于需要细线分辨率的厚膜客户,当仅通过丝网印刷无法可靠地获得细线清晰度时,通常使用湿化学蚀刻作为减少导体线路和空间的手段。湿化学蚀刻通常具有将导体线宽度从印刷定义的3 mil (75 μm)减少到低至1 mil (25 μm)的线和空间的方法。当考虑到必要的工艺限制时,执行这种化学蚀刻的过程是耗时和昂贵的。由于湿法化学蚀刻所带来的问题,厚膜客户面临着高工艺成本、成像过程造成的产量损失,以及昂贵的废水/环境处理法规。因此,激光刻蚀将成为各种厚膜导体产品湿法化学刻蚀的替代方法。多年来,专门的金配方已经蚀刻使用典型的湿化学蚀刻工艺。将探索通常不适合湿化学蚀刻的标准和成本较低的导体合金,可能为各种不同的应用打开大门,这些应用将受益于利用这种激光蚀刻方法。通过能够利用不同的导体合金(Ag, Cu等),激光蚀刻为其中一些应用提供了替代解决方案,具有降低成本和提高吞吐量的额外好处。例如,由于金属形状因素和需要专用玻璃,在某些情况下,银导体的湿化学处理已被证明是非常具有挑战性的。通过选择激光烧蚀银,一个潜在的优势和成本效益的选择现在是可能的。考虑到陶瓷上厚膜导体的激光蚀刻是一种相对较新的方法,本文将集中讨论它可以提供的一些机会/优势。它将说明激光蚀刻的边界,以及它与湿化学蚀刻的比较,同时确定/比较对几个特性的影响,包括附着力,信号传播,线条定义,以及最终应用中烧制膜的其他重要定义特性。