Additive Manufacture of Metal-Ceramic-Joints by means of Selective Laser Melting

通过选择性激光熔化增材制造金属陶瓷接头

• 批准号: 434962551
• 负责人: Professor Dr.-Ing. Jörg Ernst Franke
• 金额: --
• 依托单位: Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik (FAPS)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/434962551?language=en
• 关键词: Additive; Manufacture; Metal; Ceramic; Joints

This project deals with the research of additive production of metal-ceramic composites by means of selective laser melting for power electronics. Currently, ceramic circuit carriers are manufactured using DBC- (direct bonded copper) or AMB- (active metal brazing) processes, that are mostly used as power electronic substrate materials. Both processes involve the bonding of a ceramic substrate to a metallic, electrically conductive thin (0.2-0.5 mm) layer, usually in the form of foils. In the DCB process, the two materials are joined by wetting of the molten Cu2O at the bottom side of the copper foil in direct contact with an oxide ceramic (usually Al2O3) in a firing process at approx. 1064 °C. This process results in a cohesive bond, which is necessary in the use of power electronic circuit carriers due to the CTE differences between ceramics and metallization. In the AMB process, titanium additions to a solder alloy (usually Ag-Cu-solders) form a reaction layer during the firing process in contact with ceramic materials. This solder therefore acts as an interface between the ceramic substrate and a metal foil. However, both processes show weaknesses in the areas of flexibility, 3D capability of the metallization and the consumption of resources. In order to finally preserve the conductive structures of the circuit carrier, various lithography-, etching- and washing-processes are necessary, which significantly extend the process chain and additionally harm the environment by using chemicals. Selective laser melting offers an alternative: powder materials can be selectively melted on ceramic substrates at approx. 500 °C in a single process step, which leads to the final metallization. This process can be described as selective laser brazing (SLB). In this research project, Cu-Ti powder is used as metallization material based on the analysis of the state of the art and the extensive preliminary work carried out. Al2O3 will serve as the substrate material. At the beginning of the research project, the melting behaviour of the powder materials without ceramic substrate material will be qualified. However, the main objective of the research is the determination of the wetting behaviour of the powders on the heated Al2O3 with the associated parameter studies. As qualification methods, adhesion tests, current carrying capabilities as well as long-term stabilities of the metallization before and after a thermal post-treatment in inert / evacuated atmosphere are tested. On the basis of EDX and WDX analyses, the core question of the research project - the possibility of a cohesive connection of titanium-containing powder with Al2O3 in the form of the creation of magneli-phases by means of SLB/SLM - is to be answered.

本项目主要研究利用选择性激光熔化技术增材制造电力电子用金属-陶瓷复合材料。目前，陶瓷电路载体是使用DBC-（直接键合铜）或AMB-（活性金属钎焊）工艺制造的，其主要用作电力电子基板材料。这两种工艺都涉及将陶瓷基底结合到金属导电薄层（0.2-0.5 mm）上，通常为箔的形式。在DCB工艺中，两种材料通过在约100 ℃的烧制过程中，在铜箔的底侧处与氧化物陶瓷（通常为Al 2 O3）直接接触的熔融Cu 2 O的润湿而结合。1064 °C。由于陶瓷和金属化之间的CTE差异，该过程导致内聚结合，这在电力电子电路载体的使用中是必要的。在AMB工艺中，添加到焊料合金（通常是Ag-Cu焊料）中的钛在烧制过程中与陶瓷材料接触形成反应层。因此，该焊料充当陶瓷基板和金属箔之间的界面。然而，这两种工艺在灵活性、金属化的3D能力和资源消耗方面都显示出弱点。为了最终保护电路载体的导电结构，需要各种光刻、蚀刻和清洗工艺，这些工艺显著地延长了工艺链，并且通过使用化学品额外地损害环境。选择性激光熔化提供了一种替代方案：粉末材料可以在大约100 ° C的温度下选择性地熔化在陶瓷基底上。500 °C，这导致最终的金属化。该过程可以被描述为选择性激光钎焊（SLB）。本课题在分析国内外金属化技术发展现状的基础上，进行了大量的前期工作，选择了Cu-Ti粉末作为金属化材料。Al 2 O3将用作衬底材料。在研究项目开始时，将对不含陶瓷基体材料的粉末材料的熔化行为进行定性。然而，研究的主要目的是确定粉末在加热的Al 2 O3上的润湿行为以及相关的参数研究。作为鉴定方法，测试了在惰性/真空气氛中进行热后处理之前和之后的附着力测试、载流能力以及金属化的长期稳定性。在EDX和WDX分析的基础上，该研究项目的核心问题--含钛粉末与Al 2 O3以通过SLB/SLM产生镁合金相的形式进行内聚连接的可能性--有待回答。