Issue link: https://iconnect007.uberflip.com/i/1527952
80 PCB007 MAGAZINE I OCTOBER 2024 als, each of which has its own distinct electri- cal, chemical, physical, and thermal proper- ties. We started thinking, "If we have all these metals with unique properties, then theoreti- cally at least some of them should be able to be used for specific applications." ere should be, perhaps, other metals beyond what we have been using that would also be able to meet the requirements of a particular application. at's why I started my presentation that way. What was the feedback? A couple of chemists came up to me and said that they had also never exam- ined other metals in so much detail. In our education, we all learned a little bit about metallic bonding, how met- als are built up, and what they have in common, but never how each of these distinct metals behaves. In PCB manufacturing, we use cop- per, gold, tin, nickel, silver, and some palladium—things we are well versed in because we know everything that should or could happen. We typically don't change anything until forced. How does sputtering enter into the discussion? At Dyconex, we have successfully employed sputtering since 2018. Sputtering technology uses different techniques. We employ physical vapor deposition (PVD). In our process, you have the solid metal material which is called the target. Kinetically high energy argon plasma is bombarded onto the target of which material is ejected or deposited onto the target, which in our case is a PCB. is allows us to create very thin and controlled layers of metal. Chemical vapor deposition (CVD) is another sputtering methodology which needs to be operated at temperatures close to the melting points of the metals since the material being sputtered is already evaporated. Instead, PVD is used at room temperature and metals with very high melting points are sputtered. Hence it is very effective for our applications. What is nice about this technology is that the depos- ited material has a very similar composition to the material of the target. e adhesion of the PVD-sputtered films to the dielectric substrate is superior to that of evaporated films. ere- fore, it has higher reliability for most applica- tions. We have been quite successful in employ- ing this method in our products. Figure 1: Principle of Sputtering = Solid "target" is bombarded by energetic particles of plasma or gas. Material is ejected from target surface. Deposition of material onto a substrate. Evelyne Parmentier