Materials Science 101 with EIPC Chairman Alun Morgan
Meet Alun Morgan, Technology Ambassador for Ventec, a world leader in the production of high quality, high performance copper clad laminates and prepregs with a world-wide distribution network. Alun interacts with customers around the world promoting Ventec materials, and brings the latest market requirements to Ventec in order to develop new products.
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- Alun is a Material Scientist, with a B.Sc. Hons in Metallurgy from the University of Surrey. Once he became involved in PCB manufacturing he found it such a fascinating field that he has spent his entire career refining his knowledge.
- Everything Ventec does can also apply to smaller scale operations who are making PCBs.
- Alun was a Keynote Speaker at AltiumLive
- The FR-4 we use today has it roots around 60 years ago; there was an FR1, 2 and 3, as well as FR-5. According to the NEMA specification from the 1960s, FR is defined as Flame Retardant.
- FR-4 also means the fourth generation of materials in the NEMA classifications system. It defines the resin kind and the reinforcement type.
- FR-4 is an epoxy resin and the reinforcement is typically woven glass fibres for strength.
- The substrate itself is a composite of these two materials; the resin, the reinforcement and the conductor which is copper.
- Why the different composites? The main reason is its strength, it’s a very good insulator, and it’s available. It also bonds chemically to glass fibres very well.
- Lead-Free soldering created a major change about 20 years ago when lead was banned from electronic assemblies causing a range of performance issues.
- Higher temps expand materials dramatically, and because there is no reinforcement in the Z-axis, the expansion is considerable.
- When materials are heated beyond the TG, or Glass Transition temperature, thermal expansion is rapid and massive.
- The solution to this is adding inorganic fillers to modified, lead-free compatible materials to reduce the Z-axis expansion of which there are several types such as silica-based materials.
- Losses impact - some inorganic fillers have lower loss than the epoxy resin they’re replacing.
- How to choose materials? Talk to your manufacturers about the correct materials, ask which material they use the most and which of them work most successfully. Do beware of SI though, as this is a very fast-moving aspect currently.
- It is strongly advised to attend materials courses, and ask questions. Ventec is always ready to assist and answer questions. Go to a boardshop and see how these things are produced.
- Alun is also the EIPC Chairman and anyone involved with PCBs is welcome to attend their events. There are two conferences every year and the next will be in Austria, on June 14th and 15th. This will include a facility tour of ATNS, the biggest grossing PCB shop in Europe.
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