The Centre for Process Innovation (CPI) is working as part of a consortium to improve airtight bonding in OLED lighting for aerospace and defence applications.
CPI is working on the project with lead partner Oxford Lasers Limited, alongside Glass Technology Services Ltd, Coherent Scotland Limited, Heriot Watt University, Gooch & Housego Limited, and Leonardo MW Limited.
The UltraWELD project, which has been part-funded by Innovate UK, the UK’s innovation agency, will develop photonic-based processes for highly dissimilar material joining – a common technique used in the manufacturing of complex electro-optics.
Existing technology to join dissimilar materials is mainly focused upon adhesive bonding. While adhesive bonding is highly flexible and low-cost, it cannot provide truly hermetic bonds, which leads to reduced performance or optical damage.
The project will focus primarily on the bonding of glass to metal, for example in the hermetic sealing of thin glass Organic Light Emitting Diode (OLED) devices and optical components for electro-optics, miniature lasers and sensors. CPI will use state-of-the-art equipment on glass up to 100 microns thick to make OLED devices, which will be provided to a partner to carry out laser hermetic sealing. Using material combinations of crystal quartz to stainless steel and BK7 glass to aluminium, the improved bonding technique will have applications in defence and aerospace.
CPI’s extensive in-house facilities and expertise across the manufacturing and testing of OLED devices will support the development of a laser prototype machine that will produce robust repeatable welds and deliver associated process monitoring and post-process inspection. High repetition rate ultrafast lasers will also be used to achieve high precision laser welding in confined glass-metal interfaces.
The 30-month project will additionally explore secondary benefits, such as airtight sealing for vacuum insulated glazing. This includes toughened safety glass on metal for lightweight vehicle windows, hermetic sealing of microfluidic devices and glass window bonding to silicon PV panels to protect against moisture.
Dr Sam Chan, CPI Senior Scientist and UltraWELD Project Manager, said: “UltraWELD provides CPI an excellent opportunity to prove the manufacture of flexible glass OLEDs. Working with the project consortium enables laser hermetic sealing of OLEDs, a perfect protection against moisture, which can be used for all Optoelectronics devices and can enhance their lifetime. CPI will use gained knowhow in the manufacture of flex glass OLEDs to further build and disseminate UK-OLED manufacturing knowledge to our partners in the High Value Manufacturing Catapult and their customers.”
Oxford Lasers Limited will both coordinate the programme and build a laser prototype machine to demonstrate new developments based on advanced ultrafast laser micro-joining of highly dissimilar materials.
Oxford Lasers Limited’s Project Manager, Dr Dimitris Karnakis, said: “This is a first-class opportunity to work with a top team of UK experts in leading industrial and academic organisations and establish presence in a growing new laser niche. We expect to be able to offer customised laser micro-joining systems and subcontract services to the defence and aerospace and thin glass OLED sectors by 2020. We will also extend our reach to other application areas with some synergy such as photonics, microfluidics, solar PV and glass microprocessing technology, which are well aligned to benefit from our microwelding advances.”
Professor Duncan Hand, Academic Lead at Heriot-Watt University, said: “For Heriot-Watt, UltraWELD is the culmination of six years of research into the picosecond laser welding process for joining highly dissimilar materials, a process with great potential for a wide range of applications. The project brings together the perfect consortium of industry and RTOs to convert this novel process into a commercial reality.”
Mantas Butkus, Coherent Product Line Manager, said: “Based on photonic technologies, the project allows Coherent Scotland Limited to work along world-leading technology developers and adapters in order to advance the next-generation ultrafast laser sources for the challenging and exciting applications of bonding highly dissimilar materials.”
Professor Robert Lamb, CTO (EO) at Leonardo, said: “UltraWELD is a major opportunity to develop laser bonding into a certified engineering process. As an end-user, Leonardo is keen to support its take-up in our supply chain and exploit it in production.”
Rob Ireson, GTS Innovation Team Leader, said: “GTS is a globally recognised independent expert in glass research and development, testing and consultancy. Its team works with partners and customers at every stage of the development cycle and supply chain to drive innovation, growth and sustainability in glass. Within the UltraWELD project, GTS will be providing expertise in glass science and materials processing to help maximise the robustness of the final bonded components. GTS will also be exploiting its extensive networks within the glass industry and related sectors to identify new applications which might benefit from the UltraWELD technology.”
Dr Peter MacKay, Principal Technologist for Gooch and Housego UK, said: “The consortium is tackling the issue of outgassing of epoxies generally used in optical assemblies by providing a completely new bonding technology. This will enable Gooch and Housego to supply mounted optical components to applications such as high power laser systems and UV systems, where contamination and damage caused by outgassing is a significant issue.”