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Emerald Group Publishing Limited
Copyright © 2006, Emerald Group Publishing Limited
Intellect Technical Workshop, Coventry, 23 June 2005
Intellect Technical Workshop, Coventry, 23 June 2005
Keywords: Keywords Lean production, Electronics industry, Conferences
Lean manufacturing in interconnection technology
Pete Starkey welcomed delegates to the offices of Rohm and Haas Electronic Materials in Coventry and introduced the subject of Lean Manufacturing with a brief history of continuous improvement methodologies.
First speaker was Dave Wayness, Rohm and Haas Technical Marketing Manager, who described advances in inkjet materials for interconnect applications and how inkjet imaging techniques offered opportunities to overcome registration problems and save on materials, labour and process time. Rohm and Haas had drawn upon their wide experience in graphic arts in developing ink jet materials for printed circuit applications. Although they were actively investigating processes for etch mask and legend, they believed that the most urgent market need was for a high-resolution solder mask system which did not compromise existing material qualifications. Therefore, they had applied some lateral thinking and chosen not to pursue the direct inkjet option, which presented a number of significant difficulties in the formulation of material and the fluid dynamics of ink jetting. Their innovative route was to use established, approved and qualified liquid photoimageable solder resists and coating processes, but to replace the conventional phototool, and its associated dimensional and conformal limitations, with a created-in situ negative image in UV-opaque ink. They had developed a hot-melt material, delivered by a heated inkjet head, which had very low viscosity at jetting temperature, but gelled instantly upon hitting the surface of the solder mask, enabling extremely sharp image definition. The work could be blanket-exposed, developed by the normal process for the particular mask, the UV-opaque dispersing in aqueous developers without re-deposition, then final-cured as normal. Wayness showed examples of very cleanly-defined 50 μm solder dams produced on a comparatively low-resolution laboratory printer, and work was continuing in cooperation with inkjet print-head manufacturers and printed circuit fabricators to industrialise the process for formal launch at Productronica 2005.
With his customary pragmatism, Circatex Chairman Steve Jones painted a grim picture of the continued downward trend in the global market share of the European printed circuit industry. In a 50 billion euro world market, South Korea produced as much as all of Europe put together, and Taiwan produced half as much again. The European industry faced the prospect of continuing demands for cost-reduction and Jones made it clear that in his own experience in Circatex, he could not compete with Far Eastern volume prices even at 100 per cent yield. The future lay in the development of the service model, with higher mix and smaller batches. Lean manufacturing philosophies and methodologies were an essential element in his vision and he listed: maintaining pride in a clean working environment, moving from batch processing to single piece processing, engineering-out processes and engineering-in quality, moving from MRP to kanban, empowering people to make decisions and training them to make the right ones, never resting, never being satisfied and being fanatical. But even with all of these principles established, radical thinking was necessary to escape from entrenched perceptions of the printed circuit manufacturing process. Innovative technology would be the differentiator; the traditional process was too long and too complicated – Jones considered that his 14-stage inner layer sequence was not so much a process, more a conspiracy by the supply industry to take his money – and digital direct-write techniques offered a logical way forward. Jones reviewed some of the attributes of inkjet printing, including mechanisms of droplet formation and distribution, interactions droplet-to-droplet and droplet-to-surface, and limitations of addressability. His ambition was to establish the capability to print 30 × 24 inch panels at high resolution, one every 5s – outrageous maybe, but if he did not aim high, he could only hit low. To achieve this throughput required a printer with 80,000 nozzles, each firing at 150 KHz, each with eight greyscale levels, together with 120 Gigabits per second data processing capacity. Circatex's inner layer area was already planned-out, a clean room in place to accommodate the proof-of-concept machine, and configured to produce sequential, collated inner layers, feeding directly to a continuous bonding process. The objective was to produce 500-off 20-layer panels per day with a total manufacturing cycle time of 9h. Circatex continued to form partnerships with innovative people and companies, committed to driving forward the concept of ultra-fast manufacturing.
Tony Wilson, Research Associate with the Innovative Manufacturing and Construction Research Centre at Loughborough University, reviewed Part II of the STRATEC project in a presentation entitled Flexible, Lean and Agile Design to Manufacture. STRATEC explored technology strategies for small UK firms within the globalised electronics manufacturing industry and research had involved mapping the status of the UK industry and generating case studies to illustrate some of the strategic options available to small firms. It had been concluded that the UK had an electronics industry worth protecting, which was dominated by SMEs and by design-related activities. There remained a small manufacturing industry, whose relationship with the design community was strategically important, and Wilson described a framework for lean enterprises which encompassed flexibility, lean-ness and agility in design and manufacture. Flexible design hierarchies accommodated radical rather than incremental innovation, promoted exploration rather than exploitation, targeted new rather than existing value networks and reflected new rather than previous design system architecture. He illustrated the principles of phase gate control in the design cycle, and a case study of an agile design-to-manufacture process, shown in the form of a spreadsheet running to many pages as each of the iterative cycles of design input/design output/DFX interface unfolded, in a concurrent engineering environment. All of the stages through prototype development, functional verification, reliability testing, NPI build, yield optimisation and volume transition were explained. Wilson concluded by summarising the system of synergistic and mutually supporting techniques and activities necessary to run a lean manufacturing operation.
The formal presentations provoked much interactive discussion and debate, and delegates benefited substantially from the interchange of individual ideas and opinions.
The hospitality of Rohm and Haas in hosting the event was gratefully acknowledged.
Pete StarkeyJune 2005