The Institute of Circuit Technology Annual Conference

Citation

(2012), "The Institute of Circuit Technology Annual Conference", Soldering & Surface Mount Technology, Vol. 24 No. 4. https://doi.org/10.1108/ssmt.2012.21924daa.015

The Institute of Circuit Technology Annual Conference

Article Type: Conferences and exhibitions From: Soldering & Surface Mount Technology, Volume 24, Issue 4

Imperial War Museum, Duxford, Cambridgeshire Tuesday 12 June 2012

ICT, with a nod in the direction of “Boys’ Own”, have a knack of holding their annual conferences in places of great interest, such as museums, initially in one for motorcycles, and now in an aviation museum, a famous one to boot. So whilst there may have been some old veterans suspended from the ceiling in one room, there were many industry veterans, not-so-young and not-so-old, somewhat less suspended in another one listening to the excellent range of speakers.

ICT Vice-Chairman Dr Andy Cobley opened the symposium, welcomed the many delegates and introduced keynote speaker Bill Burr, who captured the attention of the audience with his views on inspirational intuition, with particular reference to the development of PCB technology from Paul Eisler to the present day and beyond: “Knowledge plus perseverance plus intuition equals the anatomy of a brainstorm, and intuition is one of the most brilliant aspects of the higher unconscious. People who lived the problem developed and invented solutions”, he continued: “Inspiration is the fruit of perception and perspiration”.

Taking microvia technology as an example of an innovation that enabled a whole new generation of electronics, Bill made it clear that it was PCB manufacturers who developed the technology and invariably the PCB manufacturer occupied the position of translator – standing between the material supplier and the subsystem manufacturer, understanding the languages of both sides and turning materials into electronic function – effectively translating smart molecules into smart products.

Moving back to the future, he discussed added value and how western-world PCB manufacturers could retain value by providing enabling technology in order to regain the high ground, break away from the commodity trap and make a difference by studying industry trends, new and emerging applications, product characteristics, global issues, component packaging trends and customer roadmaps.

Against this backdrop, he described a project in which he was co-operating with Nick Pearne of BPA called Metal-in-the-Board, MiB. Increasing power density in electronic devices in general, and the rapidly increasing utilisation of electronic control of electrical power opened up a new generation of opportunity for innovation in thermal management, particularly in automotive and electro-mobility applications. Bill advised the delegates to stay alert for opportunity, to watch and guard the added value, and to sell the advantage, not the commodity.

Bob MacRae from Taiyo America, explored all the options, advantages and disadvantages of via-hole plugging techniques. Typical reasons for plugging vias were to prevent corrosion of the via connection, to improve vacuum performance at in-circuit test, to prevent solder wicking into via holes connected to SMT pads, to prevent contamination under components, to gain back outer layer real estate and, in sequential builds, to fill buried vias without voids and reduce prepreg loss. Three decades ago, it had become common practice to tent via holes with dry-film solder mask and since the introduction of liquid photo-imageable solder masks there had been many permutations of procedure for achieving the equivalent with liquid materials. In most cases, removal of solvent was a major issue hindering the success of these techniques and, unless a two-stage final cure or a vacuum chamber were used, popping or outgassing could occur during soldering. Incomplete hole plugging could lead to chemical entrapment and result in field failure as well as skip plating of ENIG.

High-performance hole-filling pastes were now available which offered the best combination of performance and reliability. These were based on zero-solvent formulations which showed little or no shrinkage on curing, giving flat, planar plugs which could be plated-over. Moreover, these materials were compatible with high-performance laminates in terms of glass transition temperature and thermal expansion characteristics.

Pete Starkey spoke knowledgeably about the ASPIS Project being run under Framework seven of the EU Research Programme. Members of this project include the University of Leicester, the Lithuanian Institute of Chemistry (LIOC), TNO Eindhoven, ITRI, EIPC, Somacis and Graphic plc. The focus is on developing more reliable processes and materials whilst investigating failure modes and mechanisms of ENIG coatings. The aim is to develop an ENIG screening tool, whilst developing improved coating methods and materials (aqueous and ionic liquid). This is a three year project, about halfway through now, and LIOC are doing most of the work at this stage, specifically with identifying failure modes; their initial findings are that the corrosion of the nickel surface which results in black pad failures is down to the immersion gold process, and the good interface between the nickel and the gold is down to surface preparation. Most surface preparation is inadequate, which leads to particulate deposits giving plating stress internally, and there is an inherent deviation from optimum ENIG properties.

TNO in Eindhoven are looking at the conditions that can result in failure, and at capacitive measurements using acoustic microscopy; ITRI are working with Merlin Circuits on an evaluation of commercially available ENIG processes, and ITRI have now developed solutions which show better solderability than current coatings from proprietary solutions. At the University of Leicester they are working on improved nickel and/or gold coatings with aqueous and ionic plating processes. Thus, far Au Cyanide salts have shown interesting results, with cyanide – free being preferred for obvious reasons. ICT are involved with the dissemination process, as well as training and exploitation, and EIPC are as usual involved with dissemination, with other industry media being used as well (www.aspis-pcb.org).

Peter touched on another project, entitled Susonence, which is a project on electroplating in which ultrasonics are used to upset diffusion layers, and the results so far look very interesting indeed, with decreased chemical consumption, reduced use of toxic chemicals, and an ability to electroplate on materials hitherto incompatible with the process. A look at www.susonence.eu will reveal all.

Manfred Walchshofer from Panasonics spoke about the material innovations being developed in his company to give high soldering reliability for thick copper PCBs, including long term reliability, insulation, and heat dissipation. Herr Walchshofer illustrated why their laminate, compared to conventional FR4, has better CTE, with their 1,577 as a halogen free material. CAF was explained, which is conductive anodic filament, a phenomenon which occurs along fibres in inner layers between holes, mainly as a result of humidity. CAF failure will be found in a humid and warm environment, and the other causes of CAF were explained: 25 per cent is down to the material, 50 per cent to the PCB process itself, and 25 per cent to material performance. One of the process failures is called gauging – influenced by drill bits, drill bit wear, entry material and stack heights employed. They have two new resins, one especially for halogen-free requirements, which will give good CAF resistance.

With increased power being required, heat can be a problem. Manfred described the approaches made at Panasonic to improve heat dissipation in their laminate, where the fillers in the pre-preg play an important role. Panasonic have a product which will meet all requirements, it would appear, but the key is having a fibre integrally encased within the resin.

Lawson Lightfoot is the Sales Director of Rainbow Technology, and came to tell the conference about the Rainbow Technology for fine line imaging. The brainchild of Jonathan Kennet, Rainbow was founded in 2005; by 2006 the innovative technology was found to be feasible, and a production line was built between 2008 and 2010, with a fully automated line following in 2011. The line incorporates much equipment that had to be designed and built from scratch. Now employing 15 staff, the company is growing fast, and later this year the first production machine will be installed in Glasgow for customer visits and trials. The process offers faster production capability, low energy consumption, low space requirements, small footprint, with only one person being required to run the line, and is for substrates of 50 um upwards, with features down to 5 μm. The fully automated system uses a 100 per cent solids resist developed for them by Electra Polymers, and the line coats, exposes and develops in one line at a rate of 200 panels per hour; there is double-sided exposure, with excellent front to back registration, fine line resolution, and low power consumption.

Coating, printing and nano-imprinting for printed electronics was the title of a paper from Thomas Kolbusch of Coatema Coating Machinery. The German company of coating specialists began their life with the textile industry, and thus have expertise in roll-to-roll printing. This lends itself well to the burgeoning Printed Electronics market, but they have also moved into the areas of small scale and batch scale production. In the 2001 they were the first company to enter the EL field, their equipment tackling the high volume large area organic PV production for lighting, and display, as well as electrical components, and integrated circuits as potential markets for PE. They offer a range of equipment from prototype, a “smart” printer, the roll to roll process; they are all in-line, and operate at high speed, with full registration control and edge tension control. Thomas, along with many others, is of the opinion that the biggest challenge for printed electronics is finding a market for the products. When that days dawns, his company have a system that will meet any demand.

Lean manufacturing and benchmarking are subjects close to the heart of management consultant Mark Knowlton of KPS Limited. He introduced us to the five golden rules for cash flow, the eight lean competencies, as well as some supply chain case studies, and how to use benchmarking tools. In the good old days companies would base their SP on their manufacturing cost plus an agreed margin. Nowadays it is all about the value chain, about how to retain profit, and the skill of working more with less. Improve or die, said Mark. Business growth=generating cash within the business. Growth is increased business, or reduced costs, but “lean” can assist in both areas. Smaller batches=less cash required. Larger batch sizes=more cash required. The five golden rules for manufacture are:

1. 1.

   speed up order fulfilment;

2. 2.

   only make what you can sell;

3. 3.

   only buy what you need;

4. 4.

   reduce work in progress; and

5. 5.

   collect what you are owed.

The eight competencies are:

1. 1.

   leadership;

2. 2.

   customer focus;

3. 3.

   empowerment;

4. 4.

   communication;

5. 5.

   core processes;

6. 6.

   machines and equipment;

7. 7.

   support processes; and

8. 8.

   the supply chain.

This would be familiar territory for the manufacturers amongst the delegates.

A thoroughly sound ICT Conference, in an excellent venue and generous hospitality. ICT is a popular and expanding organisation, and from a day such as this one can see why.

John LingAssociate Editor