Bob Willis presented the The SMART Group Mission to Japan Report Seminar for SMART Group Scotland with some assistance from other team members all be it on video clips.

Over the period 19-23 February 2001, the SMART Group mission to Japan on Lead-free soldering visited 7 companies: Sony, Senju Metals, Matsushita, Koki, TDK, NEC, Denso; METI (was MITI, the Japanese equivalent to DTI); and Osaka University. In addition, a presentation was given on the first day to a substantial invited audience at the British Embassy followed by participation in the JEITA1 forum held following the seminar.

The companies visited comprised several large OEMs plus soldering equipment and materials manufacturers. The mission was well received by all the companies visited as well as those met at the embassy.

Bob Willis presenting the issue of solder fillet lifting with Sn/Ag/Cu and how the size of the land, hole and resist can be modified to reduce the problem. This was based on data produced by NEC.

This mission sought to determine the status of lead-free soldering in Japan; the drivers for change; and the technological problems faced and solutions found. The mission found that the implementation of lead-free soldering in Japan was well advanced and widespread with companies broadly keeping to their declared aggressive timetables for implementation. This is initially mainly taking place on higher value, lower volume product lines where production is located in Japan but will be imposed on suppliers and overseas plants in the very near future and has already started in some cases.

Contrary to expectation, the drivers for change were not overtly based on winning market share, nor any longer is impending legislation the driver. The term most used was 'corporate environmental consciousness'. Although this might be interpreted as a ploy for winning market share, it was apparent that the companies visited really do consider their environmental image.

There were no big surprises on materials and process issues but there is still a plethora of alloys in use, which have been developed using a pragmatic approach. Assemblers have driven the investigations and a consensus seems to be developing but the range of alloys being evaluated and actually used in shipped products remains remarkably high. None of the alloys discussed are unknown in Europe but many of them have been dismissed on the grounds that they are unsuitable. While this may be true, the decision in Europe (and the US) has been reached on the basis of interpolation from known materials properties and process issues. In Japan, materials have been dismissed, or more accurately ranked in order of suitability, on the basis of actual product builds.

The biggest technological challenge to the introduction of lead-free soldering has been the increase in the solder processing temperatures used. For consumer products, where long term reliability is not an issue, alloys with melting points as close to tin lead solder have been employed. These alloys allow processes to be developed where optimised process windows can use existing materials and equipment.

For professional higher reliability products, alloys with higher melting points have been used or identified. Work on these has been concentrated on minimising the ?T across boards by optimising process windows and re-designing equipment to give better heat transfer and distribution characteristics.

Given time no doubt, components, laminates and materials will develop to allow higher processing temperatures. In the meantime soldering equipment will have to evolve to cater for the new alloys whilst existing users' equipment will need to be carefully re-tuned to obtain optimum performance.

Bob presented a bottle for the lucky dip winner of the day Martin Tarr, Bob refused a glass as he was driving back from the airport!!!

It was a good day and as always the hospitality of SMART Group Scotland was second to non for the delegates who all received a copy of the SMART Group Mission to Japan Report.

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