KISS goodbye to the long tyranny of solder?
14 April 2008
Lead-free solder? How about NO Solder at all? Simplicity is an overlooked virtue in modern life, and nowhere more so than in electronics manufacturing. In fact one company has developed a new process that, it claims, could change the whole electronics assembly process.
The process in question, provisionally dubbed the Occam process, really only came onto the agenda of the chattering classes in the electronics industry during the latter stages of last year. Throughout this year, starting about now, it is intended that various trials will prove the process in different applications, and can iron out any problems before being launched into commercial reality. I will not go into detail on the process here as the inventor, Joseph Fjestad of Verdant Electronics, has written a full account for EMTWorldWide, which you can read here.
However, in a nutshell it involves placing components, encapsulating them and then making the connections by drilling and copper plating. No need for solder and no need for a thermal process (not one at ‘reflow’ temperatures anyway). Looking at an overview of the process it does seem to have several potential benefits, including the environmental ones that were paramount during its conception. However, there are still some unanswered questions, notably in terms of design flexibility, overall assembly time (if each layer needs to include an encapsulation and curing stage then the beat time for a board could be days rather than minutes), and is rework possible at all? If not then there would need to be a rigorous testing procedures of both components and circuits at every layer of construction.
I do not in any way want to diminish the principles involved here. If someone took a step back from current electronics manufacture in an attempt to re-evaluate the whole process, I suspect that there are several issues that would be considered undesirable. The high temperature of lead-free soldering would be at the top of this list. So maybe the problems I suspect might exist may not be insurmountable if the Occam process gathers momentum. It might only take a brave commitment from one manufacturer on a high–volume product to put this process into mainstream.
I started talking about simplicity as this is at the core of the Occam process. Verdant’s process took its name from William of Occam - a 14th century English monk and philosopher who is credited with saying: ‘It is vanity to do with more that which can be done with less’ - a principle that has become known as Occam’s Razor. Essentially it is saying that the simplest solution is the best. This is quite clearly not always true. The simplest way of placing components on a PCB is to do it by hand. You could then stick it in a fire and hope for reflow. However, machines can obviously do it more accurately, reliably and quicker. You could also argue that virtually every improvement to a process, or machine, makes it more complicated from a technological point of view, yet easier to use. A bit like the computer I am writing this on it is now, it has become instinctive to use (I haven’t got Windows Vista!) yet what goes on inside the box is way beyond my comprehension.
But despite this apparent conflict in technological evolution, I am sure that the underlying principal holds true – simple solutions can sometimes be the most effective, whether it is dealing with technology or the way we lead our lives. For a slightly off-beat example, I was visiting an EMS company a few years back. It came to 4.48pm and everyone on the shop floor made for the door. I commented that this was a slightly unusual time for the staff to bid their retreat for the day, but the production manager explained that the factory previously worked to 5.00pm everyday except Friday, when down-tools was an hour earlier. However, it appeared that many people lived in the local town and relied on the bus to get them to and from work. By losing their hour on a Friday, but instead leaving 12 minutes early every day, they all could catch an earlier bus, rather than having to wait around at a bus stop for half an hour every day. So everyone was happy. A simple solution to an everyday problem.
I am sure there are ways we could improve so many things just by taking a step back and identifying exactly what it is we need and want something to do. The aforementioned Windows Vista is, arguably, a case in point where style is over-riding substance. There is no point in developing really clever stuff for the computer literate if you are leaving a trail of alienated and confused users in your wake.
Recognition of this was even in evidence at APEX, where I saw one company marketing its KISS range, KISS being an acronym for Keep It Simple Soldering. The idea of these selective soldering systems was not just to make the operator interfaces easy to use, but to keep the machines mechanically straightforward. The less bits that move, the less bits can go wrong. As long as it performs its function properly then it makes sense.
And to round up on the Occam process, if it does what it claims, without the problems that I envisage, we could be looking at a wholesale change in the electronics assembly industry. At least we won’t have to worry about the reliability of lead-free solders!
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