(2001), " humdrum issues like the environment", Microelectronics International, Vol. 18 No. 3. https://doi.org/10.1108/mi.2001.21818cag.001
Emerald Group Publishing Limited
Copyright © 2001, MCB UP Limited
humdrum issues like the environment
… humdrum issues like the environmentKeywords: Environment, Internet
I am afraid that I cannot agree with Mrs Thatcher, as she then was, that anything to do with the environment is humdrum. Unfortunately, I have a shrewd suspicion that she would be very supportive of President George W. Bush's position. As I write this, a number of events have occurred, some of which have been very disappointing. The first of them was, of course, President Bush's refusal to accept the provisions of the Kyoto Protocol. Two days later, he cut funding for solar power generation research by 48 percent. Even worse was his announcement that the USA would require about 1,000 new fossil fuel powered generating stations over the next two decades, as well as a handful of large nukes. I consider this as totally unacceptable, but I'm sure that my little voice will have no effect whatsoever! Of course, his position is not surprising considering that his family fortune was made on fossil fuels, so I am sure that he feels an obligation to promote them. He probably does not sense the need to declare his vested interest because it is widely known. However, one item of news, much closer to home, broke on 15 May. This was that the European Parliament had accepted the proposals of the Waste in Electrical and Electronics Equipment directive, albeit with a few amendments. If ever there was a piece of bad legislation, it is this. It is based on bad science; its wording is atrocious, often with meaningless terminology; it is ambiguous in many places and, above all, it was produced without any risk assessment of the consequences. Apart from the economic cost of such measures, the overall effect on the environment will be far worse than any good that may result from it. Whether we like it or otherwise, this directive will affect all of us whether we are in Europe or elsewhere. Believe it or not, it even suggests that electrical equipment should be made without copper or any other heavy metal! More specifically, the major immediate effects are the banning of lead in solder and of brominated fire retardants in printed circuit laminates. Secondarily, the infliction of recycling to a maximum in order to reduce waste is praiseworthy, but the cost must be borne by the consumer by means of an imposition on the selling price. Perhaps the most stupid aspect is that it mandates every man, woman and child in every country within the EU to throw away an average of 6kg of electrical or electronic equipment every year or Brussels will give the Member State what for. It also encourages countries to violate the Basel Convention on the Transboundary Transport of Hazardous Waste, as unserviceable equipment which contains heavy metals must be classed as such.
Not all the news was bad, however. There are two items which I would like to bring to your attention, because I do feel that they are newsworthy. The first can be found at the Web site of the Inter-governmental Panel on Climate Change at http://www.ipcc.ch/. Click on WG I "Climate Change 2001: The Scientific Basis" and you will download a 20 page document giving the latest developments in the science of climate change due to man-made emissions of global warming gases. New modelling reveals an extraordinary fit which correlates global temperature and such emissions. In all fairness, there is still much work to be done in this field before we can consider that there is a scientific proof that we are changing the climate. Notwithstanding, the circumstantial evidence is beginning to be overwhelming – I am sure that many people have been hanged on slimmer evidence than this! I very strongly recommend to anyone in any way interested in the environment to download, free of charge, this document and to read it thoroughly, no matter whether their leanings are towards the policies of President Bush or otherwise.
The second item which is positive comes from a slightly surprising source. The Institution of Electrical Engineers (IEE), hitherto extremely conservative with respect to the environment, has launched a series of Professional Networks. One of these is Engineering for a Sustainable Future. This will be officially launched in the week following my writing of this sentence. For those of you who are not aware of the IEE, it is the largest technical learned society in the world, with about 180,000 members . To see what this Network is all about, I invite you to go to http://pn.iee.org/ and click on "Sustainable Eng". This network is free of charge and open to everybody, whether they are members or not of the Institution. Its Web site will inform the public about many different aspects of sustainable engineering with a number of discussion forums. If you are really into the subject, why not enter the New Spirit Challenge? This is a competition, open to all, to encourage ways and means of improving the future of life on this planet. There will be a number of prizes, including complete funding (up to a limit) of one or more projects submitted in the Challenge. In order to be very fair, I must declare a vested interest in this professional network, as I am one of the Executive Team and a judge for the New Spirit Challenge. I therefore cannot enter into any correspondence regarding the latter.
Another matter in which I have been very closely involved is in the preparation of a report concerning n-propyl bromide. By the time you read this, the report will be available at http://www.teap.org/ . For those not aware of it, n-propyl bromide (nPB) is a solvent which has been used to some extent in the electronics industry, particularly for cleaning thick film hybrid circuits after reflow. It is very controversial, because it is highly toxic and ozone-depleting. I had the honour of being co-chair of the Task Force which had been mandated by the Parties to the Montreal Protocol to provide information for the Scientific Assessment Panel, in order that calculations may be made of its potential effect over the next 50 years on the ozone layer. At the time of writing, although the use of nPB is permitted in most countries, the latest information on the toxicology would seem to make one think that it may not be a very good idea to have it around. The recommended Operator Exposure Limit has been very drastically reduced by the manufacturers themselves over the last few months. Furthermore, there are indications that it may need to be further reduced again. The lowest OEL published up to the date of writing this report is 10ppm, a value which would be very difficult to maintain under the conditions of an industrial workshop.
I have also been examining some installations in developing countries, notably in the Far East and North Africa, with a view to monitoring whether ozone-depleting solvents have been correctly phased out or not. I have been pleasantly surprised at the progress that has been made in this field, in several countries, although there is still a certain amount to be done, especially for small and medium enterprises. The funding supplied by the United Nations has, on the whole, been quite well spent. Secondarily, I also examined the general environmental plus health and safety aspects of the phase-out and, here, I cannot be quite so enthusiastic. Many of the projects that I visited left me with the impression that considerable improvements could be made. In a couple of cases, I was even shocked: in one, some pre-adolescent juveniles were working in an area with a relatively high concentration of perchloroethylene. In another, a cleaning machine, which was designed for aqueous spray cleaning, was being used with a highly flammable solvent, without any precautions whatsoever – a carburettor-cum-time bomb waiting to explode. However, we cannot be complacent about our own achievements because I have seen many "hairy" conditions of use of solvents in some of the most highly developed countries. This is an extremely competitive business and many corners, compromising both the work force and the environment, have been cut by both equipment and materials suppliers.
As I seem to have drifted onto the subject of cleaning, I propose to do some reviews of Internet pages relevant to this subject, as opposed to complete sites. This is a change from my usual technique: if you find it more (or less) useful please let me know. My method is to insert "cleaning hybrid circuit" into a search engine, select pages which seem appropriate and comment on them, as they appear, with little or no looking at other pages on the same site. With this method, I shall not give a score for each site. The search engine that I shall be using is Google, which has brought up 7,810 references, which should be enough to choose from! Because of the large number of pages reviewed, I shall not illustrate this article with the representation of the screen from a given site, as has been my custom.
Although it is old, the information on this page is quite interesting. It is a technical paper, presented at ISHM in 1987, entitled "Use of argon plasma for cleaning hybrid circuits prior to wire bonding". In reality, the technology has not changed a great deal in the last 14 years and the results which have been concluded are probably still just as valid.
This page gives a more general view of plasma cleaning. Unfortunately, it is somewhat difficult to read because the font chosen is quite fine and the background is fussy. It provides a good comparison between plasma and wet cleaning processes.
The Asahi Glass Company is well known for its range of cleaning solvents. This page describes the potential uses of their HCFC-225 range of solvents which can be used for defluxing hybrid circuits. It should be noted that the solvent is ozone-depleting and regulated under the Montreal Protocol for phase-out within this decade. It is probably the nearest thing we have to a "drop in" replacement for the old, popular CFC-113 range of solvents.
This page illustrates a manufacturer of hybrids, which are used specifically within the auditive prosthesis industry. It is actually quite interesting and well illustrated. The advance within this industry has been very remarkable, especially with the introduction of "in-canal" hearing aids. It should be mentioned that if you are looking for some information on cleaning, this page is not very informative; the only mention is that they use an aqueous process.
This is another very good general introduction to plasma cleaning, giving a comparison between oxidising, active and reducing gases. It is also fairly old (1992) and a few sentences, particularly in relation to ozone-depleting substances, reveal this, without the value of the article being reduced. However, if this page were to be updated, I would recommend that the references to fluorinated gases be deleted, because of their high global warming potential.
For me, this page could not be more interesting! It is a statement by the Electronic Industries Association of Japan describing a Voluntary Action Plan concerning measures to limit the emissions of HFCs and other gases in the electronics industries. This is because of the high global-warming potential of these gases. In terms of global warming, it is estimated that the total consumption and emissions of these gases in Japan is equivalent to 7,568,000 tonnes of carbon dioxide per year – and Japan is not the only consumer! This illustrates how polluting the electronics industry really is. Although this voluntary agreement was triggered by the Japanese government, the industries association is to be congratulated for taking measures towards making this world a better place to live in.
This page is totally off-topic, but I promise you that it did come up on the search engine. It is very funny.
This is the page of another custom, sub-contracting, hybrid circuit manufacturer. It is quite well set out with illustrations. The only mention of cleaning is in the company's list of facilities, stating that they have plasma and ultrasonic cleaning available.
Kyzen, of course, is well known for its range of cleaning solvents. This page gives the data sheet for one of the more popular products useful for cleaning hybrid circuits. I regret that the page did not have a link to the MSDS, otherwise it would have been very good.
Strangely, this seems to be the first page that has come up describing cleaning equipment, yet we are about 60 entries into the list. This page describes a range of plasma cleaners. It is not very attractive but at least it gives some general details which may be of interest to prospective customers.
This is another custom hybrid manufacturer, this time in Taiwan. Again, the page catalogues what the company can do and has illustrations of some samples. Unfortunately, at the time of viewing, the download time was very long, presumably due to either overloading of the server or a very slow server itself. I cannot emphasise enough the importance of ensuring that the server is sufficiently rapid and that the total aggregate file size is small enough for the complete page to be downloaded via a phone line modem in just a few seconds. In this case, we had both problems, resulting in a download time of nearly two minutes.
The page here is an EPP article entitled "Lead-free solder to impact precision cleaning". This is a subject which is likely to affect most of us within a few years. It is very likely that it has been edited down from a longer paper. It does contain a small number of inaccuracies, one of which may be considered as grave: this states that nPB has been given SNAP approval pending toxicity testing. This is simply not true, although the EPA has been promising a decision on SNAP approval for a number of years. It has not been able to do so until the ozone-depleting potential of nPB has been determined, as well as deciding whether it is safe to use. In the meanwhile, pending approval or otherwise, it is available for sale.
OK then, that is a short paragraph about each of a dirty dozen pages on cleaning, chosen out of the first 80 references that Google came up with. Are you wondering why your site has not appeared? The most probable reason is that it was not in the first 80. This probably means either that you do not have the necessary keywords embedded in your site or that you haven't announced it to the various search engines. (Of course, it may be in the remaining 7,730, but can you really expect people to wade through page after page of references in the hope that, in the end, they will select yours?) Perhaps I should mention that there were a handful of pages listing the products that a company may have for resale but giving no technical information and another handful which were in PDF format. I did not take either of these into consideration. By the way, my own Web site did come up several times but modesty forbade me from saying that it was wonderful!
The Rt. Hon. Margaret Thatcher, Prime Minister. "It is exciting to have a real crisis on your hands, when you have spent half your political life dealing with humdrum issues like the environment". On the Falklands campaign, 1982; speech to Scottish Conservative Party conference, 14 May 1982, in Hugo Young, One of Us (1990) ch. 1.