Keywords
Citation
Ellis, B. (2006), "And, in the last analysis, he is on the side of those with plenty of money", Soldering & Surface Mount Technology, Vol. 18 No. 2. https://doi.org/10.1108/ssmt.2006.21918bag.001
Publisher
:Emerald Group Publishing Limited
Copyright © 2006, Emerald Group Publishing Limited
And, in the last analysis, he is on the side of those with plenty of money
And, in the last analysis, he is on the side of those with plenty of money[1]
Keywords: Internet, Design, Broadband networks, Solder
In this column, I have often mentioned the fact that it is foolhardy to design a web site that can be conveniently viewed only by those with a broadband connection. Of course, this is especially so if you are using your site to sell a product or a service. Nobody is going to wait 2 or 3 min for your site to appear on his screen. I found some data on the internet about the number of broadband connections in the world, as estimated by various authorities and I reproduce the figures here (Table I), along with some interesting percentages.
It is, of course, well-known that South Korea is the country with the highest percentage of broadband connections in the world and a high penetration of internet access to the population. Sweden has the highest penetration, but less than one-sixth of the Swedes who have internet access profit from broadband. Even in the USA, five out of six “Internauts” still have no broadband connection. Worse still, in the UK, only one in ten have a fast connection, with one in eight in the top-20 internet-connected countries. As for the rest of the world, only 2.8 percent of internet users have broadband. Interestingly, six out of the top-ten countries are Asian and, out of these, China needs special attention; although it has the third-highest percentage of broadband connections, it has proportionally fewer subscribers able to connect than any other country, bar Brazil. So, nearly 90 percent of the internet users in the world still cannot surf with a high-speed connection. I was unable to find data splitting these up to users with ISDN, 56 k bit/s (nominal), 28 k bit/s and slower. What I do know is that I recently had to send a drawing to an e-mail correspondent, as an attachment, and he warned me beforehand that I should reduce the file size to an absolute minimum because he was restricted to a snail-paced 9.6 k bit/s.
At the time of writing, these figures are 10 months old, so may have changed a little as more ADSL and cable networks are implemented, but that does not change the general situation.
We see astounding statistics of the number of mobile phone subscriptions in the world, I think over 2 milliard[2] at this time, about three times as many internet connections. This explosion of telecommunications power, even in many very poor countries, would seem to be the antithesis of the slow penetration of broadband internet but, possibly, it may even be the cause. Cellular infrastructure does not come cheap, but it is less costly to construct a cell in a remote village than to connect many kilometres of copper for a hundred lines, far less an optical fibre. The choice many telecomms service providers have is to install cellular telephone antennae or to implement high-speed internet over existing lines – the answer is obvious when you look at the bottom line.
Coming back to my first statement, if you wish your website to be viewed easily, even in developed countries – and that includes where I am – then make sure the aggregate size of your home page is as small as you can possibly make it. Eye-catching multimedia should be a strict no-no. Graphics should be minimalised. If you must use a Flash introduction, make sure the surfer can short-circuit it; better still abstain from it (I frequently just stop downloading such arrogant inconsideration and go on to a different, competitive, site, potentially meaning lost sales for the web owner). Test your site with a 56 k bit/s modem; if it takes more than about 15 s to download the Home Page, then you need to do something. Do not be like someone I read about, who stated, “If they can’t afford broadband, they can’t afford my products!”
Now for a brief diversion away from the internet. I try to write these columns informally but using reasonable English grammar. No one is perfect, though! Sometimes I may deliberately use what purists consider to be bad grammar for effect, such as the first sentence of this paragraph. I do not consider it a great sin to wilfully split an infinitive, like I have just done, although I try to avoid it where possible. I have a “thing” about where I place “only”: I only go to town twice a week is not the same as I go to town only twice a week. And I have been known to start a sentence with a conjunction. Sometimes the proof-readers even modify my grammar, often for the worse. What is this leading up to? I have a shelf full of books about grammar, punctuation, style and language, and I consult them frequently. A recent addition, though, has caused me some pain. It is almost an amusing book (http://eu.wiley.com/WileyCDA/WileyTitle/productCd-0471 223832.html) purportedly reporting the 47 most common mistakes that journalists make. It is nit-picking in the extreme, to the extent that I had occasional difficulty in identifying the faults in a few of the quotations (although the author agrees with me about “only”!). However, I identified some grammar errors in the text of the book (discussed and confirmed with my daughter, who is an English teacher)… No one is perfect, though!
Much has been written about the impact of lead-free solder on the environment, although relatively little specific to microelectronics, whether in terms of pin-out terminations, such as BGAs, or soldering thick- or thin-film circuits. Some of the documents have been wisely worded, full of fact. Others have been highly prejudiced, often displaying total technical ignorance (perhaps the RoHS and WEEE directives fall into this category!). The US EPA has published a massive 472-page report on their studies. I am sure that you and I do not have the time to read it in detail, so a 51-page synopsis, Solders in Electronics: A Life-cycle Assessment Summary, has also been published at: www.epa.gov/dfe/pubs/solder/lca/lca-summ2.pdf and I propose we peruse this together. One word of warning, though, if you wear glasses, polish them carefully, because the authors have seen fit to use a violet typeface that could have been easier to read and will not normally print black. To make my interpretaion easier, I will put direct quotations into italics.
After an introduction, the subject has been divided into ten questions.
The purpose of the lead-free solder study is three-fold:
- 1.
to evaluate the life-cycle environmental impacts of selected lead-based and lead-free solder alternatives using life-cycle assessment (LCA);
- 2.
to evaluate the effects of lead-free solders on leachability, recycling, and reclamation at the end-of-life; and
- 3.
to identify data gaps or other potential areas of analysis for future investigation by EPA or industry.
This seems to cover most things, provided that it is done fully.
“The … LCA considers impacts related to material consumption, energy use, air resources, water resources, landfills, human toxicity, and ecological toxicity, as well as leachability and recycling”.
However, we can examine the scope better as we go along.
There is another point in the Introduction that may be subject to discussion.
“Consumer demand for lead-free products may also increase as the general public becomes more aware of lead issues”.
This kind of sentence alarms me without a qualification as to why. Avalanches of disinformation from interested parties have buried our own industry, without many being able to discriminate fact from fiction. How can the “general public” judge better than we can what the issues are without factual information?
Question 1. What is a LCA?
This is a valid premiss of the whole document and the EPA has chosen a four-stage approach:
- 1.
goal definition and scoping;
- 2.
life-cycle inventory (LCI);
- 3.
life-cycle impact assessment (LCIA); and
- 4.
improvement assessment or interpretation of results.
This is done for each of the five stages in the life cycle, each with its inputs and outputs. These are the acquisition of the raw materials; the processing of the raw materials; the product manufacture; the product use and the final disposition.
Question 2. Which solders were investigated during the project?
Obviously, this is an all-important part of the project. Eutectic tin-lead was used as the baseline and four lead-free alloys were selected: tin/copper, tin/silver/copper, bismuth/tin/silver and tin/silver/bismuth/copper. An assumption was made that a solder joint requires the same volume of solder, no matter which alloy is used, and I have no problem accepting this.
Question 3. How were life-cycle environmental and health impacts evaluated?
This is where the report starts to be controversial. A figure in it is a block flow diagram of the processes involving SnPb paste solder. This is very abbreviated as it starts with the metals, not with the ores in the ground. Even so, there were 25 identified inputs or transfers of materials and energy to the different stages.
Given the enormous amount of data involved in inventorying all of these inputs and outputs, decision rules were used to determine what to include in the LCI.
In other words, decisions were made as to what was really valid and what could be ignored, Note that I am not saying that the decisions were wrong or falsified the results but they do mean that anyone studying the report would be well advised to evaluate for himself whether they really mattered in the context of his own interpretation.
Obviously, I cannot go into the details of how the 16 categories of impact, neatly tabulated, are determined. The categories themselves appear logical and I do not think that anyone could really argue with how it is set-up. However, I reserve my thoughts on how one can score different categories; for example, which is worse, ten points scored because a product is toxic or ten points because it depletes a non-renewable source? Maybe this will become clearer as we proceed.
Question 4. How do the environmental and health impacts compare among paste solders?
The question is ambiguously worded! In this chapter SnCu solder is not considered. I hope the full report can answer some of the many questions that must arise, because this summary does not. For example, does the category of non-renewable resource use include such items as the destruction of tropical rain forest for obtaining tin ore in alluvial mining and whether the impact of such destruction on reduced carbon sequestration is considered? At this point, no attempt is made to equate the positive and negative impacts of different categories into an overall score. However, I feel a certain arbitrariness creeping in, despite a paragraph explaining each category and its impacts. At this stage, another question is beginning to appear before my eyes. How does the impact change according to the country of production? Electricity may be generated from various fossil fuels, from hydraulic sources, from nuclear fission or from other renewable sources. Is it fair to compare the impact of electrolytic metal purification from different energy sources? I do not think this is nit-picking, because such refining uses much energy.
Question 5. How do the environmental and health impacts compare among bar solders?
This has an identical argument to the previous question, so needs no further discussion. Of course, the impacts are different.
Question 6. What are the limitations of the study?
In fact, there are a number of limitations and data uncertainties, not the least of which are missing data. A few of these are examined in more detail. For example, two reflow ovens of varying efficiency were used in the impact assessments, but were these representative of real-life conditions? One factor that is mentioned is leachate toxicity in landfills.
This leachability contributed to the large public non-cancer and aquatic ecotoxicity impacts for the SnPb solder as compared to the other solders for both the paste and the bar solder results.
Two important points must be made here:
- 1.
the leach test is highly artificial and can, in no way, be assimilated to real-life conditions in a landfill; and
- 2.
this is totally irrelevant in the European context because WEEE generally imposes recycling and not landfilling, solder being the easiest component of an assembly to recycle.
Question 7. What can electronics manufacturers do to reduce environmental and health impacts?
Now, there is a question! And I am flummoxed with the answers given. The first part deals with something over which the manufacturer has no control: the source of the metals in the solder. I am very puzzled, for instance, why the percentage of virgin tin, compared with the total tin, should be higher in all the lead-free alloys than in SnPb solder. I would have thought that the solder manufacturers would use the same incoming tin for all the different alloys. On the other hand, I fully concur with the single factor mentioned that is under the manufacturers’ control; the use of energy saving reflow ovens. This could also be extended to other equipment, in my opinion, especially those using inefficient compressed air. Nothing is mentioned about the impact to air or water from post-soldering cleaning.
Question 8. What are the challenges to implementing lead-free soldering?
This is rather academic for European manufacturers at this stage. If you have not implemented it by the time you read this, you are in deep trouble! In reality, this is a good aide-mémoire of the principal problems which you have hopefully overcome, although I fear that 100 percent compliance will still be difficult on 1 July 2006, if only because of inventories of components with lead and the inevitable interpretational errors from a badly written directive. Some emphasis has been placed here of failure of solder pots being a severe health and safety issue, which I know, from experience, some manufacturers have not addressed. Not nice to have 250 kg of molten solder at 260°C falling on your feet
Question 9. What are the performance differences among the solders?
An all-important question with answers that are only vague. However, as befits a summary, they are tabulated, over two pages, from 11 references, some of which are commercial and some others from doubtful sources. None of the “standard” works, such as Hwang or Klein-Wassink are used. What some may consider alarming is that the word “reliability” is not used once in the whole table, although some of the factors that influence reliability, such as creep and fatigue, are mentioned. (In fact, “reliability” is used only four times in the whole document, once in a reference title, once referring to laminates and twice in the answer to question 8.) This table is followed by a series of graphical comparisons of various mechanical and thermal properties of different alloys under consideration and some data about other alloys. What puzzled me is that some of the SAC mechanical data is given as water-quenched: really? Water-quenched? Uh? Am I missing something here? No attempt appears to be made to offer guidance of what the data means, translated into practical terms.
Question 10. What are the potential market impacts of a switch to lead-free solders?
This question is answered only in the US context (naturally enough) and only in relation to 2003 metal prices. In my opinion, this is a false premiss, because if the conversion caused a significantly increased worldwide demand of a metal, then the market price of that metal would rise. As it is presented, if the whole US electronics industry were to convert from SnPb to SAC, the estimated financial impact would be about $28 million for the change in tin demand, plus $99 million for silver, plus $0.17 million for copper, less $6 million for lead (rounded figures). No consideration is given to the increased costs at the manufacturers’ plants, which must be at least as much again in energy and equipment costs, alone. Even worse, if infrastructure costs, such as R&D, increased component and laminate costs, reliability and lifetime data, etc. are all factored in, then the figures must become astronomical.
What conclusions can I draw from this study? Of course, this reflects only my opinion, but the summary is lacunary and many of the premisses must be queried. My biggest question is how the different impact categories can be correlated to provide a “best” solution to the problem of changing from a lead-bearing to a lead-free solder. Where the document is very valuable must lie in its very broad scope, in its attempt to mention all aspects of the problem, even if some of them are not considered in the analysis. I recommend that everyone concerned with balling BGAs, tinning or soldering in our industry read it carefully. Those who may wish to study the subject further can always refer to the full 472-page document, which may be found in sections or in extenso at www.epa.gov/dfe/pubs/solder/lca/index.htm
Brian EllisCyprusbne@bnellis.com
Dieu est avec tout le monde… Et, en fin de compte, il est toujours avec ceux qui ont beaucoup d’argent et de grosses armées (God is on everyone’s side… And, in the last analysis, he is on the side of those with plenty of money and large armies). Jean Anouilh, L’Alouette (1953) p. 120.
I prefer using milliard rather than billion as being unambiguous for 109, billion in the UK meaning 1012.