With all the talk about counterfeits — most of which takes the manner of the over-the-backyard-fence gossip — I was glad to see this announcement today.
A company that makes bearings announced the confiscation of over 30 tons of counterfeits at a non-authorized dealer in northeast Czech Republic. (The raid also uncovered faked products from other bearing manufacturers.)
It’s not so much that the rats were caught. It’s that SKF, the bearing maker, went public with the news.
Typically, companies prefer to keep such news hush-hush, probably so as not to unnerve potential customers. Shining the light is better, however. It makes clear the scope of the problem, the steps being taken to counter it, and most important, it reminds customers to buy only from authorized sources.
There aren’t a whole lot of measures we can take to protect ourselves from counterfeits. But the measures we can take are highly effective — provided we follow them, and all the time.
Even scarier than the number itself is the unmeasurable amount of experience and brain power that has been drained away, much of it likely for good. Talented engineers and technicians don’t stay on the sidelines long; they find other jobs — often in other industries.
When all is said and done, that may be a legacy we as an industry will be coming to grips with long after the order books have filled again.
My friend Dominique Numakura writes from Japan that consumer electronics is rebounding in Taiwan, Korea, China and Japan. But, that bit of good news is tempered, he says, by constrained capacity — so many companies cut inventories and took down production lines, they now face material, component and labor shortages, he says.
“Everyone’s warehouses are almost empty! Distributors and suppliers can’t feed the manufacturing houses fast enough. Manufacturing companies have secured large orders for products, but materials are back-ordered, and there are not enough workers to accommodate these new sales.
The result, he notes, is material price spikes.
In Southern China, he adds, things are more grim, with reportedly more than 200 area EMS companies unable to obtain sufficient materials for production, and caught between the higher materials prices and lower end-product margins. Many will close.
This is not unusual. Several case studies have shown as many companies exit an industry in recovery
as do leave during a downturn. They get caught in the cash flow trap, where the upfront costs and associated risk to running the business outweigh the margin.
Counterfeit electronics components supposedly are destroying the integrity of our hardware.
One estimate holds that “five to 20% of electronic components in distributors’ chains are probably counterfeit” at a cost to industry of some $100 billion a year.
In response, several organizations (not to mention a cottage industry of consultants) have jumped on the bandwagon, launching programs to warn of the hazards (death! destruction! locusts!).
Let’s put aside, for the moment, the obviously inflated numbers ($100 billion, after all, is more than the sum of all the semiconductor revenues of Intel, Samsung, Toshiba, TI, STMicroelectronics, Infineon and Renesas — in other words, the world’s top 7 semiconductor OEMs — in 2007.
The SIA, for example, now has an anti-counterfeiting task force, and is working in concert with SEMI to combat the problem. “Counterfeiting is a serious and growing problem in the worldwide electronics industry,” says SIA president George Scalise. “Counterfeit products pose a significant risk to consumers as well as to the manufacturers of semiconductors and electronic products.
In the UK, something called the Component Obsolescence Group published a list of best practices said to help minimize the risks associated with the growing supply of faked parts.
And of course, makers of traceability software, XRF and other gear have ramped up marketing efforts to pitch their solutions.
But…in all the hue and cry, one thing is missing: The guilty users. Over the past few companies, I’ve asked at least two dozen EMS companies if they’ve seen any counterfeit components. None would admit to it.
Now, we estimate that there are at least 1300 EMS sites in the US, so my sample is hardly representative. Still, is the problem overblown? Or are my contacts – gasp! – lying?
And if they are fibbing, in the end, who gets hurt? (Answer: The customer.) Is it worth it?
All sorts of nonsense is erupting in our industry’s corner of the environmental arena this past week. Let’s go to the tape:
On May 14, Rep. Michael Burgess (R-TX) introduced a bill that essentially codifies the EU RoHS Directive for the US as well. The bill proposes to prohibit the manufacture after July 1, 2010 of “electroindustry products” that contain lead, mercury, cadmium, hexavalent chromium, PBBs, and PBDEs above the maximum concentration levels specified in the European Union’s RoHS Directive.
Today, the Electronics TakeBack Coalition issued a statement opposing a toxic e-waste bill scheduled to be introduced in the House later this week. The bill, sponsored by Rep. Gene Green (D-TX) (how’s that for irony?), Rep. Mary Bono-Mack (R-CA) and Rep. Mike Thompson (D-CA), permits e-waste exports under a loophole under which any type of entity can export toxic e-waste to developing nations for reuse and refurbishment, the Coalition asserts.
“By passing a law that only appears to restrict exports to developing countries without actually doing so, the bill would undermine those recycling companies which are in fact managing their e-waste responsibly, and providing jobs here at home. This bill fails in serious and even critical ways.”
And in between, IPC issued a press release boasting how 22 of its 2700-odd members managed to trek to Washington in support of a permanent R&D tax credit, something that just about every technology company operating in the US already supports anyway — and many of which are priming the lobbying pump to ensure it goes through.
So in summary, we have a Republican from Texas trying to overlay (absurd) European laws onto US manufacturers, an industry environmental advocacy group trying to shoot down new proposed environmental regs, and the major US PCB trade association completely in the dark about all of it.
I was recently asked to give a presentation and audit an assembly line regarding minimizing “tombstoning” of passives at a major electronics assembler. As my presentation brought out, tombstoning can be caused by many factors: the reflow profile, the solder metal composition (for lead-free applications, SAC 387 tends to tombstone more than SAC 305), off-center placement, nitrogen reflow atmosphere, buried vias, etc. After two hours of talking, I walked the line that “had a problem with tombstoning.”
As I started asking, it became clear that no one knew the magnitude of the problem.
“How many passives are on each board?” I asked. No one knew.
“How many DPMO (defects per million opportunities) for tombstones have you had recently?” Also unknown.
As people scurried to get the data, it dawned on us that tombstoning might not be as big an issue as was thought. It was more of a local legend.
Finally, we got some data. Each board had about 1000 passives, and the company had produced 100 boards with a total of two tombstones in the past two hours. Tombstones were the only defect. Hmmmmm, two bad boards out of 100 = 98% first-pass yield, not bad! From a DPMO perspective, they had two defects per 200,000 (two defect opportunities per passive) opportunities or 10 DPMO, which is beyond world-class. This level of DPMO would be very difficult to improve on without massive engineering investment. It is “in the noise” and it is likely caused by “common cause” variation.
I then asked how much money it costs to repair a tombstone; as expected, no one knew. My guess was less than $2. This situation is the rare case where yields are so good, it may not pay to make engineering investment to improve them.
This isn’t the point of the story, however. In a case like this, the response — whatever it is — must be data driven. Only with the proper failure rate data, plotted in a Pareto chart, and a complete understanding of all costs, can the appropriate action plan be developed.
If tin pest were a living thing it might complain, “I can’t get no respect.” Reason: Tin whiskers get so much attention, while tin pest is forgotten.
Although my feeling is that tin whiskers are a greater concern, the number of recorded fails related to tin whiskers is less than 100. Compare this to the number of hard drive fails — about 100 million! With that in mind, let’s learn a little about tin pest.
Tin is a metal that is allotropic, meaning that it has different crystal structures under varying conditions of temperature and pressure. Tin has two allotropic forms. “Normal” or white beta tin has a stable tetragonal crystal structure with a density of 7.31g/cm3. Upon cooling below about 13.2ºC, beta tin turns extremely slowly into alpha tin. “Gray” or alpha tin has a cubic structure and a density of only 5.77g/cm3. Alpha tin is also a semiconductor, not a metal. The expansion of tin from white to gray causes most tin objects, afflicted with tin pest, to crumble.
The macro conversion of white to gray tin takes on the order of 18 months. The photo — likely the most famous modern photograph of tin pest — shows the phenomenon quite clearly.
This photo is titled “The Formation of Beta-Tin into Alpha-Tin in Sn-0.5Cu at T <10ºC" and is referenced from a paper by Y. Karlya, C. Gagg and W.J. Plumbridge, "Tin Pest in Lead-Free Solders," in Soldering and Surface Mount Technology, vol. 13 no. 1. 2000, 39-40.
The tin pest phenomenon has been known for centuries and there are many interesting, probably apocryphal, stories about tin pest. Perhaps the most famous is of the tin buttons on Napoleon’s soldiers’ coats disintegrating on their retreat from Moscow. Since tin pest looks like the tin has become diseased, many in the middle-ages attributed it to Satan as many tin organ pipes in Northern European churches fell victim to the effect.
Initially, tin pest was called “tin disease” or “tin plague.” I believe that the name “tin pest” came from the German translation for the word “plague” (i.e., in German plague is “pest”).
To most people with a little knowledge of materials, the conversion of beta to alpha tin at colder temperatures seems counterintuitive. Usually materials shrink at colder temperatures, not expand. Although it appears that the mechanism is not completely understood, it is likely due to gray alpha tin having lower entropy than white beta tin. With the removal of heat at the lower temperatures a lower entropy state would likely be more stable.
Because the conversion to gray tin requires expansion, the tin pest will usually nucleate at an edge, corner or surface. The nucleation can take scores of months, but once it starts, the conversion can be rapid, causing structural failure within months. The effect is also cumulative, so warming the sample will stop the growth, but it will continue once the sample is cold again.
Although tin pest can form at <13.2ºC, most researchers believe that the kinetics are very sluggish at this temperature. There seems to be general agreement in the literature that the maximum rate of tin pest formation occurs at -30º to -40ºC.
What is the real risk of tin pest in Pb-free electronics? Not great. Modern researchers have had trouble reproducing it, even in the lab. The reason for this is likely that test samples contain small amounts of metal "contaminates" (<0.1%), such as bismuth, antimony, lead and a few other metals. These trace metals solid solution strengthen the solder and inhibit the expansion needed to form tin pest. Unfortunately, copper and silver (the typical Pb-free metals added to tin), do not appear tin inhibit tin pest growth.
Don’t be fooled by iSuppli’s latest report saying that consumers are going green. The data actually say the opposite.
The research firm issued a press release today stating more than half of US LCD-TV buyers say that environmental issues “influenced their decision when selecting a set to purchase.”
A look at the rest of the picture tells a different story.
According to the April survey, 27.5% of LCD-TV buyers “listed green factors as important influences” in their purchasing decisions. Another 23.1% responded that they looked for green features when buying an LCD-TV, but those features were not an important consideration [bolds mine] in the overall purchasing decision.
From this, iSuppli somehow concludes that “more than half of US LCD-TV buyers are paying attention to environmental features, making ‘green’ a key selling point that needs to be highlighted wherever possible in branding and marketing efforts.”
Here’s the rub: Fewer than 16% of respondents highlighted recyclability as a feature on their purchase.
Say it with me: Electronics aren’t green. They require lots of mining and other nasty actions to produce, consume billions of tons of plastic, and hog energy. And if you can’t recycle it, it’s even less environmentally friendly.
Not long ago, I spent 30 minutes or so standing in the electronics department of the Seabrook, NH, Wal-Mart, asking customers why they chose their TV. (I’d say I did this just for fun, but have you ever tried randomly starting a conversation at a Wal-Mart? It’s not easy.) The most common answers? Price and “it looked good.” Not one customer mentioned environmental reasons. Not one.
Granted, there’s nothing scientific about my poll. And customers don’t shop at Wal-Mart because they like the pretty store décor.
Solder pastes are a very complex “fluid” of high viscosity. Their behavior, when experiencing shear stresses, is “non-Newtonian,” meaning that their viscosity is not constant as the shear stress varies. The viscosity of solder pastes is high when there is little or no shear stress and low when shear stresses are high such as when the paste is forced through a stencil aperture. This property is called thixotropy. The solder paste being thixotropic is ideal, as it enables the stencil printed “brick” of solder paste to retain its shape after it is printed, yet the low viscosity, when stressed, allows good filling of the stencil aperture.
Many might assume that this relatively complex phenomenon is the end of the story. However, there is at least one other well-known property of solder pastes during printing that is important: response to pause. A solder paste with a poor response to pause will stiffen when permitted to idle for as few as 15 minutes. When this occurs, the first print likely will have insufficient solder paste for effective assembly. Hence, response to pause is a critical variable to measure when evaluating a potential solder paste.
Another important solder paste property has only recently become well known: shear thinning. My Indium Corp. colleague Tim Jensen was one of the first to point this out. Shear thinning is a property of some solder pastes in which the viscosity becomes lower and lower as the paste is repeatedly printed (see figure below). The x axis is number of prints, the y axis is the viscosity. It is normal for the viscosity to go down during the print, but the viscosity should recover as the “good paste” does, not have a downward trend as the “bad paste.” The resulting drop in viscosity that the bad paste exhibits will often result in too much paste being printed and potentially lead to defects such as shorts or solder balls. Unfortunately, if not tested for, shear thinning might first be observed after a paste has been implemented on the line.
If you are interested in a method to test a paste for its resistance to shear thinning, send me a note and I will send a test protocol.
Tuesday marks the opening of Apex, the largest electronics assembly trade show in North America. With it, the industry suppliers hope buyers will turn out in force for the Las Vegas event. The early returns don’t look promising, with suggestions that preregistration attendance numbers are down some 15% or more from last year, coupled with travel bans by several major OEMs. Here’s hoping this week marks not another nail in the coffin but the beginning of the turnaround.
Tonight, CIRCUITS ASSEMBLY will announce winners of its NPI and Service Excellence Awards. Check back for frequent updates.
A bit of early gossip: IPC will induct Dan Feinberg to its Hall of Fame on Tuesday. Years ago, Feinberg was president of the dry film and soldermask division of Morton (now owned by Rohm & Haas) and was a major driver behind the IPC Printed Circuits Expo trade show.