Burn In

Musings on Metals: Copper

It could be argued that civilization began with the smelting of copper.  Although thousands of years before, humans fired clay to make figurines and containers, smelting required several non-obvious steps.  After all, the firing of clay, at some level, can be accomplished by simply dropping clay into a fire.

To smelt copper, our ancestors had to:

1. Take malachite (see photo) or another copper ore, grind it up or break it into small pieces
2. Mix the ground malachite with carbon
3. Heat the mixture in a vessel to 1,085^oC. 

Malachite Ore

Achieving this temperature with a wood fire is, to me, astounding.  Think about those days when you are grilling some burgers.  You leave the grill on after the burgers are done, to burn off the grease.  You come back 20 minutes later and the grill is at 500^oF.  You can feel the heat.  Even touching the knob to turn the gas off is intimidating, as the heat drives you back.  This temperature, 500^oF, is only 260^oC!  The ancients reaching 1,085^oC with wood and bellows is, indeed, impressive. By the way, a good rule of thumb to convert degrees C to degrees F from 100^oC to 1,500⁰C is that 2XC=F, this fast approximation is accurate to about 10% in this range.

The confluence of the three procedures is not only non-intuitive, but think how many times the smelter of old could only reach 900^oC and failed.  I have argued that if copper melted at 1,200^oC or so, civilization would have never gotten started.  This temperature is perhaps a little too high to reach with a wood fire.  The smelting of copper encouraged investigations into other metals, eventually resulting in the discovery of the processing of iron, an even less intuitive process than smelting copper.  So, I believe that the success with copper was necessary to the production of steel. 

Copper smelting became an industry that encouraged permanent settlements and stimulated trade, which encouraged writing and ciphering.  An effective copper smelter would likely keep secret some of his craft as he wanted a competitive advantage.  He could make more by smelting copper than doing anything else, so he almost certainly was an early specialist.

Considering all of this, I believe that without the discovery of copper smelting, we might still be living in huts or teepees, using stone tools, and living a nomadic existence without commerce, writing, or mathematics.  Examples to support this thesis are the state of native peoples in the Americas in the 1400s.  These native peoples had never learned to smelt metals and hence also lacked the follow-on aspects of civilization mentioned above.

Today, copper is a foundation material for electronics, given its excellent electrical conductivity, second only to silver.  Copper’s ductility likely aids in the formation of PWB traces and plated through-holes in that it resists cracking.

Additionally, copper's ability to form an electrical and mechanical bond with solder is another trait that makes it a winner as an electrically-conductive assembly material in modern electronics.

Copper has been used for more than 10 millennia, but, as with most metals, 90 to 95% of it has been mined since 1900.  About 15,000,000 metric tons (MT) are used each year, third to aluminum’s   22,000,000 MT and steel’s unequaled 1,000,000,000 MT.

In the next installment, we will discuss tin and how it forms an intermetallic with copper during soldering.  Thus making solder paste, solder wire, and solder preforms critical components of electronics assembly.

 Cheers,

Dr. Ron

Folks,

Let's look in on Rob:

Rob looked at the new photo of Patty and their twin sons Peter and Michael. What a handful those two 18 month-olds were. Just like their mother! Rob was still pinching himself that he was lucky enough to have Patty as his wife. Rumors were that she would make VP soon, and a few of his buddies asked him if her success bothered him. 

He would always respond, “Let’s see: beautiful, successful, athletic, fun to be with, great mother, and most of all she loves me. What’s not to like?”

Rob really meant it. He felt Patty deserved her success. One of her great assets was her high energy level. She went to bed at 11:30PM and was up at 5AM to run two miles, lift weights, shower, and then take care of the kids. Rob just couldn’t keep up on less than seven and a half hours of sleep. So he got up at 7AM. Rob had to insist that they have some quiet time each night after the boys were in bed, to talk and maybe even watch some mindless TV. But Patty would often sneak her laptop out to work while NCIS was on. Patty, the workaholic!

Rob and Patty spoke Mandarin at home one day each week and Spanish another night. The boys were picking up all three languages. It was amazing to both Patty and Rob as they watched this miracle.

Well anyway, Rob did have one thing up on Patty: math. Rob was close to a math genius and also good at writing software. He was the “go to” guy for math modeling and writing software for the math models. He even helped the Professor improve ProfitPro. Rob also wrote a program that could be used to design an SMT line for maximum throughput. The software could do what Arena did in hours of simulation, in seconds.

Rob was startled from his daydreaming by the phone ringing. It was Sam the site GM.

“Hey Rob, we need your help in our plant in Guadalajara. Can you come right down to discuss it?” Sam asked.

“I’ll be right there,” Rob replied.

Rob walked to Sam’s office with a feeling of exhilaration. It was always fun and exciting to be sent on a trouble shooting mission.

“Rob, thanks for coming right down. This issue is QFN reliability. About 5% of the Druid mobiles phones in our Guadalajara plant are coming back with some of the QFNs burned out,” Sam began.

“Sounds like a voiding issue under the QFN thermal pad,” Rob interrupted.

“Wow, you seem to know quite a bit about this type of problem,” Sam remarked.

“Remember how I pleaded with you to go to SMTAI,” Rob teased.

“Yep,” Sam replied.

“Seth Homer gave a talk on this issue at the show last week. It was a terrific overview of the problem. From what you described the connection may need more solder. We may have to use solder fortification preforms to solve this. Optimizing the solder paste printing process may not be enough,” Rob summarized.

“Well, go there and solve the problem. The warranty issues are costing us a fortune,” Sam commanded.

After a moment of contemplative silence, Sam asked, “Do you need anything?”

“It would be nice to have Pete come. He knows the people there and is well connected. His Spanish is also terrific,” Rob said.

“OK, no problem. Since you sleep with Pete’s boss, you can work out the details with her. I need you to go this week,” Sam said.

“No problem,” Rob said.

As Rob left the office, he was elated with his new assignment. He had to admit though, he thought it was unprofessional and a little annoying of Sam to say, “since you sleep with Pete’s boss, you can work out the details with her,” but it wasn’t the first time someone said this. Truth be told, Patty might be a little annoyed. She really depended on Pete.

Will Patty be angry at Rob for taking Pete to Guadalajara? 
Will Rob solve the QFN problem?
How does Patty get by on only 5.5 hrs of sleep each night?
Stay tuned for the exciting conclusion.

Recent test results show that solder fluxes handle high reflow temperatures (>450°C), providing better-than-expected visual results of flux residue!  

Solder fluxes have not traditionally been used with AuSn, AuGe, or AuSi eutectic solder, because their peak reflow temperatures were very close to or above the flux activation range. An average flux activates at approximately 125°C and is not recommended for temperatures in excess of 350°C. Although AuSn solder melts at 280°C, peak reflow temperatures are recommended to be >300°C, nearing the maximum suggested temperature of flux. AuGe and AuSi alloys melt at 356°C and 363°C respectively, which exceed the documented flux activation range.

Since these alloys contain ≥80% gold and are resistant to oxidation, flux is not always necessary. Other methods have conventionally replaced the flux function, such as mechanical scrubbing, or forming gas purging. If these technologies are not available, or assembly speed is priority though, a flux may be required.

So I, along with my fellow engineer, Brandon Judd, sought out to test some of our best fluxes with Au alloys at these high temperatures. The result: Not all, but a few of these fluxes work extremely well up to temperatures as high as 450°C!!!

The reflow profiles used tested the extreme abilities of our fluxes:

·         Peak temperature 410°C

·         Nitrogen Purge

·         Time above liquidus: 137 seconds

·         80AuSn solder preforms 0.249” square x 0.002”

Some fluxes did what we expected- they charred and burned. They simply were not designed for this environment. 

Others, such as our TacFlux010® were very resilient at these temperatures. 

For more information about these test results, please contact myself or Brandon.

Happy Testing!!

Amanda

• Gun Control
• Politics
• Religion

• the organization behind the nuse: it cheapens your value proposition when you use news to indirectly imply that your products or services are superior - or that those of your competition are inferior.
• the media: when news is used to inflate readership and attention, it weakens the moral high ground that media could command.
• the target audience: when the readership, the target audience, begins to distrust parts of the media, and the organizations behind the stories, they begin to distrust ALL that they receive.

Today (March 3rd) I start my 25th year at Indium Corporation.  It seems like just yesterday that the minor league hockey team I was doing PR for folded and I was forced to look for a new job.

I knew after the first week that I had made a huge mistake.  Going from a world of writing and promoting and ticket selling to day after day of science and chemistry and math couldn't be right for me.  But I needed the job so I stuck it out.  For 24 years so far!  I'll bet I am not the only one with that story to tell.
And it turned out that the move was right for me.  Because Indium is a great place to work with great, smart people but also because every day is different from the day before.  I knew nothing about Indium or indium (the metal) before I started here (other than they were one of the hockey team's season ticket holders and our sports intern's mother worked here).  But I have sure learned a lot since that fateful first week.  Especially about indium metal.  Terms like Solder Preform, Burn In, Thermal Interface and Hermetic Sealing have replaced road trip, slap shot and overtime.

Over the next few weeks I will share with you some of the things I have learned during my tenure here at Indium.  I hope you find them as interesting (and hopefully usable) as I do.

At the heart of it, NanoFoil^® is simply the aluminum and nickel chemical reaction just waiting to happen.  A lot of energy and a lot of heat strapped into thousands of alternating layers of atoms.  Each atomic layer of aluminum is waiting for just the right energy to move into the nickel layer and combine - to release up to 1250 Joules of energy per gram of material and as much as 1500ºC (2730ºF).

But, why don’t nickel and aluminum just react in real life? And more importantly, how do we make the NanoFoil react to release heat precisely where we want it? 

The former question is answered by going back to basic chemistry and a concept called activation energy.  Activation energy is defined as that energy that must be overcome in order for a chemical reaction to take place.  In regular use, when aluminum and nickel come into contact with one another they do not react, and this is a good thing. Imagine if your nickel-coated nickel reacted with your aluminum money clip in your pocket…hot!  The activation energy of the reaction is too high to promote this reaction naturally.  ‘

 There are a few ways to reduce this activation energy, the most common being via a catalyst, which is a substance that modifies the transition state which, in turn, lowers the activation energy of the reaction.   In the case of the NanoFoil, instead of a chemical modifier we have taken advantage of a physical modifier, surface area.  By layering the aluminum and nickel atoms very thinly and in a very precise method, we rely on the increase in surface area to decrease the activation energy necessary to start the reaction…in most demos we use only a 9 volt battery!   

 The second question is a frequent one fielded by Indium engineers, and worth a deeper look!

 How is the NanoFoil Activated/Ignitied?

The reason I will use the term "activation" over "ignition" is that ignition implies the beginning of a sustained burn, where the NanoFoil is a reaction that lasts for less than a millisecond, and only requires activation.

The reaction will start with 250ºC of localized heat, or a very localized form of energy.  The trick is getting a very concentrated form of energy to come into contact with the NanoFoil.  Touching the NanoFoil with the point of a resistance soldering iron that is at 250ºC is much more likely to activate the NanoFoil than throwing the NanoFoil on a hot plate that has been heated to 250ºC.  In general, there are three types of energy you can put into foil to activate it.

1. Mechanical Energy
2. Thermal Energy
3. Electrical Energy
   

Mechanical Energy – In the case of mechanical energy, dropping the NanoFoil on a concrete or hard surface could activate it IF it lands on its edge and all of the impact energy is concentrated on the corner.  Generally, the NanoFoil does not go off with contact, but friction between the NanoFoil and itself, in the form of a small shard, has produced enough energy to activate the NanoFoil.

Thermal Energy – In the case of thermal energy, as discussed above, a concentrated amount of 250C heat will activate the NanoFoil.  In the case of ohmic heating, which is what we do in demos, by shorting the leads of a battery, the current must be 100-120Amps for a 15um contact diameter, and 250-300 Amps for a 300µm contact diameter.  A hot filament or flame, such as a lighter, will also activate the NanoFoil.

Electrical Energy – In this case a spark will activate the NanoFoil, but it is about concentration of power, or power density.  With a momentary point contact from an electrical probe, 10 Amps and 5 Volts is sufficient as long as it is POINT contact.  The foil can be activated remotely through the use of a dedicated trace on a board, and this requires testing to determine the amount of energy that will travel the distance of the trace.

In my next blog post I will talk about Laser Ignition, ESD sensitivity, and some of the tools that Indium has developed to control the activation.

上周在加州Santa Clara, CA的Semi-Therm展會上，Indium 公司的Eric Bastow 向大家介紹了我們公司系列金屬或是合金的熱管理材料(TIM)，還有納米技術的Nanofoil材料。

金屬或是合金的熱管理材料，是專門針對高性能高可靠性產品的散熱管理的。 比如説IGBT的系列焊接/散熱應用，CPU/GPU的Burn-in或是散熱應用（TIM1, TIM2,TIM1.5），功率放大器(power amplifier)的焊接/散熱應用，LED，等。 而Indium公司的Nanofoil材料，對於大元件的焊接，無論是機械性能還，電性能，還是散熱要求上，都比傳統的焊接優越許多，特別是那些對溫度敏感的元件。

除了加州/美國當地的與電子/電子組裝相關的公司參加了這個盛會，許多遠在亞洲的公司（中國，日本，韓國等），也專門派工程/技術代表來了解新技術，或是需求熱管理解決方案。

Cheers! 

每次展會都有些小驚喜：有兩個亞洲樣貌的男士前來，我上前詢問他們在尋求什麽樣的熱管理解決方案。聊了一會兒，我聼出他們應該是日本人，但是他們的胸牌一直是反放的，看不見名字和公司。我想：會不會是同行朋友。於是我笑問：你們不會是FBI吧？ 他們笑了笑，把自己的胸牌反過來了，顯示出名字和公司，是一個TXXX的公司，我聞所未聞。我們三人繼續聊…終于，我問他們可不可以留下名片，他們想了一會，才瑟瑟的拿出名片。原來是Toyota的人！TXXX是他們組的簡稱！  他們倆不好意思說：The company is in big trouble!  哦，原來他們怕我“消費者”，對他們公司有意見，所以一直不敢以正面目示人。無論如何，我馬上向他們示，我本人還是很喜歡Toyota 的產品的。

In a statement Accenture said, "...given the circumstances of the last two weeks, after careful consideration and analysis, the company has determined that he is no longer the right representative for its advertising."

Figure 1: 15% Voiding with air reflow

Figure 2: ~0% Voiding after vacuum reflow

Figure 3: Multiple voids

While at the Semicon West 2009 show in July, I had a chance to sit down with Herr Klaus Roemer of Pink GmbH. PINK is most famous in the die-attach and power module manufacturing world for their reflow ovens with vacuum, but are also known in the medical and aerospace industries for manufacturing extremely high precision, one-off, vacuum equipment for applications as diverse as particle-accelerators for ion bombardment, and large-volume chambers for helium leak-detection. I asked him some questions about Pink vacuum soldering technology.

Cheers! Andy

Folks,

I will be speaking at SMTA's 25th anniversary dinner at SMTAI on Monday, October 5 at 6:30 PM.  Come and join me and say hello.  An overview of the talk follows:

Cheers,

Dr. Ron

Indium Corporation (I say "Indium Corporation": it's actually me and my colleague Tim Jensen) is in the middle of drafting a position statement on halogen-free electronics and semiconductor assembly materials. In talking to Tim, who is Indium's guru on all matters related to the drive towards halogen-free, we became rather confused by something that is missing in the debate.

We know that the current best method for preparing "halogens" in flux materials for quantitative analysis, is to convert the two different chemical types (ionic and covalent) to the ionic halide salts by using a so-called "oxygen bomb", whereby the material to be tested is placed in a metal chamber that is pressurized with oxygen and then heated. The residue in the chamber is then eluted with a known quantity of a halogen-free solvent (usually water), and analyzed. For the former boy scouts and girl guides amongst you, you will recall that burning a piece of wood leaves behind a lot of residual ash. Tim and I realized that there is something wrong with this if the material is a pure organic flux: which is a much simpler material than wood. For the non-chemists among you, this is the issue:

A standard organic flux material, as used in SMT, Semiconductor Assembly or Power Semiconductor Assembly, is a mixture of several different organic chamicals. It can be represented generically as:

C(a) H(b) N(c) O(d) Y(e), where C is carbon, H is hydrogen, N is nitrogen, O is oxygen and Y is a halogen (the usual ones of interest are chlorine, Cl, and bromine, Br). (a) to (e) are simple ratios.

If you then heat this in oxygen to the point of complete combustion (reaction with oxygen), the end products are therefore:

CO(2) , H(2)O, NO(2), residual oxygen gas (O(2) and .....some product from Y.

The assumption has always been that the Y will be a solid ionic halide, of form X(f)Y(g).

So what is "X" here, the metallic cation to balance the halide anion, "Y"? Whatdunnit? The simple answer is that it is probably a reaction with the inside of the metallic container, which is usually steel (so Cr or Fe or Ni could be correct). Other theories involving the acid formation (HY) are probably wrong, as the vapor pressure is too high. Theories about oxides of halogen also don't hold up to scrutiny, either because in YO(j), the Y halogen is in the wrong oxidation state (plus not minus) or they are unstable or a combination of both.

What do you think is going on here?

Cheers!

Andy

Extreme skiiers astonish us on the day of the show. To acquire the skills and abilities that get them there, they become comfortable with the ol' crash and burn during practices. You should, too.

I just received an email invitation to a webinar. It is promised that I will learn (quoted):

• How B2B marketers and marketing budgets specifically have been affected by the worldwide recession

• How much of marketing budgets are allocating their budget among digital media options

• How to re-examine your own spending based on what the rest of the B2B world is doing

It struck me kind of funny that this was it. It wasn't the intro of the webinar, it was THE webinar.

Now, I don't mind knowing these things. In fact, they could be parts of a valuable baseline of information. But, if you are to become a B2B Marcom leader, then you aren't being paid to be average. You aren't supposed to emulate typical B2B Marketers - you're supposed to blow them all away!

The SMART voice in my head tells me that, when such a seminar is given, EVERYONE learns the info ... and the average shifts. Most people move in a pack and remain average. I am not paid to be average. So, it continually comes down to:

• listen to this "average" information - to know where the baseline is. Then, vow to step far away from it.
• cultivate your own "above average" practice with your trusted network of B2B Marcom experts. Implement it and distinguish your organization.

How do you identify leading-edge Marcom gurus, experts, and creators, so you can assemble your B2B Marcom Dream Team? I look for people who are in the trenches, actually implementing ideas and seeing the results. These people also have to be extremely curious, open-minded, and energetic. They also seek information and education constantly. And they are not afraid to stumble. They are comfortable with tripping and falling from time to time - and they never consider these events to be "failures" (watch a trick skiier or skateboard rider practicing. It looks like they are a mess ... far from it.). In fact, these people might actually scare you from time to time. They have far out notions, and try very "interesting" things. Pay attention! Sometimes these people crash, other times they invent something amazing. When they do crash, they are "failing forward". You'd think that no one wants to fail, that everyone actually prefers the simpler and less painful, "forward". Not true. True leaders need to know where the boundaries and borders are. They NEED to define the limits - and that requires the occasional crash.

So, be careful with these seminars and training opportunities. They clearly have a value, but they can lull you into a sense of complacency if you start believing that you've learned the golden nugget or been to the mountain top. Bottom line, "forward" is critical - but standing above the average is mandatory. So, "get" what everyone else is doing, but go far beyond.

Identify the opportunities to acquire "baseline" info - and use them appropriately. More importantly, cultivate your cadre of Marcom gurus and, together, get all messed up creating the new leading edge.

Image: CNN.

Virtual Trade Shows are a great alternative to staying home and doing nothing.

The economy is really putting the kibosh on travelling, attending seminars, and all sorts of spending. But, is staying in the office, burning the midnight oil the only B2B Marcom alternative? No! The show must go on!  How?

Virtual Trade Shows!

I've touched on this subject here and here.

The following crossed my desk just this week (kinda' tells us what's hot, right?):

The Rising Tide of Virtual Events

With the economy continuing in a downward spiral, many companies and trade groups are turning to virtual events, whether for large, outward-facing shows or internal meetings, as a cost cutting tool. According to an ON24, Inc. survey, of the 10,000 enterprise executives asked about their events and attendance in 2009, 42% said that the economy would decrease their company's participation in physical trade shows compared to 2008 (20% by at least half) and 64% said that they would have fewer or no (22%) physical sales kick offs.

 

More from VirtualWorldNews:

http://www.virtualworldsnews.com/2009/01/76-of-enterprise-executives-predict-rise-in-virtual-events-for-2009.html

 

ON24 just completed a survey of more than 10,000 enterprise executives which polled the anticipated use in 2009 of "in-person" trade shows, conventions and seminars versus virtual events such as webinars and virtual shows. The survey showed significant growth for virtual events in 2009, with physical events projected to decline more than 40%.

• 76% of the survey participants said their companies have already begun using virtual events or plan to begin using them in 2009 to supplement some of their physical events.

• 75% appreciate that there is no travel required when an event is conducted virtually.

• 64% value the ability to attend a virtual session on their own time schedules.

• 58% found it useful to be able to forward to their colleagues the virtual sessions that they thought would be of interest.

http://www.on24.com/

 CNN NewsRoom Report on Virtual Conferences and Exhibitions. 

Virtual PCB, the industry's first virtual trade show and conference for PCB
designers, fabricators and assemblers, will be held February 24-25, 2009.

·         Participate in live group chats with industry experts

·         Attend webinars

·         Access targeted technical information

www.virtual-pcb.com

One of the common reasons for halogen elimination in electronics is based around the possibility that halogens can form dioxins when that halogenated product is burned. Dioxins are considered to be likely carcinogens. During uncontrolled incineration, the dioxins can be breathed in by any person or animal in close proximity to the fire. In a photograph published last year by National Geographic (shown here), you can see an indivdual in India buring the insulation off of copper wires in an open pit. Copper has value, but most companies won't buy back copper with the insulation on them. Therefore, this individual has decided the easiest way is to just burn it off. The wires most likely have PVC coatings on the outside which does contain the halogen chlorine. By buring the halogenated wires, this person is putting his own life and others nearby at risk. I can't find the source right now, but it was documented that about 40% of dioxins in the air are a result of "backyard" or open pit burning of materials. My personal opinion is that we can eliminate the halogens to reduce dioxin formation, but does that really make these types of burning practices "safe?" I don't think so...

The environmental push of companies toward halogen-free is driven by environmental organizations such a Greenpeace providing examples of poor recycling conditions in 3rd world countries. One such example is a report by Greenpeace in which they assess the e-waste being burned in Ghana.

The report addresses a serious problem of dangerous recycling conditions and child labor that is occuring in Ghana. The issue that I have is they are focusing on the elimination of hazardous materials as the key solution to the problem. Regardless of whether or not the materials being burned are hazardous, having children working around open fire pits will never be safe. In addition, smoke inhilation can be a health problem even without PVC and brominated flame retardants.

The large electronics companies (Philips is being targeted hare by Greenpeace), are not the ones actually shipping the e-waste to Ghana. I would like to see someone trace the e-waste backward and find out the companies that are profiting by shipping the waste here. What about targeting people/companies who are buying the reclaimed metal from these people in Ghana?

I think that if you want to stop countries like Ghana from using bad practices to recycle and reclaim metals, then you need to target those profiting by shipping waste to them in the first place and those saving money by purchasing low cost metals from these scrap yards.

http://upload.wikimedia.org/wikipedia/commons/b/ba/Thermometer.jpg

Operational temperature

Metallizations
Flux usage
Reflow method
Temperature limitations
Special conditions

Whether the market is communications, automotive, energy, military, medical or aerospace, choosing the correct solder is essential to making a quality product. A solder joint plays a very important role in an electrical or mechanical assembly. How this solder is selected for this joint is extremely important to the application, so following a guideline will insure that this is accomplished.

Before choosing a solder for an application, the operational or service temperature must be known; i.e. the minimum and maximum temperatures the assembly will see, during testing and in service. Continuous operational temperatures above 125°C will require the use of precious metal solders or hard solders such as Au/Sn, Au/Ge, or Au/Si.

Generally, it is best with soft solders to choose one that will melt at least 50°C higher than the expected service temperature of the assembly. (This includes temperature cycling during test and burn-in). If the difference in temperature (Delta T) between operational and the solidus temperature of the solder is too small, this could result in excessive scavenging, leaching and intermetallic growth. These unwanted conditions could lead to problems and eventual joint failure. 

After the correct temperature range for the solder is determined, consideration needs to be given to what metallizations in the joint will interact with the solder.

Metallizations will be addressed next in our series of steps to consider when designing a trouble-free solder joint.

A Chinese child sits amongst a pile of wires and e-waste. Children can often be found dismantling e-waste containing many hazardous chemicals known to be potentially very damaging to children's health.

同事Kelly Huang与大家分享了一则关于电子废弃产品的有毒物质相关消息，引人深思；特别是看见那个可怜的中国孩子图片时。

"The world is consuming more and more electronic products every year. This has caused a dangerous explosion in electronic scrap (e-waste) containing toxic chemicals and heavy metals that cannot be disposed of or recycled safely. But this problem can be avoided. We are pressing leading electronic companies to change; to turn back the toxic tide of e-waste.

无论是以前的无铅(Pb-free)还是现在的无卤素(Halogen-free)，Indium 公司一向提供前沿的技术和环保的产品，协助我们的客户们become "green", 让大家都成为一个更加有社会责任感的企业(Corporate Social Responsibility)!

Pic and story source: www.greenpeace.org

Last year Amanda Whittemore and I had the pleasure of attending a 2 day seminar “IC Fab East” in Albany, NY.  Ernest Levine (the instructor) combines his industry experience with insider information to teach the background of semiconductor fabrication and cutting edge trends.  As I thought about that seminar recently, it became clear that I should have the man himself shed some light on a couple issues upstream that could have an impact on wafer bumping and semiconductor packaging:

Jim: What defects in FEOL or BEOL could show up during packaging?

Ernest: First and foremost, cracking of the chip from too much stress during packaging.  Need to assess plastic molding and its resistance to avoiding stress cracking of the chip.  Witness recent game maker that reported thermal loads cracked chip.  Dicing before packaging can damage the chip and cause failure during packaging.  Besides that, when one packages and subjects to burn-in, any defect in front or back end can manifest itself as a fail as usually one exercises circuits never exercised before.  Thus near opens, shorts, BEOL voids etc. can all propagate to failure.  Stress from wire bonding can crack the low-k chip whose modulus is far below quartz. 

Jim: Are there any chemicals that could remain on the wafer surface and hinder wire bonding, bumping or wafer-level packaging?

Ernest: Sure, drying residue will hinder wire bonding.  Here I assume that we are bonding to Al bonding pads.  Stains of any kind will not allow a bond to occur.

Jim: I noticed a large cross-section of engineers attending your class, are there any notably interesting attendees you’ve hosted?

Ernest: They are all interesting.  They are from user companies like Microsoft and Cisco and from Vendors such as LAM and KLA.  My pleasure is in getting people so they really understand the material.

Ernest has another class coming up October 6^th and 7^th.  If you are interested in the IC Fabrication and Yield course, you can contact Ernest at ELevine@uamail.albany.edu

1. I never made plans to get the Singapore video to my US-based post-production team. So, on the fly, I tried hooking both sides together. FTP address here, a different FTP address there. Format issues, file compressing problems, no familiarity with each other, and you guessed it: it is taking FOREVER to get the video into the hands of my post-production team. I finally resorted to having the video guy put it onto a DVD and mail it to the USA. How archaic!!! This story is still not done yet.
2. Being semi-burned (at that point I didn't know things were going to get worse) by the portion of this nightmare that was unfolding while still on the road, I took the actual raw video tape, in hand, from Vietnam to home. I personally handed it to my post-production team. They emailed me and said, this is in PAL! We need to get it converted to NTSC. No big deal, but we are now searching for someone locally who can do this for us. Geez!

So, I've made a B2B Marcom mess of things. Nothing that I can't dig my way out of, but time is the critical element in most transactions - and these projects are lasting about 4x longer than they should - a disaster!!! And I know better!

The moral of the story, sometimes it LOOKS easy, but that is when a well-oiled machine swings into action. When we are throwing things together on the fly, or using new/unfamiliar talent, or when we cross technology borders, we need to slow down and think harder, plan better. I didn't do that well-enough and I am now paying the humiliating price. Aaarrgghhhh!!!