Fabrinet’s Changing of the Guard

Were you as surprised as I was at Fabrinet’s choice of a new CEO?

During the 17 years of its existence, having been formed in 2000 when ex-Seagate exec Tom Mitchell took on the lease of his former employer’s plan in Chokchai, Thailand, there has been no EMS company so successful over the past two decades. That initial $21 million investment is now worth $1.35 billion in market value, not to mention the consistently most profitable business in the industry.

It would have been conventional, then, had Mitchell chosen longtime No. 2 Harpal Gill to assume the mantle. Dr. Gill has been Fabrinet’s chief operating officer since 2009 and president since 2011.

Instead, Mitchell went outside for Grady Seamus from rival Sanmina, where he headed the  Mechanical Systems division.

Some analysts believe the move foreshadows a coming diversification from fiber optics into non-optical manufacturing. Writes Stifel Nicolaus’s Patrick Newton:

[W]e see Seamus as having extensive leadership experience with both optical manufacturing (background at Lucent; Mechanical Systems Division at Sanmina manufactures the cabinets/chassis/frames/racks/ and storage cabinets integrated with electronic components and sub-systems that optical components are supplied into) and non-optical manufacturing (focus Medical experience at Sanmina). We view this competency in both optical and non-optical manufacturing as likely to be an aid in helping the company move beyond its optical focus to a 50/50 optical/non-optical mix long-term. We emphasize that our recent conversations with Fabrinet’s management highlighted that Fabrinet was targeting its next CEO to have a combination of operational excellence, deep technical expertise, and strength with customers as they will have to be customer facing.

Mitchell set the bar so high, any successor would be challenged to maintain it. Seamus is widely seen as a talented executive. But will he attempt to write Fabrinet’s next chapter with — or without — the team Mitchell put in place?

Moore’s Law: Broken?

Nvidia founder and CEO Jensen Huang is the latest tech luminary to call the end for Moore’s law.

There’s nothing new about this, of course. He joins the MIT Technology Review, Ars Technica writer Peter Bright, former Intel former chief architect Bob Colwell, and the International Technology Roadmap for Semiconductors.

(For the record, Gordon Moore himself disagrees.)

What do you think?

Mistakes Were Made — Too Much Ground Isolation

I recently ran a batch of my Neo Pixel clock boards through the factory here. It’s an Arduino UNO-based design that I made for myself not long ago. It sports an Atmega328P, with bootloader, an FT231X USB chip, and a DS3231 real time clock (RTC) chip. Pretty standard stuff. It doesn’t even use small parts. All the passives are 0805 size. There’s nothing exotic here. So, where did I go wrong?

I also used my 3D printer to make a clock frame to hold this board and a 60-pixel ring of NeoPixels, from Adafruit. I found that with the micro USB connector on the top of the board, it’s a little awkward to plug in the USB cable, so I put pads for the connector on the back side of the board. Depending on exactly where and how the board will be used, the micro-USB, button switches, and clock backup battery can all go on either the front or back surface of the board.

Programming the bootloader worked as expected, so I assumed it was just a job well done. Except it wasn’t. When I plugged in the micro USB cable, the RX and TX LEDs flickered briefly, but the board wasn’t recognized by my PC.

Take a look at the back side of the PCB and see if you can find my mistake (spoilers after the photo).

I ran a 24 mil trace around the back side of the board to supply power to the NeoPixels. That’s not a problem, except that I closed the loop on that trace, and didn’t put a path for the ground to get across the trace.

Follow it around, and notice that the ground connections to the u-USB connector don’t go anywhere except to this part of the plane. Ugh.

Duane Benson
Cassini’s gone now.

When Fake Buys Make Real News

M&A specialists in the electronics industry seem to have caught a case of merger mania. In the process, they unfortunately have seem to have learned the worst traits of the buyout crowd.

A pair of unsolicited bids were announced this week. In one instance, a small EMS company announced its interest in a much larger competitor. In the other, a Chinese connector manufacturer made a play for a smallish Canadian EMS/ODM.

What makes these cases interesting are the details.

In the former, Cemtrex, a company with trailing four quarter revenues of $125 million and a market cap of $31 million, made a play for Key Tronic, a top 50 worldwide EMS that reported sales of $468 million for its just completed fiscal year. Key Tronic’s market cap is $74 million, so Cemtrex’s offer of a one-for-one stock swap was a huge discount to Key Tronic’s value.

Not only that, says Key Tronic, it wasn’t really even  an offer:  “Based on (Cemtrex’s) current SEC filings, Key Tronic understands that Cemtrex has not commenced a formal exchange offer and that any such offer would require additional SEC filings by (Cemtrex),” Key Tronic said.

In the latter, Shenzhen Kaizhong Precision Technology made a written offer for Pacific Insight Electronics. The wrinkle here is, not only was Pacific Insight taken by surprise, it is already under agreement to be purchased by Methode Electronics.

The ODM today confirmed receipt of a written buyout proposal from Chinese connector maker. However, Pacific Insight has already agreed to be acquired by Methode Electronics, whose offer Pacific Insight says is superior to Kaizhong’s. Pacific immediately urged shareholders to reject the unsolicited bid.

Publicly traded companies such as Key Tronic and Pacific Insight have a fiduciary responsibility to their shareholders. However, from time to time outsiders try to make waves or generate publicity by pulling stunts like these. I’m not saying the interest communicated by Cemtrex or  Kaizhong is false, or even misplaced. But in both cases, I think the suitors are overplaying their hands.

 

Dont’ Forget PCB West Next Week!

Next week is the 26th annual PCB West, the preeminent trade show in the Silicon Valley for the electronics supply chain.

As those who have attended before know – and there are quite a few of you – PCB West focuses on the design and manufacture of PCBs, HDI, electronics assembly and printed circuit board test, and gives engineers, designers, fabricators, assemblers and managers an opportunity to improve skills, increase knowledge and network with peers, colleagues and experts. With an emphasis on training – half the presentations
are at least 2 hours in length – there is no place better to get real, practical, in-depth information.

Our three-day conference features:
• More than 70 presentations on the hottest topics, including noise control, flex circuits, and diagnosing assembly defects. This is our largest conference yet!
• More than 15 day-long tutorials or half-day seminars

• Sessions for all levels of experience and training, from novice designer and engineer to seasoned pro
• Speakers from Analog Devices, TTM Technologies, NXP Semiconductor and many more top companies
• The ever-popular Rick Hartley, Doug Brooks and Susy Webb
• An all new PCB/EMS Management track with special sessions aimed at helping executives make the capital investment and hiring decisions that shape their companies
• Three free day-long tracks on Sept. 13, with topics ranging from signal integrity and IoT PCBs to 3D printing technologies.

Also next week, a special 2.5-day IPC Designers Council Certification Program powered by EPTAC.

All conference attendees receive free admittance to the one-day exhibition Wednesday, Sept. 13, which includes a complimentary luncheon and evening reception, both on the show floor.

For more information or to register, click here.

Looking forward to seeing you at the show! And as always, please feel free to share your thoughts.

It All Adds Up at Count on Tools

When you work from a home office, nothing is more enticing than an opportunity to “get out” and see a customer and take a facility tour. So, last week, “get out” I did and hit the road from Fayetteville, GA, up to participate in a tour of Count on Tools in Gainesville, GA.  (For those unfamiliar with Georgia geography and traffic – yes, that is a bit of a drive, but, thankfully, I-85 has been repaired.)

This tour was organized by the Georgia Manufacturing Alliance. This group serves manufacturing businesses in the state and provides monthly plant tours, educational sessions and networking opportunities  “designed to help make profitable business connections for our members.” They put on all sorts of very cool tours throughout the state – including one I was sorry I missed of the KIA plant. Jason Moss, the founder and CEO of GMA, has, in fact, been a great supporter of our local SMTA Atlanta Chapter as well as a featured keynote.

But, I digress. Back to Count on Tools – longtime CIRCUITS ASSEMBLY friend, supporter and 2017 Service Excellence Award winner for Automation and Handling Equipment. I was greeted warmly at the door by Curt Couch, president and CEO, and we chatted about how nice it was to see each other outside the confines of a busy trade show.  He and his wife, Rene, started this business about 26 years ago literally in their backyard. And what an amazing success story from such an unassuming but obviously visionary guy. He said he never expected this level of growth, but here they are today with about 40 employees and a 20,000-sq. ft. facility.

For those who may not know, COT is a precision component manufacturer specializing in CNC Swiss automatic machining using standard to exotic materials including stainless steel, titanium, Inconel and PEEK. They are a global supplier of precision engineering components to a wide range of industries. And, of course, in our industry we know them for their nozzles and tooling, automation tooling and component handling equipment. Just this month, they finished an expansion of their manufacturing facility.

The consistent comment from the tour group (which was comprised of professionals from other manufacturing and service facilities throughout Georgia) – “what a beautiful, clean facility, well run and organized.”  And, the camaraderie among the Count on Tools employees was evident as well.

Zach Shook, operations director, Marketing and IT was also on hand, and we discussed our upcoming travel plans for SMTAI and Productronica. I caught up with my friend Tom Foley from ASM, who is a customer of COT. Prime, a contract manufacturer here in Georgia, was also represented as well. (Shameless plug  – our next SMTA chapter meeting will be held at Prime, and our speaker with be Jeff Timms, managing director of ASM Americas.  He will speak on “Enabling the Digital World” which highlights many of the upcoming and future technologies which will drive the electronics assembly industry into the future.)

All In all, Count On Tools is an impressive manufacturing success story and a day well spent!  Thank you Curt, Rene, Zach and the Count on Tools team for your hospitality.

Frances Stewart is vice president for PCD&F/CIRCUITS ASSEMBLY.

QFN Center Pad Revisited

The QFN (quad flat pack, no leads) package can no longer be considered exotic. It was when I first wrote about it a decade ago, but not anymore. In fact, with the wafer-scale BGA, it’s one of the more common packages for new chip designs.

Not all QFNs come with an exposed metal pad underneath, but most do, and that can cause problems with reflow solder. The pad itself isn’t the problem, but improper solder paste stencil layer design can be.

The default stencil layer in the CAD library footprint might have an opening the full size of the metal pad. If that’s the case, modify the footprint so that there will be 50% to 75% coverage with solder paste (Figure 1). If you don’t, it may result in yield problems. With a 100% open area, the likely result is too much solder in the middle. The part will ride up, or float, and may not connect with all of the pads on the sides of the part.

Figure 1

Figure 1. The optimal QFN footprint will have 50% to 75% solder paste coverage.

 

Figure 2 shows a stencil with too large an opening in the center, a segmented paste layer in the CAD footprint, and the resultant segmented stencil.

Figure 2

Figure 2. Stencils shown with too large an opening in the center (left), segmented paste layer (center), and the resultant segmented stencil (right).

 

You may note that I said to shoot for 50% to 75% coverage and ask: “Well, is it 50% or 75%? What gives?”

True, that is a bit of ambiguity. Anything in that range should be fine for prototype boards, however. If the assembly is headed for volume production, work with the manufacturer to tweak the design for best high-volume yield.

The good news on this front is that many QFN manufacturers and parts library creators have taken notice. It’s far more likely now than it was 10 years ago to find a datasheet correctly illustrating this, and footprints created correctly. But, always check your footprints to make sure.

Duane Benson

http://blog.screamingcircuits.com

Don’t Fire Up the Grill Yet, Wisconsin

Dear Wisconsin,

I know you are excited about the news Foxconn will build a high-end display manufacturing plant in your backyard. But don’t break out the brats and beer yet, cheeseheads: Foxconn has a long track record of pulling the football away right before you go to kick it.

Signed,

Brazil

Indonesia

Vietnam

India

Phillipines

Harrisburg, PA

How Far Can We Go to Replace Lead?

The end is nigh for lead in solder, as our columnist Tim O’Neill writes this month in CIRCUITS ASSEMBLY.

Rules governing use of the materials — Directive 2015/863, aka RoHS 3 — are coming online and will be in full force by 2019.

Suppliers have until July 22, 2019 to meet the stricter provisions, which includes no more than 0.1% lead in medical devices, which are joining consumer, industrial and other electronics products on the effectively banned list.

The question Tim poses is, What comes next? Already, the future of commonplace unleaded alloys such as SAC is being questioned. As Tim writes, “It is even feasible SAC 305 will be dislodged by a new de facto alloy that better serves the needs of the market.”

A Norwegian scientist believes he may have the answer. As noted in Phys.org this week, Dr. Henrik Soensteby of the University of Oslo is working on an alternative alloy that contains nothing but common — and essentially benign — elements. In conjuring up his alloy, Soensteby is mixing sodium, potassium and oxygen with niobium, a very strong metal typically used in steel. While niobium dust is reported to cause eye and skin irritation, it reportedly is nontoxic, at least in the volumes used.

It’s not so clear yet how much niobium would be needed. Brazil is the biggest supplier of niobium, producing more than 85% of it each year. Other sources include Zaire, Russia, Nigeria and Canada. World production is relatively light: around 25,000 tonnes per year. Some scientists believe there are ample supplies still in the ground. There’d better be: Some 5 million tonnes a year of lead ores are mined each year, although obviously not all that goes into electronics.

Soensteby is optimistic he can use atomic layer deposition (ALD), a vapor phase method that uses gas at controlled temperatures to stimulate a reaction with the substrate; the output is thin films. It is an emerging technology in semiconductor manufacturing. There are many, many questions, of course. First and foremost, does the alloy actually, you know, work? Also, ALD typically involves higher temperatures than are used in electronics assembly: Would it work with today’s packaging? Will other technologies such as 3D printing or Joe Fjelstad’s solderless Occam process supplant the need for solder in any form?

Still, materials science is the most exciting area of electronics today. We may make fun of folks who walk around with smartphones seemingly permanently tethered to their ears, but we also have them to thank.

 

Register now for PCB West the Silicon Valley’s largest PCB industry trade show: pcbwest.com! Now with full-day electronics assembly tutorials!

 

Intermetallics and Kirkendall Voids Continue to Grow at Room Temperature

Folks,

In my last post, I discussed intermetallic compounds (IMCs) and what I referred to as the “miracle of soldering.” I also mentioned that research focused on the brittle nature of IMCs suggests that failures in stress tests are more likely due to failures between the interfaces of the IMCs and the solder, the IMCs and the copper, or the IMCs (Cu6Sn5 with Cu3Sn) themselves and are not related to any perceived brittle nature of the IMCs.

Another weakening mechanism in soldering and thermal aging of solder joints is Kirkendall voids. Kirkendall voids form when one metal diffuses more rapidly into another metal than vice versa. A copper-tin interface displays such a mechanism. Copper diffuses into the tin more rapidly than the tin into the copper. This mechanism can result in actual voids in the copper at the metal interface. See the image below. In addition to causing a possible weakness at the interface, the excess copper that diffuses into the tin creates compressive stresses than can result in tin whiskers.

Kirkendall voids

(Source: http://www.jfe-tec.co.jp/en/electronic-component/case/img/case_solder_02.png)

IMCs and Kirkendall voids are formed quite quickly at soldering temperatures. However, even at room temperature IMCs and Kirkendall voids continue to grow, albeit at a much reduced rate. The reason for this continued growth is that on the absolute temperature or Kelvin scale, room temperature is a considerable fraction of the melting temperature of solders. As an example, the melting temperature of SAC is about 219°C, this temperature is equal to 492K (219+273), whereas room temperature is 295°K, so room temperature is 60% of the way to the melting point of SAC solder (295/492 = 0.60). Compare this situation to steel, which melts at about 1480°C. The steel would be red hot at 60% (780°C) of its melting point on the absolute scale. So, since room temperature is 60% of the way to melting, the IMC and Kirkendall forming processes don’t stop at room temperature. Hence, IMCs and Kirkendall voids continue to grow, as do related effects such as tin whiskers.

Stay tuned. Next time we will discuss IMC growth rates and resulting effects in stress testing as we wrap up this series on IMCs.

Cheers,

Dr. Ron