Category Archives: Laying It Out

Off-grid thoughts from a burned-out designer turned editor.

Component Footprint Rotation

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Before we (or any old assembly house) go about putting surface mount parts on a board, we need to program our assembly robots. I’m oversimplifying, but essentially, the machine program needs to know the X / Y coordinates, relative to the board origin (which is the lower left-hand corner), the part rotation, and the side of the board.

In years past, we needed a centroid file (AKA pick-and-place file) containing all of that information. In some cases, we still need the centroid, but not always. Today, we can get the same information from ASCII CAD files, ODB++ CAD files or Eagle .brd files. You only need a centroid if you send us your board files in Gerber format.

If you do send us a centroid file, you no longer need to worry about rotation. The IPC has defined the zero degree orientation, as well as proper rotation direction, but too many part footprints set the zero degree at different angles. We can’t rely on the data.

While we have to ignore rotation and figure it out with other means, we still do strongly recommend that you follow IPC standards when you make your own footprints. The illustrations below show how footprints are supposed to be oriented.

Duane Benson
There’s no earthly way of knowing
which direction we are going
There’s no knowing where we’re rowing

Package origins

Passives orientation r2

Chip rotation

Quad and BGA

Three-pin parts

Hats Off to Gary

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Congratulations to Gary Ferrari, who last month became the 33d person to gain induction to the IPC Hall of Fame. For printed circuit board designers, this is something of a symbolic victory, as Ferrari is just the third designer (after Dieter Bergman and Vern Solberg) to make it in the IPC Hall.

Ferrari, who has been an occasional contributor to PCD&F over the years, needs little in the way of introduction to the current generation of designers, in the US and abroad. He has his name on all the major industry design and fabrication standards, having led the development of IPC-D-275 and IPC-RB-276 (now IPC-2221/2222 and IPC-6011/6012, respectively). He, along with Bergman, helped found the IPC Designers Council and drove the certification program. Along the way, he has trained or taught several thousand engineers and designers on a variety of topics from layout to heat management to standards to fabrication and assembly. While not the person whose name you will see on a book, Ferrari is still one of the first phone calls anyone with an engineering problem is likely to make.

The timing is bittersweet in that it occurred just months after the death of Bergman, Ferrari’s longtime friend and colleague. Still, it is a long time coming for one of the true iron men of the industry. I am thrilled for my friend.

The Best-Read PCD&F Articles in 2014

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As we did with CIRCUITS ASSEMBLY on Monday, here’s the list of the best-read new articles at PCDandF.com this year.

Leading the pack was IMI president Peter Bigelow, whose piece “When ‘Scaling Up’ Leads to ‘Belly Up’ ” received the most hits of his 10-year career as our columnist.

Next up was “A Two-Team Race?” Dr. Hayao Nakahara’s annual list of the largest PCB fabricators.

Coming in third was “Design for Reliability with Computer Modeling.” Dr. Randy Schueller and Cheryl Tulkoff, both with DfR Solutions, explained a new CAD tool that imports design files and quantitatively predicts product life.

They narrowly beat out “Magnification vs. Resolution in Visual Examination Specifications,” by Louis Hart of Compunetics and consultant Robert Simmons.

Coming in fifth was “Design Practices for Panelization and Depanelization,” by Phil Lerma, fabrication manager at NexLogic Technologies.

In sixth was Patrick Carrier’s “Maximizing Capacitor Effectiveness,” the first of multiple contributions from Mentor Graphics.

Next was “Power Electronics Packages with Embedded Components – Recent Trends and Developments,” by Lars Boettcher, Stefan Karaszkiewicz, Dionysios Manessis and Andreas Ostmann, who summed the work of a cross-industry team’s development and testing of a PCB-based embedded chip technology for an under-the-hood automotive application.

They were followed by “Qualification vs. First Article Inspection,” authored by Charles Hill and Karen Ebner of Raytheon.

The ninth most-read piece was “Effectively Managing PCB Design Constraints,” by John McMillan of Mentor Graphics.

And closing out the Top 10 was yet another Mentor offering, “Passing Electrical Signoff,” by Rod Dudzinski and Minoru Ishikawa.

The top written staff articles were “The One-Stop SoCal Shop,” senior editor Chelsey Drysdale’s look inside Murrietta Circuits, and “Good Values in Vegas,” our staff writeup of the 2014 IPC Apex Expo trade show.

We want to thank all our contributors from last year, and especially our loyal readers. Happy new year!

The Most-Read CIRCUITS ASSEMBLY Articles of 2014

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People often ask what our most popular topics are. There are many ways to slice and dice that, but what we’ve done the past few years is announced the Top 10 most-read articles of each year.

Number one in 2014 was “Advances in Fine-Pitch Printing Process Technology,” by Isaiah Smith of Speedline. It narrowly beat out “Circuits Disassembly: Materials Characterization and Failure Analysis,” by a quartet of Raytheon authors led by  John Wolfgong.

Coming in third was “Solder Joint Integrity Test for Finding Latent Defects in PCBs,” by Hiroshi Yamazaki of Hioki E.E. Corp.

The next four continued the technical bent:

4. “Shielding Effectiveness of Polyimide Tape during Rework,” by Adam Gaynor and Bob Wettermann of BEST.

5. “Advances in Concentration Monitoring and Closed-Loop Control,”by Umut Tosun and Axel Vargas of Zestron and Dr. Bryan Kim of Pressure Products.

6. “Automated Dispensing of 2 Component Materials in Electronics Assembly,” by Per Orla-Jensen of Nordson Asymtek.

7. “Printing Miniaturized Devices for the Automotive and Industrial Manufacturing Sectors,” by Clive Ashmore and Mark Whitmore of DEK (now ASM).

Rounding out the Top 10, coincidentally enough, the final three most-read articles were staff-written.

8. “Libra Industries Finds Its Balance,” Mike Buetow’s profile of the Ohio EMS company.

9. “ASM Takes Root in SMT,” in which Chelsey Drysdale detailed her visit to ASM’s European headquarters in Munich.

10. “A Muddled Recovery,” by Mike Buetow, our annual list of the Top 50 EMS Companies.

Interestingly enough, Nos. 5, 7 and 10 were cover stories in the print edition, while Nos. 3 and 6 were web-only. Given that more than 30,000 people see the print edition each month, it would be neat to know how the numbers would have changed if we were truly measuring apples to apples.

I will note that the data might also be skewed this year because of changes to our website. We launched the new CircuitsAssembly.com site late last spring, and in doing so reset the hit counters, not to mention introduced more splashy graphics that highlight the latest articles, so there’s a bias toward features that were published later in the year.

Tomorrow we will list the Top 10 most-read articles at PCDandF.com.

The December Issue of PCD&F/CA

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Our December issue hits the digital streets today and features a cover story from Terry Munson at Foresite, who performed a comparison of analytical techniques using 25 conformal-coated no-clean assemblies after environmental testing for 40°C/90%RH for 168 hr. Terry found FTIR, SEM/EDS and ion chromatography need an assist when determining the true source of contamination.

Another major feature reviews system design methodology for complex PCB designs.

Other highlights include discussion of pad-to-via clearance’s effects on solder joint strength, minimizing bottom termination component voiding, printer tooling, controlling solder paste slump and how to deal with an unhappy OEM.

As always in December, we look back at our industry friends and colleagues who passed away this year.

Finally, is free CAD a good thing? That’s the question I ask in my editorial this month.

Optimal at Optimum

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As corporate models go, Optimum Design Associates isn’t unique. Several firms have launched as design shops only to add EMS capability as they matured.

But one thing ODA does that I really like is provide a much greater level of detail about its financials on its website.  See below:

Financial Disclosure

Financials through 12/31/2013

Ownership Private
Annual Revenue $19 million
Credit Access $5 million
Loan Balance $133,000
Principal Payments $3,700
Access to additional financing Yes
Executive changes last 90 days No
Ownership changes last 90 days No
Return on Assets (last quarter) 3.6%
Current Ratio 2.2
Quick Ratio 1.21
Capitalization 23%
Cashflow 5.45
Debt to Equity Ratio .003

 

For a privately held company, that level of public disclosure is unusual. For a small business, it’s unheard of. Certainly any OEM worth its salt would ask for verification of financial stability prior to engaging, but having that data on hand upfront makes determining whether ODA is the right fit a little easier for potential customers (which could also be a time-saver for ODA), and moreover offers a high degree of confidence that ODA will be above board.

Perhaps that’s willingness to break the mold is why ODA is again on the Inc. list of the fastest-growing companies. (It also made the 2007 and 2008 rankings.)

Congratulations to Nick and the gang at ODA.

VTP: Very Tiny Parts

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A while back, I wrote about a new ARM Cortex M0+ chip from Freescale. It’s not the first M0+, but I do believe that it’s the smallest. I’ve been checking stock off and on and finally found the smallest package to be in stock and available to ship. 

I actually bought a couple of different types. First, there’s the WLCSP 20. It’s got 32K Flash, 2K SRAM and an 8K bootloader. The real kicker is that the package is only 1.6 X 2.0 mm. I also got a few in the QFM-16 package, which is a bit more workable at 3 X 3mm.

Finally, I bought a Freedom development board with the 4 X 4mm QFN-24 package. The dev board is hardware compatible with Arduino shields, so that will make for some interesting possibilities.

Anyway, here at Screaming Circuits, I’m most interested in that 1.6 X 2.0mm package to see how easy (or difficult) it is to use – see if there are any particular layout challenges. The other stuff is just for after hours play time.

Duane Benson
I’m not a number. I’m a free development board!
(Free, as in named “Free…”, not free as in “don’t cost nothin”)

http://blog.screamingcircuits.com/

The HP Split

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Those wondering how the HP split might shake out should read this piece in Bloomberg today. In summary, HP’s PC group just lost some of its pricing advantage, as the servers and other business-oriented gear are going with the new Hewlett-Packard Enterprise company. HP is currently Intel’s largest customer, but that will change as the two primary hardware lines are separated. (HP’s server gurus have been working on a competitive line using Applied Micro chipsets, so that ranking might eventually have been in jeopardy either way.)

On the other hand, given HP’s deservedly stodgy reputation in tablets and handheld PCs — despite, or perhaps because of, its acquisition of Palm in 2010 — the shakeup could enable the new HP Inc. to focus on trendier designs for the mobile market.

What’s not clear is whether each group will retain a certain number of chip designers. This is an area of strength for Apple, and HP Inc. will need to ensure it has the internal talent to advance in the hypercompetitive PC space.

Cost Reduction in Design — More Advice

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If you’re looking for the absolute, cheapest possible assembly service, you’ll need to look outside of North America. If you really need a decent price with good quality and good service, you can keep your gaze West of the Atlantic and East of the Pacific.

Like everything else in the modern world, design decisions can have a pretty big impact on your cost. So, lets take a look at some design decisions that can make your manufacturing more affordable.

  • Accept longer lead times

Lead times are one of the biggest factors in electronics manufacturing. Screaming Circuits can turn a kitted assembly job overnight, but it costs a lot of money to do that. Screaming Circuits also has a 20 day turn-around that is much, much more affordable. Accepting longer lead times on PCB fab will drop your cost as well.

  • Avoid leadless packages like QFNs and BGAs

We build tons of QFN and BGA boards – even down to 0.3mm pitch micro-BGAs. That’s great if you need those packages. However, since all of the leads are underneath, we have to x-ray every part. That adds a bit of cost to the process. If you can, stick with TSSOPs and other parts with visible leads.

  • Use reels, or 12″ or longer continuous strips

We will gladly assemble parts on strips of almost any size. But, to save costs, use full or partial reels or continuous strips of at least 12″ long. It costs us less time to work with reels and continuous strips, and we pass those saving on.

  • Stick with surface mount

These days, through-hole components tend to be hand-soldered. That costs more than machine assembly, so use surface mount wherever possible. Surface mount components tend to be less expensive than through-hole too. If you do need a few through-hole parts, this is an opportunity to put in a little sweat equity by soldering the through-hole yourself and save a bit of money.

  • Panelize small boards

We can work with really tiny boards individually, but sticking with a larger size makes the job easier, and, again, we’ll pass those saving on. If your PCB is smaller than 16 square inches, panelize it. We put in less labor and you get a price break.

By following these guidelines, you get a decent price and really good quality and service.

Duane Benson
That would be telling

http://blog.screamingcircuits.com/

The End of the Viasystems Era

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At long last, the hunter became the hunted.

TTM Technologies today announced its pending acquisition of Viasystems. The deal, expected to close in early 2015, will vault TTM to second place among the world’s largest PCB fabricators.

No matter how the deal turns out for TTM, Viasystems will remain one of the most talked about PCB companies in the industry’s history, held in awe for its audacity and blamed on multiple continents for nearly single-handedly devastating local supply chains.

For the entirety of its 18 years, Viasystems was worth 10 times its revenue in industry controversy and chatter. It sprung on the scene in fall 1996, the brainchild of New York investment firm Hicks, Muse, which in quick order bought up AT&T’s board shop in Virginia, Circo Craft, Kalex, Forward Group, ISL, Mommers and Zinocelere, plus several EMS and peripheral businesses. They were the Yankees of the PCB world, albeit without the same level of success.

Then came the Tech Recession of 2001, and Viasystems’ debt ballooned to over $1 billion. Two Chapter 11 restructurings and countless lawsuits later, the company stabilized and managed to spend the better part of the rest of the decade simply managing the business.

In 2010 the veil was lifted. Viasystems resumed its buying ways, snatching up Merix and then, two years later acquiring DDi (which in turn had gobbled up Coretec). Yet consolidation didn’t bring happiness. Over the years Viasystems found it nearly impossible to turn a consistent profit. Debt, a persistent problem dating to its Hicks, Muse days, now sits at $561 million.

TTM is getting Viasystems for $16.46 per share, or about 6.8 times adjusted EBITDA. You tell me if that’s worth it.

I would expect TTM will sell off Viasystems’ wire harness business, which is small ($174.6 million in 2013) relative to the rest of the business and has shown operating losses in five of the past seven quarters. Viasystems has already consolidated its China manufacturing base, so I would not expect much change there. TTM is running at 75% capacity in China but only 60% in North America. TTM has seven sites in North America and Viasystems has nine, including a combined three in the Silicon Valley and two in Orange County. Perhaps they will seek to consolidate here in order to boost rates.

Viasystems changed the way the world viewed the industry. It forced Wall Street to take notice. It laid waste to the regional landscape, ultimately closing millions of sq. ft. of some of the once-best shops in the world. Some will say this was inevitable. Viasystems bought plants that were obsolete or quickly headed that way, whose workforces could not change even while the technology was quickly shifting away from them. And the firm tied up enormous amounts of capital in dubious debt deals that may have enriched a few but certainly did not leave their business units with the balance sheets necessary to operate in such a cyclical market.

There’s still time for the deal to fall through, and it took about 18 seconds before shareholder lawsuits began piling up. No matter what happens on the ground, come next spring, Viasystems will again occupy the rarest air of the PCB world. It just won’t be as Viasystems.