Taking the ‘Pulse’ of Productivity

On PCB Chat this week we talk with Mark Hepburn, the new director of product management at Cadence. Some industry veterans may remember Mark from a few years back — he was with Viewlogic, Innoveda and Mentor in the late 1990s and mid 2000s. He spent the past eight years with Perception Software, a developer of collaboration software.

Fittingly, he joined Cadence just in time for its launch of Allegro Pulse, a new web-based platform for collaboration and productivity measurement and analysis.

Take a listen here.

EDA, All the Way

The market for electronics design software continues to outpace gains in overall electronics demand, with sales up 8% year-over-year in the September quarter. PCB/MCM tools rose even faster — up 13.4% for the period.

Wally Rhines, president and CEO of Mentor and spokesman for the ESD Alliance of EDA companies, spoke with me about the results for the latest PCB Chat podcast.

 

Laminate Companies: On the Move

It took until the second business day of the new year for the chips to start falling in the US printed circuit laminate industry.  On the same day, Isola changed hands and Park Electrochemical announced it was putting its PCB unit up for sale.

As the East Coast braced for a winter blizzard of epic proportions, Park Electrochemical sent a cold shiver down the spines of more than a few industry observers with its announcement of a “strategic evaluation” of its core printed circuit materials business, one that could result in a sale.

Park has been paring its PCB operations over the past few years amid falling revenues and tighter margins. Said revenues have been falling despite a rebound in the overall PCB market: Even as aerospace revenues have grown, overall Park sales have fallen year-over-year in 10 of the past 11 quarters, more than half the time by double digits.

Although it generates most of its revenue from the PCB materials unit, sources indicate the firm sees more upside in its aerospace materials division, which isn’t as susceptible to the commodity pricing pressures of board-level laminate. The sale or closure of the division could further disrupt the North America supply chain, however.

Park’s long history is heavily intertwined with that of the North American PCB industry, and one of the last remaining “family” firms. Cofounded in 1954 by Jerry Shore, his son Brian is now CEO and grandson Ben a senior vice president. Its sale, whenever that day comes, will truly mark the end of an era.

Meanwhile, in Arizona, Isola completed the transfer of its equity ownership to an investment group led by Cerberus Capital Management. This deal was not a surprise: Isola had reportedly been trying to restructure a debt load of more than half-a-billion dollars since last summer.

Isola was primarily owned by the investment firms TPG Capital and Oaktree Capital Group. It’s unclear at present how the stakes in the company are now divided. No doubt Isola won’t be one of the bidders for Park, however.

Couple this with the changes at Arlon over the past two years, and the US laminate industry continues to be in flux. Many of the other major players appear stable: Kingboard, Shengyi Technology, Nanya, Panasonic, Ventec (which merged with TMT in 2016). Among US-based vendors, Rogers’ position at the high-end has enabled it to remain financially sound. It may be the only one.

Demand for lower-tech materials isn’t enough to sustain footprints in higher-cost markets. M&A can result in stronger, more viable companies. Let’s hope that the future for Park (or whomever buys it) and Isola are brighter than the present, as the North American supply chain depends in large part on their success.

Jan. 5 update: Investment bank Needham & Co. says the Electronics unit could bring $50 million to $80 million in a sale.

The Ideal Bill of Materials

A good portion of a quality build is simply the result of clear information. One of the more important pieces of information we deal with is the bill of materials, called “the BoM.”

The BoM is a list of all the components to be placed on the PCB. The file typically includes an index number, the number of times a specific component will be used on the board, the reference designator from the schematic, the component manufacturer, and the manufacturer’s part number.

If a specific component is used more than once – a common bypass capacitor, for example – it will still only take up one line in the BoM. One field in the BoM will list the number of times the component is used, and another field will list all the reference designators for that part number.

For example, line 5 in my BOM on this slide, is a 0.1 microfarad, 10V capacitor.

The first field in the table has a line item index, 5, because this is the fifth unique part number in my BoM. The next field has a quantity of this component used on the board, which is 5. Field three holds reference designators C1, C2, C3, C4 and C5. The next field has the manufacturer, and the final field has the manufacturer’s part number.

You will likely have additional fields, such as a distributor part number, a description, the package type and other tidbits, as I have here.

But the first five columns in this example show what is generally considered to be the minimum data set for a good bill of materials.

Note the three lines at the bottom highlighted in red with the label “DNS” in the Type column.

DNS means “do not stuff.” That’s an instruction to the manufacturer to not install that component during the assembly phase. Some people use DNP, for do not place, or DNI, for do not insert. It’s always best to consult with your manufacturer to get their preferred labeling.

You may also want to include alternate parts for components likely to go out of stock. Passives, such as capacitors and resistors, are notorious for going out of stock without notice. Invariably, though, a half dozen nearly identical parts will fit the bill just as well.

Create an alternates list so the purchasing folks or manufacturer won’t get stuck not knowing if a substitute is valid or not.

Duane Benson
In the 90’s, when people said good things were “the bom”, this is what they were talking about

 

The Return of PCB Chat

After a hiatus, we have relaunched PCB Chat as a podcast.

Our first guest is Mike Konrad of Aqueous Technologies, who shares his experience with what happens when a contract manufacturer follows its customer’s instructions to the detriment of the product. The outcome: Product failures, blame, drama, and a really big lawsuit.

We apologize in advance for the imperfect audio; we are still getting up to speed on the editing tools. But we think you’ll enjoy this, the first in what will be a regular series of interviews and conversations.

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.

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.

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

So Long, Sola

I have to say, I didn’t think Jure Sola would or could last this long. The cofounder of Sanmina, Sola was one of the poster boys for wanton M&A excess, snatching up more than a dozen companies or OEM plants during the late 1990s and early 2000s. The spree culminated in the purchase of SCI Systems in mid 2001, a $6 billion deal that saddled the company with so much debt, when the ensuring tech collapse occurred, it was forced to take 20 straight quarters of “one-time” charges.

Most execs couldn’t have survived such a bloodletting. Sola wasn’t most execs, however. He continued to place his bets on fabricating in the US — in a memorable line, he told an IPC Printed Circuit Expo audience that “plating was in his blood” — and Sanmina remains the second (or third) largest board supplier in North America. Moreover, he correctly swung to the military and aerospace markets, eschewing the PCs that SCI was so dominant in.

Today the company is half the size in revenue of its peak, but consistently profitable.

Come October Sola will ride off into the sunset with his legacy intact, perhaps not the most beloved man to run a major PCB company, but a success nonetheless. In this era, that’s no small thing.

 

Green Herring

For those newbies, Bob Herring was the perfect example of good timing, building up and selling not one but two board shops. The first, Industrial Circuits, was sold in 1989 for $60 million. The latter one, Herco Technology (which we profiled multiple times in PC Fab), went for $122 million in 2000, just a year before the tech crash. (The buyer of Herco, Teradyne, closed it less than two years later. The former Industrial Circuits lasted less than one year longer before Toppan shut the doors.)

In case you were wondering where Bob went, well, he started his own network cable news channel. It now is televised in some 30 million homes.

Guess there is life after PCBs!