Screaming Circuits: Industry


Let's Get Small, as in 0.3mm

Not long ago, I wrote about a 0.3mm pitch wafer scale BGA we received and were asked to place. The gist of that article was that those parts are very small and we d0n't yet have a process that we feel will give the quality, reliability and consistency that we want to deliver. That means officially, we don't, at the moment, support that form-factor.

However, as it turned out, we went ahead and built it and the x-rays all said it looked good. Whew! We still don't officially support it, but we're working on it. If you have one of these things, you can always give us a call and see if it's something our manufacturing engineers are comfortable with. If they say "sure, send it in", It will be a non-standard, essentially, experimental, operation so our normal guarantees won't apply. It will be "we'll do our best."

But that's not the point. The point is that there are still a number of unanswered questions with 0.4mm pitch, and now we have a smaller one??!!

I've only seen 0.3mm pitch in two places: some data from Amkor, and the data sheet for this part.The part in questions is a Maxim MAX98304 Mono 3.2 Watt Class D amplifier. The entire package is just 1mm x 1mm.

There is still a lot of difference of opinion on solder mask defined (SMD) vs. non solder mask defined (NSMD) at super small pitch like this. For BGAs 0.5mm and lager, the general consensus and IPC recommendation is NSMD. At 0.4mm, the Beabgleboard folks at Ti recommend SMD to reduce bridging. But I've had other folks say they get good results with NSMD. For 0.4mm, we've had best results with SMD. It's more than just that though, you also need to religiously follow the manufacturer's recommended pad sizes and such.

Shrinking BGA pitchFor this part, the datasheet shows the pad size (0.18mm), but doesn't cover the SMD vs. NSMD question. Instead, it refers to a Maxim app note (#1891) for that bit of information.

Of course, this is where it gets sticky. That app note, as of this writing, shows 0.5mm and 0.4mm, but no 0.3mm. It does reference IPC-7351, which is a very good thing, but I don't think IPC-7351 has 0.3mm pitch covered yet. Ugh. The 0.3mm part we placed used SMD pads.

Duane Benson
It's not just Facebook where you can designate something: "It's complicated."

 

It (.3 mm) Finally Happened

Back in January of 2012, I wrote about the possibility of 0.3 mm pitch BGAs being used here and there. I predicted that in a year, we'd see some 0.3 mm pitch BGAs showing up. I was about three month's off. Almost to the day.

I delivered a session at PCBWest last month and asked if anyone had used a part with that pitch yet. One hand went up. That actually surprised me. What surprised me even more was when one of them (a .3mm pitch BGA, not a hand) arrived on our shipping dock in a parts kit earlier this week.

0.3mm pitch trimFor comparison, the land pattern for an 0402 passive component is about one millimeter long. This specific part is just shy of a millimeter square. Even as small as it is, this part can supply 750 mA continuous. The olden days are so very long gone.

We do many, many complex parts and PCBs. We've put 5,000 parts on a single PC board. We've built boards to be shot up in rockets and dunked way down in the ocean. Some very crazy stuff has come though our shop, but we don't do everything. We don't do 01005 passive components at the moment. Our machines have the technical capability, but we don't rework them, which has to go along with the assembly capability, so we don't support that form factor for now. 0.3mm pitch components pretty much fall into that camp. Our machines can physically pick up and place the component, but until we've developed to process to assemble those parts with the quality people expect from us, we won't be supporting them.

I expect we'll be getting more and more requests for the form factor, so we'll be looking at it. Keep checking back. One of these days, we'll have the process down and reliable.

Duane Benson
It's (Huey mm, Dewey mm, and Louie mm)/10

To Mod or Not to Mod? That is The Question

Many years ago, I was a product manager at a business-consumer electronics company developing some pretty leading edge display equipment. Prototyping back then was a long and painful process. A PC board might take a month or two to arrive from fabrication. Parts had to be sourced by digging through massive catalogs and then hoping that what you needed would be on the companies approved vendor list. The whole process was a bear.

Well, the soldering up part wasn't always so bad - unless you were the poor soul tasked with wire-wrapping or hand soldering the prototype.

Based on how difficult and expensive a board spin was back then, common practice was to just mod up the boards, even in production. Any given PCB might have a dozen or more cuts and mod wires. Those changes might not make it into the PCB for months. These days, though, you can get board fabbed Mod wireovernight, your parts delivered over night, and when you have all of those parts and PCBs, you can get them assembled overnight. I suspect that increase in speed is the major reason mod wires seem to be nearing extinction these days. (note that Screaming Circuits didn't build the board in this picture. It's from my personal collection)

It may not seem cheap to pay to have someone re-spin a board so speedily; especially when set next to hand soldering. But when compared to the cost of idle engineers waiting for the next rev, the cost of adding mods, the reduced reliability from having mods and the additional manufacturing time caused by modding a board; today's quick-turn parts, fab and assembly options can end up saving gobs of time and money in the long run.

Duane Benson
There are more wires in heaven and earth, Horatio, Than are soldered on your pc board.

Ode to Competition

Thanks to Theodore Roosevelt, we almost all have competition of some sort or another. I'm not a big fan of the statement made so often: "We welcome the competition, It validates the market." or similar such sentiments. You usually hear that from a spokesperson when a new competitor enters the market. My guess is that most people who say that are probably thinking to themselves: "Yeah. In a pig's eye" while stating it.

Theodore RoseveltI'm also not a big fan of the phrase so often heard in start-up companies: "We don't have any competition." To me, that's a warning sign. You might not have much competition, but you always have some. At minimum, other companies (maybe even with non-competing products) are competing for the same dollars. If someone thinks they don't have competition, I would suggest they look a little closer at what their customers need and are doing.

The number three statement that I'm not a big fan of: "Imitation is the fondest form of flattery." I do understand it. If someone is copying you, that must mean that you're doing something right (the possibility of the blind leading the blind not withstanding). In a business context I do believe that all three of those statements are a form of saving face. You can't stop competition from showing up, but you can pretend to be noble and welcome it. It's not always possible to stop people from copying you, but you can pretend it's a complement.

Here's what I think about competition: It's my job to give you better value than our competition. Plain and simple. If you come to me for business and I give you better value: What you want, when you want it at a fair price, then I have earned your business. If a competitor gives you better value, it means that I'm not doing my job right. We are all in this to make money, but we're in this to make money in such a way that we are the best value for you. Not the lowest price, but when you add up our reliability, quality and technical capabilities, doing business with us should save you time, aggravation and money.

So why the maefesto? It annoys me when competitors place comments on our blog linking to their website. Especially when they don't identify themselves. Yes, it means that they believe that we are doing things right. Yes, it means they think we have enough customers that it's worth trying to lure some away from us. So, in a sense, it is validation that they think we're doing a good job. I don't really see that form of "validation" as being worth much though. What I really care about is that the people who give us money think we're doing a good job and that they get their money's worth.

Duane Benson
We are with you, sire! For Sparta, for freedom, to the... to the... Um...
to the sucess of your project!

Who Are You?

A lot of events are preceded with a "meet and greet" session. It gives you something to do for an hour or so before the real activity takes place. I'm not much of a schmoozer myself, but if the crowd is right, there is value in the activity. It's good to get to know folks with similar interests or vocations.

On the Internet, Facebook is kind of known as the place for that sort of thing. The problem with it though is the low signal to noise ratio. Too much drivel to sort through to find the valuable nuggets. But Common ground 0402s schdon't despair. All is not lost. Over at EEWeb, they have something pretty close in their "Featured Engineer" series. As of this writing, they have well North of a hundred profiles. Peruse through and get to know some or the people making things happen in the world these days.

If you look close, you can find yours truly in the list. And the first person to name the science fiction movie I'm thinking about gets a free Screaming Circuits polo shirt. The first person who can correctly identify the lighthouse gets one too. (the lighthouse is small in the photo, but if you've been there, you'll recognise the area) Only in the U.S. though. Sorry, but customs gets me down so I'll only ship to a U.S. address. It might not be the same shirt I'm wearing, but close.

Duane Benson
In life I was your partner, Jacob Marley.

Screaming Circuits and Element14

Screaming Circuits has entered into a partnership with electronics distributor Newark/element14 to offer PCB assembly services through its online engineering community, the knode.

As support staff, schedules and components shrink, design workload stays the same or increases. The Knode on element14 is an intelligent online search and knowledge tool that helps to quickly find the right solutions for all phases of the design cycle. It saves time by centralizing unbiased information, components, advice and services in one common location.

With this agreement, Screaming Circuits’ pcb assembly services are now available via the Knode. This provides a one-stop shopping experience that can deliver machine assembled prototypes in as little as 24 hours, in quantities as few as one.

“The addition of Screaming Circuits extends our commitment to providing engineers access to a full range of design solutions from the best suppliers in the industry,” said David Shen, Group Senior Vice President and Global Head of EDE and Technical Marketing of Premier Farnell, parent company of Newark/element14. “We are pleased to add direct access to instant quotes for these PCB assembly services to the Knode on element14 to augment designers’ choices for doing on-line research and sourcing of best-in-class design solutions.”

Duane Benson

Zzzzzzzap!!! Static be Bad

Engineers these days have so many issues to worry about just in component handling alone:

  • Do my parts need baking to get the moisture out before reflow soldering?
  • Are my parts in stock?
  • Are my parts real or are they counterfeit or secretly remanufacturerd?
  • Are my parts really lead free?
  • Are my passive components small enough to make it out of the holes in my salt shaker so I can put them on the PCB?
  • Are my parts too small form my manufacturer to handle?
  • Are my parts too complex for my manufacturer to assemble?
  • Have my parts been zapped by static electricity either before or after assembly?

Static electricity is really something that no engineer should have to worry about these days. We know how it gets created. We know how to artificially create it and we know how to guard against it. There's really no excuse - especially from those that an engineer entrusts to build his or her designs.

Tesla_colorado_adjusted 500

People can carry around a static charge anywhere from several thousand volts to more than ten thousand volts; just by walking around. Joe Volta would be proud. Touching an electronic component or assembly the wrong way at the wrong time can discharge much of that through the electronics. Yes, most chips are better able to handle static electricity than the old 4000 series CMOS that could get zapped just by being looked at harshly, but pretty much any active component is susceptible to static damage to some degree. What makes it so Anti stat shoesinsidious is that the damage may be done in handling or in assembly but might not show up until the unit fails in the field.

The whole world knows how to keep electronics safe (that's an exaggeration, but at least most people in the Industry know how), and the whole industry understands the risks, so why would anti-static handling or packaging be an extra cost option? If it's you're own stuff, then fine. It's up to you. But someone you're paying? I don't get it.

Take a close look at the picture on the right. If you ever get a tour through Screaming Circuits, you'll see a lot of this. The floor is conductive. The bright green straps on the shoes are not a fashion statement. They're grounding straps. The blue jacket is conductive. Parts and PCBs are protected from static through these means and others all the way in and all the way back out to the customer. It's the right thing to do and the healthy way to do it and it doesn't cost extra. It shouldn't cost extra. Follow good static mitigation procedures yourself and make sure that whomever is assembling your parts does the same. That's my two cents worth.

Duane Benson
Frankenstein was grounded through his neck bolts, so he's okay.

 

40 Years of 4004

I'm assuming eight pages excerpted out of 142 qualifies as fair use. I had forgotten that I had this thing buried in a box in my garage. I have a lot of old junk hidden in boxes out there, but this one piece seems most appropriate today.

  4004 005 4004 006 4004 007 4004 008

4004 009 4004 011 4004 012 4004 013

 

 

 

 

 

 

 

 

 

 

 

 

This user's manual covers the 4004 and the chip set that went along with it. It also has some pretty detailed information about a couple of computers based on the 4004; such as the SIM4-03, MCB4-20 and Intellec 4. I didn't get this new. I found it in a garage sale back in the early 80's. I wish the unit had been there too.

Duane Benson
4 bit data bus, anyone?

Major Major and Standard Standard

We ask for your bill of materials, Gerber and centroid files to assemble your pcbs. All of those pieces of information are necessary to properly program our machines to place your parts. That's pretty standard stuff, but did you know that when the Gerber format reference book was first published, Jimmy Carter was President of the United States, Russia was the "Soviet Union" and Voyager 1 was well inside the Solar System? Use of the format has been going on even longer. Yeah. It's been around a while. For some reason, it has been very difficult to get everyone to agree to and use a standard file format. Gerbers really don't have enough information in them to do the job properly, but it is the standard. Hopefully not for too much longer. How many of you reading this were even born when Gerber was new?

XKCD 15th standard
(Drawing courtesy of XKCD) <- worth spending time on

There are a number of formats around that are better than gerber and Screaming Circuits will accept many of them. First, your CAD software probably will export an "ASCII CAD file". This is a good format. Some export ODB++, which is one of the newer formats, again a good choice. One of the newest standards is the IPC-2581. It's been around a few years and is now getting a lot of attention. If you happen to use Eagle CAD, you can also send us the Eagle ".brd" file.

IPC-2581 includes the best of ODB++ and GenCAM. It has all of the fab data, assembly data, netlist and BOM. Everything needed in one convenient file. My understanding of the format is that you can exclude portions of the data set that you consider proprietary. You can learn more about the format here. There's more background information on the subject over at Circuits Assembly magazine too.

Duane Benson
Where's Henry? I need an inductor.

Speaking of Small Packages...

T'was a a dark and stormy night when the news came through. Joe Layout had been both dreading and preparing for years. But it had always been little more than rhumors from a far off land. It was a looming threat, always dancing in the distance, but never quite real.

Until now. 1.27mm, 1.0mm, 0.8mm, 0.5mm, 0.4mm... and now... drum roll please 0.3mm pitch. I just got Shrinking BGA pitchan email announcing an Amkor 8 x 8mm 368 ball BGA at 0.3mm pitch. Yikes.

There's still some controversy over the best way to make a 0.4mm pitch BGA land pattern. Some say says you need to use solder mask defined pads. Some say you still need to use the non-solder mask defined pads. Now we throw something 25% smaller into the mix.

The image isn't to exact actual scale - because I don't know how big your monitor is - but the parts are in relative scale from 1.27 pitch to 0.3 pitch.

Duane Benson
If you can't see it, you shouldn't eat it