Screaming Circuits: Company and Partners

Top 5 Things to Know When Moving from Hand Assembly to Robotic Assembly

A lot of factors go into the decision to hand build or outsource circuit boards. I hand build my own sometimes, simply because I enjoy the challenge. Of course most of the projects I design are for my own use, so timeliness isn't that important. When I do design something that will go out to a customer, like my electronic business card holder, I will send the board through our shop. In those cases, quality is important, as is delivery, and the quantity is often too high TI TPS62601 front and backto hand build. Machine building also allows me to use smaller and more complex parts.

That same decision - hand build or outsource - takes place in the heads of designers all over the country. When the decision is to outsource, there are a few important things to consider. Some things that work fine when hand soldering may stand in the way of quality, repeatability, and reliability when machine assembling.

Here are five of the most important considerations when changing from hand built to outsourced at a place like Screaming Circuits

1. Use solder mask and silk screen

A good solder joint needs the right amount of solder in the right place. Solder will tend to flow down bare copper, bleeding outside of the area it belongs, and down exposed copper traces and vias.

The main purpose of solder mask is to keep the solder where it belongs. It also protects the traces, but that's a longevity issue. Solder bleeding is a manufacturing and reliability issue. This isn't a problem when hand soldering. In fact, it can even work to your advantage when hand soldering really small parts. It gives you more room for your soldering iron to hit metal.

Not so with solder paste and machine assembly. Use solder mask.

2. Avoid the pseudo panel

Keeping small boards in a panel is the recommended best practice in the manufacturing industry. We appreciate it and, while not always necessary, can reduce your costs. We sometimes see what we call a "pseudo panel." This is a board where multiples of the board are put in the same PCB, like a panel, but unlike a panel, the boards don't have routing or V-score between them. Sometimes the designer will put a bunch of vias to outline the board, or just ask that we use a band saw to separate them.

That's a time consuming, expensive, and potentially damaging process. The vibration of the saw can crack solder joints, and, you're unlikely to get boards that are all the same size. Have small boards panelized by your board house.

3. family panel (pseudo or not)

Similar to the pseudo panel is the family panel. A family panel is a case where a project is made up of several different PC boards, and they are all laid out together, as though they are one design. If the board isn't routed between to designs, you'll have the pseudo panel problem described above.

The bigger problem, though, comes with reference designators. We typically see family panels with duplicate reference designators. Each design, for example, will have its own C1, R1, Q1, etc. We use the reference designators as position identifiers/ If you have three different parts labeled R5, our machine programmers will have a problem with it. It's even worse if the values differ; on one design, C1 is a 0.1uf capacitor, while on another design, it's a 22pf cap.

If you're making a family panel, give each and every placement a different reference designator. One way would be to us extra digits. For example on one design on the family panel could have C100, C101, C102... The next would be C200, C201, C203, and so on.

And - don't forget the routing or V-score between the designs.

4. QFN - hole  in the middle

A common technique in the hand soldering world, for soldering QFNs and other parts with thermal pads underneath is to put a big via in the middle of the center pad. By doing so, you can stick a soldering iron and some solder down through the hole and get a good solder connection on the bottom pad.

This doesn't work with machine assembly. the solder paste will flow down and out the hole in the reflow oven. You'll end up with a poor connection (or no connection) to the thermal pad, and solder slop on the back side of the board.

BOM line items 0055. Parts and the Bill of Materials (BOM)

When I build my hobby projects, I often get a bit carefree with the bill of materials. It's not good practice, but I do. I'll put a part in the BOM that I used before, and not check to see if it's still in stock. I'll put parts in the BOM with just the values and not any part numbers. Things of that sort require tribal knowledge, which only the designer has.

When building, sometimes I'll just grab a part that's close. If I need an 0805 1uf, 10 volt capacitor, I can grab a 16 volt, 25 volt, etc. I can even make an 0603 part work. You as the designer may know that something close will work, but an outside house can't know. You need to tell them exactly what the part is.

Before sending anything through our shop, I do clean up the BOM. In order for us, or any manufacturer, to build the boards, the BOM needs:

  • A unique reference designator for each part placement
  • The quantity of each part used on the board
  • The manufacturer
  • The manufacturer's part number
  • Digikey part numbers can be used as well

Here's our web site page explaining the BOM format in more detail.

The transition from hand building to outsourced machine building can be an intimidating one. But, with a few considerations, it can be an easy and rewarding transition.

Duane Benson
Put the right part in
Put the wrong part out
Put the right part in
But please don't shake it all about


Old and New: 60 Years at Milwaukee Electronics

In 1954, one of my favorite movies, "THEM!", premiered in U.S. theatres. An even more significant (to us, anyway) event took place in Milwaukee, Wisconsin: The founding of Milwaukee Electronics.

We are excited to announce that our parent company, Milwaukee Electronics has been in business for 60 years! After six decades of dedicated service to customers, and several name and logo changes, Milwaukee Electronics is updating it's image. Click here to view more details.

Without Milwaukee Electronics, Screaming Circuits would not be possible. 60 years of expertise, plus our unique perspective, gives us the ability to offer something that no one else can: real-time, on-line turn-key quote and order of quick-turn prototype and small-lot production assembly.

Duane Benson

How Do You Know?

This isn't a Thanksgiving blog. It is Thanksgiving day, and if it were a Thanksgiving blog, I would have to be working today, but we're shut down for the holiday, so I'm not working. I just woke up pondering what it would be like to do business with us (or anyone like us) and decided that I wanted to hear myself speak (metaphorically) for a bit. A word of warning though; I'm in a long-winded rambling mood today.

Take an example; the Beagleboard. I use that because it's a complex board that's open source, so I can freely talk about it. It was originally put together by Gerald Coley and Jason Kridner. I don't know how Beagleboard face onlong they spent designing it, but according to a UBM study, a typical product design cycle is about a year.

So, what we're really talking about is a year of a couple of engineer's lives. It can be a lot of cash money too. When ordered in large quantities, the Beagleboard and it's progeny are inexpensive enough to be sold for quite a decent price. However, when purchased in small quantities - say five - it can cost several thousand dollars.

When the Beagleboard was new, we built a few just to kind of show off. We took the open source files and ordered all of the parts. We tried to get some PCBs fabbed, but in that quantity, they would have cost us $1,200. Instead, I posted a request on the forum and found someone with some bare Beagleboard fabs.

I got those boards and the parts and ran them through our system. Had a customer quoted the build, it would have cost somewhere (if my memory serves correctly) around $800 per board for assembly. That would be $10,000 for a set of prototypes. That may seem like a lot for a board that retails for $150.00, but that's the difference between ordering hundreds of thousands and ordering five.

That cost comparison isn't the point. If you're in this business you know that getting small quantities of complex stuff in short notice is expensive in direct dollars, but more than worth it in time and effort saved. The point is that, while we build a lot of sub-$1,000 orders, we are frequently given orders that are valued at $10,000 or more. Sometimes CONSIDERABLY more. We've seen projects where parts alone are tens of thousands of dollars. I've seen a single FPGA cost several thousand dollars alone. Yikes!

You've spent a year of hard labor on a design. You hit "Save" for the last time. If you're like me, you want nothing more than to get a working board into your hands. The gap between that save and a fully built board is painful for me. But the prospect of shelling out $20,000 to some unknown company for the purpose of turning that year of my life into a physical product is positively terrifying.

Well, if you don't already do business with us, we are that "some unknown company." That makes me wonder how this all happens. I design boards myself - not the big ones, but I do design a fair number of them. Right now, I have four boards I'm actively working on and about that many that I've shelved for a few months. I understand a bit of the fear of handing a design off. Of course, I have an unfair advantage. I can just send some boards through our shop and get them done just about any time.

It's easy for me to trust us. I got a job here and I know that I take the stewardship of that big check and year of your life very seriously. I treat it like it were my own. I also know that I don't work for companies that don't share that philosophy. I've tried, out of necessity, twice in my career, working for companies that didn't treat customers they way I would and I ended up pushing my agenda so hard that I got fired. It wasn't pretty.

I've established that I (as in me) trust us. How do you get to the point that you can give us (or anyone else) the same trust? The Beagleboard guys didn't know us enough to do so. We built some of their boards on our own. Plenty of people do know us well or are somehow willing to make that leap. We quite literally* have built things that have gone up into space, down into the ocean and everywhere in between. It's pretty fun to look through our customer list and see so many names of companies doing really cool stuff.

All of the marketing mumbo-jumbo I spit out is designed to somehow convince you to let us take care of your design. But those are just words. Words are meaningless without the deeds. It's what all of the other people in my company do that really counts. I spill out glurge. They do their best to treat your project with the same respect and care that you do. I'm thankful for that, because if they didn't do that, I wouldn't want to work here. If they didn't do that, my job would be meaningless and stupid. Hey - this did turn out to be a Thanksgiving post!

Happy Thanksgiving!

Duane Benson
* The word "literally" is terribly misused these days, but I'm actually using it by the correct definition. Well, okay, the "everything in between" isn't quite literal, but "space" and "under water" are. And it's comprehensive a representative sample that I'm in the spirit of "literal."


Usually, these days, I seem to hear the word "what" as a part of a "Wait... What?" statement, as in a short-cut for: "That sounds good" - pause - "No, it doesn't. It doesn't even make sense." It can be funny in that context, but I think it's wearing a little thin at this point. My prediction is that the expression has another year. Two at most.

But that really has nothing to do with this blog post.This blog post is about what we can do for you. Obviously, we are a company that wants to be profitable and stay in business. I would assume that most companies want to do that. But what's important is the way we become profitable and stay in business. It's not a matter of being profitable no matter what. There are a lot of ways to be profitable and stay in business that I really don't like and don't want to have anything to do with. For example, bank robbery is not allowed here (actually, to be precise, no kind of robbery is allowed here). Being a pirate isn't allowed either.

It's also not about never making mistakes. While we aspire to that, I have yet to find someone that doesn't ever make mistakes, and if I do find that person, I'll probably be too intimidated to talk to them. So, it's not about profit at all costs and it's not about never making mistakes. What then, is our purpose?

Tactically, our purpose is to put parts on PC boards. We can buy the stuff or you can send it to us, but that's fundamentally the physical activity that we perform: we put parts on boards. "We put parts on boards." Five words. Not a lot to think about. But, since that's not a lot to think about, what else do we fill our brains with?

Sometimes we fill our brains with Dr. Who or with motorized wireless beanie cap networks. When we're on the job though, the word "what" comes into play. As in: "What can we do for you?" What can we do for you?

  • The purpose of our website is to make it as easy as possible for you to get your work done and be happy with the part of it that we do for you. It has no other point.
  • The purpose of this blog is to pass on bits of information that might be helpful to you or anyone in the electronics industry. Non-electronics people can read it too, but it likely won't make much sense.
  • The purpose of our people is to make all of that happen.

What we want to do is make you happy that you did business with us, happy that you read this blog and learned something, happy that you referred someone two us, happy that it didn't snow last night - things like that.

If it's not helping you, then there's really no point - I'd just stay home and re-read "The Lord of the Rings" for about the 20th time. If for some reason, what we've done isn't helping you, then it's a good idea to let us know. You can call us, comment on this blog, email us, knock on our front door, send us a message on Twitter, whatever the case, as long as you get the message to us. Flying a plane overhead with a banner behind it probably won't do the job though because we're in Oregon. It's usually raining and cloudy, so we couldn't see it on, maybe, 302 days out of the year.

Duane Benson
I leave you with this thought:
How can you tell if an introvert likes you?
He or she is staring at your shoes instead of their own.

Something Completely Different

Here's something you don't see every day. We, at Screaming Circuits, have had folks jump on a commercial airplane and fly here from another state to pick up boards we've assembled for them, but we've never had a personal helicopter land in our back yard to to pick up an order. But then, our back yard has buildings in it and behind that, trees, so it's not as if there's a lot of room for a helicopter to set down.

Our board fab partner, Sunstone Circuits, had just that happen the other day with customer Robert Ford. You can find more details on their Facebook page, but here's the video they posted of the happening. Sometimes even overnight shipping is not fast enough. Now that is an eager customer!

If I'm not mistaken, that's a Robinson R44 he's flying. There are two variants of the R44 with the difference being fuel injection verses a carburetor. The fuel injected version has just a slightly higher payload and quite a bit higher hover ceiling. The important stats; range and cruising speed are nearly identical at 135/130 mph (117/113 kts) and 350 miles range (no reserve) for both. I believe the FAA requires minimum reserve is 30 minutes for VFR (visual flight rules) operation. That would leave a range of about 285 miles. When I was flying, I preferred an hour, as did most pilots I knew. That would leave a range of 220 miles.

The point of origin was Chehalis-Centralia Airport (CLS), Washington. Sunstone is just about close enough to be in the landing pattern for Mulino State Airport (4S9), Oregon. The two airports are 89 nautical miles apart, which will take about an hour and a half for both legs. That leaves 42 miles (or about 20 minutes) fuel for a sightseeing trip. I'd take that.

Duane Benson
Carburators man. That's what life is all about.

Sharing With Sunstone

Sharing is what our partner Sunstone Circuits would like today - sharing your stories. We've been partners with Sunstone Circuits for a very long time. When we purchase boards turn-key, we go to them first. They even build a fair number of the boards that we don't personally order. We can tell by the labels on the boxes on our receiving dock.

Naturally, when I had some projects to build, (like this one) I went to Sunstone for PCBs. I've run a few other projects with their boards as well. The reason I bring this up is that they are running a design story contest right now ( It looks to be a fun way to run a contest and you can make a game of it. They want you to submit a story involving their PCBs, share it and get your friends to vote for it. The contest ends December 16 of this year, so if it's the year 2015 and you're reading this in the archives; too late.

Personally, I would recommend that everyone vote for my story, except that I haven't submitted it yet. And, if I do end up submitting mine, I'll be like a third party candidate and steal votes from one of the true contenders. Being a Sunstone partner, I wouldn't be eligible for a prize, but I could still upset the whole balance of promotion by grabbing votes that would otherwise go to a more worthy candidate. So, if I ever do get my story uploaded, don't vote for me.

Duane Benson
I'm not red or blue. I'm sepia

Coming Soon!

If  you happened by our booth at DesignEast, you may have gotten a personal preview of our new automated parts quoting system. If you didn't get to see it, you will shortly. It's in the final stages of beta.

Order cost - new


This sample shows what you might see when you order Screaming Circuits assembly along with Sunstone PCBs, and components from our website.

In the meantime, you can still quote your assembly and PCB prices online here, and you can have us quote your parts offline.





Duane Benson
Maybe not today. Maybe not tomorrow, but soon and for the rest of your life.
You won't regret it.

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


SMT Geiger PCB

Looks like it to me. I got a couple of nice PCBs from Sunstone here. The parts, except for the Geiger tubes are here from Digi-Key too. The tubes are someplace between the Ukraine and Canby. All I have left to do is kit it up and place the order here at Screaming Circuits. It may seem silly that I have to go through the effort of placing an order on our web site when I work here. But it's not.

Doing so does two things. It reminds me of what it's like to be a customer. Always a good thing. And, it doesn't disrupt the shop floor with something that is outside of our process.

In case you haven't been following, this is my SMT re-layout of the open source Geiger counter designed by Jeff Keyzer of

Duane Benson
Tick. Tick. Tick. Tick. Tick. (actually, I hope not)

More Geigering

SMT Geiger 2nd I didn't get back to this at the same bat channel and same bat time. Sorry if anyone tuned in and found the Penguin instead. I think I'm ready now though. I did a bit more layout tweaking, moved the MCU bypass cap closer to the supply pins and added in a MAX3232 so that I won't need an external driver / transceiver board if I want data on my PC.

I'm calling it done. I have my gerbers in a .ZIP file, my centroid and the completed BOM . Next step is to get some PCBs fabbed up. I'm trying out the ValueProto service from our partner, Sunstone Circuits. As I said before, if, after assembly, this design actually works and counts Geigers, I'll post all of the design files as needs to be done with Open Source hardware.

Here we are at ValueProto. The PCB is 4" x 2.7". I'm not going to do a quick build and my zip is 97013. $57.40 for one. $34.90 each in quantity ten. That's all the questions I need to answer. I upload my .ZIP file, check a few boxes and the order is now placed. Next, I'll get some parts, kit it up and send it through Screaming Circuits. The NOS Soviet Geiger Mueller tube is one the way from the Ukraine.

I'm not sure what I'll use as a radiation source to test it out with once it's built. I hadn't really thought that far ahead. I'll have to come up with something.

If you're going to be at the Embedded Systems Conference in Boston next month (September 27, 28), we'll be there in booth 615, across the isle from Element14. Stop in and take a look at it. While you're there, ask for fabulous prizes and gifts. We have a smattering of Screaming Circuits shirts and flashlights for the asking.

Duane Benson
No baked beans, please