Screaming Circuits: January 2007

Future Customers / Co-workers

On Saturday, the 13th, I attended the Oregon state-level First Lego Robotics League (FIRST) tournament. A month ago, I watched the regional tournament for the Canby area and a year ago, I actually participated by giving the theme presentation and a demonstration of home-built robots. The state contest this year hosted 79 teams from schools and communities around Oregon this year.

If you aren't familiar with the program, take a look at this blog and the FIRST web site. When mostLittle_bot_in_action  people think of Lego, they thinks of kids stuff - building forts, cars, little house and the like. The Lego MindStorms robots though are pretty serious. It has a 32-bit Arm7 microcontroller and an 8-bit AVR micro-controller. It's primarily programmed with a tool based on a graphical object oriented programming system from National Instruments.

The most amazing part of the whole program is that the competitors are 5th through 8th graders. These are kids, but the are kids already preparing to become the next generation of hardware engineers, software developers and systems engineers.

State_robotic_tournement_arena_1 From a distance, the activity in the darkened arena could almost be mistaken for a 19th century boxing match off in the warehouse district of old Chicago. But it's all 21st century - all about technology, teamwork and friendly competition. All about building a foundation in these kids to someday do what you and I do.

My son's team, Robiki, didn't make the Nationals this year. But they had a good time, showed great team spirit and ate a lot of pizza. That's important too.

Duane Benson
Robots - Not just for World domination anymore

Jennifer Twist, Engineer

Jennifer has been tasked with building an embedded video communications system. She’s been using Arm7 LPC2138 processors in prior designs but needs quite a bit more horsepower for this project so she stepped up to the Arm11 i.MX31 from Freescale. She’s got a few software hotshots that already have experience with the platform so that isn’t a worry. The big deal for her is moving from a relatively easy 64 lead QFP to the much more serious 457 ball .5mm pitch BGA.

She’s used a few small 1mm pitch BGAs before, but never anything close to this. It wasn’t just the package that got to her. She just about said “no” after reading about the 500MHz core speed for the new chip. Fortunately though, the i.MX has a rather large frequency pre-multiplier allowing for a rather sedate 32KHz reference clock to generate the screaming 500MHz+ internal clock. Still, there will be plenty of video speed and other high frequency signals running around. It will be a challenge.

There are some pretty intimidating parts here. A year ago, Jennifer wouldn’t have seen this challenge as anything but fun. The company had three layout specialists with experience on all kinds of high-speed designs. Two of those guys were laid off this spring and the last guy is dedicated to higher priority projects. It would have been nice if she could have gotten some formal training with the layout half of the CAD package but it’s all on-the-job training at this point.

Duane Benson

Need to inform others?

Do you want other people in your company to receive updates about the status of your orders?

When you place an order and at a few points in the process, we will send out confirmation / status emails to you. If you also need this information to go to others on your team, you can add their email address to your account. We won't do anything else with those emails except send them the order status. We won't give those emails address to anyone else. They are only used for status updates.Email_addresses

It's rather easy to do. Once you are logged in, select the MY ACCOUNTS section from the top menu. Then select the EMAIL ACCOUNTS section. You'll see your email and an empty entry box. Simply put the new address in the box and click the "Add Email" button.

Duane Benson

Loose Parts

Everybody has a few loose components lying around. Sometimes it's a few chip caps left over from a hand-rework task. Sometimes it's a tiny QFN or big old BGA.

From time to time, we do get asked if we can take in and assemble loose parts. Well, the answer is an indefinite "maybe." On our services page, we do have loose parts (or bulk SMT) listed as a special process. Special means that you have to call us and discuss the specifics before we will commit to doing it.

And here is why. If you have a couple of SMB TVS diodes or a few 1206 resistors, we can probably go ahead and put them in an empty cut strip - if we happen to have one. More than a few, though, and it will start taking so much time that it is less expensive to just buy some more parts.

The real trouble comes with BGAs and fine pitch ICs. The leads on the fine pitch parts tend to bend when jumbled up. We can't use ICs with bent leads. BGAs can have solder balls knocked off. That might just ruin your whole day.

If you have loose parts, you are probably best off just buying new ones. If you don't have a choice, go ahead and give us a call. We'll do our best to help you out. We may say no or we may charge extra, but you never know.

Duane Benson
Loose chips sink in dips

Soldering LGA parts

LGA (Land Grid Array) packaged parts are most commonly found on socketed processors in personal computers. It's not that different a package than a BGA (Ball Grid Array) except of course there are no solder balls on the part.

We've started getting a few requests to solder on LGA parts and I expect that we will be seeing more and more as time goes on. The BGA, of course, is a very well known and well used part. The package does have a few disadvantages though:

  • Sometime the balls will fall off with handling or transport
  • You have to source either leaded or lead-free versions to match the rest of your board - RoHS board, use lead-free BGAs; non-RoHS board, use BGAs with leaded balls.

LGA parts don't have any solder on them prior to assembly, so you can use the same part (provided it meets the RoHS heat requirements) for RoHS and non-RoHS assemblies. Of course, you also don't have to worry about missing balls. Further, the part will have a lower profile once assembled which may be better for heat sink mounting or small form-factor applications.

The important considerations are, again, very similar to those of BGA parts. The stencil aperture must be carefully considered and NSMD (Non-Solder Mask Defined) pads are recommended. Take a look at this application note from Freescale for LGA notes relative to their parts.

We can assemble LGA parts for you. Count them as a BGA when you quote. For now, we'd like you to note the LGA part in the special instructions when placing your order. We'll probably give you a call to discuss the application before running them through.

Duane Benson

Our year 2006 in review

Looking globally at 2006, I'm not sure if it would be accurate to say that it was a good year or a bad year. Certainly, it was a year. For Screaming Circuits, though, it was a really good year. Based on the amount of work all of you sent our way and the comments we received, I'm guessing that it was a pretty good year for most of you as well. Looking back, here is a bit of the good and the bad from 2006 at Screaming Circuits.

Good: We put three and a third million parts on some 40,000 boards last year. Our customers range from people who shoot stuff into outer space to hobbyists trying their hand at an after-work small business. Our largest non-governmental customer has a third of a million employees and our smallest has just the one.

Here are just a few of the comments we have received from the likes of you in 2006:

  • "Excellent Service. Congratulations!!!"
  • "Keep up the good work! Very professional staff, courteous and accessible!"
  • "Great service for quick-turn around & prototyping - no more wirewrap!"
  • "I am very happy with the service. This was my fourth order and I have not had any problems."

Bad: There was that month in late summer when we couldn't seem to do anything right. We take a lot of pride in our quality and our on-time delivery rates. That one month, though... A bit more than five percent of you had problems with the boards we built for you during that period and about five percent of you had your boards come back late that month. That's horrible as far as we are concerned.

That month gave us cause to take a hard look at things here. We had grown so much so fast and we just let it get away from us. After that month, we hired some more people and put in some new systems and processes. Every month since, we've done better in both quality and on-time delivery.

The paycheck is certainly a part of why we all come to work. But here at Screaming Circuits, we want to earn that paycheck by giving all of you more value and better service than you can get anywhere else.

Duane Benson
Wishing you a happy and low-job-stress new year.

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