Xpedition Enterprise Blog

Learn about the industry's most innovative PCB design flow, providing integration from system design definition to manufacturing execution.

We'll keep you updated on the latest design trends, and other interesting tech tidbits in the industry.

11 April, 2014

This is the second post in this routing series. View the introduction post here.

To increase fabrication yield, it is important to center the traces between the fanout vias inside the BGA area. Large BGAs are usually 1mm pitch and medium sized ones are 0.8mm. Then we go down to 0.65, 0.5, 0.45 and 0.4. Is anybody designing with even finer pitch BGAs?

In any case, it is important to center the traces between the ball pads and/or the fanout vias. If the routing is on the outer layers, then it is important that the traces do not get exposed with the soldermask openings. Of course, if the BGA pads are soldermask defined, then the problem of exposure is eliminated; however, this method is not always used.

On inner layers, any increase in the via-to-trace spacing will help to prevent shorts during the fabrication process. When fabricating boards, “Spacing is King.” You may also want to force the traces to be centered so they will not cross anti-pads on the plane adjacent to the signal routing.

Difficulties include various pin pitches, and we also have to deal with differential pairs along with the single-ended routing. As the pin pitches vary, rule areas can accommodate finer trace widths and spacing, and if set just right, it can automatically force either the differential pairs or individual traces to be centered. The problem is with “either.” If both differential pairs and individual traces need to be centered, a single spacing value will not force all the traces to be centered.

There is a method in existing Expedition PCB and Xpedition Layout that can be used to accommodate the centering of both single ended nets and differential pairs.

Solution: DRC Visualization and Repair

The step-by-step instructions are as follows:

1. Differential Pairs:  In the Constraint Manager, increase the trace-to-via (or if on the mount layer,  trace-to-pad) clearance to a value so that the differential signal will be centered. You can do this in the default rules, and if you are using rule areas around the BGA, you can do this for each of the rule areas.  I trust you can do the math.

2.Turn on visibility of all routing layers. Run the DRC Visualization routine.


3. There is no need to look at all the violations – there will be many. After the DRC completes, select the traces you want to have centered, and click the right mouse button.

This menu will appear:


4. Choose “Repair Selected” and all the DRC violations that can be repaired will be repaired by pushing the traces away from the pads and vias.

5. Set your Gloss to “Local Gloss,” frame-select the traces that you just repaired, and then choose “Gloss.” This will remove any small segments that might have been created.

6. Do this method for all the BGAs that have differential pairs running through them.

7. Set the trace-to-via and trace-to-pad clearances back to the original values. You can also accomplish this by exporting the original constraints and then importing them back into the design.

8. Single-Ended-Nets:  After the differential pairs have been centered, go through the same cycle with single-ended-nets. The differential pairs will not be affected by this operation for single-ended nets.

9. Once the rules are reset to the original rules, do a full DRC to ensure that no other problems may exist or have been created during this centering process.

At this point, the vast majority of the traces will be centered as desired. It may read like a lot of steps, however, it is certainly much more effective than centering the traces manually.

Here is a video that illustrates centering of differential pairs.

Are there other methods that you would like to offer?

2 April, 2014

PlacementChallenges#1Long before video games, children had simpler means of entertainment. Boys had their army men and marbles. Girls had their coloring books and paper dolls. As a young boy, I used to watch my sister carefully cut out dolls and clothes to glue on them, and thought yuck!

15 years later I found myself doing the same thing…well kind of. If you have been in the PCB design industry for as long as I have, you likely remember the days when we placed boards by cutting out shapes for components to be placed on the boards and called them “Paper Dolls.” Back then, placement was not complex. We tried as best we could to get parts close to each other, but boards were nowhere near as dense as they are today. It was easier to get close when it came to placement; there weren’t many restrictions as long as you stay on that 100 Mil grid.

Today everything has changed. I am so glad to have CAD tools, because I do not think I could make a paper doll of a 01005 capacitor, considering they are about the size of a grain of sand. And, I can now place several parts in that 100 Mil, not just one. PCB designs today have much different placement challenges: density, thermal, mechanical, and more!

As a designer, it used to be that placement was easy and routing was tough, but that has changed. Advanced routers help shorten design schedules, but achieving the same for placement is much more difficult. Dense boards with thousands of components can take weeks to just get placed.

So, how do we solve this as designers? Placement strategy is a huge part of the success of a design. What new strategies can we invoke to place a board with the efficiency and quality we need in our product?

In this series, I will discuss some of the current challenges that face us during the placement phase of a design, plus how we can remove these challenges with sound placement strategies.

In the rest of this series, I will also cover some technology that’s included in the latest Xpedition release. In the meantime, take a look at this webinar which shows the new planning and placement technology available in this release.

What placement challenges are you facing on a daily basis?

26 March, 2014

You’ve likely heard that there has been a new release of the product formerly known as Expedition Enterprise, called Xpedition. So, what’s this release all about? How does the new functionality compare to the tools you use today and what’s in it for you?

I’m Vern Wnek, Technical Marketing Engineer for the Xpedition software group. But, before I lose you with that let me explain my background and why the discussions you and I will have through this blog are relevant. I’m a PCB designer by trade and have been in the industry for over 35 years. After designing boards, working in board houses, assembly houses and test facilities, I have landed where I’m at now. I’ve worked for service bureaus and large companies from military to commercial.

I’ve encountered the challenges and seen the industry evolve to better address them. I’m going to discuss efficiency in tools, processes, and technology trends. But most of all, I care about your challenges.

What are your challenges? What’s your take on the paradigm shifts of the industry and have any of them changed the way you look at PCB design?

Expedition has been the source of my livelihood since the days of Veribest. I have seen new versions come and go and tested a number of PCB design tools. Mentor Graphics is the best of the best and I’m not just saying that because I work here. I’m looking for you to challenge me. Prove me wrong. Show me what we’re missing. Let’s discover all that makes up Xpedition and how it’s relevant to you.

Here’s a glimpse of what’s to come:Xpedition Layout
•    Placement challenges and new strategies
•    New auto-assisted routing paradigms
•    3D integrated layout
•    System and multi-board design
•    PCB layout designer resource challenges
•    Industry trends in design technology and manufacturing of PCBs

Through our discussions on this blog, I think you’ll see that Xpedition VX is SO much more than just a rebranded name on a slightly new version of the Expedition Enterprise product. This latest release really has earned a new name and I’m looking forward to showing you why.

21 March, 2014

This is the first of a series of blog topics related to routing PCBs

My name is Charles Pfeil and my role at Mentor Graphics is one in which I always have a primary focus on routing technology and methods – although I do get involved in numerous other projects. I began in this industry working my summers in high school inspecting Ruby-Lithe designs for scratches and repairing them. Sounds rather antiquated? Indeed, this began in 1966 (some would say “way back” in 1966). I went to college to study architecture but soon realized that my passion for PCB design was so strong that I should pursue that instead.

After years of working as a job-shopper designing boards, I opened my own design service bureau, Sunshine Design. We started out with manual design and tape-ups. I still have some of those Mylar sheets with black tape-ups if anyone knows of a museum that might be interested them…I suddenly feel very old. In 1978, we made the change from manual design to CAD after getting two Racal-Redac Minis. During this transition, we lost all our customers who weren’t interested in CAD data. Fortunately, we were able to hook up with some customers who also used the Racal-Redac systems. At that point, CAD routing technology, both manual and automatic, became of great interest to me.

Since then I have worked at Racal-Redac, ASI, Cadence, Intergraph, VeriBest and Mentor Graphics. This industry has been very good to me and my career. I am grateful for all the wonderful people that I have met and worked with over these years.


My goal for this blog is to provide meaningful discussion of routing problems and their solutions. Over the years the routing task has become much more complicated, not only due to evolving component and fabrication technology, but also the need to fulfill high-speed requirements and manage the signal integrity concerns. I look forward to hearing your ideas and methods and hope that the discussions we have will help better equip us to solve the routing challenges that we face.
Here are some topics I look forward to discussing with you:

  • Length of time needed to manually route a design
  • Difficulty of phase match tuning
  • The dense, tangled netlines between BGAs are hard to route
  • The need to center traces between vias in BGA fanout array
  • Fanout pattern complications and the difficulty of adding them

What challenges are you encountering? Are there any topics you would like me to add to my list?

19 November, 2013

Both veterans and newcomers to PCB systems design may appreciate this video on our website that showcases the evolution of PCB design over the past decades and the role that Mentor Graphics has played in this journey. While visiting our website, you may notice something else—we have introduced Xpedition, the new identity for our flagship PCB design flow.

Why have we introduced this new identity?

The technology in our upcoming release is groundbreaking and serves as a foundation for the next generation of proven, innovative thinking. It is so substantial that we believe it deserves a unique identity platform. But there is more to it than that.

Xpedition Identity

Xpedition represents the value and importance of the overall PCB design-to-manufacturing flow. For development organizations to be successful, they need to exploit every opportunity to drive greater productivity in their design flow while continuing to adjust for increasing complexity. This means they must reduce and eliminate process bottlenecks by deploying effective strategies for system definition, virtual prototyping, routing productivity, new product introduction, IP management, and design concurrency.

Proven Innovation

Since the 2005 release of Expedition Enterprise, Mentor Graphics has had a strong track record of delivering innovation tools including XtremePCB, CES, DxDesigner, and the world’s most productive PCB layout environment. This has made us the global leader, by far, in PCB systems design solutions. Xpedition builds on this legacy to deliver next-generation leadership technologies for modern PCB development teams.
Thank you to our customers for partnering with us in this ongoing journey. To those not yet familiar with us – we look forward to showcasing technologies that are, “jaw dropping…a huge leap in thinking and power,” as one Beta customer remarked.