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Register for U2U Santa Clara
Register now for Mentor Graphics User Group Meeting in Santa Clara, CA on Tuesday, April 26, 2011 at the Santa Clara Marriott. This complimentary one day meeting will include product roadmap and technical sessios on Calibre, Functional Verification, Silicon Test & Yield Analysis, Custom IC/AMS, PCB Flow and Place & Route. Learn, share, and network with your peers: http://www.mentor.com/user2user
Tags: U2U
HDI Value Benefit
In an article published in CircuiTree called “A Fresh Look at MicroVias”, I mentioned that some companies who are in the process of moving to HDI have taken a through-hole design and converted it to HDI first. With this approach, Happy Holden has found that a number of projects like this have not resulted in what he would call a “successful” HDI design because many of the same through-hole methods were applied using micro-vias. When this occurs, the value benefit of converting to HDI is not realized. The full article can be found here: http://www.circuitree.com/Articles/Feature_Article/BNP_GUID_9-5-2006_A_10000000000000953428.
By “value benefit” I mean that although an HDI board costs more than an FR4 laminate board with the same number of layers, has the HDI design taken advantage of the ability to increase functional density and decrease the area (size and layer count)? The primary reason why companies have not converted to HDI is because of cost. My point is that if micro-vias are used in a way to reduce the layer count and to make the design smaller, then the total cost (considering increased functionality and decreased size) can be justified. The article presents methods in which micro-vias can be applied to the routing task in a manner that does indeed enable a value benefit with HDI.
What is your experience? Is there a significant push to increase functionality in the same area? If so, HDI may be the solution.
HDI Via-In-Pad (VIP)
When designing HDI boards, one question that needs to be resolved up-front is whether or not to use VIP, and if so, what type? Happy Holden’s book “HDI Handbook” (available at www.hdihandbook.com) has quite a few references in the Index that describe the use of VIP. I wrote an article recently in CircuiTree called “A Fresh Look at MicroVias”, in which a few paragraphs describe the various forms of VIP and their advantages in the context of routing. The full article, which expands upon this blog, can be found here: http://www.circuitree.com/Articles/Feature_Article/BNP_GUID_9-5-2006_A_10000000000000953428
The different forms of VIP include:
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VIP – The microvia in the center of the ball pad. Great for very fine pitch BGAs.
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Offset VIP – Via inside the ball pad, but allows for fanout patterns that increase route density.
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Partial VIP – Here the center of the via is on the edge of the ball pad. Also increases route density.
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Near VIP – The via hole is located outside the ball pad which enables fanout patterns using columns and rows, which maximizes route density.
If using VIP is new to you, the CircuiTree article and the HDI Handbook provides good information about the advantages of different patterns and the effects on fabrication and assembly of the board. Are you using VIP and do you have some information about them that you would like to share?
Tags: hdi, MicroVia, PCB, PCB Design, Via-In-Pad
Stack or Stagger MicroVias?
In a December article I wrote that was published in CircuiTree called “A Fresh Look at MicroVias”, I presented the value of stacking microvias in the context of increased route density. The full article can be found here: http://www.circuitree.com/Articles/Feature_Article/BNP_GUID_9-5-2006_A_10000000000000953428
In this blog, I am interested in getting feedback about stacking or staggering microvias so that we can get a sense of how quickly (or not) the industry is moving to stacked microvias. From what I can determine (based on numerous visits to design centers and fabricators) staggering microvias is still more common; however, more and more fabricators are offering stacking methods not only on 2+N+2 HDI configurations; but some fabricators are creating boards with multiple buildup layers with just a two layer inner core. Even more advanced are the boards that are 100% buildup layers.
Has your company evaluated stack methods? Is the additional cost or the current limit on number of layers the primary reason for not moving to them? Maybe the fabricator you are working with can only stagger microvias?
Please let us know what your experience is and what you expect your company to do in the future. It would also be interesting to note which segment your HDI designs target; for example, handset, computer, networking, etc.
PCB Design – How Many Monitors?
I am wondering how common it is for PCB designers to have two monitors. Sometimes when I look at demos of our products, it appears to me that with interaction between dialogs and graphics, it would be a lot easier to just have two monitors, one for the graphics, one for the dialogs. What kind of setup do you have? What % of the PCB Designer community do you think have dual monitors?
Interactive Routing – What would you like to see improved or added?
What features would you like to see improved or added to interactive routing? I am asking this question for two reasons. First, I suspect that what you want may already be available but it is not obvious. Second, in a never ending quest to improve interactive routing, I would like to know what is of interest to users. Yes I know there are hundreds of requests for this and that in our Support Net and enhancement databases and believe me, I know of many things that can be improved. 
But this is a blog and a good place to discuss this stuff!
Tags: enhancements, interactive routing, PCB
Personalized Menus – Use them?
While we are on the subject of user interfaces, what about Personalized Menus? They are an optional method in Office 2003, accessed through the Customize dialog. They don’t exist in Office 2007; but since there has been general agreement (at least from most of the people I discuss it with) that the Office 2003 Menus, I thought I would bring them up to see if they are preferred or not.
If you uncheck “Always show full menus” then you will get the Personalized Menus that look like this:
The double arrow at the bottom is a cascade menu (double arrow) that shows you the menu items that you have used infrequently. The intent is to only display those menu items that you use regularly. Apparently the algorithm to determine which items should be hidden in the cascade; but it reportedly does a good job.
What do you think?
Do you use Personalized Menus?
Considering that some Menus may be quite long in Expedition PCB, is this a reasonable method to shorten the menus?
Or, do you use toolbars mostly and don’t visit the Menus very often?
Would you be interested in a Favorites Menu in which you could put your favorite menu items?
Tags: Expedition PCB, menus, personalized menus
Ribbon Menus – Do you like them?
I have been using Office 2007 for a little over a year now and as a contributor to the user interface design in Expedition PCB, I am wondering if the Ribbon Menu style that was implemented in Microsoft Office 2007 should be considered for our products. Here is what it looks like in Word.
For those of you not familiar with this style, the “normal” File, Edit, View, Tools, Window, Help pull-down menus are replaced by menus that provide a ribbon of icons as opposed to the list of menu items. My experience is as follows:
- The appearance is nice – it looks pretty.
- The height of the ribbon is significant and it obscures quite a bit of graphics area for edits. On a notebook, especially a small notebook, the remaining editing area is quite small.
- It is difficult to memorize the locations of the less used functions. The ribbon menus have been completely reorganized. For example, if you want to edit your header, you would think it would be under the “Page Layout” ribbon; however, it is in the “Insert” ribbon.
- When hunting for certain functions, it is not uncommon to simply not find what is desired. After looking through every ribbon, I will then go to the obscure “Options” dialog that is hidden under the “Office” button.
- The menus change when resizing the application window – this makes it difficult for me to remember exactly where all the functions are.
- There is only one custom toolbar where you can add your most used icons, in the lower left as shown in the previous message.
You may be getting my drift that I don’t particularily like these ribbon menus. 
It is true, other than the nice appearance, I don’t find other positives about them. So I am wondering if any of you have had a different experience with Ribbon menus and if you could tell me why you like them. Or if anyone has had other difficult experiences with Ribbon menus, please add to this discussion.
Regards,
Charles
Tags: Ribbon menu
Where do you draw the line?
This morning I was sent the following comment (name changed to protect the innocent):
I don’t need Mentor to fix anything because I don’t do “crappy” work. (Actually a different term was used, but not appropriate for this forum). I don’t do DRC or if I do I ignore the errors and warnings. I just export the gerber files and examine them. DRC is for those who don’t want to learn how to layout a PCB or those that are hired from the street corner.
Just my opinion.
Joe
At first glance, my reaction to this is that this fellow should not be using Mentor tools, he should use AutoCAD.
After second thought however, it is clear to me that every designer draws a line to define a threshold in terms of what they expect the software to manage and what should be left up to the designer. For example, I am quite sure that Joe would not like it if when moving a part, we did not move the padstacks with it. So at some level he expects the software to be correct-by-construction. Joe appears to have drawn a line where he wants to craft every trace manually. So I now wonder if he has timing requirements – does he expect any feedback to tell him if the delays are as desired? Does he expect that we will keep diff pairs together? Or maybe he doesn’t define diff pairs and just routes them close together as he sees fit?
So, in the end, every designer assumes that the software will automatically manage the design to a certain extent. As a software vendor however, we need to have software flexible enough so that the system can be tuned to draw that line at the “right” place and allow the designer the freedom to craft as desired.
Where do you draw that line? Are your boards so big and complex that the only way they can be completed on schedule is with a very high level of DRC and automatic management of constraints? Or are your designs simple enough that you don’t want any DRC? Or maybe it doesn’t matter how complex your designs are, your boss requires full and complete DRC with every project? Please provide some feedback, it will help us understand better what our customers need to be successful.
U2U Expedition PCB Questions, Issues and Answers – Part I
In this post and some following ones, I want to bring up the issues and questions that customers brought up to me during the U2U meetings. This includes not only during the BGA Fanout workshop, the Expedition PCB Update presentation, but also in meetings with individual customers.
1. Display Control Scheme Naming - When the user applies a scheme to Display Control and then makes an edit and wants to save and overwrite the original scheme, today the user has to either hunt for the scheme name or remember it and properly type it in the name field. It would be better for the GUI to remember the last scheme name and have that as the default entry.
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Answer: We are in the process of enhancing our schemes and this is one of the items being addressed. Target date for delivery is not set yet.
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2. Grids - In Display Control if you turn off the visibility of a grid, the snapping to the grid is also turned off. We should use the Editor Control and toolbar on/off for snapping of the grid, not Display Control.
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Answer: We are in the process of enhancing Display Control dialog and this is one of the items being addressed. Target date for delivery is not set yet.
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3. User Properties in Cells - One of the enhancements to cells in EE2007.3 is the ability to add user-properties. The question was if these user-properties were available in Drawing and Mechanical cells as well as Package cells.
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Answer: In EE2007.3, user-properties are only available in Package cells.
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Question for Customers: Do you have a need to include user-properties in Drawing and/or Mechanical cells?
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*4. Curved Multiplow* – I showed a slide in which curved, any-angle Multiplow was introduced in EE2007.3. The question is, “Which licence is required for this functionality?”
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Answer: The Flex license is required to support curved Multiplow; however, any-angle Multiplow is available in the standard Pinnacle license.
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That’s all for right now, more questions, issues and answers coming up!
Tags: BGA, Control Scheme, Expedition PCB, Fanout, gui
About Charles Pfeil's blog
Latest Posts
- Santa Clara U2U Coming Up On April 26
- HDI Value Benefit
- HDI Via-In-Pad (VIP)
- Stack or Stagger MicroVias?
- PCB Design – How Many Monitors?
- Interactive Routing – What would you like to see improved or added?