waters corporation chooses blueprint-pcb as enterprise-wide...

Tel: 800.535.3226 • 508-970-0670 • www.downstreamtech.comDownStream Technologies, LLC. ©2009 All rights reserved. CAM350® and BluePrint for Printed Circuit Boards® are registered trademarks of DownStream Technologies, LLC. All other trademarks are the property of their respective companies.

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IN THIS ISSUE:

Waters Chooses BluePrintEnterprise-Wide Documentation Solutionpages 1-3

QualComm Adopts BluePrintAs Global Documentation Solutionpage 3-4

DownStream Product TrainingBluePrint and CAM350 Courses ScheduledApril 20 and 21page 4

DownStream EventsQuick Schedule 2010page 2

CAM350 Tech TipsIPC Netlist CompareAn In-depth View for 10.0pages 5-10

BluePrint Tech TipsQ & A Regarding Drill Chartspages 11-18

Waters Corporation ChoosesBluePrint-PCB® as Enterprise-WideDocumentation Solution

Customer Requirement:Waters Corporation required an easy-to-use, customizable and CAD-tool-independent solution for creating comprehensive documentation.

DownStream Solution:BluePrint-PCB®

Results:Within days of installing BluePrint-PCB, Waters was creating very detaileddocumentation, saving valuable time for their designers. In addition, Watersuses BluePrint-PCB for creating all Fabrication and Assembly drawings andmanaging Parts Lists for all PCBs.

Company OverviewFounded in 1958, Waters Corporation (www.waters.com) is a global manufacturer of advanced liquid chromatography (LC) and mass spectrometry(MS) systems, thermal analysis and rheometry instruments, LC and MC consumables and software. Waters products are purchased by university,independent and government laboratories as well as pharmaceutical, foodand beverage, and personal care product development and quality control laboratories.

Waters Corporation, a publicly traded corporation (NYSE:WAT) headquar-tered in Milford, Massachusetts, operates in 27 countries with more than5,000 employees and reported $1.58 billion in 2008 revenues. In 2009,BusinessWeek Magazine added the company to its BusinessWeek Top 50rankings.

http://www.downstreamtech.com

http://www.waters.com

Tel: 800.535.3226 • 508-970-0670 • www.downstreamtech.comDownStream Technologies, LLC. ©2009 All rights reserved. CAM350® and BluePrint for Printed Circuit Boards® are registered trademarks of DownStream Technologies, LLC. All other trademarks are the property of their respective companies.

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EVENT SCHEDULE

DownStreamProduct SeminarsOnline technical product seminars will be

announced on our website each month.

Please watch for new dates and topics.

DownStream will be exhibiting atthese industry trade shows in 2010:

• DesignCon 2010 - February 1-4

• Virtual PCB 2010 - March 2-4

• PCB West 2010 - September 28-30

For complete details visit:http://downstreamtech.com/events.html

Customer SituationWaters Corporation’s new product development process utilizes printed circuitboard (PCB) design solutions from Mentor Graphics®. During a company-wide migration from Mentor's BoardStation® PCB design tool suite to theirExpedition® solution, Waters identified documentation as a major weaknessin their current design process. They felt their methods were not efficientbecause the tools they used were not created specifically for documentation,the process was not standardized across the enterprise and the resulting documentation was never as comprehensive as it needed to be. “While wewere very happy with our decision to stay with a Mentor PCB Design solution(Expedition) we felt we needed a more comprehensive and forward-lookingPCB Documentation tool,” said Robert Laman, Engineering Apps Manager for Waters. “The previous solution we used fell well short of our overallrequirements,” he added.

Customer GoalsWaters was looking for a tool that offered a completely new methodology forcreating PCB documentation, one that allowed their designers to focus onwhat they do best — PCB design. Such a tool would need to combine severaloften conflicting attributes — reduce the time required to create PCB docu-mentation while at the same time creating more detailed documentation,seamlessly integrate with the EDA Vendor tool flow and be easy-to-use and maintain.

Laman's group came across BluePrint-PCB® and began to investigate itsability to meet their requirements. “We were very impressed with the product'scapabilities. At least on paper, it was the only tool on the market that showedany promise of meeting our goals. We undertook an evaluation and quicklylearned that BluePrint brought even more to the table than we expected. Itnot only helped us address the problems we knew we had, but it also broughtadditional benefits we had not considered as a requirement,” said Laman.

BluePrint SolutionWater's recognized that documentation was a critical part of the PCB designflow as it defines the specification on how an electronic product is to be built.The more detailed the documentation, the less likely manufacturing mistakeswill occur. Comprehensive documentation also ensures that repeat builds ofthe same product are consistent, reduces manufacturing deviations andmakes final inspections easier.

Prior to engaging with DownStream, Waters used a myriad of tools to createtheir PCB documentation. The process was long, cumbersome and never ascomplete as it needed to be. “We continually spent more time than weexpected creating our documentation and never seemed to get exactly whatwe needed. I knew we needed to find a better solution,” said Laman. “Whenwe found BluePrint, we were amazed not only how comprehensive the toolwas but also how easy-to-use it was. Within a few days we were able to create very detailed documentation, and do so in minutes instead of hoursand hours instead of days,” he added.

BluePrint's patent-protected technology allows the PCB CAD database to beimported and then automatically creates and links unlimited PCB views anddetails, while at the same time maintaining the design intelligence. In addition,any change made in the CAD file can be quickly updated in BluePrint by simply re-importing the new CAD data back into BluePrint. Once imported,

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Tel: 800.535.3226 • 508-970-0670 • www.downstreamtech.comDownStream Technologies, LLC. © 2009 All rights reserved. CAM350® and BluePrint for Printed Circuit Boards® are registered trademarks of DownStream Technologies, LLC. All other trademarks are the property of their respective companies.

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BluePrint updates all instances of the CAD data in the documentation automatically, greatly reducing the amount of time to makethese changes when compared to the alternative methods. “Prior to BluePrint, Engineering Change Orders basically meant re-creatingour documentation from scratch. With BluePrint, we simply re-import the CAD data and it creates a new set of documentation inminutes. This saves us a tremendous amount of time,” said Laman.

Within days of installing BluePrint-PCB, Waters was creating very detailed documentation,

saving valuable time for their designers.

Waters has implemented BluePrint-PCB enterprise-wide for the creation of all Fabrication and Assembly drawings. An additionaltime-saving benefit has been realized because they use the product to create and manage Parts List for their PCBs. This allows adesigner to start with a “generic” Parts List to begin the PCB design process and then marrying the “final” parts list — including allWaters parts attributes — later in the design process.

After making BluePrint the standard solution for creating PCB documentation across the enterprise, Waters realized other significant,unplanned benefits. “As Waters has grown through acquisition, were able to deploy BluePrint with the legacy PCB CAD tools weacquired because BluePrint is CAD-tool independent,” said Laman. “In addition, because so much manufacturing is done offshore,BluePrint allows us to create a complete, electronic release package that can be viewed and shared by everyone along the manufacturing process,” he said.

“BluePrint has allowed us to greatly reduce the time required to create very detailed PCB documentation — what used to takemany hours now takes only a few minutes. With BluePrint, there is never a reason for a manufacturer to interpret what the designintent was because the documentation and instructions are so complete,” said Laman. “It reduces our risk significantly and givesmy team the confidence it needs and in today's competitive environment, that is worth more than anyone can imagine,” he commented.

Qualcomm Chooses BluePrint-PCB® as Global DocumentationSolutionProduct Customization and Independence Cited as Key Decision FactorsDownStream Technologies, LLC has announced that Qualcomm Inc., a recognized leader in the worldwide wireless technology and services provider, has adopted BluePrint-PCB® as the global documentation solution for both the PCB and IC Packaginggroups. BluePrint will be deployed across the Qualcomm enterprise and will help both groups increase productivity by providing anautomated, ECAD vendor independent solution for creating comprehensive documentation. With this initial installation, Qualcommbecomes DownStream’s largest user of BluePrint in the world.

The process of choosing BluePrint-PCB began when Qualcomm undertook an ECAD Layout Tool evaluation. Prior to selectingCadence Allegro® as the new layout tool, Qualcomm used a self-developed documentation system that had been modified overthe years to work with their old PCB layout tools. This system provided “push button” documentation but since it would no longerbe compatible with the newly selected Allegro product line, Qualcomm needed to replace that system. Qualcomm’s requirementsfor the new documentation solution included:

• ECAD vendor independence

• Support for multiple ECAD layout systems

• Robust API so as to reproduce their prior system

• Able to provide “push-button” documentation creation


“During the process of searching for a new documentation solution, we discovered that BluePrint was the only product on the marketthat met all of our requirements,” said Stephen LoCicero, Senior Director of Engineering at Qualcomm.

At the same time the PCB Layout Group was evaluating BluePrint-PCB, Qualcomm’s IC Packaging Group began an evaluation toaddress their specific documentation needs. As existing users of DownStream’s CAM350® design analysis tool, they wanted to takeadvantage of the integration between BluePrint-PCB and CAM350 in their design flow to not only automate the documentationprocess, but also ensure the design integrity.

The two groups put BluePrint through an extensive evaluation, and in the process identified advanced functionality they would need inorder to implement BluePrint as the standard tool for documentation. DownStream R&D worked closely with Qualcomm's CorporateEDA team to develop and incorporate their specific functional needs into BluePrint. “DownStream was not only able to provide thebase functionality we needed, but they also were able to understand our needs and incorporate custom solutions into the product,”continued LoCicero.

Qualcomm’s goal of minimizing the time and effort spent on creating the most comprehensive PCB documentation possible is a goal shared by many electronics companies. Out of the box, BluePrint delivers a very efficient and easy-to-use solution that drasticallyreduces the amount of time needed to create very detailed fabrication and assembly documents. This underlying capability, coupledwith BluePrint’s Application Program Interface (API) technology, which allows for full customization to fit any process, enables companies to reduce what typically accounts for 20% of the PCB layout process to a process that takes mere minutes or even seconds, as Qualcomm has done.

“We are very proud to have been chosen by Qualcomm as it validates our commitment to the post-processing phase of the newproduct development process, which to date, really has been ignored by the mainstream EDA vendors,” said Joe Clark, one of theFounders of DownStream. “The selection by Qualcomm justifies our continued commitment to developing this important technology,”he added.

About QualcommQualcomm Incorporated (Nasdaq: QCOM) is a leader in developing and delivering innovative digital wireless communications productsand services based on CDMA and other advanced technologies. Headquartered in San Diego, Calif., Qualcomm is included in theS&P 100 Index, the S&P 500 Index and is a 2009 FORTUNE 500® company. For more information, please visit www.qualcomm.com

DownStream Product TrainingWhatever your reason for wanting to attend training courses, it is always a good investment. As software packages becomemore robust and powerful with each release, it is wise to brushup on your skills and learn the new features and functionalities.Of course if you are new to the software, training is a great wayto familiarize yourself with the new product and company.

BluePrint-PCB: April 21st, Marlborough MAThis training course will emphasize getting to learn the basicsof BluePrint-PCB. The attendees will learn how to use thepowerful features within the tool to generate documents anddocuments sets. Emphasis will be placed on using the Galleryand Document Templates to automate the process.Topics include:

• User Interface• Documentation Hierarchy • Generating a release package• Create Fabrication drawings• Create an Assembly Drawing• Creating a parts list• Creating Engineering Change Orders• More Details

CAM350 Release 10: April 20th, Marlborough MAThe CAM350 course is focused on Design Verification andPCB Post Processing. This is a great opportunity to learnabout Release 10.0 and to get more out of your software. This course includes:

• Getting familiar with the new Graphical User Interface• Output of data from various CAD systems - using the

direct interface• Gerber identification and import • Streams Rule Checking • Netlist Comparison • Design Rule Checking • Design for Fabrication • Putting together the completed design package for

Fabrication• Introduction to Universal Release Package Navigator• More Details

For more details, and to register, please contactDownStream directly:

• Call 800-535-3226 x623 • Email: [email protected] 4


http://www.qualcomm.com

http://www.downstreamtech.com/support/Training_BluePrint.html

http://www.downstreamtech.com/support/Training_CAM350.html

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IPC Netlist Compare in DepthUpdated for CAM350 10.0

Netlist Compare is the only way to find opens and shorts in yourGerber database. It is likely the most important pre-fabricationcheck one can do in CAM350.

The Netlist Compare process extracts a netlist from your graphicdata and compares it against a netlist from an external source.Without the external netlist there is no way for CAM350 tounderstand that the graphic data may not match what wasintended. Thus DRC and other graphics checks cannot possiblyfind opens or shorts.

Netlist Compare is also useful when editing a board. Netlistcompare can catch mistakes that alter the net. Just extract anetlist from the Gerber data, make it external with Analysis | Nets| Update External Nets from CAM Nets and then do your edits.Use Utilities>Netlist Extract to a new netlist after edits then runAnalysis>Nets>Compare External Nets afterwards to make surethe net has not been altered.

The Navigation Pane in CAM350 v 10.0 adds the ability to easilylocate and highlight extracted nets (sometimes called CAM nets)and external nets. This makes it much easier to locate the causes of shorts.

PreparationSome import and preparation problems can result in netlistextract problems, and thus alter the results of a netlist compare.Being aware of these issues can minimize false errors and leadto a more accurate check.

If you have control over the generation of the Gerber data,adjustments to the output settings in your CAD program canreduce or eliminate all preparation issues. Such settings varydepending on the CAD program. To discuss such matters, contact support.

Files

IPC netlists (either IPC-D-356 or IPC-D-356a) are preferable fornetlist compare. Using a CAD netlist that is reference designatorbased is problematic as the netlist you extract from your Gerberdata is not referenced designator based. Thus they cannot becompared without using CAM350 to build parts. Building partsis very time consuming.

It is better to get an IPC netlist from the Gerber data source (the CAD system). If the CAD system does not export IPCnetlists, you may be able to get around this problem by usingODB++ or one of CAM350’s direct CAD interfaces. The DirectCAD interfaces are found under File>Import>Cad Data. By

importing intelligent data info CAM350 you can then export anIPC netlist. This is a common solution of PADS netlist compares.

Understanding the IPC format is important to netlist compare,especially if you find errors. Parts of this article will refer to IPCdata and assumes some familiarity. Learn how to read anIPC netlist

As for the Gerber Files, the only thing that is important is that thedata be imported properly. Errors as part of either the importdialog, or those visible on screen after import must be dealt withaccordingly.

Non-Gerber database compares

One can also use the compare process on other database formats as well. ODB++ and CAD formats could be used. The problem with such data is that there is no requirement in theformat that the graphical data match the CAM netlist. Thus it isimportant that a netlist be extracted and an external netlist beused for the compare process. The process is still concernedwith checking the validity of the graphics, so following the normal process is important.

As the existence of parts can modify netlist extract results, it iscritical that you use EDIT | CHANGE | EXPLODE | PARTS –Select ALL on all data after import and before running netlistextract. ODB++ data includes an external net as part of thedatabase, which can be used normally in the compare process.

Other than the Explode | Parts step, the process with Non-Gerber Databases is exactly the same as it is with Gerber data.

The Importance of NC (drill) Data

Drill data is critical for a good Netlist Extract. CAM350 uses it todetermine how the layers connect. When no drill data is present,CAM350 will create through vias at any location with coincidenttop and bottom pads. This is not ideal as CAM350 is essentiallyguessing.

Align Gerber data

If data is not aligned, you cannot extract a good netlist. This istrue for all electrical layers and drill data. For info on how to alignlayers, see help under Contents | CAM Editor, Edit>Layers>AlignOR the Align article from Fall 2009 Dataflows

Setup Layer Sets if Necessary

If data has Blind and Buried Drills or it uses MCM technology,use Tables>Layer Sets to define how the data stacks up.

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http://www.downstreamtech.com/Support_CAM/Advisories/IPCD356_Simplified.pdf

http://www.downstreamtech.com/Support_CAM/Advisories/IPCD356_Simplified.pdf

http://www.downstreamtech.com/newsletter/Issues/DataFlows_Fall09.pdf


For Blind and Buried, the thru drill layer is assumed. Do notdefine it other than to select it in the “thru drill” box in the lowerleft corner of the dialog.

For MCM Layer Sets, stack them up in order with an insulatorlayer between each conductive layer. With no insulator layerbetween layers, the connection is broken.

For more info on Layer Sets, see Help under the Contents | CAMEditor topic Tables > Layer Sets.

Draw 2 Flash

Run on top and bottom layers only. Netlists only include netpoints on the top and bottom of the board. While Trace andpolygon drawn pads will typically pass a netlist compare, theycan lead to false errors in some situations.

To see if you have drawn pads, select Tables>Layers andchange the Flash color for your top and bottom layers. Thenlook around on the layer and make sure your pads are the flashcolor.

If you have rotated pads or other unusual pads, Draw toFlash>Interactive (and Interactive any angle) is the best way toflash them. In some cases, such as with round boards, youmight end up with many drawn pads at various rotations.Flashing all of them may take a while. In such cases an alterna-tive would be to copy the drill layer to the top and bottom layers.This will create a flashed pad at each via, which is enough toextract a good netlist.

View the external net

Select “Settings>View Options>View Imported Nets” to turn onExternal Net View. Viewing the external net is very helpful inpreparation as you can use it to make sure the net data alignswith the Gerber data. If an external net point misses the pad it issupposed to be on, then the Compare will not work. It is notimportant that the point be centered on the pad though. Suchminor misalignment is not a problem.

Another thing to note when viewing the external net is if thereare net points on isolated pads. If there are, make sure that youuse the “Single Pin Nets” option when extracting your netlist.Here we can see an isolated topside net with a external net pointon it.

Cad systems are very consistent on the matter of single pin nets.So if you have a CAD source that includes single pin net info,then it will probably do so for all netlists it generates.

You can change display color of imported nets by clicking onDetails. Net points are displayed as follows.

Top side point

Bottom side point

Through hole6



The through hole X can be confusing when dealing with denseboards. After all it looks exactly the same as a top and bottomside test point at the same location. Using Settings | ViewOptions | Details you can change the default X to another shapesuch as a target. You can also adjust the size of the displayedtest points to aid visibility.

Align net to Data

The external net must line up with graphics, otherwise NetlistCompare will fail. View the external net to see if there is a problem.If it is not aligned, there are a few ways to fix this problem. All ofthem involve moving the graphic data to the external nets. Youcannot move net data. In the figure below, the net is offset tothe lower left.

Edit>Change>Origin has the best options to fix misaligned netproblems. By changing the origin all the Gerber data movesaccordingly. If there is a net point on the origin, find the pad thatlines up with that and use Edit>Change>Origin>Space Origin toselect it. In the origin should line up with one of the pads on thelower left corner.

If you made the netlist by importing CAD data into CAM350,use that imported database to find a point on the net and notethe coordinates. Use the Datum Coordinate option underEdit>Change >Origin to select that point and type in the proper coordinates.

Lacking any other option, you could open the external netlist file in a text reader (such as notepad), and use it to find the coordinates for a point to use with Edit>Change>Origin>DatumCoordinate. Check your top silk and top layer and pick a part.Now use the search function of your text reader to look for thepart name. When you find it, it will look like this (if your part was C7).

327$Net60 C7 -1 A01X+ 3325Y+ 15500X 600Y600 S1

The info above says that pin 1 of C7 is on the top tide (A01) ofthe board at .3325 x 1.55 inches. Use Edit>Change>Origin>Datum Coordinate and select pin 1 of C7. Type in the propercoordinates in mils (332.5:155). When you click OK the origin ismoved so that the selected coordinate is at the coordinates youtyped in, and the netlist should now line up with the Gerber data.

Using Streams Netlist CompareOpen the Streams Menu by selecting View>Streams RC. TheStreams List dialog box appears on screen up and to the right.Use this dialog box to add a new stream (or select an existing one).

Setup the stream check using the “Stream – DFF Stream box”that appears at the bottom of the screen once you add or selecta stream. Add a Netlist Compare check and then select theDetails Tab. If you expand the Details Property in the NetlistCompare Check you can see a number of options.

One of these options is Import External Netlist. Rather thanmanually importing the netlist, you can set a pointer to it.

When the Netlist Compare process starts, it will import thereferenced net. You should also set the Netlist format usingthe pull down menu.

There are three options under Extract CAM Netlist. “AllowCAM nets without pads” is not an option that you shouldnormally be using. Using this option will extract a net onany trace or polygon on an electrical layer. This will typicallyresult in extra nets as text and borders and other artworkare drawn with traces and polygons. If you have flashedpads there is no need. If your pads are not flashed, thenyou should run draw to flash on the data instead.

Allow Single point CAM nets should be used if your netlisthas single point nets. To check for this, look at your isolat-

ed pads on the top or bottom layer and see if there is an exter-nal net point on them. To see the external net points, you willhave to view the imported net (see above section Preparation).

Treat Net Planes as Single CAM net (no split in Pane) slightlyspeeds up the netlist extract process on older systems. Usingthis option is not recommended as if a single plane is split, itwould make an open that would be missed if this option is used. The minor gain in speed is not worth the risk.

Final section is “Run Netlist Compare”. This section has 2options only available in streams netlist compare. “Ignore ExtraExternal Nets at CAM Points” and “Ignore Missing External Netsfor CAM Nets” prevent errors of their type from being reported.This is helpful with data that ends up reporting a large number offalse errors of these types. Occasionally you will get less than

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ideal data for the compare process. For example, rotated padsfrom PADS are drawn with traces. On a round board with manyrotated SMT pads, flashing all of them would be difficult.

Manual Netlist Compare described below does not have theseoptions to ignore certain error types.

If you have text or other items thatare outside the boarder and wish tohave Netlist compare ignore then,use the “Run one-up boarder”option. Use “Utilities | Draw to Oneup Boarder” to set this up. This isanother feature not available inManual Netlist Compare

To run Netlist Compare in Streams,select the Green arrow to the left onthe checks tab.

The Results tab in Streams displays any errors. Each timeyou run it a new record is added to the results tab with a timeand date. These errors can be saved as part of the CAM350database for later review.

Manual Netlist compareUnlike running the test in Streams, the external netlist must beimported manually first. This is found under Analysis>Nets>Import IPC.

You must also extract a net. Just as with the Streams netlistextract settings, if you have well prepared data, there is no needto use any of the options. The exception is if you have single pinnet in your external net.

Netlist Compare can be run by selectingAnalysis>Nets>Compare External Nets.

Understanding the ResultsA number of different error types can be reported. These are thecommon ones to get when doing an IPC based netlist compare.More are described in help under the Netlist Compare topic.

Open: Extracted net does not connect all points as defined inthe associated external net. In the display one net will be high-lighted in grey and the other in white. Opens between layers areoften caused by missing drill data, so make sure you check thethru drill layer. Seeing an open is not difficult.

To the Left: An Open is displayed.One net highlighted in white, theother in Grey. The external net hasthese items connecting, but theGerber data has no connection. Inthis case, there is an obvious prob-lem of a missing segment in thetrace.

Short: 2 or more points in theexternal net are shorted together inthe extracted Net. Finding shortscan be difficult. The following aresome tools that are helpful in locat-ing such problems.

To the Left: Using the NavigationPane, you can select an externalnet for display. In Settings | Viewoptions, uncheck “View ExternalNets”. This hides external net view.When you select an external net inthe NAV Pane, that net is displayed(using the setting you have inOptions). Select one of your shorting Nets

To the Right: Another method ofselecting an external net.Info>Find>Net to find one of the 2external nets. Towards the end ofthe Find>Net pull down you willfind the external nets listed.

To the Left: Nav Bar has beenused to find 1 of the 2 external netsinvolved in a short. Net points forthat net are highlighted in white.We can see the upper Oval pad hasa point on the selected net. Thelower oval pad is not on that net.Thus it must be on a different net.Highlighting one of the 2 externalnets allows you to find the areawhere the 2 nets merge. In thiscase the short occurs towards thebottom of this image.

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More methods for tracking shorts are described later inthis article.

No Copper: The external net has a point, where there is no cop-per (graphic data on a net). If you see copper data there, queryit. It will not have any net data on it. To fix false no coppererrors you need to figure out why there is no net on the graphicdata. Typically such a problem results from unflashed pads ormissing drill data. Using standard netlist extract settings you willget a net on any pad that shorts to something else. So if youonly have trace data, no netlist will normally be extracted.

To the Left: A typical NoCopper error. There is anexternal net point (picturedin blue), but no graphicdata there on the top side.

Missing External Net forCAM Net: CAM350 has anet in a location where the

external netlist has none. Such errors are caused by misalignednet data. It can also be caused by using the “allow single PointCAM nets” option on netlist extract when the external netlistdoes not contain any such nets. This kind of error can be suppressed as an option in Netlist Compare in Streams.

To the Left: A MissingExternal Net for CAM Neterror is displayed. Thehighlighted pad is the padwith the CAM net. Thereare no external Net pointsvisible there. There are noTraces running into thepad, nor any drill. If thepad to the left has the

same type of error, then this is probably a case where the external net does not list single point nets.

Re-extract the net using the proper settings. If using streams,change the extra setting and run the Stream check again.

Extra External Net at Pt: A point on drawn data, with no net,is the location for an external net. Typically you will get this kindof error if your external net contains single pin nets, but thenetlist extracted did not have that option checked. You will alsoget this error if you run netlist compare without extracting anetlist. This kind of error can be suppressed as an option inNetlist Compare in Streams.

To the Left: a topside pad with no net,but with an extra external net at thatpoint. This kind of error could be suppressed in Streams, or you couldre-extract the netlist using the “SinglePoint Nets” option.

Finding ShortsFinding a short is the hardest part of netlist verification.Unfortunately CAM350 cannot show exactly where a shortappears. So you will need to search for it. When CAM350 displays a short, it highlights the short area, which is the entiretyof all the shorted nets. Looking around for it does not work, you can use this system to help out.

When a short is difficult to find, it is a good idea to limit theamount of data you are looking at. While the Netlist CompareBrowser bar is helpful, it sometimes shows too much informationon a short. So take some notes on the shorting net names andclose the browser.

Shorts come in groups. When this happens, pick the error that involves the smallest net to investigate. A net that does notshort to a power or ground plane is the best as it limits theamount of data to look at. Typically finding one short will helpexplain all other shorts as well. So even if you get 500 shorts,just try to understand one of them.

You can find the smallest net just by making a list and checkingeach net on it using the External Nets section in the Nav Pane.If you leave external net view off, only the net selected in theNAV pane is displayed. Zoom in on some of the points to viewthe Pads at those locations on the top or bottom layer. Followthe Traces and see if they lead to pads that have no net datadisplayed (and thus on a different external net).

Don’t Forget the Drill Data

Drill hits make shorts between layers. Missing Drill hits make an open between layers. Extra drill hits make shorts. So as youlook the net over, leave the drill layer on and see if there is a hitthat creates a though hole that is not mentioned in the external net.

Finding Shorts with Text Editor

When you have major shorts that you cannot figure out using thegraphic interface, you can use a text editor to look directly at theexternal netlist. Also false errors can be caused by bad external

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netlist data. So checking the external net is a good idea whennormal methods fail. Also with extremely large shorts, having atext list of all the points on the net to work from is helpful.

You can open the external netlist in a text editor. This will allowyou to find the shortest net as well. Once you have a nice shortnet, make note of the coordinates and the points on that net.

317$Net53 VIA D 280PA00X+ 12500Y+ 4000S0

327$Net53 U1 -4 M A01X+ 12250Y+ 5750X240Y 900 S2

327$Net53 U2 -4 A01X+ 12250Y+ 12250X240Y 900 S2

317$Net53 J1 -9 MD 280PA00X+ 12500Y+ 4000X550Y S0

Above is a sample net short net. It only has 4 points on it. Thisis ideal for finding a problem. Even if this net shorts to ground,all you have to do is analyze these 4 points and see how to getfrom them to the ground layer.

The 4 points above in order are

1. a through-hole (A00 is through-hole) at 1.23x.4, sizeis not listed.

2. a topside (topside is A01) pad at 1.225 x .575, a pad 24x90mils in size.

3. a topside pad at 1.225x1.225, also 24x90

4. a through-hole at 1.25x.4, a 55 mil round.

Use the info in the netlist to zoom to the coordinates one by oneand look around. Use the Coordinate Bar (View>Coordinate Bar)for zooming. If a point is a though hole, check it on each layer.Make sure the though hole as a drill hit on the drill layer. Try tofind something connecting the net to a point that is notdescribed in the netlist.

Another way to look at them is to go back to the NAV pane, and highlight the net you are looking at. Highlight the displayednet points one by one and figure out which one is on your listbefore looking around for problems.

Technical SupportWhen all else fails. The Downstream Technologies Tech supportdepartment is ready to help you understand the netlist compareprocess and any errors you may have encountered. You cancontact Technical Support for help.

• Support: [email protected]

• Support Hotline: 408-971-2241

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Customer question:I have a 14-layer design with blind vias that go down to layer 13. The via stackup detail shows the thru vias and the blindvia detail perfectly. What I would like to do is sort the particular via counts in the drill table according to thru and blind. Isthere a way to do that? It is currently ‘clumping’ both the thru hole and layer 13 drill counts together for the .010” holes.

DownStream Answer:Yes, absolutely you can create your drill table to sort out the via counts. This is done in BluePrint by sorting the drills bySTART LAYER and END LAYER.

Below is an example. I have a Blind & Buried (B&B) via design where the layer stackup shows the thru-holes and the B&B vias fine, just as yours. But note that the drill chart lumps all the thru holes and B&Bs together as .037” holes:

So, what I need to do is go to FABRICATION DRAWING MANAGER in the Fabrication tool Pallet, Open (“click”), and select the “Tool Type” icon on left side:

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You need to now check the box for START LAYER and the box for END LAYER. This is telling BluePrint that you want the drills defined(ie, sorted) by not only the defaults of diameter, plating and slot length, but also by start and end layer:

Click OK, and then YES to the dialogue that appears, and you will see your drill chart get updated to separate out the drills by start and end layer. See my updated drill chart below – note the splitting out of the .037 drills:

Note that BluePrint auto-assigned new drill symbols to each drill layer pair. If you wanted to keep the symbol for hole size .037”’ the remain the same for all vias – B&B and Thru Hole - then you would instruct BluePrint to do so also using the fabrication manager(go to DRILL TABLE icon on left of Fabrication Drawing Manager dialogue) as shown on the following page:

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Customer question:I have a blind and buried via design, and I want to be able to show the start layer and the end layer for each via type in my drill chart? Is this possible with BluePrint?

DownStream Answer:Yes, you can display the start layer and end layer in your drill chart for each via type in your design. This requires that you customize your BluePrint drill chart template. To demonstrate this, I will continue with the previous example.

Here again is the drill chart from my previous example:

The first thing I need to do is to change my drill chart back to its base template so I can modify it and re-execute it. I do this by selecting the drill chart on my drawing sheet, using my right mouse button to display the context sensitive menu, and selected“Edit Template”, as shown on the following page:

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This results in the underlying Drill Chart template being displayed:

Now I will modify my template to include a column for START LAYER and a column for END LAYER. First I delete the top row which I will add back again at the end – this is the single cell containing the text “Drill Chart” in my example - to allow me to insert cellsbetween existing cells. If I do not delete the top row, then inserting cells will only append the new cells on the left side or the right sideof the template, exactly the same function as with MS Word tables.

So I select the row I want to delete (to do this, just click in cell, right mouse button, and select “Select Cell”), and use the TABLEToolbar to “Delete Rows”:

The result should look as follows:



Now I select the cells where I want to insert a new column (to do this, click in cell, hold left mouse button, slide mouse across cells in column, and release mouse button), and use the TABLE Toolbar once again to “Insert Column” either left or right:

The result should look as follows:

I repeat this step again so I have two empty columns in my template:

Next I add the headers I want for each column. I will add “Start Layer” and “End Layer”. All I do is select the cell I want (simply click inside), and enter the text. Then I can format the text (i.e., size, location in cell, etc.) as I wish:

Next I select each empty cell, use my right mouse button for the context sensitive menu, and I select “Format Cells”:

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Select the DATA FIELDS tab in the FORMAT DRILL CHART template that appears, and using the pull down menu for the FIELD select “Drills.StartLayer” and click OK.

Repeat for the remaining empty cell, this time selecting “Driils.EndLayer”, and my new template should look as follows:

Now I want to add back my header. To do this I select the row where I want to add my new row above or below (to do this, click insidecell, hold left mouse button, drag mouse across all cells in row, and then release mouse button), and using the TABLE toolbar I select“Insert Rows Above”:

The result will look as follows:

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Next I select all the cells in the top row, and using the TABLE toolbar I select “Merge Cells “:

Now I type in the desired text (“Drill Chart”) using the same procedure described above, and the result will be as follows:

With the template selected, right mouse button to select “Execute Template” from the context sensitive menu:

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And my new drill chart will look as follows:

As an alternative format showing the start and end layers, I could have created the drill chart shown below. The key point is thatBluePrint allows the user great flexibility to create the tables, charts, and graphical details that best suits your company goals and needs.

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