THE NEW DIRECTION FOR AUTHORING PCB...

Tel: 800.535.3226 • 508-970-0670 • www.downstreamtech.comDownStream Technologies, LLC. © 2008 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.

IN THIS ISSUE:

The New Direction forAuthoring PCB DocumentationMeet BluePrint pages 1–2

Who Else is Using BluePrint?The List Continues to Grow page 2

CAM350 9.5.2 The Latest Release page 3

Compare LayersUseful tool inside CAM350 page 3

BluePrint Tech TipsFrequently Asked Questions pages 4–6

CAM350 Tech TipsIPC Netlist Compare pages 7–12

Product TrainingHelp Shape the Program page 12

EVENT CALENDARFree Technical BluePrint-PCB ProductSeminars scheduled monthly– check online for available dates.

CAM350 Webinar schedule now availableonline – watch for new topics coming inQ2, 2008.

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



THE NEW DIRECTION FORAUTHORING PCB DOCUMENTATIONPrinted Circuit Board documentation provides the fabrication manufacturerand circuit assembly shops the instructions to build and assemble circuitboards. Printed Circuit Board documentation is a necessary “evil” required toachieve timely quality production. No CAD designer wants to spend muchtime on documentation; however, it is crucial that the PCB documentation be complete and accurate to reduce iterations in the manufacturing and test process.

BluePrint-PCB is an authoring tool for PCB documentation. BluePrint is notyour typical EDA CAD tool. In fact, it is not a CAD tool. BluePrint-PCB’s solepurpose is to document a completed CAD design. As a CAD Designer, youmust step “outside the box” to understand how BluePrint works and acts. Itworks in a manner unlike your basic assumptions for CAD software. BluePrintwas written using state of the art techniques to merge Microsoft® standardpractices for command definition and user interface. You already know howto use BluePrint-PCB (seriously), because you know how to use Microsoft®Office. BluePrint integrates your CAD data into the PCB authoring flow. All ofyour CAD data objects and relationships are available in BluePrint. BluePrintimplements intelligent PCB documentation elements that automate theauthoring and maintenance of your documentation.

Before describing details of BluePrint-PCB functionality, let’s describe whatBluePrint is not. It is not a CAD design system. On the contrary, BluePrint isdesigned to only read your CAD data and is not permitted to change to youroriginal CAD design. BluePrint is not a mechanical drafting tool. BluePrintdoes provide robust drafting and dimensioning commands; however,



BluePrint-PCB is not a replacement for AutoCAD®. BluePrint isnot a PLM (Product Lifecycle Management) system. BluePrintdoes support ECO revisions and interfaces to corporate SQLdatabases using the Microsoft ODBC interface standard; however, BluePrint does not support full PLM revision management and control.

What BluePrint-PCB is, is a PCB Documentation authoringtool. Think of BluePrint as a word processor on steroids.BluePrint merges industry GUI standards from Microsoft Officetools. BluePrint implements commands that follow theMicrosoft Office standard command framework; this enablesyou to find a familiar and predictable command set that isreadily mastered. Support for fonts, table creation and editing,hyperlinking to multimedia and OLE embedding and linking areall available in BluePrint-PCB, following Microsoft GUI guide-lines. ODBC support in BluePrint allows you to access yourcorporate data stores for part definitions and BOM updates.

BluePrint further integrates your CAD design data into the PCBdocumentation, bringing all the CAD intelligence to bear ondocumentation tasks which include: Layer Stackups, DrillCharts, Parts List, Exploded Views and more. Your CAD data isused to automatically fill so-called templates that becomedetailed final images. The CAD data exists in a supportingframework within BluePrint for your PCB documentation; thisallows seamless ECO updates for your existing documentation.Just reload your revised CAD design data into an existingBluePrint-PCB documentation set, and all the appropriate dataobjects are automatically updated based on the newly revisedCAD data.

Unlike any CAD design tool or any mechanical drafting tool,BluePrint-PCB provides intelligent objects that specificallyaddress PCB documentation. You can drag and drop commonobjects for drawing sheets, which include Sheet Borders, TitleBlocks, Revision Blocks and Note Blocks. All these objectscarry intelligence for PCB documentation. For example, NoteBlocks are not mere text paragraphs. In BluePrint-PCB, NoteBlocks are intelligent outlines that support automated featuressuch as hyper linking, callout references and page splitting.

All documentation objects placed on your PCB drawing sheetscan be manipulated by predictable drag and drop and ContextMenu operations. On Fabrication Drawing Sheets, you candrag and drop Drill Patterns, Drill Charts, Layer Stackups. OnAssembly Drawing Sheets, you can drag and drop Top andBottom Assembly Views, Side and Sectional Views, ExplodedViews, and more. In general, each documentation object canbe considered a view of your CAD data. You are able to set afilter on how the CAD data is viewed in a documentationobject. For example, Top and Bottom Assembly Views are so-called PCB View objects. PCB Views support extensive filters,based on CAD data types, layers, Assembly Variants andProcess Steps. BluePrint-PCB supports robust placement features for component reference designator and attribute text.

Templates are defined in BluePrint-PCB to provide reusablepatterns that are to be filled in with your CAD data. For example,you can specify a Parts List template with your company preferences for the number of columns and the header text.The repeatable row in your Parts List template is based onyour part type definition. Your Parts List template can then besaved in an external company gallery which can be shared forreuse. When your CAD data is loaded, the Parts List templateis executed and the rows for the Parts List are automaticallyfilled in. A similar concept exists for the Layer Stackup template.You define a Layer Stackup template based on your companystandards for layer and dielectric display. Repeatable blocksare added to the Layer Stackup template. When your CADdata is loaded, the Layer Stackup template expands to displaythe layer count and layer names for your specific design.

Printed Circuit Board documentation is crucial to timely and quality production. BluePrint-PCB provides a new focus and a new tool set for PCB Documentation for the CAD Designer.BluePrint goes beyond the past solutions for PCB documenta-tion. BluePrint is an authoring tool that uses the knowledge in your completed PCB CAD design. BluePrint automates PCBdocumentation objects and processes to deliver complete andaccurate PCB documentation sets.

Recent Industry Leaders toHarnass the Power of BluePrint



CAM350® RELEASE 9.5.2– Released January 14, 2008

This new build contains 20 customer requested softwareenchancements further improving upon CAM350’s quality andreliability. In CAM350® 9.5, DownStream added a variety ofnew features and enhancements including:

• Vista® support - Release 9.5 has been updated to support installation and execution on Microsoft Vista.Updated FLEX lm Version 11.4 and Sentinel Driver 7.3.2for Vista are included as well.

• AutoImport Templates - allowing you to predefine howGerber files are viewed in CAM350. You can define layertypes, sequence, and colors. The AutoImport Templateallows you to view the design data in a consistent mannereach time you load the information. Generic Templatesare included with 9.5 for the more common CAD outputs.You can customize these further, or create templates ofyour own. Templates can also be shared between multi-ple installations of CAM350.

• PADS Layout® Import Interface - The PADS ASCII Importoption has been updated to support PADS 2007 release.PADS ASCII Import will now support the automatic cre-ation of NC Drill layers. The silkscreen in the PADS ASCIIImport now more closely matches the Gerber equivalentoutput of PADS Layout.

• ODB++ Interface - The ODB++ Import now supports theCAD Netlist as a reference Netlist in CAM350. The exter-nal or reference Netlist in CAM350 will now be output asthe CAD Netlist in ODB++ output.

• Border To Layer Command - The One-Up Border ToLayer command converts the one up border to graphicsand the Panel Border To Layer converts the panel borderto graphics. These are used in creating panel drawingsand NC milling programs.

• License Borrowing - CAM350 now supports licensingborrowing in Network installations. Mobile users can checkout a license from the server for a defined period of time,use the software while not connected to the server, andthe license is checked back in after a set period of time.

Compare LayersDid you know CAM350 has a powerful tool for comparingdata used by the board shop to the data suppliedfrom design?

Did you know that CAM350 can help you identifydesign differences from one revision to another?

Compare Layers in CAM350 helps you validate the tooled dataused to manufacture designs. By requesting the tooled datafrom the PCB shop, you can compare it to the data sent,enabling you to identify any changes that have been made.The Compare Layer option allows you to filter out smallchanges such as line width enhancements, while still identifyingmajor changes such as rerouted traces.

At the design stage, often designs may be worked on by morethan one designer. The current designer might not be aware ofthe revision history, and by using Compare Layers, changescan be identified.

Often it is desirable to know what the differences are from revto rev of a design. In the board shop, this may help save costs,as differences can sometimes be minimal.

Compare Layers in CAM350 9.5 allows all of these issues tobe easily identified.

In Release 10.0 of CAM350, Compare Layers becomes eveneasier. By leveraging the power of the Streams checklist, youwill be able to compare two designs at the same time. Resultsof all the differences will be compiled and ready for review withthe results from Streams Rule Checking. Notes can be added,and the results can also be verified in CAMVu as well as inCAM350.

http://www.downstreamtech.com/Support_CAM/Download_options.html



Can I control how the Parts List splits when generated across more than one sheet?

Short AnswerYes. The format dialog for the Parts List drawing element allowsyou to control the number of rows generated before it splits intoa new Parts List section. You can also control how many PartsList sections are displayed on a sheet.

Long AnswerYes. The format dialog for the Parts List drawing element allowsyou to control the number of rows generated before it splits intoa new Parts List section. You can also control how many PartsList sections are displayed on a sheet. The BluePrint Parts Listis a table template which is automatically populated with datafrom the imported CAD database. If the Parts List is very largeit will split at the end of the page (or when it encounters anotherdrawing element on the page) and a new page will be insertedfor each section of the Parts List created. You have control overhow many rows will be created before the table is split into 2 ormore sections. The number of sections created we refer to ascolumns. For instance, a table that is executed and results in 20rows (1 column by 20 rows) can be formatted to display as 2sections, each with 10 rows (2 columns by 10 rows) or 4 sections,each with 5 rows (4 columns by 5 rows.) You can also formatthe Parts List to generate a header on each new section displayed.

Let’s say you have a Parts List with 60 rows that creates 2 Asizeportrait sheets and you want the Parts List to display on a singlesheet. You can:

1. Format the sheet to be Bsize landscape.

2. Drag and drop the Parts List on the sheet in the upperleft corner of the sheet. It may overflow to a secondsheet.

3. Select the first section of the Parts List and select theFormat Parts List command from the context menu.

4. Under the Options tab under Auto-break change columnsto 2 and rows to 30. Select OK and the Parts List willrefresh as 2 sections on 1 Bsize sheet.

Can I create a Parts List with one row perreference designator?

Short AnswerYes. BluePrint’s Parts List Manager allows you to define thePart Type. If you define the Part Type to include ref des then theParts List will auto-generate with one row for each referencedesignator.

Long AnswerYes. BluePrint’s Parts List Manager allows you to define thePart Type. If you define the Part Type to include ref des then theParts List will auto-generate with one row for each referencedesignator. BluePrint’s PartType definition is defined asPartName by default. Follow these steps to change the PartType definition:

1. Invoke BluePrint and create a new Assembly Drawing.

2. Import the CAD file using BluePrint’s File – Import –PADS ASCII ( or ODB++) command.

3. Select and invoke the Parts List Manager in the AssemblyTools Palette. See that the data is formatted with onePartName per row and multiple RefDes per PartName.

4. On the bottom right of the Parts List Manager – MasterData dialog you will see the definition for Part Type set toPartName. Select the browse button to the right of thePart Type definition. This selects the Part Type wizard.

5. In the Part Type wizard, under field, select the RefDescheckbox so that the Part Type definition is nowPartName and RefDes (make sure PartName remainsselected as well.)

6. Select Next on all the following Part Type wizard dialogsand then Finish to complete the new Part Type definition.

7. The Parts List Manager will now refresh with the Partdata formatted as one Part Name and Ref Des per row.Select OK to close the Parts List Manager.

8. Drag and Drop a Parts List drawing element onto thedrawing sheet. It will create the Parts List table formattedwith one ref des per row.

FREQUENTLY ASKED QUESTIONS



Can I create a template that always displays theSST layer for each CAD design I import?

Short and Long AnswerYes. Once you import CAD data you can place a PCB Viewand format it to display an inner layer. If you later import newCAD data into that BluePrint document the PCB View will retainit’s format settings and apply them to the new data. BluePrintapplies inner layer format settings based on layer name and notlayer sequence. The new CAD data imported must have thesame layer name as the original CAD data that the PCB Viewtemplate was formatted with. Otherwise, BluePrint will assume itis a new layer and will not display it. This is so you can displaythe “SST” layer no matter where that layer is in the layersequence and no matter how many layers there are in the CAD database.

Can I display Component Attribute Text on aPCB View?

Short AnswerYes. The Add Component Attribute Text command in BluePrintallows you to add attribute text to a single component or aselection of components in a PCB View. Using this commandyou can choose the attribute to be displayed, the text color andwhether or not to display the attribute name with the value.Once the attribute text is displayed it can be selected, formattedand positioned.

Long AnswerYes. The Add Component Attribute Text command in BluePrintallows you to add attribute text to a single component or aselection of components in a PCB View. Using this commandyou can choose the attribute to be displayed, the text color andwhether or not to display the attribute name with the value.Once the attribute text is displayed it can be selected, formattedand positioned.

Here are the steps:

1. Drag and drop a PCB View (for instance a top-side viewfrom the Assembly drawing palette)

2. When the PCB View is selected the PCB View toolbar isvisible across the top of the application to the right of theNavigation toolbar. Select the button on the PCB ViewToolbar for Toggle Selection of PCB Components.

3. Now you can group select a number of components.You can do this in the PCB view using the cursor andcreating a selection rectangle by click-drag-release. Youcan also select a single component and the PCB ViewFormat Pane will become visible on the right side of theapplication. You can CTRL-select or SHIFT-select toselect multiple components.

4. Move the cursor over the selection in the PCB View andselect Add component Attribute Text from the contextmenu (RMB).

5. In the Add Attribute Text dialog select the attribute youwant to display from the drop-down menu. Select theAttribute Value Only or Attribute Name and Value radiobutton. Select OK. Attribute text will now be visible forall selected components.

6. Now toggle-OFF the Toggle Selection of PCBComponents on the PCB View Toolbar and toggle-ONthe Toggle Selection of Component Attributes. Selectand format the attribute text.

Can I draft, save and reuse a drawing detail in BluePrint?

Short AnswerYes. Think of BluePrint’s Detail drawing element as a container.In the container you can draw, insert graphics, insert an importedDXF or any other BluePrint drawing element. You can then savethis detail to the BluePrint element gallery for reuse.

Long AnswerYes. BluePrint’s Detail drawing element in the Common Toolspalette is a container for you to create, save and reuse a drawingdetail. The Finger Chamfer in the Fabrication Tools palette is anexample of a detail that we created and ship with the product.You can see that the Finger Chamfer detail is a combination ofgraphics and text we created using the drafting tools. A detailhas callout, link and pictorial sections you can control as well ascaption names. The way you create your own drawing detail is:

1. Drag and drop the drawing Detail on your sheet

2. Select the detail, RMB and select Edit Detail from thecontext menu

3. Use the drafting tools to create your detail drawing andadd text in the detail’s Pictorial section.



4. When you are done drawing, select Close Detail from thecontext menu or select outside the detail on the sheet toclose the detail

5. You can select format on the detail to control the visibilityof the Caption and Link or to set the Caption or Pictorialnames.

6. Select Save to Gallery from the context menu to save for reuse.

Can I modify the Drill Chart to add new columnsand attributes?

Short AnswerYes. The Drill Chart element is a BluePrint template stored in theelement gallery. Templates may be opened, modified, and re-savedas existing or new templates. You can add new columns androws to the Drill Chart template. You can also reference any drillattributes that were imported with the CAD design database. All new templates

are displayed in the Drill Chart dialog when a single click is performed on the Drill

Chart element in the Fabrication Drawing palette. To access atemplate simply drag it from the Gallery Palette onto any documentsheet, modify it, and save it back to the gallery in the same folderlocation with a new or existing name.

Long AnswerWe also have a long detailed answer we can supply to you aswell. It is very informative and instructional; if you require thislevel of detail, please email using the address below.

Can you save and share BluePrint settings?

Short and Long AnswerYes. When you change settings in BluePrint, the changes aresaved in the Windows registry so the next time you run BluePrintthe changed settings are used. You can also save the settings in a BluePrint profile which is a file with a .bpp extension. Youcan set up several profiles that you use when documenting different types of designs or you can share these profiles withother people in your group so the documentation is consistent.For instance, you may set up settings for dimensioning formatsand sheet sizes that you want everyone in your group or companyto use. The way you create a profile is by using the Tools -

Options dialog to create your settings and then using the Tools -Options - General - Export command. You can then laterimport that profile from the same dialog.

What is the difference between BluePrint’sdrawing types?

Short AnswerBluePrint supports 3 drawing types, Fabrication Drawings,Assembly Drawings and Custom Drawings. A BluePrint releasepackage can contain any number of these drawing types andeach drawing can contain multiple sheets. The FabricationDrawing type is intended for documenting fabrication drawings.The Assembly Drawing type is intended for documenting assembly,sub-assembly, and mechanical assembly drawings. The CustomDrawing type is intended for documenting anything else you maywant to document.

Long AnswerYes, there is a long answer to this question as well. The answergoes in-depth to describe the three drawing types. If you wishto learn more, please email using the address below.

With Blueprint, users drag and drop document content to quickly create complex PCB drawings

for fabrication and assembly.

mailto:[email protected]



Netlist Compare is the only way to find opens and shorts in aboard. DRC and other checks cannot find them. DRC meas-ures data to make sure they are within a user defined range. SoNetlist Compare is the only way to be sure that your Gerber datais electrically correct.

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 to make sure the boardsnet has not been altered.

PreparationDepending on the quality of the data, you many have one ormore issues that can alter the results of a netlist compare. Beingaware of these issues can minimize false errors and lead to amore accurate check.

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

FilesIPC 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 no referenced designator based. Thus they cannot becompared without using CAM350 to build parts. Building parts is very time consuming.

It is better to get an IPC netlist from the Gerber data source (theCAD system). If the CAD system does not export IPC netlists,you may be able to get around this problem by using ODB++ orone of CAM350’s direct CAD interfaces. The Direct CAD interfacesare found under File>Import>Cad Data. By importing intelligentdata info CAM350 you can then export an IPC netlist. This is acommon 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.

To learn how to read an IPC netlist, see the document:http://www.downstreamtech.com/Support_CAM/Advisories/IPCD356_Simplified.pdf

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.

Align Gerber dataIf 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>Align

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

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 |CAM Editor topic Tables > Layer Sets.

Draw 2 FlashRun 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. Then lookaround on the layer and make sure your pads are the flash color.

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. Flashingall of them may take a while. In such cases an alternative wouldbe to copy the drill layer to the top and bottom layers. This willcreate a flashed pad at each via, which is enough to extract agood netlist.

IN DEPTH LOOK AT IPC NETLIST COMPARE

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



View the external netSelect “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 there are 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 point on it.

Cad systems are typically consistent on the matter of single pinnets. So if you have a CAD source that includes single pin netinfo, 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.

Align Net to DataThe external net must line up with graphics, otherwise NetlistCompare will fail. By viewing the external net you can see if thisis a problem. If it is not aligned, there are a few ways to fix thisproblem. All of them involve moving the graphic data to theexternal nets. You cannot move net data. In the figure below,the net is offset to the 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.

Top Side Point

Bottom Side Point

Through Hole



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 filein a text reader (such as notepad), and use it to find the coordi-nates 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 600Y 600 S1

The info above says that pin 1 of C7 is on the top tide of theboard at .3325 x 1.55 inches. Use Edit>Change>Origin>DatumCoordinate and select pin 1 of C7. Type in the proper coordi-nates 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. TheSteams List dialog box appears on screen up and to the right.Use this dialog box to add a new stream (or select an existingone).

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. Whenthe Netlist Compare process starts, it will import the referencednet. You should also set the Netlist format using the pull downmenu.

There are three options under Extract CAM Netlist. “Allow CAMnets without pads” is not an option that you should normally beusing. Using this option will extract a net on any trace or poly-gon on an electrical layer. This will typically result in extra nets astext and borders and other artwork are drawn with traces andpolygons. If you have flashed pads there is no need. If yourpads are not flashed, then you should run draw to flash on thedata instead.

Allow Single point CAM nets should be used if your netlist hassingle point nets. To check for this, look at your isolated padson the top or bottom layer and see if there is an external netpoint on them. To see the external net points, you will have toview 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 thanideal 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 that are outside the boarder andwish to have Netlist compare ignore then, use the “Run one-upboarder” option. Use “Utilities | Draw to One up Boarder” to setthis up. This is another feature not available in Manual NetlistCompare

To run Netlist Compare in Streams, select the Green arrow to theleft on the checks tab.

The Results tab in Streams displays any errors. Each time you 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 underAnalysis>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 you have single pinnets 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.

Shown Above: An Open is displayed. One net highlighted inwhite, the other in Grey. The external net as these items con-necting, but the Gerber data has no connection. In this case,there is an obvious problem of a missing segment in the trace.

Short: 2 or more points in the external net are shorted togetherin the extracted Net. Finding shorts can be difficult. Still takinga look at the data may allow you to find the problem.

Shown Above: A good method of reducing the search area is touse Info>Find>Net to find one of the 2 external nets. Towardsthe end of the Find>Net pull down you will find the external netslisted.

Shown Above: We have a section of a shorted net displayed.Info>Find>Net has been used to find 1 of the 2 external nets.Net points for that net are highlighted in white (just as the net is).We can see the upper Oval pad has a point on the “found” net.The lower oval pad is not on that net. Thus it must be on a different net. Highlighting one of the 2 external nets allows youso find the area where the 2 nets merge. In this case the shortoccurs towards the bottom of this image.

More methods for tracking shorts are described later in this article.

No Copper: The external net has a point, where there is nocopper (graphic data on a net). If you see copper data there,query it. 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.



Shown Above: A typical No Copper error. There is an externalnet point (pictured in blue), but no graphic data there on the topside.

Missing External Net for CAM Net: CAM350 has a net in alocation where the external netlist has none. Such errors arecaused by misaligned net data. It can also be caused by usingthe “allow single Point CAM nets” option on netlist extract whenthe external netlist does not contain any such nets. This kind of error can be suppressed as an option in Netlist Compare in Streams.

Shown Above: A Missing External Net for CAM Net error is displayed. The highlighted pad is the pad with the CAM net.There are no external Net points visible there. There are noTraces running into the pad, nor any drill. If the pad to the lefthas the same type of error, then this is probably a case wherethe 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.

Shown Above: a topside pad with no net, but with an extraexternal net at that point. This kind of error could be suppressedin Streams, or you could re-extract the netlist using the “SinglePoint Nets” option.

Tracking Down ShortsTracking down shorts 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. When looking around for it does notwork, you can use this system to help out.

Typically, shorts come in groups. When this happens, pick theerror that involves the shorted possible net to investigate. A netthat does not short to a power or ground plane is the best.

You will need to open the external netlist in a text editor. Thiswill allow you to find the shortest. Once you have a nice shortnet, make note of the coordinates and the points on that net.

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

327$Net53 U1 -4M A01X+ 12250Y+ 5750X 240Y 900 S2

327$Net53 U2 -4 A01X+ 12250Y+ 12250X 240Y 900 S2

317$Net53 J1 -9 MD 280PA00X+ 12500Y+ 4000X 550Y 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, size is not listed.

2. a topside (topside is A01) pad at 1.225 x .575, a pad 24x90 mils 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.

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

Did you remember DownStream offers an area online to shareyour custom macros and CAM350 scripts? The most recent oneadded to the site was Layer Title Block. Visit Macro Exchangefor more information -

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

February 7 - Fremont California - CAM350 TrainingThis course is focused entirely on Design Verification usingCAM350. We will cover the process and procedure for usingCAM350 to verify data prior to release to Fabrication. Specificoutline include: Output of data from various CAD systems,Gerber identification and import, Streams Rule Checking andDFM, Netlist Comparison, Design Rule Checking, and finally putting together the completed design package for Fabrication.

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

Want to visit Lake Tahoe? DownStream's training headquarters are located in Lake TahoeNevada. Upon request, we host training at this facility. Thiswould be a great escape from the day-to-day grind to focus onyour software investment. You could even bring the family andspend an extended weekend. We can cater the focus of thesecourses to fulfill your exact product needs and questions. BothCAM350 and BluePrint training are offered in Lake Tahoe.

Contact DownStream to request more information today –[email protected]

Help shape DownStream’s Training Program In order to help DownStream better meet your training needsand requirements, please visit us online and complete our shortsurvey. We want you to voice your opinion on training locations(regional, Lake Tahoe, your office), training costs, technical andtopic focus, course size, course outline, course materials, coursestructure and layout, etc…

We want our courses to better meet your needs, and the morewe understand your requirements the more comprehensive wecan design our training program. Thank you for your continuedsupport and input.

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