<!DOCTYPE html
  PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<!--
Copyright (c) 2006 UGS Corp.

All Rights Reserved.

This software and related documentation are proprietary to UGS Corp.
-->
<html>
   <head>
      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
      <title>Managing detailed component parts</title>
      <script language="javaScript">
        abridged="false";
        displayConditions=new Array();
      </script>
      <link type="text/css" href="../css/main_styles.css" rel="stylesheet">
   </head>
   <body class="bodydocs" onload="top.pageLoader()" bgcolor="#FFFFFF">
      <div class="title_topic2" id="xps10_pagetitle">Managing detailed component parts</div>
      <hr noshade="true">
      <p class="para_topic">This article addresses the requirements necessary for building collections of detailed component parts to be used with PCB.xchange.</p>
      <p class="para_topic">PCB assemblies that are imported from ECAD to NX produce their own collection of parts, each representing the component footprint extruded to a height. However, you can also substitute any extruded component part with an identically-named detailed component part (see <a class="links" href="javascript:void(0)" onclick="top.openFile('pcb/xu_idf_to_nx.html');return(false);"> Importing ECAD Files into NX</a>). You can also create PC boards, PCB components and PCB assemblies from scratch in NX, and later export them to ECAD.
      </p>
      <p class="para_topic">The part files required for these work methods require careful preparation and management. Also important is an understanding of how the IDF format interprets data from NX.</p>
      <div class="title_division"> Setting up a PCB component collection in NX</div>
      <p class="para_division">You should work with collections of standard components in order to use the PCB.xchange toolbar most effectively when creating and modifying PCB assemblies that containing detailed parts.</p>
      <p class="para_division">You must manually ensure that the components created in the NX Modeling application correspond to those in the ECAD component database in terms of footprint, origin, orientation, and package name.</p>
      <div class="title_division"> Component collections</div>
      <p class="para_division">Component collections (which may be called component libraries, component databases, and so on) are an important part of the ECAD/MCAD design process. Since parts have very different representations in MCAD and ECAD, these collections contain very different data in ECAD and MCAD. Typically, the definition and purpose of a part in MCAD has very little in common with the definition and purpose of the same part in ECAD. Therefore it would not be useful to share complete part data between systems in most cases. Rather than attempting to create a common collection for both systems, PCB.xchange uses the IDF standard to reference component definitions from each CAD system's own collection (or library).</p>
      <p class="para_division">Because of the differing requirements of various ECAD and MCAD systems, the only geometric component data supported by the IDF standard are as follows:</p>
      <ul>
         <li>
            <p class="para_item">On which side of the board the component is placed</p>
         </li>
         <li>
            <p class="para_item">The X-Y distance from the board origin to the component origin (placement)</p>
         </li>
         <li>
            <p class="para_item">Component footprint</p>
         </li>
         <li>
            <p class="para_item">Component height</p>
         </li>
         <li>
            <p class="para_item">Component rotation in degrees</p>
         </li>
         <li>
            <p class="para_item">Z-distance from the board surface to the component origin (mounting offset)</p>
         </li>
      </ul>
      <table border="0">
         <tr>
            <td valign="top" align="left"><img align="left" src="../graphics/note.gif" alt="Note" title="Note"></td>
            <td valign="bottom" align="left" width="100%">
               <div class="para_note">
                  <p class="para_note_body">Note that some geometric data that may be required for ECAD or MCAD purposes is missing.</p>
               </div>
            </td>
         </tr>
      </table>
      <p class="para_division">The package name and part number provides the common reference between the ECAD and MCAD systems. Collections in each system recognize the package name and supply all additional component data required for that system.</p>
      <p class="para_division">Referencing components requires conscientious coordination of the MCAD and ECAD component collections. Each part definition in the two collections must have the same origin and &quot;as-built&quot; orientation. Otherwise, the different component location information transferred between ECAD and NX will result in different placements in the two systems. It is very risky to attempt to exchange component location coordinates without implementing a process to create, QA, and manage coordinated ECAD and MCAD collections.</p>
      <div class="title_division"> Working without coordinated libraries</div>
      <p class="para_division">In the absence of coordinated component collections, it is still possible to transfer critical component locations from MCAD to ECAD by showing the outline and pin one location. Although this requires ECAD to manually place components using these cues, it is still a much better method than transferring drawings only. Using this approach, MCAD (through the PCB.xchange Toolbar) uses a Place Region to outline each component after it is placed and creates a hole at the component's origin (often pin 1). In ECAD, the exact location of the component determined from the hole location (which should be redefined as a simple marking, or removed after the component is placed), and the orientation is implied by the Place Region outline. To determine which component is to be placed, a name can be associated with the Place Region in MCAD (e.g. reference designator or part number).</p>
      <div class="title_division"> Working with existing PCB assemblies</div>
      <p class="para_division">The IDF standard (versions 2, 3 and 4) supports 3 labels for identifying components on the PCB. They are Reference Designator, Package Name (sometimes referred to as Geometry Name or Footprint Name) and Part Number (sometimes referred to as Component Number). Typically the primary identifier of a component part in EDA is its Part Number. Its identifier in a particular board design is the Reference Designator (analogous to component name in the NX assembly). Part number is used to identify an actual component part. The part number is used as the basis for component identification in an MRP system, for example. Package names and part numbers provide the means for mapping between ECAD components and MCAD components. Both are required to provide a complete mapping between the two CAD applications.</p>
      <p class="para_division">However, ECAD component name and number don't directly map to the Unigraphics concept of part name and part number. Package name describes the physical packaging. Many component part numbers can share the same package name. For example, many electrical components use DIP16 packages. If the MCAD user was to create a unique part for every electrical component number, versus a unique part for every component package (unique geometry) the MCAD component collection could be as much as 10 times larger. Because of this issue, PCB.xchange ignores the component part number and stores it as a PCB Assembly component attribute.</p>
      <p class="para_division">The following defines the mapping of component labels between ECAD and NX.</p>
      <table bgcolor="#f7f7f7" border="0" cellpadding="2" cellspacing="4" width="544" align="center">
         <colgroup span="1">
            <col span="1" width="4801*">
            <col span="1" width="4927*">
         </colgroup>
         <tr>
            <th bgcolor="silver" colspan="1" rowspan="1">
               <p class="para_th">ECAD Label</p>
            </th>
            <th bgcolor="silver" colspan="1" rowspan="1">
               <p class="para_th">NX Terminology</p>
            </th>
         </tr>
         <tr>
            <td colspan="1" rowspan="1">
               <p class="para_td">Package Name (also called Geometry or Footprint Name)</p>
            </td>
            <td colspan="1" rowspan="1">
               <p class="para_td">Part Name</p>
            </td>
         </tr>
         <tr>
            <td colspan="1" rowspan="1">
               <p class="para_td">Part Number</p>
            </td>
            <td colspan="1" rowspan="1">
               <p class="para_td">Stored as PCB assembly component attribute</p>
            </td>
         </tr>
         <tr>
            <td colspan="1" rowspan="1">
               <p class="para_td">Reference Designator</p>
            </td>
            <td colspan="1" rowspan="1">
               <p class="para_td">NX assembly component name</p>
            </td>
         </tr>
      </table><br></body>
</html>