Synchronizing a Multi-board Assembly

Overview

In mechanical design, the standard approach to developing a product is to build the device from a number of assemblies. Altium's electronic design software supports a similar concept, where multiple PCBs can be brought together to create an assembly of PCBs, in ECAD it is called a Multi-Board Assembly. This assembly can also include the enclosure and other mechanical elements.

A multi-board assembly open in Altium's ECAD Multi-board Assembly editor.

The process of assembling the printed circuit boards into the enclosure is best performed in MCAD. However, the ECAD engineer may also need to perform electro-mechanical checks, such as component-to-component and component-to-enclosure clearances; as well as checking the access to and labeling of the human interface elements, such as indicators and displays, buttons, and connectors. To do this, the mechanical and electrical engineers need to be able to pass the assembly back and forth between MCAD and ECAD. This can be done using Altium MCAD CoDesigner. Synchronizing an assembly of boards between the MCAD and ECAD domains has numerous advantages, including the ability to quickly verify the current state of the assembled device by both the mechanical and electronic design teams. 

Workflow

The slides below show a summary of synchronizing a Multi-board assembly between MCAD and ECAD. This order of steps is not fixed, for example, the slides show a sequence where the individual PCBs have been Pulled from ECAD and assembled into the MCAD enclosure, before deciding to transfer the entire assembly to ECAD.

The numbered steps below show the same process but in a different sequence. This time the MCAD device enclosure is linked to the ECAD Multi-board assembly first, and then the PCBs are added to the device enclosure.

1. Transfer each PCB from ECAD to MCAD

Notes:

1. In ECAD, use the MCAD CoDesigner panel to Push each board from ECAD to the Workspace. 

2. In MCAD, use the Altium CoDesigner panel to Pull each board from the Workspace, saving each as an MCAD assembly. Note that board-level synchronization must be maintained independently of the synchronization of the assembly that those boards become part of.  

   • In MCAD, if the current mechanical assembly is a PCB the Altium CoDesigner panel does not display the Pull button (). To be able to pull another board into MCAD, create a new empty assembly and the Pull button will be displayed on the Altium CoDesigner panel ().

   • Additional PCBs can also be pulled and built as new MCAD assemblies at any point during the Multi-board synchronization process, as required.

2. Push the ECAD Multi-board Assembly from ECAD

Notes:

1. If board alignment is to be performed in MCAD, once the PCBs have been added into the ECAD multi-board assembly document, the ECAD assembly is ready to be Pushed to MCAD. After positioning and orienting the boards in MCAD, the location and orientation information can then be transferred back to ECAD. Learn more about Multi-board design in ECAD.

2. It is recommended that mates are defined in the MCAD device assembly, rather than in the ECAD Multi-board Assembly.

3. Create the Device Assembly in MCAD and Link the ECAD Multi-board Assembly

Notes:

1. Create a new device assembly in MCAD.

2. If required, add the enclosure to the device assembly, and save the assembly.

3. Link the MCAD device assembly to the ECAD Multi-board assembly (MBA). This is done by clicking the Link Multiboard button in the Altium CoDesigner panel, as shown in the above image. If CoDesigner is connected to the same Workspace that the Multi-board Assembly was pushed to, the ECAD MBA will be listed in the Select Project from Company Workspace dialog (). Select the MBA and click OK to establish the link.

4. Pull the Multi-board Assembly into MCAD

Notes:

1. Once the assembly-level link has been established, CoDesigner will check for differences between the MCAD assembly and the ECAD MBA. If differences are detected it will be flagged in the Altium CoDesigner panel (), click Pull to detail the differences (shown in the image above).

2. Since the PCBs are present in the ECAD assembly but not in the MCAD assembly, the PCBs need to be added to the MCAD assembly. A change highlighted in yellow indicates that CoDesigner cannot complete this change without assistance. Hover the cursor over the Change to display a tooltip, with information about how to resolve the problem, as shown in the image above. 

3. The first time the assembly is Pulled, CoDesigner will not know where to source the MCAD versions of the PCBs from. Click the Location ellipsis button () to display the Open dialog, use the dialog to define the location of each missing board. Note that you will be searching for the MCAD version of each PCB, so they must have already been pulled into MCAD and saved as an MCAD assembly. Once a board has been located, that board's Change item will no longer be highlighted in yellow, and that change can now be applied.

4. When a change is highlighted in red, it indicates that it cannot be applied and that CoDesigner cannot assist in resolving it. An example would be when a PCB in the assembly has not yet been pushed from ECAD.

5. Working with the MCAD Device Assembly

Notes:

1. Once the Changes have been applied, the MCAD Device Assembly will include the PCBs. The MCAD assembly now includes multiple items that can be synchronized between MCAD and ECAD, including each PCB as well as the entire assembly. You choose the item you would like CoDesigner to synchronize with ECAD in the dropdown at the top of the Altium CoDesigner panel, as shown in the image above. For example, if one of the PCBs needs to be edited, select it in the dropdown, perform the edits, and then Push those board changes to ECAD in the usual way ().

   • Keep an eye on which item CoDesigner is currently monitoring, the panel content reflects the synchronization status of the item selected in the dropdown.

6. Define the Enclosure in MCAD

Notes:

1. The enclosure(s) can also be synchronized between MCAD and ECAD. Once you have identified the enclosure to CoDesigner, The numbers in the image above show the steps to do this:

   1. Select the enclosure(s) in the MCAD model tree.

   2. Click the Enclosure button on the Altium CoDesigner ribbon, this tells CoDesigner that the selected object(s) are part of the enclosure.

   3. Click OK in the dialog that appears, confirming that CoDesigner has correctly identified the enclosure.

   4. Confirm that the enclosure is detailed in the Altium CoDesigner panel.

2. As well as the physical enclosure, you can also synchronize other mechanical items with ECAD, such as fasteners or cable assemblies, by identifying them as belonging to the enclosure.

7. Prepare the Device Assembly and Push to ECAD

Notes:

1. Position and mate the PCBs within the enclosure.

2. Confirm that the Multiboard assembly is selected as the active item in the dropdown at the top of the Altium CoDesigner panel.

3. Push the entire Assembly from MCAD to ECAD, as shown above. 

8. Pull the Assembly into ECAD

Notes:

1. A notification will appear in the MCAD CoDesigner panel, warning that changes have been detected (). If the warning does not appear automatically, click the Pull button to initiate a check.

2. Changes will include location updates to the PCBs, as well as the enclosure if it has been included in MCAD.

3. It is not necessary to have all of the PCBs already included in the ECAD Multi-board Assembly, CoDesigner will Add any missing PCBs during MCAD to ECAD Multi-board synchronization.

4. If MCAD design changes have been made to a child PCB in the assembly, those updates must be Pulled into the child PCB project first, and then the PCB must be updated in the ECAD Multi-board Assembly (). CoDesigner does not manage updates that are internal to ECAD.

9. The Assembly ready for the ECAD Engineer

Notes:

1. Any required ECAD tasks can now be performed, such as clearance checking and visual confirmation of the fit of the PCBs. The image above shows a section view of the Multi-board assembly in ECAD.