Parent page: Designing Systems with Multiple Boards
A printed circuit board does not exist in isolation, they are often assembled and connected together with other boards, which are then housed inside a case or enclosure.
Helping to move through this stage of the design process, the software supports creating a multiple-board assembly, referred to as a Multi-board assembly.
A multi-board assembly is created by first defining a multi-board project (
*.PrjMbd). The logical structure of the system is defined in a multi-board schematic (
*.MbsDoc ), with each logical block in the multi-board schematic referring to a PCB design (
The physical multi-board design is then created by transferring the system design into an empty multi-board assembly document (
*.MbaDoc). This process will load the PCB referenced by each logical block in the multi-board schematic, into the multi-board assembly editor. This article discusses that process.
To learn more about the logical design stage of a multi-board assembly, refer to the page Capturing the Logical System Design.
The multi-board assembly is the physical representation of printed circuit boards in your system.
To create a new multi-board assembly document:
*.MbaDoc) to the multi-board project, and save it.
To add a new multi-board assembly document to the active project, you can use the following commands:
Once the assembly document has been added to the project, right-click on it to save (and name) it.
The multi-board design is transferred from the multi-board schematic to the multi-board assembly document using either of the following commands:
When you run one of these commands, the software interrogates each Module on the multi-board schematic, identifies the PCB that has been selected for each of the child PCB projects, and presents the list of modifications required to add each of those boards to the assembly, in the Engineering Change Order dialog.
When the Execute Changes button is clicked, the boards are loaded into the multi-board Assembly editor. Each board is placed in the workspace in the same orientation that it has in the PCB project. This process will take some time, as the full dataset for each PCB must be analyzed and loaded.
Multi-board assemblies created in a previous version of Altium NEXUS must be imported due to file format changes required to support the 3D engine and the improved feature set.
When an old-format
MbaDoc is opened, the Legacy document import dialog will open.
Select the Design » Import command in the multi-board Assembly editor to generate ECOs that will reload the child modules. This process may take some time, as the multi-board Assembly editor loads the entire PCB file data.
In mechanical CAD software, the concept of relating two objects in space is a fundamental part of the design process, which is a process known as mating those two objects. When two objects have been mated they can be manipulated as a single object. These mated objects can then be mated to another object, and through this process, a set of discrete objects are formed into an assembly - the very essence of mechanical design. Basically, objects are no longer related by aligning and positioning them, now they are mated.
A mate is a connection formed between two separate objects. The connection is at a user-selected point on a surface on each object. Once mated the objects will re-orient so their surface planes and their perpendicular axes are aligned.
To define a mate, perform the following steps:
The workspace view can be changed while you are defining a Mate:
To modify a Mate, double-click it in the Multiboard Assembly panel then use the Mate mode of the Properties panel to adjust its settings. Note that the Status bar indicates when the mate is in editing mode.
In line with the schematic and PCB editors, the multi-board Assembly editor includes an Active Bar located at the top of the workspace.
All editing controls are located on the Active Bar, including Measurement mode, Mating and Section View features.
|Click to enter Mating mode. The cursor will highlight potential mate sites on each surface, as the cursor is moved over the surface. Two mating sites on different objects must be nominated, these will be bought together after the second one is chosen. Press Esc to exit Mating mode. Refer to the Working with Mates section to learn more.|
|Click to enter Measurement mode. Click one object and then click a second object, the distance between their closest edges/surfaces will be displayed. Press Esc to exit Measurement mode.|
|Click to enter Section View mode. The board will be sectioned along the section plane. Click the button a second time to exit Section View.|
Collisions are flagged whenever two objects have surfaces that touch or intersect. Mated surfaces are not considered to be colliding.
The multi-board assembly editor supports rigid-flex PCBs. The multi-board assembly editor displays the PCB in the final folded state as defined in the PCB editor.
When you first transfer the boards into the Assembly editor, they are neatly placed on the same plane - you can imagine them as all being laid out next to each other on a virtual table. Within a few minutes, you will have moved this one, rotated that one, and pulled another one closer to you! And then you will have rotated the view, now you're not even sure which way is up!
Working in a 3D design space requires skill in managing your view into that space, and skill in manipulating the objects within that space. These are separate skills, controlling your view of the space, and positioning the boards within that space - let's start with the techniques you use to control your view of the space.
Once you have mastered reorienting the view, you will be ready to learn how to position and orient the boards.
You can change the view of the assembly editor to Perspective or Orthographic by toggling the View » Toggle Projection Type command (or use the P shortcut) from the main menus.
On the bottom left of the Assembly editor workspace is a red/green/blue axis marker, this is referred to as the Workspace Gizmo. When you select a board another gizmo appears; that one is called the Object Gizmo (more details below).
The Workspace Gizmo is used to change the orientation of your view into the workspace.
Each workspace axis, and its corresponding plane, is assigned a color:
As you hover the mouse over a colored Gizmo element it will become lighter, indicating that it is active. When you click on that color, the view will reorient so that you are looking down that axis into the assembly. A second click will flip the view over, looking down the same axis from the other direction. The table below gives more details about the various behaviors.
These shortcuts align the view to the Workspace Axes:
|Z key, or click Blue on the Workspace Gizmo||Re-orient the view to be looking down the Z axis, directly into the X-Y plane. Click Blue a second time to view from the opposite direction, or use the Shift+Z shortcut.|
|X key, or click Red on the Workspace Gizmo||Re-orient the view to be looking down the X axis, directly into the Y-Z plane. Click Red a second time to view from the opposite direction, or use the Shift+X shortcut.|
|Y key, or click Green on the Workspace Gizmo||Re-orient the view to be looking down the Y axis, directly into the X-Z plane. Click Green a second time to view from the opposite direction, or use the Shift+Y shortcut.|
Many of the view movements you can perform are not referenced from the workspace axes, instead, they are referenced to your current view. Your current view is referred to as the Current View Plane, it is the plane you are currently seeing looking into your monitor. For example, when you zoom in the workspace contents are bought closer to you, regardless of the current angle of the workspace axes.
These shortcuts are relative to your Current View Plane:
|Right-click_n_drag||Displays the panning hand cursor as you slide the view of the workspace around, in the current view plane.|
|Shift+Right-click_n_drag||Rotate the view of the workspace around the current X & Y view plane axes. The click and drag location defines the center of rotation. Drag Up/Down to rotate the view around the current view plane X axis, drag Left/Right to rotate the view around the current view plane Y axis.|
|Shift+Ctrl+Right-click_n_drag||Rotate the view of the workspace around the current view plane Z axis. The click and drag location defines the center of rotation. Drag left to rotate the view anti-clockwise around the current view plane Z axis, drag right to rotate clockwise.|
|Ctrl+PgDn||Zoom the view to fit all objects, including the origin marker.|
Now that you are comfortable with rotating and turning your view using the Workspace Gizmo and the keyboard and mouse shortcuts, the next step is to learn how to orient and position the boards (and other objects) within the workspace.
When you click on a board, it will highlight in the selection color (the default is green), and colored orientation lines and arcs will appear. These colored lines and arcs are collectively referred to as the Object Gizmo, which you use to move and reorient that board within the workspace.
Each board in the assembly is loaded into the workspace with the same orientation as it was designed in the PCB editor. The object will retain the same X, Y & Z axes it had when it was created in the PCB editor, regardless of that board's current orientation in the Assembly editor.
When the Object Gizmo is displayed, click and hold on a(n):
A section view is one that can be used to reveal detail within an assembly that might normally not be visible. This is achieved by defining planes where a section of the assembly is sliced or cut away. The multi-board assembly editor supports defining a section plane along each of the three axes, allowing the section definition to be in 1, 2, or 3 directions.
The Section View can be Off, On, or in Edit mode. In Edit mode, the Section Planes are displayed; each plane is indicated by a colored semi-transparent surface radiating away from the Section View origin. The Section View origin is defined by the three colored arrows, referred to as the Section View Gizmo. You can enable their display and configure their direction in the View Configuration panel in the Section View region.
To work with the Section View:
The assembly can be exported in STEP 3D or Parasolid format. To export the entire assembly in STEP 3D, select File » Export » STEP 3D from the main menus. To export the entire assembly in Parasolid format, select File » Export » Parasolid from the main menus.
You also can load additional objects into a multi-board assembly (as well as the PCBs referenced in the multi-board schematic). Additional objects (referred to as parts) can be loaded using the Design menu or by using the buttons located at the top of the Multi-board Assembly panel.
Click the appropriate button (or use the command in the Design menu) to:
- Insert another multi-board assembly into this assembly.
- Insert another PCB into this assembly.
- Insert a STEP format mechanical model into this assembly.
Note that a part is inserted into the multi-board assembly as a single entity. For example, if you insert the STEP model for a case, which consists of a top half and a bottom half, you will not be able to manipulate these halves independently. In this situation, you need to insert each half into the assembly separately.
To lock/unlock a part, select or hover over the desired part, right-click then choose the Lock Selected Part/Unlock Selected Part command to lock/unlock the part (or mated parts) at its current location in the assembly editor workspace.