This article lists and describes pre-defined layers available in Fusion.
Important: Layer names have been updated to map more closely with industry terms. This change does not affect legacy files. You may see new names, legacy names, or a combination of the two as you work with the product.
The Layer Category groups layers by their functional role in the design, such as Copper, Mechanical, Silkscreen, Simulation, Connectivity, Documentation, and more. This categorization helps users quickly identify, filter, and manage the many types of layers that can exist in a complex schematic or PCB design. By organizing layers into categories, users can:
Layer categories streamline navigation and layer management, making it easier to maintain clarity and control as your design grows in complexity.
| Category | Description |
|---|---|
| Copper | These include your copper signal layers—used for routing electrical connections Pads, vias, and unrouted airwires are also in this category. |
| Mechanical | Used for board outlines, milling paths, drill holes, and test points. These layers define the board’s physical structure. |
| Silkscreen | Contain printed component labels, reference designators, and graphics visible on the board surface. |
| Mask Openings | Include solder mask and paste stencil layers that define where solder should or shouldn’t be applied. |
| Exclusions | Used to restrict component or via placement in specific areas. |
| Documentation | Layers that include supplementary information that is not part of the electrical functionality of the board but is essential for manufacturing and assembly. Hold reference drawings, measurements, and notes for manufacturing or review. |
| User Defined | Custom layers created by the user for specialized needs or workflows. |
| Legacy | Layers from older designs preserved for backward compatibility. |
| Category | Layer Id Prefix | Layer Id | Name | Usage |
|---|---|---|---|---|
| Copper | c | ct | Top | Top copper |
| c2 | Route2 | Inner copper layer | ||
| c3 | Route3 | Inner copper layer | ||
| c4 | Route4 | Inner copper layer | ||
| c5 | Route5 | Inner copper layer | ||
| c6 | Route6 | Inner copper layer | ||
| c7 | Route7 | Inner copper layer | ||
| c8 | Route8 | Inner copper layer | ||
| c9 | Route9 | Inner copper layer | ||
| c10 | Route10 | Inner copper layer | ||
| c11 | Route11 | Inner copper layer | ||
| c12 | Route12 | Inner copper layer | ||
| c13 | Route13 | Inner copper layer | ||
| c14 | Route14 | Inner copper layer | ||
| c15 | Route15 | Inner copper layer | ||
| c16 | Route16 | Inner copper layer | ||
| c17 | Route17 | Inner copper layer | ||
| c18 | Route18 | Inner copper layer | ||
| c19 | Route19 | Inner copper layer | ||
| c20 | Route20 | Inner copper layer | ||
| c21 | Route21 | Inner copper layer | ||
| c22 | Route22 | Inner copper layer | ||
| c23 | Route23 | Inner copper layer | ||
| c24 | Route24 | Inner copper layer | ||
| c25 | Route25 | Inner copper layer | ||
| c26 | Route26 | Inner copper layer | ||
| c27 | Route27 | Inner copper layer | ||
| c28 | Route28 | Inner copper layer | ||
| c29 | Route29 | Inner copper layer | ||
| c30 | Route30 | Inner copper layer | ||
| c31 | Route31 | Inner copper layer | ||
| c32 | Route32 | Inner copper layer | ||
| c33 | Route33 | Inner copper layer | ||
| c34 | Route34 | Inner copper layer | ||
| c35 | Route35 | Inner copper layer | ||
| c36 | Route36 | Inner copper layer | ||
| c37 | Route37 | Inner copper layer | ||
| c38 | Route38 | Inner copper layer | ||
| c39 | Route39 | Inner copper layer | ||
| c40 | Route40 | Inner copper layer | ||
| c41 | Route41 | Inner copper layer | ||
| c42 | Route42 | Inner copper layer | ||
| c43 | Route43 | Inner copper layer | ||
| c44 | Route44 | Inner copper layer | ||
| c45 | Route45 | Inner copper layer | ||
| c46 | Route46 | Inner copper layer | ||
| c47 | Route47 | Inner copper layer | ||
| c48 | Route48 | Inner copper layer | ||
| c49 | Route49 | Inner copper layer | ||
| c50 | Route50 | Inner copper layer | ||
| c51 | Route51 | Inner copper layer | ||
| c52 | Route52 | Inner copper layer | ||
| c53 | Route53 | Inner copper layer | ||
| c54 | Route54 | Inner copper layer | ||
| c55 | Route55 | Inner copper layer | ||
| c56 | Route56 | Inner copper layer | ||
| c57 | Route57 | Inner copper layer | ||
| c58 | Route58 | Inner copper layer | ||
| c58 | Route59 | Inner copper layer | ||
| c60 | Route60 | Inner copper layer | ||
| c61 | Route61 | Inner copper layer | ||
| c62 | Route62 | Inner copper layer | ||
| c63 | Route63 | Inner copper layer | ||
| cb | Bottom | Bottom copper | ||
| cp | Pads | Pads (through-hole) | ||
| cv | Vias | Vias (through-hole, blind, buried and uvias ) | ||
| cu | Unrouted | Airwires (rubber bands) | ||
| Mechanical | m | m1 | BoardOutline | Board outlines (circles for holes) * |
| m2 | TestTop | Testing features, top side | ||
| m3 | TestBottom | Testing features, bottom side | ||
| m4 | Drills | Conducting through-holes | ||
| m5 | Holes | Non-conducting holes | ||
| m6 | Milling | Milling | ||
| Silkscreen | s | s1 | SilkscreenTop | Silk screen, top side |
| s2 | SilkscreenBottom | Silk screen, bottom side | ||
| s3 | NamesTop | Service print, top side (component NAME) | ||
| s4 | NamesBottom | Service print, bottom side (component NAME) | ||
| s5 | ValuesTop | Component VALUE, top side | ||
| s6 | ValuesBottom | Component VALUE, bottom side | ||
| Mask Openings | o | o1 | SolderMaskTop | Solder stop mask, top side (gen. autom.) |
| o2 | SolderMaskBottom | Solder stop mask, bottom side (gen. autom.) | ||
| o3 | StencilTop | Solder cream, top side | ||
| o4 | StencilBottom | Solder cream, bottom side | ||
| o5 | FinishTop | Special finish/plating, top side | ||
| o6 | FinishBottom | Special finish/plating, bottom side | ||
| o7 | GlueTop | Glue mask, top side | ||
| o8 | GlueBottom | Glue mask, bottom side | ||
| Exclusions | e | e1 | ComponentExcludeTop | Restricted areas for components, top side |
| e2 | ComponentExcludeBottom | Restricted areas for components, bottom side | ||
| e3 | RestrictCopper | Restricted areas for copper. The Restricted Layers property on each object determines which routing layers are affected. | ||
| e4 | RestrictVias | Restricted areas for vias | ||
| Documentation | d | d1 | Measures | Measures |
| d2 | Document | Additional manufacturing notes | ||
| d3 | Reference | Reference marks for fiducials | ||
| d4 | DocumentTop | Detailed top screen print | ||
| d5 | DocumentBottom | Detailed bottom screen print | ||
| User Defined | u | u1 | Layer_100 | User Defined Layer |
| Legacy | l | l1 | Retains legacy name | Layers from legacy files |
* Holes generate circles with their diameter in this layer. They are used to place restrictions on the Autorouter.
| Category | Description |
|---|---|
| Simulation | Support analysis workflows such as signal integrity, power integrity, and behavioral modeling. |
| Connectivity | Manages the logical relationships between components. |
| Documentation | Includes layers used for annotations, reference designators, and schematic notes. |
| User Defined | Custom layers created by the user for specialized needs or workflows. |
| Legacy | Layers from older designs preserved for backward compatibility. |
| Category | Layer Id Prefix | Layer Id | Name | Usage |
|---|---|---|---|---|
| Simulation | ss | ss1 | SimResults | Simulation Results |
| ss2 | SimProbes | Simulation Probes | ||
| Connectivity | sc | sc1 | Modules | Module instances and ports |
| sc2 | Nets | Nets | ||
| sc3 | Busses | Busses | ||
| sc4 | Pins | Connection points for symbols with additional information | ||
| Documentation | sd | sd1 | Symbols | Shapes of components |
| sd2 | Names | Names of component symbols | ||
| sd3 | Values | Values/component types | ||
| sd4 | Info | Additional information/hints | ||
| sd5 | Guide | Guiding lines for symbol alignment |