吃瓜tv / Rigid-flex engineering
Rigid-Flex PCB Stackup: Region & Layer Mapping
Map copper continuity, materials and thickness by region instead of drawing one uniform stack.
Read a stackup by region, not only by total layer count
In this six-layer example, L3 and L4 continue through the flex bridge. L1, L2, L5 and L6 exist only in the rigid sections. The flex therefore has two copper layers, while the rigid section has six; the total is not eight.
| Top-to-bottom section | Rigid region A and B | Flex bridge F |
|---|---|---|
| Top protection | Solder mask / exposed pads | Coverlay / specified openings |
| L1 | Copper L1 | Absent in this flex region |
| Between L1 and L2 | Selected dielectric / bonding system | No rigid dielectric across the free flex |
| L2 | Copper L2 | Absent in this flex region |
| Between L2 and L3 | Selected dielectric / bonding system | No rigid dielectric across the free flex |
| L3 | Copper L3 | Copper L3 continues |
| Between L3 and L4 | Selected dielectric / bonding system | Flexible dielectric |
| L4 | Copper L4 | Copper L4 continues |
| Between L4 and L5 | Selected dielectric / bonding system | No rigid dielectric across the free flex |
| L5 | Copper L5 | Absent in this flex region |
| Between L5 and L6 | Selected dielectric / bonding system | No rigid dielectric across the free flex |
| L6 | Copper L6 | Absent in this flex region |
| Bottom protection | Solder mask / exposed pads | Coverlay / specified openings |
| Alternative concept | Continuing flex copper | Design consequence |
|---|---|---|
| 4 total / 2 flex | 尝2鈥揕3 | Two rigid-only copper layers; verify routing and reference planes. |
| 6 total / 2 flex | 尝3鈥揕4 | Four rigid-only layers; document which signals transition into the flex. |
| 8 total / 2 flex | 尝4鈥揕5 | Six rigid-only layers; more rigid routing does not increase flex routing capacity. |
| 8 total / 4 flex | 尝3鈥揕6 | Four conductors in the flex; bonded versus separate leaves changes the mechanical structure. |
These are layer-mapping examples, not approved stackups. For the PCB manufacturing review, add selected laminate and adhesive grades, copper weights, dielectric thicknesses, finished thickness by region and tolerances. In a conventional build, a rigid-region through-hole spans L1鈥揕6; any 尝3鈥揕4 connection within the free flex must be explicitly reviewed, especially near a bend.
Use the workbench below to check the arithmetic. It does not generate the missing bonding schedule or solve impedance through a transition.
Construction reference
Gallery references illustrate board forms. They do not certify the construction, dimensional limits or operating life of your design.
Region and bend workbench
Use consistent layer numbering and actual finished thicknesses. The calculator checks one contiguous flex span; it does not infer bonding materials or approve a manufacturing process.
Rigid-Flex Region & Bend Workbench
Continue with the next engineering decision
Reference documentation
Use the documentation for your installed software version and the selected material grades. describes its region and bending workflow. These references support design communication; they are not manufacturing approval for a particular board.
Send a complete project brief
Include the flat outline and installed view, layer/region mapping, material grades, finished thicknesses, bend duty, copper artwork, drill information and quantities. Add the BOM, placement file and acceptance requirements when assembly is included.
Mark unresolved choices rather than guessing. Download tool results if they help describe your request. Contact does not automatically receive calculator inputs.