Semi-flex printed circuit boards are manufactured using a process which mills a section of a rigid FR4 board down to a thickness of 0.20mm +/- 0.10mm. This enables the board to be bent to fit inside a casing such as that used in automotive and data communications applications.

With simple depth-milling a standard printed circuit board can be prepared for flexible installations. So called "semi-flexible" printed circuits are offering a cost-efficient solution. They save connectors and increase reliability while decreasing size of the application and time needed for assembly.

Semi-flexible PCBs are the perfect solution if you have flex-to-install requirements only and there is no dynamic bending during operation.

Often layout designers are reluctant to upgrade from a standard PCB with connectors to a notoriously expensive rigid-flexible printed circuit. The advantages are immense, but so are the costs and the layout requirements compared to standard PCBs. Many times this "jump" from standard technology to a high-tech segment is not necessary.

Many printed circuits do not require dynamic bending capabilities in operation but only need to be fit into the housing neatly. This is called a "flex-to-install" requirement and here semi-flex offers a really cost-saving alternative technology.

Production of a semi-flexible PCB is identical with the manufacturing process of standard printed circuits. Semi-flexilbe boards can be produced as single-layer, double-layer or multilayer PCBs. With the exemption of a special solder mask that sustains bending, the materials are also identical to standard printed circuits.

The only difference happens at the end of the production process when dedicated bending areas are milled down by z-axis routing. The remaining material can be bend and is thin enough to only carry the copper traces and little base material.

To optimize transportation-safety and assembly, semi-flexible PCBs should always be produced in panels. You can easily seperate the prints from the panel after assembly and install the boards.

— Cost
Compared with polyimide flex rigid boards, semi-flex is a cheaper alternative as it is only made from FR4. It avoids the need for traditional connective materials such as cables and binders, which can be expensive and increase the cost of assembly.

— Reliability
Using cables or other connectors causes frequent failure but semi-flex provides a reliable alternative. Components can be mounted before the board is bent into its final position, avoiding many issues including entanglement and welding difficulties.

— Time-saving
Semi-flex PCBs save time in the design phase as well as during manufacture and assembly.

— Easy to fit
Semi-flex printed circuit boards can fit more easily into the final housing or box.