A circuit board according to an embodiment includes a first insulating layer; a second insulating layer disposed on the first insulating layer; a first electrode part disposed on the second insulating layer; a second electrode part disposed on the first electrode part; a second insulating layer disposed on the second electrode part; and a fourth insulating layer disposed on the third insulating layer, wherein an upper surface of the first insulating layer includes a plurality of first convex parts, wherein a lower surface of the fourth insulating layer includes a plurality of second convex parts, and wherein at least one of distances between adjacent first convex parts among the plurality of first convex parts includes a region different from at least one of distances between adjacent second convex parts among the plurality of second convex parts.

An integrated optically functional multilayer structure including a flexible, substrate film arranged with a circuit design including electrical conductors on a first side of the substrate film; at least one light source provided upon the first side of the substrate film and connected to the circuit design the at least one light source internally illuminates at least a portion of the structure for external perception; and an optically transmissive layer-produced upon the first side of the substrate film and the at least one light source said optically transmissive layer at least partially covering the substrate film and embedding the at least one light source; wherein the substrate film defines holes therethrough and upon one or more of them the optically transmissive layer defines an outcoupling surface, configured to redirect and reflect, incident light emitted by light sources of the at least one light source.

A method is for making an electronic device that includes a multilayer circuit board having a non-planar three-dimensional shape defining a membrane switch recess therein. The multilayer circuit board may include at least one liquid crystal polymer (LCP) layer, and at least one electrically conductive pattern layer thereon defining at least one membrane switch electrode adjacent the membrane switch recess to define a membrane switch. The electronic device may further include a compressible dielectric material filling the membrane switch recess. The electronic device may also include at least one spring member within the membrane switch recess.

A circuit board and a method of fabricating the same are provided. The circuit board has a connecting part and a bending part, and this circuit board includes a plurality of flexible circuit substrates electrically connected to each other and an elastic material. The flexible circuit substrate with a corrugated region is located on the bending part and is disposed on another flexible circuit substrate. A spacing is formed between those two flexible circuit substrates, while this spacing is located at the bending part. The elastic material is located at one of the flexible circuit substrates and located inside the spacing, and the elastic material is located inside a trough of the corrugated region.

A circuit board and a method of fabricating the same are provided. The circuit board has a connecting part and a bending part, and this circuit board includes a plurality of flexible circuit substrates electrically connected to each other and an elastic material. The flexible circuit substrate with a corrugated region is located on the bending part and is disposed on another flexible circuit substrate. A spacing is formed between those two flexible circuit substrates, while this spacing is located at the bending part. The elastic material is located at one of the flexible circuit substrates and located inside the spacing, and the elastic material is located inside a trough of the corrugated region.