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 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 manufacturing method of copper foil and circuit board assembly for high frequency transmission are provided. Firstly, a raw copper foil having a predetermined surface is produced by an electrolyzing process. Subsequently, a roughened layer including a plurality of copper particles is formed on the predetermined surface by an arsenic-free electrolytic roughening treatment and an arsenic-free electrolytic surface protection treatment. Thereafter, a surface treatment layer is formed on the roughened layer, and the roughened layer is made of a material which includes at least one kind of non-copper metal elements and the concentration of the non-copper metal elements is smaller than 400 ppm. By controlling the concentration of the non-copper elements, the resistance of the copper foil can be reduced.

A film 1 for a metal layer laminate board is used for lamination of a metal layer 5. The film 1 for a metal layer laminate board includes a porous resin layer 2 and a skin layer 3 in order in a thickness direction. The porous resin layer 2 has an average pore size W in the entire thickness direction of 7.0 μm or less. The porous resin layer 2 includes a first region 11 to a fifth region 15 disposed in order in a direction away from the skin layer 3 when the porous resin layer 3 is equally divided into five in the thickness direction. A ratio (A1/A5) of an average pore size A1 of the first region 11 to an average pore size A5 of the fifth region 15 is 0.45 or more and 1 or less.

The wiring board according to the present disclosure includes: a first insulating layer including insulating particles; a plurality of first conductors located on the first insulating layer at an interval of a first distance from each other; a second conductor located on the first insulating layer at an interval of a second distance from the first conductor; and a second insulating layer located on the first insulating layer to cover the first conductor and the second conductors and including the insulating particles. When a boundary portion between the first insulating layer and the second insulating layer is viewed in cross-section in the thickness direction, the ratio of a first area occupied by the insulating particles in a first boundary portion including the first distance is higher than the ratio of a second area occupied by the insulating particles in a second boundary portion including the second distance.

In order to maintain high haze value of thermoplastic liquid crystalline polymer while to improve total light transmittance, provided is a thermoplastic liquid crystalline polymer molded body having a haze value of 99% or higher, and a thermal expansion coefficient of 16 to 27 ppm/° C., and satisfying a correlation between a light absorption coefficient (ε) and a thickness (x) as: ε≤0.21x.sup.−0.55.

A method of processing liquid crystal polymer film is provided. The method includes the following steps. A metal substrate is provided. A liquid crystal polymer film is provided. The liquid crystal polymer film and the metal substrate are laminated to form a composite layer. The composite layer is heated at a first temperature and a processed liquid crystal polymer film is obtained through the separation of the heated liquid crystal polymer film from the substrate. A processing device of liquid crystal polymer film is further provided, including a lamination member, a transport member, a heating member, and a separation member.

A method for manufacturing a metal clad laminated plate includes hot pressing a laminated body by a double belt press method. The laminated body includes an insulating film containing the liquid crystal polymer and the metal foil lying on the insulating film. In hot pressing the laminated body, a highest heating temperature is higher than or equal to a temperature lower than a melting point of the insulating film by 5° C. and lower than or equal to a temperature higher than the melting point by 20° C. The highest heating temperature is maintained for longer than or equal to 20 seconds and shorter than or equal to 120 seconds.

A circuit board includes, in order in a stacking direction, a first insulating layer, a second insulating layer in contact with the first insulating layer, and a conductor layer, the first insulating layer includes a liquid crystal polymer as a main component, and the second insulating layer includes a fluoropolymer including at least one of polytetrafluoroethylene and a perfluoroalkoxy alkane and includes a polyimide resin with an imidization rate of about 90% or more, the polyimide resin being present in an amount of about 0.5 parts or more by weight and less than about 20 parts by weight per 100 parts by weight of the fluoropolymer.

An ESD protection device includes a first terminal and a second terminal defining a first balanced port, a third terminal and a fourth terminal defining a second balanced port, and a ground terminal. A first coil and a third coil are provided between the first terminal and the third terminal to cancel an inductance component of a first ESD protection circuit. A second coil and a fourth coil are provided between the second terminal and the fourth terminal to cancel an inductance component of a second ESD protection circuit.

A bulk substrate for stretchable electronics. The bulk substrate is manufactured with a process that forms a soft-elastic region of the bulk substrate. The soft-elastic region includes a strain capacity of greater than or equal to 25% and a first Young's modulus below 10% of a maximum local modulus of the bulk substrate. The process also forms a stiff-elastic region of the bulk substrate. The stiff-elastic region includes a strain capacity of less than or equal to 5% and a second Young's modulus greater than 10% of the maximum local modulus of the bulk substrate.