A circuit board according to an embodiments includes an insulating portion comprising a plurality of insulating layers, wherein the insulating portion includes: a first insulating portion; a second insulating portion disposed on the first insulating portion and having a coefficient of thermal expansion corresponding to the first insulating portion; and a third insulating portion disposed under the first insulating portion and having a coefficient of thermal expansion corresponding to the first insulating portion; wherein the first insulating portion includes a prepreg including glass fibers, and wherein the second and third insulating portions include a resin coated copper (RCC) with a coefficient of thermal expansion in the range of 10 to 65 (10.sup.−6 m/m.Math.k).

A multilayer resin substrate includes resin layers that are laminated, a first copper foil on the resin layers and including first and second main surfaces having first and second surface roughnesses, respectively, and a second copper foil on the resin layers and including third and fourth main surfaces having third and fourth surface roughnesses, respectively. A distance between the first main surface and the second copper foil is shorter than a distance between the second main surface and the second copper foil. When the first, second, third, and fourth surface roughnesses are denoted as SR1, SR2, SR3, and SR4 respectively, a relationship SR1<SR3≤SR4<SR2 is satisfied.

A printed circuit board and method of manufacturing a printed circuit board are disclosed. In one example, the method comprises embedding an electronic component in a laminate, and protecting the electronic component against electrostatic discharge during at least part of the manufacturing process by an electrically conductive electrostatic discharge protection structure integrated in the laminate and connected to the electronic component.

The laminate includes a multilayer polyimide film having thermoplastic polyimide layers on both sides of a core layer which is a non-thermoplastic polyimide film and a surface layer contacting the thermoplastic polyimide layer on one surface-side of the multilayer polyimide film. The surface layer may be an inorganic layer having a thickness of 1 to 200 nm or a resin layer having a thickness of 0.1 to 5 μm. A single-sided metal-clad laminate is formed by laminating a metal layer on the thermoplastic resin layer on the surface layer non-formed surface of the laminate.

A method of making a printed circuit board structure including a closed cavity is provided. The method can include the steps of forming a cavity in a core structure of a core layer, laminating each of a top surface and a bottom surface of the core structure with an adhesive layer and a metal layer to prepare a laminate structure and cover the cavity to define a closed cavity. The method also includes forming vias through the laminate structure, and patterning the metal layers in the laminate structure.

Methods, systems, devices, and products for constructing a downhole tool electronics module. Methods may include creating a circuit board by metallizing at least part of a first surface on a first side of a substrate to define at least one metallized area on the first surface, wherein the substrate comprises a ceramic material and includes: the first side, including at least (i) the first surface, and (ii) an elevated surface elevated from the first surface, and a second side opposite the first side; flattening at least partially the elevated surface to a predefined first flatness to create a mounting portion by removing material from the elevated surface; attaching an electronics component to the first surface; and mounting the circuit board on an electronics carrier by adhering at least part of the mounting portion to a mounting surface on the electronics carrier. Flattening at least partially the elevated surface to the predefined first flatness may be carried out by removing the material by areal grinding.

A method for manufacturing a wiring board includes preparing a core substrate having first and second surfaces, forming a first build-up structure including interlayer insulating layers and conductor layers on the first surface of the substrate, and forming a second build-up structure including interlayer insulating layers and one or more conductor layers on the second surface of the substrate. The forming of the first structure includes laminating the insulating layers and metal layers on first surface side of the substrate and forming the conductor layers from all of the metal layers on the first surface side, and the forming of the second structure includes laminating the insulating layers and metal layers on second surface side of the substrate, forming the one or more conductor layers from one or more of the metal layers on the second surface side, and entirely removing the other metal layers on the second surface side.

A resin multilayer substrate includes a multilayer body including resin layers and adhesive layers that are laminated, via conductors in the resin layers, and bonding portions in the adhesive layers. The bonding portion is connected to the via conductor. One of the resin layer and the adhesive layer is a gas high-permeable layer having a higher gas permeability than the other one. The bonding portion includes an organic substance, or has a higher void content rate per unit plane sectional area than the via conductor. At least a portion of each of the bonding portions contacts the gas high-permeable layers.

A flexible laminated sheet manufacturing method includes thermocompression-bonding an insulation film formed of a liquid crystal polymer onto a metal foil between endless belts to form a flexible laminated sheet. The thermocompression bonding includes heating the flexible laminated sheet so that the maximum temperature of the sheet is in the range from a temperature that is 45° C. lower than the melting point of the liquid crystal polymer to a temperature that is 5° C. lower than the melting point. The thermocompression bonding also includes slowly cooling the flexible laminated sheet so that an exit temperature, which is a temperature of the sheet when transferred out of the endless belts, is in the range from a temperature that is 235° C. lower than the melting point of the liquid crystal polymer to a temperature that is 100° C. lower than the melting point.

A wiring substrate for improving connection reliability with an electronic component, a component embedded substrate that incorporates an embedded component into the wiring substrate, and a package structure including an electronic component mounted on the wiring substrate or the component embedded substrate. The wiring substrate includes a metal plate, and a wiring layer including a plurality of insulating layers and a conductive layer arranged on the plurality of insulating layers arranged on at least one principal surface of the metal plate. The plurality of insulating layers includes a first insulating layer to contact the principal surface of the metal plate and has a larger thermal expansion rate in the planar direction than the metal plate and a second insulating layer which is laminated on the first insulating layer to contact the first insulating layer and has smaller thermal expansion rate in the planar direction than the metal plate.