A stretchable circuit substrate includes: a base material being stretchable; a wiring which is on a first surface side of the base material, and which includes a bellows-like member including a plurality of ridges and recesses arranged in a first direction which is one of in-plane directions in the first surface of the base material; and an adjustment layer which includes the bellows-like member and is on the first surface side of the base material so as to at least overlap, in a plan view, a wiring region in which the wiring is positioned; wherein the adjustment layer has a Young's modulus smaller than a Young's modulus of the wiring.

This wiring board comprises: a substrate having a first elastic modulus and including a first surface and a second surface positioned on the opposite side of the first surface; wiring positioned on the first surface side of the substrate and connected to an electrode of an electronic component mounted on the wiring board; and a reinforcing member having a second elastic modulus greater than the first elastic modulus and at least including a first reinforcing part that is positioned on the first surface side of the substrate or on the second surface side of the substrate and that at least partially overlaps the electronic component mounted on the wiring board when viewed along the normal direction of the first surface of the substrate. The wiring includes a section that does not overlap the reinforcing member when viewed along the normal direction of the first surface and that has a meandering shape section including pluralities of peaks and valleys aligned along an planar direction of the first surface of the substrate.

A method for producing an electronic assembly includes providing a printed circuit board with a first face, a second face facing away from the first face, and a first component arranged on the first face. The method further includes arranging the circuit board such that the second face lies on a reference surface, and applying a sealing material which is substantially not flowable prior to being cured onto the first face. The sealing material surrounds a sub-region of the first face of the circuit board. The method further includes arranging a second component at least partly on the reference surface such that the second component is pressed into the sealing material, electrically connecting the second component to the circuit board via an electric connection line, and applying a covering material onto the circuit board first face sub-region surrounded by the sealing material and onto the first component.

Provided is an electronic circuit substrate in which any excess space is not necessary around an electronic component, and position deviation at a time of mounting the electronic component can be prevented with high precision. An electronic circuit substrate 100 includes a printed wiring board 10 and an electronic component 20. The printed wiring board 10 has a first land 11 and a second land 12. The electronic component 20 has a first bond portion 24 which is bonded to the first land 11 with solder, and a second bond portion 25 which is bonded to the second land 12 with solder. The bond area of the first land 11 and the first bond portion 24 is larger than the bond area of the second land 12 and the second bond portion 25. In one direction D1, the position of an outer side edge 24b of the first bond portion 24 is set so as to match the position of the outer side edge 11b of the first land 11.

A circuit board includes: a metal core base material including a first main surface, a second main surface on an opposite side of the first main surface, a side surface, and a projection that projects from the side surface; an outer cover including a first insulation layer that covers the first main surface, a second insulation layer that covers the second main surface, and a third insulation layer that covers the side surface; a first wiring layer provided in the first main surface with the first insulation layer interposed between the first wiring layer and the first main surface; a second wiring layer provided in the second main surface with the second insulation layer interposed between the second wiring layer and the second main surface; and a sealing portion that is made of an insulation material embedded in the outer cover and covers an end surface of the projection.

In one example, a flexible circuit board includes a signal line disposed between a first ground and a second ground; a dielectric disposed between the first ground and the signal line and between the second ground and the signal line; and a flatness improvement portion disposed on an upper portion of the second ground.

One or more channels are provided in the surface of a conductive layer of a PCB substrate in an area on which a component is to be placed. The channels can help reduce or prevent shifting of the component during reflow soldering through surface tension/capillary forces of the solder paste material in the channels. Such channels also can be used, for example, by an image processing system to facilitate accurate positioning and/or alignment of the component. The image processing system can use the location of the channels alone, or in combination with other features such as a solder mask or other alignment marks, to position and/or align the component with high accuracy.

A flexible printed circuit board includes: a base material including a principal face; at least one first wiring pattern disposed on the principal face of the base material and extending along a first direction; and a first member and a second member disposed on the first wiring pattern so as to be spaced from each other in the first direction. In the first direction, the first member and the second member divide the flexible printed circuit board into: a first region located opposite to the second member with respect to the first member in the first direction, a second region located between the first member and the second member, a third region located opposite to the first member with respect to the second member, a fourth region in which the first member is disposed, and a fifth region in which the second member is disposed.

A wiring board includes, a base plate that has a first surface, a second surface opposite to the first surface, and a side surface coupled to the first surface and the second surface, a conductor provided on the side surface, and a protrusion provided over the side surface. The protrusion partitions the conductor into a first portion on the side surface that extends to the first surface and a second portion on the side surface that extends to the second surface. The protrusion has a solder wettability lower than the conductor and protrudes from the conductor.

A printed wiring board includes a resin insulating layer, a conductor circuit formed on the resin insulating layer, an outermost resin layer formed on the resin insulating layer such that the outermost resin layer covers the conductor circuit, and multiple metal posts formed on the conductor circuit such that the metal posts have end portions exposed from the outermost resin layer and that the metal posts form a pad group. The outermost resin layer has a dam structure forming part of the outermost resin layer such that the dam structure is formed to surround at least part of the pad group including the metal posts.