A bonding pad such as for a ball grid array includes a conductive pad having a top surface and a first interface surface in contact with a signal trace of a substrate, and a plating layer having a bottom surface in direct contact with the top surface of the conductive pad. The plating layer includes one or more protrusions extending toward the signal trace in a direction generally parallel to a longitudinal axis of the signal trace. Each of the one or more protrusions includes two parallel sidewalls extending upwardly from the bottom surface of the plating layer, and a second interface surface contiguous with the bottom surface of the plating layer. The second interface surface is positioned over and in direct contact with a top surface of the signal trace. The protrusions prevent the connection to the signal trace from being compromised.

A substrate that is stretchable; wiring positioned on a first surface side of the substrate, the wiring having a meandering shape section including peaks and valleys aligned along a first direction that is one of planar directions of the first surface of the substrate; and a stretching control mechanism that controls extension and contraction of the substrate. The substrate has a component region and a wiring region adjacent to the component region. The component region includes a component-fixing region overlapping an electronic component mounted on the wiring board when viewed along the normal direction of the first surface of the substrate and a component-surrounding region positioned around the component-fixing region. The stretching control mechanism is positioned in the component-surrounding region and at least includes a stretching control part that spreads to the border between the component-surrounding region and the component-fixing region.

A method for forming a resist fine pattern uses inkjet printing for printing an ink along a path to form a resist fine pattern on a substrate having the same surface energy. The method includes an ejecting step of simultaneously discharging a photocurable resist ink and a partition-forming ink that are spaced from each other on the front side and the rear side of the path and applying the light energy to the discharged photocurable resist ink. The intensity of light is set so that, as the photocurable resist ink is semi-cured and is ejected on the substrate in a gelatinous state, the ink forms a boundary that is vertical with respect to the partition-forming ink ejected on the substrate and the spreading of the photocurable resist ink is prevented, and the photocurable resist ink is cured after both the photocurable resist ink and the partition-forming ink are completely ejected.

A circuit board having a high reflectivity includes a wiring board, a first solder resist layer, and a second solder resist layer. The wiring board includes a wiring layer on an outer side, the wiring layer including wiring and a bond pad spaced from the wiring. The first solder resist layer, with opening and groove, covers the wiring layer, the bond pad is exposed from the opening but spaced from the first solder resist layer. The second solder resist layer infills the groove and covers the first solder resist layer but does not make contact with the mounting surface of the bond pad. A method for manufacturing such circuit board is also disclosed.

A wiring board (10) includes a substrate (11) that is transparent and a wiring pattern region (20) that is disposed on the substrate (11) and that includes a plurality of wiring lines (21, 22). The wiring pattern region (20) has a sheet resistance of less than or equal to 5 Ω/sq, and each wiring line (21, 22) has a maximum width of less than or equal to 3 μm when viewed at a viewing angle of 120°.

An electronic circuit unit includes a circuit substrate having a rectangular shape and is obtained by cutting an integral substrate along a vertical cut line and a horizontal cut line to be separated; a copper foil land soldered to components; and a substrate outer edge, which is formed by cutting, of two sides orthogonal to each other. The copper foil land and the substrate outer edge are positioned in the vicinity of a corner of the circuit substrate. Solder resist is provided around the copper foil land. A plurality of substrate exposure portions without the solder resist is provided in the vicinity of the substrate outer edge.

A method for applying ink to a printed circuit board to form a pattern, the method may include flooding the printed circuit board with ink, such that the ink advances within edges of the pattern; freezing the ink before the ink exceeds the edges of the pattern; and vibrating the printed circuit board during a vibration period that at least partially overlaps at least one of the flooding and the freezing.

A circuit board having a high reflectivity includes a wiring board, a first solder resist layer, and a second solder resist layer. The wiring board includes a wiring layer on an outer side, the wiring layer including wiring and a bond pad spaced from the wiring. The first solder resist layer, with opening and groove, covers the wiring layer, the bond pad is exposed from the opening but spaced from the first solder resist layer. The second solder resist layer infills the groove and covers the first solder resist layer but does not make contact with the mounting surface of the bond pad. A method for manufacturing such circuit board is also disclosed.

A through-hole electrode substrate includes a substrate including a through-hole extending from a first aperture of a first surface to a second aperture of a second surface, an area of the second aperture being larger than that of the first aperture, the through-hole having a minimum aperture part between the first aperture and the second aperture, wherein an area of the minimum aperture part in a planer view is smallest among a plurality of areas of the through-hole in a planer view, a filler arranged within the through-hole, and at least one gas discharge member contacting the filler exposed to one of the first surface and the second surface.

A substrate that is stretchable and that at least has a wiring region; wiring at least positioned in the wiring region on a first surface side of the substrate, the wiring having a meandering shape section that includes peaks and valleys aligned along a first direction that is one of planar directions of the first surface of the substrate; and a stretching control mechanism that controls extension and contraction of the substrate. The stretching control mechanism at least includes stretching control parts that are positioned in the wiring region of the substrate and that are aligned along the first direction.