A circuit board includes a base layer, an electrode layer formed on the base layer, a passivation layer formed on the electrode layer while opening a part of the electrode layer, and a surface treatment layer formed on the open surface of the electrode layer. The surface treatment layer may contain 70 to 40% of copper and 30 to 60% of nickel.

A wiring substrate includes an insulating substrate, a conductor and an Ni film. The insulating substrate has a first surface and a second surface on a side opposite the first surface, and contains AlN. The conductor is disposed on the first surface and contains Cu. The Ni film is disposed so as to extend across an upper surface and a side surface of the conductor to the first surface. Ti oxide is scattered so as to be at a plurality of points on the first surface.

A wiring board according to the present disclosure has at least a structure in which a wiring conductor layer is layered on a surface of an insulating layer containing particles of silica, and some particles of silica among the particles of silica contained in the insulating layer are partially exposed on the surface of the insulating layer. The wiring conductor layer includes a seed layer in contact with the insulating layer and a plated conductor layer formed on a surface of the seed layer. At a contact surface between the exposed portions of the particles of silica and the seed layer, an amorphous layer of silica derived from the particles of silica and an amorphous layer of metal derived from metal forming the seed layer are present.

[Object]

To provide a copper clad laminate that is capable of achieving a good volume resistivity at an electroless copper plating layer of a low dielectric resin film while suppressing a transmission loss when being applied to a flexible circuit board, and a method for producing the copper clad laminate.

[Solving Means]

A copper clad laminate of the present invention includes a low dielectric resin film having a relative permittivity of 3.5 or lower and a dissipation factor of 0.008 or lower at a frequency of 10 GHz, and an electroless copper plating layer laminated on at least one surface of the low dielectric resin film. An Ni content in the electroless copper plating layer is 0.01 to 1.2 wt %, and the electroless copper plating layer has a volume resistivity of 6.0 μΩ.Math.cm or lower.

A wiring substrate includes a substrate, a first metal and a second metal. The substrate has a first surface, a second surface opposite the first surface, and a side surface connected to the first surface and the second surface. The first metal film is disposed so as to extend from the first surface to the side surface. The second metal film is disposed so as to extend from the second surface to the first metal film disposed on the side surface.

Provided is a method for manufacturing a circuit board including: (a) preparing a mixture of a metal powder, an anti-sintering agent, and an activator; (b) immersing a dielectric substrate in the mixture; (c) forming a metal-containing layer on the surface of the dielectric substrate by heating the mixture under an inert atmosphere or under a reducing atmosphere; (d) forming a first metal layer on the metal-containing layer by electroless plating and forming a second metal layer thereon by electroplating; and (e) forming a metal pattern on the dielectric substrate, wherein the first metal layer includes Cu, Ni, Co, Au, Pd, or an alloy thereof, the second metal layer includes Cu, Ni, Fe, Co, Cr, Zn, Au, Ag, Pt, Pd, Rh, or an alloy thereof, and the method further includes performing heat treatment at least once after step (c).

Embodiments of the present disclosure relate to a printed circuit, a backlight unit, and a display device. The printed circuit on which a light source is mounted can be easily manufactured in a single form, by depositing and arranging a wiring layer on a substrate and mounting the light source on the wiring layer. Further, the printed circuit is arranged so that the wiring layer includes a plurality of bonding metal layers and a plurality of wiring metal layers, and a part of the bonding metal layer positioned between the plurality of wiring metal layers and disposed in an area overlapping a pad portion of the light source is removed. Therefore, even though the main metal layer of the wiring layer is removed during reworking, it is possible to provide the printed circuit capable of electrically connecting to the light source by the sub-metal layer of the wiring layer.

Provided is a method for manufacturing a circuit board including: (a) preparing a mixture of a metal powder, an anti-sintering agent, and an activator; (b) immersing a dielectric substrate in the mixture; (c) forming a metal-containing layer on the surface of the dielectric substrate by heating the mixture under an inert atmosphere or under a reducing atmosphere; (d) forming a first metal layer on the metal-containing layer by electroless plating and forming a second metal layer thereon by electroplating; and (e) forming a metal pattern on the dielectric substrate, wherein the first metal layer includes Cu, Ni, Co, Au, Pd, or an alloy thereof, the second metal layer includes Cu, Ni, Fe, Co, Cr, Zn, Au, Ag, Pt, Pd, Rh, or an alloy thereof, and the method further includes performing heat treatment at least once after step (c).

Embodiments of the present disclosure relate to a printed circuit, a backlight unit, and a display device. The printed circuit on which a light source is mounted can be easily manufactured in a single form, by depositing and arranging a wiring layer on a substrate and mounting the light source on the wiring layer. Further, the printed circuit is arranged so that the wiring layer includes a plurality of bonding metal layers and a plurality of wiring metal layers, and a part of the bonding metal layer positioned between the plurality of wiring metal layers and disposed in an area overlapping a pad portion of the light source is removed. Therefore, even though the main metal layer of the wiring layer is removed during reworking, it is possible to provide the printed circuit capable of electrically connecting to the light source by the sub-metal layer of the wiring layer.

There is provided a laminate in which a decrease in the release function of a release layer can be suppressed even when the laminate is heat-treated under either temperature condition of low temperature and high temperature. This laminate includes a carrier; an adhesion layer on the carrier and containing a metal M.sup.1 having a negative standard electrode potential; a release-assisting layer on a surface of the adhesion layer opposite to the carrier and containing a metal M.sup.2 (M.sup.2 is a metal other than an alkali metal and an alkaline earth metal); a release layer on a surface of the release-assisting layer opposite to the adhesion layer; and a metal layer on a surface of the release layer opposite to the release-assisting layer, and T.sub.2/T.sub.1, a ratio of a thickness of the release-assisting layer, T.sub.2, to a thickness of the adhesion layer, T.sub.1, is more than 1 and 20 or less.