A circuit board has a dielectric core, a foil top surface, and a thin foil bottom surface with a foil backing of sufficient thickness to absorb heat from a laser drilling operation to prevent the penetration of the thin foil bottom surface during laser drilling. A sequence of steps including a laser drilling step, removing the foil backing step, electroless plating step, patterned resist step, electroplating step, resist strip step, tin plate step, and copper etch step are performed, which provide dot vias of fine linewidth and resolution.

A substrate W having a non-plateable material portion 31 and a plateable material portion 32 formed on a surface thereof is prepared, and then, a catalyst is selectively imparted to the plateable material portion 32 by performing a catalyst imparting processing on the substrate W. Thereafter, a plating layer 35 is selectively formed on the plateable material portion 32 by supplying a plating liquid M1 onto the substrate W. The plating liquid M1 contains an inhibitor which suppresses the plating layer 35 from being precipitated on the non-plateable material portion 31.

A method of manufacturing a printed circuit board includes: forming first and second resist films, respectively having first and second openings exposing a first metal layer disposed on one surface of an insulating layer; forming a second metal layer on the first metal layer, exposed through the first and second openings, to fill at least a portion of each of the first and second openings; and removing the first and second resist films. The first and second openings have different widths in a cross-section.

[Object]

To provide a copper clad laminate that is capable of achieving high adhesion between a low dielectric resin film and a copper plating layer and a good volume resistivity 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. A weighted average size of crystallites in the electroless copper plating layer is 25 to 300 nm, and an adhesion strength between the resin film and the electroless copper plating layer is 4.2 N/cm or more.

A printed circuit board includes an insulating layer, a circuit pattern embedded in the insulating layer and including a first metal layer, a second metal layer and a third metal layer disposed between the first metal layer and the second metal layer, and a connection conductor disposed on one surface of the insulating layer and connected to the circuit pattern, wherein the first metal layer is exposed through the one surface of the insulating layer.

The present invention refers to a method of preparing a high density interconnect printed circuit board (HDI PCB) including microvias filled with copper comprising the steps of: a1) providing a multi-layer substrate comprising (i) a stack assembly of an electrically conductive interlayer embedded between two insulating layers, (ii) a cover layer, and (iii) a microvia extending from the peripheral surface and ending on the conductive interlayer; b1) depositing a conductive layer; or a2) providing a multi-layer substrate comprising (i) a stack assembly of an electrically conductive interlayer embedded between two insulating layers, (ii) a microvia extending from the peripheral surface and ending on the conductive interlayer; b2) depositing a conductive layer; and c) electrodepositing a copper filling in the microvia and a first copper layer on the conductive layer which form together a planar surface and the thickness of the first copper layer is from 0.1 to 3 μm.

The present invention refers to a method of preparing a high density interconnect printed circuit board (HDI PCB) or IC substrates including through-holes and/or grate structures filled with copper, which comprises the steps of: a) providing a multi-layer substrate; b) forming a non-copper conductive layer or a copper layer on the cover layer and on an inner surface of the through-hole, respectively on an inner surface of the grate structure; c) forming a patterned masking film; d) electrodepositing copper; e) removing the masking film; and f) electrodepositing a copper filling.

A printed circuit board includes an insulating layer, a circuit pattern embedded in the insulating layer and including a first metal layer, a second metal layer and a third metal layer disposed between the first metal layer and the second metal layer, and a connection conductor disposed on one surface of the insulating layer and connected to the circuit pattern, wherein the first metal layer is exposed through the one surface of the insulating layer.

The present invention provides photosensitive compositions comprising: (a) a novel polymeric binder; (b) a polymerizable compound; (c) a photoinitiator; and (d) a photosensitizer. The photosensitive compositions having improved developing and/or stripping performance with comparable adhesion and resolution.

Light reflection from a metal mesh touch sensor is reduced or prevented by encasing the metal lines with a passivation coating and including non-reflective nanoparticles in the patterning photoresist. The photoresist is mixed with catalytic nanoparticles wherein the nanoparticles are formed to minimize light reflection. The nanoparticles may be carbon coated metallic particles, or uncoated palladium nanoparticles. Also, a standoff photoresist layer may be included between the substrate and the photoresist composition to prevent reflection from the edges of the metallic lines.