The present invention relates to an etching solution composition for selectively etching only silver, a silver alloy, or a silver compound, and to a circuit forming method using the composition. The circuit forming method according to the present invention is characterized in that, in a substrate material in which an electrically conductive seed layer and a circuit layer are formed of heterogeneous metals, only the seed layer is selectively etched to enable the implementation of fine pitches. In addition, the present invention relates to a circuit forming method and an etching solution composition, wherein only a seed layer of silver (Ag), a silver alloy, or a silver compound is selectively etched without etching a copper (Cu) plated circuit.

A method of etching an electrically conductive layer structure during manufacturing a component carrier is provided. The method includes carrying out a first etching of at least one exposed region of an electrically conductive layer structure by a first etching composition having a photo-hardenable compound to thereby form a recess in the electrically conductive layer structure, hardening the photo-hardenable compound by irradiation with photons selectively on an upper side wall portion of the recess to thereby cover the upper side wall portion with a photo-hardened compound, carrying out a second etching by a second etching composition selectively on a side wall portion and/or bottom portion of the recess being not covered with the photo-hardened compound, and subsequently removing the photo-hardened compound from the side wall portion. In addition, a component carrier is provided.

After a copper plate 14 is bonded to at least one surface of a ceramic substrate 10 via an active metal containing brazing filler metal 12 which contains silver, the unnecessary portion of the copper plat 14 and active metal containing brazing filler metal 12 is removed, and thereafter, an unnecessary portion of the copper plate 14 is removed by chemical polishing so as to cause the active metal containing brazing filler metal 12 to protrude from the side face portion of the copper plate 14, and then, a silver layer 18 adhered to the surface of the copper plate 14 by the chemical polishing is removed.

A fabrication method of a circuit includes drilling holes in a substrate, so as to form a plurality of first opening holes and second opening holes in the substrate. A cover film is attached onto the substrate, so as to cover the first opening holes and the second opening holes. A portion of the cover film covering the first opening holes is removed, so as to expose the first opening holes. The first opening holes are filled.

A ceramic substrate is provided in which an inclined protrusion is formed on boundary surface of a metal layer bonded to a ceramic base so as to increase bonding strength; and a manufacturing method therefor. The inclined protrusion may include: a tapered protrusion and a multi-stepped protrusion formed on the boundary surface of the metal layer according to an interval between the metal layer bonded to the ceramic base and a neighboring metal layer, wherein a multi-stepped protrusion having an inclination angle within a predetermined angle range with respect to the ceramic base may be formed on the boundary surface of the metal layer where stress is concentrated, such as the short edge, apex, corner, and the like, and a tapered protrusion may be formed on a remaining portion of the boundary surface of the metal layer.

A phosphoric acid-free etchant composition and a method of forming a wiring, the composition including about 40 wt % to about 60 wt % of an organic acid compound; about 6 wt % to about 12 wt % of a glycol compound; about 1 wt % to about 10 wt % of nitric acid, sulfuric acid, or hydrochloric acid; about 1 wt % to about 10 wt % of a nitrate salt compound; and water, all wt % being based on a total weight of the phosphoric acid-free etchant composition.

The present disclosure is directed to etching compositions that are useful for, e.g., selectively removing titanium nitride (TiN) from a semiconductor substrate without substantially forming a cobalt oxide hydroxide layer.

A printed circuit board according to one embodiment of the present invention comprises an insulation board and a plurality of metal electrodes disposed on the insulation board, wherein: the plurality of metal electrodes include a first electrode and a second electrode; the first electrode includes a first surface parallel to an upper surface of the insulation board, a second surface facing the first surface, a first side surface disposed between the first surface and the second surface, and a second side surface facing the first side surface; a part of the first side surface and a part of the second side surface protrude toward the outside of the first electrode in the direction parallel to the upper surface of the insulation board; the first side surface protrudes farther in an area adjacent to the first surface than in an area adjacent to the second surface; and the second side surface protrudes farther in the area adjacent to the second surface than in the area adjacent to the first surface.

The present invention relates to a method for forming a circuit using a seed layer. The method for forming a circuit using a seed layer according to the present invention, may realize a fine pitch, increase the adhesion of the circuit, and prevent the migration phenomenon.

According to one embodiment, a method for manufacturing a ceramic circuit board is disclosed. The ceramic circuit board includes a copper plate bonded to at least one surface of a ceramic substrate via a brazing material layer including Ag, Cu, and a reactive metal. The method includes: preparing a ceramic circuit board in which a copper plate is bonded on a ceramic substrate via a brazing material layer, and a portion of the brazing material layer is exposed between a pattern shape of the copper plate; a first chemical polishing process of chemically polishing the portion of the brazing material layer; and a first brazing material etching process of etching the chemically polished portion of the brazing material layer by using an etchant having a pH of 6 or less and including one type or two types selected from hydrogen peroxide and ammonium peroxodisulfate.