A circuit layer is formed by drilling vias and forming channels in a circuit layer which has catalytic particles exposed on the surfaces, channels, and vias. A first flash electroless deposition is followed by application of dry film, followed by selective laser ablation of the dry film channels and vias. A second electroless solution is applied which provides additional deposition over the first flash electroless deposition but only on the vias and trace channel areas. An electrodeposition follows, using the first deposition as a cathode. The dry film is stripped and the first electroless layer is etched, leaving only depositions in the channels and vias.

A circuit for supplying electrical power (20) at a rated direct current of between 20 kA and 100 kA to an electrolysis cell (21) comprising an upstream busbar (25), a downstream busbar (26), the two upstream (25) and downstream (26) busbars being connected to each other by means of a short-circuiting device (22) which, when closed under the action of an actuating mechanism (229), allows the two busbars to be electrically connected to each other in order to cut off the electrical power supply to the cell (21), an anode bar (213) equipped with an anode connection interface (215) for connection to the anode (211) of the cell, and a cathode connection interface (214) for connection to the cathode (212) of the cell. According to the main features of the invention, the cathode connection interface is connected to the downstream busbar by means of a flexible electrical connector (27), the circuit comprises means for absorbing the movement of the various constituent elements of the circuit due to thermal expansion and a disconnector (23) connected, on the one hand, to the upstream busbar (25) and, on the other hand, to the anode bar (213), the disconnector is opened by an actuating mechanism (239) and electrically disconnects the upstream busbar and the anode bar from each other after a non-zero time interval Tm when the short-circuiting device has been closed, the time interval Tm corresponding to the time of establishment of the rated current in the short-circuiting device (22).

The invention relates to a washing solution for a tin plating film after electroless tin plating and before water washing. The invention also relates to a method for forming a tin plating film, the method includes a step of washing step using the washing solution. The washing solution according to the present invention is an acidic aqueous solution containing an acid, a complexing agent, a stabilizer and a chloride ion. The washing solution has a chloride ion concentration of 2 wt % or more, and a tin concentration of 0.5 wt % or less. The washing solution according to the present invention has good washing property for a tin plating film surface, and allows a tin plating film to easily maintain its properties. In addition the washing solution causes little influence on a tin plating film surface even when continuously used and is excellent in temporal stability.

A plating apparatus can perform a plating process on an entire surface of a substrate uniformly. A plating apparatus 20 includes a substrate holding/rotating device 110 configured to hold and rotate a substrate 2; a discharging device 21 configured to discharge a plating liquid toward the substrate 2 held on the substrate holding/rotating device 110; and a controller 160 configured to control the substrate holding/rotating device 110 and the discharging device 21. Further, the discharging device 21 includes a first nozzle 40 having a multiple number of discharge openings 41 arranged in a radial direction of the substrate 2 or having a discharge opening 42 extended in the radial direction of the substrate 2; and a second nozzle 45 having a discharge opening 46 configured to be positioned closer to a central portion of the substrate 2 than the discharge opening of the first nozzle 40.

Horizontal methods of electroless metal plating with ionic catalysts have improved plating performance by reducing undesired foaming. The reduced foaming prevents loss of ionic catalyst from the catalyst bath and prevents scum formation which inhibits catalyst performance. The horizontal methods also inhibit ionic catalyst precipitation and improve adhesion of the ionic catalyst to the substrate. The horizontal method can be used to plate through-holes and vias of various types of substrates.

The invention relates to an aqueous alkaline pre-treatment solution for use prior to deposition of a palladium activation layer on a substrate in manufacturing an article with an integrated circuit and a method and use thereof, wherein the solution comprises: at least one hydroxycarboxylic acid or salt thereof according to the general formula (I)

[RCH.sub.2—(RCH).sub.n—COO.sup.−].sub.m M.sup.m+  (I)

wherein n is integer from 2 to 4 and m is 1 or 2, R is independently H or OH with proviso that at least one R is OH, and wherein M.sup.m+ with m: 1 is hydrogen, ammonium or alkali metal; or M.sup.m+ with m: 2 is earth alkali metal, at least one polyoxyethylene sorbitan fatty acid ester, at least one sulphonated fatty acid or a salt thereof.

Disclosed herein is a method for fabricating a wiring board in which a target substrate having via holes and/or trenches is subjected to an electroless plating process while being immersed in an electroless plating solution to fill the via holes and/or the trenches with a plating metal. The method includes the steps of: supplying the electroless plating solution to under the target substrate; diffusing an oxygen-containing gas into the electroless plating solution supplied under the target substrate; and allowing the electroless plating solution to overflow from over the target substrate.

At least one plating pen is brought into aligned relationship with at least one hole defined in a board. The pen includes a central retractable protrusion, a first shell surrounding the protrusion and defining a first annular channel therewith, and a second shell surrounding the first shell and defining a second annular channel therewith. The protrusion is lowered to block the hole and plating material is flowed down the first channel to a surface of the board and up into the second channel, to form an initial deposit on the board surface. The protrusion is raised to unblock the hole, and plating material is flowed down the first annular channel to side walls of the hole and up into the second annular channel, to deposit the material on the side walls of the hole.

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.