A circuit board for a light-emitting diode assembly according to an embodiment includes a substrate layer, dimming zones formed on one surface of the substrate layer, each of the dimming zones comprising a predetermined number of LED landing pads, and a wiring bundle disposed between the dimming zones neighboring in a row direction to extend in a column direction, the wiring bundle including wirings connected to the LED landing pads at the same level.

A solder composition contains: a flux composition containing an (A) rosin resin, a (B) activator, a (C) thixotropic agent, and a (D) solvent; and (E) solder powder, in which the (B) component contains a (B1) dicarboxylic acid having 3 to 8 carbon atoms, the (C) component contains at least one selected from the group consisting of a (C1) amide thixotropic agent having a hydroxy group in one molecule and a (C2) glycerol thixotropic agent having a hydroxy group in one molecule, and the solder composition satisfies a condition represented by Numerical Formula (F1) below provided that a total of contents of the (C1) component and the (C2) component is defined as X and a content of the (B1) component is defined as Y,

[00001]$\text{X}\text{}/\text{}2\le \text{Y}\le 5\text{X}$

A transmission line device includes a first multilayer substrate with a transmission line including laminated insulating base materials and a conductor pattern on the insulating base materials, and a second multilayer substrate defining a connected member to which the transmission line of the first multilayer substrate is connected. The conductor pattern includes a signal conductor pattern and a signal electrode pad electrically connected to the signal conductor pattern. The first multilayer substrate includes a resist film provided on a surface of a laminate of the insulating base materials, and the resist film includes an opening that is separated from an outer edge of the signal electrode pad in a surface direction of the laminate of the insulating base material and exposes the signal electrode pad.

A printed wiring board includes a lower layer including conductor layers and insulating layers, a conductor layer formed on the outermost insulating layer in the lower layer, and a solder resist layer formed on the conductor layer such that the solder resist layer is covering the conductor layer on the outermost insulating layer, and a two-dimensional code structure formed on the lower layer and including the conductor layer and a portion of the solder resist layer such that the portion of the solder resist layer has openings forming exposed portions of the conductor layer and that the openings of the solder resist layer and the exposed portions of the conductor layer form the two-dimensional code structure. The conductor layer includes a portion corresponding to the two-dimensional code structure such that the portion of the conductor layer has a residual copper rate that allows the two-dimensional code structure to be read.

A method of forming a solderable solder deposit on a contact pad, comprising the steps of providing an organic, non-conductive substrate which exposes said contact pad under an opening of a first non-conductive resist layer, depositing a conductive layer inside and outside the opening such that an activated surface results, thereby forming an activated opening, electrolytically depositing nickel or nickel alloy into the activated opening such that nickel/nickel alloy is deposited onto the activated surface, electrolytically depositing tin or tin alloy onto the nickel/nickel alloy, with the proviso that the electrolytic deposition of later steps results in an entirely filled activated opening, wherein the entirely filled activated opening is completely filled with said nickel/nickel alloy, or in the entirely filled activated opening the total volume of nickel/nickel alloy is higher than the total volume of tin and tin alloy, based on the total volume of the entirely filled activated opening.

A transmission line device includes a first multilayer substrate with a transmission line including laminated insulating base materials and a conductor pattern on the insulating base materials, and a second multilayer substrate defining a connected member to which the transmission line of the first multilayer substrate is connected. The conductor pattern includes a signal conductor pattern and a signal electrode pad electrically connected to the signal conductor pattern. The first multilayer substrate includes a resist film provided on a surface of a laminate of the insulating base materials, and the resist film includes an opening that is separated from an outer edge of the signal electrode pad in a surface direction of the laminate of the insulating base material and exposes the signal electrode pad.

One or more channels are provided in the surface of a conductive layer of a PCB substrate in an area on which a component is to be placed. The channels can help reduce or prevent shifting of the component during reflow soldering through surface tension/capillary forces of the solder paste material in the channels. Such channels also can be used, for example, by an image processing system to facilitate accurate positioning and/or alignment of the component. The image processing system can use the location of the channels alone, or in combination with other features such as a solder mask or other alignment marks, to position and/or align the component with high accuracy.

A printed wiring board includes a lower layer including conductor layers and insulating layers, a conductor layer formed on the outermost insulating layer in the lower layer, and a solder resist layer formed on the conductor layer such that the solder resist layer is covering the conductor layer on the outermost insulating layer, and a two-dimensional code structure formed on the lower layer and including the conductor layer and a portion of the solder resist layer such that the portion of the solder resist layer has openings forming exposed portions of the conductor layer and that the openings of the solder resist layer and the exposed portions of the conductor layer form the two-dimensional code structure. The conductor layer includes a portion corresponding to the two-dimensional code structure such that the portion of the conductor layer has a residual copper rate that allows the two-dimensional code structure to be read.

A method of forming a solderable solder deposit on a contact pad, comprising the steps of providing an organic, non-conductive substrate which exposes said contact pad under an opening of a first non-conductive resist layer, depositing a conductive layer inside and outside the opening such that an activated surface results, thereby forming an activated opening, electrolytically depositing nickel or nickel alloy into the activated opening such that nickel/nickel alloy is deposited onto the activated surface, electrolytically depositing tin or tin alloy onto the nickel/nickel alloy, with the proviso that the electrolytic deposition of later steps results in an entirely filled activated opening, wherein the entirely filled activated opening is completely filled with said nickel/nickel alloy, or in the entirely filled activated opening the total volume of nickel/nickel alloy is higher than the total volume of tin and tin alloy, based on the total volume of the entirely filled activated opening.

A method for manufacturing a printed circuit board, comprising in order steps (i) providing a non-conductive substrate having on a surface copper circuitry with a copper surface, wherein said surface is chemically treated by (a) oxidation and subsequent reduction reaction and/or (b) organic compound attached to said surface, a permanent, non-conductive, not fully polymerized cover layer covering at least partially said surface, (ii) thermally treating the substrate with the cover layer at temperature from 140 C. to 250 C. in atmosphere containing molecular oxygen at 100000 ppm or less, based on the total volume of the atmosphere, wherein a substrate with a permanent, non-conductive cover layer is obtained, with the provisos that (ii) is after (i) but before any metal or metal alloy is deposited onto the cover layer, and that in (ii) the cover layer is fully polymerized in one thermal treating step, if the cover layer is a solder mask.