Abstract:
A printed circuit board (PCB) includes a base substrate (232), an electrical wiring (233,2331), a dummy pad (234) and a thermally conductive adhesion member (236). The base substrate includes a light-emitting diode (LED) mounted on a first surface of the base substrate. The electrical wiring is electrically connected to the LED (231). The dummy pad is formed on the first surface to be connected to the electrical wiring. The thermally conductive adhesion member is attached to a second surface of the base substrate. Therefore, superior heat radiation may be obtained, thereby reducing or preventing damage to the LED and the LCD device using the LED by radiating the heat from the LED used as a light source.
Abstract:
[PROBLEMS] Conventional Sn-Zn, lead-free solder pastes have disadvantages in that they are liable to form coarse Zn crystals of tens of micrometers in size and the formation of such coarse crystals can hardly be inhibited and that it is difficult to enhance the joint strength without changing the soldering temperature. Although an alloy improved in the strength by the addition of a slight amount of a group 1B element was developed, the alloy is disadvantageous in that it cannot reflow according to the same temperature profile as that of Sn-Pb paste because of its enhanced melting temperature. [MEANS FOR SOLVING PROBLEMS] A solder paste prepared by incorporating a powder of an Sn-Zn, lead-free solder paste with both an ethanol solution containing nanoparticles of 5 to 300nm in diameter containing at least one member selected from among Ag, Au and Cu and a flux forms, in soldering, an alloy consisting of Ag, Au and/or Cu and Zn and thereby forms fine clusters in the liquid phase, thus giving a fine solder texture after melting.
Abstract:
An electroless plating solution comprises an aqueous solution containing 0.025 to 0.25 mol/L of a basic compound, 0.03 to 0.15 mol/L of a reducing agent, 0.02 to 0.06 mol/L of copper ion and 0.05 to 0.3 mol/L of tartaric acid or a salt thereof. Another electroless plating solution comprises an aqueous solution containing a basic compound, a reducing agent, copper ion, tartaric acid or a salt thereof and at least one metal ion species selected from the group consisting of nickel ion, cobalt ion and iron ion. The electroless plating solution is used in an electroless plating process performing electroless copper plating, more specifically in a process for manufacturing a printed circuit board which comprises immersing a resin insulating substrate board in the electroless plating solution. The electroless plated film has a stress of 0 to +10 kg/mm 2 when formed on a roughened surface of the resin insulating substrate board.
Abstract:
A method of soldering electronic component (6) having solder bumps (7) formed thereon to substrate (12), wherein bumps (7) are pressed against a flux transferring stage on which a thin film is formed of flux (10) containing metal powder (16) of good wettability to solder so as to cause metal powder (16) to penetrate oxide films (7a) and embed in the surfaces on the bottom parts of bumps (7), and bumps (7) in this state are positioned and mounted to electrodes (12a) on substrate (12). Substrate (12) is then heated to melt bumps (7) and allow the melted solder to flow and spread along the surfaces of metal powder (16) toward electrodes (12a). The method can thus provide solder bonding portions of high quality without any soldering defect and deterioration of the insulating property.
Abstract:
In a multilayer printed wiring board comprising a multilayer core (1) board having conductor layers in its innerlayer, and interlaminar resin (3) insulating layers and conductor layers alternately laminated on a substrate to form buildup wiring layer connecting the conductor layers through via-hole (12), the multilayer core board has a resin insulating layer covering the innerlayer conductor circuits formed on the core material, and a via-hole is formed in the resin insulating layer so as to arrive at the innerlayer conductor circuit through the layer, and a through-hole (10) is formed in the resin insulating layer and a filler (8) is filled in the through-hole. A part of the via-hole (19) in the buildup wiring layer is located just above the through-hole (10) and connected to the through-hole. Even if the core board is multilayered, there can be provided a multilayer printed wiring board suitable for the high densification of through-holes which can sufficiently ensure the electrical connection to the innerlayer circuits in the core board through the through-holes.
Abstract:
A method of soldering electronic component (6) having solder bumps (7) formed thereon to substrate (12), wherein bumps (7) are pressed against a flux transferring stage on which a thin film is formed of flux (10) containing metal powder (16) of good wettability to solder so as to cause metal powder (16) to penetrate oxide films (7a) and embed in the surfaces on the bottom parts of bumps (7), and bumps (7) in this state are positioned and mounted to electrodes (12a) on substrate (12). Substrate (12) is then heated to melt bumps (7) and allow the melted solder to flow and spread along the surfaces of metal powder (16) toward electrodes (12a). The method can thus provide solder bonding portions of high quality without any soldering defect and deterioration of the insulating property.
Abstract:
An electroless plating solution comprises an aqueous solution containing 0.025 to 0.25 mol/L of a basic compound, 0.03 to 0.15 mol/L of a reducing agent, 0.02 to 0.06 mol/L of copper ion and 0.05 to 0.3 mol/L of tartaric acid or a salt thereof. Another electroless plating solution comprises an aqueous solution containing a basic compound, a reducing agent, copper ion, tartaric acid or a salt thereof and at least one metal ion species selected from the group consisting of nickel ion, cobalt ion and iron ion. The electroless plating solution is used in an electroless plating process performing electroless copper plating, more specifically in a process for manufacturing a printed circuit board which comprises immersing a resin insulating substrate board in the electroless plating solution. The electroless plated film has a stress of 0 to +10 kg/mm 2 when formed on a roughened surface of the resin insulating substrate board.