An aspect of the present invention is a resin composition, which contains a polyphenylene ether compound, a curing agent, boron nitride, and an inorganic filler other than the boron nitride, in which the content of boron nitride is 15 to 70 parts by volume with respect to 100 parts by volume of the sum of the polyphenylene ether compound and the curing agent.

A method for manufacturing a functionally graded composite material for a printed circuit board (PCB) is proposed. The method may include preparing two or more types of mixed powders with different contents of polymer or ceramic powder, each mixed powder comprising (i) a metal powder comprising a powder made of aluminum or an aluminum alloy and a powder of magnesium and (ii) the polymer or ceramic powder. The method may also include laminating the two or more types of mixed powders to form a functionally graded laminate in which a ratio of the content of the polymer or ceramic powder to the content of the metal powder in each of layers stacked in sequence from bottom to the top of the laminate differs. The method may further include preparing a functionally graded composite material by sintering the functionally graded laminate by pressureless sintering or spark plasma sintering.

A printed wiring board includes a resin insulating layer including resin and particles, and a conductor layer formed on a surface of the resin insulating layer. The particles in the resin insulating layer include first particles and second particles such that the first particles are partially embedded in the resin and the second particles are completely embedded in the resin, and the resin insulating layer is formed such that the first particles has exposed surfaces exposed from the resin and covered surfaces covered by the resin, respectively, the surface of the resin insulating layer includes the first exposed surfaces, and a ratio of a second area to a first area is in a range of 0.1 to 0.25 where the first area is an area of the surface of the resin insulating layer, and the second area is obtained by summing areas of the exposed surfaces of the first particles.

Pastes are disclosed that are configured to coat a passage of a substrate. When the paste is sintered, the paste becomes electrically conductive so as to transmit electrical signals from a first end of the passage to a second end of the passage that is opposite the first end of the passage. The metallized paste contains a lead-free glass frit, and has a coefficient of thermal expansion sufficiently matched to the substrate so as to avoid cracking of the sintered paste, the substrate, or both, during sintering.

A method for making a via (3) in a carrier layer (1) made of a ceramic comprising:

providing the carrier layer (1),

realizing a passage recess (2) in the carrier layer (1),

at least partially filling the passage recess (2) with a paste (3), and

performing a bonding process, in particular an active soldering process or a DCB process, for bonding a metallization (5) to the carrier layer (1), the via (3′) being realized from the paste (3) in the passage recess (2) when the bonding process is performed.

An anisotropic conductive film which suppresses occurrence of short circuit at the time of anisotropic conductive connection, prevents reduction in capturing capability of electrically conductive particles, enables favorable pushing of electrically conductive particles and exhibits not only favorable initial conductivity but also favorable conduction reliability, contains a first electrically conductive particle group and a second electrically conductive particle group, each including a plurality of electrically conductive particles, in an insulating binder. The first electrically conductive particle group and the second electrically conductive particle group are present in a first region and a second region, respectively, which differ from each other in the thickness direction of the anisotropic conductive film and are parallel to the plane direction. Moreover, the first electrically conductive particle group and the second electrically conductive particle group differ from each other in an existence state of the electrically conductive particles.

The present invention addresses the problem of providing a composite nanometal paste which is relatively low in price and is excellent in terms of bonding characteristics, thermal conductivity, and electrical property. The present invention is a copper-filler-containing composite nanometal paste that contains composite nanometal particles each comprising a metal core and an organic coating layer formed thereon. The metal paste contains a copper filler and contains, as binders, first composite nanometal particles and second composite nanometal particles which differ from the first composite nanometal particles in the thermal decomposition temperature of the organic coating layer, wherein the mass proportion W1 of the organic coating layer in the first composite nanometal particles is in the range of 2-13 mass %, the mass proportion W2 of the organic coating layer in the second composite nanometal particles is in the range of 5-25 mass %, and these particles satisfy the relationships W1.

Pastes are disclosed that are configured to coat a passage of a substrate. When the paste is sintered, the paste becomes electrically conductive so as to transmit electrical signals from a first end of the passage to a second end of the passage that is opposite the first end of the passage. The metallized paste contains a lead-free glass frit, and has a coefficient of thermal expansion sufficiently matched to the substrate so as to avoid cracking of the sintered paste, the substrate, or both, during sintering.

A method for repairing a fine line is provided. Nano metal particles are filled in a defect of a circuit board. The nano metal particles in the defect are irradiated by a laser, or heated, such that the nano metal particles in the defect are metallurgically bonded to an original line of the circuit board. A surface of the circuit board is cleaned to remove residual nano metal particles on parts of the circuit board where metallurgical bonding is not performed, thereby completing line repairing of the circuit board.

Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44 wt % and 83 wt %, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5 wt % to 44 wt %, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.