A display device includes a display panel. A flexible printed circuit board is electrically connected to the display panel. A first pad is disposed on the display panel. A second pad is disposed on the flexible printed circuit board and overlaps the first pad. A first anisotropic conductive film is disposed between the first pad and the second pad. The first anisotropic conductive film is configured to bond the first pad to the second pad. The first anisotropic conductive film includes a conductive polymer. The first anisotropic conductive film includes at least one first conductive region that electrically connects the first pad and the second pad and at least one first insulating region.

A printed circuit board includes an insulating body, a wiring structure at least disposed on the insulating body; and a shielding portion including a conductive via disposed around the wiring structure of the insulating body. The conductive via includes first and second metal layers having different degrees of magnetic permeability.

A wiring substrate includes a core substrate, and a build-up part laminated on the substrate and including resin insulating layers. The insulating layers include a first insulating layer, the build-up part includes a conductor layer on the first insulating layer, a second insulating layer on the first insulating layer and covering the conductor layer, and a recess penetrating through the second insulating layer and exposing portion of the conductor layer such that the conductor layer includes component mounting region that places an electronic component in the recess and a conductor pad forming bottom surface of the recess, the insulating layers include inorganic filler such that all insulating layers or all insulating layers other than the first insulating layer include the inorganic filler and that inorganic filler content rate of the first insulating layer is lower than inorganic filler content rate of the insulating layers other than the first insulating layer.

The prepreg includes a first resin layer and a second resin layer disposed on both surfaces of the first resin layer. The first resin layer is a half-cured product of a first resin composition that includes a glass cloth impregnated with the first resin composition and contains no hexagonal boron nitride. The second resin layer is a half-cured product of a second resin composition containing hexagonal boron nitride. The glass cloth has a warp and weft weave density of 54 pieces/25 mm or more. The hexagonal boron nitride has an average particle size ranging from 10 μm to 30 μm. The hexagonal boron nitride is contained in an amount ranging from 20 parts by mass to 40 parts by mass relative to 100 parts by mass of a residual component other than the hexagonal boron nitride in the second resin composition.

A connection structure: a first electronic component having a terminal pattern in which a plurality of terminals are arranged side by side in a radial form and a second electronic component having a terminal pattern corresponding to the terminal pattern of the first electronic component are anisotropically conductively connected using an anisotropic conductive film, (i) the effective connection area per terminal is 3000 μm.sup.2 or more, and the number density of conductive particles in the anisotropic conductive film is 2000 particles/mm.sup.2 or more and 20000 particles/mm.sup.2 or less, (ii) as the anisotropic conductive film, adopted is an anisotropic conductive film in which the conductive particles are arranged in a lattice form, and the arrangement pitch and the arrangement direction are configured such that each terminal captures three or more conductive particles, or (iii) as the anisotropic conductive film, adopted is an anisotropic conductive film having a multiple circular region.

This invention relates to a curable adhesive composition. In particular, the present invention relates to a curable adhesive composition for die attach, which eliminates the void issue, minimizes the fillet, and has lower bond line thickness and tilt trend, when cured.

A circuit board according to an embodiment of the present invention comprises: a first metal layer; an insulating layer disposed on the first metal layer and comprising boron nitride agglomerate particles coated with a resin; and a second metal layer disposed on the insulating layer, wherein: one of both surfaces of the first metal layer, on which the insulating layer is disposed, is in at least partial contact with one surface of the insulating layer; one of both surfaces of the second metal layer, on which the insulating layer is disposed, is in at least partial contact with the other surface of the insulating layer; a plurality of grooves are formed on a surface which is one of both surfaces of at least one of the first metal layer and the second metal layer and which has the insulating layer disposed thereon; at least some of the particles are arranged in at least some of the plurality of grooves; the width (W) of at least one of the plurality of grooves is 1 to 1.8 times D50 of the particles; and a ratio (D/W) of the depth (D) to the width (W) of at least one of the plurality of grooves is 0.2 to 0.3.

A stretchable mounting board that includes a stretchable substrate having a main surface, a stretchable wiring disposed on the main surface of the stretchable substrate, a mounting electrode section electrically connected to the stretchable wiring, solder electrically connected to the mounting electrode section and including bismuth and tin, and an electronic component electrically connected to the mounting electrode section with the solder interposed therebetween. The mounting electrode section has a first electrode layer on a side thereof facing the stretchable wiring and which includes bismuth and tin, and a second electrode layer on a side thereof facing the solder and which includes bismuth and tin. A concentration of the bismuth in the first electrode layer is lower than a concentration of the bismuth in the second electrode layer, and the concentration of the bismuth in the second electrode layer is constant along a thickness direction thereof.

Provided is an electronic device capable of supplying large current to a circuit pattern, without employing a thick film structure for the circuit pattern. The electronic device includes a substrate, a wiring layer placed on the upper surface of the substrate, an electronic component mounted above the wiring layer, and a bonding layer placed between the electronic component and the wiring layer. The wiring layer and the bonding layer are porous layers containing pores. The bonding layer has higher volume density than the wiring layer except underneath the electronic component.

A printed circuit board includes an insulating body, a wiring structure at least disposed on the insulating body; and a shielding portion including a conductive via disposed around the wiring structure of the insulating body. The conductive via includes first and second metal layers having different degrees of magnetic permeability.