A method of forming a semiconductor package is provided. The method includes forming a metallization stack over a semiconductor die. Polymer particles are mounted over the metallization stack. Each of the polymer particles is coated with a first bonding layer. A heat spreader lid is bonded with the semiconductor die by reflowing the first bonding layer. A composite thermal interface material (TIM) structure is formed between the heat spreader lid and the semiconductor die during the bonding. The composite TIM structure includes the first bonding layer and the polymer particles embedded in the first bonding layer.

A thermosetting composition for use as an underfill material contains: a mono- or bifunctional acrylic compound; a thermo-radical polymerization initiator; silica; and an elastomer including a 1,2-vinyl group. The thermosetting composition is liquid and has a property of turning, when cured thermally, into a cured product having a relative dielectric constant of 3.2 or less at 25° C. and a dielectric loss tangent of 0.013 or less at 25° C.

A thermosetting composition for use as an underfill material contains: a mono- or bifunctional acrylic compound; a thermo-radical polymerization initiator; silica; and an elastomer including a 1,2-vinyl group. The thermosetting composition is liquid and has a property of turning, when cured thermally, into a cured product having a relative dielectric constant of 3.2 or less at 25° C. and a dielectric loss tangent of 0.013 or less at 25° C.

Disclosed is a temporary protective film for semiconductor sealing molding 10 including a support film 1; and an adhesive layer 2 provided on the support film 1 and containing an acrylic rubber. A solid shear modulus at 200° C. of the temporary protective film for semiconductor sealing molding 10 may be 5.0 MPa or higher.

Disclosed is a temporary protective film for semiconductor sealing molding 10 including a support film 1; and an adhesive layer 2 provided on the support film 1 and containing an acrylic rubber. A solid shear modulus at 200° C. of the temporary protective film for semiconductor sealing molding 10 may be 5.0 MPa or higher.

A semiconductor device includes a semiconductor element made up of a semiconductor substrate, an element electrode formed on the substrate, and a wiring layer electrically connected to the element electrode. The semiconductor device further includes a lead frame supporting the semiconductor element, a first conductive member electrically connecting the semiconductor element and the lead frame, a second conductive member overlapping with the semiconductor element as seen in plan view, and a sealing resin covering the semiconductor element, a part of the lead frame, and the first and second conductive member. The wiring layer includes a first pad portion and a second pad portion. The second conductive member has a first connecting portion bonded to the first pad portion and a second connecting portion bonded to the second pad portion.

A semiconductor device includes a semiconductor element made up of a semiconductor substrate, an element electrode formed on the substrate, and a wiring layer electrically connected to the element electrode. The semiconductor device further includes a lead frame supporting the semiconductor element, a first conductive member electrically connecting the semiconductor element and the lead frame, a second conductive member overlapping with the semiconductor element as seen in plan view, and a sealing resin covering the semiconductor element, a part of the lead frame, and the first and second conductive member. The wiring layer includes a first pad portion and a second pad portion. The second conductive member has a first connecting portion bonded to the first pad portion and a second connecting portion bonded to the second pad portion.

A power amplification device includes: a first semiconductor chip including a first main surface and a second main surface; a first field-effect transistor, a first drain finger part, a plurality of first gate finger parts, and a source finger part; a sub-mount substrate including a third main surface and a fourth main surface; and a first filled via provided penetrating from the third main surface to the fourth main surface. In plan view, the first filled via has a rectangular shape. A long side direction of the first filled via is parallel to a long side direction of the plurality of first gate finger parts. In plan view, the first filled via is positioned to overlap part of one first gate finger part included in the plurality of first gate finger parts.

A power amplification device includes: a first semiconductor chip including a first main surface and a second main surface; a first field-effect transistor, a first drain finger part, a plurality of first gate finger parts, and a source finger part; a sub-mount substrate including a third main surface and a fourth main surface; and a first filled via provided penetrating from the third main surface to the fourth main surface. In plan view, the first filled via has a rectangular shape. A long side direction of the first filled via is parallel to a long side direction of the plurality of first gate finger parts. In plan view, the first filled via is positioned to overlap part of one first gate finger part included in the plurality of first gate finger parts.

A semiconductor device includes a substrate, an adhesive layer formed on a lower surface of the substrate, a semiconductor element adhered to a lower surface of the adhesive layer, a through hole extending through the substrate and the adhesive layer and exposing a first electrode arranged on an upper surface of the semiconductor element, a via wiring formed in the through hole, a wiring layer formed on an upper surface of the substrate and electrically connected to the first electrode through the via wiring, and a protective insulation layer formed on the lower surface of the adhesive layer. The protective insulation layer covers an entirety of all side surfaces of the semiconductor element and a peripheral part of a lower surface of the semiconductor element and exposes a central part of the lower surface of the semiconductor element.