Abstract: A semiconductor device includes a package substrate having a first surface and a second surface. A semiconductor chip is provided on the first surface of the package substrate and includes a semiconductor element. An adhesive is provided between the semiconductor chip and the package substrate. A metal bump is provided on the second surface. A package substrate is a multilayer substrate that includes first to fourth wiring layers and first to third resin layers. CTE1<CTE2<CTE3<CTE4 is satisfied where coefficients of thermal expansion of the semiconductor chip, the first to third resin layers, the first to fourth wiring layers, and the adhesive are CTE1 to CTE4, respectively. EM1>EM3>EM2>EM4 is satisfied where elastic moduli of the semiconductor chip, the first to third resin layers, the first to fourth wiring layers, and the adhesive are EM1 to EM4, respectively.

Abstract: A semiconductor device includes a package substrate having a first surface and a second surface. A semiconductor chip is provided on the first surface of the package substrate and includes a semiconductor element. An adhesive is provided between the semiconductor chip and the package substrate. A metal bump is provided on the second surface. A package substrate is a multilayer substrate that includes first to fourth wiring layers and first to third resin layers. CTE1<CTE2<CTE3<CTE4 is satisfied where coefficients of thermal expansion of the semiconductor chip, the first to third resin layers, the first to fourth wiring layers, and the adhesive are CTE1 to CTE4, respectively. EM1>EM3>EM2>EM4 is satisfied where elastic moduli of the semiconductor chip, the first to third resin layers, the first to fourth wiring layers, and the adhesive are EM1 to EM4, respectively.

Abstract: An injection molding process for forming cross-linked, foamed moldings of an ethylenic polymer by passing a molding composition comprising an ethylenic polymer/cross-linking agent/foaming agent blend through the cylinder of an injection molding machine without substantially decomposing the cross-linking agent and the foaming agent, introducing the molding composition into a molding composition holding chamber provided at the exit end of the cylinder of the injection molding machine to decompose the cross-linking agent and the foaming agent therein, and injecting the molding composition into a mold.The invention also provides apparatus for carrying out the process comprising an injection molding cylinder for conveying and plasticizing the molding composition and a molding composition holding chamber provided at the exit end of the cylinder.