Platinum-catalyzed addition-curing silicone compositions are used as adhesives and sealant/filling agents for electronic components because they have the ability to cure rapidly upon heating or at room temperature with the formation of cured silicone gels or silicone rubbers that have excellent physical and electrical properties. Curable silicone compositions of this type can be exemplified as follows: the curable silicone composition for coating semiconductor elements taught in Japanese Patent Publication (Kokoku) Number Hei 4-2624 (2,624/1992) and comprising diorganovinylsilyl-endblocked dimethylsiloxane-methylphenylsiloxane copolymer, triorganosilyl-endblocked organohydrogenpolysiloxane, and a platinum catalyst; the adhesive taught in Japanese Patent Application Laid Open (Kokai or Unexamined) Number Hei 3-157474 (157,474/1991) and comprising organopolysiloxane containing at least 2 silicon-bonded alkenyl groups in each molecule, organopolysiloxane containing at least 2 silicon-bonded hydrogen atoms in each molecule, an organosilicon compound containing silicon-bonded alkoxy and silicon-bonded alkenyl or silicon-bonded hydrogen, and a platinum catalyst; and the molding material for electrical equipment taught by Japanese Patent Application Laid Open (Kokai or Unexamined) Number Hei 7-192929 (192,929/1995) that comprises vinyl-functional polyorganosiloxane, active hydrogen-containing organohydrogensiloxane, and curing catalyst and that cures to give a gel with a Young's modulus of 10.sup.3 to 10.sup.5 dyne/cm.sup.2.
The existing curable silicone compositions have recently proven unable to satisfy the demands imposed by the miniaturization of electronic components and the desire for productivity improvements. Thus, while curable silicone compositions as taught in Japanese Patent Publication (Kokoku) Number Hei 4-2624 do provide cured silicone with an excellent stress-relaxing capacity at low temperatures, compositions of this type nevertheless have a very poor degassing behavior and as a result cannot support the highly efficient production of electronic components. In addition, the entrapped bubbles prevent substantial improvements in electronic component reliability. In the case of the cured silicone gels afforded by the cure of a curable silicone composition as taught in Japanese Patent Application Laid Open (Kokai or Unexamined) Number Hei 7-192929, these gels exhibit an excellent stress-relaxing capacity at ambient temperature, but at low temperatures suffer from a diminished stress-relaxing capacity and hence are unable to provide improvements in electronic component reliability.
USPTO Backgrounds
USPTO Backgrounds