Abstract: Three lenses formed of ZnS are used in combination. A first lens is a meniscus lens having a middle portion which is convex on an object side. A second lens has a middle portion that is a meniscus, which is concave on an object side and has positive refractive power, and a peripheral portion, which is convex on the object side. The first and second lenses have positive refractive power in combination. A third lens is provided adjacent to the second lens with a distance therebetween 1 mm or less and has a middle portion, which is a convex meniscus on an object side, and a peripheral portion which is concave on the object side. A diffraction surface is formed in either surface of the lens.

Abstract: An infrared lens 1a includes first to third lenses L1 to L3 which are made of zinc sulfide and arranged in this order from an object side. Each of the first to third lenses L1 to L3 is configured as a positive meniscus lens of which convex surface is opposed to the object. The lenses L1 to L3 are formed by heat-press molding raw powder of zinc sulfide using a lens-shaped mold. In addition, a concave surface (the surface opposed to the image side) of the first lens L1 is formed as a diffractive surface.

Abstract: A pressure sensitive adhesive sheet to be used in producing an extremely thin semiconductor chip which is free of breakage and discoloration by a predicing process and a method of use thereof are provided. The pressure sensitive adhesive sheet is used in a method for producing a semiconductor chip, in which the method involves the steps of: forming a groove having depth smaller than thickness of a wafer on a surface of the wafer on which a semiconductor circuit is formed; reducing the thickness of the wafer and finally dividing the wafer into individual chips by grinding a back face of the wafer.

Abstract: Provided is a pressure sensitive adhesive sheet that does not adhere to other apparatuses, even when it is used in a manufacturing scheme using heat treatment or treatment involving heat generation. More particularly, the pressure sensitive adhesive sheet is suited for semiconductor wafer processing, possessing unprecedented high-temperature heat resistance. The pressure sensitive adhesive sheet can be used as a surface protective sheet, a dicing sheet or a pickup sheet, by imparting properties such as a protective function of an uneven circuit surface or expanding properties. The pressure sensitive adhesive sheet comprises a base material obtained by film-forming and curing a first curable resin, a top coat layer formed on the base material by coating and curing a second curable resin, and a pressure sensitive adhesive layer formed on the opposite side of the base material.

Abstract: A pressure sensitive adhesive sheet to be used in producing an extremely thin semiconductor chip which is free of breakage and discoloration by a predicing process and a method of use thereof are provided. The pressure sensitive adhesive sheet is used in a method for producing a semiconductor chip, in which the method involves the steps of: forming a groove having depth smaller than thickness of a wafer on a surface of the wafer on which a semiconductor circuit is formed; reducing the thickness of the wafer and finally dividing the wafer into individual chips by grinding a back face of the wafer.