Patent ID: 7993727

Claim:
An advanced grid structure, comprising: a first tape prepreg group including a plurality of first tape prepregs, each first tape prepreg including first carbon fibers that are aligned in a first direction and that form first grid sides, a plurality of the first grid sides being spaced apart from one another at equal intervals and being aligned in the first direction; a second tape prepreg group including a plurality of second tape prepregs, each second tape prepreg including second carbon fibers that are aligned in a second direction inclined counterclockwise at 60 degrees with respect to the first direction and that form second grid sides, a plurality of the second grid sides being spaced apart from one another at equal intervals and being aligned in the second direction; a third tape prepreg group including a plurality of third tape prepregs, each third tape prepreg including third carbon fibers that are aligned, in a third direction inclined clockwise at 60 degrees with respect to the first direction and that form third grid sides, a plurality of the third grid sides being spaced apart from one another at equal intervals and being aligned in the second direction, the first tape prepreg group, the second tape prepreg group, and the third tape prepreg group being laminated repetitively in the stated order so that two of the first tape prepreg group, the second tape prepreg group, and the third tape prepreg group overlap on top of each other, and being heated under pressure, to form the advanced grid structure; a first grid side group formed of the plurality of the first grid sides; a second grid side group formed of the plurality of the second grid sides; and a third grid side group formed of the plurality of the third grid sides, wherein a structure ratio of the advanced grid structure is larger than 0 and 0.107 or less, the structure ratio being obtained by dividing a width of one of the first, second, or third grid sides, by, a distance between a center point of a first region where the second grid side group and the third grid side group cross each other and a center point of a second region where the second grid side group and the third grid side group cross each other, the first and second regions being two regions in a single plane closest to one another, a thermal expansion coefficient of the advanced grid structure is −0.9 ppm/K or more and 0.9 ppm/K or less, and the first, second, and third carbon fibers have a tensile modulus of elasticity of 280 GPa or more and 330 GPa or less.