| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent plate parts from bending even when a large shock or load acts thereon, by integrally forming a plurality of columns of a cassette body so as to form a casing. SOLUTION: A square easing-form frame body 15 formed at the back face side of a casette 10 for wafers is provided with an opening 15a at the central part and constituted of two columns 31, 32 parallelly erected and a horizontal plate connecting these columns at the upper and lower parts. These are integrally formed. And hence, a rigid structure is provided in the cassette and deformation against the loads of coltunns 31, 32 is small. And ribs for separation of wafers are formed so that the middle part is thicker than both ends, at the same level with the ribs 21 for separation of wafers formed at the side walls 13, 14, in these columns 31, 32 to lessen the contact area with the wafer bottom. Grooves having the same pitch with the grooves 20 are vertically formed in a line by such ribs.</p> |
