To obtain a reinforcing frame capable of securing sufficient reinforcing strength and adhesive strength while suppressing a manufacturing cost by omitting a rim-like frame. A reinforcing frame is adhered to a rear surface, which is a non-light receiving surface of a solar battery panel, and includes a cylindrical portion that has a cylindrical shape along a longitudinal direction of the reinforcing frame and on which an adhesive surface for adhering to the solar battery panel is formed, and protruding portions that protrude from end portions along a longitudinal direction of the adhesive surface and that are substantially parallel to the adhesive surface.

The invention relates to a heliostat sub-assembly and to a method of forming such a sub-assembly. The method of mounting a concave mirror to a supporting structure of a heliostat includes the steps of bonding a plurality of risers at predetermined spaced intervals to a rear face of the mirror, each riser having a bonding pad and a stem extending from the bonding pad, and applying a predetermined concave curvature to the mirror by conforming the front face of the mirror with a convex forming jig or die. The supporting structure and curved mirror are then aligned, and the supporting structure is clinched to the stems of the risers when the curved mirror is conformed with the forming die. The riser stems may be coupled to the bonding pads via multi-axial joint assemblies to enable limited multi-pivotal movement of the stems relative to the bonding pads to facilitate alignment of faces of the stems with the faces of the ribs defined by webs, and relative expansion and contraction of the mirror and supporting structure, the overlap between the riser stems and the webs being sufficient to accommodate clinching with variations in curvature of the glass sheet.