| 摘要 |
PURPOSE:To improve the surface roughness of the inner face of an electroforming build-up layer and the roundness and to realize a high performance antenna by adopting such constitution that the outer circumferential surface of a fusible spacer forming the electroforming build-up layer via a zinc substitution layer is to be a machined face in the electroforming method using an electroforming core metal. CONSTITUTION:Stepped fins 2a, 2b, 2c are laminated stepwise while fusible spacers 21a, 21b, 21c are sequentially inserted, and pressed and inserted together with end plates 301a, 301b in a rotationally symmetric state and the machining (A') is applied. Outer circumferential surfaces 2211a-2211c of the fusible spacers result from the machining (B') in a prescribed sized. In this case, the upper lower face of tips 201a-201c of the stepped fins is notched by a small quantity so than no fusible material of the fusible spacers remains. The zinc substitution layer 501 is used to improve the close contact between the fusible spacers and the electroforming build-up layer 11a and the zinc replacement layer of the tips 201a-201c is removed by the machine work A after the electroforming build-up layer 11a. A thickness difference of the electroforming layer 11b is adjusted in the machining B and the inner face is machined in a prescribed dimension after the end of electroforming in the machining C. |
