| 摘要 |
PURPOSE:To form a cored bump having uniform quality by slight man-hours by using a metallic mask when the cored bump is formed on the surface of a substrate for a leadless chip carrier. CONSTITUTION:Substrates 1 for a leadless chip carrier are arranged regularly on a metallic tray 21 while upward directing the surfaces on which pads are disposed. Windows 27 for metallic masks formed made to correspond to the pads on the substrates 1 are arranged so as to be positioned on the pads. When a large number of solder balls having large diameters are placed on the metallic masks in the tray 21 and shaken, the solder balls naturally fall into circular sections 24. When a large number of core sections having small diameters are entered and shaken, the core sections fall into circular sections 25 in the windows. The tray 21 is fed into an electric furnace, and heated and cooled. |
