| 摘要 |
PURPOSE:To enable bonding a pellet to a lead frame surely and at low cost by a method wherein the back-side electrode layer of an Si pellet is formed of a metal layer having excellent adhesiveness to Si and of an electrode layer which can be soldered. CONSTITUTION:The back-side electrode layer 28 provided on the side of the back surface of the Si pellet 22 is composed of a Ti layer 30, an Ni layer 32 and an Sn layer 34 which have excellent adhesiveness to Si. Moreover, on the side of the back surface of the layer 34 is provided a solder layer 36 constituting a surface part to be connected to a tab 20 of a lead frame. On the other hand, an Ni layer 40 and an Ag layer 42 are connected to the tab 20 and the Ag layer 42 is bonded to the solder layer 36. This constitution makes material cost very inexpensive, since Au material is not used for the electrode 28. In addition, the Sn layer 34 bonding the Ni layer and the solder layer 36 has the very excellent adhesiveness to the solder equal to or more than that of Au. |
