Title:
LEAD-FREE SOLDER CONNECTION STRUCTURE BODY
Document Type and Number:
Japanese Patent JP3832151
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To achieve solder composition where a joint cannot cause release easily by adding Sn, Ag, Cu, In, and Bi with a specific range of weight as solder or adding other small amount of elements to them when connecting a chip to an insulation substrate by lead-free solder.
SOLUTION: An Mo plate 2 (a thermal diffusion plate with low thermal expansion and Ni plating 5) and a Cu plate heat sink 9 (Ni plating) are soldered at a maximum of 270°C in an inactive atmosphere using a solder foil 8 where the melt point of Sn-7Sb of 0.15 mmt ranges from 235 to 244°C so that an alumina substrate 3 can be sandwiched in a power device. Then, an Si chip 1 is placed on the rear side (Ni plating) of the joined Mo by a solder foil 7 of Sn-3 Ag-0.7Cu-3In-3Bi for soldering in an inactive atmosphere similarly at a maximum of 230°C, thus forming a solder composition for preventing a joint from being released easily.
Inventors:
Tasao Soga
Hidee Shimokawa
Toshiharu Ishida
Hidee Shimokawa
Toshiharu Ishida
Application Number:
JP20721399A
Publication Date:
October 11, 2006
Filing Date:
July 22, 1999
Export Citation:
Assignee:
株式会社日立製作所
International Classes:
H01L23/40; B23K35/26; H01L21/52; (IPC1-7): H01L23/40
Domestic Patent References:
| JP10193169A | ||||
| JP10314980A | ||||
| JP11031715A | ||||
| JP8192291A | ||||
| JP8206874A | ||||
| JP2000319738A | ||||
| JP2000353709A |
Attorney, Agent or Firm:
Manabu Inoue