| 摘要 |
PURPOSE:To enhance the insulating and heat sink properties by bonding a ceramic member for placing a semiconductor chip onto a copper tungsten alloy substrate via high melting point brazing material, and bonding the substrate onto a copper base via low melting point brazing material. CONSTITUTION:A beryllia member 13, an alumina frame 17 and outer leads 14 are silver-brazed at 400-1,000 deg.C onto a copper tungsten alloy substrate 12. In this case, Mo paste is previously coated on the member 13, and a necessary conductor pattern, and a metallized layer is formed at the necessary portion on the frame. After the silver-brazing, Ni-plating and Au-plating are performed. Then, a semiconductor chip is placed by eutectic alloy of AuSi in N2 gas atmosphere. The chip is connected to the external leads by thermal press-bonding. The head is sealed with cap. Then, the substrate 12 is bonded to a copper base 11 via low melting point brazing material having 140-400 deg.C of melting point. |
