| 摘要 |
PURPOSE:To improve the mechanical life of a chip by raising the bulk of a chip bonding portion, thereby absorbing a stress due to the difference of a thermal expansion coefficient between a substrate and the chip. CONSTITUTION:A frame 10 has a permanent magnet 7 magnetized elevationally, a temperature sensitive magnetic material 8 laterally opposed in the magnetizing direction and a soft magnetic material 9 having wider width than both and integrated oppositely. A Permalloy film 6 of approx. 5mum thick is formed on the back surface of a chip 5, and the chip height after bonded to a substrate 2 becomes approx. 1mm. When the frame 10 is coated with the chip 5 disposed in advance at a center and passed through an electric furnace, a solder ball is melted to bond the substrate 2 to a bump 3, and the magnetization of the material 8 is inverted from horizontal to vertical direction. Accordingly, the material 9 is also magnetized to form a magnetic circuit for coupling the material 9, the film 6 and the material 9. Thus, the chip 5 is attracted to the material 9, and raised by 0.5mm. When the chip 5 is removed from the furnace in this state, the solder ball is solidified in the state as it is. Therefore, the ball 12 is secured in the elongated state. |
