Method of manufacturing semiconductor device capable of enhancing bonding strength between connection terminal and electrode
A method of manufacturing a semiconductor device includes forming a barrier metal film on a surface of at least one of a first electrode of a wiring board and a second electrode of a semiconductor element, providing a connection terminal between the first and second electrodes, the connection terminal being made of solder containing tin, bismuth and zinc, and bonding the connection terminal to the barrier metal film by heating the connection terminal and maintaining the temperature of the connection terminal at a constant temperature not lower than a melting point of the solder for a certain period of time.
1. A method of manufacturing a semiconductor device, comprising:
forming a barrier metal film on a surface of at least one of a first electrode of a wiring board and a second electrode of a semiconductor element;
providing a connection terminal between the first and second electrodes, the connection terminal being made of solder containing tin, bismuth and zinc; and
connecting the first electrode and the second electrode by bonding the connection terminal to the barrier metal film by heating the connection terminal and maintaining the temperature of the connection terminal at a constant temperature not lower than a solidus temperature of the solder for a certain period of time,
wherein the constant temperature is a temperature at which solid-phase solder and liquid-phase solder coexist in the connection terminal.
2. The method of manufacturing a semiconductor device, according to claim 1 , wherein the barrier metal film is a metal layer containing a nickel film.
3. The method of manufacturing a semiconductor device, according to claim 2 , wherein the metal layer is a laminated film obtained by laminating the nickel film and a gold film in this order.
4. The method of manufacturing a semiconductor device, according to claim 2 , wherein the metal layer is a laminated film obtained by laminating the nickel film, a palladium film and a gold film in this order.
5. The method of manufacturing a semiconductor device, according to claim 1 , wherein the constant temperature is a temperature not higher than a temperature obtained by adding the solidus temperature with 10° C.
6. The method of manufacturing a semiconductor device, according to claim 1 , wherein the certain period of time is 15 seconds or more.
7. The method of manufacturing a semiconductor device, according to claim 1 , wherein, in the heating of the connection terminal, the temperature of the connection terminal is raised to a temperature higher than the constant temperature after a lapse of the certain period of time.
8. The method of manufacturing a semiconductor device, according to claim 1 , wherein main components of the solder are the tin and the bismuth.
9. The method of manufacturing a semiconductor device according to claim 1 , wherein the concentration of the zinc in the solder is more than 0.1 wt % and not more than 1 wt %.
10. The method of manufacturing a semiconductor device according to claim 1 , wherein the solder consists of an alloy of the tin, the bismuth and the zinc, where any one of cobalt and phosphorous being added to the alloy.
11. The method of manufacturing a semiconductor device according to claim 1 , wherein, in the heating of the connection terminal, the temperature of the connection terminal is raised, without being lowered, to a temperature higher than the constant temperature after a lapse of the certain period of time.