Manufacturing method of semiconductor device

1. A manufacturing method of a semiconductor device, comprising the steps of:

preparing a mother chip and a daughter chip, the mother chip including,

first and second electrodes, and

a passivation film formed on a substrate and having openings exposing upper surfaces of the first and second electrodes;

forming metal layers on the upper surfaces of the first and second electrodes, respectively; each metal layer includes

barrier metal formed on the upper surface of the corresponding electrode and on the passivation film, and

a metal post formed on the barrier metal;

forming solder balls on the metal posts of the metal layers formed on the first electrodes so that the solder balls are located above the first electrodes;

making flip chip bonding of a daughter chip on a circuit face of the mother chip to electrically connect the daughter chip to the metal posts of the metal layers formed on the second electrodes after the step of forming solder balls; and

making flip chip bonding of the mother chip on a circuit board by using the solder balls.

2. The manufacturing method of a semiconductor device according to claim 1 , wherein

the step of forming solder balls is carried out to a plurality of mother chips formed on one wafer; said method further comprising a step of:

separating the plurality of mother chips into individual mother chips by dicing after the step of making flip chip bonding of the daughter chip.

3. The manufacturing method of a semiconductor device according to claim 1 , wherein the step forming solder balls comprises the steps of:

forming on the passivation film a resist which has openings to the metal layers formed on the first electrodes;

filling up the openings of the resist with solder paste; and

forming the solder balls by heating the mother chip and melting the solder paste after removing the resist.

4. The manufacturing method of a semiconductor device according to claim 1 , wherein the step forming solder balls comprises the steps of:

piling up on the mother chip a metal mask having openings so that the metal layers formed on the first electrodes fit in the openings of the metal mask;

filling up the openings of the metal mask with solder paste; and

forming the solder balls by heating the mother chip and melting the solder paste after removing the metal mask.

5. The manufacturing method of a semiconductor device according to claim 1 , wherein the step of forming metal layers includes the steps of:

forming barrier metal on the passivation film;

forming patterned resist on the barrier metal;

forming the metal posts in openings of the patterned resist formed over the first and second pads;

removing the patterned resist; and

removing a part of the barrier metal using the metal posts as a mask.

6. The manufacturing method of a semiconductor device according to claim 1 , wherein an upper surface of the passivation film is made higher relatively to the upper surfaces of the first and second electrodes, and

the whole of the upper surface of each metal post is made higher relatively to the upper surface of the passivation film.

7. A manufacturing method of a semiconductor device comprising the steps of:

forming solder balls on a circuit face of a mother chip;

making flip chip bonding of a daughter chip on the circuit face of the mother chip after the step of forming solder balls; and

making flip chip bonding of the mother chip on a circuit board using the solder balls, wherein

the flip chip bonding of the daughter chip is made while a temperature of the mother chips is made lower than a melting point of the solder balls.

8. The manufacturing method of a semiconductor device according to claim 7 , wherein

in the step of making flip chip bonding of the daughter chip, the daughter chip is heated when a metal post formed on the mother chip and a metal post formed on the daughter chip are made to bond by thermo-compression via a joining member.

9. The manufacturing method of a semiconductor device according to claim 7 , wherein

in the step of making flip chip bonding of the daughter chip, supersonic vibration is applied to the daughter chip when a metal post formed on the mother chip and a metal post formed on the daughter chip are made to bond by thermo-compression.

10. The manufacturing method of a semiconductor device according to claim 7 , wherein the daughter chip includes a jointing member of solder, and

in the step of making flip chip bonding of the daughter chip, the daughter chip is heated at a temperature higher than a melting point of the joint member.