Fabrication method of semiconductor device
View Patent ↗A technique with which die bonding can be carried out without forming a void in a bond area is provided. A vacuum supply line that connects to a vacuum chuck hole formed in the bottom face of a vacuuming collet and supplies the vacuuming collet with reduced pressure for vacuum chucking a chip is constructed of two systems. That is, the vacuum supply line is so structured that a first pipe and a second pipe connect to the vacuuming collet. The first pipe supplies the vacuuming collet with a vacuum that provides suction force when a chip is unstuck from a dicing tape and transported to a mounting position on a wiring substrate. The second pipe supplies the vacuuming collet with a vacuum that provides suction force when a chip is mounted over a wiring substrate. The intensity of the vacuum (suction force) supplied to the vacuuming collet is controlled by opening or closing valves respectively installed in the pipes.
1. A fabrication method of a semiconductor device comprising the steps of:
(a) preparing a semiconductor wafer in which a principal surface thereof is partitioned into a plurality of chip areas by parting areas, an integrated circuit is formed in each of the chip areas, and an adhesive tape is stuck to a rear surface of the semiconductor wafer;
(b) cutting the semiconductor wafer along the parting areas to divide the semiconductor wafer into a plurality of semiconductor chips, and holding the semiconductor chips by the adhesive tape;
(c) vacuuming and holding an upper face of a first semiconductor chip of the plurality to be unstuck from the adhesive tape by a first suction force with a vacuuming collet to unstick the first semiconductor chip from the adhesive tape; and
(d) after the step (c), vacuuming and holding the upper face of the first semiconductor chip by the first suction force to transport the first semiconductor chip to a chip mounting position, and, after said transporting, vacuuming and holding the upper face of the first semiconductor chip by a second suction force, smaller than the first suction force, with the vacuuming collet for mounting and die-bonding of the lower face of the first semiconductor chip to a chip mounting area,
wherein the first suction force is a suction force sufficient to unstick the first semiconductor chip from the adhesive tape, and the second suction force is a suction force sufficient to prevent the first semiconductor chip from dropping from the vacuuming collet.
2. The fabrication method of a semiconductor device according to claim 1 ,
wherein the vacuuming collet is coupled to a first vacuum supply system to supply the first suction force and is coupled to a second vacuum supply system to supply the second suction force,
wherein at the step (c), the first vacuum supply system is opened and the second vacuum supply system is closed to supply the first suction force to the vacuuming collet, and
wherein, for supply of the second suction force at the step (d), the first vacuum supply system is closed and the second vacuum supply system is opened to supply the second suction force to the vacuuming collet.
3. The fabrication method of a semiconductor device according to claim 1 , wherein the thickness of the first semiconductor chip is not more than 100 μm.
4. The fabrication method of a semiconductor device according to claim 3 , wherein the second suction force is not more than 10 kPa.
5. The fabrication method of a semiconductor device according to claim 3 , wherein the chip mounting area is located over a principal surface of a mounting board or over a different semiconductor chip mounted over the principal surface of the mounting board.
6. The fabrication method of a semiconductor device according to claim 1 , wherein said die-bonding the lower face of the first semiconductor chip to a chip mounting area is by thermocompression.
7. The fabrication method of a semiconductor device according to claim 1 , wherein, to supply the first suction force, the first vacuum supply system is open and the second vacuum supply system is open, and to supply the second suction force, the first vacuum supply system is closed and the second vacuum supply is open.
8. The fabrication method of a semiconductor device according to claim 1 , wherein the first and second suction forces are of a magnitude to prevent warping of the first semiconductor chip during vacuuming and holding.