Stacked chip semiconductor device and method for manufacturing the same
A stacked chip semiconductor device including: a substrate having electrode pads; a first semiconductor chip that is flip-chip-packaged on the substrate via a first adhesive layer; a second semiconductor chip that is mounted on an upper part of the first semiconductor chip and that has electrode pads; wires for electrically connecting the electrode pads of the second semiconductor chip and the electrode pads of the substrate; and a molded resin for encapsulating the first semiconductor chip, the second semiconductor chip and the wires, the first adhesive layer forming a fillet at the periphery of the first semiconductor chip. The first semiconductor chip is disposed with its central axis being offset from a central axis of the substrate, the offset being provided so that the first semiconductor chip is shifted toward a side opposite to a side where the fillet has a maximum length from the periphery of the first semiconductor chip. Thereby, influences of the fillet made of the adhesive are suppressed, allowing miniaturization of the device and improvement in the mass-productivity.
1. A method for manufacturing a stacked chip semiconductor device, comprising:
flip-chip mounting a first semiconductor chip having electrode pads to a substrate;
injecting an adhesive into a gap between the substrate and the first semiconductor chip so as to form a first adhesive layer of the adhesive with a fringe protruding from an edge of the first semiconductor chip to form a fillet;
bonding a second semiconductor chip on an upper part of the first semiconductor chip via a second adhesive layer;
connecting electrode pads of the second semiconductor chip and the electrode pads of the substrate via wires; and
encapsulating the first semiconductor chip, the second semiconductor chip and the wires with a molded resin, wherein
in the flip-chip mounting, the first semiconductor chip is disposed with its central axis being offset from a central axis of the substrate, the offset being provided so that the first semiconductor chip is shifted toward a side opposite to a side from which the adhesive is injected in the underfilling.
2. The method according to claim 1 , wherein the second semiconductor chip is mounted substantially at a center of the substrate.
3. The method according to claim 1 , wherein the step of bonding the second semiconductor chip is carried out before the step of injecting the adhesive.
4. The method according to claim 3 , wherein the second semiconductor chip is mounted in the stack-die-bonding so as to be flush with the side of the first semiconductor chip at which the adhesive is injected.
5. The method according to claim 1 , wherein a size of the second semiconductor chip is smaller than that of the first semiconductor chip.
6. The method according to claim 5 , wherein at least one pair of edges on opposite sides of the first semiconductor chip project from corresponding edges of the second semiconductor chip, respectively, and projecting lengths of the first semiconductor chip in a direction of the offset are different from each other.