Semiconductor device and manufacturing method thereof

A semiconductor device, comprising:

• first inner leads;
• second inner leads which are arranged separately from the first inner leads in a horizontal direction and have lead parts longer than those of the first inner leads;
• a plurality of bare chips which are stacked across a spacer on the second inner leads and have pads formed along one side;
• and
• a plurality of bonding wires which connect the first inner leads to pads of the plurality of bare chips and the second inner leads to pads of the plurality of bare chips,
• wherein the bonding wires which connect the pads of the bare chips at one end side of the spacers to the corresponding first or second inner leads are arranged not to contact the bare chip at the other end side of the same spacer.

A method of manufacturing a semiconductor device, comprising:

• mounting a first bare chip on a first main surface of a support substrate via a binding material;
• attaching a first spacer on a surface of the first bare chip via the binding material;
• connecting the pads of the first bare chip and inner leads by bonding wires and arranging the bonding wires so that a maximum height of the bonding wires become lower than a top end of the first spacers;
• attaching a second bare chip on a surface of the first spacer via the binding material;
• connecting pads of the second bare chip and the inner leads by the bonding wires;
• attaching a third bare chip on a second main surface of the support substrate via the binding material in parallel to one of the processings of mounting the first bare chip, attaching the first spacer, connecting the pads, attaching the second bare chip and connecting the pads, or after the all the processings are finished;
• attaching a third spacer on a surface of the third bare chip via the binding material;
• connecting pads of the third bare chip and the inner leads by the bonding wires and arranging the bonding wires so that a maximum height of the bonding wires become lower than a top end of the third spacer;
• attaching a four bare chip on a surface of the third spacer via the binding material;
• and
• connecting pads of the four bare chip and the inner leads by the bonding wires.