US 7,405,486 B2 · Circuit device

Abstract

In stack packaging, an IC chip in an upper layer and an IC chip in a lower layer are insulated from each other by use of an insulating adhesive and the like. Thus, if an analog IC chip is stacked in the upper layer, a substrate is set in a floating state. Accordingly, there arises a problem that desired characteristics cannot be obtained. A conductive layer is disposed on an IC chip, and an analog IC chip is fixed on the conductive layer. The conductive layer is connected to a fixed potential pattern through a bonding wire and the like. Thus, a fixed potential can be applied to a rear surface (substrate) of the analog IC chip. Consequently, a mounting structure including the analog IC chip stacked in the upper layer can be realized. In addition, versatility of stack packaging for a circuit device including the analog IC chip can be improved, and a mounting area can be reduced. Moreover, characteristics can be improved.

Claims10

Dependent claims

A circuit device comprising:

a plurality of conductive patterns including a fixed potential pattern, wherein the fixed potential is either a VDD potential or a GND potential;
a plurality of IC chips which include an IC chip having a fixed substrate potential, wherein the fixed substrate potential is either a VDD potential or a GND potential;
a conductive layer electrically connected to a rear surface of the IC chip having the fixed substrate potential and to the fixed potential pattern, wherein the IC chip having the fixed substrate potential is fixed on the conductive layer, and further wherein the IC chip having the fixed substrate potential is electrically connected to the fixed potential pattern through the conductive layer;
and
an insulating layer between the conductive layer and a second IC chip beneath the IC chip having a fixed substrate potential.

2 more elements

Dependencies are inferred from the claim text.

Circuit device

Life of this patent

Circuit device

Life of this patent

Abstract

Claims10