Flexible circuit connector for stacked chip module
View Patent ↗The present invention provides a flexible circuit connector for electrically coupling IC devices to one another in a stacked configuration. Each IC device includes: (1) a package having top, bottom, and peripheral sides; and (2) external leads that extend out from at least one of the peripheral sides. In one embodiment, the flexible circuit connector comprises a plurality of discrete conductors that are adapted to be mounted between the upper side of a first package and the lower side of a second package. The flexible circuit connector also includes distal ends that extend from the conductors. The distal ends are adapted to be electrically connected to external leads from the first and second packages to interconnect with one another predetermined, separate groups of the external leads. In this manner, individual devices within a stack module can be individually accessed from traces on a circuit card. This flexible capability is beneficial in modules such as memory modules with multiple, stacked memory devices.
1. A stacked IC module comprising:
(a) first and second packages, each of the first and second packages comprising: (1) top, bottom, and peripheral sides; and (2) external leads that extend out from at least one of the peripheral sides;
(b) a flexible circuit connector mounted between the first and second packages; and
(c) the flexible circuit connector including discrete conductors each with distal ends that interconnect selected external leads of the second package only to selected external leads of the first package.
2. The stacked IC module of claim 1 in which the flexible circuit connector is mounted between the first and second packages with a thermally conductive adhesive.
3. The stacked IC module of claim 2 in which the thermally conductive adhesive is a dry film adhesive.
4. The stacked IC module of claim 2 in which the thermally conductive adhesive is a liquid adhesive.
5. The stacked IC module of claim 1 in which at least some of the discrete conductors overlap one another.
6. A stacked IC module comprising:
(a) first and second IC packages each having top, bottom, and peripheral sides and external leads that extend from at least one peripheral side;
(b) a flexible circuit connector having an upper side and a lower side, the flexible circuit connector being disposed between the first and second IC packages, the flexible circuit connector having:
a set of singular conductors, each one of the set of singular conductors having at least one distal extension, each of the distal extensions connecting a selected external lead of the second IC package only to a selected external lead of the first IC package.