Thin multi-chip flex module
A flexible circuit comprises two flexible dielectric sheets having conductive patterns on their surface(s) to which microelectronic device(s) are attached. A bond layer joins the two sheets over a portion of their respective surface areas so that a remaining portion of their areas remain unbonded and a bifurcated structure is thereby formed. Electrical contacts are provided on the unbonded or bifurcated portions of the flexible sheets. The flex may be attached to a rigid frame and provided with protective heat spreading covers.
1 . A flexible circuit comprising:
a first flexible dielectric sheet having a conductive pattern on at least one surface thereof;
a second flexible dielectric sheet having a conductive pattern on at least one surface thereof;
at least one microelectronic device operably coupled to said conductive pattern on at least one of said first and second dielectric sheets;
a bond layer joining a portion of the surface areas of said first and second dielectric sheets, wherein a portion of said first and second dielectric sheets are not bonded together; and,
a plurality of electrical contacts on said portions of said first and second dielectric sheets that are not bonded together.
2 . The flexible circuit of claim 1 wherein each of said first and second dielectric sheets has a conductive pattern on both sides thereof.
3 . The flexible circuit of claim 1 wherein a plurality of microelectronic devices are operably coupled to said conductive pattern on one side of said first dielectric sheet and a plurality of microelectronic devices are operably coupled to said conductive pattern on one side of said second dielectric sheet.
4 . The flexible circuit of claim 1 wherein said microelectronic device is selected from the group consisting of: memory circuits, logic circuits, buffer devices, interface devices, optoelectronic devices, and microprocessors.
5 . The flexible circuit of claim 1 further comprising at least one passive electronic device selected from the group consisting of chip resistors, chip capacitors, thin- and thick-film resistors and capacitors, inductors, thermistors, and varistors
6 . The flexible circuit of claim 1 wherein said bond layer comprises a bonding medium selected from the group consisting of: continuous adhesive layers, discontinuous adhesive layers, anisotropic conductive adhesive, isotropic conductive adhesive, and solder.
7 . The flexible circuit of claim 1 further comprising a substantially rigid frame.
8 . The flexible circuit of claim 1 further comprising a heat spreading cover.
9 . The flexible circuit of claim 1 wherein at least some of said electrical contacts are configured to engage corresponding contacts on a second similar circuit so that said first and second circuits may be stacked.
10 . A flexible circuit comprising:
a first flexible dielectric sheet having conductive patterns on both surfaces thereof;
a second flexible dielectric sheet having conductive patterns on both surfaces thereof;
a plurality of microelectronic devices operably coupled to said conductive patterns on at least one side of each of said first and second dielectric sheets;
a bond layer joining a portion of the surface areas of said first and second dielectric sheets, wherein a portion of said first and second dielectric sheets are not bonded together; and,
a plurality of electrical contacts on said portions of said first and second dielectric sheets that are not bonded together.
11 . The flexible circuit of claim 10 wherein said microelectronic devices are selected from the group consisting of: memory circuits, logic circuits, buffer devices, interface devices, optoelectronic devices, and microprocessors.
12 . The flexible circuit of claim 10 further comprising at least one passive electronic device selected from the group consisting of: chip resistors, chip capacitors, thin- and thick-film resistors and capacitors, inductors, thermistors, and varistors
13 . The flexible circuit of claim 10 wherein said bond layer comprises a bonding medium selected from the group consisting of continuous adhesive layers, discontinuous adhesive layers, anisotropic conductive adhesive, isotropic conductive adhesive, and solder.
14 . The flexible circuit of claim 10 further comprising a substantially rigid frame.
15 . The flexible circuit of claim 10 further comprising a heat spreading cover.
16 . The flexible circuit of claim 1 wherein at least some of said electrical contacts are configured to engage corresponding contacts on a second similar circuit do that said first and second circuits may be stacked.