Flexible electronic circuits with embedded integrated circuit die

• US 9,899,330 B2
• Filed: 09/30/2015
• Issued: 02/20/2018
• Est. Priority Date: 10/03/2014
• Status: Active Grant

• Current Assignee: Medidata Solutions Incorporated (Dassault Systemes SA)
• Original Assignee: MC10, Inc.
• Inventors: Dalal, Mitul, Gupta, Sanjay
• Primary Examiner(s): Soward, Ida M
• Application Number:
  US14/870,719
• Publication Number:
  US 20160099214A1
• Time in Patent Office: 874 Days
• CPC Class Codes: B32B 2250/40 Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
• CPC Class Codes: B32B 27/281 comprising polyimides
• CPC Class Codes: B32B 37/02 characterised by a sequence of laminating steps, e.g. by adding new layers at consecutive laminating stations
• CPC Class Codes: C09J 123/06 Polyethene
• CPC Class Codes: C09J 163/00 Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
• CPC Class Codes: C09J 169/00 Adhesives based on polycarbonates; Adhesives based on derivatives of polycarbonates
• CPC Class Codes: C09J 2479/086 in the substrate
• CPC Class Codes: C09J 7/385 Acrylic polymers
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/8385 using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/92144 the second connecting process involving a build-up interconnect
• CPC Class Codes: H01L 23/293 Organic, e.g. plastic
• CPC Class Codes: H01L 23/3121 a substrate forming part of the encapsulation
• CPC Class Codes: H01L 23/49827 Via connections through the substrates, e.g. pins going through the substrate, coaxial cables H01L23/49822, H01L23/49833, H01L23/4985, H01L23/49861 take precedence
• CPC Class Codes: H01L 23/4985 Flexible insulating substrates H01L23/49572 and H01L23/49855 take precedence
• CPC Class Codes: H01L 23/5384 Conductive vias through the substrate with or without pins, e.g. buried coaxial conductors H01L23/5383, H01L23/5385 take precedence; pins attached to insulating substrates H01L23/49811
• CPC Class Codes: H01L 23/5385 : Assembly of a plurality of insulating substrates
• CPC Class Codes: H01L 23/5387 : Flexible insulating substrates H01L23/5388 takes precedence
• CPC Class Codes: H01L 23/5389 : the chips being integrally enclosed by the interconnect and support structures
• CPC Class Codes: H01L 24/00 : Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
• CPC Class Codes: H01L 24/24 : of an individual high density interconnect connector
• CPC Class Codes: H01L 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 24/82 : by forming build-up interconnects at chip-level, e.g. for high density interconnects [HDI] interconnection structure between a plurality of semiconductor chips H01L23/5389
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/92 : Specific sequence of method steps
• CPC Class Codes: H01L 25/16 : the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/0635 : Acrylic polymer
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/07025 : Polyimide
• CPC Class Codes: H01L 2924/07802 : not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/12043 : Photo diode
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H05K 1/0283 : Stretchable printed circuits
• CPC Class Codes: H05K 1/145 : Arrangements wherein electric components are disposed between and simultaneously connected to two planar printed circuit boards, e.g. Cordwood modules
• CPC Class Codes: H05K 1/147 : at least one of the printed circuits being bent or folded, e.g. by using a flexible printed circuit H05K1/148 takes precedence
• CPC Class Codes: H05K 1/185 : Components encapsulated in the insulating substrate of the printed circuit or incorporated in internal layers of a multilayer circuit semiconductor chips encapsulated by interconnect and support structures H01L23/5389, H01L24/00
• CPC Class Codes: H05K 2201/0129 : Thermoplastic polymer, e.g. auto-adhesive layer; Shaping of thermoplastic polymer
• CPC Class Codes: H05K 2201/0141 : Liquid crystal polymer [LCP]
• CPC Class Codes: H05K 2201/0154 : Polyimide
• CPC Class Codes: H05K 2201/0355 : Metal foils
• CPC Class Codes: H05K 2201/042 : Stacked spaced PCBs; Planar parts of folded flexible circuits having mounted components in between or spaced from each other
• CPC Class Codes: H05K 3/4635 : laminating flexible circuit boards using additional insulating adhesive materials between the boards

Abstract

Flexible integrated circuit (IC) modules, flexible IC devices, and methods of making and using flexible IC modules are presented herein. A flexible integrated circuit module is disclosed which includes a flexible substrate and a semiconductor die attached to the flexible substrate. An encapsulating layer, which is attached to the flexible substrate, includes a thermoplastic resin and/or a polyimide adhesive encasing therein the semiconductor die. The encapsulating layer may be an acrylic-based thermally conductive and electrically isolating polyimide adhesive. Optionally, the encapsulating layer may be a B-stage FR-4 glass-reinforced epoxy thermoplastic polymer or copolymer or blend. The die may be embedded between two flexible substrates, each of which includes a layer of flexible polymer, such as a polyimide sheet, with two layers of conductive material, such as copper cladding, disposed on opposing sides of the layer of flexible polymer.

Claims

1. A flexible integrated circuit (IC) module comprising:

a flexible substrate;

a semiconductor die attached to the flexible substrate; and

an encapsulating layer attached to the flexible substrate, the semiconductor die being encased between the flexible substrate and the encapsulating layer, the encapsulating layer including a polyimide adhesive, wherein the polyimide adhesive comprises an acrylic-based thermally conductive and electrically isolating polyimide adhesive.

2. The flexible integrated circuit module of claim 1, wherein the encapsulating layer further includes a thermoplastic resin.

3. The flexible integrated circuit module of claim 2, wherein the thermoplastic resin comprises a B-stage FR-4 glass-reinforced epoxy thermoplastic polymer or copolymer or blend.

4. The flexible integrated circuit module of claim 1, wherein the flexible substrate comprises a layer of flexible polymer and two layers of conductive material, each of the layers of conductive material being disposed on a respective side of the layer of flexible polymer.

5. The flexible integrated circuit module of claim 4, further comprising a second flexible substrate attached to the encapsulating layer on the opposite side of the flexible substrate, the second flexible substrate including one or more vias extending therethrough to the semiconductor die.

6. A flexible integrated circuit (IC) module comprising:

a flexible substrate;

a semiconductor die attached to the flexible substrate; and

an encapsulating layer attached to the flexible substrate, the encapsulating layer including a thermoplastic resin or a polyimide adhesive, or both, the semiconductor die being encased between the flexible substrate and the encapsulating layer,

wherein the thermoplastic resin comprises a B-stage FR-4 glass-reinforced epoxy thermoplastic polymer or copolymer or blend.

7. The flexible integrated circuit module of claim 6, wherein the polyimide adhesive comprises an acrylic-based thermally conductive and electrically isolating polyimide adhesive.

8. The flexible integrated circuit module of claim 6, wherein the semiconductor die comprises a wafer of electronic-grade silicon with an integrated circuit formed thereon.

9. The flexible integrated circuit module of claim 6, wherein the flexible substrate comprises a layer of flexible polymer and two layers of conductive material, each of the layers of conductive material being disposed on a respective side of the layer of flexible polymer.

10. The flexible integrated circuit module of claim 9, further comprising a second flexible substrate attached to the encapsulating layer on the opposite side of the flexible substrate, the second flexible substrate including one or more vias extending therethrough to the semiconductor die.

11. A flexible integrated circuit (IC) module comprising:

a flexible substrate;

a semiconductor die attached to the flexible substrate, the semiconductor die comprising a wafer of electronic-grade silicon with an integrated circuit formed thereon, and

an encapsulating layer attached to the flexible substrate, the semiconductor die being encased between the flexible substrate and the encapsulating layer, the encapsulating layer including a polyimide adhesive.

12. A flexible integrated circuit (IC) module comprising:

a flexible substrate including a layer of flexible polymer and two layers of conductive material, each of the layers of conductive material being disposed on a respective side of the layer of flexible polymer;

a semiconductor die attached to the flexible substrate; and

an encapsulating layer attached to the flexible substrate, the encapsulating layer including a thermoplastic resin or a polyimide adhesive, or both, the semiconductor die being encased between the flexible substrate and the encapsulating layer.

13. The flexible integrated circuit module of claim 12, wherein the layer of flexible polymer comprises a sheet of thermoset polyimide polymer, and the layers of conductive material each comprises a copper coating.

14. The flexible integrated circuit module of claim 13, wherein the layers of copper coating are each patterned on a respective side of the sheet of thermoset polyimide polymer.

15. The flexible integrated circuit module of claim 12, further comprising a second flexible substrate attached to the encapsulating layer on the opposite side of the flexible substrate.

16. The flexible integrated circuit module of claim 15, wherein the second flexible substrate comprises a second layer of flexible polymer and two second layers of conductive material, each of the second layers of conductive material being disposed on a respective side of the second layer of flexible polymer.

17. The flexible integrated circuit module of claim 16, wherein the second layer of flexible polymer comprises a sheet of thermoset polyimide polymer, and the second layers of conductive material each comprises a copper coating.

18. The flexible integrated circuit module of claim 15, wherein the second flexible substrate further comprises one or more vias extending therethrough to the semiconductor die.

19. The flexible integrated circuit module of claim 12, wherein the thermoplastic resin comprises a B-stage FR-4 glass-reinforced epoxy thermoplastic polymer or copolymer or blend and wherein the polyimide adhesive comprises an acrylic-based thermally conductive and electrically isolating polyimide adhesive.

20. The flexible integrated circuit module of claim 12, wherein the semiconductor die comprises a wafer of electronic-grade silicon with an integrated circuit formed thereon.

21. A flexible integrated circuit (IC) package for an extremely flexible electronic device, the flexible IC package comprising:

a first flexible substrate including a first layer of flexible polymer and a first pair of layers of conductive material, each of the first layers of conductive material being disposed on a respective side of the first layer of flexible polymer;

a silicon die attached to the first flexible substrate, the silicon die including a wafer of electronic-grade silicon with an integrated circuit formed thereon;

a second flexible substrate including a second layer of flexible polymer and a second pair of layers of conductive material, each of the second layers of conductive material being disposed on a respective side of the second layer of flexible polymer; and

an encapsulating layer disposed between and laminated to the first and second flexible substrates, the encapsulating layer including a thermoplastic resin or a polyimide adhesive, or both, encasing the silicon die.

22. The flexible integrated circuit package of claim 21, wherein the polyimide adhesive comprises an acrylic-based thermally conductive and electrically isolating polyimide adhesive.

23. The flexible integrated circuit package of claim 21, wherein the thermoplastic resin comprises a B-stage FR-4 glass-reinforced epoxy thermoplastic polymer or copolymer or blend.

24. The flexible integrated circuit package of claim 21, wherein the second flexible substrate further comprises one or more vias extending therethrough to the silicon die.