FLEXIBLE HYBRID INTERCONNECT CIRCUIT

• US 20200137882A1
• Filed: 10/29/2019
• Published: 04/30/2020
• Est. Priority Date: 10/29/2018
• Status: Active Grant

• Current Assignee: Cellink Corporation
• Original Assignee: Cellink Corporation
• Inventors: Coakley, Kevin Michael, Brown, Malcolm Parker, Juarez, Jose, Hernandez, Emily, Pratt, Joseph, Stone, Peter, Viswanath, Vidya, Findlay, Will
• Granted Patent: US 10,694,618 B2
• Time in Patent Office: Days
• CPC Class Codes: H01B 11/00 Communication cables or conductors
• CPC Class Codes: H01B 7/0838 Parallel wires, sandwiched between two insulating layers
• CPC Class Codes: H01B 7/0861 comprising one or more screens
• CPC Class Codes: H05K 1/0219 Printed shielding conductors for shielding around or between signal conductors, e.g. coplanar or coaxial printed shielding conductors
• CPC Class Codes: H05K 1/0225 Single or multiple openings in a shielding, ground or power plane H05K1/0227 takes precedence
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence
• CPC Class Codes: H05K 1/028 Bending or folding regions of flexible printed circuits H05K1/0283 takes precedence
• CPC Class Codes: H05K 1/0326 containing O
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 1/118 specially for flexible printed circuits, e.g. using folded portions
• CPC Class Codes: H05K 2201/0145 Polyester, e.g. polyethylene terephthalate [PET], polyethylene naphthalate [PEN]
• CPC Class Codes: H05K 2201/0154 Polyimide
• CPC Class Codes: H05K 2201/052 Branched
• CPC Class Codes: H05K 2201/068 wherein the coefficient of thermal expansion is important
• CPC Class Codes: H05K 2201/0715 provided by an outer layer of PCB
• CPC Class Codes: H05K 2201/0723 provided by an inner layer of PCB
• CPC Class Codes: H05K 2201/09509 Blind vias, i.e. vias having one side closed
• CPC Class Codes: H05K 2201/09563 Metal filled via
• CPC Class Codes: H05K 2201/0959 Plated through-holes or plated blind vias filled with insulating material
• CPC Class Codes: H05K 2201/10401 Eyelets, i.e. rings inserted into a hole through a circuit board

Abstract

Provided are flexible hybrid interconnect circuits and methods of forming thereof. A flexible hybrid interconnect circuit comprises multiple conductive layers, stacked and spaced apart along the thickness of the circuit. Each conductive layer comprises one or more conductive elements, one of which is operable as a high frequency (HF) signal line. Other conductive elements, in the same and other conductive layers, form an electromagnetic shield around the HF signal line. Some conductive elements in the same circuit are used for electrical power transmission. All conductive elements are supported by one or more inner dielectric layers and enclosed by outer dielectric layers. The overall stack is thin and flexible and may be conformally attached to a non-planar surface. Each conductive layer may be formed by patterning the same metallic sheet. Multiple pattern sheets are laminated together with inner and outer dielectric layers to form a flexible hybrid interconnect circuit.

Claims

1. A flexible hybrid interconnect circuit, having a length, a width, and a thickness, the flexible hybrid interconnect circuit comprising:

a first outer dielectric;

a second outer dielectric;

a signal transmission portion, disposed between the first outer dielectric and the second outer dielectric along the thickness of the flexible hybrid interconnect circuit, the signal transmission portion comprising;

a signal line;

a first shield;

a second shield, wherein the signal line is disposed between the first shield and the second shield along the width of the flexible hybrid interconnect circuit;

a third shield; and

a fourth shield, wherein the signal line is disposed between the third shield and the second shield along the thickness of the flexible hybrid interconnect circuit.

2. The flexible hybrid interconnect circuit of claim 1, wherein each of the first shield and the second shield is disposed between the third shield and the second shield along the thickness of the flexible hybrid interconnect circuit.

3. The flexible hybrid interconnect circuit of claim 2, wherein a size of a gap between the first shield and the third shield, a gap between the first shield and the fourth shield, a gap between the second shield and the third shield, and a gap between the second shield and the fourth shield along the thickness of the flexible hybrid interconnect circuit is less than 1 millimeter.

4. The flexible hybrid interconnect circuit of claim 2, wherein a size of a gap between the first shield and the third shield, a gap between the first shield and the fourth shield, a gap between the signal line and the third shield, a gap between the signal line and the fourth shield, a gap between the second shield and the third shield, and a gap between the second shield and the fourth shield along the thickness of the flexible hybrid interconnect circuit is substantially the same.

5. The flexible hybrid interconnect circuit of claim 1, wherein the signal line is electrically insulated from each of the first shield, the second shield, the third shield, and the fourth shield.

6. The flexible hybrid interconnect circuit of claim 1, further comprising a power transmission portion, disposed between the first outer dielectric and the second outer dielectric and offset relative to the signal transmission portion along the width of the flexible hybrid interconnect circuit, the power transmission portion comprising a first power conductor, a second power conductor, and a third power conductor, such that the third power conductor is disposed between the first power conductor and the second power conductor along the thickness of the flexible hybrid interconnect circuit.

7. The flexible hybrid interconnect circuit of claim 6, wherein a size of a gap between the signal line and the third shield, a gap between the signal line and the fourth shield, a gap between the first power conductor and the third power conductor, and a gap between the second power conductor and the third power conductor along the thickness of the flexible hybrid interconnect circuit is substantially the same.

8. The flexible hybrid interconnect circuit of claim 1, further comprising:

a first inner dielectric, disposed between the signal line and the third shield; and

a second inner dielectric disposed between the signal line and the fourth shield.

9. The flexible hybrid interconnect circuit of claim 8, wherein at least one of the first inner dielectric and the second inner dielectric comprises crosslinked low density polyethylene (LDPE).

10. The flexible hybrid interconnect circuit of claim 8, wherein:

the first inner dielectric comprises;

a first inner base, comprising polyethylene terephthalate (PET);

a first inner outer-facing adhesive; and

a first inner inner-facing adhesive; and

the first inner base is disposed between the first inner outer-facing adhesive and the first inner inner-facing adhesive along the thickness of the flexible hybrid interconnect circuit.

11. The flexible hybrid interconnect circuit of claim 10, wherein:

the first inner outer-facing adhesive directly interfaces the third shield; and

the first inner inner-facing adhesive directly interfaces the signal line.

12. The flexible hybrid interconnect circuit of claim 8, wherein the first inner dielectric directly interfaces the second inner dielectric between the signal line and the first shield.

13. The flexible hybrid interconnect circuit of claim 12, wherein at least one the first inner dielectric or the second inner dielectric is at least partially disposed between the signal line and the first shield.

14. The flexible hybrid interconnect circuit of claim 8, wherein at least one the first inner dielectric or the second inner dielectric comprises a flame retardant.

15. The flexible hybrid interconnect circuit of claim 1, wherein a thickness of each of the signal line, the first shield, and the second shield along the thickness of the flexible hybrid interconnect circuit is the same.

16. The flexible hybrid interconnect circuit of claim 1, wherein a composition of each of the signal line, the first shield, and the second shield is the same.

17. The flexible hybrid interconnect circuit of claim 1, wherein the signal line, the first shield, and the second shield are made from the same metal sheet.

18. The flexible hybrid interconnect circuit of claim 1, wherein the third shield comprises an opening.

19. The flexible hybrid interconnect circuit of claim 1, wherein the signal line comprises a signal tab extending outside of space between the first outer dielectric and the second outer dielectric.

20. The flexible hybrid interconnect circuit of claim 1, wherein the first outer dielectric comprises a first outer base and a first outer adhesive, the first outer adhesive directly interfacing the third shield.