INTERCHIP COMMUNICATION USING A DIELECTRIC WAVEGUIDE

• US 20130265732A1
• Filed: 04/04/2012
• Published: 10/10/2013
• Est. Priority Date: 04/04/2012
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Payne, Robert F., Corsi, Marco, Haroun, Baher S., Ali, Hassan, Herbsommer, Juan A.
• Granted Patent: US 9,405,064 B2
• Time in Patent Office: Days
• US Class Current: 361/774
• CPC Class Codes: G02B 6/12004 Combinations of two or more optical elements
• CPC Class Codes: G02B 6/1228 Tapered waveguides, e.g. integrated spot-size transformers for coupling with fibres G02B6/305
• CPC Class Codes: H01L 2223/6627 Waveguides, e.g. microstrip line, strip line, coplanar line
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01P 3/121 integrated in a substrate
• CPC Class Codes: H01P 3/16 Dielectric waveguides, i.e. without a longitudinal conductor
• CPC Class Codes: H05K 1/0239 Signal transmission by AC coupling
• CPC Class Codes: H05K 1/0243 Printed circuits associated with mounted high frequency components
• CPC Class Codes: H05K 1/025 Impedance arrangements, e.g. impedance matching, reduction of parasitic impedance H05K1/024 and H05K1/0243 take precedence; for semiconductor devices H01L23/66
• CPC Class Codes: H05K 1/0274 Optical details, e.g. printed circuits comprising integral optical means H05K1/0269 takes precedence; coupling light guides with opto-electronic components G02B6/42
• CPC Class Codes: H05K 1/115 Via connections; Lands around holes or via connections H05K1/112 takes precedence
• CPC Class Codes: H05K 1/18 Printed circuits structurally associated with non-printed electric components H05K1/0201, H05K1/023, H05K1/0243, and H05K1/16 take precedence
• CPC Class Codes: H05K 2201/0187 with regions of different dielectrics in the same layer, e.g. in a printed capacitor for locally changing the dielectric properties
• CPC Class Codes: H05K 2201/037 Hollow conductors, i.e. conductors partially or completely surrounding a void, e.g. hollow waveguides
• CPC Class Codes: H05K 2201/09618 Via fence, i.e. one-dimensional array of vias
• CPC Class Codes: H05K 2201/10098 Components for radio transmission, e.g. radio frequency identification [RFID] tag, printed or non-printed antennas

Abstract

An apparatus is provided. There is a circuit assembly with a package substrate and an integrated circuit (IC). The package substrate has a microstrip line, and the IC is secured to the package substrate and is electrically coupled to the microstrip line. A circuit board is also secured to the package substrate. A dielectric waveguide is secured to the circuit board. The dielectric waveguide has a dielectric core that extends into a transition region located between the dielectric waveguide and the microstrip line, and the microstrip line is configured to form a communication link with the dielectric waveguide.

Claims

1. An apparatus comprising:

a circuit board having a first side, a second side, and a first ground plane, wherein the first ground plane is formed on the first side of the circuit board;

a package substrate that is secured to the first side of the circuit board, wherein the package substrate includes;

a second ground plane that is electrically coupled to the first ground plane;

a microstrip line that is substantially parallel to the first and second ground planes, wherein the microstrip line has;

a first portion that overlays at least a portion of the second ground plane and that is separated from the second ground plane by a first distance, wherein the first portion of the microstrip line is dimensioned to have an impedance to propagate radiation having a wavelength; and

a second portion that overlays at least a portion of the first ground plane and that is separated from the first ground plane by a second distance, wherein the second distance is greater than the first distance, and wherein the second portion of the microstrip line is dimensioned to have the impedance to propagate the radiation having the wavelength, and wherein the second portion of the microstrip line is located within a transition region;

an integrated circuit (IC) that is secured to the package substrate and that is electrically coupled to the first portion of the microstrip line; and

a dielectric waveguide that is secured to the circuit board, wherein the dielectric waveguide includes a core that overlies at least a portion of the first ground plane and extends into the transition region.

2. The apparatus of claim 1, wherein the wavelength is less than or equal to about 1 mm.

3. The apparatus of claim 2, wherein the dielectric waveguide further comprises a cladding, and wherein the core has first dielectric constant, and wherein the cladding has a second dielectric constant, and wherein the first dielectric constant is greater than the second dielectric constant.

4. The apparatus of claim 3, wherein the package substrate has first and second sides, and wherein the microstrip line is formed on the first side of the package substrate, and wherein the IC is secured to the first side of the package substrate, and wherein the first ground plane is formed on the second side of the package substrate.

5. The apparatus of claim 4, wherein at least one solder ball is secured to the first and second ground planes.

6. The apparatus of claim 5, wherein the impedance is about 50 Ω

.

7. The apparatus of claim 6, wherein the first portion of the microstrip line is generally rectangular, and wherein the second portion of the microstrip line is generally rectangular.

8. An apparatus comprising:

a circuit board having a first side, a second sides, and a plurality of circuit board ground planes, wherein each circuit board ground plane is formed on the first side of the circuit board;

a plurality of package substrates, wherein each package substrate is secured to the first side of the circuit board, and wherein each is collocated with at least one of the circuit board ground planes, wherein each package substrate includes;

a package substrate ground plane that is electrically coupled to its circuit board ground plane;

a microstrip line that is substantially parallel to its package substrate ground plane and its circuit board ground plane, wherein the microstrip line has;

a first portion that overlays at least a portion of its package substrate ground plane and that is separated from its package substrate ground plane by a first distance, wherein the first portion of the microstrip line is dimensioned to have an impedance to propagate radiation having a wavelength; and

a second portion that overlays at least a portion of its circuit board ground plane and that is separated from its circuit board ground plane by a second distance, wherein the second distance is greater than the first distance, and wherein the second portion of the microstrip line is dimensioned to have the impedance to propagate the radiation having the wavelength, and wherein the second portion of the microstrip line is located within a transition region;

a plurality of ICs, wherein each IC is secured to at least one of the package substrates and is electrically coupled to the first portion of its microstrip line; and

a dielectric waveguide network that is secured to the circuit board, wherein a core from dielectric waveguide network the overlies at least a portion of each circuit board ground plane and extends into its transition region.

9. The apparatus of claim 8, wherein the wavelength is less than or equal to about 1 mm.

10. The apparatus of claim 9, wherein the dielectric waveguide network further a plurality of dielectric waveguides having a cladding, and wherein the core has first dielectric constant, and wherein the cladding has a second dielectric constant, and wherein the first dielectric constant is greater than the second dielectric constant.

11. The apparatus of claim 10, wherein each package substrate has first and second sides, and wherein the microstrip line is formed on the first side of the package substrate, and wherein the IC is secured to the first side of the package substrate, and wherein the package substrate ground plane is formed on the second side of the package substrate.

12. The apparatus of claim 11, wherein at least one solder ball is secured to the circuit board ground plane and the package substrate ground planes for each package substrate.

13. The apparatus of claim 12, wherein the impedance is about 50 Ω

.

14. The apparatus of claim 13, wherein the first portion of the microstrip line is generally rectangular, and wherein the second portion of the microstrip line is generally rectangular.

15. An apparatus comprising:

a circuit board having a first side, a second sides, a first ground plane, and a second ground plane, wherein the first and second ground planes are formed on the first side of the circuit board, and wherein the first and second ground planes are separated from one another;

a first package substrate that is secured to the first side of the circuit board, wherein the first package substrate includes;

a third ground plane that is electrically coupled to the first ground plane;

a first microstrip line that is substantially parallel to the first and third ground planes, wherein the first microstrip line has;

a first portion that overlays at least a portion of the third ground plane and that is separated from the third ground plane by a first distance, wherein the first portion of the first microstrip line is dimensioned to have an impedance to propagate radiation having a wavelength; and

a second portion that overlays at least a portion of the first ground plane and that is separated from the first ground plane by a second distance, wherein the second distance is greater than the first distance, and wherein the second portion of the first microstrip line is dimensioned to have the impedance to propagate the radiation having the wavelength, and wherein the second portion of the first microstrip line is located within a first transition region;

a first IC that is secured to the package substrate and that is electrically coupled to the first portion of the first microstrip line;

a second package substrate that is secured to the first side of the circuit board, wherein the second package substrate includes;

a fourth ground plane that is electrically coupled to the second ground plane;

a second microstrip line that is substantially parallel to the second and fourth ground planes, wherein the second microstrip line has;

a first portion that overlays at least a portion of the fourth ground plane and that is separated from the fourth ground plane by a third distance, wherein the first portion of the second microstrip line is dimensioned to have the impedance to propagate the radiation having the wavelength; and

a second portion that overlays at least a portion of the second ground plane and that is separated from the second ground plane by a fourth distance, wherein the fourth distance is greater than the third distance, and wherein the second portion of the second microstrip line is dimensioned to have the impedance to propagate the radiation having the wavelength, and wherein the second portion of the second microstrip line is located within a second transition region;

a second IC that is secured to the package substrate and that is electrically coupled to the first portion of the second microstrip line; and

a dielectric waveguide having;

a core with first and second ends, wherein the core is secured to the circuit board and overlies at least a portion of the first and second ground planes, and wherein the first end of the core extends into the first transition region, and wherein the second end of the core extends into the second transition region, and wherein the core has a first dielectric constant; and

a cladding that is secured to the core, wherein the cladding has a second dielectric constant, and wherein the first dielectric constant is greater than the second dielectric constant.

16. The apparatus of claim 15, wherein the wavelength is less than or equal to about 1 mm.

17. The apparatus of claim 16, wherein each of the first and second package substrates has first and second sides, and wherein its microstrip line is formed on the first side of the package substrate, and wherein its IC is secured to the first side of the package substrate, and wherein its first ground plane is formed on the second side of the package substrate.

18. The apparatus of claim 17, wherein at least one solder ball is secured to the first and third ground planes, and at least one solder ball is secured to the second and fourth ground planes.

19. The apparatus of claim 18, wherein the impedance is about 50 Ω

.

20. The apparatus of claim 19, wherein the first portion of each of the first and second microstrip lines is generally rectangular, and wherein the second portion of each of the first and second microstrip lines is generally rectangular.