STACKABLE OPTOELECTRONICS CHIP-TO-CHIP INTERCONNECTS AND METHOD OF MANUFACTURING

• US 20050224946A1
• Filed: 02/26/2005
• Published: 10/13/2005
• Est. Priority Date: 02/27/2004
• Status: Active Grant

• Current Assignee: Banpil Photonics, Inc.
• Original Assignee: Banpil Photonics, Inc.
• Inventors: Dutta, Achyut Kumar
• Granted Patent: US 7,271,461 B2
• Time in Patent Office: Days
• US Class Current: 257/686
• CPC Class Codes: G02B 2006/12147 Coupler
• CPC Class Codes: G02B 6/12002 Three-dimensional structures
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/4224 using visual alignment markings, e.g. index methods
• CPC Class Codes: G02B 6/4257 having a supporting carrier or a mounting substrate or a mounting plate G02B6/3648 takes precedence
• CPC Class Codes: G02B 6/4268 Cooling of semiconductor devices H01L23/24; of electric apparatus H05K7/20; of instruments G12B15/00
• CPC Class Codes: G02B 6/4279 Radio frequency signal propagation aspects of the electrical connection, high frequency adaptations
• CPC Class Codes: G02B 6/428 containing printed circuit boards [PCB]
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16238 the bump connector connecting to a bonding area protruding from the surface of the item
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48106 the connector being orthogonal to a side surface of the semiconductor or solid-state body, e.g. parallel layout
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 24/17 : of a plurality of bump connectors
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 25/167 : comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/10329 : Gallium arsenide [GaAs]
• CPC Class Codes: H01L 2924/10335 : Indium phosphide [InP]
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/12043 : Photo diode
• CPC Class Codes: H01L 2924/1432 : Central processing unit [CPU]
• CPC Class Codes: H01L 2924/1434 : Memory
• CPC Class Codes: H01L 2924/1461 : MEMS
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01S 5/02325 : Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/0237 : by soldering
• CPC Class Codes: H01S 5/183 : having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
• 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 1/141 : One or more single auxiliary printed circuits mounted on a main printed circuit, e.g. modules, adapters H05K1/142 and H05K1/147 take precedence
• CPC Class Codes: H05K 1/144 : Stacked arrangements of planar printed circuit boards
• CPC Class Codes: H05K 1/181 : associated with surface mounted components
• CPC Class Codes: H05K 2201/10121 : Optical component, e.g. opto-electronic component
• CPC Class Codes: H05K 2201/10515 : Stacked components
• CPC Class Codes: H05K 2201/10734 : Ball grid array [BGA]; Bump grid array
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

An optoelectronics chip-to-chip interconnects system is provided, including packaged chips to be connected on printed-circuit-board (PCB), multiple-packaged chip, optical-electrical(O-E) conversion means, waveguide-board, and PCB. Single to multiple chips interconnects can be possible using this technique. The packaged-chip includes semiconductor-die and its package based on the ball-grid array or chip-scale-package. The O-E board includes the optoelectronics components and multiple electrical contacts. The waveguide board includes electrical conductors transferring signal from O-E board to PCB and the flex optical waveguide easily stackable onto the PCB, to guide optical signal from one chip-to-other chip. The chip-to-chip interconnects system is pin-free and compatible with the PCB. The main advantages are that standard packaged-chip and conventional PCB technology can be used for low speed electrical signal connection. Also, the part of the heat from the packaged chip can be transmitted to PCB through conductors, so that complex cooling system can be avoided.

Claims

1. An optoelectronics chip-to-chip interconnects system comprising,

(a) a single or plurality of packaged chip;

(b) single or plurality of E-O board located in close physical proximity of each said packaged-chip, and said E-O board comprising;

(i) an E-O means for converting the high speed electrical signal from the said packaged-chip to optical signal;

(ii) an O-E means for converting the high speed optical signal to the electrical signal for feeding to the said packaged-chip, and;

(iii) a plurality of the electrical contacts means to transfer the electrical connections (other than the high speed signal connection) from the said packaged-chip to the external board;

(c) a waveguide board located in close physical proximity to the said E-O board, and the said waveguide board comprising;

(i) a single or plurality of the waveguides as optical media in the said waveguide board for transmitting and receiving the optical signal, wherein each waveguide has the beam directing portions located at the end of each transmitting and receiving sides, and;

(ii) a set of the electrical contacts for external electrical connection, and;

(d) a single-layered or multilayered printed circuit board with the said packaged chip, the said waveguide board located on the top surface, and with low speed electrical paths for the electrical connections.

2. The said packaged-chip as claimed in claim 1, comprising,

(a) die of electronics very-large scale integrated circuit, and;

(b) packaged-chip.

3. The said die, as claimed in claim 2 is made from silicon or III-V based semiconductor materials.

4. The said packaged-chip, as claimed in claim 1 is made from chip scale packaging, wherein the chip is bonded using fine ball-grid-array (FBGA) or micro-ball-grid array (MBGA).

5. The said packaged-chip as claimed in claim 1, further comprising,

(a) die of electronics very-large scale integrated circuit, and;

(b) a set of electrical contacts for external connections.

6. The said O-E (or E-O) board as claimed in claim 1 has plurality of electrical connections on both sides, wherein the said chip package is connected on one side, and the printed circuit board is connected to other side.

7. The O-E (or E-O) board as claimed in claim 1 further comprising,

(a) a substrate;

(b) a plurality of the electrical contacts in both sides of the O-E ( or E-O) board, and;

(c ) a set of optical components for converting electrical signal of the said packaged-chip to optical signal for transmitting to single or plurality of packaged-chip through the said waveguide, and vice versa, for converting received optical signal electrical signal for communicating single or plurality of packaged-chip.

8. The said substrate of the O-E (or E-O) board, as claimed in claim 7 includes non-electrically conductive materials.

9. The said substrate of the O-E (or E-O) board, as claimed in claim 7 includes the rigid or flexes substrate.

10. The O-E board as claimed in claim 1, wherein each contact within the plurality of electrical contacts in front (top) side is arranged in such a way that the pitch of the contacts in front side is the same as those of the said packaged-chip, so as to make easiness in mounting, bonding, or stacking.

11. The O-E board as claimed in claim 1, wherein the contacts in opposite side of the said O-E (or E-O) board are arranged in such as way that the high-speed electrical signal lines are in the same row(s), and the power and ground lines are arranged in different rows or arranged in peripherals of the board.

12. The high-speed electrical signal lines as claimed in claim 11, are arranged in one or multiple rows so that optoelectronics devices can be bonded on the O-E (or E-O) board in discrete or in array form.

13. The contacts for the power and ground lines in opposite (bottom) side of the said O-E (or E-O) board as claimed in claim 11 are connected to the underlying printed circuit board by using of appropriate solder bumps having appropriate height so as not to touching the optical components to the printed circuit board.

14. The said O-E board as claimed in claim 7, wherein the optical devices include surface emitting type transmitting source and surface incidence type receiving device.

15. The surface emitting type transmitting sources as claimed in claim 14 include the transmitting means which emits light beam having the wavelengths of 600 nm, 650 nm, 780 nm, 850 nm, 980 nm, or 1310 nm or 1550 nm, and they are fabricated onto the compound semiconductor substrates (GaAs or InP).

16. The surface emitting type transmitting sources as claimed in claim 14 include the top or bottom emitting type surface emitting laser diode (VCSEL) which is bonded onto the said O-E board in upside down so as to direct the light beam to the said waveguide.

17. The surface emitting type transmitting sources as claimed in claim 14 includes the edge emitter type laser diode bonded on the carrier with a 45 degree mirror to direct the light beam in vertical direction, the edge emitter with carrier is bonded onto the said O-E board so as to direct the out-coming light beam corresponding to the electrical signal to the said waveguide located onto the printed circuit board.

18. The surface emitting type transmitting sources as claimed in claim 14 further comprising the laser diode integrated modulator and the carrier with 45 degree mirror to direct the modulated light beam in vertical direction, the modulator integrated laser diode with carrier is bonded onto the said O-E board so as to direct the out-coming light beam corresponding to the electrical signal to the said waveguide located onto the printed circuit board.

19. The surface incident type receiving devices as claimed in claim 14 include the p-i-n based or metal-semiconductor-metal based photodetector, bonded onto the said O-E board facing towards the light beam receiving from waveguide to convert to electrical signal proportional to the received optical signal.

20. The substrate of the said O-E board as claimed in claim 1, wherein the optical components are bonded using the flip-chip technique using of the solder bumps.

21. The optical components as claimed in claim 20 wherein the bump comprises a material selected from the group consisting of solders, conductive polymers and plated metals.

22. The said O-E board as claimed in claim 1 further comprises polymer layer having the refractive indices from 1.3 to 3.7, and transparent to the wavelength of the light beam, and formed on the optical components.

23. The polymer layer as claimed in claim 22, wherein the material is electrical non-conductive.

24. The packaging of the said O-E (or E-O) board and said packaged-chip, comprising,

(a) single or plurality of semiconductor optical components comprising first face for emitting or receiving light, and a second (opposite) face having plurality of electrical contacts;

(b) flex circuit board having the first side and second side, wherein plurality of peripheral electrical contacts are on the first side in ball grid array or fine ball grid array, and a plurality of electrical contacts on the second side in ball grid array or fine ball grid array in electrical communication with the external contacts, arranged in a way compatible to the electrical contacts of the said packaged-chip;

(c) single or multiple separation layer in between the flex-circuit board and packaged-chip, and;

(d) the packaged-chip having peripheral plurality of electrical contacts on the face, and each contact comprising a bump or electrical pad;

wherein the said semiconductor optical component and flex circuit board form the O-E (or E-O) board and the said semiconductor optical component bonded on the second side of the flex circuit board.

25. The semiconductor optical components as claimed in claim 24 are bonded using the flip-chip-technique using of the solder bumps.

26. The semiconductor optical components as claimed in claim 24 wherein the bump comprises a material selected from single of multiple groups, consisting of solders, conductive polymers and plated metals.

27. The semiconductor optical components as claimed in 24 cover the semiconductor die having light receiving or emitting capability in vertical direction, and also its package comprising the semiconductor optical components die and the carrier to redirect the light in vertical direction.

28. The semiconductor optical components as claimed in claim 24 further comprising the passivation layer immersing the semiconductor optical components.

29. The semiconductor optical components as claimed in claim 24 further comprise the lens on the top of the passivation layer.

30. The passivation layer as claimed in claims 28 comprises a polymer material selected from the groups of materials having the lower refractive index and the low adherence to moisture.

31. The lens as claimed in the claim 29 comprises the material of same of passivation layer or the different polymer material.

32. The optical components as claimed in claim 24 wherein the contacts comprise bond pads.

33. The said separation layer as claimed in claim 24 comprises isotropic or anisotropic conductive material.

34. Anisotropic conductive material as claimed in claim 33 comprises a z-axis anisotropic adhesive or polymer material.

35. The said separation layer as claimed in claim 24 comprises an electrically insulating adhesive layer.

36. The packaging of the said O-E board comprising,

(a) the packaged-chip having a face and a plurality of electrical contacts with first bumps or pads formed thereon;

(b) single or plurality of semiconductor optical components comprising the first face for emitting or receiving light, and second (opposite) face having plurality of electrical contacts;

(c) a flex circuit, comprising a polymer substrate with an external electrical contact formed on one face, and a conductor passing through the flex circuit substrate in electrical communication with the external electrical contacts located on opposite face, said conductor including an opening therein proximate to the first bump, and;

(d) a second bump located on one side of the said flex circuit are connected to the opposite side by the said conductor, and the said first and second bumps configured to form a electrical connection between the O-E board and the packaged-chip;

wherein the said openings are arranged in such a way that when pushing by the tilt, the conductor would get bent and make electrical connection between O-E board and the said packaged-chip.

37. The package as claimed in claim 36 wherein the first and second bumps comprise a material selected from the class consisting of gold and palladium, or any conductive polymer.

38. The package as claimed in claim 36, wherein the second bump includes a peripheral shoulder engaging the opening in the conductor.

39. The package as claimed in claim 36 wherein the said flex circuit includes a plurality of external contacts in a ball grid array or fine ball grid array.

40. The package as claimed in claim 36 wherein the first and second bumps comprise metal bumps formed using a wire bonding apparatus or a ball bumper apparatus.

41. The optical components as claimed in claim 36 wherein the contacts comprise bond pads.

42. The semiconductor optical components as claimed in 36 cover the semiconductor die having the light receiving or emitting capability in vertical direction, and also the package comprising the semiconductor optical components die and the carrier to redirect the light in vertical direction.

43. The semiconductor optical components as claimed in claim 42 further comprising the passivation layer immersing the semiconductor optical components.

44. The semiconductor optical components as claimed in claim 42 further comprise the lens on the top of the passivation layer.

45. The passivation layer as claimed in claims 43 comprises a polymer material selected from the groups of materials having the lower refractive index and the low adherence to moisture.

46. The lens as claimed in the claim 44 comprises the material of same of passivation layer or the different polymer material.

47. The packaging as claimed in claim 36 wherein the conductive polymer layer comprises a z-axis anisotropic adhesive.

48. The said waveguid board as claimed in claim 1 comprising,

(a) single or plurality of the waveguides;

(b) single or plurality of the electrical contacts located on both sides of the said waveguide board, wherein each electrical contact in one side is connecting to one contact in other side of the said waveguide-board;

(c) a flex substrate on which the waveguide is formed, a 45 degree mirror formed at the end of each said waveguide to redirect the light beam vertically, and;

(d) with or without microlens, discretely or monolithically onto the said 45 degree mirror.

49. The said waveguide board as claimed in claim 1 comprising,

(a) single or plurality of the optical fibers;

(b) single or plurality of the electrical contacts located on both sides of the said waveguide board, wherein each electrical contact in one side is connecting to one contact in other side of the said waveguide-board;

(c) a flex substrate on which the waveguide is formed;

(d) a 45 degree mirror formed at the end of each said optical fiber to redirect the light beam vertically, and;

(e) with or without microlens, discretely or monolithically onto the said 45 degree mirror.

50. The said waveguid board as claimed in claim 1 comprising,

(a) single or plurality of the waveguide;

(b) a flex substrate on which the waveguide is formed;

(c) a 45 degree mirror formed at the end of each waveguide to redirect the light beam vertically, and;

(d) with or without microlens, discretely or monolithically onto the said 45 degree mirror.

51. The said waveguide board as claimed in claim 1, comprising,

(a) single or plurality of the optical fibers;

(b) a flex substrate on which the waveguide is formed;

(c) a 45 degree mirror formed at the end of each fiber to redirect the light beam vertically, and;

(d) with or without focusing means based on microlens (or grating), discretely or monolithically onto the said 45 degree mirror.

52. The said waveguide as claimed in claim 48, comprising, (a) a flex substrate;

(b) core layer, and;

(c) clad layer.

53. The said optical fiber as claimed in claim 49, comprising, (a) a flex substrate;

(b) core layer, and;

(c) clad layer.

54. The said fibers as claimed in claim 49 are made using the bare fiber, the etching and/or molding using of master mold.

55. The said master-mold as claimed in claim 54 is made by patterning the substrate and the metal plating, and the master mold pattern height is equal to the depth of the core.

56. The said electrical contacts as claimed in claim 1 covers all low-speed electrical signals (ground, power line, and control), and are arranged either as the same as of the said packaged chip or in peripheral outlined.

57. The said chip-to-chip interconnects system as claimed in claim 1 covers also to efficient heat dissipation through the electrical conductors claimed for the low speed electrical signal.