Integrated electro-optical flexible circuit board

Abstract

An integrated electro-optical circuit board comprises a first flexible substrate (10) having a top side and a bottom side, at least one first optical circuit (12) located on the bottom side of the first flexible substrate (10) and connected to the top side thereof through a filling hole (20), at least one first metal line (26) located on the top side of the first flexible substrate (10), an optical adhesive layer (16) connecting the bottom side of the first flexible substrate (10) to the top side of a second flexible substrate (18), and at least one second metal line (30) located on the bottom side of the second flexible substrate (18) and connected to the at least one first metal line (26) through a filling hole (22) passing through the second flexible substrate (18), the optical adhesive layer (16) and the first flexible substrate (10).

Description

Technical Field

[0001] The present invention relates to integrated circuit boards, and more particularly to integrated optical circuits with electronic circuit boards. Background Art

[0002] To support future devices with high-speed, high-capacity data transmission such as high-performance computing (HPC), optical interconnects are the technology of choice. Traditional electronic circuits with copper interconnects no longer meet the requirements due to their data bandwidth limitations and signal integrity issues. Optical interconnects offer many advantages for high-performance devices, achieving large data transmission rates at lower attenuation / loss, latency, and power consumption, while being virtually unaffected by electromagnetic interference and noise. At the same time, electrical interconnects are more suitable for power distribution and signal processing and control. Electrical interconnects are also a mature technology with a well-established infrastructure in the industry, so they have a clear cost advantage.

[0003] In recent years, flexible electronic devices have become a reliable solution for device miniaturization because they have many advantages over rigid electronic devices of printed circuit boards (PCBs), including higher circuit density, thinner profile, lighter weight, and good shape adaptability (foldable and bendable). In order to obtain higher circuit density, flexible electronic devices use a multi-layer circuit architecture, in which the circuits between the layers are connected by via holes filled with signal transmission materials.

[0004] By integrating optical and electronic interconnects into a single package, the advantages of both systems can be achieved. This is an attractive solution to meet the complex and demanding technical requirements of high-performance devices such as supercomputers, the Internet of Things (IoTs), telecommunication networks, image detection, smart displays, etc.

[0005] However, combining the two interconnect systems to achieve a compact packaging module poses significant challenges from a materials and processing perspective.

[0006] In optical circuits, optical signals are transmitted through a core material that must be completely enclosed by a cladding material. Since optical signals are transmitted based on the principle of total internal reflection, the refractive index of the core material must be higher than that of the cladding material. The core that acts as a waveguide to transmit optical signals is usually made of silicon, III-V semiconductors (III-V), glass or other polymer materials. In electronic circuits, electronic signals are usually transmitted through copper wires between insulating dielectric materials. As mentioned above, electronic interfaces have been properly formed, where copper is deposited, patterned, and etched on a dielectric surface (usually a flexible polyimide material) to form circuits. Since the requirements of each interface are significantly different, a novel material stacking combination is the key to realizing integrated electro-optical flexible circuit board modules. In this regard, glass has emerged as an attractive material due to its various unique properties and can be used for both optical and electronic interconnects. In optical interfaces, glass is suitable as a cladding material for a wide range of core materials due to its relatively low refractive index. In an electronic interface, glass provides excellent insulation performance with almost no dielectric loss for copper wire and via interconnects. Glass also has excellent thermal stability, and its thermal expansion coefficient is close to that of mainstream semiconductor materials such as silicon.

[0007] Many U.S. patents discuss opto-electronic integration, optical adhesives, and cyclic olefin polymers, including U.S. Patent Nos. 6,910,812 (Pommer et al.), 9,130,254 (Izadian), 9,110,200 (Nichol et al.), 10,089,516 (Popovich et al.), and U.S. Patent Application Nos. 2018 / 0138346 (Simavoryan et al.) and 2018 / 0226014 (Komanduri et al.). Summary of the invention

[0008] The main purpose of the present invention is to provide a method for embedding an optical circuit on a flexible electronic circuit.

[0009] Another object of the present invention is to provide an integrated electro-optical flexible circuit board.

[0010] Another object of the present invention is to provide an integrated electro-optical flexible circuit board coated with electronic and optical interconnects.

[0011] According to the purpose of the present invention, an integrated electro-optical flexible circuit board is provided, which includes a first flexible substrate having a top side and a bottom side, at least one first optical circuit located on the bottom side of the first flexible substrate and connected to its top side through a filled via, at least one first metal wire located on the top side of the first flexible substrate, an optical adhesive layer connecting the bottom side of the first flexible substrate to the top side of a second flexible substrate, and at least one second metal wire located on the bottom side of the second flexible substrate and connected to the at least one first metal wire through a filled via that passes through the second flexible substrate, the optical adhesive layer and the first flexible substrate.

[0012] According to the purpose of the present invention, an integrated electro-optical flexible circuit board is further provided, which includes a first flexible substrate having a top side and a bottom side, at least one first optical circuit located on the bottom side of the first flexible substrate and connected to its top side through a filled via, at least one first metal wire located on the top side of the first flexible substrate, an optical adhesive layer connecting the bottom side of the first flexible substrate to the top side of a second flexible substrate, at least one second metal wire located on the top side of the second flexible substrate, and at least one third metal wire located on the bottom side of the second flexible substrate and connected to the at least one second metal wire through a filled via passing through the second flexible substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In the accompanying drawings, which constitute an integral part of this specification, there is shown:

[0014] Figure 1 is an isometric schematic diagram of a first preferred embodiment of the present invention.

[0015] Figure 2 is an isometric schematic diagram of a second preferred embodiment of the present invention.

[0016] Figure 3 is an isometric schematic diagram of a third preferred embodiment of the present invention.

[0017] Figure 4 is an isometric schematic diagram of a fourth preferred embodiment of the present invention.

[0018] Figure 5 is a cross-sectional view of a fifth preferred embodiment of the present invention.

[0019] Figure 6 It is a cross-sectional view of a complete package of the present invention.

[0020] Description of Figure Numbers:

[0021] 10, 18, 19, 47, 49——Substrate

[0022] 12, 42——Optical circuit

[0023] 14, 44——Microscope

[0024] 16——Optical adhesive layer

[0025] 20, 22, 40, 54, 60, 61, 76——Through holes

[0026] 24, 28, 51, 56, 62, 66, 72, 78 - Seed layer

[0027] 26, 30, 53, 58, 64, 68, 74, 80——Metal wire

[0028] 50——Adhesive layer

[0029] 90——Surface Mount Device

[0030] 100 - Electronic devices

[0031] 102——Photoelectric devices

[0032] 104——Optical Interface

[0033] 106 - Signal DETAILED DESCRIPTION

[0034] The present invention discloses various versions of integrated electro-optical flexible circuit boards (EOFCB). The functions of these circuit boards include electronic and optical circuits, flexible electronic components and glass materials. Electronic circuits usually have low-speed signals and are usually used for power distribution, with low circuit density. Optical circuits usually have high-speed signals and high circuit density. Flexible electronic products have a small appearance and are relatively inconspicuous. They usually have a high wiring density and are foldable and bendable. Glass materials have a smooth, transparent surface and low dielectric signal loss.

[0035] The concept of the present invention is to embed an optical circuit on a flexible electronic circuit, and the manufacturing will be carried out on the same glass plate used for the flexible electronic circuit to provide better isolation characteristics. The present invention uses optical adhesive to form a core-clad structure on a waveguide, and directly metallizes the glass surface with copper through surface modification. The electro-optical flexible circuit board of the present invention has high coupling efficiency and low optical attenuation, wherein the coupling efficiency refers to the loss of the signal when it propagates between different interfaces / mediums, and the attenuation refers to the decrease in signal strength during transmission within the interface / medium.

[0036] The smooth glass surface of the substrate is suitable for thin film processing, thereby minimizing transmission losses. Due to the inherent properties of glass, the routing and through-hole layout will have minimal dielectric losses. Compared with separate optical modules and electronic modules that must be assembled on a printed circuit board (PCB) to form an interconnection, the present invention can significantly reduce the size through high-density wiring, multi-layer stack-up, and simplified module assembly process. Since cumbersome assembly steps can be avoided, the overall process can be simplified.

[0037] More specifically, please refer to Figure 1 , which shows an isometric schematic diagram of a first preferred embodiment of the present invention. The present invention provides a flexible glass 10 as a base film material. The thickness of the glass substrate ranges from about 12.5 to 100 μm. In an alternative, a cyclic olefin polymer (COP) can be used to replace the glass substrate to obtain higher bendability and flexibility. The core waveguide material is deposited on the glass substrate 10, and the refractive index of the waveguide material should be higher than the refractive index of the glass substrate 10. Various alternative materials for the waveguide material include silicon, silicon dioxide, gallium arsenide, gallium phosphide, and various types of polymers thereof, and the thickness of the waveguide material ranges from about 4 to 15 μm.

[0038] The waveguide material is patterned to form an optical circuit 12. A tapered structure with a 45° angle is formed at a specific location on the waveguide sidewall, and a 45° micro-mirror 14 is deposited on the top of the tapered surface.

[0039] The optical adhesive material 16 is laminated on the patterned waveguide optical circuit and the base film 10, and the optical adhesive must have the same refractive index as the flexible glass material 10. Various alternative materials for the optical adhesive material include epoxies, polyurethanes, silicone elastomers, UV-cured acrylics, and cyanoacrylates, and the thickness of the optical adhesive is between about 25 and 50 μm.

[0040] Next, a second base film material 18 , which may be flexible glass or cyclic olefin polymer (COP), is laminated on the other side of the optical adhesive, and the thickness of the second base film 18 is about 12.5 μm to 100 μm.

[0041] Through glass vias (TGV) 20 and 22 are formed by passing through a designated interface. For the optical through hole 20, the through glass via only passes through the base film interface 10, and the diameter of the through glass via can be 15 to 25 μm. The waveguide material can be selectively deposited and completely fill the optical through hole 20.

[0042] The outer surface of the flexible glass substrates 10 and 18 is modified to form a Si oligomer structure, followed by a stable Pd catalyst deposition through pentagonal ring coordination. A circuit pattern is formed on the modified flexible glass surface to form a copper circuit and fill the glass through hole 22 to connect one side of the circuit to the other side, wherein the thickness of the copper circuit ranges from 4 to 15 μm. The electronic interface is formed on the outer surface of the glass or COP substrates 10 and 18. For example, a seed layer composed of nickel phosphorus (Ni-P), copper, silver or any type of metal alloy (such as nickel-chromium alloy) can be formed on the outer surface of the substrates 10 and 18 according to the desired pattern. Then, copper wires can be plated on the seed layer, and the seed layer 24 and copper wires 26 are located on the outer surface of the substrate 10, and the seed layer 28 and copper wires 30 are located on the outer surface of the substrate 18. The filled glass through hole 22 connects at least one of the copper wires 30 to at least one of the copper wires 26.

[0043] Figure 2 This is the second preferred embodiment of the present invention. As in the first embodiment, this embodiment also provides a flexible glass 10 as a base film material. The thickness of the glass substrate ranges from about 12.5 to 100 μm. The core waveguide material is deposited on the glass substrate 10, wherein the refractive index of the waveguide material should be higher than the refractive index of the flexible glass substrate 10. Various alternative materials for the waveguide material include silicon, silicon dioxide, gallium arsenide, gallium phosphide, and various types of polymers thereof, and the thickness of the waveguide material ranges from about 4 to 15 μm.

[0044] The waveguide material is patterned to form an optical circuit 12. A tapered structure with a 45° angle is formed at a specific location on the waveguide sidewall, and a 45° micro-mirror 14 is deposited on the top of the tapered surface.

[0045] This embodiment provides a flexible glass 18 as a second base film material, with a thickness between about 12.5 and 100 μm, and a core waveguide material identical to the waveguide material 12 is deposited on the second glass substrate 18. The waveguide material is patterned to form a second optical circuit 42, a tapered structure with a 45° angle is formed at a specific position of the waveguide sidewall, and a second 45° micromirror 44 is deposited on the top of the tapered surface.

[0046] Glass substrates 10 and 18 are laminated together with optical adhesive material 16. Optical circuits 12 and 42 are laminated face to face in the optical adhesive. As mentioned above, the refractive index of the optical adhesive must be exactly the same as the refractive index of the flexible glass materials 10 and 18. Alternative materials for the optical adhesive include epoxy resin, polyurethane, silicone elastomer, UV curable acrylic and cyanoacrylate, and the optical adhesive has a thickness range of about 25 to 50 μm.

[0047] The package of this embodiment is similar to the first embodiment, having through glass vias (TGVs) 20 and 40 connected to optical circuits 12 and 42 respectively, and the TGL 22 connects the copper wire 26 on the first glass substrate 12 to the copper wire 30 on the second glass substrate 18 .

[0048] Figure 3 It is a third preferred embodiment of the present invention, as Figure 3 As shown, the second glass substrate 18 is replaced by polyimide (PI), modified polyimide (MPI), liquid crystal polymer (LCP), polyester (PET), polyethylene-naphtalate (PEN), polytetrafluoroethylene (poly tetra fluoro ethylene), or replaced by a laminate substrate 19 of epoxy resin (epoxies) and BT, or Teflon, or modified Teflon; the thickness of the second base film 19 ranges from 12.5 to 100um.

[0049] The optical circuit 12 and the micromirror 14 are formed on the bottom side of the glass substrate 10. The outer surface of the second substrate layer 19 is modified to form a polyamic acid (PAA) layer with a thickness ranging from 5-15 nm, followed by palladium catalyst deposition (Pdcatalyst deposition), and then the electronic circuit 53 and the seed layer 51 are formed on the top side of the substrate layer 19 and the metal line 30 and the seed layer 28 are formed on the bottom side of the substrate layer 19. The through hole 54 passes through the substrate 19 to connect at least one of the metal lines 53 on one side of the substrate layer 19 with at least one of the metal lines 30 on the opposite side of the substrate layer 19.

[0050] Figure 4 This is the fourth preferred embodiment of the present invention. This embodiment is similar to the third embodiment, wherein the second substrate 18 is replaced by polyimide (PI), modified polyimide (MPI), liquid crystal polymer (LCP), polyester (PET), polyethylene-naphtalate (PEN), polytetrafluoroethylene (PTFE), or replaced by a laminated substrate of epoxies and BT, or Teflon, or a modified Teflon layer 19. In the fourth embodiment, instead of using a single substrate layer 19, a multi-metal layer substrate of electronic interfaces is used, wherein bonding films are inserted between these interfaces.

[0051] In the fourth preferred embodiment, the optical circuit 12 and the micromirror 14 are formed on the bottom side of the glass substrate 10, the metal wire 53 having the seed layer 51 is formed on the top side of the substrate layer 19, and the metal wire 58 having the seed layer 56 is formed on the bottom side of the substrate layer 19. The through hole 54 passes through the substrate layer 19 to connect at least one of the metal wires 53 on one side of the substrate layer 19 with at least one of the metal wires 58 on the other side of the substrate layer 19. Similarly, the metal line 64 with the seed layer 62 is formed on one side of the second substrate layer 49, wherein the material of the substrate layer 49 can be polyimide (PI), modified polyimide (MPI), liquid crystal polymer (LCP), polyester (PET), polyethylene-naphtalate (PEN), polytetrafluoroethylene (PTFE), or a laminated substrate of epoxies and BT, or Teflon, or a modified Teflon layer. The two substrate layers 19 and 49 are laminated together with an adhesive layer 50 therebetween. The adhesive layer may be a fiber-reinforced adhesive film such as epoxy, cyanide ester, acrylic adhesive, modified polyimide (MPI) with epoxy, etc., and has a thickness between about 10 and 50 μm, and preferably about 25 μm.

[0052] As described above, the multi-metal layer substrate 19 / 50 / 49 is laminated to the base film board 10 using the optical adhesive 16, and then the top and bottom vias and traces are formed. Glass through holes 20 and 22 pass through the substrate 10 and the optical adhesive 16. The waveguide material can be selectively deposited and completely fill the optical through hole 20. The outer surface of the flexible glass substrate 10 is modified to form a Si oligomer structure, and then the palladium catalyst deposition is stabilized by pentagonal ring coordination. The electronic interface is formed on the outer surface of the glass substrate 10. For example, a seed layer of nickel phosphorus (Ni-P), copper, silver or any type of metal alloy (such as Nickel-Chromium) can be formed on the outer surface of the substrate 10 according to the desired pattern. Then, copper wires are plated on the seed layer, and the seed layer 24 and copper wires 26 are located on the outer surface of the substrate. The filled through glass via 22 connects at least one of the copper wires 26 to at least one of the copper wires 53 on the flexible multi-metal substrate 19 .

[0053] Likewise, through holes 60, 61 are formed through the base film 49 of the flexible multi-metal substrate and the adhesive film 50. The outer surface of the outer base film 49 is modified to form a polyamic acid (PAA) layer with a thickness ranging from 5 to 15 nm, followed by palladium catalyst deposition, and then an electronic circuit 68 with a seed layer 66 is formed on the outer surface of the base film layer 49.

[0054] Figure 5 This is the fifth preferred embodiment of the present invention. In this embodiment, there is a folded flexible polyimide substrate 47. A glass or COF substrate 10 is located between both ends of the folded flexible substrate 47. On one surface of the substrate 10 on which the waveguide circuit 12 having the micromirror 14 is formed, an optical adhesive layer 16 connects the substrate 10 to the flexible substrate 47. On the opposite other surface of the substrate 10, an adhesive film 50 connects the substrate 10 to an opposite arm of the flexible substrate 47.

[0055] Figure 6 The flexible circuit board is an integrated electro-optical flexible circuit board. Figure 1Similar. However, it should be understood that any of the first to fifth embodiments may be used in the manufacturing steps now described. Electronic devices 100 such as amplifiers and driver integrated circuits are mounted on top of copper traces 26 on one outer surface of the flexible circuit board. Optoelectronic devices 102 such as vertical-cavity surface-emitting lasers (VCSEL) and photodetector (PD) modules are mounted on the copper traces 26 on the same outer surface of the flexible circuit board. These devices 102 are aligned to the optical glass through holes 20. For example, the devices 100 and 102 can be mounted to a surface mount device (SMD) 90 by surface mount technology (SMT) such as flip chip or wire bonding. The optical interface 104 acts as a waveguide (medium) for incoming signals 106 from any other module, or for outgoing signals from the module of this packaging architecture.

[0056] The present invention has described various embodiments of an integrated electro-optical flexible circuit board. The electro-optical flexible circuit board of the present invention provides high coupling efficiency and low optical attenuation, and significantly reduces the size based on high-density wiring and multi-layer stacking.

[0057] Although the preferred embodiments of the present invention and details thereof have been disclosed above, it will be readily appreciated by those skilled in the art that various modifications may be made without departing from the spirit of the present invention or the scope of the appended claims.

Claims

1. An integrated electro-optical circuit board, comprising: a first flexible substrate having a top side and a bottom side; at least one first optical circuit located on the bottom side of the first flexible substrate and connected to the top side through a first filling hole; at least one first metal line located on the top side of the first flexible substrate; the first flexible substrate is glass or cyclic olefin polymer (COP); an optical adhesive layer connecting the bottom side of the first flexible substrate to a top side of a second flexible substrate; and at least one second metal line located on a bottom side of the second flexible substrate and connected to the at least one first metal line through a second filling hole passing through the second flexible substrate, the optical adhesive layer and the first flexible substrate. 2 . The integrated electro-optical circuit board as claimed in claim 1 , wherein a thickness of the first flexible substrate is 12.5-100 μm.

3. The integrated electro-optical circuit board as claimed in claim 1, wherein the at least one first optical circuit is a waveguide comprising silicon, silicon dioxide, gallium arsenide, gallium phosphide, or polymers thereof, and having a thickness of 4 to 15 μm and a refractive index higher than that of the first flexible substrate.

4. The integrated electro-optical circuit board as claimed in claim 3, further comprising a 45° micromirror located between the first optical circuit and the first filling hole.

5. The integrated electro-optical circuit board as claimed in claim 1, wherein the material of the optical adhesive layer comprises epoxy resin, polyurethane, silicone elastomer, UV-cured acrylic acid or cyanoacrylate, and has a thickness of 25 to 50 μm and a refractive index equivalent to that of the first flexible substrate. 6 . The integrated electro-optical circuit board as claimed in claim 1 , wherein the first metal line and the second metal line comprise copper with a thickness of 4 to 15 μm and a phosphorus nickel seed layer with a thickness of 0.01 to 0.5 μm thereunder. 7 . The integrated electro-optical circuit board as claimed in claim 1 , further comprising at least one second optical circuit located on the top side of the second flexible substrate. 8 . The integrated electro-optical circuit board as claimed in claim 1 , wherein the second flexible substrate is a flexible glass or cyclic olefin polymer (COP) with a thickness of 12.5-100 μm.

9. The integrated electro-optical circuit board as claimed in claim 1, further comprising: at least one electronic device mounted on the at least one first metal line; and at least one optoelectronic device mounted on the at least one first optical circuit.

10. The integrated electro-optical circuit board of claim 9, wherein the at least one electronic device and the at least one optoelectronic device are mounted by surface mounting technology (SMT) including flip chip and wire bonding.

11. An integrated electro-optical circuit board, comprising: a first flexible substrate having a top side and a bottom side; at least one first optical circuit located on the bottom side of the first flexible substrate and connected to the top side through a first filling hole; at least one first metal line located on the top side of the first flexible substrate; an optical adhesive layer connecting the bottom side of the first flexible substrate to a top side of a second flexible substrate; and at least one second metal line located on a top side of the second flexible substrate, and at least one third metal line located on a bottom side of the second flexible substrate and connected to the at least one second metal line via a second filling hole passing through the second flexible substrate. 12 . The integrated electro-optical circuit board as claimed in claim 11 , wherein the first flexible substrate is glass or cyclic olefin polymer (COP) with a thickness of 12.5-100 μm.

13. The integrated electro-optical circuit board of claim 11, wherein the at least one first optical circuit is a waveguide comprising silicon, silicon dioxide, gallium arsenide, gallium phosphide, or polymers thereof, and having a thickness of 4-15 μm and a refractive index higher than that of the first flexible substrate.

14. The integrated electro-optical circuit board as claimed in claim 13, further comprising a 45° micromirror located between the first optical circuit and the first filling hole.

15. The integrated electro-optical circuit board of claim 11, wherein the optical adhesive layer is made of epoxy resin, polyurethane, silicone elastomer, UV-cured acrylic acid or cyanoacrylate, and has a thickness between 25 and 50 μm and a refractive index equal to that of the first flexible substrate. 16 . The integrated electro-optical circuit board as claimed in claim 11 , wherein the first metal line, the second metal line and the third metal line comprise copper with a thickness of 4 to 15 μm and a phosphorus nickel seed layer with a thickness of 0.01 to 0.5 μm thereunder.

17. The integrated electro-optical circuit board as claimed in claim 11, wherein the second flexible substrate comprises polyimide (PI), modified polyimide (MPI), liquid crystal polymer (LCP), polyester (PET), polyethylene naphthalate (PEN), polytetrafluoroethylene, or a laminate substrate comprising epoxy resin and BT, Teflon or modified Teflon, and has a thickness of 12.5 to 100 μm.

18. The integrated electro-optical circuit board of claim 11, wherein the second flexible substrate comprises a multi-metal layer substrate.

19. The integrated electro-optical circuit board as claimed in claim 18, wherein the multi-metal layer substrate comprises a third flexible substrate and a fourth flexible substrate with an adhesive film therebetween, wherein a fourth metal line and a fifth metal line are formed on and pass through the third flexible substrate, a sixth metal line and a seventh metal line are formed on and pass through the fourth flexible substrate and the adhesive layer, the third flexible substrate and the fourth flexible substrate comprise polyimide (PI), modified polyimide (MPI), liquid crystal polymer (LCP), polyester (PET), polyethylene naphthalate (PEN), polytetrafluoroethylene, or a laminate substrate comprising epoxy resin and BT, Teflon or modified Teflon, and have a thickness of 12.5 to 100 μm.

20. The integrated electro-optical circuit board of claim 19, wherein: The multi-metal layer substrate includes a third flexible substrate, including polyimide (PI), modified polyimide (MPI), liquid crystal polymer (LCP), polyester (PET), polyethylene naphthalate (PEN), polytetrafluoroethylene, or a laminated substrate including epoxy resin and BT, Teflon or modified Teflon, and having a thickness of 12.5 to 100 μm; the fourth metal line is formed on and passes through a first half of the third flexible substrate; the second metal line and the third metal line are formed on and pass through a second half of the third flexible substrate; An adhesive film connects the first half of the third flexible substrate to a top side of the first flexible substrate; an electrical connection is formed between the first metal wire and the second metal wire; and the optical adhesive layer connects the bottom side of the first flexible substrate to the second half of the third flexible substrate.

21. The integrated electro-optical circuit board as claimed in claim 11, further comprising: at least one electronic device mounted on the at least one first metal line; and at least one optoelectronic device mounted on the at least one first optical circuit.

22. The integrated electro-optical circuit board of claim 21, wherein the at least one electronic device and the at least one optoelectronic device are mounted by surface mounting technology (SMT) including flip chip and wire bonding.

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