JP2001044582A - Photoelectric mixed wiring board, drive method therefor and electronic circuit device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric mixed wiring board, in which the electric and optical mixed connection coping with optical interconnection can be realized at a low power consumption and a low cost, while electronic integrated elements are mounted by the conventional IC package, etc. SOLUTION: In photoelectric mixed wiring boards 1 and 2, an electric wiring 3 and an optical waveguide are formed on the same wiring board, and the wiring board is provided with optical elements 8 and 9 for photoelectrically converting the signal of an electronic integrated element 6 to input/output by an optical signal, a wiring to the optical elements 8 and 9, and a mounting part exposing an electrical terminal 5 for mounting the electronic integrated element 6. By only connecting electric terminals 5 and 10 with each other and mounting the electronic integrated element 6 to the mounting part, a signal can be given and received between the electronic integrated element 6 and wiring boards 1 and 2, at least partly through optical signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an opto-electric hybrid wiring board connected to an electronic integrated device constituting an electronic apparatus, and more particularly to a method for mounting an electronic integrated device and exchanging signals by optical interconnection. And a method of driving the same.

[0002]

2. Description of the Related Art In recent years, with the speeding up of computer environments including information processing, displays, printers, and the like, high-speed LSI (large scale integration) has been developed.
on) is under development. Then, IC (integrated circuit) in the LSI chip
In the board, MCM (multi-chip-modul)
e) In the connection of electronic devices such as high-speed connections such as backplanes in supercomputers, between boards, computers, peripheral devices and audio-visual (AV) devices, signal delay and heat generation due to electric wiring. And problems such as generation of EMI (electromagnetic radiation noise) have surfaced. However, it is difficult to take countermeasures, and it is clear that the limitations of electrical wiring will be seen in the near future.

In order to solve the problem that occurs in the electric wiring, a board using a rambus-type microstrip line in a board or a differential signal (LVDS: low voltage diage) having a small amplitude between boards is used.
A method of transmitting a ferential signal through a shield line is being developed. In the former Rambus system, signal transmission over 400 MHz has been achieved, and the next PC (personal computer) has been achieved.
r). However, there are restrictions on the wiring method, mounting on the LSI side, pin arrangement, and the like. Therefore, there is a problem that the cost of the chip is increased, the wiring is not suitable for long wiring, and the multi-bit wiring is limited in terms of high density in order to avoid crosstalk and the substrate becomes large. Also,
In the latter case, high-speed serial transmission using LVDS (up to 1 Gb
ps) has been put to practical use, but the range of use is limited due to the expensive interface ICs and cables.

On the other hand, an optical interconnection technique is being developed as a method of overcoming the limitations of the electric wiring. The optical interconnection converts an electric signal from an IC or the like into E (electricity) / O (light), and converts the converted optical signal to another IC or board through an optical wiring (such as an optical waveguide) formed in the board. The signal is transmitted to the photodetector, and then converted to an electrical signal by O / E conversion to exchange signals. This method is expected as a next-generation wiring technology because there is no signal delay due to parasitic capacitance as in the case of electric wiring, signal deterioration due to ground instability, EMI radiation radiated from the wiring, and the like. In this optical interconnection, the O / E and E / O conversion portions and the optical waveguide portion are important, and how to efficiently replace a part of the electrical wiring with the optical wiring while reducing the cost is important. It is an issue.

[0005] An example of an optical wiring is disclosed in Japanese Patent Application Laid-Open No. 5-6777.
As disclosed in Japanese Patent Application Publication No. 0, there is a device in which an optoelectronic IC chip on which a light emitting element is mounted is mounted on an optical wiring board having an optical waveguide and a reflection mirror instead of the pins of the IC chip. This is shown in FIG. Optoelectronic IC chip 100
4, a light emitting element 1011 is provided on the back side,
001 has an inclined portion 1005 serving as a reflection mirror, and an optical signal from the light emitting element 1011 is transmitted to the optical waveguide (core) 100.
8 and the light receiving element 1012 of another chip 1004
The signals are exchanged through the reception of the light. However, in this example, although there is a description of a method of optical coupling between the optical elements 1011 and 1012 and the optical waveguide (core) 1008, the electronic circuit unit 1010 and the optical elements 1011 and 101 are described.
No specific integration method or driving method with No. 2 is described. In addition, 1002 is a reflective film, 1006 is a convex part, 10
Reference numeral 07 denotes a silicon oxide film.

On the other hand, as an example of a method of driving an optical element for optical wiring, as described in Japanese Patent Application Laid-Open No. 9-96746, a signal output from a laser is output by a coupler formed by a planar optical waveguide. E / O with an electro-absorption optical modulator or a Mach-Zehnder optical switch
Conversion methods are known. This example is shown in FIG. In this case, since the electric wiring section and the optical wiring section are designed independently as described in FIG. 13B, the substrate is not complicated, and there is no need to prepare a special IC for driving the optical element. Therefore, since it is only necessary to add an optical wiring section to a conventional electric printed circuit board or the like, the method is easy to introduce into an electronic device.

[0007]

However, in the method shown in FIG. 13, the optical wiring section may be provided separately from the electric circuit, but the thickness is increased, so that the size is larger than that of the opto-electronic hybrid board shown in FIG. It will be. In addition, in the case of multi-channels, the cost is increased due to the provision of a plurality of high-performance elements such as optical modulators and optical switches, and the reliability of electrode contacts from electrical signals to the modulator, mounting restrictions, and modulation The problem of crosstalk between devices occurs. Further, since the light is branched by the coupler and further coupled to an optical modulator or the like, light loss is large, and power consumption becomes a problem in securing the output power of the laser.

On the other hand, although the configuration is unknown in the system of FIG. 12, the optical element and the electric element are packaged in the same package.
It is thought that miniaturization can be achieved by high integration, and the reliability of wiring and the like is also improved. However, the opto-electronic integrated circuit packaged in the same package requires a fundamental design change of the mounting method of the conventional electronic integrated circuit. Therefore, in order to introduce this into an electronic device, it takes time to maintain a manufacturing technique such as a change of a design or a manufacturing apparatus, and an initial cost may be increased.

Accordingly, an object of the present invention is to provide an electric / optical hybrid connection corresponding to an optical interconnection, with a low power consumption and low cost, with the electronic integrated device to be mounted being a conventional IC package or the like. It is an object of the present invention to provide an opto-electric hybrid wiring board configured as described above, a driving method thereof, and the like.

[0010]

According to the opto-electric hybrid wiring board of the present invention for mounting an electronic integrated device which achieves the above object, an electric wiring and an optical waveguide are formed on the same wiring board. The wiring board is provided with an optical element for performing photoelectric conversion for performing input / output of a signal of the integrated element by an optical signal, a wiring to the optical element, and an exposed mounting portion of an electric terminal for mounting the electronic integrated element. The electronic integrated device is configured such that at least a part of transmission and reception of a signal between the electronic integrated device and the wiring substrate can be performed by an optical signal only by electrically mounting the electronic integrated device to the mounting portion by coupling the electric terminals. It is characterized by having. As a result, the O / E and E / O converters are the same on the mounting substrate side without changing the package of the electronic integrated device to perform optical interconnection with small size, low power consumption and low cost. An opto-electric hybrid board integrated on the substrate can be realized. In this configuration, O / E,
Only the optical element for performing the E / O conversion is integrated with the optical wiring layer, which is further integrated with the electric wiring board, and the wiring between the electrode on which the electronic integrated element is electrically mounted and the optical element is formed over a short distance. By doing so, it is possible to simultaneously achieve small size, low power consumption, and low cost in mixing optical wiring and electric wiring.

Based on this basic configuration, the following suitable modes are possible. The optical element is a surface-type optical element, and the optical element is surface-mounted with its surfaces in contact with the light input / output ends of the optical waveguide. Thereby, the arrangement of the optical element and the wiring to the optical element can be easily performed. An array of optical elements is also easy. Further, when mounting an optical element on an opto-electric hybrid wiring board in which an electric wiring board and a layer on which an optical waveguide is formed are stacked, the light input / output end face of the optical element and the light input / output end face of the optical waveguide can be easily and accurately determined. Can be aligned to In particular, by using a surface emitting laser with a low threshold as a light emitting element for performing E / O conversion, low power consumption driving is possible, and optical coupling between an optical element and an optical waveguide and arraying of optical elements are easy. It is possible to realize an opto-electric hybrid board.

The following arrangements are possible for the arrangement of the optical elements. An optical waveguide running parallel to the wiring board is cut at a vertical plane to expose a light input / output end, and an optical element is provided on the vertical plane so as to be optically coupled to the optical waveguide. In this case, the exposed mounting portion of the electric terminal may be formed to be surrounded by the vertical surface.

The optical waveguide running perpendicular to the wiring board is cut along a horizontal plane to expose a light input / output end, and the optical element is arranged on the horizontal plane so as to be optically coupled to the optical waveguide. In this case, a reflection mirror is provided below the input / output end, so that the waveguide of the optical waveguide running parallel to the wiring board and the optical element can be optically coupled. Further, an exposed portion of the electric terminal may be formed adjacent to the horizontal plane on which the optical element is provided. In this case, in the exposed portion of the electric terminal, the wiring to the optical element is electrically connected to the electric terminal, or the wiring to the optical element is electrically connected to the electric terminal. Together with the mounting portion. Further, the optical element is provided on both sides of the wiring board, the mounting portion is provided on both sides of the wiring board, and the wiring board is formed by laminating a layer having an optical waveguide formed on both sides of the electric wiring board. In some cases, a through hole through which light can pass is provided in a part of the electric wiring board so that an optical signal can be connected between the optical waveguides on both surfaces.

Still more specifically, the optical elements are arranged in an array, and the independent electrodes of each element are attached to a second wiring board different from the wiring board by flip-chip mounting, and the light transmitting Windows are provided on the second wiring board, are aligned so that they can be optically coupled to the optical waveguide, are bonded to the input / output end faces of the optical waveguide, and are provided through the second wiring board. It is configured such that an electric terminal or an exposed electric terminal of the mounting portion can be electrically connected to the optical element. By mounting a flip chip on a wiring board for independently driving an optical element, a low-power driving can be realized, and an inexpensive opto-electric hybrid wiring board that can be easily coupled with an optical waveguide or easily formed into an array and can be realized.

Further, the optical element is a surface emitting laser, and the surface emitting laser is mounted in a form sandwiched between a plate-like structure and the second wiring board. And a structure in which the semiconductor substrate is removed while leaving only the resonator layer including the active layer. By removing the compound semiconductor substrate on which the surface emitting laser is formed, a smaller and more environmentally safe opto-electric hybrid board can be realized.
After bonding to a plate-like structure with a surface-emitting laser, the compound semiconductor substrate such as GaAs or InP that constitutes the surface-emitting laser is removed, electrodes are formed on the surface that has appeared, elements are separated, and flip-chip mounting is performed. By adhering to the wiring substrate after bonding to the waveguide by using the method described above, it is possible to realize an opto-electric hybrid wiring substrate having a smaller size and high environmental safety.

The optical device is a surface emitting laser, and the surface emitting laser is formed by bonding the second wiring substrate on a plate-like structure and mounting the second wiring substrate on the second wiring substrate by flip chip mounting. It has a structure in which the semiconductor substrate is removed leaving only the resonator layer including the reflection mirror and the active layer, and a common electrode of the surface emitting laser is formed on the surface opposite to the surface on which the flip chip is mounted. The electrode is provided with a window for taking out light, is aligned so as to be capable of optically coupling to the optical waveguide, is adhered to the incident end face of the optical waveguide, and is provided with an electronic integrated device via the second wiring substrate. It is also possible to adopt a configuration in which the electric terminal or the exposed electric terminal of the mounting portion is electrically connected to the surface emitting laser. Also in this configuration, the compound semiconductor substrate on which the surface emitting laser is formed is removed, and a smaller and more environmentally safe opto-electric hybrid board can be realized. After flip-chip mounting on a wiring substrate on a plate-like structure with a surface-emitting laser, the compound semiconductor substrate such as GaAs or InP that constituted the surface-emitting laser was removed, and a common electrode was formed on the surface that appeared. By bonding so as to be aligned with the waveguide, it is possible to realize a smaller-sized and environmentally safe opto-electric hybrid board.

More specifically, a layer on which an optical waveguide for optical wiring is formed in the mounting portion for mounting an electronic integrated device is hollowed out, and the side of the hollowed-out portion is provided with the optical waveguide. An input / output end face of the waveguide is formed, and an optical element for photoelectric conversion is aligned so as to enable optical coupling to the optical waveguide, and is bonded to the input / output end face.
As a result, optical coupling between the O / E and E / O converters and the optical waveguide can be achieved easily and at low cost, and an inexpensive opto-electric hybrid wiring board can be realized.

Further, on a part of the surface opposite to the mounting portion on which the electronic integrated element is mounted, a layer forming an optical waveguide for optical wiring is hollowed out. The input and output ends of the optical waveguide are formed on the surface of the layer on which the optical waveguide is formed in an array along the vicinity, and a reflection mirror is provided below the input and output ends to provide light to the optical waveguide. The optical element for photoelectric conversion is aligned and adhered to an input / output end formed on the surface so as to enable optical coupling. This also
Optical coupling between the O / E and E / O converters and the optical waveguide can be achieved simply and at low cost, and an inexpensive opto-electric hybrid wiring board can be realized.

The wiring board is formed by laminating layers each having an optical waveguide formed on both sides of an electric wiring board. A plurality of optical elements to be subjected to photoelectric conversion are mounted on both sides, and a part of the electric wiring board is provided with an optical element. A through-hole is provided to allow transmission of optical signals between the optical waveguides on both surfaces, so that transmission and reception of signals between the electric integrated elements can be performed in a mixture of electricity and light. Thus, the optical waveguides are laminated and integrated on both sides of the substrate for electric wiring, and the photoelectric conversion unit is integrated by the above-described method to perform electric / optical connection / wiring. By forming through-holes in the board between the terminals, signals can be transmitted and received, high-density mounting can be performed at low cost, and MCMs (multi-chip modules) for electronic devices that can transmit high-speed signals with low EMI. Can be provided.

According to the above-mentioned method of driving an opto-electric hybrid wiring substrate including a surface emitting laser as an optical element to achieve the above object, the surface emitting laser is directly driven by turning on / off a CMOS buffer in an output stage of an electronic integrated device. The adjustment of the driving current of the laser is performed by a resistor inserted in series. Here, the on / off driving of the surface emitting laser is performed by switching with a transistor in an output stage such as an LSI, and a resistor and a surface emitting laser are connected in series to a power supply voltage, and the surface emitting laser is connected by the resistance value. Since the amount of current of the laser is determined, there is no special circuit change, and a low-cost and low-power-consumption optical element driving method can be realized.

An electronic circuit device which achieves the above object has a plurality of electric integrated devices such as a large-scale central processing unit (MPU) and a random access memory mounted on the above-mentioned opto-electric hybrid board including an optical element including a surface emitting laser. The present invention is characterized in that the surface emitting laser is driven by the above driving method.

Using the opto-electric hybrid wiring board and the driving method as described above, an MCM (multi-chip module) for high-speed, low-EMI electronic equipment can be provided.

Here, the features of the present invention will be described with reference to a specific example. A surface-emitting laser array that can emit light with a simple drive system with low power consumption is integrated on an opto-electric hybrid board as shown in Fig. 1 in which an electric wiring board and an optical wiring layer are integrated, and a normal electronic integrated element is electrically mounted. The description will be made using an example in which the electrical connection and the optical connection are simultaneously realized by simply performing the above operations.

The electronic integrated device 6 is mounted on a BGA (Ball
(Grid Array) type package with a solder ball 10 and O / O attached to the end face of the optical wiring layer 2.
The E and E / O converters 8 and 9 are wired to the electrodes mounted with the solder balls, and convert a part of the electric signal to an optical signal for optical wiring. Since the optical coupling between the O / E and E / O converters and the optical waveguide is aligned and fixed to the waveguide 4 when adhering to the side surface of the optical wiring layer 2, the coupling loss may not fluctuate. Absent. Surface emitting laser has an operating current of 3 mA
, An output of about 100 μW is obtained.
Can be sufficiently driven by a simple circuit configuration of turning on / off by a CMOS buffer as shown in FIG. Therefore, since it is possible to connect the MOS transistor at the output stage of the conventional LSI to the resistor integrated on the opto-electric hybrid board and the surface emitting laser in series, there is almost no change in the circuit configuration of the LSI. At the same time, it is possible to realize opto-electric hybrid wiring at low cost. Here, assuming that the laser has a power of 100 μW and the minimum receiving sensitivity of the photodetector is −25 dBm, an optical loss of up to 15 dB is permitted, and it is considered that there is a sufficient margin for short-distance connection in the board. . In addition, as shown in FIG. 8, there is also a method in which light enters and exits perpendicular to the substrate, and a method in which light is mounted on both surfaces as shown in FIG.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] The present invention typically employs I
Without changing the form of the C chip, an optical wiring layer composed of an optical waveguide is integrated on an electric wiring board on which the chip is mounted, and the O / E and E / O converter ( Optical-electrical conversion unit). Thus, a part of the signal transmission between the chips is performed by the optical wiring, and the speed of the signal transmission, the EMI, and the power consumption are reduced. This embodiment is shown in FIG. 1 as a first embodiment.

The configuration shown in FIG.
The multilayer optical wiring layer 2 is laminated on the BGA (Ball).
An electronic integrated device 6 formed of a (Grid Array) type package is mounted on a concave portion formed by removing a part of the optical wiring layer 2 on the substrate and used. Therefore, this element 6 is adapted to make electrical contact vertically below the recess and to make optical coupling horizontally at the side of the recess. In FIG. 1, reference numeral 11 denotes a pedestal for mounting a solder ball 10, and reference numeral 7 denotes a plate having good thermal conductivity as a base for mounting an IC chip. A heat dissipating means such as a fin (not shown) is provided on the upper part of the case.

In order to mount the electronic integrated device 6 on the substrate 1, the solder balls 10 arranged in an array on the electrode portion below the device 6 and the corresponding electrodes 5 of the substrate 1 are aligned, and flip-chip mounting is performed. Do. At this time, the self-alignment effect at the time of reflow of the solder ball 10 can be used to perform positioning with a high yield. In order to further increase the positioning accuracy, a pin may be provided below the electronic integrated element 6 and inserted into a guide (not shown) provided on the opto-electric hybrid board 13 side, or PGA may be used instead of BGA. (Pin G
A package of a (Rid Array) type may be provided by inserting a socket on the substrate 1 side.

When the electronic integrated device 6 is mounted on the printed circuit board 1 while obtaining electrical contact in this manner, the O / E conversion unit 8 and the E / O In the converter 9, a part of the signal becomes an optical signal and exchanges the signal with another chip.

The optical wiring is shown in FIG.
This is performed by the optical waveguide layer 2 attached thereon, and the portion of the optical waveguide layer 2 where the electronic integrated element 6 is mounted is penetrated as described above, and the optical waveguide 4 is attached to the penetrated end face.
O / E and E / O converters 8 and 9 are attached in alignment with the input / output ends. On the other hand, the electric signal is connected to other elements and a power supply through the electric wiring 3 provided on the multilayer wiring board 1 as usual. In the wiring in which electricity and light are mixed in this manner, for example, a logic signal or an analog signal, which is a relatively slow power supply line to the element, is transmitted through the electrical wiring 3,
The assignment may be made such that a high-speed clock pulse or a logic signal is performed by the optical wiring 4.

Next, the optical-electrical conversion unit according to the present embodiment is
The E / O converter 9, that is, a part for converting an electric signal to an optical signal will be described with reference to FIG. Pedestal plate 1
5, an array type surface light emitting element 16, and a wiring flexible tape (such as a TAB tape) 19 are stacked in the order shown in FIG. The electrode 22 of the TAB tape 19 and the common electrode on the surface of the pedestal plate 15 are electrically connected to the electric wiring 3 of the electric wiring board 1 by soldering or the like. TA
A window 21 is provided in a portion corresponding to the surface type optical element of the B tape 19 so that light can enter and exit.
The window 21 may be a mere hole, or may be a lens having a light condensing function or a transparent plate for protecting an optical element.

As described above, the light input / output end 12 is formed at the same pitch as the surface light emitting element on the end face of the optical wiring layer 2 which is hollowed out for chip mounting. The E / O conversion unit is aligned with the light input / output end 12 so as to perform optical coupling, and is attached with an adhesive or the like. For alignment, passive alignment is performed by fitting pins 24 provided on the base plate 15 into grooves 25 provided on the edge of the optical waveguide layer 2.

The current injection into the optical element 16 is performed on the light emitting section 18 side.
Ring-shaped electrode 17 and ring-shaped electrode of TAB tape 19
20 are attached to each light-emitting portion via the wiring 26 independently.
Can do it. Here, plate 15 and TA
The material of B tape 19 is heat conduction for heat dissipation of optical element.
The plate 15 is preferably made of metal or Al. ₂
O₃Ceramic thin film, TAB tape 19 is Al₂O₃powder
A polyimide film or the like is used. Also, TA
The electrical wiring of the B tape 19 can be used to degrade high-speed electrical signals without deterioration
Microstrip line can be transmitted
May be formed. Also, the TAB tape 19
By forming a through hole, the electrode 22 is connected to the wiring 26.
Electrical connection with the electric wiring board 1
A combination may be performed. Also, without using TAB tape etc.
Then, a wiring pattern is formed directly on the optical waveguide layer 2 by vapor deposition or the like.
Of course, it is good.

Here, a surface emitting laser having high luminous efficiency was used as the surface emitting device. Since the light emission angle of the surface emitting laser is as small as 10 ° or less, optical coupling with the optical waveguide 4 is possible with low loss without a lens.

Normally, a surface emitting laser is formed by disposing a resonator including an active layer on an n-substrate with a DBR (Distributed B).
A structure sandwiched by a rag reflector (mirror reflector) is epitaxially grown to form a constricted structure that allows current to flow only in the light emitting portion, and can be easily formed into a two-dimensional array as indicated by reference numeral 16 in FIG. Here, G
An AlAs / AlGaAs multilayer epimirror was grown on an aAs substrate, and an 830 nm surface emitting laser having a GaAs / AlGaAs multiple quantum well active layer was used. In this case, the common electrode is a cathode, and the electrode 17 for independent driving is an anode.

FIG. 5B is a conceptual diagram of a circuit for driving the surface emitting laser. Since the CMOS buffer inverter 53 is usually configured and integrated at a portion connected to the electrode at the last stage of the LSI so that current can be driven from a pin, the output current from the LSI is directly used here. Drives the surface emitting laser to output light. That is, no electric circuit serving as a laser driver for driving the surface emitting laser is used, and no special circuit design for E / O conversion is required.
The driving current capability of the CMOS buffer is usually about 10 mA, but the surface emitting laser used here has a threshold of about 1 mA.
Since the operating current at the time of output of mA and 100 μW is as very low as 3 mA, it can be driven sufficiently. Surface emitting laser 54
Since the operating voltage when a current of 3 mA flows through is about 2.5 V, in the case of 3.3 V CMOS, the series resistance R is (3.3-2.5) / 3 × 10 ⁻³ = 267Ω. May be inserted. This resistance corresponds to TA in FIG.
What is necessary is just to insert in the wiring 26 of the B tape 19 (indicated by the code | symbol 23).

However, in this system, the current is driven by the p-channel of the CMOS in order to operate with the cathode common, so that the switching time is slow, and there is a limit in increasing the speed. On the other hand, if the common anode type is used as shown in FIG. 5A, a CMOS driven by an n-channel MOS can be selected. For this reason, the present invention has also developed a technique of removing the n-substrate of the surface-emitting laser and separating the n-side electrode to make the anode common. FIG. 3 shows a manufacturing method thereof.

FIG. 3 shows a cross section of an array of only two surface emitting lasers for simplicity. 3A, on an n-GaAs substrate 40, an n-AlAs layer (not shown) serving as an etch stop layer, and an n-
After growing GaAs (not shown), n-AlAs / A
lGaAs multilayer mirror 41, undoped GaAs /
One-wavelength resonator layer 42 composed of an AlGaAs multiple quantum well active layer and an AlGaAs layer, p-AlAs / AlGaAs
The multilayer mirror 43 is epitaxially grown by a metal organic chemical vapor deposition method or the like. Thereafter, in order to form the current confinement layer 46, etching is performed in a ring shape to form a concave portion 47, and then an insulating film 44 such as SiN _x is formed except for a light emitting region to form an electrode 45.

Next, in FIG. 3B, the entire p-side electrode 45 is applied to the entire surface electrode (not shown) of the pedestal plate 15 by A.
After bonding with uSn solder, the GaAs substrate 40
Is removed by polishing and chemical etching. At this time, the etchant uses a mixed solution of H ₂ O ₂ and NH ₃ , and the etching can be stopped at the AlAs layer grown on the GaAs substrate 40. Then immediately HC
1 removes the AlAs layer to expose the GaAs layer growing on the lowermost surface of the mirror 41. Subsequently, FIG.
In FIG. 3C, the inter-element portion of the mirror layer 41 exposed on the surface is wet-etched with a sulfuric acid-based etchant or the like to form a separation groove 48, and the n-side electrode 17 is opened in the window 18.
Is formed while forming.

Next, the electrodes 20 around the holes 21 of the TAB tape 19 attached to the pedestal plate 15 and the electrodes 17 of the surface-emitting laser are bonded together with AuSn solder or the like. Further, this is adhered to the input / output end 12 of the waveguide 4 of the optical wiring layer 2 by passive alignment as described above so that the laser light is coupled. Thus, an anode common type surface emitting laser capable of coupling the light from the window 21 to the waveguide 4 can be manufactured.

Also, there is a method as shown in FIG. 4 with a slight difference in the manufacturing method. In this case, the configuration is slightly different from that of FIG. 3, in which the wiring TAB tape 19 comes out of the pedestal plate 15. In FIG. 4A, FIG.
A surface emitting laser structure is manufactured as in the case of (a),
In order to extract light from the p mirror layer 43 side, a window 50 for extracting light is opened in the electrode 45. At this time, in order to enhance the heat radiation from the laser, the metal film serving as the electrode 45 is thickened to 10 μm or more. Further, the p side is attached to the quartz glass plate 49 with electron wax or the like.

In FIG. 4B, the electrode 17 is formed by removing the GaAs substrate 40 as in the case of FIG. 3B. At this time, a through-hole 51 is formed in a part of the laser layer so that the p-electrode 45 serving as a common electrode can be taken out from the same surface.
To form the anode electrode 52 on the same side as the cathode electrode 17. Then, the TAB tape 19 is attached to the pedestal plate 15, and the electrode 20 on the TAB tape is bonded to the laser cathode electrode 17 and the common anode electrode 52. At this time, there is no need to open a window to prevent light from being extracted from this side. In order to facilitate these operations, the p-side is attached to the quartz glass plate 49.

In FIG. 4C, the quartz glass plate 49 is removed, and the electrode 45 on this side is bonded to the input / output end 12 so that light is coupled to the waveguide 4.

As described above, in the configuration in which the GaAs substrate 40 is removed, the functional layer for oscillating the laser beam is thin, and the E / O converter becomes very compact.
As the As content can be greatly reduced, the environmental safety also increases.

A light emitting diode can be used as the surface light emitting element. However, the operating current is about 30 mA, which is an order of magnitude higher, so that power consumption is increased and a device for the driver is required. Although the O / E converter has not been described in detail, the structure and manufacturing method are similar, and the GaAs pin structure is manufactured by epitaxial growth and diffusion. The material is Si or InGaAs
May be.

Although the example of the 830 nm band is shown here, another wavelength band, that is, 0.9 nm band by InGaAs is used.
Of course, an 8 μm band or a 1.3 μm band made of InGaAsP may be used.

Here, the description returns to the opto-electric hybrid board 13. The multilayer wiring substrate 1 for electric wiring may be a general-purpose PCB substrate or a ceramic substrate such as a polyimide substrate or AlN. On the other hand, the optical waveguide layer 2 for optical wiring may be conveniently formed of a resin such as fluorinated PMMA, epoxy resin, or polyimide. The manufacturing method will be briefly described with reference to FIG.

As shown in FIG. 6A, the electric wiring substrate 1
First, a resin 61 serving as a clad is applied and cured by a spinner or the like. Thereafter, as shown in FIG. 6B, a layer 62 having a slightly higher refractive index serving as a core is applied, and the shape of the waveguide (for example, 3) is formed using photolithography and etching.
(0 μm × 30 μm) to form a wiring pattern, and further buried with a clad 63. In case of multi-layer, CM
P (chemical mechanical poli)
Through a flattening step by shing, an optical waveguide 64 is formed in the same manner as shown in FIG. At this time, in the case of a two-row array, the cladding 63 can be made thinner by setting it in a staggered position as shown in FIG.
In the case of two layers, the thickness of the entire optical waveguide layers 61 to 65 is about 2
It became 00 μm.

There are various other materials for the waveguide, and silica glass may be used as the low-loss material. In this case, P-doped silica glass (PSG)
Is used, mass transport occurs by heating, and the surface can be flattened. Therefore, it is easy to manufacture the multilayer optical wiring layer 2. In this case, if the refractive index is controlled by GPSG further doped with Ge as the core layer, the optical waveguides 62 and 64 can be controlled.
Can be configured. Heat flattening (reflow) temperature is usually 8
Since the temperature is as high as about 00 ° C., after forming a waveguide on a substrate such as Si through a heating flattening process or the like, the waveguide layers 61 to 65 are formed.
Is bonded to the electric wiring substrate 1 and the Si substrate is removed, whereby the opto-electric hybrid board 13 can be manufactured without any problem. FIG.
In the embodiment, the optical wiring layer 2 has two layers, but may have more layers or one layer.

FIG. 7 shows an example of an overall image of the opto-electric hybrid board thus constructed. In FIG. 7, reference numeral 30 denotes a motherboard as the opto-electric hybrid board described above,
32 is a large-scale central processing unit (MPU), 31 is a primary cache memory, and 33 is an MCM module with a DRAM mounted on a motherboard as a daughter board.

The high-speed logic and the clock signal are transmitted through the optical waveguide 34 formed on the motherboard 30 and the daughter board 33. Power supply lines and low-speed signals are connected by electric wiring configured in the same board. The optical connector 35 and the optical waveguide sheet 36 can be used to connect to another board in an optical signal state. The optical waveguide sheet 36 is used as a bus line to transfer signals in parallel.

The optical connection between the motherboard 30 and the daughter board 33 is made by forming a 45 ° mirror (not shown) at the daughter board insertion port of the motherboard 30. When the optical wiring is used as a bus, an optical amplifier may be inserted into the connection portion to compensate for optical attenuation, or a light emitting element functioning as a repeater may be installed on the board.

For exchanging signals with an external storage device such as a hard disk drive, serial high-speed transfer using the connector 38 and the cable 37 may lead to cost reduction of the cable. Therefore, the connector 38
Is equipped with a transmission unit used for optical fiber communication capable of performing a parallel-serial conversion and capable of a rate of about 10 Gbps. Although only the main parts of the board are shown in FIG. 7, a necessary circuit configuration enables a next-generation computer whose clock rate exceeds 1 GHz to be configured.

At this time, there are fewer restrictions on wiring and pins as compared with the use of the lumbus method, and furthermore, high speed and miniaturization are achieved.
It is possible to provide a board that can reduce power consumption and can easily perform EMI measures. Further, not only computers but also recent electronic devices such as mobile phones and digital cameras require higher speed and smaller size, and at the same time, lower EM.
Since the use of I is essential, the opto-electric hybrid system according to the present invention is very effective for these devices.

[Second Embodiment] In a second embodiment of the present invention, as shown in FIG. 8, an optical waveguide layer 80 is provided on the surface opposite to the surface on which the electronic integrated element 81 is mounted, and the E / O , O / E converters 83 and 84 perform optical input / output in a direction perpendicular to the opto-electric hybrid board. Therefore, FIG.
A 45-degree mirror 90 is provided as shown in FIG.
The light coupled from the input / output end 91 to the opto-electric hybrid board propagates through the optical waveguide 4 in the horizontal direction, propagates through the optical waveguide 4 in the horizontal direction, and couples from the input / output end 91 to the O / E converter 84. Comes out vertically. The configuration of the waveguide 4 may be the same as that of the first embodiment, but in this embodiment, a single optical wiring layer 80 is used.

On the other hand, the electronic integrated device 81 and E / O, O / E
The electrical connection between the converters 83 and 84 is made via a through hole of the electrical wiring board 1 from an electrode 85 connected to the electrical wiring 86 on the surface on which the optical waveguide layer 80 is formed, as in the case of the first embodiment. This is performed using the substrate 82. Therefore, there is a portion of the optical waveguide layer 80 that extends through the surface of the electric wiring board 1. The optoelectronic integrated device 81 used here is a μ-BGA (or CS) having a ball array 10 for electrical contact at the center as shown in FIG.
P: Chip Size Package), which is a small package.

E / O, O / E converter 8 used in this embodiment
Numerals 3 and 84 have the same structure as in the first embodiment and are aligned and bonded so as to be optically coupled to the light input / output end 91 (FIG. 9). For the alignment, as in the first embodiment, a guide pin (not shown) or the like is prepared so that passive alignment can be performed. E / O, O
The temperature of the / E converters 83 and 84 may rise during operation, resulting in unstable operation. Therefore, a radiation fin (not shown) or the like may be provided on a plate on the surface of the conversion unit to prevent the temperature from rising. When the heat radiation fin is attached, the mounting method of this embodiment is suitable.

Further, the electronic integrated device 81 which is a heat source and E
By separating the / O and O / E converters 83 and 84 on the front and back of the opto-electric hybrid board, thermal crosstalk can be avoided.

[Third Embodiment] In a third embodiment of the present invention, as shown in FIG. 10, optical waveguide wiring layers 93 and 94 are provided on both surfaces of a multilayer wiring board 1 to mount electronic integrated devices 6 and 81 on both surfaces. Therefore, the mounting density on the substrate can be increased. The configurations of the opto-electric hybrid boards 1, 93 and 94 and the electronic integrated elements 6 and 81 are the same as those of the first and second embodiments, and the portions having the same functions are denoted by the same symbols. The E / O and O / E converters are coupled to the waveguide 4 in a direction parallel to the substrate surface and in a direction perpendicular to the substrate surface.

A feature of this embodiment is that the optical wiring on the front surface and the back surface can be formed through through holes as shown in FIG. In FIG. 11, reference numeral 95 denotes a through hole formed in the electric wiring board 1, and light emitted from the E / O converter 83 passes through the through hole 95 via the waveguide 96 of the upper optical wiring layer 93. The light can be coupled to the optical waveguide 4 by a 45-degree mirror 90 provided in the lower optical waveguide layer 94. The same applies to the case of light reception. Further, in the case of the system of the first embodiment in which light is incident parallel to the substrate surface, light may be reflected by a 45-degree mirror and passed through the through-hole.

Here, the through hole may be a mere air layer, or may be a material in which the same material as the core layer of the waveguide layer 93 is embedded. If the diameter of the through hole 95 is about 100 μm, there is almost no light loss due to diffraction or reflection if the thickness of the electric wiring board 1 is about 5 mm. By adopting such a structure, the degree of freedom in wiring is increased, and the MCM (Mul) for electronic devices that is small, high-density, and easily EMI countermeasure is easy.
A ti-Chip-Module) board can be provided.

In the above example, the electric wiring board 1 is sandwiched between the optical wiring layers 93 and 94. However, the electric wiring layer and the optical wiring layer are further provided with a multilayer electric wiring layer on the optical wiring layer. May be laminated in multiple layers.

In the above embodiments, the light was emitted or emitted from the optical element downward or sideways.
The connection with another element or another board may be made by spatial propagation or an optical waveguide tube, an optical waveguide film, or the like.

Further, the form of the package of the electronic integrated device is not limited to the above embodiment, but may be a QFP.
(Quad Flat Package), DIP (D
The present invention can be applied to any form such as a normal in-line package. Also, an example is shown in which only one LSI substrate is mounted in the package. However, a three-dimensional LSI is formed by using a three-dimensional stacked LSI by CSP mounting or a multilayer wiring technology on a Si substrate. There may be.

[0065]

As described above, according to the present invention, an optical integrated circuit for implementing optical interconnection with a small size, low power consumption and low cost can be mounted without changing the package of a normal electronic device. An opto-electric hybrid wiring board in which elements are integrated on the same substrate can be realized. Further, by mounting the surface emitting laser integrally on the wiring substrate to form an E / O converter, an opto-electric hybrid board with low power consumption driving, high speed driving and easy multi-bit wiring can be realized.

The on / off driving of the surface emitting laser is L
This is done with a transistor at the output stage of the SI, and a special LSI
Also, there is provided a method for driving an opto-electric hybrid board with low cost and low power consumption without any change in the electric circuit. Further, a high-speed, low-EMI multichip module using optical interconnection can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a separated state of an opto-electric hybrid board and an electronic integrated device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the E / E of the opto-electric hybrid wiring board according to the present invention;
FIG. 4 is an exploded perspective view illustrating a configuration of an O conversion unit.

FIG. 3 is a cross-sectional view for explaining a manufacturing process of a surface emitting laser leaving only a functional layer.

FIG. 4 is a cross-sectional view illustrating another manufacturing process of the surface emitting laser leaving only the functional layer.

FIG. 5 is a view for explaining a method of driving a light emitting element of the opto-electric hybrid wiring board according to the present invention.

FIG. 6 is a cross-sectional view illustrating a method for manufacturing a multilayer optical waveguide.

FIG. 7 is a perspective view showing an example of an MCM constituted by using an opto-electric hybrid wiring board and an electronic integrated device according to the present invention.

FIG. 8 is a perspective view showing a state in which an opto-electric hybrid board and an electronic integrated device are separated according to a second embodiment of the present invention.

FIG. 9 is a sectional view illustrating optical coupling of a second embodiment according to the present invention.

FIG. 10 is a perspective view showing a state where an opto-electric hybrid board and an electronic integrated device are separated according to a third embodiment of the present invention.

FIG. 11 is a cross-sectional view for explaining optical wiring of the opto-electric hybrid wiring board according to the present invention.

FIG. 12 is a diagram of a first conventional example of an optical wiring board.

FIG. 13 is a diagram of a second conventional example of an optical wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric wiring board 2, 80, 93, 94 Optical wiring layer 3, 26, 86 Electric wiring 4, 34, 96, 1003 Optical waveguide 5, 85 Electrode pad of electric wiring board 6, 31, 32, 39, 81 Electronic integration Element 7 Base plate 8, 84, 1012 O / E converter 9, 83, 1011 E / O converter 10 Solder ball 11 Pedestal 12, 91 Optical waveguide input / output end 13, 30, 33 Opto-electric hybrid board 15 Pedestal plate 16 Surface light emitting element 17 Element electrode 18 Light emitting section 19, 82 Flexible wiring board 20 Wiring board electrode 21, 50 Light transmission window 22 Electrode pad 23, 55 Resistor 24 Guide pin 25 Guide groove 35, 38 Optical connector 36 Optical waveguide sheet 37 Optical waveguide cable 40 Semiconductor substrate 41, 43 Semiconductor multilayer reflection mirror 42 Active layer 44 Insulating film 45, 52 Common electrode 46 Light emitting part 47 Current constriction part 48 Element isolation groove 49 Quartz plate 51 Through hole wiring 53 CMOS buffer inverter 54 Laser diode 61, 63, 65 Cladding 62, 64 Core 90, 1002 Reflecting mirror 95 Through hole optical waveguide 1001 Optical wiring board 1004 Optoelectronic IC chip 1005 Inclined surface 1006 Convex part 1007 Silicon oxide film 1010 Electronic circuit part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04B 10/00 G02B 6/12 B 5K002 H05K 1/18 H04B 9/00 A // H01L 27/15 F term (Ref.) 5K002 AA07 BA01 BA07 BA13 BA21 BA31 GA07

Claims (21)

[Claims] In a wiring board for mounting an electronic integrated device, electrical wiring and an optical waveguide are formed on the same wiring substrate. An optical element to be converted, wiring to the optical element, and an exposed mounting portion of an electric terminal for mounting the electronic integrated element are provided on the wiring board, and the electronic integrated element is connected to the electric terminals to form the electric terminal. An opto-electric hybrid wiring board, characterized in that at least a part of transmission and reception of signals between the electronic integrated element and the wiring board can be performed by optical signals only by electric mounting on a mounting portion. 2. The opto-electric hybrid wiring board according to claim 1, wherein the optical element is a surface-type optical element, and the optical element is surface-mounted with the surfaces in contact with the light input / output ends of the optical waveguide. 3. The opto-electric hybrid wiring board according to claim 2, wherein the light emitting element among the optical elements is a surface emitting laser. 4. An optical waveguide running parallel to a wiring substrate is cut at a vertical plane to expose a light input / output end, and an optical element is provided on the vertical plane so as to be optically coupled to the optical waveguide. The opto-electric hybrid wiring board according to claim 1, 2 or 3. 5. The opto-electric hybrid board according to claim 4, wherein the exposed mounting portion of the electric terminal is formed so as to be surrounded by the vertical surface. 6. An optical waveguide running perpendicular to a wiring board is cut along a horizontal plane to expose a light input / output end, and an optical element is provided on the horizontal plane so as to be optically coupled to the optical waveguide. Item 4. The opto-electric hybrid board according to item 1, 2 or 3. 7. An optical / electrical hybrid wiring according to claim 6, wherein a reflection mirror is provided below said input / output end, and a waveguide of an optical waveguide running parallel to said wiring board is optically coupled to an optical element. substrate. 8. An exposed portion of an electric terminal is formed adjacent to a horizontal plane on which an optical element is provided.
The opto-electric hybrid board described in the above. 9. The opto-electric hybrid board according to claim 8, wherein a wiring to said optical element is electrically connected to said electric terminal at an exposed portion of said electric terminal. 10. The opto-electric hybrid wiring board according to claim 8, wherein a wiring to the optical element is electrically connected to the electric terminal and the mounting portion is formed in an exposed portion of the electric terminal. . 11. The opto-electric hybrid wiring board according to claim 1, wherein the optical elements are provided on both surfaces of the wiring board. 12. The opto-electric hybrid wiring board according to claim 1, wherein said mounting portions are provided on both sides of the wiring board. 13. A wiring board comprising a layer in which an optical waveguide is formed on both sides of an electric wiring board, and a through hole through which light can pass is provided in a part of the electric wiring board. 13. The opto-electric hybrid wiring board according to claim 1, wherein an optical signal is connected between the optical waveguides. 14. The optical elements are arranged in an array, the independent electrodes of each element are attached to a second wiring board different from the wiring board by flip-chip mounting, and a light transmitting window is provided on the second wiring board. And an optical terminal of the electronic integrated device or the mounting via the second wiring substrate, which is aligned so as to be capable of optically coupling to the optical waveguide and is bonded to the input / output end face of the optical waveguide. The opto-electric hybrid wiring board according to any one of claims 1 to 13, wherein the exposed electric terminals and the optical element are configured to be electrically connected. 15. An optical device is a surface emitting laser, said surface emitting laser being mounted in a sandwiched manner between a plate-like structure and said second wiring board, and comprising a multilayer reflection mirror. The opto-electric hybrid board according to claim 14, having a structure in which the semiconductor substrate is removed while leaving only the resonator layer including the active layer. 16. An optical element is a surface emitting laser, wherein the surface emitting laser is formed by bonding the second wiring board on a plate-like structure and mounting the second wiring board on the second wiring board by flip chip mounting. It has a structure in which the semiconductor substrate is removed leaving only the resonator layer including the reflection mirror and the active layer, and a common electrode of the surface emitting laser is formed on the surface opposite to the surface on which the flip chip is mounted. The electrode is provided with a window for extracting light, is aligned so as to be capable of optically coupling to the optical waveguide, is adhered to the incident end face of the optical waveguide, and is integrated with the electronic integrated device via the second wiring substrate. 15. The opto-electric hybrid board according to claim 14, wherein the electric terminal or the exposed electric terminal of the mounting portion is electrically connected to the surface emitting laser. 17. A mounting layer for mounting an electronic integrated device, wherein a layer forming an optical waveguide for optical wiring is hollowed out, and the input / output end face of the optical waveguide is formed on a side surface of the hollowed portion. An optical element which is formed, and which is to be subjected to photoelectric conversion, is aligned so as to enable optical coupling to the optical waveguide, and is bonded to the input / output end face.
17. The opto-electric hybrid board according to any one of 1 to 16. 18. A layer on which an optical waveguide for optical wiring is formed in a part of a surface opposite to the mounting part on which the electronic integrated element is mounted, The input and output ends of the optical waveguide are formed on the surface of the layer on which the optical waveguide is formed in an array along the vicinity, and a reflection mirror is provided below the input and output ends to provide light to the optical waveguide. 7. An optical element for photoelectric conversion is aligned and adhered to an input / output end formed on the surface so as to enable optical coupling.
17. The opto-electric hybrid board according to any one of claims 16 to 16. 19. The wiring board is formed by laminating layers in which optical waveguides are formed on both sides of an electric wiring board. A plurality of optical elements for photoelectric conversion are mounted on both sides, and an optical element is provided on a part of the electric wiring board. 2. A device according to claim 1, wherein a through-hole through which light is transmitted is provided so that an optical signal is connected between the optical waveguides on both surfaces, and a signal is exchanged between the electric integrated devices in a mixed manner of electricity and light. 20. The opto-electric hybrid board according to any one of claims to 19. 20. The method of driving an opto-electric hybrid wiring board according to claim 1, wherein the optical element includes a surface emitting laser. The driving of the surface emitting laser is performed by a CMOS buffer in an output stage of the electronic integrated device. A driving method which is performed directly by turning on and off, and adjusting the driving current of the laser by using a resistor inserted in series. 21. A plurality of electric integrated devices such as a large-scale central processing unit (MPU) and a random access memory are mounted on the opto-electric hybrid board according to claim 1, wherein the optical device includes a surface emitting laser. 21. An electronic circuit device configured to drive a surface emitting laser by the driving method according to claim 20.