JP2012043999A - Electronic device, package board, and package board type semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increased development cost when converting electric signal communication between semiconductor devices on a package board into optical communication.SOLUTION: At least one pair or more input/output devices of an optical communication device for converting an electric signal into an optical signal is provided on a package board for each semiconductor device, on the package board right below, i.e., in the vicinity (wiring connection having a chip-to-chip minimum distance of 2 mm or smaller) of the mounted semiconductor devices. Each semiconductor device mounted on the package board performs at least inputting and outputting through electric signals, while wiring connection is made between each optical communication device formed on the package board through optical signals via an optical waveguide. By this, design to incorporate circuits related to optical communication into the mounted semiconductor device side and development of manufacturing process become unnecessary, and an optical semiconductor device is achieved by the development of the optical communication semiconductor device on the package board side. Also, with a simplified structure on the optical communication device for accommodating an optical receiving circuit in the optical communication device on the package board, further cost reduction is achieved.

Description

  The present invention relates to an electronic device that performs communication between semiconductor devices via a mounting substrate, a mounting substrate, and a mounting substrate type semiconductor device.

  When the operating frequency of the semiconductor device is increased to the GHz band, the metal waveform causes a signal waveform curve and delay due to physical restrictions. If the power supply is increased as one of the methods for correcting this, heat generation and power consumption increase this time, which hinders stable operation of the semiconductor device. Therefore, as means for solving these problems, there are cases where the signal transmission speed between the semiconductor devices cannot follow the operating frequency of the semiconductor devices. Therefore, it has been studied to perform communication between semiconductor devices using light (for example, Patent Documents 1 and 2). In Patent Documents 1 and 2, an optical receiving element and an optical transmitting element are incorporated into a semiconductor chip that constitutes a semiconductor device, so that communication between the semiconductor devices can be performed with light.

JP 2006-084766 A JP-A-6-236941

  As an example, in order to form a light receiving circuit or a light emitting circuit on a semiconductor substrate having a logic circuit, it is necessary to apply a material or a special shape that is not included in a process for forming a conventional logic circuit. In this case, a large change or addition is required in the manufacturing process of the semiconductor device, and as a result, the development cost of the process increases significantly. This problem occurs every manufacturing process. This means that all redevelopment assets need to be redeveloped, making it impossible to make use of past assets.

According to the present invention, a first semiconductor device that outputs at least an electrical signal;
A mounting substrate on which the first semiconductor device is mounted;
A second semiconductor device mounted on the mounting substrate and receiving a signal output from the first semiconductor device;
A first optical communication unit that is provided on the mounting substrate, converts an electrical signal output from the first semiconductor device into an optical signal, and transmits the optical signal to the second semiconductor device;
An electronic device is provided.

  According to the present invention, the first and second communication module sections are arranged in the vicinity of each of the first and second semiconductor devices mounted on at least one set of the mounting boards, and the communication section in the mounting board is provided. There is provided a semiconductor device having a plurality of functions as input / outputs, each of which has a function of connecting an optical signal to each other and converting each of the optical signal into an electric signal in each communication module.

  According to the present invention, the first and second optical communication units are incorporated in the mounting board, not on the first and second semiconductor devices. For this reason, it is not necessary to greatly change the structure of the semiconductor device, and it can be developed as an optical communication module unit alone. Therefore, an increase in development cost for each semiconductor device can be suppressed.

According to the present invention, a mounting substrate on which a first semiconductor device and a second semiconductor device are mounted,
The first semiconductor device outputs at least an electronic signal;
An external connection terminal connected to the output terminal of the first semiconductor device;
A first optical communication unit that converts an electrical signal input to the external connection terminal into an optical signal and transmits the optical signal to the second semiconductor device;
A mounting substrate is provided.

  According to the present invention, there is provided a mounting substrate that shares an optical communication function using an inter-semiconductor signal optical communication unit and an optical waveguide, and metal wiring used for power supply and signal transmission as a stacked structure on the mounting substrate.

  According to the present invention, a mounting substrate type semiconductor in which an optical waveguide and an optical communication module are embedded in a wiring substrate, a mounting surface is shaped flat, and a layer having a light shielding property, an insulating property, and a heat dissipation property is formed thereon. An apparatus is provided.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the cost of an electronic device increases.

1 is a cross-sectional view of an electronic device according to a first embodiment. FIG. 2 is a schematic plan view of a mounting board used in the electronic device shown in FIG. 1. It is a cross-sectional enlarged view for demonstrating the connection structure of a semiconductor device and a mounting substrate. It is a block diagram which shows the function structure of an optical communication module. It is a block diagram which shows the function structure of an optical transmission / reception part. It is sectional drawing of the electronic device which concerns on 2nd Embodiment. It is a cross-sectional enlarged view for demonstrating the connection structure of a semiconductor device and a mounting substrate. It is a cross-sectional enlarged view which shows the modification of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(First embodiment)
FIG. 1 is a cross-sectional view of the electronic device according to the first embodiment. FIG. 2 is a schematic plan view of the mounting substrate 100 used in the electronic device shown in FIG. The electronic device includes a first semiconductor device (first semiconductor device 200), a mounting substrate 100, a second semiconductor device (second semiconductor device 200), and a first optical communication unit (optical communication module 300). Yes. The first semiconductor device 200 outputs at least an electrical signal and is mounted on the mounting substrate 100. The second semiconductor device 200 is mounted on the mounting substrate 100 and receives a signal output from the first semiconductor device 200. The optical communication module 300 is provided on the mounting substrate 100, converts an electrical signal output from the first semiconductor device 200 into an optical signal, and transmits the optical signal to the second semiconductor device 200. Details will be described below.

  As shown in FIG. 2, in the present embodiment, the mounting substrate 100 is a motherboard, for example, and a plurality of semiconductor devices 200 are mounted thereon. Each of the plurality of semiconductor devices 200 performs both input and output by electric signals. The mounting substrate 100 is provided with the optical communication module 300 for each of the plurality of semiconductor devices 200. Each of the optical communication modules 300 overlaps the semiconductor device 200 to which the optical communication module 300 is connected in plan view.

  The mounting substrate 100 is provided with an optical waveguide 140 for connecting the optical communication modules 300 to each other. When each optical communication module 300 receives an electrical signal from the semiconductor device 200 to which the optical communication module 300 is connected, the optical communication module 300 converts the electrical signal into an optical signal, and converts the converted optical signal to another optical signal via the optical waveguide 140. Transmit to the optical communication module 300. When each optical communication module 300 receives an optical signal from another optical communication module 300 via the optical waveguide 140, the optical communication module 300 converts the received optical signal into an electrical signal, and the semiconductor device 200 to which the optical communication module 300 is connected. Output to.

  The mounting substrate 100 usually has at least one metal wiring layer (power supply metal wiring or low-speed signal metal wiring formed in the same layer as the electrode pads such as 112, 113, and 114) and a protective insulating layer 106 thereabove. The optical communication module 300 and the optical waveguide 140 are formed on the wiring board 120 via the light shielding and insulating heat radiation layer 104 below the printed wiring layer 103. That is, the mounting substrate 100 can form an optical high-speed transfer semiconductor device using a hybrid substrate that transmits both supply power, low-speed electrical signal system metal wiring, and high-speed signal transfer optical signal wiring.

  In the example illustrated in FIG. 1, the semiconductor device 200 is, for example, a semiconductor package. The semiconductor device 200 is connected to the electrodes of the external connection terminals 112 and 114 of the mounting substrate 100 via high-speed signal line external connection terminals 212 and 214, for example, solder balls. The output unit of the semiconductor device 200 is connected to the optical communication module 300 via the external connection terminal 212, the electrode 112, and the via 107, and the input unit of the semiconductor device 200 is connected to the external connection terminal 214, the electrode 114, and the via 108. It is connected to the optical communication module 300 via The vias 107 and 108 penetrate the light-shielding insulating heat radiation layer 104 and are connected to electrode pads located under the protective insulating film 106.

  FIG. 3 is an enlarged cross-sectional view for explaining a connection structure between the semiconductor device 200 and the mounting substrate 100. The semiconductor device 200 is obtained by flip-chip mounting a semiconductor chip 202 on an interposer 204. External connection terminals 212 and 214 are specially provided on the lower surface of the interposer 204 without using an interposer so as to minimize the optical signal wiring distance. The external connection terminals 212 and 214 are connected to the input / output dedicated line electrodes 112 and 114 on the optical communication module 300 side as described above. Note that a terminal 213 other than the external connection terminals 212 and 214 (for example, a power supply terminal, a ground terminal, a low-speed metal signal line and connected to the electrode 113) is provided on the lower surface of the interposer 204. Although not shown in the drawing, metal wiring is formed between 104 light-shielding insulating heat-dissipating layers and 106 protective insulating layers in at least one layer at the time of pad formation (which can be laminated with a metal + insulating layer as before). The metal wiring is formed on the mounting board as before.

  FIG. 4 is a block diagram showing a functional configuration of the optical communication module 300. The optical communication module 300 includes an optical transmission / reception unit 340 illustrated in FIG. 5, and the optical transmission / reception unit 340 includes an optical output unit 350 and an optical reception unit 360. FIG. 4 shows a configuration example of the optical transmission / reception unit 340 for two surfaces, three surfaces, and four surfaces as an example. Since the optical waveguide portion cannot be bent at an acute angle because of its characteristics, unlike the metal wiring, it is devised to cope with this by forming a multi-sided input / output surface. Further, since the example of the transmission unit in FIG. 3 is an optical transmission unit having 20 rows per side, it is added that the transmission unit row per plane can be increased or decreased depending on the usage depending on the usage. As shown in the configuration of FIG. 5, the incoming signal from the terminal 112 is configured to be capable of both multi-byte parallel high-speed transmission and multiple 1-bit high-speed communication via the interface 352 and the controller 354. FIG. 4 shows an arrangement example when a plurality of units are installed on each surface of the transmission / reception unit.

  The arrangement of the optical transceiver 340 and the number of light receiving units for each surface are appropriately set based on the arrangement position of the semiconductor device supported by the optical communication module 300 and the number of communication destination units. In the example shown in FIG. 4A, two optical transmission / reception unit units 340 are arranged side by side, and a dedicated controller unit 320 is arranged on the side of the two optical transmission / reception units 340. Further, in the example shown in FIG. 4B, in addition to the example shown in FIG. 4A, an optical transmission / reception unit section 340 is further provided. In the example shown in FIG. 4C, a controller unit 320 (a general term for the optical transmission / reception unit 340 and the optical transmission unit 350) is arranged inside the four optical communication units. The number of optical waveguides between the optical transmission unit 350 and the optical reception unit 360 described above must be the same according to the number of units per surface. Depending on the circuit configuration, a plurality of transmission waveguides may be split. In addition, it is added that the light receiving side unit may increase by that amount.

  FIG. 5 is a block diagram illustrating the functional configuration of the optical transmission unit 350 and the optical reception unit 360 that are constituent units of the transmission / reception device 340 of FIG. 4 as described above. The optical transmission / reception unit 340 includes an optical transmission unit 350 and an optical reception unit 360. The optical transmission unit 350 includes a plurality of light emitting elements 356. The light emitting element 356 is connected to the electrode 112 via the interface 352 and the controller 354 of the controller unit 320. The light receiving unit 360 includes a plurality of photoelectric conversion elements 362. The photoelectric conversion element 362 is connected to the electrode 114 via the reception circuit 364 and the interface 366 of the controller unit 320. The reception circuit 364 includes a circuit that demodulates a signal, an amplifier group, and a controller.

  Next, the operation and effect of this embodiment will be described. As described above, in order to form a light receiving element and a light emitting element on a semiconductor chip having a conventional logic circuit, a material or a special shape that is not included in the conventional process for forming the conventional logic circuit is applied. There is a need. In this case, it is a well-known fact that a significant change or process addition is required in the semiconductor device manufacturing process. Currently, several hundred processes are required to manufacture semiconductor devices. However, when an optical transceiver unit is mounted on-chip on a current semiconductor chip, design changes and manufacturing process changes occur for each semiconductor device. It is clear to do. And, if the above changes and additions are made, it is obvious from the number of semiconductor devices on the current device substrate that the development cost will be enormous when implemented for each semiconductor device. Obviously, this is the biggest obstacle to the optical signal generation of semiconductor devices. In addition, the on-chip optical transmission / reception unit causes a decrease in the yield of the semiconductor device and an increase in the size of the semiconductor chip due to the provision of the light receiving element and the light emitting element, which causes a deterioration in productivity.

  In addition, when the light receiving element or the light emitting element is mounted on the semiconductor chip as described above, it is necessary to change the circuit of the light receiving element or the light emitting element and to change the reticle accordingly. Also from this point, the development cost of the semiconductor device is significantly increased. And if the development cost of semiconductor devices rises, the price of electronic devices also rises, so that the technology can only be applied to specific expensive products at a stretch, and it becomes a foothold that does not make optical semiconductors progress. On the other hand, the improvement in the overall speed is a factor that creates a state where the speed does not progress at a stretch.

  On the other hand, in this embodiment, the optical communication module 300 is incorporated in the hybrid substrate 100 instead of the semiconductor device 200. For this reason, it is not necessary to incorporate an optical element for each existing semiconductor device, and the semiconductor device itself does not need to be greatly changed in structure. Also, the optical transceiver unit can be developed as a dedicated process and developed as an optical transceiver unit as several general-purpose products. Further, there is a merit that it is easy to promote quality improvement, characteristics and price improvement as an optical semiconductor unit alone. Therefore, an increase in the development cost of the semiconductor device can be suppressed. On the other hand, as the hybrid substrate 100, it is necessary to embed an optical semiconductor device and an optical waveguide, which are not conventional, but this is an extension of the existing wiring substrate technology, and already researches both optical semiconductor units and optical waveguides. In view of the fact that it has already been developed at a level, but considering a smooth transition to an optical semiconductor device in terms of development cost, it is nothing but a technology that contributes greatly.

  Further, since the semiconductor device is separated from the light receiving element and the light emitting element, the light receiving element and the light emitting element can be formed using a semiconductor (for example, a compound semiconductor such as GaAs) different from the semiconductor chip 202. The characteristics of the light emitting element can be improved. Further, since it is not necessary to provide the light receiving element and the light emitting element on the semiconductor device, it is possible to suppress the enlargement of the semiconductor chip and the decrease in the manufacturing yield. Furthermore, since the semiconductor device and the mounting substrate can be developed separately, there are many accompanying merits such as easy to increase product variations.

  In addition, since the signal system wiring is performed by the optical waveguide 140, in the case of the hybrid type mounting substrate 100, it is possible to omit other than the power system wiring in an extreme case, and the wiring for transmitting the electrical signal is greatly reduced. This is also freed from problems such as noise considerations for signal lines, and the current 7-layer and 8-layer substrate metal wiring layers can be greatly reduced, resulting in increased manufacturing costs due to the embedding of optical signal related devices. It can also be greatly reduced.

  The electrical signal output from the semiconductor device 200 needs to be connected in the shortest in consideration of delay and the like. However, when viewed only from the transfer distance to the optical communication module 300, the electrical signal output from the semiconductor device 200 is Compared with the case of transmitting to another semiconductor device 200 as it is, the output of the electrical signal output from the semiconductor device 200 can be reduced. Therefore, the output amplifier formed in the semiconductor device 200 can be reduced or omitted. Actually, the use of a high output amplifier for improving the signal waveform distortion is changed to an impedance matching circuit for extracting a pure signal waveform, and a great improvement in power consumption and heat generation can be expected.

    Further, depending on the usage (specifically, setting of the input / output specifications of the optical transceiver module), the semiconductor device 200 according to this embodiment can be used without adding a function to the already designed semiconductor device. . For this reason, it can further suppress that the development cost of the semiconductor device 200 increases. Further, since there is no need to change the manufacturing process of the semiconductor device 200, it is possible to suppress an increase in the number of manufacturing steps and a decrease in the yield of the semiconductor device 200.

  In the present embodiment, the optical communication module 300 overlaps the semiconductor device 200 in plan view. For this reason, even if the optical communication module 300 is provided, an increase in the size of the mounting substrate 100 can be suppressed. Further, in order to shorten the wiring length between the optical communication module 300 and the semiconductor device 200 as much as possible from the viewpoint of increasing the signal speed other than the optical transmission / reception unit on-chip technology, for example, shortening to 2 mm or less. In consideration of the above, it is inevitable that there is no alternative to arrange an optical transmission / reception module directly under a conventional semiconductor.

(Second Embodiment)
FIG. 6 is a cross-sectional view of the electronic device according to the second embodiment, and corresponds to FIG. 1 in the first embodiment. FIG. 7 is an enlarged cross-sectional view for explaining a connection structure between the semiconductor device 200 and the hybrid substrate 100 in the electronic device shown in FIG. 6, and corresponds to FIG. 3 in the first embodiment. The electronic device according to the present embodiment is the same as that of the first embodiment except that the input to the semiconductor device 200 is performed by an optical signal.

  That is, in the present embodiment, the optical communication module 300 transmits the optical signal received from the optical waveguide 140 to the semiconductor device 200 as it is. The hybrid mounting substrate 100 is provided with an optical signal capturing terminal convex portion 116, and an optical signal capturing terminal concave portion 206 is provided without using the interposer 204 of the semiconductor device 200. The convex portion 116 is fitted into the concave portion 206. The convex portion 116 is provided with an optical waveguide, and the optical receiving portion 208 is provided on the bottom surface of the concave portion 206. The optical signal transmitted from the optical communication module 300 is efficiently transmitted from the end of the optical waveguide of the convex portion 116 through the condensing microlens 209 to the optical waveguide 210, and the optical receiver 208 of the semiconductor device 200 receives the optical signal. The optical signal is transmitted as it is from the end face on the semiconductor chip side to the optical receiving unit on a predetermined semiconductor chip.

  Also in this embodiment, the output from the semiconductor device 200 is performed by an electrical signal. The output electrical signal is converted into an optical signal in the optical communication module 300.

  The manufacturing process of the photoelectric conversion element of the light receiving unit 360 has no problem in size in the existing CCD manufacturing process, but there is a problem in speed, but it is realized by devising the circuit configuration and devising the manufacturing process. I think that it is at a level where the possibility of Therefore, compared with the manufacturing process of a light emitting element, it exists in the condition where it is easy to incorporate in the manufacturing process of the conventional logic circuit or memory circuit. Therefore, according to this embodiment, the same effect as that of the first embodiment can be obtained. In addition, since it is not necessary to provide the optical receiver 360 in the optical communication module 300, the circuit configuration of the optical communication module 300 can be simplified.

  As shown in the enlarged cross-sectional view of FIG. 8, in the case of a semiconductor device that requires only high-speed signal reception and the transmission signal may be a conventional metal wiring, an optical communication module 300 is provided below the semiconductor device 200. It does not have to be. In this case, the semiconductor device 200 performs signal reception using light, and transmits signals to other semiconductor devices 200 using electrical signals.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

100 metal, optical hybrid board (mounting board)
102 Wiring board
103 Printed Wiring Layer 104 Light-shielding Insulation Heat Dissipation Layer 106 Protective Insulating Film 107 Via
108 via (terminal row for high-speed signal reception of semiconductor device)
112 Semiconductor Device Signal Transmitting Electrode Pad
113 Electrode pads other than terminals for high-speed signal transmission / reception (via interposer)
114 External connection terminal 116 Optical signal capturing terminal convex portion 120 Wiring board 140 Optical waveguide 200 Semiconductor device 202 Semiconductor chip 204 Interposer 206 Optical signal capturing terminal concave portion 208 Optical receiving portion 209 Condensing microlens 210 Optical waveguide 212 Electrical signal external connection terminal (High-speed signal line input terminal from semiconductor devices)
213 Electrical signal external connection terminal (terminal other than high-speed signal transmission / reception terminal)
214 Electrical signal external connection terminal (High-speed signal line output terminal to semiconductor device)
300 Optical communication module 320 Controller, interface (Details 352, 354)
340 Optical transceiver module (Details 350, 360)
350 Optical transmission module 352 Electric signal input interface 354 Optical transmission controller 355 Silicon laser unit group (20UNIT)
356 Optical waveguide interface (20UNIT)
357 Light modulator group (20UNIT)
358 Optical waveguide (output): Waveguide group 359 Optical waveguide (input): Waveguide group 360 Optical receiver 362 Photoelectric conversion element 364 Receiver circuit 366 Electric signal output interface

Claims (10)

A first semiconductor device that at least outputs an electrical signal;
A mounting substrate on which the first semiconductor device is mounted;
A second semiconductor device mounted on the mounting substrate and receiving a signal output from the first semiconductor device;
A first optical communication unit that is provided on the mounting substrate, converts an electrical signal output from the first semiconductor device into an optical signal, and transmits the optical signal to the second semiconductor device;
An electronic device comprising: The electronic device according to claim 1,
The second light that receives the optical signal from the first optical communication unit of the mounting substrate via the optical waveguide by the second optical communication unit on the mounting substrate and transmits it as an electrical signal to the second semiconductor device. An electronic device further comprising a communication unit. The electronic device according to claim 1,
In plan view, the first optical communication unit is an electronic device overlapping the first semiconductor device. The electronic device according to claim 2.
In plan view, the first optical communication unit overlaps the first semiconductor device, and the second optical communication unit overlaps the second semiconductor device. The electronic device according to claim 2 or 4,
The first optical communication unit and the second optical communication unit are connected to each other, and a transmission / reception electrical signal between the first semiconductor device and the second semiconductor device is simultaneously converted into a transmission / reception optical signal to mediate a high-speed signal. An electronic device having a plurality of signal lines for the purpose. The electronic device according to claim 5.
Has three or more semiconductor devices,
An electronic device in which communication is performed by the first optical communication unit and the second optical communication unit between a plurality of sets of the semiconductor devices. In the electronic device according to any one of claims 1 to 6,
The second semiconductor device is input by an optical signal,
An electronic device further comprising an optical waveguide provided on the mounting substrate and configured to input the optical signal output from the first optical communication unit to the second semiconductor device. A mounting substrate on which the first semiconductor device and the second semiconductor device are mounted,
The first semiconductor device outputs at least an electronic signal;
An external connection terminal connected to the output terminal of the first semiconductor device;
A first optical communication unit that converts an electrical signal input to the external connection terminal into an optical signal and transmits the optical signal to the second semiconductor device;
A mounting board comprising:   A mounting substrate that shares an optical communication function using an inter-semiconductor signal optical communication unit and an optical waveguide, and metal wiring used for power supply and signal transmission as a stacked structure on the mounting substrate. A mounting substrate type semiconductor device in which an optical waveguide and an optical communication module are embedded in a wiring substrate, a mounting surface is shaped flat, and a layer having a light shielding property, an insulating property, and a heat dissipation property is formed thereon.

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