JPS5915423B2 - Optical connection method between motherboard and package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a connection system between a motherboard mounted in a rack such as a switching equipment and a package 5 mounted on the motherboard.

Traditionally, electrical connectors have been used for this type of connection.

In this case, as the number of transmission signals on the package increases, the number of connector terminals increases. In order to be able to mount many terminals on a package, the terminals and pitch of the connector must be reduced, which is technically quite difficult.
Therefore, there was a drawback that the amount of transmitted signals was limited.
This invention multiplexes the transmission signals of the package, converts them into optical signals, and sends and receives signals to and from other packages via the motherboard provided with an optical waveguide, thereby transmitting large-capacity signals between the package and the motherboard. This provides a connection method that enables transmission.

According to this invention, on the package mounted on the motherboard, there is a multiplexing circuit for multiplexing electrical signals, an electrical-to-optical conversion circuit for converting the multiplexed signal from the multiplexing circuit into an optical signal, and a light emitting element. , an optical-to-electrical conversion circuit and a light receiving element that convert optical signals into electrical signals, and a demultiplexing circuit that multiplexes and demultiplexes electrical signals 25 from the optical-to-electrical conversion circuit.

An optical waveguide is provided on the motherboard, and the optical waveguide is optically coupled to a light emitting element and a light receiving element of the package so that optical signals can be transmitted and received. Next, an embodiment of the present invention will be described with reference to the drawings. A package 2 is mounted on the motherboard 1. On each package 2 are a multiplexing circuit 3, a demultiplexing circuit 4, a module 5 including an electro-optical conversion circuit and a light emitting element array, and a module 6 including an optical-electric conversion circuit and a light receiving element array.
35 are provided. A plastic optical waveguide 9 is formed on the motherboard 1. A connector 7 that connects the optical waveguide 9 and the light emitting element array of the module 5;
A connector 8 is provided to optically couple the light receiving element array of the module 6 and the optical waveguide 9. Electrical signals generated on the package 1 are multiplexed by a multiplexing circuit 3, and the multiplexed signals are converted into optical signals by a module 5.

The optical signal is transmitted via the connector 7 to a plastic optical waveguide 9, from which it is sent as a signal to, for example, another package. In addition, signals from other packages etc. are transmitted as optical signals to the connector 8 through the plastic optical waveguide 9.
The signal enters the module 6 via the input signal and is converted into an electrical signal. The electrical signal is demultiplexed by a demultiplexing circuit 4,
It is transmitted into package 1. The plastic optical waveguide 9 can be formed in a plastic film in any desired pattern by the method described in Japanese Patent Publication No. 53-26813 [Method for Manufacturing Optical Circuits]. A simpler optical wiring can be achieved.

The optical waveguide 9 is not limited to plastic; for example, a glass waveguide in which an optical waveguide is formed by implanting ions into a glass plate or by ion diffusion can also be used, and one of these waveguides can be selected depending on the application. can do.

In addition, when distinguishing between packages to be transmitted, for example, the multiplexing circuit 3 multiplexes the signals in a time-division manner, and the multiplexed signals are sent to predetermined time slots according to the contents of the control memory according to the packages to be transmitted. Assign to.

Furthermore, it is only necessary to extract only the time slots predetermined by the package based on the contents of the control memory from the electrical signals from the optical-to-electrical conversion circuit, and select only the electrical signals for that package. As explained above, this invention includes a multiplexing circuit and a demultiplexing circuit, an electric-to-optical conversion circuit and a light emitting element, an optical to electric conversion circuit and a light receiving element, a light emitting element, a light receiving element, and a plastic waveguide circuit on a package. By using a motherboard equipped with an optical waveguide and converting the signals between the motherboard and the package into optical signals for sending and receiving signals, the number of terminals of the electrical connector can be increased. solve the problem of
This has the effect of allowing large capacity transmission between the motherboard and the package.

Since the signal is converted into a multiplexed optical signal in this way, its multiplicity can be significantly increased, and it is easier to use coupling converters such as optical waveguides, opto-electricity, and electro-optic conversion than when transmitting electrical signals or radio waves. The configuration can also be made smaller.

[Brief explanation of the drawing]

The figure is a perspective view showing an optical connection system between a motherboard and a package according to an embodiment of the present invention. 1: A motherboard on which a plastic optical waveguide is formed,
2: Package, 3: Multiplexing circuit, 4: Demultiplexing circuit,
5: Module including an electrical-to-optical conversion circuit and a light-emitting element array; 6: Module including an optical-to-electrical conversion circuit and a light-receiving element array; 7: Connector for optically coupling the light-emitting element array and the motherboard 1; 8: Light-receiving element Connector for optically coupling the array and motherboard 1; 9: plastic optical waveguide;

Claims (1)

[Claims] 1. In signal transmission between a motherboard and a package mounted on the motherboard, a multiplexing circuit for multiplexing electrical signals and an electrical circuit for converting the multiplexed signal from the multiplexing circuit into optical signals are installed on the package. An optical conversion circuit and a light-emitting element, an optical-electrical conversion circuit and a light-receiving element that convert an optical signal into an electrical signal, and a demultiplexing circuit that multiplexes and demultiplexes the electrical signals from the optical-electrical conversion circuit are provided, and the motherboard is equipped with An optical connection method between a package and a motherboard in which an optical waveguide is formed and the optical waveguide is optically coupled to a light emitting element and a light receiving element on the package.