KR20020077081A - Optical Module for Small Form Pluggable - Google Patents

Abstract

PURPOSE: A socket type small-sized optical module is provided to reduce a loss of a signal and an interference between signals by providing electric contacts between inner active elements and an external printed circuit board, forming a matching circuit between the contacts, and installing a connector projected a rear direction of a package. CONSTITUTION: An optical transmission module is formed with an integrated module package(115), a substrate(101), a light emitting element(103), and a light receiving element(104). A condensing portion is arranged on a front face of the integrated module package(115). The substrate(101) is adhered on a bottom portion of an inner room of the integrated module package(115). The light emitting element(103) is adhered on an upper portion of the substrate(101). The light receiving element(104) is used for controlling an optical output of the light emitting element(103). The condensing portion is formed with a lens insertion hole(122), a transmission lens(116), and a transmission guide pipe(118). A projection structure(120) is formed on a bottom portion of the substrate(101) or a bottom portion of the inner room the package(115). The projection structure(120) is combined with a groove portion. A cover(126) is formed on an upper face of the package(115). A connector(124) is adhered on one side of the package(115). Electric contacts(C,C') are formed between the light emitting element(103), the light receiving element(104), and an external circuit substrate(125). A matching circuit portion(129) is formed between the electric contacts(C,C').

Description

Socket-type Small Form Element Optical Module {Optical Module for Small Form Pluggable}

The present invention relates to a small element-type optical module, and more particularly, to provide an electrical contact between an external circuit board and an internal active element, and is provided with a constant voltage circuit unit that implements impedance matching between the active element and the two contacts. Disclosed is an optical module comprising a connector configured to protrude to the rear of a package in parallel with an optical axis.

With the advent of the information age, there is a need for an optical module using light capable of transmitting a large amount of information. Among them, the optical module using light is required to have a high reliability of not only having excellent characteristics of the module itself but also maintaining its characteristics for a long time. Low prices must be maintained to facilitate the dissemination of optical modules for the implementation of fiber to the home (FTTH). In particular, as the capacity of the optical transmission system increases, efforts are being made to increase the number of modules that can be mounted per unit area by reducing the size of the optical module mounted in the optical transmission system.

In general, active alignment methods (such as laser diodes and photodiodes) of optical modules and optical fibers for converting an electrical signal into an optical signal or an electrical signal are classified into an active alignment method and a passive alignment method. Two methods of passive alignment method are used.

In the process of aligning the active element and the optical fiber, the active alignment method finds the position where the light output is best while moving finely by using a device having a resolution of um or less. In addition, it is difficult to reduce the cost of the optical module because additional components are required to perform the active alignment method.

Passive alignment is a method of accurately aligning the active element and the optical fiber without injecting current into the active element, where the position of the optical fiber is exactly aligned and the position of the active element is exactly aligned in the step before the process of aligning the optical fiber Only the best light output can be obtained.

Optical modules, which are mainly manufactured until now, are manufactured by active sorting method, which uses expensive equipment that can control up to um or less in the process of arranging optical fibers. This has the disadvantage of being expensive and lowering productivity.

In addition, in the case of the conventional TO-can package 10 of FIG. 1, the pins 11 are formed parallel to the optical axis, so that the circuit board 12 for driving an active element inside the TO-can-shaped package is provided. In order to connect the pin 11 must be bent and fixed to the circuit board. In this case, by fixing the pins to the circuit board by bending the pins, problems such as signal interference between the pins occur, and it is very difficult to adjust the length of the pins to match the impedance, making it difficult to operate a high-speed device of 2.5 Gbps or more. Even when the package 20 of the Mini-DIL type of FIG. 2 is used, since the pins attached to the outer surface of the mini-DIL package are formed in a direction perpendicular to the optical axis, the miniature element-type package 22 In order to mount, the mini-DIL package must be rotated at an angle of 90 degrees and then mounted on the circuit board 23. In order to do this, the circuit board itself into which the mini-DIL package is inserted must also be mounted on the module at an angle of 90 degrees to the module direction. Therefore, using the mini-DIL package to manufacture the module is a complicated and difficult manufacturing process. In addition, by fixing the pins to the circuit board in this manner, problems such as signal interference between the pins occur, and it is very difficult to adjust the length of the pins to match the impedance, which makes it difficult to operate the high-speed device of 2.5 Gbps or more. .

Disclosure of Invention An object of the present invention is to provide an optical module that can be easily attached and detached to an optical communication system and obtains high frequency characteristics with minimized signal loss or interference between signals.

It is still another object of the present invention to provide an optical module in which manual alignment of a substrate and a package is very easy in a pre-arranged manner without driving an active element.

1 is a conventional To-Can package structure

2 is a conventional mini-DIL package structure

3 is a cross-sectional view of the optical transmission module according to the present invention.

Fig. 4 is a (a) plan view, (b) perspective view, and (c) bottom view of a transmission substrate with an active element attached thereto.

5 is an exploded perspective view of the optical transmission module according to the present invention.

6 is a cross-sectional view of the optical receiving module according to the present invention.

7 is a front view, a perspective view, and a bottom view of a receiving substrate with a light receiving element attached thereto.

8 is an exploded perspective view of the light receiving module according to the present invention.

9 is an exploded perspective view of the optical transmission module according to the present invention.

* Description of Signs of Main Parts of Drawings *

101,107: substrate 102: light reflecting groove

103: light emitting element 104,108: light receiving element

111,113: fiber 112,114: Peruvian wool

115,115 ': Package 116,117: Lens

118, 119: guide pipe 124, 124 ', 310: connector

129: matching circuit unit 125, 320: electronic circuit board

321: socket

An optical transmission module comprising a substrate having an active element attached to a predetermined position, a light converging means for transmitting light generated from a light emitting element to an optical fiber, and a package having an electrical contact between the active element and an external circuit board.

Contact points for electrically connecting the internal active element and the external circuit board are respectively formed at both ends, and a constant voltage circuit part for implementing impedance matching with the active element is provided between the both contacts, and the contact part with the external circuit board is provided on one side of the package. It includes an optical transmission module characterized in that the connector is provided to protrude horizontally from.

In addition, the present invention is preferably a projection structure of a predetermined shape is formed on one of the bottom portion of the substrate or the bottom portion of the inner compartment of the package, and the other side is provided with a groove portion to match the protrusion structure, the manual alignment by the attachment of the protrusion structure and the groove portion It includes an optical transmission module forming a.

Hereinafter, the content of the present invention will be described in detail with reference to preferred embodiments as shown in FIGS. 3 to 5.

According to the drawing shown as a preferred embodiment of the present invention, the optical transmission module 100 includes an integrated module package 115 having a light collecting means on the front surface, a substrate 101 attached to an inner chamber bottom surface of the package; It includes a light emitting element 103 attached to the upper substrate and a light receiving element 104 provided to the sensor to control the light output of the light emitting element.

The light converging means constituting the embodiment includes a lens insertion hole 122 and a transmission lens 116 formed on the front of the package, and a hollow portion in which the transmission Peru wool 112 is inserted in communication with the lens insertion hole. The transmission guide pipe 118 in which 118a was formed is included.

The location of the light collecting means need not always be fixed to the front of the package. If the light emitting surface of the light emitting device is formed in a direction perpendicular to the plane, the light collecting means should also be formed on the upper surface of the package. Therefore, it should be noted that the position of the light collecting means can be flexibly implemented on the package according to the position of the light emitting surface of the light emitting device.

In general, the transmitting lens 116 may be implemented as a ball lens, and the pre-calculation in the lens insertion hole 122 may be performed so that the light from the light emitting element 103 is concentrated on the core of the optical fiber 111 in the transmitting Peru wool 112. It is fixed in the fixed position.

The transmission guide pipe 118 is provided with the hollow part 118a into which the Peru wool 112 in which the optical fiber 111 was mounted is inserted. The shape of the Peruvian wool is not particularly limited, but preferably, when the Peruvian wool is cylindrical, the inner diameter 118b of the hollow portion substantially coincides with the outer diameter of the Peruvian wool so that the core of the optical fiber 111 may be inserted in any direction. Make sure the light is focused correctly.

The package 115 is not particularly limited in material, but generally, a ceramic material or a metal (including alloy) and an equivalent material may be used. The bottom surface of the package chamber is preferably provided with a protrusion structure 120 having a predetermined shape formed to fix the substrate 101, and an opening and a cover 126 for introducing the substrate are provided on the upper surface of the package (the In this case, the position of the opening can also be installed fluidly according to the position of the light collecting means, and is not particularly fixed).

The protrusion structure 120 formed on the bottom surface of the package inner compartment fixes the substrate having a height adjusted in advance so that the light emitting device 103 can inject light from the optimal position to the lens to the transmitting lens 116. It is provided as a means for. The shape of the protrusion structure is not particularly limited. Therefore, a mesa structure having a V-groove or a sidewall inclined at a predetermined angle may be included therein so as to easily attach the substrate.

The connector 124 is attached to one surface of the package to form an integral part with the package. The connector 124 has electrical contacts (C, C ') formed at both ends of the internal active elements 103 and 104 and the external circuit board 125, respectively, and has a matching that implements impedance matching between the active elements. The circuit unit 129 is provided. In addition, the contact portion C ′ with the external circuit board 125 is easily connected to the external circuit board by protruding horizontally from one surface of the package to the outside.

The matching circuit portion 129 may be implemented on a substrate 128 having a constant dielectric constant (not shown, 128 'and 128 "respectively represent an insulating plate), and preferably, a predetermined protection circuit is provided to minimize signal interference and the like. The detailed circuit structure of the matching circuit unit 129 may be appropriately selected by those skilled in the art according to required characteristics (for example, the circuit structure may be determined according to the permittivity of the substrate to be used). It does not constitute a subject matter.

In addition, of course, the constant voltage circuit portion to the protection circuit portion may be implemented in a multilayer structure. According to the configuration described above, problems such as signal loss and mutual interference between signals can be minimized, so that the present invention can be applied as a high speed device of 2.5Gbps or more.

The substrate 101 is preferably a semiconductor substrate, for example, a silicon material may be used. The light emitting element 103 is attached by the solder 105 in front of the upper surface 101a of the substrate 101, the height of which is adjusted in advance so that optimal light is incident on the lens 116, and the light emitting element behind the light emitting element. A monitor light receiving element 104 for detecting the intensity of light irradiated from the rear surface of the light emitting device 104 is attached by the solder 105, and a light reflecting groove 102 having a predetermined shape is provided under the light receiving element. The light reflecting groove 102 reflects light irradiated from the rear surface of the light emitting element 103 and enters the surface of the light receiving element 104. Preferably, the light reflecting groove 102 includes a V-shaped groove having a predetermined width and depth determined by the crystallinity of the substrate, but is sufficient to perform the above function. It is not limited to this.

The positions of the light emitting element and the light receiving element are not necessarily limited to the above embodiment. For example, the light emitting device may be stacked on the monitor light receiving device, and a predetermined amount of light emitted from the light emitting device may be reflected and incident on the upper surface of the light receiving device.

In addition, the substrate 101 is provided with contacts 132 and 133 and a pattern at a predetermined position such that the light emitting device 103 and the light receiving device 104 are electrically connected to the connector 124 providing electrical contact with the outside.

The light emitting device 103 may typically use a laser diode. Preferably, the bottom portion of the laser diode may be provided with a concave-convex structure (not shown) having a predetermined height and size due to the orientation determined by the crystallographic characteristics of the single crystal. In this case, a predetermined height and size are also given to a predetermined position of the substrate 101 to which the light emitting device 103 is attached, and a concavo-convex structure having a corresponding structure is given to the substrate 101 without introducing a special alignment method. The light emitting device 103 can be seated in the correct position.

The photodetector 104 for a monitor can typically use a photodiode. The light receiving element 104 is used to control the intensity of light irradiated from the front surface of the light emitting element 103 by sensing the intensity of light incident on the surface. At this time, the specific control circuit can be implemented on the external electronic circuit board 125, the details thereof will be omitted as will be apparent to those skilled in the art.

The substrate 101 is provided with a recess portion 106 that matches in shape and size with the protrusion structure 120 provided in the package inner chamber bottom portion at the bottom portion 101b. As a specific method for forming the recessed portion, all conventional etching methods known to date may be used, and the present invention is not particularly limited.

As described above, manual alignment may be simply performed through mutual bonding between the recess 106 of the substrate and the protrusion structure 120 of the bottom of the package. That is, the final position of the light emitting device is implemented in a pre-adjusted manner so that the optical axis is precisely concentrated in the core of the optical fiber 111 in the Peru wool 112, and then only a one-step process of inserting the Peru wool 112 into the package is simple. Manual sorting is possible.

The present invention includes a multi-type optical transmission module configured to integrate the package by at least two or more parallel to the optical transmission module.

In another aspect, the present invention provides a light receiving module including a substrate having a light receiving element attached to a predetermined position, a light collecting means for transferring light from the optical fiber to the light receiving element, and a package having an electrical contact between the passive element and the external circuit board. In

Contact points for electrically connecting the internal passive element and the external circuit board are respectively formed at both ends, and a constant voltage circuit portion for implementing an impedance matching between the active element and the two contacts is provided, and the contact portion with the external circuit board is provided on one side of the package. It includes a light receiving module characterized in that the connector is provided to protrude horizontally from.

In addition, the present invention is preferably a projection structure of a predetermined shape is formed on one of the bottom portion of the substrate or the bottom portion of the inner compartment of the package, and the other side is provided with a groove portion to match the protrusion structure, the manual alignment by the attachment of the protrusion structure and the groove portion It includes a light receiving module constituting.

Hereinafter, with reference to a preferred embodiment of the optical receiving module shown in Figures 6 to 8 will be described in more detail.

According to the drawing shown as a preferred embodiment of the present invention, the light receiving module 200 is an integrated module package 115 ′ having a light collecting means on the front surface, and a substrate 107 attached to an inner chamber bottom surface of the package. And a light receiving element 108 attached to the front of the substrate.

The light collecting means constituting the embodiment includes a lens insertion hole 123 and a receiving lens 117 formed at the front of the package, and a hollow portion in which the receiving Peru wool 114 is inserted in communication with the lens insertion hole. The receiving guide pipe 119 in which the 119a was formed is included.

The location of the condensing means need not always be fixed to the front of the package as in the optical transmission module.

Typically, the receiving lens 117 may be implemented as a ball lens and is fixedly installed at a predetermined position in the lens insertion hole 123 so that light is concentrated on the light receiving portion of the light receiving element 108 from the optical fiber 113.

The receiving guide pipe 119 has a hollow portion 119a into which the Peru wool 114 into which the optical fiber 113 is mounted is inserted. The shape of the Peruvian wool is not particularly limited, but preferably, when the Peruvian wool is cylindrical in shape, the inner diameter 119b of the hollow portion substantially coincides with the outer diameter of the Peruvian wool so that the Peruvian wool may be inserted in any direction. Make sure the light is focused exactly on the light-receiving part of

The inner bottom of the package 115 'is provided with a protrusion structure 121 having a predetermined shape formed to fix the substrate 107, and an opening and a cover 126' for introducing the substrate are provided on the upper surface of the package. (In this case, the position of the opening can also be installed in a flexible manner depending on the position of the light collecting means as in the optical transmission module, and is not particularly fixed).

The protrusion structure 121 formed on the bottom surface of the package inner compartment is configured to fix the substrate, which is pre-adjusted so that the focus of light incident from the optical fiber 113 to the lens 117 is located at the light receiving portion of the light receiving element 108. Provided by means. The protrusion structure is not particularly limited in shape. Therefore, a mesa structure having a V-groove or a sidewall inclined at a predetermined angle may be included therein so as to easily attach the substrate.

A connector 124 'is attached to one surface of the package to form an integral part with the package. The connector 124 'has electrical contacts between the internal light receiving element 108 and the external circuit board at both ends, respectively, and has a matching circuit portion for impedance matching with the light receiving element as in the optical transmission module. do. In addition, the contact portion C ′ with the external circuit board is easily connected to the external circuit board by protruding horizontally from one surface of the package to the outside.

The matching circuit unit may be implemented on a substrate having a constant dielectric constant, and preferably, may be provided with a protection circuit for minimizing signal interference. The detailed structure of the matching circuit portion may be appropriately selected by those skilled in the art according to required characteristics (for example, the circuit structure may be determined according to the permittivity of the substrate to be used) and does not constitute the gist of the present invention.

In addition, the matching circuit portion to the protection circuit portion may be implemented in a multilayer structure, of course. According to the configuration described above, problems such as signal loss and mutual interference between signals can be minimized, so that the present invention can be applied as a high speed device of 2.5Gbps or more.

The substrate 107 is not particularly limited, but a ceramic material may be used. The substrate 107 is provided with a predetermined contact 134 such that the light receiving element 108 is attached to the front surface 107a by the solder 109 and is electrically connected to the contact C of the connector.

The light receiving element 108 is preferably a photodiode, and the light receiving element 108 is fixedly aligned at a predetermined position on the substrate 107 so as to face substantially in a straight line with the central axis of the receiving lens 117.

The substrate 107 is provided with a recess 110 in the bottom portion 107b to mate with the protrusion structure 121 provided on the bottom surface of the package interior chamber. The recess is not particularly limited because the recess may be manufactured through a mold or may be manufactured by performing a separate cutting process.

As described above, manual alignment may be simply performed through mutual bonding between the recess 110 of the substrate and the protrusion structure 121 of the bottom surface of the package. That is, since the light receiving element 108 is fixed in a pre-adjusted manner so that the light emitted from the optical fiber 113 in the Peru wool 114 on the front surface of the substrate is concentrated in the light receiving portion of the device, the Peru wool ( It is possible to perform manual alignment simply by the one-step process of inserting and fixing 114).

The present invention includes a multi-type optical receiving module configured to integrate the package by at least two or more parallel to the optical receiving module.

In addition, the present invention includes an optical transmission module 300 that is integrally configured with the optical transmission module 100 and the optical reception module 200.

As shown in FIG. 9, in the package of the optical transmission / reception module, the transmission and reception guide pipes 118 and 119 as described above are communicated with a set of lens insertion holes 122 and 123, respectively, and are formed on the front of the package, respectively. The protrusion structures 120 and 121 of predetermined shapes are formed on the bottom surfaces of the inner chambers A and B divided into two parts 305. In addition, the bottom portion of the substrate for transmitting and receiving has grooves 106 and 110 that match the protrusion structure in shape and size so that the bottom surface of the substrate is seated in a precisely aligned manner in the package chamber.

The connector 310 is integrally attached to the back of the package. The external contact portion C ′ of the connector is configured to protrude horizontally, thereby making electrical connection simple through fastening with the socket 321 formed on the external circuit board 320.

The upper surface of the package has a predetermined opening through which the openings for mounting the substrates 101 and 107 to which the active elements are attached are formed and covered.

In addition, the optical transmission module can also be implemented as a multi-type optical transmission module configured by integrating a package at least two or more in parallel.

Hereinafter, the manufacturing process of the optical transmission module will be described in detail through a preferred embodiment of the present invention. However, since the electrical connection process such as wire bonding is obvious to those skilled in the art, it will be omitted here.

The integrated module package 115 is placed on a stage (not shown), and the silicon substrate 101 to which the laser diode 103 and the photodiode 104 for the monitor are attached is picked up and an inner chamber of the package module 115 is integrated. After moving to (A), the groove having a slanted sidewall formed on the bottom surface of the silicon substrate 101 and having a flat rectangular bottom surface and the recess portion formed on the bottom surface of the inner chamber of the integrated module package 115 And the mesa structure 120 having the inclined sidewalls conforming in shape to seat the silicon substrate 101 at the correct position on the bottom surface of the package module 115. In this case, a solder having a predetermined melting point is coated on the upper surface of the mesa structure 120.

In the same manner, the ceramic block 107 to which the photodiode 108 is attached is picked up and moved to the other inner chamber B of the package 115 for the integrated module, and has an inclined sidewall formed on the bottom of the ceramic block 107. Package module 115 for the integrated module 115 by a mesa structure 121 having a flat rectangular shape groove portion 110 and the inclined side wall matching the groove portion formed in the inner surface of the integrated module package 115 in size and shape. The ceramic block 107 is seated in the correct position on the bottom surface.

The stage is heated to melt the solder on the mesa structures 120 and 121 to fix the silicon substrate 101 for transmission and the ceramic block 107 for reception to the integrated module package 115 in the correct position.

After the silicon substrate 101 for transmission and the ceramic block 107 for reception are fixed to the inside of the package 115 for the integrated module, the cover 126 on the package 115 for the integrated module is electrically welded in a nitrogen atmosphere. To fix it.

The transmitting silicon substrate 101 and the receiving ceramic block 107 are seated in the correct positions on the inner chambers A and B of the integrated module package 115, and then attached to the front surface of the integrated module package 115. Receiving including a transmitting Peru wool 112 and a receiving optical fiber 113 including a transmitting optical fiber 111 in the hollow of the pair of transmitting guide pipe 118 and the receiving guide pipe 119. Completion of each of the Peru wool 114 is fixed by laser welding or the like.

According to the present invention, by implementing a matching circuit with an active element on the connector, signal loss or interference between signals can be minimized, so that it can be applied to a high-speed device of 2.5 Gbps or more, and also without driving a light emitting or receiving element. Manual sorting of the package is possible, and the optical module is manufactured in a pre-aligned manner, so it can be easily installed, which greatly reduces the time required for alignment.

Claims (18)

An optical transmission module comprising a substrate having an active element attached to a predetermined position, a light converging means for transmitting light generated from a light emitting element to an optical fiber, and a package having an electrical contact between the active element and an external circuit board. Contact points for electrically connecting the internal active element and the external circuit board are respectively formed at both ends, and a constant voltage circuit portion for implementing impedance matching with the active element is provided between the two contacts, and the contact portion with the external circuit board is formed from one surface of the package. Optical transmission module characterized in that the connector is provided to protrude horizontally The method of claim 1, The constant voltage circuit unit is formed on a substrate having a constant dielectric constant optical transmission module The method of claim 1, Optical transmission module, characterized in that the constant voltage circuit portion is implemented in a multi-layer structure The method of claim 1, A projection structure having a predetermined shape is formed on one of the bottom portion of the substrate or the bottom portion of the inner compartment of the package, and the other side is provided with a groove portion matching with the protrusion structure, and the optical transmission module manually aligned by attachment of the protrusion structure and the groove portion. The method of claim 4, wherein Optical transmission module, characterized in that the bottom surface of the package is provided with a projection of the mesa structure having an inclined side wall at a predetermined angle The method of claim 1, The light transmitting module is characterized in that the material of the package is selected from ceramic or metal and equivalent materials. The method of claim 1, The inner diameter of the guide pipe constituting the light collecting means is substantially matched with the outer diameter of the Peru wool, the optical transmission module, characterized in that configured to be in close contact In a light receiving module comprising a substrate having a light receiving element attached to a predetermined position, a light collecting means for transferring light from the optical fiber to the light receiving element, and a package having an electrical contact between the passive element and the external circuit board, Contact points for electrically connecting the internal passive element and the external circuit board are respectively formed at both ends, and a constant voltage circuit portion for implementing an impedance matching between the active element and the two contacts is provided, and the contact portion with the external circuit board is formed from one surface of the package. Optical receiving module characterized in that the connector is provided to protrude horizontally The method of claim 8, The constant voltage circuit unit is formed on a substrate having a constant dielectric constant optical receiving module, characterized in that The method of claim 8, Optical receiving module, characterized in that the constant voltage circuit portion is implemented in a multi-layer structure The method of claim 8, A projection structure having a predetermined shape is formed on one of the bottom portion of the substrate or the bottom portion of the inner compartment of the package, and the other side is provided with a groove portion that matches the protrusion structure, and the optical receiving module manually aligned by attachment of the protrusion structure and the groove portion. The method of claim 11, Optical receiving module, characterized in that the bottom surface of the package is provided with a projection of the mesa structure having an inclined side wall at a predetermined angle The method of claim 8, The light receiving module is characterized in that the material of the package is selected from ceramic or metal and equivalent materials. The method of claim 8, The inner diameter of the guide pipe constituting the light collecting means is substantially matched with the outer diameter of the Peru wool, the light receiving module, characterized in that configured to be in close contact The optical transmission module composed of the optical transmission module selected from any one of claims 1 to 7 and the optical reception module selected from any one of claims 8 to 14. Multi-type optical transmission module, characterized in that the package is configured by integrating at least two or more optical transmission module of any one of claims 1 to 7 in parallel. The multi-type optical reception module, characterized in that the package is formed by integrating at least two or more optical reception module of any one of claims 8 to 14 in parallel. Multi-type optical transmission module characterized in that the package is formed by integrating at least two optical transmission module of claim 15 in parallel