JP2016035984A - Optical module - Google Patents

Abstract

An optical module capable of improving shielding performance and positioning accuracy of components is provided. A TOSA 7 having a sleeve 12 and a flange 18 extending from the sleeve 12, a ROSA 8 having a sleeve 14 and a flange 19 extending from the sleeve 14, an upper housing 2 for accommodating the TOSA 7 and the ROSA 8, and a conductive property And a sheet 22 having elasticity, and a plate-like holding member 21 that holds the flanges 18 and 19 inside the upper housing 2. The upper housing 2 includes a rear wall 15 having a hole through which the sleeves 12 and 14 are inserted, and a concave portion 20 that accommodates the seat 22, the flanges 18 and 19, and the holding member 21. The flanges 18 and 19 are accommodated in the recess 20 while being sandwiched between the sheet 22 and the holding member 21. [Selection] Figure 5

Description

  The present invention relates to an optical module that performs signal conversion on communication light.

  Patent Document 1 describes a pluggable transceiver. This pluggable transceiver includes a housing, an optical assembly having a cylindrical sleeve and two flanges, and a holder for holding the optical assembly. In this pluggable transceiver, the position of the optical assembly in the optical axis direction is determined by the two flanges sandwiching the latch piece of the holder. Further, the holder is positioned with respect to the housing by inserting the latch piece of the holder into the groove on the side wall of the housing. A conductive elastic body is provided between the flange and the holder and between the side wall and the holder, and component tolerances are absorbed by the conductive elastic body.

  Patent Document 2 describes an optical communication module including a housing, an optical subassembly, and a holder. The optical subassembly includes an optical device and a sleeve, and the sleeve is provided with a flange. By inserting the flange into the groove of the housing, the optical subassembly is positioned with respect to the housing. Moreover, component tolerance is absorbed by interposing a non-woven fabric having conductivity between the flange and the housing.

  Patent Document 3 describes an optical transceiver including a housing, an optical receptacle, and an optical subassembly having a sleeve. The sleeve is provided with a flange, which is sandwiched between the rear wall of the optical receptacle and the wall of the housing. Further, the optical receptacle includes a pressing portion protruding from the side surface thereof, and the optical receptacle is positioned with respect to the housing by inserting the pressing portion into the groove of the housing. In addition, since the pressing portion has a spring structure, component tolerance is absorbed by inserting the pressing portion into the groove.

JP 2005-316475 A JP 2011-129629 A JP 2011-232701 A

  By the way, in an optical transceiver, an optical element subassembly (OSA), a circuit board, a mechanism part, and the like are provided, and electromagnetic waves may leak from a gap between the parts. Therefore, in order to prevent leakage of electromagnetic waves and improve shielding properties, a gasket may be disposed in the gap. Further, in the optical transceiver, it is necessary to increase the positioning accuracy of the OSA, and it is required to improve the shielding performance and the positioning accuracy of the parts. In addition, it receives the PC (Physical Contact) load generated when connecting the ferrules of the optical connector, and increases the positional accuracy between the optical reference plane (ORP: Optical Reference Plane) and the machine reference plane (MRP: Mechanical Reference Plane). A structure to be secured is required.

  This invention is made | formed in view of such a situation, and makes it a subject to provide the optical module which can improve the positioning accuracy of components while improving a shielding property.

  An optical module according to an aspect of the present invention includes an optical assembly having a sleeve and a flange extending from the sleeve, a housing for housing the optical assembly, a sheet member having conductivity and elasticity, and a flange held inside the housing. A plate-shaped holding member, and the housing includes a wall having a hole through which the sleeve is inserted, and a recess that accommodates the sheet member, the flange, and the holding member, and the flange includes the sheet member and the holding member. It is accommodated in the recess while being sandwiched.

  According to the optical module of the present invention, it is possible to improve the shielding performance and the positioning accuracy of components.

1 is a perspective view showing an embodiment of an optical module according to the present invention. It is a perspective view which shows the internal structure of the optical module of FIG. It is a perspective view which shows an upper housing | casing, TOSA, and ROSA. It is a top view which shows an upper housing | casing, TOSA, ROSA, and a holding member. It is a top view which shows an upper housing | casing, TOSA, ROSA, a holding member, and a sheet | seat. It is a perspective view which shows a holding member. It is a perspective view which shows a lower housing | casing and a holding member. It is a perspective view which shows an upper housing | casing, TOSA, ROSA, and a sheet | seat. It is a perspective view which shows the state which inserts a holding member in the recessed part of an upper housing | casing.

  Hereinafter, embodiments of an optical module according to the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a perspective view showing an appearance of an optical module 1 according to the present embodiment. The optical module 1 is a component used for optical communication, and performs photoelectric conversion in optical communication. The optical module 1 is inserted into the cage of the host system. As shown in FIG. 1, the optical module 1 includes an upper housing (housing) 2, a lower housing 3, an insertion / extraction mechanism 4, an optical receptacle 5, and a circuit board 6.

  The upper housing 2 and the lower housing 3 are made of aluminum or zinc alloy and can be manufactured by die casting. The upper housing 2, the lower housing 3, and the insertion / removal mechanism 4 are elongated. In the following, for convenience of explanation, the description will be made with the directions defined as “front”, “rear”, “upper”, “lower”, “left”, and “right”. The side on which the insertion / extraction mechanism 4 is provided is the front, and the side on which the circuit board 6 that is the opposite side is provided is the rear. Further, the side on which the upper housing 2 is provided is the upper side, and the side on which the lower housing 3 that is the opposite side is provided is the lower side. And let the direction orthogonal to the up-down direction and the front-back direction be the left-right direction. These directions are merely for convenience of explanation and do not limit the scope of the present invention.

  FIG. 2 shows an outline of the internal structure of the optical module 1 and is a perspective view of the inside of the upper housing 2 with the lower housing 3 and the insertion / removal mechanism 4 removed. As shown in FIG. 2, an internal space S of the optical module 1 is formed by the upper housing 2. In this internal space S, a circuit board 6, a TOSA (optical assembly) 7, a ROSA (optical assembly) 8, and two FPCs 9 and 10 are accommodated.

  The upper housing 2 constitutes the upper surface and side surfaces of the optical module 1. The lower housing 3 functions as a lid that covers the bottom of the upper housing 2. The upper housing 2 and the lower housing 3 prevent leakage of electromagnetic radiation generated inside the optical module 1 to the outside. The insertion / extraction mechanism 4 and the optical receptacle 5 are provided at the front ends of the upper housing 2 and the lower housing 3. The optical receptacle 5 receives an external optical connector. The optical receptacle 5 is connected to the upper housing 2.

  The TOSA 7 and the ROSA 8 are accommodated in the internal space S in a state of being arranged in the left-right direction on the front side of the upper housing 2. The TOSA 7 and the circuit board 6 are connected to each other by the FPC 9, and the ROSA 8 and the circuit board 6 are connected to each other by the FPC 10. The ROSA 8 converts an optical signal received from the outside of the optical module 1 via an optical fiber into an electrical signal. The electrical signal converted by the ROSA 8 is transmitted to the circuit board 6 via the FPC 10. In addition, an electrical signal is output from the circuit board 6, and this electrical signal is transmitted to the TOSA 7 via the FPC 9. The TOSA 7 converts the electrical signal received from the circuit board 6 into an optical signal, and outputs the converted optical signal to the outside of the optical module 1.

  The TOSA 7 includes a main body 11 that is a rectangular box-shaped package, a cylindrical sleeve 12 that protrudes from a side surface (front surface) of the main body 11, and a flange 18 (see FIG. 3) that extends from the sleeve 12. The ROSA 8 also includes the same main body 13, sleeve 14 and flange 19 as described above.

  The main bodies 11 and 13 and the sleeves 12 and 14 are joined by YAG welding. In order to enable this YAG welding, for example, the sleeves 12 and 14 are made of SUS. The TOSA 7 and the ROSA 8 are arranged such that the front sides of the sleeves 12 and 14 protrude from the rear toward the inside of the optical receptacle 5. Further, the TOSA 7 and the ROSA 8 have mechanical dimensions that conform to the standard of the optical receptacle (optical connector) 5 (LC connector standard or the like).

  FIG. 3 is an enlarged perspective view of the rear part of the optical receptacle 5, the front part of the TOSA 7, and the front part of the ROSA 8. As shown in FIG. 3, the optical receptacle 5 is molded integrally with the upper housing 2. The optical receptacle 5 can be manufactured by metal die casting using Al or Zn as a whole. A rear wall 15 is provided at the rear portion of the optical receptacle 5, and circular holes 16 through which the sleeves 12, 14 pass are formed in the rear wall 15. The diameter D1 of the hole 16 is slightly larger than the outer diameter (diameter D2) of the sleeves 12 and 14. Therefore, smooth insertion of the sleeves 12 and 14 into the holes 16 is guaranteed. In addition, the base side (the main body 11 side) of the flange 18 in the sleeve 12 is a constriction 12a whose diameter is reduced from the flange 18, and the base side of the flange 19 in the sleeve 14 is also a constriction 14a.

  Further, the positions of the sleeves 12 and 14 (the relative positions of the sleeves 12 and 14 with respect to the internal space of the optical receptacle 5) in the vertical and horizontal directions (a plane orthogonal to the optical axis) must be set within the standard value of the receptacle. Here, in the optical module 1, by inserting the sleeves 12 and 14 into the respective holes 16, the mounting positions of the TOSA 7 and ROSA 8 in the vertical and horizontal directions and the relative positions of the sleeves 12 and 14 with respect to the optical receptacle 5 are high. Determined by accuracy.

  FIG. 4 is an enlarged plan view of the optical receptacle 5, the front part of the TOSA 7, and the front part of the ROSA 8. As shown in FIG. 4, at the front end of the internal space S, the rear wall 15 described above, a pair of convex portions 17 projecting inward from the side wall 2 a of the upper housing 2 behind the rear wall 15, and the rear wall A concave portion 20 is provided between 15 and the convex portion 17. The recess 20 includes a holding member 21 that holds the flanges 18 and 19 in the internal space S, a flange 18 of the TOSA 7 and a flange 19 of the ROSA 8, and a sheet (sheet member) 22 (see FIG. 5) having conductivity and elasticity. Are accommodated in this order from the rear.

  As shown in FIG. 5, since the sheet 22 is compressed in the state of being accommodated in the recess 20, the sum of the thickness of the sheet 22, the thicknesses of the flanges 18 and 19, and the thickness of the holding member 21 is the recess 20. It becomes equal to the width in the front-rear direction. However, the sum of the thickness of the sheet 22, the thicknesses of the flanges 18 and 19, and the thickness of the holding member 21 in a state where it is not accommodated in the recess 20 is longer than the width of the recess 20 in the front-rear direction.

  Both the sleeve 12 of the TOSA 7 and the sleeve 14 of the ROSA 8 are inserted from the rear into the hole 16 of the rear wall 15 and protrude into the internal space of the optical receptacle 5. Further, the rear surfaces 18 a and 19 a of the flanges 18 and 19 having a diameter larger than that of the sleeves 12 and 14 come into contact with the front surface 21 a of the holding member 21. The rear surface 21 b of the holding member 21 contacts the front surface 17 a of each convex portion 17 located on both sides of the holding member 21.

  Here, when the optical receptacle 5 accommodates the external connector, the latch mechanism of the external connector is engaged with the optical receptacle 5 and the ferrule of the external connector is pressed against the sleeves 12 and 14 (rear side). The stress due to the pressing is transmitted from the flanges 18 and 19 to the holding member 21, and is absorbed by the rear surface 21 b of the holding member 21 coming into contact with the front surface 17 a of each convex portion 17. Therefore, the positions of the sleeves 12 and 14 in the front-rear direction (optical axis direction) are firmly held.

  FIG. 6 is a perspective view of the holding member 21. As shown in FIG. 6, the holding member 21 is formed in a rectangular shape. The thickness of the holding member 21 is, for example, 0.6 to 1.0 mm. For example, SUS304 or SUS301 can be used as the material of the holding member 21. The holding member 21 has a pair of first cuts 21d formed by cutting one long side 21c of the holding member 21 into a U shape, and corners positioned at both ends of the other long side 21e of the holding member 21. And a pair of second cuts 21f.

  The first notches 21d of the holding member 21 correspond to the sleeve 12 of the TOSA 7 and the sleeve 14 of the ROSA 8 respectively. That is, the first notch 21d can be inserted through the constriction 12a of the sleeve 12 and the constriction 14a of the sleeve 14. The width W1 of the first cut 21d is larger than the diameter D2 of the sleeves 12 and 14 and smaller than the diameter D3 of the flanges 18 and 19. Therefore, the rear surfaces 18a and 19a of the flanges 18 and 19 can be brought into contact with the front surface 21a of the holding member 21 without inserting the flanges 18 and 19 into the first cut 21d. In addition, the accuracy of the diameter D1 of the hole 16 and the diameter D2 of the sleeves 12 and 14 is higher than the accuracy of the width W1 of the first cut 21d and the diameter D2 of the sleeves 12 and 14. Is required.

  FIG. 7 is a perspective view showing the positional relationship between the lower housing 3 and the holding member 21. As shown in FIG. 7, the length of the long side 21 e of the holding member 21 is shorter than the width W <b> 2 of the lower housing 3. In addition, a groove 3a for accommodating a gasket extends in the front, rear, left and right in the lower housing 3, and a convex portion 3c protruding from the groove 3a is provided inside the groove 3a. When the second cuts 21f are fitted into the convex portions 3c, rattling of the holding member 21 in the left-right direction is reduced. The gasket accommodated in the groove 3 a is disposed between the upper housing 2 and the lower housing 3 and has a function of shielding the optical module 1. As this gasket, a rubber tube having conductivity and elasticity is used.

  As shown in FIG. 8, the sheet 22 has a rectangular shape. As the material of the sheet 22, for example, a material in which nickel graphite or carbon particles are added using rubber as a base material can be used. Circular holes 22 a are formed at positions corresponding to the sleeves 12 and 14 of the sheet 22. The diameter of the hole 22a is equal to or slightly larger than the diameter D2 of the sleeves 12 and 14. That is, the diameter of the hole 22 a is approximately the same as the diameter of the hole 16 formed in the rear wall 15. The diameter of the hole 22a is smaller than the diameter D3 of the flanges 18 and 19, and smaller than the width W1 of the first cut 21d of the holding member 21.

  Next, assembly of the TOSA 7 and the ROSA 8 with respect to the upper housing 2 will be described. 8 and 9 are perspective views showing an assembly process of the TOSA 7 and the ROSA 8 with respect to the upper housing 2. First, as shown in FIG. 8, the sheet 22 is attached to the rear surface 15 a of the rear wall 15. At this time, the sheet 22 is affixed to the rear surface 15a so that the positions of the holes 22a of the sheet 22 in the vertical and horizontal directions coincide with the positions of the holes 16 of the rear wall 15.

  Further, a heat radiating sheet is attached to a location where the main body 11 of the TOSA 7 comes into contact with a location where the main body 13 of the ROSA 8 comes into contact with the inner surface of the upper housing 2. Then, the TOSA 7 sleeve 12 is inserted through the holes 22 a and 16 from the rear, and the ROSA 8 sleeve 14 is inserted through the holes 22 a and 16 from the rear. Thereafter, as shown in FIG. 9, the holding member 21 is inserted into the recess 20 with the first notches 21d of the holding member 21 facing downward, and the sleeves 12 and 14 are inserted through the first notches 21d. State. When the holding member 21 is inserted into the recess 20, the sheet 22 is pushed forward and compressed. Since the holding member 21 and the flanges 18 and 19 are in surface contact with each other in the front-rear direction, a situation in which the flanges 18 and 19 rattle in the recess 20 is avoided.

  By the way, there is a method of suppressing rattling between the holding member 21 and the flanges 18 and 19 by driving a wedge-shaped member into the recess 20 instead of the sheet 22. However, the method of driving a wedge-shaped member into the concave portion 20 has a problem that the contact between the holding member 21 and the flanges 18 and 19 and the contact between the holding member 21 and the convex portion 17 are not uniform. Therefore, there is a difference in the resistance to the flanges 18 and 19 between the one long side 21c side of the holding member 21 and the other long side 21e side. This difference may cause a decrease in reliability due to optical axis misalignment or nonuniform contact stress. Furthermore, there is a possibility that stress concentrates on the root portions of the sleeves 12 and 14 (portions on the main body 11 and 13 side).

  On the other hand, in this embodiment, since the rectangular sheet 22 is accommodated in the concave portion 20, the contact between the holding member 21 and the flanges 18 and 19 and the contact between the holding member 21 and the convex portion 17 are uniform. Can be. Therefore, the problem as described above does not occur. Finally, the assembly of the optical module 1 is completed by superimposing the lower housing 3 and the upper housing 2 and screwing them together.

  As described above, in the optical module 1, the holding member 21 and the sheet 22 are accommodated in the recess 20 together with the flanges 18 and 19. Since the flanges 18 and 19 are sandwiched between the holding member 21 and the sheet 22 in the recess 20, the positions of the sleeves 12 and 14 in the optical axis direction can be determined, and the positions of the TOSA 7 and ROSA 8 can be set to the upper casing. It can be fixed inside the body 2.

  Further, by inserting the holding member 21 into the recess 20, the conductive sheet 22 is compressed in the recess 20. Therefore, sufficient contact and conductivity of the flanges 18 and 19 (sleeves 12 and 14) can be ensured. Thus, the position of the TOSA 7 and the ROSA 8 can be easily fixed by simply inserting the holding member 21 into the recess 20 without being influenced by the degree of assembly. Furthermore, the shielding property of the optical module 1 can be improved by accommodating the sheet 22 in the recess 20. Further, the positioning accuracy of the TOSA 7 and the ROSA 8 can be increased, and a state in which the positional accuracy between the optical reference surface and the machine reference surface is ensured is realized.

  Further, as described above, the sum of the thickness of the sheet 22, the thicknesses of the flanges 18 and 19, and the thickness of the holding member 21 when not accommodated in the recess 20 is longer than the width of the recess 20. Therefore, since the sheet 22 is accommodated in the recessed portion 20 in a compressed state, the contact property of the upper housing 2, the sheet 22, the flanges 18 and 19, and the holding member 21 is further enhanced.

  Further, the upper housing 2 has a pair of convex portions 17 projecting inward of the upper housing 2 toward the sleeves 12 and 14 accommodated in the upper housing 2, and the concave portion 20 is paired with the rear wall 15. Between the convex portion 17 and the convex portion 17. Therefore, since the recessed part 20 is comprised by the rear wall 15 and a pair of convex part 17, the structure for accommodating the holding member 21, the flanges 18 and 19, and the sheet | seat 22 can be simplified.

  The holding member 21 has a first cut 21d through which the sleeves 12 and 14 are inserted. Therefore, the flanges 18 and 19 can be easily held only by inserting the holding member 21 into the recess 20 from above.

  As mentioned above, although preferred embodiment which concerns on this invention has been described, this invention is not limited to embodiment mentioned above. That is, it is easily recognized by those skilled in the art that various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

  For example, in the above embodiment, an example in which both the TOSA 7 and the ROSA 8 include the box-shaped main bodies 11 and 13 has been described. However, the configuration of the optical assembly such as the TOSA and the ROSA is not limited to the above embodiment. For example, the present invention can be applied to an optical assembly including a CAN type package and a sleeve. Further, the shapes and sizes of the optical receptacle, the sheet member, and the holding member are not limited to the above embodiment and can be changed as appropriate.

DESCRIPTION OF SYMBOLS 1 ... Optical module, 2 ... Upper housing | casing (housing), 3 ... Lower housing | casing, 4 ... Insertion / extraction mechanism, 5 ... Optical receptacle, 6 ... Circuit board, 7 ... TOSA (optical assembly), 8 ... ROSA (optical assembly) 9, 10 ... FPC, 11, 13 ... main body, 12, 14 ... sleeve, 12a, 14a ... constriction, 15 ... rear wall (wall), 15a ... rear surface, 16 ... hole, 17 ... convex portion, 17a ... front surface, 18, 19 ... flange, 18a, 19a ... rear surface, 20 ... recess, 21 ... holding member, 21a ... front surface, 21b ... rear surface, 22 ... sheet, 22a ... hole.

Claims (6)

An optical assembly having a sleeve and a flange extending from the sleeve;
A housing that houses the light assembly;
A sheet member having conductivity and elasticity;
A plate-like holding member that holds the flange inside the housing, and
The housing includes a wall having a hole through which the sleeve is inserted, and a recess that houses the sheet member, the flange, and the holding member,
The flange is accommodated in the recess in a state sandwiched between the sheet member and the holding member.
Optical module. The sum total of the thickness of the sheet member, the thickness of the flange, and the thickness of the holding member in a state not accommodated in the recess is larger than the width of the recess.
The optical module according to claim 1. The housing has a pair of protrusions protruding inside the housing,
The concave portion is constituted by the wall and the pair of convex portions,
The optical module according to claim 1 or 2. One surface of the holding member is in contact with the flange, and the other surface of the holding member is in contact with the pair of convex portions.
The optical module according to claim 3. The sheet member is made of rubber,
The optical module as described in any one of Claims 1-4. The holding member has a cut for inserting the sleeve.
The optical module as described in any one of Claims 1-5.

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