JP3800154B2 - Optical module - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot-swap optical module.
[0002]
[Prior art]
Optical modules are widely used in data communication systems that use light as an information transmission medium, optical communication systems such as optical LANs, and the like. As an example of a conventional optical module, a housing is provided, and a substrate is provided on the bottom surface. A light emitting element assembly, a light receiving element assembly, an electronic component, and the like are mounted on the substrate. The electronic component includes a driver element for driving the light emitting element (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
US Pat. No. 6,335,869 B1
[Problems to be solved by the invention]
By the way, since the light emitting element included in the light emitting element assembly is easily affected by heat, in order to improve the reliability and performance of the optical module, it is necessary to prevent the temperature in the vicinity of the light emitting element from becoming as high as possible.
[0005]
Accordingly, an object of the present invention is to provide an optical module that can further improve the temperature conditions in the vicinity of the light emitting element.
[0006]
[Means for Solving the Problems]
The present inventors conducted various experiments using the optical module described in Patent Document 1. In the experiment, the inventors of the optical module described in Patent Document 1 have a light-emitting element assembly and a substrate that are connected by lead, so that heat from the substrate to the light-emitting element assembly via the lead can be obtained. Focusing on conduction, we have found that this is one of the factors that deteriorate the temperature conditions near the light emitting element. The present invention has been made based on these findings.
[0007]
An optical module of the present invention is an optical module having a housing member, a first substrate, a second substrate, and a heat conducting member, and the first substrate is an electronic component that exchanges electric signals with a photoelectric conversion element. The first electronic component including the first electronic component is mounted, and is gripped between the housing member and the heat conducting member. The second substrate mounts the second electronic component cooperating with the first electronic component , and further conducts heat. The heat conduction member is mounted on the member and forms a shell in cooperation with the housing member, and further transfers heat generated by at least one of the first electronic component and the second electronic component. It is characterized by that.
[0008]
According to the optical module of the present invention, the heat generated by the specific electronic component is transmitted to the heat conducting member, and the heat is conducted through the heat conducting member to reach the outer shell. It can be conducted to the outer shell of the optical module. Therefore, heat transmitted from the first substrate or the second substrate to the photoelectric conversion element via the lead can be reduced, and thus the temperature condition in the vicinity of the photoelectric conversion element such as a light emitting element can be further improved.
[0009]
In the optical module of the present invention, it is also preferable that the heat conducting member is in contact with at least one electronic component via a heat dissipation sheet. The heat to which an electronic component is generated is transmitted to the heat conducting member via the heat dissipation sheet can be conducted more efficiently heat one electronic component is generated in the outer of the optical module.
[0010]
In the optical module of the present invention, it is also preferable that the one electronic component is mounted on the main surface of the first substrate facing the heat conducting member. Since the main surface on which the one electronic component is mounted and the heat conducting member face each other, the heat generated by the one electronic component can be efficiently conducted to the heat conducting member.
[0011]
In the optical module of the present invention, it is also preferable that the second substrate is mounted on the heat conducting member so that the second electronic component is mounted only on the main surface, and the main surface faces the first substrate. Heat the second electronic components mounted on the second substrate is also generated transmitted to the heat-conducting member, it is possible to heat confinement of between the first substrate and the second substrate further improve, in the vicinity of the electronic component The temperature condition can be further improved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The knowledge of the present invention can be easily understood by considering the following detailed description with reference to the accompanying drawings shown for illustration only. Subsequently, embodiments of the present invention will be described with reference to the accompanying drawings. Where possible, the same parts are denoted by the same reference numerals, and redundant description is omitted.
[0013]
FIG. 1 is a perspective view showing an optical module 10 according to the present embodiment and a host board 40 into which the optical module 10 is fitted. As shown in FIG. 1, the optical module 10 is inserted into a cage 42 provided on the host board 40. Then, a protrusion (not visible in FIG. 1) formed on the optical module 10 engages with a hook 41 provided on the host board 40, and the optical module 10 is fixed to the host board 40. A mode in which the protrusion and the hook 41 are engaged is shown in FIGS. 3 (a) and 3 (b). As shown in FIGS. 3A and 3B, the optical module is configured such that the hook 41 provided on the host board 40 and the protrusion 11a provided on the optical module 10 are engaged with each other. It is fixed to the board 40.
[0014]
FIG. 2 is an exploded perspective view of the optical module 10. The optical module 10 includes a housing (housing member) 11, a mounting substrate 12, a heat radiation block (heat conducting member) 13, a cover 14, a light emitting element assembly 15, a light receiving element assembly 16, an OSA block 17, and a holder. 18, a bracket 19, a shield 20, a radiation fin 21, a bail actuator 22, a tail cap 23, and a board stopper 24.
[0015]
The housing 11 is a part that houses functional components such as the light emitting element assembly 15, the light receiving element assembly 16, and the mounting substrate 12. The housing 11 includes a light emitting element assembly 15, a light receiving element assembly 16, and a recess 11 b in which a lower layer substrate (first substrate) 12 a of the mounting substrate 12 is accommodated. The housing 11 is made of an alloy containing zinc or aluminum as a component, or aluminum.
[0016]
Electronic components (first electronic components) are mounted on both surfaces of the lower layer substrate 12a. In the case of the present embodiment, a driver element (electronic component, specific electronic component) that transmits and receives an electrical signal to drive the light emitting element (photoelectric conversion element) of the light emitting element assembly 15 is mounted on the main surface of the lower layer substrate 12a. It is mounted so that the surface opposite to the main surface faces the housing 11. A light emitting element assembly 15 and a light receiving element assembly 16 are attached to the lower layer substrate 12a via brackets 19 and lead pins (not shown). The lower layer substrate 12 a is disposed in the recess 11 b of the housing 11 and is temporarily fixed by the substrate stopper 24.
[0017]
A light emitting element assembly 15 including a light emitting element as a photoelectric conversion element and a light receiving element assembly 16 including a light receiving element as a photoelectric conversion element are placed on a semicircular portion of the OSA block 17 and fixed by a holder 18. . A shield 20 is sandwiched between the OSA block 17 and the housing 11. FIG. 4 shows how the functional components such as the lower layer substrate 12a, the light emitting element assembly 15, and the light receiving element assembly 16 are attached to the housing 11 in this manner.
[0018]
In FIG. 4, the bail actuator 22 is attached to the housing 11 together with functional components such as the lower layer substrate 12 a, the light emitting element assembly 15, and the light receiving element assembly 16. The bail actuator 22 moves the protrusion (not visible in FIG. 4) provided on the housing 11 to the housing 11 side using the so-called lever principle, and the hook of the host board described with reference to FIG. It is a part to remove from.
[0019]
Further, fins 21 are placed on the light emitting element assembly 15 and the light receiving element assembly 16. FIG. 5 shows a state where the fins 21 are placed. FIG. 6 is a cross-sectional view in the longitudinal direction in FIG. According to FIG. 6, the silicon sheet 25 is placed on the bracket 19 attached to the light emitting element assembly 15 and the light receiving element assembly 16. One end of the fin 21 is in contact with the light emitting element assembly 15 through the silicon sheet 25. The other end of the fin 21 is also in contact with the housing 11.
[0020]
Therefore, the light receiving element assembly 15 and the light emitting element assembly 16 and the housing 11 are configured to transfer heat. For example, the heat generated in the light emitting element assembly 16 is transferred to the fins 21 via the bracket 19 and the silicon sheet 25 and transferred to the housing 11. Further, the fin 21 is provided with a protruding portion 21a. The protruding portion 21a is configured to come into contact with the cage 42 when the optical module 10 is inserted into the cage 42. Therefore, the heat transferred to the fins 21 is also efficiently transferred to the cage 42. Further, the light emitting element assembly 15 and the like and the housing 11 and the like are electrically insulated by the silicon sheet 25, a signal ground is applied to the light emitting element assembly 15 and the like, and a frame ground potential is applied to the housing 11 and the like. . Therefore, by separating the grounds and providing them separately, the influence of external noise on the housing 11 can be reduced as compared with the case where the grounds are not separated. In the case of this embodiment, each of the fin 21, the bracket 19, and the holder 18 is formed of an alloy containing copper as a component.
[0021]
From the state of FIG. 6, the heat dissipation block 13 is placed on the housing 11. The heat dissipation block fixes the lower substrate 12 a and the fins 21 by sandwiching them between the housing 11. A tail cap 23 is attached to the end of the heat dissipation block 13. Details of fixing the lower substrate 12a to the heat dissipation block 13 will be described later. In the case of this embodiment, the heat dissipation block 13 is formed of an alloy containing aluminum as a component or aluminum.
[0022]
An accommodation recess 13b is provided on the upper surface of the heat dissipation block 13, and the upper substrate (second substrate) 12b is placed with the main surface on which electronic components are mounted facing the heat dissipation block 13 side. Further, the upper layer substrate 12b and the lower layer substrate 12a are connected by a flex substrate 12c, and electronic components mounted on the upper layer substrate 12b and the lower layer substrate 12a cooperate to constitute an electronic circuit. The flex substrate 12 c is configured to fit in a notch 13 a provided on the side surface of the heat dissipation block 13. This is shown in FIG.
[0023]
As shown in FIG. 8, the upper substrate 12 b is placed on the upper surface of the heat dissipation block 13. Since the upper substrate 12b is placed with the main surface on which the electronic components are mounted facing the heat dissipation block 13, the electronic components are not exposed to the outside. A flex substrate 12c that connects the upper layer substrate 12b and the lower layer substrate (not visible in FIG. 8) is accommodated in the notch 13a of the heat dissipation block 13. When the copper cover 14 is attached so as to cover the upper substrate 12b from this state, the assembly of the optical module 10 is completed. FIG. 9 shows the optical module 10 that has been assembled.
[0024]
As shown in FIG. 9, the cover 14 covers the upper substrate 12 b and holds it between the heat dissipation block 13. The cover 14 further holds the heat dissipation block 13 between the housing 11. Since the cover 14 is configured to cover a part of the heat radiating block 13, the other part of the heat radiating block 13 is exposed. Therefore, the exposed part of the heat dissipation block 13 constitutes a part of the outer shell of the optical module 10 together with the housing 11.
[0025]
FIG. 10 shows a state where the optical module 10 is viewed from the side. The cover 14 is provided with a claw 14a. The claw 14a fits into a predetermined portion of the housing 11, and the cover 14 and the housing 11 are fixed. Further, the protrusion 21 a of the fin 21 is disposed at a position corresponding to the protrusion 11 a of the housing 11. Therefore, when the optical module 10 is fitted into the cage 42 mounted on the host board 40 shown in FIG. 1, the projection 21a of the fin 21 comes into contact with the inside of the cage 42, and the projection 11a of the housing 11 is contacted by the contact. Is urged toward the host board 40.
[0026]
FIG. 11 is a sectional view taken along the line II of FIG. Electronic components are mounted on both surfaces of the lower layer substrate 12a. When the lower layer substrate 12 a is disposed in the housing 11, the electronic component mounted on the surface facing the main surface is accommodated in the recess 11 b of the housing 11. The lower layer substrate 12 a is sandwiched and fixed between the housing 11 and the heat dissipation block 13. The electronic components mounted on the main surface of the lower layer substrate 12 a are accommodated in the recesses of the heat dissipation block 13. Of the electronic components mounted on the main surface of the lower layer substrate 12a, for example, a silicon sheet (heat dissipation sheet) 26 is applied to a heat generating electronic component such as a driver element for driving the light emitting element included in the light emitting element assembly 15. It is touched. The silicon sheet 26 is further in contact with the heat dissipation block 13 and transfers heat generated by electronic components such as driver elements to the heat dissipation block 13. Therefore, heat generated by electronic components such as driver elements mounted on the lower layer substrate 12 a is efficiently transmitted to the heat dissipation block 13.
[0027]
On the upper substrate 12b, electronic components are mounted only on the main surface on the heat dissipation block 13 side. The upper substrate 12b is sandwiched and held between the heat dissipation block 13 and the cover 14. The heat generated by the electronic components mounted on the upper substrate 12b is radiated mainly to the heat dissipation block 13 side. This heat is transmitted to the heat dissipation block 13 and radiated to the outside of the optical module 10.
[0028]
In the present embodiment, heat generated by electronic components such as driver elements mounted on the lower layer substrate 12a is transmitted to the heat dissipation block 13, and the heat is conducted through the heat dissipation block 13 to reach the outer periphery thereof. The generated heat can be efficiently conducted to the outer shell of the optical module 10. Accordingly, since heat transmitted from the lower layer substrate 12a or the upper layer substrate 12b to the light emitting module 15 via the lead pins (not shown) can be reduced, the temperature condition in the vicinity of the light emitting module 15 including the light emitting element can be further improved.
[0029]
Further, since the heat dissipation block 13 is in contact with at least the driver element via the silicon sheet 26, the heat generated by the driver element is transmitted to the heat dissipation block 13 via the silicon sheet 26. Therefore, the heat generated by the driver element can be more efficiently conducted to the outer periphery of the optical module 10.
[0030]
Further, since the main surface on which the electronic component is mounted on the upper substrate 12b is opposed to the lower substrate 12a, the heat generated by the electronic component mounted on the upper substrate 12b is also transmitted to the heat dissipation block 13. Therefore, since the heat accumulation between the lower layer substrate 12a and the upper layer substrate 12b can be further improved, the temperature condition in the vicinity of the light emitting element assembly 15 including the light emitting element can be further improved.
[0031]
Since the heat generated by the light emitting element assembly 15 is transferred through the fins 21, the heat generated by the light emitting element assembly 15 can be efficiently conducted to the outside of the optical module 10. In addition, since the fin 21 has a protrusion 21 a which is a part of the fin 21 and contacts the cage 42, the protrusion 11 a of the housing 11 is urged toward the host board 40, so that the optical module 10 is securely attached to the host board 40. It will be attached.
[0032]
Further, since the fin 21 is in contact with the light emitting element assembly 15 via the silicon sheet 25, heat generated by the light emitting element assembly 15 is transmitted to the fin 21 via the silicon sheet 25. Therefore, the heat generated by the light emitting element assembly 15 can be more efficiently conducted to the outside of the optical module 10.
[0033]
Further, the driver element is mounted on the main surface of the lower layer substrate 12a, and the lower layer substrate 12a is held between the housing 11 and the heat dissipation block 13 so that the main surface faces the heat dissipation block 13. The main surface on which the driver element is mounted and the heat dissipation block 13 are opposed to each other, so that the heat generated by the driver element can be efficiently conducted to the heat dissipation block 13.
[0034]
Further, since the fins 21 are in contact with the cage 42 of the host board 40, the frame ground potential of the housing 11, the heat dissipation block 13, and the cover 14 can be strengthened, and the noise characteristics of the optical module 10 are improved.
[0035]
【The invention's effect】
According to the present invention, the heat generated by the specific electronic component is transmitted to the heat conducting member, and the heat is conducted through the heat conducting member to reach the outer wall, so that the heat generated by the specific electronic component can be efficiently transferred to the optical module. Can be conducted to the outer shell. Therefore, heat transmitted from the first substrate or the second substrate to the photoelectric conversion element via the lead can be reduced, and thus the temperature condition in the vicinity of the photoelectric conversion element such as a light emitting element can be further improved. Therefore, the optical module which can improve the temperature conditions near the light-emitting element, which is an object of the present invention, can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing an optical module and a host board according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view showing an optical module according to an embodiment of the present invention.
FIG. 3 is a diagram showing a portion in which an optical module according to an embodiment of the present invention is fitted into a host board.
FIG. 4 is a diagram showing a part of an optical module according to an embodiment of the present invention.
FIG. 5 is a view showing a part of an optical module according to an embodiment of the present invention.
FIG. 6 is a view showing a part of an optical module according to an embodiment of the present invention.
FIG. 7 is a view showing a part of an optical module according to an embodiment of the present invention.
FIG. 8 is a view showing a part of an optical module according to an embodiment of the present invention.
FIG. 9 is a diagram showing an optical module according to an embodiment of the present invention.
FIG. 10 is a diagram showing an optical module according to an embodiment of the present invention.
11 is a cross-sectional view taken along the line II of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Optical device, 11 ... Housing, 12a ... Lower layer board, 12b ... Upper layer board, 12 ... Mounting board, 13 ... Radiation block, 14 ... Cover, 15 ... Light emitting element assembly, 16 ... Light receiving element assembly, 17 ... OSA block, 18 ... Holder, 19 ... Bracket, 20 ... Shield, 21 ... Fin, 22 ... Bale actuator, 23 ... Tail cap.

Claims (4)

An optical module having a housing member, a first substrate, a second substrate, and a heat conducting member,
The first substrate is mounted with a first electronic component including an electronic component that exchanges electric signals with a photoelectric conversion element, and is further held between the housing member and the heat conducting member,
The second substrate mounts a second electronic component that cooperates with the first electronic component , and is further mounted on the heat conducting member,
The heat conducting member forms an outer shell in cooperation with the housing member, and further transfers heat generated by at least one of the first electronic component and the second electronic component. And optical module. The thermally conductive member is in contact with said at least one electronic component via a heat dissipation sheet, the optical module according to claim 1. The optical module according to claim 1, wherein the one electronic component is mounted on a main surface of the first substrate facing the heat conducting member . The said 2nd board | substrate mounts the said 2nd electronic component only in the main surface, and is mounted in the said heat conductive member so that this main surface may oppose the said 1st board | substrate. The optical module according to claim 1 .

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