JP2010153469A - Heat sink, and heat dissipation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve cooling efficiency of an optical transceiver by optimizing fluid resistance of fins and increasing the amount of heat dissipation from the fins. <P>SOLUTION: A heat sink 15 has a base plate 151 and a plurality of fins on a first surface r1 of the base plate 151, and is arranged such that a second surface r2 of the base plate 151 is in thermal contact with the optical transceiver 13. The base plate 151 has a first area (a) where the second surface r2 comes into thermal contact with the optical transceiver 13 and a second area (b) where the second surface r2 projects from an end of the optical transceiver 13. In the second area (b), a plurality of fins 152 are provided even on the second surface r2 as well as the first surface r1. Further, the arrangement pitch of the plurality of fins 152 is different between the first area (a) and second area (b). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat sink for dissipating heat generated by an optical transceiver or the like and a heat dissipation device including the heat sink.

  An optical transceiver includes a light emitting and receiving element, and transmits and receives an optical signal via an optical connector. The optical connector is detachably connected to a main body portion in which a plurality of electronic components, electronic circuits, and a circuit board are stored. And a receptacle. The optical transceiver is also referred to as a pluggable optical transceiver, and is normally inserted into and removed from a metal cage installed on the host board in a hot-wire state, connected to an electrical connector disposed at the back of the cage, and into the cage. Insertion is latched.

  FIG. 5 shows an example of an XFP type optical transceiver known as a standard, which is used by being mounted on a host device. The host device includes a host board 1 and a metal cage 2 installed on the host board 1. The opening 2a of the cage 2 is exposed from the bezel 1a, and the optical transceiver 3 is inserted and removed through the cage opening 2a. An electrical plug 4 is provided at the rear end of the optical transceiver 3, and the electrical plug 4 and the electrical connector 5 on the host board 1 are connected in the cage 2, so that the optical transceiver 3 is connected to the host device. Thus, communication (signal transmission / reception, power supply to the optical transceiver 3) is established. Further, a heat sink 6 for dissipating heat generated by the optical transceiver 3 is disposed on the upper portion of the cage 2 using a clip 7.

  FIG. 6 is a diagram schematically illustrating a configuration example of a heat sink provided in a conventional host device. In recent years, the communication speed of the optical transceiver 3 has reached 10 Gbps to 100 Gbps, and the power consumption of electronic components mounted on the optical transceiver 3 has increased, and higher heat dissipation efficiency has been demanded. The heat sink 6 is provided with fins (heat radiating fins) 62 for heat radiation on the upper surface of the base plate 61, and the heat of the optical transceiver 3 is generated by bringing the lower surface of the base plate 61 into thermal contact with the upper surface of the optical transceiver 3. Is efficiently radiated by the fins 62. Further, in order to promote heat conduction between the optical transceiver 3 and the heat sink 6, a heat dissipation sheet (not shown) is interposed between the optical transceiver 3 and the heat sink 6.

  In the heat sink 6 that radiates heat by being in thermal contact with the upper surface of the optical transceiver 3, the amount of heat generated by the optical transceiver 3 increases with an increase in communication speed exceeding 100 Gbit / s. The heat sink 6 having a size larger than that of the conventional one is required. For this reason, it is necessary to make the base plate 61 of the heat sink 6 larger than the upper surface of the optical transceiver 3 as described above. Conventionally, the base plate 61 is expanded so as to protrude rearward from the upper surface of the optical transceiver 3. Often installed in shape. In this case, the heat sink 6 is formed with a protrusion p that protrudes backward from the end of the optical transceiver 3.

Regarding the configuration of the heat sink as described above, Patent Document 1 and Patent Document 2 describe the configuration of a heat sink that is larger in size than the optical transceiver main body and has a shape expanded in the insertion / extraction direction of the optical transceiver with respect to the cage. .
US Pat. No. 6,822,875

  The height of the host device as described above is determined by an industry standard, but with the miniaturization of the transmission system, the gap between the fins 62 of the heat sink 6 and the top plate 81 of the device housing 8 incorporating the host device. Is narrower. For example, in the example of the configuration as shown in FIG. 6, the inner height of the device housing 8 incorporating the host device is, for example, 45 mm, and the height to the top of the fin 62 of the heat sink 6 is about 38 mm. The gap between the fins 62 of the heat sink 6 and the top plate 81 of the apparatus housing 8 is narrower.

  Here, inside the device housing 8 incorporating the host device, heat is radiated from the fins 62 of the heat sink 6 by the wind of cooling means such as a fan. However, the gap between the top plate 81 and the fins 62 of the device housing 8 is small, and the host device itself has a large fluid resistance in the device housing 8. At this time, due to the air resistance of the fins 62, the cooling air does not pass through the fins 62 and flows through a region where the air resistance in the apparatus housing 8 is small, which causes a reduction in heat dissipation efficiency.

FIG. 7 is a diagram for explaining an example of the analysis result of the thermal fluid in the apparatus housing in which the optical transceiver is arranged. Here, the host device equipped with the optical transceiver is arranged in parallel in the device casing, and the state of the cooling air inside the device casing is analyzed.
As shown in FIG. 7, the optical transceiver 3 (3 </ b> A, 3 </ b> B) has a fluid resistance against the cooling air, and it can be seen that the cooling air flows inside the device housing 8 so as to avoid the optical transceiver 3. In particular, as shown in FIG. 7, in the configuration in which the two optical transceivers 3A and 3B are arranged in parallel, the cooling wind to the leeward optical transceiver 3B is reduced due to the influence of the leeward optical transceiver 3A, and the leeward light There arises a problem that the heat radiation of the transceiver 3B is not sufficient.

  Further, as described above, the heat sink 6 is installed such that the base plate 61 of the heat sink 6 is expanded and the base plate 61 protrudes from the upper surface of the optical transceiver 3 in response to a heat dissipation request accompanying an increase in communication speed. In this case, as shown in FIG. 6, a space F corresponding to the height of the optical transceiver 3 is formed below the base plate 61 in the protruding portion p protruding from the upper surface of the optical transceiver 3. Since this space F has a lower air resistance than the upper surface side of the base plate 61 where the fins 62 are present, most of the cooling air in the apparatus housing 8 passes through the space F below the base plate 61, and is essential. There is a problem that heat exchange with the fins 62 is hindered.

  Further, the above Patent Documents 1 and 2 do not disclose the fin design concept and configuration in consideration of the influence of the fluid resistance of the optical transceiver including the heat sink on the cooling air.

  The present invention has been made in view of the above-described circumstances. A heat sink that optimizes the fluid resistance of the fin, increases the amount of heat released from the fin, and improves the cooling efficiency of the optical transceiver, and the heat sink An object of the present invention is to provide a used heat dissipation device.

  The heat sink according to the present invention includes a base and a plurality of fins on the first surface of the base, and is arranged so that the second surface of the base is in thermal contact with the heating element. The base has a first region in which the second surface is in thermal contact with the heating element, and a second region in which the second surface protrudes from the end of the heating element. In the region, a plurality of fins are provided on the second surface. Further, the arrangement pitch of the plurality of fins provided in the first region is different from the arrangement pitch of the plurality of fins provided in the second region.

Further, in the present invention, the heating element with which the heat sink is in thermal contact is an optical transceiver. The heat sink is in contact with the optical transceiver through a resin heat dissipation sheet.
In the heat dissipation device of the present invention, a plurality of the heat sinks are arranged in the direction of the cooling air.

  According to the present invention, it is possible to optimize the fluid resistance of the fins, increase the heat radiation amount from the fins, and improve the cooling efficiency of the optical transceiver. In particular, in the present invention, in the heat sink that thermally contacts the optical transceiver, which is a heating element, to dissipate the heat of the optical transceiver, fins are provided in a region protruding from the end of the optical transceiver, and further, the arrangement between the fins By adjusting the pitch, the fluid resistance of the fins can be optimized, the heat radiation from the fins can be increased, and the cooling efficiency of the optical transceiver can be improved.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a host device of an optical transceiver using a heat sink according to the present invention. In the figure, 10 is a host device, 11 is a host board, 11a is a bezel, 12 is a cage, 12a is a cage opening, 12b is a cage side part, 12c is a window part, 13 is an optical transceiver, 14 is a transceiver housing, and 14a is A contact surface 15 indicates a heat sink.

  The basic configurations of the optical transceiver and the host device to which the heat sink of the present invention is applied are the same as those shown in the conventional example of FIG. 5, but in the embodiment according to the present invention, the shape of the heat sink is different. As shown in FIG. 1, the host device 10 includes a host substrate 11 and a metal cage 12 installed on the host substrate 11, and a pluggable optical transceiver 13 that is a heating element is inserted into and removed from the cage 12. It is a configuration. A cage opening 12 a at the front end of the cage 12 is exposed to the outside from the bezel 11 a of the host device 10 and serves as an insertion port for the optical transceiver 13.

  The optical transceiver 13 is covered with a metal transceiver housing 14, and when inserted into the cage 12, the upper surface side thereof is a contact surface 14 a that is in thermal contact with the contact surface of the heat sink 15. The cage 12 is mounted on the host substrate 11 in a state of being grounded (not shown). An electrical connector (not shown) is disposed on the host board 11 at the back of the cage 12 and is connected to the circuit by pressing an electrical plug provided at the rear end of a transceiver circuit board (not shown) included in the optical transceiver 13. Communication (signal transmission / reception, power supply to the optical transceiver, etc.) is established between the optical transceiver 13 and the host device 10.

  A soft heat-dissipating sheet (not shown) is bonded and held on either the lower surface of the heat sink 15 or the contact surface 14a of the transceiver housing 14. As a result, the contact surface 14a of the transceiver housing 14 and the lower surface of the heat sink 15 are thermally bonded with the heat dissipation sheet interposed therebetween, and the contact interface between the contact surface 14a of the transceiver housing 14 and the lower surface of the heat sink 15 is reached. Even if there are irregularities, the heat dissipation effect can be improved.

  A window portion 12c is provided in the cage upper portion 12b, and the heat sink 15 having heat radiation fins is disposed so as to be exposed from the window portion 12c. The heat sink 15 is extended rearward (in the right rear direction in FIG. 1) from the position where the optical transceiver 13 is to be inserted in order to increase heat dissipation efficiency, and has a shape protruding rearward from the inserted optical transceiver 13. .

  FIG. 2 is a schematic view showing a configuration example of the heat sink in the present invention. The heat sink 15 is in thermal contact with the optical transceiver 13 via a heat dissipation sheet. In FIG. 2, illustration of the heat dissipation sheet is omitted. The heat sink 15 includes a base plate (base) 151 and a plurality of fins 152 formed integrally with the base plate 151. As described above, the heat sink 15 has a shape that extends and protrudes behind the optical transceiver 13 (leftward in FIG. 3) in a state where the optical transceiver 13 is mounted on the host device. Here, the heat sink 15 of this example includes fins 152 on the upper side of the base plate 151 (opposite side of the optical transceiver 13), and also includes fins 152 in a region behind the optical transceiver 13 on the lower side of the base plate 151.

  That is, the heat sink 15 includes a base plate 151 and a plurality of fins on the first surface r1 of the base plate 151, and the second surface r2 is disposed so as to be in thermal contact with the optical transceiver 13 that is a heating element. Here, the second surface r2 is a surface on which the base plate 151 is in thermal contact with the optical transceiver 13, and the first surface r1 is an upper surface opposite to the second surface r2. The base plate 151 includes a first region a in which the second surface r2 is in thermal contact with the optical transceiver 13 and a second region b in which the second surface r2 protrudes from the end of the optical transceiver 13. Have. In the second region b, a plurality of fins 152 are also provided on the second surface r2 in the same manner as the first surface r1.

  In the heat sink 15, the arrangement pitch of the plurality of fins 152 is varied according to the region of the base plate 151. In other words, in the first surface r1 on the upper side of the base plate 151, the rear of the first region a as compared with the arrangement pitch of the fins 152 in the first region a above the optical transceiver 13 mounted on the host device. The arrangement pitch of the fins 152 in the second region b, which is the protruding portion, is increased. Furthermore, on the second surface r2 in the region b, the arrangement pitch of the fins 152 is made the same as the arrangement pitch of the first surface r1 in the second region b.

  In this example, since the fluid resistance due to the presence of the optical transceiver 13 is high with respect to the cooling air blown from the side surface (perpendicular to the paper surface), the arrangement pitch of the fins 152 on the first surface r1 of the optical transceiver 13 is The first region a may be narrow. Further, on the first surface r1 of the second region b, the arrangement pitch of the fins 152 is made wider than that of the first region a, the fluid resistance of the cooling air is lowered, and the cooling air is easily passed. Further, in the second region b, the fin 152 that is not conventionally provided is also provided on the lower second surface r2 so as to increase the fluid resistance. As a result, the fluid resistance in the space behind the optical transceiver 13 is increased, and the decrease in the heat radiation area due to the increase in the arrangement pitch of the fins 152 on the first surface r1 of the second region b is compensated.

  In the configuration as shown in FIG. 2, by providing the fin 152 in the lower region of the heat sink 15, the air resistance of the region through which the cooling air has conventionally passed increases, and as a result, the cooling air flows to the upper surface of the heat sink 15. It passes between the fins 152. As a result, the cooling efficiency is improved, and the flow of air to the optical transceiver, which is leeward of the cooling air, is promoted inside the apparatus housing where the plurality of optical transceivers 13 are mounted in parallel, and the cooling effect of the entire apparatus is also high. Become.

  FIG. 3 is a diagram for explaining an example of the analysis result of the thermal fluid in the apparatus housing in which the optical transceivers are arranged in parallel. This corresponds to an embodiment of the heat dissipation device of the present invention in which a plurality of optical transceivers 13 are arranged. Here, FIG. 3 (A) shows the analysis result of the thermal fluid in the apparatus casing using the conventional heat sink for comparison, and FIG. 3 (B) shows the heat sink according to the present invention shown in FIG. The analysis result of the thermal fluid in the used apparatus housing | casing is shown. In FIG. 3, p is the protrusion of the heat sink.

  As shown in FIG. 3B, the cooling air flowing between the fins 152 of the heat sink 15 is increased by using the configuration in which the fins 152 are also provided on the lower side (second surface r2) of the heat sink 15. And it turns out that a cooling wind comes to flow more also with respect to the optical transceiver 13B located in the leeward side (illustration lower side), heat exchange by the heat sink 15 is accelerated | stimulated, and the cooling efficiency of the optical transceiver 13 is improved. It was.

  As described above, in the heat sink 15 that is in thermal contact with the optical transceiver 13 and dissipates the heat of the optical transceiver 13, the fin 152 is provided in the region behind the optical transceiver 13 mounted on the host device. By adjusting the arrangement pitch between 152, the fluid resistance of the fins 152 can be optimized, the amount of heat radiation from the fins 152 can be increased, and the cooling efficiency of the optical transceiver 13 can be improved.

  FIG. 4 is a diagram illustrating a configuration example for ensuring thermal contact between the heat sink and the optical transceiver. The optical transceiver 13 mounted on the host device comes into contact with the heat sink 15 via the heat dissipation sheet 16. That is, the heat sink 15 is in thermal contact with the optical transceiver 13 in order to dissipate the heat generated by the optical transceiver 13. As a configuration in which the heat sink 15 is placed in thermal contact with the upper surface of the optical transceiver 13, for example, an elastic force such as a spring is applied to the heat sink 15 and the heat sink 15 is pressed against the optical transceiver 13 via the heat dissipation sheet 16. It is done.

  4A, when the heat sink 15 is inclined with respect to the optical transceiver 13, sufficient heat contact between the heat sink 15 and the optical transceiver 13 cannot be ensured, and cooling is performed. Efficiency is reduced. In addition, as described above, the optical transceiver 13 has remarkably increased in calorific value as its high-speed communication is performed, and in order to ensure sufficient heat dissipation characteristics, the protrusion of the heat sink protruding rearward of the optical transceiver 13 It is possible that the size will also increase. If the protrusion of the heat sink 15 becomes large, it can be said that the inclination of the heat sink 15 with respect to the optical transceiver 13 is more likely to occur.

  As a configuration in which the heat sink 15 is arranged in thermal stable contact with the upper surface of the optical transceiver 13, considering the assembly workability, the base plate 151 of the heat sink 15 has other portions as shown in FIG. A thicker region F is provided. This region F is provided on the front side when the optical transceiver 13 is inserted into and removed from the host device. That is, a region F having a thickness greater than the others is provided on the base plate 151 on the side opposite to the protruding portion p of the heat sink 15. In this case, when the heat sink 15 is disposed on the upper surface of the optical transceiver 13, it is preferable to balance the weight so that the heat sink 15 does not tilt and fall.

1 is a perspective view showing a host device of an optical transceiver using a heat sink according to the present invention. It is the schematic which shows the structural example of the heat sink in this invention. It is a figure for demonstrating an example of the analysis result of the thermal fluid in the apparatus housing | casing which arrange | positioned the optical transceiver in parallel. It is a figure which shows the structural example for ensuring the thermal contact of a heat sink and an optical transceiver. It is a figure which shows an example of the XFP type | mold optical transceiver known as a standard. It is a figure which shows roughly the structural example of the heat sink provided in the conventional host apparatus. It is a figure for demonstrating an example of the analysis result of the thermal fluid in the conventional apparatus housing | casing which has arrange | positioned the optical transceiver.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Host substrate, 1a ... Bezel, 2 ... Cage, 2a ... Opening, 3, 3A, 3B ... Optical transceiver, 4 ... Electrical plug, 5 ... Optical transceiver, 6 ... Heat sink, 7 ... Clip, 8 ... Device housing, DESCRIPTION OF SYMBOLS 10 ... Host apparatus, 11 ... Host board | substrate, 11a ... Bezel, 12 ... Cage, 12a ... Cage opening, 12b ... Cage upper part, 12c ... Window part, 13, 13A, 13B ... Optical transceiver, 14 ... Transceiver housing, 14a ... Contact surface, 15 ... heat sink, 16 ... heat dissipation sheet, 61 ... base plate, 62 ... fin, 81 ... top plate, 151 ... base plate, 152 ... fin.

Claims (5)

A heat sink that includes a base and a plurality of fins on a first surface of the base, and is disposed so that the second surface of the base is in thermal contact with a heating element;
The base includes a first region in which the second surface is in thermal contact with the heating element, and a second region in which the second surface protrudes from an end portion of the heating element, The heat sink according to claim 2, wherein a plurality of fins are provided on the second surface in the second region.   2. The heat sink according to claim 1, wherein an arrangement pitch of the plurality of fins provided in the first region is different from an arrangement pitch of the plurality of fins provided in the second region.   The heat sink according to claim 1 or 2, wherein the heat generating element in thermal contact with the heat sink is an optical transceiver.   The heat sink according to any one of claims 1 to 3, wherein the heat sink is in contact with the heating element via a resin heat dissipation sheet.   A plurality of heat sinks according to any one of claims 1 to 5 are arranged in the direction of cooling air.