Optical module

Abstract

The present disclosure provides an optical module capable of maintaining the temperature of an optical semiconductor element within a predetermined range with low power consumption. An optical module is provided with: a temperature buffer member having a first surface and a second surface facing the first surface; an optical semiconductor element which is connected to the first surface and which generates heat by itself; and the heat dissipation component is connected to the second surface, and the temperature buffering component is made of a phase change material with the heat conductivity coefficient changing with the phase change temperature as the boundary.

Description

Technical Field

[0001] The present disclosure relates to optical modules. Background Art

[0002] Patent Document 1 discloses a semiconductor laser module that includes a semiconductor laser and controls the wavelength of light emitted from the semiconductor laser. Patent Document 1 discloses that, in the semiconductor laser module, the wavelength is controlled by a heating element without Peltier cooling.

[0003] Patent Document 2 discloses a submount having a mounting surface on which three or more semiconductor laser elements are mounted side by side in a first direction. Patent Document 2 discloses that the submount includes a heating element for increasing the temperature of the three or more semiconductor laser elements.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2001-094200

[0007] Patent Document 2: Japanese Patent Application Publication No. 2018-160520

[0008] In an optical module, it is required to maintain the temperature of an optical semiconductor element within a predetermined range with low power consumption (to perform temperature control on the optical semiconductor element). Summary of the invention

[0009] The present disclosure provides an optical module capable of maintaining the temperature of an optical semiconductor element within a predetermined range (temperature regulating the temperature of the optical semiconductor element) with low power consumption.

[0010] One scheme of the present disclosure is an optical module, which includes: a temperature buffer component having a first surface and a second surface opposite to the first surface; an optical semiconductor element connected to the first surface, the optical semiconductor element self-heating; and a heat dissipation component connected to the second surface, the temperature buffer component is composed of a phase change material whose thermal conductivity changes at a phase change temperature.

[0011] Another embodiment of the present disclosure is an optical module comprising: a temperature buffer component having a first surface and a second surface opposite to the first surface; an optical semiconductor element connected to the first surface; a heating component connected to the first surface and receiving electric power from the outside to generate heat; and a heat dissipation component connected to the second surface, wherein the temperature buffer component is composed of a phase change material whose thermal conductivity changes at a phase change temperature.

[0012] Effects of the Invention

[0013] According to the optical module of the present disclosure, the temperature of the optical semiconductor element can be maintained within a predetermined range (the temperature of the optical semiconductor element can be temperature-regulated) with low power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view schematically showing the optical module according to the first embodiment.

[0015] Figure 2 This is a diagram for explaining a usage state of the optical module according to the first embodiment.

[0016] Figure 3 This is a diagram for explaining the temperature of the temperature buffer member included in the optical module.

[0017] Figure 4 This is a diagram for explaining the thermal resistance of a temperature buffer member included in an optical module.

[0018] Figure 5 This is a diagram for explaining the operation results of the optical module according to the first embodiment.

[0019] Figure 6 This is a diagram for explaining the operation results of the optical module according to the first embodiment.

[0020] Figure 7 This is a diagram for explaining the operation results of the optical module according to the first embodiment.

[0021] Figure 8 This is a diagram for explaining the operation results of the optical module according to the first embodiment.

[0022] Fig. 9 It is a perspective view schematically showing an optical module according to a second embodiment.

[0023] Fig.10 This is a diagram for explaining a usage state of the optical module according to the second embodiment.

[0024] Fig.11 This is a diagram for schematically explaining the functional configuration of the optical module according to the second embodiment.

[0025] Fig.12 This is a diagram for explaining the operation results of the optical module according to the second embodiment.

[0026] Fig.13 These are diagrams for explaining a modified example of the optical module according to the second embodiment.

[0027] Description of Reference Numerals

[0028] 1, 1A, 2: optical module;

[0029] 10: Optical semiconductor components;

[0030] 15: Carrier;

[0031] 20: Temperature buffer component;

[0032] 20d: cryosphere;

[0033] 20S1: first side;

[0034] 20S2: Side 2;

[0035] 20u: high temperature layer;

[0036] 30, 33: heat dissipation components;

[0037] 31: board;

[0038] 32: packaging;

[0039] 40: heating component;

[0040] 45: Temperature regulation object;

[0041] 50: temperature detection element;

[0042] 60: Control unit;

[0043] 70: Lens;

[0044] A1, A2: area;

[0045] Lex, Lref1, Lref2: line;

[0046] Tcase, Tld: temperature;

[0047] TCd, TCu: thermal conductivity;

[0048] Tpt: phase transition temperature;

[0049] TRd, TRu: thermal resistance value. DETAILED DESCRIPTION

[0050] [Description of Embodiments of the Present Disclosure]

[0051] First, embodiments of the present disclosure will be described by way of examples.

[0052] (1) The optical module disclosed in the present invention comprises: a temperature buffer member having a first surface and a second surface opposite to the first surface; an optical semiconductor element connected to the first surface, the optical semiconductor element self-heating; and a heat dissipation member connected to the second surface. In addition, the temperature buffer member is composed of a phase change material whose thermal conductivity changes at a phase change temperature.

[0053] According to the optical module of the present disclosure, the temperature of the optical semiconductor element can be maintained within a predetermined range with low power consumption.

[0054] (2) In the above (1), the heat conductivity of the heat dissipating member may be greater than the heat conductivity of the temperature buffering member. This is because increasing the heat conductivity of the heat dissipating member can relatively increase the change in temperature of the optical semiconductor element by the phase change material.

[0055] (3) In the above (1) or (2), when the temperature of the second surface is equal to the phase transition temperature, the first surface has a first temperature higher than the phase transition temperature. In addition, when the temperature of the first surface is equal to the phase transition temperature, the second surface has a second temperature lower than the phase transition temperature. Furthermore, a first temperature difference between the first temperature and the phase transition temperature may be set to be smaller than a second temperature difference between the phase transition temperature and the second temperature. Thus, heat dissipation is promoted when the temperature of the optical semiconductor element is high.

[0056] (4) In the above (3), the first temperature may be set to a temperature lower than the upper limit operating temperature of the optical semiconductor element. This is because the optical semiconductor element can be stably operated.

[0057] (5) In the above (3) or (4), when the temperature of the second surface is equal to the phase change temperature, the temperature buffer member may have a first thermal resistance between the first surface and the second surface. In addition, when the temperature of the second surface is equal to the second temperature, the temperature buffer member may have a second thermal resistance between the first surface and the second surface that is greater than the first thermal resistance. This is because it enables the optical semiconductor element to operate stably.

[0058] (6) In the above (5), the resistance value of the second heat resistor may be larger than twice the resistance value of the first heat resistor. This is because the optical semiconductor element can be stably operated.

[0059] (7) In any one of (1) to (6) above, the phase change material may have a phase change temperature of 70° C. to 100° C. This promotes heat dissipation when the temperature of the optical semiconductor element is high.

[0060] (8) In any of (1) to (7) above, the phase change material may include any one of silver sulfide, silver chalcogenide, and copper gallium telluride. This is because the temperature of the optical semiconductor element can be maintained within a predetermined range with low power consumption.

[0061] (9) In any of the above (1) to (8), any one of heat dissipation grease, solder and metal paste may be provided between the second surface of the temperature buffer member and the heat dissipation member. This is because the heat transfer efficiency between the temperature buffer member and the heat dissipation member can be improved.

[0062] (10) The optical module disclosed in the present invention comprises: a temperature buffer member having a first surface and a second surface opposite to the first surface; an optical semiconductor element connected to the first surface; a heating member connected to the first surface and receiving power from the outside to generate heat; and a heat dissipation member connected to the second surface. In addition, the temperature buffer member is composed of a phase change material whose thermal conductivity changes at a phase change temperature.

[0063] According to the optical module of the present disclosure, the temperature of the optical semiconductor element can be adjusted with low power consumption.

[0064] (11) In the above (10), the thermal conductivity of the heat dissipation member may be greater than the thermal conductivity of the temperature buffer member. This is because increasing the thermal conductivity of the heat dissipation member can suppress the temperature rise of the optical semiconductor element and adjust the temperature to a desired value.

[0065] (12) In the above (10) or (11), when the temperature of the second surface is equal to the phase transition temperature, the first surface has a first temperature higher than the phase transition temperature. In addition, when the temperature of the second surface is lower than the phase transition temperature, the temperature of the first surface may be maintained at the first temperature by adjusting the power of the heating member. This is because the temperature of the optical semiconductor element can be adjusted with low power consumption.

[0066] (13) In the above (12), the first temperature may be set to a temperature lower than the upper limit operating temperature of the optical semiconductor element. This is because the optical semiconductor element can be stably operated.

[0067] (14) In any of the above (10) to (13), when the temperature of the first surface is equal to the phase transition temperature, the second surface has a second temperature lower than the phase transition temperature. In addition, it is also possible to set that when the temperature of the second surface is equal to the phase transition temperature, the temperature buffer member has a first thermal resistance between the first surface and the second surface, and when the temperature of the second surface is equal to the second temperature, the temperature buffer member has a second thermal resistance between the first surface and the second surface that is larger than the first thermal resistance. Thereby, heat dissipation is promoted when the temperature of the optical semiconductor element is high.

[0068] (15) In the above (14), the resistance value of the second heat resistor may be larger than twice the resistance value of the first heat resistor. This is because the optical semiconductor element can be operated stably.

[0069] (16) In any one of (10) to (15), the phase change material may have a phase change temperature of 70° C. to 100° C. This promotes heat dissipation when the temperature of the optical semiconductor element is high.

[0070] (17) In any one of (10) to (16) above, the phase change material may include any one of silver sulfide, silver chalcogenide, and copper gallium telluride. This is because the temperature of the optical semiconductor element can be adjusted with low power consumption.

[0071] (18) In any one of the above (10) to (17), a temperature detection element may be further provided, the temperature detection element being connected to the first surface and generating a detection signal according to the temperature of the first surface. This is because the temperature of the optical semiconductor element can be adjusted with low power consumption.

[0072] [Details of the embodiments of the present disclosure]

[0073] Hereinafter, specific examples of the optical module disclosed in the present invention will be described with reference to the accompanying drawings. It should be noted that the present invention is not limited to these examples, but is indicated by the claims, and is intended to include all changes within the meaning and scope equivalent to the claims.

[0074] Regarding the descriptions and drawings of the various embodiments, for components having substantially the same or corresponding functions, repeated descriptions may be omitted by marking the same reference numerals. In addition, for ease of understanding, the proportions of the various parts in the drawings may be different from the actual ones.

[0075] Hereinafter, although embodiment will be described, at least part of the embodiment described below may be arbitrarily combined.

[0076] The optical module of the first embodiment comprises: a temperature buffer member having a first surface and a second surface opposite to the first surface; an optical semiconductor element connected to the first surface, the optical semiconductor element self-heating; and a heat dissipation member connected to the second surface. In addition, the temperature buffer member in the optical module of the first embodiment is composed of a phase change material whose thermal conductivity changes at a phase change temperature.

[0077] <Configuration of Optical Module According to First Embodiment>

[0078] The optical module according to the first embodiment will be described using a specific example. Figure 1 1 is a perspective view schematically showing an optical module 1 as an example of the optical module according to the first embodiment.

[0079] The optical module 1 includes an optical semiconductor element 10 , a temperature buffer member 20 , and a heat dissipation member 30 .

[0080] [Optical semiconductor element 10]

[0081] The optical semiconductor element 10 is an element including a semiconductor that converts light into electricity. The optical semiconductor element 10 generates heat by itself. The optical semiconductor element 10 is, for example, a laser diode. A laser diode generates heat when emitting light.

[0082] For example, the oscillation wavelength of a laser diode changes at a rate of 0.1 nm / ° C. depending on the operating temperature. Therefore, in particular in wavelength division multiplexing communications, it is necessary to keep the laser diode within a predetermined temperature range.

[0083] It should be noted that, although the optical semiconductor element 10 is described using an example of a laser diode, the optical semiconductor element 10 is not limited to a laser diode, and may be, for example, an LED (Light Emitting Diode). The optical semiconductor element 10 may also be an electric field absorption modulator integrated laser in which a laser diode that outputs continuous light and an electric field absorption modulator that modulates the continuous light are integrated on a semiconductor chip. In addition, the optical semiconductor element 10 is not limited to a light emitting element, and may be applied to all optical semiconductor elements that require temperature adjustment.

[0084] [Temperature buffer member 20]

[0085] The temperature buffer component 20 is a component whose thermal resistance changes according to temperature. The temperature buffer component 20 is composed of, for example, a phase change material whose thermal conductivity changes with a phase change temperature as a boundary. The phase change material includes, for example, any one of silver sulfide, silver chalcogenide, and copper gallium telluride. When considering the operating range of the optical module 1, it is preferable that the temperature buffer component 20 has a phase change temperature of, for example, 70°C or more and 100°C or less. It should be noted that the thermal resistance mentioned here is the thermal resistance when the heat generated in the optical semiconductor element 10 is transferred to the heat dissipation component 30 via the temperature buffer component 20.

[0086] The phase change material constituting the temperature buffer component 20 is a material whose state changes between a high temperature phase and a low temperature phase with the phase change temperature as the boundary. For example, the thermal conductivity of the phase change material in the high temperature phase is different from the thermal conductivity of the phase change material in the low temperature phase. In other words, the thermal resistance of the phase change material in the high temperature phase is different from the thermal resistance of the phase change material in the low temperature phase. It should be noted that the phase change material constituting the temperature buffer component 20 may also have an intermediate phase having intermediate properties between the high temperature phase and the low temperature phase near the phase change temperature.

[0087] As the phase change material, for example, a silver chalcogenide containing sulfur and selenium may be used. More specifically, Ag, which is a silver chalcogenide, may be used as the phase change material. 2 S 0.2 Se 0.8 、Ag 2 S0.4 Se 0.6 、Ag 2 S 0.6 Se 0.4 and Ag 2 S 0.8 Se 0.2 Any one of .

[0088] The silver chalcogenide is solid within the operating temperature range of the optical module 1, for example, within the temperature range of -20°C to 80°C. In addition, in the silver chalcogenide, the chalcogen atoms form a cubic lattice in the high temperature phase. In addition, in the silver chalcogenide, the silver atoms are easy to move in the high temperature phase. That is, the silver chalcogenide is a superionic conductor in the high temperature phase. In addition, in the silver chalcogenide, the thermal conductivity changes significantly with the transition from the low temperature phase to the high temperature phase. In addition, in the silver chalcogenide, the thermal conductivity changes significantly within a narrow temperature range.

[0089] The temperature buffer member 20 has a first surface 20S1 (see Figure 2 ) and a second surface 20S2 (refer to Figure 2 ). The optical semiconductor element 10 is connected to the first surface 20S1. The heat dissipation component 30 is connected to the second surface 20S2. Therefore, the heat generated in the optical semiconductor element 10 is conducted from the first surface 20S1 to the second surface 20S2 inside the temperature buffer component 20, and is thereby transferred to the heat dissipation component 30. When the above-mentioned thermal resistance is relatively large, the amount of heat conducted from the first surface 20S1 to the second surface 20S2 is reduced, and when the above-mentioned thermal resistance is relatively small, the amount of heat conducted from the first surface 20S1 to the second surface 20S2 is increased. It should be noted that, when the heat dissipation component 30 is connected to the temperature buffer component 20, any one of heat dissipation grease, solder, and metal paste may also be provided between the second surface 20S2 and the heat dissipation component 30. Thereby, the thermal resistance between the second surface 20S2 and the heat dissipation component 30 can be reduced. For the heat dissipation of the heat generated in the optical semiconductor element 10, it is preferred that the thermal resistance between the second surface 20S2 and the heat dissipation component 30 is small.

[0090] [Heat dissipation member 30]

[0091] The heat dissipation member 30 dissipates heat generated in the optical semiconductor element 10 to the outside. The heat dissipation member 30 is formed of, for example, metal. The heat dissipation member 30 is formed of, for example, aluminum nitride. The heat dissipation member 30 may be, for example, a part of a housing that houses the optical semiconductor element 10.

[0092] The thermal conductivity of the heat dissipation member 30 may be greater than the thermal conductivity of the temperature buffer member 20. By making the thermal conductivity of the heat dissipation member 30 greater than the thermal conductivity of the temperature buffer member 20, the operating temperature of the optical semiconductor element 10 can be reduced when the thermal conductivity of the phase change material of the temperature buffer member 20 is large. Generally, an upper limit is set for the operating temperature of the optical semiconductor element 10, and it is preferable to efficiently dissipate the generated heat to the outside to reduce the operating temperature.

[0093] In order to reduce the increase in the operating temperature of the optical semiconductor element 10 when radiating the heat generated in the optical semiconductor element 10 to the outside, it is desirable that the heat dissipation member 30 has sufficient heat capacity and heat dissipation capability.

[0094] <Temperature Characteristics of Optical Module of First Embodiment>

[0095] The temperature characteristics of the optical module according to the first embodiment will be described using the optical module 1 as an example of the optical module according to the first embodiment. Figure 2 This is a diagram for explaining a usage state of an optical module 1 as an example of the optical module according to the first embodiment.

[0096] exist Figure 2 In the embodiment, a case where the temperature (operating temperature) of the optical semiconductor element 10 is higher than the temperature of the heat dissipation member 30 is described. In the case where the optical semiconductor element 10 generates heat by itself, the operating temperature is higher than the temperature of the heat dissipation member 30. In the configuration in which the temperature buffer member 20 is sandwiched between the optical semiconductor element 10 and the heat dissipation member 30, the heat generated in the optical semiconductor element 10 is transferred from the optical semiconductor element 10 to the heat dissipation member 30 via the temperature buffer member 20. At this time, the direction of heat transfer is equal to the arrangement direction (first direction) of the optical semiconductor element 10, the temperature buffer member 20, and the heat dissipation member 30.

[0097] When the optical module 1 is operated, the optical semiconductor element 10 will generate heat by itself, thereby the temperature will rise. It is assumed that the heat dissipation component 30 is maintained at a substantially constant temperature. For example, when the thermal resistance between the heat dissipation component 30 and the outside is much smaller than the thermal resistance of the temperature buffer component 20 and the heat capacity of the heat dissipation component 30 is much larger than the self-heating of the optical semiconductor element 10, the temperature change of the heat dissipation component 30 can be ignored. It should be noted that the temperature of the heat dissipation component 30 is considered to be substantially equal to the external temperature (for example, the outer shell temperature of the housing or the ambient temperature around the optical module 1).

[0098] The operating temperature of the optical semiconductor element 10 is set to temperature Tld, and the temperature of the heat dissipation member 30 is set to temperature Tcase. The temperature Tld as the operating temperature of the optical semiconductor element 10 is, for example, the temperature of the surface of the optical semiconductor element 10 in contact with the first surface 20S1. The temperature Tcase of the heat dissipation member 30 is, for example, the temperature of the surface of the heat dissipation member 30 in contact with the second surface 20S2. The phase change temperature of the phase change material constituting the temperature buffer member 20 is set to phase change temperature Tpt. As a temperature condition, it is assumed that the phase change temperature Tpt is higher than the temperature Tcase of the heat dissipation member 30 and lower than the temperature Tld of the optical semiconductor element 10.

[0099] It is considered that in the optical module 1, the temperature (internal temperature) of the temperature buffer member 20 between the optical semiconductor element 10 and the heat dissipation member 30 changes according to the distance from the self-heating optical semiconductor element 10. That is, the closer to the optical semiconductor element 10, the higher the internal temperature, and the farther away from the optical semiconductor element 10, the lower the internal temperature. Therefore, Figure 2 As shown, the temperature buffer member 20 is divided into a high temperature layer 20u and a low temperature layer 20d. The high temperature layer 20u is a layer of the temperature buffer member 20 at a temperature higher than the phase change temperature Tpt. In other words, the high temperature layer 20u is a layer in which the phase change material is in a high temperature phase. The low temperature layer 20d is a layer of the temperature buffer member 20 at a temperature lower than the phase change temperature Tpt. In other words, the low temperature layer 20d is a layer in which the phase change material is in a low temperature phase.

[0100] When the temperature of the heat dissipation member 30 is kept constant, when the temperature Tld of the optical semiconductor element 10 becomes higher, the thickness Lu of the high temperature layer 20u becomes thicker. In addition, when the temperature Tld of the optical semiconductor element 10 becomes lower, the thickness Lu of the high temperature layer 20u becomes thinner. It should be noted that when the temperature Tld of the optical semiconductor element 10 is lower than the phase change temperature Tpt, the high temperature layer 20u does not exist. In this case, the temperature buffer member 20 is only the low temperature layer 20d.

[0101] When the temperature Tld of the optical semiconductor element 10 becomes lower while the temperature of the heat dissipation component 30 is kept constant, the thickness Ld of the low-temperature layer 20d becomes thicker. In addition, when the temperature Tld of the optical semiconductor element 10 becomes higher, the thickness Ld of the low-temperature layer 20d becomes thinner. It should be noted that when the temperature Tcase of the heat dissipation component 30 is higher than the phase change temperature Tpt, the low-temperature layer 20d does not exist. In this case, the temperature buffer component 20 is only the high-temperature layer 20u. The thickness Lu of the high-temperature layer and the thickness Ld of the low-temperature layer increase and decrease in opposite ways to each other. That is, when the thickness Lu of the high-temperature layer increases, the thickness Ld of the low-temperature layer decreases, and when the thickness Lu of the high-temperature layer decreases, the thickness Ld of the low-temperature layer increases. The sum of the thickness Ld of the high-temperature layer and the thickness Lu of the low-temperature layer is equal to the thickness of the temperature buffer component 20 (the distance between the first surface 20S1 and the second surface 20S2).

[0102] The relationship between the temperature Tld of the optical semiconductor element 10 and the temperature Tcase of the heat dissipation member 30 when the optical semiconductor element 10 is operated will be described. Figure 3 This is a diagram for explaining the temperature of the temperature buffer member 20 included in the optical module 1 as an example of the optical module according to the first embodiment.

[0103] Figure 3 The horizontal axis in represents the temperature Tcase (unit: °C) of the heat dissipation member 30 . Figure 3 The vertical axis in represents the temperature Tld (unit: °C) of the optical semiconductor element 10. It should be noted that the phase change temperature Tpt of the phase change material constituting the temperature buffer member 20 is set to 60°C. In addition, it is set that in the temperature buffer member 20, the thermal conductivity TCu of the high-temperature phase (the portion whose internal temperature is higher than the phase change temperature Tpt) is higher than the thermal conductivity TCd of the low-temperature phase (the portion whose internal temperature is lower than the phase change temperature Tpt). To be precise, for example, even inside the high-temperature phase, the thermal conductivity changes depending on the distance from the optical semiconductor element 10, so the value of the thermal conductivity TCu may change depending on the change in thickness Lu, but it is treated as a constant value here. Similarly, the thermal conductivity TCd is also treated as a constant value. In other words, it is set that in the temperature buffer member 20, the thermal resistance value TRu of the high-temperature phase is lower than the thermal resistance value TRd of the low-temperature phase. The thermal resistance value TRu and the thermal resistance value TRd are also treated as constant values, respectively.

[0104] When the temperature Tld of the optical semiconductor element 10 is lower than 60°C, in other words, when the temperature Tcase of the heat dissipation member 30 is lower than 0°C, the temperature buffer member 20 is composed of only the low temperature layer 20d. Therefore, the thermal resistance of the temperature buffer member 20 is the thermal resistance when the entire phase change material constituting the temperature buffer member 20 is in the low temperature phase. Figure 3As shown, when the temperature Tld is below 60°C, since the thermal resistance of the temperature buffer component 20 is a constant value when it is only a low temperature layer, the temperature Tld of the optical semiconductor element 10 is proportional to the temperature Tcase of the heat dissipation component 30. It should be noted that the fact that the temperature Tld of the optical semiconductor element 10 is 60°C when the temperature Tcase of the heat dissipation component 30 is 0°C is determined by the relationship between the heat generated by the optical semiconductor element 10 and the thermal resistance of the temperature buffer component 20. For example, when the thermal resistance of the temperature buffer component 20 is 60°C / W, when the heat generation per unit time of the optical semiconductor element 10 is 1W, the temperature Tld of the optical semiconductor element 10 when the temperature Tcase of the heat dissipation component 30 is 0°C is calculated to be 60°C (it should be noted that even if the thermal resistance is 120°C / W and the heat generation is 0.5W, it is still the same temperature). Figure 2 When the area of ​​the first surface 20S1 is equal to the area of ​​the second surface 20S2 and the cross-sectional area of ​​the temperature buffer member 20 between the first surface 20S1 and the second surface 20S2 is also equal to the area, the thermal resistance of the temperature buffer member 20 can be calculated by multiplying the inverse of the thermal conductivity of the temperature buffer member 20 by the length of the temperature buffer member 20 (the distance between the first surface 20S1 and the second surface 20S2) and dividing the result by the area.

[0105] When the temperature Tld of the optical semiconductor element 10 is higher than 60° C. and lower than 85° C., in other words, when the temperature Tcase of the heat dissipation member 30 is higher than 0° C. and lower than 60° C., the temperature buffer member 20 is composed of the high temperature layer 20 u and the low temperature layer 20 d .

[0106] When the temperature Tld of the optical semiconductor element 10 is 60°C, the temperature Tld of the optical semiconductor element 10 is equal to the phase change temperature Tpt of the temperature buffer member 20. Therefore, when the temperature Tld of the optical semiconductor element 10 is lower than 60°C, the entire temperature buffer member 20 is the low temperature layer 20d. When the temperature Tld of the optical semiconductor element 10 is higher than 60°C, a portion of the temperature buffer member 20 close to the optical semiconductor element 10 is the high temperature layer 20u.

[0107] exist Figure 3 In the example, when the temperature Tld of the optical semiconductor element 10 is 60°C, the temperature Tcase of the heat dissipation member 30 is 0°C. As described above, whether the temperature Tld of the optical semiconductor element 10 is 60°C when the temperature Tcase of the heat dissipation member 30 is 0°C is determined by the heat generation per unit time of the optical semiconductor element and the thermal resistance of the temperature buffer member 20.

[0108] When the temperature Tcase of the heat dissipation member 30 is higher than 0°C and the temperature Tld of the optical semiconductor element 10 is higher than the phase transition temperature Tpt, the thickness of the high temperature layer 20u in the temperature buffer member 20 becomes thicker. Therefore, when the temperature Tld is higher than the phase transition temperature Tpt, the thermal conductivity of the temperature buffer member 20 becomes higher. In other words, when the temperature Tld is higher than the phase transition temperature Tpt, the thermal resistance value of the temperature buffer member 20 becomes lower.

[0109] When the temperature Tld of the optical semiconductor element 10 is higher than 60° C. and lower than 85° C., the thermal resistance of the temperature buffer member 20 gradually decreases. Figure 3 As shown, although the temperature Tld of the optical semiconductor element 10 and the temperature Tcase of the heat dissipation member 30 are proportional, the slope is gentler than when the temperature Tld of the optical semiconductor element 10 is lower than 60°C. This is because by reducing the thermal resistance value of the temperature buffer member 20, the difference between the temperature Tld of the optical semiconductor element 10 and the temperature Tcase of the heat dissipation member 30 becomes smaller as the temperature Tcase rises. It should be noted that it is assumed here that the heat generation of the optical semiconductor element 10 is constant and does not depend on the temperature Tld of the optical semiconductor element 10.

[0110] When the temperature Tcase of the heat dissipation member 30 is 60°C, the temperature Tcase of the heat dissipation member 30 is equal to the phase change temperature Tpt of the temperature buffer member 20. Therefore, in this case, the entire temperature buffer member 20 is the high temperature layer 20u. When the temperature Tcase of the heat dissipation member 30 is lower than 60°C, a portion of the temperature buffer member 20 close to the heat dissipation member 30 is the low temperature layer 20d.

[0111] exist Figure 3 In the example, when the temperature Tcase of the heat dissipation member 30 is 60°C, the temperature Tld of the optical semiconductor element 10 becomes 85°C. That is, the temperature difference between the temperature Tld of the optical semiconductor element 10 and the temperature Tcase of the heat dissipation member 30 becomes 25°C. This is less than half of the temperature difference of 60°C when the temperature Tld of the optical semiconductor element 10 becomes 60°C when the temperature Tcase of the heat dissipation member 30 is 0°C. The temperature Tld of the optical semiconductor element 10 when the temperature Tcase of the heat dissipation member 30 is 60°C is determined by, for example, the thermal resistance of the temperature buffer member 20. Therefore, the reduction in the thermal resistance of the temperature buffer member 20 will cause the above-mentioned decrease in the temperature difference.

[0112] When the temperature Tcase of the second surface 20S2 is the phase transition temperature Tpt, Figure 3In the example, when the temperature Tcase is 60°C, which is the phase transition temperature Tpt, the temperature Tld of the first surface 20S1 is 85°C. That is, when the temperature Tcase of the second surface 20S2 is the phase transition temperature Tpt, the temperature difference (first temperature difference) between the temperature Tld of the first surface 20S1 and the phase transition temperature Tpt is 25 degrees. It should be noted that when the temperature Tcase of the second surface 20S2 is the phase transition temperature Tpt, the temperature Tld of the first surface 20S1 is set to a temperature lower than the upper limit of the operating temperature of the optical semiconductor element 10 (operating upper limit temperature).

[0113] When the temperature Tld of the first surface 20S1 is the phase transition temperature Tpt, Figure 3 In the example, the temperature Tcase is 0° C. That is, when the temperature Tld of the first surface 20S1 is the phase transition temperature Tpt, the temperature difference (second temperature difference) between the temperature Tcase of the second surface 20S2 and the phase transition temperature Tpt is 60 degrees.

[0114] As described above, by making the thermal conductivity TCu of the high temperature phase greater than the thermal conductivity TCd of the low temperature phase in the temperature buffer member 20 , the first temperature difference is smaller than the second temperature difference.

[0115] When the temperature Tld of the optical semiconductor element 10 is higher than 85°C, in other words, when the temperature Tcase of the heat dissipation member 30 is higher than 60°C, the temperature Tcase of the heat dissipation member 30 is higher than the phase change temperature Tpt. Therefore, when the temperature Tld of the optical semiconductor element 10 is higher than 85°C, the temperature buffer member 20 is composed of the high temperature layer 20u. Therefore, the thermal resistance of the temperature buffer member 20 is the thermal resistance when the phase change material constituting the temperature buffer member 20 is in the high temperature phase. Figure 3 As shown in FIG. 1 , when the temperature Tld is 85°C or above, the temperature Tld of the optical semiconductor element 10 is proportional to the temperature Tcase of the heat dissipation member 30 because the thermal resistance of the temperature buffer member 20 is a constant value. More specifically, when the temperature Tcase of the heat dissipation member 30 changes, the temperature Tld of the optical semiconductor element 10 changes by the same amount as the change in the temperature Tcase of the heat dissipation member 30. For example, when the temperature Tcase of the heat dissipation member 30 rises by 5°C, the temperature Tld of the optical semiconductor element 10 rises by 5°C.

[0116] The relationship between the thermal resistance of the temperature buffer member 20 and the temperature Tcase of the heat dissipation member 30 when the optical semiconductor element 10 is operated will be described. Figure 4 This is a diagram for explaining the thermal resistance of the temperature buffer member 20 included in the optical module 1 as an example of the optical module according to the first embodiment.

[0117] Figure 4The horizontal axis in represents the temperature Tcase (unit: °C) of the heat dissipation member 30 . Figure 4 The vertical axis in represents the thermal resistance of the temperature buffer member 20 (unit: K / W). The thermal resistance represents the thermal resistance related to the heat conduction from the first surface 20S1 to the second surface 20S2 of the temperature buffer member 20. It should be noted that it is assumed that: the phase change temperature Tpt of the phase change material constituting the temperature buffer member 20 is 60°C. In addition, it is assumed that: in the temperature buffer member 20, the thermal conductivity TCu of the high-temperature phase is higher than the thermal conductivity TCd of the low-temperature phase. In other words, the thermal resistance value TRu of the temperature buffer member 20 when the entire temperature buffer member 20 is in the high-temperature phase is lower than the thermal resistance value TRd of the temperature buffer member 20 when the entire temperature buffer member 20 is in the low-temperature phase. It should be noted that in the temperature buffer member 20, the thermal resistance value TRd of the low-temperature phase may also be greater than twice the thermal resistance value TRu of the high-temperature phase.

[0118] like Figure 4 As shown, when the temperature Tcase of the heat dissipation member 30 is lower than 0°C, the thermal resistance of the temperature buffer member 20 is equal to the thermal resistance value TRd when the entire temperature buffer member 20 is in a low temperature phase and is a constant value. In addition, when the temperature Tcase of the heat dissipation member 30 is higher than 0°C and lower than 60°C, the thermal resistance of the temperature buffer member 20 decreases at a constant slope relative to the temperature Tcase. Moreover, when the temperature Tcase of the heat dissipation member 30 is higher than 60°C, the thermal resistance of the temperature buffer member 20 is equal to the thermal resistance value TRu when the entire temperature buffer member 20 is in a high temperature phase and is a constant value.

[0119] When the thermal resistance is constant at the thermal resistance value TRd or the thermal resistance value TRu, as described above, the temperature Tld of the optical semiconductor element 10 changes by the same amount as the change in the temperature Tcase of the heat dissipation member 30. On the other hand, when the thermal resistance decreases in proportion to the temperature Tcase, the temperature of the optical semiconductor element 10 changes by a smaller amount than the change in the temperature Tcase of the heat dissipation member 30. For example, Figure 3 As shown, when the temperature Tcase of the heat dissipation member 30 increases from 0° C. to 60° C., the increase in the temperature Tld of the optical semiconductor element 10 is 25° C., which is less than 60° C. It should be noted that the numerical values ​​shown above are only examples, and the temperature and thermal resistance values ​​can be appropriately determined based on the specifications of the optical module 1 and the optical semiconductor element 10.

[0120] <Operation Results of the Optical Module of the First Embodiment>

[0121] The results of operating the optical module according to the first embodiment will be described. Figures 5 to 8 Each of these diagrams is for explaining the operation results of the optical module 1 as an example of the optical module according to the first embodiment.

[0122] Figure 5 and Figure 6 Each of these is a diagram showing the relationship between the temperature Tcase of the heat dissipating member 30 and the temperature Tld of the optical semiconductor element 10 when the optical module 1 is operated. Figure 6 Yes Figure 5 A magnified view of area A1 in FIG.

[0123] Figure 5 and Figure 6 Each horizontal axis represents the temperature Tcase (unit: °C) of the heat dissipation member 30 . Figure 5 and Figure 6 Each vertical axis represents the temperature Tld (unit: °C) of the optical semiconductor element 10. The line Lex represents the temperature Tld (unit: °C) of the optical semiconductor element 10 using the silver chalcogenide (Ag 2 S 0.4 Se 0.6 ) as an example of the temperature buffer member 20. Line Lref1 shows the result of using glass instead of the temperature buffer member 20. Line Lref2 shows the result of using aluminum nitride instead of the temperature buffer member 20.

[0124] like Figure 5 and Figure 6 As shown respectively, the optical module 1 can suppress the temperature rise of the temperature Tld of the optical semiconductor element 10 relative to the temperature rise of the temperature Tcase of the heat dissipation member 30 within the range of, for example, 50° C. to 70° C. That is, the change of the temperature Tld of the optical semiconductor element 10 represented by the line Lex is about half compared with the line Lref1 and the line Lref2.

[0125] On the other hand, Figure 5 and Figure 6 As shown in Figures 1 and 2, when glass or aluminum nitride is used instead of the temperature buffer member 20, the temperature Tld of the optical semiconductor element 10 increases in proportion to the temperature Tcase of the heat dissipation member 30. That is, since the thermal resistance is constant, the temperature Tld of the optical semiconductor element 10 changes by the same amount as the change in the temperature Tcase of the heat dissipation member 30. For example, when the temperature Tcase of the heat dissipation member 30 increases by 10°C, the temperature Tld of the optical semiconductor element 10 increases by 10°C.

[0126] Figure 7 and Figure 8 These are graphs showing the relationship between the temperature Tcase of the heat dissipation member 30 and the peak wavelength of the emitted light from the optical semiconductor element 10 when the optical module 1 is operated. Figure 8 Yes Figure 7 A magnified view of area A2 in FIG.

[0127] Figure 7 and Figure 8 Each horizontal axis represents the temperature Tcase (unit: °C) of the heat dissipation member 30 . Figure 7 and Figure 8 Each vertical axis represents the peak wavelength (unit: nm) of the emitted light of the optical semiconductor element 10. The line Lex represents the peak wavelength (unit: nm) of the emitted light of the optical semiconductor element 10 using the silver chalcogenide (Ag 2 S 0.4 Se 0.6 ) as an example of the temperature buffer member 20. Line Lref1 shows the result of using glass instead of the temperature buffer member 20. Line Lref2 shows the result of using aluminum nitride instead of the temperature buffer member 20.

[0128] like Figure 7 and Figure 8 As shown, the optical module 1 can reduce the change in wavelength of the light emitted from the optical semiconductor element 10 with respect to the temperature rise of the temperature Tcase of the heat dissipation member 30 in the temperature range of 50° C. to 70° C. This is because the temperature change of the temperature Tld of the optical semiconductor element 10 is reduced as described above.

[0129] On the other hand, Figure 7 and Figure 8 As shown respectively, when glass or aluminum nitride is used instead of the temperature buffer member 20 , the wavelength of the emitted light from the optical semiconductor element 10 changes in proportion to the temperature Tcase of the heat dissipation member 30 .

[0130] By providing the optical module of the first embodiment with a temperature buffer member, when the operating temperature of the optical semiconductor element is low, the heat dissipated from the self-heated heat in the optical semiconductor element to the heat dissipation member can be reduced. In addition, by providing the optical module of the first embodiment with a temperature buffer member, when the operating temperature of the optical semiconductor element is high, the heat dissipated from the self-heated heat in the optical semiconductor element to the heat dissipation member can be increased.

[0131] By providing the optical module of the first embodiment with a temperature buffer member, it is possible to reduce the temperature variation of the optical semiconductor element with respect to the temperature variation of the heat dissipation member 30. Since the optical module of the first embodiment reduces the temperature variation of the optical semiconductor element, it is possible to suppress the influence of the temperature variation of the optical semiconductor element on the optical characteristics and electrical characteristics of the optical module.

[0132] With the rapid increase in demand for data centers in recent years and the trend of reducing environmental loads around the world, there is a demand for lower power consumption of optical modules. In the demand for lower power consumption of optical modules, it is expected that a significant reduction in power consumption can be achieved by removing temperature control components such as Peltier elements that account for a large proportion of the power consumption of optical modules.

[0133] According to the optical module of the first embodiment, the temperature variation of the optical semiconductor element relative to the change of the ambient temperature can be reduced by having a temperature buffer component. Since the optical module of the first embodiment reduces the temperature variation of the optical semiconductor element, the temperature of the optical semiconductor element can be maintained within a specified range without performing temperature control by cooling or heating. In addition, since the optical module of the first embodiment reduces the temperature variation of the optical semiconductor element by having a temperature buffer component, the temperature of the optical semiconductor element can be maintained within a specified range without consuming the power required for temperature control. Therefore, the optical module of the first embodiment can maintain the operating temperature of the optical semiconductor element within a specified range with low power consumption. In other words, the optical module of the first embodiment can achieve a greater effect in reducing power consumption.

[0134] The optical module of the second embodiment comprises: a temperature buffer member having a first surface and a second surface opposite to the first surface; an optical semiconductor element connected to the first surface; a heating member connected to the first surface and receiving power from the outside to generate heat; and a heat dissipation member connected to the second surface. In addition, the temperature buffer member of the optical module of the second embodiment is composed of a phase change material whose thermal conductivity changes at a phase change temperature.

[0135] <Configuration of Optical Module According to Second Embodiment>

[0136] The optical module according to the second embodiment will be described using a specific example. Fig. 9 It is a perspective view schematically showing an optical module 1A as an example of the optical module according to the second embodiment.

[0137] The optical module 1A includes an optical semiconductor element 10 , a temperature buffer member 20 , a heat dissipation member 30 , and a heating member 40 .

[0138] [Optical semiconductor element 10]

[0139] The optical semiconductor element 10 is an element including a semiconductor that converts light into electricity. The optical semiconductor element 10 is the same as the optical semiconductor element 10 of the first embodiment.

[0140] [Temperature buffer member 20]

[0141] The temperature buffer member 20 is a member whose thermal resistance changes according to temperature. The temperature buffer member 20 is the same as the temperature buffer member 20 of the first embodiment, but the optical semiconductor element 10 and the heating member 40 (temperature control object 45 described later) are connected to the first surface 20S1 to conduct the heat generated in the temperature control object 45.

[0142] [Heat dissipation member 30]

[0143] The heat dissipation member 30 dissipates heat generated in the temperature adjustment object 45 to the outside. The heat dissipation member 30 is the same as the heat dissipation member 30 of the first embodiment.

[0144] [Heating member 40]

[0145] The heating member 40 receives electric power from the outside to generate heat. The heating member 40 is, for example, a resistor element. The heating member generates Joule heat when electric current flows therein.

[0146] <Temperature Characteristics of Optical Module of Second Embodiment>

[0147] The temperature characteristics of the optical module according to the second embodiment will be described using an optical module 1A as an example of the optical module according to the second embodiment. Fig.10 This is a diagram for explaining the use of an optical module 1A as an example of an optical module according to the second embodiment. Fig.10 In the embodiment, the optical semiconductor element 10 and the heating member 40 are integrated and described as the temperature control object 45. To be precise, the temperature of the optical semiconductor element 10 and the temperature of the heating member 40 may be different from each other, but in the following description, it is assumed that the temperature of the optical semiconductor element 10 and the temperature of the heating member 40 are respectively the same as the temperature of the temperature control object 45. It should be noted that the heating member 40 can be as follows: Fig. 9 As shown, the heating member 40 is disposed in contact with the temperature buffer member 20 together with the optical semiconductor element 10 , but the heating member 40 may be placed on the optical semiconductor element 10 so that the heating member 40 and the temperature buffer member 20 sandwich the optical semiconductor element 10 .

[0148] exist Fig.10 In the embodiment, a case where the temperature of the temperature control object 45 is higher than the temperature of the heat dissipation member 30 is described. When the temperature control object 45 generates heat, the temperature of the temperature control object 45 is higher than the temperature of the heat dissipation member 30. In the configuration in which the temperature buffer member 20 is sandwiched between the temperature control object 45 and the heat dissipation member 30, the heat generated in the temperature control object 45 is transferred from the temperature control object 45 to the heat dissipation member 30 via the temperature buffer member 20. At this time, the direction of heat transfer is equal to the arrangement direction (first direction) of the temperature control object 45, the temperature buffer member 20, and the heat dissipation member 30.

[0149] When the optical module 1A is operated, the optical semiconductor element 10, for example, will self-heat, thereby increasing the temperature. It is assumed that the heat dissipation member 30 is maintained at a substantially constant temperature. For example, when the thermal resistance between the heat dissipation member 30 and the outside is much smaller than the thermal resistance of the temperature buffer member 20 and the heat capacity of the heat dissipation member 30 is much larger than the self-heat of the optical semiconductor element 10, the temperature change of the heat dissipation member 30 can be ignored. It should be noted that the temperature of the heat dissipation member 30 is considered to be substantially equal to the external temperature (for example, the outer shell temperature of the housing or the ambient temperature around the optical module 1A). The heating member 40 heats the optical semiconductor element 10 in such a manner that the temperature (operating temperature) of the optical semiconductor element 10 is maintained constant. For example, when the operating temperature of the optical semiconductor element 10 is 50°C, the heating member 40 generates heat to heat the optical semiconductor element 10 in such a manner that the operating temperature rises by 40°C to 90°C. In addition, for example, when the operating temperature of the optical semiconductor element 10 is 70°C, the heating member 40 generates heat to heat the optical semiconductor element 10 in such a manner that the operating temperature rises by 20°C to 90°C. In this way, when the temperature of the optical semiconductor element 10 is kept constant by the heat generated by the heating member 40 , the temperature of the temperature control target 45 is substantially equal to the operating temperature of the optical semiconductor element 10 .

[0150] The temperature of the temperature control object 45 is set to the temperature Tld, and the temperature of the heat dissipation member 30 is set to the temperature Tcase. The temperature Tld of the temperature control object 45 is, for example, the temperature of the surface of the temperature control object 45 in contact with the first surface 20S1. The temperature Tcase of the heat dissipation member 30 is, for example, the temperature of the surface of the heat dissipation member 30 in contact with the second surface 20S2. The phase change temperature of the phase change material constituting the temperature buffer member 20 is set to the phase change temperature Tpt. As the temperature condition, it is assumed that the phase change temperature Tpt is higher than the temperature Tcase of the heat dissipation member 30 and lower than the temperature Tld of the temperature control object 45.

[0151] It is considered that in the optical module 1A, the temperature (internal temperature) of the temperature buffer member 20 between the temperature control object 45 and the heat dissipation member 30 changes according to the distance from the temperature control object 45. That is, the closer to the temperature control object 45, the higher the internal temperature, and the farther away from the temperature control object 45, the lower the internal temperature. Fig.10 As shown, the temperature buffer member 20 is divided into a high temperature layer 20u and a low temperature layer 20d. The high temperature layer 20u is a layer of the temperature buffer member 20 at a temperature higher than the phase change temperature Tpt. In other words, the high temperature layer 20u is a layer in which the phase change material is in a high temperature phase. The low temperature layer 20d is a layer of the temperature buffer member 20 at a temperature lower than the phase change temperature Tpt. In other words, the low temperature layer 20d is a layer in which the phase change material is in a low temperature phase.

[0152] When the temperature of the heat dissipation member 30 is kept constant, when the temperature Tld of the temperature adjustment object 45 becomes higher, the thickness Lu of the high temperature layer 20u becomes thicker. In addition, when the temperature Tld of the temperature adjustment object 45 becomes lower, the thickness Lu of the high temperature layer 20u becomes thinner. It should be noted that, when the temperature Tld of the temperature adjustment object 45 is lower than the phase change temperature Tpt, the high temperature layer 20u of the temperature buffer member 20 does not exist. In this case, when the temperature Tld of the temperature adjustment object 45 is lower than the phase change temperature Tpt, the temperature buffer member 20 is only the low temperature layer 20d.

[0153] When the temperature Tld of the temperature regulating object 45 becomes lower, the thickness Ld of the low temperature layer 20d becomes thicker. In addition, when the temperature Tld of the temperature regulating object 45 becomes higher, the thickness Ld of the low temperature layer 20d becomes thinner. It should be noted that when the temperature Tcase of the heat dissipation member 30 is higher than the phase change temperature Tpt due to the heat from the temperature regulating object 45, the low temperature layer 20d in the temperature buffer member 20 will become non-existent. In this case, when the temperature Tcase of the heat dissipation member 30 is higher than the phase change temperature Tpt, the temperature buffer member 20 is only a high temperature layer 20u. The thickness Lu of the high temperature layer and the thickness Ld of the low temperature layer increase and decrease in opposite ways to each other. That is, when the thickness Lu of the high temperature layer increases, the thickness Ld of the low temperature layer decreases, and when the thickness Lu of the high temperature layer decreases, the thickness Ld of the low temperature layer increases. The sum of the thickness Ld of the high temperature layer and the thickness Lu of the low temperature layer is equal to the thickness of the temperature buffer member 20 (the distance between the first surface 20S1 and the second surface 20S2).

[0154] The relationship between the temperature Tld of the temperature control object 45 and the temperature Tcase of the heat dissipation member 30 when the optical semiconductor element 10 and the heating member 40 are operated and Figure 3 The relationship between the temperature Tld of the optical semiconductor element 10 and the temperature Tcase of the heat dissipation member 30 when the optical semiconductor element 10 of the first embodiment is operated is the same.

[0155] <Functional Configuration of Optical Module of Second Embodiment>

[0156] Regarding the optical module according to the second embodiment, a function of adjusting the temperature of the optical semiconductor element will be described. Fig.11 This is a diagram for schematically explaining the functional configuration of an optical module 1A as an example of the optical module according to the second embodiment.

[0157] The optical module 1A further includes a temperature detection element 50 and a control unit 60. It should be noted that the control unit 60 may be provided outside the optical module 1A.

[0158] [Temperature detection element 50]

[0159] The temperature detection element 50 is an element for measuring the temperature in the vicinity of the optical semiconductor element 10. The temperature detection element 50 is, for example, a thermistor, a temperature measuring resistor, or a thermocouple.

[0160] [Control unit 60]

[0161] The control unit 60 controls the heating member 40 so that the temperature of the optical semiconductor element 10 is within a desired range based on the temperature detected by the temperature detection element 50. The control unit 60 calculates the temperature of the optical semiconductor element 10 based on the change in the resistance value of the temperature detection element 50, for example. For example, the control unit 60 adjusts the power supplied to the heating member 40 so that the temperature of the optical semiconductor element 10 is within a desired range, for example, by PID (Proportional-Integral-Differential) control. The control unit 60 applies a predetermined voltage to the heating member 40 to flow a predetermined current, thereby causing the heating member 40 to generate heat.

[0162] The control unit 60 may control the heating member 40, for example, in such a manner that the temperature Tld of the first surface 20S1 is maintained at the temperature Tld of the first surface 20S1 when the temperature Tcase of the second surface 20S2 is equal to the phase change temperature Tpt. In other words, when the temperature Tcase of the second surface 20S2 is lower than the phase change temperature Tpt, the control unit 60 may control the heating member 40 in such a manner that the temperature Tld of the first surface 20S1 is maintained at the temperature Tld of the first surface 20S1 when the temperature Tcase of the second surface 20S2 is equal to the phase change temperature Tpt. Thus, for example, even if the temperature Tcase of the second surface 20S2 changes, the temperature Tld of the first surface 20S1 can be maintained at the temperature Tld of the first surface 20S1 = 85°C when the temperature Tcase of the second surface 20S2 is equal to the phase change temperature Tpt = 60°C.

[0163] <Operation Results of the Optical Module of the Second Embodiment>

[0164] The results of operating the optical module according to the second embodiment will be described. Fig.12 This is a diagram for explaining the operation of an optical module 1A as an example of the optical module according to the second embodiment.

[0165] Fig.12It is a diagram showing the relationship between the temperature Tcase of the heat dissipation component 30 and the power (unit: mW) supplied to the heating component 40 when the optical module 1A is operated. It should be noted that the power is controlled in such a way that the temperature of the optical semiconductor element 10 becomes 90°C. The optical semiconductor element 10 generates heat by consuming power when it is in operation. For example, when the temperature Tcase is 70°C, the temperature of the optical semiconductor element 10 is 90°C due to the self-heating of the optical semiconductor element 10. When the temperature Tcase is lower than 70°C, the temperature of the optical semiconductor element 10 will be lower than 90°C, so the heating component 40 will generate heat to maintain the temperature of the optical semiconductor element 10 at 90°C. As the temperature Tcase becomes lower, the power of the heating component 40 becomes larger to increase the heat generated by the heating component 40.

[0166] Fig.12 The horizontal axis of represents the temperature Tcase (unit: °C) of the heat dissipation member 30 . Fig.12 The vertical axis of represents the power (unit: mW) supplied to the heating member 40. The line Lex represents the power (unit: mW) supplied to the heating member 40 using the silver chalcogenide (Ag 2 S 0.4 Se 0.6 ) as an example of the temperature buffer member 20. Line Lref represents the result of using glass instead of the temperature buffer member 20.

[0167] like Fig.12 As shown, for example, when controlling the temperature of the optical semiconductor element 10 within a temperature range of 70° C. or less, the optical module 1A can reduce the power consumption of the heating member 40 compared to the case where glass is used instead of the temperature buffer member 20 .

[0168] By providing the optical module 1A of the second embodiment with the temperature buffer member 20, Figure 4 As shown, as the temperature Tcase decreases, the thermal resistance of the temperature buffer member 20 increases. Therefore, when the temperature Tcase of the optical module is lower than the phase change temperature Tpt, the temperature of the optical semiconductor element 10 can be efficiently increased by the heat emitted by the heating member 40. Therefore, when the temperature Tcase of the optical module 1A is lower than the phase change temperature Tpt, the optical module 1A of the second embodiment can reduce the power required for heating by the heating member 40 compared to the case where the temperature buffer member 20 is not used. In addition, by providing the optical module 1A of the second embodiment with the temperature buffer member 20, when the temperature Tcase of the optical semiconductor element 10 is higher than the phase change temperature Tpt, the thermal resistance of the temperature buffer member 20 becomes smaller, thereby promoting the heat generated by the self-heating of the optical semiconductor element 10 to be dissipated through the heat dissipation member 30. As a result, the operating temperature of the optical semiconductor element 10 can be suppressed from excessively rising.

[0169] By providing the optical module 1A of the second embodiment with the temperature buffer member 20, it is possible to reduce the power required for adjusting the temperature of the optical semiconductor element 10. In particular, when the temperature of the optical semiconductor element 10 is maintained at a predetermined value by the heat generated by the heating member 40, the lower the temperature of the optical module 1A, the more the power can be reduced.

[0170] With the recent rapid growth in demand for data centers and the trend of reducing environmental loads around the world, there is a demand for lower power consumption of optical modules. Reducing the power consumption required for temperature control of optical modules will greatly contribute to lower power consumption of optical modules.

[0171] According to the optical module of the second embodiment, the temperature buffer member can suppress power consumption when adjusting the temperature of the optical semiconductor element. Since the optical module of the second embodiment suppresses power consumption when adjusting the temperature of the optical semiconductor element, it can achieve a significant effect in reducing power consumption.

[0172] <Modification>

[0173] A modification of the optical module according to the second embodiment will be described. Fig.13 This is a diagram for explaining an optical module 2 as an example of an optical module according to the second embodiment.

[0174] The optical module 2 includes an optical semiconductor element 10, a carrier 15, a temperature buffer member 20, a heat dissipation member 33, a heating member 40, a temperature detection element 50, and a lens 70. For each of the optical semiconductor element 10, the temperature buffer member 20, the heating member 40, and the temperature detection element 50, it is assumed that the above description is referred to, and the detailed description is omitted here.

[0175] [Carrier 15]

[0176] The carrier 15 is a substrate on which the optical semiconductor element 10, the heating member 40, and the temperature detection element 50 are mounted. The carrier 15 is formed of, for example, a material having low electrical conductivity and high thermal conductivity. More specifically, the carrier 15 is formed of aluminum nitride. The carrier 15 is connected to the temperature buffer member 20. The carrier 15 is equivalent to Fig.10 The temperature regulation object 45 is shown in the figure.

[0177] [Heat dissipation member 33]

[0178] The heat dissipation member 33 dissipates heat generated in the optical semiconductor element 10. The heat dissipation member 33 includes a plate 31 and a package 32. The plate 31 is connected to the temperature buffer member 20. The package 32 is connected to the plate 31.

[0179] The plate 31 is formed of, for example, aluminum nitride. The package 32 is formed of, for example, aluminum nitride. The plate 31 and the package 32 may be formed integrally.

[0180] [Lens 70]

[0181] The lens 70 converts, for example, light emitted from the optical semiconductor element 10 into parallel light. Also, the lens 70 collects light from the outside onto the optical semiconductor element 10. The lens 70 is formed of, for example, glass or resin.

[0182] The lens 70 is placed on, for example, the temperature buffer member 20 .

[0183] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is indicated by the claims rather than the above meanings, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. An optical module, comprising: a temperature buffer member having a first surface and a second surface opposite to the first surface; An optical semiconductor element connected to the first surface, the optical semiconductor element generating self-heat; and a heat dissipation component connected to the second surface, The temperature buffer member is made of a phase change material whose thermal conductivity changes at a phase change temperature.

2. The optical module according to claim 1, in, The heat conductivity of the heat dissipation member is greater than the heat conductivity of the temperature buffer member.

3. The optical module according to claim 2, in, When the temperature of the second surface is equal to the phase transition temperature, the first surface has a first temperature higher than the phase transition temperature, When the temperature of the first surface is equal to the phase transition temperature, the second surface has a second temperature lower than the phase transition temperature, A first temperature difference between the first temperature and the phase change temperature is set to be smaller than a second temperature difference between the phase change temperature and the second temperature.

4. The optical module according to claim 3, in, The first temperature is set to a temperature lower than an upper limit operating temperature of the optical semiconductor element.

5. The optical module according to claim 3, in, When the temperature of the second surface is equal to the phase change temperature, the temperature buffer member has a first thermal resistance between the first surface and the second surface. Furthermore, when the temperature of the second surface is equal to the second temperature, the temperature buffer member has a second thermal resistance between the first surface and the second surface that is greater than the first thermal resistance.

6. The optical module according to claim 5, in, The resistance value of the second thermal resistor is greater than twice the resistance value of the first thermal resistor.

7. The optical module according to any one of claims 1 to 6, in, The phase change material has the phase change temperature of 70° C. or more and 100° C. or less.

8. The optical module according to any one of claims 1 to 6, in, The phase change material includes any one of silver sulfide, silver chalcogenide, and copper gallium telluride.

9. The optical module according to any one of claims 1 to 6, in, Any one of heat dissipation grease, solder, and metal paste is further provided between the second surface of the temperature buffer member and the heat dissipation member.

10. An optical module comprising: a temperature buffer member having a first surface and a second surface opposite to the first surface; an optical semiconductor element connected to the first surface; A heating member connected to the first surface and receiving electricity from the outside to generate heat; as well as a heat dissipation component connected to the second surface, The temperature buffer member is made of a phase change material whose thermal conductivity changes at a phase change temperature.

11. The optical module according to claim 10, in, The heat conductivity of the heat dissipation member is greater than the heat conductivity of the temperature buffer member.

12. The optical module according to claim 10, in, When the temperature of the second surface is equal to the phase transition temperature, the first surface has a first temperature higher than the phase transition temperature, When the temperature of the second surface is lower than the phase change temperature, the temperature of the first surface is maintained at the first temperature by adjusting the electric power of the heating member.

13. The optical module according to claim 12, in, The first temperature is set to a temperature lower than an upper limit operating temperature of the optical semiconductor element.

14. The optical module according to claim 12, in, When the temperature of the first surface is equal to the phase transition temperature, the second surface has a second temperature lower than the phase transition temperature, The temperature buffer member has a first thermal resistance between the first and second surfaces when the temperature of the second surface is equal to the phase change temperature, and has a second thermal resistance between the first and second surfaces greater than the first thermal resistance when the temperature of the second surface is equal to the second temperature.

15. The optical module according to claim 14, in, The resistance value of the second thermal resistor is greater than twice the resistance value of the first thermal resistor.

16. The optical module according to any one of claims 10 to 15, in, The phase change material has the phase change temperature of 70° C. or more and 100° C. or less.

17. The optical module according to any one of claims 10 to 15, in, The phase change material includes any one of silver sulfide, silver chalcogenide, and copper gallium telluride.

18. The optical module according to any one of claims 10 to 15, further comprising: A temperature detection element is connected to the first surface and generates a detection signal according to the temperature of the first surface.

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