JP2008282965A - Semiconductor laser module and cabinet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser module where a drying agent can easily be replaced and to provide a cabinet used therefor. <P>SOLUTION: The cabinet 20 has a body 21 having an opening 21A, and a top lid 22 for covering the opening 21A. An O ring 23 is provided between the body 21 and the top lid 22. The top lid 22 has a recess therein as a drying agent receiving portion 22A, and the drying agent 30 is received in the drying agent receiving portion 22A. When the temperature inside the module rises, the drying agent 30 can be removed together with the top lid 22 from the body 21 and can easily be replaced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor laser module in which a semiconductor laser is accommodated in a casing, and a casing used for the semiconductor laser module.

  For example, in a DVD (Digital Versatile Disk) application, a semiconductor laser is often attached to a device in a bare state that cannot be put in a casing, and is used by controlling the temperature and humidity of the external environment as necessary. However, depending on the application, it may be used in the form of a semiconductor laser module housed in a housing. In that case, for example, the semiconductor laser is housed in the housing in an environment where the humidity is extremely low, and welding is performed. It is trying to seal. However, if the casing is completely sealed by welding or the like, it cannot be opened for maintenance, and therefore a sealing method having a relatively low sealing property such as an O-ring is usually used together. Therefore, it is difficult to completely block the moisture ingress path from the outside into the housing.

In patent document 1, it is proposed to enclose a desiccant in a housing. This desiccant is provided to prevent condensation of a cooler such as a Peltier element that cools the semiconductor laser.
JP 2006-49605 A

  However, in the structure described in Patent Document 1, since the desiccant was disposed on the bottom surface of the housing together with the semiconductor laser and the like, when the humidity inside the module increased, the housing was opened and the desiccant was removed, Had to be replaced with new desiccant. In addition, since silica gel was used as the desiccant, in addition to a significant decrease in moisture absorption capability at a low temperature of 0 ° C. or lower, there was also a problem that it did not function effectively because the equilibrium humidity at room temperature was as high as about 20%. It was.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a semiconductor laser module and a housing used therefor in which the desiccant can be easily replaced.

The first semiconductor laser module according to the present invention has the following structural requirements (A) to (C).
(A) Semiconductor laser (B) A main body that contains a semiconductor laser and has an opening on its upper surface, an upper lid that covers the opening and is provided with a desiccant containing portion, and is made of an elastic material and has a cavity inside A desiccant accommodated in a desiccant accommodating portion of the upper lid of the casing (C) having an elastic ring-shaped sealing member provided between the main body and the upper lid

The casing according to the present invention has the following structural requirements (A) to (C).
(A) A main body that contains a semiconductor laser and has an opening on the upper surface (B) An upper lid that covers the opening and is provided with a desiccant containing portion (C) It is made of an elastic material and has a cavity inside, Elastic ring-shaped sealing member provided between the upper lid

The second semiconductor laser module of the present invention has the following constituents (A) to (C).
(A) Semiconductor laser (B) Main body having a semiconductor laser and an opening on the upper surface, and a casing having an upper lid covering the opening (C) A desiccant provided in the casing

  In the first semiconductor laser module of the present invention or the housing of the present invention, the upper lid provided with the desiccant container and the main body are hermetically sealed with an elastic ring sealing member in between, and the desiccant for the upper lid Since the desiccant is accommodated in the accommodating portion, when the humidity inside the module increases, the desiccant is removed from the main body together with the upper lid, and can be easily replaced.

  In the second semiconductor laser module of the present invention, since the desiccant is provided in the housing, an increase in humidity in the housing is suppressed and dew condensation is prevented.

  According to the first semiconductor laser module of the present invention or the casing of the present invention, the upper lid provided with the desiccant accommodating portion and the main body are sealed with the elastic ring sealing member interposed therebetween, and the desiccant accommodated in the upper lid is accommodated. Since the desiccant is accommodated in the part, the desiccant can be removed from the main body together with the upper lid and can be easily replaced.

  According to the second semiconductor laser module of the present invention, since the desiccant is provided in the housing, an increase in humidity in the housing can be suppressed and condensation can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The following embodiments pay attention to the influence of dew condensation on the semiconductor laser, and in order to suppress this, the semiconductor laser is housed in the housing together with the desiccant, and the moisture permeability of the housing is further improved to improve the effect of the desiccant. It is intended to increase. Therefore, before entering into the description of the specific embodiments, as the premise underlying the present invention, the influence of dew condensation on the semiconductor laser and the necessity of housing the semiconductor laser in the housing will be described based on experimental results. To do.

(Experiment)
A red semiconductor laser as shown in FIG. 1 was produced. In this red semiconductor laser, a semiconductor laser array 13 formed on a GaAs substrate with a copper (Cu) heat sink 11 and a silicon carbide (SiC) submount 12 in between is formed of indium (In) -silver (Ag). The solder layer 14 and the solder layer 15 made of gold (Au) -tin (Sn) are joined, and the thickness and constituent materials of each layer are general. The obtained red semiconductor laser is cooled to about −40 ° C. using a Peltier device in a general living space (room temperature and humidity) in a bare state that cannot be put in the case, and the change is observed with an optical microscope. did. Note that the environment of −40 ° C. is a situation that actually occurs in an aircraft cargo compartment or the like above about 10,000 m.

(Results and analysis)
Rapid cooling was started from 50 ° C., and condensation started at −10 ° C. This is because the water contained in the air began to condense when it became below freezing point. Freezing started at −27 ° C., frost grew at −39 ° C., and needle-like crystals grew at −45 ° C. After 2 minutes at −45 ° C., the needle-like crystal further grew, and after 4 minutes at −45 ° C., the red semiconductor laser was completely covered with frost. Thereafter, when the temperature was returned to room temperature again, the melting of ice started at 5 ° C., and a large water droplet was generated at 7 ° C., and the main emission side end face of the semiconductor laser array 13 was covered with the water droplet. The ice melted completely at 51 ° C and the water evaporated at 68 ° C.

  When the end face of the semiconductor laser array 13 having dew condensation was confirmed with a microscope, it was normal that the end face had a uniform blue color, but in some places, a portion turned yellowish brown was observed. This is an example of a defect due to condensation of the semiconductor laser array 13. When the discolored portion was observed with an SEM, indium (In) deposits were observed, and indium (In) was detected as a specific element even in EDX. Therefore, the cause of discoloration is migration of components contained in the solder layers 14 and 15, and is particularly noticeable when indium (In) is contained in the solder layer 14 between the heat sink 11 and the submount 12. I understood. This defect is irreversible and has caused fatal damage such as a large increase in drive current.

  On the other hand, when subjected to a temperature cycle under the condition of no condensation, the above-mentioned defects did not occur and the end face was clean. In addition, as conditions which do not condense, it applied to the temperature cycle, blowing dry air on the emitting end surface of the red semiconductor laser mentioned above. As described above, it has been found that the end face discoloration completely corresponds to the presence or absence of condensation, and it is necessary to accommodate the semiconductor laser in the casing and to prevent the condensation.

  Hereinafter, specific embodiments will be described based on the experimental results.

  2 and 3 show the configuration of the semiconductor laser module according to one embodiment of the present invention. This semiconductor laser module is used for a projector display, for example, and has a configuration in which the semiconductor laser 10 is accommodated in a housing 20.

  FIG. 4 shows an example of the configuration of the semiconductor laser 10. The semiconductor laser 10 is used as a red light source of a laser projector or the like, and is a red semiconductor laser having an oscillation wavelength in a wavelength range of 630 nm to 690 nm. In this semiconductor laser 10, a semiconductor laser array 13 is joined to a heat sink 11 with solder layers 14 and 15 (not shown in FIG. 4, see FIG. 1) with a submount 12 in between.

  The heat sink 11 is made of, for example, copper (Cu), and a thin film made of gold (Au) or the like is attached to the surface. The submount 12 is made of, for example, silicon carbide (SiC). The semiconductor laser array 13 is a red semiconductor laser bar made of an AlGaInP-based compound semiconductor layer formed on a GaAs substrate, and its configuration is general.

  On the heat sink 11, for example, an electrode member 16 made of the same material is fixed by screws 16A and 16B, for example. An insulating plate 17 made of an insulating resin such as glass or epoxy is provided between the heat sink 11 and the electrode member 16, and the heat sink 11 and the electrode member 16 are electrically insulated. The electrode member 16 is provided with a step 16C at one corner on the semiconductor laser array 13 side. The step 16C is made of, for example, a gold (Au) wire or gold (Au) foil having a thickness of 50 μm. One end of the wire 18 is joined. The other end of the wire 18 is joined to the semiconductor laser array 13, and the electrode member 16 and the semiconductor laser array 13 are electrically connected via the wire 18. That is, the heat sink 11 and the electrode member 16 also have a function as a pair of electrodes of the semiconductor laser array 13. A protective member 19 made of the same material as the heat sink 11 is fixed to the step portion 16C of the electrode member 16 with screws 19A in order to protect the wires 18, the semiconductor laser array 13, and the like.

  The housing 20 shown in FIGS. 2 and 3 has a main body 21 and an upper lid 22. The main body 21 is a rectangular parallelepiped box made of aluminum (Al), for example, and has a rectangular opening 21A on the upper surface. The main body 21 has a window 21 </ b> B for emitting light generated by the semiconductor laser 10 to the outside on one side surface (for example, the front surface). The space between the main body 21 and the window 21B is sealed with a sealant (not shown). Further, the main body 21 has a connector portion 25 for supplying power to the semiconductor laser 10 and the like on the other side surface (for example, the back surface).

  FIG. 5 shows the configuration of the upper lid 22. The upper lid 22 covers the opening 21 </ b> A of the main body 21, and is made of aluminum (Al) like the main body 21. The upper lid 22 has a concave portion inside as a desiccant accommodating portion 22A, and the desiccant 30 is accommodated in the desiccant accommodating portion 22A. Thereby, in this semiconductor laser module, the desiccant 30 can be easily replaced.

  An O-ring 23 for sealing and sealing is provided between the main body 21 and the upper lid 22. The O-ring 23 is a ring-shaped member that is made of an elastic material such as rubber and that has a hollow inside and has a circular cross section. The O-ring 23 corresponds to a specific example of an “elastic ring sealing member” according to the present invention.

  The desiccant 30 has, for example, a metal fitting (not shown) for fixing, and the metal fitting is screwed to the upper lid 22. It may be fixed with an adhesive tape (not shown) or the like. The specific mode of the desiccant container 22A is not limited to the recess, and for example, a pocket made of a net of metal or the like may be provided inside the upper lid. Further, a nested structure in which a double or triple drying chamber is provided separated by a semi-permeable membrane or the like may be used.

It is preferable that the desiccant 30 satisfies the following conditions (1) to (3).
(1) The equilibrium value of relative humidity at the minimum ambient temperature is less than 100% (2) The maximum moisture absorption amount is larger than the product of the moisture transmission rate and the service life of the housing 20 (3) The moisture absorption rate is the housing 20 Hereinafter, these conditions (1) to (3) will be described in detail in order.

  The condition (1) means that no condensation occurs at the minimum environmental temperature (that is, the humidity is less than 100%). The minimum environmental temperature under the condition (1) is set to −40 ° C. assuming an aircraft cargo compartment. In order to prevent condensation at the minimum ambient temperature of −40 ° C., the equilibrium humidity at 25 ° C. is calculated to be 0.6% or less. Only a limited desiccant such as zeolite meets this condition.

  FIG. 6 shows a case in which a square box-shaped casing made of aluminum is actually manufactured, and a zeolite is incorporated in the casing as a humidity sensor and a desiccant, and is sealed with an adhesive and an O-ring. It represents the experimental results subjected to a temperature cycle of ° C. In addition, as the adhesive, an epoxy adhesive excellent in vacuum sealing performance named Tall Seal was used. Toll seal is a two-part epoxy adhesive with reduced organic components. FIG. 6 also shows the results of a temperature cycle in which a desiccant is not added to the housing and only the humidity sensor is built in.

  As can be seen from FIG. 6, when the desiccant was built in, the humidity was almost 0% and no dew condensation occurred. On the other hand, when no desiccant was added, the relative humidity inside the housing changed in inverse proportion to the temperature, and the relative humidity at −40 ° C. reached about 85%. This is because the display has reached its limit due to the limit of the performance of the sensor, and it is considered that dew condensation exceeds 100% according to the calculation. That is, it was found that if zeolite is incorporated as a desiccant that satisfies the condition (1), dew condensation can be suppressed even in a low temperature environment of −40 ° C.

  Further, this semiconductor laser module preferably incorporates a humidity sensor 40 as a humidity sensing member for sensing the humidity in the housing 20. If the zeolite as the desiccant 30 is functioning effectively, the condition of (1) should be satisfied, but if any problem occurs such as an increase in humidity in the module by providing the humidity sensing member This is because it can be detected and a warning or the like can be issued if necessary, and an appropriate measure such as removing the desiccant 30 together with the upper lid 22 from the main body 21 and replacing it with a new desiccant 30 becomes possible. As the humidity sensing member, for example, in addition to the humidity sensor 40, a portion for displaying the humidity due to a color change or the like is added to the window 21B, or a tablet whose color changes depending on the humidity is arranged in the main body 21, and the color of the tablet is changed. You may enable it to observe from the window 21B.

  The condition (2) is for the desiccant 30 to continue to function effectively until the expected lifetime (service life) of the semiconductor laser module. For example, zeolites fail when they absorb about 20% of their mass by weight. Therefore, the relational expression (mass of zeolite × 0.2)> (moisture permeability rate of housing 20 × service life) needs to be satisfied. Since the mass and the service life of the desiccant 30 are limited by product design and customer requirements, in order to establish this relational expression, the moisture transmission rate of the casing 20 (the moisture permeation into the casing 20) It is necessary to take measures against moisture permeation of the housing 20 so as to make the intrusion speed as small as possible.

  Specifically, it is preferable that the casing 20 has the following measures for moisture permeability.

  First, the connector portion 25 is preferably formed integrally with the main body 21. The connector portion 25 is a large point that affects the moisture transmission speed of the housing 20, and the connector portion 25 is formed integrally with the main body 21 to eliminate the joint, thereby minimizing the moisture intrusion route to the housing 20. This is because it can be limited. For example, the connector portion 25 is formed in a cylindrical shape integrally with the main body 21 around an opening 21 </ b> D provided on a side surface (for example, the back surface) of the main body 21. A plurality of pins 26 are passed through the opening 21 </ b> D and filled with a sealant 27. Note that at least two pins 26 are provided and are electrically connected to the heat sink 11 and the electrode member 16, which are a pair of electrodes of the semiconductor laser 10, respectively. In the case where a humidity sensor, a light output sensor of the semiconductor laser 10 or the like is provided in the housing 20, pins for supplying power may be added.

  The sealant 27 for sealing the opening 21D and the sealant (not shown) between the main body 21 and the window 21B are made of a highly airtight material mainly composed of epoxy such as an epoxy adhesive. Is preferred. This is because moisture can be prevented from entering.

  Thus, when the connector part 25 is formed integrally with the main body 21, the moisture intrusion path to the housing 20 is (i) the O-ring 23 of the upper lid 22, (ii) between the main body 21 and the window 21B. And (iii) There are only three locations of the opening 21D of the connector portion 25. Therefore, if (ii) the main body 21 and the window 21B and (iii) the opening 21D of the connector portion 25 is sealed with a highly airtight material mainly composed of epoxy, (i) the O-ring 23 The moisture permeation rate is a factor that regulates the moisture permeation rate of the housing 20, and the performance of the O-ring 23 itself appears as the moisture permeation rate of the housing 20.

Specifically, the moisture permeation rate of the housing 20 measured under the conditions of a temperature of 85 ° C. and a humidity of 85% is preferably 1.0 × 10 ⁻⁴ (g / hour) or less. If it is within this range, it can be considered that the moisture transmission rate of the O-ring 23 determines the rate of moisture penetration into the housing 20, and it can be said that there is no other large moisture penetration path. In addition, when the average moisture transmission rate of the O-ring 23 was examined by experiment, it was 5.5 × 10 ⁻⁵ (g / hour). Therefore, the moisture transmission rate of the housing 20 under the condition (2) is Similarly to this, it can be set to 5.5 × 10 ⁻⁵ (g / hour), for example.

  Further, the O-ring 23 has curved portions 23A corresponding to the four corners of the opening 21A, and the radius of curvature of the curved portion 23A is preferably R10 or more. This is because moisture intrusion from the curved portions 23A at the four corners of the O-ring 23 can be reduced.

  Table 1 shows a case 20 in which the connector part 25 is integrated with the main body 21 and the opening 21D is sealed with a filler 27, and is actually produced in a high-temperature and high-humidity environment (a constant temperature bath at a temperature of 85 ° C. and a humidity of 85%). 3 shows the result of measuring the humidity increase in the housing 20 and calculating the moisture transmission rate of the housing 20.

  For comparison, a separate housing is connected to a main body made of aluminum, and a housing having a conventional structure in which a gap between both is sealed with an O-ring is manufactured. The moisture transmission rate was calculated in the same manner as the body 20. The results are also shown in Table 1.

  Table 2 shows the result of calculating the moisture transmission rate of the O-ring 23 in the same manner as the case 20 of the present embodiment described above. The specification of the O-ring 23 was EPDM (ethylene propylene diene monomer), hardness 70, and the calculation was performed for two cases where the radius of curvature of the curved portion 23A was R3.75 and R10.

  As can be seen from Tables 1 and 2, the moisture permeation rate of the case 20 of the present embodiment is about one-third that of the case of the conventional structure, and the minimum moisture permeation rate of the O-ring 23 alone. It was equivalent to the value (in the case of R10).

  Further, the moisture transmission rate of the O-ring 23 was improved by about 40% when the radius of curvature of the curved portion 23A was R10, compared to when R3.75 was used.

Using the moisture permeation rate (3.68 × 10 ⁻⁵ (g / hour)) of the housing 20 obtained in Table 1, assuming that the mass of the zeolite as the desiccant 30 is 1 g, the lifetime of this semiconductor laser module is calculated. It takes about one year in an environment of 85 ° C and 85%. When converted to an environment of 25 ° C. and 50%, it is considered that this corresponds to about 26 times acceleration from the comparison of the amount of water contained in the air, so that a lifetime of 10 years or more can be obtained even if a margin is taken into account. That is, it can hold a state of no condensation even at −40 ° C. for 10 years. Here, since the usage time of 10 years is considered to be an acceptable level as a product, it is appropriate that the useful life in the condition (2) is 10 years.

  FIG. 7 explains the condition (3) described above. The condition (3) relates to the relationship between the moisture absorption rate of the desiccant 30 and the moisture permeation rate of the housing 20, and between them, (the moisture absorption rate (Vd1) of the desiccant 30 >> (housing 20 As shown in Fig. 7, (the moisture absorption rate (Vd2) of the desiccant 30) <(the moisture transmission rate (Vm) of the casing 20). If this is the case, the humidity inside the housing 20 will gradually increase, resulting in a situation where condensation can occur at low temperatures, where the moisture absorption rate of the desiccant 30 is proportional to the surface area of the desiccant 30. It is conceivable that after reaching the equilibrium state after gradually decreasing from the initial state, the surface area is correlated with the mass if the shape is the same, so that the desiccant 30 needs a certain amount of mass, and its moisture absorption rate is the moisture permeability of the housing 20. Must exceed the speed.

  FIG. 8 shows the results of a moisture permeability test (85 ° C. and 85% environment) of the housing 20 with the mass of the zeolite as the desiccant 30 being 1.11 g and 0.14 g. As can be seen from FIG. 8, the humidity hardly increased when the mass of the zeolite was 1.11 g, whereas the maximum of 0.14 g of zeolite was obtained when the mass of the zeolite was 0.14 g. The increase in humidity occurred in a very short time (after about 12 hours) than the life calculated from the amount of moisture absorption. This is probably because the mass of the zeolite is sufficient, but the moisture absorption rate is smaller than the moisture transmission rate of the housing 20 because the surface area is small. That is, it was found that if the condition (3) that the moisture absorption rate of the desiccant exceeds the moisture transmission rate of the housing 20 is satisfied, an increase in humidity in the housing 20 can be suppressed.

From the above, it is preferable that the desiccant 30 satisfies the following conditions.
(1) Hygroscopicity (equilibrium humidity) @Type of desiccant 30 <100% @-40°C=0.6%@25°C ∝ Minimum environmental temperature (2) Maximum moisture absorption amount ∝ Mass of desiccant 30 (W)> (Moisture permeation rate of housing 20 x service life)
(3) Moisture absorption rate (Vd) 表面積 surface area of desiccant 30 x moisture content in air> moisture permeability rate of housing 20 (Vm)

Moreover, the required amount W of the desiccant 30 of (2) can be calculated | required by a following formula.
W = {R · A · t · (Henv−Hm)} / {(C2−C1) × 10 ⁻² } ≈ (R · A · t · Henv) /0.2
(W is the required amount (g) of the desiccant 30; R is the moisture transmission rate (g / m ² · h) of the housing 20; A is the cross-sectional area (m ² ) of the moisture intrusion path; Period (h), Henv is the average humidity (%) of the outside air, Hm is the average humidity (%) inside the case 20, C1 is the moisture absorption rate (%) of the desiccant 30 at the start of use, and C2 is the inside of the case 20 Representing the equilibrium moisture absorption rate (%) of the desiccant at the maximum relative humidity of (R∝Tenv, Henv, Hm≈0%, C1 = 0%, C2 = 20%)

  This semiconductor laser module can be manufactured, for example, as follows.

  First, the main body 21 made of the above-described material and integrally formed with the connector portion 25 and the upper lid 22 having the desiccant accommodating portion 22A are formed. Next, the semiconductor laser 10 is accommodated in the main body 21 and the pins 26 and the like are electrically connected. Further, the desiccant 30 is accommodated in the desiccant accommodating portion 22 </ b> A of the upper lid 22. Subsequently, an O-ring 23 is disposed between the main body 21 and the upper lid 22, and the opening 21 </ b> A of the main body 21 is covered with the upper lid 22 and sealed with the O-ring 23. Thus, the semiconductor laser module shown in FIGS. 2 and 3 is completed.

  In this semiconductor laser module, light is generated in the semiconductor laser 10, and this light is emitted to the outside from the window 21 </ b> B on the front surface of the main body 21. Here, the upper lid 22 provided with the desiccant accommodating portion 22A and the main body 21 are sealed with the O-ring 23 interposed therebetween, and the desiccant 30 is accommodated in the desiccant accommodating portion 22A of the upper lid 22, When the humidity inside the module rises, the desiccant 30 is removed from the main body together with the upper lid 22 and can be easily replaced.

  As described above, in the present embodiment, the upper lid 22 provided with the desiccant accommodating portion 22A and the main body 21 are sealed with the O-ring 23 interposed therebetween, and the desiccant 30 is accommodated in the desiccant accommodating portion 22A of the upper lid 22. Therefore, the desiccant 30 can be removed from the main body 21 together with the upper lid 22 and easily replaced.

  In the above embodiment, the case where the connector portion 25 is formed integrally with the main body 21 has been described. However, the housing 20 itself can be configured as an electrode of the semiconductor laser 10 and the connector portion can be eliminated. . That is, as shown in FIG. 9, by providing the insulating plate 28 and the O-ring 23 between the main body 21 and the upper lid 22, the main body 21 and the upper lid 22 are electrically insulated, and the main body 21 is heat sink. 11, the upper lid 22 may be electrically connected to the electrode member 16 via the conductor 16D.

  While the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment, and various modifications can be made. For example, the material and thickness of each layer, the film formation method, and the film formation conditions described in the above embodiment are not limited, and other materials and thicknesses may be used. It is good also as conditions.

  For example, in the above-described embodiment, the configuration of the semiconductor laser module has been specifically described. However, it is not necessary to include all the components, and other components may be further included. For example, the O-ring 23 may not be provided, and the main body 21 and the upper lid 22 may be bonded and sealed with an epoxy resin. By doing so, it is possible to reduce the moisture intrusion path into the housing 20 to improve the sealing performance and further reduce the moisture transmission rate of the housing 20.

  Furthermore, in order to prevent the irreversible failure such as the end face discoloration due to the condensation described above, the desiccant 30 only needs to be provided in the housing 20 such as the bottom surface of the main body 21 as shown in FIG. However, it is not always necessary to be provided in the desiccant accommodating portion 22A of the upper lid 22. However, the upper lid 22 is provided with a desiccant accommodating portion 22A, and the desiccant 30 is accommodated therein so that the upper lid 22 and the desiccant 30 can be replaced with each other, thereby facilitating maintenance and preventing condensation. Can be made.

  In addition, although the semiconductor laser has been described as an example in the above embodiment, the present invention can be applied to other semiconductor light emitting elements such as a superluminescent diode in addition to the semiconductor laser.

It is sectional drawing showing the structure of the semiconductor laser used in the experiment which investigated the influence of the dew condensation with respect to a semiconductor laser. It is sectional drawing showing the structure of the semiconductor laser module which concerns on one embodiment of this invention. It is a top view showing the state which removed the upper cover of the semiconductor laser module shown in FIG. FIG. 3 is a perspective view illustrating a configuration of the semiconductor laser illustrated in FIG. 2. FIG. 3 is a plan view and a cross-sectional view illustrating a configuration of an upper lid illustrated in FIG. 2. It is a figure showing the result of having investigated the difference in the humidity change in a housing | casing by the presence or absence of a desiccant. It is a figure for demonstrating the relationship between the moisture absorption speed of a desiccant, and the moisture transmission speed of a housing | casing. It is a figure showing the result of having investigated the difference in the humidity change in a housing | casing by changing the mass of a desiccant. FIG. 6 is a cross-sectional view illustrating a modification of the semiconductor laser module illustrated in FIG. 2. FIG. 10 is a cross-sectional view illustrating another modification of the semiconductor laser module illustrated in FIG. 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Semiconductor laser, 11 ... Heat sink, 12 ... Submount, 13 ... Semiconductor laser array, 14, 15 ... Solder layer, 16 ... Electrode member, 17 ... Insulating plate, 18 ... Wire, 19 ... Protection member, 20 ... Housing 21 ... Main body, 21A ... Opening, 21B ... Window, 22 ... Upper lid, 22A ... Desiccant container, 23 ... O-ring, 24 ... Screw, 25 ... Connector part, 26 ... Pin, 27 ... Sealant, 28 ... Insulating plate, 30 ... desiccant

Claims (11)

A semiconductor laser;
A main body that contains the semiconductor laser and has an opening on the upper surface, an upper lid that covers the opening and is provided with a desiccant containing portion, and is made of an elastic material and has a cavity therein, and the main body and the upper lid A housing having an elastic ring-shaped sealing member provided between
A semiconductor laser module comprising: a desiccant accommodated in a desiccant accommodating portion of the upper lid. The semiconductor laser module according to claim 1, wherein the desiccant accommodating portion is a recess provided on an inner surface of the upper lid. 3. The semiconductor according to claim 1, wherein a moisture permeation rate of the housing measured under conditions of a temperature of 85 ° C. and a humidity of 85% is 1.0 × 10 ⁻⁴ (g / hour) or less. Laser module. The semiconductor laser module according to claim 3, further comprising a connector portion for supplying power to the semiconductor laser, wherein the connector portion is formed integrally with the main body. The semiconductor laser module according to claim 4, wherein the connector portion is sealed with an epoxy adhesive. The said main body has a window which emits the light which generate | occur | produced with the said semiconductor laser to the exterior on the side surface, The said main body and the said window are sealed with the epoxy adhesive agent. The semiconductor laser module according to claim 5. The opening of the main body is rectangular, the elastic ring-shaped sealing member has curved portions corresponding to the four corners of the opening, and the radius of curvature of the curved portion is R10 or more. The semiconductor laser module according to claim 6. By providing the insulating plate and the elastic ring type sealing member between the main body and the upper cover, the main body and the upper cover are electrically insulated, and the main body and the upper cover are each a pair of the semiconductor laser. The semiconductor laser module according to claim 1, wherein the semiconductor laser module is electrically connected to the electrode. The semiconductor laser module according to any one of claims 1 to 8, further comprising a humidity sensing member that senses humidity in the housing. A body containing the semiconductor laser and having an opening on the top surface;
An upper lid covering the opening and provided with a desiccant container;
A casing comprising an elastic material and having a cavity inside, and an elastic ring-shaped sealing member provided between the main body and the upper lid. A semiconductor laser;
A main body that houses the semiconductor laser and has an opening on the upper surface, and a housing having an upper lid that covers the opening;
A semiconductor laser module comprising: a desiccant provided in the housing.

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