JP2006278361A - Semiconductor light-emitting device module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device module that is capable of accurate fixed output by temperature compensation due to appropriate feedback control, can be miniaturized, and can be made inexpensive. <P>SOLUTION: In a module 1, a semiconductor laser element 21 is mounted on an element mounting section 231 of a metal stem 23 via a submount 22. The stem 23 is pressed into a hole 40H in a heat sink 40 made of metal, and the heat sink 40 and the stem 23 are in contact in the hole 40H. The heat sink 40 opposes a circuit board 10 and is in contact with it. A thermistor is assembled onto the circuit board 10. A control circuit for controlling the output of the laser element 21 comprises a constant-current supply section for supplying a constant current to the laser element 21, and a compensation current supply section that has the thermistor and supplies a compensation current that is varied based on the detection temperature by the thermistor to the laser element 21. The total current of the constant current and the compensation current are supplied to the laser element 21. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor light emitting device module used in, for example, a lighting device, and more particularly to a temperature compensation technique for light output.

  In general, in a semiconductor light emitting device such as a light emitting diode or a semiconductor laser, the temperature increases as the light output increases, and the decrease in the light output due to the temperature increase increases. In particular, in the case of a semiconductor laser, since there is a threshold current, the light output fluctuation due to temperature is large, and in some cases, the light does not turn on.

  For this reason, there is a conventional technique in which a part of the radiated light is received by a light receiving element, the light output is monitored and the drive current is changed to make the light output constant (first conventional technique).

  A configuration in which a light emitting circuit 100 shown in FIG. 11 is provided in a semiconductor laser device is disclosed in Patent Document 1 (second prior art). According to the second prior art, a thermistor 158 having a negative temperature resistance coefficient is provided in series with the semiconductor laser (light emitting portion) 101a, and the drive current is changed by the resistance change of the thermistor 158.

  In Patent Document 2, an operational amplifier in which a thermistor is connected to an input and a transistor base is connected to an output is used, and the current value of the semiconductor laser is changed by changing the base voltage of the transistor with a temperature change of the thermistor. A technique is disclosed (third prior art).

Japanese Patent Laid-Open No. 3-145171 JP-A-8-316560

  The first prior art described above requires an optical component or the like for monitoring a part of the emitted light from the light emitting element, and therefore there is a problem that it is difficult to promote downsizing and cost reduction.

  Further, in the second and third prior arts mentioned above, there is no mention of where the thermistor is specifically arranged. However, according to a general method, the thermistor is a device on which a circuit board for driving is placed. It is considered that the temperature of the inside atmosphere is detected and temperature compensation is performed based on the detection result.

  If the drive current is changed by detecting the ambient temperature in the apparatus, it is difficult to control the light output to be constant because appropriate feedback is not given to the temperature change of the light emitting element itself. That is, according to the light output control based on such an ambient temperature, the light emitting element is provided with a heat dissipation device having a very large heat capacity and high heat dissipation, and there is no heat source other than the light emitting element, and the atmosphere Exact light output control is not possible unless the temperature is proportional to the temperature of the light emitting element.

  In addition, when the thermistor 158 is inserted in series in the path through which the drive current of the light emitting element flows as in the second prior art (see FIG. 11), the drive current flows through the thermistor 158 and the thermistor itself becomes a heat source. For this reason, the light output control becomes more difficult.

  Note that it can be said that not only the thermistor detects the ambient temperature but also the method of detecting the temperature change of the light emitting element indirectly by detecting the temperature of another heat source has the same problem as described above.

  The present invention has been made in view of such problems, and a semiconductor light-emitting device module that is capable of temperature compensation through appropriate feedback control, enables accurate constant output, and can be reduced in size and price. The purpose is to provide.

  In order to achieve the above object, the present invention provides a semiconductor light emitting device module, a semiconductor light emitting device including a circuit board, a semiconductor light emitting element thermally connected to the circuit board, and a thermal connection to the circuit board. And a control circuit that controls the output of the semiconductor light emitting element based on the temperature detected by the temperature detector.

  According to such a configuration, since the heat generated in the semiconductor light emitting element is transmitted to the temperature detector via the circuit board, the temperature (change) detected by the temperature detector is the temperature (change) of the semiconductor light emitting element. Almost equal. For this reason, the control circuit controls the output of the light emitting element based on the temperature of the semiconductor light emitting element. Therefore, as compared with the configuration in which the output is controlled by detecting the ambient temperature or the temperature of another heat source related to the heat generation of the semiconductor light emitting element, it is possible to perform appropriate feedback control, and as a result, accurate constant output is possible. Furthermore, compared to the configuration in which the output light from the semiconductor light emitting element is monitored and the output is made constant, there is no need to provide an optical component for such monitoring, so the semiconductor light emitting device module according to the invention has a simple configuration. As a result, downsizing and cost reduction can be achieved. In general, a semiconductor light emitting device (semiconductor light emitting element) requires attention to heat dissipation, surge current, etc., but according to a semiconductor light emitting device module, the semiconductor light emitting device (semiconductor light emitting element) and a control circuit are modularized. It is easy to handle.

  In addition, it is preferable that a heat conductive component having a higher thermal conductivity than the circuit board is further provided, and the semiconductor light emitting element is thermally connected to the circuit board through the heat conductive component.

  According to such an invention, heat generated in the semiconductor light emitting device is transmitted to the circuit board via the heat conducting component. In particular, since the heat conductivity of the heat conducting component is higher than that of the circuit board, heat spreads more quickly in the heat conducting component than in the circuit board. For this reason, heat can be quickly transmitted to the entire circuit board, and heat can be reliably transmitted from the semiconductor light emitting element to the temperature detector. In addition, since heat spreads in the heat conduction component, the degree of freedom in the arrangement position of the temperature detector is higher than a configuration in which heat is spread in the circuit board without using the heat conduction component. In addition, since heat spreads quickly in the heat conduction component, the time lag of temperature detection depending on the heat conduction and the position of the temperature detector can be reduced, and a constant output can be stably obtained.

  The semiconductor light emitting device preferably further includes a metal stem on which the semiconductor light emitting element is mounted and press-fitted into the heat conducting component.

  According to such a configuration, the stem on which the semiconductor light emitting element is mounted is made of metal, and the stem is press-fitted into the heat conducting component (that is, the stem is in contact with the heat conducting component). Heat generated in the semiconductor light emitting element is quickly and reliably transmitted to the heat conducting component via the metal stem. As a result, heat generated in the semiconductor light emitting element can be transmitted to the temperature detector quickly and reliably.

  Further, the control circuit includes a constant current supply unit that supplies a constant current to the semiconductor light emitting element and the temperature detector, and supplies a compensation current that varies based on the detected temperature to the semiconductor light emitting element. And a compensation current supply unit, wherein a total current of the constant current and the compensation current is preferably supplied to the semiconductor light emitting element.

  According to such a configuration, since the current flowing through the temperature detector is smaller than the current flowing through the semiconductor light emitting element (the total current of the constant current and the compensation current), the current flowing through the temperature detector and the current flowing through the semiconductor light emitting element Compared with a configuration in which the temperature detector is the same, heat generation of the temperature detector itself can be suppressed. For this reason, the temperature of the semiconductor light emitting element can be detected more accurately, and therefore, a more accurate constant output can be achieved by appropriate feedback control.

  The temperature detector is preferably a negative thermistor whose resistance value decreases as the temperature rises. According to such a configuration, the heat generation of the semiconductor light emitting element is transmitted to the thermistor via the circuit board. Therefore, when the temperature of the semiconductor light emitting element rises, the temperature of the thermistor rises, and as a result, the resistance of the thermistor decreases. By utilizing such characteristics, the compensation current supply unit having the thermistor can know the temperature of the semiconductor light emitting element and can generate a compensation current.

  The temperature detector is preferably assembled on the circuit board. According to such a configuration, when the temperature detector is arranged at a location different from the circuit board, a wiring member that connects the necessary temperature detector and the circuit pattern on the circuit board is not necessary. Therefore, it is possible to reduce the size and price of the semiconductor light emitting device module.

  Moreover, it is preferable to further include a heat conductive agent filled between the temperature detector and the circuit board. According to such a configuration, heat transfer between the temperature detector and the circuit board can be more reliably performed.

  The circuit board includes a first surface facing the heat conducting component, and the heat conducting component includes a second surface facing the circuit board, and the first surface. It is preferable that the circuit board and the heat conducting component are arranged so that the entire surface of the second surface and the second surface face each other. According to such a configuration, a sufficient heat transfer area can be secured for heat transfer from the heat conducting component to the circuit board, and at the same time, the semiconductor light emitting device module can be downsized.

  Further, it is preferable that the temperature detector is disposed so as to overlap an area where the semiconductor light emitting device is projected onto the circuit board. According to such a configuration, since the semiconductor light emitting element and the temperature detector are arranged close to each other, the heat generated by the semiconductor light emitting element can be transmitted to the temperature detector more quickly, and more of the generated heat can be detected by the temperature. Can be transmitted to the vessel. Furthermore, the influence (airflow, heat irradiation, etc.) received from the outside can be made the same between the semiconductor light emitting element and the temperature detector by such close arrangement. As a result, constant output can be achieved more accurately and stably.

  According to the present invention, it is possible to obtain a semiconductor light-emitting device module that can be compensated for temperature by appropriate feedback control, can perform accurate constant output, and can be reduced in size and price.

  1 and 2 are a perspective view and a plan view of a semiconductor laser device module 1 which is an embodiment of a semiconductor light emitting device module according to the present invention. FIG. 3 shows a perspective view of a semiconductor laser device 20 as a semiconductor light emitting device, which the semiconductor laser device module 1 has. Further, FIG. 4 shows a cross-sectional view of the semiconductor laser device module 1.

  As shown in FIGS. 1 and 2, the semiconductor laser device module 1 includes a circuit board 10, various components (semiconductor laser apparatus 20 and the like) mounted on the circuit board 10, and a heat sink 40 (as described below, the present invention). It also serves as a heat conduction component according to

  The circuit board 10 is formed by forming a predetermined circuit pattern (or wiring pattern) on an insulating substrate such as glass epoxy resin, and is also called a printed board. In addition, in order to avoid complication of drawing, illustration of a circuit pattern is abbreviate | omitted. In the example of FIG. 1 and the like, the insulating substrate constituting the circuit board 10 is a plate-like member having main surfaces 10S and 10T having a substantially rectangular shape, and has a cut or notch in the center of both short sides of the plate-like member. is doing.

  As shown in FIGS. 1, 2, and 4, the semiconductor laser device 20 is mounted on one main surface 10 </ b> S of the circuit board 10, and the variable resistor 311 and the other main surface 10 </ b> T of the circuit board 10 are mounted. A thermistor 321 as a temperature detector for detecting the temperature of the semiconductor laser element 21, a resistor 322, a PNP transistor 323, a driver IC (Integrated Circuit) 38, and a connector 39 are mounted ( Assembled). In particular, the thermistor 321 is a negative element whose resistance value decreases as the temperature increases (see FIG. 7 described later), and is assembled close to the circuit board 10. The circuit board 10 has a hole penetrating in the thickness direction, and the lead terminal 25 of the semiconductor laser device 20 is inserted into the hole. The lead terminal 25 has a circuit pattern on the main surface 10T side. Electrically connected. The circuit configuration of the semiconductor laser device 20 and the like will be described later.

  Here, the semiconductor laser device 20 will be described with reference to FIGS. 3 and 4. The semiconductor laser device 20 includes a semiconductor laser element (or semiconductor laser chip) 21 as a semiconductor light emitting element according to the present invention, a submount 22, a stem 23, a cap 24, and a lead terminal 25.

  First, the stem 23 is made of, for example, metal, and is roughly divided into a base portion 230 and an element mounting portion (or chip mounting portion) 231 that is a portion protruding from the base portion 230. In the example of FIGS. 3 and 4, the base portion 230 is made of a disk-like member (a plate-like member having a substantially circular main surface), and has a notch or a notch at the periphery. Note that the peripheral portion of the base portion 230 is referred to as the collar portion 232. A submount 22 is disposed on the element mounting portion 231 of the stem 23, and the semiconductor laser element 21 as a light emitting source is disposed on the submount 22 (die-bonded). That is, the semiconductor laser element 21 is mounted on the element mounting portion 231 of the stem 23 via the submount 22. Here, the submount 22 is made of a high heat conductive material, for example, a ceramic such as silicon carbide (SiC). Note that the semiconductor laser element 21 may be directly mounted (die-bonded) on the element mounting portion 231 without providing the submount 22.

  A cap 24 is put on the element mounting portion 231 on which the semiconductor laser element 21 is mounted, and the cap 24 is coupled to the base portion 230 of the stem 23. The cap 24 is made of, for example, a metal member (in the example of FIG. 3, has a cylindrical shape), and the semiconductor laser element 21 is accommodated in the cap 24. The cap 24 is provided with a window portion 241, and output light from the semiconductor laser element 21 is emitted through the window portion 241.

  Lead terminals 25 are provided to electrically connect the semiconductor laser element 21 in the cap 24 to an external circuit. One end of the lead terminal 25 is electrically connected to the semiconductor laser element 21 in the cap 24 by, for example, a metal wire (not shown), and the other end of the lead terminal 25 is outside the cap 24 via the base portion 230 of the stem 23. Has been pulled out. As described above, the lead terminal 25 is inserted into the hole of the circuit board 10 and the other end of the lead terminal 25 is electrically connected to the circuit pattern formed on the main surface 10T side of the circuit board 10. (See FIG. 4).

  The heat radiating plate 40 is made of, for example, a plate-like member made of metal such as aluminum or copper, and the heat radiating plate 40 includes a main surface (first surface) 10S of the circuit board 10 and the heat radiating plate 40 as shown in FIGS. One main surface (second surface) 40S is disposed so as to face and contact. In detail, the outline or outer peripheral shape of the main surface 40S of the heat sink 40 is substantially equal to that of the main surface 10S of the circuit board 10 (and is therefore generally rectangular), and the heat sink 40 and the circuit board 10 are rectangular. It arrange | positions so that long sides may adjoin or overlap, and short sides adjoin or overlap. That is, the heat sink 40 and the circuit board 10 are arranged so that the entire main surface 40S and the entire main surface 10S face each other. The heat sink 40 has the same notch or notch at the same position as the circuit board 10.

  As shown in FIGS. 1 and 4, the heat sink 40 has a hole 40 </ b> H penetrating in the thickness direction of the heat sink 40 at a position corresponding to the semiconductor laser device 20 on the circuit board 10. The semiconductor laser device 20 is disposed in 40H. At this time, the flange portion 232 of the stem 23 of the semiconductor laser device 20 is press-fitted into the hole 40H (pressed under pressure), and the heat sink 40 and the flange portion 232 of the stem 23 are in the hole 40H. In contact. In the example of FIGS. 1 and 4, the hole 40 </ b> H has substantially the same circular shape as the outline or outer periphery of the base portion 230 of the stem 23 in plan view.

  In the semiconductor laser device module 1, heat generated by the semiconductor laser element 21 is transmitted to the thermistor 321 as follows. First, since the submount 22 (see FIG. 4) is made of, for example, ceramic, which is a highly heat conductive material, the heat generated in the semiconductor laser element 21 is quickly and reliably transmitted to the stem 23 via the submant 22. Furthermore, since the stem 23 is made of, for example, metal, the transmitted heat is quickly and reliably transmitted to the entire stem 23. Since the stem 23 is press-fitted into the hole 40H of the heat radiating plate 40 (therefore, the heat radiating plate 40 and the stem 23 are in contact with each other in the hole 40H). Heat is transmitted. Further, since the heat radiating plate 40 is made of, for example, metal, the transmitted heat spreads quickly throughout the heat radiating plate 40. Furthermore, since the heat sink 40 faces the circuit board 10, heat is transferred from the heat sink 40 to the circuit board 10 (the resin board). From this point, it can be said that the heat radiating plate 40 also works as a heat conducting component. Then, heat is transmitted to the thermistor 321 assembled on the circuit board 10 in the vicinity of the circuit board 10.

  Thus, in the semiconductor laser device module 1, the semiconductor laser element 21, the submount 22, the stem 23, the heat sink 40, the circuit board 10 and the thermistor 321 are sequentially thermally connected to form a heat transfer path. As a result, the heat generated by the semiconductor laser element 21 is quickly and reliably transmitted to the thermistor 321 on the circuit board 321.

  Here, the “thermally connected” form means a form arranged so as to be able to conduct heat, not only a form in which the members are in contact with each other, but also a gap between the members as long as heat conduction is possible. The form in which the member is interposed is also included. At this time, the semiconductor laser element 21 is thermally connected to the circuit board 10 via the submount 22, the stem 23, and the heat sink 40 (as will be described later, between the main body of the thermistor 321 and the circuit board 10. It can be said that the thermistor 321 is thermally connected to the circuit board 10.

  Next, FIG. 5 shows a circuit diagram of the control circuit 30 of the semiconductor laser device module 1. The control circuit 30 includes the above-described semiconductor laser element 21, variable resistor 311, thermistor 321, resistor 322, and PNP transistor 323, and is connected to the drive power supply 33. The drive power supply 33 is connected through, for example, a connector 39 (see FIG. 2). The semiconductor laser element 21 is also connected to the driver IC 38 (see FIG. 2), but is omitted from the circuit diagram of FIG.

  As shown in FIG. 5, the anode of the semiconductor laser element 21 is connected to the high potential side output of the drive power supply 33 via the variable resistor 311, and the cathode of the semiconductor laser element 21 is connected to the low output of the drive power supply 33. It is connected. The low-potential side output of the drive power supply 33 is grounded. The emitter of the transistor 323 is connected to the high potential side output of the drive power supply 33, and the collector of the transistor 323 is connected to the anode of the semiconductor laser element 21. A resistor 322 is connected between the emitter and base of the transistor 323, and the base is connected to the lower output of the drive power supply 33 via the thermistor 321.

  Here, FIGS. 6 and 7 show temperature characteristics of the optical output and drive current of the semiconductor laser element 21. FIG. FIG. 7 also shows the temperature characteristics of the resistance value of the thermistor 321. 6 and 7 is not the ambient temperature, but the temperature of the semiconductor laser element 21 and the thermistor 321 (more specifically, the case temperature). As shown in FIG. 6, the semiconductor laser element 21 (including a general semiconductor laser element) decreases in light output as the temperature rises when there is no temperature compensation, and the temperature rises as shown in FIG. As a result, the drive current value required to obtain a predetermined light output increases. Further, as shown in FIG. 7, the resistance value of the negative thermistor 321 decreases as the temperature rises. As described above, the driving current of the semiconductor laser element 21 and the resistance value of the thermistor 321 show the opposite tendency with respect to the temperature change.

  According to the control circuit 30 of FIG. 5, when the temperature of the semiconductor laser element 21 rises, the temperature is transmitted to the thermistor 321 via the circuit board 10 or the like, so that the temperature of the thermistor 321 also rises. As a result, the resistance value of the thermistor 321 decreases. As the resistance value of the thermistor 321 decreases, the base voltage of the transistor 323 decreases. In the PNP transistor 321, the current amount I2 to the collector increases when the base voltage decreases. That is, the temperature of the semiconductor laser element 21 is detected by the thermistor 321, and the current I2 varies based on the detected temperature.

  On the other hand, since the semiconductor laser element 21 and the variable resistor 311 are connected in series to the drive power supply 33, the current I1 flowing through the variable resistor 311 is constant after the variable resistor 311 is adjusted to a predetermined resistance value. It is.

  Therefore, according to the control circuit 30, the drive current I0 flowing through the semiconductor laser element 21 is a total (combined) current of the constant current I1 flowing through the variable resistor 311 and the current I2 flowing through the collector of the transistor 323. The drive current I0 varies by the amount. That is, when the temperature of the semiconductor laser element 21 increases, the current I2 increases, and the drive current I0 increases accordingly. As described above with reference to FIG. 7, the current required to keep the optical output constant increases as the temperature of the semiconductor laser element 21 increases. However, an increase in the required current value can be supplied by increasing the current I2. As a result, the light output can be kept substantially constant as shown in FIG. That is, temperature compensation is performed by the current I2.

  In the control circuit 30, the variable resistor 311 (or the configuration including the variable resistor 311 and the drive power supply 33) is referred to as a constant current supply unit 31, and the configuration including the thermistor 321, the resistor 322, and the PNP transistor 323 (or The configuration comprising these elements 321, 322, 323 and the drive power supply 33) is called the compensation current supply unit 32, and the current I2 is called the compensation current. At this time, since the compensation current supply unit 32 includes the negative thermistor 321, the temperature of the semiconductor laser element 21 can be known and the compensation current I2 can be generated.

  According to such a control circuit 30, the thermistor 321 is not connected in series with the semiconductor laser element 21, and the current flowing through the thermistor 321 is the current I 0 (= constant current I 1 + compensation current I 2) flowing through the semiconductor laser element 21. Smaller than. For this reason, compared with the structure (for example, 2nd prior art (refer FIG. 11)) which the thermistor and the semiconductor laser element are connected in series, and the electric current value which flows through both is the same, the heat_generation | fever of the thermistor 321 itself is suppressed. be able to. Therefore, the temperature of the semiconductor laser element 21 can be detected more accurately, and more accurate constant output can be achieved by appropriate feedback control.

  In particular, according to the semiconductor laser device module 1, as described above, the heat generated in the semiconductor laser element 21 is transmitted to the thermistor 311 via the submount 22, the stem 23, the heat sink 40, and the circuit board 10. The temperature (change) detected by 321 is substantially equal to the temperature (change) of the semiconductor laser element 21. For this reason, the control circuit 30 controls the output of the semiconductor laser element 21 based on the temperature of the semiconductor laser element 21. Therefore, it is possible to perform appropriate feedback control as compared with a configuration (for example, the second and third prior arts) in which the output is controlled by detecting the ambient temperature or the temperature of another heat source related to the heat generation of the semiconductor laser element. Accurate constant output is possible. That is, since the optical output of the semiconductor laser element 21 changes due to its own heat generation (see FIG. 6), a configuration that directly detects the temperature of the semiconductor laser element 21 like the semiconductor laser device module 1 is preferable.

  Furthermore, according to the semiconductor laser device module 1, compared with a configuration (for example, the first prior art) in which the output light from the semiconductor laser element is monitored to obtain a constant output, an optical component or the like for such monitoring is provided. Since it is not necessary to provide the semiconductor laser device module 1, the configuration of the semiconductor laser device module 1 is simple.

  In general, the semiconductor light emitting device (the semiconductor light emitting element thereof) requires attention to heat dissipation, surge current, and the like. However, according to the semiconductor light emitting device module 1, the semiconductor light emitting device 20 (the semiconductor light emitting element 21 thereof) and the control circuit 30 are provided. Since the heat sink 40 and the like are modularized, handling is easy.

  Further, since the heat radiating plate 40 is made of, for example, metal as described above, the heat radiating plate 40 has a thermal conductivity approximately 1000 times that of the insulating substrate made of, for example, glass epoxy resin that forms the circuit board 10. The heat generated in the semiconductor laser element 21 is transmitted to the circuit board 10 via the heat sink 40 that also functions as a heat conduction component. However, the heat transferred to the heat sink 40 spreads quickly in the heat sink 40, thereby causing the circuit. Since heat can be quickly transferred to the entire substrate 10, heat can be reliably transferred from the semiconductor laser element 21 to the thermistor 321 regardless of the position of the thermistor 321. At this time, the degree of freedom of the arrangement position of the thermistor 321 is higher than the configuration in which heat is spread in the circuit board 10 without using the heat sink 40. Moreover, since heat spreads quickly in the heat radiating plate 40, the time lag of temperature detection depending on the heat conduction and the arrangement position of the thermistor 321 can be reduced, and a constant output can be stably obtained. The same effect can be obtained even if the heat radiating plate 40 is made of another member having a higher thermal conductivity than the glass epoxy resin, such as ceramic.

  At this time, since the heat dissipation plate 40 has higher thermal conductivity than the circuit board 10 as described above, the heat transmitted to the heat dissipation plate 40 spreads over the entire surface of the heat dissipation plate 40, and the circuit board 10 is planarly (planar). Transmitted). In particular, since the main surface (first surface) 10S of the circuit board 10 and the main surface (second surface) 40S of the heat sink 40 are in contact with each other, the circuit from the heat sink 40 as a heat conducting component is used. A sufficient heat transfer area can be secured for heat transfer to the substrate 10. At the same time, the semiconductor laser device module 1 can be downsized. That is, the larger the heat sink plate 40 is, the more preferable in terms of heat dissipation and heat conduction, while the larger the circuit board 10 (the main surface 10S) becomes, the larger the entire module becomes. According to the semiconductor laser device module 1, these are reduced. It can be compatible.

  Further, since the thermistor 321 is assembled on the circuit board 10, that is, the thermistor 321 is incorporated in the control circuit 30 using the circuit pattern on the circuit board 10, the thermistor 321 is installed at a location different from the circuit board 10. A wiring member that connects the thermistor 321 and the circuit pattern of the circuit board 10 required when the thermistor 321 is disposed is not necessary. Therefore, the semiconductor light emitting device module 1 can be reduced in size and price.

  By the way, depending on the shape of the thermistor 321, a gap may be formed between the thermistor 321 and the circuit board 10, and the thermistor 321 may not be in close contact. In such a case, as shown in FIG. 8 which is a partially enlarged view of the semiconductor laser device module 1, a gap between the body portion of the thermistor 321 and the circuit board 10 is filled with a thermal conductive agent 50 such as grease. May be. Thereby, the heat transfer between the thermistor 321 and the circuit board 10 can be ensured.

  Further, the thermistor 321 may be arranged like a semiconductor laser device module 1B shown in FIG. 9 (plan view) and FIG. 10 (cross-sectional view). In the semiconductor laser device module 1B, the configuration other than the arrangement position of the thermistor 321 is the same as that of the semiconductor laser device module 1 described above.

  As shown in FIGS. 9 and 10, in the semiconductor laser device module 1 </ b> B, the whole thermistor 321 is arranged so as to overlap the region 20 </ b> A where the semiconductor laser device 20 is projected onto the circuit board 10. According to such an arrangement, since the semiconductor laser element 21 and the thermistor 321 are arranged close to each other, the heat generated by the semiconductor laser element 21 can be transmitted to the thermistor 321 more quickly, and more of the generated heat can be transferred to the thermistor. 321 can be transmitted. Further, due to such proximity arrangement, the influence (airflow, heat irradiation, etc.) received from the outside can be made the same between the semiconductor laser element 21 and the thermistor 321. As a result, constant output can be achieved more accurately and stably.

  At this time, a portion of the thermistor 321 may be disposed so as to overlap the region 20A. However, as shown in FIGS. 9 and 10, it is preferable that the thermistor 321 be disposed so that the entire thermistor 321 fits within the region 20A. The above effects can be obtained more remarkably. Also in the semiconductor laser device module 1B, the gap between the thermistor 321 main body and the circuit board 10 may be filled with a thermal conductive agent 50 (see FIG. 8) such as grease.

  Instead of the semiconductor laser element 21, a semiconductor light emitting device module can be configured by applying a semiconductor diode element as a semiconductor light emitting element. Further, instead of the thermistor 321, a semiconductor light emitting device module can be configured by applying a thermocouple as a temperature detector.

These are the perspective views of the semiconductor laser apparatus module which concerns on embodiment of this invention. These are the top views of the semiconductor laser apparatus module which concerns on embodiment of this invention. These are the perspective views of the semiconductor laser apparatus of the semiconductor laser apparatus module which concerns on embodiment of this invention. These are sectional views of a semiconductor laser device module according to an embodiment of the present invention. These are the circuit diagrams of the control circuit of the semiconductor laser apparatus module which concerns on embodiment of this invention. These are the figures for demonstrating the temperature characteristic of the optical output of the semiconductor laser apparatus in the semiconductor laser apparatus module which concerns on embodiment of this invention. These are the figures for demonstrating the temperature characteristic of the drive current of the semiconductor laser apparatus in the semiconductor laser apparatus module which concerns on embodiment of this invention. These are the elements on larger scale of the semiconductor laser apparatus module which concerns on embodiment of this invention. These are the top views of the other semiconductor laser apparatus module which concerns on embodiment of this invention. These are sectional drawings of other semiconductor laser device modules concerning an embodiment of the present invention. These are the figures of the light emission circuit of the conventional semiconductor laser apparatus.

Explanation of symbols

1,1B Semiconductor laser device module (semiconductor light emitting device module)
10 Circuit board 10S Main surface (first surface)
20 Semiconductor laser device (semiconductor light emitting device)
20A region 21 semiconductor laser element (semiconductor light emitting element)
23 Metal Stem 30 Control Circuit 31 Constant Current Supply Unit 32 Compensation Current Supply Unit 321 Thermistor (Temperature Detector)
40 Heat sink (heat conduction component)
40S main surface (second surface)
50 Thermal Conductive Agent I0 Total Current I1 Constant Current I2 Compensation Current

Claims (9)

A circuit board;
A semiconductor light emitting device including a semiconductor light emitting element thermally connected to the circuit board;
A semiconductor light emitting device module comprising: a temperature detector thermally connected to the circuit board; and a control circuit for controlling an output of the semiconductor light emitting element based on a temperature detected by the temperature detector. . A heat conductive component having a higher thermal conductivity than the circuit board;
The semiconductor light emitting device module according to claim 1, wherein the semiconductor light emitting element is thermally connected to the circuit board via the heat conducting component.   The semiconductor light emitting device module according to claim 2, wherein the semiconductor light emitting device further includes a metal stem on which the semiconductor light emitting element is mounted and press-fitted into the heat conducting component. The control circuit includes:
A constant current supply unit for supplying a constant current to the semiconductor light emitting element;
A compensation current supply unit that includes the temperature detector and supplies a compensation current that varies based on the detection temperature to the semiconductor light emitting element;
4. The semiconductor light emitting device module according to claim 1, wherein a total current of the constant current and the compensation current is supplied to the semiconductor light emitting element. 5.   5. The semiconductor light-emitting device module according to claim 4, wherein the temperature detector is a negative thermistor whose resistance value decreases as the temperature rises.   6. The semiconductor light emitting device module according to claim 1, wherein the temperature detector is assembled on the circuit board.   The semiconductor light emitting device module according to claim 6, further comprising a thermal conductive agent filled between the temperature detector and the circuit board. The circuit board includes a first surface facing the heat conducting component;
The thermally conductive component includes a second surface facing the circuit board;
8. The circuit board and the heat conducting component are arranged such that the first surface and the second surface face each other. 8. The semiconductor light-emitting device module as described.   9. The semiconductor light emitting device module according to claim 1, wherein the temperature detector is arranged so as to overlap an area where the semiconductor light emitting device is projected onto the circuit board. 10.

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