Optical semiconductor device

Abstract

An optical semiconductor device according to the present disclosure is provided with: a base having a first surface and a second surface on the opposite side from the first surface; a semiconductor laser provided on the first surface side of the base; a lead pin penetrating the base from the first surface to the second surface; and a heat dissipation block having a third surface and a fourth surface on the opposite side to the third surface, the third surface being in contact with the second surface of the base, the heat dissipation block having formed therein a groove that cuts a side surface connecting the third surface and the fourth surface and penetrates from the third surface to the fourth surface, an insulating film is provided on an inner surface of the heat dissipation block on which the groove is formed, and the lead pin is inserted into the groove of the heat dissipation block.

Description

Technical Field

[0001] The present disclosure relates to an optical semiconductor device. Background Art

[0002] Patent document 1 discloses a laser package, in which a laser is hermetically sealed in a package consisting of a package base and a cover. The laser is fixed to the package base. A plurality of wiring pins including a power supply wiring pin for supplying a driving current to the laser are led out from the package base. A heat dissipation component having a higher thermal conductivity than the package base is mounted on the bottom surface of the package base. The heat dissipation component has a single or multiple insertion holes for the wiring pins to be inserted through.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2007-27413

[0004] As optical components become more powerful and operate at higher speeds, the heat generated by semiconductor laser chips, driver IC chips, and chip cooling Peltier elements built into the package increases. If the temperature of the laser chip rises with the increase in heat, it may cause a decrease in light output, degradation of high-speed optical signals, and laser chip failure.

[0005] As a solution, a structure in which the heat sink is in contact with the side of the tube seat and the side of the lens cover can be considered. However, compared with a structure in which the heat sink is arranged on the back of the tube seat, this structure tends to make the heat dissipation path longer. In addition, it is difficult to expand the contact area between the heat sink and the tube seat, and the heat dissipation efficiency may be reduced. In Patent Document 1, the heat dissipation distance can be shortened by making the heat sink contact with the back of the tube seat. However, since the lead pins are passed through the insertion holes formed in the heat sink, there may be restrictions on the installation method or assembly sequence of the heat sink. In addition, the position and size of the insertion holes and the formation of the insulator covering the inside of the insertion holes may require high processing accuracy. Summary of the invention

[0006] An object of the present disclosure is to obtain an optical semiconductor device that can be easily manufactured.

[0007] The optical semiconductor device involved in the first disclosure comprises: a stem having a first surface and a second surface on the side opposite to the first surface; a semiconductor laser arranged on the first surface side of the stem; lead pins penetrating the stem from the first surface to the second surface; and a heat sink having a third surface and a fourth surface on the side opposite to the third surface, the third surface being in contact with the second surface of the stem, a groove is formed in the heat sink by cutting a side surface connecting the third surface and the fourth surface and penetrating from the third surface to the fourth surface, an insulating film is provided on the inner side surface of the heat sink forming the groove, and the lead pins are inserted into the groove of the heat sink.

[0008] The optical semiconductor device involved in the second disclosure comprises: a stem, having a first surface and a second surface on the side opposite to the first surface; a semiconductor laser arranged on the first surface side of the stem; a plurality of lead pins penetrating the stem from the first surface to the second surface; and a heat sink having a third surface and a fourth surface on the side opposite to the third surface, the third surface being in contact with the second surface of the stem, an insulating film being arranged on the side surface of the heat sink connecting the third surface and the fourth surface, and the heat sink extending from the center portion of the second surface of the stem through between the plurality of lead pins.

[0009] In the optical semiconductor device of the first disclosure, the heat sink block is formed with a groove which cuts the side surface connecting the third surface and the fourth surface and penetrates from the third surface to the fourth surface. The lead pin is inserted into the groove. Therefore, it is easy to attach the heat sink block to the stem, and the optical semiconductor device can be easily manufactured.

[0010] In the optical semiconductor device according to the second disclosure, the heat sink block extends from the center of the second surface of the stem through the plurality of lead pins. Therefore, there is no need to form insertion holes in the heat sink block, and the optical semiconductor device can be easily manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a cross-sectional view of the optical semiconductor device according to the first embodiment.

[0012] Figure 2 It is a cross-sectional view of the optical semiconductor device according to the first embodiment.

[0013] Figure 3 This is a cross-sectional view of an optical semiconductor device according to a first modification of the first embodiment.

[0014] Figure 4 This is a cross-sectional view of an optical semiconductor device according to a second modification of the first embodiment.

[0015] Figure 5 It is a cross-sectional view of the optical semiconductor device according to the second embodiment.

[0016] Figure 6 It is a cross-sectional view of the optical semiconductor device according to the second embodiment.

[0017] Figure 7 It is a cross-sectional view of an optical semiconductor device according to Embodiment 3.

[0018] Figure 8 It is a cross-sectional view of an optical semiconductor device according to Embodiment 3.

[0019] Fig. 9 It is a cross-sectional view of an optical semiconductor device according to a modification of the third embodiment.

[0020] Fig.10 It is a cross-sectional view of an optical semiconductor device according to a fourth embodiment.

[0021] Fig.11 This is a perspective view of a heat dissipation block according to the fourth embodiment.

[0022] Fig.12 It is a cross-sectional view of an optical semiconductor device according to the fifth embodiment.

[0023] Fig.13 This is a perspective view of a heat dissipation block according to the fifth embodiment. DETAILED DESCRIPTION

[0024] The optical semiconductor device according to each embodiment will be described with reference to the drawings. The same or corresponding components are denoted by the same reference numerals and repeated description may be omitted.

[0025] Implementation Method 1

[0026] Figure 1 , Figure 2 1 is a cross-sectional view of an optical semiconductor device 100 according to Embodiment 1. Hereinafter, a plane perpendicular to the light emitting direction 81 of the optical semiconductor device 100 is defined as an XY plane, and a direction parallel to the light emitting direction 81 is defined as a Z direction. The optical semiconductor device 100 includes a stem 10 having a first surface 11 and a second surface 12 on the opposite side of the first surface 11. A semiconductor laser 16 is provided on the first surface 11 side of the stem 10. Figure 1 It is a YZ cross-sectional view passing through the center of the tube base 10 . Figure 2 It is cut by straight line A-B Figure 1 The obtained XY cross section is a diagram viewed from the second surface 12 side of the stem 10 .

[0027] A plurality of lead pins 30 penetrate the stem 10 from the first surface 11 to the second surface 12. The stem 10 and the lead pins 30 are formed of a metal containing iron or the like. The stem 10 and the lead pins 30 may also be gold-plated on the surface. The stem 10 is, for example, in the shape of a disk having a diameter of 5.6 mm and a thickness of about 1.2 mm. The diameter of the lead pins 30 is, for example, 0.4 mm. A portion of the lead pins 30 having a length of about 15 mm is led out from the second surface 12 side of the stem 10. A sealing material 32 made of an insulating material such as glass is filled between the stem 10 and the lead pins 30. Thus, the stem 10 is electrically insulated from the lead pins 30. Among the plurality of lead pins 30, there may also be a pin that is electrically short-circuited with the stem 10.

[0028] A mounting block 14 formed of a metal material is mounted on the first surface 11 of the stem 10. A semiconductor laser 16 is mounted on the mounting block 14 in such a way that light is emitted along the Z direction. The semiconductor laser 16 is, for example, an end-emitting laser chip. As long as the semiconductor laser 16 is a light-emitting element, it can also be a surface-emitting laser or an LED. In addition, the semiconductor laser 16 is electrically connected to the lead pins 30 using gold wires or wiring substrates not shown in the figure. By injecting current from the lead pins 30, the semiconductor laser 16 can be operated.

[0029] A cylindrical lens barrel 34 made of metal is welded to the first surface 11 of the stem 10. A glass lens 36 is mounted on the distal end of the lens barrel 34. The lens barrel 34 and the glass lens 36 cover and seal the mounting block 14 and the semiconductor laser 16.

[0030] The heat sink 20 has a third surface 23 and a fourth surface 24 on the opposite side to the third surface 23. The third surface 23 is in contact with the second surface 12 of the stem 10. Figure 2 In the figure, the position of the stem 10 is indicated by a dotted line. The heat sink 20 is formed of metal. A groove 26 is formed in the heat sink 20, which cuts the side surface 21 connecting the third surface 23 and the fourth surface 24 and passes through from the third surface 23 to the fourth surface 24. A plurality of lead pins 30 are inserted into the groove 26. The groove 26 is formed in such a way that the heat sink 20 does not interfere with the lead pins 30. Figure 2 In the example, the groove 26 of the heat sink 20 is rectangular, but may be polygonal or U-shaped. The depth of the groove 26 from the side surface 21 is, for example, greater than the spacing between the plurality of lead pins 30. The outer periphery of the second surface 12 of the stem 10 is in contact with the third surface 23 of the heat sink 20.

[0031] An insulating film 28 of polyimide or the like is provided on the inner side surface of the formation groove 26 of the heat sink 20. Thus, even if the lead pin 30 is in contact with the heat sink 20, conduction between the lead pin 30 and the heat sink 20 can be suppressed.

[0032] Next, the operation of the optical semiconductor device 100 is described. If the lead pin 30 is connected to a power supply for current injection, the semiconductor laser 16 generates laser oscillation light. The laser oscillation light passes through the glass lens 36 and is emitted in the Z direction. At this time, heat is generated in the semiconductor laser 16 together with the laser oscillation. As shown by the arrow 80, the heat is transmitted from the mounting block 14 with high thermal conductivity to the stem 10 and escapes. At this time, by configuring the heat dissipation block 20 in a manner connected to the second surface 12 of the stem 10, the heat can escape from the second surface 12 toward the heat dissipation block 20 via a short heat dissipation path. As a result, it is possible to suppress the excessive temperature rise of the semiconductor laser 16 when current is injected. Therefore, it is possible to suppress the reduction of light output characteristics and reliability.

[0033] Usually, the package is assembled so that the light emission point of the semiconductor laser 16 as the heat source is located near the center of the stem 10. Therefore, if the heat sink 20 is in contact with the stem 10 in a region close to the center of the second surface 12 of the stem 10, the heat dissipation efficiency can be improved.

[0034] Next, effects of the optical semiconductor device 100 according to the first embodiment will be described. Figure 3 1 is a cross-sectional view of an optical semiconductor device 200 according to a first variant of the first embodiment. In the optical semiconductor device 200, the flexible substrate 40 is connected to the lead pins 30 on the side of the fourth surface 24 of the heat sink 20. A plurality of holes for inserting the lead pins 30 are formed in the flexible substrate 40. In addition, the flexible substrate 40 has electrical wiring such as a wiring pattern. As a comparative example of the present embodiment, a structure in which a through hole for inserting the lead pins 30 is provided in the heat sink is considered. In the comparative example, the heat sink needs to be installed along the Z direction from the side of the second surface 12 of the stem 10. Therefore, in the comparative example, the heat sink needs to be installed before the flexible substrate 40 is installed on the lead pins 30.

[0035] On the other hand, the heat sink 20 according to the first embodiment can be mounted on the stem 10 from two directions, the Z direction and the X direction. Therefore, in the present embodiment, the heat sink 20 can be mounted on the stem 10 after the flexible substrate 40 is mounted on the lead pins 30. Thus, in the present embodiment, the degree of freedom of the mounting method or assembly sequence of the heat sink 20 can be increased, and the flexibility of the manufacturing process can be increased.

[0036] In addition, in the above-mentioned comparative example, if the size or position of the insertion hole of the heat sink is offset, the lead pin 30 may be bent. In addition, the heat sink may not be installed due to interference between the heat sink and the lead pin 30. In addition, the inside of the insertion hole with a diameter of several mm needs to be covered by an insulator. Therefore, high processing accuracy is required, and the processing cost of the heat sink may increase. In contrast, in the present embodiment, there is no need to form a through hole in the heat sink 20 and to form an insulator inside the through hole. Therefore, high processing accuracy is not required, and the manufacturing cost can be suppressed.

[0037] In addition, in the present embodiment, since the lead pin 30 only needs to be inserted into the groove 26, the heat sink 20 and the lead pin 30 can be easily aligned. Therefore, the heat sink 20 can be easily mounted on the stem 10. Therefore, the assembly cost can be suppressed. In this way, in the present embodiment, the optical semiconductor device 100 can be easily manufactured. In addition, the heat sink 20 of the present embodiment can be manufactured with less metal material than the heat sink with the insertion hole involved in the comparative example. Therefore, the material cost can be suppressed.

[0038] Figure 41 is a cross-sectional view of an optical semiconductor device 300 according to a second variant of the first embodiment. The structure of the heat sink 320 of the optical semiconductor device 300 is different from that of the optical semiconductor device 100. The other structures are the same as those of the optical semiconductor device 100. The heat sink 320 may also be formed with a plurality of grooves 26 according to the arrangement of the lead pins 30. In the optical semiconductor device 300, the contact area between the stem 10 and the heat sink 320 can be made larger than that of the optical semiconductor device 100. Therefore, the heat dissipation efficiency can be improved.

[0039] The shapes of the heat sink 20 and the groove 26 of this embodiment are not limited to Figure 1 to Figure 4 The heat sink 20 may be rectangular, polygonal, circular, or elliptical when viewed from the Z direction. The groove 26 is not limited to a rectangular shape, but may be polygonal or U-shaped. In addition, the number of lead pins 30 is not limited.

[0040] The above-mentioned modifications can be appropriately applied to the optical semiconductor devices according to the following embodiments. In addition, since the optical semiconductor devices according to the following embodiments have many common points with the first embodiment, the description will be centered around the differences from the first embodiment.

[0041] Implementation Method 2

[0042] Figure 5 , Figure 6 It is a cross-sectional view of an optical semiconductor device 400 according to the second embodiment. Figure 5 It is a YZ cross-sectional view passing through the center of the tube base 10 . Figure 6 By cutting with the C-D straight line Figure 5 The XY cross section is a view obtained by viewing the second surface 12 side of the stem 10. The structure of the heat sink 420 of the optical semiconductor device 400 is different from that of the optical semiconductor device 100. The other structures are the same as those of the optical semiconductor device 100. The groove 26 is formed in the side surface 21 of the heat sink 420 so that the Y direction becomes the depth direction. That is, the groove 26 opens toward the negative direction of the Y axis.

[0043] Generally, the semiconductor laser 16 is arranged so that light is emitted from the center of the XY plane of the stem 10. Therefore, the mounting block 14 on which the semiconductor laser 16 is mounted is often arranged at a position deviated from the center of the stem 10. In the present embodiment, the mounting block 14 on which the semiconductor laser 16 is mounted is also arranged at a position deviated from the center of the stem 10 to one side on the first surface 11 of the stem 10. Figure 5 The positive direction of the Y axis.

[0044] The bottom of the groove 26 of the heat sink 420 is disposed on one side, i.e., the positive direction side of the Y axis. Thus, the distance between the bottom of the groove 26 of the heat sink 420 and the mounting block 14 can be reduced. In the present embodiment, since the contact portion between the second surface 12 of the stem 10 and the heat sink 420 is close to the mounting block 14, the heat dissipation path from the semiconductor laser 16 to the heat sink 420 can be shortened as indicated by the arrow 82. Therefore, the heat dissipation efficiency can be improved.

[0045] Implementation 3

[0046] Figure 7 , Figure 8 1 is a cross-sectional view of an optical semiconductor device 500 according to Embodiment 3. The structure of a heat sink 520 of the optical semiconductor device 500 is different from that of the optical semiconductor device 100. The other structures are the same as those of the first embodiment. Figure 7 It is a YZ cross-sectional view passing through the center of the tube base 10 . Figure 8 By cutting with straight line E-F Figure 7 The obtained XY cross section is a diagram viewed from the second surface 12 side of the stem 10 .

[0047] As in the first embodiment, the third surface 23 of the heat sink 520 is in contact with the second surface 12 of the stem 10. The heat sink 520 is, for example, shaped so as to be able to pass between the plurality of lead pins 30 and to be disposed at the center of the second surface 12 of the stem 10. That is, the heat sink 520 extends from the center of the second surface 12 of the stem 10 through the plurality of lead pins 30. The heat sink 520 is, for example, a rectangular parallelepiped. That is, the heat sink 520 is rectangular when viewed from a direction perpendicular to the second surface 12.

[0048] An insulating film 28 made of polyimide or the like is provided on the side surface 21 connecting the third surface 23 and the fourth surface 24 of the heat sink 520. The insulating film 28 is provided to prevent conduction between the lead pins 30 and the heat sink 520. The insulating film 28 only needs to be provided on the surface of the side surface 21 facing the lead pins 30.

[0049] In this embodiment, the same effect as in Embodiment 1 can be obtained. That is, the optical semiconductor device 100 can be easily manufactured, and the material cost can be suppressed. In addition, in this embodiment, it is not necessary to perform groove processing on the heat sink 520. Therefore, the processing cost can be suppressed. In addition, in this embodiment, since the heat sink 520 can be arranged in the center of the stem 10, the heat dissipation path from the semiconductor laser 16 to the heat sink 520 can be shortened as shown by the arrow 83. Therefore, heat can be efficiently escaped.

[0050] The heat sink 520 may be in any shape as long as it does not interfere with the lead pins 30 , and may be in a cylindrical shape or a shape having projections and depressions. Fig. 9 1 is a cross-sectional view of an optical semiconductor device 600 according to a variation of Embodiment 3. The optical semiconductor device 600 includes a heat sink 620. The heat sink 620 is cross-shaped when viewed from a direction perpendicular to the second surface 12. In the heat sink 620, the contact area between the stem 10 and the heat sink 620 can be enlarged compared to the heat sink 520. Therefore, the heat dissipation efficiency can be improved. On the other hand, the heat sink 620 can be mounted on the stem 10 only from the Z direction. Therefore, compared with Embodiment 1, the manufacturing process is limited.

[0051] Similar to the first embodiment, the flexible substrate 40 may be connected to the plurality of lead pins 30 on the fourth surface 24 side of the heat sink 520 .

[0052] Implementation 4

[0053] Fig.10 It is a cross-sectional view of an optical semiconductor device 700 according to the fourth embodiment. Fig.11 1 is a perspective view of a heat sink 720 according to Embodiment 4. The structure of the heat sink 720 of the optical semiconductor device 700 is different from that of the optical semiconductor device 100. The other structures are the same as those of Embodiment 1. The heat sink 720 is, for example, semicircular when viewed from the Z direction. In the heat sink 720, as in the heat sink 20, a groove 26 is formed for passing the lead pins 30. In addition, the heat sink 720 has a step portion 722 extending from the third surface 23 toward the stem 10 side and in contact with the side surface 13 of the stem 10 connecting the first surface 11 and the second surface 12. The step portion 722 has a height d from the third surface 23.

[0054] In this embodiment, the same effect as that of Embodiment 1 can be obtained. In addition, the heat sink 720 is in contact with the second surface 12 and the side surface 13 of the tube holder 10. Therefore, as shown by the arrow 84, the heat dissipation path from the side surface of the tube holder 10 to the heat sink 720 is increased, so that heat can be more efficiently dissipated. When the height d is greater than the thickness of the tube holder 10, the contact area between the step portion 722 and the side surface 13 of the tube holder 10 is the largest, and the heat dissipation is also the largest. However, even if the height d is smaller than the thickness of the tube holder 10, a certain heat dissipation can be obtained. In addition, the step portion 722 also functions as an assembly guide. The step portion 722 can determine the positional relationship between the tube holder 10 and the heat sink 720, and assembly deviation can be suppressed.

[0055] Implementation method 5

[0056] Fig.12 It is a cross-sectional view of an optical semiconductor device 800 according to the fifth embodiment. Fig.131 is a perspective view of a heat sink according to Embodiment 5. The structure of the heat sink 820 of the optical semiconductor device 800 is different from that of the optical semiconductor device 500. The other structures are the same as those of Embodiment 3. In this embodiment, the heat sink of Embodiment 3 is provided with a step portion of Embodiment 4. The heat sink 820 extends from the center of the second surface 12 of the stem 10 through the plurality of lead pins 30. The heat sink 820 has a step portion 822 extending from the third surface 23 toward the stem 10 side and in contact with the side surface 13 of the stem 10.

[0057] The heat sink 820 is in contact with the second surface 12 and the side surface 13 of the stem 10. Therefore, compared with Embodiment 3, in this embodiment, heat can be more efficiently dissipated. Compared with Embodiment 4, in this embodiment, since the center portion of the stem 10 close to the semiconductor laser 16 is in contact with the heat sink 820, heat can be efficiently dissipated from the second surface 12 of the stem 10. On the other hand, in this embodiment, the contact area between the side surface 13 of the stem 10 and the step portion 822 is smaller than that in Embodiment 4. Therefore, Embodiment 4 is higher in heat dissipation efficiency from the side surface 13 of the stem 10. In addition, similarly to Embodiment 4, in this embodiment, assembly deviation can be suppressed by the step portion 822.

[0058] The technical features described in each embodiment may be used in combination as appropriate.

[0059] Description of reference numerals:

[0060] 10…tube holder; 11…first surface; 12…second surface; 13…side surface; 14…mounting block; 16…semiconductor laser; 20…heat sink block; 21…side surface; 23…third surface; 24…fourth surface; 26…groove; 28…insulating film; 30…lead pin; 32…sealing material; 34…lens barrel; 36…glass lens; 40…flexible substrate; 100…optical semiconductor device; 200…optical semiconductor device; 300…optical semiconductor device; 320…heat sink block; 400…optical semiconductor device; 420…heat sink block; 500…optical semiconductor device; 520…heat sink block; 600…optical semiconductor device; 620…heat sink block; 700…optical semiconductor device; 720…heat sink block; 722…stepped portion; 800…optical semiconductor device; 820…heat sink block; 822…stepped portion.

Claims

1. An optical semiconductor device, characterized in that: have: A tube seat having a first surface and a second surface opposite to the first surface; A semiconductor laser is disposed on the first surface side of the stem; Lead pins, passing through the stem from the first surface to the second surface; and The heat sink has a third surface and a fourth surface opposite to the third surface, wherein the third surface contacts the second surface of the tube holder. The heat dissipation block has a groove formed therein, which is cut into a side surface connecting the third surface and the fourth surface and passes through from the third surface to the fourth surface. An insulating film is provided on the inner side surface of the heat sink block where the groove is formed. The lead pins are inserted into the grooves of the heat slug.

2. The optical semiconductor device according to claim 1, wherein A mounting block is provided on the first surface at a position offset to one side from the center of the stem and on which the semiconductor laser is mounted, The bottom of the groove is arranged on the one side.

3. The optical semiconductor device according to claim 1 or 2, wherein: A plurality of the grooves are formed in the heat dissipation block.

4. The optical semiconductor device according to any one of claims 1 to 3, wherein The heat sink block has a step portion extending from the third surface toward the stem and in contact with a side surface of the stem connecting the first surface and the second surface.

5. The optical semiconductor device according to any one of claims 1 to 4, wherein: A flexible substrate connected to the lead pins is provided on the fourth surface side of the heat dissipation block.

6. An optical semiconductor device, characterized in that: have: A tube seat having a first surface and a second surface opposite to the first surface; A semiconductor laser is disposed on the first surface side of the stem; A plurality of lead pins penetrate the stem from the first surface to the second surface; and The heat sink has a third surface and a fourth surface opposite to the third surface, wherein the third surface contacts the second surface of the tube holder. An insulating film is provided on the side surface of the heat sink connecting the third surface and the fourth surface. The heat sink block extends from a central portion of the second surface of the stem to pass between the plurality of lead pins.

7. The optical semiconductor device according to claim 6, wherein: The heat dissipation block is rectangular when viewed from a direction perpendicular to the second surface.

8. The optical semiconductor device according to claim 6, wherein The heat dissipation block has a cross shape when viewed from a direction perpendicular to the second surface.

9. The optical semiconductor device according to any one of claims 6 to 8, wherein The heat sink block has a step portion extending from the third surface toward the stem and in contact with a side surface of the stem connecting the first surface and the second surface.

10. The optical semiconductor device according to any one of claims 6 to 9, wherein A flexible substrate connected to the plurality of lead pins is provided on the fourth surface side of the heat dissipation block.

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