JP2008085272A - Submount and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a submount capable of miniaturizing a product while suppressing the deterioration of characteristics of the product. <P>SOLUTION: The submount 20 is provided with a submount substrate 21 and a metal film 22 which is formed on the surface of the submount substrate 21, and connected to an upper electrode 3a of a semiconductor laser element 3 via a solder layer 25. In the metal film 22, a solder forming region 24 where the solder layer 25 is formed, and a metal film removed part 26 where the submount substrate 21 is exposed, are formed. The metal film removed part 26 is extended toward the arrow direction Y, and arranged in a pair to be opposed to each other via the solder forming region 24. Moreover, the metal film removed part 26 is formed over substantially whole length in the submount substrate 21, and formed along the whole length of the solder layer 25 formed in the solder forming region 24. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a submount and a semiconductor device using the same, and more particularly to a submount on which a semiconductor element is mounted and a semiconductor device using the same.

  Conventionally, a submount on which a semiconductor element is mounted and a semiconductor device using the submount on which the semiconductor element is mounted are known (see, for example, Patent Document 1 and Patent Document 2).

  Patent Document 1 describes a submount capable of mounting a semiconductor light emitting element on a surface with high accuracy. In this submount, a metal electrode to which a semiconductor light emitting element (semiconductor element) is connected is formed on the surface, and a solder layer for connecting the semiconductor light emitting element on the submount is formed in a predetermined region of the metal electrode. A solder region to be formed is provided. In addition, a marker for alignment of the semiconductor light emitting element is formed on a part of the metal electrode, and the semiconductor light emitting element is accurately mounted by performing alignment of the semiconductor light emitting element using the marker as a mark. It becomes possible.

Further, in Patent Document 2, in a semiconductor device in which a laser diode (semiconductor element) is mounted on a submount via a solder layer, the solder layer melts and spreads between the submount substrate and the solder layer. A semiconductor device in which a solder barrier layer (Pt layer) for suppression is formed is described. The submount of this semiconductor device has a structure in which a laminated film composed of a Ti film and a Pt film, an Au film, a solder barrier layer (Pt layer), and a solder layer are sequentially laminated on a submount substrate. is doing.
Japanese Patent Laid-Open No. 2005-93804 JP 2003-258360 A

  However, in the submount described in Patent Document 1, when connecting the semiconductor light emitting element on the submount, the solder layer for connecting the semiconductor light emitting element on the submount melts and spreads beyond the solder region. There is an inconvenience. For this reason, it is difficult to keep the solder layer within a certain range including the solder region, and thus there is a disadvantage that it is difficult to secure a region other than the solder region such as a region where wire bonding is performed. As a result, it becomes difficult to change the size of the area other than the solder area, and it becomes difficult to downsize the submount, and accordingly, the semiconductor light emitting device using the submount is downsized. There is a problem that it becomes difficult.

  Moreover, in the semiconductor device described in Patent Document 2, since the solder barrier layer (Pt layer) is formed between the Au film and the solder layer, it is possible to suppress the melting and spreading of the solder layer. On the other hand, since one extra solder barrier layer (Pt layer) is formed, this solder barrier layer (Pt layer) has the disadvantage that the heat conduction to the submount is reduced. For this reason, there is an inconvenience that it is difficult to dissipate the heat generated by the laser diode to the submount, and thus there is an inconvenience that the light emission efficiency of the laser diode is lowered. As a result, there is a problem that the product characteristics deteriorate.

  The present invention has been made to solve the above-described problems, and one object of the present invention is a submount capable of downsizing a product while suppressing deterioration in product characteristics, and It is to provide a semiconductor device using the same.

  In order to achieve the above object, a submount according to the first aspect of the present invention is formed on a surface of the submount substrate and the submount substrate, and the electrode portion of the semiconductor element is connected via a solder layer. The metal film includes a solder formation region where a solder layer is formed and a metal film removal portion where the submount substrate is exposed, and the metal film removal portion is formed on a side end surface of the submount substrate. It is formed along the entire length of the solder formation region in the direction along.

  In the submount according to the first aspect, as described above, the metal film removal portion where the submount substrate is exposed is formed along the entire length of the solder formation region, so that the semiconductor element is metalized via the solder layer. When connecting on the film, the melting and spreading of the solder layer can be stopped at the position of the metal film removing portion, so that the solder layer can be prevented from melting and spreading beyond the metal film removing portion. That is, the portion of the metal film removal portion where the submount substrate is exposed has poor solder wettability compared to the metal film, so the portion of the metal film removal portion where the submount substrate is exposed has a solder layer. It becomes difficult to melt and spread. For this reason, even when the solder layer melts and spreads, the metal film removal portion formed along the entire length of the solder formation region causes the solder layer to melt and spread within a predetermined range (region) including the solder formation region. Therefore, it is possible to ensure a large range (region) that is not affected by the melting and spreading of the solder layer. As a result, it is possible to secure an area for wire bonding and the like, and to easily change the size of the area other than the solder formation area, so that the submount can be downsized.

  In the first aspect, the metal film formed on the surface of the submount substrate is formed with a metal film removal portion from which the submount substrate is exposed, so that the solder is interposed between the metal film and the solder layer. Since the melting and spreading of the solder layer can be suppressed without forming a Pt layer or the like for suppressing the melting and spreading of the layer, the Pt layer or the like causes a disadvantage that the heat conduction to the submount is lowered. Can be suppressed. For this reason, compared with the case where a Pt layer or the like is formed between the metal film and the solder layer, the heat generated by the semiconductor element can be easily radiated to the submount, so that the light emission efficiency of the semiconductor element is reduced. Can be suppressed. As a result, deterioration of product characteristics can be suppressed. By forming the metal film removal portion, it is not necessary to form a Pt layer or the like for suppressing the melting and spreading of the solder layer, so that the manufacturing cost can be reduced accordingly.

  Further, in the first aspect, the metal film removal portion from which the submount substrate is exposed is formed along the entire length of the solder formation region, so that the melting and spreading of the solder layer includes the solder formation region as described above. Since it can be kept within a predetermined range (region), the solder amount (soldering amount) between the semiconductor element and the metal film of the submount decreases (varies) due to the melting and spreading of the solder layer. ) Can be suppressed. For this reason, since it can suppress that the adhesiveness of a semiconductor element and the metal film of a submount falls, it can suppress that the heat dissipation to a submount via a metal film falls. As a result, it is possible to suppress a decrease in the light emission efficiency of the semiconductor element, and thus it is also possible to suppress a decrease in product characteristics.

  In the submount according to the first aspect, preferably, the metal film removing portions are provided in a pair so as to face each other with the solder formation region interposed therebetween. If comprised in this way, when connecting a semiconductor element on a metal film via a solder layer, since a pair of metal film removal parts can suppress melt spread of a solder layer on both sides of a solder layer, Even when the solder layer melts and spreads, the range (region) where the solder layer melts and spreads can be easily kept within a predetermined range (region) including the solder formation region. For this reason, since it is possible to secure a larger range (region) that is not affected by the melting and spreading of the solder layer, it is possible to easily secure a region for performing wire bonding and the like in regions other than the solder formation region. The size can be easily changed. As a result, the submount can be easily downsized. Further, with this configuration, as described above, the melting and spreading of the solder layer can be easily retained within a predetermined range (region) including the solder forming region, so that the solder layer is melted and spread. As a result, it is possible to easily suppress a decrease (fluctuation) in the amount of solder (amount of soldering) between the semiconductor element and the metal film of the submount. For this reason, since it can suppress easily that the adhesiveness of a semiconductor element and the metal film of a submount falls, it can suppress easily that the heat dissipation to a submount via a metal film falls. Can do. As a result, it is possible to easily suppress a decrease in the light emission efficiency of the semiconductor element, and thus it is possible to easily suppress a decrease in product characteristics.

  In the submount according to the first aspect, preferably, the metal film removal portion is formed over substantially the entire length of the submount substrate in a direction along the side end surface of the submount substrate. With this configuration, when the semiconductor element is connected to the metal film via the solder layer, even if the solder layer melts and spreads, the solder film is removed in a region opposite to the solder formation region with respect to the metal film removal portion. Since it is possible to easily suppress the melting and spreading of the layer, almost all of the area opposite to the solder forming area with respect to the metal film removal portion is set as a range (area) that is not affected by the melting and spreading of the solder layer. Can be secured. As a result, it is possible to easily secure a region for wire bonding and the like, and to easily change the size of the region other than the solder formation region, so that the submount can be more easily downsized. it can.

  In the submount according to the first aspect, preferably, at least one of the one end and the other end of the metal film removing portion is formed at a position spaced a predetermined distance from the end face of the submount substrate. If comprised in this way, since it has the area | region where the metal film removal part is not formed in the end surface vicinity of a submount board | substrate, even when there is much solder amount of the solder layer formed in a solder formation area | region, a metal film Excess solder can be released through the region where the removal portion is not formed. Thereby, since it can suppress that a solder adheres to the side surface and end surface of a semiconductor element, the short circuit of a semiconductor element, etc. can be suppressed. As a result, it is possible to suppress deterioration of product characteristics.

  A semiconductor device according to a second aspect of the present invention is a semiconductor device using the submount according to the first aspect. With this configuration, it is possible to easily obtain a semiconductor device capable of downsizing a product while suppressing deterioration of product characteristics.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. In the present embodiment, a case where the present invention is applied to a can package type semiconductor laser device 30 which is an example of a semiconductor device will be described.

  FIG. 1 is an overall perspective view of a semiconductor laser device using a submount according to an embodiment of the present invention. FIG. 2 is an overall perspective view of the submount according to the embodiment of the present invention shown in FIG. FIG. 3 is a plan view of the submount according to the embodiment of the present invention shown in FIG. 4 to 9 are views for explaining the submount according to the embodiment of the present invention shown in FIG. 1 and a semiconductor laser device using the submount. With reference to FIGS. 1-9, the semiconductor laser apparatus 30 using the submount 20 by one Embodiment of this invention is demonstrated. 2, 3, 5, and 6, the arrow A direction is the laser beam emission direction (front-side emission direction).

  As shown in FIG. 1, the semiconductor laser device 30 using the submount 20 according to one embodiment is attached to the disk-shaped stem 1, the heat sink 2 fixed on the upper surface of the stem 1, and the heat sink 2. The submount 20, the semiconductor laser element 3 mounted on the submount 20, the photodiode 4 provided on the upper surface of the stem 1, and the upper surface of the stem 1 are attached so as to cover the semiconductor laser element 3 and the like. A cap 5 and three lead pins 6, 7 and 8 are provided. The semiconductor laser element 3 is an example of the “semiconductor element” in the present invention.

  The stem 1 is comprised from metal materials, such as iron or copper, and is formed in disk shape. The surface of the stem 1 may be subjected to a surface treatment such as gold plating. The stem 1 has a diameter of about 5.6 mm and a thickness of about 1.0 mm. Further, as shown in FIGS. 1 and 8, on the outer surface of the stem 1, notched portions 1a and 1b having a V-shaped flat cross section and a notched portion 1c having a U-shaped flat cross section, The stem 1 is provided so as to extend in the thickness direction. The stem 1 also has a function of holding the semiconductor laser device 30 by being mounted on a holder portion of the device or the like when the semiconductor laser device 30 is mounted on the device or the like. The notches 1 a, 1 b, and 1 c function to position the semiconductor laser device 30 by engaging with an engaging portion (not shown) of the holder portion when holding the semiconductor laser device 30. have.

  The heat sink 2 is made of a metal material such as copper, and is fixed near the center of the upper surface (main surface) of the stem 1. The heat sink 2 has a function of radiating the heat of the semiconductor laser element 3 through the submount 20. Note that the surface of the heat sink 2 may be subjected to a surface treatment such as gold plating in the same manner as the stem 1. Further, the heat sink 2 may be configured integrally with the stem 1.

  Further, as shown in FIGS. 1 and 9, the submount 20 is disposed in a predetermined region on one side surface of the heat sink 2 (the surface on the center side of the stem 1) via a solder layer 9 (see FIG. 9). It is fixed. As shown in FIGS. 2 and 4, the submount 20 includes a submount substrate 21 and metal films 22 and 23 formed on the upper surface and the lower surface of the submount substrate 21, respectively. Further, as shown in FIG. 3, the submount 20 has a length L1 in a direction (arrow Y direction) along the side end surface of the submount substrate 21 of about 600 μm to about 1500 μm, and about 600 μm to about 1500 μm. It has a width W1 in the direction (arrow X direction) orthogonal to the side end face of the submount substrate 21 of about 900 μm. The submount 20 has a function of radiating heat of the semiconductor laser element 3 connected to the submount 20 and a function of relaxing stress applied to the semiconductor laser element 3.

  As shown in FIG. 4, the submount substrate 21 constituting the submount 20 is made of AlN and has a thickness of about 340 μm to about 350 μm. The metal film 22 formed on the upper surface of the submount substrate 21 includes a Ti film 22a having a thickness of about 0.06 μm and a Pt film 22b having a thickness of about 0.2 μm from the submount substrate 21 side. The Au film 22c having a thickness of about 0.3 μm is sequentially laminated. Further, the metal film 23 formed on the lower surface of the submount substrate 21 includes a Ti film 23a having a thickness of about 0.06 μm and a Pt film 23b having a thickness of about 0.2 μm from the submount substrate 21 side. , And an Au film 23c having a thickness of about 0.3 μm are sequentially stacked.

  The metal film 22 of the submount 20 is provided with a solder formation region 24 in which a solder layer 25 for connecting the semiconductor laser element 3 to the metal film 22 is formed, as shown in FIGS. Yes. As shown in FIG. 3, the solder formation region 24 extends in the center of the submount 20 in the width direction (arrow X direction) and extends in the length direction of the submount 20 (arrow Y direction). 21 is provided over almost the entire length. As shown in FIGS. 2 to 4, a solder layer 25 made of AuSn (Au: about 70 wt%) is formed on the entire surface of the solder formation region 24 on the upper surface of the solder formation region 24.

  The solder layer 25 is configured to have substantially the same size as the upper electrode 3a (see FIG. 7) of the semiconductor laser element 3. That is, as shown in FIG. 6, the submount 20 is configured such that the semiconductor laser element 3 is mounted over substantially the entire length in the arrow Y direction. With this configuration, it is possible to reduce the size of the submount 20 also in the arrow Y direction. The upper electrode 3a of the semiconductor laser element 3 is an example of the “electrode part” in the present invention.

  Here, in the present embodiment, as shown in FIGS. 2 and 3, the metal film 22 of the submount 20 has a width W2 in the direction of the arrow X of about 50 μm and the solder layer 25 is formed. A pair of metal film removal portions 26 facing each other across the region 24 are formed so as to extend in the direction along the side end surface of the submount substrate 21 (arrow Y direction). As shown in FIG. 4, the metal film removing portion 26 is formed by removing the metal film 22 to a depth at which the submount substrate 21 is exposed by etching.

  In the present embodiment, as shown in FIG. 3, the metal film removal portion 26 is formed over the substantially entire length of the submount substrate 21 in the arrow Y direction, so that the solder formed on the solder formation region 24 is formed. It is configured to be formed along the entire length of the layer 25. The pair of metal film removal portions 26 are formed so as to extend in parallel to each other. Since the metal film removal portion 26 has a function of suppressing the melting and spreading of the solder layer 25, as shown in FIG. 5, outside the pair of metal film removal portions 26 (on both sides of the solder formation region 24). Are formed with regions 27 that are not affected by the melting and spreading of the solder layer 25. However, in FIG. 5, from the viewpoint of drawing drawing that it is difficult to draw a wavy line and a solid line in an overlapping manner, a wavy line region indicating an area 27 that is not affected by the melting and spreading of the solder layer 25 is inside the solid line. However, the region 27 is not limited to the region surrounded by the wavy line, and is a region on the metal film 22 outside the pair of metal film removal units 26.

  Further, in the present embodiment, as shown in FIG. 3, the one end 261 of the metal film removing unit 26 is formed at a position separated from the one end surface 21 a of the submount substrate 21 by a predetermined distance L2. That is, on the metal film 22 in the vicinity of the one end face 21a of the submount 20, there is a region 28 where the metal film removal portion 26 is not formed. Note that the distance L2 is set to an extremely short distance because it is sufficient that there is a distance that allows the solder to flow out as much as the volume has increased due to melting. Further, the other end 262 of the metal film removing portion 26 is formed up to the other end surface 21 b of the submount substrate 21.

  Further, the metal film removal portion 26 is formed at a position spaced apart from the solder formation region 24 by a predetermined interval W3. As a result, even when the solder amount of the solder layer 25 formed in the solder formation region 24 is large, excess solder can be released to the region between the solder formation region 24 and the metal film removal portion 26. It is possible to prevent solder from adhering to the side surface of the laser element 3 or the like. As a result, the short circuit of the semiconductor laser element 3 due to the adhesion of solder is suppressed. Note that the distance W3 is sufficient if there is a distance for the solder to flow out due to the increase in volume due to melting, so it is formed at an extremely narrow distance of about 10 μm.

  In addition, the pair of metal film removal units 26 are arranged so that the intermediate position between the metal film removal units 26 coincides with the center M of the submount substrate 21 in the arrow X direction. As shown in FIGS. 2 and 3, the pair of metal film removal portions 26 have edge portions 263 that extend linearly in the arrow Y direction. The edge 263 is formed with high accuracy by etching, and is used as a positioning reference line in the width direction (arrow X direction) of the submount 20 when the semiconductor laser element 3 is connected to the submount 20. Further, since the intermediate position (center M) of the submount 20 can be recognized by detecting the intermediate position between the edge portions 263, the semiconductor laser element 3 is positioned in the width direction (arrow X direction) of the submount 20. It becomes possible to arrange at the center M with high accuracy. Note that the edge 263 of the metal film removing portion 26 can be used as a positioning reference line when the submount 20 is connected to the heat sink 2.

  Further, as shown in FIG. 3, the pair of metal film removal units 26 each have a metal film removal unit 26 a having a square shape when seen in a plan view. The metal film removing portion 26a is formed to be symmetric with respect to the center M in the arrow X direction of the submount 20, and the length L3 of the metal film removing portion 26a in the arrow Y direction and the arrow X Each of the direction widths W4 is formed to be about 100 μm. Similarly to the metal film removal unit 26, the metal film removal unit 26a is also formed by etching to a depth at which the submount substrate 21 is exposed. Moreover, the metal film removal part 26a has the edge part 260a extended in the arrow X direction. The edge portion 260a is formed with high accuracy by etching, and is used as a positioning reference line N in the width direction (arrow X direction) of the submount 20 when the semiconductor laser element 3 is connected to the submount 20. . In addition, it is also possible to use the edge part 260a of the metal film removal part 26a as the positioning reference line N when the submount 20 is connected to the heat sink 2.

  As shown in FIGS. 5 and 6, one end of the bonding wire 10 is connected to a region 27 that is not affected by the melting and spreading of the solder layer 25. That is, wire bonding is performed in the region 27 where the influence of the melting and spreading of the solder layer 25 is not exerted. As shown in FIG. 1, the other end of the bonding wire 10 is connected to the heat sink 2, whereby the metal film 22 of the submount 20 and the heat sink 2 are electrically connected.

  As shown in FIGS. 1, 6, and 7, the semiconductor laser element 3 is connected to the metal film 22 via the solder layer 25 on the upper surface of the submount 20. The semiconductor laser element 3 is formed of, for example, a visible light semiconductor laser element using an AlGaInP-based compound that emits red light, and is connected in a junction-down manner.

  Further, the semiconductor laser element 3 is configured to be within a region (range) where the solder layer 25 is formed when connected via the solder layer 25. That is, the semiconductor laser element 3 is configured such that the upper electrode 3a is accommodated in the region (range) of the solder layer 25 after melting. Further, even when the solder layer 25 melts and spreads when the semiconductor laser element 3 is connected to the submount 20, the range in which the solder layer 25 melts and spreads is suppressed by the pair of metal film removal portions 26. Therefore, the area (range) in which the solder layer 25 spreads out remains in the predetermined area 29 (the hatched portion in FIG. 5) including the solder formation area 24. As shown in FIG. 8, the semiconductor laser element 3 is configured such that its light emitting point is located at the center point P of the disc-shaped stem 1.

  As shown in FIGS. 1 and 9, the photodiode 4 is fixed to a region on the upper surface (main surface) of the stem 1 facing the rear emission surface 3 c (see FIG. 9) of the semiconductor laser element 3. . The photodiode 4 has a function of receiving the laser beam emitted from the rear emission surface 3 c of the semiconductor laser element 3 and monitoring the light intensity of the laser beam emitted from the front emission surface 3 d of the semiconductor laser element 3. is doing.

  As shown in FIG. 1, the cap 5 is made of a metal material such as copper and has a cylindrical shape with one surface open. A flange portion 5 a is provided at the open end of the cap 5, and an emission hole 5 b for taking out the laser light emitted from the semiconductor laser element 3 is provided at the closed end of the cap 5. The emission hole 5b is covered with glass 5c. The cap 5 is fixed on the upper surface of the stem 1 so as to cover the semiconductor laser element 3 and the like by welding the flange portion 5 a to the stem 1. The cap 5 has a function of protecting the semiconductor laser element 3 from external dust, external stress, and optical interference. The semiconductor laser element 3 is hermetically sealed by the stem 1 and the cap 5.

  Of the three lead pins 6, 7, and 8, the lead pin 6 is directly attached to a region on the back side of the stem 1 that is located immediately below the heat sink 2. The lead pin 6 is electrically connected to the upper electrode 3a (see FIGS. 7 and 9) of the semiconductor laser element 3 via the heat sink 2, the bonding wire 10, and the submount 20. The lower electrode portion (not shown) of the photodiode 4 is also electrically connected. On the other hand, among the three lead pins 6, 7 and 8, the lead pins 7 and 8 are insulators 11 and 12, respectively, such that one end thereof protrudes to the upper surface side of the stem 1, as shown in FIG. Insulatingly fixed to the stem 1 via One end of the lead pin 7 is electrically connected to the lower electrode 3b (see FIG. 9) of the semiconductor laser element 3 via the bonding wire 13, and one end of the lead pin 8 is connected to the bonding wire 14 Is electrically connected to the upper electrode portion 4a of the photodiode 4.

  In the present embodiment, as described above, the metal film removal portion 26 from which the submount substrate 21 is exposed is formed along the entire length of the solder layer 25 formed in the solder formation region 24, whereby the solder layer 25 is formed. When the semiconductor laser device 3 is connected to the metal film 22 via the solder layer 25, the melting and spreading of the solder layer 25 can be stopped at the position of the metal film removal portion 26, so that the solder layer 25 exceeds the metal film removal portion 26. It can suppress melting and spreading. That is, the portion of the metal film removal unit 26 where the submount substrate 21 is exposed has poor solder wettability compared to the metal film 22, and therefore the portion of the metal film removal unit 26 where the submount substrate 21 is exposed. Is difficult to melt and spread the solder layer 25. For this reason, even when the solder layer 25 is melted, the metal film removal portion 26 formed along the entire length of the solder forming region 24 causes the solder layer 25 to melt and spread within a predetermined region 29 including the solder forming region 24. Therefore, it is possible to secure a large area 27 that is not affected by the melting and spreading of the solder layer 25. As a result, it is possible to secure an area for wire bonding and the like, and to easily change the size of the area other than the solder formation area 24, so that the submount 20 can be downsized.

  In the present embodiment, the metal film removing portion 26 is provided in a pair so as to face each other with the solder formation region 24 interposed therebetween, so that the solder layer 25 is melted and spread by the pair of metal film removing portions 26. 25, even when the solder layer 25 is melted, a predetermined region 29 including the solder formation region 24 sandwiched between the pair of metal film removal portions 26 is melted and spread by the solder layer 25. It can be easily kept inside. For this reason, since the region 27 that is not affected by the melting and spreading of the solder layer 25 can be secured on both sides of the submount 20 in the width direction (arrow X direction), a region where wire bonding is performed is easily secured. In addition, the size of the submount 20 in the width direction (arrow X direction) can be reduced. As a result, the submount 20 can be easily downsized.

  In the present embodiment, the metal film 22 and the solder layer 25 are formed by forming the metal film removal portion 26 where the submount substrate 21 is exposed on the metal film 22 formed on the surface of the submount substrate 21. Since the melting and spreading of the solder layer 25 can be suppressed without forming a Pt layer or the like for suppressing the melting and spreading of the solder layer 25, the heat conduction to the submount 20 by the Pt layer or the like. It is possible to suppress the inconvenience of lowering. For this reason, compared with the case where a Pt layer or the like is formed between the metal film 22 and the solder layer 25, the heat generated by the semiconductor laser element 3 can be easily radiated to the submount 20, so that the semiconductor laser element 3 can be prevented from decreasing. As a result, deterioration of product characteristics can be suppressed. Since it is not necessary to form a Pt layer or the like for suppressing the melting and spreading of the solder layer 25, the manufacturing cost can be reduced accordingly.

  In the present embodiment, the metal film removal portion 26 from which the submount substrate 21 is exposed is formed along the entire length of the solder layer 25 formed in the solder formation region 24, so that the solder layer is formed as described above. 25 can be kept in a predetermined region 29 including the solder formation region 24, so that the solder layer 25 melts and spreads, and the semiconductor laser element 3 and the metal film 22 of the submount 20 It is possible to suppress a decrease (fluctuation) in the amount of solder (amount of soldering). For this reason, since it can suppress that the adhesiveness of the semiconductor laser element 3 and the metal film 22 of the submount 20 falls, it suppresses that the heat dissipation to the submount 20 via the metal film 22 falls. can do. As a result, it is possible to suppress a decrease in the light emission efficiency of the semiconductor laser element 3, and thus it is also possible to suppress a decrease in product characteristics.

  Further, in the present embodiment, the metal film removing portion 26 is formed over substantially the entire length of the submount substrate 21 in the direction indicated by the arrow Y in FIG. 3 so that the semiconductor laser element 3 is placed on the metal film 22 via the solder layer 25. Even when the solder layer 25 melts and spreads when connecting to the solder layer 25, the solder layer 25 melts in a region opposite to the solder formation region 24 (regions on both sides of the solder formation region 24) with respect to the metal film removal portion 26. Since spreading can be easily suppressed, almost all of the region opposite to the solder formation region 24 with respect to the metal film removal portion 26 is secured as a region 27 that is not affected by the melting and spreading of the solder layer 25. be able to. As a result, it is possible to easily secure a region for performing wire bonding and the like, and it is possible to easily change the size of the region other than the solder formation region 24, so that the submount 20 can be more easily downsized. be able to.

  Further, in the present embodiment, the one end 261 of the metal film removing portion 26 is formed at a position separated from the one end surface 21a of the submount substrate 21 by a predetermined distance L2, so that the vicinity of the one end surface 21a of the submount substrate 21 is obtained. Therefore, even if the solder amount of the solder layer 25 formed in the solder formation region 24 is large, the region 28 where the metal film removal portion 26 is not formed is provided. Excess solder can be released. Thereby, since it can suppress that a solder adheres to the side surface and end surface of the semiconductor laser element 3, the short circuit of the semiconductor laser element 3 etc. can be suppressed. As a result, it is possible to suppress deterioration of product characteristics.

  Further, in the present embodiment, by using the submount 20 for the semiconductor laser device 30, it is possible to easily obtain the semiconductor laser device 30 capable of downsizing the product while suppressing deterioration of product characteristics. .

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, an example in which the present invention is applied to a can package type semiconductor laser device is shown as an example of a semiconductor device. However, the present invention is not limited to this, and the present invention is applied to a frame package type semiconductor laser device. May be applied. Further, the present invention may be applied to a semiconductor device other than the semiconductor laser device as long as it is a semiconductor device using a submount.

  Moreover, in the said embodiment, although the example which provided the metal film removal part in a pair so as to oppose on both sides of a solder formation area was shown, this invention is not restricted to this, The solder layer formed in the solder formation area As long as the metal film removal portion is formed along the entire length, the metal film removal portion may not be a pair.

  Moreover, in the said embodiment, although the example which formed the metal film removal part over the substantially full length of the submount board | substrate was shown, this invention is not restricted to this, Along the full length of the solder layer formed in the solder formation area | region. If the metal film removal portion is formed, the metal film removal portion may be configured not to be formed over almost the entire length of the submount substrate.

  Moreover, in the said embodiment, although the one end of the metal film removal part showed the example formed in the position spaced apart from the one end surface of the submount board | substrate, this invention is not limited to this, A metal film You may comprise so that the both ends of the one end and other end of a removal part may be formed in the position which respectively separated predetermined distance from the one end surface and other end surface of a submount board | substrate.

  In the above embodiment, the semiconductor laser device is configured to be mounted over the entire length of the submount substrate. However, the present invention is not limited to this, and the semiconductor laser device is formed on a part of the submount substrate. You may comprise so that it may be mounted.

  In the above-described embodiment, the example in which the size of the solder layer before melting formed in the solder formation region is substantially the same as the size of the upper electrode of the semiconductor laser element is shown. Is not limited to this, and if the upper electrode of the semiconductor laser element is within the range of the solder layer after melting, the solder layer before melting is placed on the upper side of the semiconductor laser element in consideration of melting and spreading due to melting of the solder layer. You may comprise so that it may become smaller than the magnitude | size of an electrode.

  Moreover, although the example which comprised the submount board | substrate with AlN was shown in the said embodiment, this invention is not limited to this, You may make it comprise a submount board | substrate using materials other than AlN. As a material other than AlN, for example, SiC can be considered.

1 is an overall perspective view of a semiconductor laser device using a submount according to an embodiment of the present invention. FIG. 2 is an overall perspective view of a submount according to the embodiment of the present invention shown in FIG. 1. It is a top view of the submount by one Embodiment of this invention shown in FIG. FIG. 3 is a cross-sectional view taken along line 100-100 in FIG. 2. It is a top view of the submount by one Embodiment of this invention shown in FIG. FIG. 2 is an overall perspective view of a state in which a semiconductor laser element is mounted on a submount according to an embodiment of the present invention shown in FIG. 1. It is sectional drawing along the 200-200 line | wire of FIG. FIG. 2 is a top view of the semiconductor laser device using the submount according to the embodiment of the present invention shown in FIG. 1. It is sectional drawing of the semiconductor laser element periphery of the semiconductor laser apparatus using the submount by one Embodiment of this invention shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stem 2 Heat sink 3 Semiconductor laser element (semiconductor element)
3a Upper electrode (electrode part)
4 Photodiode 5 Cap 20 Submount 21 Submount Substrate 22, 23 Metal Film 24 Solder Formation Area 25 Solder Layer 26, 26a Metal Film Removal Section 30 Semiconductor Laser Device (Semiconductor Device)

Claims (5)

A submount substrate,
A metal film formed on the surface of the submount substrate and connected to the electrode portion of the semiconductor element via a solder layer;
The metal film includes a solder formation region where the solder layer is formed, and a metal film removal portion where the submount substrate is exposed,
The submount, wherein the metal film removing portion is formed along the entire length of the solder formation region in a direction along a side end surface of the submount substrate.   2. The submount according to claim 1, wherein the metal film removal portion is provided in a pair so as to face each other with the solder formation region interposed therebetween.   3. The submount according to claim 1, wherein the metal film removing portion is formed over substantially the entire length of the submount substrate in a direction along a side end surface of the submount substrate.   4. At least one of the one end and the other end of the metal film removal portion is formed at a position spaced a predetermined distance from the end face of the submount substrate. Submount as described in section.   A semiconductor device using the submount according to claim 1.

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