JP2019186328A - Semiconductor module and manufacturing method thereof - Google Patents

Abstract

To prevent pop-out and adhesion of solder, when solder joining a component including a solder joint surface, larger than a solder joined surface, to the solder joined surface.SOLUTION: A semiconductor module, where a second component is joined onto a first component, includes the first component having a first metallization on the surface, the second component having a second metallization provided continuously on the reverse face and the lateral face, and a solder for joining the first and second metallizations. In a projection region projecting the reverse face of the second component perpendicularly to the surface of the first component, the first metallization is included, and the solder wet spreads on the second metallization provided on the lateral face of the second component.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a semiconductor module and a manufacturing method thereof, and more particularly, to an optical semiconductor module used for optical communication and a manufacturing method thereof.

  Along with the development of the multimedia society, a wavelength division multiplex communication system in which a plurality of optical signals having different wavelengths are simultaneously placed on a single optical fiber cable has been adopted. For wavelength division multiplexing communication, for example, an optical semiconductor module that optically couples the light emitted from a plurality of integrated light modulation elements to an optical multiplexer / demultiplexer with a corresponding lens and outputs the combined light is used. (See Patent Document 1).

  In this optical semiconductor module, a lens for optically coupling the emitted light of each of the plurality of integrated light modulators to the multiplexer is disposed between the integrated light modulator and the optical multiplexer / demultiplexer. For example, it is fixed with solder on the electrode pattern of the insulating substrate. At this time, by making the area of the electrode pattern of the insulating substrate smaller than the area of the solder joint surface of the lens base, the insulating substrate itself can be made smaller, and the optical semiconductor module can be further miniaturized.

  However, when excessive solder is supplied between the lens base and the electrode pattern, the solder jumps out of the electrode pattern or scatters at the time of soldering, for example, adheres to the mounting area of the optical multiplexer / demultiplexer, As a result, the optical multiplexer / demultiplexer cannot be assembled or misaligned. In order to prevent this, it has been proposed to move the nozzle closer to the boundary of the solder joint during solder joining and suck out excess solder (see Patent Document 2).

JP 2017-059628 A JP 2007-324414 A

  However, optical semiconductor modules with multiple integrated optical modulation elements have many components that must be mounted compared to conventional optical semiconductor modules, and the components have different heat-resistant temperatures, so all components are mounted at once. The parts are assembled in a plurality of processes using a plurality of solders having different melting points and a plurality of bonding materials such as a resin adhesive. In order to reduce the size of the optical semiconductor module, it is necessary to reduce the distance between the components. For this reason, when soldering the lens base, another component is already installed in the vicinity of the lens base, and it is impossible to suck the excess solder by bringing the nozzle close to it. .

  Accordingly, an object of the present invention is to prevent adhesion due to solder jumping or scattering when a component having a solder joint surface having a larger area is soldered to a solder joint surface in an optical semiconductor module. To do.

The present invention
A semiconductor module in which a second component is bonded onto a first component,
A first part with a first metallization on the surface;
A second component comprising a second metallization provided continuously on the back and side surfaces;
A solder for joining the first metallization and the second metallization;
The first metallization is included in the projection area obtained by vertically projecting the back surface of the second component onto the surface of the first component,
The semiconductor module is characterized in that the solder spreads on the second metallization provided on the side surface of the second component.

The present invention also provides:
Preparing an insulating substrate or thermo module having a first metallization on the surface;
A step of preparing a semiconductor carrier in which a submount to which an optical semiconductor element is soldered is bonded to a front surface or a side surface, and a second metallization is continuously provided on the back surface and the side surface;
Supplying solder on the first metallization;
Melting the solder; and
Spreading the solder over the second metallization provided on the side surface of the semiconductor carrier by bringing the back surface of the semiconductor carrier into contact with the solder and pressing in the first metallization direction;
And a step of solidifying the solder at a position where the first metallization is included in a projection region obtained by vertically projecting the back surface of the semiconductor carrier onto the surface of the insulating substrate or the thermo module. .

  According to one aspect of the present invention, when soldering a part having a solder joint surface having a larger area to the solder joint surface, the metallization is provided up to the side surface of the part to be joined, so that the solder is spread. By doing so, it is possible to prevent the excessively supplied solder from jumping out or being scattered as a solder ball.

  Further, the area of the solder joint surface can be made smaller than the parts to be joined. As a result, the parts to be joined can be miniaturized and the optical semiconductor module can be miniaturized and the cost can be reduced.

  In addition, by observing the solder that has leaked to the side surfaces of the joining component, it is possible to inspect the appearance of the joining state of the solder.

It is sectional drawing of the optical semiconductor module concerning Embodiment 1 of this invention. It is sectional drawing at the time of seeing the semiconductor module of FIG. 1 in the II-II direction. It is a perspective view of the lens base used for the optical semiconductor module concerning Embodiment 1 of this invention. It is a perspective view of the other lens base used for the optical semiconductor module concerning Embodiment 1 of this invention. It is a perspective view of the other lens base used for the optical semiconductor module concerning Embodiment 1 of this invention. It is sectional drawing of the other optical semiconductor module concerning Embodiment 1 of this invention. It is a top view of the lens base used for the optical semiconductor module concerning Embodiment 1 of this invention. It is a side view of the lens base used for the optical semiconductor module concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the optical semiconductor module concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the optical semiconductor module concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the optical semiconductor module concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the optical semiconductor module concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the optical semiconductor module concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the conventional optical semiconductor module. It is sectional drawing of the manufacturing process of the conventional optical semiconductor module. It is sectional drawing of the optical semiconductor module concerning Embodiment 2 of this invention.

  An optical semiconductor module according to an embodiment of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals. In addition, in order to avoid the description from becoming unnecessarily redundant and facilitate understanding, a detailed description of already well-known matters and a redundant description of substantially the same configuration may be omitted. The contents of the following description and drawings are not intended to limit the subject matter described in the claims.

  Between the drawings, the size or scale of each corresponding component is independent. For example, the size or scale of the same component may be different in a diagram in which a part of the configuration is changed and a diagram in which the configuration is not changed. In addition, when actually implementing the optical semiconductor module, it is necessary to provide some configurations. However, for the sake of simplicity, only the portions necessary for the description are described, and the other portions are described. Omitted.

  In the following, an optical semiconductor module will be described as an example. However, in addition to light, the present invention can be applied to a power semiconductor module having a similar problem and a semiconductor module handling a normal current. Is possible.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of an optical semiconductor module according to a first embodiment of the present invention, the whole being represented by 100, and FIG. 2 is a cross-sectional view when FIG. 1 is viewed in the II-II direction. .

  As shown in FIGS. 1 and 2, the optical semiconductor module 100 includes a metal block 30 as a semiconductor carrier. On the metal block 30, submounts 21, 22, 23, and 24 are joined with solder 61 at regular intervals. On the submounts 21, 22, 23, and 24, semiconductor laser chips (LD) 11, 12, 13, and 14 are joined by solder 62. The metal block 30 is joined to the thermo module 40 with solder 63.

  Further, as shown in FIG. 1, the lens base 50 is bonded onto the thermo module 40 by solder 63. A lens 51 is bonded on the lens base 50 by a resin adhesive 71. In FIG. 1, only one lens 51 is shown, but four lenses are bonded at regular intervals corresponding to each of the semiconductor laser chips 11, 12, 13, and 14.

  The thermo module 40 is joined to the bottom surface of the case 80 by the solder 64 and accommodated in the case 80. Further, a multiplexer 90 is joined to the bottom surface of the case 80 by a resin adhesive 72. 1 and 2, only the basic configuration of the optical semiconductor module 100 is illustrated, and other configurations such as a capacitor, a case, and a wire are omitted.

  Next, each component of the optical semiconductor module 100 will be described.

(1) Semiconductor laser chips 11-14
The semiconductor laser chips 11 to 14 convert electrical signals into optical signals or vice versa. For example, an LD (Laser Diode) or a PD (Photo Diode) is used for the semiconductor laser chips 11 to 14. In the first embodiment, an LD is used. In the first embodiment, each of the semiconductor laser chips 11 to 14 has one laser light generator, but a plurality of laser light generators may be formed. In the first embodiment, the number of the semiconductor laser chips 11 to 14 is four, but the number of the semiconductor laser chips 11 to 14 is not limited to this.

(2) Submounts 21-24
The submounts 21 to 24 include a ceramic base material, electrodes formed on the surface of the ceramic base material, and electrode patterns formed on the back surface (not shown). The ceramic base material is an electrical insulator, and in order to effectively cool the semiconductor laser chips 11 to 14, a material having a high thermal conductivity is preferable. For example, a ceramic such as AlN or Al ₂ O _{3 having a} thickness of 0.3 mm is preferable. A plate is used. In the first embodiment, the semiconductor laser chips 11 to 14 are bonded to the submounts 21 to 24 one by one, but a plurality of semiconductor laser chips may be bonded to one submount. In the first embodiment, the number of submounts 21 to 24 is four, but is not limited thereto.

  In general, the same material is used for the electrode patterns on the front and back surfaces of the submounts 21 to 24. The semiconductor laser chips 11 to 14 are soldered by solder 62 to the electrode pattern on the surface side corresponding to the circuit side. Furthermore, by forming a bonding portion on the electrode pattern with an Au wire or the like, it is electrically connected to surrounding members and the surfaces of the semiconductor laser chips 11 to 14. Thus, since the electrode pattern on the front surface side is also a wiring member for electrically connecting the semiconductor laser chips 11 to 14 and an external circuit, a metal having a small electric resistance is preferable. Metallization with Au or the like of 3.0 μm or less is used.

  On the other hand, the metal block 30 is joined to the electrode pattern on the back side corresponding to the heat radiating side by the solder 61. In this case, the laser output directions of the semiconductor laser chips 11 to 14 joined to the surface at equal intervals. They are bonded so that the multiplexer 90 faces and the distances from the multiplexer 90 to the semiconductor laser chips 11 to 14 are equal.

(3) Metal block 30
The metal block 30 that is a semiconductor carrier is made of a material that transfers heat and electricity well, such as a metal such as Cu, Fe, or Al, or an insulator such as ceramic or resin coated with a metal. The metal block 30 is joined to the thermo module 40 with the solder 63 so that the surface (main surface) on which the submounts 21 to 24 are soldered is the surface (main surface) and the surface is oriented in the positive direction of the Z axis in FIG. Here, the metallization 30a is formed on all the surfaces of the metal block 30, but the present invention is not limited to this.

  In order to effectively wet and spread the solder, for example, Au having a thickness of 3.0 μm or less is used for the metallization 30a. In the first embodiment, when the metal block 30 is soldered to the thermo module 40 by covering the side surface of the metal block 30 with the metallization 30a, an excessive amount of solder 63 is applied from the bottom surface of the metal block 30 to the side surface in contact with the bottom surface. Gets wet.

(4) Thermo module 40
The thermo module 40 transmits the heat received by the upper heat absorbing portion to the lower heat radiating portion via the Peltier element and releases the heat from the heat radiating portion. The heat absorbing plate and the heat radiating plate are made of a ceramic having a metallized surface, for example. In the first embodiment, the thermo module 40 is joined to the case 80 with the solder 64 so that the surface on which the metal block 30 and the lens base 50 are joined is the front surface and faces the positive direction of the Z axis in FIG. . Thereby, the temperature of the semiconductor laser chips 11 to 14 is controlled by the thermo module 40, and continuous stable operation becomes possible.

  Further, the metallization 40a is formed on the solder joint surface (first region) with the metal block 30 of the thermo module 40, and the metallization 40b is formed on the solder joint surface (second region) with the lens base 50, respectively. Further, a metallized 40 c is formed on the solder joint surface with the case 80. The same material is preferably used for the metallizations 40a, 40b, 40c. For the metallizations 40a, 40b, 40c, for example, Au having a thickness of 3.0 μm or less is used in order to effectively wet and spread the solder.

  In the first embodiment, the metallizations 40a, 40b, and 40c are formed with an area smaller than the projected area on the XY plane of the solder joint surfaces of the metal block 30, the lens base 50, and the case 80 to be soldered. . The solder 63 wets and spreads over the entire surfaces of the metallized 40a and metallized 40b, and excess solder wets and spreads on the side surfaces of the metal block 30 and the lens base 50, respectively. On the other hand, the solder 64 wets and spreads on the entire surface of the metallized 40 c, and excess solder spreads on the bottom surface of the case 80.

(5) Lens base 50
The lens base 50 is made of an insulator such as a metal such as Cu, Fe, or Al, ceramic, or resin. Unlike the metal block 30, since it is not a conduction path for electricity and heat, there is no problem even if it is not a material that conducts heat and electricity well. However, the lens base 50 is joined by the solder 63 with the surface to which the lenses 51 to 54 are bonded as the surface, and the surface faces in the positive Z-axis direction of FIG. 1 and in the laser output direction of the semiconductor laser chips 11 to 14. Is done.

  The metallized 50a is formed on the solder joint surface of the lens base 50, and the metallized 50b is also formed on the side surface in contact with the metallized 50a so as to be in contact with the metalized 50a. The metallized 50a and the metallized 50b are preferably formed from the same material. For the metallization 50a and the metallization 50b, in order to effectively wet and spread the solder, for example, Au having a thickness of 3.0 μm or less is used. In the first embodiment, the metallized 50b is formed on the side surface of the lens base 50 in contact with the metallized 50a over the entire circumference of the metalized 50a from the position in contact with the metallized 50a to a height of 0.5 mm. It goes up and is joined with the thermo module 40.

(6) Lenses 51-54
Lenses 51 to 54 (lenses 52 to 24 are not shown) are formed of glass or transparent resin, and condense the laser beams emitted from the semiconductor laser chips 11 to 14, respectively. In the first embodiment, the number of lenses 51 to 54 is four, but is not limited to this.

(7) Solder 61, 62, 63, 64
The solder 61 joins an electrode pattern (not shown) formed on the back surfaces of the submounts 21 to 24 to the surface of the metal block 30. In the manufacturing process of the optical semiconductor module 100, the metal block 30 is not yet joined to the thermo module 40 when the submounts 21 to 24 are joined to the metal block 30 by the solder 61. Therefore, the material of the solder 61 is preferably a metal having a melting point higher than that of the solder 63 and high thermal conductivity so that the solder 61 does not remelt when the solder 63 is joined. General solder contains Sn, Pb, Au, Ag, Cu, Zn, Ni, Sb, Bi, In, Ge, etc., and an alloy having a melting point of less than 450 ° C. is used. It is preferable to use an alloy mainly containing Sn or Ge in Au and having a melting point of 250 ° C. or higher. The thickness of the solder 61 is preferably 0.1 mm or less in order to obtain good heat dissipation.

  The solder 62 joins the electrode patterns 21b to 24b formed on the surfaces of the submounts 21 to 24 to the semiconductor laser chips 11 to 14. When the semiconductor laser chips 11 to 14 are joined to the submounts 21 to 24 by the solder 62, the submounts 21 to 24 are not yet joined to the metal block 30 or just after being joined to the metal block 30. Therefore, the material of the solder 62 is preferably a metal having a melting point higher than that of the solder 63 and high thermal conductivity so that the solder 62 does not remelt when the solder 63 is joined. In order to save the trouble of switching the solder material, it is preferable to use the same material as the solder 61.

  When the semiconductor laser chips 11 to 14 are bonded to the submounts 21 to 24 before the submounts 21 to 24 are bonded to the metal block 30, the melting point of the solder 62 is preferably higher than that of the solder 61. For this reason, it is preferable to use an alloy containing Sn, Ge, or the like in Au and having a melting point of 250 ° C. or higher. Also, the thickness of the solder 62 is preferably 0.1 mm or less, like the solder 61, in order to obtain good heat dissipation.

  The solder 63 joins the metal block 30 and the lens base 50 to metallizations 40a and 40b formed on the surface of the thermo module 40, respectively. When the metal block 30 is joined by the solder 63, the semiconductor laser chips 11 to 14 are already connected to the submounts 21 to 24 by the solder 62, and the submounts 21 to 24 are already attached to the surface of the metal block 30 by the solder 61. It is joined. Therefore, the material of the solder 63 is preferably a metal having a melting point lower than that of the solders 61 and 62 and high thermal conductivity so that the solder 61 and the solder 62 do not remelt when the solder 63 is joined. For this reason, it is preferable to use an alloy containing Ag, Cu or the like in Sn and having a melting point of less than 250 ° C. for the solder 63.

  The solder 64 joins the metallized 40 c formed on the back surface of the thermo module 40 to the bottom surface of the case 80. At the time when the thermo module 40 is joined to the case 80 by the solder 64, the metal block 30 and the lens base 50 are not yet joined to the thermo module 40. Therefore, the material of the solder 64 is preferably a metal having a melting point higher than that of the solder 63 and a high thermal conductivity so that the solder 64 does not remelt when the solder 63 is joined. For this reason, it is preferable to use an alloy containing Sn, Ge, or the like in Au and having a melting point of 250 ° C. or higher. The thickness of the solder 64 is preferably 0.1 mm or less, like the solder 61 and the solder 62, in order to obtain good heat dissipation. In order to save the trouble of switching the solder material, it is preferable to use the same material as the solder 61 and 62.

(8) Resin adhesive 71, 72
The resin adhesive 71 bonds the lens base 50 and the lenses 51 to 54, and the resin adhesive 72 bonds the case 80 and the multiplexer 90. At the time when the respective members are bonded by the resin adhesives 71 and 72, other components such as the submount are already joined by the solders 61 to 64. Therefore, the material of the resin adhesives 71 and 72 is such that the heating temperature necessary for bonding is such that the melting points of the solders 61 to 64 do not remelt the solders 61 to 64 at the time of bonding or the components to be bonded are destroyed. It is preferable that the resin be lower than the heat resistance temperature of the parts joined by the solders 61 to 64. It is more preferable if it is a resin that can be cured and adhered by a method other than heating such as irradiation with ultraviolet rays. Further, since the lens base 50 and the lenses 51 to 54 bonded by the resin adhesives 71 and 72 in the first embodiment and between the case 80 and the multiplexer 90 are not conductive paths, resin bonding The agents 71 and 72 do not need to be conductive.

(9) Case 80
The case 80 includes a flat bottom portion to which the thermo module 40 is joined by the solder 64, and a plurality of side portions provided on the outer edge of the bottom portion. Further, as shown in FIG. 1, on one side portion of the case 80, there is an emitting portion for guiding the laser light multiplexed by the multiplexer 90 and wavelength-multiplexed to an optical fiber (not shown). The emission portion is provided and sealed by a lens 81.

(10) Multiplexer 90
The multiplexer 90 multiplexes the emitted light from the semiconductor laser chips 11 to 14 and outputs the combined light. The multiplexed light output from the multiplexer 90 is transmitted as a wavelength multiplexed signal through a lens 81 provided in the case 80 through an optical waveguide such as an optical fiber. In some cases, a duplexer is used instead of the multiplexer.

  Next, a specific effect obtained by the optical semiconductor module 100 according to the first embodiment configured as described above will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, in the optical semiconductor module 100 including the plurality of semiconductor laser chips 11 to 14, the lens base 50 and the lenses 51 to 54, as compared with the conventional optical semiconductor module, as described above. There are many parts that must be mounted, such as the multiplexer 90. In addition, there are many parts that must be stacked and joined, such as the case 80, the thermo module 40, the metal block 30, the submounts 21 to 24, and the semiconductor laser chips 11 to 14.

  In particular, in the optical semiconductor module 100, it is necessary to multiplex the light emitted from the plurality of semiconductor laser chips 11 to 14 and output the combined light, so that the semiconductor laser chips 11 to 14 and the lenses 51 to 54 are multiplexed. It is very important to assemble so that the relative distance from the device 90 is always constant, and particularly high accuracy is required. For this reason, the optical semiconductor module 100 including the plurality of semiconductor laser chips 11 to 14 includes a plurality of types of bonding materials having different heating temperatures necessary for bonding, such as solders 61 to 64, resin adhesives 71 and 72, and the like. In general, the parts are assembled in order in a plurality of processes.

  Further, in the conventional optical semiconductor module, the component to be mounted at the time of soldering is generally smaller than the component to be mounted, that is, the component that becomes the lower part at the time of soldering. However, in the optical semiconductor module 100 according to the first embodiment, in order to make the optical semiconductor module 100 as small as possible, the thermomodule 40 is made smaller than the metallized parts 40a and 40b which are solder joint surfaces of the thermomodule 40. The area of the solder joint surface of the metal block 30 and the lens base 50 mounted thereon is larger. That is, the thermo module 40 is made smaller than the minimum size of the metal block 30 and the lens base 50 necessary for joining the submounts 21 to 24 and mounting the lenses 51 to 54, and the entire optical semiconductor module 100 is made smaller. We are trying to make it.

  However, on the other hand, by setting the area of the solder joint surface of the metal block 30 and the lens base 50 to be larger than that of the metallizations 40a and 40b, excess solder is provided between the metallizations 40a and 40b and the metal block 30 and the lens base 50. There is no space for 63 to spread out. For this reason, there is a possibility that the excessively supplied solder 63 protrudes on the thermo module 40 or becomes a solder ball and is scattered around.

  Solder balls that protrude from between the metallized layers 40a and 40b and between the metal block 30 and the lens base 50 or scatter around the metallized layers adhere to the side walls of the case 80 and are electrically connected to the metallized 40a. This is a problem because the multiplexer 90 adheres to an empty space where the multiplexer 90 is to be bonded in the process and cannot be bonded.

  In addition, in order to reduce the size of the optical semiconductor module 100, the metal block 30, the lens base 50, and the side walls of the case 80 are separated from each other by a minimum necessary distance. Since it is narrow, a nozzle or the like for sucking excess solder 63 protruding between the metallizations 40a and 40b, the metal block 30 and the lens base 50 cannot be inserted.

  In addition, if the supply amount of the solder 63 is reduced so that the excessively supplied solder 63 does not protrude or scatter as solder balls, in order to confirm the joining state of the solder joint, the solder joint However, since the bottom surface and side wall of the case 80 exist on the side and the bottom of the solder 63, the solder joint cannot be visually observed. Therefore, the solder 63 is sufficiently wet and spread between the metallizations 40a and 40b and the metal block 30 and the lens base 50, and it becomes impossible to inspect whether or not the solder wetting defect has occurred, and the solder wetting defect cannot be found.

  On the other hand, in the optical semiconductor module 100 according to the first embodiment, the metallization 30a is formed on the entire surface of the metal block 30, and the metallization 50b is formed on the side surface in contact with the solder joint surface of the lens base 50. The supplied solder 63 wets and spreads to the side surfaces of the metal block 30 and the lens base 50. For this reason, it is possible to prevent the excessively supplied solder 63 from becoming a solder ball and protruding or scattered.

  In particular, as shown in the first embodiment, when a component such as a multiplexer 90 that is bonded with the resin adhesive 72 after the solder bonding step is present in the vicinity of the solder bonded portion, the excessively supplied solder 63 scatters as solder balls, adheres to the bonding planned area of the multiplexer 90 on the bottom surface of the case 80, and the multiplexer 90 cannot be bonded. For this reason, by providing a metallization that spreads the solder on the side surfaces of the parts such as the metal block 30 and spreading the solder on the side surfaces, the excess solder becomes solder balls and scatters around. It is possible to prevent adhesion to the adhesion planned area.

  Furthermore, the solder 63 that spreads wet on the side surfaces of the metal block 30 and the lens base 50 can be visually observed from the opening above the case 80. For this reason, by visually inspecting whether the solder 63 spreads on the side surfaces of the metal block 30 and the lens base 50, the solder joint between the metallization 40a, 40b and the metal block 30 and the lens base 50 is It can be confirmed whether sufficient solder wetting is obtained.

  In the first embodiment, the metallization 30a is formed on the entire surface of the metal block 30, and in the lens base 50, the metallization 50b is formed on the side surface in contact with the solder joint surface. However, the formation region of the metallization is not limited to this, and another shape may be used as long as the excessively supplied solder 63 spreads all over the metallization.

  FIG. 3A is a perspective view of another lens base 50 used in the optical semiconductor module 100 shown in FIG. In FIG. 3A, metallizations 50 a and 50 b are provided on the bottom surface and four side surfaces of the lens base 50, respectively, but the configuration is not limited to this as long as excessive solder leaks.

  For example, as shown in FIG. 3B, the metallization 50b may be formed only on two opposite surfaces of the bottom surface of the lens base 50 and the side surface in contact with the solder joint surface.

  Further, as shown in FIG. 3C, the metallized 50b may be formed not to the entire side surface in contact with the solder joint surface of the lens base 50 but to a height of several mm (1 mm in FIG. 3C) from the portion in contact with the solder joint surface. . In particular, when the metallized layer 50b is formed only on the side surface in contact with the bonding surface of the lens base 50 that faces the Y direction in FIG. 1 up to about half the height from the side in contact with the soldered surface, the solder spreads wet on the metalized layer 50b. 63 can be prevented from adhering to the side portion of the case 80, and the path of the laser light passing through the lenses 51 to 54 can be prevented from being obstructed by wet solder.

  Such a metallization configuration on the side surface of the lens base 50 may be applied to a metallization configuration on the side surface of the metal block 30.

  Further, in the first embodiment, the area of the solder joint surface between the metal block 30 and the lens base 50 is larger than the area of the metallizations 40a and 40b. Also good. FIG. 4 is a cross-sectional view of another optical semiconductor module according to the first embodiment of the present invention, the whole of which is represented by 150, as viewed in the II-II direction of FIG. The same reference numerals as those in FIG. 1 indicate the same or corresponding portions. In the optical semiconductor module 150, some of the submounts 21 and 24 protrude from the metal block 30 and are joined by soldering, thereby reducing the size of the metal block 30 and reducing the size of the optical semiconductor module 150.

  In addition, by making the size of the component to be mounted larger than that of the lower component, the solder joint area becomes smaller than that of the component to be mounted, so that it becomes difficult to transfer the heat of the mounted component to the lower component. For this reason, like the lens base 50 of the first embodiment, the lenses 51 to 54 mounted on the lens base 50 do not generate heat, and the joint portion is not a heat dissipation path, or the metal block 30 It is preferable to apply this configuration to a part in which the reduction of the solder joint area in the thermo module 40 mounted on the metal block 30 does not greatly affect the overall thermal resistance due to heat spreading in the metal block 30.

  In the optical semiconductor modules 100 and 150 according to the first embodiment, both the metal block 30 and the lens base 50 have a rectangular parallelepiped shape, but the shapes of the metal block 30 and the lens base 50 are not limited thereto.

  5A and 5B are plan views of the lens base 50 mounted on the thermo module 40 as viewed from above. As shown in FIG. 5A, a recess 55 penetrating from the front surface to the back surface may be formed on the side surface in contact with the solder joint surface so that a part of the metallized 40b can be seen. Here, the recess 55 has a semi-cylindrical shape whose central axis extends in the Z-axis direction, but is not limited thereto, such as a prismatic shape.

  Further, as shown in FIG. 5B, a concave portion 57 is provided below the lens base 50, the YZ cross-sectional shape of the lens base 50 is convex downward, and the width in one direction of the rear surface of the lens base 50 is the surface. By providing the concave portions 57 on the two opposing side surfaces of the lens base 50 so as to be narrower than the width in the same direction, the projected area of the lens base 50 in the solder joint surface direction (Z-axis direction in FIG. 1) While making it larger than the metallized 40b, the area of the metallized 50a, which is the actual solder joint surface, may be smaller than the metallized 40b.

  When the concave portion 55 is formed so that a part of the metallization 40b is exposed when viewed in the Z-axis direction as in the structure of FIG. 5A, the excess solder 63 preferentially spreads in the concave portion 55. A solder fillet of the solder 63 is formed by the inside of 55 and the metallized 40b. Thereby, the strength of the solder joint between the lens base 50 and the thermo module 40 is increased, the thermal shock resistance is improved, and the life of the optical semiconductor module 100 can be extended.

  Further, by making the shape of the YZ cross section of the lens base 50 convex downward as in the structure of FIG. 5B, the solder joint area between the metallized 40 b and the lens base 50 is a rectangular parallelepiped. However, there is no problem with a component that does not become a heat dissipation path, such as the lens base 50. On the contrary, the solder spreads on the side surface of the concave portion 57 of the lens base 50, and a solder fillet of the solder 63 is formed by the concave portion 57 of the lens base 50 and the metallized 40 b, and the solder joint between the lens base 50 and the thermo module 40 is formed. The thermal shock resistance of the part is increased, and the lifetime of the optical semiconductor module 100 can be extended. Further, by designing the dimensions of the recess 57 so that the solder joint between the lens base 50 and the thermo module 40 can be visually observed from the opening of the case 80, the solder joint between the metallized 40b and the lens base 50 is designed. It is possible to visually confirm the quality.

  As described above, in the optical semiconductor modules 100 and 150 according to the first embodiment, the metallized 40a formed on the thermo module 40 from the projected area in the XY plane of the solder joint surfaces of the metal block 30 and the lens base 50. , 40b, the metallization 30a is formed on the side surface of the metal block 30, and the metallization 50b is formed on the side surface of the lens base 50, respectively. As a result, the excessively supplied solder 63 wets and spreads on the metallized 30a and the metallized 50b, so that solder balls that protrude or scatter from between the metallized 40a, 40b, the metal block 30, and the lens base 50 are surrounded by the surroundings. By adhering to each other, it is possible to prevent electrical conduction between components, or adhesion to a bonding region of a subsequent component and occurrence of a bonding defect.

  In addition, since the appearance of the solder 63 wetted and spread on the metallized 30a and the metallized 50b can be inspected from the opening of the case 80, the wettability of the solder joint between the metallized 40a and 40b and the metal block 30 and the lens base 50 is visually checked. Pass / fail can be determined.

  Furthermore, by making the metallizations 40a and 40b smaller than the metal block 30 and the lens base 50, the thermo module 40 can be downsized as compared with the conventional optical semiconductor module. As a result, the area necessary for soldering the thermo module 40 to the case 80 can be reduced, the entire optical semiconductor module 100 can be reduced in size, and the cost and quality can be reduced.

  Then, the manufacturing method of the optical semiconductor module 100 concerning Embodiment 1 of this invention is demonstrated using FIG. 6A-FIG. 6E. This manufacturing method includes the following steps (a) to (e).

Step (a)
A case 80 and a thermo module 40 are prepared. Metallizations 40a and 40b are provided on the front surface of the thermo module 40, while metallization 40c is provided on the back surface. Then, the thermo module 40 is joined to the bottom surface of the case 80 using the solder 64 under an N ₂ atmosphere.

  Next, the solder 63 is placed on or supplied to the metallizations 40 a and 40 b of the thermo module 40. The solder 63 may be formed in advance on the metallizations 40a and 40b of the thermo module 40 by vapor deposition or plating. Subsequently, as shown in FIG. 6A, the case 80 is placed on the hot plate 1.

Step (b)
As shown in FIG. 6B, the entire optical semiconductor module 100 is heated from the bottom of the case 80 to a temperature not lower than the melting point of the solder 63 and lower than the melting point of the solder 64 by the hot plate 1 to melt the solder 63. For example, when AuSn solder having a melting point of 280 ° C. is used for the solder 64 and SnAgCu solder having a melting point of 230 ° C. is used for the solder 63, the heating temperature of the hot plate 1 is 270 ° C.

Step (c)
As shown in FIG. 6C, the metal block 30 and the lens base 50 respectively held by the collets 301 and 302 are placed on the melted solder 63 and pressed in the direction of the thermo module 40. As a result, the solder 63 wets and spreads on the metallized 40a and the metallized 30a, and the metallized 40b and the metallized 50a.

  Furthermore, since the areas of the metallizations 40a and 40b formed on the thermo module 40 are smaller than the areas of the metallization 30a of the metal block 30 and the metallization 50a of the lens base 50, the excessively supplied solder 63 is used as the metallization 30a, The metallization 50a wets and spreads to areas where the metallizations 40a and 40b do not exist. At this time, in the optical semiconductor module 100, since the metallized 30 a is formed on the entire surface of the metal block 30 and the metallized 50 b is formed on the side surface of the lens base 50 in contact with the metallized 50 a, the excessive solder 63 is added to the metal block 30. And the metallization 30a on the side surface and the metallization 50b on the side surface of the lens base 50, respectively. As a result, excessive solder 63 does not jump out of the metal block 30, the lens base 50, and the thermo module 40 and adhere to the side surface or bottom surface of the case 80.

Step (d)
As shown in FIG. 6D, the case 80 is removed from the hot plate 1 and cooled to the ambient temperature, and then the resin adhesive 72 is supplied onto the bottom surface of the case 80 between the thermo module 40 and the lens 81. In this manufacturing method, since the excessively supplied solder 63 does not adhere to the bottom surface of the case 80, the resin adhesive 72 can be supplied without any problem.

Step (e)
As shown in FIG. 6E, the multiplexer 90 is placed on the resin adhesive 72. The case 80 on which the multiplexer 90 is placed is placed in a thermostatic bath or the like and heated to below the melting point of the solder 63 to cure the resin adhesive 72. The temperature of the thermostat or the like is 130 ° C., for example. Since the solder 63 does not adhere to the bottom surface of the case 80, as shown in FIG. 7B, the multiplexer 90 can be bonded without being inclined.

  Here, FIG. 7A and FIG. 7B are cross-sectional views showing the manufacturing process of the conventional optical semiconductor module, and correspond to FIG. 6D and FIG. 6E of the present invention, respectively. As shown in FIG. 7A, since the metal block 30 and the side surface of the lens base 50 are not provided with metallization, excessive solder 63 protrudes from the thermo module 40 and adheres to the side wall of the case 80. Further, the excessive solder 63 becomes a solder ball and adheres to a planned installation area of the multiplexer 90 on the bottom surface of the case 80. For this reason, the resin adhesive 72 gets on the solder 63. As a result, as shown in FIG. 7B, when the multiplexer 90 is bonded with the resin adhesive 72, the multiplexer 90 is inclined or cannot be bonded due to the influence of the solder 63.

  As described above, in the manufacturing method of the present invention, the excessive solder 63 spreads on the metallization 30a on the side surface of the metal block 30 and the metallization 50b on the side surface of the lens base 50. And the lens base 50 and the thermo module 40 do not jump to the outside and adhere to the side surface or bottom surface of the case 80, because of the conduction between the metal block 30 and the case 80 and the solder 63 attached to the bottom surface of the case 80. When the multiplexer 90 is bonded by the resin adhesive 72, it is possible to prevent problems such as tilting of the multiplexer 90.

  In addition, the solder 63 that has spread on the side surfaces of the metal block 30 and the lens base 50 can be visually observed from the opening above the case 80. As shown in FIG. 6E, the solder 63 that spreads wet on the side surfaces of the metal block 30 and the lens base 50 is obtained after the solder 63 wets and spreads on the entire surfaces of the metallized 40a and the metallized 30a, and the metallized 40b and the metallized 50a. This is the excessive solder 63 that has spread to the area where no solder exists. Therefore, conversely, even if the solder 63 is supplied in an excessively small amount and the solder 63 is completely melted and spreads, the metal block 30 and the metallized 40a and the metallized 30a, the metallized 40b and the metallized 50a are not wetted and spread all over. The solder 63 does not spread to the side surface of the lens base 50. For this reason, an excessive amount of solder 63 is supplied to the entire surfaces of the metallized 40a and the metallized 30a, and the metallized 40b and the metallized 50a so that the solder 63 gets wet, and the side surfaces of the metal block 30 and the lens base 50 are supplied. By making the solder 63 wet and spread, it is possible to determine whether the solder joint is good or not by inspecting whether the solder is sufficiently spread on the joint surface.

Embodiment 2. FIG.
FIG. 8 is a cross-sectional view of the optical semiconductor module according to the second embodiment of the present invention, indicated as a whole by 200, and the same reference numerals as those in FIG. 1 indicate the same or corresponding parts. The optical semiconductor module 200 according to the second embodiment basically has the same configuration as the optical semiconductor module 100 according to the first embodiment, but differs in the following points. Here, differences will be described, and description of the same components will be omitted. In FIG. 8, only the basic components of the optical semiconductor module 200 are shown, and the other components are not shown.

  In the second embodiment, as shown in FIG. 8, the submounts 21 to 24 (submounts 22 to 24) in which the semiconductor diode chips 15 to 18 (the semiconductor diode chips 16 to 18 are not shown) are joined by solder 62. Is different from the optical semiconductor module 100 according to the first embodiment in that it is soldered to the side surface of the metal block 30 by solder 61. Further, in FIG. 8, an insulating substrate 41 is used in place of the thermo module 40.

  In the optical semiconductor module 200 according to the second embodiment, the semiconductor laser chips 11 to 14 are not LDs (Laser Diodes) but semiconductor diode chips 15 to 18 composed of PDs (Photo Diodes), so that they are compared with LDs. As a result, the temperature does not rise during operation. For this reason, it is not necessary to control the temperature of the semiconductor diode chips 15 to 18 by the thermo module 40, and there is no problem even if the solder joint area between the metallized 41a and the metal block 30 is small. Further, the thermo module 40 may be changed from the thermo module 40 to the insulating substrate 41.

  In addition, by joining the submounts 21 to 24 to the side surface of the metal block 30, it is necessary for the optical semiconductor module 200 such as a capacitor or an amplifier on the upper surface of the metal block 30 (the surface in the Z-axis direction in FIG. 5). Other components 28 can be joined. Thus, by arranging the component 28 on the metal block 30, the entire optical semiconductor module 200 can be further downsized.

  11, 12, 13, 14 Semiconductor laser chip, 15, 16, 17, 18 Semiconductor diode chip, 21, 22, 23, 24 Submount, 30 Metal block, 30a Metallization, 40 Thermo module, 40a, 40b, 40c Metallization, 41 Insulating substrate, 41a Metallized, 50 Lens base, 50a, 50b Metallized, 51, 52, 53, 54 Lens, 61, 62, 63, 64 Solder, 71, 72 Resin adhesive, 80 Case, 81 Lens, 90 Combined 100, 150, 200 Optical semiconductor module.

Claims (15)

A semiconductor module in which a second component is bonded onto a first component,
A first part with a first metallization on the surface;
A second component comprising a second metallization provided continuously on the back and side surfaces;
Solder for joining the first metallization and the second metallization;
The first metallization is included in a projection region obtained by vertically projecting the back surface of the second component onto the surface of the first component;
A semiconductor module, wherein the solder spreads on the second metallization provided on a side surface of the second component. The first component is a thermo module or an insulating substrate,
The semiconductor module according to claim 1, wherein the second component is a semiconductor carrier in which an optical semiconductor element solder-bonded to a submount is solder-bonded to a front surface or a side surface. A first metallization of the first part is formed in the first region and the second region;
A third part having a third metallization continuously provided on the back surface and the side surface is joined to the second region different from the first region to which the second component is joined by soldering;
The projection region obtained by vertically projecting the back surface of the third component onto the front surface of the first component includes the second region of the first metallization,
2. The semiconductor module according to claim 1, wherein the solder wets and spreads on the third metallization provided on a side surface of the third component. The first component is a thermo module or an insulating substrate,
The second component is a semiconductor carrier in which an optical semiconductor element fixed to a submount is soldered to the surface or side surface,
The semiconductor module according to claim 3, wherein the third component is a base block having a lens fixed on a surface thereof.   The semiconductor module according to claim 1, wherein the second metallization on the side surface of the second component is provided on at least a part of the side surface of the second component.   5. The semiconductor module according to claim 3, wherein the third metallization of the side surface of the third component is provided on at least a part of the side surface of the third component.   The semiconductor module according to any one of claims 1 to 4, wherein a concave portion penetrating from the front surface to the back surface is provided on a side surface of the second component, and the second metallization is provided inside the concave portion. A side surface of the second component is provided with a recess penetrating from the front surface to the back surface, and the second metallization is also provided in the inside thereof, and / or
5. The semiconductor module according to claim 3, wherein a concave portion penetrating from the front surface to the back surface is provided on a side surface of the third component, and the third metallization is provided therein.   Recesses are provided in two opposing side surfaces of the second component so that the width in one direction on the back surface of the second component is smaller than the width in the same direction on the front surface, and the second metallization is also provided in the inside thereof. The semiconductor module according to claim 1, wherein the semiconductor module is provided. Recesses are provided on opposite side surfaces of the second component so that the width in one direction of the back surface of the second component is smaller than the width in the same direction on the front surface, and the second metallization is also provided in the inside thereof. And / or
Recesses are provided on opposite side surfaces of the third component so that the width in one direction of the back surface of the third component is narrower than the width in the same direction on the front surface, and the third metallization is also provided in the inside thereof. The semiconductor module according to claim 3 or 4, wherein the semiconductor module is formed.   The melting point of the solder that joins the first metallization and the second metallization is higher than the melting point of the solder that joins the semiconductor carrier and the submount and the solder that joins the submount and the optical semiconductor element. The semiconductor module according to claim 2, wherein the semiconductor module is low. Case and
A duplexer provided on the bottom of the case, and
The semiconductor module according to claim 4, wherein light emitted from the optical semiconductor element passes through the lens and enters the duplexer. Preparing an insulating substrate or thermo module having a first metallization on the surface;
A step of preparing a semiconductor carrier in which a submount to which an optical semiconductor element is soldered is bonded to a front surface or a side surface, and a second metallization is continuously provided on the back surface and the side surface;
Supplying solder onto the first metallization;
Melting the solder;
The surface of the semiconductor carrier is brought into contact with the solder and pressed in the direction of the first metallization to wet the solder over the second metallization provided on the side surface of the semiconductor carrier; and
Solidifying the solder at a position where the first metallization is included in a projection region obtained by vertically projecting the back surface of the semiconductor carrier onto the surface of the insulating substrate or thermo module. Method. The first metallization of the insulating substrate or thermo module is provided in a first region and a second region, and the semiconductor carrier is bonded to the first region;
Preparing a base block in which a lens is fixed to the front surface and the third metallization is continuously provided on the back surface and the side surface;
Supplying solder onto the first metallization of the second region;
Melting the solder;
The surface of the base block is brought into contact with the solder and pressed in the direction of the first metallization to wet the solder over the third metallization provided on the side surface of the base block; and
Solidifying the solder at a position where the second region of the first metallization is included in a projection region obtained by vertically projecting the back surface of the semiconductor carrier onto the surface of the insulating substrate or thermo module. A method for manufacturing a semiconductor module according to claim 13.   15. The method of manufacturing a semiconductor module according to claim 13, wherein the melting point of the solder supplied on the first metallization is lower than the melting point of other solders.

Images