JP2001077262A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stem for semiconductor laser device by drawing a thin metal plate, and secure strength and heat radiation. SOLUTION: To form a stem in a semiconductor laser device with a thin metal plate, an annular wall portion is formed on a base 1 by press working of the thin metal plate. An out lead 4 is disposed in a space formed in this annular wall portion and fixed by filling and solidifying m insulating thermosetting resin. A mounting portion (heat sink) 3 for mounting a silicon submount on the base 1 is formed integrally with the base 1 by press working. Insufficient strength and heat radiation due a thin metal plate stem is compensated by formation of the continuous walls.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device having a stem formed by processing a thin metal plate by sheet metal working with a press, and more particularly to a semiconductor laser device having improved heat radiation.

[0002]

2. Description of the Related Art The stem of a conventional semiconductor laser device is
For example, as shown in FIG. 10, a base 1, an outlead 4 attached to the base 1, and a heat sink 3 which is a mounting portion of a silicon submount for mounting a semiconductor laser light emitting element and the like are provided. 1.2m
A disk made of an iron material having a thickness of 5.6 mm and having a diameter of 5.6 mm is formed by forging with a press die, and at this time, the heat sink portion 3 is formed by either crushing the peripheral portion of the disk or raising the center portion. Is formed. The outlead 4 is fixed to the base 1 by the insulating fused glass 12.

[0003]

However, when manufacturing a stem by the conventional method, it is difficult to reduce the manufacturing cost because of the following problems. (1) A thick metal plate is used for the forging die, which increases the material cost. In addition, since the thick metal plate is forged, it is easily worn or broken. (2) Since high precision is required for the side dimensions of the base of the stem, in the case of forging, in addition to forging the peripheral portion of the disk, processing of the side face and the like is also required. (3) The bonding between the base and the outlead has a melting point of 1000
Although the temperature is higher than the melting point of gold, the temperature is higher than the melting point of gold. Therefore, the out-lead gold plating must be performed after bonding to the base. Accordingly, the base must be gold-plated in accordance with the outlead, although Ni-plating is normally sufficient. Further, when mounting on an optical pickup, if heat radiation is not so problematic, the base may be reduced (see the drawing) to reduce the mounting surface, but the base formed by conventional forging is cut by cutting or the like. Otherwise, there is a problem that the mounting area cannot be reduced and a simple method such as punching with a press cannot be adopted. In order to solve such a problem, for example, in a semiconductor laser device having a stem, it is conceivable to form the base of the stem from a thin metal plate of, for example, about 0.1 mm to 0.5 mm by pressing. Unlike the base formed by stamping out a relatively thick metal plate of about 1.2 mm by forging, the thin metal plate has a weak strength when applied to the pickup, and causes new problems such as bending and warpage. In some cases, it is difficult to say that the heat radiation characteristics are sufficient. In addition, with the emergence of light emitting elements with short wavelengths or high output light emitting elements in recent years, stems with higher heat dissipation properties are required.

[0004]

According to a first aspect of the present invention, there is provided a semiconductor laser device having a base, a mounting portion for a laser light emitting element or the like formed integrally with the base, and a stem comprising an outlead. A semiconductor laser device formed by bending a metal plate to have an annular wall portion. According to a second aspect of the present invention, in the semiconductor laser device according to the first aspect, the annular wall portion is formed by bending a sheet metal at an interval from a peripheral edge thereof, and mounting the laser light emitting element and the like. The portion is formed by cutting and raising the upper surface of a sheet metal to form the annular wall portion. According to a third aspect of the present invention, in the semiconductor laser device according to the first aspect, the annular wall portion is formed by bending a peripheral edge of a sheet metal, and a mounting portion for the laser light emitting element or the like cuts and raises the upper surface of the sheet metal. A semiconductor laser device characterized by being formed. According to a fourth aspect of the present invention, in the semiconductor laser device according to the first or second aspect, the outlead is joined to the base by a thermosetting resin sealed in the annular wall. Semiconductor laser device. A fifth aspect of the present invention is the semiconductor laser device according to the first or second aspect, wherein the outlead and the base are plated with different materials. A sixth aspect of the present invention is the semiconductor laser device according to the first or second aspect, wherein the annular wall portion is a radiation fin. According to a seventh aspect of the present invention, in the semiconductor laser device having a stem, the stem has a base having an annular wall portion formed by bending a sheet metal on a peripheral edge, and a heat sink member is sealed in the annular wall portion. A semiconductor laser device characterized in that: The invention according to claim 8 is the semiconductor laser device according to claim 7, wherein the heat sink member is an insulated copper material. According to a ninth aspect of the present invention, in the semiconductor laser device having a stem, the stem has an annular wall portion formed by bending a clad material in which two kinds of metals having different thermal conductivities are attached in a stripe shape. It has a base, and at least an attachment part of a laser light emitting element or the like integrally formed with the base is molded so as to be formed of a metal part having high thermal conductivity among the different metals. Semiconductor laser device. The invention of claim 10 is
In a semiconductor laser device having a stem, the stem has a base having an annular wall portion formed by bending a clad material in which two kinds of metals having different thermal conductivities are adhered to the front and back surfaces, and the base has a base. A semiconductor laser device characterized in that only a mounting portion of a laser light emitting element or the like formed integrally is molded so as to be formed of a metal portion having high thermal conductivity among the different metals. According to an eleventh aspect of the present invention, in the semiconductor laser device according to the ninth or tenth aspect, one of the metals having different thermal conductivities is iron and the other is copper. is there. According to a twelfth aspect of the present invention, in the semiconductor laser device including a base, a mounting portion for a laser light emitting element, and the like, and a stem including an outlead, the base has an annular wall portion formed by bending a metal plate. A mounting portion for a laser light emitting element or the like is formed integrally with the outlead, and the outlead is joined to the base by a thermosetting resin sealed in the annular wall portion. Semiconductor laser device. Claim 1
A third aspect of the present invention is the semiconductor laser device according to the twelfth aspect, wherein a heat sink member is further sealed in the annular wall portion.

[0005]

FIG. 1 shows a first embodiment of a stem according to the present invention.
1A is a perspective view thereof, and FIG. 1B is a sectional view thereof. As shown in the figure, a mounting portion (heat sink) 3 for mounting the base 1 of the stem and a laser light emitting element or the like via a silicon submount is made of a thin metal plate, for example, a metal plate of about 0.1 mm to 0.5 mm. It is formed by punching and performing sheet metal working on the annular wall portion 1A 'by bending the central portion while leaving the flange-shaped peripheral portion 1A.
Attachment part (heat sink) 3 integrally formed with a part of A 'is formed. In the figure, reference numeral 6 denotes a gold wire, which electrically connects the outlead 4 to each terminal. Reference numeral 7 denotes a silicon submount, which is bonded to the folded surface 3A (FIG. 2) of the mounting portion (heat sink) 3 with a conductive paste such as a silver paste. 8 is an LD (laser diode) as a light emitting element, and 9 is the L
4 shows a light receiving element for monitoring a laser beam emitted from D. As illustrated, both the LD 8 and the light receiving element 9 are electrically connected to the outlead 4 by the gold wire 6.

FIG. 2 is a view for explaining a step of forming the stem base 1 according to the present invention. FIG. 2A shows a blank of a metal plate such as iron. FIG. 2B shows an ashtray or a hat-shaped intermediate workpiece formed by drawing the blank, that is, a flange-shaped portion 1A followed by an annular wall portion 1A 'and a flat surface on the annular wall portion 1A'. . FIG.
C is a portion 3A which becomes the mounting portion (heat sink) 3 as a heat sink by using the flat surface of the intermediate workpiece thus formed.
2D, and finally, as shown in FIG. 2D, a portion 3A serving as the mounting portion (heat sink) 3
To form an attachment portion (heat sink) 3 having an L-shaped cross section. The annular wall portion 1 of the base 1 formed by the above steps
Three outleads 4 are arranged in a space surrounded by A ′, and a thermosetting resin is filled and heated in this state, and the outleads 4 are fixed to the base 1 (FIG. 1). here,
As shown in the figure, the Gnd terminal 4A is used to secure electrical conduction during bonding.
3 penetrates.

According to this embodiment, the connection between the base 1 and the outlead 4 is made of a thermosetting resin instead of the conventional low-melting glass, and even if the resin is thermoset. Since the temperature is only about 200 ° C., the out lead 4 can be bonded to the base 1 after gold plating by using the resin. That is, according to the present embodiment, since the base 1 and the outlead 4 can be separately plated, the base 1 does not need to be plated with the same gold as the outlead 4, and can be plated with Ni, for example. There is an advantage. Further, even when the pickup mounting area needs to be reduced, the base 1 can be easily cut by simply punching out the base 1 with a press. It should be noted that a conductive paste such as a silver paste is used for the DB (die bonding) material to secure the adhesive strength. The stem according to the first embodiment of the present invention described above can solve the above-mentioned conventional problem, but has a thickness of the base 1 of about 0.25 to 0.3 mm and a thickness of the conventional product (about 1.2 mm). Due to the thinness, the strength at the time of application to the pickup is weak, and problems such as bending and warping may occur. Further, it is difficult to say that the heat radiation characteristics are sufficient.

Next, an embodiment in which this point is improved will be described. FIG. 3 shows a second embodiment of the present invention. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals. The feature of this embodiment is that, in order to cope with the fact that the thickness of the base 1 of the stem of the present invention is thinner than that of the conventional product, the peripheral edge of the disc-shaped metal blank is bent substantially at right angles to form the annular wall 1A, The central part is plane 1B
And a mounting portion (heat sink) 3 for a laser light emitting element or the like cut and raised from the plane. In this embodiment, the annular wall portion 1A 'is used as a radiation fin, and the width of the annular wall portion is adjusted so that required heat radiation can be secured.

FIG. 4 shows the manufacturing process.
FIG. 4A shows a metal blank. FIG. 4B shows an intermediate workpiece in which a peripheral portion of the metal blank is bent downward to form a bent portion and a central portion is flat. FIG. 4C shows a state in which a portion 3A serving as a mounting portion (heat sink) 3 for attaching the laser light emitting element or the like is cut out from the center plane portion of the intermediate work via a silicon submount, and is cut out. Further, in FIG. 4D, a portion 3A to be the mounting portion (heat sink) 3 is erected to form the mounting portion (heat sink) 3 having an L-shaped cross section.

In this embodiment, since the thermosetting resin is sealed in the inner space of the annular side wall formed by bending the peripheral edge of the base 1, the base 1 is formed of a thin metal plate. In addition, since the strength can be increased and the portion is used as a contact reference surface when the pickup is mounted, there is no possibility that bending, warping, or the like occurs. Further, since the heat radiation area can be increased by increasing the width L of the bent portion, the problem of heat radiation during the LD operation as in the first embodiment can be solved.

FIG. 5 shows a third embodiment of the stem according to the present invention, FIG. 5A is a perspective view thereof, and FIG. 5B is a sectional view thereof.
The base 1 of the stem has a peripheral portion as shown in FIG.
The annular continuous wall 1A 'bent downward at a substantially right angle in FIG.
A mounting portion (heat sink) 3 for mounting a laser light emitting element or the like is integrally formed on one side of the opening of the upper surface 1B via a silicon submount. The metal plate used here is, for example, 0.1 mm to
It is an iron plate of about 0.5mm. In the figure, reference numeral 6 denotes a gold wire, which electrically connects the outlead 4 to each terminal.
Reference numeral 7 denotes a silicon submount, which is joined to the folded surface of the mounting portion (heat sink) 3 with a conductive paste such as a silver paste. Reference numeral 8 denotes an LD (laser diode) serving as a light emitting element, and 9 denotes a light receiving element for monitoring a laser beam emitted from the LD. As illustrated, both the LD 8 and the light receiving element 9 are electrically connected to the outlead 4 by the gold wire 6. In the stem configured as described above, since the outer peripheral edge of the base 1 is bent to form the annular wall portion 1A ', the base 1 can be strengthened and the annular wall portion can be used as a radiation fin. By adjusting the width, the necessary heat radiation can be ensured even by the base 1 itself. However, in order to further enhance the heat dissipation of the stem, in this embodiment, as shown in FIG. 5B, a heat sink disk 5A for heat dissipation such as a copper material is provided in a space surrounded by the annular wall 1A '. The heat sink disk 5A is housed in a state insulated from the lead 4 and further filled and sealed with an insulating thermosetting resin 5B in a space below the lead.
Is sealed. With this configuration, the heat radiation of the stem can be adjusted by adjusting the thickness M of the copper plate for the heat radiation heat sink in addition to the width L of the continuous wall, so that the optimal heat radiation for the semiconductor laser device to be used can be easily achieved. Obtainable.

The manufacturing process of the stem base 1 of this embodiment is the same as that in the second embodiment described with reference to FIG. That is, FIG. 4A shows a blank cut out from a thin iron plate having the above thickness. FIG. 4B shows a bowl-shaped intermediate workpiece having an annular continuous wall obtained by bending the peripheral edge of the blank at a substantially right angle, and FIG. 4C shows the mounting portion (heat sink) 3 on a central plane portion of the intermediate workpiece. 3A shows a cut-out state with a portion 3A remaining. Further, FIG. 4D shows the mounting portion (heat sink).
The portion 3A that becomes 3 is bent and raised to form a mounting portion (heat sink) 3 having an L-shaped cross section.

Next, a fourth embodiment of the stem of the present invention having improved heat dissipation will be described. In this embodiment, as shown in FIG. 6A, a mounting member (heat sink) 3 for attaching a laser light emitting element or the like via a silicon submount of a stem uses a copper material C having excellent heat dissipation and a base having little heat conduction. The outer peripheral portion is made of an iron material F in order to reduce costs and secure the strength of the stem. In order to fabricate this, as shown in FIG. 6B, for example, a clad material M1 in which metals are stuck alternately in a stripe shape in the order of iron-copper-iron-copper-. A circular blank B is punched out, and sheet metal processing is performed so that the copper portion C of the blank B comes to the mounting portion (heat sink) 3. The processing steps are the same as in the case of the third embodiment described with reference to FIG.

FIG. 7A shows a stem according to a fifth embodiment of the present invention from directly above, that is, in a plan view. The fourth
In the embodiment, the clad material M1 in which the iron F and the copper C are stuck alternately was used, but in this embodiment, the thickness direction of the plate,
That is, using a clad material M2 in which a copper material C and an iron material F are superposed and adhered on the front and back surfaces thereof (FIG. 7B), a blank for stem processing is punched from the clad material M2, and the stem is formed by the method already described in FIG. To form
In this case, in the sheet metal processing of the stem, the periphery of the blank is bent at substantially right angles so that the iron material F comes to the front side of the base 1 of the stem, and the center of the blank is a mounting portion (heat sink) serving as a silicon submount mounting portion. Then, the mounting portion (heat sink) 3 is bent upright. By erecting the mounting portion (heat sink) 3, the copper material C on the back surface of the clad material first appears on the front side. That is, as shown in FIG. 7A, the mounting surface side of the silicon submount becomes the copper material C, and the excellent thermal conductivity of copper can be utilized. On the other hand, since the iron material F appears on the surface in other parts, the excellent strength characteristics of the iron material can be utilized. As a result, it is possible to obtain a stem excellent in terms of strength or heat dissipation by making good use of the characteristics of each material.

In each of the stems of the semiconductor laser device described above, the LD mounting portion is formed integrally with the base 1, but in the stem of the sixth embodiment shown in FIG. It is formed integrally with the lead 4 (Gnd terminal) (FIG. 8A). Here, the meaning of being integrally formed includes not only a case where the LD mounting portion and the outlead are literally formed integrally, but also a case where the LD mounting portion and the outlead are joined by means of welding or the like. The outlead 4 is fixed to the base 1 by an insulating thermosetting resin filled in a space surrounded by the annular wall 1A 'of the base 1 formed by bending (FIG. 8B). As in the second embodiment, the stem thus formed is formed with an annular wall portion 1A 'by bending the outer peripheral edge of the base, so that the base 1 itself can secure necessary heat radiation. it can. Similarly to the third embodiment, a heat sink disk 8A made of, for example, copper for heat dissipation such as a copper material is accommodated in a space surrounded by the annular wall 1A 'in a state insulated from the outlead 4. Further, an insulating thermosetting resin 8B may be filled and sealed in the lower space, and the heat sink disk may be sealed together with the outlead 4 (FIG. 8C). FIG. 9 is a view for explaining a molding step of the stem base 1 according to the present invention. FIG. 9A shows a blank of a metal plate such as iron. FIG. 9B shows an intermediate workpiece in which the periphery of the blank is bent downward to form a bent portion and the center is a plane. FIG. 9C shows the base 1 formed by providing a hole 4B for inserting a lead in the plane portion of the intermediate workpiece.

[0016]

According to the first to thirteenth aspects of the present invention, a relatively simple press work such as punching or bending is performed on a thin metal plate, so that the mold is less likely to be worn or damaged. The stem can be formed inexpensively, and even when the pickup mounting area needs to be reduced, the base can be easily cut by simply punching out the base with a press. Furthermore, since the annular wall is formed by bending the metal plate, the outlead can be sealed with the thermosetting resin in the internal space, and the strength can be ensured even though the metal plate is thin. . Effect corresponding to the invention of claim 5; since the thermosetting resin for fixing the terminal can be cured at a low temperature, the gold-plated terminal can be fixed to the stem, so that the terminal and the base of the stem are made of different materials. Can be plated.
Advantageous Effects Corresponding to the Invention of Claim 6: The annular wall portion can be used as a radiation fin, and an appropriate radiation area can be obtained by adjusting its length. Claims 7 and 8
Advantageous Effects According to the Invention: A semiconductor to be applied by adjusting the width of the annular wall portion and the thickness of the heat sink member while ensuring heat dissipation by the annular wall portion and the heat sink member formed on the periphery of the base. The heat radiation characteristics can be optimized according to the laser device.
Effects corresponding to the invention of claim 9; use of a material having excellent heat conduction characteristics in unnecessary parts can be greatly restricted, so that a semiconductor laser device excellent in heat dissipation while reducing costs can be obtained. Can be. Effect corresponding to the invention of claim 10; a semiconductor laser having excellent strength and excellent heat dissipation while reducing costs because a material having excellent heat conductivity and a material having excellent strength can be used separately. A device can be obtained. Effect corresponding to the invention of claim 11: By using a clad material composed of a copper material and an iron material, a low-cost stem having both strength and heat dissipation can be obtained, and a semiconductor laser device excellent in performance can be obtained. It can be obtained at low cost.

[Brief description of the drawings]

FIG. 1 shows a stem of a first embodiment of a stem of a semiconductor laser device of the present invention, FIG. 1A is a perspective view thereof, and FIG. 1B is a sectional view thereof.

FIG. 2 is a diagram illustrating a manufacturing process of a stem base according to the first embodiment.

FIG. 3 is a perspective view showing a stem according to a second embodiment of the present invention.

FIG. 4 is a perspective view illustrating a manufacturing process of a stem base according to a second embodiment.

FIG. 5 shows a stem of a third embodiment of the semiconductor laser device of the present invention, and FIG.
B shows a sectional view.

FIG. 6 shows a perspective view of a stem and a plan view of a base material of the stem according to a fourth embodiment of the semiconductor laser device of the present invention.

FIG. 7 shows a plan view of a stem and a cross-sectional view of a base material of the stem according to a fifth embodiment of the semiconductor laser device of the present invention.

FIG. 8 shows a stem of a semiconductor laser device according to a sixth embodiment of the present invention, and FIG. 8A is a perspective view thereof, FIGS. 8B and 8C.
Shows a sectional view.

FIG. 9 is a perspective view illustrating a step of manufacturing a stem base according to a sixth embodiment.

FIG. 10 shows a sectional view of a stem of a conventional semiconductor laser device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base, 2 ... Annular wall part, 3 ... Mounting part (heat sink), 4 ...
・ Outlead, 6 ... gold wire,
7 ... Con submount, 8 ... LD (laser diode) 9 ... Light receiving element.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/36 H01S 5/022 23/373 H01L 23/36 C H01S 5/022 M

Claims (13)

[Claims] 1. A semiconductor laser device comprising a base, a mounting portion for a laser light emitting element or the like formed integrally with the base, and a stem comprising an outlead, wherein the base is formed by bending a metal plate so as to have an annular wall portion. A semiconductor laser device characterized by being formed by: 2. The semiconductor laser device according to claim 1, wherein the annular wall portion is formed by bending a sheet metal at a distance from a peripheral edge thereof, and a mounting portion for the laser light emitting element or the like is formed. A semiconductor laser device characterized in that a sheet metal upper surface is cut and raised and formed on the annular wall portion. 3. The semiconductor laser device according to claim 1, wherein the annular wall portion is formed by bending a peripheral edge of a sheet metal, and a mounting portion for the laser light emitting element or the like is formed by cutting and raising an upper surface of the sheet metal. A semiconductor laser device characterized in that: 4. The semiconductor laser device according to claim 1, wherein said outlead is joined to said base by a thermosetting resin sealed in said annular wall portion. Laser device. 5. The semiconductor laser device according to claim 1, wherein said outlead and said base are plated with different materials. 6. The semiconductor laser device according to claim 1, wherein said annular wall is a radiation fin. 7. A semiconductor laser device having a stem, wherein the stem has a base having an annular wall portion formed by bending a sheet metal on a peripheral edge, and a heat sink member is sealed in the annular wall portion. Characteristic semiconductor laser device. 8. The semiconductor laser device according to claim 7, wherein said heat sink member is an insulated copper material. 9. A semiconductor laser device having a stem, wherein the stem has a base having an annular wall formed by bending a clad material in which two kinds of metals having different thermal conductivities are stuck in a stripe shape. Wherein at least the mounting portion of the laser light emitting element or the like integrally formed on the base is molded so as to be formed of a metal portion having high thermal conductivity among the different metals. Semiconductor laser device. 10. A semiconductor laser device having a stem, the stem having a base having an annular wall portion formed by bending a clad material having two kinds of metals having different thermal conductivities adhered to the front and back, and having a peripheral edge. A semiconductor laser device characterized in that only a mounting portion of a laser light emitting element or the like integrally formed on the base is formed of a metal portion having high thermal conductivity among the different metals. 11. The semiconductor laser device according to claim 9, wherein one of the metals having different thermal conductivities is iron and the other is copper. 12. A semiconductor laser device comprising a base, a mounting portion for a laser light emitting element or the like, and a stem composed of an outlead, wherein the base has an annular wall portion formed by bending a metal plate. A semiconductor, wherein an attachment portion for an element or the like is formed integrally with the outlead, and the outlead is joined to the base by a thermosetting resin sealed in the annular wall portion. Laser device. 13. The semiconductor laser device according to claim 12, wherein a heat sink member is further sealed in said annular wall portion.