JP3233837B2 - Semiconductor laser device and optical pickup device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a semiconductor laser device and an optical pickup device used for optical information processing, optical measurement and optical communication.

[0002]

FIG. 23 is an exploded perspective view of a conventional semiconductor laser device. In the figure, 101 is a semiconductor laser chip, 102 is a heat sink substrate, 103 is a light receiving element for monitoring laser output light, 104 is a stem, 105 is a cap having a window 105a, 106 is an electrode terminal, 107
Is an insulating material, and 108 is a bonding wire.

In the package structure of the semiconductor laser device shown in FIG. 23, since each package is independent, it is difficult to handle each package in an assembling process at the time of mass production. There is a problem that the production cost becomes very high due to the high price.

Accordingly, it has been expected to introduce a lead frame used in ICs and the like, which can be individually cut after mounting and assembling 10 to 20 semiconductor laser chips at once. . FIG. 24 shows the lead frame 109. In the figure, 110 is a die pad on which a semiconductor laser chip is mounted, and 111 is an electrode terminal.

As a semiconductor laser device using such a lead frame 109, there is a technique disclosed in Japanese Patent Application Laid-Open No. 3-34387. In this semiconductor laser device, as shown in FIG. 25, the whole is resin-sealed with an insulating material 112 made of a transparent resin. In the mounting method using the lead frame 109, usually, resin molding is performed after mounting to protect the semiconductor laser chip 101, and the electrode terminals 111 are fixed even after each element is cut out from the lead frame 109. I have. I
In C and the like, a black resin is used as the molding resin. However, since the emission light of the semiconductor laser chip 101 cannot be extracted with the black resin, resin emission is performed with a transparent resin to secure the emission light of the semiconductor laser chip 101. That's what we do. In FIG. 25, the same components as those in FIG. 23 are denoted by the same reference numerals. The same applies to FIGS. 26 and 27 showing the following conventional examples.

[0006]

However, in the above-described technique of performing resin molding with a transparent resin, the following problem occurs because the insulating material made of the transparent resin directly contacts the semiconductor laser chip.

First, the light emitting portion of the semiconductor laser chip includes:
Since the light output of several mW or more is confined within a range of about 10 μm in diameter, the transparent resin that constitutes the insulating material is deteriorated due to its heat and high light energy density, and yellowing or thermal deformation is caused. This causes a problem that light emission characteristics are deteriorated.

When the insulating material is molded, the resin is usually poured in a high temperature state and thermally cured or cooled. However, at this stage, the flow of the resin tends to stagnate at the edge portion of the complicated chip structure, and the resin flows. Stress is generated in itself, and unevenness of the refractive index of the resin itself occurs, or in severe cases, the resin itself is cracked, and the wavefront of the emitted light is greatly disturbed,
When used in an optical device such as an optical pickup device, there is a problem that its characteristics are deteriorated.

Therefore, Japanese Patent Laid-Open No. 2-2097 shown in FIG.
No. 86, the semiconductor laser chip 101
A technique has been proposed in which the periphery of the substrate is covered with a heat-resistant and elastic resin material 113 such as silicone, and then the resin is sealed with an insulating material 112 made of a transparent resin.

However, according to this method, the interface between the resin material 113 and the insulating material 112 does not become a clean flat surface, and the wavefront of the light emitted from the semiconductor laser chip 101 is disturbed. When the semiconductor laser chip 101 is covered with the resin material 113 having a stress, the stress applied to the resin itself is reduced and unevenness of the refractive index and cracks are not caused, but on the other hand, when the tensile stress is applied, the resin is immediately separated. Therefore, there is a problem that the light emission characteristics are disturbed if the peeled portion occurs near the light emitting portion of the semiconductor laser chip 101.

Further, even with a heat-resistant resin, the glass transition point is at most about 200 ° C., and considering long-term reliability, the problem of deterioration of optical characteristics due to heat and light density is completely solved. I can't say.

[0012] Also, Japanese Patent Application Laid-Open No. 6-53603 shown in FIG.
As in the technology disclosed in Japanese Patent Application Publication No.
There is also proposed a semiconductor laser device in which the light receiving element 103 is covered with a semiconductor laser chip 101 and a part of the light receiving element 103 covers the semiconductor laser chip 101.

In this case, of the front light 115 and the rear light 116 emitted from the semiconductor laser chip 101, the front light 115 is not exposed to the resin, but the light emitting portion of the rear light 116 used for the light quantity monitor is the resin. When the resin deteriorates and the refractive index changes, the rear end face reflectivity of the semiconductor laser chip 101 changes, and the light amount ratio between the front light 115 and the rear light 116 of the semiconductor laser chip 101 changes. There is a problem that the light amount monitoring function is hindered.
In FIG. 27, reference numeral 114 denotes an insulating frame.

Further, in this structure, the lead frame 10
When the semiconductor laser device is used in an optical pickup device, the light beam is reflected by the optical disk from a direction substantially similar to the emission direction and includes a signal component of the optical disk. Will come back. In the case of integrating a photodetector circuit for receiving the returned light beam, in this structure, the light receiving area is formed on a cross section of the silicon substrate constituting the heat sink substrate, and the light receiving area is formed on the cross section of the wafer surface. There is a problem that it is not easily realized with the current silicon process mainly including the process.

The package used is one in which an insulating frame 114 is resin-molded on the lead frame 109 before the semiconductor laser chip 101 and the heat sink substrate 102 are mounted on the lead frame 109, and is called a so-called pre-mold package. Technology. In this case, the insulating frame 114 to be formed has a die bonding property of the semiconductor laser chip 101 and the heat sink substrate 102.
The distance between the chip and the insulating frame and the thickness of the insulating frame must be increased in consideration of the problems such as the wire bonding property between the package terminal and the chip, and the strength of the resin molding itself (the strength is generally weak due to the hollow part). However, there is a problem that miniaturization is difficult. Further, this is basically not completely sealed, and there is a problem that the chip end surface and the exposed portion of the heat sink substrate are adversely affected by oxygen and humidity in the air.

The present invention has been made in view of the foregoing, and an object of the present invention is to prevent an insulating material for sealing a semiconductor laser chip from being deteriorated by heat generated from the semiconductor laser chip. is there.

[0017]

In order to achieve the above object, the present invention is characterized in that a light emitting portion of a semiconductor laser chip is covered by an optical member. Taken.

That is, the first to fourteenth solutions of the present invention relate to a semiconductor laser device. The first solution is mounted directly on a die pad or via a heat sink substrate, and is provided around an outer periphery of the die pad. A semiconductor laser chip electrically connected to the arranged electrode terminals, a transparent optical member provided to cover a light emitting portion that emits light emitted from the semiconductor laser chip, the semiconductor laser chip, a die pad, and a heat sink substrate And a transparent insulating material for sealing the electrode terminal and the optical member except for the outer terminal portion of the electrode terminal.

A second solution is to provide a semiconductor laser chip mounted directly on a die pad or via a heat sink substrate and electrically connected to an electrode terminal disposed around the die pad. A transparent optical member provided so as to cover the light emitting portion that emits the emitted light, and the semiconductor laser chip, the die pad, the heat sink substrate, the electrode terminal and the optical member passing through the outer terminal portion of the electrode terminal and the laser light passing through the optical member. And an insulating material for sealing except for the region.

According to a third aspect of the present invention, in the first or second aspect, the semiconductor laser chip is a surface-emitting type semiconductor laser chip.

According to a fourth aspect of the present invention, in the first or the second aspect, the semiconductor laser chip is an edge resonator type semiconductor laser chip.

With the above arrangement, in the first to fourth solutions, each element such as a semiconductor laser chip is hermetically sealed with an insulating material so as not to be exposed to the outside air, and the insulating material sufficiently functions as a protective package. Play. In addition, the light emitting portion of the semiconductor laser chip is covered with an optical member and does not directly touch the insulating material, and optical characteristics such as local heat of the light emitting portion of the semiconductor laser chip and material deterioration of the insulating material due to high light energy density are reduced. Does not deteriorate. Further, the semiconductor laser chip does not deteriorate due to the stress at the time of sealing. Further, since only an optical member needs to be interposed between the semiconductor laser chip and the insulating material, the entire device becomes compact. In particular, the second
In the above solution, since the laser beam passage area of the optical member has no insulating material and the portion is exposed to the outside, the emitted light emitted from the semiconductor laser chip does not pass through the insulating material. It is not affected by refractive index unevenness or cracks generated inside the insulating material, bubbles or dust mixed in the resin material, and is very effective in securing the characteristics of emitted light.

According to a fifth aspect of the present invention, in the fourth aspect, a 45 ° reflecting mirror for reflecting light emitted from the semiconductor laser chip is formed on the heat sink substrate.

With the above arrangement, in the fifth solution,
Even if the end face resonator type semiconductor laser chip emits 4 light
The light is emitted in the vertical direction of the substrate by the reflection mirror of 5 mm, and can be practically treated as a surface emitting laser. By combining with a photodetection circuit formed on the heat sink substrate, light can be input and output in the vertical direction of the substrate. A light emitting and receiving device can be realized.

According to a sixth aspect of the present invention, in the first or the second aspect, a light detection circuit for detecting light entering from the outside and detecting light emitted from the front or rear of the semiconductor laser chip. A light detection circuit, a current-to-voltage conversion circuit for converting a signal current detected from these light detection circuits into a voltage, an amplification circuit for amplifying a signal from the current-to-voltage conversion circuit, and an operation for calculating a signal from the amplification circuit Circuit for digital-to-analog conversion of a signal from the arithmetic circuit
At least one of the A-conversion circuit and the driving circuit for driving the semiconductor laser is formed on a semiconductor laser chip or a heat sink substrate.

With the above arrangement, in the sixth solution,
A more effective element can be obtained.

According to a seventh aspect of the present invention, in the first or the second aspect, a concave portion is formed in the optical member so as not to come into contact with the light emitting portion of the semiconductor laser chip so as to correspond to the laser beam passage area. I do.

With the above arrangement, in the seventh solution,
The adhesive for adhering the optical member to the semiconductor laser chip does not enter the light emitting portion, and contact can be avoided.

According to an eighth aspect, in the first or the second aspect, the optical member is provided with an optical function such as a hologram optical element, a diffraction grating, a beam splitter, a mirror, a polarizing plate, a lens, an optical filter or a wavelength plate. It is characterized by having.

With the above arrangement, the eighth solution means:
The hologram optical element or the like allows the outgoing light to be split or the input signal light to be diffracted and deflected in the direction of the light detection circuit.

According to a ninth solution, in the first or the second solution, at least one of the insulating material and the optical member is provided with a non-reflective coating, a coating having a predetermined reflectance, or a polarizing coating. And

With the above arrangement, in the ninth solving means,
A complicated light input / output structure becomes possible.

According to a tenth solution, in the first or the second solution, the insulating material has an optical function such as a hologram optical element, a lens or a reflection surface.

According to the above configuration, in the tenth solution, the outgoing light can be split or the input signal light can be diffracted and deflected in the direction of the photodetection circuit as in the eighth solution.

According to an eleventh solution, in the first or the second solution, at least a part of the outer surface of the insulating material is formed into a curved surface or a spherical surface.

According to the eleventh aspect of the present invention, in the eleventh solving means, the element is formed by inserting the curved surface or the spherical shape into an engagement hole formed in a mating member to be assembled in advance corresponding to the curved surface or the spherical shape. Is easily and accurately performed, and the rotational adjustment about the emission optical axis can be performed.

According to a twelfth solution, in the first or the second solution, a concave portion is formed on an outer surface of the insulating material so as to correspond to the laser beam passage area.

With the above arrangement, in the twelfth solution, the influence of uneven refractive index and cracks caused by the passage of the outgoing light emitted from the semiconductor laser chip through the insulating material, bubbles and dust mixed in the resin material is reduced, The characteristics of the emitted light are ensured.

According to a thirteenth aspect, in the first or the second aspect, the hologram optical element, the diffraction grating, the beam splitter, the mirror, the polarizing plate, the lens,
An optical member having an optical function, such as an optical filter, a wavelength plate, or an optical fiber, is arranged corresponding to a laser light passage area.

According to the above configuration, in the thirteenth solution means, similarly to the eighth solution means, the emitted light can be divided or the input signal light can be diffracted and deflected in the direction of the light detection circuit.

According to a fourteenth aspect, in the first or the second aspect, a heat conduction path or a heat radiating means for radiating heat generated from the semiconductor laser chip to the outside is provided in the die pad.

With the above configuration, in the fourteenth solution, heat is efficiently released to the air, and the reliability is improved.

According to a fifteenth aspect of the present invention, there is provided an optical pickup device, comprising: the semiconductor laser device according to any one of the first to fourteenth aspects; and a light beam emitted from the semiconductor laser device. And a light condensing means for condensing light on an optical information recording medium.

According to the fifteenth aspect of the present invention, a small and light semiconductor laser device has a very small overall shape, and a light-weight semiconductor laser device can realize a high-speed response pickup.

[0045]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIGS. 1A to 1C show a semiconductor laser device according to a first embodiment of the present invention, and FIG. 2 shows a modification thereof.

1 (a) to 1 (c), reference numeral 1 denotes a lead frame, which is provided with a die pad 2 in the vicinity of the center, and a plurality of electrode terminals 3 on the outer periphery of the die pad 2. Is arranged. A surface emitting type semiconductor laser chip 4 is directly mounted on the die pad 2, and the semiconductor laser chip 4 is electrically connected to an inner terminal portion of the electrode terminal 3 by a bonding wire 5. Also, as a feature of the present invention, an optical member 6 made of transparent glass is mounted on the upper surface of the semiconductor laser chip 4 so as to cover a light emitting portion 9 for emitting the emission light 10 of the semiconductor laser chip 4 from above. Are fixed by the adhesive 7 so as not to be separated. Further, the semiconductor laser chip 4, die pad 2, electrode terminal 3, bonding wire 5 and optical member 6 are hermetically sealed with an insulating material 11 made of a transparent resin except for the outer terminal portion of the electrode terminal 3. A light detection circuit 8 for detecting light entering from outside is formed on the upper surface of the semiconductor laser chip 4 so as to face both sides of the optical member 6.

As described above, in the first embodiment, each element such as the semiconductor laser chip 4 is hermetically sealed with the insulating material 11 to protect it from touching the outside air. As a functioning enough. In addition, since the light emitting portion 9 of the semiconductor laser chip 4 is covered with the optical member 6 so as not to directly touch the insulating material 11, the insulating material made of a transparent resin as in the conventional example shown in FIG. Exposure to 112 does not occur, and the problem of characteristic change of the emitted light 10 such as yellowing deterioration of the resin due to local heat of the light emitting portion 9 of the semiconductor laser chip 4 and high light energy density can be eliminated. The problem of deterioration of the semiconductor laser chip 4 due to stress at the time of resin sealing can be eliminated.

In the first embodiment, a surface-emitting type semiconductor laser chip is used as the semiconductor laser chip 4. However, if the emitted light 10 is emitted upward in FIG. The resonator type or the horizontal resonator type may be used. Further, it is not limited to a surface emitting laser.

In the first embodiment, the light detecting circuit 8 for detecting light entering from the outside is formed on the upper surface of the semiconductor laser chip 4. However, in addition to the light detecting circuit 8, various electric circuits, For example, a light detection circuit for detecting light emitted from the front or rear of the semiconductor laser chip 4, a current-voltage conversion circuit for converting a signal current detected from these light detection circuits into a voltage, and a current-voltage conversion circuit By forming an amplifier circuit for amplifying the signal of the above, an arithmetic circuit for calculating the signal from the amplifier circuit, a DA converter circuit for digital-to-analog conversion of the signal from the arithmetic circuit, a drive circuit for driving the semiconductor laser, and the like, An effective element can be obtained.

As described above, the more electric circuits are formed on the semiconductor laser chip 4, the more the number of electrode terminals increases.
In the conventional package technology of a semiconductor laser device which is not a lead frame type as shown in FIG.
Since 06 is fixed to the stem 104 via the insulating material 107, it is difficult to arrange many electrode terminals 106 at a short pitch, and it is difficult to reduce the size of the package. For example, the current 9 mm diameter stem 104 is the insulating material 1
07 occupies a diameter of about 1 mm, so that only an electrode arrangement at least at a distance of 2 mm can be realized. When 20 electrode terminals 106 are required, the diameter of the stem 104 is 13 to 15 m.
m. Further, the direction of taking out the electrodes is vertical in the conventional package shown in FIG. 23, but is horizontal in the first embodiment, which is also effective in reducing the thickness of the package. This problem can be solved by using a pre-mold type package as shown in FIG. 27. However, the insulating frame 114 itself must be arranged outside the wire bond position, and the size of the wire bond capillary is further reduced. In consideration of the size of the collet of the die bond and the strength of the package (it is generally weaker than the filling type because it is hollow), the outer shape of the insulating frame 114 is smaller than that of the surface emitting type semiconductor laser chip. Will be much larger. For example, if the width of the surface emitting type semiconductor laser chip is 1 mm, the distance to the wire bond position is 0.7 mm, the margin to the inside of the insulating frame 114 is 0.5 mm, and the thickness of the insulating frame 114 itself is 1 mm, the total width is 5 mm. .4 mm, which cannot be said to be effectively using the lead frame technology. On the other hand, if the technique of the present invention is used, since the insulating frame 114 itself is not present, the thickness of the insulating frame 114 in the above calculation does not need to be 1 mm. Is possible.

Further, in the first embodiment, only the light emitting portion 9 of the semiconductor laser chip 4 is covered with the optical member 6, but if the light detecting circuit 8 is also covered, the light can be incident on the light detecting circuit 8 from outside. This is advantageous because it is possible to reduce the influence of the light beam generated by unevenness, bubbles, dust and the like of the transparent resin forming the insulating material 11.

In the first embodiment, a resin is used as the material of the insulating material 11. However, any other material such as a glass material can be used as long as it can ensure the insulation between the electrode terminals 3 and the emission light characteristics. I do not care. The same applies to the following embodiments.

In the modification shown in FIG. 2, a concave portion 6a is formed on the lower surface of the optical member 6, and the concave portion 6a corresponds to the laser beam passage area so as not to contact the light emitting portion 9 of the semiconductor laser chip 4. It is formed. Accordingly, it is possible to prevent the adhesive 7 for bonding the optical member 6 to the semiconductor laser chip 4 from entering the light emitting unit 9 and making contact therewith. Further, this structure prevents the optical member 6 itself from coming into contact with the light emitting portion 9 having heat and a high light energy density, so that the optical member 6 made of glass can be made of resin. This applies to the following embodiments.

Second Embodiment FIGS. 3A and 3B show a semiconductor laser device according to a second embodiment of the present invention.
(A) and (b) show the modified examples, respectively.

FIGS. 3A and 3B show a heat sink substrate 12 made of silicon mounted on the die pad 2 and a semiconductor laser chip 4 mounted on the die pad 2 via the heat sink substrate 12. The detection circuit 8 is formed on the heat sink substrate 12. Also, in the figure,
Reference numeral 13 denotes a monitoring photodiode formed on the heat sink substrate 12 for detecting light emitted from the surface emitting laser.
The other parts are the same as those of the first embodiment. Therefore, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

Therefore, in the second embodiment, the same functions and effects as those of the first embodiment can be obtained.

In the modification shown in FIGS. 4A and 4B, a concave portion 6a larger than that of the modification of the first embodiment is formed on the lower surface of the optical member 6, and the optical member 6 is formed by the concave portion 6a. It is mounted on the heat sink substrate 12 so as to straddle the semiconductor laser chip 4 and cover the photodetection circuit 8.

As described above, by covering the light detection circuit 8 on the heat sink substrate 12 with the optical member 6 as well, the light beam incident on the light detection circuit 8 from the outside may cause unevenness or bubbles in the resin constituting the insulating material 11. , Dust and the like can be reduced.

(Third Embodiment) FIGS. 5A and 5B show a semiconductor laser device according to a third embodiment of the present invention.

In the third embodiment, the semiconductor laser chip is an edge resonator type semiconductor laser chip 14 and the concave portion 6a of the optical member 6 is large to form a space between the semiconductor laser chip 14 and the semiconductor laser chip. Semiconductor laser chip 1
The first point is that the optical member 4 does not contact the optical member 6.
This is significantly different from the embodiment. FIG. 5 (a),
15B, reference numeral 15 denotes a front light emitting portion of the semiconductor laser chip 14, 16 denotes a rear light emitting portion of the semiconductor laser chip 14, 1
Reference numeral 2a denotes a 45 ° reflecting mirror 12a formed on the heat sink substrate 12, and reflects outgoing light 10 emitted from the front light emitting section 15 by the reflecting mirror 12a to form a 90 ° reflecting mirror.
The direction is changed upward. Reference numeral 17 denotes a monitoring light detection circuit for detecting the emitted light 16a emitted from the rear light emitting section 16. The heat sink substrate 12 on which the reflection mirror 12a is formed is formed by anisotropic etching of a silicon single crystal substrate (a (111) crystal plane forming 54 ° with respect to a (100) substrate is obtained).
0) It can be easily obtained by applying it to a 9 ° off-angle substrate. Otherwise, the second embodiment is the same as the second embodiment, so that the same components are denoted by the same reference numerals and detailed description thereof will be omitted.

Therefore, in the third embodiment, the same functions and effects as those of the second embodiment can be obtained.

In addition, in the third embodiment, the outgoing light 10 is reduced to 45 even in the semiconductor laser chip 14 of the edge resonator type.
Since the light can be emitted in the vertical direction of the substrate by the reflection mirror 12a of こ と が, it can be practically handled as a surface emitting laser. A light-emitting and light-receiving device capable of inputting and outputting data can be realized.

In the third embodiment, the semiconductor laser chip 14 and the light detection circuit 8 are covered with the optical member 6, but the same effect can be obtained by covering only the semiconductor laser chip 14. However, by covering the light detection circuit 8, the light beam incident on the light detection circuit 8 from the outside is less affected by unevenness, bubbles, dust and the like of the resin constituting the insulating material 11, so that it is more effective. Is as described in the first embodiment.

In the third embodiment, the reflection mirror 1
Although 2a is constituted by the inclined surface formed on the heat sink substrate 12, a separately prepared reflection mirror may be attached to the substrate. Further, although the photodetection circuit 8 cannot be formed, the same effect can be obtained by forming the 45 ° reflection mirror 12a on a metal substrate by a method such as pressing or attaching a mirror.

(Fourth Embodiment) FIG. 6 shows a semiconductor laser device according to a fourth embodiment of the present invention, and FIG. 7 shows a modification thereof.

In the fourth embodiment, a concave portion 11a is formed on the upper surface which is the outer surface of the insulating material 11 so as to correspond to the laser beam passage area (the passage area of the emitted light 10 emitted from the front light emitting section 15). The upper surface of the optical member 6 is exposed to the outside.
Otherwise, the third embodiment is the same as the third embodiment, so that the same components are denoted by the same reference numerals and detailed description thereof will be omitted. The formation of the concave portion 11a in the insulating material 11 can be easily realized by the shape of a mold used for molding the insulating material 11.

Therefore, in the fourth embodiment, the same functions and effects as those of the third embodiment can be obtained.

In addition, in the fourth embodiment, the insulating material 11
Since the upper surface of the optical member 6 is exposed to the outside by forming a concave portion 11a in the hole, the emitted light 10 emitted from the semiconductor laser chip 14 does not pass through the insulating material 11, and the insulating material 11 is formed when the insulating material 11 is formed. It is possible to completely eliminate the influence of unevenness of refractive index and cracks generated inside 11, bubbles and dust mixed in the resin material, and it is very effective to secure the characteristics of the emitted light 10.

The modified example shown in FIG. 7 has a structure in which the concave portion 11a formed in the insulating material 11 is made shallow so that the optical member 6 is not exposed to the outside.

By forming the concave portion 11a in this manner, the thickness of the laser light passage area of the insulating material 11 can be reduced, and accordingly, the probability of generation of bubbles and dust in the laser light passage area decreases, and The effect of the refractive index unevenness is reduced only, and the same effect as when the optical member 6 is exposed can be obtained.

(Fifth Embodiment) FIG. 8 shows a semiconductor laser device according to a fifth embodiment of the present invention, and FIGS.
To 4 are respectively shown.

In the fifth embodiment, as in the modification of the fourth embodiment, a shallow concave portion 11a is formed in the insulating material 11, and a hologram pattern 11b is formed on the outer surface of the concave portion 11a.
Is formed so that the insulating material 11 has an optical function as a hologram optical element. In the figure, 10a, 10b,
10c indicates that the output light 10 is the hologram pattern 1
-1 order, 0 order, +1 order diffracted light diffracted by 1b, 1
Reference numeral 8 denotes an input signal light returned from the outside, reference numeral 18a denotes a diffracted light obtained by diffracting the input signal light 18 by the hologram pattern 11b, and reference numeral 19 denotes a light detection circuit for detecting a diffracted light.

Therefore, in the fifth embodiment, the same functions and effects as those of the modification of the fourth embodiment can be obtained.

In addition, in the fifth embodiment, the insulating material 11
By using the hologram pattern 11b formed in the concave portion 11a, the emitted light 10 can be divided, and the input signal light 18 can be diffracted and deflected toward the light detection circuit 19.

The hologram pattern 11b is
Not only a linear pattern but also various function patterns can be formed. For example, it is possible to provide a lens effect by a concentric function or to generate an aberration by a hyperbolic function.

In the fifth embodiment, only the + 1st-order diffracted light is described as the diffracted light 18a of the input signal light 18 in order to avoid complication of the drawing. Light can be detected by a light detection circuit.

In the first modification shown in FIG. 9, a hologram pattern 6b is formed on the upper surface of the optical member 6 so that the optical member 6 has an optical function as a hologram optical element. 11a and the third embodiment (FIG. 5)
(See (a)).

In a second modification shown in FIG. 10, a hologram pattern 6b is formed on the lower surface of the optical member 6 so that the optical member 6 has an optical function as a hologram optical element. As in the modification of the fourth embodiment (see FIG. 7), the recess 11a is formed shallow.

In these modifications 1 and 2, the same operation and effect as in the fifth embodiment can be obtained. Further, although not shown, the insulating member 11 and the optical member 6
If the hologram patterns 11b and 6b are formed on both of them, a more functional element can be obtained.

In the third modification shown in FIG. 11, the projections 11 c and 6 c are formed on the outer surface of the upper surface of the insulating material 11 and the inner surface of the upper surface of the optical member 6.
By forming each of c, a convex lens effect is provided. In addition, it is possible to provide a concave lens effect or other desired wavefront conversion effect by making the shape concave according to the purpose.
Can be corrected. Further, by combining the material characteristics of the optical member 6 and the insulating material 11 in various ways, or by changing the design of the optical member 6 and the shape of the insulating material 11, it is possible to design a lens with less aberration as a combined lens.

Modification 4 shown in FIG. 12 employs an optical member having a beam splitter function. The optical member 20 is provided with a polarizing reflective coating to form a polarizing reflective coating film 21. On the other side, a coating having a predetermined reflectance is provided to form a reflective coating film 22. ing.
Further, a reflective coating film 23 and a non-reflective coating film 24 are also formed on the insulating material 11. 10d is a polarizing reflective coating film 21 and a reflective coating film 22
Reference numeral 25 denotes a light detection circuit for detecting the reflected light 10d and monitoring the front light of the semiconductor laser chip 14.

As described above, the optical member 20 and the insulating material 11 are provided in the laser beam passage area of the light 10 emitted from the front light emitting unit 15.
And a polarization reflection coating film 21 or a reflection coating film 22 provided on the inclination boundary, a complicated light input / output structure becomes possible.

(Sixth Embodiment) FIG. 13 shows a semiconductor laser device according to a sixth embodiment of the present invention, and FIGS. 14 to 17 show modifications 1 to 4, respectively.

In the sixth embodiment, an optical member 26 made of transparent glass having a hologram pattern 26a as an optical function is provided on the outer surface of the upper part of the insulating material 11 by the front light emitting portion 15
It is the same as the modified example of the fourth embodiment (see FIG. 7) except that it is arranged so as to correspond to the laser light passage area through which the outgoing light 10 passes.

In a first modification shown in FIG. 14, an optical member 27 composed of a compound prism is disposed on the upper outer surface of the insulating member 11 instead of the optical member 26 of the sixth embodiment. The hologram pattern 11b is formed on the bottom surface. In the figure, 10e is the front light emitting unit 15
Is the reflected light of the prism surface of the outgoing light 10.

As a result, it is possible to control the wavefront of the light 18 reflected by the optical member 27 composed of the compound prism and entering the element, and to detect the division.

In the modification 2 shown in FIG. 15, two concave portions 11d are formed on the upper outer surface of the insulating material 11, one of the concave portions 11d is provided with an optical member 28 made of an outgoing optical fiber, and the other is provided with a concave portion 11d. An optical member 29 made of an input optical fiber is inserted and arranged from above.

As a result, the optical member 28,
By forming the recess 11d corresponding to the fiber diameter of 29, the positioning of the optical members 28, 29, the semiconductor laser chip 14, and the photodetection circuit 19 can be easily performed simply by inserting the optical members 28, 29 into the recess 11d. Accuracy is possible.

In a modification 3 shown in FIG. 16, two concave portions 11d are formed on the outer surface of the side of the insulating material 11, and an optical member 28 made of an optical fiber for emission is formed in one concave portion 11d, and in the other concave portion 11d. In the figure, the optical members 29 each composed of an input optical fiber are inserted and arranged from the side. Also,
Near the bottom of the concave portion 11a formed on the upper outer surface of the insulating material 11, a polarizing reflective coating film 21 and a reflective coating film 22 are formed as in Modification 4 of the fifth embodiment (see FIG. 12).

Thus, similarly to the second modification, the optical member 2
8, 29, semiconductor laser chip 14, and light detection circuit 1
9 can be easily performed with high accuracy, and an element capable of inputting / outputting light in the same direction can be obtained.

In a modification 4 shown in FIG. 17, an optical member 30 made of a bidirectional optical fiber is inserted from above into a concave portion 11d formed on the upper outer surface of the insulating material 11 and arranged. Also, a hologram pattern 6b is formed on the upper outer surface of the optical member 6 covered with the insulating material 11.

Thus, the optical member 2 is formed similarly to the second modification.
8, 29, semiconductor laser chip 14, and light detection circuit 1
9 can be easily adjusted with high accuracy, and the input light 18 is diffracted by the hologram pattern 6b and can be detected by the light detection circuit 19, so that an element capable of bidirectional communication can be obtained.

(Seventh Embodiment) FIG. 18 shows a semiconductor laser device according to a seventh embodiment of the present invention, and FIG. 19 shows a modification thereof.

In the seventh embodiment, two substantially elliptical blocks 11e having a curved surface 11f with one side curved in a convex shape are protruded from the upper outer surface of the insulating material 11.

By inserting the block 11e into an engagement hole formed in a mating member to be assembled in advance corresponding to the shape of the block 11e, the element can be easily positioned with high accuracy and the emitted light can be adjusted. Rotation adjustment about an axis becomes possible.

In the modification shown in FIG. 19, a spherical surface 11h is formed on the upper outer surface of the insulating material 11, and the concave portion 1 is formed on the top.
1a.

By inserting the spherical surface 11h into an engaging hole formed in a mating member to be assembled in advance corresponding to the shape of the spherical surface 11h, the element can be easily positioned with high accuracy and the spherical surface 11h can be aligned. The tilt adjustment centering on the origin of 11h becomes possible.

(Eighth Embodiment) FIG. 20 shows a semiconductor laser device according to an eighth embodiment of the present invention, and FIG. 21 shows a modification thereof.

In the eighth embodiment, a heat radiating pad 31 is provided on the rear surface of the die pad 2. The heat radiating pad 31 is formed such that the die pad 2 is formed to be thicker than the electrode terminal 3 and has a large thickness. It is configured with a thick part.
Otherwise, the configuration is the same as that of the third embodiment (see FIG. 5A).

As a result, heat is radiated to the air by the heat radiation pad 3.
1 can efficiently reduce the thermal resistance, and if a heat conduction path is secured on the set side where this element is used, the thermal resistance can be extremely reduced, and the reliability of the semiconductor laser device can be reduced. It is very effective in improving the performance.

The modification shown in FIG. 21 is different from the eighth embodiment in that the radiation fins 32 are arranged on the lower outer surface of the insulating material 11 so as to be in contact with the radiation pads 31.

Thus, the heat radiation to the air can be further improved, and the reliability can be further improved.

(Ninth Embodiment) FIG. 22 shows an optical pickup device according to a ninth embodiment of the present invention.

In the figure, reference numeral 33 denotes a semiconductor laser device comprising a semiconductor laser / photodetector integrated element (LD / PD element) including a hologram pattern according to the present invention; 34, an actuator movable section; 35, a reflection mirror;
36 is an objective lens, 37 is a wire suspension, 38
Denotes an optical disk as an optical information recording medium, 39 denotes a support base, and a condensing means for condensing a light beam emitted from the semiconductor laser device 33 on the optical disk 38 by the reflection mirror 35 and the objective lens 36 is configured. Have been.

That is, a semiconductor laser device 33 composed of an LD / PD element is fixed to a side surface of an actuator movable portion 34, a reflection mirror 35 for reflecting the emitted light in the disk direction is disposed, and an objective lens is provided in the optical path. The so-called integrated drive pickup in which the objective lens 36, the semiconductor laser device 33, and the photodetector circuit move integrally can be configured by fixing the 36 and fixing the whole to the support base 39 with a suspension such as the wire suspension 37. . In this method, the laser emission light is focused on the optical disk 38, and the reflected light is detected by the light detection circuit of the semiconductor laser device 33, and the focus error signal, the tracking error signal, and the disk information signal are read.

In the optical pickup device having the structure shown in FIG. 22, a small and light LD / PD element according to the present invention makes it possible to realize a pickup capable of high-speed response because the overall shape is very small and light.

The optical member and the insulating material having the optical function are not limited to those described in each of the embodiments, but include a hologram optical element, a diffraction grating, a beam splitter, a mirror, a polarizing plate, a lens, an optical filter, and a wavelength plate. , A reflecting surface, an optical fiber, or the like.

[0109]

As described above, according to the first aspect of the present invention, the light emitting portion of the semiconductor laser chip is covered with the optical member so as not to touch the insulating material. And deterioration of the semiconductor laser chip due to stress at the time of sealing can be prevented. Moreover, a compact device can be obtained. In particular, according to the second aspect of the present invention, since the laser light passage area of the optical member is exposed to the outside, the outgoing light emitted from the semiconductor laser chip has uneven refractive index and cracks generated inside the insulating material. Without being affected by
Outgoing light characteristics are secured.

[0110]

According to the third aspect of the present invention, since various circuits such as a photodetection circuit are formed on a semiconductor laser chip or a heat sink substrate, more effective elements can be obtained.

According to the fourth aspect of the present invention, since the concave portion is formed in the optical member so as not to come into contact with the light emitting portion of the semiconductor laser chip, the adhesive for bonding the two enters the light emitting portion. Can be prevented.

[0113]

According to the fifth aspect of the present invention, since at least one of the insulating material and the optical member is provided with a non-reflective coating or a reflective or polarizing coating, a complicated light input / output structure can be realized. it can.

According to the sixth aspect of the present invention, since the insulating material has various optical functions such as a hologram optical element, the emitted light is divided and the input signal light is deflected in the direction of the light detection circuit. Can be made possible.

[0116] According to the present invention according to claim 7, since the curved surface or spherical surface at least a portion of the outer surface of the insulating material,
By simply inserting the element into a mating member having a corresponding engaging hole, the element can be easily and accurately positioned. Further, it is possible to adjust the rotation about the emission optical axis.

According to the eighth aspect of the present invention, since the concave portion is formed on the outer surface of the insulating material, the influence of unevenness of the refractive index and cracks due to the passage of the light emitted from the semiconductor laser chip through the insulating material can be reduced. As a result, the characteristics of the emitted light can be secured.

According to the ninth aspect of the present invention, an optical member having various optical functions such as a hologram optical element is arranged on the outer surface of the insulating material. A deflection in the direction can be made possible.

According to the tenth aspect of the present invention, since the heat conduction path or the heat radiating means for radiating the heat generated from the semiconductor laser chip to the outside is provided in the die pad, the heat is efficiently radiated to the air and the reliability is improved. Can be improved.

According to the eleventh aspect of the present invention, the claims
Since the semiconductor laser device described in any one of 1 to 10 is used for an optical pickup device, the entire device can be reduced in size, and a light-weight, high-speed pickup can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a semiconductor laser device according to a first embodiment.

FIG. 2 is a schematic configuration diagram of a semiconductor laser device according to a modification of the first embodiment.

FIG. 3 is a schematic configuration diagram of a semiconductor laser device according to a second embodiment.

FIG. 4 is a schematic configuration diagram of a semiconductor laser device showing a modification of the second embodiment.

FIG. 5 is a schematic configuration diagram of a semiconductor laser device according to a third embodiment.

FIG. 6 is a schematic configuration diagram of a semiconductor laser device according to a fourth embodiment.

FIG. 7 is a schematic configuration diagram of a semiconductor laser device showing a first modification of the fourth embodiment;

FIG. 8 is a schematic configuration diagram of a semiconductor laser device according to a fifth embodiment.

FIG. 9 is a schematic configuration diagram of a semiconductor laser device showing a first modification of the fifth embodiment;

FIG. 10 is a schematic configuration diagram of a semiconductor laser device according to a second modification of the fifth embodiment.

FIG. 11 is a schematic configuration diagram of a semiconductor laser device showing a third modification of the fifth embodiment;

FIG. 12 is a schematic configuration diagram of a semiconductor laser device showing a fourth modification of the fifth embodiment;

FIG. 13 is a schematic configuration diagram of a semiconductor laser device according to a sixth embodiment.

FIG. 14 is a schematic configuration diagram of a semiconductor laser device showing a first modification of the sixth embodiment.

FIG. 15 is a schematic configuration diagram of a semiconductor laser device showing a modification 2 of the sixth embodiment.

FIG. 16 is a schematic configuration diagram of a semiconductor laser device showing a third modification of the sixth embodiment.

FIG. 17 is a schematic configuration diagram of a semiconductor laser device showing a fourth modification of the sixth embodiment.

FIG. 18 is a schematic configuration diagram of a semiconductor laser device according to a seventh embodiment.

FIG. 19 is a schematic configuration diagram of a semiconductor laser device showing a modification of the seventh embodiment.

FIG. 20 is a schematic configuration diagram of a semiconductor laser device according to an eighth embodiment.

FIG. 21 is a schematic configuration diagram of a semiconductor laser device showing a modification of the eighth embodiment.

FIG. 22 is a schematic configuration diagram of an optical pickup device according to a ninth embodiment.

FIG. 23 is an exploded perspective view of a conventional semiconductor laser device.

FIG. 24 is a schematic configuration diagram of a lead frame used for mounting with an IC or the like.

FIG. 25 is a schematic configuration diagram of a conventional semiconductor laser device using a lead frame.

FIG. 26 is a schematic configuration diagram of another conventional semiconductor laser device using a lead frame.

FIG. 27 is a schematic configuration diagram of another conventional semiconductor laser device using a lead frame.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Lead frame 2 Die pad 3 Electrode terminal 4, 14 Semiconductor laser chip 6, 20, 26-30 Optical member 6a, 11a Depression 6b, 11b, 26a Hologram pattern 8, 17, 19, 25 Light detection circuit 9, 15, 16 Light emission Part 10 Emitted light 12 Heat sink substrate 21 Polarizing reflective coating film 22, 23 Reflective coating film 24 Non-reflective coating film 31 Heat dissipation pad (heat dissipation means) 32 Heat dissipation fins (heat dissipation means) 33 Semiconductor laser device 35 Reflection mirror (light focusing means) 36 Objective lens (light collecting means) 38 Optical disk (optical information recording medium)

Continuation of the front page (72) Inventor Akio Yoshikawa 1-1, Sachimachi, Takatsuki City, Osaka Prefecture Inside Matsushita Electronics Corporation (56) References JP-A-4-147691 (JP, A) JP-A-6-203403 (JP, A) JP-A-4-114456 (JP, A) JP-A-63-186469 (JP, A) JP-A-5-183072 (JP, A) JP-A-61-168663 (JP, A) Kaisho 61-83067 (JP, U) JP-A-3-75542 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01S 5/00-5/50

Claims (11)

(57) [Claims] 1. A semiconductor laser chip mounted on a die pad via a heat sink substrate and electrically connected to electrode terminals arranged on the outer periphery of the die pad, and a light emitting unit for emitting light emitted from the semiconductor laser chip. comprising a transparent optical member provided so as to cover the semiconductor laser chip, the die pad, a heat sink substrate, a transparent insulating material of the electrode terminals and the optical member for sealing except for the outer terminal portion of the electrode terminal, wherein Semiconduct
The semiconductor laser chip is of an end face resonator type, and the semiconductor laser chip is mounted on the heat sink substrate.
A reflection mirror is formed to reflect the light emitted from the light section
A semiconductor laser device characterized by being performed . 2. The method according to claim 1, wherein the insulating material is a laser beam of the optical member.
2. The device according to claim 1, wherein the sealing is performed except for the transmission region.
The semiconductor laser device of the mounting. The method according to claim 3, wherein said semiconductor laser chip or the heat <br/> sink substrate, the light detection circuit for detecting light intruding from the outside, the light emitted from the front or rear of the semiconductor laser chip A photodetector circuit for detecting, a current-voltage converter circuit for converting a signal current detected from these photodetector circuits into a voltage, an amplifier circuit for amplifying a signal from the current-voltage converter circuit, and calculating a signal from the amplifier circuit 2. The semiconductor laser device according to claim 1 , wherein at least one of an arithmetic circuit for performing the operation, a DA conversion circuit for performing a digital-to-analog conversion of a signal from the arithmetic circuit, and a drive circuit for driving the semiconductor laser chip is formed. . To wherein said optical member according to claim 1, characterized in that the recess so as not to contact the light emitting portion of the semiconductor laser chip is formed corresponding to the laser beam transmission region
13. The semiconductor laser device according to claim 1. 5. The semiconductor laser according to claim 1, wherein at least one of the insulating material and the optical member is provided with a non-reflective coating, a coating having a predetermined reflectance, or a polarizing coating. apparatus. 6. The insulating material has an optical function such as a hologram optical element, a lens or a reflection surface.
The semiconductor laser device according to claim 1 . 7. At least a portion of the outer surface of the insulating material,
Claims, characterized in that it exhibits a curved surface or spherical surface
2. The semiconductor laser device according to 1 . The outer surface of wherein said insulating material, wherein the recess is formed to correspond to the laser beam passage region 請
The semiconductor laser device according to claim 1 . The outer surface of wherein said insulating material, the hologram optical element, a diffraction grating, beam splitter, mirror, polarizer,
2. The semiconductor laser device according to claim 1 , wherein an optical member having an optical function, such as a lens, an optical filter, a wavelength plate, or an optical fiber, is arranged corresponding to the laser light passage area. The method according to claim 10, wherein the die pad, claim 1, wherein, wherein the semiconductor laser thermal conduction path or dissipating means releasing heat generated from the chip to the outside is provided
13. The semiconductor laser device according to claim 1. 11. A semiconductor laser device according to claim 1 , further comprising: a light condensing means for condensing a light beam emitted from the semiconductor laser device on an optical information recording medium. An optical pickup device.