JPH09102650A - Semiconductor laser device and optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of material and optical characteristics by bringing an insulating member as sealing material into contact with a laser light emitting point. SOLUTION: A semiconductor laser chip 4 is mounted on a die pad 2. A light emitting part 9 of the semiconductor laser chip 4 is covered with a transparent optical member 6. The semiconductor laser chip 4, the die pad 2, electrode terminals 3 and the optical member 6 are covered with a transparent insulating member 11, except outer terminal parts of the electrode terminals 3. Thereby a semiconductor laser device mounted on a lead frame 1 which is free from deterioration of optical characteristics and suitable for mass production is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

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 the packages are independent one by one, it is difficult to handle each package in the assembly process during mass production, and the number of assembly steps is large and the package itself is large. There is a problem that the manufacturing cost becomes very high because of the high price.

Therefore, it has been expected to introduce a lead frame used in ICs or the like, which is capable of individually mounting and assembling 10 to 20 semiconductor laser chips at one time and then assembling them. . 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 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, resin molding is usually 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. There is. I
Black resin is used as the mold resin in C and the like, but since the emitted light of the semiconductor laser chip 101 cannot be extracted with the black resin, resin molding is performed with a transparent resin to secure the emitted light of the semiconductor laser chip 101. Is what you are doing. Note that, in FIG. 25, the same components as those of FIG. 23 are denoted by the same reference numerals. The same applies to FIGS. 26 and 27 showing each conventional example below.

[0006]

However, in the technique of resin-molding with the above-mentioned transparent resin, since the insulating material made of the transparent resin directly contacts the semiconductor laser chip, the following problems occur.

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

Further, when the insulating material is molded, the resin is usually poured at a high temperature to be thermoset or cooled and hardened, but at this stage, the resin flow is apt to be stagnation at the edge portion of the complicated chip structure, Stress is generated in itself, unevenness in the refractive index of the resin itself occurs, in severe cases, the resin itself cracks, the wave front 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. 2097/1990 shown in FIG.
As in the technique of Japanese Patent No. 86, the semiconductor laser chip 101
A technique has also been proposed in which the periphery of the above is covered with a heat-resistant and elastic resin material 113 such as silicone, and then this is further sealed with an insulating material 112 made of a transparent resin.

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

Further, even a heat-resistant resin has a glass transition point of about 200 ° C. at most, and in view of long-term reliability, it completely solves the problem of optical characteristic deterioration due to heat and light density. I can't say.

Further, Japanese Patent Laid-Open No. 6-53603 shown in FIG.
Insulating material 112 made of transparent resin as in the technique of Japanese Patent Publication
There is also proposed a semiconductor laser device in which the light receiving element 103 is covered with and a part of it 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 is deteriorated and the refractive index changes, the rear facet reflectance of the semiconductor laser chip 101 changes, and the light amount ratio of the front light 115 and the rear light 116 of the semiconductor laser chip 101 changes. There is a problem that the light quantity monitor function is hindered.
In FIG. 27, 114 is an insulating frame.

Further, in this structure, the lead frame 10
A light beam is emitted in a direction parallel to 9 and, when this semiconductor laser device is adopted in an optical pickup device, the light beam is reflected by the optical disc in a direction substantially similar to the emission direction and includes a signal component of the optical disc. Will come back. In the case of integrating the photodetector circuit that receives the returned light beam, in this structure, it is necessary to form the light receiving region on the cross section of the silicon substrate that constitutes the heat sink substrate. There is a problem that it is difficult to realize easily with the current silicon process which is mainly a process.

The package used is a so-called premolded package in which the 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. It is a technology that is used. In this case, the molded insulating frame 114 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 problems such as wire bondability between the package terminal and the chip, and the strength of the resin molding itself (the strength is generally weak due to hollow holes). 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 above points, and an object thereof 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 with an optical member. Specifically, the following solving means is provided. I took it.

That is, the first to fourteenth solving means of the present invention relates to a semiconductor laser device, and the first solving means is mounted on a die pad directly or via a heat sink substrate, and is provided on the outer periphery of the die pad. A semiconductor laser chip electrically connected to the arranged electrode terminals, a transparent optical member provided so as to cover a light emitting portion that emits emitted light of the semiconductor laser chip, the semiconductor laser chip, a die pad, and a heat sink substrate. A transparent insulating material that seals the electrode terminal and the optical member excluding the outer terminal portion of the electrode terminal.

A second solution is to mount the semiconductor laser chip directly on the die pad or via the heat sink substrate and electrically connect to the electrode terminals arranged on the outer periphery of the die pad, and the semiconductor laser chip of the semiconductor laser chip. The transparent optical member provided so as to cover the light emitting portion that emits the emitted light, the semiconductor laser chip, the die pad, the heat sink substrate, the electrode terminal and the optical member through the outer terminal portion of the electrode terminal and the laser light of the optical member. And an insulating material for sealing except the region.

A third solving means is characterized in that, in the first or second solving means, the semiconductor laser chip is a surface emitting type semiconductor laser chip.

A fourth solving means is characterized in that, in the first or second solving means, the semiconductor laser chip is an end face cavity type semiconductor laser chip.

With the above arrangement, in the first to fourth solving means, 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. Is playing. Moreover, since the light emitting portion of the semiconductor laser chip is covered with the optical member and does not directly contact the insulating material, the optical characteristics such as deterioration of the material of the insulating material due to local heat of the light emitting portion of the semiconductor laser chip or high light energy density are not exhibited. Does not deteriorate. Further, the semiconductor laser chip does not deteriorate due to the stress at the time of sealing. Furthermore, since it is only necessary to interpose an optical member between the semiconductor laser chip and the insulating material, the entire device becomes compact. In particular, the second
In the solving means, since the laser light passage region 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 very effective for ensuring the characteristics of the emitted light without being affected by uneven refractive index or cracks generated inside the insulating material, bubbles and dust mixed in the resin material at all.

A fifth solving means is characterized in that, in the fourth solving means, a 45 ° reflection mirror for reflecting the emitted light of the semiconductor laser chip is formed on the heat sink substrate.

With the above arrangement, in the fifth solving means,
Even with an edge-cavity type semiconductor laser chip, the emitted light is 4
The 5 ° reflection mirror emits light in the vertical direction of the substrate, and it can be treated as a surface emitting laser substantially. By combining with a photodetector circuit formed on the heat sink substrate, it is possible to input and output light in the vertical direction of the substrate. A light emitting and receiving device can be realized.

A sixth solving means is the first or second solving means, wherein a light detecting circuit for detecting light entering from the outside and light emitted from the front or rear of the semiconductor laser chip are detected. Photodetection circuits, current-voltage conversion circuits for converting signal currents detected by these photodetection circuits into voltages, amplification circuits for amplifying signals from the current-voltage conversion circuits, operations for calculating signals from the amplification circuits Circuit, D for digital-analog converting signals from the arithmetic circuit
At least one of the A conversion circuit and the drive circuit for driving the semiconductor laser is formed on the semiconductor laser chip or the heat sink substrate.

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

A seventh solving means is characterized in that, in the first or second solving means, a recess 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 region. To do.

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

An eighth solving means is the first or second solving means, wherein the optical member is 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 wave plate. It is characterized by having it.

With the above arrangement, in the eighth solving means,
The hologram optical element or the like allows the emitted light to be split or the input signal light to be diffracted and deflected toward the photodetector circuit.

A ninth solving means is characterized in that, in the first or second solving means, at least one of the insulating material and the optical member is provided with a non-reflection coating, a coating having a predetermined reflectance or a polarizing coating. And

With the above arrangement, the ninth solving means is
A complex light input / output structure is possible.

A tenth solving means is characterized in that, in the first or second solving means, the insulating material has an optical function such as a hologram optical element, a lens or a reflecting surface.

With the above arrangement, in the tenth solving means, similarly to the eighth solving means, the emitted light can be split or the input signal light can be diffracted and deflected toward the photodetector circuit.

An eleventh solving means is characterized in that, in the first or second solving means, at least a part of the outer surface of the insulating material is a curved surface or a spherical surface.

With the above arrangement, in the eleventh solving means, the curved surface or the spherical shape is inserted into the engaging hole formed in the mating member to be assembled in advance corresponding to the curved surface or the spherical shape. The position adjustment can be performed easily and with high accuracy, and rotation adjustment around the emission optical axis can be performed.

A twelfth solving means is characterized in that, in the first or second solving means, a recess is formed on the outer surface of the insulating material so as to correspond to the laser beam passage region.

With the above structure, in the twelfth solving means, influences of unevenness in refractive index and cracks due to passage of the emitted light emitted from the semiconductor laser chip through the insulating material, bubbles and dust mixed in the resin material are reduced, The characteristics of the emitted light are secured.

A thirteenth solving means is the same as the first or second solving means, wherein a hologram optical element, a diffraction grating, a beam splitter, a mirror, a polarizing plate, a lens is provided on the outer surface of the insulating material.
It is characterized in that an optical member having an optical function such as an optical filter, a wave plate or an optical fiber is arranged corresponding to the laser light passage region.

With the above arrangement, in the thirteenth solving means, the emitted light can be split or the input signal light can be diffracted and deflected in the direction of the photodetector circuit as in the eighth solving means.

A fourteenth solving means is characterized in that, in the first or second solving means, a heat conduction path or a heat radiating means for releasing heat generated from the semiconductor laser chip to the outside is provided in the die pad.

With the above arrangement, the fourteenth solving means efficiently radiates heat to the air and improves the reliability.

A fifteenth solving means of the present invention relates to an optical pickup device, and the semiconductor laser device according to any one of the solving means of the first to fourteenth solving means, and a light beam emitted from the semiconductor laser device. Is provided on the optical information recording medium.

With the above arrangement, in the fifteenth means for solving the problem, the small and light semiconductor laser device makes the overall shape very small, and since it is light in weight, a pickup capable of high-speed response can be realized.

[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 the first embodiment of the present invention, and FIG. 2 shows a modification thereof.

In FIGS. 1A to 1C, 1 is a lead frame, which is provided with a die pad 2 near the center thereof, and a plurality of electrode terminals 3 are provided around the die pad 2. Are 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 the inner terminal portion of the electrode terminal 3 by a bonding wire 5. Further, 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 emitted light 10 of the semiconductor laser chip 4 from above, and around the light emitting portion 9. Are fixed by an adhesive 7 so as not to come off. Further, the semiconductor laser chip 4, the die pad 2, the electrode terminal 3, the bonding wire 5 and the 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 photodetector circuit 8 for detecting light entering from the 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 so as not to be exposed to the outside air. Therefore, the insulating material 11 is a protective package. Fully fulfills its function as. Moreover, not only that, but 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. Therefore, the insulating material made of a transparent resin as in the conventional example shown in FIG. Since it is not exposed to 112, it is possible to eliminate 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, and It is possible to eliminate the problem of deterioration of the semiconductor laser chip 4 due to the stress during resin sealing.

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

Further, in the first embodiment, the photodetector circuit 8 for detecting the light coming from the outside is formed on the upper surface of the semiconductor laser chip 4, but various electric circuits other than the photodetector circuit 8 are formed. For example, a photodetector circuit that detects light emitted from the front or rear of the semiconductor laser chip 4, a current-voltage converter circuit that converts the signal current detected by these photodetector circuits into a voltage, or a current-voltage converter circuit By forming an amplifier circuit for amplifying the signal of No. 1, an arithmetic circuit for arithmetically operating the signal from the amplifier circuit, a DA conversion circuit for digital-analog converting 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, as more electric circuits are formed on the semiconductor laser chip 4, the number of electrode terminals increases.
In the conventional package technique of the semiconductor laser device as shown in FIG. 23, which is not the lead frame type, the electrode terminal 1
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 an insulating material 1
Since 07 occupies a diameter of about 1 mm, it is possible to realize only an electrode arrangement with an interval of at least 2 mm. When 20 electrode terminals 106 are required, the diameter of the stem 104 is 13 to 15 m.
It is thought to be m. Further, the electrode lead-out direction is also the vertical direction in the conventional package shown in FIG. 23, but is horizontal according to the first embodiment, which is also effective in reducing the thickness of the package. Although this point can be solved by using a pre-mold type package as shown in FIG. 27, the insulating frame 114 itself must be arranged outside the wire bond position, and further, the size of the wire bond capillaries. Considering the size of the collet of the die bond and the strength of the package (which is generally weaker than the filling type because it is hollow), the outer shape of the insulating frame 114 is larger than that of the surface emitting type semiconductor laser chip. Will also be much larger. For example, if the width of the surface emitting type semiconductor laser chip is 1 mm, 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. Since it is 0.4 mm, it cannot be said that the technology of the lead frame is effectively used. On the other hand, when the technique of the present invention is used, since the insulating frame 114 itself does not exist, the thickness of the insulating frame 114 in the above calculation is 1 mm, so that both sides can be reduced by 2 mm to achieve 3.4 mm, which is a significantly small size. Can be realized.

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 is incident on the light detecting circuit 8 from the outside. This is advantageous because it is possible to reduce the influence of the generated light beam on the unevenness of the transparent resin forming the insulating material 11, bubbles, dust, and the like.

Although resin is used as the material of the insulating material 11 in the first embodiment, any other material such as glass material may be used as long as it can ensure the insulation between the electrode terminals 3 and the emitted light characteristics. I do not care. This content is the same in each of 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 region so as not to contact the light emitting portion 9 of the semiconductor laser chip 4. Is formed. As a result, the adhesive 7 for bonding the optical member 6 to the semiconductor laser chip 4 can be prevented from entering the light emitting section 9 and coming into 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. The contents are the same in the following embodiments.

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

3A and 3B show a silicon heat sink substrate 12 mounted on the die pad 2 and the 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 is a monitor photodiode formed on the heat sink substrate 12 for detecting the rear light of the surface emitting laser.
Since the other points are the same as those in the first embodiment, the same components are designated by the same reference numerals and detailed description thereof will be omitted.

Therefore, in the second embodiment, the same operational effect as that of the first embodiment can be obtained.

In the modification shown in FIGS. 4A and 4B, a recess 6a larger than that in 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 recess 6a. It is mounted on the heat sink substrate 12 so as to straddle the semiconductor laser chip 4 and cover the photodetector circuit 8.

In this way, by covering the photodetector circuit 8 on the heat sink substrate 12 with the optical member 6 as well, the light beam incident on the photodetector circuit 8 from the outside causes unevenness and bubbles in the resin forming the insulating material 11. It is possible to reduce the influence of dust and the like.

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

In this third embodiment, a space is formed between the semiconductor laser chip being the edge-cavity type semiconductor laser chip 14 and the recess 6a of the optical member 6 being large and the semiconductor laser chip 14. Semiconductor laser chip 1
The first point is that 4 does not contact the optical member 6.
This is a big difference from the embodiment. FIG. 5 (a),
In (b), 15 is a front light emitting portion of the semiconductor laser chip 14, 16 is a rear light emitting portion of the semiconductor laser chip 14, 1
Reference numeral 2a denotes a 45 [deg.] Reflection mirror 12a formed on the heat sink substrate 12. The emitted light 10 emitted from the front light emitting section 15 is reflected by the reflection mirror 12a to form 90 [deg.].
It is designed to turn upward. Reference numeral 17 denotes a monitor 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 made of silicon (10) by anisotropic etching of a silicon single crystal substrate ((111) crystal plane forming 54 ° with respect to the (100) substrate is obtained).
0) It can be easily obtained by applying it to a 9 ° off-angle substrate. Since the other points are the same as those of the second embodiment, the same components are designated by the same reference numerals and detailed description thereof will be omitted.

Therefore, in the third embodiment, the same operational effect as that of the second embodiment can be obtained.

In addition, in the third embodiment, the emitted light 10 is 45 in the end face resonator type semiconductor laser chip 14 as well.
Since the light can be emitted in the vertical direction to the substrate by the reflection mirror 12a of 8 °, it can be substantially treated as a surface emitting laser. By combining with the photodetector circuit 8 formed on the heat sink substrate 12, light can be emitted in the vertical direction to the substrate. It is possible to realize a light emitting and receiving device capable of inputting and outputting.

In the third embodiment, the semiconductor laser chip 14 and the photodetector 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 photodetector circuit 8 as well, the light beam entering the photodetector circuit 8 from the outside is less affected by the unevenness of the resin forming the insulating material 11, bubbles, dust, etc., which is more effective. That is as described in the first embodiment.

Further, in the third embodiment, the reflecting mirror 1
Although 2a is composed of the inclined surface formed on the heat sink substrate 12, a reflection mirror prepared separately 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 the 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, the recess 11a is formed on the upper surface which is the outer surface of the insulating material 11 so as to correspond to the laser light passage region (the passage region of the emitted light 10 emitted from the front light emitting portion 15). The upper surface of the optical member 6 is exposed to the outside.
Since the other points are the same as those in the third embodiment, the same components are designated by the same reference numerals and detailed description thereof will be omitted. The formation of the recess 11a in the insulating material 11 can be easily realized depending on the shape of the mold used for molding the insulating material 11.

Therefore, in the fourth embodiment, the same operational effect as that of the third embodiment can be obtained.

In addition, in this fourth embodiment, the insulating material 11
Since the upper surface of the optical member 6 is exposed to the outside by forming the concave portion 11a in the concave portion, 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 molded at the time of molding the insulating material 11. It is possible to completely eliminate the influences of uneven refractive index and cracks generated inside 11 and bubbles and dust mixed in the resin material, and it is very effective for securing the characteristics of the emitted light 10.

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

By forming the recess 11a in this manner, the thickness of the laser beam passage region of the insulating material 11 can be reduced, and the probability that bubbles and dust are generated in the laser beam passage region is reduced by that amount, and the thickness is reduced. However, the influence of uneven refractive index is reduced, 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.
4 respectively.

In the fifth embodiment, similar to the modification of the fourth embodiment, the recess 11a is formed shallow in the insulating material 11, and the hologram pattern 11b is formed on the outer surface of the recess 11a.
And the insulating material 11 has an optical function as a hologram optical element. In the figure, 10a, 10b,
In 10c, the emitted light 10 is the hologram pattern 1 respectively.
-1st order, 0th order, + 1st order diffracted light diffracted by 1b, 1
Reference numeral 8 is an input signal light returning from the outside, 18a is a diffracted light obtained by diffracting the input signal light 18 by the hologram pattern 11b, and 19 is a photodetection circuit for detecting the diffracted light.

Therefore, in the fifth embodiment, the same operational effect as the modification of the fourth embodiment can be obtained.

In addition, in this fifth embodiment, the insulating material 11
With the hologram pattern 11b formed in the concave portion 11a, the emitted light 10 can be split or the input signal light 18 can be diffracted and deflected toward the photodetector 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 give a lens effect by a concentric circle function or 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, but 0th and -1st order lights are also generated. It is also possible to detect light with 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. There is no 11a, and the third embodiment (FIG.
It is flat as shown in (a).

In the 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 shallowly formed.

Also in these modified examples 1 and 2, the same operational effect as the fifth embodiment can be obtained. Further, although not shown, the insulating material 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 Modification 3 shown in FIG. 11, convex portions 11c and 6 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 c respectively, a convex lens effect is given. It should be noted that it is possible to provide a concave lens effect and other desired wavefront conversion effects by forming the shape of the concave portion according to the purpose, and further, the semiconductor laser chip 14 can be used.
The astigmatism of can be corrected. Further, by combining various material characteristics of the optical member 6 and the insulating material 11, and further by changing the design of the shape 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.

The 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, and the opposite side is coated with a coating having a predetermined reflectance to form a reflective coating film 22. ing.
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 is a light detection circuit for detecting the reflected light 10d and monitoring the front light of the semiconductor laser chip 14.

In this way, the optical member 20 and the insulating material 11 are provided in the laser beam passage region of the emitted light 10 from the front light emitting section 15.
A complex light input / output structure can be realized by providing an inclined boundary with the polarization reflective coating film 21 and the reflective coating film 22 on the inclined boundary.

(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 thereof.

In the sixth embodiment, the optical member 26 made of transparent glass having the hologram pattern 26a as an optical function is provided on the outer surface of the upper portion of the insulating material 11 in the front light emitting portion 15.
The modification is the same as the modification (see FIG. 7) of the fourth embodiment except that the light is emitted from the laser light passing through the laser light passing region.

In a modified example 1 shown in FIG. 14, an optical member 27 composed of a composite prism is arranged on the outer surface of the upper portion of the insulating material 11 instead of the optical member 26 of the sixth embodiment, and further, the concave portion 11a of the insulating material 11 is arranged. The hologram pattern 11b is formed on the bottom surface. In the figure, 10e is the front light emitting portion 15
It is the light reflected from the prism surface of the outgoing light 10 from.

As a result, it becomes possible to perform wavefront control and split detection of the light 18 reflected by the optical member 27 composed of the composite prism and entering the inside of the element.

In Modification 2 shown in FIG. 15, two recesses 11d are formed on the upper outer surface of the insulating material 11, one of the recesses 11d is provided with an optical member 28 made of an optical fiber for emission, and the other recess 11d is provided. Optical members 29 made of input optical fibers are inserted and arranged from above.

As a result, the insulating member 11 has the optical member 28,
By forming the recess 11d corresponding to the fiber diameter of 29, the optical members 28, 29, the semiconductor laser chip 14, and the photodetector circuit 19 can be easily aligned by simply inserting the optical members 28, 29 into the recess 11d. It is possible with precision.

In Modification 3 shown in FIG. 16, two recesses 11d are formed on the outer surface of the side of the insulating material 11, one of the recesses 11d is provided with an optical member 28 made of an optical fiber for emission, and the other recess 11d is provided. Is an optical member 29 formed of an input optical fiber and inserted and arranged from the side. Also,
A polarizing reflective coating film 21 and a reflective coating film 22 as in the modified example 4 of the fifth embodiment (see FIG. 12) are formed near the bottom of the recess 11a formed on the upper outer surface of the insulating material 11.

As a result, as in the second modification, the optical member 2
8, 29, semiconductor laser chip 14, and photodetector circuit 1
The position of 9 can be easily adjusted with high accuracy, and an element capable of inputting / outputting light in the same direction can be obtained.

In the 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. Further, a hologram pattern 6b is formed on the outer surface of the upper portion of the optical member 6 covered with the insulating material 11.

As a result, like the second modification, the optical member 2 is provided.
8, 29, semiconductor laser chip 14, and photodetector circuit 1
9 can be easily aligned with high accuracy, and the input light 18 is diffracted by the hologram pattern 6b and can be detected by the photodetector 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 kamaboko-shaped blocks 11e each having a curved surface 11f whose one side surface is curved in a convex shape are provided on the upper outer surface of the insulating material 11 so as to project therefrom.

Thus, by inserting the block 11e into the engaging hole formed in the mating member to be assembled in advance corresponding to the shape of the block 11e, the element can be easily aligned with high accuracy and the emitted light It is possible to adjust the rotation around the axis.

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 recess 1 is formed on the top.
1a.

Thus, by inserting the spherical surface 11h into the engaging hole formed in the mating member to be assembled in advance corresponding to the shape of the spherical surface 11h, the element can be easily aligned with high accuracy and the spherical surface can be easily aligned. It is possible to adjust the tilt around the origin of 11h.

(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, the heat radiation pad 31 is provided on the back surface of the die pad 2. The heat radiation pad 31 is formed by forming the die pad 2 into a thick wall projecting downward from the electrode terminal 3. It is composed of a thick part.
Other than that, the configuration is similar to that of the third embodiment (see FIG. 5A).

As a result, the heat radiation to the air is eliminated by the heat radiation pad 3
1, the thermal resistance can be reduced efficiently, and if the 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 improved. It is very effective in improving sex.

In the modification shown in FIG. 21, the heat radiation fins 32 are arranged on the lower outer surface of the insulating material 11 so as to be in contact with the heat radiation pads 31 in the eighth embodiment.

As a result, 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 the ninth embodiment of the present invention.

In the figure, 33 is a semiconductor laser device comprising a semiconductor laser / photodetector integrated element (LD / PD element) including a hologram pattern according to the present invention, 34 is an actuator movable part, 35 is a reflection mirror,
36 is an objective lens, 37 is a wire suspension, 38
Is an optical disc as an optical information recording medium, 39 is a support, and the reflecting mirror 35 and the objective lens 36 constitute a condensing means for condensing the light beam emitted from the semiconductor laser device 33 onto the optical disc 38. Has been done.

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

In the optical pickup device having the structure shown in FIG. 22, the compact and lightweight 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 the weight is light.

The optical members and insulating materials having an optical function are not limited to those mentioned in each of the embodiments, and hologram optical elements, diffraction gratings, beam splitters, mirrors, polarizing plates, lenses, optical filters, wave plates. , A reflective surface, an optical fiber, or the like.

[0109]

As described above, according to the present invention according to claims 1 to 4, the light emitting portion of the semiconductor laser chip is covered with the optical member so as not to touch the insulating material. It is possible to prevent the semiconductor laser chip from deteriorating due to deterioration or stress during sealing. Moreover, the device can be made compact. In particular, according to the present invention as defined in claim 2, since the laser light passage region of the optical member is exposed to the outside, the emitted light emitted from the semiconductor laser chip is uneven in refractive index or cracked inside the insulating material. The output light characteristics are secured without being affected by the above.

According to the fifth aspect of the present invention, since the 45 ° reflection mirror is formed on the heat sink substrate, the edge-cavity type semiconductor laser chip can be substantially treated as a surface emitting laser. Further, by combining with a photodetector circuit formed on the heat sink substrate, it is possible to realize a light emitting and receiving device capable of inputting and outputting light in the substrate vertical direction.

According to the sixth aspect of the present invention, various circuits such as a photodetector circuit are formed on the semiconductor laser chip or the heat sink substrate, so that a more effective element can be obtained.

According to the present invention of claim 7, 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 adhering the both enters the light emitting portion. Can be prevented.

According to the eighth aspect of the present invention, since the optical member has various optical functions such as a hologram optical element, the outgoing light is split and the input signal light is deflected toward the photodetector circuit. Can be enabled.

According to the ninth aspect of the present invention, since at least one of the insulating material and the optical member is provided with the antireflection coating, the reflective and polarizing coating, it is possible to realize a complicated light input / output structure. it can.

According to the tenth aspect of the present invention, since the insulating material has various optical functions such as a hologram optical element, the emitted light is split and the input signal light is deflected toward the photodetector circuit. Can be enabled.

According to the eleventh aspect of the present invention, since at least a part of the outer surface of the insulating material is formed into a curved surface or a spherical surface, the position of the element can be adjusted only by inserting it into a mating member having an engaging hole corresponding thereto. The alignment can be performed easily and with high accuracy. In addition, it is possible to enable rotation adjustment around the outgoing optical axis.

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

According to the thirteenth aspect of the present invention, since the optical member having various optical functions such as the hologram optical element is arranged on the outer surface of the insulating material, the outgoing light is split and the input signal light is detected by the photodetector circuit. Deflection in a direction can be possible.

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

According to the fifteenth aspect of the present invention, since the semiconductor laser device according to any one of the first to fourteenth aspects is used for the optical pickup device, the entire device can be made compact, and the weight and the speed are high. A responsive pickup can be realized.

[Brief description of the drawings]

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

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

FIG. 3 is a schematic configuration diagram of a semiconductor laser device of 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 of a third embodiment.

FIG. 6 is a schematic configuration diagram of a semiconductor laser device of 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 of 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 showing 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 modified example 4 of the fifth example.

FIG. 13 is a schematic configuration diagram of a semiconductor laser device of 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 second modification of the sixth embodiment.

FIG. 16 is a schematic configuration diagram of a semiconductor laser device showing a modified example 3 of the sixth embodiment.

FIG. 17 is a schematic configuration diagram of a semiconductor laser device showing a modified example 4 of the sixth embodiment.

FIG. 18 is a schematic configuration diagram of a semiconductor laser device of 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 of 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 of 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 on 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]

1 Lead frame 2 Die pad 3 Electrode terminal 4,14 Semiconductor laser chip 6,20,26-30 Optical member 6a, 11a Recess 6b, 11b, 26a Hologram pattern 8,17,19,25 Photodetector 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 Radiating pad (radiating means) 32 Radiating fin (radiating means) 33 Semiconductor laser device 35 Reflecting mirror (focusing means) 36 Objective Lens (Condensing Means) 38 Optical Disk (Optical Information Recording Medium)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H01L 23/48 (72) Inventor Akio Yoshikawa 1-1 Sachimachi, Takatsuki-shi, Osaka Matsushita Electronics Industrial Co., Ltd. In the company

Claims (15)

[Claims] 1. A semiconductor laser chip mounted directly on a die pad or via a heat sink substrate and electrically connected to electrode terminals arranged on the outer periphery of the die pad, and light emission for emitting light from the semiconductor laser chip. A transparent optical member provided so as to cover the semiconductor laser chip, the die pad, the heat sink substrate, the electrode terminal and the optical member except for the outer terminal portion of the electrode terminal. A semiconductor laser device characterized by the above. 2. A semiconductor laser chip mounted directly on a die pad or via a heat sink substrate and electrically connected to electrode terminals arranged on the outer periphery of the die pad, and light emission for emitting light from the semiconductor laser chip. A transparent optical member provided so as to cover the portion, the semiconductor laser chip, the die pad, the heat sink substrate, the electrode terminal and the optical member except the outer terminal portion of the electrode terminal and the laser beam passage region of the optical member. A semiconductor laser device comprising: an insulating material for sealing. 3. The semiconductor laser device according to claim 1, wherein the semiconductor laser chip is a surface emitting type semiconductor laser chip. 4. The semiconductor laser device according to claim 1, wherein the semiconductor laser chip is an edge-cavity type semiconductor laser chip. 5. The semiconductor laser device according to claim 4, wherein the heat sink substrate is formed with a reflection mirror of 45 ° for reflecting the light emitted from the semiconductor laser chip. 6. A semiconductor laser chip or a heat sink substrate, a photodetector circuit for detecting light entering from the outside, a photodetector circuit for detecting light emitted from the front or rear of the semiconductor laser chip, and these. Current-voltage conversion circuit for converting the signal current detected by the photodetection circuit into a voltage, an amplification circuit for amplifying a signal from the current-voltage conversion circuit, an arithmetic circuit for calculating a signal from the amplification circuit, and the arithmetic circuit D-to-analog convert the signal from the
2. At least one of an A conversion circuit and a drive circuit for driving a semiconductor laser is formed.
Alternatively, the semiconductor laser device according to item 2. 7. The semiconductor laser device according to claim 1, wherein a recess 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 region. . 8. The semiconductor according to claim 1, wherein the optical member has 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 wave plate. Laser device. 9. The semiconductor laser according to claim 1, wherein at least one of the insulating material and the optical member is provided with a non-reflection coating, a coating having a predetermined reflectance or a polarizing coating. apparatus. 10. The semiconductor laser device according to claim 1, wherein the insulating material has an optical function such as a hologram optical element, a lens or a reflecting surface. 11. The at least part of the outer surface of the insulating material has a curved surface or a spherical surface.
Alternatively, the semiconductor laser device according to item 2. 12. The semiconductor laser device according to claim 1, wherein a concave portion is formed on the outer surface of the insulating material so as to correspond to the laser light passage region. 13. An optical member having 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, a wavelength plate or an optical fiber is provided on the outer surface of the insulating material in the laser beam passage region. 3. The semiconductor laser device according to claim 1, wherein the semiconductor laser device is arranged in correspondence with. 14. The semiconductor laser device according to claim 1, wherein the die pad is provided with a heat conducting path or a heat radiating means for allowing heat generated from the semiconductor laser chip to escape to the outside. 15. A semiconductor laser device according to claim 1, and a condensing means for condensing a light beam emitted from the semiconductor laser device onto an optical information recording medium. An optical pickup device characterized in that