JPH1049897A - Optical pick-up device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pick-up device of high quality which enables precise-alignment and fixation of a laser light-emitting device and a signal detection light-receiving device. SOLUTION: In the optical pick-up device having a laser diode 25, a photodiode 23, and a base 21, on which the laser diode 25 and the photodiode 23 are set, at least one of the laser diode 25 and the photodiode 23 is mounted on mounting stages 22, 24, and transit terminals 26, 28 for connecting the laser diode 25 and the photodiode 23 mounted on the mounting stages 22, 24 to an external circuit 33 are provided in a unified manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device for reading, for example, a signal from an optical disk and a method for manufacturing the same.

[0002]

2. Description of the Related Art An optical pickup device for reading a signal from an optical disk comprises a laser diode as a laser light emitting element, a hologram optical element and a photodiode as a light receiving element for signal detection. Then, the laser light emitted from the laser diode passes through the hologram optical element, forms an image on the optical disk by the imaging lens, and the reflected light returns along the same optical path and enters the hologram optical element again. I have. The laser light split and deflected by the hologram optical element is incident on the light receiving surface of the photodiode.

Here, the photodiode is an element divided into a plurality of parts, and controls tracking and focusing of the optical pickup device. In recent years, the track pitch has become smaller as the recording density of optical discs has increased, and the depth of focus of imaging lenses has become smaller. I have. That is, in assembling the optical pickup device, a high positional accuracy of the photodiode with respect to the laser diode is required.

FIG. 8 shows a part of a conventional optical pickup device, and 1 is a base such as a metal block. The base 1 has a horizontal plane 1a and a vertical plane 1b which are orthogonal to each other.
A photodiode 2 is mounted on a horizontal surface 1a of the base 1, and a laser diode 3 is mounted on a vertical surface 1b. The photodiode 2 is an element divided into a plurality of parts, the light receiving surface 2a thereof faces a hologram optical element (not shown), and the light emitting point 3a of the laser diode 3 faces the hologram optical element.

In order to assemble the optical pickup device, first, the laser diode 3 is fixed to the vertical surface 1b of the base 1 with an adhesive or the like, and then the photodiode is mounted to the horizontal surface 1a of the base 1. In this case, the accuracy of ± 5 μm is required in the XYZ directions so that the light receiving point of the photodiode 2 is at a constant distance with respect to the light emitting point 3a of the laser diode 3.

Further, in the next step, the photodiode 2
And the laser diode 3 are electrically connected to the external circuit 4, respectively. First, the laser diode 3 is wire-bonded to the relay terminal 5 provided on the vertical surface 1b of the base 1 by a gold wire 6 or the like. The photodiode 2 is wire-bonded to the relay terminal 7 provided on the horizontal surface 1a of the base 1 by a gold wire 8 or the like. Further, the relay terminals 5 and 7 and the external circuit 4 are wired by lead wires 9.

In order to position the photodiode 2 and the laser diode 3 with high precision, a passive alignment method for mechanically positioning the laser diode 3 with high accuracy is required. An active alignment method of performing positioning while observing an output signal of the diode 2 is performed. In the passive alignment method, machining of machine parts, assembly accuracy,
There are problems in accuracy due to backlash, alignment mark recognition accuracy, etc., device cost, alignment time, etc. An active alignment method is a method for reducing these problems.

In the active alignment method, positioning is performed by observing the output of the photodiode 2, so that the accuracy of the mounter is not required as compared with the passive alignment method. However, in order to adjust the position while the unfixed semiconductor element is in the operating state, the connection (contact) method of the electric wiring,
It is necessary to devise a method for reliably gripping a minute semiconductor element.

FIG. 9 shows a case where the photodiode 2 is aligned in the operating state. The photodiode 2 is movable in the XY directions on the horizontal surface 1a of the base 1. A probe pin 10 is in contact with each electrode 2b of the photodiode 2 for extracting an electric signal. Furthermore, the photodiode 2 is held from both sides by a grip 11 for holding and adjusting the position of the photodiode 2.

In this case, a mechanism for aligning the electrode 2b on the photodiode 2 held by the grip 11 with the probe pin 10 is required.
The movement of the grip 11 and the probe pin 10 must be linked in order to perform the positioning while observing the output signal of the above, so that the positioning mechanism must be complicated.

Further, as shown in FIG. 9, since the photodiode 2 and the electrode 2b are formed on the surface of the photodiode 2, only the side surface of the photodiode 2 can be used for holding. In the photodiode 2 made of a semiconductor, so-called chipping in which an edge is missing easily occurs, and there is a great risk of damaging the photodiode 2. When the alignment is completed, the photodiode 2 is fixed at the position, the probe pin 10 and the grip 11 are removed, and then the electrode 2b and the relay terminal 7 are connected by wire bonding.

[0012]

However, in the above-described passive alignment, since mechanical accuracy close to the limit is required, the apparatus is expensive, it takes a long time to maintain the accuracy, it is technically difficult, and There were problems such as a long matching time. In the active alignment, the position of the semiconductor element in the operating state is moved and the positioning mechanism becomes complicated. There are problems such as chipping easily caused by the holding mechanism, and it is desired to solve these problems.

As shown in FIG. 10, since the horizontal surface 1a and the vertical surface 1b of the base 1 are formed as flat surfaces, when the photodiode 2 is fixed to the horizontal surface 1a and when the laser diode 3 is 1b has many degrees of freedom when fixing it, and it is difficult to position it at a desired position.
A lot of man-hours are required for positioning and fixing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to easily and precisely position a relative position between a laser light emitting element and a signal detecting light receiving element, and to fix the position. An object of the present invention is to provide an optical pickup device that does not sometimes damage an element and a method of manufacturing the same.

[0015]

In order to achieve the above object, the present invention provides a laser light emitting element for irradiating a laser beam to an object to be irradiated, and a laser light emitting element for reflecting the laser beam reflected from the object to be irradiated. In an optical pickup device comprising a light receiving element for signal detection for receiving and photoelectrically converting, and a base on which the laser light emitting element and the light receiving element for signal detection are mounted, the laser emission mounted on the base is provided. At least one of the element and the signal detection light receiving element is mounted on the base via a mount base, and the mount base is provided integrally with a relay terminal for connecting the element and an external circuit. Features.

A second aspect of the present invention is characterized in that the element mounted on the mount table of the first aspect and the relay terminal are connected by wire bonding. According to a third aspect of the present invention, at least one of the laser light emitting element and the signal detection light receiving element mounted on the base of the first aspect is mounted on the base via a mount base, and the mount base is a relative element. It is characterized by being movable with respect to the base so that the position can be adjusted.

Preferably, the laser light emitting element irradiates the object to be irradiated with laser light, the signal detecting light receiving element for receiving the laser light reflected from the object to be subjected to photoelectric conversion, and the laser light emitting element. And a base on which the signal detection light-receiving element is mounted, wherein at least one of the laser light-emitting element and the signal detection light-receiving element mounted on the base is mounted on a mount base. A first step of mounting on the base via a second step of connecting an element mounted on the mount with a relay terminal integrally provided on the mount and connected to an external circuit. And a third step of moving at least one of the mount tables to align the relative positions of the laser light emitting element and the signal detection light receiving element.

According to a fifth aspect of the present invention, in the third step of the fourth aspect, the laser light emitting element and the signal detecting light receiving element are operated, and at least one of the mount bases is moved based on the output signal of the signal detecting light receiving element. It is characterized by moving and aligning the relative positions of the elements.

A laser light emitting element for irradiating the object to be irradiated with laser light, a signal detecting light receiving element for receiving the laser light reflected from the object to be irradiated and photoelectrically converting the laser light, and the laser light emitting element And a base on which the signal detecting light receiving element is mounted, wherein the laser light emitting element is positioned by pressing the laser light emitting element against the laser light emitting element mounting portion of the base. A positioning portion is provided.

A seventh aspect of the present invention is characterized in that the positioning portion of the sixth aspect positions the laser light emitting element by pressing a mount table on which the laser light emitting element is mounted.

An eighth aspect of the present invention is characterized in that the positioning portion of the sixth aspect has a positioning groove into which a mount table on which the laser light emitting element is mounted is fitted. Claim 9
A laser light emitting element for irradiating the irradiation target with laser light, a signal detection light receiving element for receiving the laser light reflected from the irradiation target and photoelectrically converting the laser light, the laser light emitting element and the signal detection light reception In the optical pickup device including a base on which the element is mounted, a positioning part for positioning by pressing the signal detection light receiving element is provided on the signal detection light receiving element mounting part of the base. Features.

A tenth aspect of the present invention is characterized in that the positioning part of the ninth aspect positions the detection light receiving element by pressing a mount base on which the signal detection light receiving element is mounted. I do.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment, and FIG. 1 shows a part of an optical pickup device. 21
Is a base as a stem made of a metal block, and the base 21 has a horizontal plane 21 a and a vertical plane 21
b and the protrusion 21c. A photodiode mount (hereinafter, referred to as a PD mount 22) made of a metal plate is placed on a horizontal surface 21 a of the base 21, and the PD mount 22 is provided with a photo as a light receiving element for signal detection. The diode 23 is attached by fixing means such as soldering or an adhesive.

On the vertical surface 21b, there is provided a laser diode mount base (hereinafter, referred to as an LD mount base 24) made of a metal plate.
Is mounted with a laser diode 25 as a laser light emitting element by fixing means such as soldering or an adhesive.

The photodiode 23 is an element divided into a plurality of parts, the light receiving surface 23a thereof faces a hologram optical element (not shown), and the light emitting point 25a of the laser diode 25 faces the hologram optical element. .

At the edge of the photodiode 23, an electrode 23b electrically connected to the element is provided.
A relay terminal 26 is provided on the PD mount base 22 located near the electrode 23b, and the electrode 23b and the relay terminal 26 are wire-bonded by a gold wire 27 or the like.

Similarly, at the edge of the laser diode 25, an electrode 25b electrically connected to the element is provided. A relay terminal 28 is provided on the LD mount table 24 located near the electrode 25b.
And the relay terminal 28 are wire-bonded by a gold wire 29 or the like.

As shown in FIG. 2, the relay terminal 26 (28) has a bonding terminal portion 30 to which the gold wire 27 (29) is bonded and a screw terminal portion 32 to which the lead wire 31 is connected. One end of a lead wire 31 is connected to the screw terminal 32, and the other end of the lead wire 31 is connected to an external circuit 33.

Next, a method of manufacturing the optical pickup device having the above-described structure will be described. First, the laser diode 25 is soldered to the LD mount table 24 and fixed by fixing means such as an adhesive.
5 electrode 25b and relay terminal 28 of LD mount base 24
Are bonded by a gold wire 29 or the like.

Next, the rear surface of the LD mount table 24 on which the laser diode 25 is mounted is attached to the vertical surface 21 of the base 21.
b, after being attached to the screw terminal portion 32 of the relay terminal 28 by soldering or fixing means such as an adhesive.
Lead 31 to be connected to the laser diode 2
5 and the external circuit 33 are electrically connected.

Next, the photodiode 23 is soldered to the PD mount base 22 and fixed by fixing means such as an adhesive, and the electrode 23b of the photodiode 23 and the relay terminal 26 of the PD mount base 22 are connected to the gold wire 27. Wire bonding is performed by the method described above.

Next, the PD mount 22 on which the photodiode 23 is mounted is placed on the horizontal surface 21a of the base 21. Here, a PD on which the photodiode 23 is mounted
The mount table 22 is movable in the XY directions on a horizontal plane 21a, and grips both sides of the PD mount table 22 with grips (not shown).

In this state, the laser diode 25 and the photodiode 23 are operated by a signal from the external circuit 33. That is, laser light L is emitted from the laser diode 25, and reflected light from an optical disk (both not shown) is received by the photodiode 23 via the lens system. While observing the output signal of the photodiode 23, the PD mount base 22 is gripped by a grip (not shown).
With the light-emitting point 25a of the laser diode 25 fixed at the reference position, the output value of the photodiode 23 is checked by about ± 5 μm while observing the output value of the photodiode 23 so that the light-receiving point of the photodiode 23 comes to a predetermined position. Is adjusted to find a desired position. After the photodiode 23 is positioned at a desired position, the PD mount base 22 is soldered to the horizontal surface 21a of the base 21 and fixed by fixing means such as an adhesive.

At this time, the photodiode 23 is fixed to the PD mount base 22, and the electrode 23b of the photodiode 23 and the relay terminal 26 of the PD mount base 22 are wire-bonded by a gold wire 27 or the like. Since the photodiode 23 and the relay terminal 26 move integrally with the PD mount base 22, no external force due to tension or looseness is applied to the gold wire 27, and there is no fear that the gold wire 27 or the bonding point is disconnected. Absent.

In the first embodiment, the laser diode 25 is mounted on the base 2 via the LD mount 24.
1, the position is adjusted with the photodiode 23 mounted on the PD mount 22. Alternatively, the photodiode 23 may be fixed first, and the position of the laser diode 25 may be adjusted. .

Therefore, the mount tables 22 and 24 are used for both the laser diode 25 and the photodiode 23.
Among them, the elements to be fixed first may be directly fixed to the base 21 without using the mount tables 22 and 24.

Further, the laser diode 25 is mounted on the base 21.
And the photodiode 23 is fixed to the horizontal surface 21a of the base 21.
5 is the horizontal plane 2 of the base 21 in the same manner as the photodiode 23.
1a, the laser beam L emitted from the laser diode 25 may be reflected by a mirror or the like in the vertical direction.

FIG. 3 shows a second embodiment, in which a positioning structure of the photodiode 23 and the laser diode 25 is shown. On one side of the base 21, a protruding wall 35 is provided integrally at right angles to the protruding portion 21c. The protruding wall 35 has a protruding portion 35a protruding forward from the vertical surface 21b and a horizontal surface 21a.
It has a protruding portion 35b that protrudes upward.

Then, a laser diode positioning portion 36 is formed by the vertical surface 21b as a laser light emitting element mounting portion and the protruding portion 35a. Further, a photodiode positioning portion 37 is formed by the horizontal surface 21a as a signal detection light receiving element mounting portion, the protrusion 21c, and the protrusion 35b.

The laser diode positioning section 36 has a mount table 38 having a right-angled L-shaped step section 38a.
The laser diode 25 is pressed against the stepped portion 38a in the XY direction by pressing the laser diode 25 against the step 1b and the protruding portion 35a. In addition, the photodiode 23 is
Is pressed against the horizontal surface 21a, the protrusion 21c, and the protrusion 35b, thereby positioning in the XYZ directions.

As described above, the laser diode 25 and the photodiode 23 are connected to the respective positioning portions 36 and 37.
The light emitting point 25a of the radar diode 25 and the light receiving point 23b of the photodiode 23 can be fixed to the base 21 by soldering or an adhesive in the positioned state since the positioning is performed by pressing the light emitting element 25 onto the base 21. Can be positioned and fixed with high precision.

FIG. 4 shows a plan view and a front view of the third embodiment, and shows a positioning structure of the photodiode 23. The photodiode positioning portion 39 is formed by the projection 21c of the base 21 and the horizontal surface 21a. The photodiode 23 is placed on the horizontal surface 21a, the photodiode 23 is slid (advanced) and positioned by pressing its end face against the projection 21c, and then the photodiode 23 is slid (retracted) to the horizontal surface 2a.
1a can be positioned at a desired position. In this case, a groove 21e is provided in the base 21 and the groove 21e is formed.
The protrusion 23e provided with the photodiode 23 is fitted to the position e, thereby performing the positioning in the Y direction.

FIGS. 5A and 5B are a plan view and a front view of the fourth embodiment, respectively, showing a positioning structure of the laser diode 25. FIG. A vertical groove 21 is formed on the vertical surface 21b of the base 21 as a laser light emitting element mounting portion, and a laser diode positioning portion 41 is formed by the groove 40. A mount table 42 to which the laser diode 25 is fixed is fitted into the laser diode positioning section 41, and the laser diode 25 is positioned in the XYZ directions because the mount table 42 is positioned by pressing the mount table 42 against the lower end surface of the groove 40. be able to. In this case, the positioning in the Y direction is performed by the groove 21e and the protruding portion 23e.

FIG. 6 shows a fifth embodiment, and shows a structure for positioning the photodiode 23 and the laser diode 25. A mount base 44 having a right angle L-shaped step 44a is fixed to the laser diode positioning section 43 on the vertical surface 21b of the base 21, and the laser diode 2 is mounted on the step 44a.
5, the laser diode 25 also becomes X
It is positioned in the Y direction. Further, a photodiode positioning portion 45 is formed by the horizontal surface 21a of the base 21 and the projection 21c. The photodiode 23 is located on the horizontal surface 21 of the photodiode positioning portion 45.
a, It is positioned in the XYZ directions by pressing against the projection 21c. In this case as well, positioning in the Y direction is performed by the groove 21e and the projecting portion 23e provided on the photodiode 23.

FIG. 7 shows the sixth embodiment, and shows the positioning structure of the photodiode 23. On one side of the base 21, a protruding wall 35 is provided integrally at right angles to the protruding portion 21c. The projecting wall 35 has a projecting portion 35b projecting above the horizontal surface 21a. A photodiode positioning portion 46 is formed by the horizontal surface 21a, the protrusion 21c, and the protrusion 35b. The photodiode 23 is positioned in the XYZ directions by pressing the photodiode 23 against the photodiode positioning portion 46.

In the second to sixth embodiments, the photodiodes 23 and / or the laser diodes 25 are separately mounted on mount bases having relay terminals, and are pushed onto the respective positioning portions via the mount bases. It may be positioned in the XYZ directions by touching.

[0047]

According to the first to fourth aspects of the present invention, at least one of the laser light emitting element and the signal detecting light receiving element is mounted on a mount base, and the element mounted on the mount base is connected to an external circuit. In this case, the relative positions of the laser light emitting element and the signal detecting light receiving element can be easily positioned and fixed without damaging the element during positioning adjustment. Therefore, the conventional probe pin for electrical connection and its position adjusting mechanism are not required, and the apparatus can be simplified and provided at low cost.

According to the fifth aspect, the positioning is performed while observing the output signal of the signal detecting light receiving element, so that the positioning can be performed with high accuracy. According to the sixth to tenth aspects, the positioning portion for positioning by pressing the laser light emitting device and the light receiving device for signal detection is provided on the device mounting portion of the base, so that the device is inadvertently moved at the time of positioning. Therefore, there is an effect that positioning and fixing are easy and assembling workability can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an optical pickup device according to a first embodiment of the present invention.

FIG. 2 is a side view of the relay terminal of the embodiment.

FIG. 3 is a plan view of an optical pickup device according to a second embodiment of the present invention.

FIG. 4 is a plan view and a side view of an optical pickup device according to a third embodiment of the present invention.

FIG. 5 is a plan view and a side view of an optical pickup device according to a fourth embodiment of the present invention.

FIG. 6 is a plan view of an optical pickup device according to a fifth embodiment of the present invention.

FIG. 7 is a plan view of an optical pickup device according to a sixth embodiment of the present invention.

FIG. 8 is a perspective view of a conventional optical pickup device.

FIG. 9 is a perspective view for explaining the conventional operation.

FIG. 10 is a plan view and a side view of a conventional optical pickup device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 ... Base 22 ... PD mount stand 23 ... Photodiode 24 ... LD mount stand 25 ... Laser diode 26, 28 ... Relay terminal 33 ... External circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuo Ando 33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside Toshiba Production Technology Laboratory Co., Ltd. (72) Inventor Akira Ushijima 33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Address Co., Ltd., Toshiba Production Technology Laboratory

Claims (10)

[Claims] 1. A laser light emitting element for irradiating a laser beam to an irradiation target, a signal detecting light receiving element for receiving the laser light reflected from the irradiation target and photoelectrically converting the laser light, the laser light emitting element and the signal An optical pickup device comprising: a base on which a light receiving element for detection is mounted; and at least one of the laser light emitting element and the light receiving element for signal detection mounted on the base via a mount base. And a relay terminal for connecting the element and an external circuit is integrally provided on the mount base. 2. The optical pickup device according to claim 1, wherein the element mounted on the mount base and the relay terminal are connected by wire bonding. 3. At least one of a laser light emitting element and a signal detection light receiving element mounted on a base is mounted on the base via a mount base, and the mount base aligns the relative positions of the elements. 2. The optical pickup device according to claim 1, wherein the optical pickup device is movable with respect to the base. 4. A laser light emitting element for irradiating a laser beam to an irradiation target, a signal detecting light receiving element for receiving the laser light reflected from the irradiation target and photoelectrically converting the laser light, the laser light emitting element and the signal A method of manufacturing an optical pickup device comprising: a base on which a detection light-receiving element is mounted; and at least one of a laser light-emitting element and a signal detection light-receiving element mounted on the base via a mount base. A first step of mounting on a base, and a second step of connecting an element mounted on the mount and a relay terminal provided integrally with the mount and connected to an external circuit. ,
A third step of moving at least one of the mount tables to align the relative positions of the laser light emitting element and the signal detection light receiving element. 5. The method according to claim 5, wherein the third step is to operate the laser light emitting element and the light receiving element for signal detection, and to move at least one of the mount bases based on an output signal of the light receiving element for signal detection to move the relative position of the element. The method for manufacturing an optical pickup device according to claim 4, wherein the positions are aligned. 6. A laser light emitting element for irradiating a laser beam to an irradiation target, a signal detection light receiving element for receiving the laser light reflected from the irradiation target and performing photoelectric conversion, the laser light emitting element, and the signal An optical pickup device comprising: a base on which a light receiving element for detection is mounted; and a positioning part for positioning the laser light emitting element by pressing the laser light emitting element against a laser light emitting element mounting part of the base. An optical pickup device characterized by being provided. 7. The optical pickup device according to claim 6, wherein the positioning portion positions the laser light emitting element by pressing a mount table on which the laser light emitting element is mounted. 8. The optical pickup device according to claim 7, wherein the positioning section has a positioning groove into which a mount table on which the laser light emitting element is mounted is fitted. 9. A laser light emitting element for irradiating a laser beam to an irradiation target, a signal detecting light receiving element for receiving the laser light reflected from the irradiation target and performing photoelectric conversion, the laser light emitting element, and the signal An optical pickup device comprising: a base on which a light receiving element for detection is mounted; and a positioning part for positioning by pressing the light receiving element for signal detection on a light receiving element mounting part for signal detection of the base. An optical pickup device. 10. The light according to claim 9, wherein the positioning portion is configured to position the light receiving element for detection by pressing a mount base on which the light receiving element for signal detection is mounted. Pickup device.