JPH11162004A - Optical pickup device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably perform wire-bonding. SOLUTION: A step part 10 is formed on a heat sink 2 and a relay substrate 11 for wire-bonding between a first photodetector 5 and a wiring substrate 1 is provided on this step part 10. When electric connection between the first photodetector 5 and the wiring substrate 1 is performed, these step differences are reduced, the inconvenience that a wire is pulled downward by a bonding capillary at a bonding time, the loop shape of the wire isn't stabilized, the wire is brought in contact with the edge of the first photodetector 5 and adjacent wires are brought in contact with each other, etc., is not generated and the stable wire-bonding is performed.

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 irradiating a laser beam output from a laser element onto an optical disk or the like, receiving the reflected laser beam by a photodetector and reading information on the optical disk, and a method of manufacturing the same. About.

[0002]

2. Description of the Related Art In recent years, CDs (compact disks) and LDs (la
The spread of optical recording media such as ser disks has been remarkable, and the importance of optical pickups has increased accordingly. Recently, DVD (digital vi
With the advent of large-capacity and high-density recording media such as deo discs, optical pickup devices with higher precision than ever are required, especially with respect to the mounting accuracy of laser elements and photodetectors in optical pickup devices. Accurate ones are required.

[0003] These optical recording media are not only used for reproducing sound and moving images, but also for the RO of personal computers.
It is also used as an M, etc., and is incorporated in various devices, and a demand for a small and thin optical pickup device has been required.

FIG. 10 is a configuration diagram of such an optical pickup device. The wiring substrate 1 is formed by forming a pattern on a ceramic substrate using a conductive material. This wiring board 1
A heat sink 2 made of Cu or the like is provided at the center of the wiring board 1 so as to penetrate the wiring board 1. The heat sink 2 radiates heat to the housing when the optical pickup is mounted.

[0005] A submount substrate 3 made of AlN, SiC or the like is joined to a side surface (vertical surface) of the heat sink 2, and a laser element 4 is mounted on the submount substrate 3.

On the other hand, a first light detecting element 5 is joined to the upper surface of the heat sink 2. The first light detecting element 5 has a function of receiving laser light emitted upward from the laser element 4 and reflected on the surface of the optical disk, and converting the laser light into an electric signal.

In this case, since the relative mounting position of the laser element 4 and the first light detecting element 5 is related to the accuracy of reading information from the optical disk, high accuracy is required.
For example, in the figure, ± 40 μm in the Z direction and ± 10 in the Y direction.
It is required to be within the range of μm. Therefore,
The detection surface of the first light detection element 5 is located at the same height as the height of the laser light emitting point of the laser element 4 in the upward direction, and the wiring board 1 and the first light detection element 5 Is about 2 mm.

The heat sink 2 below the laser element 4
The second photodetector 6 is mounted thereon. The second light detecting element 6 monitors the output of the laser light emitted downward from the laser element 4, and is provided with an angle of about 10 ° with respect to a horizontal plane to prevent the laser light from being reflected upward. It is mounted.

A drive IC 7 for operating the laser element 4 and a first light detecting element 5 are provided on the wiring board 1.
A preamplifier IC 8 for amplifying the output signal of the above is mounted.

The laser element 4 and the wiring board 1
And between the drive IC 7 and the wiring board 1, between the preamplifier IC 8 and the wiring board 1, between the first photodetector 5 and the wiring board 1, respectively. Wire bonding is performed by the method.

With such a configuration, the laser element 4
Is operated by the drive IC 7 and emits laser light upward. The heat generated during the operation of the laser element 4 is radiated through the heat sink 2.

The laser light emitted from the laser element 4 is applied to the optical disk, and the laser light reflected on the surface of the optical disk enters the first light detecting element 5. The first light detection element 5 receives the laser light reflected on the optical disk surface, converts the laser light into an electric signal, and outputs the electric signal. Thereafter, the output signal of the first photodetector 5 is amplified by the preamplifier IC 8 and read as information from the optical disk.

[0013]

However, in the above device, the laser element 4 is mounted on the side surface of the heat sink 2, the first photodetector 5 is mounted on the upper surface of the heat sink 2, and the second photodetector 5 is further mounted. The mounting surfaces of the laser element 4 and the first and second photodetectors 5 and 6 are all different from each other, such that the laser element 6 is mounted on the surface of the heat sink 2 below the laser element 4. Therefore, the height of the heat sink 2 is also increased.

In particular, the first light detecting element 5 must be disposed at the highest position of the heat sink 2, and the step between the first light detecting element 5 and the wiring board 1 is as large as about 2 mm. turn into.

Usually, a wire bonding method using a wire such as Au is applied to the electrical connection between the first photodetecting element 5 and the wiring board 1. In this wire bonding method, the above-mentioned 2 mm is used. Due to the large step, the wire is pulled downward by the bonding capillary at the time of bonding, so that the loop shape of the wire is not stabilized, and the wire comes into contact with the edge of the first light detection element 5 or the adjacent wires come into contact with each other. Troubles such as running.

As for other elements, for example, the laser element 4 is electrically connected to the wiring board 1 through a relay pin or the like, or the laser element 4 is connected to the wiring board 1 by a three-dimensional wire bonding method or the like. There is a method such as direct wire bonding, which is not a major problem.

In the second light detecting element 6, the step is 1 mm.
The following is not a serious problem in wire bonding, and the inclination of the element of about 10 ° is not a problem if the ball bonding method is used, because the ball formed on the wire at the time of the first bonding absorbs the inclination.

As described above, since the step between the first light detecting element 5 and the wiring board 1 is as large as about 2 mm, stable wire bonding is difficult, and the wire contacts the edge of the first light detecting element 5. Troubles such as rubbing and contact between wires occur. Therefore, an object of the present invention is to provide an optical pickup device capable of performing stable wire bonding and a method of manufacturing the same.

[0019]

According to a first aspect of the present invention, there is provided an optical pickup device provided with a heat sink on which a laser element and a photodetector optically aligned with the laser element are mounted. An optical pickup device which is formed higher than on a surface and in which a relay step means for electrically connecting a photodetector and a wiring board with a wire is formed.

According to a second aspect of the present invention, in the optical pickup device according to the first aspect, the relay step means has at least one step portion having an intermediate height between the height of the photodetector, the height of the wiring board, and the heat sink. A relay board for electrically connecting the photodetector with the wiring board by a wire was provided at the step.

According to a third aspect of the present invention, in the optical pickup device according to the first aspect, the relay step means has at least one step portion having an intermediate height between the height of the photodetector, the height of the wiring board, and the heat sink. An electronic component for processing the output signal of the photodetector is provided at the step, and the photodetector and the wiring board are electrically connected to each other by wires via the electronic component.

According to a fourth aspect of the present invention, in the optical pickup device according to the first aspect, the relay step means has at least one of a height between the height of the photodetector and the height of the wiring substrate on the wiring substrate. Electronic components were mounted, and the photodetector and the wiring board were electrically connected to each other by wires via the electronic components.

According to a fifth aspect of the present invention, in the optical pickup device according to the first aspect, the relay step means forms a step on the wiring board and processes an output signal of the photodetector on the step. Electronic components were provided, and the photodetector and the electronic components were electrically connected by wires.

According to the sixth aspect, in the optical pickup device according to the first aspect, the light detecting element is mounted on the heat sink via an insulating adhesive containing an insulating member. According to claim 7, in the optical pickup device according to claim 6, the size of the insulating member is variable.

According to the eighth aspect, in the optical pickup device according to the sixth aspect, the optical pickup device is a particle or a bump. According to a ninth aspect, in the method for manufacturing an optical pickup device including a laser element and a light detection element optically aligned with the laser element, at least one
A first step of joining a heat sink having two step portions, a second step of mounting a relay board for electrically connecting the photodetector and the wiring board on the step portion of the heat sink, and a heat sink. A third step of mounting a laser element and a photodetector on the substrate, and a fourth step of electrically connecting wires between the photodetector and the relay board and between the relay board and the wiring board, respectively. And a method for manufacturing an optical pickup device having:

According to a tenth aspect of the present invention, in a method of manufacturing an optical pickup device including a laser element and a photodetector optically aligned with the laser element, at least one step is formed on the wiring board. A first step of joining the heat sink, a second step of mounting an electronic component for processing an output signal of the light detection element on a step of the heat sink, and mounting the laser element and the light detection element on the heat sink. And a fourth step of electrically connecting each of the wires between the photodetector and the electronic component and between the electronic component and the wiring board by wires. is there.

According to an eleventh aspect of the present invention, in a method for manufacturing an optical pickup device including a laser element and a photodetector optically aligned with the laser element, a first heat sink is joined to the wiring board. A second step of mounting an electronic component having a predetermined height lower than the height of the heat sink for processing an output signal of the light detection element near the heat sink on the wiring board; and a laser element and a light detection element with respect to the heat sink. Manufacturing an optical pickup device, comprising: a third step of mounting the optical pickup; and a fourth step of electrically connecting the photodetector with the electronic component and the electronic component with the wiring board by wires. Is the way.

According to a twelfth aspect of the present invention, there is provided a method of manufacturing an optical pickup device including a laser element and a photodetector optically aligned with the laser element, comprising a wiring board having a step. A first step of bonding a heat sink to the wiring board, a second step of mounting an electronic component for processing an output signal of the photodetector on a stepped portion of the wiring board, A method for manufacturing an optical pickup device, comprising: a third step of mounting a detection element; and a fourth step of electrically connecting a light detection element and an electronic component with a wire.

According to a thirteenth aspect, in the method for manufacturing an optical pickup device according to the first aspect, the light detecting element is mounted on the heat sink via an insulating adhesive containing an insulating member. Having a process.

[0030]

(1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The same parts as those in FIG. 10 are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 1 is a configuration diagram of the optical pickup device.

The heat sink 2 is provided with a step portion 10 for forming a relay step means at an intermediate height position. The step portion 10 is provided between the step surface and the heat sink 2.
Is formed so that the height position with respect to the upper surface is about 1 mm.

On the surface of the step 10, a relay board (wiring board) 11 for electrically connecting the first photodetector 5 and the wiring board 1 with wires is fixed. The relay substrate 11 is formed of a glass epoxy substrate, a ceramic substrate, or the like.

The step 10 is formed so as to be about 1 mm as described above, but the step between the upper surface of the wiring substrate 1 and the upper surface of the relay substrate 11 and the upper surface of the first photodetector 5 The step from the upper surface of the relay board 11 may be formed to be about 1 mm.

On the other hand, the electrical connection between the first photodetector 5 and the wiring board 1 is made by a wire bonding method using a metal wire such as Au or Al via the relay board 11. .

That is, first, wire bonding is performed between the first photodetector 5 and the relay board 11, and subsequently, wire bonding is performed between the relay board 11 and the wiring board 1.

As another element, the laser element 4 is bonded to the wiring board 1 by wire bonding or three-dimensional wire bonding to the relay pin.

Further, between the drive IC 7 and the wiring board 1,
Wire bonding is also performed between the preamplifier IC 8 and the wiring board 1 and between the first photodetector 5 and the wiring board 1 by a three-dimensional wire bonding method using an Au wire or the like.

Next, a method of manufacturing the optical pickup device will be described with reference to a manufacturing flowchart shown in FIG. First, the heat sink 2 is fixed to the wiring board 1 by silver brazing or the like.

Next, the drive IC 7 is mounted on the wiring board 1 with silver paste or the like, and then the preamplifier IC 8 is mounted on the wiring board 1 with silver paste or the like.

Next, the second photodetector 6 is mounted on a 10 ° inclined surface of the heat sink 2 with silver paste or the like. Next, the relay board 11 is mounted on the step portion 10 of the heat sink 2 by using silver paste or the like.

Then, the silver paste is cured by heating at about 150 ° C. On the other hand, when the laser element 4 is made of AlN or Si
Gold on the submount substrate 3 formed of C or the like.
The submount 3 is mounted on the side surface of the heat sink 2 by eutectic solder or the like. At this time, the laser element 4 is mounted so as to be located above the second light detection element 6.

Next, the first photodetector 5 is mounted on the upper surface of the heat sink 2 with UV (ultraviolet) resin or the like.
Temporary curing by irradiation of UV light for about several tens of seconds, after this,
The main curing is performed by heating at about 150 ° C.

Finally, a three-dimensional wire bonding step is performed, and the bonding temperature is set to about 150 ° C. because there is a connection portion made of eutectic solder. First, wire bonding is performed between the drive IC 7, the preamplifier IC 8, and the wiring substrate 1 between the drive IC 7, the preamplifier IC 8, and the second photodetector 6, which have substantially the same height position on the bonding surface.

The second light detecting element 6 and the wiring board 1
Since the wire passes above the second photodetector 6 when the laser element 4 and the submount substrate 3 are bonded to each other, wire bonding is performed before that.

Next, wire bonding is performed between the relay board 11 and the wiring board 1, and then wire bonding is performed between the first photodetector 5 and the relay board 11. Finally, wire bonding is performed between the laser element 4 and the wiring substrate 1 and between the submount substrate 3 and the wiring substrate 1.

As described above, in the first embodiment, the step portion 10 is formed on the heat sink 2, and the first photodetector 5 and the wiring board 1 are wire-bonded to the step portion 10. When the electrical connection between the first photodetector 5 and the wiring board 1 is made, these steps should be reduced to about 1 mm, which is about half of the step of the conventional device. The wire is pulled downward by the bonding capillary at the time of bonding as in the past, and the loop shape of the wire is not stable,
A stable wire bonding can be performed without causing a problem such as a wire contacting the edge of the first light detection element 5 or a contact between adjacent wires. (2) Next, a second embodiment of the present invention will be described.
The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 3 is a configuration diagram of the optical pickup device. The heat sink 2 is provided with stepped portions 12 and 13 having two different height positions. These steps 12,
Reference numeral 13 designates a relay step means, which includes a height position between the upper surface of the heat sink 2 and the upper surface of the step portion 12, a height position between the upper surfaces of the step portions 12, 13;
Are formed so that the height position between the upper surface of the substrate and the wiring substrate 1 is about 1 mm each.

On each of the surfaces of these steps 12, 13, a relay board 14, which constitutes a relay step means, is provided.
15 is fixed. These relay boards 14 and 15
The relay substrate 14 is formed of a glass epoxy substrate, a ceramic substrate, or the like, and the relay substrate 14 is for electrically connecting the first photodetector 5 and the relay substrate 15 with a metal wire such as Au or Al. The relay board 15 is for electrically connecting the relay board 15 and the wiring board 1 with metal wires.

On the other hand, the electrical connection between the first photodetector 5 and the wiring board 1 is made by a wire bonding method via the relay boards 14 and 15. For example, first, wire bonding is performed between the first photodetector 5 and the relay substrate 14, and then the relay substrate 14 and the relay substrate 1
5, and then wire bonding is performed between the relay board 15 and the wiring board 1.

Next, a method of manufacturing the optical pickup device will be described. First, the heat sink 2 is fixed to the wiring board 1 by silver brazing or the like. Next, the drive IC 7 is mounted on the wiring board 1 with silver paste or the like, and then the preamplifier IC 8 is mounted on the wiring board 1 with silver paste or the like, and then the second photodetector 6 is mounted on the heat sink 2. It is mounted on a 10 ° inclined surface with silver paste or the like.

Next, the relay board 14 is mounted on the step 12 of the heat sink 2 with silver paste or the like, and the relay board 15 is mounted on the step 13 of the heat sink 2 with silver paste.

Then, the silver paste is cured by heating at about 150 ° C. On the other hand, the laser element 4 is mounted on the sub-mount substrate 3 by gold-tin eutectic solder or the like, and then the sub-mount substrate 3 is mounted on the side surface of the heat sink 2 by eutectic solder or the like. At this time, the laser element 4
Is mounted so as to be located above the second light detecting element 6.

Next, the first photodetecting element 5 is mounted on the upper surface of the heat sink 2 with a UV resin or the like, and is temporarily cured by irradiation of UV light for about several tens of seconds, and thereafter is fully cured by heating at about 150 ° C. I do.

Finally, the wire bonding step is performed, and the bonding temperature is set to about 150 ° C. because there is a connection portion made of eutectic solder as described above. First, the drive IC 7 in which the height position of the bonding surface is almost the same,
Wire bonding is performed between the preamplifier IC 8, the second photodetector 6, and the wiring board 1.

Next, wire bonding is performed between the relay board 15 and the wiring board 1, then wire bonding is performed between the relay board 14 and the relay board 15, and then the relay board 14 and the first photodetector are connected. 5 is wire-bonded.

Finally, the laser element 4 and the submount substrate 3
Are wire bonded. As described above, in the second embodiment, the two step portions 12 and 13 are formed on the heat sink 2 and the relay boards 14 and 15 are provided on these step portions 12 and 13, respectively. When making an electrical connection between the element 5 and the wiring board 1, these steps 12 and 13 can be suppressed to 1 mm or less, respectively, and the wire is pulled down by a bonding capillary at the time of bonding as in the related art. In addition, the loop shape of the wire is not stable, and a stable wire bonding can be performed without causing a problem such as the wire contacting the edge of the first light detection element 5 or the contact between adjacent wires. (3) Next, a third embodiment of the present invention will be described.
The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 4 is a configuration diagram of the optical pickup device. The heat sink 2 is provided with a step portion 16 that constitutes a relay step means. The step 16 is formed such that the height between the upper surface of the step and the upper surface of the heat sink 2 and the height between the upper surface of the step and the wiring board 1 are each about 1 mm.

The surface of the step 16 has a preamplifier I
C8 is mounted. Note that the steps of the step portion 16 are actually formed so that the height position between the preamplifier IC 8 and the upper surface of the heat sink 2 and the height position between the upper surface of the preamplifier IC 8 and the wiring board 1 are each about 1 mm. .

The preamplifier IC 8 is connected to the first photodetector 5
And a function as a configuration of a relay step means for electrically connecting the first photodetector 5 and the relay substrate 15 with a metal wire such as Au or Al. .

That is, the electrical connection between the first photodetector 5 and the wiring board 1 is made by the wire bonding method via the preamplifier IC8. For example, first, wire bonding is performed between the first photodetector 5 and the preamplifier IC 8, and then wire bonding is performed between the preamplifier IC 8 and the wiring board 1.

Next, a method of manufacturing the optical pickup device will be described. First, the heat sink 2 is fixed to the wiring board 1 by silver brazing or the like. Next, the drive IC 7 is mounted on the wiring board 1 with silver paste or the like, and then the second photodetector 6 is mounted on the heat sink 2 with a 10 ° inclined surface using silver paste or the like.

Next, the preamplifier IC 8 is connected to the heat sink 2.
Is mounted on the step portion 16 with silver paste. Then, the silver paste is cured by heating at about 150 ° C.

On the other hand, the laser device 4 is
Mounted on top with gold-tin eutectic solder, etc.
The submount substrate 3 is made of a heat sink 2 by eutectic solder or the like.
Mounted on the side of At this time, the laser element 4
It is mounted so as to be located above the second light detecting element 6.

Next, the first photodetector 5 is mounted on the upper surface of the heat sink 2 with UV resin or the like, and is temporarily cured by irradiation of UV light for about several tens of seconds, and thereafter, is fully cured by heating at about 150 ° C. Is done.

Finally, a wire bonding step is performed, and the bonding temperature is set to about 150 ° C. because there is a connection portion made of eutectic solder as described above. First, the drive IC 7 in which the height position of the bonding surface is almost the same,
Wire bonding is performed between the second photodetector 6 and the wiring board 1.

Next, wire bonding is performed between the preamplifier IC 8 and the wiring board 1, and then the preamplifier I
Wire bonding is performed between C8 and the first light detection element 5.

Finally, wire bonding is performed between the laser element 4 and the wiring substrate 1 and between the submount substrate 3 and the wiring substrate 1. As described above, in the third embodiment, the step 16 is formed on the heat sink 2 and the preamplifier IC 8 is mounted on the step 16, so that the electrical connection between the first photodetector 5 and the preamplifier IC 8 is made. When making the electrical connection, the step between the upper surface of the first photodetector 5 and the upper surface of the preamplifier IC 8 and the step between the upper surface of the preamplifier IC 8 and the wiring board 1 can be suppressed to 1 mm or less, respectively. At the time of bonding, the wire is pulled downward by the bonding capillary, the loop shape of the wire is not stabilized, and problems such as contact of the wire with the edge of the first photodetector 5 and contact of adjacent wires occur. A stable wire bonding can be performed without any problems. (4) Next, a fourth embodiment of the present invention will be described.
The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 5 is a configuration diagram of the optical pickup device. An electronic component 17 is mounted between the heat sink 2 and the preamplifier IC 8 on the wiring board 1.

The electronic component 17 is provided with the first photodetector 5
A filter element or a bypass capacitor array for removing a noise component included in a signal output from and input to the preamplifier IC 8 is electrically connected by a wiring pattern on the wiring board 1.

The electronic component 17 is selected to have a height of about 1 mm when mounted on the wiring board 1, and the step between the upper surface of the first photodetector 5 and the wiring board 1 is 1 m.
m.

Next, a method of manufacturing the optical pickup device will be described. First, the heat sink 2 is fixed to the wiring board 1 by silver brazing or the like. Next, the drive IC 7 is mounted on the wiring board 1 with silver paste or the like, and then the preamplifier IC 8 is mounted on the wiring board 1 with silver paste or the like. Mounted with paste etc.,
Next, the second light detection element 6
° Mounted on an inclined surface with silver paste or the like.

Then, the silver paste is cured by heating at about 150 ° C. On the other hand, the laser element 4 is mounted on the sub-mount substrate 3 by gold-tin eutectic solder or the like, and thereafter, the sub-mount substrate 3 is mounted on the side surface of the heat sink 2 by eutectic solder or the like. At this time, the laser element 4 is mounted so as to be located above the second light detection element 6.

Next, the first photodetecting element 5 is mounted on the upper surface of the heat sink 2 with a UV resin or the like, and temporarily cured by irradiation of UV light for about several tens of seconds, and thereafter, fully cured by heating at about 150 ° C. Is done.

Finally, a wire bonding step is performed, and the bonding temperature is set to about 150 ° C. because there is a connection portion made of eutectic solder as described above. First, the drive IC 7 in which the height position of the bonding surface is almost the same,
Wire bonding is performed between the second photodetector 6 and the wiring board 1.

Next, wire bonding is performed between the preamplifier IC 8 and the wiring board 1, and then wire bonding is performed between the preamplifier IC 8 and one connection terminal formed on the upper surface of the electronic component 17. The other connection terminal formed on the upper surface of the first photodetector 17 and the first photodetector 5 are wire-bonded.

Finally, the laser element 4 and the submount substrate 3
Are wire bonded. As described above, in the fourth embodiment, the electronic component 17 having a height of about 1 mm when mounted on the wiring board 1 is mounted between the heat sink 2 and the preamplifier IC 8 on the wiring board 1. When making an electrical connection between the first photodetector 5 and the preamplifier IC 8, a step between the upper surface of the first photodetector 5 and the upper surface of the electronic component 17 and the upper surface of the electronic component 17 and the wiring board 1 Can be suppressed to 1 mm or less, and the wire is pulled downward by the bonding capillary at the time of bonding as in the related art, so that the loop shape of the wire is not stabilized, and the wire is not connected to the edge of the first photodetector 5. The wire bonding can be stably performed without causing troubles such as contact with the wires and contact between adjacent wires. (5) Next, a fifth embodiment of the present invention will be described.
The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 6 is a configuration diagram of the optical pickup device. The wiring substrate 18 is formed by forming a pattern on a ceramic substrate using a conductive material, and has a step portion 1 on one side.
9 are formed.

The step 19 is formed to a height of about 1 mm, and the step between the step 19 and the first photodetector 5 is about 1 mm. A preamplifier IC 8 is mounted on the step 19, and the preamplifier IC 8 and the first photodetector 5 are wire-bonded with a metal wire.

Next, a method of manufacturing the optical pickup device will be described. First, the heat sink 2 is fixed to the wiring board 18 by silver brazing or the like.

Next, the drive IC 7 is mounted on the wiring board 18 with silver paste or the like, and then the preamplifier IC 8 is mounted on the step 19 of the wiring board 18 with silver paste or the like. The light detecting element 6 is mounted on the inclined surface of the heat sink 2 by a silver paste or the like.

Then, the silver paste is cured by heating at about 150 ° C. On the other hand, the laser element 4 is mounted on the sub-mount substrate 3 by gold-tin eutectic solder or the like, and thereafter, the sub-mount substrate 3 is mounted on the side surface of the heat sink 2 by eutectic solder or the like. At this time, the laser element 4 is mounted so as to be located above the second light detection element 6.

Next, the first photodetector 5 is mounted on the upper surface of the heat sink 2 with a UV resin or the like, and is temporarily cured by irradiation of UV light for about several tens of seconds, and thereafter is fully cured by heating at about 150 ° C. Is done.

Finally, a wire bonding step is performed, and the bonding temperature is set to about 150 ° C. because there is a connection portion made of eutectic solder as described above. First, the drive IC 7 in which the height position of the bonding surface is almost the same,
Wire bonding is performed between the second photodetector 6 and the wiring board 18.

Next, the preamplifier IC on the step 19
8 and the wiring board 18 are wire-bonded, and then the preamplifier IC 8 and the first photodetector 5 are wire-bonded.

Finally, the laser element 4 and the submount substrate 3
Are wire bonded. As described above, in the fifth embodiment, the step 19 is formed on the wiring board 18 and the preamplifier IC 8 is mounted on the step 19, so that the gap between the first photodetector 5 and the preamplifier IC 8 can be reduced. When the electrical connection is made, the step between the upper surface of the first photodetector 5 and the preamplifier IC 8 can be suppressed to 1 mm or less, and the wire is pulled downward by the bonding capillary at the time of bonding as in the conventional case. The wire loop shape is not stable, and a stable wire bonding can be performed without causing a problem such as the metal wire contacting the edge of the first light detection element 5 and the adjacent wires contacting each other. (6) Next, a sixth embodiment of the present invention will be described.
The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 7 is a structural view showing the first light detecting element 5 mounted on the heat sink 2 in the optical pickup device. On the heat sink 2 formed of copper,
The first light detection element 5 is mounted via an insulating adhesive 20 such as a UV resin. The insulating adhesive 20 contains several percent of insulating particles 21 as an insulating member such as silica or resin balls. The insulating particles 21 are formed, for example, to have a particle diameter of about 10 μm.

The back surface of the first photodetector 5 has an S
An iO ₂ film 22 is formed. With such a configuration, even if the minute projections 23 are formed on the heat sink 2,
Since the height of the minute projections 23 is, for example, about 5 μm, a short circuit between the heat sink 2 and the first photodetector 5 can be prevented.

That is, since the first light detecting element 5 is conventionally mounted on the heat sink 2 via the insulating adhesive 20 as shown in FIG.
When 3 occurs, this breaks through the insulating adhesive 20 and comes into contact with the first light detection element 5. An SiO ₂ film 22 is formed as an insulating film on the back surface of the first light detecting element 5. However, since the SiO ₂ film 22 is formed by heating the element, it can be formed only to a thickness of about 0.5 μm. The heat sink 2 and the first light detecting element 5
Had been electrically connected (short).

In the present embodiment, the insulating particles 2
The particle diameter of the fine projections 2 on the heat sink 2
By changing the height according to the height of the micro-projection 3, it is possible to prevent a short circuit between the heat sink 2 and the first photodetector 5 in accordance with the height of the minute projection 23.

The heat sink 2 and the first light detecting element 5
At the time of bonding with the first light detecting element 5,
Will come into contact with the SiO ₂ film 22 formed on the back surface of the substrate. However, even if the SiO ₂ film 22 is broken, there is no electrical problem since the contact is made with the insulating particles 21.

The insulating particles 21 for the insulating adhesive 20
Is also added to the order of several percent, so that the adhesive strength is not remarkably reduced. On the other hand, the mounting accuracy of the first photodetector 5 is required to be quite high, for example, ± 40 μm in the Z direction.
The thickness is ± 10 μm in the m and Y directions, but by adding such insulating particles 21 to the insulating adhesive 20, the adhesive thickness at the time of bonding the heat sink 2 and the first photodetector 5 can be reduced. It is possible to stabilize the mounting accuracy of the first photodetecting element 5 by making it constant.

In the sixth embodiment, the insulating particles 21 are used as the insulating member. However, the present invention is not limited to this, and the same effect can be obtained by using a fibrous material such as glass fiber. it can. (7) Next, a seventh embodiment of the present invention will be described.
The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 9 is a configuration diagram showing the first light emitting element 5 mounted on the heat sink 2 in the optical pickup device. The first light detection element 5 is mounted on the heat sink 2 via an insulating adhesive 24 such as a UV resin. At least three insulating bumps 25 as insulating members made of epoxy resin or the like are formed on the outer periphery of the back surface of the first photodetector 5. These insulating bumps 25
Can be formed by a screen printing method or the like, and thereby, is formed to a predetermined thickness with high accuracy. These insulating bumps 25 are formed, for example, to a height of about 10 μm.

With such a configuration, the heat sink 2
Even if the fine projections 23 are formed thereon, the height of the fine projections 23 is, for example, about 5 μm, so that a short circuit between the heat sink 2 and the first photodetector 5 can be prevented.

The height of the insulating bumps 25 is changed according to the height of the minute projections 23 generated on the heat sink 2, so that the height of the minute bumps 23 and the heat sink 2 and the first photodetector are changed in accordance with the height of the minute projections 23. 5 can be prevented.

The heat sink 2 and the first light detecting element 5
At the time of bonding, the insulating bump 25 comes into contact with the SiO ₂ film 22 formed on the back surface of the first photodetector 5, but even if the SiO ₂ film 22 is broken,
Since it comes into contact with the insulating particles 21, there is no electrical problem.

On the other hand, the mounting accuracy of the first photodetecting element 5 is required to be quite high as described above, for example, ± 40 μm in the Z direction and ± 10 μm in the Y direction.
Insulating bump 25 formed by screen printing or the like
Is used, the thickness of the adhesive at the time of bonding the heat sink 2 and the first light detection element 5 can be made constant, the mounting accuracy of the first light detection element 5 can be stabilized, and the connection accuracy in the Z direction can be further improved. Can also be improved.

In the seventh embodiment, the insulating bumps 25 are formed on the outer periphery of the back surface of the first photodetector 5, but the same effect can be obtained by forming them on the heat sink 2. be able to.

[0099]

As described in detail above, claims 1 to 5 of the present invention.
According to 5, an optical pickup device capable of performing stable wire bonding can be provided. Claims 6 to 8 of the present invention.
According to the above, it is possible to provide an optical pickup device that can prevent a short circuit between the heat sink and the photodetector even if minute projections are formed on the heat sink.

Further, according to the ninth to twelfth aspects of the present invention, it is possible to provide a method of manufacturing an optical pickup device capable of performing stable wire bonding. Further, according to the thirteenth aspect of the present invention, it is possible to provide an optical pickup method capable of preventing a short circuit between the heat sink and the photodetector even if minute projections are formed on the heat sink.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of an optical pickup device according to the present invention.

FIG. 2 is a manufacturing flowchart showing a manufacturing method of the device.

FIG. 3 is a configuration diagram showing a second embodiment of the optical pickup device according to the present invention.

FIG. 4 is a configuration diagram showing a third embodiment of the optical pickup device according to the present invention.

FIG. 5 is a configuration diagram showing a fourth embodiment of the optical pickup device according to the present invention.

FIG. 6 is a configuration diagram showing a fifth embodiment of the optical pickup device according to the present invention.

FIG. 7 is a configuration diagram illustrating a first photodetector mounted on a heat sink in an optical pickup device according to a sixth embodiment of the present invention.

FIG. 8 is a view showing a short-circuit state caused by minute projections between the heat sink and the first photodetector.

FIG. 9 is a configuration diagram showing a first photodetector mounted on a heat sink in an optical pickup device according to a seventh embodiment of the present invention.

FIG. 10 is a configuration diagram of a conventional optical pickup device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Wiring board, 2 ... Heat sink, 3 ... Submount board, 4 ... Laser element, 5 ... 1st light detection element, 6 ... 2nd light detection element, 7 ... Drive IC, 8 ... Preamplifier IC, 10 ... Step part, 11 ... Relay board (wiring board), 12, 13 ... Step part, 14, 15 ... Relay board, 16 ... Step part, 17 ... Electronic component, 18 ... Wiring board, 19 ... Step part, 20: Insulation Adhesive, 21: insulating particles, 22: SiO ₂ film, 23: minute projection, 25: insulating bump.

Claims (13)

[Claims] 1. An optical pickup device comprising: a wiring board provided with a laser element and a heat sink on which a light detection element optically aligned with the laser element is mounted. An optical pickup device, wherein a relay step means for electrically connecting a photodetector with the wiring board by a wire is formed. 2. The relay step means, wherein at least one step portion having an intermediate height between the height of the light detecting element and the height of the wiring board is formed on the heat sink, and the light detecting element is formed on the step portion. 2. The optical pickup device according to claim 1, further comprising a relay board for electrically connecting the wiring board and the wiring board by the wire. 3. The relay step means, wherein at least one step portion having an intermediate height between the height of the light detection element and the height of the wiring board is formed on the heat sink, and the light detection element is formed on the step portion. Electronic components for processing the output signals of
2. The optical pickup device according to claim 1, wherein the light detection element and the wiring board are electrically connected to each other by the wire via the electronic component. 4. The relay step means mounts at least one electronic component having a height intermediate between the height of the photodetector and the height of the wiring substrate on the wiring substrate, and via the electronic component. 2. The optical pickup device according to claim 1, wherein the light detecting element and the wiring board are electrically connected by the wire. 5. The relay step means forms a step on the wiring board, and on the step, an electronic component for processing an output signal of the photodetector is provided. 2. The optical pickup device according to claim 1, wherein the component and the component are electrically connected by the wire. 6. The optical pickup device according to claim 1, wherein the photodetector is mounted on the heat sink via an insulating adhesive containing an insulating member. 7. The optical pickup device according to claim 6, wherein the size of the insulating member is variable. 8. The optical pickup device according to claim 6, wherein the insulating member is a particle or a bump. 9. A method of manufacturing an optical pickup device comprising a laser element and a photodetector optically aligned with the laser element, wherein a heat sink having at least one step formed on a wiring board is joined. A second step of mounting a relay board for electrically connecting the photodetector and the wiring board on a step portion of the heat sink; and a laser element for the heat sink. And a third step of mounting the photodetector, and a fourth step of electrically connecting the photodetector with the relay board and the relay board with the wiring board by wires. And a method for manufacturing an optical pickup device. 10. A method for manufacturing an optical pickup device comprising a laser element and a photodetector optically aligned with the laser element, wherein a heat sink having at least one step formed on a wiring board is joined. A first step of mounting; a second step of mounting an electronic component for processing an output signal of the light detection element on a step portion of the heat sink; and mounting the laser element and the light detection element on the heat sink. And a fourth step of electrically connecting the photodetector with the electronic component and the electronic component with the wiring board by wires, respectively. Manufacturing method of an optical pickup device. 11. A method of manufacturing an optical pickup device including a laser element and a light detection element optically aligned with the laser element, wherein: a first step of bonding a heat sink to a wiring board; A second step of mounting an electronic component having a predetermined height lower than the height of the heat sink for processing an output signal of the photodetector near the heat sink on the substrate; and the laser element and the light with respect to the heat sink. A third step of mounting a detection element; and a fourth step of electrically connecting the photodetection element and the electronic component, and the electronic component and the wiring board with wires, respectively. A method for manufacturing an optical pickup device, comprising: 12. A method for manufacturing an optical pickup device comprising a laser element and a photodetector optically aligned with the laser element, comprising: a wiring board having a stepped portion; A first step of bonding a heat sink; a second step of mounting an electronic component for processing an output signal of the photodetector on the step portion of the wiring board; A method of manufacturing an optical pickup device, comprising: a third step of mounting a light detection element; and a fourth step of electrically connecting the light detection element and the electronic component with a wire. . 13. The optical pickup device according to claim 9, further comprising a step of mounting the light detecting element on the heat sink via an insulating adhesive containing an insulating member. Manufacturing method.