JPS6337677A - Printed board carrying optical element - Google Patents

Abstract

PURPOSE:To simplify complicated wirings for fine optical elements and facilitate position adjustment of the optical elements to a support member which supports the optical elements by making the carrier parts which carry the optical elements able to be bent independently from the other parts. CONSTITUTION:Carrier parts 29-31 which carry a semiconductor laser 10, a monitor photodiode 11 and a quartered photodiode 13 respectively are half separated from the other parts by apertures 33 and so formed as to be able to be bent independently from the other parts. When the relative position between the semiconductor laser 10 and the quartered photodiode 13 is adjusted, the relative position is adjusted by moving the quartered photodiode 13 only while the semiconductor laser 10 is being fixed. The semiconductor laser 10, the monitor photodiode 11 and the quartered photodiode 13 are attached to the respective carrier parts 29-31 of a printed board 32 beforehand by thermocompression bonding and fixed to the respective holders 8 and 9 with adhesive by bending the respective carrier parts suitably.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a printed circuit board that is connected to an optical element having an electrode portion, such as a semiconductor laser in the form of a chip as an original element.

BACKGROUND ART Discs such as video discs or digital audio discs, which are information recording media, have their recording surface irradiated with minute spot light to form pits in the form of spiral tracks in accordance with information signals. The information signal is recorded by Further, when reproducing an information signal recorded in this manner, a spot light is irradiated onto the track, and the original information signal is reproduced by changing the reflected light or transmitted light.

Various optical head devices for recording and reproducing as described above have already been developed. Specifically, the optical head device includes a light emitting element such as a semiconductor laser, an objective lens for focusing the irradiation light emitted by the light emitting element on the disk recording surface as a spot light, and a light reflected from the disk recording surface. It has a light receiving element such as a photodiode that ultimately receives a signal and emits a signal according to the state of the received light.

As shown in FIG. 6, in the optical head device that has already been developed, a semiconductor laser 51 in a chip state as an original element includes a cylindrical body 52, a glass plate 53, and a lid body 54.
It is housed in an airtight package 55 made up of the following optical elements, is connected to a terminal 56 by wiring (not shown), and is attached to a body 57 together with other optical elements as shown in FIG. Further, as shown in FIG. 8, photodiodes 59 and 60 in chip form are sealed in a resin mold package 61 and connected to a terminal 62 by wiring (not shown), as shown in FIG. It is attached to the body 57 as shown in FIG. Note that the relative positions of the semiconductor laser and the photodiode are adjusted with high precision so that the light emitted from the semiconductor laser 51 and reflected on the recording surface of the disk 64 is accurately incident on the photodiode 59, 60.

In this way, in order to assemble the semiconductor laser 51 and the photodiodes 59 and 60 while maintaining a predetermined relative positional relationship with each other, conventionally, these are each housed in dedicated packages 55 and 61, and each package is further housed in the body 57. It is being installed on.

The semiconductor laser 51 and photodiode 59 described above.
Although the components 60 themselves are extremely small, the packages 55, 61 that surround them are relatively large, and therefore the body 57 that supports each package is also a large member. Therefore, this has become a problem that must be solved in order to further reduce the size of the optical head device.

Therefore, in recent years, it has been considered to assemble semiconductor lasers and photodiodes in the form of chips as original elements without using the above-mentioned packages. However, as described above, since semiconductor lasers and photodiodes are small (poles), it is not easy to assemble them while setting their mutual positional relationship with high precision.

When adjusting the relative position of a semiconductor laser and a photodiode, basically each wire is wired to each and power is supplied to measure the incident state of the irradiation light emitted from the semiconductor laser onto the photodiode using a predetermined measuring device. Based on this API determination, the positions of the two are relatively moved. It is particularly difficult to create complex wiring for small semiconductor lasers and photodiodes so that they can move freely, and there has been a desire to develop wiring that facilitates this.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its object is to provide a wiring member connected to an electrode portion of a micro optical element in the form of a chip, for example, having an electrode portion, It is an object of the present invention to provide a wiring member that allows easy wiring and facilitates position adjustment of an optical element with respect to a support member on which the optical element is to be supported.

The wiring member according to the present invention is a printed circuit board, which is connected to an electrode part of a micro-optical element, supports the optical element on a supporting part, and the supporting part is bent independently of other parts. It is characterized by being formed to obtain.

EXAMPLE Hereinafter, an optical head device including an optical element-carrying printed circuit board as an example of the present invention will be described with reference to the accompanying drawings.

As shown in FIGS. 1 to 3, the optical head device includes a package body 2 having an internal space 1 that is open on three sides, and a lid 3 that closes the open portion. ing. A cylindrical portion 4 is formed at the upper end of the package body 2, and an objective lens 5 is provided at the upper end of the cylindrical portion. As shown in FIG. 2, the objective lens 5 focuses irradiation light emitted from a semiconductor laser, which will be described later, onto the recording surface of the disk 7.

Two holders 8 and 9 are arranged in the internal space 1 of the package body 2. A semiconductor laser 10 as a light emitting element and a monitor photodiode 11 as a light receiving element are attached to one holder 8. However, the semiconductor laser 10 is attached to an inclined surface 12 formed on the holder 8, and is inclined by 45@ with respect to the optical path. Furthermore, a four-part photodiode 13, which is a light receiving element, is attached to the other holder 9. Semiconductor laser 10. The monitor photodiode 11 and the 4-division photodiode 13 are in a chip state as an elementary element,
It is protected by nitrogen gas injected into the interior space 1 described above. Note that the four-division photodiode 13 ultimately receives the reflected light from the recording surface of the disk 7 and emits a signal according to the state of the received light. Further, the monitor photodiode 11 is used to detect output fluctuations of the semiconductor laser 10, particularly fluctuations due to temperature, and thereby perform feedback control of the output.

A plane-parallel plate 14 is disposed near the four-part photodiode 13 and is fixed to the inner wall surface of the package body 2.

Here, the optical path of the optical head device and the functions of each optical element will be briefly explained.

The irradiation light emitted from the semiconductor laser 10 is transmitted to the plane-parallel plate 14.
The light is reflected by the semi-transparent mirror surface 15, and is further irradiated as a spot light onto the recording surface of the disk 7 by the objective lens 5.

Reflected light from the disk recording surface based on this irradiation light is focused by the objective lens 5, transmitted through the semi-transparent mirror surface 15 of the plane-parallel plate 14, and reflected at the reflective surface 16. plane parallel plate 1
4 is provided so that its entrance surface (semi-transparent mirror surface 15) is inclined with respect to the optical axis of the reflected light from the disk 7,
It gives astigmatism to the light that passes through it. The reflected light that has been given astigmatism by the plane-parallel plate 14 enters the four-split photodiode 13 . By imparting astigmatism, the shape of the reflected light that is imaged on the light receiving surface of the 4-split photodiode 13 is determined by the positional relationship between the recording surface of the disk 7 and the focal point of the light irradiated onto the disk. Change. In order to detect changes in the shape of this reflected light, the 4-split photodiode 13 is arranged so as to be divided into 4 parts by two straight lines perpendicular to each other, and the light-receiving surface is constituted by four mutually independent elements. (Focus error is zero)
The light receiving surface is arranged so that the light receiving surface is located at a position where the shape of the reflected light is circular.

Then, the summed outputs of the elements arranged on opposite sides with respect to the center of the light-receiving surface of the four-split photodiode 13 are obtained, and the difference between these summed outputs is derived as a focus error signal. In response to this focus error signal, the entire configuration shown in FIG.
The objective lens 5 is servo driven in two directions: the optical axis direction of the objective lens 5 and a direction perpendicular thereto.

Next, a configuration for adjusting the relative positions of the semiconductor laser 10 and the quadrant photodiode 13 will be described.

As shown in FIGS. 1 to 3, the holder 8 holding the semiconductor laser 10 together with the monitor photodiode 11 is directly and firmly fixed to the package body 2 by two screws 18. On the other hand, the holder 9 holding the four-part photodiode 13 is attached to the package body 2 with screws 21 via an intermediate member 20.

The screw 21 loosely fits into a round hole 22 formed at the lower end of the package body 2 with a predetermined clearance, and is screwed into the intermediate member 20 at its tip. As is particularly clear from FIG. 3, the intermediate member 20 is formed with a rectangular prism-shaped protrusion 23 that extends linearly, and the holder 9 is fitted into the protrusion with a square hole 24 formed therein. 26 in FIG.
The parts indicated by are fixed to the intermediate member by being fused together by irradiating a laser beam. Note that the holder 9 is formed with a pair of through holes 27 into which adjustment jigs, which will be described later, are engaged.

As shown in FIG. 1, FIG. 4, and FIG. 5 (ω or C), the semiconductor laser 10, monitor photodiode 11, and four-part photodiode 13 described above are supported by a supporting portion 29 that supports them, respectively. Each electrode portion thereof is connected to a printed circuit board 32 having an angle of 30.degree. 31, and is attached to the holders 8 and 9 via the printed circuit board. As is clear from FIG. 4, each of the supporting parts 29, 30, 31 supporting the semiconductor laser 101, the monitor photodiode 11, and the 4-part photodiode 13, respectively, has the opening 3.
It is semi-separated from other parts by 3 and is formed to be able to bend independently of the other parts.

In addition, as shown in FIG. 1, the above-mentioned printed circuit board 3
The end portion of 2 is drawn out to the outside through a slit 34 formed in the body 3. Further, nitrogen gas (described above) as a protective gas is injected into the internal space 1 through the small hole 35 formed below the slit 34. However, when the injection of nitrogen gas is completed, the micropores 35 are closed.

Next, the semiconductor laser 10 and the 4-split photodiode 1
The adjustment of the relative position in step 3 will be explained.

However, in this case, the semiconductor laser 10 is fixed, and relative position adjustment is performed only by moving the four-divided photodiode 13. Further, the semiconductor laser 10, the monitor photodiode 11, and the 4-split photodiode 13 are thermocompressed in advance onto the respective supporting parts 29, 30, 31 of the printed circuit board 32, and the respective supporting parts are appropriately bent to form the respective holders 8. and 9 with adhesive.

First, as shown in FIG. 2, an adjustment jig consisting of a pointed pin 36 and a frame 37 is prepared, and the pointed pin is engaged with the through hole 27 of the holder 9. This adjustment jig is driven in the three axes of X, Y, and Z directions by, for example, a robot hand that makes extremely precise movements.

In this state, the semiconductor laser 10 is energized to generate irradiation light. Then, the light receiving state of the 4-split photodiode 13 is measured by a predetermined M1 meter, and the holder 9 and therefore the 4-split photodiode 13 are moved and adjusted so that the measured value becomes a desired value. In addition, movement in the Z direction is
Due to the movement of the screw 21 within the clearance within the round hole 22 of the package body 2, movement in the X and Y directions is caused by the movement between the square hole 24 of the holder 9 and the square columnar protrusion 2 of the intermediate member 20.
Due to movement within the clearance with 3. Once the relative positions of the semiconductor laser 10 and the 4-split photodiode 13 have been set in this way, the parts indicated by the reference numeral 26 in FIG. Tighten firmly. This completes the relative position adjustment, and then the adjustment jig is removed.

Effects of the Invention As detailed above, the wiring member according to the present invention consists of a printed circuit board (32), and includes a micro optical element (semiconductor laser 1).
0. connected to the electrode portion provided on the monitor photodiode 11 and the 4-split photodiode 13), and
The optical element is supported by a supporting part (29, 30, 31), and the supporting part is formed to be able to bend independently with respect to other parts.

Since it is a printed circuit board, complicated wiring for the micro-optical element can be done extremely easily, and the independent flexibility of the supporting section allows the positioning of the optical element with respect to the support member that supports the optical element. Adjustments can be made easily.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a main part of an optical head device according to the present invention, FIG. 2 is a view taken along the ■-■ arrow in FIG. 1, FIG. 3 is an exploded perspective view of the main part, and FIG. 4 , FIG. 5 (ω to C) is a diagram showing a printed circuit board, and FIGS. 6 to 8 are diagrams for explaining a conventional optical head device. Explanation of symbols for main parts 1...Inner space 2...Package body 3...Lid 5...Objective lens 7...Disc 8.9...
・Holder 10...Semiconductor laser 11...Monitor photodiode 13...
...Four-divided photodiode 14...Plane-parallel plate 29.30.31...Carrying part 32...Printed circuit board

Claims (1)

[Claims] A printed circuit board connected to an electrode part of an optical element having an electrode part, the printed circuit board having a support part for supporting the optical element, and formed so that the support part can be bent independently of other parts. An optical element-carrying printed circuit board characterized by: