JPH09251655A - Optoelectronic part and optical memory system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the electromagnetic wave to be generated from the oscillation circuit driving a laser diode from being radiated without incuring the increasing of the number of parts. SOLUTION: A part main body 14 is provided with the laser doide 16 emitting a laser beam L and the high frequency supcrposing oscillation circuit 17 turning a light output ON and OFF at high speed by driving the laser doide 16 with a high frequency current. Here, the high frequency superposing oscillation circuit 17 is covered with the metalized surface 15c of the wiring board 15 having flexibility and whose one side is made to be a wiring surface 1 5b on which wirings 23 electrically connecting the part main body 14 and a system driving part 22 are formed and on the other side of which is made to be the metalized surface 15c on which a metallic thin film 24 is formed with respect to the part main body 14.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optoelectronic component,
In particular, the present invention relates to a technique effectively applied to an optoelectronic component used as a light source of an optical memory system.

[0002]

2. Description of the Related Art Today, the amount of information is increasing, and an optical memory system capable of condensing a laser beam to a wavelength almost equal to the wavelength of light to realize an extremely high recording density is used for a large amount of data such as documents and images. Since it is suitable for the accumulation of, there are great expectations.

In an optical memory system, for example, a magneto-optical disk system in which information is recorded by changing the magnetic state of a magnetic film by heat generated by light irradiation, a laser diode module, that is, an optoelectronic component is used as a light source of the system. Is used. This optoelectronic component is composed of a composite of a combination of a laser diode that irradiates laser light and a high-frequency superimposed oscillation circuit (HyIC) for suppressing laser noise generated when the system operates.

As described above, since the above-mentioned oscillation circuit is used as a countermeasure against noise in optoelectronic components used as a light source of a magneto-optical disk system or the like, radiation of electromagnetic waves is generated from the oscillation circuit.

Radiation of the oscillation circuit may adversely affect peripheral parts, so it is necessary to prevent external leakage.
For that purpose, it is possible to cover the optoelectronic component with a metal cover or a metallized shield sheet.

Examples of detailed description of the optical memory system include, for example, "Applied Optoelectronics Handbook" (published April 10, 1989), Shokodo Co., Ltd., P547 to P625, and particularly The magnetic disk system is described in P583 to P594 thereof.

[0007]

However, in the above-mentioned technique, firstly, a metal cover and a shield sheet are required, resulting in an increase in material cost, price competitiveness as a product, and cost reduction. There is a problem of being against the request. Secondly, the above-mentioned work of attaching the cover and the sheet is required in the manufacturing stage, which causes a problem that the number of steps is increased.

Therefore, an object of the present invention is to provide a technique capable of preventing the radiation of an electromagnetic wave generated from an oscillation circuit for driving a laser diode without increasing the number of parts.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0010]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the optoelectronic component of the present invention is a component body provided with a laser diode for irradiating laser light and an oscillator circuit for driving the laser diode with a high frequency current to turn on / off the light output at high speed. The side is the wiring surface on which the wiring that electrically connects the component body and the system drive section is formed, and the other side is the metallized surface on which the metal thin film is formed, and the metallized surface is attached to the component body so as to cover the oscillation circuit. And a wiring board having flexibility.

Further, a component body having a laser diode for irradiating a laser beam and an oscillating circuit for driving the laser diode with a high-frequency current to turn on / off the light output at high speed, and a component body on one side and a system drive section. And a metallized surface on which a metal thin film is formed and which is attached to the component body so as to cover the oscillation circuit with the wiring and metallized surface. And a substrate.

In these optoelectronic components, the metal thin film can be made of copper, aluminum, chromium or nickel.

The optical memory system of the present invention is characterized in that the above-mentioned optoelectronic component is used as a light source.

According to the above-mentioned means, since the metallized surface or the wiring / metallized surface is formed on the wiring board to cover the oscillation circuit, unnecessary radiation of electromagnetic waves is prevented without increasing the number of components. You can

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, members having the same functions are denoted by the same reference numerals, and their repeated description is omitted.

(Embodiment 1) FIG. 1 is a schematic diagram showing a magneto-optical disk system which is an optical memory system using an optoelectronic component according to an embodiment of the present invention, and FIG.
2 is a perspective view showing an optoelectronic component used in the magneto-optical disk system of FIG. 3, FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2 in which the oscillation circuit is covered with a wiring board, and FIGS. FIG. 3 is a plan view showing a wiring surface and a metallized surface of the wiring board of FIG.

As shown in FIG. 1, the magneto-optical disk system according to the present embodiment has a disk 1 as a recording medium in which a perpendicular magnetization film 1b is formed on the main surface of a substrate 1a made of, for example, plastic or glass. ing. A guide groove 2 having a V-shaped cross section that defines an information track is formed on the disk 1 in a spiral shape from the inner circumference to the outer circumference. An optoelectronic component 3 for irradiating the disc 1 with a laser beam L is provided as a light source for recording and reproducing information on the disc 1.

On the path of the laser beam L from the optoelectronic component 3 to the disc 1, the coupling lens 4 for converting the irradiated laser beam L into a parallel beam, and the laser beam L are provided.
Beam splitter 6 that directs the return light from the disk 1 to the photodetector 5 described below without returning to the optoelectronic component 3, a galvano mirror 7 that bends the laser light L in the disk direction, and a laser in a predetermined area of the disk 1. Light L
A focusing lens 8 that collects light is arranged. Disc 1
An electromagnetic coil 9 for reversing the direction of the magnetization by the laser light L applied by applying a magnetic field to the perpendicular magnetization film 1b is installed apart from the disc 1 at a position opposed to the focusing lens 8 with the laser beam L applied therebetween. By reversing such a direction, the recording magnetization domain 10 is formed in the flat portion between the guide grooves 2 to record information.

The laser beam L reflected from the disc 1 and passing through the focusing lens 8, the galvanometer mirror 7 and the beam splitter 6 which is reflected by the disc 1 and reaches the photodetector 5 has a laser beam. In the half-wave plate 11 that rotates the polarization plane of the light L to generate a half-wavelength optical path difference between the linearly polarized lights, the condenser lens 12 that condenses the laser light L, and the plurality of photodetectors 5. A polarization beam splitter 13 that guides the laser light L is arranged. As a result, the reflected light of the laser light L emitted from the optoelectronic component 3 is reflected by the photodetector 5.
The light is received by and the reproduction signal is obtained.

Here, the optoelectronic component 3 is shown in FIGS.
As shown in FIG. 1, the component main body 14 and the wiring board 15 are included.

The component body 14 radiates a laser diode 16 for irradiating the laser beam L, a high frequency superposed oscillation circuit (oscillation circuit) 17 for driving the laser diode 16 and heat generated when these components operate to the outside. Of a heat sink 18 made of aluminum, for example. A circuit mounting portion 19 is formed on the heat sink 18 by cutting out a part of a box shape across two surfaces, and the oscillation circuit 17 is attached to the heat sink 18 with its lead 17a protruding outward. There is. A fitting hole 20 is formed so as to penetrate from the bottom surface of the circuit mounting portion 19 to the opposite surface, and the laser diode 16 is press-fitted and fixed therein with the light emitting portion 16a facing outward. The laser diode 16 is electrically connected to the laser diode 16 so that the lead 16b penetrates the oscillator circuit 17. The laser diode 16 is driven by a high frequency current of about 500 MHz which is generated by the oscillator circuit 17 and overlaps, so that the optical output is high speed. Is turned on and off. As a result, when the magneto-optical disk system operates, a part of the reflected light from the disk 1 returns to the laser diode 16 irradiating the laser light L, and both the lights interfere with each other, and the laser oscillation becomes unstable. The laser noise generated due to In addition, screw holes 18a corresponding to the fixing holes 15a of the wiring board 15 are formed on both sides of the circuit mounting portion 19 in a direction orthogonal to the protruding direction of the leads 17a.

As shown in FIGS. 4 and 5, the wiring board 1
One side of the base material 21 made of, for example, a polyimide film 5 is the component body 14 (FIGS. 2 and 3) and the system drive unit 2.
Wiring 23 made of, for example, a copper foil for electrically connecting to 2
And the metallized surface 15 on the other side of which is formed a metal thin film 24 made of, for example, copper, aluminum, chromium, nickel or the like.
c. Therefore, the wiring board 15 has flexibility and can be freely bent. The constituent members of the wiring 23 and the metal thin film 24 are not limited to the above-mentioned metals, and other various members having conductivity can be used.

On the electronic component side of the wiring board 15, for example, 4
The oscillator circuit 17 is positioned so as to be located at the end of the wire 23 of the book.
Mounting holes 15d through which the leads 17a of FIGS. 2 and 3 are penetratingly connected are provided, and fixing holes 15a corresponding to the screw holes 18a of the heat sink 18 (FIGS. 2 and 3) are formed on both sides in the width direction. Has been established. Therefore, when the lead 17a is connected to the wiring 23 through the mounting hole 15d and the wiring board 15 is fixed to the heat sink 18 by using a screw, the heat sink 18 is closed so as to close the circuit mounting portion 19.
The wiring board 15 that bends along the two surfaces of the oscillator circuit 1
7 will be covered. In addition, Embodiment 2 described later
Including the case shown in (1), the component main body 14 may be attached to the system drive unit by using a screw for fixing the wiring board 15 to the heat sink 18, for example.

As shown in FIG. 3, the oscillation circuit 17 is covered by the metallized surface 15c of the wiring board 15. As a result, the electromagnetic waves radiated from the oscillation circuit 17 are shielded, and the adverse effects of unwanted radiation on peripheral components are prevented. Although a space is formed between the oscillation circuit 17 and the metallized surface 15c in the illustrated case,
In order to shield the electromagnetic wave more reliably, it is desirable that the two are in close contact with each other.

Here, including the case of the second embodiment, the metal thin film 24 on the metallized surface 15c does not necessarily have to be formed on the entire surface, and the oscillation circuit 17 is provided.
It is enough if it is large enough to cover. Also,
In the case shown in FIG. 3, the wiring board 1 is oriented with the wiring surface 15b facing outward and the metallized surface 15c facing inward, that is, toward the oscillator circuit 17.
Although 5 is attached to the component body 14, it may be attached in the opposite direction to cover the oscillation circuit 17 with the metallized surface 15c facing outward. Further, since the oscillator circuit 17 needs to be covered with the wiring board 15 so that it is not exposed, depending on the shape of the heat sink 18 and the circuit mounting portion 19 formed on the heat sink 18,
The wiring board 15 may cover almost the entire surface, or only a small portion may be covered.

In such a magneto-optical disk system, information is recorded on the recording magnetization domain 10 by Curie point recording in which the direction of a part of the magnetization is reversed by irradiating the laser light L while applying a magnetic field to the perpendicular magnetization film 1b. It is performed by forming. In addition, information reproduction is performed in the recording magnetization domain 10
Is performed by irradiating the laser beam L with the laser light L, and the Kerr effect in which the plane of polarization of the reflected light slightly rotates according to the direction of magnetization is converted into a light amount change by a photodetector to detect the presence of magnetic domains. In these cases, the optical output of the laser diode 16 of the optoelectronic component 3 is turned on and off at high speed by the oscillation circuit 17, so that the laser noise due to the interference between the irradiation light and the reflected light is suppressed.

Since the oscillation circuit 17 is covered with the metallized surface 15c of the wiring board 15, it is possible to prevent unnecessary radiation of electromagnetic waves without using a metal cover or a shield sheet. As a result, the number of parts does not increase, and unnecessary radiation can be prevented at a low cost. Further, since the work of attaching the cover and the seat as described above is unnecessary, the cost is not increased due to the increase in the number of assembling steps.

(Embodiment 2) FIG. 6 is a plan view showing a wiring / metallized surface of a wiring board according to another embodiment of the present invention.

In the optoelectronic component according to the present embodiment, as shown in the drawing, a wiring 23 for electrically connecting the component main body and the system driving unit is formed on one side of the wiring substrate 15, and further, in the remaining region thereof. The wiring and metallized surface 15e on which the metal thin film 24 is formed, that is, the wiring 23 and the metal thin film 24 are formed on the same surface. The base material 21 of the wiring board 15 is made of, for example, a polyimide film, and the wiring 23 and the metal thin film 24 are made of, for example, copper foil or aluminum foil, and has flexibility as a whole. Reference numeral 15d is a mounting hole for penetrating the lead of the oscillation circuit to connect it to the wiring 23, and reference numeral 15a is a fixing hole for screwing the wiring board 15 to the heat sink with a screw. Further, the component main body has the same configuration as that shown in the first embodiment.

In the wiring board having such a structure, the leads of the oscillation circuit are penetrated through the mounting holes 15d to fix the ends, and the side portions are fixed to the heat sink by the fixing holes 15a.
The area surrounded by the broken line in FIG. 6 covers the oscillation circuit. The wiring / metallized surface 15e may be attached either outward or inward.

Thus, the wiring 23 and the metal thin film 24
If the wiring and metallization surface 15e are formed on the same surface and the oscillation circuit is covered with the wiring and metallization surface 15e, unnecessary radiation from the oscillation circuit can be prevented. Therefore, since it is no longer necessary to use a metal cover or the like, it is possible to suppress an increase in cost due to an increase in the number of parts and an increase in the number of assembly steps.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the embodiment, and various modifications may be made without departing from the gist of the invention. It goes without saying that it is possible.

For example, in the present embodiment, a rewritable type magneto-optical disk system is shown as an optical memory system using optoelectronic components, but a read-only type or write-once type optical disk system may be used. . Further, the optical recording medium is not limited to the disc 1, and various other types such as cards and tapes can be applied.

[0035]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) In other words, according to the technique of the optoelectronic component of the present invention, since the metallized surface or the wiring / metallized surface is formed on the wiring substrate to cover the oscillation circuit, a metal cover or a shield sheet is used. It becomes possible to prevent unnecessary radiation of electromagnetic waves without using such new parts.

(2) As a result, the number of parts does not increase, so that unnecessary radiation from the oscillation circuit can be prevented at a low cost.

(3) Further, since no new parts are required, there is no increase in cost due to an increase in the number of assembling steps.

[Brief description of drawings]

FIG. 1 is a perspective view showing a magneto-optical disk system using an optoelectronic component according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an optoelectronic component used in the magneto-optical disk system of FIG.

FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2 in a state in which the oscillation circuit is covered with the wiring board.

FIG. 4 is a plan view showing a wiring surface of the wiring board of FIG.

5 is a plan view showing a metallized surface of the wiring board of FIG. 2. FIG.

FIG. 6 is a plan view showing a wiring / metallized surface of a wiring board according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Disk 1a Substrate 1b Perpendicular Magnetization Film 2 Guide Groove 3 Optoelectronic Components 4 Coupling Lens 5 Photodetector 6 Beam Splitter 7 Galvano Mirror 8 Focusing Lens 9 Electromagnetic Coil 10 Recording Magnetization Domain 11 1/2 Wave Plate 12 Condensing Lens 13 Polarization beam splitter 14 Component body 15 Wiring board 15a Fixing hole 15b Wiring surface 15c Metallized surface 15d Mounting hole 15e Wiring / metallized surface 16 Laser diode 16a Light emitting part 16b Lead 17 High frequency superposed oscillation circuit (oscillation circuit) 17a Lead 18 Heat sink 18a Screw hole 19 Circuit mounting part 20 Fitting hole 21 Base material 22 System drive part 23 Wiring 24 Metal thin film L Laser light

Claims (4)

[Claims] 1. A component body including a laser diode for irradiating laser light and an oscillation circuit for driving the laser diode with a high-frequency current to turn on / off a light output at high speed, and one side of the component body and the system drive. A wiring surface on which a wiring for electrically connecting the parts is formed, and the other side is a metallized surface on which a metal thin film is formed, and the metallized surface is attached to the component body so as to cover the oscillation circuit. An optical electronic component comprising: a wiring board having: 2. A component main body comprising a laser diode for irradiating laser light and an oscillator circuit for driving the laser diode with a high frequency current to turn on / off the optical output at high speed, and one side of the component main body and system drive. And a metallized surface on which a metal thin film is formed and which is attached to the component body so as to cover the oscillation circuit with the wiring and metallized surface. An optical electronic component comprising: a wiring board having: 3. The optoelectronic component according to claim 1 or 2, wherein the metal thin film is copper, aluminum, chromium or nickel. 4. An optical memory system, wherein the optoelectronic component according to claim 1, 2 or 3 is used as a light source.