JP3533765B2 - Manufacturing method of optical pickup - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element, an optical disk and the like.
Optical pickup for recording or reproducing information to / from Made of Construction
It is about the method. 2. Description of the Related Art FIG.
It will be described using FIG. FIG. 26 shows a conventional optical pickup unit.
FIG. 4 is a cross-sectional view illustrating the packaging of In FIG.
401 is a light source made of a semiconductor laser or the like, and 402 is a light source.
A submount 402 is a block, and 403 is a block.
And the block 403 holds the light source 1 and
Has the function of releasing excessive heat generated in
A set of these three members is called an LD block). 4
Reference numeral 04 denotes a heat sink, and a heat sink 404 mounts an LD block or the like.
That dissipates heat from the LD block to the outside
It is. Reference numeral 405 denotes a light guide member.
Is inclined with respect to the incident direction of the light emitted from the light source 401.
Has a plurality of inclined surfaces, and the plurality of inclined surfaces are respectively
It is arranged almost in parallel, and various light
A light guide member 406 formed with a chemical element;
The light receiving element 406 converts light transmitted through the light guide member into electricity.
Convert to a signal. 408 is a package, package 4
Reference numeral 08 stores the above-described members and opens on the upper surface thereof.
Has a mouth. A cover 409 covers the opening of the storage member.
The member is usually formed from a light-transmitting material such as glass.
Has been established. Next, a method of manufacturing the optical pickup shown in FIG.
The method will be described with reference to FIGS. First
First, the light source 401 is mounted on the submount 402,
Create an LD block with the
To make. Then place the LD block on the heat sink 404
Fix to the surface. Further, the connecting member 40 is previously placed on the heat sink 404.
7 is mounted, and the package 408a is attached.
A light receiving element is provided in a portion surrounded by the cage 408a and the heat sink 404.
The signal from the light receiving element 406
The connecting member 407 to be taken out to the
Connection. After that, the predetermined
The attachment is performed at a predetermined position of the light guide member 405 and the position.
Irradiation of ultraviolet rays as a bonding material used at that time
UV curing adhesive that cures instantaneously and moisture-curing instantaneous contact
An adhesive was used. At this time, the light source 401 and the light guide member 40
Fine adjustment of the relative position with respect to 5 is performed using a predetermined method. This
Accordingly, the position of the light guide member 405 with respect to the light source 401
Can be determined very accurately. Light guide member 4
After positioning 05, irradiate ultraviolet rays and use UV adhesive
To solidify. [0004] In addition, even if it is not a UV adhesive for fixing,
A method of applying an instant adhesive after the determination is also conceivable. On the spot
Type that does not whiten during drying so as not to block light
Use something. Next, the light receiving element 406 is moved to a predetermined position on the heat sink 404.
Attach in the position. Before mounting, receive UV adhesive.
It is applied on the optical element 406 or the heat sink 404.
Also in this case, the light reflected at the optical medium
Must be accurately guided on each light receiving part of the light receiving element 406
Therefore, the light receiving element 406 and the light guide member 405 are not
Dense relative alignment is performed using a predetermined method. Receiving
After the optical element 406 is positioned, ultraviolet light is
Allow the V adhesive to solidify. And then for air tweezers
Is sealed using an epoxy potting agent. [0006] Finally, cover the top surface of the package 408b.
Cover the interior of the optical pickup with a bar member 409 and seal
I was [0007] However, the above-mentioned
In the next configuration, if a UV adhesive is used
First, apply UV adhesive to the light guide member and the holding member.
After adjusting the relative position of
To solidify the UV adhesive and join those members
After the operation is completed,
Adhesive was applied because the elements were bonded in the same process.
And two UV irradiation processes are required, and
It is very difficult to apply an adhesive between the
Difficult work has to be performed and extremely work efficiency
Was bad. Also with other methods when using UV adhesive
And apply UV adhesive to the two joints in advance.
The holding member and the light guide member, and the light guide member and the light receiving element
UV light after each position adjustment with the child
One assembly when irradiating to cure the UV adhesive
Problems such as taking a very long time to work
Was. The present invention solves the above-mentioned problems, and
Work time is short, and the adhesive can be easily applied.
Manufacturing method of optical pickup capable of
Manufactured with sufficient mounting strength and
The purpose is to provide a high-quality optical pickup
You. [0009] In order to achieve this object,
Used when joining the light guide member and the holding member
Used when bonding the adhesive, light guide member and light receiving element
The properties of the adhesive used are different. Or each contact
A plurality of different types of adhesives are used in the joint. With this configuration, good workability can be achieved.
Therefore, the number of steps can be reduced and the adhesive strength can be improved. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first optical pickup according to an embodiment of the present invention will be described below.
The packaging of the
You. FIGS. 1 and 2 show an embodiment of the present invention.
Showing the configuration of the optical pickup packaging
FIG. Reference numeral 1 denotes a light source, and the light source 1 is a semiconductor laser.
Various lasers such as gas lasers such as He-Ne
It is. Here, the smallest of these, the whole equipment is small
Output of several mW to tens of mW at a low unit price
It is preferable to use a semiconductor laser having the following. Semiconductor
The material of the laser is AlGaAs, InGaAsP, I
nGaAlP, ZnSe, GaN, etc. are considered.
Is the most commonly used, and inexpensive AlGaAs
Using. When performing high-density recording,
Can be made smaller, and AlGaAs
InGaAlP, ZnSe, etc., whose wavelength is shorter than s
It is preferable to use the semiconductor laser described above. 2 is a submount, and submount 2 is
Has a rectangular parallelepiped or plate shape, and a light source
1 is attached. This submount 2 is a light source 1
To dissipate the heat generated by the light source 1
have. Heat is applied to join submount 2 and light source 1
Considering conductivity etc., Au-Sn, Sn-Pb, In etc.
Pressure bonding of high temperature foil (several μm to several tens μm) at high temperature
Preferably, it is used. Light source 1 and submount 2
If it is not mounted substantially horizontally, it may cause aberration of the optical system.
Therefore, at the time of joining, the light source 1
It is preferred that the device be mounted almost horizontally at a predetermined height.
No. Further, the lower surface of the light source 1 is
An electrode surface 2a is provided so as to be in gaseous contact. This
The electrode surface 2a for supplying power to the light source 1
Consider the conductivity and corrosion resistance of the metal film that constitutes a.
It is preferable to use a thin film of Au. Further submount
2 is a problem such as heat generated from the light source 1 or attachment to the light source 1
The heat conductivity is high and the coefficient of linear expansion is
(About 6.5 × 10 ^-6 / ° C) is preferred. Concrete
Typically, the coefficient of linear expansion is 3 to 10 × 10 ^-6 / ° C, thermal conductivity
Is 100 w / mK or more, such as AlN, Si
C, T-cBN, Cu / W, Cu / Mo, Si, etc.
Very high thermal conductivity when using high power lasers
Use diamonds when you have to comb
Is preferred. Linear expansion coefficient of light source 1 and submount 2
Are the same or close to each other, light source 1 and sub
The occurrence of distortion between the mounts 2 can be suppressed.
Then, the mounting portion between the light source 1 and the submount 2 may come off,
It is possible to prevent inconveniences such as cracks in the light source 1.
Wear. However, if it is out of this range, light source 1 and
A large distortion occurs between the submounts 2 and the light source
1 and the submount 2 may come off,
The likelihood of cracks and the like increases. Also submount
By making the thermal conductivity of
The heat generated by the source 1 can be efficiently released to the outside
You. However, if the thermal conductivity is below this limit,
Since it is difficult for the heat generated in the light source 1 to escape to the outside,
As the temperature rises, the output of the light source 1 decreases,
If the life is shortened or in the worst case the light source 1 is destroyed
Inconveniences such as inconvenience tend to occur. In this embodiment, the ratio
Relatively inexpensive and very good in either of these two properties
AlN was used. Further, light is applied to the upper surface of the submount 2.
From the submount 2 to improve the connection with the source 1
A thin film is formed in the order of Ti, Pt, and Au toward the light source 1
Preferably. 3 is a block, and block 3 is basically a block.
It is a rectangular parallelepiped and has a large projection 3a on its side.
The submount 2 is mounted on the upper surface. This
Block 3 is also the light source 1
Due to the heat generated and problems such as attachment to the submount 2,
High conductivity and linear expansion coefficient close to that of submount 2
Material such as the material shown in the submount 2 material example
Using Mo, Cu, Fe, Kovar, 42 alloy, etc.
Preferably. However, the requirement for these property values
Is not so severe compared to submount 2
Therefore, it is preferable to make a selection with emphasis on cost. here
It is very inexpensive compared to AlN, and has relatively superior properties.
The block 3 was formed of a material such as Cu, Mo or the like. Also
In order to join the block 3 and the submount 2, the thermal conductivity etc.
Considering this, it is the same as in the case of submount 2 and light source 1.
Thus, although somewhat expensive, Au-Sn, Sn-Pb, I
n and other foils (thickness of several μm to several tens μm)
Is preferred. Reference numeral 4 denotes a heat sink, and the heat sink 4 is generated by the light source 1.
And transmitted through the submount 2 and block 3 by conduction.
It has the function of releasing the heat that has come out to the outside,
Various members forming the optical pickup are placed on the
It is a substrate for caging. Block 3 is row
It is fixed to the upper surface of the radiator plate 4 by attaching, soldering foil or the like. Release
Examples of the material of the hot plate 4 include Cu, Al, and F having high thermal conductivity.
e and the like are conceivable. Here, the submount 2 and the block 3
Were formed separately, but the output of the light source 1 was high.
If high thermal conductivity is required for these components,
These parts are integrally formed to improve conductivity
Is preferred. In this case, those materials are made of AlN or the like.
It is preferable to use one having extremely high thermal conductivity. The block 3 is larger than the submount 2.
It is desirable to increase the contact area with the heat sink 4
Good. Further, the heat sink 4 is provided with a hole 4a for adjustment.
You. The light source 1 needs to have high accuracy with respect to the optical axis.
Required, the upper surface of the submount 2 is horizontal with high accuracy.
It is preferable that Therefore, submount 2, block
Pay close attention to the mounting of the heat sink 3 and the heat sink 4
Is preferred. Reference numeral 5 denotes a light guide member.
It has a rectangular parallelepiped shape, with multiple slopes and
It has various films formed on these slopes,
Emit the emitted light and determine the returned light
Has the function of guiding to the position. The light guide member 5 has a block on its side.
3 is bonded to the end face 3b of the projection 3a. For this
High bonding strength to the bonding material used, fixed at any moment
Workability, volume before and after drying, and temperature and humidity
Is small, that is, a condition such as low shrinkage is required.
To improve workability and stability of the joint surface.
Can be up. Here, as such a bonding material
Irradiating with visible light (wavelength 3800-8000８)
Use a visible light curable adhesive that cures more quickly
Is preferred. And make sure it has enough mounting strength
Area between the block 3 and the light guide member 5
(S) is S> 1mm ^Two It is preferable that Especially
If workability is important, use a moisture-absorbing and curing instant adhesive.
Once fixed, then use an epoxy-based adhesive or
It is preferable to fix using a visible light curing type adhesive.
This reduces the impact resistance of the instant adhesive to epoxy-based
It can be supplemented with an adhesive or a visible light curable adhesive. Reference numeral 13 denotes a light receiving element, and the light receiving element 13 has a plate shape.
Composed of various electric circuits formed on semiconductor wafers
And is attached to the bottom of the light guide member 5.
You. Mounting of the light receiving element 13 and the light guide member 5
Work with high adhesive strength, can be fixed at any moment
, Body volume due to change in volume before and after curing and temperature and humidity
This requires conditions such as a small change in the product, that is, a low shrinkage ratio.
By satisfying these, workability and stability of the joint surface are improved.
Up. Here, ultraviolet rays are applied as such a bonding material.
UV curable adhesive that cures instantaneously by
Lower UV adhesive). Also emphasizes workability
If necessary, fix it once with a moisture-curing instant adhesive.
And then use epoxy adhesive or UV adhesive
And fixed. This allows instant glue
Compensate for low impact resistance with epoxy adhesive or UV adhesive
I can. Further, the light guide member 5 and the block 3
Use a visible light curable adhesive to join the
A UV adhesive should be used for joining the material 5 and the light receiving element 13.
Is preferred. In this way, the visible light curable adhesive is
The joint surface between the block 3 and the light guide member 5 has a UV contact
Apply the adhesive to the joint surface between the light receiving element 13 and the light guide member 5
After being applied, the light guide member 5 is irradiated with visible light first.
And block 3 and then irradiate with ultraviolet light
The guide member 5 and the light receiving element 13 can be joined.
You. This makes it possible to achieve both assembly workability and mounting strength.
Can be. The light receiving element 13 is emitted from the light source 1,
Light reflected back by the light guide member 5 or the recording medium, etc.
It has a plurality of light receiving sections for receiving signals. In this light receiving part
The detected optical signal is converted to an electrical signal according to the amount of light.
Is done. This electrical signal has the magnitude of the current value at the beginning of conversion.
You. However, this current is very weak and noise
There is a disadvantage that it is easy to pick up the noise. For this reason
Here, as the light receiving element 13, the current value is converted to a correlated voltage value.
An IV amplifier having the function of converting and amplifying is formed.
It is preferable to use one that is available. However, the incident frequency of light
It is required that the output voltage response
You. Further, on the surface of the light receiving element 13, the received information is represented as a signal.
Multiple electrodes composed of a thin film of Al etc.
A pole 13a is provided. Reference numeral 14 denotes a package.
The above-described block 3 and light guide member 5
It is provided so as to surround the light receiving element 13 and the like.
Out of the light receiving element 13 and the power of the light source 1
Lead frame 14a used for power supply etc. is molded
Have been. The shape of this package 14 is hollow at the center
It has a rectangular parallelepiped shape and a lead frame 1
On the inner surface of the package 14 on the side where 4a is molded
Is a step 14 so that the foot 14b of the lead frame is exposed.
c is provided. Note that the outer shape of the package 14
May be cylindrical or the like. And the light receiving element 13
Provided on the package 14 to extract electric signals from
Foot 1 of the lead frame exposed on the step 14c
4b and a plurality of electrodes provided on the surface of the light receiving element 13
13a with a wire 14d made of Au, Al or the like.
They are connected by ear bonding. In addition, the light source 1
In order to supply the light source, the upper surface of the light source 1 and the package
Of the lead frame exposed on the step 14c
b with the wire 14d and further sub-mount
On the upper surface of the light source 1 so as to make electrical contact with the lower surface of the light source 1.
Electrode surface 2a and the package 14
With the lead frame feet 14b exposed on the step 14c
Is also wire bonded with wire 14d
More connected. The material of the package 14 is low
Excellent water absorption and low outgassing properties are required
However, here, the most common type of IC mold is
A thermosetting resin such as a oxy resin is used. Also Lee
The material of the metal frame 14a is Cu, 42 alloy, F
Use a metal such as e plated with Ag, Au, etc.
There are many. Here, Cu is plated with Ni, and A
A u-plated one was used. With package 14
Large adhesive strength, low for mounting between heat sink 4
Has properties such as water absorption and high airtightness (low leak characteristics)
Use a bonding material. This makes the joint surface and joint position stable
Into the optical pickup packaging
Impurities can be prevented from being mixed. Here a little
Although it takes time to bond, these properties are excellent and inexpensive
A oxy-based adhesive was used. Reference numeral 15 denotes a shell, and the shell 15 is also a package.
The outside that cuts through the center of the rectangular parallelepiped like page 14
And its horizontal cross section is
It has almost the same shape. Also, the material
Low absorption to prevent impurities from entering the inside of the caging
Characteristics such as aqueous properties and low outgassing properties are required. here
Polybutylene terephthalate, which has excellent properties,
Lower PBT). However, especially strength and dimensional accuracy
When superior characteristics are required, it is better than PBT
Even if using LCP which is expensive but has excellent properties,
good. And the bonding between the shell 15 and the package 14
Similar to the mounting of the package 14 and the heat sink 4 described above.
For that reason, an epoxy-based adhesive was used. This shell 1
5 instead of using 5
Instead of the light guide member 5
Is also good. Reference numeral 16 denotes a cover member.
Dirt, dust, etc. adhere to the guide member 5, the light receiving element 13, etc.
Epoxy on the top of the shell 15
It is attached with a system adhesive. Also cover member
Examples of 16 materials include BK-7, FK-1, and K-3.
Glass, urethane, polycarbonate, acrylic, etc.
It is preferable to use a resin or the like having a high light transmittance.
In the case of reading a magneto-optical signal, the light transmittance is high.
It is not preferable to use a member having birefringence. Further
The upper and lower surfaces of the cover member 16 are anti-reflective to prevent reflection.
A stop film 16a is formed. This antireflection film 16a is made of M
gF _Two It is preferred to be formed of such a material. But hippo
-When reflection on the surface of the member 16 is not a problem
Need not be provided with the antireflection film 16a. In the packaging of the optical pickup,
From the viewpoint of preventing oxidation of the light source 1 and the light receiving element 13,
N as dry antioxidant gas _Two Gas such as Ar, N
It is preferable to fill an inert gas such as e or He. So
In the case of, the gap existing between the heat sink 4 and the light receiving element 13
17 with small shrinkage, low water absorption, high airtightness (excellent
(E.g., epoxy)
It must be filled with a system potting agent or solder. this
Thereby, the inside airtightness can be improved. By using the configuration shown above,
The heat generated by the light source 1 can be easily released to the outside.
And two openings on both sides of the packaging.
This makes it easy to enclose the antioxidant gas.
Can be. In the optical system, a light source 1 and a light guide unit
Correct the relative positional relationship between the material 5 and the light receiving element 13 and
Because they can be held firmly, their position shifts
No erroneous operation or extra optical aberrations are caused. Next, an optical pickup according to an embodiment of the present invention will be described.
The operation of the tip will be described. FIG. 3 shows one embodiment of the present invention.
FIG. 4 is a view showing a configuration of a light guide member in FIG.
FIG. 7 is a diagram illustrating the operation of the optical pickup in one embodiment.
You. In FIGS. 3 and 4, the sub-
Mounted horizontally via und 2 and block 3
The laser light emitted horizontally from the light source 1 has a plurality of parallel light beams.
From the surface 5f of the light guide member 5 having the slope, the light guide member
5 is formed on the second surface 5 b of the light guide member 5.
Change the diffusion angle of the emitted light with respect to the diffusion angle of the incident light.
Reflection (hereinafter referred to as NA conversion) function
And reaches the diffusion angle conversion hologram 7. Diffusion angle conversion
The light whose NA has been converted and reflected by the program 7 is
The zero-order light is reflected by the reflection type diffraction grating 6 formed on one surface 5a.
Diffracted light (hereinafter referred to as main beam) and ± 1st-order diffracted light (hereinafter referred to as main beam)
Lower side beam). For diffraction grating 6
Therefore, the generated main beam and side beam are
Polarization-selective beam splitter film 9 (hereinafter simply referred to as
(Referred to as one polarization beam splitter film). first
The first polarization of the light incident on the polarization beam splitter film 9
Light transmitted through the light beam splitter film 9 is
Used as monitor light for emitted light. Also, the first polarized light
Main beam and beam reflected by the beam splitter film 9
The id beam transmits through the surface 5e of the light guide member 5, and
Incident on the lens 26, and the light condensing action of the objective lens 26
An image is formed on the recording medium surface 27a of the recording medium 27. this
At this time, two side beams are generated on the recording medium surface 27a.
The imaging spots 29a and 29c are the imaging spots of the main beam.
An image is formed at a position substantially symmetrical about the pot 29b.
You. Main beam and side with respect to recording medium surface 27a
By the beam imaging spots 29b and 29a, 29c
Information recording or reproduction signal and tracking, focus
Reads a so-called servo signal. The divergence angle conversion hologram 7 is
Of the incident light to be incident on the diffusion angle conversion hologram 7
The diffusion angle conversion hologram 7
The angle of diffusion of the light reflected from the object is converted. Also, the diffusion angle conversion
By the program 7, it becomes parallel light which has no diffusion angle.
Can also be converted. Also, the same diffusion angle conversion hologram 7
As shown in FIG.
The wavefront aberration in which the luminous flux is integrated on the way is removed.
An imaginary spherical wave 30 is obtained. Therefore, the objective lens 26
The incident light becomes an ideal spherical wave 30 and is reflected by the objective lens 26.
The imaging spot on the recording medium 27 is narrowed down to almost the diffraction limit.
To the ideal size for recording or reproducing information.
It can be done easily. The recording medium surface 27a of the recording medium 27
The reflected main beam and side beam return light
Of the object lens 26 and the light guide member 5 Face 5e Pass again,
Again, the first polarizing beam formed on the second surface 5b of the light guide member
Incident on the beam splitter film 9. First polarization beam sp
The liter film 9 has a vibration component parallel to the incident surface.
Almost 100% with respect to light (hereinafter simply referred to as P-polarized component)
And a vertical vibration component (hereinafter simply referred to as an S-polarized
Has a constant reflectance. The first polarized light of the return light from the recording medium 27
The light transmitted from the beam splitter film 9 is a light guide member.
5 formed on a third surface 5c parallel to the first surface 5a.
Polarization-selective beam splitter film 11 (hereinafter simply referred to as
To the second polarizing beam splitter film).
The second polarizing beam splitter film 11 is a first polarizing beam splitter.
Almost 100 for the P-polarized light component as in the case of the splitter film 9.
% Transmittance and constant reflectance for S-polarized light component
Having. Here, the second polarizing beam splitter film 11
A description will be given of the transmitted light 117 among the light fluxes incident on the light emitting device.
The transmitted light 117 is a polarization plane conversion group laminated on the third surface 5c.
The light enters the plate 31. FIG. 5 shows the polarization plane change in one embodiment of the present invention.
FIG. 6 is a perspective view of a replacement substrate, and FIG.
FIG. 4 is a diagram illustrating a light-receiving unit arrangement and signal processing for backup.
The polarization plane conversion substrate 31 is provided with a first other slope 31a (hereinafter referred to as a first slope 31a).
Simply called the first other slope) and parallel to the first other slope 31a.
A second other slope 31b (hereinafter simply referred to as a second other slope).
The reflection film 126 is provided on the first other slope 31a.
(2) The polarization separation film 12 is formed on each of the other slopes 31b.
You. The transmitted light 117 is reflected by the polarized light formed on the second other slope 31b.
The light enters the light separation film 12. The second other slope 31b is the transmitted light 1
17 has an angle of about 4 between the polarization plane 117a and the entrance plane 128.
5 ° (2n + 1), where n is an integer
ing. As a result, the P-polarized light component 117P of the transmitted light 117 and
The S-polarized component 117S has an intensity ratio of about 1: 1.
Become. P-polarization component having a polarization component parallel to the entrance surface 128
Nearly 100% is transmitted by the polarized light separating film 12
On the other hand, the S-polarization having a polarization component
The light component 117S is applied to the polarization separation film 12 on the second other slope 31b.
100% is reflected on the first other slope 31a.
And reflected by the reflection film 126 to the light receiving element 13.
Be guided. Next, the second polarization beam split shown in FIG.
Of the reflected light 123 in the light flux incident on the
explain. The reflected light 123 is a reflection type hollow on the second surface 5b.
Incident on the hologram 10 which generates astigmatism formed in grams
I do. The reflected light 123 is generated by the astigmatism generating hologram 10.
Is reflected while generating astigmatism.
The reflected light of the main beam reflected by the reflection film 125 is received.
The light receiving sensor 172 on the optical element 13
The return light reaches the light receiving sections 176 and 177 on the light receiving element 13.
Reach. Next, in the first embodiment of the present invention,
Configuration of optical pickup compatible with variable optical disc
This will be described with reference to the drawings. Phase change optical disc
The crystal structure in the recording medium is changed by irradiating light
It records information and is used to change the crystal structure.
Requires more light than conventional optical recording / reproducing devices
Therefore, a more efficient optical system is required. FIG.
Light for a phase change optical disc according to an embodiment of the present invention
It is a conceptual diagram of operation | movement of a pickup. 1 and 2
3 and members having the same numbers as those shown in FIG.
Are the same in operation and configuration, and therefore description thereof is omitted. The laser light emitted horizontally from the light source 1 is
Surface 41f of light guide member 41 having a plurality of parallel slopes
Incident on the light guide member 41 from the
7 and a polarization-selective beam splitter film 35 (hereinafter referred to as a beam splitter film 35).
Light guide member through the lower beam splitter film)
The light is emitted from the surface 41e of the reference numeral 41. Here the beam split
Unlike the case of the first embodiment, the
The reflectance is 95% or more, and the reflectance of the P-polarized component is about 1%.
It is about. Light incident on the beam splitter film 35
The light transmitted through the beam splitter film 35 (P-polarized light component
Is about several percent of the total light amount) is the light emitted from the light source 1.
Used as monitor light for Surface of light guide member 41
The light emitted from 41e is provided on the cover member 16.
The light passes through the λ / 4 plate 33. FIG. 24 is a perspective view of the λ / 4 plate 33.
FIG. The λ / 4 plate 33 is incident from the light guide member 41.
The extraordinary optical axis is π / 4 · (2m-
1); (where m is a natural number; the same applies hereinafter)
The phase difference between the extraordinary light component and the ordinary light component of the incident light is π
/ 2 · (2m-1).
In general, the material constituting the λ / 4 plate 33 is a uniaxial crystal.
Use materials. Among them, low cost and excellent light transmission
It is preferable to use a quartz crystal. Extraordinary light in uniaxial crystals
There is an axis 616 and an ordinary optical axis 617, and for each optical axis
Extraordinary light refractive index n _e And ordinary light refractive index n _o Different called
It has a refractive index. The traveling speed of light in extraordinary light and ordinary light
Since the thickness is different, the substrate thickness of the λ / 4 plate 33 is QD, the wavelength of the incident light.
, A phase difference Δ determined by the following relational expression is generated. λ
The thickness QD of the / 4 plate 33 is such that the phase difference Δ is π / 2 · (2 m
-1). Δ = 2π · (n _e -N _o ) · QD / λ In this embodiment, the wavelength λ = 790 nm and the extraordinary light refractive index ne
= 1.5477, refractive index of ordinary light no = 1.5388 (only
The refractive index differs depending on the cutout angle of the substrate. Here is the extraordinary light
Cut out parallel to the plane containing both the axis and the ordinary optical axis
Was. ), The thickness of the λ / 4 plate 33 is 2
1.9 · (2m−1) μm. Under these conditions
As a result, light that is incident on the linearly polarized light at an incident angle of 0 degrees
It can be converted to circularly polarized light. That is, the light source 1
Converts linearly polarized light containing only S-polarized component to circularly polarized light
can do. In this case, the λ / 4 plate 33 is used
Although 21.9 μm crystal was provided on the bar member 16,
Provided on the surface 41e of the light guide member and the objective lens 26
There is also. Light that has passed through the λ / 4 plate 33 and has become circularly polarized
Is incident on the objective lens 26, and the light condensing action of the objective lens 26
The image is formed on the recording medium surface 27a of the recording medium 27 by
Is reflected. Circular polarization reflected on the recording medium surface 27a
The returned light reverses its rotation direction, so the returned light is
When the light passes through the laser beam 26 and again passes through the λ / 4 plate 33, P
The light is converted into linearly polarized light containing only a polarized light component. Like this
The returned light passes through the surface 41e of the light guide member 41 again.
And formed again on the second slope 41b of the light guide member 41.
The beam is incident on the beam splitter film 35 thus formed. Beams
The splitter film 35 has a vibration component parallel to the incident surface.
Light (hereinafter simply referred to as P-polarized light component)
It has a transmittance of 0% and a vertical vibration component (hereinafter simply referred to as S-polarized
Has a constant reflectance. Therefore
The return light having only the P-polarized light component is the beam splitter film 3
5 is almost transmitted. The return light is reflected by the first light guide member 41.
C formed on a third slope 41c parallel to the slope 41a.
Into the mirror 34. The half mirror 34 enters
Function to reflect a certain amount of the light
Have. Here, the light flux entering the half mirror 34 is
The transmitted light 117 is provided on the light receiving element 36 shown in FIG.
The light is guided to the light receiving unit 37 which is turned off. Next, the light enters the half mirror 34 shown in FIG.
The reflected light 123 of the light beam will be described. reflected light
123 is a reflection type hologram on the second slope 41b.
The light enters the astigmatism generating hologram 10 thus formed. Reflection
The light 123 is astigmatized by the astigmatism generating hologram 10.
While the difference occurs, the reflection film 124 and the reflection film 125
The reflected light of the main beam is reflected on the light receiving element 36.
The return light of the side beam is applied to the light receiving section 38 on the light receiving element 36.
At the light receiving portions 39 and 40 of the light emitting device. An optical pickup having the above configuration
In this case, the λ / 4 plate is connected to the beam splitter film 35 and the recording medium 27.
And output light that is linearly polarized light of the S-polarized
The light is converted into polarized light, and then reflected by the recording medium 27.
The circularly polarized light whose rotation direction is reversed is converted to P-polarized light only.
Is converted into linearly polarized light and enters the beam splitter film 35.
The light reflected by the recording medium 27
Since the light can be guided onto the light receiving element 36, the beam split
The reflectance of the S-polarized light component of the
Therefore, the amount of light applied to the recording medium 27 is increased.
be able to. Next, an optical pick-up according to the first embodiment of the present invention will be described.
See figure for manufacturing method of packaging up
I will explain while. FIGS. 7 to 11 show an embodiment of the present invention.
Diagram showing the manufacturing procedure of the optical pickup packaging
is there. First, light source 1, submount 2 and block
Assemble step 3 (hereinafter referred to as LD block). Assembly
In particular, the end face 3b of the block 3
It is necessary to process it so that it is almost vertical
You. Submount 2 and block 3 are pre-plated A
By cutting out the 1N plate using a dicing saw
It is made. At that time, the surface roughness, flatness, and verticality are sufficiently output.
If not, wrapping may be considered.
You. Attach the light source 1 to a predetermined position on the submount 2
You. Mounting is several μm of Au-Sn, Sn-Pb, In, etc.
This is pressed at high temperature using a foil with a thickness of m to several tens μm.
It is performed by a method such as Usually at the same time as the submount
2 and the block 3 are mounted in the same manner. However
While attaching the light source 1 and the submount 2,
For mounting the part 2 and the block 3 in different ways
In this case, it is necessary to mount
It is necessary. Note that a film of Ti or Pt is formed on the joining surface of these members.
Is formed, and a film of Au is further formed thereon.
It is preferable to join. Especially light source 1 and submount 2
This method can be used for mounting between
It is very preferable because it leads to an improvement in the reliability. Again
When assembling these members, the aberration of light increases.
So that the light emitting surface of the light source 1 and the
The end 3a of the raised portion 3a is substantially parallel to the end surface 3b, and the distance between both surfaces is incorrect.
Care must be taken that the difference is less than 10 μm.
No. By setting the error value in this way,
Fluctuation can be suppressed. Next, the LD block assembled in this manner is
Attach to the specified position of the heat sink 4 in the specified state
You. A method such as soldering is used for attachment,
At this time, the joint used to assemble the LD block
Be careful not to melt the material and reduce the assembly accuracy.
Need to be First by not melting
Optical pipes that can maintain the assembly accuracy and do not malfunction
Production of backup units becomes possible. Same at this time
Next, a Ti film is formed on the bonding surface, and Ni or P is formed thereon.
forming a film of t, further forming a film of Au thereon,
Therefore, it is preferable to join them. But not much here
Since high bonding strength is not required, Ti-Au, Ti
It may be joined by a film of -Ni. As another assembling method, the block 3 and the
The above-mentioned various thin films are formed on the hot plate 4 in advance.
g Attach the block 3 and the heat sink 4 with a wax or the like.
Remove the mount 2 with cream solder or the various foils described above.
Attach the light source 1 using the various foils described above.
It is also conceivable that Next, the heat sink 4 incorporating the LD block
The package 14 is mounted on a predetermined position. Installation
An epoxy-based adhesive is used for this. And light receiving element 1
3 in a package 14 and each signal of the light receiving element 13
Extraction electrodes and corresponding lead frame feet
14b with a wire 14d. This
The length of the wire 14d used for wire bonding
Is often adjusted because the position of the light receiving element 13 is finely adjusted later.
It is preferable to keep it a little longer. Also at this time
Light for the power source of the light source 1 is transmitted through the upper surface of the light source 1 and the Au surface.
Electrode surface 2a of submount 2 in contact with the bottom of source 1
And the lead 14b of the lead frame and the wire 14d
Wire bonding is performed beforehand. In this case,
The optical element 13 dissipates heat only by wire bonding
It is attached and fixed to the plate 4 or the light guide member 5.
Not. Next, the light guide member 5 and the end face 3 of the block 3
b and the light guide member 5 and the light receiving element 13
The mounting will be described. First, the light guide member 5 and the block 3
At least one of the end faces 3b has a visible light curing type contact.
The adhesive is applied, and the light guide member 5 and the light receiving element 13
A UV adhesive is applied to at least one of them.
In that state, first, the light guide member 5 and the block 3
Adjust the position. Then, fine adjustment of the precise position is performed.
This fine adjustment requires very high precision. The way
Will be described in detail with reference to FIGS. 12, 13 and 14.
You. FIG. 12 shows an image observed with a CCD according to an embodiment of the present invention.
FIG. 13 is a conceptual diagram showing the mismatch between the zero-order light and the first-order light.
0th order light and 1th order observed by the CCD in one embodiment of the present invention.
FIG. 14 is a conceptual diagram showing coincidence with the next light, and FIG.
FIG. 3 shows a conceptual diagram of an observation experiment in an example. First, power is supplied to the light source 1 to emit light.
Light is introduced into the guide member 5. Introduced into light guide member 5
The diffracted light is diffracted by the NA conversion hologram 7 into the 0th and 1st order diffracted light.
The light is separated from the light,
Is emitted. The emitted light is a collimator lens (not shown).
And the recording medium 27 passing through the objective lens 26
Image at the same position. At this time, if the light source 1 and the light guide unit
If the relative position with the material 5 is correct, the NA conversion hologram
The 0th-order diffracted light and the 1st-order diffracted light converted in step 7 have a depth of focus.
Just different points, focus at the same point so record
On the medium 27, as shown in FIG.
You. If the relative position between the light source 1 and the light guide member 5 is
If not correct, 0 converted by the NA conversion hologram 6
The first order diffracted light and the first order diffracted light have depth of focus and focus points
12 are different on the recording medium 27, as shown in FIG.
Two different circles. Utilizing this, recording media
Charge-coupled device camera 32 (hereinafter referred to as CCD) at body position
And measure the deviation between the 0th order diffracted light and the 1st order diffracted light
The deviation width and the direction of the deviation are fed back, and
Two light guide members 5 viewed by CCD 32 according to the amount of
Is moved so that the image of light of the component is concentric. This
As a result, the position of the light guide member 5 with respect to the light source 1 becomes very large.
It can be determined with high accuracy. In this way, the light guide section
After positioning the material 5, it is irradiated with visible light and cured with visible light
Allow the mold adhesive to solidify. As a positioning method, first order diffracted light is used.
Optical aberrations are measured using a wavefront aberration measuring instrument, etc.
There is also a method of positioning to minimize
You. However, the tracking signal detection method is a 3-beam method
Side beam incident on wavefront aberration measuring instrument
To measure three different lights at the same time.
Therefore, it is difficult to use this method. Next, the light receiving element 13 is moved to a predetermined position on the heat sink 4.
Attach to Also in this case, the light is reflected by the recording medium 27 again.
Incoming light is not correctly guided on each light receiving part of the light receiving element 13
Between the light receiving element 13 and the light guide member 5
Precise relative alignment is required. This alignment
Before explaining the method of the shift,
Focus error signal detection by astigmatism method and this embodiment
The state of astigmatism in will be described with reference to the drawings. FIGS. 15 to 17 show that the recording medium 27 is in focus.
Position, the recording medium 27 is closer to the in-focus position.
When the recording medium 27 moves away from the in-focus position.
It is an external view of an astigmatism light beam. 18 to FIG.
Astigmatism generating hologram 10 in FIGS. 15 to 17
Light received on the light receiving element 13 of the light generated by the
The spots at the parts 172a, 172b, 172c, 172d
FIG. Astigmatism generating hologram 10
Indicates that the light-receiving unit 172 is
To move the first focal point 178 downstream with respect to the light receiving section 172
A second focal point 179 is generated at the point shown in FIGS.
When the X-axis direction and the Y-axis direction are taken, the position of the first focal point 178 is obtained.
At the position of the second focal point 179
A line image on the X axis will be formed. If the recording medium 27 is
X-axis and Y-axis caused by astigmatism when in focus position
The diameter of each spot in the
The hologram 10 with astigmatism is designed at the position where
Is done. The focus error signal is transmitted to the light receiving section 172a,
172b, 172c, and 172d.
I172)
a, I172b, I172c, and I172d, FIG.
As can be seen from the circuit diagram of
You. F. E. FIG. = (I172a + I172c)-(I172b + I172d) When the recording medium 27 is at the in-focus position, FIG.
As can be seen, each spot diameter in the X-axis and Y-axis directions
172a
And the total received light amount at 170c and the sum at 172b and 170d.
The focus error signal is
It becomes the formula of. F. E. FIG. = 0 when the recording medium 27 is closer than the in-focus position, as shown in FIG.
The first focus generated by the astigmatism generating hologram 10
The point 178 and the second focus 179 are far from the focus error detecting element.
Therefore, the light receiving sections 172a, 172b, 172c, 172
The spot shape on d is in the Y-axis direction as shown in FIG.
It becomes an elliptical light beam having a long axis and the light receiving units 172a and 172c
Is larger than the light receiving amounts of the light receiving sections 172b and 172d.
The focus error signal is given by the following equation. F. E> 0 when the recording medium 27 is separated from the in-focus position, as shown in FIG.
Focus generated by the astigmatism generating hologram 10
178 and the second focal point 179 are the astigmatism generating hologram 10
172a, 172b, 172c, 1
The spot shape on 72d is in the X-axis direction as shown in FIG.
It becomes an elliptical light beam having a long axis in the direction, and the light receiving portions 172b, 17
The amount of light received by 2d is smaller than the amount of light received by light receivers 172a and 172c.
The focus error signal is given by the following equation. F. E <0 The focus error signal detection method described above is astigmatism.
Known as the law. Therefore, in this embodiment, light is received using this principle.
The element 13 is positioned. Ie some way
(Here, the light receiving element 1 is inserted through the hole provided in the heat sink 4.
3 uses air tweezers to adsorb the back)
Holds the optical element 13 and enables fine adjustment of the installation position.
Further, a reflection plate (not shown) is installed at the position of the recording medium 27.
Keep it. At this time, the bottom surface of the light guide member 5 or the light receiving element
A UV adhesive is applied to the upper surface of the child 13 in advance. It
First, receive the intensity of the light reflected back by the reflector.
It is monitored by the light receiving sections 170 and 171 of the optical element 13 and the like.
To determine a rough optimal position. And then divided into four
Light receiving units 172a and 172 of the
2b, 172c, and 172d (receiving)
While monitoring the light intensity (proportional to the amount of light).
Vibration is intentionally made parallel to the optical axis using an azo element or the like. This
As a result, the reflection plate moves closer to or farther from the light receiving element 13.
It will be distracted. At this time, the light receiving section 172a,
The light amounts of 172b, 172c, and 172d are almost equal, respectively.
If the light receiving element 13 is moved so that
Precise positioning of light receiving element 13 with respect to member 5 is possible
Become. At this time, the light receiving sections 172a and 172b
The state of these signals is shown in FIGS. Like this
After positioning the light receiving element 13 with ultraviolet light,
Allow the UV adhesive to solidify. And then air tweezers
Epoxy potting to seal the hole 4a
The gap 17 is closed using an agent or solder. It should be noted that a visible light curing type adhesive and a UV adhesive were used.
When using together, be sure to first emit visible light
The curable adhesive is cured, and then irradiated with ultraviolet light.
To cure the UV adhesive.
If UV light is applied first, visible light-curing adhesive
The agent also solidifies at the same time. As a fixing method, a UV adhesive or a young
Is instant glue instead of either visible light curable adhesive
It is also conceivable to use agents. In this case, after positioning,
Apply adhesive between them. Whitening when drying as instant adhesive
It is preferable to use a type that does not. Further, the recording medium 2 is actually provided without installing a reflection plate.
7 is arranged, and the recording medium 27 is rotated to generate surface runout.
Then, the position may be adjusted accordingly. Further here
Is the positioning of the light source 1 and the light guide member 5, and the light guide portion
About the positioning method between the material 5 and the light receiving element 13
The method of making the light source 1 emit light has been described.
And image recognition of each part using a CCD etc.
Recognize the product and the reference position, and determine the relative position
It is also conceivable to position them so as to have dimensions. Finally, in another step, an epoxy-based adhesive
Attach cover member 16 on top of shell 15 using
The bottom surface of the integrated member is
Mount on top of Epoxy type connection is mainly used for installation.
Use an adhesive. In addition, this work _Two , He, Ne, Ar
By performing in a dry antioxidant gas atmosphere such as
Purging inside the optical pickup packaging
it can. According to the manufacturing method described above,
The optical pickup packaging is completed. like this
Workability is improved by using
The number of processes and the assembly time can be reduced.
Wear. According to the present invention, the light guide member and other constituent members are provided.
Good by using multiple adhesives when joining
Workability while reducing the number of processes and improving adhesive strength.
The optical pickup package can be improved
Can improve the yield. Also light source and
At least one of the light receiving means and the light guide member
Adhesive strength is improved by joining using a number of adhesives.
Can be up.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view illustrating a configuration of an optical pickup according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a configuration of an optical pickup according to an embodiment of the present invention. FIG. 3 is a diagram showing a configuration of a light guide member according to one embodiment of the present invention. FIG. 4 is a conceptual diagram showing an operation of an optical pickup according to one embodiment of the present invention. FIG. 6 is a perspective view of a polarization plane conversion substrate. FIG. 6 is a view showing a light receiving portion arrangement and signal processing of an optical pickup according to an embodiment of the present invention. FIG. 7 is a manufacturing procedure of an optical pickup packaging according to an embodiment of the present invention. FIG. 8 is a view showing a manufacturing procedure of an optical pickup packaging in one embodiment of the present invention. FIG. 9 is a manufacturing procedure of an optical pickup packaging in one embodiment of the present invention. FIG. 10 is a diagram showing a manufacturing procedure of the optical pickup packaging in one embodiment of the present invention. FIG. 11 is a diagram showing a manufacturing procedure of the optical pickup packaging in one embodiment of the present invention. FIG. 13 is a conceptual diagram showing a discrepancy between the 0th-order light and the 1st-order light observed by the CCD according to one embodiment of the present invention. FIG. 14 is a conceptual diagram of an observation experiment in one embodiment of the present invention. FIG. 15 is an external view of an astigmatic light beam in one embodiment of the present invention. FIG. 16 is an embodiment of the present invention. FIG. 17 is an external view of an astigmatic light beam in an example. FIG. 17 is an external view of an astigmatic light beam in one embodiment of the present invention. FIG. 18 shows a spot shape of a beam on a light receiving sensor in one embodiment of the present invention. FIG. 19 shows an embodiment of the present invention. FIG. 20 is a diagram showing a beam spot shape on a light receiving sensor according to an embodiment of the present invention. FIG. 20 is a diagram showing a beam spot shape on a light receiving sensor according to an embodiment of the present invention. FIG. 22 is a diagram showing a sensor light amount on a sensor. FIG. 22 is a diagram showing a sensor light amount on a light receiving sensor in one embodiment of the present invention. FIG. 23 is a light for a phase change optical disk in one embodiment of the present invention. FIG. 24 is a perspective view of a λ / 4 plate according to an embodiment of the present invention. FIG. 25 is a layout diagram of light receiving elements of an optical pickup for a phase change optical disc according to an embodiment of the present invention. FIG. 26 is a view showing a configuration of a conventional optical pickup packaging. FIG. 27 is a view showing a manufacturing procedure of a conventional optical pickup packaging. FIG. 28 is a view showing a conventional optical pickup packaging. FIG. 29 is a diagram illustrating a manufacturing procedure of a conventional optical pickup packaging. FIG. 30 is a diagram illustrating a manufacturing procedure of a conventional optical pickup packaging. FIG. 31 is a diagram illustrating a conventional optical pickup packaging. [Description of reference numerals] 1 Light source 2 Submount 2a Electrode surface 3 Block 3a Projection 3b End surface 4 Heat sink 4a Hole 5 Light guide member 5a First surface 5b Second surface 5c Third surface 5e Surface 5f Surface 6 Diffraction grating 7 Diffusion angle conversion hologram 9 First polarization beam splitter film 10 Astigmatism generation hologram 11 Second polarization beam splitter film 12 Polarization separation film 13 Light receiving element 14 Package 14a Lead frame 14b Lead frame foot 14c Step 14d Wire 15 shell 16 cover member 16a antireflection film 17 gap 26 objective lens 27 recording medium 27a Recording medium surface 29a Side beam imaging spot 29b Main beam imaging spot 29c Side beam imaging spot 30 Ideal spherical wave 31 Polarization plane conversion substrate 31a First other slope 31b Second other slope 32 CCD 33 λ / 4 Plate 34 Half mirror 35 Beam splitter film 36 Light receiving elements 37, 38, 39, 40 Light receiving section 41 Light guide member 41a First slope 41b Second slope 41c Third slope 41e Surface 117 Transmitted light 117a Polarization surface 117s S-polarized light Component 117p P polarization component 123 Reflected light 124 Reflective film 125 Reflective film 126 Reflective film 128 Incident surfaces 170, 171, 172, 172a, 172b, 172
c, 172d, 176, 177 Light receiving unit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-124455 (JP, A) JP-A-6-203420 (JP, A) JP-A-6-119675 (JP, A) JP-A-6-119675 4928 (JP, A) JP-A-4-360034 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B ^7/ 08-7/22

Claims (1)

(57) Claims: 1. A light source, a block member for mounting the light source at a predetermined position and supplying power to the light source, and a tilt member for light emitted from the light source. A method for manufacturing an optical pickup having a light guide member having a plurality of inclined surfaces formed therein and a light receiving means having a plurality of light receiving elements, wherein the light guide member is previously provided between the incident surface of the block member and the light guide member. Applying a visible light curable adhesive and applying an ultraviolet curable adhesive between the light receiving means and the light guide member, and irradiating visible light first to join the light guide member between the incident surfaces, Thereafter, ultraviolet light is applied to join the light receiving means and the light guide member to each other.