JPH06331869A - Optical device and its production - Google Patents

Abstract

PURPOSE:To obtain sufficient strength of adhesion without increasing curing time while maintaining the accuracy as the optical device by curing adhesives of a high curing rate, then curing adhesives having the high strength of adhesion. CONSTITUTION:The UV curing type adhesives 6a, 6b are extremely high in curing rate but are relatively weak as the strength of adhesion. On the other hand, the thermosetting type epoxy adhesives 7a to 7d have the characteristics of the low curing rate and the high strength of adhesion. If an optical alignment position is determined, this state is maintained and first, the UV curing type adhesives 6a, 6b are irradiated with UV rays from both sides and are cured. The irradiation quantity of the irradiation with the UV rays from these two directions is so set that the positional deviation by a difference between the respective curing rates of the UV curing type adhesives 6a and 6b is not generated and that the alignment accuracy is maintained by obtaining balance. The optical device is then put into an electric furnace and is heated to a prescribed temp. to cure the thermosetting type epoxy adhesives 7a to 7d, by which a lens barrel 4 and a sensor package 1 are normally fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device having a plurality of members and a method of manufacturing the same.

[0002]

2. Description of the Related Art An optical pickup unit used in a compact disc player, a so-called CD device, an autofocus sensor unit for a camera, or the like, generally has an optical system unit such as a lens and an optical sensor (for example, PIN) as a light receiving element. Diode).

In the manufacturing process of such an optical pickup, it is necessary to accurately align the members forming the optical system unit and the members forming the optical sensor and then bond and fix them.

Conventionally, in an optical pickup unit for a CD device, a UV (ultraviolet) curing type adhesive is applied to the bonding surface between a member forming an optical system unit and a member forming an optical sensor, and after alignment, The both parts were fixed by irradiating the adhesive part with ultraviolet rays and curing it.

[0005]

Since the optical pickup unit for a CD device has a comparatively light weight, the adhesive force is relatively weak as compared with other adhesives. The agent was enough.

However, an optical pickup unit used in a camera autofocus sensor unit or the like has a lens barrel and a lens barrel so that the two sets of lenses and the optical sensor are arranged and fixed at a required distance. The optical system including the lens and the sensor package become large and heavy.

In such an optical pickup unit,
To obtain the necessary mechanical strength for bonding and fixing the member forming the optical system and the member forming the optical sensor, U
With V-curable adhesives, the amount of adhesive must be increased and the adhesion area must be increased.

If the amount of UV-curable adhesive is increased to increase the adhesive area in order to obtain sufficient adhesive strength, the ultraviolet rays will not reach the adhesive sufficiently during irradiation, and the curing time will inevitably increase. Therefore, it causes a decrease in productivity. Moreover, if the intensity of the ultraviolet rays is increased to accelerate the curing, the curing distortion increases and the alignment accuracy deteriorates, which adversely affects the performance of the optical pickup.

An object of the present invention is to provide an optical device having a structure in which a plurality of members are adhered to each other so as to obtain sufficient adhesive strength without lengthening the curing time while maintaining the accuracy of the optical device, and a manufacturing method thereof. To provide.

[0010]

A method of manufacturing an optical device according to the present invention comprises a step of applying a plurality of adhesives having different curing rate and adhesive strength between a plurality of members of the optical device, Among the plurality of adhesives, the step of curing the adhesive having a faster curing rate than other adhesives, and the step of curing the adhesive having a faster curing rate, and then the bonding than the adhesive having a faster curing rate And a step of curing the adhesive having high strength.

In the optical device according to the present invention, a plurality of members of the optical device are bonded by a plurality of adhesives having different curing speed and adhesive strength, and the plurality of adhesives are different from each other. The adhesive includes an adhesive having a faster curing rate than the adhesive and an adhesive having a higher adhesive strength than the adhesive having a faster curing rate.

[0012]

A plurality of adhesives having different adhesive properties including an adhesive having a faster curing speed and an adhesive having a stronger adhesive strength are applied between members. Among the plurality of adhesives, the adhesive having a faster curing speed than the other adhesives is first cured to maintain the alignment state, and then the adhesive having higher adhesive strength is cured.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical device and a method of manufacturing the same according to embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1A is a plan view of a sensor package of an autofocus sensor unit for a camera according to an embodiment of the present invention as seen from a light incident direction, and FIG. 1B shows the unit. It is a side view and the optical module is shown in sectional drawing.

In FIG. 1, a sensor package 1 is a semiconductor package in which a semiconductor photosensor such as a CCD and its peripheral circuits are integrated, and a light receiving window 2 transparent to the light to be detected is provided in front of the photosensor part. Have. Also,
On the side surface of the sensor package 1, a plurality of lead pins 3 which can be soldered to a circuit board or the like are arranged.

The optical module includes a lens barrel 4 and two sets of lenses 5.
a and 5b are arranged and fixed at a predetermined interval. Next, a method of assembling the sensor package 1 and the lens barrel 4 will be described. As shown in FIG. 1 (a), UV curable adhesives 6a and 6b are applied to two places on both outer sides of the light receiving window 2 of the sensor package 1, and thermosetting epoxy adhesives 7a and 7b are further applied. , 7c, 7d are applied to four places.

The UV curable adhesives 6a and 6b are selected to have a high thixotropy and do not flow in the applied state to maintain the required height. Wedge-shaped cutouts 8a, 8 are formed on the bottom of the lens barrel 4 in contact with the UV-curable adhesives 6a, 6b, and expand at a certain angle toward the outside of the unit.
b is provided. When the lens barrel 4 is placed on the sensor package 1, the notches 8a and 8b are filled with the UV curable adhesives 6a and 6b.

Although the notch is formed in the lens barrel, the notch may be formed in the sensor package. Of course, notches may be provided in both the lens barrel (optical module) and the sensor package.

The thermosetting epoxy adhesives 7a to 7d have an appropriate viscosity and fill a small gap between the bottom surface of the lens barrel 4 and the sensor package 1. The UV curable adhesives 6a and 6b have a very high curing speed, but their adhesive strength is relatively weak. On the other hand, thermosetting epoxy adhesive 7a-
7d has a characteristic that the curing speed is slow, but the adhesive strength is high.

Position alignment between the sensor package 1 and the lens barrel 4 is performed while holding the sensor package 1 and the lens barrel 4 individually in a state before they are applied and cured. The alignment may be performed by a conventional optical method, or a method of finding the optimum alignment while monitoring the output of the optical sensor.

When the optimum alignment position is determined, the state is maintained and first the ultraviolet rays are irradiated from both sides of the UV curable adhesives 6a and 6b to be cured. The irradiation amount of the ultraviolet irradiation from these two directions is adjusted so that the positional deviation due to the difference in curing speed between the UV curable adhesives 6a and 6b does not occur.
It is set to balance and maintain alignment accuracy.

The shapes of the notches 8a and 8b at the bottom of the lens barrel 4 are set so that ultraviolet rays are efficiently applied to the UV curable adhesives 6a and 6b. At this point, the thermosetting epoxy adhesives 7a to 7d are not yet cured.

FIG. 2 shows an embodiment of an alignment apparatus for performing the adhesive application step, the alignment step, and the ultraviolet ray irradiation step described above. The sensor package 1 is placed on a movable holding jig 10, and a UV curable adhesive application device 1
1 and the UV curable adhesives 6a and 6b are applied. Further, the sensor package 1 is placed under the thermosetting epoxy adhesive application device 12, and the thermosetting epoxy adhesives 7a to 7d are applied. The two kinds of adhesives may be applied at the same time or separately.

Next, the sensor package 1 coated with two kinds of adhesives is placed on the alignment adjusting stage 13.
The alignment adjustment stage 13 is composed of movable stages 16 and 17 driven by motors 14 and 15, respectively, and is capable of moving the sensor package 1 in an arbitrary direction within a two-dimensional plane.

With the lens barrel 4 held by the holding jig 18,
Sensor package 1 by moving movable stages 16 and 17
And the lens barrel 4 are aligned. When the alignment is completed, with the lens barrel 4 and the sensor package 1 kept stationary, the cuts 8 are made from the ultraviolet condenser lenses 19a and 19b.
The UV curable adhesives 6a and 6b of a and 8b are irradiated with ultraviolet rays to be cured within a short time to temporarily fix the lens barrel 4 and the sensor package 1. A light guide 21 for guiding ultraviolet rays from an ultraviolet ray generation source 20 to the ultraviolet ray condensing lenses 19a and 19b.
Ultraviolet rays are supplied via a and 21b.

After the alignment and the curing of the UV curable adhesive are carried out by the above alignment apparatus, the thermosetting epoxy adhesive 7a is placed in an electric furnace 30 as shown in FIG. 3 and heated at a predetermined temperature. ~ 7d is hardened to permanently fix the lens barrel 4 and the sensor package 1. The curing process in the electric furnace 30 is more efficient when a large number of temporarily fixed sensor units 25 are put into the electric furnace 30 at one time. In addition, 31 is a temperature control apparatus.

Since the thermosetting epoxy adhesive is in a very narrow gap between the lens barrel 4 and the sensor package 1, sufficient adhesive strength can be obtained with a small amount of adhesive for a wide adhesive area. Therefore, the amount of shrinkage during curing can be suppressed. In addition, since there is no need for rapid curing, residual strain is small.

As described above, in this embodiment, an adhesive having a fast curing time for temporary fixing and an adhesive having a high adhesive strength for main fixing are used at the same time. As the former adhesive having a quick curing time, in addition to the UV curable adhesives of the above-mentioned examples,
Instant adhesives can also be used.

As the latter adhesive having a high adhesive strength, a thermosetting epoxy adhesive (polyimide), a two-component epoxy adhesive or an anaerobic adhesive can be used. Combinations of these adhesives can also be used.

Other than these adhesives, an adhesive having a fast curing time and an adhesive having a large adhesive strength can be used. The type of adhesive is not limited to two types as in the embodiment, and more types may be used together.

When an anaerobic adhesive is used as an adhesive having a high adhesive strength, it is necessary to finish the alignment before the anaerobic adhesive is applied and cured. Examples of the optical device according to the present invention include an optical pickup unit of an optical disc device, a lens unit and a CCD module of a video camera, a substrate of a liquid crystal display device, and the like, in addition to those of the above embodiments. It can also be applied to a combination of a light emitting element and an optical system.

The present invention is not limited to the embodiments described above, and it goes without saying that various modifications and improvements can be made by those skilled in the art from the disclosure of the present specification and the drawings.

[0033]

According to the present invention, the following effects can be obtained by using an adhesive having a fast curing time and an adhesive having a high adhesive strength.

Since a small amount of an adhesive having a short curing time is used and main fixing is performed with an adhesive having a high adhesive strength, temporary fixing can be performed in a very short time, and the amount of the adhesive used can be minimized.
In addition, main fixing can be performed in large quantities at one time outside the alignment device.

Therefore, it is possible to obtain a high-quality optical device having high productivity, strong adhesive force, little curing distortion, and maintaining alignment accuracy.

[Brief description of drawings]

FIG. 1 is a plan view of a sensor package of an autofocus sensor unit for a camera according to an embodiment of the present invention and a side view of the unit.

FIG. 2 is a diagram of an alignment apparatus for carrying out a manufacturing method according to an embodiment of the present invention.

FIG. 3 is a diagram of an electric furnace for carrying out a manufacturing method according to an embodiment of the present invention.

[Explanation of symbols]

 1 sensor package 2 light receiving window 3 lead pin 4 lens barrel 5a, 5b lens 6a, 6b UV curable adhesive 7a, 7b, 7c, 7d thermosetting epoxy adhesive 8a, 8b notch

Claims (8)

[Claims] 1. A method of manufacturing an optical device including a plurality of members, comprising: applying a plurality of adhesives having different curing speed and adhesive strength to each other between the plurality of members; Among the adhesives, a step of curing the adhesive having a faster curing rate than other adhesives, and the adhesive strength is higher than that of the adhesive having a faster curing rate after curing the adhesive having a faster curing rate. And a step of curing a large adhesive. 2. The optical device according to claim 1, further comprising a step of aligning the plurality of members between the step of applying the plurality of adhesives and the step of curing the adhesive having a high curing rate. Device manufacturing method. 3. In the step of applying the plurality of adhesives, the adhesive having a high curing rate is selected from an ultraviolet curable adhesive and an instant adhesive, and the adhesive having a high adhesive strength is a thermosetting epoxy. 3. The method of manufacturing an optical device according to claim 1, wherein the method is selected from an adhesive, a two-component epoxy adhesive, and an anaerobic adhesive. 4. The optical device includes an optical member and an optical sensor member, and the step of aligning the plurality of members includes the step of aligning the optical member and the optical sensor member. 4. The method for manufacturing an optical device according to any one of 3 to 3. 5. The ultraviolet curable adhesive is used as the fast curing adhesive, the thermosetting epoxy adhesive is used as the high adhesive strength adhesive, and the fast curing adhesive is used. The step of curing includes a step of irradiating the ultraviolet curable adhesive with ultraviolet rays, and the step of curing the adhesive having a high adhesive strength is an electric furnace for the optical member and the optical sensor member that have performed the alignment step. The method for manufacturing an optical device according to claim 4, further comprising: 6. An optical device comprising a plurality of members, wherein the plurality of members are bonded by a plurality of adhesives having different curing speed and adhesive strength. Includes an adhesive having a faster curing rate than other adhesives, and an adhesive having a higher adhesive strength than the adhesive having a faster curing rate. 7. The optical device includes an optical member and an optical sensor member, and the adhesive having a high curing speed includes an ultraviolet curable adhesive, and an adhesive surface between the optical member and the optical sensor member, 7. The optical device according to claim 6, wherein a wedge-shaped gap whose cross-section expands toward the outside of the optical device is provided, and the ultraviolet curable adhesive is placed in the gap. 8. The optical device according to claim 7, wherein the adhesive having a high adhesive strength includes a thermosetting epoxy adhesive and is applied to a contact surface between the optical member and the optical sensor.