JPH11251619A - Photo interrupter manufacturing method - Google Patents

Abstract

(57) [Problem] To provide a light-emitting element and a light-receiving element without breaking a light-emitting element and a light-receiving element when forming a slit for an optical path of a photo-interrupter without requiring an expensive mold. It is an object of the present invention to provide a method of manufacturing a photointerrupter capable of manufacturing a high-resolution photointerrupter. SOLUTION: A light emitting element 1 and a light receiving element 2 are mounted on a lead frame 4 and internally connected to each other.
In the method for manufacturing a photointerrupter in which the surface of the light-transmitting resin 5 is covered with a light-blocking material and a part of the light-blocking material is removed to form the light-path slit 5a, In the step of forming 5a, a light-curable material 6 is used as a light-shielding material, and a light path slit 5a is formed by exposure with a mask 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for manufacturing a photointerrupter capable of detecting the presence or absence of an inspection object in a non-contact and non-contact manner.

[0002]

2. Description of the Related Art A conventional method for manufacturing a transmission type photointerrupter will be described with reference to FIG. 5A is a plan view, FIG. 5B is a front view, FIG. 5C is a side view, and FIG. 5D is a cross-sectional view taken along line AA ′ of FIG. As shown in FIG. 5, in this photo interrupter, a light emitting element 1 and a light receiving element are mounted on a lead frame 4, internally connected by gold wires 3, and molded with a light transmitting resin 25. The light-shielding resin 26 is integrally formed so as to expose a portion (a slit for light passage) 25a through which light enters and exits.

At this time, since the width of the slit 25a is determined by molding using a mold for the translucent resin 25, the width greatly changes depending on the precision of the mold processing and the dimensional accuracy at the time of molding.

Next, a method for manufacturing a conventional reflection type photointerrupter will be described with reference to FIG. 6A is a front view, FIG. 6B is a bottom view, and FIG.
FIG. 4 is a cross-sectional view taken along a cutting line AA ′ in FIG. FIG.
As shown in FIG.
And the light receiving element are mounted on the lead frame 4 and the gold wire 3
And the light-transmitting resin 35 is independently connected to each other.
Is molded. Then, the surrounding surface is coated with a resin 36 containing a paint or the like to a predetermined thickness.

[0005] Then, in order to form a portion (slit for light passage) 35a through which light enters and exits, a portion of the resin 36 where the slit 35a is formed is burned off with a laser to expose that portion.

[0006]

However, the above-described conventional method for manufacturing a photointerrupter has the following problems.

First, in the case of the transmission type shown in FIG. 5, the width of the slit 25a is determined by the mold used for molding the translucent resin 25. However, the width of the slit 25a is limited to about 0.15 mm in terms of a mold processing and a molding process, and it is difficult to form a narrower slit width than this. In addition, in the case of changing the slit width in manufacturing the photointerrupter, an expensive molding die is required each time.

In the reflection type shown in FIG. 6, when forming the slit 35a, the laser beam is transmitted through the translucent resin 35 at the moment when the resin 8 is burned off by a laser, and the light emitting element inside the resin 8 is formed. 1 or the light receiving element 2, and there is a problem that those elements are destroyed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to change the size of a slit without forming an expensive mold when forming a slit for a light path of a photo-interrupter. It is another object of the present invention to provide a method of manufacturing a photointerrupter capable of manufacturing a high-resolution photointerrupter without breaking a light emitting element and a light receiving element.

[0010]

According to the first aspect of the present invention, a light emitting element and a light receiving element are mounted on a lead frame and internally connected to each other, and the periphery of the light emitting element and the light receiving element is made of a transparent resin. After molding, the light-transmitting resin is coated on its surface with a light-shielding material, and a part of the light-shielding material is removed to form an optical-path slit. Then
A light-curable material is used as the light-shielding material, and the slit for the light path is formed by exposure using a mask.

According to the first aspect of the present invention, in the light path slit forming step, a light curable material is used as a light shielding material, and the light path slit is formed by exposure using a mask, so that expensive gold is used. The size of the slit can be changed without using a mold, and a high-resolution photointerrupter can be manufactured without destroying the light emitting element and the light receiving element.

Further, according to the invention described in claim 2, in the method for manufacturing a photointerrupter described in claim 1,
In the step of molding with a light-transmitting resin, the light-emitting element portion and the light-receiving element portion are molded with a light-transmitting resin independently and connected by the same frame. The frame connecting the portion and the light receiving element is bent so that the light path slit on the light emitting element side and the light path slit on the light receiving element side face each other.

According to the second aspect of the present invention, in the molding step using the light-transmitting resin, the light-emitting element portion and the light-receiving element portion are formed independently by the light-transmitting resin so as to be connected by the same frame. After molding and forming the slit for the light path, the frame connecting the light emitting element part and the light receiving element part is bent so that the light path slit on the light emitting element side and the light path slit on the light receiving element side face each other. Therefore, even in the transmission type, the size of the slit can be changed without requiring an expensive mold, and a high-resolution photointerrupter can be manufactured without breaking the light emitting element and the light receiving element. .

According to a third aspect of the present invention, in the method for manufacturing a photointerrupter according to the first or second aspect, the thickness of the light-shielding material film made of a photocurable material is set to about 50 μm. .

According to the third aspect of the present invention, the thickness of the light-shielding material film made of a photocurable material is set to about 50 μm, and the film thickness is optimized in consideration of the light-shielding effect and the process. The photocurable resin can be used for the light-shielding material coating while sufficiently fulfilling its role, not burdening the process, and reducing the cost.

According to a fourth aspect of the present invention, in the method of manufacturing a photointerrupter according to the first, second, or third aspect, the width of the slit for the optical path is 50 to 100 μm.
It is decided to be.

According to the fourth aspect of the present invention, the width of the slit for the optical path is set to 50 to 100 μm, and the width of the slit for the optical path, which is narrower than the limit of about 0.15 mm in the conventional molding, is reduced. Therefore, it is possible to manufacture a high-resolution photointerrupter without destroying the light emitting element and the light receiving element without using a slit formed by laser baking.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same reference numerals are used for the same components as those of the above-described conventional technology.

As a first embodiment, a method of manufacturing a reflection type photointerrupter will be described with reference to FIG. First, the light emitting element 1 and the light receiving element 2 are mounted on the lead frame 4 and are internally connected by the gold wire 3. Then, molding (primary molding) is performed with the translucent resin 5 so that the portion including the light emitting element 1 and the portion including the light receiving element 2 are independent (FIG. 1A). Thereafter, a photo-curable material 6 is applied to the surface of the mold resin (translucent resin) 5 at a thickness of about 50 μm and is temporarily cured (FIG. 1B).

The temporary curing is to solidify the applied liquid photoresist, for example, to perform a heat treatment for about tens of minutes in an oven. In the present embodiment, a negative type photoresist which is an ultraviolet curable material is used as the photocurable material 6.

Next, a mask which is not irradiated with ultraviolet rays only on the area where the light passing slits 5a are to be formed is arranged on the surface where the light passing slits 5a are formed, and is exposed to ultraviolet rays. Then, in the present embodiment, since the negative type photoresist is used as the photocurable material 6, the resist is completely cured at the portion irradiated with the ultraviolet rays (FIG. 1C).

Next, this is immersed in an etching solution to remove a portion of the resist that has not been irradiated with ultraviolet rays, thereby forming a slit 5a for passing light (FIG. 1).
(D)).

Thereafter, by performing lead cut forming (shape processing by cutting, bending or the like on an external lead frame), a reflection type photo interrupter as shown in the perspective view of FIG. 2 can be manufactured.

As a second embodiment, a method of manufacturing a transmission type photointerrupter will be described with reference to FIG. 3, (a) is a plan view, (b) is a front view, (c) is a right side view, and (d) is a perspective view.

This transmission type photo interrupter is shown in FIG.
And it is manufactured in substantially the same manner as the first embodiment shown in FIG. The present embodiment is different from the first embodiment in that the lead frame 4 (see FIGS. 1 and 2) of the first embodiment is replaced with a lead frame 4 which is a connection frame as shown in FIG. Is changed to '. That is, in the present embodiment, at the time of lead cut forming, the lead frame 4 'is bent so that the light path slit 5a on the light emitting element 1 side and the light path slit 5a on the light receiving element 2 face each other. Is applied to produce a transmission type photo interrupter as shown in FIG.

In both the first embodiment and the second embodiment, the width of the light passing slit 5a is set to 5 mm.
It could be easily formed with a thickness of 0 to 100 μm.

According to the first and second embodiments, in the step of forming the slit for the light path, an ultraviolet curable material is used as the light-shielding material, and the light path is irradiated by irradiating the ultraviolet light curable material using a mask. Since the slits were formed, the size of the slits could be changed without requiring an expensive mold, and a high-resolution photointerrupter could be manufactured without destroying the light emitting element and the light receiving element. Furthermore, the thickness of the ultraviolet curable material is set to about 50 μm, and the thickness is optimized in consideration of the light-shielding effect and the process. The photocurable resin could be used for the light-shielding material film.

Further, according to the second embodiment, in the molding step using the light-transmitting resin, the light-emitting element portion and the light-receiving element portion are formed with the light-transmitting resin so as to be connected independently and by the same frame. After the molding and the slit forming step for the light path, the frame connecting the light emitting element part and the light receiving element part is bent so that the light path slit on the light emitting element side and the light path slit on the light receiving element face each other. Therefore, even in the transmission type, the size of the slit can be changed without requiring an expensive mold, and a high-resolution photointerrupter can be manufactured without breaking the light emitting element and the light receiving element.

Next, as in the first and second embodiments,
The slit width for light passage of the photo interrupter is 50 to 10
The effectiveness of being able to be 0 μm will be described. In personal computers at present, it is common to use a CD-ROM device as a peripheral device.
The photo interrupter is used in the CD-ROM device. The basic configuration of a CD-ROM device will be described with reference to FIG.

The CD-ROM device shown in FIG.
An optical pickup 12 for reading information from the ROM disk 11, a shaft 13 having a screw-shaped groove for moving the optical pickup 12 back and forth by rotation, a gear 14 connected to the shaft 13 and transmitting power thereto,
It comprises a motor 15 for applying power to the shaft 13 via a gear 14, and a rotating disk 16 connected to the motor 15 and provided with a slit for detecting the number of rotations.

A photo interrupter 17 is used to detect the number of rotations of the rotary disk 16, and the position of the optical pickup 12 is controlled according to the detection result.
Therefore, in such a configuration, if an attempt is made to improve the access time of the CD-ROM, the optical pickup 1
It is necessary to control the position 2 as accurately as possible. For that purpose, the width of the light passing slit of the photo interrupter 17 may be reduced. Specifically, at present, it is said that a slit width of about 100 μm is required.

Further, in the future, rewritable optical disks are expected to be applied not only to peripheral devices of computers but also to various information recording devices such as video recording devices. In such a case, a photo-interrupter having a narrow slit for light passage is required.

Therefore, like the photointerrupters of the first and second embodiments, the width of the slit for passing light is 5
The fact that the width can be narrowed to 0 to 100 μm has the effect of enabling high-precision optical pickup position control in the above-described present and future optical disk devices.

[0034]

As described above, according to the first aspect of the present invention, in the light path slit forming step, a light curable material is used as the light shielding material, and the light path slit is formed by exposure using a mask. Therefore, the size of the slit can be changed without requiring an expensive mold, and a high-resolution photointerrupter can be manufactured without breaking the light emitting element and the light receiving element.

Further, according to the second aspect of the present invention,
In the molding step with the light-transmitting resin, the light-emitting element portion and the light-receiving element portion are molded with the light-transmitting resin so as to be connected independently and by the same frame. The frame connecting the part and the light receiving element is bent so that the light path slit on the light emitting element side and the light path slit on the light receiving element face each other. The size of the slit can be changed without the necessity, and a high-resolution photointerrupter can be manufactured without breaking the light emitting element and the light receiving element.

Further, according to the third aspect of the present invention,
The thickness of the light-shielding material film made of a photocurable material is about 50 μm.
As m, the film thickness is optimized in consideration of the light-shielding effect and the process, so it plays a sufficient role, does not impose a burden on the process, suppresses the cost, and converts the photocurable resin into a light-shielding material film. Can be used.

Further, according to the invention described in claim 4,
By setting the width of the slit for the optical path to 50 to 100 μm, a slit width for the optical path that is narrower than the limit of about 0.15 mm in the conventional mold molding can be realized without using the conventional slitting by laser printing. Therefore, a high-resolution photointerrupter can be manufactured without breaking the light emitting element and the light receiving element.

Further, the width of the light passing slit is set to 50 to 10
The fact that the width can be reduced to 0 μm enables highly accurate position control of an optical pickup in an optical disk device used for various information recording such as a CD-ROM device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part for describing a method for manufacturing a reflective photointerrupter according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a schematic structure of a reflective photointerrupter manufactured according to the first embodiment.

3A and 3B are diagrams illustrating a schematic structure of a transmission type photointerrupter according to a second embodiment, wherein FIG. 3A is a plan view, FIG. 3B is a front view, FIG. 3C is a right side view, and FIG. FIG.

FIG. 4 is a schematic configuration diagram showing a basic configuration of a CD-ROM device.

5A and 5B are diagrams showing a schematic structure of a conventional transmission type photointerrupter, wherein FIG. 5A is a plan view, FIG. 5B is a front view, and FIG.
Is a side view, and (d) is a cross-sectional view taken along a cutting line AA ′ in (b).

6A and 6B are diagrams showing a schematic structure of a conventional reflective photointerrupter, wherein FIG. 6A is a front view, FIG. 6B is a bottom view, and FIG.
FIG. 4 is a cross-sectional view taken along a cutting line AA ′ in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light emitting element 2 Light receiving element 4, 4 'Lead frame 5 Translucent resin 5a Light slit 6 Light curable material 7 Mask

Claims (4)

[Claims] 1. A light-emitting element and a light-receiving element are mounted on a lead frame and internally connected to each other, and the periphery thereof is molded with a light-transmitting resin. In the method of manufacturing a photointerrupter for forming a slit for an optical path by removing a part of a light-transmitting material, the step of forming a slit for an optical path includes using a photocurable material as a light-shielding material, and exposing the optical path by a mask. Forming a slit, and a method for manufacturing a photo interrupter. 2. The method for manufacturing a photointerrupter according to claim 1, wherein in the molding step using the translucent resin, the light emitting element portion and the light receiving element portion are connected independently and by the same frame. Molded with a light-transmitting resin, after the light path slit forming step, bending a frame connecting the light emitting element portion and the light receiving element portion,
A method for manufacturing a photointerrupter, wherein a light path slit on a light emitting element side and a light path slit on a light receiving element side are opposed to each other. 3. The method for manufacturing a photointerrupter according to claim 1, wherein the thickness of the light-shielding material film made of a photocurable material is about 50 μm. 4. The method for manufacturing a photointerrupter according to claim 1, wherein the width of the slit for an optical path is 50 to 100 μm.