JPS62259482A - Photocoupler - Google Patents

Abstract

PURPOSE:To stably assure long interface distance of a photo-guiding member and improve dielectric breakdown strength by providing a sheet material having light transmitting property and electical insulation property between a light emitting element and a photodetector and by protruding the external circumference of such sheet material to the outside of photo-guiding member. CONSTITUTION:A sheet material 17 which is extended perpendicularly to the plane including a light emitting element 11 and a photodetector 12 is provided between the light emitting element 11 and photodetector 12. This sheet material 17 has the light transmitting and electrical insulation properties and is formed like a disk. A kind of silicon resin 18 is injected to both sides of sheet material 17 as the photoguiding member having the light transmitting and electrical insulation properties. Thereby, the light emitting element 11 and photodetector 12 are covered with the silicon resin 18, thus forming a right path extending to the photodetector 12 from the light emitting element 11. Moreover, the external circumference of sheet material 17 is protruded to the outside in the radius direction from the silicon resin 18. Thereby, long and stable distance of interface between the silicon resin 18 and epoxy resin 19 can be asured and dielectric breakdown strength can also be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a photocoupler such as a photocoupler, and more specifically, a light-emitting element and a light-receiving element are arranged opposite to each other within the same plane. The present invention relates to an optical coupling element in which a light guiding member having transmissive properties and electrical insulation properties is interposed in an optical path between a light emitting element and a light receiving element.

Background technology A photocoupler has an input side and an output side. 3. It is an optical coupling element that can transmit an optical signal from the input side to the output side.
This is a device whose applications are expanding with increasing transparency. Such a photocoupler is mainly required to have three performances. The first is that the trust 3 (1 house effect) is high, and the second
requires a dielectric strength between the input side and the output side, and although the level differs depending on the application, high quality is also required from a safety standpoint. Since the third performance is used for the purpose of removing noise, a high common-mode signal rejection ratio is required.

Among the above-mentioned required cores, the input end-output HtDI
The structure of a photocoupler with an excellent in-phase signal rejection ratio between the two is shown in FIG. This photocoupler 1 includes a light emitting element 2 and a light receiving element 3 disposed facing the light emitting element 2 on the same plane. The light emitting element) 2 is realized by an infrared light emitting diode. The receiving heel element 3 is constructed from a chip that integrates a phototranostar, a photoguio Y, and an Ig-addition circuit.

The light emitting element 2 is firmly bonded to the lead terminal 4a, and the light receiving element 3 is firmly bonded to the lead terminal 4b.

Translucent silicon tj is placed between the light emitting element 2 and the light receiving element 3.
The silicon resin 5 forms an optical path from the light emitting element 2 to the light receiving element 3. The silicon O (resin 5) forming the light path is molded with black epoxy 4111t6, and this black epoxy base 6 prevents the light from the light emitting element 2 from fading and disturbance light from entering. In other words, the light travels within the optical path of the silicone resin 5 and reaches the light receiving element 3 while being reflected at the interface with the epoxy resin 5.

Problem to be Solved by the Invention, α In the above-mentioned advance technique, it is actually quite difficult to form the silicone resin 5 so that the interface distance is long as shown in FIG. Causes variation. Such variations not only cause variations in optical transmission efficiency, but also lead to variations in dielectric strength between the input side and the output side, which can lead to fatal defects in the device. This is because silicone resin 5 and epoxy 6 do not necessarily have good adhesion, and their expansion coefficients are significantly different, resulting in dielectric breakdown across the interface.The interface distance is If the voltage applied between the input side and the output side is equal to the voltage, and if there is no gap, the dielectric strength will be stable, but variations in the shape of the optical path will easily cause the dielectric strength to fall below the bottom.

An object of the present invention is to solve the above-mentioned technical problems, and to provide an optical coupling element which ensures a good and stable interface 7 of a light guide member constituting an optical path and improves dielectric strength. It is to provide.

Means for Solving the Problems The present invention provides a light-emitting element and a light-receiving element that are arranged facing each other in the same plane, and a light-transmitting and electrically insulating light path between the light-emitting element and the light-receiving element. A light-transmitting and electrically insulating sheet body is interposed between the light-emitting element and the light-receiving element, and the outer periphery of this sheet body is is an optical coupling element characterized by protruding outward beyond the light guide member.

According to the present invention, a light-transmitting and electrically insulating sheet body is interposed between the light-emitting element and the light-receiving element, and the outer periphery of this sheet body protrudes outward beyond the light guiding member. As a result, the creepage distance at the interface between the light guide member and the epoxy resin (3) that covers the light guide member can be maintained stably and the dielectric strength can be improved. .

Example FIG. 1 is a sectional view of one embodiment of the present invention.

The photocoupler 10 as an optical coupling element includes a light emitting element 11 and a light receiving element 3 disposed facing the light emitting element 11 on the same plane. Light emitting element 1] is realized by a light emitting diode. The light-receiving element 12 is realized by e)) a lannostar, a photodiode, and a Sennobu integrated signal amplification circuit. The light emitting element 11 and the light receiving element 12 are mounted on lead terminals 14-a, 4-b of the lead frame 13, respectively, as shown in FIG. The light emitting element 11 and the light receiving element 12 are connected by bonding wires 16 through lead terminals 15a and 15bl of a lead frame 13, respectively.

A sheet body 17 is interposed between the light emitting element 11 and the light receiving element 12, as shown in FIG. 3, and extending perpendicularly to the plane containing the light emitting element 7-11 and the light receiving element 12. This sheet body 17 is transparent, has strong insulation properties, and is formed into a disk shape. A silicone resin 13 as a light guide member having translucency and electrical insulation is injected into both sides of the sheet body 17, and the light emitting element 11 and the light receiving element 12 are covered with the silicone resin 13, so that the light emitting element 11 An optical path leading to the light receiving element 12 is formed. Note that the outer peripheral portion of the sheet body 17 is purchased so as to protrude outward in the radial direction from the IJ) t 1 :3.

These silicone resin 4 and sheet 17 are molded with a light-shielding black epoxy resin 19.

This epoxy ATIX9 prevents light leakage from the two-light element 11 and invasion of outside 6L light. This epoxy layer 19 not only has a light-shielding property but also a light-reflecting property.
By using a silicone resin with a high
Reflection of light at the interface with the material is large, and the light transmission rate can be increased.

In this way, the outer periphery of the sheet body 17 is
Since it is made to protrude outward in the radial direction from r118, it is possible to ensure a long and stable creepage distance at the interface between the silicone resin 18 and the epoxy iJ4 resin 19,
It is possible to improve the dielectric strength.

FIG. 4 is a sectional view of an embodiment of the pond of the present invention, and FIG. 5 is a perspective view of a sheet body used in the embodiment shown in FIG. This embodiment is similar to the previous embodiment and corresponding parts bear the same reference numerals. In this embodiment, the sheet body 17
a has a through hole 20 in its center as shown in FIG.
is formed.

As a result, the silicone resin 18 is also injected into the through hole 20 as shown in Figure #S4. Therefore, it is possible to prevent a reduction in light transmission rate due to reflection at the interface between the sheet body 17g and the silicone resin 18. Note that the other structures are the same as those of the above-mentioned embodiments, and therefore P3. Noh is preserved.

612I is a perspective view of a further embodiment of the present invention, and FIG. 7 is a sheet body 17 used in the embodiment shown in FIG.
1], and FIG. 8 is a plan view taken along the cutting plane line ~T in FIG.
-'rI h・It is a sectional view seen from. This y, tough example is,
This embodiment is similar to the embodiment described in 1iif, and corresponding parts are given the same reference numerals. In this embodiment, the sheet body 17t+ has a through hole 20 formed in the center thereof, and mounting holes 21a are formed on both sides of the through hole 20 in this embodiment. , 21b are formed. Light emitting element 11
At the tip of the lead end T-15a of 111, there is a mounting hole 21a.
An insertion portion 31a to be inserted into and a clamping portion 32m are formed. Similarly, connect lead terminal 15 to 2■η.
At the tip of 11, there is an insertion part 311) and a clamp E & 321]
is formed.

When installing the sheet body 17b, insert the insertion portion 31a
is inserted into the mounting hole 21a, and another insertion part 31 is inserted into the mounting hole 21a.
b is inserted into the mounting hole 2111. With this structure, when silicone (sheet body 171) is injected with fat 18 (sheet body 171 due to the weight of fat 18)
Note that in this embodiment, although there is a risk of dielectric breakdown occurring through the interface between the sheet body 171J and the silicone resin 18, there is a possibility that the central portion of the sheet body 171+, which serves as the optical path, is transparent. Since the holes 20 are formed, the creepage distance can be maintained well. In addition, for discharge at the interface between silicon υ (resin 18 and epoxy resin 19), as in the case of the embodiment described if, silicon
Creepage distance can be ensured by the sheet body 171+ protruding from 18.

Effects As described above, according to the present invention, the creepage distance of the interface can be increased and stabilized without reducing the optical transmittance. Therefore, it is possible to improve the dielectric strength.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, tIS2 is a perspective view of the vicinity of the lead frame 13, and No. 3I71 is a sheet body 1
7 is a perspective view showing a state in which silicone (3) (oil 13) is injected, No. 3 is a sectional view of another embodiment of the present invention, and FIG. 5 is a sheet body 17a used in the embodiment shown in No. 4. The perspective view of FIG.
11 - A perspective view showing the state where it is attached to the V7 frame 13, a plan view of the 7th [2I is the sheet body 171), and the 8th
The figure is a sectional view taken along the section line ①--l in Fig. 6, and Fig. 9 is a sectional view of the first technique.

Claims (1)

[Scope of Claims] A light guide member in which a light emitting element and a light receiving element are arranged facing each other in the same plane, and the optical path between the light emitting element and the light receiving element is transparent and electrically insulating. A light-transmitting and electrically insulating sheet body is interposed between the light-emitting element and the light-receiving element, and the outer periphery of this sheet body is located outwardly from the light guide member. An optical coupling element characterized by a protrusion.