JPH04368184A - Facing type photocoupler - Google Patents

Abstract

PURPOSE:To provide a photocoupler device of good photoelectric transfer efficiency by mounting a light emitting element and a photosensitive element on one lead frame and by making optical axis of both elements coincide with each other. CONSTITUTION:First and second element setting pieces 3, 6 which are formed with a step in a lead frame 21 are formed and a light emitting element 4 and a photosensitive element 7 are mounted in opposition each other. A mounting position of the light emitting element 4 or the photosensitive element 7 is corrected to make optical axis of both the elements 4, 7 coincide with each other.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facing type photocoupler in which a light emitting element and a light receiving element are opposed and optically coupled.

0002

2. Description of the Related Art As a photocoupler of this type, one shown in FIG. 3 is known. In the same figure, lead frame 1
Element setting pieces 3 and 6 are provided protruding from the lead frame 2 and are arranged so that their main surfaces 3a and 6a face each other. A light emitting element 4 is mounted on the element setting piece 3 of the lead frame 1.
However, the light receiving elements 7 are attached to the element setting pieces 6 of the lead frame 2 via a conductive adhesive 5 by die bonding. The light emitting surface 4a of the light emitting element 4 and the light receiving surface 7a of the light receiving element 7 are opposite to each other.
are optically coupled.

As shown in FIG. 4, a connection piece 11 is attached to the frame portion 10 of the lead frame 1 on which the element setting piece 3 is set.
are arranged in parallel, the element 4 and the connecting piece 11 are connected via the metal wire 8 by wire bonding, and a fifth
As shown in the figure, a connecting piece 13 is arranged in parallel on the frame 12 of the lead frame 2 on which the element setting piece 6 is set, and the element 7 and the connecting piece 13 are connected via a metal wire 9 as well. It is connected.

[0004] The lead frame 2 is turned upside down to face the lead frame 1, and a light emitting element 4 and a light receiving element 7 are disposed facing each other as shown in FIG. Both elements 4 and 7 are
Resin molding is carried out in the area shown by the chain line A in FIG. 3, and each external terminal piece 3b, 6b, 1
1a and 13a are cut to form a photocoupler.

[0005]

[Problem to be Solved by the Invention] In this type of photocoupler, it is important to align the optical axis of the light emitting element and the optical axis of the light receiving element in order to improve the photoelectric conversion efficiency of incident light. It is. In the conventional photocoupler described above, positional deviation occurs when both the elements 4 and 7 are attached to the respective lead frames 1 and 2, and when the two lead frames 1 and 2 are integrated. Even if you try to correct the above positional deviation when integrating lead frames 1 and 2, it will not work as shown in Figure 3.
As shown in , the setting piece 6 of the lead frame 2 covers both elements and the mounting position cannot be seen, and the setting positions of the lead frame 1 and lead frame 2 cannot be changed, so it is necessary to correct the above positional deviation. I can't. For this reason, it has been virtually impossible to precisely align the optical axes of both elements 4 and 7.

The present invention was made to solve the above problem, and the mounting position of either the light emitting element or the light receiving element is adjusted in accordance with the mounting position of the other element, and the optical path of both elements is strictly controlled. The objective is to provide a photocoupler with high photoelectric conversion efficiency.

[0007]

[Means for Solving the Problems] In the photocoupler according to the present invention, one of the elements is mounted on the main surface of a lead frame by down-face bonding. 1
Preferably, both elements are mounted on a single lead frame.

[0008]

[Function] According to the above structure, when one element is mounted by down-face bonding, it is possible to correct the deviation of the optical path with respect to the other element. Mounting both elements on one lead frame reduces the number of parts and eliminates the work of integrating the lead frames, improving production efficiency.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an example of a photocoupler according to the present invention, and the same parts as in the conventional photocoupler are given the same reference numerals, and detailed explanation thereof will be omitted. In FIG. 1, the lead frame 21 includes a rectangular frame portion 10, an element setting piece 3, a connecting piece 11 formed separately on the longitudinal extension thereof, and a connecting piece 11 on both sides of each piece 3, 11. Four element setting pieces 6 are provided separately and arranged in parallel. As shown in FIG. 2, the element setting pieces 6 are set on substantially the same plane, and the element setting pieces 3 and the connection pieces 11 are bent with steps.

A light emitting element 4 is set on the setting piece 3,
Further, connection parts 14 made of gold, for example, are provided at the four corners of the light-receiving surface 7a of the light-receiving element 7, and the light-receiving element 7 is connected to the terminal setting piece 6 so as to face the light-emitting element 4 via the connection parts 14. It is installed.

First, the light emitting element 4 is attached to the element setting piece 3 by die bonding, and the light emitting element 4 and the terminal piece 11 are connected by wire bonding. Next, the light-receiving element 7 having the connection part 14 on the light-receiving surface is bonded to each tip 6a of the four element setting pieces 6 by down-face bonding.
, 6b, 6c, and 6d. At this time, the light emitting element 4
Since the position of the light receiving element 7 can be visually recognized, it is possible to adjust the mounting position of the light receiving element 7 so that the optical axes of the light receiving element 7 and the light emitting element 4 are aligned. Thereafter, the connecting portion 14 is brazed and fixed, and the region indicated by the chain line A is resin-molded, and a photocoupler can be constructed through predetermined steps. Note that in the above embodiment, it goes without saying that the light emitting element 4 may be aligned with respect to the light receiving element 7.

In this way, the light receiving element 7 is set after the light emitting element 4 is set on one lead frame 21, so the mounting position of the light receiving element 7 is adjusted so that the optical axes of both elements 4 and 7 coincide. can be adjusted, it is possible to provide a photocoupler with high photoelectric conversion efficiency. Furthermore, since it is now possible to mount both the elements 4 and 7 on one lead frame 1 and make them face each other, the number of parts is reduced and production efficiency is improved.

[0013]

As described above, according to the present invention, a light emitting element and a light receiving element are mounted on one lead frame, and the optical axes of both elements are aligned, thereby producing a photocoupler with high photoelectric conversion efficiency. It becomes possible to provide

[Brief explanation of drawings]

FIG. 1 is a plan view of a main part of a lead frame for explaining the process of manufacturing a photocoupler according to the present invention.

FIG. 2 is a schematic cross-sectional side view of the photocoupler.

FIG. 3 is a schematic cross-sectional side view of a conventional photocoupler.

FIG. 4 is a plan view of a main part of one lead frame for explaining the manufacturing process of a conventional photocoupler.

FIG. 5 is a plan view of essential parts of the other lead frame of the photocoupler.

[Explanation of symbols]

4 Light emitting element 4a　Light emitting surface 7 Photo receiving element 7a Photo-receiving surface 21 Lead frame A Resin mold area

Claims (1)

[Claims] 1. A plurality of substantially coplanar first element setting pieces formed on a lead frame, and a second element setting piece formed on the lead frame with a step difference with respect to the first element setting pieces. 1. A facing type photocoupler comprising: a light-emitting element and a light-receiving element that are set opposite to each other on the first and second element setting pieces;