JPH0568869B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a light emitting element array with no variation in light emitting power.

(Prior Art) Light emitting element arrays are used as light sources for optical printers, facsimile machines, copiers, and other devices using optical systems. For example, in the literature ("Nikkei Electronics", 5-25, (1981), published by Nikkei Maguro-Hill, p. 114-128), it is reported that an electronic An example of forming a photographic printer is disclosed.

As shown in this document, 10 per mm
In a light emitting element array having several light emitting parts, the pitch in the space for wire bonding to connect the individual electrodes to the wiring conductor is too narrow, so the individual electrodes from the light emitting parts are placed one on each side of the row of light emitting parts. A configuration is adopted in which the elements are arranged alternately, that is, in a staggered manner. FIG. 2A shows such a staggered arrangement of individual electrodes.

FIG. 2A is a plan view schematically showing a portion of a conventional light emitting device array. In the figure, 1 is a semiconductor substrate such as gallium phosphide, and 2
1, 22, 23, 24, . . . 2m are light emitting portions 31, 31, 32, 33, 34, .
. . 3m is an individual electrode provided on the substrate 1 so as to be connected to the light emitting area forming each of the light emitting parts 21 to 2m, and is made of a conductive material such as aluminum.

(Problems to be Solved by the Invention) However, when manufacturing a light emitting element array having such a structure, individual electrodes are formed on the light emitting region in electrical contact with the light emitting region, so that the tips of the electrodes are The surface area of the light emitting part is determined by the position. However, as shown in the figure, the odd-numbered and even-numbered individual electrodes are arranged on opposite sides of the row of light emitting parts, so if the mask used to form the individual electrodes is shifted in the direction perpendicular to the arrangement direction, , the position of the tip of the formed electrode also shifts in one direction corresponding to the shift. Therefore, there was a drawback that variations occurred in the area of the light emitting portion.

This state is shown in FIG. 2B. This figure shows the light emitting part 2.
FIG. 1 is a diagram representatively showing portions of electrodes 1 and 22 and individual electrodes 31 and 32 related thereto. Assuming that the predetermined length of the light emitting section in the direction orthogonal to the arrangement direction of the light emitting section is l, and that the individual electrodes 31 and 32 are shifted upward in the figure by a amount due to mask misalignment, the odd-numbered light emission The length of part 21 is (l-a)
Therefore, the length of the even-numbered light emitting section 22 is (l+
Because of a), variations occur in the light emitting area.

Such variations occur, for example, in the case of a light emitting element array having around 10 light emitting parts per 1 mm.
The length of the light emitting part is 40 to 50 μm, so it is only 4
Even if the mask misalignment is ~5 μm, it will be around ±10%. As a result, the luminous power and variation are ±10%.
Before and after.

Furthermore, due to the process of forming the light emitting region, the shape of the light emitting part may become irregular, and in that case, the area of each light emitting part will vary, and as a result, the light emitting power will also vary. There were flaws.

The purpose of this invention is to solve the conventional problems such as variations in light emission power due to misalignment of the mask for forming individual electrodes as described above, irregularities in the shape of light emission, and variations in light emission power due to irregularities in the shape of light emission. Another object of the present invention is to provide a light emitting element array in which the shape of light emission and the power of light emission are made uniform.

(Means for Solving the Problems) In order to achieve this object, the present invention provides a substrate, a plurality of light emitting regions arranged in alignment on the substrate, and electrically connected to the light emitting regions. In the light emitting element array, the light emitting element array includes individual electrodes respectively provided on the light emitting region and a part of the light emitting region as a light emitting part, a transparent insulating layer provided on the light emitting region and the individual electrodes, and a transparent insulating layer provided on the transparent insulating layer. and a light-shielding part in which a window defining the shape of the light-emitting part is formed with a window area narrower than the surface area of the light-emitting region.

(Function) With this configuration, the shape and area of the light emitting part are determined by the shape and area of the window of the light shielding part. The shape of this window can be simply and easily formed as designed using normal semiconductor technology, and its area is narrower than the surface area of the light emitting region. If the light shielding part is provided on the substrate so as to be located inside the light emitting part, the shape and area of each defined light emitting part can be made uniform. Therefore, variations in light emission power do not cause malformation of the light emission shape.

(Example) An example of the light emitting element array of the present invention will be described below with reference to FIGS. 1A and 1B.

In these figures, components having the same functions as those shown in FIGS. 2A and 2B are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 1A is a partial plan view schematically showing an example of the light emitting element array of the present invention, and FIG.
It is a sectional view on the -Y line.

In this embodiment, a plurality of light emitting regions 2 having PN junctions are arranged in a semiconductor substrate 1, and individual electrodes 31 to 3m are electrically connected to a portion of these light emitting regions 2. Provide one on each side of the array alternately, that is, in a staggered manner.

A transparent insulating layer 4 is provided on the light emitting region 2 and the individual electrodes 31 to 3m. A light-shielding portion 5 made of, for example, aluminum or other suitable light-shielding material is provided on the transparent insulating layer 4 . The light shielding section 5 includes a window 6 for transmitting light, and the window 6 has a shape that defines the shape of the light emitting sections 21 to 2m with a window area smaller than the surface area of the light emitting region 2. This window may be a through hole provided in the light shielding part 5, or may be filled with any suitable material that transmits light.

This window 6 is located above the light emitting region 2 and is located inside the region of the light emitting region 2 facing the substrate surface,
Moreover, the window 6 is arranged outside the window so that it is not obstructed by the individual electrodes 31 to 3m.

In this way, these windows 6 define the shape and light emitting area of each light emitting section 21 to 2m of the light emitting element array.

It should be noted that the present invention is not limited only to the embodiments described above. For example, the light emitting element array may be arranged in a different arrangement than in a straight line, and although the individual electrodes are provided in a staggered manner on both sides of the light emitting section arrangement, these electrodes may be unevenly distributed on one side of the light emitting section arrangement. .

Further, the shape of the window is not limited to the rectangular shape shown in the illustrated example, but can be any suitable shape that meets the desired purpose.

Further, the materials, dimensions, and arrangement relationships of each component can be appropriately set as required.

(Effects of the Invention) As is clear from the above description, according to the light-emitting element array of the present invention, if the area and shape of the window of the light-shielding part are formed accurately, the mask can be placed in a predetermined position when forming the individual electrodes. Even if the formation position of the light emitting part deviates from the position where the light emitting part is formed, or even if the shape of the region that should become the light emitting part becomes irregular, the light emitting area, position, and shape of the light emitting part can be defined by the window of the light shielding part.
Formation of this window is simple and easy, and moreover, this window can be simply and accurately placed at a position above the light-receiving area and away from the individual electrodes. Therefore, there is an advantage that the light emitting shape and light emitting power of each light emitting part of the formed light emitting element array can be made substantially uniform without variation.

[Brief explanation of the drawing]

1A and 1B are partial plan views schematically showing one embodiment of the light emitting device array of the present invention; FIG. 1B
1A is a sectional view taken along the X-Y line in FIG. 1A, and FIGS. 2A and 2B are partial plan views schematically showing a conventional light emitting element array. 1...Substrate, 2...Light emitting area, 21~2m...
Light emitting section, 31 to 3 m...Individual electrode, 4...Transparent insulating layer, 5...Light shielding section, 6...Window of the light shielding section.

Claims (1)

[Claims] 1. A device comprising a substrate, a plurality of light emitting regions arranged in alignment on the substrate, and individual electrodes each provided in electrical connection with the light emitting regions, and comprising a part of the light emitting region. In a light emitting element array having a light emitting part, the light emitting part has the following features: a transparent insulating layer provided on the light emitting region and the individual electrodes; and a window area provided on the transparent insulating layer and having a window area smaller than the surface area of the light emitting region. A light-emitting element array comprising: a light-shielding portion in which a window defining a light-shielding portion is formed.