JPS6158998B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a method for producing a high-brightness, high-density light emitting diode (LED) dot array using a high-brightness substrate on which a PN junction is formed by liquid phase growth or the like. It is about the method.

Conventionally, high-density LEDs used in LED printers, etc.
When making dot arrays, P
-The N-junction method was used. However, in this method, the PN junction is created by diffusion, so the luminous efficiency is poorer and the brightness is insufficient compared to the PN junction created by liquid phase growth.

Also, if you want to make other LED dot arrays,
As shown in FIGS. 1a and 1b, there is a method of separating the PN junction by dicing it in a grid pattern. In other words, 1 is the light emitting part of the LED element, and 2 is the light emitting part of the LED element.
The non-light emitting part of the LED element, 3, is a dicing groove. However, in this case, the dicing width W was at least 50 μm, and it was impossible to separate the dots at intervals smaller than this.

This invention was developed in view of the above points, and in a method of manufacturing an LED dot array by dicing, by diagonally inserting dicing lines in one direction, electrical distance between each LED element, that is, between dots can be improved. High brightness that allows dots to be separated, but optically the separation width is zero, or the dots can overlap optically with the adjacent dots.
A method for manufacturing an LED dot array is provided.

The present invention will be explained in detail below with reference to the drawings.

Figures 2a to 2c show an embodiment of the present invention. Figure 2a is a partial plan view for explaining dicing, and Figure 2b is a diagram showing a state in which wiring has been applied to the electrode section.
FIG. 2c is a partial perspective view of the LED dot array, and is a sectional view taken along the line X--X in FIG. 2b. Figure 2a
As shown, the dicing width _W1 in the A direction is 125μ.
m, and the dicing in the B direction is relative to the A direction.
Dice at an angle of 63.43° to a dicing width W ₂ of 56 μm. Dicing pitch _P1 in direction A is 350
μm, dicing pitch _P2 in B direction is 250μm
Dice each.

The reason why the dicing in the B direction is set at the above angle with respect to the dicing in the A direction is to ensure that each dot is optically continuous when observed from a direction perpendicular to the dicing in the A direction, which is the longitudinal direction of the dot array. This is to do so. Note that the dicing should be done to a depth that exceeds the PN junction so that each dot is electrically isolated (see FIG. 2c).

In FIG. 2b, 1a indicates a light emitting section in column a, and 1b indicates a light emitting section in column b, each of which corresponds to one dot. Column a and column b are each light emitting section 1a,
1b are arranged in a staggered manner at intervals of 125 μm. Therefore, for example, by running the photosensitive surface in the direction of the arrow, first causing the light emitting section 1a to selectively emit light according to the pattern, and when the photosensitive surface exposed by the light emitting section 1a moves to the column b, the light emitting section 1a that has not emitted light until then will emit light. Hot light emitting part 1
selectively emit light. By doing so, the photosensitive surface can be exposed uniformly without gaps between dots. In addition, in FIGS. 2 a to c, 4 is an LED element, 5 is a wire bond, and 6 is a wire bond.
is the electrode lead.

FIG. 3 shows another embodiment of this invention,
The dicing width W ₁ in the A direction is 100 μm, the dicing pitch P ₁ is 350 μm, and the dicing width in the B direction is 100 μm.
W ₂ is 45μm and its dicing pitch _P2 is 250μm.
An example is shown in which the light emitting parts 1a and 1b are arranged so as to overlap each other by about 16.7% by dicing at an angle of 63.43 degrees with respect to the m and A directions. That is, when viewed perpendicularly from the longitudinal direction (direction C), the portions h overlap. Whether the light emitting parts 1a and 1b are arranged to overlap or not overlap is determined depending on whether the pattern to be exposed is negative or positive.

Although FIGS. 2 and 3 only explain 8 pieces/mm, the dicing widths W ₁ , W ₂ in the A and B directions,
It goes without saying that even higher density LED dot arrays can be made by appropriately changing the dicing pitches P ₁ and P ₂ and the angle.

Further, although FIG. 3 shows an example in which the light emitting parts 1a and 1b overlap by about 16.7%, it goes without saying that this can be selected as appropriate from the above explanation, and the distance between the light emitting parts can be increased as necessary. can.

Light leakage from the dicing groove 3 can also be prevented by covering the dicing groove 3 with an absorbing material or a reflective material. It goes without saying that the parts other than the light emitting part 1 can be masked with a thin film of light absorbing material or reflecting material.

As described in detail above, the present invention allows the use of a substrate with a highly efficient PN junction surface, making it possible to produce a high-brightness LED monolithic dot array. In addition, this invention separates the LED elements by dicing, and dices the other diagonally to one dicing direction, so that multiple rows of diode arrays can be formed on the same substrate and adjacent A high-density diode dot array of 10 or more diode dots can be manufactured with a structure in which rows of LED elements are alternately arranged. Furthermore, by changing the vertical and horizontal dicing widths and angles, an LED dot array with no optical breaks between dots can be created. Furthermore, it is possible to easily manufacture a device in which the light between the dots overlaps, or, conversely, a device in which the light between the dots is separated, as required.

Furthermore, in the method of the present invention, the planar light-emitting surface of the PN epitaxial growth substrate that emits planar light is divided by direct dicing, and multiple rows of dot arrays can be formed directly on this substrate. The desired dot arrangement can be achieved by simply determining the width and manufacturing is easy.

Furthermore, if the LED dot array manufactured according to the present invention is used as a light source for a facsimile machine or a light source for a copying machine, a compact and high-output light source can be constructed.
Further, when used in a light emitting diode printer or a light emitting diode reading device, there are many advantages such as being able to construct a compact and high speed device.

[Brief explanation of the drawing]

Figure 1 a and b are LEDs made by conventional dicing.
A plan view of the dot array and a cross-sectional view taken along the X-X line,
Figures 2a, b, and c show one embodiment of the present invention; Figure 2a is a partial plan view for explaining dicing; Figure 2b is a partial perspective view of an LED dot array; Figure 2b is a partial perspective view of an LED dot array; 2c is a sectional view taken along line XX in FIG. 2b, and FIG. 3 is a schematic plan view showing another embodiment of the present invention. In the figure, 1, 1a, and 1b are light emitting parts, 2 is a non-light emitting part, 3 is a dicing groove, 4 is an LED element, 5 is a wire bond, and 6 is an electrode lead.

Claims (1)

[Claims] 1. In a method for manufacturing a high-brightness light emitting diode dot array using a PN epitaxially grown substrate, separation between each column to form a plurality of columns is performed by dicing, while separation between elements in each column is performed. A method for manufacturing a high-brightness light emitting diode dot array, wherein the separation is performed by dicing obliquely to the separating dicing direction between each row so that the rows are optically continuous when viewed at right angles from the longitudinal direction of the rows.