JPS5941190B2 - Manufacturing method of solid state display device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a solid-state display device.

In recent years, devices have been proposed that display images, etc. by arranging a large number of light emitting diodes in rows and columns on a substrate, but the biggest problem in manufacturing such devices is how to arrange a large number of light emitting diodes in an orderly and orderly manner. It is difficult to do so. The present invention has been made in view of the above points, and will be described in detail below in Examples.

FIG. 1 shows the first step, in which column electrodes 2, 2, .
is formed.

A silicon crystal plate having an oxide film on the surface is suitable as the auxiliary substrate 1, but other ceramic plates can also be used.
FIG. 2 shows the second step, in which a green light emitting diode pellet 4 made of gallium phosphide crystal is prepared.

The pellet has a PN junction surface 5 parallel to both its front and main surfaces, and is further provided with back electrodes (i.e., P-side ohmic electrodes) 6, 6, arranged in rows and columns on its back main surface. It has a window T corresponding to each of the back electrodes 6 on its main surface, and includes front electrodes (i.e., N-side ohmic electrodes) 8, 8, . . . that are continuous in the row direction of the matrix arrangement. . FIG. 3 shows the third step, in which grooves 9 and 10 are carved in the row and column directions from the back main surface of the pellet 4, and the PN junctions under each of the back electrodes are separated.

FIG. 4 shows the fourth step, in which the back surface of the pellet 4 is fixed onto the auxiliary substrate 1.

At this time, the back electrodes 6 belonging to the same group are arranged to be aligned with the corresponding column electrodes 2 of the auxiliary substrate 1, and the corresponding back electrodes 6 and column electrodes 2 are fixed with a conductive adhesive, and If necessary, the other main surfaces on the back side of the pellet and the surface of the auxiliary substrate 1 are firmly fixed with a suitable insulating adhesive. FIG. 5 shows the fifth step, in which cuts 11 are provided that correspond to and reach the grooves 9, 9, . . . in the row direction from the main surface of the pellet 4, and the pellets 4 are separated.

The above-mentioned cuts in this step are usually performed by a dicing method, but since grooves 9, 9, etc. of an appropriate depth are previously cut from the back main surface side of the pellet 4,
The above-mentioned cutting operation can be easily performed without damaging the pellet 4. FIG. 6 shows the final step, in which a plurality of the above-mentioned auxiliary substrates 1 are juxtaposed and fixed on an insulating main substrate 15 formed separately, and then each of the column electrodes 2 of each auxiliary substrate and the main substrate 1 are fixed.
between each of the external column terminals 16 provided on the main substrate 15, and between each of the surface electrodes 8 of the left pellet and each of the common row terminals 17 provided on the main substrate 15; The surface electrodes 8 are connected to each other by thin metal wires 18, respectively. In the above device, when a forward voltage is selectively applied to each of the external column terminals 16 and row terminals 17, green light emission occurs at the PN junction at the intersection of the selected row and column electrodes, and such light emission occurs directly above. is taken out upward through the electrode window 7 of
For example, a two-digit character is displayed by the two pellets 4,4.

At this time, the green light in the gallium phosphide crystal has a wavelength smaller than the interband energy of the crystal, so it is relatively easily attenuated within the crystal. Since the optical path length is larger, the attenuation is large and the amount of light emitted from other electrode windows can be ignored. In the above embodiment, the relationship between rows and columns may be reversed, and it goes without saying that the front electrodes 8 may initially have a shape in which all rows are continuous.

As is clear from the above description, according to the present invention, the pellet is substantially separated into individual light emitting diodes while being fixed on the auxiliary substrate, and when the pellet is separated, predetermined grooves are carved in the back main surface of the pellet in advance. Since a cut is made corresponding to the groove from the main surface of the pellet, a large number of light emitting diodes can be easily and regularly arranged on the auxiliary substrate, and the display quality can be improved. Furthermore, since the surface electrodes are common to each row (or column), wiring work using thin metal wires is also simplified, and furthermore, the auxiliary substrate having pellets as described above can be placed side by side on the main substrate. Therefore, it is possible to easily increase the size of the device.

[Brief explanation of the drawing]

FIGS. 1 to 6 are perspective views showing steps of an embodiment of the present invention.

Claims (1)

[Claims] 1. A process of forming a light emitting diode pellet that has parallel PN junctions on both the front and back main surfaces and emits light of a wavelength smaller than the interband energy of the semiconductor crystal, and a back electrode arranged in a matrix on the back main surface of the pellet. In addition, a front electrode having a window corresponding to each of the back electrodes on the front main surface and continuous at least in the row (or column) direction of the matrix arrangement is provided, and further grooves extending from the back main surface in the row and column directions are provided. a step of carving and separating the PN junctions under each of the back electrodes; a step of providing wiring electrodes extending in the column (or row) direction of the matrix arrangement on the auxiliary substrate;
A step of aligning and fixing the back electrodes belonging to the same column (or row) to the wiring electrodes in the corresponding column (or row) of the substrate, from the main surface of the pellet fixed on the substrate to the row (or column) A method for manufacturing a solid-state display device, comprising the steps of: providing a cut corresponding to and reaching the groove in the direction; and fixing a plurality of the above-mentioned auxiliary substrates side by side on the main substrate.