JPH0244311Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to the improvement of a dot matrix light-emitting display, and particularly to a structure in which a mask substrate is provided above the display substrate to improve the visibility of the light-emitting display. The present invention relates to a dot matrix light-emitting display.

Prior Art A mask substrate with through holes corresponding to the light emitting parts is provided on the upper surface of a dot matrix light emitting display to prevent leakage of the luminous flux of the light emitting parts and increase the luminous flux density. The idea of improving the visibility of a light-emitting display by increasing its diameter has existed for some time.

However, this type of light-emitting display body, which has been known in the past, is formed using a so-called solid-state lamp in which the light-emitting part is formed by encapsulating a semiconductor chip (LED chip) that is encapsulated in advance with a thermosetting resin. It was hot.

Problems to be Solved by the Invention The present invention embodies the above idea and uses a light-emitting display body whose manufacturing process is simplified compared to the case of the solid-state lamp, that is, a light-emitting part is formed directly with a semiconductor chip. As with the case of solid-state lamps, a new structure for improving visibility is provided for light-emitting displays as well, but the background to the establishment of this invention is as follows. .

(1) A mask substrate is bonded to the top surface of a light-emitting display substrate whose light-emitting portion is formed from light-emitting elements such as LED chips, and a translucent thermosetting resin is directly filled into the through holes of the mask substrate. When the light-emitting portion is sealed in such a manner, the shrinkage force generated during thermosetting of the sealing resin affects the mask substrate, causing warping and distortion, which is a major factor in the failure of the display substrate.

In addition, in order to increase the apparent diameter of the light emitting part, the thickness of the mask substrate must be increased, and the greater the thickness, the more the shrinkage force generated in the sealing resin during heat curing will be applied to the mask substrate. The degree of influence increases, causing further warping, distortion, etc., and causing the display substrate to become defective.

Furthermore, this is further amplified as the area of the mask substrate becomes larger.

(2) For the purpose of airtightness and protection of the light-emitting elements of a light-emitting display substrate whose light-emitting parts are formed from light-emitting elements such as LED chips, a liquid translucent thermosetting resin is applied to the top surface of this substrate. When a film is formed over one surface, liquid leakage occurs during the film formation, resulting in poor workability.

Means for Solving the Problems The present invention was developed in view of the above circumstances, and has the following features.

That is, there is a display substrate in which light emitting parts formed by providing light emitting elements such as light emitting diodes are arranged in a matrix, and a display board provided on the upper surface of this display substrate and corresponding to the light emitting parts of the display substrate. A dot matrix light-emitting display comprising a three-layer structure of an insulating plate having through holes and a mask substrate having through holes corresponding to the through holes of the insulating plate, Each of them is filled with a thermosetting translucent resin to seal the light emitting portion, and the insulating plate and the mask substrate are fixed in a non-adhesive state.

Embodiment of the invention An embodiment of the invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an exploded perspective view of a display substrate, an insulating plate, and a mask substrate that constitute the present invention.

In the figure, 1 is a display substrate, 2 is a light emitting part thereof, 3 is a mask substrate, and 4 is an insulating plate.

The display substrate 1 has conductive patterns of an upper electrode 22 and a lower electrode 24 formed by etching copper foil provided on the upper and lower surfaces of a copper-clad laminate, etc., and a light emitting diode is formed at the overlapping part. The light emitting section 2 is formed by providing light emitting elements such as the above.

The light-emitting parts 2 are scattered in a matrix on the upper surface of the display substrate 1, and the details will be described in the second section.
As shown in the figure.

That is, to explain the structure of the light emitting part 2 with reference to FIG. 2, insulating parts 23 are formed on the upper electrode 22 at predetermined intervals, and the semiconductor chips 2a are placed in the center of the insulating parts 23 using silver paste or the like. A cross-shaped conductive part 21 is attached to the cross-shaped conductive part 21, and a through hole 7 is provided in the center of the cross-shaped conductive part 21, which is connected to a lower electrode 24 provided on the lower side of the insulating plate 10. (See Figure 3). Note that 22a is the insulating part 2
The bonding wires 8, 8 led out from the upper part of the semiconductor chips 2a, 2a are connected to this conductive plating part 22a, and are connected to the upper electrode 2.
The structure is connected to 2.

FIG. 3 shows the longitudinal cross-sectional structure of the light emitting part of the matrix substrate of the present invention.

An insulating plate 4 having through holes 41 is integrally bonded to the upper surface of the display substrate 1, and each through hole 41
is filled with a translucent thermosetting resin 5 to seal the light emitting part 2.

Here, in the present invention, liquid epoxy resin is generally employed as the translucent thermosetting resin 5 sealed in each of the through holes of the insulating plate 4 because of its good workability. In addition, the insulating plate 4 prevents leakage when filling the liquid thermosetting resin 5 into the light emitting part 2 and improves work efficiency, and also seals each light emitting part 2 individually. It is used to alleviate warpage and distortion of the light-emitting display body caused by the difference in thermal expansion that occurs when the light-emitting elements are collectively sealed with synthetic resin.

The mask substrate 3 is fixed to the upper surface of the insulating plate 4 in a non-adhesive state so that its through hole 31 is aligned with the through hole 41 formed in the insulating plate 4. The through hole 4 of the insulating plate 4 is used to seal the
The thermosetting resin 5 filled with the thermosetting resin 1 alleviates the shrinkage force generated during thermosetting.

Such a fixing means may include, for example, providing a protrusion (not shown) on the lower surface of the mask substrate 3 and fitting this protrusion into a hole (not shown) provided in the insulating plate 4 and the display substrate 1. This is made possible by

The mask substrate 3 has through holes 31 when the light emitting section 2 is turned on.
In order to make the outline of the light-emitting part 2 clear, it is desirable to apply a light-absorbing color such as black to the surface, but in order to increase the reflection efficiency of the light-emitting part 2, the inner peripheral surface of the through-hole 31 should be painted with white, silver, etc. Paints with high light reflectance are preferably applied.

Further, it is preferable that the through hole 31 provided in the mask substrate 3 be shaped into a so-called mortar shape, in which the upper opening is larger than the lower opening, in order to increase the viewing angle. Photoresin 6
It is desirable to mix a light diffusing agent (regardless of whether it is thermosetting or thermoplastic) to improve the light scattering properties of the light emitting part 2.

Further, the thickness d of the mask substrate 3 is desirably about 0.5 to 1.5 times the opening diameter r of the through hole 31, considering the viewing angle of the display and the degree of light absorption, and the inclination angle φ of the through hole 31 is Considering the clarity of the outline of the light emitting part 2 and the viewing angle, it is appropriate to set the angle between 75 degrees and 85 degrees.

Further, titanium, glass beads (fine powder), etc. are suitable as the light diffusing agent mixed into the transparent resin 6 filled in the through holes 31 of the mask substrate 3, and the total light transmittance is 70~ Diffusion rate 20 for 90%
~50% is desirable.

The transparent resin 6 filled in the through holes 31 of the mask substrate 3 may have a convex or concave upper surface as shown in FIGS. As shown above, instead of filling with resin, a translucent resin plate 6'
may be inserted.

Further, in the above embodiment, an example was explained in which the display substrate 1 corresponds to one mask substrate 3 to constitute a dot matrix light emitting display (8×8 dots), but the present invention The present invention is not limited to this example, and a dot matrix substrate may be constructed by making a plurality of display substrates (the light emitting parts do not necessarily have to be arranged in a matrix) correspond to one mask substrate.

Furthermore, FIG. 7 shows another example of the display substrate according to the present invention, in which the display substrate provided with the light emitting section 2 is separated into individual segments 1', and the manufacturing process is easy. Sometimes, these segment bodies 1' are joined together on the upper surface of an insulating substrate 11 on which a conductive pattern 11a is formed to form one dot matrix light emitting display substrate.

FIG. 8 shows an enlarged longitudinal cross-sectional structure of the light emitting section when the present invention is constructed using such a display substrate. As shown in the figure, the conductive part 21 provided with the light emitting element 2a of the light emitting part 2 of the segment body 1' is attached to the insulating substrate 11 by silver paste 7' via a plating layer 71 formed on the inner surface of the through hole 7. It is connected and attached to the conductive pattern 11a on the upper surface.

On the other hand, the mask substrate 3 is fixed to the upper surface of the insulating plate 4 in a non-adhesive state, and its through holes 31 are filled with a light-transmitting resin 6 mixed with a light diffusing agent, as in the above-described embodiment. ing.

Effects of the invention According to the invention, a light-emitting display body in which a light-emitting part is directly formed using a small semiconductor chip can be made to have improved visibility, warping distortion, and workability, and the following unique effects are achieved. Ru.

(1) It has a three-layer structure in which a thermosetting resin is filled through the hole in the insulating plate bonded to the top surface of the display substrate, and a mask substrate is placed on top of it. It is possible to prevent luminous flux leakage, increase luminous flux density, and increase the apparent diameter of the light emitting part.

(2) Since the insulating plate bonded to the top surface of the display substrate and the mask substrate are fixed in a non-contact state, shrinkage force is generated when the thermosetting resin sealing the light emitting part is thermoset. However, this shrinkage force does not affect the mask substrate, and warpage, distortion, etc. are less likely to occur. Further, for this reason, the thickness and area of the mask substrate can be freely designed, and the apparent diameter of the light emitting portion can be increased to obtain a large-sized display.

(3) On the top surface of the display substrate, an insulating plate is provided with through holes corresponding to the light emitting parts, so when the light emitting parts are sealed by filling liquid thermosetting resin through the through holes. In addition, it is possible to prevent the liquid thermosetting resin from leaking from the display substrate, thus improving workability.

(4) Because the light-emitting part is formed by directly installing a light-emitting element such as a light-emitting diode, equipment and work are required less than in the case of solid-state lamps, where only the solid-state lamp must be formed in a separate process. Cost reduction can be achieved through simplification.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention;
Fig. 2 is an enlarged view of a light emitting part provided on the display substrate, Fig. 3 is an enlarged longitudinal cross-sectional view of the light emitting part, and Figs. 4 to 6 are enlarged longitudinal cross-sectional views of the light emitting part in other examples. , FIG. 7 shows another example of the display substrate, and FIG. 8 shows an enlarged vertical cross-sectional view of the light emitting part when a light emitting display is constructed using the display substrate shown in FIG. 7. Explanation of symbols: In the figure, 1 and 1' are the display substrate, 2 is the light emitting part, 3 is the mask substrate, 31 is the through hole, 4 is the insulating plate, and 5 is the transparent heat sealing part of the light emitting part. The curable resin 6 indicates a translucent resin filled in the through holes of the mask substrate.

Claims (1)

[Claims for Utility Model Registration] A display substrate in which light-emitting parts formed by providing light-emitting elements such as light-emitting diodes are arranged in a matrix, and a display substrate provided on the upper surface of the display substrate. A dot matrix light-emitting display formed in a three-layer structure of an insulating plate having through-holes corresponding to the light-emitting parts of the insulating plate and a mask substrate having through-holes corresponding to the through-holes of the insulating plate, Each of the through holes of the insulating plate is filled with a thermosetting translucent resin to seal the light emitting part, and the insulating plate and the mask substrate are fixed in a non-adhesive state. A dot matrix light-emitting display.