JPH11224063A - Resin molding type display device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the manufacture process and to make the device inexpensive, thin, and small-sized by providing a substrate, light emission bodies constituting pixels on the surface of the substrate, and a transparent resin part which is molded covering each light emission part. SOLUTION: The substrate 1 is made of, for example, a liquid crystal polymer, BT resin, etc., and at a part where the respective light emission part 2 are formed, one through hole 11 is formed for each light emission part 2. Each light emission part 2 has electrode patterns 12 and 13 formed with patterns made of copper, gold, etc., respectively. The light emission part 2 is so constituted that, for example, a red LED chip 21 is connected to the electrode patterns 12 and 13 electrically and a current is applied for light emission. The transparent resin part 3 is made of epoxy resin or the like which is transparent to the light emitted by the light emission part 2 and molded by transfer molding in the shape of segments covering the light emission part 2 on the substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin mold type display device using a semiconductor light emitting element chip such as a numeric display, a dot matrix display, and a character display used for a display unit such as a measuring instrument and a pachinko machine. . More specifically, the present invention relates to a resin-molded display device that is easy to manufacture and that can be reduced in size and thickness.

[0002]

2. Description of the Related Art A conventional semiconductor light emitting element chip (hereinafter referred to as L
A display such as a 7-segment (numerical display) using an ED chip) has a structure as shown in FIGS. 4 (a) and 4 (b) with a schematic perspective view and a sectional view of one segment portion. ing. That is, for example, 7
A case 56 in which an LED chip 52 constituting a light-emitting portion of each segment is connected to both electrodes 53 and 54 of each segment by a die bonding material and a wire 55 (not shown), and the periphery thereof has a light shielding wall for partitioning each segment. Surrounded by a transparent resin 5
7 is filled. The electrodes 53 and 54 of each segment are led out to the end of the substrate 51 by wiring (not shown) provided on the substrate 51, and the terminal electrodes 60 are collectively provided at the end. That is, a light emitting portion constituting each segment is formed by an LED chip on an insulating substrate, and a case having a light shielding wall is covered on the substrate surface so as to partition each light emitting portion, and each light emitting portion surrounded by the light shielding wall is covered by the light emitting portion. Only the portion is filled with the transparent resin.

Although not shown, a light emitting portion of each segment is formed on the substrate, and the partition of each segment is formed while covering the back surface of the substrate with a white resin, and the surface other than the light emitting portion is blackened. In addition, there is also a structure in which leads of each light emitting unit are extended on the back surface side of the substrate.

[0004]

SUMMARY OF THE INVENTION These conventional LEDs
In a display device that displays numbers and the like using a chip, as described above, pixels such as each segment are divided by a light-shielding wall and a transparent resin is filled therein, so that the thickness of the light-shielding wall is increased. I have to provide some pod width,
There is a limit to the thinness, and the interval between segments is large, so that delicate display cannot be performed. Therefore, there is a problem that there is a limit in downsizing, and that the number of manufacturing steps is increased and the cost cannot be sufficiently reduced.

On the other hand, in the case of a single semiconductor light emitting device, a chip type light emitting device having a structure in which a peripheral wall is not covered with a light shielding wall is formed in a small size. If this structure is applied to a display such as a seven-segment display, as shown in FIG. 3, each segment is connected by a runner 58 to form a transparent resin portion 57 of each segment. The transparent resin portions 57 constituting the segments are connected by the runners 58. For this reason, light leakage occurs between adjacent segments, and a problem occurs in that a segment that is not turned on is lit thinly, and a light emitting unit that constitutes a segment on a substrate such as a single light emitting unit chip-type light emitting element. Cannot be formed in a resin-molded display device in which each is directly covered with a transparent resin.

The present invention has been made in order to solve such a problem. By directly covering each light emitting portion with a transparent resin, the manufacturing process can be simplified and
It is an object of the present invention to provide an inexpensive resin-molded display device that can achieve a reduction in thickness and size, and a method for manufacturing the same.

[0007]

According to the present invention, there is provided a resin-molded display device comprising: a substrate; a plurality of light-emitting portions provided to form pixels on the surface of the substrate; and each light-emitting portion of the plurality of light-emitting portions. The light emitting section is covered for each section, and the transparent resin section is formed by molding.

[0008] Here, a pixel means one element that can form a part of a number, a character, or a picture, such as each segment forming a 7 segment or each dot forming a dot matrix display.

With this configuration, each pixel is separately formed directly by resin molding without covering the case having the reflecting wall on the substrate, so that a very thin and small display device can be obtained. can get.

The opaque resin is filled in the gaps between the transparent resin portions of the respective light emitting portions, so that the display portion and the background have flat surfaces in the same manner as a conventional light shielding wall is provided between each segment. A thin display device with excellent contrast can be formed.

A resin-filled through-hole for forming the transparent resin portion is provided for each light-emitting portion of the substrate, so that resin is injected from the back surface of the substrate to form a transparent resin portion for each light-emitting portion. It is convenient to form.

The method of manufacturing the resin-molded display device according to the present invention comprises the steps of: (a) forming, on a substrate, an electrode pattern for forming a light emitting portion constituting each pixel, a wiring pattern connected to the electrode pattern, and each light emitting portion; A through hole is provided for each
(B) a light-emitting element chip is mounted on each of the light-emitting portions to be electrically connected to an electrode pattern; and (c) the substrate is placed in a molding die having a cavity formed on each of the light-emitting portions. Connecting the gate of the mold to the through hole on the back surface side of the substrate, and injecting resin.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a resin mold type display device of the present invention will be described with reference to the drawings.

The resin-molded display device of the present invention is shown in FIG.
As shown in (a) and (b) in a perspective view of a seven-segment display according to one embodiment and an enlarged view of a part of the segment, a pixel (each of seven segments) is formed on the surface of the substrate 1. A plurality of light-emitting portions 2 provided to form a segment), and a transparent resin portion 3 formed by molding for each light-emitting portion 2 of the plurality of light-emitting portions.

The substrate 1 is made of, for example, a liquid crystal polymer or BT.
It is made of resin, glass epoxy resin, or the like, and at least one through hole 11 is formed for each light emitting unit 2 in a portion where each light emitting unit 2 is formed. And
Where the light emitting portions 2 are formed, the electrode patterns 12, 1
3 are each formed by a pattern made of copper, gold, or the like. The electrode patterns 12 and 13 are provided on the surface of the substrate 1 or, for example, through the inside of the through hole 11.
Is drawn out to the end of the substrate by a wiring pattern (not shown) formed in the same manner as the electrode pattern on the back surface of the substrate 1.
The terminal electrode 15 is formed at the end of the. Since the wiring pattern is formed on the back surface of the substrate 1 through the above-described through hole 11, the wiring pattern can be formed without being affected by the arrangement of the segments on the front surface. And the display device is excellent in display quality.

The light emitting section 2 is die-bonded so that, for example, a red LED chip 21 has one electrode connected to the electrode pattern 12, and the other electrode is electrically connected to the electrode pattern 13 by a wire 22 such as a gold wire. It is formed so as to be connected and emit light when a current is applied.

The transparent resin portion 3 is made of an epoxy resin or the like which is transparent to the light emitted from the light emitting portion 2, and is formed on the substrate by molding such as transfer molding.
Is formed in the shape of a segment so as to cover. As a result, the light emitted from the light emitting portion 2 in the transparent resin portion 3 spreads over the entire transparent resin portion 3, emits light over the entire transparent resin portion 3 of the segment, and shines as a segment in that shape. Since the transparent resin portion 3 needs to cover the light emitting portion 2, the height of the light emitting portion 2 (dimension from the surface of the substrate 1 to the upper end portion where the wire is stretched) is slightly higher than about 0.5 mm, and is 0.5 mm. It is formed at a height of about 7 to 2 mm. In order to form the transparent resin portion 3 having this shape, as described later, the substrate 1 is placed on a lower mold in which a gate connected to the through hole 11 on the back surface of the substrate 1 is formed. By covering the upper part of the substrate 1 with the upper mold having the cavity formed therein and pouring the resin, an arrow A shown in FIG.
As shown in the figure, the resin flows from below the through hole 11 of the substrate 1 to form the transparent resin portion 3 along the shape of the upper mold.

In order to manufacture this resin-molded display device, the substrate 1 is punched by a punching die, so that the through-hole 16 in the portion where the terminal electrode 15 is to be formed and the through-hole 11 to be formed in the light emitting section 2 are simultaneously formed. Form. Then, a film of copper or the like is formed on the entire surface by vapor deposition or the like, masking of a photoresist or the like is performed, and etching is performed to form the electrode patterns 12 and 13, a wiring pattern (not shown), and the terminal electrode 15. At this time, the metal pattern is left in the through hole 16 at the terminal electrode 15 and is connected to a terminal (rear surface) electrode (not shown) provided on the back surface of the substrate 1 so as to be mounted on the circuit board. Surface soldering that can be directly soldered. At this time, when a wiring pattern is formed on the back surface of the substrate 1, the pattern is also formed in the through hole 11 at the same time. Then, a copper film or the like is similarly formed on the back surface of the substrate, and a back electrode and, if necessary, a wiring pattern are formed on the back surface of the substrate 1.

Next, an LED chip 21 is die-bonded on the electrode pattern 12 of each light emitting portion 2 by a conductive adhesive to electrically connect one electrode to the electrode pattern.
The light emitting unit 2 is formed by electrically connecting the other electrode to another electrode pattern 13 by the wire 22.

Next, an upper mold in which a hollow portion corresponding to the segment shape of the light emitting portion of each segment is formed,
A transparent epoxy resin is injected into a molding die composed of a lower die having a gate formed so that a resin injection portion is located at the through hole 11 on the back side of the substrate. Then, by curing the resin, as shown in FIG. 1, the transparent resin portion 3 constituting each segment is formed. Thereafter, the resin adhering to the gate portion on the back surface of the substrate is removed, so that the back surface is flat and the terminal electrode 15 is formed at the end of the back surface, and each segment is not connected by the resin portion. And a resin-molded display device of a surface mount type in which no leakage occurs.

According to the present invention, since the transparent resin portion directly covered with the transparent resin is formed for each light emitting portion constituting the segment provided on the substrate, a cover provided with a light shielding wall or the like is covered. No need. Therefore, in the conventional structure using the case having the light shielding wall, the height of the substrate surface is limited to about 5 mm, but it can be formed with a height of about 1 mm, and can be made extremely low. And the spacing between segments can be reduced,
A thin and small display device can be obtained. On the other hand, since the transparent resin portion of each segment is formed by injecting resin from the back surface of the substrate, it is formed independently on the light emitting portion side, and light leaks between the segments to perform display. It does not blur. As a result, only a thick and large display device in which the transparent resin of the segment portion was poured into the cover having the light-shielding wall could be configured, but only the segment portion on the substrate surface is covered with the transparent resin portion. A very thin and small resin-molded display device can be realized.

In the above-described example, the transparent resin portion constituting each segment is simply formed on the surface of the substrate on the surface of the substrate. However, the space between the transparent resin portions 3 is further filled with a resin that does not transmit light. By doing so, it is possible to form a light-shielding wall similar to a case having a conventional reflecting wall. Even in this case, the gap shown in FIG. 1 is formed by filling the gap with the opaque resin only by closing the surface of the transparent resin portion 3 with a mold and pouring the resin. There is no change, and a very thin and small resin-molded display device can be obtained.

In the above-described example, the 7-segment is used. However, the present invention is not limited to the 7-segment. In other display devices such as a dot matrix display, a through-hole is directly formed for each pixel from the back surface of the substrate. A thin resin-molded display device can be formed by filling the resin through the resin. FIG. 2 is a perspective view showing an example in which a dot matrix display device is formed by the resin mold of the present invention. In FIG. 2, the light emitting unit is not shown, but FIG.
Each electrode of the LED chip is formed by being connected to an electrode pattern in the same manner as shown in FIG. In addition,
1 are given the same reference numerals. In this case, since the number of pixels (dots) is particularly large, by forming a wiring pattern on the back surface of the substrate, it is not necessary to increase the distance between dots due to wiring, and a dot matrix having a narrow display quality between dots is excellent. A display device is obtained.

[0024]

According to the present invention, an inexpensive display device having a small number of parts, a simple assembly, and a small number of assembling steps can be obtained since a case having a light shielding wall is not required.
Also, the surface of the substrate can be formed very thin,
A thin display device capable of surface mounting is obtained.

Further, since the transparent resin portions constituting each pixel can be formed independently of each other, it is possible to freely form a lens shape such as having directivity according to the pixel, and to apply the display device. The range can be expanded.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of one embodiment of a resin mold type display device of the present invention.

FIG. 2 is an explanatory view of another embodiment of the resin mold type display device of the present invention.

FIG. 3 is a diagram illustrating a problem when a display device is formed by a resin mold type.

FIG. 4 is an explanatory diagram of a configuration of a conventional 7-segment display.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Light emitting part 3 Transparent resin part 11 Through hole 21 LED chip

Claims (4)

[Claims] 1. A substrate, a plurality of light-emitting portions provided to form pixels on the surface of the substrate, and each light-emitting portion of the plurality of light-emitting portions is covered with the light-emitting portion and formed by molding. And a transparent resin portion. 2. The resin-molded display device according to claim 1, wherein an opaque resin is filled in a gap between the transparent resin portions of each of said light emitting portions. 3. The resin-molded display device according to claim 1, wherein a through hole for filling the resin for forming the transparent resin portion is provided for each light emitting portion of the substrate. And (a) providing, on a substrate, an electrode pattern for forming a light emitting portion constituting each pixel, a wiring pattern connected to the electrode pattern, and a through hole for each light emitting portion. A) mounting a light emitting element chip on each of the light emitting portions and electrically connecting to the electrode pattern;
(C) The substrate is placed in a mold for molding having a cavity formed on each of the light-emitting portions, and a resin is injected by connecting a gate of the mold to the back surface of the substrate in the through hole. A method for manufacturing a resin-molded display device, comprising: