JPH0519705A - Light emission display body and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide the light emission body which is highly reliable and sufficiently withstands outdoor use by radiating the heat that an LED chip generates effectively into the outside air, improving the display contrast, and absorbing and reducing thermal stress. CONSTITUTION:Many LED chips 2 which perform spot lighting are arranged on a discoid display body substrate 1 and a film formed body which has projection parts 7a projecting in a temple bell shape to the front side corresponding to the LED chips 2 is superposed; and a rubber elastic body is filled in the respective projection parts 7a to constitute light emission dots 3 wherein the LED chips are sealed hermetically. The film formed body 7 has the concave lens type projection parts 7a molded by vacuum forming corresponding to the respective LED chips 2 by using a transparent synthetic resin film having superior light transmissivity and flat surfaces 7d between projection root parts 7c where the projection parts 7a are raised and the respective projection parts 7a are formed into light nonreflective surfaces 7a colored in black by printing, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting display constructed by using a light emitting element such as an LED chip which emits light in a point manner and a method for manufacturing the same.

[0002]

2. Description of the Related Art Among light-emitting displays, for example, as shown in FIG. 9, one in which an LED lamp 100 which emits light is inserted into a display substrate 101 and arranged and wired, is known.
It is housed in a case 102 having an opening on the front side, and the inclined rear end surface is attached to an outdoor wall surface or the like for use. As shown in FIG. 10, the LED lamp 100 is formed by sealing an LED chip 103 that emits point light with a transparent resin 104, and has a spherical tip formed to serve as a circular convex lens. The directional characteristics are sharpened by converging the light of the LED chip 103. Then, in order to enhance the display contrast when the LED chip 100 is turned on and off, for example, a black sealant 10 is provided between the LED lamps 100 attached to the display substrate 100.
5 is filled or a black mask plate (not shown) or the like is inserted.

[0003]

However, in the light-emitting display body shown in FIG. 9, most of the LED lamps 100 are filled with the sealant 105 filled therein, and therefore, contact with the outside air occurs. Each LED doing
The surface area of the lamp 100 is extremely small due to normal use. Therefore, the heat generated when each LED lamp 100 is turned on does not escape to the outside air, and
There is a problem that the D lamp 100 becomes high in temperature and may be destroyed in some cases.

Further, even when a mask plate is inserted between the LED lamps 100, the LED lamps 100 are in contact with the outside air.
The surface area of was reduced, which hindered the heat dissipation.

[0005]

In order to solve the above-mentioned problems, the light-emitting display body of the present invention has a projection base of each protrusion of a film molded body in which a large number of convex lens-shaped protrusions are molded, and a flatness between the protrusions. Each of the surfaces is a light non-reflective surface, and a large number of LED chips arranged on the surface of the display substrate are sealed with rubber elastic bodies corresponding to the respective protrusions.

The method for manufacturing a light emitting display body of the present invention is
A large number of LED chips are arranged on the display substrate, and a part of the film is formed in which the convex lens-like protrusions are to be formed in correspondence with the positions of the LED chips. Selective black coating is applied to the flat film surface beforehand by screen printing to form a non-reflecting surface on the film surface, and then the projected part to be formed is formed on each projecting part by vacuum forming, etc. To form a film molded body, and the protrusions of the film molded body are arranged downward to supply uncured rubber elastic resin liquid into the respective protrusions, and then the uncured rubber elastic resin liquid After immersing each corresponding LED chip with the LED chip mounting surface side of the display substrate facing downward, the uncured rubber elastic resin liquid is cured to put each LED chip through the rubber elastic body. Correspond That wherein the sealing to each protrusion.

[0007]

In the light-emitting display unit having the above structure, the light emitted from each LED chip is refracted in the convex lens-shaped protrusion filled with the rubber elastic body and is condensed and emitted to the front side, and the light is scattered around. It becomes difficult, the brightness at the position of the practical field of view is improved, and the visibility is improved. In addition, since the protrusion bases of the protrusions and the flat surface between the protrusions are non-light-reflecting surfaces, the display contrast at the time of lighting and at the time of extinguishing is good even when the surroundings are arranged in a bright place. . In addition, since each LED chip is sealed in the convex lens-shaped protrusion of the film molded body through the rubber elastic body, heat generated when each LED chip is turned on is outside air from the entire surface of the convex lens-shaped protrusion. Diverged inside. Therefore, the temperature of the protrusion does not rise and the life of the LED chip is extended. Further, the rubber elastic body absorbs and relaxes the thermal stress caused by the temperature change caused by turning on / off the LED chip, and the display body itself is prevented from being distorted or warped, so that the light emitting display body has improved reliability.

Further, the above-mentioned method for manufacturing a light-emitting display is carried out by screen-printing or the like so that the entire surface including a part of a projected portion forming portion on the flat film surface is made into a black light non-reflection surface in advance. By selectively printing a non-light-reflecting surface on the film surface, and then forming these projecting portions to be formed into convex lens-shaped projecting portions by vacuum forming, the rise of each projecting portion It is possible to easily form a film molded body in which the protruding base portion and the flat surface between the protruding portions are non-reflecting surfaces. Then, uncured rubber elastic resin liquid is injected into each protrusion of the film molded body, and each LED chip disposed on the display substrate is dipped in the uncured rubber elastic resin liquid in the corresponding protrusion. The display substrate and the film molded body can be easily joined and integrated by simply heating and curing afterwards, and each LED chip is hermetically sealed in each projection of the film molded body via the rubber elastic body, and efficiently emits light. A display body can be manufactured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a light emitting display according to an embodiment of the present invention, and FIG. 2 is a schematic sectional view taken along line AA of FIG.

In the light emitting display body of this embodiment, a large number of LED chips 2 for point emission are arranged concentrically on a disc-shaped display body substrate 1, and a bell is provided on the front side corresponding to each LED chip 2. Forming the light emitting element portion 3 protruding in a
It is housed and arranged in a case 9 having an open front.

The display substrate 1 has a conductive pattern 4a (eg, cathode side) formed on its surface by means such as etching a copper-clad laminate having a glass epoxy resin or paper phenol as a base material. In addition, a conductive pattern 4b (for example, the anode side) is formed on the back surface, and the conductive pattern 4b on the back surface is led out to the front surface through the through holes 5 corresponding to each LED chip 2. Then, each LED chip 2 is die-bonded to the conductive pattern 4a and connected to the conductive pattern 4b on the surface of the display substrate 1 by the bonding wire 6 to form a lighting circuit.

In this case, each LED chip 2 is, for example,
By arranging chips with different emission colors such as red emission and green emission in combination, a circuit capable of selectively (or simultaneously) turning on / off each emission color is configured.

Each LED arranged on the display substrate 1
Each light emitting element portion 3 formed corresponding to the chip 2
Is a bell-shaped convex lens-like protruding portion 7a of a film molded body 7 integrally joined to the display substrate 1 filled with a cured translucent rubber elastic body 8.
The chip 2 is hermetically sealed in each protrusion 7a by the rubber elastic body 8. In addition, in the embodiment, an example in which one LED chip is arranged in the light emitting element section 3 is shown, but it goes without saying that a plurality of LED chips may be arranged in each light emitting element section 3. Nor.

The film molded body 7 is formed of a synthetic resin film which is transparent and excellent in translucency, for example, a synthetic resin film such as polycarbonate or PET film, by vacuum forming to form the convex lens-like protruding portions 7a corresponding to the respective LED chips 2. The flat surface 7d between the projecting base 7c and each projecting portion 7a, which is the rising edge of the projecting portion 7a, becomes the light non-reflective surface 7b colored in black by screen printing or the like, and the flat surface 7d and the display substrate 1 And are joined together. If the thickness of the film molded body 7 is too thin, the shape retention of the protruding portion 7a deteriorates. On the other hand, if the thickness is too thick, molding is difficult and the light emitted from the light emitting element portions 3 ineffective in the lateral direction. Since it tends to occur, it is preferable to set the thickness to about 0.1 to 0.3 mm. In addition, the protruding base portion 7 rising from the flat surface 7d
The relationship between the height h of c and the height H to the top of the protruding portion 7a is H / 2 ≦ h ≦ 2H / 3, because the balance between the light emission efficiency and the display contrast improving effect is good. It is more effective and more preferable.

As the rubber elastic body 8 which is filled and hardened in the respective projecting portions 7a formed corresponding to the respective LED chips 2,
For example, transparent silicone rubber or the like having transparency is preferably used. This rubber elastic body 8 is used for each LED chip 2
The LED chip 2 is sealed and absorbs heat stress generated due to heat generation when each LED chip 2 is turned on or a change in ambient temperature to prevent warpage or distortion of the display substrate 1 caused by a temperature change. It is intended to prevent the disconnection of 6 and the like.

The case 9 is substantially the same as the conventional case shown in FIG. 9, in which the upper part of the front surface extends and opens in a canopy shape, and the rear end surface becomes an inclined surface and is used as a wall surface outdoors. The light-emitting display body is configured to face downward when attached.

In the light emitting display body having the above-mentioned structure, since a large number of LED chips are arranged on the display body substrate 1 and sealed by the convex lens-like protruding portion 7a of the film molded body 7 through the rubber elastic body, The entire surface of the protruding portion 7a comes into contact with the outside air, the area for radiating heat to the outside air increases, and the heat when each LED chip 2 is turned on easily escapes from the surface of each protruding portion 7a, so that the heat radiation effect is effective. To work. for that reason,
There is no fear that each LED chip 2 will be exposed to high temperature and will be destroyed. Further, the thermal stress caused by the temperature change due to the turning on / off of each LED chip 2 is absorbed and relaxed by the rubber elastic body 8 filled in each protruding portion 7a, so that the light emitting display body itself is distorted or warped. Is prevented, and the light-emitting display has improved heat reliability.

Further, the light emitted from each LED chip 2 is focused along the substantially center line thereof by the light refraction effect of the rubber elastic body 8 filled in the corresponding convex lens-shaped protruding portion 7a, and is sandwiched. The viewing angle becomes almost linear and uniform and sharp, and the brightness becomes good at the practical viewing position.
Moreover, since the flat surface 7d of the film molded body 7 is the light non-reflective surface 7b colored in black and the projection base portion 7c that is the rising edge of each projection portion 7a is also the light non-reflective surface 7b, the LED chip 2 The display contrast when the light is turned on and off is improved. Therefore, even when the large-sized matrix display body is configured by arranging the light emitting display body as one display pixel on a bright wall surface outdoors, each LED chip 2 can be displayed even when desired characters, symbols, figures, etc. are lit up and displayed. As described above, the light emitted from the light source has uniform and sharp directional characteristics, is bright in a practical visual field position, has a good display contrast, and can be displayed with improved visibility.

The LED chips 2 sealed in the rubber elastic body 8 due to the shape of the protruding portion 7a of the film molded body 7.
Since it is possible to change the directional characteristic of the light emitted by, the shape of the protruding portion 7a can be designed so as to have a desired directional characteristic within a range of the luminance half value angle of ± 50 ° to ± 3 °. In this case, it is particularly practically effective to make the half-value luminance angle a narrow angle of about ± 20 ° to ± 3 °.

The light emitting display having the above structure is manufactured as follows. That is, first, as shown in FIG. 3, a disk-shaped film 10 having a larger plane area than the display substrate 1 is prepared, and the projections 7a are concentrically formed so as to correspond to the LED chips 2.
The planned formation portion 10a of the
As the boundary portion 10b for providing the projection base portion 7c which becomes the light non-reflective surface 7b inside the portion 10a where the a is to be formed, screen printing is performed up to a portion other than the inside of the boundary portion 10b which is the outer shape position of the display body substrate 1. The light non-reflective surface 7b is formed in advance by coloring and printing in black by the above method. As will be described later, since the film 10 is cut and divided at the outer shape position of the display body substrate 1, the light non-reflective surface 7b colored in black is surrounded by the outer shape position of the display body substrate 1 and the periphery thereof. There is no particular problem even if it is formed up to. In this case, the position of the boundary portion 10b is set so that the height h of the protrusion base portion 7c rising from the flat surface 7d and the protrusion portion 7a are taken into consideration in consideration of the elongation of the film 10 when the vacuum forming process described later is performed. The relationship with the height H to the top may be determined so that the film molded body 7 having a position in the range of H / 2 ≦ h ≦ 2H / 3 can be obtained.

The light non-reflective surface 7b is formed by screen printing by coloring it in black except the boundary portion 10b in the projected portion formation planned portion 10a on the surface of the flat film 10, and vacuum-forming the film 10. As shown in FIG. 4, the bell-shaped convex lens-shaped protruding portions 7a are formed at the positions of the projected portions 10a of the respective protruding portions 7a, and at the same time, the film 10 located outside the outer shape of the display substrate 1 is formed. A groove 10c is formed around the. As a result, the convex lens-like protrusion 7a having a transparent front end portion and the protrusion base 7c being a black light non-reflection surface 7b, and the flat surface 7d between the respective projections 7a are black light non-reflection surfaces 7b. The molded body 7 is formed.

On the other hand, the conductive pattern 4 is formed on the display substrate 1.
a and 4b are formed by etching or the like, and the LED chip 2 is die-bonded to a predetermined position of one conductive pattern 4b by a conductive adhesive such as a silver paste so as to be integrally joined, and an LED corresponding to the other conductive pattern 4a is formed. The surface of the chip 2 is wire-bonded to the surface of the chip 2 to form a lighting circuit.

The above-mentioned display substrate 1 and film molded body 7
When the and are prepared, as shown in FIG. 5, the projecting portions 7a of the film molded body 7 are arranged downward, and the uncured rubber elastic resin liquid 8a such as silicone rubber is placed in each of the projecting portions 7a. A little more than that is supplied, and the film molded body 7 and the display substrate 1 are superposed on each other by lowering the display substrate 1 with the side where the LED chips 2 are disposed facing downward. As a result, each L
The ED chip 2 is dipped in the uncured rubber elastic resin liquid 8a supplied to the corresponding protrusion 7a. At this time, L
Excessive rubber elastic resin liquid 8b overflowing from the inside of the protruding portion 7a due to the immersion of the ED chip 2 is stored in a groove 10e provided around the film molded body 7 as shown in FIG. Become. At this time, air bubbles and the like existing through the through holes 5 formed in the vicinity of each LED chip 2 arranged on the display body substrate 1 are extruded to the outside, and the film molded body 7 and the display body substrate 1 are bonded to each other. Become one.

Thereafter, this is placed in a heating furnace or the like to cure the uncured rubber elastic resin liquid 8a. The cured rubber elastic body 8 seals each LED chip 2 in each corresponding protruding portion 7 a of the film molded body 7.

Finally, cutting is carried out along the outer peripheral edge of the display substrate 1 shown by the alternate long and short dash line in FIG. 6 to separate the concave groove 10c in which the hardened surplus rubber elastic body is accumulated, and each projection of the film molded body 7 is cut. Each LED corresponding to the rubber elastic body 8 in the portion 7a
A light emitting display body in which the chip 2 is sealed is manufactured.

In the manufacturing method of the present invention, the display substrate 1 is previously prepared.
A plurality of LED chips 2 arranged in the same direction as the projection base 7c of the convex lens-shaped projection 7a and the flat surface 7d between the projections 7a are the boundary portions 1 on the film 10 serving as the light non-reflective surface 7b.
0b is screen-printed on the flat film surface in advance, and thereafter, by vacuum forming, the light non-reflective surface 7b and the convex lens-like protruding portion 7a can be easily formed. After supplying the uncured rubber elastic resin liquid therein, the display body substrates 1 are superposed and the uncured rubber elastic resin liquid is cured, and each LED chip makes a convex lens through the rubber elastic body 8. It is possible to easily manufacture a light-emitting display body that is hermetically sealed in the protruding portion 7a and has the light non-reflecting surface 7b between the protruding base portion 7c and each protruding portion 7a.

Further, as shown in FIG. 7, as the convex lens-shaped protrusion, a film molded body is formed by molding a convex lens-shaped protrusion 71a having a rod shape corresponding to the row of the LED chips 2 arranged on the display substrate 11. 11, the protrusions 71a are filled with the rubber elastic body 8 to form the light emitting element portion 31.
And the projection base 71c of each convex lens-shaped projection 71a.
Any of the flat surfaces 71d between the projections 71a and the projections 71a may be a light-emitting display body having a light non-reflection surface 71b.

In such a light emitting display, the entire surface of the convex lens-like protruding portion 71a having a rod shape comes into contact with the outside air like the above-mentioned light emitting display, and the contact surface area with the outside air is wide, so that heat radiation to the outside air is possible. The area is increased, the heat dissipation effect becomes more effective, and the destruction of each LED chip 2 due to the temperature rise can be prevented. In addition, each convex lens-shaped protruding portion 71a having each rod shape
The vertical light emitted from each of the LED chips 2 sealed inside is narrowed down, and the practically useful left and right viewing angles are secured. Then, since the protrusion base 71c of each convex lens-shaped protrusion 71a and the flat surface 71d between the protrusions 71a, which are rod-shaped constituting the respective light-emitting element portions 31, are the non-light-reflecting surface 71b, the lighting / lighting is performed. Good display contrast when light is off.

In order to manufacture such a light emitting display, as shown in FIG. 8, a convex lens-shaped protrusion 71a having a rod shape.
11a is formed on the flat surface of the film 11 so that the projection base portion 71c of the projection portion 71a and the respective flat surfaces 71d are black light non-reflective surfaces 71b.
It can be manufactured by the same method as described above after selectively black-painting by screen printing so as to form 1b, and then subjecting this film 11 to vacuum forming to form the protrusion 71a. Needless to say, screen printing of the flat surface of the film 11 and molding of the convex lens-like protrusions 71a may be carried out by a method in which a large number of them are combined into one set.

Further, the shape of the convex lens-like protrusion is not limited to the bell shape or the rod shape as described above, and various design changes can be made such that directivity in the vertical direction or in an appropriate direction can be obtained. In addition, a light diffusing agent or the like can be mixed depending on the case. Further, in the embodiment, an example of a circular light emitting display is shown, but it goes without saying that the shape is not particularly limited, such as a square shape.

[0032]

As is apparent from the above description, the light emitting display body of the present invention can be used in a state where the entire convex lens-shaped projection is in contact with the outside air, and therefore the projection is provided with a rubber elastic body. The heat generated when the sealed LED chips are turned on is radiated to the outside air more efficiently than the entire surface of the protruding portion, and the rubber elastic body prevents thermal stress caused by the temperature change caused by turning on / off the LED chips. Absorption is alleviated, distortion and warpage of the display body itself are prevented, and a light emitting display body with improved reliability is obtained. In addition, the light emitted from each LED chip is refracted in the convex lens-shaped protrusion filled with the rubber elastic body and is condensed and emitted to the front side, so that the visibility at the practical visual field position is improved and each protrusion is formed. Since the protrusion base and the flat surface between the protrusions are light non-reflective surfaces,
The display contrast when the chip is turned on and off is extremely good, and the light-emitting display is bright and easy to see at a practical visual field position. Further, according to the manufacturing method of the present invention, it is possible to easily manufacture a light emitting display having both of the above effects.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a light emitting display body according to an embodiment of the present invention.

FIG. 2 is a schematic enlarged cross-sectional view of the same embodiment taken along the line AA of FIG.

FIG. 3 is a plan view of a film used in the manufacturing method of the present invention.

4 is a schematic enlarged cross-sectional view of the film molded body taken along the line BB of FIG.

FIG. 5 is a schematic enlarged cross-sectional view showing a superposed state of a film molded body and a display substrate.

FIG. 6 is a schematic enlarged cross-sectional view showing the final stage of the manufacturing method of the present invention.

FIG. 7 is a schematic plan view of a light emitting display body according to another embodiment of the present invention.

FIG. 8 is a plan view of a film relating to the manufacture of the light emitting display body of the same example.

FIG. 9 is a schematic cross-sectional view of a conventional light emitting display body.

FIG. 10 is a schematic sectional view of an LED lamp used in a conventional light emitting display.

[Explanation of symbols]

1 Display substrate 2 LED chips 3,31 luminous dots 7,11 Film molding 7a, 71a convex lens-like protrusion 7b, 71b Light non-reflective surface 7c, 71c Projection base 7d, 71d flat surface 10a, 11a Projected portion for forming protrusion 8 rubber elastic body 8a Uncured rubber elastic resin liquid

Claims (2)

[Claims] 1. A projection base of each projection and a flat surface between the projections of a film molding having a large number of convex lens-shaped projections formed as light non-reflective surfaces, and a large number of the projections are arranged on the surface of a display substrate. A light-emitting display body, characterized in that the provided LED chips are hermetically sealed via rubber elastic bodies so as to correspond to the respective projections. 2. A planner for forming the projection portion of a flat film, in which a large number of LED chips are arranged on a display substrate, and a projection lens-shaped projection portion is planned to be formed at a position corresponding to each LED chip. A film molded body in which each film is formed by printing on the flat film surface so that the film surface becomes a light non-reflecting surface including a part of the inside, and thereafter, the projecting portion to be formed is subjected to molding processing. And each protrusion of the film molded body is arranged downward to supply uncured rubber elastic resin liquid into each protrusion, and then the above-mentioned indicator is placed in the uncured rubber elastic resin liquid. After dipping each corresponding LED chip with the LED chip mounting surface side of the substrate facing downward, the uncured rubber elastic resin liquid is cured to cause each LED chip to protrude through the rubber elastic body. To be sealed in part Method for manufacturing a light-emitting display body, wherein.