JPS62269984A - Thin planar display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] a Detailed description of the invention "Industrial application field" The present invention relates to a thin flat display device.

``Prior art'' Conventionally, as shown in Fig. 11.12, the LED chip (4) is mounted on the back side of a lead frame (! ,
An electric circuit is formed by connecting the LED chip and another lead frame (9) with a bonding wire, and the lead frames (9) (9) are placed in a case trowel having a reflective surface on the back side. Install this lead frame @l
! 5° C. and the LID chip (4) was filled with transparent HA resin to form a flat display lamp (product) having a light transparent part. Therefore, the thickness of the illuminated part of conventional indicator lights is 5 to 10
mm is 9.

``Problems to be Solved by the Invention'' However, in order to have the minimum required strength, the lead frame needs to have a width of approximately 0.2 mm, so as shown in FIG. There is a drawback that the shadow (51α) is projected onto the diffuser plate. Therefore, a certain distance is required between the frame and the diffuser plate, resulting in a problem that the display device becomes thick. In particular, 1 this display device can be used, for example, as a liquid crystal display device (
In order to use it as a backlight (not shown), it is necessary to reduce the wall thickness.

``Means for rounding the problem to make it thinner'' The present invention was made in view of the above-mentioned points, and consists of individually attaching metal thin films having translucency and conductivity to the back surface of a thin base material. LF)D is connected to the chip by a bonding wire to form an electric circuit, and an electrode part remains at the end of the metal thin film and is covered with a transparent resin to provide a protective part,
The above-mentioned problem is solved by a configuration in which a flat surface provided on the outside of the protective portion is provided with sloped surfaces on all four sides, and the flat surface and the sloped surfaces are formed as reflective surfaces.

"Function" By using a thin base material as a supporting member, a thin metal film forming an electric circuit is attached to the base material and formed.
Since the protective portion that protects the metal thin film and the reflective surface that reflects the light emitted from the LFliD chip are attached to the base material, the thickness can be reduced without requiring a lead frame or a case.

``Example'' To explain the example of the present invention with drawings, (1) is a base material made of a thin glass material or hard resin having a light diffusion function, for example, 0.2 to Q, and a thickness of about 3 mm. have.

(2) is a metal thin film that is thin enough to be transparent (several microns thick) and has conductivity on the back side of the base material (1), as shown in Figure 2, each with a constant gap (3 ) and formed by vapor deposition, painting, etc. on the back side of the base material (1), and provided on each negative side of each metal thin film (2).
(4) and the other side of each metal thin film are connected by bonding wires (5) and (5) to form an electric circuit. In this case, filmless parts (6) (6) exposing the base material are formed on both left and right sides of the gold R thin film (2) (2), and furthermore, the base material (1) is formed in the vertical direction of the metal thin film. ) to form an electrode portion (7) c7i. Next, the back side of this base material (1) is coated with a transparent epoxy resin or the like to cover the metal thin layer (2), the L'ED chip (4), and the bonding wire (5) to form a protective part (8). Form. A flat surface (7) is formed at the center of this protective portion (8), and each of the four circumferences of this flat surface αO has a downward slope ■(
9) Form (9), and further provide a mirror-finishing part (to) with white paint on the outside of this protective part (8) to make the reflective surface α℃(
6) are respectively formed on the inner surface.

Here, the base material (1) is basically formed transparent;
The side opposite to the surface on which the metal thin film is attached, that is, the front side, is textured to diffuse reflection, and in the case of a glass plate, it is made of frosted glass to make it translucent to provide a light diffusion function.

Furthermore, a milky white film with a thickness Q of about 1 mm may be attached to the front side of the transparent plate by gluing or inserting it.

The second embodiment of the present invention will be explained based on FIG. 8.9. For each LIID chip (4) attached to the back surface of the base material (1), a flat plate with four periphery slopes (9α) Ic formed. (10α) and nine protective portions (8α) are formed, and the outside of these protective portions (8α) is coated with white paint to form mirror-finished portions (13α), and each inner surface is provided with a reflective surface (13α). 1 uα) (12α) is formed. In this case, the electrode parts (7) (7) integral with the metal thin film (2) (2) are exposed outside the protective part (8α) and formed on both upper and lower ends of the back surface of the base material (1).

Next, to explain the effect of this example, the base material (1)
Since it has the role of a support member as well as a light diffusion function, it is made of hard resin or glass material, so it is easy to maintain flatness. It is possible to provide a protective part (8) by adhesion.

Moreover, this base material (1) is strong against bending. Further, by attaching this metal thin film (2) to the back surface of the base material (1), the base material can function as a support member even if it is thin enough to have translucency. Also, metal thin g(2), L
The central part of the waist retaining part (8) formed by covering the ED chip (4) and the bonding wire (5) with transparent resin has a flat surface α01, and each of the four circumferential surfaces of the flat surface α has inclined surfaces (9). Since the outer surface of the LIID chip (13α) is mirror-finished, the light from the LIID chip (4) passes through the protective portion (8) made of transparent resin and is reflected by the reflective surface C11) or (6). The light is reflected and travels toward the front side of the base material (1). In this case, since the metal thin film (2) is thin enough to have translucency, the shadow that appears on the base material (1) is only that of the LFfD chip (4) itself, so the shadow is very small. , is hardly noticeable.

As shown in Fig. 4.5, a slightly wide flat surface αO made of transparent resin is formed at the center of the back surface of the base material (1), and the outside of the sloped surface (9) is formed around the four circumferences of this flat surface. It is also possible to form a reflective surface by providing a mirror and a dark processing part (to) on the 8.
As shown in Fig. 9, a mirror-finished part (13α) is provided on the flat surface (10α) and the inclined surface (9α) for each LED chip (4) on the surface of the base material (1) to form a reflective surface (12α). )(11α
) may be formed.

That is, as shown in FIG. 7, there is a case where the protective part attached to the back surface of the base material has a sloped surface, and as shown in FIG.
Comparing the cases where each LlD chip has sloped surfaces on the four circumferences, as shown in Figure 7, when the LlD chips do not have sloped surfaces, it is not noticeable when the spacing between LED chips is narrow, but it is wide. In this case, a range of total reflection, that is, a dark area (1) occurs in the middle part of each LED chip.In this case, if the distance to the reflective surface is long, dark areas are less likely to occur. The more they are formed, the wider the area for the dark areas and the greater the contrast, which increases the manufacturing effort, but it is better to provide each LED chip with sloped surfaces around each of its four circumferences, as shown in Figure 10. Dark portions η do not occur.

"Effect of the invention" The present invention has the following effects.

(2) Since the base material serves both as a light diffusing plate and a supporting member, it can be made as thin as a thin metal film forming a circuit.

- Since the shadow of the lead frame is removed and the shadow is only the LED chip, the shadow is significantly smaller and less noticeable than that of conventional products.

■ Metal thin film, L1! A transparent resin for covering the ID chip and bonding wires is provided on the back surface of the base material, and the center of this protective part is flat, and slopes are formed around the center, so that the outer side of this protective part is flat. By providing the entire surface with a polished surface, a reflective surface can be formed on each back surface of the protective section.

■ As mentioned above, since the base material serves as a supporting member, the metal thin film, protective part, and mirror-finished part do not have any strength, so these parts can be made thinner, which eliminates the need for a case or lead frame. By reducing the number of parts and reducing the number of parts, the illumination part can be made even thinner, making it possible to
It can be done in about 100 seconds, and the process speed is comparable to that of conventional ones. It can be made thicker.

■ When used as a backlight for a liquid crystal display (LO, D), it has the advantage that the thinner the liquid crystal display is, the easier it is to use when it is installed in an ultra-small device, such as a push button switch such as a key top. be.

(2) Since the base material has electrode portions on both the upper and lower ends of the back surface, and the base material remains on both the left and right ends, it can be integrated into other devices and connected to circuits.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a front view of the base material, FIG. 2 is a back view of the base material with a metal thin film, LFfD chip, and bonding wire attached to the back surface, and FIG. The figure is an electric circuit diagram, the figure 4 is a back view of the nine-stage state with a transparent protective part on the surface of the thin metal membrane, and the fifth figure is the figure 4 with a mirror finish applied to the outer surface of the waist protective part. - An enlarged sectional view in the direction of the A line, Fig. 6 is an enlarged sectional view of the main part, Fig. 7 is an explanatory diagram showing the state of light reflection, and Fig. 8 shows the second embodiment, which is mirror-finished. Fig. 9 is a rear view of the state without the protective part, Fig. 8 is a sectional view taken along the line - Fig.
11 is an enlarged cross-sectional view of a conventional device, and FIG. 12 is an enlarged cross-sectional view taken along line C--O in FIG. 11. (1)... Base material) (2... Metal thin film, (4)...
LED chip, (7) (7)... to the rod part, (8)...
...Protective part, Qη(9)...Reflecting surface. Figure 6 Figure 3 Figure 11 Figure 1

Claims (1)

[Claims] Light-transmitting and conductive metal thin films are individually attached to the back side of the thin base material, each metal thin film is connected to the LED chip with a bonding wire to form an electric circuit, and an electrode part is attached to the end of the metal thin film. A thin film made by leaving a protective part remaining and covering it with a transparent resin, forming sloped surfaces around the four circumferences of a flat surface provided on the outside of this protective part, and forming the flat surface and the sloped surface as reflective surfaces. Shape flat display device.