TWI384181B - Back light module, its manufacture method and electrical device having the back light module - Google Patents

Description

Backlight module, manufacturing method thereof and electronic device using the same

The invention relates to a backlight module, in particular to a backlight module with a silver paste circuit, a manufacturing method thereof and an electronic device using the same.

The traditional thin film keyboard applies a silver paste circuit to one surface of the light guide plate, and the light source enters the light from the side of the light guide plate, and the light guide plate is coated with the silver paste circuit by using the existing light guiding property of the light guide plate. The surface is lighted so that the membrane keyboard can provide a light source to the outside.

However, since the silver paste circuit itself has high absorption rate and low reflectance for the input light source, and destroys the total reflection angle inside the light guide plate, when the light of the light source is emitted toward the silver paste circuit in the light guide plate, the light is not only Will be absorbed by the silver paste circuit and only a small part of the light is reflected back, and can not provide external light and cause the light can not be effectively transmitted in the light guide plate. In addition, the surface of the light guide plate will be colored, so that the light of the light source is reduced. Utilization rate.

In view of this, how to propose a solution that can effectively improve the above-mentioned shortcomings and inconveniences is an important issue that the relevant industry is currently unable to delay.

The invention discloses a backlight module, a manufacturing method thereof and an electronic device using the same, which are used for improving the light reflectivity and reducing the chance of light being absorbed by the silver paste circuit, thereby improving the utilization rate of the light source.

The invention discloses a backlight module, a method for manufacturing the same, and an electronic device using the same, which is used for reducing the probability of color deviation when the light guide plate emits light and improving the light quality of the backlight module.

The backlight module, the method of manufacturing the same, and the electronic device using the backlight module. The backlight module includes a light guide plate, a light source, a reflective layer and a silver paste circuit layer. The light guide plate has a light incident surface and a light exit surface. The light source is located on the light incident surface of the light guide plate. The reflective layer has a first pattern and is disposed on the light emitting surface of the light guide plate. The silver paste circuit layer has a second pattern and is disposed on the first pattern.

In one embodiment of the invention, the second pattern of the silver paste circuit layer has a pattern range that is less than, greater than or equal to, the pattern range of the first pattern of the reflective layer.

In an embodiment of the invention, the reflective layer comprises a resin material.

In one embodiment of the invention, the reflective layer is white or silver.

In one embodiment of the invention, the reflective layer is transparent and the refractive index of the reflective layer is less than the refractive index of the light guide plate.

In one embodiment of the present invention, the light guide plate is a flexible circuit substrate having a plurality of optical microstructures respectively located on the light incident surface thereof, the other surface of the substrate opposite to the light exit surface, or both of the light incident surface and the substrate opposite to each other. The other side of the light surface.

In an embodiment of the invention, the electronic device is a mouse, a keyboard, a mobile phone, a camera, a camera, a game machine, a watch, a music player, an electronic mail transceiver, a map navigator or a digital photo frame.

In another aspect of the present invention, the method for manufacturing the backlight module includes the steps of: providing a light guide plate, wherein the light guide plate has a light exiting surface, and then forming a reflective layer on the light guide plate according to a first pattern. On the light exiting surface, a silver paste circuit layer is formed on the first pattern according to a second pattern.

Thus, by the reflective layer between the silver paste circuit layer and the light guide plate, when the light in the light guide plate faces the region of the light mask circuit layer, the reflective layer can be reflected back to the light guide plate, and then the light exit surface does not have The area of the reflective layer or the silver paste circuit layer emits light, so that more light-emitting opportunities can be added, and the light-emitting and light source utilization ratio can be provided.

The present invention will be apparent from the following description and the detailed description of the embodiments of the present invention, which may be modified and modified by the teachings of the present invention without departing from the invention. The spirit and scope.

The invention provides a backlight module, a method for manufacturing the same, and an electronic device using the backlight module. Before the silver paste circuit is fabricated on the light guide plate, a reflective layer is formed at a corresponding position to be set in the silver paste circuit. In this way, when the light is guided to the silver paste circuit, it is reflected back into the light guide plate by the reflective layer to improve the light reflectivity and reduce the chance of the light being absorbed by the silver paste circuit, thereby alleviating the problem of unintended color shift of the light guide plate. Thereby, the utilization rate of the light source and the light quality are improved.

Please refer to FIG. 1 to FIG. 3 . FIG. 1 is a plan view of the backlight module 100 of the present invention in an embodiment. Figure 2 is a cross-sectional view along line 2-2 of Figure 1 and a ray motion diagram. Figure 3 is a cross-sectional view along line 3-3 of Figure 1 and a ray motion diagram.

The backlight module 100 includes a light guide plate 200, a light source 300, a reflective layer 400, and a silver paste circuit layer 500. The light guide plate 200 has a light incident surface 210 and a light exit surface 220. The light source 300 is, for example, a Cold Cathode Fluorescent Lamp (CCFL) or a light-emitting diode (LED), which is located substantially on the light incident surface 210 of the light guide plate 200 and emits light toward the light incident surface 210. . The reflective layer 400 is present on the surface of the light exit surface 220 in a first pattern. The silver paste circuit layer 500 is presented on the first pattern of the reflective layer 400 in a second pattern, which is a circuit pattern. The circuit layouts can be electrically connected externally and perform specific functions.

In this manner, when the light of the light source 300 enters the light guide plate 200, the light may be emitted from the light emitting surface 220 without the reflective layer 400 or the region 222 of the silver paste circuit layer 500; or, because the reflective layer 400 is located in the silver paste circuit layer 500 and the light guide plate 200. When the light of the light source 300 travels to the reflective layer 400 in the light guide plate 200, the light can be reflected back into the light guide plate 200 by the reflective layer 400, and the light-emitting surface 220 does not have the reflective layer 400 or the silver paste circuit layer 500. 222 light.

Therefore, the light traveling in the direction of the silver paste circuit layer 500 in the light guide plate 200 is not absorbed by the silver paste circuit layer 500, and further provides more light to the light exit surface 220 to provide higher light emission brightness. Increase the utilization of the light source 300.

In one embodiment of the present invention, as shown in FIGS. 1 and 3, the pattern outline of the second pattern is exactly the same as the pattern outline of the first pattern, and the pattern range of the second pattern is equal to the pattern range of the first pattern. For example, the first pattern is composed of one or more first lines 401. This second pattern is composed of one or more second lines 501. The line width 502 of the second line 501 of the second pattern is equal to the line width 402 of the first line 401 of the first pattern (as shown in FIG. 3).

Alternatively, the first pattern and the second pattern may also include geometric figures, such as a circle (not shown)

In other words, the reflective layer 400 is completely interposed between the silver paste circuit layer 500 and the light guide plate 200, that is, the first pattern of the reflective layer 400 cannot be observed by the light guide plate 200 through the top view. As such, when the second pattern is completely superposed on the surface of the reflective layer 400, the second pattern completely covers the first pattern to provide more regions 220 of the light-emitting surface 220 without the reflective layer 400 or the silver paste circuit layer 500. Provides higher illumination brightness and utilization of the light source 300.

Referring to FIG. 4 and FIG. 5, FIG. 4 is a plan view of the backlight module of the present invention in another embodiment. Figure 5 is a cross-sectional view taken along line 5-5 of Figure 4 and a ray motion diagram.

In another embodiment of the backlight module 101 of the present invention, the pattern of the second pattern is substantially the same as the pattern of the first pattern, except that the pattern range of the second pattern is smaller than the pattern range of the first pattern. For example, the first pattern is composed of one or more first lines 401. This second pattern is composed of one or more second lines 501. The line width 502 of the second line 501 of the second pattern is smaller than the line width 402 of the first line 401 of the first pattern (Fig. 5). Alternatively, the first pattern and the second pattern may also comprise geometric figures (eg, circles). (not shown)

In other words, when the second pattern is stacked on the surface of the reflective layer 400, the second pattern cannot completely cover the first pattern. Thus, since the pattern range of the second pattern of the silver paste circuit layer 500 is smaller than the pattern range of the first pattern of the reflective layer 400, the second pattern can provide more opportunities for reflection, thereby improving the light from the light exit surface 220 without a reflective layer. The chance of light exiting the area 222 of the 400 or silver paste circuit layer 500.

Referring to FIG. 6, FIG. 6 is a cross-sectional view and a ray motion diagram of a backlight module of the present invention in still another embodiment. In still another embodiment of the backlight module 102 of the present invention, the pattern of the second pattern is substantially the same as the pattern of the first pattern, except that the pattern range of the second pattern is larger than the pattern range of the first pattern. For example, the first pattern is composed of one or more first lines 401. This second pattern is composed of one or more second lines 501. The line width 502 of the second line 501 of the second pattern is greater than the line width 402 of the first line 401 of the first pattern, so that the second line 501 of the second pattern covers the first line 401 and the light-emitting surface 220 of the first pattern. . Alternatively, the first pattern and the second pattern may also comprise a geometric figure (eg, a circle) (not shown).

In other words, the silver paste circuit layer 500 covers both the reflective layer 400 and the light exit surface 220. As such, since the reflective layer 400 is still located between the silver paste circuit layer 500 and the light exit surface 220, the reflective layer 400 can still reflect the light to the light exit surface 220 without the reflective layer 400 or the region 222 of the silver paste circuit layer 500.

In other embodiments of the present invention, the light guide plate 200 may be, for example, a rectangular plate of uniform thickness or a wedge plate having a thickness ranging from the front to the back and the four sides of the front and back sides. The area of the front side or the back side is larger than the area of either side. Any one of the sides of the light guide plate 200 is a light incident surface 210 for guiding light into the light guide plate 200. The front surface of the light guide plate 200 is a light exit surface 220 for emitting light to the outside.

In this embodiment, the material of the light guide plate 200 is made of a transparent plastic material, such as polyethylene terephthalate (PET) or polycarbonate (PC). The R&D personnel can select the material of the light guide plate 200 according to actual needs or restrictions.

In another embodiment of the present invention, the light guide plate 200 can also be a flexible printed circuit board (FPC). The substrate has a plurality of optical microstructures (not shown), which may be located on the light incident surface 210, the other side of the substrate opposite to the light exit surface 220, or the other side of the light incident surface 210 and the substrate opposite light exit surface 220. The invention does not limit the form of the optical microstructure, and may be, for example, convex, concave, spherical or serrated, etc., to generate more refraction of the light emitted by the light source 300, and to move more uniformly. The light guide plate 200 can be used. Research and development personnel can adjust according to actual needs or restrictions.

In still another embodiment of the present invention, the reflective layer 400 is coated or printed onto the front side of the light guide plate 200 by a compound having a resin material to conform to the second pattern of the silver paste circuit layer 500. In addition, the reflective layer 400 preferably has a color of a preferred reflection effect such as white or silver. The developer can adjust the color of the reflective layer 400 according to actual needs or restrictions.

In addition, the reflective layer 400 can also be made of a transparent adhesive material (such as UV glue), wherein the reflective layer is transparent (or at least translucent), and its (light) refractive index is smaller than the (light) refractive index of the light guide plate.

Please refer to FIG. 7. FIG. 7 is a block diagram of an electronic device according to an embodiment of the present invention. In still another embodiment of the present invention, one of the backlight modules 100, 101, and 102 described above can be applied to an electronic device 10. The electronic device 10 of the present invention is not limited to one of a mouse, a keyboard, a mobile phone, a camera, a camera, a game machine, a watch, a music player, an electronic mail transceiver, a map navigator, and a digital photo frame.

FIG. 8 is a flow chart showing the manufacturing method of the backlight module of the present invention. Another aspect of the present invention provides a backlight module, such as one of the backlight modules 100, 101, or 102, for improving the utilization rate and light quality of the light source 300. The general steps include at least:

Step 801: A light guide plate 200 is provided. As can be seen from the above, the light guide plate 200 can be a light guide plate 200 with an acrylic material or a flexible printed circuit board.

Step 802: Form a reflective layer 400 on one of the light-emitting surfaces 220 of the light guide plate 200 according to a predetermined first pattern. The reflective layer 400 can be printed, transferred, coated or flattened, and the same pattern contour as the second pattern (for example, circuit layout) can be formed on the light-emitting surface 220.

Step 803: Form a silver paste circuit layer 500 having the second pattern described above on the first pattern of the reflective layer 400. In this step, the developer may select the second pattern of the silver paste circuit layer 500 to have a pattern range smaller than (FIG. 5), greater than (FIG. 6), or equal to (FIG. 3) the reflective layer 400, according to actual needs or limitations. The pattern range of the first pattern.

The silver paste circuit layer 500 can be formed on the reflective layer 400 by evaporation, electroplating, printing, solder transfer or the like.

Step 804: A light source 300, such as a Cold Cathode Fluorescent Lamp (CCFL) or a light-emitting diode (LED), is disposed on the light incident surface 210 of the light guide plate 200 to make it Lights up toward the light surface 210.

In summary, by the reflective layer 400 between the silver paste circuit layer 500 and the light guide plate 200, the present invention not only overcomes the problem that the light is absorbed by the silver paste circuit, but also increases the light output brightness of the light exit surface 220, thereby increasing the light source 300. Utilization rate.

The present invention is not limited to the embodiments of the present invention, and various modifications and refinements may be made without departing from the spirit and scope of the present invention. This is subject to the definition of the scope of the patent application.

10. . . Electronic device

100, 101, 102. . . Backlight module

200. . . Light guide

210. . . Glossy surface

220. . . Glossy surface

222. . . The area where the light-emitting surface does not have a reflective layer or a silver paste circuit layer

300. . . light source

400. . . Reflective layer

401. . . First line

402. . . First line width

500. . . Silver paste circuit layer

501. . . Second line

502. . . Second line width

2-2, 3-3, 5-5. . . Section line

801-804. . . step

The above and other objects, features, advantages and embodiments of the present invention will become more apparent and understood.

1 is a top plan view of a backlight module of the present invention in an embodiment.

Figure 2 is a cross-sectional view along line 2-2 of Figure 1 and a ray motion diagram.

Figure 3 is a cross-sectional view along line 3-3 of Figure 1 and a ray motion diagram.

4 is a top plan view of a backlight module of the present invention in another embodiment.

Figure 5 is a cross-sectional view taken along line 5-5 of Figure 4 and a ray motion diagram.

FIG. 6 is a cross-sectional view and a ray motion diagram of the backlight module of the present invention in another embodiment.

FIG. 7 is a block diagram of an electronic device of the present invention in an embodiment.

FIG. 8 is a flow chart showing the manufacturing method of the backlight module of the present invention.

100. . . Backlight module

200. . . Light guide

210. . . Glossy surface

220. . . Glossy surface

222. . . The area where the light-emitting surface does not have a reflective layer or a silver paste circuit layer

300. . . light source

400. . . Reflective layer

401. . . First line

402. . . First line width

500. . . Silver paste circuit layer

501. . . Second line

502. . . Second line width

Claims (10)

A backlight module includes: a light guide plate having a light incident surface and a light exit surface; a light source located on the light incident surface; and a reflective pattern directly formed on the light exit surface by one or more lines And a silver paste circuit pattern, which is a circuit pattern composed of one or more lines, directly superposed on the reflective pattern, wherein the pattern of the reflective pattern has the same contour as the pattern of the circuit pattern. The backlight module of claim 1, wherein a pattern range of the pattern outline of the circuit profile is smaller than, greater than or equal to a pattern range of the pattern outline of the reflective pattern. The backlight module of claim 1, wherein the reflective pattern comprises a resin material. The backlight module of claim 1, wherein the reflective pattern is white or silver. The backlight module of claim 1, wherein the reflective pattern is transparent, and the reflective pattern has a refractive index smaller than a refractive index of the light guide plate. The backlight module of claim 1, wherein the light guide plate is a flexible circuit substrate. The backlight module of claim 6, wherein the flexible circuit substrate has a plurality of optical microstructures, and the optical microstructures are located on the light incident surface or the other side of the substrate opposite to the light exit surface. An electronic device comprising the backlight module of any one of claims 1 to 7. The electronic device of claim 8, wherein the electronic device is a mouse, a keyboard, a mobile phone, a camera, a camera, a game machine, a watch, a music player, an electronic mail transceiver, a map navigator or a digital photo frame. A method for manufacturing a backlight module, comprising: providing a light guide plate, wherein the light guide plate has a light exiting surface; forming a reflective layer on the light guide plate according to a first pattern composed of one or more lines And a second pattern consisting of one or more lines, that is, a circuit pattern of a silver paste circuit layer, forming a silver paste circuit layer and directly superposing on the reflective layer In the pattern, wherein the pattern outline of the first pattern is the same as the pattern outline of the circuit pattern.