TW202109581A - Backlight module and backlight module manufacturing method thereof - Google Patents

Abstract

A backlight module is applied to a keyboard including a board and keyswitches. The keyswitches are disposed on the board. The backlight module includes a light emitting diode, a circuit layer structure, and an optical structure having a hole, a top surface, and a bottom surface. The light emitting diode is disposed in the hole for emitting light to each keyswitch via guidance of the optical structure. The circuit layer structure includes a silver-paste circuit layer and a copper layer. The silver-paste circuit layer is printed on one of the top surface and the bottom surface. The copper layer is plated on the silver-paste circuit layer and is coupled to the light emitting diode.

Description

Backlight module and its manufacturing method

The invention relates to a backlight module and a method for manufacturing the backlight module, in particular to a backlight module and a method for manufacturing the backlight module in which a silver paste circuit layer and a copper plating layer are formed on the surface of an optical structure.

In terms of current personal computer usage habits, the keyboard is one of the indispensable input devices for inputting characters, symbols or numbers. Not only that, all consumer electronic products in daily life or large-scale processing equipment used in the industry need to be equipped with a key structure as an input device to operate the above-mentioned electronic products and processing equipment.

With the development of technology, the design of the keyboard has become more and more diversified. When a user chooses a keyboard, in addition to the basic input functions, the visual effect of the keyboard is also valued by the user. For example, keyboards with luminous functions are currently on the market. In addition to visually appealing to users, they can also be used at night or in places with insufficient lighting. Therefore, keyboards with light-emitting functions are more competitive in the market.

Most keyboards with light-emitting function use a backlight module as a light source. Generally speaking, the backlight module includes a light guide plate, a light-emitting unit, a light-shielding sheet, and a reflective sheet. The light-emitting unit is arranged on one side of the light-guide plate, and the light emitted by the light-emitting unit It is guided by the light guide plate and emitted. The light-shielding sheet is arranged on the light guide plate to restrict light from being incident to the corresponding key position so that the key produces a luminous effect. The reflective sheet is arranged under the light guide plate to emit from below the light guide plate The light is reflected back into the light guide plate to solve the light leakage problem and improve the light usage efficiency of the backlight module.

In this design, it uses a flexible circuit board to control the light emission of the light-emitting diode in a telecommunication transmission mode, so that the keyboard can have more variable key light-emitting visual effects. However, since the circuits on the flexible circuit board are usually completed by a copper etching process, a lot of copper is etched and removed during the etching process, which causes unnecessary material waste and greatly improves the backlight module in the light-emitting diode circuit Manufacturing costs on the connection.

Therefore, one of the objectives of the present invention is to provide a backlight module with a silver paste circuit layer and a copper-plated layer formed on the surface of an optical structure and a method for manufacturing the backlight module to solve the above-mentioned problems.

According to one embodiment, the backlight module of the present invention is suitable for a keyboard. The keyboard includes a bottom plate and a plurality of keys. The plurality of keys are arranged on the bottom plate. The backlight module includes an optical structure and a light emitting diode. , And a circuit layer structure. The optical structure has at least one through hole and has an upper surface and a lower surface. The light-emitting diode is arranged in the at least one through hole and used for emitting light to be incident to each key through the guide of the optical structure. The circuit layer structure includes a silver paste circuit layer and a copper plating layer. The silver paste circuit layer is printed and formed on one of the upper surface and the lower surface. The copper plating layer is plated on the silver paste circuit layer and electrically connected to the light emitting diode, so that the light emitting diode is electrically connected to the silver paste circuit layer through the copper plating layer.

According to another embodiment, the backlight module manufacturing method of the present invention is applicable to a keyboard, the keyboard includes a bottom plate and a plurality of keys, the plurality of keys are arranged on the bottom plate, and the backlight module manufacturing method includes providing an optical structure The optical structure has at least one through hole and has an upper surface and a lower surface. The backlight module manufacturing method further includes printing a silver paste circuit layer on one of the upper surface and the lower surface, plating a copper plating layer on the silver paste circuit layer, and applying a light-emitting diode It is arranged in the at least one through hole and is electrically connected to the copper-plated layer so that the light-emitting diode is electrically connected to the silver paste circuit layer through the copper-plated layer. The light-emitting diode emits light to be incident on each key through the guide of the optical structure.

In summary, the backlight module of the present invention adopts a circuit stacking design in which a silver paste circuit layer is printed on the optical structure and a copper plating layer is plated on the silver paste circuit layer to be electrically connected to the light emitting diode. Instead of the prior art using an etching process to form a circuit design on a flexible circuit board, the present invention can effectively solve the problem of unnecessary material waste caused by the etching process mentioned in the prior art, thereby greatly reducing The manufacturing cost of the backlight module in the light-emitting diode circuit connection.

The advantages and spirit of the present invention can be further understood from the following detailed description of the invention and the accompanying drawings.

Please refer to Figure 1, which is a partial cross-sectional view of the keyboard 1 according to an embodiment of the present invention. As shown in Figure 1, the backlight module 10 is suitable for the keyboard 1 to provide light-emitting function, and the keyboard 1 includes a bottom plate. 3 and a plurality of buttons 5 (only three are shown in the first figure, but not limited by this), the plurality of buttons 5 are arranged on the bottom plate 3, and the buttons 5 can adopt a common button lift design, for example, buttons 5 may include a key cap 7 and a lifting mechanism 9, the lifting mechanism 9 is arranged between the bottom plate 3 and the key cap 7, and the key cap 7 can move up and down relative to the bottom plate 3 via the lifting mechanism 9. In this embodiment, the lifting mechanism 9 can preferably adopt the scissor foot mechanism design shown in Figure 1 (but not limited to this, it can be changed to other common keycap lifting designs, such as magnetic attraction Design, etc.) and can be movably connected to the keycap 7 and the bottom plate 3, whereby the button 5 can move up and down relative to the bottom plate 3 through the scissor foot connection design of the lifting mechanism 9 for the user to press and perform the input desired by the user The function.

The following is a detailed description of the component configuration and manufacturing method of the backlight module 10. Please refer to Figure 1, Figure 2, and Figure 3. Figure 2 is a backlight module according to an embodiment of the present invention. The manufacturing method is a flow block diagram. FIG. 3 is an enlarged cross-sectional schematic diagram of the forming process of the circuit layer structure 16 of FIG. 1. The manufacturing method of the backlight module of the present invention includes the following steps.

Step 200: Provide a flexible circuit substrate 20;

Step 202: Print the silver paste circuit layer 28 on the upper surface 24 of the flexible circuit substrate 20;

Step 204: Plating the copper plating layer 30 on the silver paste circuit layer 28;

Step 206: Electrically connect the light-emitting diode 14 to the copper-plated layer 30 so that the light-emitting diode 14 is electrically connected to the silver paste circuit layer 28 through the copper-plated layer 30;

Step 208: Place the flexible circuit substrate 20 under the light guide plate 18 so that the light-emitting diode 14 is placed in the through hole 22.

First, as can be seen from Figures 1 and 3, the backlight module 10 includes an optical structure 12, a light emitting diode 14, and a circuit layer structure 16. The optical structure 12 has at least one through hole 22 (one is shown in Figure 1, However, it is not limited to this) and has an upper surface 24 and a lower surface 26. The light emitting diode 14 is disposed in the through hole 22. The circuit layer structure 16 includes a silver paste circuit layer 28 (the circuit layout design is common in the prior art. It will not be repeated here) and the copper plating layer 30. In step 200, the optical structure 12 may include a light guide plate 18 and a flexible circuit substrate 20. The light guide plate 18 has perforations 22. The flexible circuit substrate 20 may preferably be composed of a flexible substrate material (for example, poly Polyethylene terephthalate (PET) or polyimide (PI), but not limited to this), and has an upper surface 24 and a lower surface 26.

Next, the silver paste circuit layer 28 can be formed on the upper surface 24 of the flexible circuit substrate 20 by a silver paste printing process (step 202, which can be as shown in Fig. 3(a), but is not limited thereto. In another embodiment, the silver paste circuit layer 28 can also be formed on the lower surface 26, and the related description can be inferred from Figure 3), and then the copper plating layer 30 is plated (for example, by a chemical electroplating process, etc.) on the silver paste circuit On the layer 28 (step 204, which can be as shown in Figure 3(b)), it should be noted that in this embodiment, the silver paste circuit layer 28 can have a non-copper-plated area 32 and a circuit contact area 34, The circuit layer structure 16 may further include a shielding layer 36 and a first conductive anti-oxidation layer 38 (preferably composed of carbon ink, gold or nickel, but not limited to this), as shown in Figure 3(b), The shielding layer 36 is formed in the non-copper-plated area 32 to limit the plating position of the copper-plated layer 30 on the silver paste circuit layer 28, and the first conductive anti-oxidation layer 38 is formed on the circuit contact area 34 for electrical connection To the control circuit board (such as a computer motherboard), so as to achieve the effect of accurately plating the copper plating layer 30 on the correct position and avoiding oxidation of the circuit contact area 34 of the silver paste circuit layer 28.

Next, in step 206, it is possible to electrically connect the light-emitting diode 14 to the copper plating layer 30 (as shown in Figure 3(c)) by a soldering process (but not limited to this), thereby The light-emitting diode 14 can be electrically connected to the silver paste circuit layer 28 through the copper plating layer 30 (compared to the silver paste circuit, the copper circuit does not have the problem of different impedance due to the different length of the circuit) for telecommunications transmission, thereby It can be used to perform subsequent electrical control of the luminous intensity and color change of the light-emitting diode 14. Finally, in step 208, after the flexible circuit substrate 20 is placed under the light guide plate 18 so that the light emitting diode 14 is placed in the through hole 22 to complete the assembly of the backlight module 10 (as shown in Figure 1) Through the above design, the light emitted by the light-emitting diode 14 can be guided by the light guide plate 18 to enter each key 5, so as to achieve the key lighting effect.

In practical applications, the position of the copper-plated layer 30 corresponding to the surrounding area of the light-emitting diode 14 can be formed with a solder mask 40 to more accurately locate the welding position of the light-emitting diode 14 on the copper-plated layer 30. In addition, In this embodiment, the circuit layer structure 16 may further include an alloy bonding layer 42, which is preferably composed of tin-bismuth alloy or tin-silver-copper alloy material (but not limited to this) and formed on Between the light-emitting diode 14 and the copper-plated layer 30, the light-emitting diode 14 can be more firmly bonded to the copper-plated layer 30.

In addition, it can be seen from Figure 3(c) that the backlight module 10 may further include a protective layer 44, which can be coated on the light-emitting diode 14 and the circuit layer structure 16 to prevent electrostatic discharge ( Electrostatic Discharge, ESD), dust-proof and water-proof protective effects, and fixed effects of preventing the light-emitting diode 14 from falling off the circuit layer structure 16, but not limited to this. For example, in another embodiment, the protective layer The 44 series can only be applied to the edge position of the light-emitting diode 14 connected to the circuit layer structure 16 to fix the light-emitting diode 14 on the circuit layer structure 16, thereby further reducing the light-emitting diode 14 on the flexible circuit substrate. The bonding height on the 20 facilitates the subsequent assembly process of the light emitting diode 14 disposed in the through hole 22 of the light guide plate 18. In addition, it can be seen from Figure 1 that the optical structure 12 may further include a light-shielding sheet 48 and a reflective sheet 50. The light-shielding sheet 48 may be disposed on the light guide plate 18 to restrict light from being incident to the position of the corresponding button 5, so that the button 5 is generated. For the light-emitting effect, the reflective sheet 50 can be arranged under the light guide plate 18 to reflect light emitted from under the light guide plate 18 back into the light guide plate 18 to solve the light leakage problem and improve the light use efficiency of the backlight module 10.

To sum up, because the backlight module of the present invention adopts a circuit stacking design in which a silver paste circuit layer is printed on the optical structure and a copper plating layer is plated on the silver paste circuit layer to be electrically connected to the light emitting diode, In order to replace the prior art using an etching process to form a circuit design on a flexible circuit board, the present invention can effectively solve the problem of unnecessary material waste caused by the etching process mentioned in the prior art, thereby greatly The manufacturing cost of the backlight module in the connection of the light-emitting diode circuit is reduced.

It is worth mentioning that the design of the electrical connection layer of the light-emitting diode on the flexible circuit substrate may not be limited to the three-layer design of the above embodiment (ie, the alloy bonding layer 42, the copper plating layer 30, and the silver paste circuit layer The configuration of 28), the present invention can be modified to adopt a five-layer structure design to complete the electrical connection of the light-emitting diode on the optical structure. For example, please refer to FIG. 4, which is a schematic cross-sectional view of a light emitting diode 14 provided on a flexible circuit substrate 20 via a circuit layer structure 16' according to another embodiment of the present invention. Here The components mentioned in the embodiment and the above-mentioned embodiments have the same number, which means that they have the same structure or function, and the related description is not repeated here. It can be seen from Figure 4 that the circuit layer structure 16' includes a silver paste circuit layer 28, a copper-plated layer 30, a shielding layer 36, a first conductive anti-oxidation layer 38, a solder resist layer 40, an alloy bonding layer 42, and a second conductive resist The oxide layer 46. In this embodiment, the first conductive anti-oxidation layer 38 and the second conductive anti-oxidation layer 46 may preferably be made of nickel or gold (for example, the first conductive anti-oxidation layer 38 is made of nickel). The second conductive anti-oxidation layer 46 is made of gold, but it is not limited to this) and can be sequentially formed between the copper plating layer 30 and the alloy bonding layer 42 to produce a layer that can reliably prevent copper plating 30 oxidation effect. It should be noted that the present invention can also adopt a four-layer structure design to simplify the design of the circuit layer structure. In short, in another embodiment, the circuit layer structure can only use a single conductive anti-oxidation layer to complete the above-mentioned prevention of plating. For the purpose of the copper layer oxidation, the related description can be deduced by referring to the above-mentioned embodiment, and will not be repeated here.

In addition, the formation position of the circuit layer structure is not limited to the above-mentioned embodiment. It can also be directly formed on the surface of other optical structures of the backlight module without the configuration of the flexible circuit substrate. For example, please Refer to FIG. 5, which is a partial cross-sectional view of a backlight module 100 according to another embodiment of the present invention. In this embodiment, the components mentioned in the above-mentioned embodiments have the same number, which means they have the same Structure or function, its related description is not repeated here. It can be seen from FIG. 5 that the backlight module 100 includes an optical structure 102, a light emitting diode 14, and a circuit layer structure 104. The optical structure 102 may include a light guide plate 103, a light-shielding sheet 48, and a reflective sheet 50. The circuit layer structure 104 is Is formed on the lower surface 26 of the light guide plate 103, and the light emitting diode 14 is electrically connected to the circuit layer structure 104 so as to be disposed in the through hole 22 of the light guide plate 103 (for example, the light emitting diode 14 may have electrical contacts 15 for The bottom-up assembly method is electrically connected to the circuit layer structure 104, but is not limited to this), so as to complete the electrical connection of the light-emitting diode 14 in the backlight module 100. As for other related descriptions of the backlight module 100 (such as circuit layer structure and layer number design, solder mask design, protective layer design, etc.), they can be analogized with reference to the above-mentioned embodiments, and will not be repeated here. It should be noted that in practical applications, the formation position of the circuit layer structure can better avoid the light-transmitting area on the light-shielding film. For example, please refer to Figures 5 and 6, and Figure 6 is Figure 5. The top view of the light-shielding sheet 48 in the figure. In this embodiment, a plurality of light-transmitting areas 49 are formed on the light-shielding sheet 48 to allow light emitted upward from the light guide plate 103 to pass through the light-transmitting areas 49 and enter each For keys, the circuit layer structure 104 may preferably not overlap with the plurality of light-transmitting regions 49, so as to avoid the light emitted upward from the light guide plate 103 from being blocked by the circuit layer structure 104 when passing through the plurality of light-transmitting regions 49 To the backlight brightness and uniformity that the backlight module 100 can provide.

In another embodiment, the present invention can be modified to adopt a light-emitting diode flip-chip design. For example, please refer to FIG. 7, which is a partial cross-section of a backlight module 150 according to another embodiment of the present invention. In a schematic diagram, the elements mentioned in this embodiment and the above-mentioned embodiments have the same number, which means that they have the same structure or function, and the related description is not repeated here. It can be seen from Figure 7 that the backlight module 150 includes an optical structure 102, a light emitting diode 14, and a circuit layer structure 152. The circuit layer structure 152 is formed on the upper surface 24 of the light guide plate 103, and the light emitting diode 14 is an electrical Connected to the circuit layer structure 152 to be disposed in the through hole 22 of the light guide plate 103 (for example, the light-emitting diode 14 may have electrical contacts 15 that are electrically connected to the circuit layer structure 152 in a flip-chip manner from top to bottom, but not This limit), so as to complete the electrical connection of the light-emitting diode 14 in the backlight module 150. As for other related descriptions of the backlight module 150 (such as circuit layer structure and layer number design, solder mask design, protective layer design, circuit layer structure to avoid the light-transmitting area of the shading sheet, etc.), please refer to the above The embodiments are analogous, and will not be repeated here.

In another embodiment, the present invention can be changed to a design in which a circuit layer structure is formed on the light-shielding sheet. For example, please refer to FIG. 8, which is an example of a backlight module 200 according to another embodiment of the present invention. It is a partial cross-sectional schematic diagram. The elements mentioned in this embodiment and the above-mentioned embodiments have the same number, which means that they have the same structure or function, and the related description is not repeated here. It can be seen from Figure 8 that the backlight module 200 includes an optical structure 202, a light emitting diode 14, and a circuit layer structure 204. The optical structure 202 may include a light guide plate 18, a light shielding sheet 206, and a reflective sheet 50. The circuit layer structure 204 is It is formed on the lower surface 26 of the light-shielding sheet 206 (but not limited to this, it can also adopt a design in which the circuit layer structure 204 is formed on the upper surface 24 of the light-shielding sheet 206), and the light emitting diode 14 is electrically connected to the circuit layer structure 204 is arranged in the through hole 22 of the light guide plate 18 to complete the electrical connection of the light-emitting diode 14 in the backlight module 200. As for other related descriptions of the backlight module 200 (such as circuit layer structure and layer number design, solder mask design, protective layer design, circuit layer structure design to avoid the light-transmitting area of the shading sheet, etc.), please refer to the above The embodiments are analogous, and will not be repeated here.

In another embodiment, the present invention can be modified to adopt a circuit layer structure formed on the reflective sheet design. For example, please refer to FIG. 9, which is an example of a backlight module 250 according to another embodiment of the present invention. It is a partial cross-sectional schematic diagram. The elements mentioned in this embodiment and the above-mentioned embodiments have the same number, which means that they have the same structure or function, and the related description is not repeated here. It can be seen from FIG. 9 that the backlight module 250 includes an optical structure 252, a light emitting diode 14, and a circuit layer structure 254. The optical structure 252 may include a light guide plate 18, a light-shielding sheet 48, and a reflective sheet 256. The circuit layer structure 254 is Formed on the upper surface 24 of the reflective sheet 256 (but not limited to this, it can also adopt a design in which the circuit layer structure 254 is formed on the lower surface 26 of the reflective sheet 256), and the light emitting diode 14 is electrically connected to the circuit layer structure 254 is arranged in the through hole 22 of the light guide plate 18 to complete the electrical connection of the light emitting diode 14 in the backlight module 250. As for other related descriptions of the backlight module 250 (such as circuit layer structure and layer number design, solder mask design, protective layer design, circuit layer structure to avoid the light-transmitting area of the shading sheet, etc.), please refer to the above The embodiments are analogous, and will not be repeated here. The foregoing descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made in accordance with the scope of the patent application of the present invention should fall within the scope of the present invention.

1: keyboard 3: bottom plate 5: Button 7: keycap 9: Lifting mechanism 14: Light-emitting diode 15: Electrical contact 18, 103: light guide plate 20: Flexible circuit board 22: Piercing 24: upper surface 26: lower surface 28: Silver paste circuit layer 30: Copper plating 32: Non-copper-plated area 34: Line contact area 36: Masking layer 38: The first conductive anti-oxidation layer 40: Solder mask 42: Alloy bonding layer 44: protective layer 46: Second conductive anti-oxidation layer 48, 206: shading sheet 49: light transmission area 50, 256: reflective sheet 10, 100, 150, 200, 250: backlight module 12, 102, 202, 252: optical structure 16, 16’, 104, 152, 204, 254: circuit layer structure Steps 200, 202, 204, 206, 208

Fig. 1 is a schematic partial cross-sectional view of a keyboard according to an embodiment of the present invention. FIG. 2 is a flow block diagram of a method for manufacturing a backlight module according to an embodiment of the present invention. Fig. 3 is a schematic enlarged cross-sectional view of the forming process of the circuit layer structure of Fig. 1. FIG. 4 is a schematic cross-sectional view of a light emitting diode provided on a flexible circuit substrate via a circuit layer structure according to another embodiment of the present invention. FIG. 5 is a schematic partial cross-sectional view of a backlight module according to another embodiment of the present invention. Figure 6 is a top view of the light-shielding sheet in Figure 5. FIG. 7 is a schematic partial cross-sectional view of a backlight module according to another embodiment of the present invention. FIG. 8 is a schematic partial cross-sectional view of a backlight module according to another embodiment of the present invention. FIG. 9 is a schematic partial cross-sectional view of a backlight module according to another embodiment of the present invention.

1: keyboard

3: bottom plate

5: Button

7: keycap

9: Lifting mechanism

10: Backlight module

12: Optical structure

14: Light-emitting diode

16: circuit layer structure

18: Light guide plate

20: Flexible circuit board

22: Piercing

24: upper surface

26: lower surface

48: shading sheet

50: reflective sheet

Claims (25)

A backlight module is suitable for a keyboard. The keyboard includes a bottom plate and a plurality of keys. The plurality of keys are arranged on the bottom plate. The backlight module includes: An optical structure having at least one perforation and having an upper surface and a lower surface; A light-emitting diode arranged in the at least one through hole for emitting light to be incident on each key through the guide of the optical structure; and A circuit layer structure, which includes: A silver paste circuit layer printed on one of the upper surface and the lower surface; and A copper-plated layer is plated on the silver paste circuit layer and electrically connected to the light-emitting diode, so that the light-emitting diode is electrically connected to the silver paste circuit layer through the copper-plated layer. The backlight module according to claim 1, wherein the optical structure includes a light guide plate and a flexible circuit substrate, the light guide plate has the at least one through hole, and the flexible circuit substrate is disposed under the light guide plate and has On the upper surface and the lower surface, the light emitted by the light emitting diode is guided by the light guide plate to enter each button. The backlight module according to claim 1, wherein the optical structure includes a light guide plate, a light-shielding sheet, and a reflective sheet, the light-guide plate has the at least one perforation, and the light-shielding sheet is disposed on the light guide plate to allow The light emitted upward from the light guide plate is incident on each button, the reflection sheet is arranged under the light guide plate to reflect the light emitted downward from the light guide plate back into the light guide plate, the light guide plate, the light-shielding sheet, and the reflection sheet One of them has the upper surface and the lower surface. The backlight module according to claim 3, wherein a plurality of light-transmitting regions are formed on the light-shielding sheet to allow light emitted upward from the light guide plate to enter each button through the plurality of light-transmitting regions, and the circuit layer structure is consistent with The plurality of light-transmitting regions do not overlap with each other. The backlight module of claim 2 or 3, wherein the silver paste circuit layer has a non-copper-plated area and a circuit contact area, the circuit layer structure further includes a shielding layer and a first conductive anti-oxidation layer, the A shielding layer is formed in the non-copper-plated area to limit the plating position of the copper-plated layer on the silver paste circuit layer, and the first conductive anti-oxidation layer is formed on the circuit contact area to be electrically connected to a control circuit board. The backlight module according to claim 5, wherein the first conductive anti-oxidation layer is made of carbon ink, gold or nickel. The backlight module according to claim 5, wherein the first conductive anti-oxidation layer is further formed between the light emitting diode and the copper plating layer. The backlight module according to claim 7, wherein the circuit layer structure further includes: A second conductive anti-oxidation layer is formed between the first conductive anti-oxidation layer and the light emitting diode and is formed on the first conductive anti-oxidation layer located on the circuit contact area. The backlight module according to claim 8, wherein the first conductive anti-oxidation layer is composed of nickel material, and the second conductive anti-oxidation layer is composed of gold material. The backlight module according to claim 8, wherein the circuit layer structure further includes: An alloy bonding layer is formed between the light emitting diode and the second conductive anti-oxidation layer. The backlight module according to claim 10, wherein the alloy bonding layer is made of tin-bismuth alloy or tin-silver-copper alloy. The backlight module of claim 1, wherein the copper-plated layer is formed with a solder mask at a position around the light-emitting diode to locate a welding position of the light-emitting diode on the copper-plated layer. The backlight module according to claim 1, which further includes: A protective layer is coated on the light-emitting diode and the circuit layer structure or is coated on an edge position of the light-emitting diode connected to the circuit layer structure. The backlight module according to claim 1, wherein the circuit layer structure further includes: An alloy bonding layer is formed between the light-emitting diode and the copper plating layer. A method for manufacturing a backlight module is suitable for a keyboard. The keyboard includes a bottom plate and a plurality of keys. The plurality of keys are arranged on the bottom plate. The method for manufacturing the backlight module includes: Providing an optical structure having at least one perforation and having an upper surface and a lower surface; Printing and forming a silver paste circuit layer on one of the upper surface and the lower surface; Plating a copper-plated layer on the silver paste circuit layer; and A light emitting diode is disposed in the at least one through hole and electrically connected to the copper plating layer so that the light emitting diode is electrically connected to the silver paste circuit layer through the copper plating layer, and the light emitting diode emits light to It is incident on each key through the guide of the optical structure. The method for manufacturing a backlight module according to claim 15, wherein the optical structure includes a light guide plate and a flexible circuit substrate, the light guide plate has the at least one through hole, and the flexible circuit substrate is disposed under the light guide plate It has the upper surface and the lower surface, and the light-emitting diode is guided by the light guide plate to enter each button. The method for manufacturing a backlight module according to claim 15, wherein the optical structure includes a light guide plate, a light-shielding sheet, and a reflective sheet, the light-guide plate has the at least one perforation, and the light-shielding sheet is disposed on the light guide plate to allow The light emitted upward from the light guide plate is incident on each button, the reflecting sheet is arranged under the light guide plate to reflect the light emitted downward from the light guide plate back into the light guide plate, the light guide plate, the light shielding sheet, and the light guide plate One of the reflective sheets has the upper surface and the lower surface. The method for manufacturing a backlight module according to claim 17, wherein a plurality of light-transmitting regions are formed on the light-shielding sheet to allow light emitted upward from the light guide plate to enter each button through the plurality of light-transmitting regions, and the circuit layer The structure and the plurality of light-transmitting regions do not overlap with each other. The backlight module manufacturing method according to claim 16 or 17, wherein the silver paste circuit layer has a non-copper-plated area and a circuit contact area, and the backlight module manufacturing method further includes: Forming a shielding layer on the non-copper-plated area to limit the plating position of the copper-plated layer on the silver paste circuit layer; and A first conductive anti-oxidation layer is formed on the circuit contact area for electrical connection to a control circuit board. The method for manufacturing a backlight module according to claim 19, which further includes: The first conductive anti-oxidation layer is formed between the light emitting diode and the copper plating layer. The method for manufacturing a backlight module according to claim 20, which further includes: A second conductive anti-oxidation layer is formed between the first conductive anti-oxidation layer and the light emitting diode and is formed on the first conductive anti-oxidation layer located on the circuit contact area. The method for manufacturing a backlight module according to claim 21, which further includes: An alloy bonding layer is formed between the light emitting diode and the second conductive anti-oxidation layer. The method for manufacturing a backlight module according to claim 15, which further includes: A solder mask is formed at the position of the copper-plated layer corresponding to the periphery of the light-emitting diode to locate a welding position of the light-emitting diode on the copper-plated layer. The method for manufacturing a backlight module according to claim 15, which further includes: A protective layer is coated on the light-emitting diode and the circuit layer structure or is coated on an edge position of the light-emitting diode connected to the circuit layer structure. The method for manufacturing a backlight module according to claim 15, which further includes: An alloy bonding layer is formed between the light emitting diode and the copper plating layer.

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