Keyboard film switch circuit board with lower circuit layer combined with bottom backlight module

Abstract

The utility model discloses a keyboard film switch circuit board with a lower circuit layer combined with a bottom backlight module, and the circuit board is characterized in that a reflector plate front shading layer and a reflector plate back shading layer are fixedly compounded on the surfaces of the front and back sides of a reflector plate substrate to form a shading reflector plate; the MEM upper layer circuit layer and the MEM lower layer circuit layer are fixedly attached to the surfaces of the front side and the back side of the MEM middle interlayer respectively to form a thin film switch, the MEM upper layer shading layer, the MEM upper layer PET layer, the thin film switch, the light guide plate, the shading reflector and the light bar are sequentially attached from top to bottom, a plurality of light-transmitting patterns are formed on the MEM upper layer shading layer, light emitted by the light bar forms uniform light after passing through the shading reflector, and the light-transmitting patterns form uniform light after passing through the light-transmitting reflector. Uniform light is guided upwards through the light guide plate to sequentially penetrate through a circuit gap between the MEM upper layer circuit layer and the MEM lower layer circuit layer of the thin-film switch, and finally the uniform light is emitted outwards through the light-transmitting patterns on the MEM upper layer light shielding layer, and the light-weight thin-film switch can fully meet the light and thin development trend of the notebook computer industry.

Description

Technical Field

[0001] This utility model relates to a keyboard circuit board, and more particularly to a keyboard membrane switch circuit board with a lower circuit layer combined with a bottom backlight module. Background Technology

[0002] In existing keyboard structures, the membrane switch assembly and the backlight module assembly are two separate, individual components, each performing different functions. The membrane switch assembly (MEM) transmits the keyboard's on / off signals, while the backlight module assembly illuminates the back of the keyboard; their functions are incompatible. The total thickness of the assembled components is approximately 0.5mm, with the membrane switch assembly itself being approximately 0.22mm and the backlight module assembly approximately 0.28mm thick.

[0003] With the widespread use of mobile computing devices, keyboard components with backlighting modules have become standard. The thickness of a simple membrane switch component for a keyboard is generally kept within 0.25mm. However, because current laptops require more advanced technology for input in dark environments and with background lighting, they need to be equipped with backlighting modules. Even the thinnest backlighting module with current technology requires a layer thickness of around 0.25mm. Therefore, to achieve backlighting in the keyboard module, the assembly space of the laptop must be extended downwards by at least 0.25mm. This contradicts the current trend of laptops becoming thinner and lighter, and therefore cannot meet the current trend of the laptop industry towards thinner and lighter designs. Utility Model Content

[0004] To overcome the above deficiencies, this utility model provides a keyboard thin-film switch circuit board with a lower circuit layer combined with a bottom backlight module. This keyboard thin-film switch circuit board with a lower circuit layer combined with a bottom backlight module successfully achieves the purpose of reducing thickness without changing the original function.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a keyboard membrane switch circuit board with a lower circuit layer combined with a bottom backlight module, including an upper MEM light-shielding layer, an upper MEM PET layer, an upper MEM circuit layer, a MEM middle partition layer, a lower MEM circuit layer, a light guide plate, a front light-shielding layer of a reflector, a reflector substrate, a back light-shielding layer of a reflector, and a light strip. The front light-shielding layer and the back light-shielding layer of the reflector are respectively fixedly bonded to the front and back surfaces of the reflector substrate. The front light-shielding layer, the reflector substrate, and the back light-shielding layer of the reflector together form a light-shielding reflector. The upper MEM circuit layer and the lower MEM circuit layer are respectively fixedly bonded to the M... A thin-film switch is formed on both sides of the EM partition layer. The light strip is fixed on the back of the light-shielding reflector. The light guide plate is fixedly attached to the front of the light-shielding reflector. The thin-film switch is fixed on the front of the light guide plate. The upper MEM PET layer is solidly laminated to the front of the thin-film switch. The upper MEM light-shielding layer is fixed on the front of the upper MEM PET layer. Several light-transmitting patterns are formed on the upper MEM light-shielding layer. The light emitted by the light strip forms uniform light after passing through the light-shielding reflector. The uniform light is guided upward by the light guide plate and sequentially passes through the gap between the upper and lower MEM circuit layers of the thin-film switch. Finally, it emits light outward through the light-transmitting patterns on the upper MEM light-shielding layer.

[0006] As a further improvement of this utility model, the upper circuit on the upper circuit layer of the MEM and the lower circuit on the lower circuit layer of the MEM are routed along the area of ​​the circuit board that needs to be shielded, thereby partially blocking the light emitted from the light guide plate, so that the upper part of the circuit board emits light only in the designated area.

[0007] As a further improvement of this utility model, some upper lines on the upper circuit layer of the MEM and some lower lines on the lower circuit layer of the MEM are arranged in a staggered and closely spaced manner to fill the gaps between adjacent lines on the same layer for light shielding, thereby making the upper and lower lines together form a widened light shielding area. Some upper lines on the upper circuit layer of the MEM and some lower lines on the lower circuit layer of the MEM are arranged in an overlapping wiring manner to reduce the light shielding width. Areas that are not traversed by the upper and lower lines form a light-transmitting area.

[0008] As a further improvement of this utility model, the MEM partition layer is provided with a plurality of hollow trigger avoidance holes. The upper MEM circuit layer and the lower MEM circuit layer are respectively attached to the upper and lower surfaces of the MEM partition layer by the upper MEM adhesive layer and the lower MEM adhesive layer. The upper contact point on the lower side of the upper MEM circuit layer and the lower contact point on the upper side of the lower MEM circuit layer are respectively aligned with the hollow trigger avoidance holes on the MEM partition layer. A pressing position is formed on the upper side of the upper MEM circuit layer, which is aligned with the position of the upper contact point. The pressing position of the upper MEM circuit layer is deformed downward under pressure, so that the upper contact point makes electrical contact and conduction with the upper contact point on the lower MEM circuit layer through the hollow trigger avoidance holes.

[0009] As a further improvement of this utility model, the light guide plate is attached to the front of the light-shielding reflector through an adhesive layer on the front of the reflector.

[0010] As a further improvement of this utility model, the front light-shielding layer, the back light-shielding layer, and the substrate of the reflective sheet are multi-layer structures formed by co-extrusion of light-shielding material and reflective material.

[0011] As a further improvement of this utility model, the upper light-shielding layer of the MEM is formed by printing light-shielding material onto the upper PET layer of the MEM.

[0012] As a further improvement of this utility model, the total thickness of the circuit board with the stacked structure formed by the light strip, the light-shielding reflector, the light guide plate, the thin film switch, the upper light-shielding layer of MEM and the upper PET layer of MEM is 0.318MM-0.338MM.

[0013] The beneficial technical effects of this utility model are as follows: This utility model combines the thin-film switch and the backlight module through a special design scheme, so that the light guide plate layer of the backlight module is applied to the lower structure of the thin-film switch assembly, eliminating the light-shielding layer of the backlight assembly. The light-shielding effect is achieved by the circuit layer of the thin-film switch. In this way, each of the two components reduces the use of one layer of basic material, and the thickness is successfully reduced without changing the original function, thus fully meeting the trend of thinner and lighter laptops in the industry. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the interlayer structure in the prior art;

[0015] Figure 2 This is a schematic diagram of the interlayer structure of this utility model;

[0016] Figure 3 This is a circuit diagram of a membrane switch in the prior art;

[0017] Figure 4 This is a circuit diagram of the membrane switch of this utility model. Detailed Implementation

[0018] Example: A keyboard membrane switch circuit board with a lower circuit layer integrated with a bottom backlight module, comprising an upper MEM light-shielding layer 1, an upper MEM PET layer 2, an upper MEM circuit layer 3, a MEM middle partition layer 5, a lower MEM circuit layer 7, a light guide plate 8, a front light-shielding layer 10 of a reflective sheet, a reflective sheet substrate 11, a back light-shielding layer 12 of a reflective sheet, and a light strip 13. The front light-shielding layer 10 and the back light-shielding layer 12 of the reflective sheet are respectively fixedly bonded to the front and back surfaces of the reflective sheet substrate 11. The front light-shielding layer 10, the reflective sheet substrate 11, and the back light-shielding layer 12 of the reflective sheet together form a light-shielding reflective sheet. The upper MEM circuit layer 3 and the lower MEM circuit layer 7 are respectively fixedly bonded to the MEM middle partition layer 5. A thin-film switch is formed on both sides of the partition layer 5. The light strip 13 is fixedly disposed on the back of the light-shielding reflector. The light guide plate 8 is fixedly attached to the front of the light-shielding reflector. The thin-film switch is fixedly disposed on the front of the light guide plate 8. The upper MEM PET layer 2 is solidly laminated to the front of the thin-film switch. The upper MEM light-shielding layer 1 is fixedly disposed on the front of the upper MEM PET layer 2. Several light-transmitting patterns are formed on the upper MEM light-shielding layer 1. The light emitted by the light strip 13 forms uniform light after passing through the light-shielding reflector. The uniform light is guided upward through the light guide plate 8 and sequentially passes through the gap between the upper MEM circuit layer 3 and the lower MEM circuit layer 7 of the thin-film switch. Finally, it emits light outward through the light-transmitting patterns on the upper MEM light-shielding layer 1.

[0019] By utilizing the lines on the upper circuit layer 3 and the lower circuit layer 7 of the MEM to block light, and forming a light-transmitting part through the gaps between the lines on the upper circuit layer 3 and the lower circuit layer 7 of the MEM, the lines on the upper circuit layer 3 and the lower circuit layer 7 of the MEM replace the light-blocking layer of the backlight assembly to block light, thereby eliminating the need for a light-blocking layer in the backlight assembly. At the same time, the remaining part of the backlight assembly is directly combined with the lower layer of the thin-film switch assembly, and a reflector replaces the bottom PET layer of the thin-film switch assembly. Thus, by organically combining the thin-film switch assembly with the backlight module assembly, this application can eliminate the multi-layer structure, significantly reducing the thickness of the entire keyboard membrane switch circuit board, thereby meeting the demand for thinner and lighter laptops.

[0020] The upper line 31 on the upper circuit layer 3 of the MEM and the lower line 71 on the lower circuit layer 7 of the MEM run along the areas of the circuit board that need to be shielded, thereby partially blocking the light emitted from the light guide plate 8, so that the upper part of the circuit board only emits light in the designated areas. By arranging the upper line 31 on the upper circuit layer 3 of the MEM and the lower line 71 on the lower circuit layer 7 of the MEM, excess light is blocked, so that the area above the membrane switch only emits light around the buttons and the keyboard, thus serving as a light-shielding layer.

[0021] The upper lines 31 on the upper layer 3 of the MEM and the lower lines 71 on the lower layer 7 of the MEM are arranged in a staggered and closely spaced manner to fill the gaps between adjacent lines on the same layer for light blocking. This results in the upper lines 31 and the lower lines 71 together forming a wider light-blocking area. The upper lines 31 on the upper layer 3 and the lower lines 71 on the lower layer 7 of the MEM are arranged in an overlapping manner to reduce the light-blocking width. Areas not traversed by either the upper lines 31 or the lower lines 71 form a light-transmitting area. The lower lines 71 are arranged in an overlapping manner, so that the lower lines 71 cover the gaps between the upper lines 31, and the upper lines 31 cover the gaps between the lower lines 71. Together, the upper lines 31 and the lower lines 71 form a light-blocking area that prevents light from propagating upwards.

[0022] The MEM middle partition layer 5 is provided with several hollow trigger avoidance holes. The MEM upper circuit layer 3 and MEM lower circuit layer 7 are respectively attached to the upper and lower surfaces of the MEM middle partition layer 5 through the MEM upper water-based adhesive layer 4 and the MEM lower water-based adhesive layer 6. The upper contact point on the lower side of the MEM upper circuit layer 3 and the lower contact point on the upper side of the MEM lower circuit layer 7 are all directly opposite to the hollow trigger avoidance holes on the MEM middle partition layer 5. A pressing position is formed on the upper side of the MEM upper circuit layer 3, which is directly opposite to the position of the upper contact point. The pressing position of the MEM upper circuit layer 3 is deformed downward under pressure, so that the upper contact point makes electrical contact and conduction with the upper contact point on the MEM lower circuit layer 7 through the hollow trigger avoidance hole.

[0023] The light guide plate 8 is attached to the front of the light-shielding reflector through the adhesive layer 9 on the front of the reflector.

[0024] The front light-shielding layer 10, the back light-shielding layer 12, and the substrate 11 of the reflective sheet are multi-layered structures formed by co-extrusion of light-shielding and reflective materials. The multi-layered film is co-extruded with the light-shielding material after homogenization, and the light is uniformly treated through the reflective and light-shielding surfaces.

[0025] The upper light-shielding layer 1 of the MEM is formed by printing light-shielding material onto the upper PET layer 2 of the MEM.

[0026] The total thickness of the circuit board formed by the stacked structure of the light strip 13, the light-shielding reflector, the light guide plate 8, the thin-film switch, the upper light-shielding layer 1 of the MEM, and the upper PET layer 2 of the MEM is 0.318 mm to 0.338 mm. In the prior art, the total thickness of the combined structure of the thin-film switch assembly and the backlight module assembly is 0.571 mm to 0.607 mm. The total thickness of the circuit board constructed in this application is much smaller than that of the prior art, which can meet the development needs of thinner and lighter laptops.

Claims

1. A keyboard membrane switch circuit board with a lower circuit layer integrated with a bottom backlight module, characterized in that: The light guide plate includes an upper MEM light-shielding layer (1), an upper MEM PET layer (2), an upper MEM circuit layer (3), a MEM middle partition layer (5), a lower MEM circuit layer (7), a light guide plate (8), a front light-shielding layer (10) of the reflector, a reflector substrate (11), a back light-shielding layer (12) of the reflector, and a light strip (13). The front light-shielding layer and the back light-shielding layer of the reflector are respectively fixedly bonded to the front and back surfaces of the reflector substrate. The front light-shielding layer, the reflector substrate, and the back light-shielding layer of the reflector together form a light-shielding reflector. The upper MEM circuit layer and the lower MEM circuit layer are respectively fixedly bonded to the front and back surfaces of the MEM middle partition layer. A thin-film switch is formed on both sides. The light strip is fixed on the back of the light-shielding reflector. The light guide plate is fixedly attached to the front of the light-shielding reflector. The thin-film switch is fixed on the front of the light guide plate. The upper MEM PET layer is solidly laminated to the front of the thin-film switch. The upper MEM light-shielding layer is fixed on the front of the upper MEM PET layer. Several light-transmitting patterns are formed on the upper MEM light-shielding layer. The light emitted by the light strip forms uniform light after passing through the light-shielding reflector. The uniform light is guided upward by the light guide plate and sequentially passes through the gap between the upper and lower MEM circuit layers of the thin-film switch. Finally, it emits light outward through the light-transmitting patterns on the upper MEM light-shielding layer.

2. The keyboard membrane switch circuit board with the lower circuit layer combined with the bottom backlight module as described in claim 1, characterized in that: The upper line (31) on the upper layer of the MEM and the lower line (71) on the lower layer of the MEM are routed along the area of ​​the circuit board that needs to be shielded, thereby partially blocking the light emitted from the light guide plate, so that the upper part of the circuit board emits light only in the designated area.

3. The keyboard membrane switch circuit board with the lower circuit layer combined with the bottom backlight module as described in claim 2, characterized in that: The upper circuits on the upper layer of the MEM and the lower circuits on the lower layer of the MEM are arranged in a staggered and closely spaced manner to fill the gaps between adjacent circuits on the same layer for light blocking, thereby making the upper and lower circuits together form a widened light blocking area. The upper circuits on the upper layer of the MEM and the lower circuits on the lower layer of the MEM are arranged in an overlapping wiring method to reduce the light blocking width. The area that neither the upper nor the lower circuits pass through forms a light-transmitting area.

4. The keyboard membrane switch circuit board with the lower circuit layer combined with the bottom backlight module as described in claim 1, characterized in that: The MEM partition layer is provided with several hollow trigger avoidance holes. The upper MEM circuit layer and the lower MEM circuit layer are respectively attached to the upper and lower surfaces of the MEM partition layer through the upper MEM water adhesive layer (4) and the lower MEM water adhesive layer (6). The upper contact point on the lower side of the upper MEM circuit layer and the lower contact point on the upper side of the lower MEM circuit layer are respectively aligned with the hollow trigger avoidance holes on the MEM partition layer. A pressing position is formed on the upper side of the upper MEM circuit layer that is aligned with the position of the upper contact point. The pressing position of the upper MEM circuit layer is deformed downward under pressure, so that the upper contact point makes electrical contact with the upper contact point on the lower MEM circuit layer through the hollow trigger avoidance hole.

5. The keyboard membrane switch circuit board with the lower circuit layer combined with the bottom backlight module according to claim 1, characterized in that: The light guide plate is attached to the front of the light-shielding reflector through the adhesive layer (9) on the front of the reflector.

6. The keyboard membrane switch circuit board with the bottom backlight module combined with the lower circuit layer according to claim 1, characterized in that: The front light-shielding layer, the back light-shielding layer, and the substrate of the reflective sheet are a multi-layer structure formed by co-extrusion of light-shielding and reflective materials.

7. The keyboard membrane switch circuit board with the lower circuit layer combined with the bottom backlight module according to claim 1, characterized in that: The upper light-shielding layer of the MEM is formed by printing light-shielding material onto the upper PET layer of the MEM.

8. The keyboard membrane switch circuit board with the bottom backlight module combined with the lower circuit layer according to claim 1, characterized in that: The total thickness of the circuit board with the stacked structure formed by the light strip, light-shielding reflector, light guide plate, thin-film switch, upper MEM light-shielding layer and upper MEM PET layer is 0.318MM-0.338MM.

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