TWM537254U - Keyswitch device and circuit board assembly - Google Patents

Abstract

A keyswitch device includes a printed circuit board, a transmissive layer, a light guide spacer, a light source, and a keyswitch assembly. The transmissive layer is located over the printed circuit board. The printed circuit board and the transmissive layer are respectively located at opposite sides of the light guide spacer. The light source is disposed on the printed circuit board and emits toward the transmissive layer. The keyswitch assembly is disposed on the transmissive layer.

Description

Button device and circuit board assembly

The present invention relates to a button device and a circuit board assembly, and more particularly to an illuminable button device and a circuit board assembly.

In terms of the current usage habits of personal computers, the keyboard is one of the indispensable input devices for inputting text or numbers. Moreover, the consumer-grade electronic products that are in contact with everyday life or the large-scale processing equipment used in the industry need to have a button structure as an input device to operate the above-mentioned electronic products and processing equipment.

In order to facilitate the use of the keyboard in a darker place, the market has developed a Light-Emitting Diode (LED) illuminated keyboard, which allows users to use it in places with dark lighting, thus making the keyboard more diverse. Increase in sex. Referring to Taiwan Patent No. I220213, there is a conventional illuminating keyboard which additionally includes a light guide body and a light emitting diode on the keyboard, so that light emitted by the light emitting diode can be incident into the light guide body, and The conduction of the light guide body is uniformly outputted or transmitted to the keycap. Today's computer products are moving in a light, thin, short, and small direction, and the keyboard is no exception. Under this development trend, the aforementioned conventional illuminated keyboard will not conform to the thickness because of the need to add a light guide. need.

Therefore, how to propose a button device that can solve the above problems is one of the problems that the industry is eager to invest in research and development resources.

In view of this, one of the purposes of the present invention is to propose a key device and a circuit board assembly that can effectively reduce the overall thickness.

In order to achieve the above object, according to one embodiment of the present invention, a button device includes a printed circuit board, a transmissive layer, a light guiding spacer, a light source, and a button assembly. The transmission layer is located above the printed circuit board. The printed circuit board and the transmissive layer are separated from opposite sides of the light guiding spacer layer. The light source is disposed on the printed circuit board and emits light toward the transmission layer. The button assembly is disposed on the transmission layer.

In one or more embodiments of the present invention, the transmissive layer is a thin film layer. The light guiding spacer layer has an accommodating space. The light source is located in the accommodating space.

In one or more embodiments of the present invention, the transmissive layer comprises a transparent substrate. The transparent substrate is provided with a reflective coating and a masking coating, and forms a transmissive region and a reflective region. The orthographic projection of the button assembly on the transmissive layer encompasses the transmissive region. The orthographic projection of the accommodating space on the transmissive layer overlaps with the reflective coating.

In one or more embodiments of the present invention, the transparent substrate described above has a top surface. The top surface faces the button assembly. The reflective coating is placed on the top surface. The masking coating covers the reflective coating.

In one or more embodiments of the present invention, the transparent substrate has a top surface and a bottom surface. The top surface faces the button assembly. The bottom surface guides the light spacer layer. The masking coating is disposed on the top surface. The reflective coating is placed on the bottom surface.

In one or more embodiments of the present invention, the transparent substrate described above has a bottom surface. The bottom surface guides the light spacer layer. The masking coating is placed on the bottom surface. The reflective coating covers the masking coating.

In one or more embodiments of the present invention, the light guiding spacer layer further has a through hole. The perforations are located directly below the button assembly. The printed circuit board contains a switching circuit. The transmission layer contains a conductive junction. The junction is configured to contact the switch circuit via the via.

In one or more embodiments of the present invention, the transmissive layer includes a reflective coating and a masking coating disposed on the light guiding spacer. The reflective coating forms a transmissive area with the masking coating. The orthographic projection of the button assembly on the transmissive layer encompasses the transmissive region. The orthographic projection of the source on the transmissive layer overlaps the reflective coating.

In one or more embodiments of the present invention, the reflective coating described above is applied to the light guiding spacer. The masking coating is applied to the reflective coating.

In one or more embodiments of the present invention, the light guiding spacer layer has a plurality of reflecting portions. The reflecting portion is located on a surface of the light guiding spacer facing the printed circuit board and corresponds to the button assembly.

In one or more embodiments of the present invention, the button device described above further includes a bottom plate. The printed circuit board is placed on the bottom plate.

In one or more embodiments of the present invention, the printed circuit board described above includes a switching circuit. The transmission layer has a first perforation. The light guiding spacer layer also has a second through hole substantially aligned with the first through hole. The button assembly contains conductive members. The conductive member is configured to electrically contact the switch circuit through the first through hole and the second through hole in sequence.

In one or more embodiments of the present invention, the conductive member is a conductive rubber member.

In order to achieve the above object, in accordance with another embodiment of the present invention, a circuit board assembly includes a printed circuit board, a transmissive layer, a light guiding spacer, and a light source. The transmission layer is located above the printed circuit board. The printed circuit board and the transmissive layer are separated from opposite sides of the light guiding spacer layer. The light source is disposed on the printed circuit board and emits light toward the transmission layer.

In summary, the key device and the circuit board assembly of the present invention provide a light source between the printed circuit board and the transmissive layer, and provide a light guiding function by using a spacer layer disposed between the printed circuit board and the transmissive layer. The function of the light shielding layer and the reflection layer is achieved by using the printed circuit board and the transmission layer. Thereby, the overall thickness of the key device can be effectively reduced. Moreover, since the key device and the circuit board assembly of the present invention integrate the switch circuit for generating the trigger signal and the power supply circuit for supplying the light source on the printed circuit board, the thin film circuit board in the conventional illuminated keyboard is not required. Further, the manufacturing cost and the assembly process can be reduced.

The above description is only used to explain the problems to be solved by the present invention, the technical means for solving the problems, the effects thereof, and the like, and the specific details of the present invention will be described in detail in the following embodiments and related drawings.

100, 200‧‧‧ button device

110‧‧‧floor

111‧‧‧ hook

120‧‧‧Printed circuit board

121‧‧‧Switch circuit

122‧‧‧Power supply circuit

130, 230‧‧‧Transmission layer

131‧‧‧Transparent substrate

131a‧‧‧ top

131b‧‧‧ bottom

132, 231‧‧‧Reflective coating

133, 232‧‧‧ mask coating

134, 233‧‧‧Transmission zone

135‧‧‧Contact points

140, 240‧‧‧Lighting spacer

141‧‧‧Perforation

142, 242‧‧‧Reflection

150‧‧‧Light source

160, 260‧‧‧ button components

161‧‧‧Connecting parts

162‧‧‧Key Cap

163, 263‧‧‧Reset parts

234‧‧‧First perforation

241‧‧‧Second perforation

263a‧‧‧Electrical parts

S‧‧‧ accommodating space

To make the above and other objects, features, advantages and embodiments of the present invention more apparent, the description of the drawings is as follows:

FIG. 1 is a perspective exploded view of a key device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a key device according to an embodiment of the present invention.

Fig. 3 is a partial cross-sectional view showing the key device of Fig. 2.

4 is a partial cross-sectional view showing the circuit board assembly of FIG. 2 in an embodiment.

Figure 5 is a partial cross-sectional view showing the circuit board assembly of Figure 2 in another embodiment.

Figure 6 is a cross-sectional view showing a key device of another embodiment of the present invention.

Fig. 7 is a partial cross-sectional view showing the key device of Fig. 6.

Figure 8 is a partial cross-sectional view showing the circuit board assembly of Figure 6.

In the following, a plurality of embodiments of the present invention will be disclosed in the drawings. For the sake of clarity, a number of practical details will be described in the following description. However, it should be understood that these practical details are not applied to limit the creation. That is to say, in the implementation part of this creation, these practical details are not necessary. In addition, some of the conventional structures and elements are shown in the drawings in a simplified schematic manner in order to simplify the drawings.

Please refer to Figure 1 and Figure 2. FIG. 1 is a perspective exploded view of a key device 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the key device 100 according to an embodiment of the present invention. As shown in FIG. 1 and FIG. 2, the button device 100 of the present embodiment may be a button for a desktop computer to use a keyboard (for example, a keyboard of a PS2 interface or a keyboard of a USB interface) or an input including a keyboard. The button of the device, but not limited to this. In other words, the concept of the key device 100 of the present invention can be applied to any electronic product that uses a button as an input interface.

As shown in FIGS. 1 and 2, in the present embodiment, the button is mounted. The device 100 includes a bottom plate 110, a printed circuit board 120, a transmissive layer 130, a light guiding spacer 140, a light source 150, and a button assembly 160. The combination of the printed circuit board 120, the transmissive layer 130, the light guiding spacer layer 140 and the light source 150 can be regarded as A separate board assembly. The circuit board assembly is disposed on the bottom plate 110. The button assembly 160 is disposed on the circuit board assembly.

Specifically, the bottom plate 110 extends with a hook 111. The printed circuit board 120 correspondingly has a through hole (not shown) for the hook 111 of the bottom plate 110 to pass through. The button assembly 160 includes a connector 161, a keycap 162, and a reset member 163. In this embodiment, the connecting member 161 is connected between the key cap 162 and the hook 111 of the bottom plate 110, and is pivotally connected by the two connecting rods, so as to drive the key cap 162 to move up and down with respect to the bottom plate 110. The reset member 163 is disposed above the circuit board assembly and between the keycap 162 and the circuit board assembly. When the keycap 162 is pressed down by receiving an external force, the reset member 163 will generate a resistance to the keycap 162, thereby providing a user's feeling of pressing, and when the external force applied to the keycap 162 is released, the reset member 163 can be provided. The pressing key cap 162 returns to the restoring force of the original unpressed position. In the embodiment, the resetting member 163 can be an elastic member such as a rubber dome, a metal dome or a spring piece.

In practical applications, the connecting member 161 can also be replaced with other connecting structures having similar functions (ie, driving the keycap 162 to move up and down relative to the bottom plate 110), such as a V-shaped, A-shaped or two-parallel connecting rod structure. The reset member 163 can also be replaced with other components having similar functions, such as magnetic components.

In practical applications, the button device 100 can also cancel the bottom plate 110 and thermally fuse a frame (not shown) on the printed circuit board 120 to engage with the bottom end of the connector 161.

As shown in FIGS. 1 and 2, in the present embodiment, the printed circuit board 120 is placed on the bottom plate 110. The transmissive layer 130 is located above the printed circuit board 120. The printed circuit board 120 and the transmissive layer 130 are separated from opposite sides of the light guiding spacer layer 140. That is, the light guiding spacer 140 separates the printed circuit board 120 from the transmitting layer 130 by its thickness. The light guiding spacer layer 140 has a through hole 141. The perforations 141 are located directly below the button assembly 160.

Further, please refer to FIG. 3, which is a partial cross-sectional view showing the key device 100 in FIG. As shown in FIG. 3, the printed circuit board 120 includes a switch circuit 121. Transmissive layer 130 includes conductive contacts 135. The contact point 135 is configured to contact the switch circuit 121 via the via 141, respectively. Specifically, when the keycap 162 is not pressed, the conductive contacts 135 on the transmissive layer 130 are electrically separated from the switching circuits 121 on the printed circuit board 120 by being separated from both sides of the light guiding spacer 140. When the keycap 162 is pressed to move toward the bottom plate 110, the keycap 162 directly or indirectly pushes the transmissive layer 130 partially into the perforation 141 of the light guiding spacer layer 140, so that the guiding point 135 on the transmissive layer 130 passes through the guide. The perforations 141 of the light spacer layer 140 contact the switch circuit 121 on the printed circuit board 120 (i.e., the triggering behavior, in the present embodiment, the transmissive layer 130 is pushed through the reset member 163 to trigger the switch circuit 121). Thereby, the switch circuit 121 then generates a trigger signal corresponding to the pressed button device 100. In some embodiments, the switch circuit 121 is a finger electrode. It should be noted that, since the switch circuit 121 is disposed on the printed circuit board 120, the transmissive layer 130 can only be provided with the conductive contact point 135 to avoid setting a complicated switching circuit, thereby preventing the light from being blocked by the switch circuit, thereby increasing the light passing through. The efficiency of the transmission layer 130.

In addition, please refer to FIG. 4, which is a circuit board in FIG. A partial cross-sectional view of an assembly in one embodiment. The light guiding spacer layer 140 has a housing space S. The light source 150 is disposed between the printed circuit board 120 and the transmissive layer 130 and located in the accommodating space S. According to the configuration of the present invention, the key device 100 of the present embodiment has the light source 150 disposed between the printed circuit board 120 and the transmissive layer 130 and utilizes the light guiding spacer 140 disposed between the printed circuit board 120 and the transmissive layer 130. Provides light guiding function. Thereby, the overall thickness of the key device and the key device 100 can be effectively reduced.

As shown in FIGS. 3 and 4, in the present embodiment, the transmission layer 130 includes a transparent substrate 131. The transparent substrate 131 is provided with a reflective coating 132 and a masking coating 133. The transparent substrate 131 has a top surface 131a and a bottom surface 131b. The top surface 131a of the transparent substrate 131 faces the button assembly 160. The bottom surface 131b of the transparent substrate 131 is guided to the light spacer layer 140. The reflective coating 132 is disposed on the top surface 131a of the transparent substrate 131, and forms a transmissive region 134 where the reflective coating 132 and the masking coating 133 are not coated (refer to FIG. 3 for cooperation). The orthographic projection of the button assembly 160 on the board assembly corresponds (e.g., encompasses) the transmissive region 134. The circuit board assembly also includes a power supply circuit 122 disposed on the printed circuit board 120. The light source 150 is disposed on the printed circuit board 120 and is powered by the power supply circuit 122.

In the present embodiment, the light source 150 is a top-emitting light-emitting diode, and the orthographic projection of the accommodating space S of the light-guiding spacer layer 140 on the transmission layer 130 overlaps with the reflective coating 132, so that the light source 150 faces the transmission layer. The light emitted by the 130 is first transmitted through the transparent substrate 131 and reflected by the reflective coating 132 into the light guiding spacer 140 for conduction, and the light source 150 is ensured by the reflective function of the reflective coating 132 of the transmitting layer 130. All of the emitted light can be efficiently conducted in the light guiding spacer layer 140 and can be used to reflect and shield the light around the light source 150. Line, to avoid the brightness of the area around the light source 150 is too high, thereby improving the uniformity of the light. When the transmitted light reaches the transmissive region 134 formed by the uncoated masking coating 133 and the reflective coating 132 (as shown in FIG. 3), it passes through the transmissive region 134 and reaches the button assembly 160, thereby reaching The effect of causing the button assembly 160 to emit light. Moreover, by providing the light source 150 between the printed circuit board 120 and the transmission layer 130, the light source 150 can also be protected from dust and water.

In practical applications, in order to meet the actual demand, the number of the transmissive regions 134 corresponding to the button assembly 160 can be flexibly increased or decreased, and the shape of the transmissive region 134 can also be flexibly adjusted.

In the present embodiment, the light guiding spacer layer 140 has a reflecting portion 142. The reflection portion 142 may be disposed on the top surface or the bottom surface of the light guiding spacer layer 140. In the present embodiment, the reflection portion 142 is disposed on the bottom surface of the light guiding spacer layer 140. In some embodiments, the reflective portion 142 can form a dot-like reflective pattern or be a recessed structure. By controlling the shape, the number, the size, and the arrangement of the reflecting portions 142, the light intensity of the light conducted in the light guiding spacer layer 140 throughout the light guiding spacer layer 140 can be uniform and uniform.

Therefore, since the key device 100 of the present embodiment integrates the switch circuit 121 for generating the trigger signal and the power supply circuit 122 for supplying the light source 150 on the printed circuit board 120, it is not required to use the conventional illuminated keyboard. The thin film circuit board can further reduce the manufacturing cost and the assembly process. Moreover, since the printed circuit board 120, the transmissive layer 130, the light guiding spacer 140 and the light source 150 can be directly fabricated as a single module, the assembled components can be reduced compared to the conventional illuminated keyboard, thereby saving Raw material cost and assembly steps.

Please refer to FIG. 5, which is a circuit board assembly in FIG. A partial cross-sectional view in another embodiment. As shown in FIG. 5, in the present embodiment, the transmission layer 130 also includes a transparent substrate 131. The transparent substrate 131 is provided with a reflective coating 132 and a masking coating 133. The difference between the circuit board assembly of the present embodiment and the circuit board assembly of FIG. 4 is that the shielding coating layer 133 of the present embodiment is disposed on the top surface 131a of the transparent substrate 131, and the reflective coating layer 132 is disposed on the transparent substrate. The bottom surface 131b of 131. That is to say, the reflective coating 132 and the shielding coating 133 shown in FIG. 4 are both located outside the transmission layer 130, and the reflective coating 132 and the shielding coating 133 shown in FIG. 5 are respectively located inside the transmission layer 130. With the outside. In addition, the shielding coating 133 may also be disposed on the bottom surface 131b of the transparent substrate 131, and the reflective coating 132 covers the shielding coating 133, that is, the reflective coating 132 and the shielding coating 133 are located inside the transmission layer 130.

In some embodiments, the bottom plate 110 may be made of a hard material (for example, metal or plastic), but the present invention is not limited thereto.

In some embodiments, the printed circuit board 120 is a substrate made of a non-transparent material having a reflective effect.

Please refer to Figure 6, Figure 7, and Figure 8. FIG. 6 is a cross-sectional view showing a key device 200 according to another embodiment of the present invention. Fig. 7 is a partial cross-sectional view showing the key device 200 in Fig. 6. Figure 8 is a partial cross-sectional view showing the circuit board assembly of Figure 6. As shown in FIG. 6 to FIG. 8 , in the present embodiment, the button device 200 includes a bottom plate 110 , a printed circuit board 120 , a transmissive layer 230 , a light guiding spacer 240 , a light source 150 , and a button assembly 260 , wherein the printed circuit board 120, the transmission layer 230, the combination of the light guiding spacer 240 and the light source 150 can be regarded as a separate circuit board assembly, and the bottom plate 110, the printed circuit board 120 and the light source 150 are the same as the embodiment shown in FIG. 2, so reference can be made to the foregoing Related Ming, I will not repeat them here. In addition, the button assembly 260 includes a connector member 161, a key cap 162, and a reset member 263. The connector member 161 and the key cap 162 are the same as those of the embodiment shown in FIG. 2, and therefore, the related descriptions are also referred to, and details are not described herein again. .

It should be noted that, in a difference between the button device 200 of the present embodiment and the button device 100 of the embodiment shown in FIG. 2, the light guiding spacer 240 of the present embodiment cancels the accommodating space S, and therefore The light source 150 on the printed circuit board 120 is illuminated by the lower side of the light guiding spacer 240 toward the light guiding spacer 240.

Another difference between the button device 200 of the present embodiment and the button device 100 of the embodiment shown in FIG. 2 is that the transmission layer 230 of the present embodiment includes the reflective coating layer 231 disposed on the light guiding spacer 240. And the masking coating 232 (that is, the transmission layer 230 of the present embodiment cancels the transparent substrate 131 of the transmission layer 130 in FIG. 2). Specifically, the reflective coating 231 is directly applied to the light guiding spacer 240, and the masking coating 232 is directly applied to the reflective coating 231. The reflective coating 231 forms a transmissive region 233 with the masking coating 232 (see Figure 8). The orthographic projection of button assembly 260 on transmissive layer 230 encompasses transmissive region 233. The orthographic projection of the light source 150 on the transmissive layer 230 overlaps with the reflective coating 231, so that the light emitted by the light source 150 is reflected by the reflective coating 231 and returned to the light guiding spacer 240 for conduction. By the reflective function of the reflective coating 231, it can be ensured that all the light emitted by the light source 150 can be efficiently conducted in the light guiding spacer 240, and can be used for reflecting and shielding the light around the light source 150, thereby avoiding the brightness of the area around the light source 150. Too high to improve light uniformity. The transmitted region formed when the transmitted light reaches the uncoated masking layer 232 and the reflective coating 231 At 233 (as shown in Fig. 8), it will pass through the transmissive area 233 and reach the button assembly 260, thereby achieving the effect of illuminating the button assembly 260. The light guiding spacer layer 240 has a reflecting portion 242. The installation position and function of the reflection portion 242 are the same as those of the reflection portion 142 shown in FIG. 4, and therefore, the related description will be referred to, and will not be described herein.

A further difference between the button device 200 of the present embodiment and the button device 100 of the embodiment shown in FIG. 2 is that the transmission layer 230 of the present embodiment has a first through hole 234, and the light guiding spacer layer 240 further has The second through hole 241 is substantially aligned with the first through hole 234. And the reset member 263 of the button assembly 260 includes a conductive member 263a. The conductive member 263a is configured to pass through the first through hole 234 and the second through hole 241 to electrically contact the switch circuit 121 on the printed circuit board 120. In this embodiment, the conductive member 263a is electrically conductive disposed at the bottom of the reset member 263. Rubber parts.

Specifically, when the keycap 162 is not pressed, the conductive member 263a on the reset member 263 and the switch circuit 121 on the printed circuit board 120 are electrically separated from each other on both sides of the light guiding spacer 240. When the keycap 162 is pressed to move toward the bottom plate 110, the keycap 162 pushes the reset member 263 toward the bottom plate 110 such that the conductive member 263a passes through the first through hole 234 of the transmissive layer 230 to partially enter the light guiding spacer layer 240. The second through hole 241, in turn, contacts the switch circuit 121 on the printed circuit board 120 (i.e., the triggering action, in the present embodiment, the conductive member 263a triggers the switch circuit 121 by moving through the reset member 263). Thereby, the switch circuit 121 then generates a trigger signal corresponding to the pressed button device 200.

From the above detailed description of the specific implementation of the present invention, it can be clearly seen that the key device and the circuit board assembly of the present invention are disposed between the printed circuit board and the transmissive layer, and are disposed on the printed circuit board by using the same. And transmission The spacer layer between the layers provides the function of light guiding while utilizing the functions of the printed circuit board and the transmissive layer to achieve the light shielding layer and the reflective layer. Thereby, the overall thickness of the key device can be effectively reduced. Moreover, since the key device and the circuit board assembly of the present invention integrate the switch circuit for generating the trigger signal and the power supply circuit for supplying the light source on the printed circuit board, the thin film circuit board in the conventional illuminated keyboard is not required. Further, the manufacturing cost and the assembly process can be reduced.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any person skilled in the art can make various changes and refinements without departing from the spirit and scope of the present creation. The scope is subject to the definition of the scope of the patent application.

100‧‧‧Key device

110‧‧‧floor

111‧‧‧ hook

120‧‧‧Printed circuit board

130‧‧‧Transmission layer

140‧‧‧Lighting spacer

141‧‧‧Perforation

150‧‧‧Light source

160‧‧‧Key components

161‧‧‧Connecting parts

162‧‧‧Key Cap

163‧‧‧Reset parts

S‧‧‧ accommodating space

Claims (24)

A button device comprising: a printed circuit board; a transmissive layer above the printed circuit board; a light guiding spacer, wherein the printed circuit board and the transmissive layer are separated from opposite sides of the light guiding spacer; a light source disposed on the printed circuit board and emitting light toward the transmission layer; and a button assembly disposed on the transmission layer. The key device of claim 1, wherein the transmissive layer is a film layer, the light guiding spacer layer has an accommodating space, and the light source is located in the accommodating space. The key device of claim 2, wherein the transmissive layer comprises: a transparent substrate, the transparent substrate is provided with a reflective coating and a masking coating, and forms a transmissive area, wherein the button assembly is An orthographic projection on the transmissive layer covers the transmissive region, and an orthographic projection of the accommodating space on the transmissive layer overlaps the reflective coating. The button device of claim 3, wherein the transparent substrate has a top surface facing the button assembly, the reflective coating is disposed on the top surface, and the masking coating covers the reflective coating. The key device of claim 3, wherein the transparent substrate has a top surface and a bottom surface, the top surface facing the button assembly, the bottom surface facing the light guiding spacer layer, and the shielding coating layer is disposed on the top surface The reflective coating is disposed on the bottom surface. The key device of claim 3, wherein the transparent substrate has a bottom surface facing the light guiding spacer, the shielding coating is disposed on the bottom surface, and the reflective coating covers the shielding coating. The button device of claim 1, wherein the light guiding spacer further has a through hole directly under the button assembly, the printed circuit board comprises a switch circuit, and the transmission layer comprises a conductive contact And the conductive contact is configured to contact the switching circuit via the via. The key device of claim 1, wherein the transmissive layer comprises a reflective coating disposed on the light guiding spacer and a shielding coating, and the reflective coating forms a transmissive region with the shielding coating. An orthographic projection of the button assembly on the transmissive layer covers the transmissive region, and an orthographic projection of the light source on the transmissive layer overlaps the reflective coating. The button device of claim 8, wherein the reflective coating is applied to the light guiding spacer layer, and the masking coating is applied to the reflective coating. The button device of claim 1, wherein the light guiding spacer layer has a reflecting portion, and the reflecting portion is located on a surface of the light guiding spacer facing the printed circuit board, and corresponds to the button assembly. The button device of claim 1, further comprising a bottom plate, wherein the printed circuit board is disposed on the bottom plate. The key device of claim 1, wherein the printed circuit board comprises a switch circuit, the transmissive layer has a first through hole, and the light guiding spacer further has a second through hole substantially aligned with the first through hole, The button assembly includes a conductive member, and the conductive member is configured to sequentially contact the switch circuit through the first through hole and the second through hole. The button device of claim 12, wherein the conductive member is a conductive rubber member. A circuit board assembly comprising: a printed circuit board; a transmissive layer above the printed circuit board; a light guiding spacer, wherein the printed circuit board and the transmissive layer are separated from opposite sides of the light guiding spacer; And a light source disposed on the printed circuit board and emitting light toward the transmission layer. The circuit board assembly of claim 14, wherein the transmissive layer is a thin film layer, the light guiding spacer layer has an accommodating space, and the light source is located in the accommodating space. The circuit board assembly of claim 15, wherein the transmission layer comprises: a transparent substrate, the transparent substrate is provided with a reflective coating and a shielding coating, and forms a transmissive area, wherein the accommodating space An orthographic projection on the transmissive layer overlaps the reflective coating. The circuit board assembly of claim 16, wherein the transparent substrate has a top surface, the reflective coating is disposed on the top surface, and the masking coating covers the reflective coating. The circuit board assembly of claim 16, wherein the transparent substrate has a top surface and a bottom surface facing the light guiding spacer layer, the shielding coating is disposed on the top surface, and the reflective coating is disposed On the bottom surface. The circuit board assembly of claim 16, wherein the transparent substrate has a bottom surface facing the light guiding spacer layer, the shielding coating is disposed on the bottom surface, and the reflective coating covers the shielding coating. The circuit board assembly of claim 15, wherein the light guiding spacer further has a through hole, and the printed circuit board comprises a switch The transmission layer includes a conductive contact, and the conductive contact is configured to contact the switching circuit via the through hole. The circuit board assembly of claim 14, wherein the transmissive layer comprises a reflective coating disposed on the light guiding spacer and a masking coating, and an orthographic projection of the light source on the transmissive layer The reflective coating overlaps. The circuit board assembly of claim 21, wherein the reflective coating is applied to the light guiding spacer layer, and the masking coating is applied to the reflective coating. The circuit board assembly of claim 14, wherein the light guiding spacer has a plurality of reflecting portions, and the reflecting portions are located on a surface of the printed circuit board facing the light guiding spacer. The circuit board assembly of claim 14, wherein the printed circuit board comprises a switch circuit, the transmissive layer has a first through hole, and the light guiding spacer further has a second through hole substantially aligned with the first through hole And the first through hole and the second through hole are configured to pass through a conductive member to electrically contact the switch circuit.