Key structure integrated with touch and pressure sensing and manufacturing method thereof

Abstract

The application discloses a kind of integrated touch pressure sensing key structure and preparation method thereof, including shell, base and touch plastic, the top of base is equipped with shell, both sides of shell are fixedly connected with heat dissipation structure, the bottom of touch plastic is equipped with diaphragm base layer, and the bottom of diaphragm base layer is equipped with character printing layer, the bottom of character printing layer is equipped with circuit layer, the bottom of character printing layer is equipped with pressure sensing mechanism.The application is by touch plastic and character printing layer fixed on the same diaphragm, then diaphragm is pasted with pressure sensor, simplify product structure to one, can satisfy display, touch, pressure sensing function, and can simplify product design structure, circuit layer on diaphragm and pressure sensor cooperate to realize capacitive touch sensing function, protective layer can protect circuit layer and pressure sensor, to achieve the purpose that touch key is convenient for sensing.

Description

Technical Field

[0001] This invention relates to the field of automotive parts technology, and in particular to a button structure with integrated touch pressure sensing and its manufacturing method. Background Technology

[0002] With the booming development of the concept of intelligent automotive surfaces, intelligent surface decoration technology based on IML (Integrated Molding Layer) technology is being applied more widely. Meanwhile, as physical buttons are gradually being replaced by touch functionality, IME (Integrated Electronic Components) technology, which integrates some electronic component functions on top of IML, also has broad development prospects. However, traditional IME technology has not solved the problem of accidental triggering.

[0003] Currently, the main pressure sensing solutions on the market include optical infrared sensing, pressure sensing diaphragms based on capacitance changes, pressure ceramics, and inductors. These various sensors are integrated into products through bonding or assembly processes to achieve pressure sensing and touch functions. Except for capacitive pressure sensing diaphragms, corresponding sensing components need to be placed on the PCB to achieve touch and pressure sensing functions.

[0004] In addition, the common IME technology solution on the market is based on attaching electronic components inside the film and injecting them together into the plastic, and then leading them out through connectors. The high temperature and impact of the injection process place higher demands on the electronic components, requiring specially made electronic components to be suitable for this type of application. Therefore, IME has been limited by this and has not been widely promoted. Moreover, the claims of other IME technologies do not include the function of pressure sensing chips.

[0005] MEMS pressure sensing chips are a type of sensor that has developed rapidly in recent years. They emit electrical signals by sensing micro-deformation of the surface, and can sensitively detect surface deformation at the micrometer level. They also have multi-level sensing capabilities. They are generally soldered onto a PCB and external pressure is transmitted to the chip through a linkage. Therefore, currently available touch buttons have limited functionality and cannot integrate touch, pressure, or sensing functions. Moreover, they have complex structures and are difficult to manufacture, so improvements are needed. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] The purpose of this invention is to provide a button structure that integrates touch pressure sensing, in order to solve the shortcomings of existing touch buttons that are difficult to integrate touch, pressure or sensing functions. (II) Summary of the Invention

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a button structure integrating touch pressure sensing, comprising a shell, a base and a touch plastic, wherein the shell is mounted on the top of the base;

[0010] The top of the outer shell is fitted with a touch plastic; the bottom of the touch plastic is fitted with a diaphragm base layer, and the bottom of the diaphragm base layer is fitted with a character printing layer, the bottom of the character printing layer is fitted with a circuit layer, and the bottom of the circuit layer is fitted with a pressure sensing mechanism.

[0011] Preferably, heat dissipation structures are fixedly connected to both sides of the outer shell. The heat dissipation structure includes a heat-conducting block, a heat sink, and a groove. The heat-conducting block is installed on both sides of the outer shell, and a heat sink is installed on one side of the heat-conducting block. Reinforcing structures are installed inside both the outer shell and the base. Grooves are provided at both ends of the heat sink, and the grooves are symmetrically distributed about the central axis of the heat sink. The grooves on the heat sink can increase the surface area of ​​the heat sink.

[0012] Preferably, the pressure sensing mechanism includes a protective layer, a mounting groove, and a pressure sensor. The protective layer is installed at the bottom of the circuit layer, and the mounting groove is provided inside the protective layer. By fixing the touch plastic and the character printing layer on the same diaphragm, and then attaching the pressure sensor to the diaphragm, the product structure is simplified into one, which can meet the display, touch, and pressure sensing functions, and can simplify the product design structure. The protective layer can protect the circuit layer and the pressure sensor.

[0013] Preferably, a pressure sensor is installed inside the mounting groove, and the outer diameter of the pressure sensor is smaller than the inner diameter of the mounting groove. The circuit layer on the diaphragm and the pressure sensor work together to realize capacitive touch sensing function.

[0014] Preferably, the reinforcing structure includes a first reinforcing rib, a second reinforcing rib, a third reinforcing rib, and a reinforcing layer. The reinforcing layer is disposed inside the outer shell and the base. The first reinforcing rib and the second reinforcing rib are disposed inside the reinforcing layer. The first reinforcing rib, the second reinforcing rib, and the third reinforcing rib are arranged at equal intervals inside the reinforcing layer. The first reinforcing rib, the second reinforcing rib, and the third reinforcing rib intersect each other. The first reinforcing rib, the second reinforcing rib, and the third reinforcing rib can enhance the structural strength of the outer shell and the base and prevent damage to the device.

[0015] Preferably, the second reinforcing ribs are arranged at equal intervals inside the reinforcing layer, and the second reinforcing ribs and the first reinforcing ribs intersect each other.

[0016] Preferably, the reinforcing layer is provided with a third reinforcing rib, which is arranged at equal intervals inside the reinforcing layer. The first, second and third reinforcing ribs can be made of steel.

[0017] This invention also discloses a method for preparing an integrated touch pressure sensing button structure, characterized by the following steps:

[0018] S1. First, a film base layer is prepared using a transparent material film as a substrate. A layer of touch plastic made of transparent PC material is then placed on the film base layer, wherein the thickness of the film base layer is 0.25-0.35mm.

[0019] S2. Then, the characters are printed onto a transparent material film by screen printing to form the character printing layer;

[0020] S3. Next, the circuit layer is screen-printed below the character printing layer, ensuring that solder pads are reserved on the circuit layer. Finally, a protective layer is printed to form the touch film. The protective layer needs to avoid the solder pad positions. The thickness of the printed touch film is 0.35-0.4mm. The touch film prepared by the above process is placed in the mold cavity, and molten PC is injected onto the non-printed surface. Then, the two-shot material needs to be injected onto the printed surface of the touch film, avoiding the circuit layer, to avoid the influence of hot melt plastic on the circuit. The plastic part prepared by the above process is then attached, and the pressure sensor and the diaphragm connector are soldered to the solder pads. Finally, the product prepared by the above process is installed on the bracket. The touch position can be identified by touching the transparent PC. When the touch position is identified as a functional area, the functional touch can be achieved by applying a pressure of about 3.5N.

[0021] (III) Beneficial Effects

[0022] The integrated touch pressure sensing touch button provided by this invention has the following advantages:

[0023] By fixing heat-conducting blocks to both sides of the outer casing, and both the heat-conducting blocks and the heat sink can be made of brass material with good thermal conductivity, when the device generates heat during operation, the heat of the outer casing can be absorbed by the heat-conducting blocks and then transferred to the heat sink. Since the heat sink has a large surface area, it can dissipate heat quickly. The grooves on the heat sink can increase the surface area of ​​the heat sink, making the heat dissipation effect of the heat sink faster, thereby achieving the purpose of facilitating heat dissipation for the touch buttons.

[0024] By fixing the touch plastic and the character printing layer onto the same diaphragm, and then attaching the pressure sensor to the diaphragm, the product structure is simplified into one, which can meet the functions of display, touch, and pressure sensing, and can simplify the product design structure. The circuit layer on the diaphragm and the pressure sensor work together to realize the capacitive touch sensing function. The protective layer can protect the circuit layer and the pressure sensor, thereby achieving the purpose of making the touch button easy to sense.

[0025] By providing a reinforcing layer inside the outer shell and base, and providing a first reinforcing rib, a second reinforcing rib, and a third reinforcing rib arranged at equal intervals inside the reinforcing layer, the first reinforcing rib, the second reinforcing rib, and the third reinforcing rib intersect each other, the first reinforcing rib, the second reinforcing rib, and the third reinforcing rib can strengthen the structural strength of the outer shell and base and prevent damage to the device, thereby achieving the purpose of strengthening the structural strength of the device by facilitating the touch button. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a frontal cross-sectional view of the present invention.

[0028] Figure 2 This is a top view cross-sectional structural diagram of the present invention;

[0029] Figure 3 For the present invention Figure 1 Enlarged cross-sectional view of a portion of point A in the middle section;

[0030] Figure 4 This is a three-dimensional structural diagram of the heat dissipation structure of the present invention;

[0031] Figure 5 This is a schematic diagram of a partial cross-sectional view of the reinforcing structure of the present invention.

[0032] Figure 6 This is a three-dimensional structural diagram of the present invention.

[0033] The reference numerals in the figure are as follows: 1. Outer shell; 2. Heat dissipation structure; 201. Heat-conducting block; 202. Heat sink; 203. Groove; 3. Base; 4. Pressure sensing mechanism; 401. Protective layer; 402. Mounting groove; 403. Pressure sensor; 5. Circuit layer; 6. Character printing layer; 7. Diaphragm base layer; 8. Touch plastic; 9. Reinforcing structure; 901. First reinforcing rib; 902. Second reinforcing rib; 903. Third reinforcing rib; 904. Reinforcing layer. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] Please see Figure 1-6 The present invention provides an embodiment of a button structure integrating touch pressure sensing, wherein a housing 1 is installed at the top of the base 3; a touch plastic 8 is installed at the top of the housing 1; a diaphragm base layer 7 is installed at the bottom of the touch plastic, and a character printing layer 6 is installed at the bottom of the diaphragm base layer 7, a circuit layer 5 is installed at the bottom of the character printing layer 6, and a pressure sensing mechanism 4 is installed at the bottom of the circuit layer 5.

[0037] Preferably, a heat dissipation structure 2 is fixedly connected to both sides of the outer shell 1. The heat dissipation structure 2 includes a heat-conducting block 201, a heat sink 202, and a groove 203. The heat-conducting block 201 is installed on both sides of the outer shell 1, and a heat sink 202 is installed on one side of the heat-conducting block 201. A reinforcing structure 9 is installed inside both the outer shell 1 and the base 3. Grooves 203 are provided at both ends of the heat sink 202, and the grooves 203 are symmetrically distributed about the central axis of the heat sink 202. In this embodiment, both the heat-conducting block 201 and the heat sink 202 can be made of brass material with good thermal conductivity. When the device generates heat during operation, the heat from the outer shell 1 can be absorbed by the heat-conducting block 201 and then transferred to the heat sink 202. Since the heat sink 202 has a large surface area, it can dissipate heat quickly. The grooves 203 on the heat sink 202 can increase the surface area of ​​the heat sink 202, making the heat dissipation effect of the heat sink 202 even faster.

[0038] Both the outer shell 1 and the base 3 are equipped with a reinforcing structure 9. The reinforcing structure 9 includes a first reinforcing rib 901, a second reinforcing rib 902, a third reinforcing rib 903 and a reinforcing layer 904. The reinforcing layer 904 is disposed inside the outer shell 1 and the base 3. The third reinforcing rib 903 is disposed inside the reinforcing layer 904 and is arranged at equal intervals inside the reinforcing layer 904.

[0039] The reinforcing layer 904 has a first reinforcing rib 901 arranged at equal intervals inside. The reinforcing layer 904 also has a second reinforcing rib 902 arranged at equal intervals inside. The second reinforcing rib 902 and the first reinforcing rib 901 intersect each other. In the above structure, the reinforcing layer 904 has a first reinforcing rib 901, a second reinforcing rib 902, and a third reinforcing rib 903 arranged at equal intervals inside. The first reinforcing rib 901, the second reinforcing rib 902, and the third reinforcing rib 903 intersect each other. The first reinforcing rib 901, the second reinforcing rib 902, and the third reinforcing rib 903 can be made of steel. The first reinforcing rib 901, the second reinforcing rib 902, and the third reinforcing rib 903 can strengthen the structural strength of the outer shell 1 and the base 3 and prevent damage to the device.

[0040] A touch plastic 8 is installed at the top of the outer casing 1, a diaphragm base layer 7 is installed at the bottom of the touch plastic 8, a character printing layer 6 is installed at the bottom of the diaphragm base layer 7, a circuit layer 5 is installed at the bottom of the character printing layer 6, and a pressure sensing mechanism 4 is installed at the bottom of the character printing layer 6. The pressure sensing mechanism 4 includes a protective layer 401, a mounting groove 402, and a pressure sensor 403. The protective layer 401 is installed at the bottom of the circuit layer 5, and a mounting groove 402 is provided inside the protective layer 401. The pressure sensor 403 is installed inside the mounting groove 402, and the outer diameter of the pressure sensor 403 is smaller than the inner diameter of the mounting groove 402.

[0041] In the above structure, by fixing the touch plastic 8 and the character printing layer 6 onto the same film, and then attaching the pressure sensor 403 onto the film, the product structure is simplified into one, which can meet the display, touch, and pressure sensing functions, and can simplify the product design structure. The circuit layer 5 on the film and the pressure sensor 403 work together to realize the capacitive touch sensing function, and the protective layer 401 can protect the circuit layer 5 and the pressure sensor 403.

[0042] This embodiment also discloses a method for preparing the integrated touch pressure sensing button structure, characterized by the following steps:

[0043] S1. First, a film base layer 7 is prepared using a transparent material film as a substrate. A layer of touch plastic 8 made of transparent PC material is then placed on the film base layer 7. The thickness of the film base layer 7 is 0.25-0.35 mm; in this embodiment, the thickness of the film base layer 7 is 0.3 mm.

[0044] S2. Then, the characters are printed onto a transparent material film by screen printing to form the character printing layer 6;

[0045] S3. Next, the circuit layer 5 is screen-printed below the character printing layer 6, ensuring that solder pads are reserved on the circuit layer 5. Finally, a protective layer is printed to form the touch film. The protective layer needs to avoid the solder pad positions. The thickness of the touch film after printing is 0.35-0.4mm. The touch film prepared by the above process is placed in the mold cavity, and molten PC is injected onto the non-printed surface. Then, the two-shot material needs to be injected onto the printed surface of the touch film, avoiding the circuit layer, to avoid the influence of hot melt plastic on the circuit. The plastic part prepared by the above process is then attached, and the pressure sensor and the diaphragm connector are soldered onto the solder pads. Finally, the product prepared by the above process is installed on the bracket. The touch position can be identified by touching the transparent PC. When the touch position is identified as a functional area, the functional touch can be achieved by applying a pressure of about 3.5N.

[0046] This invention integrates the character printing layer and the circuit layer onto the same film base layer 7. After injection molding, the plastic is on the front of the touch film, giving the characters a floating effect. The circuit layer is on the back of the touch film and has capacitive sensing function. The exposed pads on the back are used to attach the pressure sensor (MEMS pressure sensing chip in this invention) to the film using surface mounting technology (SMT). The signal is led out to an external controller through a connector. Therefore, this solution integrates touch, pressure sensing, and symbol film into one product. A single component can satisfy display, touch, and pressure sensing functions. When a human hand or other object is detected, the corresponding position of the film will generate a change in capacitance and output a signal. The pressure sensor attached to the back of the film will generate a slight deformation after receiving pressure from the plastic surface and emit an electrical signal. The external controller identifies the changes in capacitance and pressure sensor electrical signals, selects to activate or interrupt the internal circuit through appropriate judgment logic, and can set appropriate thresholds to achieve multi-level pressure sensing control. Because the pressure sensing chip is mounted onto the part after injection molding, it does not need to withstand the high-temperature impact of the molten plastic, which reduces the requirements for electronic components and greatly improves the feasibility of production and manufacturing.

[0047] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0048] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A button structure integrating touch pressure sensing, comprising a housing (1), a base (3), and a touch plastic (8), characterized in that: The top of the base (3) is fitted with a shell (1); the top of the shell (1) is fitted with a touch plastic (8); the bottom of the touch plastic is fitted with a film base layer (7), and the bottom of the film base layer (7) is fitted with a character printing layer (6), and the bottom of the character printing layer (6) is fitted with a circuit layer (5). The character printing layer (6) and the circuit layer (5) are printed on the same film base layer (7). The thickness of the film base layer (7) is 0.25-0.35mm, and the thickness of the touch film after printing and setting the protective layer is 0.35-0.4mm; the circuit layer (5) has reserved pads, and the protective layer (401) set on the circuit layer (5) avoids the pad positions; When the finished product is injection molded using in-mold injection molding technology, molten PC is injected onto the non-printing surface of the film base layer (7) to form a transparent PC layer, and the distillation material is injected onto the printing surface of the film base layer (7) avoiding the circuit area of ​​the circuit layer (5) to avoid the influence of hot melt plastic on the circuit; after the finished product is injection molded, the touch plastic (8) is on the front of the film base layer (7), so that the characters have a floating effect; A pressure sensing mechanism (4) is installed at the bottom of the circuit layer (5). The pressure sensing mechanism (4) is a MEMS pressure sensing chip. The pressure sensing mechanism (4) includes a protective layer (401), a mounting groove (402), and a pressure sensor (403). The protective layer (401) is installed at the bottom of the circuit layer (5), and a mounting groove (402) is provided inside the protective layer (401). A pressure sensor (403) is installed inside the mounting groove (402), and the pressure sensor (403) is fixed to the pad by welding. The welding is performed after the in-mold injection molding of the finished product. The outer shell (1) is fixedly connected to both sides of a heat dissipation structure (2). The heat dissipation structure (2) includes a heat-conducting block (201), a heat sink (202), and a groove (203). The heat-conducting block (201) is installed on both sides of the outer shell (1). A heat sink (202) is installed on one side of the heat-conducting block (201). A reinforcing structure (9) is installed inside both the outer shell (1) and the base (3). A groove (203) is provided at both ends of the heat sink (202), and the grooves (203) are symmetrically distributed about the central axis of the heat sink (202).

2. The button structure integrating touch pressure sensing according to claim 1, characterized in that: The outer diameter of the pressure sensor (403) is smaller than the inner diameter of the mounting groove (402).

3. The button structure integrating touch pressure sensing according to claim 2, characterized in that: The reinforcing structure (9) includes a first reinforcing rib (901), a second reinforcing rib (902), a third reinforcing rib (903), and a reinforcing layer (904). The reinforcing layer (904) is disposed inside the outer shell (1) and the base (3). The first reinforcing rib (901) is disposed inside the reinforcing layer (904), and the second reinforcing rib (902) is disposed inside the reinforcing layer (904).

4. The button structure integrating touch pressure sensing according to claim 3, characterized in that: The second reinforcing rib (902) is arranged at equal intervals inside the reinforcing layer (904), and the second reinforcing rib (902) and the first reinforcing rib (901) intersect each other.

5. The button structure integrating touch pressure sensing according to claim 3, characterized in that: The reinforcing layer (904) is provided with a third reinforcing rib (903) inside, and the third reinforcing rib (903) is arranged at equal intervals inside the reinforcing layer (904).

6. A method for preparing a button structure with integrated touch pressure sensing as described in claim 1, characterized in that: Specifically, the following steps are included: S1. First, a film base layer (7) is prepared using a transparent material film as a substrate. A layer of touch plastic (8) made of transparent PC material is set on the film base layer (7). The thickness of the film base layer (7) is 0.25-0.35 mm. S2. Then the characters are printed onto a transparent material film by screen printing to form the character printing layer (6). S3. Then, the circuit layer (5) is printed on the character printing layer (6) by screen printing, while ensuring that the circuit layer (5) has reserved pads. Finally, a protective layer is printed to form a touch film. The protective layer needs to avoid the pad position. The thickness of the touch film after printing is 0.35-0.4mm. The touch film prepared by the above process is placed in the mold cavity. Molten PC is injected onto the non-printed surface. Then, the two-shot material needs to be injected onto the printed surface of the touch film to avoid the influence of hot melt plastic on the circuit. The plastic part prepared by the above process is then attached. The pressure sensor and the diaphragm connector are then soldered onto the pads. The product prepared by the above process is then installed on the bracket. The touch position can be identified by touching the transparent PC. When the touch position is identified as a functional area, the functional touch can be achieved by applying pressure.

7. The method for fabricating an integrated touch pressure sensing button structure according to claim 6, characterized in that: The transparent material film is a PC or PMMA transparent material.

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