Capacitive electrostatic protection portable terminal

Abstract

The utility model discloses a capacitive electrostatic protection portable terminal, which comprises a screen assembly, a front shell assembly, a middle frame bracket assembly, a battery cover plate assembly, a first alloy sheet and a second alloy sheet, wherein the screen assembly, the front shell assembly, the middle frame bracket assembly and the battery cover plate assembly are sequentially arranged from top to bottom; one side edge of the screen assembly is welded with one side edge of the middle frame bracket assembly through a first alloy sheet to form an upper electrode plate of the capacitor; the other side edge of the front shell assembly is welded with the other side edge of the battery cover plate assembly through a second alloy sheet to form a lower electrode plate of the capacitor, an isolation layer is arranged on a circuit board of the front shell assembly, electrolyte is filled between every two adjacent assemblies, and the circuit board of the front shell assembly controls electrostatic absorption and discharge of the capacitor according to the capacity of the capacitor. An existing assembly structure and an alloy sheet are combined into a capacitor to absorb and discharge static electricity, the static electricity in any direction can be protected, an anti-static device does not need to be additionally arranged on each signal, and cost and occupied space are saved.

Description

Technical Field

[0001] This utility model relates to the field of antenna technology, and in particular to a portable terminal with capacitive electrostatic protection. Background Technology

[0002] As electronic devices composed of various electronic components, mobile phones require special attention to electrostatic discharge (ESD) issues. To prevent circuit board damage and signal transmission interference caused by ESD, the common anti-ESD solution is to add ESD protection devices to the circuitry. However, circuit boards contain numerous signals and have complex ESD paths, making it difficult to add ESD protection devices to every single signal, thus failing to achieve comprehensive ESD protection and incurring high costs. Furthermore, the limited space inside a mobile phone means that high-power ESD protection devices occupy a large area, hindering the miniaturization of mobile phones.

[0003] Therefore, existing technologies still need to be improved and enhanced. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a portable terminal with capacitive electrostatic protection to solve the problem that existing anti-static devices cannot achieve comprehensive electrostatic protection.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A portable terminal with capacitive electrostatic protection includes a screen assembly, a front shell assembly, a mid-frame support assembly, and a battery cover assembly arranged sequentially from top to bottom. It also includes a first alloy sheet and a second alloy sheet. One side of the screen assembly is welded to one side of the mid-frame support assembly via the first alloy sheet to form the upper electrode plate of the capacitor. The other side of the front shell assembly is welded to the other side of the battery cover assembly via the second alloy sheet to form the lower electrode plate of the capacitor. An insulating layer is provided on the circuit board of the front shell assembly, and an electrolyte is filled between adjacent components. The circuit board of the front shell assembly controls the electrostatic absorption and discharge of the capacitor according to its capacitance.

[0007] In the portable terminal with capacitive electrostatic protection, one side of the mid-frame bracket assembly is provided with an inwardly recessed first welding area, one side of the first alloy sheet is welded to one side of the screen assembly and perpendicular to the screen assembly, and the first alloy sheet is closely attached to the first welding area and welded and fixed.

[0008] In the portable terminal with capacitive electrostatic protection, the other side of the front shell assembly is provided with a recessed second welding area. One side of the second alloy sheet is welded to the other side of the battery cover assembly and is perpendicular to the battery cover assembly. The second alloy sheet is in close contact with the second welding area and is welded and fixed.

[0009] In the portable terminal with capacitive electrostatic protection, a base adhesive is sprayed onto the circuit board of the front shell assembly, the surface of each circuit module, and the pin solder joints to form the insulating layer.

[0010] In the portable terminal with capacitive electrostatic protection, the depth of the recess in the first welding area is adapted to the thickness of the first alloy sheet, and the outer side of the first alloy sheet is flush with the side of the middle frame bracket assembly.

[0011] In the portable terminal with capacitive electrostatic protection, the depth of the second welding area is adapted to the thickness of the second alloy sheet, and the outer side of the second alloy sheet is flush with the side of the front shell assembly.

[0012] In the portable terminal with capacitive electrostatic protection, the circuit board is provided with a control circuit and a switch circuit. The switch circuit is connected to the control circuit and the upper electrode plate of the capacitor, and the lower electrode plate of the capacitor is grounded.

[0013] The voltage of the output capacitor of the switching circuit is supplied to the control circuit.

[0014] When the control circuit determines that the voltage is greater than the upper threshold, it controls the switch circuit to conduct, grounding the upper electrode plate of the capacitor for electrostatic discharge; when it determines that the voltage is less than the lower threshold, it controls the switch circuit to cut off, disconnecting the upper electrode plate of the capacitor from the ground for electrostatic absorption.

[0015] In the portable terminal with capacitive electrostatic protection, the switching circuit includes a first switching transistor, a second switching transistor, and a first resistor.

[0016] The source of the first switching transistor is connected to ground and one end of the first resistor. The drain of the first switching transistor is connected to the upper electrode plate of the capacitor and the detection terminal of the control circuit. The gate of the first switching transistor is connected to the other end of the first resistor and the drain of the second switching transistor. The gate of the second switching transistor is connected to the control terminal of the control circuit. The source of the second switching transistor is grounded, and the lower electrode plate of the capacitor is grounded.

[0017] In the portable terminal with capacitive electrostatic protection, the switching circuit further includes a first diode and a second diode. One end of the first diode is connected to the gate of the second switching transistor, one end of the second diode is connected to the drain of the first switching transistor, and the other end of the first diode is connected to the other end of the second diode and ground.

[0018] In the portable terminal with capacitive electrostatic protection, the first alloy sheet and the second alloy sheet are magnesium-aluminum alloys.

[0019] Compared to existing technologies, the portable terminal with capacitive electrostatic protection provided by this utility model includes a screen assembly, a front shell assembly, a mid-frame support assembly, and a battery cover assembly arranged sequentially from top to bottom, as well as a first alloy sheet and a second alloy sheet. One side of the screen assembly is welded to one side of the mid-frame support assembly via the first alloy sheet to form the upper electrode plate of the capacitor; the other side of the front shell assembly is welded to the other side of the battery cover assembly via the second alloy sheet to form the lower electrode plate of the capacitor. An insulating layer is provided on the circuit board of the front shell assembly, and an electrolyte is filled between adjacent components. The circuit board of the front shell assembly controls the electrostatic absorption and discharge of the capacitor according to the capacitor capacity. By using the existing component structure and alloy sheet combination to form a capacitor for electrostatic absorption and discharge, it can protect against electrostatic discharge from any direction, eliminating the need to add anti-static devices to every signal, thus saving cost and space. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the portable terminal provided by this utility model.

[0021] Figure 2 This is a schematic diagram of the connection between the front shell assembly and the battery cover assembly provided by this utility model.

[0022] Figure 3 This is a circuit diagram of the switching circuit provided by this utility model. Detailed Implementation

[0023] This utility model provides a portable terminal with capacitive electrostatic protection. To make the objectives, technical solutions, and advantages of this utility model clearer and more explicit, the following detailed description, with reference to the accompanying drawings and embodiments, further illustrates the utility model. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this utility model.

[0024] Please also refer to Figure 1 , Figure 2 and Figure 3 Portable terminals, taking mobile phones as an example, the existing mobile phone stacking structure is as follows: Figure 1As shown on the right, it is composed of screen assembly 10, front shell assembly 20, mid-frame bracket assembly 30 and battery cover assembly 40 arranged vertically from top to bottom. The portable terminal with capacitive electrostatic protection provided by this utility model also includes a first alloy sheet 50 and a second alloy sheet 60. One side of the screen assembly 10 (e.g., the left side) is welded to one side of the mid-frame support assembly 30 through the first alloy sheet 50. The screen assembly 10, the first alloy sheet 50, and the mid-frame support assembly 30 form the upper electrode plate (also called the upper electrode) of the capacitor. The other side of the front shell assembly 20 (e.g., the right side) is welded to the other side of the battery cover assembly 40 through the second alloy sheet 60. The front shell assembly 20, the second alloy sheet 60, and the battery cover assembly 40 form the lower electrode plate (also called the lower electrode) of the capacitor. An insulating layer is provided on the circuit board of the front shell assembly 20, on the surface of electronic components, and at the pin soldering points. Electrolytes are filled between adjacent components (specifically, between the screen assembly 10 and the front shell assembly 20, between the front shell assembly 20 and the mid-frame support assembly 30, and between the mid-frame support assembly 30 and the battery cover assembly 40). The circuit board of the front shell assembly controls the electrostatic absorption and discharge of the capacitor according to the capacitance.

[0025] By connecting two alloy plates, the screen assembly 10 and the mid-frame bracket assembly 30 are connected together to form a U-shaped upper electrode plate, and the front shell assembly 20 and the battery cover assembly 40 are connected together to form a U-shaped lower electrode plate. Figure 1 The simplified diagram on the left shows the capacitor structure. Both the upper and lower electrode plates are assembled with inward-facing openings and staggered insertion. Electrolyte is used to prevent the two U-shaped plates from contacting each other. This effectively utilizes existing components of the phone to form the electrode plates. The electrolyte and the upper and lower electrode plates form a large-capacity planar capacitor model, absorbing and safely discharging instantaneous electrostatic energy. This eliminates the need to add anti-static devices to the circuit board for every signal, achieving comprehensive electrostatic protection.

[0026] Preferably, the electrolyte can be a liquid electrolyte, such as imidazole or pyrrolidine high-performance electrolyte fillers. The insulating layer can be achieved by spraying a filling primer onto the surface of each circuit module and the pin solder joints on the circuit board inside the front housing assembly 20, thus isolating it from the electrolyte and preventing the electrolyte from affecting the normal operation of the circuit. The two alloy sheets are preferably made of magnesium-aluminum alloy.

[0027] Please refer to the following: Figure 2In specific implementation, when one side of the screen assembly 10 is welded to one side of the mid-frame support assembly 30 via the first alloy sheet 50, given the relatively small thickness of the screen assembly 10 and the considerable thickness of the mid-frame support assembly 30, a recessed first welding area is provided on one side of the mid-frame support assembly 30 to facilitate connection. One side of the first alloy sheet 50 is directly welded to one side of the screen assembly 10 and perpendicular to the screen assembly 10. Thus, during assembly, the first alloy sheet 50 can be inserted and closely adhered to the first welding area. The depth of the recess in the first welding area matches the thickness of the first alloy sheet 50, and the size of the first welding area matches that of the first alloy sheet. After the first alloy sheet 50 is spot-welded and fixed in the first welding area, the outer surface of the first alloy sheet 50 is flush with the side of the mid-frame support assembly 30, and the first alloy sheet 50 will not protrude and affect assembly.

[0028] Similarly, please refer to the following: Figure 2 When the other side (e.g., the right side) of the front housing assembly 20 is welded to the other side of the battery cover assembly 40 via the second alloy sheet 60, given the relatively small thickness of the battery cover assembly 40 and the considerable thickness of the front housing assembly 20, a recessed second welding area 80 is provided on the other side of the front housing assembly 20 to facilitate connection. One side of the second alloy sheet 60 is directly welded to the other side of the battery cover assembly 40 and perpendicular to it. This allows the second alloy sheet 60 to be inserted into and tightly adhered to the second welding area 80 during assembly. The depth of the recess in the second welding area 80 matches the thickness of the second alloy sheet 60, and the dimensions of the second welding area and the second alloy sheet 60 are also compatible. After the second alloy sheet 60 is spot-welded and fixed in the second welding area 80, its outer surface is flush with the side of the front housing assembly 20, and it will not protrude, thus preventing assembly from being affected.

[0029] It should be understood that, in this embodiment, the sides of the front shell assembly 20 and the mid-frame support assembly 30 are typically made of metal, so the welding areas provided on them can be directly spot-welded to the corresponding alloy sheets. In specific implementations, if the sides of the front shell assembly 20 and the mid-frame support assembly 30 are not made of metal, a metal sheet (such as a copper sheet) of a suitable size can be adhered to the corresponding welding area. The metal sheet can be set as a thin metal sheet, and the depth of the concave part of the welding area can be combined to avoid the alloy sheet protruding and affecting the assembly.

[0030] The first alloy sheet 50 and the second alloy sheet 60 can be two separate pieces or a single long piece, depending on the location of the soldering area. Since the front housing assembly 20 has a circuit board and various interfaces, and the side of the mid-frame support assembly 30 has a corresponding accommodating cavity, the recessed soldering area should not affect the electronic components on the circuit board or occupy the space of the accommodating cavity. Preferably, the soldering area is located on the side of the front housing assembly 20 and the mid-frame support assembly 30, in a flat location with sufficient internal space.

[0031] In this embodiment, according to the capacitance formula C = εS / 4πkd, where ε is the dielectric constant (determined by the electrolyte material), and S is the area of ​​the two opposing electrode plates (…). Figure 1 In the shaded area, S = S1 + S2, which is equivalent to the area S1 projected from the screen component 10 onto the front shell component 20, plus the area S2 projected from the middle frame bracket component 30 onto the battery cover component 40. By electrically connecting two non-adjacent components with an alloy sheet, the area can be increased, thus increasing the capacitance. k is the electrostatic constant (a constant in a vacuum, k = 9.0 × 10^9 N·m² / C^2), and d is the distance between the upper and lower electrode plates (after the existing components are assembled, there is a certain gap between adjacent components, and they will not be in complete contact. The electrolyte is used to fill these gaps, which are irregular; the value of d can be selected as an intermediate value based on actual measurements or a fixed value can be set). By setting S, ε, and d according to requirements, the capacitance of the assembled capacitor can be adjusted.

[0032] Since the circuit board is insulated and protected by an insulating layer, an electrolyte with a high dielectric constant can be selected as the liquid electrolyte. The combination of the electrode plate structure and the electrolyte can form a supercapacitor.

[0033] To ensure that the capacitor is always at a low charge level and to ensure stable absorption of electrostatic energy, a switching circuit 70 is set on the circuit board of the front housing assembly 20, which, together with the existing control circuit (such as a SOC chip), discharges the entire capacitor system. The switching circuit 70 connects the control circuit and the upper electrode plate of the capacitor (since the mid-frame bracket assembly 30 itself is part of the upper electrode plate, the switching circuit 70 is located inside the front shell assembly 20; specifically, a wire can be set on the circuit board, one end of which is electrically connected to the corresponding electronic component on the circuit board, and the other end of which is soldered to the inner side of the side of the mid-frame bracket assembly 30). The lower electrode plate of the capacitor is grounded (since the front shell assembly 20 itself is part of the lower electrode plate, specifically, a spring can be set on the circuit board, one end of which is connected to the ground on the circuit board, and the other end of which abuts against the inner side of the side of the front shell assembly 20). The switching circuit 70 outputs the voltage of the capacitor to the control circuit. When the control circuit determines that the voltage is greater than the upper threshold, it controls the switching circuit 70 to conduct, grounding the upper electrode plate of the capacitor for electrostatic discharge. When the control circuit determines that the voltage is less than the lower threshold, it controls the switching circuit 70 to cut off, disconnecting the upper electrode plate of the capacitor from the ground for electrostatic absorption.

[0034] like Figure 3As shown, the switching circuit includes a first switching transistor Q1, a second switching transistor Q2, and a first resistor R1. The source of the first switching transistor Q1 is connected to ground and one end of the first resistor R1. The drain of the first switching transistor Q1 is connected to the upper electrode plate of the capacitor and the detection terminal of the control circuit (specifically, the ADC pin of the SOC chip). The gate of the first switching transistor Q1 is connected to the other end of the first resistor R1 and the drain of the second switching transistor Q2. The gate of the second switching transistor Q2 is connected to the control terminal of the control circuit (specifically, the GPIO pin of the SOC chip). The source of the second switching transistor Q2 is grounded, and the lower electrode plate of the capacitor is grounded.

[0035] The first switch Q1 is a PMOS transistor and the second switch Q2 is an NMOS transistor.

[0036] Preferably, the switching circuit further includes a first diode D1 and a second diode D2. One end of the first diode D1 is connected to the gate of the second switching transistor Q2, one end of the second diode D2 is connected to the drain of the first switching transistor Q1, and the other end of the first diode D1 is connected to the other end of the second diode D2 and ground. Preferably, the first diode D1 and the second diode D2 are ESD protection diodes of model WS61419S.

[0037] Taking a mobile phone as an example, the working principle of a capacitor composed of various components and alloy plates is as follows: During daily use, the upper and lower electrode plates of the capacitor absorb the electrostatic charge transmitted by the electronic components and interfaces of the circuit board in various working modes, preventing external static electricity from entering the inside of the phone and absorbing static electricity on the internal signals, thereby achieving electrostatic protection.

[0038] Static charge absorbed from the external environment or the user is stored in the capacitor. The control circuit (SOC chip and its peripheral circuits) uses the ADC pin to detect the voltage ADC_V to accurately detect the capacitance. The capacitance and voltage comparison table is shown in Table 1 below (the values ​​here are preferred values ​​from experimental testing and are not limited to specific values). If the control circuit determines that the voltage ADC_V is greater than 5.5V, it indicates that the current static charge absorbed by the capacitor, i.e., the capacitance, has reached 80%, and discharge is required. The GPIO port of the control circuit outputs a high-level control signal GPIO_Switch, controlling the second switch Q2 to conduct and ground, pulling the gate of the first switch Q1 low to turn Q1 on, thus connecting the upper electrode plate (equivalent to the positive terminal) of the capacitor to ground, thereby achieving discharge. At this time, the static electricity absorbed by the capacitor is directly discharged to ground and is not stored.

[0039] The control circuit can acquire the voltage ADC_V on the ADC pin at preset intervals until it determines that the voltage value is less than 1.4V, indicating that the capacitance is less than 20%, and then stops discharging. It outputs a low-level control signal GPIO_Switch to control the second switch Q2 to turn off and the first switch Q1 to turn off, and the capacitor continues to absorb and store electrostatic discharge.

[0040] Capacitance (%) Voltage (V) 100 6.8 80 5.5 60 4 40 2.7 20 1.4 0 0

[0041] Table 1

[0042] In summary, this portable terminal with capacitive electrostatic discharge protection utilizes the existing component structure of a mobile phone to form a capacitor through the connection of alloy sheets. Combined with voltage detection and control of the control circuit, the switching circuit autonomously switches between instantaneous electrostatic energy absorption and capacitor capacity discharge, achieving functional control of electrostatic energy storage and timely release. Utilizing existing mobile phone component structures does not significantly alter the phone's form factor or cost; furthermore, these component structures and the capacitor formed by the internal electrolyte can protect against electrostatic discharge from any direction, ensuring the internal circuit board remains unaffected and providing comprehensive protection for the mobile phone.

[0043] It should be understood that the application of this utility model is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A portable terminal with capacitive electrostatic protection, comprising a screen assembly, a front shell assembly, a mid-frame support assembly, and a battery cover assembly arranged sequentially from top to bottom, characterized in that, It also includes a first alloy sheet and a second alloy sheet. One side of the screen assembly is welded to one side of the mid-frame bracket assembly via the first alloy sheet to form the upper electrode plate of the capacitor. The other side of the front shell assembly is welded to the other side of the battery cover assembly via the second alloy sheet to form the lower electrode plate of the capacitor. An insulating layer is provided on the circuit board of the front shell assembly. Electrolyte is filled between two adjacent components. The circuit board of the front shell assembly controls the static electricity absorption and discharge of the capacitor according to the capacitance.

2. The portable terminal with capacitive electrostatic protection according to claim 1, characterized in that, The middle frame bracket assembly has a recessed first welding area on one side. One side of the first alloy sheet is welded to one side of the screen assembly and perpendicular to the screen assembly. The first alloy sheet is in close contact with the first welding area and welded to fix it.

3. The portable terminal with capacitive electrostatic protection according to claim 2, characterized in that, The other side of the front shell assembly is provided with a recessed second welding area. One side of the second alloy sheet is welded to the other side of the battery cover assembly and is perpendicular to the battery cover assembly. The second alloy sheet is closely attached to the second welding area and welded to fix it.

4. The portable terminal with capacitive electrostatic protection according to claim 3, characterized in that, The insulating layer is formed by spraying a base coat of adhesive onto the circuit board of the front housing assembly, the surface of each circuit module, and the solder joints of the pins.

5. The portable terminal with capacitive electrostatic protection according to claim 4, characterized in that, The depth of the first welding area is adapted to the thickness of the first alloy sheet, and the outer side of the first alloy sheet is flush with the side of the middle frame bracket assembly.

6. The portable terminal with capacitive electrostatic protection according to claim 4, characterized in that, The depth of the second welding area is adapted to the thickness of the second alloy sheet, and the outer surface of the second alloy sheet is flush with the side of the front shell assembly.

7. The portable terminal with capacitive electrostatic protection according to claim 1 or 5, characterized in that, The circuit board is provided with a control circuit and a switch circuit. The switch circuit is connected to the control circuit and the upper electrode plate of the capacitor, and the lower electrode plate of the capacitor is grounded. The voltage of the output capacitor of the switching circuit is supplied to the control circuit. When the control circuit determines that the voltage is greater than the upper threshold, it controls the switch circuit to conduct, grounding the upper electrode plate of the capacitor for electrostatic discharge. When the voltage is less than the lower threshold, the control switch circuit is turned off, and the upper electrode plate of the capacitor is disconnected and grounded for electrostatic absorption.

8. The portable terminal with capacitive electrostatic protection according to claim 7, characterized in that, The switching circuit includes a first switching transistor, a second switching transistor, and a first resistor; The source of the first switching transistor is connected to ground and one end of the first resistor. The drain of the first switching transistor is connected to the upper electrode plate of the capacitor and the detection terminal of the control circuit. The gate of the first switching transistor is connected to the other end of the first resistor and the drain of the second switching transistor. The gate of the second switching transistor is connected to the control terminal of the control circuit. The source of the second switching transistor is grounded, and the lower electrode plate of the capacitor is grounded.

9. The portable terminal with capacitive electrostatic protection according to claim 8, characterized in that, The switching circuit further includes a first diode and a second diode. One end of the first diode is connected to the gate of the second switching transistor, one end of the second diode is connected to the drain of the first switching transistor, and the other end of the first diode is connected to the other end of the second diode and ground.

10. The portable terminal with capacitive electrostatic protection according to claim 1, characterized in that, The first alloy sheet and the second alloy sheet are magnesium-aluminum alloys.

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