Capacitive electrostatic protection portable terminal

Abstract

The invention 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, 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] The present invention relates to the field of antenna technology, and in particular to a portable terminal with capacitive electrostatic protection. Background Art

[0002] As an electronic device that is composed of a variety of electronic components, mobile phones need to pay special attention to static electricity. In order to avoid damage to circuit boards and signal transmission interference caused by static electricity, the current common anti-static solution is to add anti-static devices to the circuit. However, there are many signals on the circuit board and the static electricity path is complex. It is difficult to add anti-static devices to each signal, which cannot achieve all-round static electricity protection and is costly. In addition, the space inside the mobile phone is limited, and high-power anti-static devices occupy a large area, which affects the miniaturization of mobile phones.

[0003] Therefore the prior art still needs to be improved and enhanced. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a portable terminal with capacitive electrostatic protection to solve the problem that the existing anti-static devices cannot achieve all-round electrostatic protection.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A capacitive electrostatically protected portable terminal comprises a screen assembly, a front shell assembly, a middle frame support assembly and a battery cover assembly arranged in sequence from top to bottom, and further comprises a first alloy sheet and a second alloy sheet. One side of the screen assembly is welded to one side of the middle frame support assembly via the first alloy sheet to form an 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 a lower electrode plate of the capacitor. An insulating layer is arranged on a circuit board of the front shell assembly, and an electrolyte is filled between two adjacent assemblies. The circuit board of the front shell assembly controls the electrostatic absorption and discharge of the capacitor according to the capacitance of the capacitor.

[0007] In the capacitive electrostatically protected portable terminal, a first welding area concave inwardly is provided on one side of the middle frame bracket assembly, one side of the first alloy sheet is welded to one side of the screen assembly and is perpendicular to the screen assembly, and the first alloy sheet is closely attached to the first welding area and fixed by welding.

[0008] In the capacitive electrostatically protected portable terminal, the other side of the front shell assembly is provided with a second welding area concave inwardly, 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, and the second alloy sheet is closely attached to the second welding area and welded and fixed.

[0009] In the capacitive electrostatically protected portable terminal, the circuit board of the front shell component, the surface of each circuit module and the pin welding position are sprayed with a filled primer to cover them, thereby forming the isolation layer.

[0010] In the capacitive electrostatically protected portable terminal, the depth of the concave portion of the first welding area matches the thickness of the first alloy sheet, and the outer side surface of the first alloy sheet is flush with the side edge of the middle frame support assembly.

[0011] In the capacitive electrostatically protected portable terminal, the depth of the indentation of the second welding area matches the thickness of the second alloy sheet, and the outer side surface of the second alloy sheet is flush with the side edge of the front shell component.

[0012] In the capacitive electrostatically protected portable terminal, a control circuit and a switch circuit are provided on the circuit board, the switch circuit connects the control circuit and the upper electrode plate of the capacitor, and the lower electrode plate of the capacitor is grounded;

[0013] The switch circuit outputs the voltage of the capacitor to the control circuit;

[0014] When the control circuit determines that the voltage is greater than the upper threshold, the control circuit controls the switch circuit to be turned on, and the upper electrode plate of the capacitor is grounded for static discharge; when the control circuit determines that the voltage is less than the lower threshold, the control circuit controls the switch circuit to be turned off, and the upper electrode plate of the capacitor is disconnected and grounded for static absorption.

[0015] In the capacitive electrostatically protected portable terminal, the switch circuit includes a first switch tube, a second switch tube and a first resistor;

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

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

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

[0019] Compared with the prior art, the capacitive electrostatically protected portable terminal provided by the present invention includes a screen assembly, a front shell assembly, a middle frame support assembly and a battery cover assembly arranged in sequence 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 middle frame support assembly through the first alloy sheet to form an 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 through the second alloy sheet to form a lower electrode plate of the capacitor. An insulating layer is set on the circuit board of the front shell assembly, and electrolyte is filled between two adjacent components. The circuit board of the front shell assembly controls the electrostatic absorption and discharge of the capacitor according to the capacitance. By utilizing the existing component structure and alloy sheets to form a capacitor for electrostatic absorption and discharge, static electricity in any direction can be protected, and there is no need to add anti-static devices to each signal, saving costs and space occupation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the portable terminal provided by the present invention.

[0021] Figure 2 It is a structural schematic diagram of the connection between the front shell assembly and the battery cover assembly provided by the present invention.

[0022] Figure 3 It is a circuit diagram of the switch circuit provided by the present invention. DETAILED DESCRIPTION

[0023] The present invention provides a portable terminal with capacitive electrostatic protection. In order to make the purpose, technical solution and advantages of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] Please also see Figure 1 , Figure 2 and Figure 3 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 a screen assembly 10, a front shell assembly 20, a middle frame support assembly 30 and a battery cover assembly 40 which are arranged in sequence from top to bottom and stacked vertically. The capacitive electrostatic protection portable terminal provided by the present invention also includes a first alloy sheet 50 and a second alloy sheet 60, one side edge (such as the left side edge) of the screen assembly 10 is welded to one side edge of the middle frame support assembly 30 through the first alloy sheet 50, the screen assembly 10, the first alloy sheet 50 and the middle frame support assembly 30 constitute an upper electrode plate (also referred to as an upper electrode) of the capacitor, the other side edge (such as the right side edge) of the front shell assembly 20 is welded to the other side edge 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 constitute a lower electrode plate (also referred to as a lower electrode) of the capacitor, an insulating layer is provided on the circuit board of the front shell assembly 20, on the surface of the electronic component and at the pin welding position, an electrolyte is filled between two adjacent components (specifically, electrolyte is filled between the screen assembly 10 and the front shell assembly 20, between the front shell assembly 20 and the middle frame support assembly 30, and between the middle frame support assembly 30 and the battery cover assembly 40), and 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 sheets, the screen assembly 10 and the middle frame support 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 schematic diagram of the capacitor structure on the left. The upper electrode plate and the lower electrode plate are both assembled together in a staggered manner with the opening facing inwards, and the two U-shaped plates are filled with electrolyte so that they do not touch each other. This is equivalent to facilitating the formation of plates by the existing components of the mobile phone. The electrolyte and the upper and lower electrode plates form a large-capacity flat-plate capacitor model to absorb and safely discharge instantaneous electrostatic energy. There is no need to add anti-static devices for each signal on the circuit board, achieving all-round electrostatic protection.

[0026] Preferably, the electrolyte can be a liquid electrolyte, such as high-performance electrolyte fillers such as imidazoles and pyrrolidines. The insulating layer can be covered by spraying a filling primer on the surface of each circuit module and the pin welding position on the circuit board in the front shell component 20, so as to be isolated from the electrolyte and prevent the electrolyte from affecting the normal operation of the circuit. The two alloy sheets are preferably made of magnesium-aluminum alloy.

[0027] Please also read Figure 2In a specific implementation, when one side of the screen assembly 10 is welded to one side of the middle frame support assembly 30 through the first alloy sheet 50, based on the small thickness of the screen assembly 10 and the certain thickness of the middle frame support assembly 30, in order to facilitate connection, a first welding area concave inward is provided on one side of the middle frame support assembly 30, and one side of the first alloy sheet 50 is directly welded to one side of the screen assembly 10 and is perpendicular to the screen assembly 10. In this way, during assembly, the first alloy sheet 50 can be inserted into and fit closely to the first welding area. The depth of the concave in the first welding area is adapted to the thickness of the first alloy sheet 50, and the first welding area is adapted to the size of the first alloy sheet. After the first alloy sheet 50 is fixed by spot welding in the first welding area, the outer side surface of the first alloy sheet 50 is flush with the side of the middle frame support assembly 30, and the first alloy sheet 50 will not protrude to affect the assembly.

[0028] Similarly, please also refer to Figure 2 , when the other side (such as the right side) of the front shell component 20 is welded to the other side of the battery cover assembly 40 through the second alloy sheet 60, based on the fact that the battery cover assembly 40 is relatively thin and the front shell component 20 has a certain thickness, in order to facilitate connection, a second welding area 80 concave inwardly is provided on the other side of the front shell component 20, and one side of the second alloy sheet 60 is directly welded to the other side of the battery cover assembly 40 and is perpendicular to the battery cover assembly 40. In this way, during assembly, the second alloy sheet 60 can be inserted and closely attached to the second welding area 80. The depth of the concave of the second welding area 80 is adapted to the thickness of the second alloy sheet 60, and the second welding area is adapted to the size of the second alloy sheet 60. After the second alloy sheet 60 is spot-welded and fixed in the second welding area 80, the outer side of the second alloy sheet 60 is flush with the side of the front shell component 20, and the second alloy sheet 60 will not protrude to affect assembly.

[0029] It should be understood that in this embodiment, the sides of the front shell assembly 20 and the middle frame support assembly 30 are usually made of metal, so the welding area set thereon can be directly spot welded with the corresponding alloy sheet. In specific implementation, if the sides of the front shell assembly 20 and the middle 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 metal thin sheet, combined with the depth of the concave setting of the welding area, to avoid the protrusion of the alloy sheet affecting the assembly.

[0030] The first alloy sheet 50 and the second alloy sheet 60 can be two separate sheets or a whole long sheet, which is determined by the position of the welding area. Since there are circuit boards and various interfaces on the front shell component 20, and there are corresponding accommodating cavities on the sides of the middle frame support component 30, when the welding area is concave, it cannot affect the electronic components on the circuit board and occupy the position of the accommodating cavity. It is preferred to set the welding area on the sides of the front shell component 20 and the middle frame support component 30, where it is flat and has space inside.

[0031] In this embodiment, according to the capacitance formula C=εS / 4πkd, where ε is the dielectric constant (determined by the material of the electrolyte), S is the area of ​​the two electrode plates facing each other ( Figure 1 In the shaded area, S=S1+S2, which is equivalent to the area S1 of the screen assembly 10 projected on the front shell assembly 20, plus the area S2 of the middle frame bracket assembly 30 projected on the battery cover assembly 40. By electrically connecting two non-adjacent components through alloy sheets, the area can be expanded and the capacitance can be increased). k is the electrostatic force constant (a constant in a vacuum, k=9.0×10^9N·m2 / C^2), and d is the spacing between the upper electrode plate and the lower electrode plate (after the existing components are assembled, there is a certain gap between the adjacent components and they will not completely contact each other. Electrolytes are used to fill these gaps. These gaps are irregular. The value of d can be selected as an intermediate value or set to a certain value based on actual measurements). S, ε and d can be set according to needs to adjust the capacitance of the combined capacitor.

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

[0033] In order to ensure that the charge of the capacitor is always at a low charge and ensure stable absorption of electrostatic energy, a switch circuit 70 is set on the circuit board of the front shell component 20, combined with the existing control circuit (such as SOC chip) to discharge the entire capacitor system. The switch circuit 70 connects the control circuit and the upper electrode plate of the capacitor (based on the fact that the middle frame bracket assembly 30 itself is part of the upper electrode plate, the switch circuit 70 is arranged in the front shell assembly 20, and specifically, a wire can be arranged on the circuit board, one end of the wire is electrically connected to the corresponding electronic component on the circuit board, and the other end of the wire is welded to the inner side surface of the side of the middle frame bracket assembly 30), and the lower electrode plate of the capacitor is grounded (based on the fact that the front shell assembly 20 itself is part of the lower electrode plate, specifically, a spring can be arranged on the circuit board, one end of the spring is electrically connected to the ground on the circuit board, and the other end of the spring is abutted against the inner side surface of the side of the front shell assembly 20); the switch circuit 70 outputs the voltage of the capacitor to the control circuit, and when the control circuit determines that the voltage is greater than the upper limit threshold, the control circuit controls the switch circuit 70 to turn on, and the upper electrode plate of the capacitor is grounded for electrostatic discharge; when it is determined that the voltage is less than the lower limit threshold, the control switch circuit 70 is turned off, and the upper electrode plate of the capacitor is disconnected and grounded for electrostatic absorption.

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

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

[0036] Preferably, the switch 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 switch tube Q2, one end of the second diode D2 is connected to the drain of the first switch tube Q1, and the other end of the first diode D1 is connected to the other end of the second diode D2 and ground. The first diode D1 and the second diode D2 are preferably ESD electrostatic 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 sheets is as follows: in daily use of the mobile phone, the upper and lower electrode plates of the capacitor absorb the electrostatic charges transmitted by the electronic components and interfaces of the circuit board under various working modes, preventing external static electricity from entering the interior of the mobile phone and absorbing static electricity on internal signals, thereby achieving electrostatic protection.

[0038] The electrostatic charge absorbed from the external environment or the user is accumulated and stored in the capacitor. The control circuit (SOC chip and its peripheral circuit) detects the voltage ADC_V through the ADC pin to achieve accurate capacitance detection. The capacitance and voltage comparison table is shown in Table 1 below (the values ​​here are the preferred values ​​of experimental tests and are not limited to specific values). If the control circuit determines that the voltage value of the voltage ADC_V is greater than 5.5V, it indicates that the electrostatic charge currently absorbed by the capacitor, that is, the capacitance has reached 80%, and it needs to be discharged. The GPIO port of the control circuit outputs a high-level control signal GPIO_Switch, controls the second switch tube Q2 to be turned on and grounded, and pulls down the gate of the first switch tube Q1 to turn on Q1, so that the upper electrode plate of the capacitor (equivalent to the positive pole) can be connected to the ground, thereby achieving discharge. At this time, the static electricity absorbed by the capacitor is directly discharged to the ground and will not be stored.

[0039] The control circuit can obtain the voltage ADC_V on the ADC pin once at a preset interval until it is determined that the voltage value is less than 1.4V, indicating that the capacitor capacity is less than 20%. The discharge can be stopped and a low-level control signal GPIO_Switch is output to control the second switch tube Q2 to be turned off and the first switch tube Q1 to be turned off. The capacitor continues to absorb and store static electricity.

[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, the capacitive electrostatically protected portable terminal of the present invention utilizes the existing component structure of the mobile phone to form a capacitor through the connection of alloy sheets, and combines the voltage detection and control of the control circuit to enable the switch circuit to switch autonomously between instantaneous electrostatic energy absorption and capacitor capacity discharge, thereby realizing the functional control of electrostatic energy storage and timely release. By utilizing the existing mobile phone component structure, the shape and cost of the mobile phone will not be greatly changed; and these component structures and the capacitor composed of internal electrolytes can protect against electrostatic discharge in any direction, ensure that the internal circuit board is not affected, and protect the mobile phone in all directions.

[0043] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A capacitive electrostatic protection portable terminal, comprising a screen assembly, a front shell assembly, a middle frame support assembly and a battery cover assembly arranged in sequence 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 middle frame support assembly through the first alloy sheet to form an 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 through the second alloy sheet to form a lower electrode plate of the capacitor. An insulating layer is set on the circuit board of the front shell assembly, and electrolyte is filled between two adjacent components. The circuit board of the front shell assembly controls the electrostatic absorption and discharge of the capacitor according to the capacitor capacity.

2. The portable terminal with capacitive electrostatic protection according to claim 1, characterized in that: A first welding area concave inwardly is provided on one side of the middle frame support assembly, one side of the first alloy sheet is welded to one side of the screen assembly and is perpendicular to the screen assembly, and the first alloy sheet is closely attached to the first welding area and is welded and fixed.

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 second welding area which is concave inwards, 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, and the second alloy sheet is closely attached to the second welding area and fixed by welding.

4. The portable terminal with capacitive electrostatic protection according to claim 3, characterized in that: The insulating layer is formed by spraying and filling the base glue on the circuit board of the front shell assembly, the surface of each circuit module and the pin welding position to cover them.

5. The portable terminal with capacitive electrostatic protection according to claim 4, characterized in that: The depth of the concave portion of the first welding area matches the thickness of the first alloy sheet, and the outer side surface of the first alloy sheet is flush with the side edge of the middle frame support assembly.

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

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 connects the control circuit and the upper electrode plate of the capacitor, and the lower electrode plate of the capacitor is grounded; The switch circuit outputs the voltage of the capacitor to the control circuit; When the control circuit determines that the voltage is greater than the upper threshold, the control circuit controls the switch circuit to be turned on, and the upper electrode plate of the capacitor is grounded to discharge static electricity; When it is determined that the voltage is less than the lower threshold, the control switch circuit is cut 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 switch circuit includes a first switch tube, a second switch tube and a first resistor; The source of the first switch tube is connected to the ground and one end of the first resistor, the drain of the first switch tube is connected to the upper electrode plate of the capacitor and the detection end of the control circuit, the gate of the first switch tube is connected to the other end of the first resistor and the drain of the second switch tube, the gate of the second switch tube is connected to the control end of the control circuit, the source of the second switch tube 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 switch circuit also includes a first diode and a second diode, one end of the first diode is connected to the gate of the second switch tube, one end of the second diode is connected to the drain of the first switch tube, 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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