A sealed probe for airtight testing of capacitive touch buttons

Abstract

The present invention discloses a sealing probe for airtightness test of capacitive touch keys, belonging to the technical field of airtightness test of capacitive touch keys. After the annular sealing portion of the sealing ring is sleeved on the outer wall of the shell, the annular sealing portion is squeezed laterally by a pressing plate so that the annular sealing portion is closely attached to the outer wall of the shell, and an inflating device inflates the inner cavity of the body through an air pipe joint, and the airtightness of the capacitive touch keys is detected through the air pressure change in the inner cavity of the body, and the waterproof performance of the capacitive touch keys is reflected through the airtightness test. The sealing probe can avoid false detection and improve the test accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of sealing test of capacitive touch buttons, and in particular relates to a sealing probe for airtight test of capacitive touch buttons. Background Art

[0002] In the design of capacitive touch buttons, capacitive touch sensors are placed under the cover layer (also called touch screen cover layer, touch surface) to reduce environmental impact and prevent ESD problems ("Electrostatic Discharge" or electrostatic discharge problems) caused by direct finger contact. Capacitive touch sensors have built-in circuits that can detect changes in capacitance. When a finger touches the cover layer, the distance and contact area between the finger and the capacitive touch sensor change, thereby changing the capacitance value between the two. After the capacitive touch sensor detects the change in capacitance, it converts this change into an electrical signal. Then, through the signal processing circuit, this electrical signal will be further processed to determine the location, intensity and other information of the touch. One advantage of capacitive touch sensors is that they do not require mechanical moving parts to detect touch, which makes them more durable and more responsive than traditional buttons, which allows them to be used in a variety of environments and applications, such as smartphones, tablets and other touch screen devices.

[0003] In some high-end applications, such as smart phones, tablets or industrial equipment, the sealing of the gap (tested gap) between the cover layer of the capacitive touch button and the shell of the capacitive touch button is very important. The sealing is usually achieved by using sealants, rubber gaskets, sealing strips or other special sealing materials. Ideally, the gap between the cover layer and the shell should be completely sealed to ensure good sealing between the shell and the cover layer to ensure that the capacitive touch button has reliable waterproof performance. At present, the reliability of the sealing test between the cover layer and the shell of the capacitive touch button (referred to as the capacitive touch button airtight test in this article) in the industry is still relatively low, resulting in an increase in the scrap rate of capacitive touch button products in the later stage. Summary of the invention

[0004] In view of this, the present invention provides a sealing probe for airtight testing of capacitive touch buttons. After the annular sealing portion of the sealing ring is sleeved on the outer wall of the outer shell, the annular sealing portion is squeezed laterally by a pressure plate to make the annular sealing portion tightly fit on the outer wall of the outer shell. The inflation device inflates air into the inner cavity of the main body through the trachea joint. The air pressure in the inner cavity of the main body changes, thereby detecting the airtightness of the capacitive touch button, and reflecting the waterproof performance of the capacitive touch button through the airtight test.

[0005] The present invention adopts the following technical solutions:

[0006] A sealed probe for airtight testing of a capacitive touch button, comprising:

[0007] The body includes a base and a vent pipe. The bottom of the base is provided with an inner cavity with an opening facing downward, the inner cavity is provided with a vent hole, and a limited position surface is provided on the base. The bottom of the vent pipe is fixedly connected to the top surface of the base, and the top extends upward, and the vent pipe, the vent hole and the inner cavity are connected;

[0008] Linear bearing: coaxially sleeved on the outer periphery of the vent pipe in a sliding manner; the linear bearing is provided with a mounting flange for fixing with the fixed structure; a limit plate is fixed at the bottom of the fixed structure, and the top surface of the limit plate is in contact with the limit surface of the base;

[0009] The first spring is coaxially sleeved on the outer periphery of the vent pipe, with the bottom in contact with the top surface of the base and the top in contact with the bottom of the mounting flange;

[0010] Trachea joint: fixed to the top of the vent pipe and connected to the vent pipe;

[0011] Guide column: The top end is fixed to the bottom of the base, and a spring is sleeved on the outer periphery;

[0012] Pressing plate: an inverted frustum hole is provided, and slidingly cooperates with the guide column;

[0013] Sealing ring: comprising an integrated fixing portion and an annular sealing portion, wherein the fixing portion is fixedly connected to the bottom of the base, and the annular sealing portion extends downward and is higher than the pressing plate; the inner diameter of the annular sealing portion is smaller than the outer diameter of the shell of the capacitive touch button to be tested, and can be sleeved on the outer wall of the shell of the capacitive touch button to be tested through elastic deformation;

[0014] When the pressing plate slides upward along the guide column, the pressing plate compresses the spring on the guide column, and the side wall of the frustum hole laterally squeezes the annular sealing part sleeved on the outer wall of the shell of the capacitive touch button to be tested.

[0015] Furthermore, the annular sealing portion expands downward from the bottom of the fixing portion into a structure with a spherical outline.

[0016] Furthermore, the radius of curvature of the spherical surface is 0.5-1.5 mm.

[0017] Furthermore, the cross-sections of the shell of the capacitive touch button to be tested and the annular sealing portion are both waist-shaped hole structures.

[0018] Furthermore, the wall thickness of the shell of the capacitive touch button to be tested is 0.1-0.3 mm.

[0019] Further, when the annular sealing portion is not compressed, the inner diameter of the annular sealing portion is 0.08-0.3 mm smaller than the outer diameter of the housing of the capacitive touch button to be tested.

[0020] Furthermore, a gap between an outer periphery of the cover layer of the capacitive touch button to be tested and an inner wall of the capacitive touch button housing is 0.01-0.03 mm, and a sealing material is provided in the gap.

[0021] Furthermore, the sealing ring is made of polyurethane;

[0022] The surface roughness of the sealing ring is less than 0.5 μm, and the dimensional accuracy is ±0.03 mm.

[0023] Furthermore, the hardness of the polyurethane is 40°~65° Shore.

[0024] Beneficial effects:

[0025] 1. The inner diameter of the annular sealing part is smaller than the outer diameter of the shell of the capacitive touch key to be tested, and can be set on the outer wall of the shell of the capacitive touch key to be tested through elastic deformation. In this way, the sealing ring can fit closely with the outer wall of the shell of the capacitive touch key to improve the sealing effect of the inner cavity of the body and ensure the accuracy of the airtightness test; moreover, because the sealing ring is set on the outer wall of the shell of the capacitive touch key to be tested, it can avoid the seal of the tested gap by the sealing ring, resulting in the occurrence of false test (because if the tested gap is sealed by the sealing ring, it cannot truly reflect the sealing effect of the sealing material in the tested gap on the tested gap), ensuring the accuracy of the airtightness test. In addition, when the pressure plate slides upward along the guide column, the top surface of the pressure plate compresses the spring on the guide column upward, and the side wall of the truncated cone hole squeezes the annular sealing part set on the outer wall of the shell of the capacitive touch key to be tested laterally, so that the inner wall of the annular sealing part fits the outer wall of the shell of the capacitive touch key to be tested. In this way, by laterally squeezing the annular sealing portion of the sealing ring through the pressure plate, the annular sealing portion can be made to fit more closely to the outer wall of the shell of the capacitive touch button to be tested, thereby improving the sealing effect on the inner cavity of the main body and ensuring the accuracy of the air-tightness detection; moreover, the pressure plate laterally squeezes the annular sealing portion of the sealing ring after the annular sealing portion is sleeved on the outer wall of the shell of the capacitive touch button to be tested, which can avoid the annular sealing portion being laterally squeezed by the pressure plate when it is located at the top of the shell of the capacitive touch button, resulting in the tested gap of the capacitive touch button being sealed by the sealing ring, causing the problem of false measurement.

[0026] 2. The annular sealing portion expands downward from the bottom of the fixed portion into a structure with a spherical outline. In this way, the annular sealing portion expands into a spherical structure, which enhances the adaptability between the sealing ring and the housing of the capacitive touch button to be tested and improves the sealing performance of the inner cavity of the body.

[0027] 3. The cross-section of the shell and the annular sealing part of the tested capacitive touch button are both waist-shaped hole structures. Because the annular sealing part of the sealing ring is very easy to wrinkle when squeezed, resulting in poor sealing effect, the cross-section of the shell and the annular sealing part of the tested capacitive touch button are both waist-shaped hole structures, which helps to distribute the pressure more evenly on the sealing ring, avoid wrinkles in the annular sealing part of the sealing ring, and improve the sealing effect of the body cavity.

[0028] 4. The most critical part of the air tightness test of capacitive touch buttons is the design of the sealing structure, and the core part of the sealing structure is the design of the sealing ring. The material of the sealing ring is polyurethane, and the surface roughness of the sealing ring is less than 0.5μm, and the dimensional accuracy is ±0.03mm, which can ensure the good elasticity and wear resistance of the sealing ring and provide long-lasting sealing performance.

[0029] 5. The design of the first spring enables the sealing probe to adapt to capacitive touch buttons of different heights. The spring arranged on the guide column enables the pressure plate to have a floating characteristic. The annular sealing portion extends downward and is higher than the pressure plate. In this way, before the sealing ring is sleeved on the outer wall of the capacitive touch button shell, the pressure plate cannot squeeze the annular sealing portion. Only after the annular sealing portion is sleeved on the outer wall of the capacitive touch button shell to be tested, the pressure plate will squeeze the annular sealing portion sleeved on the outer wall of the capacitive touch button shell. This makes it easier for the sealing ring whose inner diameter is smaller than the outer diameter of the capacitive touch button shell to be tested to be sleeved on the outer wall of the capacitive touch button shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the three-dimensional structure of a sealing probe for airtight testing of capacitive touch buttons provided by the present invention;

[0031] Figure 2 A front view of a sealing probe for airtight testing of a capacitive touch button provided by the present invention;

[0032] Figure 3 A schematic diagram of an explosion of a sealed probe for airtight testing of a capacitive touch button provided by the present invention;

[0033] Figure 4 A cross-sectional view of a sealing probe for airtight testing of a capacitive touch button provided by the present invention;

[0034] Figure 5 for Figure 4 Schematic diagram of the three-dimensional structure of the middle sealing ring;

[0035] Figure 6 for Figure 4 Front view of the middle sealing ring;

[0036] Figure 7 for Figure 4 A partial enlarged schematic diagram of point C in the middle;

[0037] Among them, 1-trachea joint, 2-linear bearing, 3-first spring, 4-main body, 401-base, 402-ventilation pipe, 403-inner cavity, 404-ventilation hole, 5-sealing ring, 501-fixing part, 502-annular sealing part, 6-housing, 7-guide column, 701-annular flange, 8-sealing ring fixing plate, 9-pressure plate, 10-measured gap, 11-covering layer, 12-limiting surface. DETAILED DESCRIPTION

[0038] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0039] Reference Figure 1 to Figure 7 , a sealed probe for airtight testing of capacitive touch buttons, comprising:

[0040] The body 4 includes a base 401 and a vent pipe 402. The base 401 has an inner cavity 403 with an open bottom facing downward, and the inner cavity 403 has a vent hole 404. The base 401 has a protrusion, and the bottom surface of the protrusion is used as a limit surface 12. The bottom of the vent pipe 402 is fixed to the top surface of the base 401, and the top extends upward. The vent pipe 402, the vent hole 404 and the inner cavity 403 are connected. The linear bearing 2 is coaxially sleeved in a sliding manner. The outer periphery of the vent pipe 402; the linear bearing 2 is provided with a mounting flange for fixing with the fixed structure, a limit plate is fixed at the bottom of the fixed structure, and the top surface of the limit plate is in contact with the limit surface 12 of the base; the first spring 3: coaxially sleeved on the outer periphery of the vent pipe 402, and the bottom is in contact with the top surface of the base 401, and the top is in contact with the bottom of the mounting flange of the linear bearing 2; the trachea connector 1: fixed to the top of the vent pipe 402 and communicated with the vent pipe 402; the guide Guide column 7: The top end is fixed to the bottom of the base 401, and a spring is sleeved on the outer circumference; Pressing plate 9: An inverted truncated cone hole is provided, and the pressing plate 9 is slidably matched with the guide column 7. More specifically, the pressing plate 9 is limited by the annular flange 701 provided at the bottom end of the guide column 7, and the pressing plate 9 will not slide off the guide column 7; Sealing ring 5: It includes an integrated fixing portion 501 and an annular sealing portion 502, the fixing portion 501 is fixed to the bottom of the base 401 through the sealing ring fixing plate 8, and the annular sealing portion 502 extends downward and is higher than the pressing plate 9; The inner diameter of the annular sealing portion 502 is smaller than the outer diameter of the shell 6 of the capacitive touch button to be tested, and can be sleeved on the outer wall of the shell 6 of the capacitive touch button to be tested through elastic deformation; When the pressing plate 9 slides upward along the guide column 7, the top surface of the pressing plate 7 upwardly compresses the spring on the guide column 7, and the side wall of the truncated cone hole laterally squeezes the annular sealing portion 502 sleeved on the outer wall of the shell 6 of the capacitive touch button to be tested.

[0041] The working principle of the sealing probe for the airtight test of the capacitive touch button is as follows: the mounting flange on the linear bearing 2 is fixedly connected to the fixed structure (not shown in the figure), a limit plate (not shown in the figure) is fixed to the bottom of the fixed structure, and the limit surface 12 of the body 4 is supported and attached to the top surface of the limit plate under normal conditions, so that the first spring 3 is in a pre-compressed state. In this way, the body 4 can only move upward relative to the limit plate, thereby compressing the first spring 3 upward, and the body 4 will not slide off the linear bearing 2. During the test, the capacitive touch key to be tested is placed on the carrier, the air pipe joint 1 is connected to the inflation device, and then the sealing probe for the capacitive touch key airtight test is brought close to the capacitive touch key on the carrier, so that the sealing ring 5 is elastically deformed and sleeved on the outer wall of the shell 6 of the capacitive touch key to be tested (although the inner diameter of the annular sealing portion 502 is smaller than the outer diameter of the shell 6 of the capacitive touch key to be tested, it is designed to be slightly smaller but not much smaller, so that the annular sealing portion 502 can be elastically deformed and sleeved on the outer wall of the shell 6 of the capacitive touch key to be tested. In this process, the first spring 3 can be compressed, and the design of the first spring 3 can be The sealing probe is adapted to capacitive touch buttons of different heights), and then the sealing probe for the capacitive touch button airtight test and the capacitive touch button on the carrier continue to approach each other so that the bottom surface of the pressure plate 9 abuts against the limiting structure on the carrier. On this basis, the sealing probe for the capacitive touch button airtight test and the capacitive touch button on the carrier continue to approach each other, so that the pressure plate 9 slides upward along the guide column 7 due to the force of the limiting structure on the carrier, so that the top surface of the pressure plate 9 compresses the spring on the guide column 7 upward, and the side wall of the frustum hole on the pressure plate 9 laterally squeezes the annular sealing portion 502 that is sleeved on the outer wall of the shell 6 of the capacitive touch button to be tested. So far, refer to Figure 7 In theory, the inner cavity 403 of the body 4, the vent hole 404, and the tube cavity of the vent tube 402 are connected, and if leakage occurs, it will not occur at the place where the annular sealing part 502 and the shell 6 are tightly fitted, and the leakage will only occur at the measured gap 10. At this time, the inflation device inflates the inner cavity 403 of the body 4 through the air pipe joint 1 (strictly speaking, the inner cavity 403 of the body 4, the vent hole 404, and the tube cavity of the vent tube 402 will be inflated), and maintains it for a certain time. By monitoring the air pressure change in the inner cavity 403 of the body 4, the air tightness of the measured gap 10 can be obtained, and the air tightness test of the capacitive touch button can be completed. The above method of bringing the sealing probe for the capacitive touch button air tightness test and the capacitive touch button on the support platform close to each other can be that the sealing probe is fixed and the support platform moves toward the sealing probe, or the support platform is fixed and the sealing probe moves toward the support platform. Of course, it can also be that the sealing probe and the support platform move towards each other.

[0042] Generally, the wall thickness of the housing 6 of the capacitive touch button and the size of the measured gap 10 provided with the sealing material are relatively small. Therefore, the measured gap 10 is easily sealed after the sealing ring 5 is squeezed and deformed, resulting in the occurrence of false detection. Therefore, special attention should be paid to avoid the measured gap 10 being sealed by the sealing ring 5. In the present embodiment, the wall thickness of the shell 6 of the tested capacitive touch key is 0.1-0.3 mm, and the tested gap is 0.01-0.03 mm. In particular, the inner diameter of the annular sealing portion 502 is 0.08-0.3 mm smaller than the outer diameter of the tested capacitive touch key shell 6. In this way, the annular sealing portion 502 of the sealing ring 5 can be closely fitted with the outer wall of the shell 6 of the capacitive touch key, thereby improving the sealing effect on the inner cavity of the body 4 and ensuring the accuracy of the airtightness detection. Moreover, because the annular sealing portion 502 of the sealing ring 5 is sleeved on the outer wall of the shell 6 of the tested capacitive touch key, it is possible to avoid the tested gap 10 being sealed by the sealing ring 5, thereby preventing the occurrence of false detection (because if the tested gap 10 between the outer periphery of the cover layer 11 of the capacitive touch key and the shell 6 is sealed by the sealing ring 5, it is not possible to truly reflect the sealing effect of the sealing material in the tested gap 10 on the tested gap 10), thereby ensuring the accuracy of the airtightness detection and reliably evaluating the waterproof performance. In addition, when the pressure plate 9 slides upward along the guide column 7, the top surface of the pressure plate 7 compresses the spring on the guide column 7 upward, and the side wall of the conical hole laterally squeezes the annular sealing portion 502 that is sleeved on the outer wall of the shell 6 of the capacitive touch button under test, so that the inner wall of the annular sealing portion 502 fits against the outer wall of the shell 6 of the capacitive touch button under test. In this way, by laterally squeezing the annular sealing portion 502 of the sealing ring 5 through the pressure plate 9, the annular sealing portion 502 can be made to fit more closely to the outer wall of the shell 6 of the capacitive touch button to be tested, thereby improving the sealing effect on the inner cavity 403 of the main body 4 and ensuring the accuracy of the airtightness detection; moreover, the pressure plate 9 laterally squeezes the annular sealing portion 502 of the sealing ring 5 after the annular sealing portion 502 is sleeved on the outer wall of the shell 6 of the capacitive touch button to be tested, which can avoid the annular sealing portion 502 being laterally squeezed by the pressure plate 9 when it is located at the top of the shell 6 of the capacitive touch button, resulting in the gap 10 to be tested being sealed by the sealing ring 10, causing the problem of false measurement.

[0043] Reference Figure 7 In this embodiment, the annular sealing portion 502 expands downward from the bottom of the fixing portion 501 into a structure with a spherical outline. In this way, the annular sealing portion 502 expands into a spherical structure, which enhances the adaptability between the sealing ring 5 and the shell 6 of the capacitive touch key to be tested, and improves the sealing performance of the inner cavity 403 of the body 4. In this embodiment, the curvature radius of the spherical surface is 0.5~1.5mm.

[0044] Reference Figure 5 and Figure 6In this embodiment, the cross-sections of the shell 6 and the annular sealing part 502 of the tested capacitive touch button are both waist-shaped hole structures. As such, as those skilled in the art know, the sealing ring 5 is very likely to wrinkle when squeezed, resulting in poor sealing effect. Therefore, in this embodiment, the cross-sections of the shell 6 and the annular sealing part 502 of the tested capacitive touch button are both set to waist-shaped hole structures, which helps to distribute the pressure more evenly on the annular sealing part 502 of the sealing ring 5, avoid wrinkling of the annular sealing part 502 of the sealing ring 5, and improve the sealing effect on the inner cavity 403 of the body 4.

[0045] In particular, in the present embodiment, the material of the sealing ring 5 is polyurethane with a hardness of 40°~65° Shore A, and the sealing ring 5 has a very high processing accuracy, with a surface roughness of less than 0.5μm and a dimensional accuracy of ±0.03mm. In order to achieve this high precision, an open mold injection molding process can be used, which can ensure the good elasticity and wear resistance of the sealing ring 5 and provide a long-lasting sealing performance.

[0046] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sealed probe for airtight testing of capacitive touch buttons, characterized in that: include: The body includes a base and a vent pipe. The bottom of the base is provided with an inner cavity with an opening facing downwards, the inner cavity is provided with vent holes, and a limited position surface is provided on the base; The bottom of the vent pipe is fixed to the top surface of the base, and the top extends upward, and the vent pipe, the vent hole and the inner cavity are connected; Linear bearing: coaxially sleeved on the outer periphery of the vent pipe in a sliding manner; the linear bearing is provided with a mounting flange for fixing with the fixed structure; a limit plate is fixed at the bottom of the fixed structure, and the top surface of the limit plate is in contact with the limit surface of the base; The first spring is coaxially sleeved on the outer periphery of the vent pipe, with the bottom in contact with the top surface of the base and the top in contact with the bottom of the mounting flange; Trachea joint: fixed to the top of the vent pipe and connected to the vent pipe; Guide column: the top end is fixed to the bottom of the base, and the outer periphery is sleeved with a second spring; Pressing plate: an inverted frustum hole is provided, and slidingly cooperates with the guide column; Sealing ring: comprising an integrated fixing portion and an annular sealing portion, wherein the fixing portion is fixedly connected to the bottom of the base, and the annular sealing portion extends downward and is higher than the pressing plate; the inner diameter of the annular sealing portion is smaller than the outer diameter of the shell of the capacitive touch button to be tested, and can be sleeved on the outer wall of the shell of the capacitive touch button to be tested through elastic deformation; When the pressing plate slides upward along the guide column, the pressing plate compresses the second spring on the guide column, and the side wall of the frustum hole laterally squeezes the annular sealing part sleeved on the outer wall of the tested capacitive touch button housing.

2. A sealed probe for capacitive touch button airtightness test according to claim 1, characterized in that: The annular sealing portion expands downward from the bottom of the fixing portion into a structure with a spherical outline.

3. The sealing probe for capacitive touch button airtightness test according to claim 2, characterized in that: The curvature radius of the spherical surface is 0.5-1.5 mm.

4. The sealed probe for capacitive touch button airtightness test according to claim 2, characterized in that: The cross sections of the shell of the capacitive touch button to be tested and the annular sealing portion are both waist-shaped hole structures.

5. The sealing probe for capacitive touch button airtightness test according to claim 4, characterized in that: The wall thickness of the shell of the capacitive touch button to be tested is 0.1-0.3 mm.

6. The sealing probe for capacitive touch button airtightness test according to claim 5, characterized in that: When the annular sealing portion is not compressed, the inner diameter of the annular sealing portion is 0.08-0.3 mm smaller than the outer diameter of the housing of the capacitive touch key to be tested.

7. A sealing probe for capacitive touch button airtightness test according to any one of claims 1 to 6, characterized in that: The gap between the outer periphery of the cover layer of the capacitive touch key to be tested and the inner wall of the capacitive touch key housing is 0.01-0.03 mm, and a sealing material is arranged in the gap.

8. A sealing probe for capacitive touch button airtightness test according to any one of claims 1 to 6, characterized in that: The sealing ring is made of polyurethane; The surface roughness of the sealing ring is less than 0.5 μm, and the dimensional accuracy is ±0.03 mm.

9. The sealed probe for capacitive touch button airtightness test according to claim 8, characterized in that: The hardness of the polyurethane is 40° to 65° Shore.

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