Plasma cleaning device and plasma cleaning method

Abstract

This application provides a plasma cleaning apparatus and a plasma cleaning method. The plasma cleaning apparatus includes a cavity, an excitation electrode, a clearance electrode, and a carrier support platform. The carrier support platform is disposed between the excitation electrode and the clearance electrode and is used to support a carrier for a fingerprint recognition module. The fingerprint recognition module includes a contact surface and a protective surface. The excitation electrode is disposed within the cavity and faces the contact surface of the fingerprint recognition module, while the clearance electrode is disposed within the cavity and faces the protective surface of the fingerprint recognition module. The plasma cleaning method utilizes the aforementioned plasma cleaning apparatus to perform plasma cleaning. This application not only reduces the erosion of the fingerprint recognition module's protective surface by plasma during the plasma cleaning process but also saves on labor and material costs.

Description

Technical Field

[0001] This application relates to the field of clean technology, and in particular to plasma cleaning apparatus and plasma cleaning method. Background Technology

[0002] Fingerprint recognition technology is now widely used, among which capacitive fingerprint recognition technology has advantages such as small size and fast fingerprint recognition speed. A capacitive fingerprint recognition module includes a capacitive fingerprint recognition chip and a protective substrate. The protective substrate is placed on top of the capacitive fingerprint recognition chip and usually includes an anti-fingerprint coating to reduce the adhesion of dirt such as skin flakes or oils on the fingers, reducing the chance of the fingerprint recognition chip being interfered with by these dirt when recognizing fingerprints.

[0003] The manufacturing process of capacitive fingerprint recognition modules typically includes multiple plasma cleaning steps to remove contaminants remaining on the module from the manufacturing process, facilitating subsequent dispensing and bonding processes. Currently, the protective substrate of the capacitive fingerprint recognition module with the anti-fingerprint coating is placed on a cutout carrier. The cutout carrier supports the edges of the protective substrate, while the cutout area exposes the anti-fingerprint coating. Therefore, during subsequent dispensing and bonding processes, the cutout area of ​​the carrier can provide additional support to the capacitive fingerprint recognition module via a support module, or it can be used to heat the module via a heating module.

[0004] However, because the cutout area of ​​the cutout carrier exposes the anti-fingerprint coating on the protective substrate, there is a risk of plasma erosion of the anti-fingerprint coating during plasma cleaning, which can easily damage the anti-fingerprint coating and affect the product yield. Therefore, during plasma cleaning, the lower surface of the cutout carrier is made to fit against the table of the plasma cleaning machine to cover the cutout area of ​​the cutout carrier. However, due to the deformation of the cutout carrier during long-term use, and the table of the plasma cleaning machine may also be damaged, the fit between the lower surface of the cutout carrier and the table of the plasma cleaning machine is not good, resulting in plasma leakage and erosion of the anti-fingerprint coating. In order to avoid the aforementioned situation of plasma leakage caused by structural deformation or damage, the cutout carrier and the table of the plasma cleaning machine must be inspected and maintained frequently, which increases the cost of manpower and materials.

[0005] To address the aforementioned issues, another current approach is to use a non-perforated carrier to support the capacitive fingerprint recognition module. The bottom surface of the non-perforated carrier shields the anti-fingerprint coating on the substrate. During subsequent dispensing and bonding processes, a perforated carrier is used to support the capacitive fingerprint recognition module. However, this requires separate design of non-perforated and perforated carriers for each capacitive fingerprint recognition module, increasing the complexity of carrier design and resulting in increased production costs. Summary of the Invention

[0006] One objective of this application is to solve the problems described in the background art.

[0007] Based on one objective of this application, this application provides a plasma cleaning apparatus, including a cavity, an excitation electrode, a clearance electrode, and a carrier support platform. The carrier support platform is disposed between the excitation electrode and the clearance electrode, and is used to support a carrier. The carrier is used to support a fingerprint recognition module. The fingerprint recognition module includes a contact surface and a protective surface. The excitation electrode is disposed in the cavity and faces the contact surface of the fingerprint recognition module, and the clearance electrode is disposed in the cavity and faces the protective surface of the fingerprint recognition module.

[0008] In one embodiment of this application, the cavity further includes an air inlet pipe, one end of which is connected to the cavity, and the other end of which is connected to a working gas supply device, which stores working gas.

[0009] In one embodiment of this application, the cavity further includes an air outlet pipe, one end of which is connected to the cavity and the other end of which is connected to a pump.

[0010] In one embodiment of this application, the pump is a vacuum pump.

[0011] In one embodiment of this application, the excitation electrode is used to dissociate the working gas in the cavity into plasma, the plasma is used to remove contaminants on the bonding surface of the fingerprint recognition module, and the avoidance electrode is used to provide an electron flow to the protective surface of the fingerprint recognition module.

[0012] In one embodiment of this application, the working gas is oxygen or argon.

[0013] In one embodiment of this application, the carrier is a hollow carrier, which includes a hollow area that exposes the protective surface of the fingerprint recognition module.

[0014] In one embodiment of this application, the bonding surface of the fingerprint recognition module is the side of the fingerprint recognition module with an anti-fingerprint coating.

[0015] In addition, based on the purpose of this application, this application also provides a plasma cleaning method, which includes providing the plasma cleaning apparatus as described above; placing a carrier carrying a fingerprint recognition module on a carrier support platform, with the contact surface of the fingerprint recognition module facing the excitation electrode and the protective surface of the fingerprint recognition module facing the avoidance electrode; dissociating the working gas into plasma through the excitation electrode, and providing an electron flow towards the carrier support platform using the avoidance electrode, thereby cleaning the contact surface of the fingerprint recognition module with plasma, and the electron flow forming a protective area, which at least covers the protective surface of the fingerprint recognition module.

[0016] In summary, this application can not only reduce the erosion of the protective surface of the fingerprint recognition module by plasma during the plasma cleaning process, but also save manpower and material costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a fingerprint recognition module.

[0018] Figure 2 A schematic diagram showing the fingerprint recognition module installed on a vehicle.

[0019] Figure 3 This is a schematic diagram of a plasma cleaning device.

[0020] Figure 4 A schematic diagram showing the protective zone formed by the avoidance electrodes of the plasma cleaning device.

[0021] Figure 5 This is a step-by-step diagram of the plasma cleaning method.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1: Fingerprint recognition module

[0024] 2: Plasma cleaning device

[0025] 3: Vehicles

[0026] 10: Protective substrate

[0027] 12: Fingerprint recognition chip

[0028] 14: Outer shell

[0029] 16: Packaging shell

[0030] 20: Cavity

[0031] 22: Excitation electrode

[0032] 24: Avoiding Electrodes

[0033] 26: Vehicle support platform

[0034] B: Adhesive surface

[0035] E: Negative charge

[0036] G: Working gas supply device

[0037] I: Intake pipe

[0038] O: Exhaust pipe

[0039] P: Protective surface

[0040] S10, S20, S30: Steps

[0041] VP: Pump Detailed Implementation

[0042] Throughout this specification, "an embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Therefore, "an embodiment" mentioned in various places throughout this specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any way in one or more embodiments.

[0043] In the description of this application, it should be noted that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0044] Please see Figure 3 and Figure 4 This application provides a plasma cleaning device 2, including a cavity 20, an excitation electrode 22, a clearance electrode 24, and a carrier support platform 26. The carrier support platform 26 is disposed between the excitation electrode 22 and the clearance electrode 24, and is used to support a carrier 3. The carrier 3 is used to support a fingerprint recognition module 1. The fingerprint recognition module 1 includes a bonding surface B and a protective surface P. The excitation electrode 22 is disposed in the cavity 20 and faces the bonding surface B of the fingerprint recognition module 1. The clearance electrode 24 is disposed in the cavity 20 and faces the protective surface P of the fingerprint recognition module 1. The excitation electrode 22 is used to dissociate the working gas in the cavity 20 into plasma. The plasma is used to remove contaminants on the bonding surface B of the fingerprint recognition module 1, while the clearance electrode 24 is used to provide an electron flow to the protective surface P of the fingerprint recognition module 1 to protect the protective surface P of the fingerprint recognition module 1 from plasma erosion.

[0045] Please see Figure 1 and Figure 2In the following embodiments of this application, the fingerprint recognition module 1 is a capacitive fingerprint recognition module. The fingerprint recognition module 1 includes a protective substrate 10, a fingerprint recognition chip 12, a housing 14, and a packaging shell 16. Since the fingerprint recognition module 1 is an example of a capacitive fingerprint recognition module, the fingerprint recognition chip 12 referred to is a capacitive fingerprint recognition chip. The fingerprint recognition chip 12 is disposed on the upper surface of the packaging shell 16. The housing 14 is fastened to the packaging shell 16, so that the housing 14 is disposed on the packaging shell 16. In addition, the housing 14 includes an opening and a substrate support sheet. The substrate support sheet is disposed at the edge of the opening of the housing 14. The protective substrate 10 is assembled at the opening of the housing 14 and is supported by the substrate support sheet. Therefore, the protective substrate 10 and the fingerprint recognition chip 12 are separated by the substrate support sheet to avoid the protective substrate 10 directly contacting the fingerprint recognition chip 12 and causing damage to the fingerprint sensing chip. In addition, the opening of the housing 14 exposes the outward-facing side of the protective substrate 10, while the outward-facing side of the protective substrate 10... One side is the side of the protective substrate 10 with an anti-fingerprint coating, that is, the side of the protective substrate 10 with the anti-fingerprint coating exposed by the outer shell 14. The side of the protective substrate 10 of the fingerprint recognition module 1 with the anti-fingerprint coating is the protective surface P of the fingerprint recognition module 1. The side of the encapsulation shell 16 of the fingerprint recognition module 1 facing outward is the bonding surface B of the fingerprint recognition module 1. The protective surface P is used to reduce the adhesion of dirt such as skin flakes or oil on the fingers. The bonding surface B is the surface used by the fingerprint recognition module 1 for subsequent dispensing and bonding processes. Therefore, before performing the dispensing and bonding processes, it is necessary to remove the contaminants on the bonding surface B by plasma cleaning.

[0046] Please see Figure 1 and Figure 2 In the following embodiments of this application, the carrier 3 is a hollow carrier, which includes at least one hollow area. The carrier 3 is used to support the fingerprint recognition module 1. When the fingerprint recognition module 1 is placed on the carrier 3, the contact surface B of the fingerprint recognition module 1 faces upward, while the protective surface P of the fingerprint recognition module 1 faces downward. The hollow area on the carrier 3 exposes the protective surface P of the fingerprint recognition module 1, that is, the hollow area on the carrier 3 exposes the side of the protective substrate 10 of the fingerprint recognition module 1 on which the anti-fingerprint coating is provided.

[0047] Please see Figure 3 and Figure 4In the following embodiments of this application, the cavity 20 is a box including a door panel, so the user can open the door panel and place the fingerprint recognition module 1 to be plasma cleaned into the cavity 20. In addition, in the following embodiments of this application, the cavity 20 also includes an air inlet pipe I, one end of which is connected to the cavity 20, and the other end of which is connected to a working gas supply device G. The working gas supply device G stores working gas, so it can deliver working gas to the cavity 20 via the air inlet pipe I. In the following embodiments of this application, the working gas supply device G is a gas cylinder, and the working gas is oxygen, but in actual implementation, it is not limited to this; the working gas can also be other gases used for plasma cleaning, such as argon. Furthermore, in the following embodiments of this application, the cavity 20 also includes an air outlet pipe O, one end of which is connected to the cavity 20. Next, the other end of the exhaust pipe O is connected to the pump VP, which is used to extract the gas in the cavity 20. Taking a vacuum pump as an example, before performing plasma cleaning, the pump VP will first extract the gas (e.g., air) in the cavity 20 to make the cavity 20 a vacuum state. Then, the working gas supply device G will deliver the working gas to the cavity 20 through the intake pipe I. The aforementioned excitation electrode 22 will then dissociate the working gas into plasma, allowing the plasma to remove contaminants on the bonding surface B of the fingerprint recognition module 1. After the plasma cleaning is completed, the pump VP will remove the gas in the cavity 20, so that the contaminants removed by the plasma will also leave the cavity 20 through the exhaust pipe O.

[0048] Please see Figure 3 and Figure 4 In the following embodiments of this application, the carrier support platform 26 is composed of a plurality of columns of the same height, which together support the carrier 3. The carrier support platform 26 also exposes the protective surface P of the fingerprint recognition module 1, so that the protective surface P of the fingerprint recognition module 1 can directly correspond to the avoidance electrode 24. The foregoing is only an example of the carrier support platform 26, and the actual implementation is not limited to this. The carrier support platform 26 may also be a platform including an opening, and the opening of the carrier support platform 26 will also expose the protective surface P of the fingerprint recognition module 1, so that the protective surface P of the fingerprint recognition module 1 can directly correspond to the avoidance electrode 24.

[0049] Please see Figure 3 and Figure 4 In the following embodiments of this application, the excitation electrode 22 is a radio frequency electrode. When the working gas flows into the cavity 20, the excitation electrode 22 emits electromagnetic waves to dissociate the working gas into plasma. The plasma reacts with the contaminants on the fingerprint recognition module 1 placed in the cavity 20, thereby removing the contaminants on the fingerprint recognition module 1.

[0050] Please see Figure 3 and Figure 4In the following embodiments of this application, the avoidance electrode 24 is an electrode sheet subjected to a negative voltage, the source of which is a DC power supply. The avoidance electrode 24 releases an electron flow. Since the electron flow is negatively charged, based on the principle of repulsion between like charges, negatively charged particles in the plasma can be prevented from approaching the area where the electron flow is located. Furthermore, the positively charged particles in the plasma are particles that release electrons after receiving energy from the excitation electrode 22. Although the released electrons have an accelerating effect and thus a corrosive effect, the positively charged particles do not have a corrosive effect. Therefore, it is only necessary to prevent the corrosion of negatively charged particles in the plasma. Thus, the area where the electron flow is located forms a protective zone, and within this protective zone, plasma corrosion can be reduced. Figure 4 The diagram shows a protected area where the negative charge E represents the region where the electron flow occurs. Therefore, in this application, by aligning the avoidance electrode 24 with the protective surface P of the fingerprint recognition module 1, and by adjusting the intensity of the electron flow generated by the avoidance electrode 24, the protected area formed by the electron flow generated by the avoidance electrode 24 at least covers the protective surface P of the fingerprint recognition module 1. This effectively reduces the risk of plasma erosion of the protective surface P of the fingerprint recognition module 1 during plasma cleaning. Furthermore, if it is also desired to protect other parts of the fingerprint recognition module 1 or the carrier 3 from plasma erosion, the electron flow released by the avoidance electrode 24 can be strengthened, expanding the electron flow range and extending the protected area to cover the other parts of the fingerprint recognition module 1 or the carrier 3 to be protected.

[0051] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 Based on the foregoing description, this application also proposes a plasma cleaning method, comprising steps S10, S20, and S30. Step S10 involves providing the plasma cleaning apparatus 2 as described above; Step S20 involves placing a carrier 3 carrying a fingerprint recognition module 1 on a carrier support platform 26, with the contact surface B of the fingerprint recognition module 1 facing the excitation electrode 22 and the protective surface P of the fingerprint recognition module 1 facing the avoidance electrode 24; Step S30 involves dissociating the working gas into plasma through the excitation electrode 22 and providing an electron flow towards the carrier support platform 26 using the avoidance electrode 24, thereby cleaning the contact surface B of the fingerprint recognition module 1 with plasma, and the electron flow forming a protective area that at least covers the protective surface P of the fingerprint recognition module 1.

[0052] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5In one embodiment of this application, a verification experiment is proposed, which is divided into an experimental group and a control group. The experimental group uses the plasma cleaning method described in this application, while the control group uses a non-perforated carrier to cover the protective surface P of the fingerprint recognition module 1 according to the current method. The water droplet angle of the bonding surface B and the protective surface P of the fingerprint recognition module 1 is measured using a water droplet angle meter before and after the plasma cleaning. The experimental results of this verification experiment are shown in Table 1 below. The experimental results in Table 1 show that the results of the experimental group and the control group are comparable. After the plasma cleaning, the water droplet angle of the bonding surface B of both the experimental group and the control group is successfully reduced, indicating that the experimental group and the control group have successfully removed the contaminants on the bonding surface B using plasma cleaning. In addition, the water droplet angle of the anti-fingerprint surface of the experimental group and the anti-fingerprint surface of the control group is comparable to that before the plasma cleaning after the plasma cleaning, which proves that the plasma cleaning method of this application can avoid damage to the anti-fingerprint surface during the plasma cleaning process while cleaning the bonding surface B of the fingerprint recognition module 1.

[0053] Table 1. Experimental results of the verification experiment

[0054]

[0055] In summary, this application not only protects the protective surface P on the fingerprint recognition module 1 from plasma erosion while performing plasma cleaning on the fingerprint recognition module 1, but also eliminates the need for the carrier 3 to be bonded to the platform inside the cavity 20. The fingerprint recognition module 1 can be directly supported by a hollow carrier, thus allowing for direct connection to subsequent dispensing and bonding processes, saving manpower and material costs.

Claims

1. A plasma cleaning device, characterized in that, The device includes a cavity, an excitation electrode, a avoidance electrode, and a carrier platform. The carrier platform is disposed between the excitation electrode and the avoidance electrode, and is used to support a carrier. The carrier supports a fingerprint recognition module, and the fingerprint recognition module includes a contact surface and a protective surface. The excitation electrode is disposed within the cavity and faces the bonding surface of the fingerprint recognition module. The excitation electrode is a radio frequency electrode used to dissociate the working gas within the cavity into plasma, thereby removing contaminants from the bonding surface. The avoidance electrode is disposed in the cavity and faces the protective surface of the fingerprint recognition module. The avoidance electrode is supplied with a negative voltage to provide an electron flow, so that the electron flow forms a protective area on the protective surface side. By repelling negatively charged particles in the plasma, the protective surface is prevented from being eroded by the plasma during the plasma cleaning process.

2. The plasma cleaning apparatus as described in claim 1, characterized in that, The cavity also includes an air inlet pipe, one end of which is connected to the cavity, and the other end of which is connected to a working gas supply device, which stores working gas.

3. The plasma cleaning apparatus as described in claim 1, characterized in that, The cavity also includes an air outlet pipe, one end of which is connected to the cavity and the other end of which is connected to a pump.

4. The plasma cleaning apparatus as described in claim 3, characterized in that, The pump is a vacuum pump.

5. The plasma cleaning apparatus as described in claim 1, characterized in that, The working gas is oxygen or argon.

6. The plasma cleaning apparatus as described in claim 1, characterized in that, The carrier is a hollow carrier, which includes a hollow area that exposes the protective surface of the fingerprint recognition module.

7. The plasma cleaning apparatus as described in claim 1, characterized in that, The bonding surface of the fingerprint recognition module is the side of the fingerprint recognition module with an anti-fingerprint coating.

8. A plasma cleaning method, characterized in that, The plasma cleaning method includes: Provide the plasma cleaning apparatus as described in claim 1; The carrier carrying the fingerprint recognition module is placed on the carrier support platform, with the contact surface of the fingerprint recognition module facing the excitation electrode and the protective surface of the fingerprint recognition module facing the avoidance electrode. The working gas is dissociated into plasma by the excitation electrode, and an electron flow is provided to the carrier platform by the avoidance electrode. The plasma cleans the bonding surface of the fingerprint recognition module, and the electron flow forms a protective area that at least covers the protective surface of the fingerprint recognition module.

9. The plasma cleaning method as described in claim 8, characterized in that, The carrier includes at least one cutout area, the cutout area of ​​the carrier exposing the protective surface of the fingerprint recognition module.

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