A cart-type large-box plasma cleaning device

Abstract

The present invention discloses a cart-type large-box plasma cleaning device, comprising a main frame and a material cart. The main frame is provided with a vacuum chamber and an electrical chamber. The vacuum chamber has a vacuum cavity with a length, width, and height greater than 1 meter. The inner sidewall of the vacuum cavity is provided with a vacuum port, an electrode feed port, a temperature measuring port, and a working gas port, which is connected to a gas source device via a gas pipeline. The material cart comprises a carrier and a material frame, a limiting track is provided on the upper surface of the base frame, and insulating fixing blocks are provided between each electrode plate and support plate and the material frame. An electrode assembly is provided on the front side of the material frame, and the electrode assembly is electrically connected to an electrode pair that constitutes plasma excitation. An electrode plate is provided below the bottom support plate, and the electrode pair includes at least all the electrode plates. The present invention can be used to simultaneously clean multiple large-area product materials, improving the quality and efficiency of plasma cleaning.

Description

Technical Field

[0001] The invention relates to a plasma technology, in particular to a cart-assembled large-box plasma cleaning device. Background Art

[0002] Vacuum plasma cleaning technology is widely used in material surface modification, etching and cleaning, plasma chemical vapor deposition, sputtering, etc. It is also used in key processes for processing silicon, quartz, niobium lithium compounds and other special materials such as ceramics or glass.

[0003] Vacuum plasma cleaning is typically used in the following stages: improving material surface energy, before bonding and coating, and before screen printing. Plasma cleaning of painted plastic surfaces can improve paint adhesion, remove inorganic matter from the surface, improve the bond between the ink and the carrier, reduce peeling, and enhance thermal dissipation. It is also widely used in the new materials industry, treating granular and irregular materials, and even powders. Furthermore, in the toy industry, plasma treatment before painting prevents paint fading and improves the adhesion of paint and ink, achieving significant improvements.

[0004] The existing vacuum plasma equipment on the market is mainly composed of a vacuum system, a control system, and a plasma generation system. Vacuum plasma equipment is often a stand-alone device that requires manual single-layer loading and unloading. Especially for some product materials with a larger area, the conventional method is to use a conveying-type spray cleaning method. For example, the plasma cleaning equipment with patent number 202020584700.0 and patent name "Double Non-Contact Cleaning Processing System" can be used to clean large-area flat products. The product is placed flat and sent into the conveying mechanism, and then sprayed and flushed from above to complete the plasma cleaning operation of the current surface. However, this approach is inefficient and requires the workpiece to be turned over before cleaning the second side. The cleaning speed is slow, and the amount of cleaning that can be completed per unit time is low; moreover, simple jet cleaning does not achieve the best effect of plasma cleaning. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a cart-assembled large-box plasma cleaning device, which can be used to clean multiple large-area product materials at the same time, thereby improving the quality and efficiency of plasma cleaning.

[0006] The technical solution of the present invention is:

[0007] A cart-assembled large-box plasma cleaning device, which includes a frame body and a material cart, wherein the frame body is provided with a vacuum chamber and an electrical chamber, and the electrical chamber is provided with a control computer device, an air source device and a power supply device; the vacuum chamber is provided with a vacuum cavity, and the vacuum cavity is a rectangular space with a length, width and height greater than 1 meter; a cavity door is provided at its front end, and the inner side wall of the vacuum cavity is made of a metal plate, and a vacuum port, an electrode feed port, a temperature measuring hole and a working gas port are provided on the side wall, and the vacuum port is connected to the vacuum device via a sealed pipe; the electrode feed port is used to be inserted and docked with the electrode assembly on the material frame of the material cart; the working gas port is connected to the air source device via a gas pipeline; a temperature sensing device is installed on the temperature measuring hole; a docking track is provided on the bottom surface of the vacuum cavity for the roller at the bottom of the material frame to cooperate;

[0008] The material vehicle is provided with a transport vehicle and a material frame, the transport vehicle is provided with a base frame and a side frame installed on one side of the base frame, and rollers are provided under the base frame; a limiting track is provided on the upper surface of the base frame, and a transfer wheel is provided at the bottom of the material frame, and the transfer wheel is limited on the limiting track, and the end of the limiting track can be aligned with the front end of the docking track; a multi-layer material plate group is provided on the material frame, and the material plate group includes a metal electrode plate and a support plate, and an insulating fixed block is provided between each of the electrode plates and the support plate and the material frame, and an electrode assembly is provided on the side surface of the front end of the material frame, and the electrode assembly is conductively connected to the electrode pair constituting plasma excitation; a pole plate is provided under the bottommost support plate; and the electrode pair includes at least all the pole plates.

[0009] As described above, the cart-assembled large-box plasma cleaning device, wherein the electrode assembly includes a positive conductive plate and a negative conductive plate, each of the electrode plates is electrically connected to the positive conductive plate and the negative conductive plate in sequence, and a plasma excitation space with a voltage difference is formed between adjacent electrode plates; two electrode columns are respectively arranged on the front end surface of the material frame, and the positive conductive plate and the negative conductive plate are respectively connected to one of the electrode columns.

[0010] As described above, the cart-assembled large-box plasma cleaning device, wherein the positive electrode conduction plate and the negative electrode conduction plate are both composed of an insulating strip with an electrode plate groove and a cover plate. A long electrode plate is fixed in the electrode plate groove. The electrode plate is pressed to the bottom of the electrode plate groove by a metal bolt. The metal bolt passes through the insulating strip and is locked into the fixing hole on the front end side of the electrode plate.

[0011] The cart-assembled large-box plasma cleaning device as described above, wherein the electrode column includes an outer cylinder, an inner cylinder, a claw-shaped electrode sheet and a conductive screw, the claw-shaped electrode sheet is a trumpet-shaped structure in which multiple electrode sheets diffuse outward, the bottom of the inner cylinder is provided with an outwardly protruding positioning column, the bottom of the outer cylinder is provided with a positioning hole allowing the positioning column to pass through, the front end of the positioning column is provided with a disc-shaped pad, the bottom of the cylinder of the claw-shaped electrode sheet is provided with a first screw hole, the conductive screw passes through the first screw hole, the second screw hole on the positioning column and the third screw hole on the pad; the conductive screw is fixed on the material frame; the conductive screw is respectively connected to the electrode sheet in the positive conductive plate or the negative conductive plate through the transverse electrode sheet.

[0012] In the cart-assembled large-box plasma cleaning device described above, the electrode plates are mesh planes made of metal strips that overlap horizontally and vertically, and the electrode pairs of the material frame are composed of the electrode plates of each layer and the bottom electrode plate. The number of layers of the material plate group of the material cart is determined by the following method:

[0013] Step 1: Determine the working pressure value P, vacuum chamber height H, plate and support plate thickness t, product maximum height h, safety distance △d, gas flow Q, power supply P 电源 , material vehicle chassis height + top safety distance D, material plate group cross-sectional area S;

[0014] Step 2: Calculate the required layer spacing and number of layers:

[0015] The interlayer spacing d = h + △ d determined by the product size;

[0016] Single-story occupied height: d+t;

[0017] The maximum number of layers of cavity height constraint is n maxheight =(HD) / (d+t) rounded;

[0018] Step 3: Calculate power requirements:

[0019] The power required for each pair of electrodes P pair Related to the electrode spacing and gas pressure, the formula is as follows:

[0020] P pair =k·P·d 间距 S(k=10 -4 W·cm -1 ·Pa -1 );

[0021] Calculate the power demand P in the layer pair层内 = k·P·d·S;

[0022] Step 4: Calculate the maximum number of layers under power constraint:

[0023] The total number of electrode pairs for an n-layer structure plus one electrode plate is n;

[0024] Total power demand P total =n·P pair层内 ;

[0025] Maximum number of layers n for power constraints maxpower =P total / P pair层内 Rounding;

[0026] Step 5: Calculation of gas flow constraints:

[0027] Minimum flow demand Q for each layer 层 =Q / n≥Q min ;n maxflow =Q / Q min ;

[0028] Step 6: Compare n maxheight 、n maxpower and n maxflow The size of , take the smallest one and determine the number of layers n.

[0029] In the cart-assembled large-tank plasma cleaning device described above, if the determined number of layers n is less than 3, the following processing is performed:

[0030] If n maxheight Less than 3, n maxpower and n maxflow If it is greater than 3, then we can determine n=n maxheight ;

[0031] If n maxflow Less than 3, n maxpower ≥n maxheight ≥3, then adjust the gas flow Q so that n maxflow ≥n maxheight , determine n=n maxheight ;

[0032] If n maxpower Less than 3, n maxflow ≥n maxheight ≥3, then reduce the power between electrodes, extend the cleaning time, or increase the power supply P 电源 , so that n maxpower ≥n maxheight , determine n=n maxheight ;

[0033] If n maxheight ≥n maxflow ≥3>n maxpower , then, reduce the power between electrodes, extend the cleaning time, or increase the power supply P 电源 , so that nmaxflow ≥n maxpower ≥3, determine n= n maxpower ;

[0034] If n maxheight ≥n maxpower ≥3>n maxflow , then, adjust the gas flow Q so that n maxpower ≥n maxflow ≥3, determine n= n maxflow .

[0035] As described above, in the cart-type large-box plasma cleaning device, if n maxflow Less than 3, n maxpower ≥n maxheight ≥3, then adjust the gas flow Q so that n maxflow ≥n maxheight , determine n=n maxheight ; or n maxheight ≥n maxpower ≥3>n maxflow , then, adjust the gas flow Q so that n maxpower ≥n maxflow ≥3, determine n=n maxflow In the case of , after completing the adjustment of the gas flow Q, according to the formula:

[0036] P new = (Q × T) / (V × C), C is the original set pumping speed of the vacuum pumping device, T is the temperature, and V is the effective volume of the vacuum chamber;

[0037] Verify the new air pressure value P in the vacuum chamber new Is the working pressure value P maintained? If there is a deviation, then:

[0038] C target = (Q×T) / (P×V), calculate the new target pumping speed value and adjust the pumping speed of the vacuum pumping device.

[0039] The cart-assembled large-box plasma cleaning device as described above, wherein the electrode pair includes the electrode plate and the support plate; the electrode plate and the support plate respectively constitute the positive electrode or negative electrode of the plasma excitation electrode pair; the distance between the electrode pair with the electrode plate at the top and the support plate at the bottom is greater than the distance between the electrode pair with the support plate at the top and the electrode plate at the bottom by 5%-10%.

[0040] From the above description, it can be seen that the present invention has the following advantages:

[0041] The cart-mounted, large-box plasma cleaning device of the present invention utilizes a large box structure, providing space for accommodating multiple layers of material frames. This also enables the present invention to handle surface cleaning operations for larger products. Furthermore, multiple layers of material frames are provided within the large-box plasma cleaning device. To achieve a better cleaning effect on the products within the material frames, improve the surface properties of the treated products, and enhance the efficiency of product surface cleaning, the present invention determines the number of material frame layers by combining the various specific conditions of multiple plasma cleaning parameters under the special circumstances of the large box. This allows the most appropriate number of material frame layers to be matched to different product sizes and structures, ensuring the most effective cleaning effect for the products, reducing production costs, and improving the efficiency of plasma cleaning of product surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic structural diagram of a preferred embodiment of the present invention;

[0043] Figure 2 This is a schematic structural diagram of a vacuum chamber according to a preferred embodiment of the present invention;

[0044] Figure 3 A schematic structural diagram of a material vehicle according to a preferred embodiment of the present invention;

[0045] Figure 4 Schematic diagram of the structure of the electrode column of the present invention.

[0046] Description of main component numbers:

[0047] The present invention:

[0048] 1: Vacuum chamber 2: Electrical chamber 3: Chamber door

[0049] 4: Vacuum port 5: Electrode feed port 6: Temperature measurement hole

[0050] 7: Material cart 8: Material frame 9: Plate

[0051] 10: Pallet 11: Limiting track 12: Roller

[0052] 13: Electrode assembly 14: Electrode column 15: Conducting screw

[0053] 16: Claw-shaped electrode 17: Inner cylinder 18: Outer cylinder

[0054] 19: Pad DETAILED DESCRIPTION

[0055] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0056] The present invention is a cart-type large box plasma cleaning device, in which the preferred embodiment is shown in FIG. Figure 1 and Figure 2 As shown, the cart-type large-box plasma cleaning device of the present invention includes a frame body and a material cart 7. The frame body is equipped with a vacuum chamber 1 and an electrical chamber 2. The electrical chamber 2 is equipped with a control computer device, an air source device, and a power supply device. The control computer device is connected to the various electronic control devices by signal and controls the various functional components through multiple electric valves. According to the plasma cleaning preparation, excitation, and cleaning processes, the control is controlled so that the surface state of the products in the vacuum chamber can be stably cleaned by plasma. The vacuum chamber 1 is equipped with a vacuum chamber, which is a rectangular space with a length, width, and height greater than 1 meter. The vacuum chamber of the present invention is mainly a large-scale box structure, mainly used for plasma cleaning operations on large panels and structural parts. A cavity door 3 is provided at its front end. The inner side wall of the vacuum cavity is made of a metal plate. A vacuum port 4, an electrode feed port 5, a temperature measuring hole 6 and a working gas port are provided on the side wall. The vacuum port 4 is connected to the vacuum device via a sealed pipe; the electrode feed port 5 is used to be inserted and docked with the electrode assembly 13 on the material frame 8 of the material vehicle 7; the working gas port is connected to the gas source device via a gas pipeline; a temperature sensing device is installed on the temperature measuring hole 6; a docking track is provided on the bottom surface of the vacuum cavity for the roller 1 at the bottom of the material frame 8 to 2. After placing the material frame 8 in the vacuum chamber, the chamber door 3 is closed to seal the vacuum chamber from the outside world. The vacuum chamber is brought to a preset vacuum level by drawing air from the vacuum pump connected to the vacuum port 4. A set flow of working gas (e.g., argon) is injected through the working gas port to maintain a stable working gas flow within the vacuum chamber. The voltage difference between the electrode pairs on the material frame 8 excites the working gas, generating plasma. The plasma impacts the surface of the product to be cleaned in the vacuum chamber, achieving a cleaning effect. A temperature sensor detects the temperature, which is then used by a control computer to control the cooling system located outside the vacuum chamber to control the temperature within the vacuum chamber, ensuring a stable and efficient plasma cleaning operation.

[0057] The material cart 7 is provided with a carrier and a material frame 8. The carrier is provided with a base frame and a side frame installed on one side of the base frame. A roller 12 is provided under the base frame; a limiting rail 11 is provided on the upper surface of the base frame, and a transfer wheel is provided at the bottom of the material frame 8. The transfer wheel is limited on the limiting rail 11, and the end of the limiting rail 11 can be matched with the front end of the docking rail. The height of the base frame of the material cart 7 is flush with the height of the bottom surface of the vacuum chamber. When the material cart 7 is close to the docking vacuum chamber, the limiting rail 11 of the material cart 7 is just aligned with the docking rail. Should be engaged, the transfer wheel of the material frame 8 can be moved directly to the docking track and enter the vacuum chamber; the material frame 8 is provided with a multi-layer material plate group, the material plate group includes a metal electrode plate 9 and a support plate 10, and an insulating fixed block is provided between each of the electrode plates 9 and the support plate 10 and the material frame 8, and an electrode assembly 13 is provided on the front side of the material frame 8, and the electrode assembly 13 is conductively connected with the electrode pair constituting the plasma excitation; a electrode plate 9 is provided under the bottom support plate 10; the electrode pair includes at least all the electrode plates 9. When the material frame 8 enters the specified position in the vacuum chamber, the electrode assembly 13 will dock with the electrode feed port 5 on the inner wall of the vacuum chamber, so that the electrode pair of the electrode assembly 13 on the material frame 8 generates a voltage difference, thereby exciting the working gas in the vacuum chamber and generating plasma to immerse the product in cleaning. The cart-combined large-box plasma cleaning device of the present invention mainly uses medium-frequency excitation to excite the working gas.

[0058] In a preferred embodiment of the cart-mounted large-box plasma cleaning device of the present invention as described above, the electrode assembly 13 includes a positive conductive plate and a negative conductive plate, each of the electrode plates 9 being electrically connected to the positive conductive plate and the negative conductive plate in sequence and at intervals, forming a plasma excitation space with a voltage difference between adjacent electrode plates 9; two electrode columns 14 are respectively disposed on the front end surface of the material frame 8, and the positive conductive plate and the negative conductive plate are each electrically connected to one of the electrode columns 14. The present invention, through a clever design, groups the electrode plates 9 or support plates 10 on the material frame 8, and connects them at intervals between the positive conductive plates and the negative conductive plates, thereby forming a multi-layer electrode pair from top to bottom in the material frame 8, each layer being capable of performing corresponding plasma excitation cleaning on the products placed therein.

[0059] In the preferred embodiment of the cart-type combined large-box plasma cleaning device of the present invention as described above, the positive and negative conductive plates are each composed of an insulating strip with an electrode sheet slot and a cover plate. A long electrode sheet is fixed in the electrode sheet slot. The electrode sheet is pressed to the bottom of the electrode sheet slot via a metal bolt. The metal bolt passes through the insulating strip and is locked into the fixing hole on the front side of the electrode plate 9. The positive and negative conductive plates of the present invention are provided with electrode sheets, replacing the conventionally used wires. The electrode sheets are preferably made of copper sheets, which makes the electrode conductivity of the present invention more stable and efficient.

[0060] In a preferred embodiment of the cart-type large-tank plasma cleaning device of the present invention, the electrode column 14 comprises an outer tube 18, an inner tube 17, a claw-shaped electrode sheet 16, and a conductive screw 15. The claw-shaped electrode sheet 16 is a trumpet-shaped structure with multiple electrode sheets extending outward. The bottom of the inner tube 17 is provided with an outwardly protruding positioning post. The bottom of the outer tube 18 is provided with a positioning hole for allowing the positioning post to pass through. A disc-shaped pad 19 is provided at the front end of the positioning post. The bottom of the claw-shaped electrode sheet 16 is provided with a first screw hole. The conductive screw 15 passes through the first screw hole, the second screw hole on the positioning post, and the third screw hole on the pad 19. The conductive screw 15 is fixed to the material frame 8. The conductive screw 15 is electrically connected to the electrode sheet in the positive or negative conductive plate via the transverse electrode sheet. The novel structural design of the electrode column 14 enables the electrode column 14 to be firmly positioned and securely connected to the electrode feed port 5 when docked.

[0061] In the preferred embodiment of the cart-assembled large-box plasma cleaning device of the present invention as described above, the electrode plate 9 is a mesh plane made of metal strips overlapping horizontally and vertically, and the electrode pair of the material frame 8 is composed of the electrode plate 9 of each layer and the electrode plate 9 at the bottom; that is, the electrode plate 9 above each layer and the electrode plate 9 above the next layer form an electrode pair, including the bottom electrode plate 9, which can excite plasma in the space where the support plate 10 is located within each layer, and perform plasma cleaning on the products on the support plate 10. Preferably, the number of material plate groups of the material cart 7 of the present invention is determined by the following method:

[0062] Step 1: Determine the preset working pressure value P, vacuum chamber height H, plate and support plate thickness t, product maximum height h, and safety distance △d, which is the height distance to ensure that the product can be placed without collision. Gas flow Q, power supply P 电源 , material vehicle chassis height + top safety distance D, material plate group cross-sectional area S;

[0063] Step 2: Calculate the required layer spacing and number of layers:

[0064] The interlayer spacing d = h + △ d determined by the product size;

[0065] Single-story occupied height: d+t;

[0066] The maximum number of layers of cavity height constraint is n maxheight =(HD) / (d+t) rounded;

[0067] Step 3: Calculate power requirements:

[0068] The power required for each pair of electrodes P pair Related to the electrode spacing and gas pressure, the formula is as follows:

[0069] P pair =k·P·d 间距 S(k=10 -4 W·cm -1 ·Pa -1 );

[0070] Calculate the power demand P in the layer pair层内 = k·P·d·S;

[0071] Step 4: Calculate the maximum number of layers under power constraint:

[0072] The total number of electrode pairs for an n-layer structure plus one electrode plate is n;

[0073] Total power demand P total =n·P pair层内 ;

[0074] Maximum number of layers n for power constraints maxpower =P total / P pair层内 Rounding;

[0075] Step 5: Calculation of gas flow constraints:

[0076] Minimum flow demand Q for each layer 层 =Q / n≥Q min ;n maxflow =Q / Q min ;

[0077] Step 6: Compare n maxheight 、n maxpower and n maxflow The size of , take the smallest one and determine the number of layers n.

[0078] For example, the structural features of this embodiment are as follows: each layer contains one plate (electrode) and one insulating support plate (only for carrying products), and adjacent plates have opposite polarities to form electrode pairs for plasma excitation; the number of electrode pairs: n layers of plates form (n-1) electrode pairs (for example, 3 layers of plates form 2 pairs of electrodes).

[0079] Basic parameters include: air pressure: 30Pa; cavity height H: 1.3m; △d is 2cm; safety distance D is 20cm; total thickness t of the plate and support plate is 5cm; maximum product height h: 8cm; temperature: 28℃; working gas flow rate: 90sccm; power supply: 800W; plate mesh structure: metal strips are 2mm wide and spaced 1.5cm in the same direction, then the opening ratio α=(1.5-0.2)² / 1.5²≈0.742 (the effective surface area of ​​the plate is 74.2% of the plane area).

[0080] Then, the layer spacing and cavity height constraint calculation:

[0081] n maxheight =(HD) / (d+t)=(130-20) / (8+2+5)≈7.3, round up to get n maxheight is 7.

[0082] Power supply power constraint calculation:

[0083] Assume that the effective area of ​​the plate S = 70cm × 70cm × 0.742 = 3635.8cm 2 ;

[0084] Power per pair of electrodes P pair层内 = k·P·d·S=10 -4 W·cm -1 ·Pa -1 ·30Pa·10cm·3635.8cm 2 =109.074W;

[0085] Maximum number of layers n for power constraints maxpower =800 / 109.074=7.33, round up, n maxpower It has 7 floors.

[0086] Assume that the minimum flow demand Q of each layer min is 15sccm (derived from actual product structure combined with experimental data, generally an empirical value approximately linearly related to the plate area); then, n maxflow =Q / Q min =90 / 15=6 floors.

[0087] Compare the number of levels of constraints in three aspects: n maxheight =7;n maxpower =7;n maxflow=6;

[0088] The minimum value is taken as the feasible number of layers: n=6 layers.

[0089] Preferably, further, determine the Paschen's law constants A and B of the working gas (for example, argon, Paschen's law constant: A=11.6Pa -1 cm -1 , B=26.4V·Pa -1 cm -1 ), used to verify whether the discharge voltage meets the requirements for plasma excitation. After determining the interlayer distance d, the interlayer excitation voltage verification calculation result is obtained using the formula: V = (B·P·d) / ln(A·P·d).

[0090] For example, the product space requirement d = h + △ d = 5cm. After substituting, V = (24.6 × 30 × 5) / ln (11.6 × 30 × 5) ≈ 530.8V;

[0091] Assuming that the power supply voltage is greater than or equal to 600V, the interlayer discharge condition can be met.

[0092] In a preferred embodiment of the cart-assembled large-box plasma cleaning device of the present invention, if the determined number of layers n is less than 3, the following processing is performed:

[0093] If n maxheight Less than 3, n maxpower and n maxflow If it is greater than 3, then we can determine n=n maxheight ;

[0094] If n maxflow Less than 3, n maxpower ≥n maxheight ≥3, then adjust the gas flow Q so that n maxflow ≥n maxheight , determine n=n maxheight ;

[0095] If n maxpower Less than 3, n maxflow ≥n maxheight ≥3, then reduce the power between electrodes, extend the cleaning time, or increase the power supply P 电源 , so that n maxpower ≥n maxheight , determine n=n maxheight ;

[0096] If n maxheight ≥n maxflow ≥3>n maxpower , then, reduce the power between electrodes, extend the cleaning time, or increase the power supply P 电源 , so that nmaxflow ≥n maxpower ≥3, determine n= n maxpower ;

[0097] If n maxheight ≥n maxpower ≥3>n maxflow , then, adjust the gas flow Q so that n maxpower ≥n maxflow ≥3, determine n= n maxflow .

[0098] In this embodiment, in order to avoid the space in the vacuum chamber from being not used most effectively, in addition to the first case where the size of the product to be cleaned limits the number of layers placed; in the case where one of the constraints is too small, the corresponding gas flow rate, inter-electrode power or power supply power is adjusted according to the above-listed cases, so that the minimum value of the constraint calculated exceeds 3 layers and is as equal to the second minimum value as possible, so as to promote the most effective use of the space in the vacuum chamber.

[0099] The cart-type large-box plasma cleaning device of the present invention, in its preferred embodiment, further includes a method for inspecting and maintaining the stability of the vacuum state under flow adjustment: if n maxflow Less than 3, n maxpower ≥n maxheight ≥3, then adjust the gas flow Q so that n maxflow ≥n maxheight , determine n=n maxheight ; or n maxheight ≥n maxpower ≥3>n maxflow , then, adjust the gas flow Q so that n maxpower ≥n maxflow ≥3, determine n=n maxflow In the case of , after completing the adjustment of the gas flow Q, according to the formula:

[0100] P new = (Q × T) / (V × C), C is the original set pumping speed of the vacuum pumping device, T is the temperature, and V is the effective volume of the vacuum chamber;

[0101] Verify the new air pressure value P in the vacuum chamber new Is the working pressure value P maintained? If there is a deviation, then:

[0102] C target= (Q × T) / (P × V), calculate the new target pumping speed value, and adjust the pumping speed of the vacuum device to ensure that the vacuum chamber of the cart-type large-box plasma cleaning device of the present invention maintains a stable vacuum state that allows plasma excitation to achieve a relatively stable effect.

[0103] In the preferred embodiment of the cart-type large-box plasma cleaning device of the present invention as described above, the electrode pair includes the electrode plate and the support plate 10; the electrode plate 9 and the support plate 10 respectively constitute the positive or negative electrode of the plasma excitation electrode pair; that is, in the first and second layers of the material frame 8, three electrode pairs are formed, including the first electrode plate and the first support plate, the first support plate and the second electrode plate, and the second electrode plate and the second support plate, that is, three pairs of electrode pairs. The distance between the electrode pair with the electrode plate above and the support plate 10 below is greater than the distance between the electrode pair with the support plate 10 above and the electrode plate 9 below by 5%-10%, so that the lower surface of the product facing the support plate 10 receives a stronger plasma effect than the upper surface, but can maintain a relatively stable plasma excitation state. The purpose of this embodiment is to target products with a smooth and flat upper surface but a more complex three-dimensional structure on the lower surface, such as a structure with recessed ribs and side walls on the lower surface. In this case, by adjusting the distance between the outer-layer electrode pairs, the excitation effect of the plasma of the outer-layer electrode pairs (the electrode pairs with the support plate above and the electrode plate below) is controlled, so that they have stronger excitation ability than the inter-layer electrode pairs (the electrode pairs with the electrode plate above and the support plate below), so that the energy, quantity and speed of the plasma between the layers are stronger than the space within the layer. In this way, when the plasma faces the complex structure of the lower surface of the product, it can have a better reaching effect, avoiding the problem of plasma being unable to achieve effective cleaning treatment effect on the complex lower surface due to distance and shadow effects.

[0104] In this embodiment, in order to reduce the distance of plasma impact transmission, when the interlayer spacing is small, it is preferable to further adjust and improve the uniformity and stability of plasma excitation by the following methods:

[0105] Compensate for the spacing difference by partitioning power supply (applying different voltages to electrodes in different layers) to make E=V / d consistent;

[0106] Lower the intermediate frequency or adjust the duty cycle to reduce the instantaneous energy concentration in the high electric field area and reduce the breakdown risk;

[0107] Introducing feedback control (such as plasma density monitoring) to dynamically adjust voltage and maintain uniformity of plasma parameters in each area;

[0108] Increasing the gas flow rate in the high electric field region (outside the layer) reduces the local plasma density through the dilution effect;

[0109] A gas spray structure is used to optimize airflow distribution and balance the ionization conditions in each area.

[0110] The cart-assembled large-box plasma cleaning device of the present invention adopts a large-box structure, which provides space for accommodating multiple layers of material frames, and also enables the present invention to be used for surface cleaning operations of larger products. At the same time, multiple layers of material frames are provided inside the plasma cleaning device of the large box. In order to achieve a better cleaning effect for the products in the material frames, to improve the surface performance of the treated products, and to improve the efficiency of the surface cleaning of the products, the present invention confirms the number of material frame layers by combining the various specific conditions of multiple parameters of plasma cleaning under the special circumstances of the large box. For different product sizes and structures, the most suitable number of material frame layers can be matched to ensure that the products achieve the most effective cleaning effect, reduce production costs, and improve the efficiency of plasma cleaning of the product surface. Furthermore, the electrode plates and support plates of the present invention are both used as electrode pairs, which can adjust the plasma cleaning effect of product structures with more complex lower surfaces to a certain extent, reducing the situation where the internal part of the lower surface structure cannot be effectively cleaned.

[0111] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A cart-type large-box plasma cleaning device, characterized in that: It includes a frame body and a material cart, wherein a vacuum chamber and an electrical chamber are provided in the frame body, and a control computer device, an air source device and a power supply device are provided in the electrical chamber; the vacuum chamber is provided with a vacuum cavity, which is a rectangular space with a length, width and height greater than 1 meter; a cavity door is provided at its front end, and the inner side wall of the vacuum cavity is made of a metal plate, and a vacuum port, an electrode feed port, a temperature measuring hole and a working gas port are provided on the side wall, and the vacuum port is connected to the vacuum device via a sealed pipe; the electrode feed port is used to be inserted and docked with the electrode assembly on the material frame of the material cart; the working gas port is connected to the air source device via a gas pipeline; a temperature sensing device is installed on the temperature measuring hole; a docking track is provided on the bottom surface of the vacuum cavity for the roller at the bottom of the material frame to cooperate with; The material vehicle is provided with a transport vehicle and a material frame, the transport vehicle is provided with a base frame and a side frame installed on one side of the base frame, and rollers are provided under the base frame; a limiting track is provided on the upper surface of the base frame, and a transfer wheel is provided at the bottom of the material frame, and the transfer wheel is limited on the limiting track, and the end of the limiting track can be aligned with the front end of the docking track; a multi-layer material plate group is provided on the material frame, and the material plate group includes a metal electrode plate and a support plate, and an insulating fixed block is provided between each of the electrode plate and the support plate and the material frame, and an electrode assembly is provided on the side surface of the front end of the material frame, and the electrode assembly is conductively connected to the electrode pair constituting plasma excitation; a plate is provided under the bottommost support plate; the electrode pair includes at least all the plates; The electrode plate is a mesh plane made of metal strips that overlap horizontally and vertically. The electrode pair of the material frame is composed of the electrode plates of each layer and the bottom electrode plate. The number of layers of the material plate group of the material vehicle is determined by the following method: Step 1: Determine the working pressure value P, vacuum chamber height H, plate and support plate thickness t, product maximum height h, safety distance △d, gas flow Q, power supply P 电源 , material vehicle chassis height + top safety distance D, material plate group cross-sectional area S; Step 2: Calculate the required layer spacing and number of layers: The interlayer spacing d = h + △ d determined by the product size; Single-story occupied height: d+t; The maximum number of layers of cavity height constraint is n maxheight =(HD) / (d+t) rounded; Step 3: Calculate power requirements: The power required for each pair of electrodes P pair Related to the electrode spacing and gas pressure, the formula is as follows: P pair =k·P·d 间距 ·S(k=10 -4 W·cm -1 ·Father -1 ); Calculate the power demand P in the layer pair层内 = k·P·d·S; Step 4: Calculate the maximum number of layers under power constraint: The total number of electrode pairs for an n-layer structure plus one electrode plate is n; Total power demand P total =n·P pair层内 ; Maximum number of layers n for power constraints maxpower =P total / P pair层内 Rounding; Step 5: Calculation of gas flow constraints: Minimum flow demand Q for each layer 层 =Q / n≥Q min ;n maxflow =Q / Q min ; Step 6: Compare n maxheight 、n maxpower and n maxflow The size of , take the smallest one and determine the number of layers n.

2. The cart-assembled large-box plasma cleaning device according to claim 1, characterized in that: The electrode assembly includes a positive conductive plate and a negative conductive plate, and each of the electrode plates is electrically connected to the positive conductive plate and the negative conductive plate in sequence, forming a plasma excitation space with a voltage difference between adjacent electrode plates; two electrode columns are respectively arranged on the front end surface of the material frame, and the positive conductive plate and the negative conductive plate are respectively connected to one of the electrode columns.

3. The cart-assembled large-box plasma cleaning device according to claim 2, characterized in that: The positive and negative conduction plates are both composed of an insulating strip with an electrode sheet slot and a cover plate. Long electrode sheets are fixed in the electrode sheet slot. The electrode sheets are pressed to the bottom of the electrode sheet slot via metal bolts. The metal bolts pass through the insulating strips and are locked into the fixing holes on the front side of the electrode plate.

4. The cart-assembled large-box plasma cleaning device according to claim 3, characterized in that: The electrode column includes an outer tube, an inner tube, a claw-shaped electrode sheet and a conductive screw. The claw-shaped electrode sheet is a trumpet-shaped structure with multiple electrode sheets diffused outward. The bottom of the inner tube is provided with an outward-convex positioning column, and the bottom of the outer tube is provided with a positioning hole allowing the positioning column to pass through. The front end of the positioning column is provided with a disc-shaped pad. The bottom of the claw-shaped electrode sheet is provided with a first screw hole, and the conductive screw passes through the first screw hole, the second screw hole on the positioning column and the third screw hole on the pad; the conductive screw is fixed on the material frame; the conductive screw is respectively connected to the electrode sheet in the positive conductive plate or the negative conductive plate through the transverse electrode sheet.

5. The cart-assembled large-box plasma cleaning device according to claim 4, characterized in that: If the determined number of layers n is less than 3, the following processing is performed: If n maxheight Less than 3, n maxpower and n maxflow If it is greater than 3, then we can determine n=n maxheight ; If n maxflow Less than 3, n maxpower ≥n maxheight ≥3, then adjust the gas flow Q so that n maxflow ≥n maxheight , determine n=n maxheight ; If n maxpower Less than 3, n maxflow ≥n maxheight ≥3, then reduce the power between electrodes, extend the cleaning time, or increase the power supply P 电源 , so that n maxpower ≥n maxheight , determine n=n maxheight ; If n maxheight ≥n maxflow ≥3>n maxpower , then, reduce the power between electrodes, extend the cleaning time, or increase the power supply P 电源 , so that n maxflow ≥n maxpower ≥3, determine n= n maxpower ; If n maxheight ≥n maxpower ≥3>n maxflow , then, adjust the gas flow Q so that n maxpower ≥n maxflow ≥3, determine n=n maxflow .

6. The cart-assembled large-box plasma cleaning device according to claim 5, characterized in that: If n appears maxflow Less than 3, n maxpower ≥n maxheight ≥3, then adjust the gas flow Q so that n maxflow ≥n maxheight , determine n=n maxheight ; or n maxheight ≥n maxpower ≥3>n maxflow , then, adjust the gas flow Q so that n maxpower ≥n maxflow ≥3, determine n=n maxflow In the case of , after completing the adjustment of the gas flow Q, according to the formula: P new = (Q × T) / (V × C), C is the original set pumping speed of the vacuum pumping device, T is the temperature, and V is the effective volume of the vacuum chamber; Verify the new air pressure value P in the vacuum chamber new Is the working pressure value P maintained? If there is a deviation, then: C target = (Q×T) / (P×V), calculate the new target pumping speed value and adjust the pumping speed of the vacuum pumping device.

7. The cart-assembled large-box plasma cleaning device according to claim 1, characterized in that: The electrode pair includes the electrode plate and the support plate; the electrode plate and the support plate respectively constitute the positive electrode or the negative electrode of the plasma excitation electrode pair; the distance between the electrode pair with the electrode plate on top and the support plate on the bottom is greater than the distance between the electrode pair with the support plate on top and the electrode plate on the bottom by 5%-10%.

Images