CN116272119B - High-precision filtering equipment for photoresist - Google Patents

Abstract

The invention discloses high-precision filtering equipment for photoresist, which is applied to photoresist production and comprises the following components: the device comprises a tank body, a tank flushing area, a first filtering area and a second filtering area, wherein the tank flushing area is communicated with a feeding end of the tank body, and the second filtering area is communicated with a discharging end of the tank body; a rotation shaft and a driving motor; a hot flow tube disposed within the flushing area; the flow equalizing disc is positioned at the lower end of the heat flow pipe, and the middle part of the flow equalizing disc is clamped on the outer side wall of the rotating shaft and rotates along with the rotation of the rotating shaft; the separating and filtering structure comprises a first filter plate and separating hoppers which are arranged to extend upwards from the top end of the first filter plate towards two sides, and the separating hoppers are communicated with an inner interlayer of the tank body; the screening structure located in the second filtering area can treat partial impurity particles inside the container, reduces the frequency of replacing the filter element by the switching filter equipment, improves the service cycle of the filter element, solves the problems of production stagnation during filter element replacement, restarting and needing to consume larger cost, and causes the cost improvement of the photoresist of the finished product.

Description

High-precision filtering equipment for photoresist

Technical Field

The invention relates to photoresist production equipment, in particular to high-precision filtering equipment for photoresist.

Background

In the production process of the photoresist, firstly, a photosensitizer is needed to be prepared, or the existing photosensitizer is directly applied, the photosensitizer is added into resin and solvent to fully react to obtain the finished photoresist, and insoluble impurities in the solution and particles brought in the production process of the photoresist are needed to be filtered out to improve the purity of the photoresist.

Because the schizolysis effect of raw materials, in fact, the whole stickness of photoresist solution is great this moment, and the impurity mixture is difficult to be filtered out in the photoresist, and prior art often adopts the mode of adding the sign indicating number when filtering the photoresist solution, through the filtration of filter core layer upon layer, constantly improves the precision of filter plate promptly, makes the impurity of photoresist solution constantly be filtered out by the layer by layer along with the mesh change of filter core.

Although the mode of adopting layer-by-layer filter plate filtration can gradually filter the photoresist clean, but the loss to the filter core is too big, in case the attachment on the filter core is too much, just need change the filter core in order to guarantee filtration efficiency and filtration quality, at the stage of changing the filter core, not only need shut down equipment, still need to unpack equipment and just can change the filter core, directly cause holistic production to stagnate, and in case production stagnates, then start again needs to consume great cost again, leads to the photoresist cost promotion of finished product, market competitiveness reduces.

The scheme aims to provide the high-precision filter equipment for the photoresist, which has small load on the filter element of the filter plate and does not need frequent replacement, and the filter precision is not affected under the condition that the filter element can be used for a long time.

Disclosure of Invention

The invention provides high-precision filtering equipment for photoresist, which can effectively solve the problems.

The invention is realized in the following way:

a high-precision filtering apparatus for photoresist, comprising:

the tank body is internally provided with a tank flushing area, a first filtering area and a second filtering area from top to bottom respectively, the tank flushing area is communicated with the feeding end of the tank body, and the second filtering area is communicated with the discharging end of the tank body;

the rotary shaft is vertically inserted into the top of the tank body and extends to the bottom of the second filtering area, and the top of the rotary shaft is connected with a driving motor;

the hot flow pipe is arranged in the tank flushing area, a feed inlet of the hot flow pipe is communicated with a discharge outlet of the feed end, and a bottom edge of the hot flow pipe is flush with a tangent line of the bottom surface of the tank flushing area;

the flow equalizing disc is positioned at the lower end of the heat flow pipe, the middle part of the flow equalizing disc is clamped on the outer side wall of the rotating shaft and rotates along with the rotation of the rotating shaft, and the top surface of the flow equalizing disc faces the discharging opening of the heat flow pipe;

the separating and filtering structure is positioned in the first filtering area and comprises a first filter plate sleeved on the outer side wall of the rotating shaft and separating hoppers which are arranged to extend upwards from the top end of the first filter plate towards two sides, and the separating hoppers are communicated with an inner interlayer of the tank body;

and the screening structure is positioned in the second filtering area and comprises a second filtering plate and a third filtering plate which are gradually increased in area.

As a further improvement, the heat flow pipe comprises an extension pipe communicated with the feeding end, a spiral guide pipe communicated with the top opening of the extension pipe, a plurality of heaters uniformly arranged on the outer side wall of the spiral guide pipe, and a bottom opening of the spiral guide pipe is welded on a partition plate between the tank flushing area and the first filtering area.

As a further improvement, the flow equalizing disc comprises an outer sleeve which is clamped on the rotating shaft, and a hollow mounting cylinder which is coaxially arranged with the outer sleeve, wherein a plurality of fan-shaped sheets are inserted in a gap between an upper plate and a lower plate of the hollow mounting cylinder, through holes are formed in the upper end and the lower end of each fan-shaped sheet, and the outer side faces of the fan-shaped sheets are abutted to the inner side wall of the tank body.

As a further improvement, the sub-filtering structure further comprises a first suction structure, the first suction structure is arranged at the bottom of the first filter plate, the first filter plate is provided with a diversion area positioned at the bottom surface of the separating hopper and a mounting area sleeved outside the diversion area, and a suction port of the first suction structure points to the diversion area.

As a further improvement, the separation bucket comprises a trapezoid barrel with a small bottom opening and a large top opening, and a shunt tube connected to the trapezoid barrel and communicated with an interlayer in the tank body, the trapezoid barrel comprises a guide surface attached to the top surface of the first filter plate, a guide cambered surface bent from the top of the guide surface to one side of the rotating shaft, one side of the guide cambered surface, facing the center of the circle, is connected with an arc-shaped groove, a plurality of convection holes are formed in the arc-shaped groove, and the inner side of the arc-shaped groove is connected with the inlet of the shunt tube.

As a further improvement, the screening structure comprises a guide frame communicated with the first filtering area, a second filtering plate sleeved on the outer side wall of the rotating shaft and positioned below the guide frame, and a third filtering plate sleeved on the outer side wall of the rotating shaft and positioned below the second filtering plate, wherein two sides of the guide frame are obliquely directed to one side of the rotating shaft, the opening area of the bottom surface of the guide frame is the same as the coverage area of the second filtering plate, and the area of the third filtering plate is larger than that of the second filtering plate and is abutted against the inner side wall of the tank body.

As a further improvement, a second suction structure is arranged between the second filter plate and the third filter plate, and the suction port of the second suction structure is directed to the second filter plate.

As a further improvement, the top of the tank body is provided with a top cover, the outer side of the top cover corresponding to the rotating shaft part is sleeved with a bearing ring, the outer side of the bearing ring is connected with an external gear, the tank body is divided into an inner tank body and an outer tank body, an interlayer is formed between the inner tank body and the outer tank body, an outer separation cylinder is inserted into the interlayer, the inner tank body is composed of a net cylinder with a plurality of net openings, the top surface of the outer separation cylinder is welded with the bottom of the external gear, the outer side of the external gear is connected with a rotating motor, and a meshing gear at the bottom drives the outer separation cylinder to rotate when the rotating motor rotates so as to switch the matching state of the outer separation cylinder and the net cylinder.

As a further improvement, the device also comprises an outer pumping structure, wherein the outer pumping structure comprises a negative pressure guide pipe inserted in the interlayer, an outer connecting pipe connected with the tail end of the negative pressure guide pipe is fixedly connected with a suction pump at the top of the outer connecting pipe, the lateral direction of the outer connecting pipe is communicated with the negative pressure structure, and impurities are pumped to the outer connecting pipe by the negative pressure structure and then pumped out by the suction pump.

As a further improvement, the second filtering area comprises a treatment area and a conveying area, wherein the inner cavity of the conveying area is communicated with the inner cavity of the treatment area through a backflow structure, and the backflow structure comprises a first pump body inserted into the conveying area, a second pump body inserted into the treatment area, and a connecting pipe for connecting the first pump body and the second pump body.

The beneficial effects of the invention are as follows:

according to the invention, through the arranged heat flow pipe and the flow equalizing disc, the solution input from the feeding end is transmitted through the heat flow pipe, the solution is heated in the transmission process, the viscosity of the photoresist solution is reduced, then the solution with reduced viscosity is introduced onto the fast rotating flow equalizing disc, the flow equalizing disc uniformly guides the solution into the first filtering area, and the first filtering area can be uniformly contacted with the solution, so that the phenomenon of excessive loss of a local filter element is reduced, the replacement period of the filter element is prolonged, the cost input of the filter element is reduced, and meanwhile, the filtering is more fully carried out.

According to the invention, through the arrangement of the sub-filtering structure, the solution which is accumulated on the first filter plate and temporarily cannot pass through the first filter plate completely can be centrifuged and thrown outwards, so that the solution rises along the separating hopper and impurities of particles are accumulated in the separating hopper, and then the impurities are pumped to an external area through the separating hopper, thereby greatly relieving the phenomenon that the impurity particles are accumulated on the filter plate, treating part of the impurity particles in the container, reducing the times of replacing the filter element by the switch filter equipment, improving the service cycle of the filter element, and simultaneously working for a long time under the condition of incomplete shutdown.

According to the invention, through the screening structure, the multistage filtering effect of gradually increasing the filtering area is performed on the basis of the filtering of the screening structure, the filtering effect is improved, and meanwhile, the loss of the filter element is only generated at a local position, so that the effects of low loss and high efficiency are achieved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some examples of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic perspective view of a high-precision filtering apparatus for photoresist according to the present invention.

Fig. 2 is a schematic diagram showing the front view of a high-precision filtering apparatus for photoresist according to the present invention.

Fig. 3 is a schematic top view of a high-precision filtering apparatus for photoresist according to the present invention.

FIG. 4 is a cross-sectional view of the invention shown in FIG. 3 A-A.

Fig. 5 is a schematic structural view of a heat flow pipe according to the present invention.

Fig. 6 is a schematic structural diagram of a flow equalizing plate according to the present invention.

Fig. 7 is a schematic structural view of a split filter structure according to the present invention.

Fig. 8 is a schematic structural view of a screening structure according to the present invention.

Fig. 9 is a schematic top view of an outer separator and a net drum according to the present invention.

FIG. 10 is a schematic view of the structure of the top cover and the inner side of the can body according to the present invention.

Fig. 11 is a schematic structural view of an external pumping structure according to the present invention.

Detailed Description

For the purpose of making embodiments of the present invention fall within the scope of the present invention. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention.

In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as referring to purposes, technical solutions and advantages of the present invention in any way. All other implementations, which can be derived by a person skilled in the art without making any inventive effort, show or imply relative importance or implicitly indicate the number of technical features indicated on the basis of the implementations in the invention. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Referring to fig. 1 to 11, a high-precision filter apparatus for photoresist includes: the tank body 10, wherein the tank body 10 is internally provided with a tank flushing area 11, a first filtering area 12 and a second filtering area 13 from top to bottom, the tank flushing area 11 is communicated with a feeding end 14 of the tank body 10, and the second filtering area 13 is communicated with a discharging end 15 of the tank body 10; a rotating shaft 20 vertically inserted into the top of the tank 10 and extending to the bottom of the second filtering area 13, wherein the top of the rotating shaft 20 is connected with a driving motor; the heat flow pipe 30 is arranged in the tank flushing area 11, a feed inlet of the heat flow pipe 30 is communicated with a discharge outlet of the feed end 14, and a bottom edge of the heat flow pipe 30 is flush with a tangent line of the bottom surface of the tank flushing area 11; the flow equalizing disc 40 is positioned at the lower end of the heat flow tube 30, the middle part of the flow equalizing disc 40 is clamped on the outer side wall of the rotating shaft 20 and rotates along with the rotation of the rotating shaft 20, and the top surface of the flow equalizing disc 40 faces the discharging opening of the heat flow tube 30; the sub-filtering structure 50 is positioned in the first filtering area 12, the sub-filtering structure 50 comprises a first filtering plate 51 sleeved on the outer side wall of the rotating shaft 20 and a separating hopper 52 extending upwards from the top end of the first filtering plate 51 towards two sides, and the separating hopper 52 is communicated with the inner interlayer of the tank body 10; a screening structure 60 in the second filtering zone 13, said screening structure 60 comprising a second filter plate 61 and a third filter plate 62 of increasing area.

For clarity of knowing the feed rate of the photoresist solution at the time of its input and the discharge rate after filtration, both the feed end 14 and the discharge end 15 are connected to a flow monitor to ensure orderly filtration of the photoresist solution and to be more easily known to the staff when it is clogged in the filtration apparatus.

The high-precision filtration adopted in the embodiment means that the filtration capacity cannot be too large in the whole filtration process, and impurities can be prevented from being mixed with the solution to enter the next stage, so that the purity of the photoresist solution is reduced, the inside of the whole tank body 10 is divided into three parts, namely a tank flushing area 11, a first filtration area 12 and a second filtration area 13, no overflowed solution is arranged in the tank flushing area 11, the solution is all positioned in a thermal flow pipe 30 and flows along the thermal flow pipe 30, and a pressurizing structure is further arranged in the tank flushing area 11, wherein the pressurizing structure is an air compressor in the prior art, and the solution in the filtration of the first filtration area 12 and the second filtration area 13 can be accessed into an external inert gas tank to be pressurized, so that the photoresist solution with viscosity can pass through a filter screen better, and the solution in the embodiment needs to be filtered at least twice, namely at least through the first filtration area 12 and the second filtration area 13.

Since the photoresist solution to be filtered has viscosity, if the solution is settled, the efficiency is inevitably affected, and in this case, the filter plates of the first filtering area 12 and the second filtering area 13 are connected to the rotating shaft 20, so that the rotating shaft 20 is driven by the driving motor, and the filter plates of the first filtering area 12 and the second filtering area 13 can be centrifugally treated on the solution, so as to increase the flow speed of the solution components in the solution passing through the filter plates.

The flow rate of the viscous solution in the pipeline is low, so that the viscosity of the viscous solution is reduced, and the acceleration of the viscous solution when the viscous solution is flushed to the filter plate can be improved, in the embodiment, the viscous solution is not directly flushed to the filter plate, but is heated through the hot flow pipe 30, and the fluidity of the viscous solution is improved after the viscous solution is heated through the hot flow pipe 30, so that the viscous solution can be flushed into the filter plate at a higher initial speed.

In order to avoid that the solution is concentrated at one position when the solution is flushed into the filter plate, so that one position on the filter plate is blocked and fails prematurely, a flow equalizing disc 40 is further arranged between the heat flow pipe 30 and the aluminum plate, and the solution is dispersed onto the filter plate through the flow equalizing disc 40 in rotation, so that the aim of uniform discharging is fulfilled.

In the conventional filter plate structure, the optimal setting is to change the material of the filter plate or add the number of the filter plates, but the filter plate is basically treated, and the filter effect is improved but the loss of the filter element is increased.

On the basis of the action of the separating and filtering structure 50, only a part of large impurity particles are filtered, and a part of small particles still exist and are not filtered, and for this purpose, the solution also needs to pass through the second filter plate 61 and the third filter plate 62 in the second filtering area 13, and it is emphasized that the precision of the first filter plate 51, the second filter plate 61 and the third filter plate 62 is sequentially increased, so that the effect of classifying and filtering is achieved, and the filter plate with too high precision is prevented from being directly blocked by the impurity particles with large particles.

The heat flow pipe 30 is not only a simple pipe, but is specifically: the heat flow pipe 30 comprises an extension pipe 31 communicated with the feed end 14, a spiral pipe 32 communicated with the top opening of the extension pipe 31, and a plurality of heaters 33 uniformly arranged on the outer side wall of the spiral pipe 32, wherein the bottom opening of the spiral pipe 32 is welded on the partition 17 between the tank flushing area 11 and the first filtering area 12, the initial height of the solution needs to be pulled up by the extension pipe 31 due to the height limitation of the tank 10, the height of the extension pipe 31 is increased without influencing the solution when the solution is pumped into the tank 10, and the heater 33 heats the outer wall surface of the spiral pipe 32 in the processing stage, so that the whole spiral pipe 32 is in a high temperature state, the solution flowing through the spiral pipe 32 can be uniformly heated, the viscosity of the solution is reduced, good conditions are provided for the flow and the acceleration filtration, the shape of the spiral pipe 32 is designed to prolong the contact time of the solution and the high temperature spiral pipe 32, the viscosity of the solution is changed enough time to ensure that the viscosity of the solution is ensured, compared with the prior art, the whole cavity is directly heated, the heat is not concentrated, and the heat loss of the whole cavity is avoided, and the heat loss is more uniformly heated at the same time.

If too much solution in the first filtering area 12 causes the liquid level to rise, the whole tank flushing area 11 is easily overflowed to destroy the air compressor in the tank flushing area 11, so that the tank flushing area 11 is separated from the first filtering area 12 by the partition 17 on the bottom opening of the spiral duct 32, only one pressurizing opening and the lower discharging opening of the spiral duct 32 are reserved, and even if the liquid level of the solution rises, the equipment in the tank flushing area 11 is not influenced.

After the viscosity of the solution is reduced by the heat flow pipe 30, the fluidity of the solution becomes faster, however, if the solution is output from the same outlet of the bottom opening of the spiral duct 32, the solution is easily and directly impacted to the same position on the first filter plate 51, so that local blockage and overload of the filter core occur at the position, therefore, the flow equalizing plate 40 is arranged below the heat flow pipe 30, specifically, the flow equalizing plate 40 comprises an outer sleeve 41 clamped on the rotating shaft 20, a hollow mounting cylinder 42 coaxially arranged with the outer sleeve 41, a plurality of fan-shaped pieces 43 are inserted in the gap between the upper plate and the lower plate of the hollow mounting cylinder 42, through holes are formed at the upper end and the lower end of the fan-shaped pieces 43 and are abutted on the inner side wall of the tank body 10, and when the rotating shaft 20 rotates, the flow equalizing plate 40 rotates along with the rotating shaft, so that the hollow mounting cylinder 42 provided with the fan-shaped pieces 43 rotates along with the flow equalizing plate, the solution falling from the heat flow pipe 30 is scattered by the fan-shaped pieces 43 and then uniformly enters the first filter area through the through holes 12, and the fan-shaped pieces fall into the through holes 43 uniformly in a linear manner, and the solution falls down through the fan-shaped holes 43 uniformly in the embodiment.

In the above description, it is mentioned that the solution is centrifuged in the sub-filtering structure 50 to separate solid from liquid, and the speed of the centrifuged photoresist solution is still slow when passing through the first filtering plate 51, and in this respect, in order to improve the filtering efficiency, the sub-filtering structure 50 further includes a first pumping structure 53, the first pumping structure 53 is mounted at the bottom of the first filtering plate 51, the first filtering plate 51 has a guiding area 511 located at the bottom of the separating funnel 52 and a mounting area 512 sleeved outside the guiding area 511, the pumping port of the first pumping structure 53 points to the guiding area 511, and the solution on the first filtering plate 51 is pumped by the first pumping structure 53, so that it can quickly flow downward along the first filtering plate 51, and in order to concentrate the acting area of the pumping force, the first pumping structure 53 is aligned only at the position of the guiding area 511 and does not act at the position of the mounting area 512.

In the stage of solid separation, since the first filter plate 51 is connected to the rotation shaft 20, the first filter plate 51 rotates along with the rotation shaft 20 during the rotation, the speed of passing over the first filter plate 51 is not so high due to the viscosity of the photoresist, and the first filter plate 51 in the rotation state can centrifuge part of the solution outwards, so that part of the solution enters the separating hopper 52, specifically: the separating bucket 52 comprises a trapezoid barrel 521 with a small bottom opening and a large top opening, and a shunt pipe 522 connected to the trapezoid barrel 521 and communicated with an inner interlayer of the tank body 10, the trapezoid barrel 521 comprises a guide surface 5211 attached to the top surface of the first filter plate 51, a guide cambered surface 5212 bent from the top of the guide surface 5211 to one side of the rotating shaft 20, an arc groove 5213 is connected to one side of the guide cambered surface 5212 facing the center of the circle, a plurality of convection holes 5214 are formed in the arc groove 5213, the inner side of the arc groove 5213 is connected with an inlet of the shunt pipe 522, a solution slides upwards along the guide cambered surface 5212, falls into the arc groove 5213 on the guide of the guide cambered surface 5212, liquid falls down along the convection holes 5214, impurity particles are left in the arc groove 5213, part of impurity particles are left in the arc groove 5213, all impurities are prevented from falling onto the first filter plate 51, and the filtering pressure of the first filter plate 51 is relieved.

The impurity particles falling into the arc-shaped groove 5213 can not be deposited therein, after a fixed period, the shunt 522 forms a suction force to the arc-shaped groove 5213 to suck the impurity particles away, the impurities waiting for the next period are accumulated, the suction time can be started after a large amount of photoresist solution is input once, the large amount of photoresist solution is prevented from being pumped out, the shunt 522 is directly inserted into the external suction structure 70, and the particles are pumped out through the external suction structure 70.

After the first filtration of the separating filter 50, at this time, the large-sized impurity particles are already blocked by the filtration in the first filter plate 51 or the arc-shaped groove 5213, and the remaining solution still carries the impurity particles of other particle diameters, and then a second filtration is required, in which the filtration is mainly performed through the separating filter 60, specifically: the screening structure 60 includes a guide frame 63 connected to the first filtering area 12, a second filtering plate 61 sleeved on the outer side wall of the rotating shaft 20 and located below the guide frame 63, a third filtering plate 62 sleeved on the outer side wall of the rotating shaft 20 and located below the second filtering plate 61, two sides of the guide frame 63 are inclined to one side of the rotating shaft 20, the opening area of the bottom surface of the guide frame 63 is the same as the coverage area of the second filtering plate 61, the area of the third filtering plate 62 is larger than that of the second filtering plate 61 and the third filtering plate 62 is abutted to the inner side wall of the tank 10, firstly, the photoresist solution is guided by the guide frame 63, the solution can flow down into the second filtering plate 61 in the filtering range of the second filtering plate 61, the area of the second filtering plate 61 is not fully covered on the plane of the whole tank 10, but is left with the space between the inner side walls of the tank 10, the second filtering plate 61 is connected with the rotating shaft 20 in the same manner as the first filtering plate 51, part of the solution can fall through the second filtering plate 61 and the other part of the solution can directly fall through the second filtering plate 61 and the third filtering plate 62 can directly fall through the third filtering plate 62 and then be thrown out to the third filtering area.

Therefore, the second filter plate 61 and the third filter plate 62 can be filtered, the second filter plate 61 is not required to bear all solution filtration, only the filtration of most of particles is borne, the impurity of part of particles is thrown to the third filter plate 62 for filtration, and the layered filtration of the two filter plates is carried out, so that the load of one filter plate is relieved, the filter plate at the front end is not required to be replaced in a short time, and in the same way, in the split filter structure 50, the load of the first filter plate 51 is relieved by adopting a mode of directly pumping away the large-particle impurity, the first filter plate 51 at the forefront end is prevented from being replaced by closing the cover after a shorter service period, and through the arrangement of the structure, the first filter plate 51, the second filter plate 61 and the third filter plate 62 can be used almost at full load in the period, all filter plates can be replaced when closing the filter plate for one time, the waste can not be caused, and the efficiency is higher.

In the same way as the first suction structure 53, a second suction structure 64 is mounted between the second filter plate 61 and the third filter plate 62, and the suction opening of the second suction structure 64 is directed to the second filter plate 61, wherein the second suction structure 64 can not only play a role of suction, but also play a role of connecting the second filter plate 61 with the third filter plate 62 and fixedly supporting the second filter plate 61.

It should be emphasized that, in the present embodiment, the first suction structure 53 and the second suction structure 64 are both negative-pressure suction structures, and the outer sides of the first suction structure 53 and the second suction structure 64 are covered with a semipermeable membrane, so that suction force can be formed without allowing the solution to be sucked into the first suction structure 53 and the second suction structure 64.

In order to make the filtration of the second filtering section 13 more thorough, the second filtering section 13 includes a treatment section 131 and a delivery section 132, the inner cavity of the delivery section 132 is communicated with the inner cavity of the treatment section 131 through a backflow structure 80, the backflow structure 80 includes a first pump 81 inserted into the delivery section 132, a second pump 82 inserted into the treatment section 131, and a connecting pipe 83 connecting the first pump 81 and the second pump 82, so that the solution in the delivery section 132 can be circulated back into the treatment section 131 through the first pump 81 and the second pump 82 before being pumped out, and can be directly circulated in the short-term filtration, and can be selectively not used in the continuous filtration process, or can be selectively circulated.

In some filtering structures, the service life of the filter core can be properly prolonged by adopting a backflushing mode, however, if proper treatment means are not adopted for particles after backflushing, the impurity particles still return to the position of the filter core, at best, the position of the particles is simply changed, for this purpose, a top cover 16 is arranged at the top of the tank body 10, a bearing ring 21 is sleeved at the outer side of the part of the inner side of the top cover 16 corresponding to the rotating shaft 20, an external gear 22 is connected at the outer side of the bearing ring 21, the tank body 10 is divided into an inner tank body 101 and an outer tank body 102, an interlayer 103 is formed between the inner tank body 101 and the outer tank body 102, an outer separation cylinder 104 is inserted in the interlayer 103, the inner tank body 101 is formed by a net cylinder 105 with a plurality of net openings, the top surface of the outer separation cylinder 104 is welded with the bottom of the external gear 22, a rotating motor 23 is connected at the outer side of the external gear 22, and when the rotating motor 23 rotates, the meshing gear at the bottom drives the outer separation cylinder 104 to rotate so as to switch the matching state of the outer separation cylinder 104 and the net cylinder 105;

in the normal rotation state of the rotation shaft 20, the whole outer separation cylinder 104 cannot rotate due to the relation of the bearing rings 21, and at the moment, the outer separation cylinder 104 seals the net mouth of the net cylinder 105, so that the net cylinder 105 cannot leak photoresist solution outwards, and normal filtration can be performed;

in the process of back flushing, the tank body 10 is temporarily not filled with photoresist solution, but is filled with clean water through the discharging end 15, the feeding end 14 is closed, the clean water is back flushed from the back of the filter plate, particles on the filter element are flushed out and suspended in the water, meanwhile, the rotating motor 23 is started, after the rotating motor 23 rotates, the external gear 22 is driven by the rotating motor 23, the external separation barrel 104 connected to the external gear 22 is further rotated, so that the external separation barrel 104 and the net barrel 105 are communicated with each other, and the back flushed clean water can drive the particles to flow into the interlayer 103.

Although the particles are flushed out, the particles can be returned to the filter core if the particles are pumped out of the tank body 10, in this embodiment, the device further comprises an external pumping structure 70, the external pumping structure 70 comprises a negative pressure guide pipe 71 inserted in the interlayer 103, an external connecting pipe 72 connected to the tail end of the negative pressure guide pipe 71, a suction pump 73 fixedly connected to the top of the external connecting pipe 72, a negative pressure structure 74 is communicated with the side of the external connecting pipe 72, the negative pressure structure 74 pumps the impurities to the external connecting pipe 72 and then pumps the impurities out through the suction pump 73, in fact, the negative pressure guide pipe 71 is connected with a negative pressure pump, the negative pressure pumps the air in the interlayer 103 and then directly pumps the clean water and the particles suspended in the clean water out, the position close to the suction pump 73 is reached, and the suction pump 73 is opened at this moment, and all the particles and the particles which have been pumped to the mouth of the external connecting pipe 72 are pumped out from the suction pump 73.

However, only a part of particles can be removed by the clean water back flushing method, particles still adhere to the filter element, and even if the clean water is completely extracted, a part of particles adhere to the interlayer 103 and cannot be extracted, and when the back flushing is performed, the input of photoresist is stopped although the cover is not required, and the construction period is also delayed, so the clean water back flushing method can only be used for 2-3 times in the whole service period of the filter element.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, and various modifications and variations may be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. A high-precision filtering apparatus for photoresist, comprising:

the novel filter tank comprises a tank body (10), wherein a tank flushing area (11), a first filtering area (12) and a second filtering area (13) are respectively arranged in the tank body (10) from top to bottom, the tank flushing area (11) is communicated with a feeding end (14) of the tank body (10), and the second filtering area (13) is communicated with a discharging end (15) of the tank body (10);

a rotating shaft (20) vertically inserted into the top of the tank body (10) and extending to the bottom of the second filtering area (13), wherein the top of the rotating shaft (20) is connected with a driving motor;

the hot flow pipe (30) is arranged in the tank flushing area (11), a feed inlet of the hot flow pipe (30) is communicated with a discharge outlet of the feed end (14), and a bottom edge of the hot flow pipe (30) is flush with a tangent line of the bottom surface of the tank flushing area (11);

the flow equalizing disc (40) is positioned at the lower end of the heat flow tube (30), the middle part of the flow equalizing disc (40) is clamped on the outer side wall of the rotating shaft (20) and rotates along with the rotation of the rotating shaft (20), and the top surface of the flow equalizing disc (40) faces the discharging opening of the heat flow tube (30);

the separating and filtering structure (50) is positioned in the first filtering area (12), the separating and filtering structure (50) comprises a first filter plate (51) sleeved on the outer side wall of the rotating shaft (20) and separating hoppers (52) which are arranged to extend upwards from the top end of the first filter plate (51) towards two sides, and the separating hoppers (52) are communicated with the inner interlayer of the tank body (10);

a screening structure (60) positioned in the second filtering area (13), wherein the screening structure (60) comprises a second filtering plate (61) and a third filtering plate (62) with gradually increased areas;

the separating hopper (52) comprises a trapezoid barrel (521) with a small bottom opening and a large top opening, and a shunt tube (522) connected to the trapezoid barrel (521) and communicated with an inner interlayer of the tank body (10), the trapezoid barrel (521) comprises a guide surface (5211) attached to the top surface of the first filter plate (51), a guide cambered surface (5212) bent from the top of the guide surface (5211) to one side of the rotating shaft (20), one side of the guide cambered surface (5212) facing the center of the circle is connected with an arc groove (5213), a plurality of convection holes (5214) are formed in the arc groove (5213), and the inner side of the arc groove (5213) is connected with an inlet of the shunt tube (522);

the top of the tank body (10) is provided with a top cover (16), the outside of the part of the top cover (16) corresponding to the rotating shaft (20) is sleeved with a bearing ring (21), the outside of the bearing ring (21) is connected with an external gear (22), the tank body (10) is divided into an inner tank body (101) and an outer tank body (102), an interlayer (103) is formed between the inner tank body (101) and the outer tank body (102), an outer separation cylinder (104) is inserted into the interlayer (103), the inner tank body (101) is formed by a net cylinder (105) with a plurality of net openings, the top surface of the outer separation cylinder (104) is welded with the bottom of the external gear (22), the outside of the external gear (22) is connected with a rotating motor (23), and the meshing gear at the bottom drives the outer separation cylinder (104) to rotate to switch the matching state of the outer separation cylinder (104) and the net cylinder (105).

2. A high-precision filtering apparatus for photoresist according to claim 1, wherein said heat flow pipe (30) comprises an extension pipe (31) communicating with the feed end (14), a spiral duct (32) communicating with the top opening of said extension pipe (31), a plurality of heaters (33) uniformly disposed on the outer side wall of said spiral duct (32), and the bottom opening of said spiral duct (32) is welded to the partition plate (17) between said tank area (11) and the first filtering area (12).

3. The high-precision filtering equipment for photoresist according to claim 2, wherein the flow equalizing disc (40) comprises an outer sleeve (41) clamped on the rotating shaft (20), a hollow installation cylinder (42) coaxially arranged with the outer sleeve (41), a plurality of sector plates (43) are inserted in a gap between an upper plate and a lower plate of the hollow installation cylinder (42), through holes are formed in the upper end and the lower end of the sector plates (43), and the outer side faces of the sector plates (43) are abutted to the inner side wall of the tank body (10).

4. The high-precision filtering device for photoresist according to claim 1, wherein the sub-filtering structure (50) further comprises a first suction structure (53), the first suction structure (53) is installed at the bottom of the first filter plate (51), the first filter plate (51) is provided with a diversion area (511) located at the bottom surface of the separation bucket (52) and an installation area (512) sleeved outside the diversion area (511), and a suction port of the first suction structure (53) points to the diversion area (511).

5. The high-precision photoresist filtering device according to claim 1, wherein the screening structure (60) comprises a guide frame (63) communicated with the first filtering area (12), a second filtering plate (61) sleeved on the outer side wall of the rotating shaft (20) and positioned below the guide frame (63), a third filtering plate (62) sleeved on the outer side wall of the rotating shaft (20) and positioned below the second filtering plate (61), two sides of the guide frame (63) are obliquely directed to one side of the rotating shaft (20), the opening area of the bottom surface of the guide frame (63) is the same as the coverage area of the second filtering plate (61), and the area of the third filtering plate (62) is larger than that of the second filtering plate (61) and the third filtering plate (62) is abutted against the inner side wall of the tank body (10).

6. A high-precision filter apparatus for photoresist according to claim 5, wherein a second suction structure (64) is installed between the second filter plate (61) and the third filter plate (62), and a suction port of the second suction structure (64) is directed to the second filter plate (61).

7. The high-precision filtering equipment for photoresist according to claim 1, further comprising an external pumping structure (70), wherein the external pumping structure (70) comprises a negative pressure guide pipe (71) inserted in an interlayer (103), an external connecting pipe (72) connected to the tail end of the negative pressure guide pipe (71), a suction pump (73) fixedly connected to the top of the external connecting pipe (72), a negative pressure structure (74) is communicated with the side of the external connecting pipe (72) upwards, and the negative pressure structure (74) pumps impurities to the external connecting pipe (72) and then pumps the impurities out through the suction pump (73).

8. A high-precision filtering apparatus for photoresist according to claim 1, wherein the second filtering section (13) comprises a processing section (131) and a conveying section (132), the inner cavity of the conveying section (132) is communicated with the inner cavity of the processing section (131) through a backflow structure (80), the backflow structure (80) comprises a first pump body (81) inserted into the conveying section (132), a second pump body (82) inserted into the processing section (131), and a connecting pipe (83) connecting the first pump body (81) and the second pump body (82).