CN105170406A - Slit coating unit, coating head and coating equipment - Google Patents

Abstract

The invention provides a slit coating unit, coating head and coating equipment. The slit coating unit comprises an outer shell; a feeding channel, a discharging channel, a partial pressure channel and a slit nozzle are arranged inside the outer shell; the width of the feeding channel is gradually decreased towards the slit nozzle. The coating head comprises multiple slit coating units which are arranged side by side. The coating equipment comprises the slit coating units or the coating head. According to the slit coating unit, as the partial pressure channel is additionally arranged between the feeding channel and the slit nozzle for fluid diversion and the feeding channel is narrowed gradually, even if the flowing velocity of fed fluid at an inlet changes, the extrusion speed of liquid at the slit nozzle is basically not affected, and then the problem that a film is not coated evenly due to unstable flowing velocity of fed materials can be solved. Both the coating head and the coating equipment comprise the slit coating units, so that the problem that the film is not coated evenly due to unstable flowing velocity of fed materials is also solved.

Description

Slot coating unit, coating head, and coating equipment

technical field

The invention relates to the technical field of liquid coating, in particular to a slit coating unit, a coating head and coating equipment.

Background technique

Slit coating has become one of the most representative thin film coating methods in the existing thin film coating field, mainly reflected in the photosensitive adhesive coating in the pixel preparation process in the liquid crystal display field. At present, there are two main methods for controlling the film thickness and uniformity of slit coating: the first is to control the amount of extrusion by adding clips in the slit, so as to further control the thickness of the coated film. Thickness, while ensuring the uniformity of the thickness; the second is through the design of the feeding system, try to ensure the stability of the feeding flow rate of the coating head, so as to help better controllability of the extruded material. Both of these methods require the flow rate of the feeding system to be kept very stable in order to achieve the requirements of uniform coating.

Contents of the invention

The technical problem to be solved by the present invention is to provide a slit coating unit, coating head and coating equipment, which can solve the problem of uneven film coating caused by unstable feed flow rate.

The technical solution adopted by the present invention to solve the problems of the technologies described above is:

The invention provides a slit coating unit, which includes a housing, and the housing is provided with a feed channel for fluid inflow, a discharge channel for fluid outflow, and a connection between the feed channel and the discharge channel. The pressure dividing channel and the slit nozzle arranged at the end of the feed channel, the width of the feed channel gradually decreases along the direction toward the slit nozzle.

As a further improvement of the above technical solution, the width of the pressure-dividing channel is the same as the width of each corresponding feed channel.

As a further improvement of the above technical solution, the width of the next stage of the feed channel is 80% of the width of the previous stage.

As a further improvement of the above technical solution, the ratio of the depth to the width of the feed channel ranges from 1:100 to 1:1.

As a further improvement of the above technical solution, the width of the feed channel is gradually reduced from 3 cm to 50 μm.

As a further improvement of the above technical solution, the speed of the fluid ranges from 0.001ml/min to 10ml/min.

The present invention provides a coating head, which includes a plurality of the above-mentioned slit coating units arranged side by side.

As a further improvement of the above technical solution, the coating head also includes a distribution unit, the distribution unit is provided with a leveling groove communicated with the slit nozzle and at least one slit flow communicated with the leveling groove channel, and the end of the slit flow channel is the coating port.

The present invention provides a coating device comprising the slit coating unit as described above.

The present invention also provides a coating device, which includes the above-mentioned coating head.

The beneficial effects of the present invention are:

The slit coating unit of the present invention divides the fluid by adopting the method of increasing the partial pressure channel between the feed channel and the slit nozzle, and carries out backflow through the discharge channel, and at the same time, the feed channel is gradually narrowed, and the inside of the feed channel The pressure of the fluid decreases gradually so that the flow rate decreases step by step. In this way, even if the flow rate of the feed fluid at the inlet changes due to the pressure change of the mechanical pump, the liquid extrusion speed at the slit nozzle is basically not affected, which can solve the problem. Unstable feed flow rates lead to problems with uneven film coating.

The coating head of the present invention adopts the above-mentioned slit coating unit, which can solve the problem of uneven film coating caused by unstable feed flow rate.

The coating equipment of the present invention adopts the above-mentioned slit coating unit or coating head, which can also solve the problem of uneven film coating caused by unstable feed flow rate.

Description of drawings

Fig. 1 is the schematic diagram of the three-dimensional structure of the slit coating unit of the present invention;

Fig. 2 is the full sectional view of slit coating unit of the present invention;

Fig. 3 is a schematic diagram of the fluid flow direction in the slit coating unit of the present invention;

Figure 4 is a full sectional view of the front view angle of the first embodiment of the coating head of the present invention;

Fig. 5 is a full sectional view of the left viewing angle of the first embodiment of the coating head of the present invention;

Fig. 6 is a full cross-sectional view of the second embodiment of the coating head according to the present invention.

Detailed ways

The idea, specific structure and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, features and effects of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative efforts belong to The protection scope of the present invention. In addition, all the connection/connection relationships involved in the patent do not simply refer to the direct connection of components, but mean that a better connection structure can be formed by adding or reducing connection accessories according to specific implementation conditions. The various technical features in the present invention can be combined interactively on the premise of not conflicting with each other.

Please refer to Fig. 1, Fig. 2 and Fig. 3 together, the slit coating unit 1 of the present invention includes a housing 10, and the housing 10 is provided with a feed channel 20 for fluid inflow and a discharge channel 30 for fluid outflow , the partial pressure channel 40 communicating with the feed channel 20 and the discharge channel 30 and the slit nozzle 50 located at the end of the feed channel 20 , the width of the feed channel 20 is along the direction toward the slit nozzle 50 The direction decreases step by step. The shapes of the feed channel 20, the discharge channel 30 and the cross-section of the partial pressure channel 40 of the slit coating unit 1 of the present invention can be flexibly selected, such as but not limited to rectangle, circle, polygon, etc., so when the feed channel 20 When the cross section of the feed channel 20 is rectangular, the width of the feed channel 20 is the distance between two parallel planes; when the cross section of the feed channel 20 is circular, the width of the feed channel 20 is the diameter.

In this embodiment, the feed channel 20 is a multi-stage structure, and the width is gradually reduced layer by layer. Preferably, the width of the next stage is 80% of the width of the previous stage. As shown in Figure 2, the second stage feed channel 22 The width is 80% of the width of the first-stage feed channel 21, the width of the third-stage feed channel 23 is 80% of the width of the second-stage feed channel 22, and so on, gradually decreasing to a suitable width, this implementation In the example, the width of the feed channel 20 is preferably decreased from 3 cm to 50 μm.

The ratio of the depth 20b to the width 20a of the feeding channel 20 ranges from 1:100 to 1:1, and the ratio is adjusted according to the specific viscosity of the fluid material to achieve an optimal coating effect. The feeding channel 20 is externally connected to a feeding system, which includes a feeding pipeline and a fluid pump, etc., the feeding system pumps the fluid material from the storage tank, and after passing through the slit coating unit 1, part of the fluid The material flows back into the storage tank through the discharge channel 30 again. The speed of the fluid ranges from 0.001ml/min to 10ml/min, and is adjusted according to the thickness of the coating film.

The pressure dividing channel 40 is mainly used to divide, decompress, and decelerate the fluid in the feed channel 20, and its width is the same as the width of each stage of the feed channel 20 corresponding to it. Specifically, as shown in Figure 2, the first The width of the first-stage pressure-dividing channel 41 is the same as the width of the first-stage feed channel 21, the width of the second-stage pressure-dividing channel 42 is the same as the width of the second-stage feed channel 22, and the width of the third-stage pressure-dividing channel 43 is the same. It is the same as the width of the third stage feeding channel 23, and so on.

Fig. 4 and Fig. 5 show the specific structure of the first embodiment of the coating head of the present invention. Please refer to Fig. 4 and Fig. 5 together, the coating head of the present invention comprises a plurality of above-mentioned slit coating units 1 arranged side by side, also comprises a distribution unit 2, and described distribution unit 2 is provided with described slit The leveling groove 60 communicated with the slit nozzle 50 and a slit flow channel 70 communicated with the leveling groove 60 , the end of the slit flow channel 70 is a coating port 80 . The "side-by-side arrangement" mentioned here is not limited to the side-by-side arrangement of multiple slit coating units 1 through various fixing methods (such as bonding, welding, bolting, etc.), but also includes the integral molding of the coating head In other words, an integrated coating head has a plurality of slit coating units 1 . The main function of the distributing unit 2 is to redistribute the fluid material of the slit nozzle 50. Taking the coating of photosensitive adhesive as an example, in the process of preparing pixels of different liquid crystal displays, their sizes are different. In this case , through the fluid material redistribution process of the distribution unit 2, it is possible to carry out the coating of various sizes and specifications, and has strong adaptability.

Fig. 6 shows the specific structure of the second embodiment of the coating head of the present invention. As shown in FIG. 6 , the difference between this embodiment and the first embodiment is that there are multiple slit channels 70 , and other structures are the same as those of the first embodiment, which will not be repeated here. Because in the coating process of the photosensitive adhesive, sometimes it is not necessary to coat the entire surface, but only at a specific position, so that multiple adaptive slit flow channels 70 can be used for targeted coating, The usage of materials is reduced and the cost is reduced.

The present invention also provides a coating device, which adopts the above-mentioned slit coating unit or coating head.

The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the described embodiments, and those skilled in the art can also make various equivalent deformations or replacements without violating the spirit of the present invention. These equivalent modifications or replacements are all within the scope defined by the claims of the present application.

Claims (10)

1. a slot coated unit, it is characterized in that: comprise shell, be provided with the feeding-passage for fluid inflow, the tapping channel for fluid outflow in described shell, be communicated with point pressure passageway of described feeding-passage and tapping channel and be located at the gap nozzle of described feeding-passage end, the width of described feeding-passage successively decreases step by step along the direction towards gap nozzle.

2. slot coated unit as claimed in claim 1, is characterized in that: the width of described point of pressure passageway is identical with the width of its each grade of corresponding feeding-passage.

3. slot coated unit as claimed in claim 1, is characterized in that: the next stage width of described feeding-passage is 80% of upper level width.

4. slot coated unit as claimed in claim 1, is characterized in that: the degree of depth of described feeding-passage and the proportion of width are 1:100 to 1:1.

5. slot coated unit as claimed in claim 1, is characterized in that: the width of described feeding-passage is decremented to 50 μm from 3cm.

6. slot coated unit as claimed in claim 1, is characterized in that: the velocity interval of described fluid is 0.001ml/min to 10ml/min.

7. a dispense tip, is characterized in that: comprise the multiple slot coated unit as described in any one of claim 1 to 6 be arranged side by side.

8. dispense tip as claimed in claim 7, it is characterized in that: described dispense tip also comprise allocation units, described allocation units are provided with the refining groove and at least one that communicate with described gap nozzle and communicate with described refining groove slit conduit, and the end of described slit conduit is coating mouth.

9. a coating apparatus, is characterized in that: comprise slot coated unit as described in any one of claim 1 to 6.

10. a coating apparatus, is characterized in that: comprise dispense tip as claimed in claim 7.