JPH0461958A - Method for adhering to base plate liquid having volume controlled per unit area of liquid - Google Patents

Abstract

PURPOSE: To obtain a method producing at a low cost, with a high efficiency and high productivity by performing a previously measured 'patch' coating which allows a liquid layer of a controlled volume per a unit area to adhere to an individual surface or a substrate in a predetermined shape and a predetermined thickness. CONSTITUTION: A positive pulse descends precipitously in a slot of a coating liquid adhering apparatus, comes out of the surface of an exit opening of the slot of the coating liquid adhering apparatus formed by a lip of the coating liquid adhering apparatus to hit the surface of a copper-coated laminate and forms a connect bead 66 of the coating liquid between the lip of the coating liquid adhering apparatus and the laminate. An inlet valve is opened simultaneously and a measuring pump starts its rotation to put a controlled volume flow of the coating liquid in or out of the coating fluid adhering apparatus. It is preferable that a pressure difference is generated between the connecting beads by a bead vacuum room 68 in order to help the connecting bead 66 to be kept apart from the lip of the adhering apparatus. By these operations, it is possible to start a sharp and uniform adhering of the coating liquid to be adhered to print circuit boards.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field] The present invention relates generally to liquid coating methods and liquid coating apparatuses, and more particularly to printed circuit boards;
A method and apparatus for coating discrete, incremental surfaces or substrates, such as integrated circuits, in pre-measured "patches" by depositing a pre-measured volume per unit area of liquid onto the surface and The liquid IiI "patch" has a defined shape and a defined coating thickness.

[Conventional technology]

In the manufacture of printed circuit boards or integrated circuits, it is often desirable to apply a liquid coating to the surface of a circuit board or IC wafer, such that the thickness of the wet coating is uniform over the entire surface of the circuit board or substrate. It is important that the In the case of photoresistors that are cured by drying or by cross-coupling with radiation or bonding agents that can be imaged with sunlight, the thickness of the final cured coating is equal to the thickness of the deposited wet coating. It is uniform as a whole.

In the manufacture of printed circuit boards, photoresists are used to transfer circuit contours to the copper surface of the printed circuit board. The term "photoresist" defines the dual functional nature of the material.

First, it is a photopolymer that changes its chemical properties when exposed to ultraviolet light. The irradiation is selectively performed through a mask that delineates the circuit to be formed. Dual functionality comes into play after developing the photopolymer exposed to UV light. After development, undesirable soft spots are washed away from the copper surface. The protective coating of cured polymer then remains only in the areas outlined by the exposure mask. In one application, the circuit board is then etched. The protective coating resists etching so that only unprotected steel surfaces are etched away. When the developed photoresist is finally chemically removed, the underlying protected copper circuit lines become the electrical conductors of the circuit board.

In current manufacturing methods for printed circuit boards, the chemical process of developing the imaged photoresist, etching the exposed copper, and removing the developed photoresist leaves the circuit board with too much material. This is all done by supplying a cleaning agent, an etching agent, or a chemical removal agent. This is usually done by spraying, and an agitation action (by spraying) is also performed to enhance the removal of softened or dissolved surface material. These methods use recycled chemicals for economic reasons and are expensive (expensive), cumbersome, and uneconomical because the surface of the circuit board is exposed to previously reacted materials. . This reduces the efficiency of chemical reactions with the surface, increases cycle times, and distorts the contours of the circuit.

Also, it becomes difficult to maintain the quality of the recycled material, which changes the rate of reaction with the surface.

[Problem to be solved by the invention]

Accordingly, the overall object of the present invention is to provide an improved coating method and apparatus.

The object of the present invention (2411) is to create a pre-measured "patch" that deposits a layer of a controlled amount of liquid per unit area onto an individual surface or substrate in a predetermined shape and with a predetermined thickness. It is an object of the present invention to provide a method and apparatus for performing coating.

Another object of the present invention is to create pre-measured "patches" that deposit controlled amounts of a plurality of liquids per unit area in superimposed relation to a surface or substrate in a predetermined shape and thickness. ``Providing a method and apparatus for applying coatings to individual incrementally coated surfaces.''

A feature of the present invention is that various printed circuit board processing fluids are not required to be supplied in excess. ! Coating methods can be employed to coat printed circuit boards with these processing liquids without any process.

Another feature of the invention is to provide an apparatus for controlling the deposition of liquid from a well-defined start to a well-defined stop of the liquid coating being deposited on a substrate surface.

The method and corresponding apparatus of the present invention are for depositing a controlled amount of liquid per unit area, at a predetermined thickness, onto individual, incremental substrates in quadrilateral pre-measured liquid "patches". . A source of liquid is fluidly coupled to the liquid containing chamber. The liquid-containing chamber expands and is fluidly connected to a liquid applicator slot having an outlet opening. When a substrate is positioned in close proximity to the outlet opening of the applicator slot, it initiates a coating "patch" by creating a positive pulse that flows out of the outlet opening of the applicator slot, causing a bead of liquid to flow out of the applicator slot. is formed to deliver a controlled volumetric flow rate of liquid through the liquid applicator O-slot. Preferably, a positive pulse of liquid is generated by jerking a volume of liquid within the liquid-containing chamber. Once a liquid interlocking bead is formed at the substrate, a controlled volumetric flow rate of liquid exiting the outlet opening of the applicator slot, combined with the relative movement between the applicator and the substrate, creates a liquid coating on the substrate surface. Attach. Termination of the liquid-coated bead is effected by a negative cutting pulse that creates a temporary vacuum in a portion of the liquid-containing chamber.

The vacuum draws the coating liquid into the applicator slot and breaks the connecting bead between the liquid coating between the applicator slot outlet opening and the substrate surface.

〔Example〕

Reference is first made to FIG. 1, in which a pre-weighed measuring method is diagrammatically shown. The processing liquid can be coated onto the surface of the printed circuit board. Processing liquids include 7-otoresist, developer,
Etching agents, chemical stripping agents, adhesive masks, etc.
Liquid chemicals can be used with pre-metered coating systems.

The term "pre-metered coating" refers to the process of delivering a controlled volumetric flow rate of a liquid coating into a coating applicator that is spaced a distance X from the surface of the substrate to be coated. As the substrate surface passes by the applicator, the coating liquid exiting the applicator slats is deposited onto the surface in a thin, uniform layer.

Pre-metered processes differ from held processes such as dip coating, continuous coating, screen coating or four-rule coating. Those processes supply an excessive amount of coating liquid to the surface of the substrate. When the excess amount is removed,
The amount retained on the substrate surface is a function of the coating liquid's rheological properties (such as viscosity) and coating parameters.

Simply put, in a pre-metered coating a fixed amount is added, while in a retained coating the excess amount is removed. In pre-metered processes, the viscosity of the liquid does not determine the thickness of the deposited wet coating. JIIIK
As shown in equation II, the citric acid thickness 〒 is a function of the volumetric flow rate V divided by the coating speed 8 and the coating width W. As with all coating processes, once the coating is dry, the dry coating thickness t is a function of the percent solids of the liquid being coated.

In all sustained coating processes, the thickness of the wet coating is a function of the viscosity of the coating liquid. In general, if the percent solids of the liquid changes due to loss of coating liquid due to evaporation, or due to overdilution of the coating liquid when a charge of solvent is added to compensate for the loss due to evaporation, the viscosity of the liquid will change. . Therefore, the percent fixation must be accurately monitored and controlled in order to maintain the Couette thickness in the coating process. Furthermore, since viscosity is temperature dependent, the temperature of the coating liquid must also be precisely controlled.

In a pre-metered coating process, there is no excess liquid to remove, so the coating liquid can be deposited onto the surface of the substrate.
The coating liquid can be confined in a closed system. This also prevents losses due to evaporation before coating. Confinement also maintains the purity of the coating liquid since exposure to external contaminants is greatly reduced.

In pre-metered processes, the wet thickness can be varied simply by changing the volumetric flow rate. For example, the volumetric flow rate is 1860a+w”/i■, and the coating speed is 610ff.
i/Otori, if the coating width is 611, the wet coating thickness will be 0.051:IwK. Therefore, the volumetric flow rate is 9
By simply decreasing the wet O thickness to 33"/3.3"/min, the wet O. The thickness is determined by the volumetric flow rate l ggQcM″/
0.013 if the volumetric flow rate is 9351”/I
In the case of IK, it is 0.000531 (see Figure 1)
.

A pre-metered "patch" coating process and apparatus is illustrated in FIGS. 2-8. Reference is first made to FIG. 2, in which a coating apparatus 10 constructed in accordance with the present invention is shown. The coating device 10 has a liquid applicator 12 . The liquid applicator 12 includes a liquid containing 1i14 and an applicator slot 11i supported by the positioning piston 11. The positioning piston 1a has a gap stop adjustment screw 20. Coating liquid 22, contained in a sealed reservoir 24 under a blanket of nitrogen gas, is connected to an inlet valve 32 via a connection 30 connected to a metering pump 28.

Its inlet valve is attached to the liquid applicator 12.

A displacement piston 3@ is also attached to the liquid applicator.

This displacement piston is connected to a displacement rod 36. The O-displacement rod is inserted into the applicator chamber 14 through the O-ring seal 40 and the liquid applicator 3s. Directly below the liquid applicator, a slot seal 42 is provided in contact with the open applicator slot. The slot seal is moved up and down along a shaft 44 that is connected to a slot seal piston 46. The slot closure 42 cleans the liquid applicator lip 48 before and after coating the coating housing 22 to the steel coating laminate (both sides).

At the same time, the slot sealer 42 seals the outlet opening 51 of the depositor slot formed by the depositor lip 4S.

The steel coating laminate to be coated) 5G is placed on the vacuum table 52. The vacuum table is mounted on linear bearings 54 so that it can move smoothly above the vacuum table near the liquid applicator.

The vacuum table 52 is fixed to the drive chain 5 through a connecting link 56. Drive chain 5 is drive sprocket 60
revolve around. The drive sprocket 6° is precisely controlled by a precision drive motor (not shown) and can be rotated at the following speeds. At the top of the drive assembly 62 are four microswitches A used to signal the order of operation.
, B, C, and D are provided.

In FIG. 2, before closing the large mouth valve 32, the coating liquid 22 is
is pumped from a sealed reservoir 24 by a pump 28 to the coated liquid containing chamber 14 and from there to the applicator slot 16.
and descends. Air entering the coating liquid containing chamber 14 is exhausted through air exhaust valves (B, V,) 84. The slot sealer 42 is filled with a solvent similar to a coating liquid. The applicator lip 48 is submerged below the surface of the solvent within the slot closure. This prevents the coating liquid from drying in the applicator slot and flushes out any remaining coating liquid on the applicator lip. Clean lips and slots are desirable because dry coating remaining on the applicator lip or slot can disrupt coating liquid flow and cause uneven coating.

A vacuum is applied inside the vacuum table, and the copper-coated laminate filling the top hole of the vacuum table is sucked by the vacuum and flattened against the top side surface of the vacuum table. When switch A is closed, rotation of the drive motor is stopped, thereby stopping the drive sprocket and activating the slot seal piston. Ninth, the slot seal is raised into contact with the coating liquid applicator, thereby sealing the outlet opening 51 of the coating liquid applicator slot.

Once the coating cycle has begun, a cancel button (not shown) is pressed to start the drive motor and rotate the drive sprocket. This moves the drive chain, which moves the vacuum table and the copper-clad laminate it rests on to the right through the connecting links, and releases the switch from the on position as shown in Figure 3. open. When the switch is opened, two types of actions occur. First, slot seal piston 46 pulls slot seal 42 to a position below the vacuum table. Second, the positioning piston II is directed downwardly relative to the gap stop adjustment screw 20 and directs the coating liquid applicator 12 into the predetermined coating gap formed between the outlet opening 51 of the applicator slot and the copper-coated laminate soo. [Move downward toward rxJ. This coating gap is equal to or narrower than 1 cM. This is US Pat. No. 4,230,
This is in contrast to a curtain coating device, such as that shown in No. 793, in which the coating gap is much wider than 10, for example 103.

When the vacuum table continues to move to the right as shown in Figure 4, press switch B. Then, the operation of type 3s is started. In the first operation, the displacement piston 34 is moved and the displacement rod 3
6 through the O-ring 40 and into the coating liquid containing chamber 14.

The length of the displacement rod 31iO stroke is controlled by an adjustable screw stop 37. The movement of liquid caused by the sudden decrease in the amount of liquid inside the coating liquid-containing chamber 14 produces a positive wave or pulse of coating liquid.

The positive pulse travels rapidly down the coating liquid appreciator slot, exits the surface of the exit opening of the coating liquid applicator slot formed by the coating liquid applicator lip, and slams onto the surface of the steel clad laminate, depositing the coating liquid. A connecting bead 66 of coating liquid is formed between the vessel lip and the laminate.

Simultaneously, the inlet valve opens and the metering pump begins to rotate to introduce a controlled volumetric flow rate of coating fluid into and out of the coating fluid applicator, as shown in FIG. . A bead vacuum chamber 68 is provided between the connecting beads 66 to help keep the connecting beads 66 separated from the applicator lip by moving the surface of the printed circuit board.
It is preferable to generate a differential pressure. Since the use of bead vacuum chamber 68 is optional, the bead vacuum chamber is only shown in FIG. These actions initiate a sharp and uniform deposition of coating liquid onto the printed circuit board.

If a relatively large positive pulse is employed, the piston can be immediately retracted to draw in excess liquid without breaking the connecting bead, as will be discussed later with reference to FIG. This oscillating action of the piston first generates a positive pulse and then a negative pulse. By sequentially using positive and negative vibration pulses, the pulse amplitude (
The volumetric displacement of the coating liquid can be larger, thereby providing a better connection of the coating liquid to the printed circuit board. Proper coupling of the coating liquid to the printed circuit board is particularly important when coating speed and/or coating gap are increased,9 or the wet thickness of the liquid is reduced. It can be carried out.

Vibration pulses can be generated by one or more displacement piston assemblies, such as one or more pistons 34 and displacement rods 36. Furthermore, the position of the displacement piston can be varied from the position shown.

Given the fluid dynamics, the piston and its volumetric displacement chamber can be located upstream of the coating fluid applicator 12 and preferably downstream of the mouth valve 32;
Furthermore, it can be seen that the desired positive and negative pulses can be generated.

Vibratory pulse motion of one displacement piston assembly from (positive pulse first, then negative pulse) to (negative pulse first,
Then, instead of generating a connecting bead, liquid is first sucked into the coated liquid slot and then the coated liquid is discharged towards the outlet opening of the coated liquid applicator slot. The p-connection bead is separated, but not enough to reconnect the connection bead to the printed circuit board. In this way, the coating liquid applicator (D) is left filled with coating liquid so that when the flow of coating liquid flowing through the slot of the coating liquid applicator stops, Eliminate air bubbles that may rise within the slot.

By adjusting the volume displacement, the duration of the individual pulses, the amplitude of the pulses and the time interval between the positive and negative pulses, the formation and removal of interlocking beads of coated liquid can be achieved. It can be done in a wide range.

Continuing the illustrated sequence of operations, as the vacuum table and laminate move to the right, a dynamic wetting action occurs, causing the liquid exiting the outlet opening of the coated liquid applicator slot to As shown in Figure 5, it is successively applied as a layer of uniform thickness to the surface of the laminate. The thickness of this layer is determined according to the above-mentioned formula shown in FIG.

Coating liquid deposition continues until the vacuum table presses switch C. When the switch C is closed, the large mouth valve 32 is closed, the metering pump 2m is stopped, and the displacement piston 34 is moved to the displacement rod 36.
is extracted from the coated liquid-containing chamber. As the displacement rod is withdrawn from the chamber containing the coating liquid, a vacuum is temporarily generated inside the chamber and a negative pulse is generated, which causes the coating liquid to evaporate as shown in FIG. The liquid is suddenly raised into the slot. At the same time, the positioning piston pulls the coated liquid applicator toward the gap stop, as indicated by the movement arrow in FIG. Their action abruptly breaks the interlocking beads of coating liquid, leaving clean, sharp edges on the surface of the printed circuit board (or substrate surface). Finally, in FIG. 7, when the vacuum table presses switch D, the drive motor stops rotating and the slot seal piston 46 raises the slot seal 42 until it contacts the coated liquid applicator lip 48. The vacuum applied to the vacuum table 52 is then removed and the coated printed circuit board 50 can be released for further processing.

For example, on a board such as a printed circuit board or an integrated circuit board,
Sometimes it is desired to deposit more than one layer in a superimposed relationship. Each layer may be chemically different and may perform different functions.

To eliminate the need to coat and dry each layer separately, the liquid layers are simultaneously applied to the substrate using a pre-metered multi-layer "batch" coating applicator as schematically shown in Figure 8. can. In FIG. 8, the same reference numerals are used as in FIG. By carefully forming the coating liquid, the deposited layers remain substantially separate and distinct. This packaging technology provides significant economic benefits in terms of yield, productivity and capital investment.

It will be appreciated that a connecting bead of coating liquid can be formed by a positive pulse before the printed circuit board 50 reaches the underside of the coating liquid applicator lip 51 in FIG. In this case, the bead is first connected to the vacuum stage 52 and then to the printed circuit board. Similarly, after the printed circuit board has passed the coated liquid applicator lip, the connecting bead can be eliminated by generating a negative pulse and/or sufficiently widening the gap distance (XC). If at any time between the formation and termination of the connected bead of liquid coating, the connected bead becomes discontinuous or breaks, a positive pulse or an oscillatory (positive then negative) stable pulse (with amplitude (preferably) can fix those problems. The effect of a stabilizing pulse can be assisted by temporarily closing the port valve 32 during the duration of the pulse or by providing a check valve (not shown) above the coated liquid containing chamber flH.

For illustrative purposes, the printed circuit board 50 is shown as a single printed circuit board in the figure, but multiple printed circuit boards can be coated on a vacuum stand so that multiple printed circuit boards can be coated at once. 52, preferably in contacting relationship. Alternatively, two or more vacuum stands can be employed to feed the corresponding printed circuit boards. The separation distance between vacuum tables, and therefore between printing circuits, should be the narrowest to minimize discontinuities in coverage. However, such discontinuities can be corrected by stabilizing pulses.

Next, refer to FIG. Steps 1-17 are a pictorial overview process flow diagram showing from beginning to end how the pre-metered "patch" coating method can be used in the manufacture of printed circuit boards. In step 1, liquid photoresist is applied to the surface of the copper-coated laminate using the pre-metered "patch" coating method and equipment described with reference to FIGS. 2-8. In step 2, the coated laminate is transferred to a dryer where the coat is solidified by evaporating the solvent using heated air. In step 3, the dried laminate is moved to the image projection section. In this image projection section, the photoresist is selectively exposed through a mask. In step 4, a developer is applied to the photoresist exposed to the image. In step 5,
A combination of heat and ultrasound is used to agitate the liquid coating, and the unexposed photoresist is softened by the developer and stripped from the surface of the copper-coated laminate. Then step 6
The laminate is then sent to a cleaning station where the loosened and softened unexposed photoresist is washed away.

In step 7, the uponate is dried before being sent to the next step.

In step 8, an etching solution is applied to the 2Z net surface. In step 9, a combination of heat and ultrasound is again used to melt only the steel surfaces of the laminate that are not protected by the developed photoresist. The laminate is then rinsed of the dissolved copper and the used etching solution in step 10, and then the laminate is completely dried in step 11.

In step 12, a chemical stripper is applied to the surface of the laminate over the developed photoresist. In step 13, by applying a combination of heat and ultrasound, the stripping agent softens the photoresist being developed and lifts it from the underlying copper surface. Next step 1
At step 4, the softened and lifted photoresist is washed away, and at step 15 the laminate is dried again. The laminate or circuit board is then tested for dimensional accuracy and electrical continuity in step 16. If the test passes, the circuit board is flipped over in step 17 to expose the other side of the copper clad laminate. The laminate is then cycled through steps 1-16 again to form the circuit on the other side of the laminate. After passing the second inspection in step 16, the completed double-sided circuit board is removed for further processing.

By operating the circuit manufacturing method as a continuous line as shown in steps 1-17 and employing a pre-metered "patch" coating method in steps 1,4°8.12
Productivity will be much higher than the current batch expansion method. Also,
Costs are significantly lower due to fewer workers and yields are higher due to reduced manual handling of circuit boards.

This pre-metered "patch" coating method also reduces chemical usage due to efficient (controlled) deposition of the required chemicals. The metered "patch" coating method provides a low cost, efficient and highly productive manufacturing method compared to current methods.

[Brief explanation of drawings]

FIG. 1 is a diagram of the liquid coating variables; FIG. 2 is a schematic diagram of the liquid coating device; FIG. 3 shows the positional relationship between the printed circuit board and the outlet opening of the coating liquid applicator slot; Another schematic representation of the apparatus, FIG. 4 shows an initial deposition of a bead on a printed circuit board, another schematic surface of the coating apparatus of FIG. FIG. 6 is another schematic representation of the coating apparatus of FIG. 2 illustrating the final application of a liquid coating onto a printed circuit board; FIG. 7 is a schematic representation of the coating apparatus of FIG. Another schematic representation of the coating apparatus of FIG. 2 showing the closure of the container slot, FIG. 8 a schematic representation of a multilayer coating apparatus for simultaneous deposition of class 281 liquid layers, and FIG. It is a schematic representation. 10...Fist/coating device, 12...Coating liquid applicator,
14...Liquid containing chamber, 16...Appressor slot, 1a...Positioning piston, 34...Displacement piston, 36...Displacement rod, 51...Slot Exit opening, 5211I111/vacuum table, 62...
drive assembly. Cleaning of the drawing "X! (no change in content) 11860cm?min1 1610cm/hoax+in+(61cnnlx, 2,

Claims (31)

[Claims] (1)A. fluidically coupling a liquid source to a liquid containing chamber, the liquid containing chamber being fluidly coupled to the applicator slot such that the liquid containing chamber and the liquid applicator slot having an outlet opening are filled with liquid; B. B. moving the substrate and the outlet opening of the liquid appreciator slot so that the outlet openings of the substrate and the applicator slot are in close proximity to each other; delivering a controlled volumetric flow rate of liquid from a liquid source to a liquid-containing chamber and thence to an appreciator slot to provide a uniform volumetric flow rate of liquid exiting each point along an exit opening of the appreciator slot; D. E. generating pulses that control the formation of connected beads of liquid that are formed before, simultaneously with, or after delivery of the controlled volumetric flow rate of liquid; E. moving the substrate and the outlet opening of the applicator slot relative to each other to deposit a uniform layer of liquid at a controlled volume per unit area of liquid. A method characterized in that a layer of liquid of controlled volume is deposited on a substrate. 2. The method of claim 1, wherein a negative pulse of liquid flows into the outlet opening of the applicator slot without disrupting the connecting bead of liquid coating after generation of the positive pulse of liquid. A method further comprising a step. 3. The method of claim 1, further comprising: sealing the outlet opening of the applicator slot after step A; and unsealing the outlet opening before the liquid exits the outlet opening of the applicator slot. A method further comprising a step. 4. The method of claim 1, wherein the outlet opening of the appreciator slot is constituted by a lip of the appressor, and further comprising the step of cleaning said lip before exiting the outlet opening of the appreciator slot. A method characterized by: 5. The method of claim 1, wherein the pulse is generated by displacing at least a portion of the connected bead of liquid. 6. The method of claim 1, wherein the pulse is generated by temporarily controlling the flow rate of the liquid. 7. The method of claim 1, wherein the layer of liquid is deposited on a substrate such that the area of the layer is within the periphery of the substrate. 8. The method of claim 1, wherein the layer of liquid is applied to a substrate such that at least a portion of the area of the layer extends beyond the periphery of the substrate. 9. The method of claim 1, wherein the substrate is proximate to the outlet opening of the appreciator slot such that the substrate is separated from the outlet opening of the appreciator slot by a distance X;
The method further comprises the step of maintaining the separation distance during E. 10. The method of claim 1, wherein the substrate includes at least one element of an integrated circuit. 11. The method of claim 10, wherein the layer of liquid is deposited on a substrate such that an area of the layer of liquid is within a periphery of the substrate. 12. The method of claim 10, wherein said layer of liquid is deposited on a substrate such that a portion of said layer of liquid overlies at least a portion of said at least one element of an integrated circuit. how to. 13. The method of claim 10, wherein the layer of liquid is applied to a substrate such that at least a portion of the area of the layer extends beyond the periphery of the substrate. (14) The method according to claim 10, wherein the liquid is a photoresist, and the method includes a step of drying the photoresist, a step of projecting an image onto the photoresist, or a step of selectively hardening the photoresist. A method further comprising: 15. The method of claim 1, wherein said relative movement is initiated prior to formation of an interlocking bead of liquid coating. 16. The method of claim 1, wherein said relative movement is initiated simultaneously with the formation of an interlocking bead of liquid coating. 17. The method of claim 1, wherein said relative movement is initiated after formation of an interlocking bead of liquid coating. 18. The method of claim 1, further comprising positioning the substrate in a flattened form proximate the outlet opening of the applicator slot. 19. The method of claim 1, further comprising fluidly coupling a source of liquid to the liquid-containing chamber to form a closed system with the liquid-containing chamber. 20. The method of claim 1, wherein in step E, after continued relative movement between the substrate and the outlet opening of the applicator slot, the side of the liquid-coated interlocking bead toward the uncoated portion of the substrate. The method further comprises the step of creating a pressure differential across the liquid-coated connecting bead such that a lower pressure is present at the interface. (21) Claims 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, 13, 14, 15, 16, 17, 1
8, 19 or 20, wherein the substrate is at a distance
The substrate is close to the outlet opening of the appreciator slot so that it is separated from the outlet opening of the appreciator slot by The method further comprises the step of terminating the contact between the substrate and the liquid by moving the substrate. (22) Claims 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, 13, 14, 15, 16, 17, 1
8, 19, or 20, further comprising the step of terminating the flow of liquid to the substrate by terminating the delivery of a controlled volumetric flow of liquid from the liquid source to the liquid-containing chamber. how to. (23) Claims 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, 13, 14, 15, 16, 17, 1
8, 19, or 20, wherein the flow of liquid to the substrate is terminated by terminating the delivery of a controlled volumetric flow of liquid from a liquid source to the liquid-containing chamber, and a vacuum is created within a portion of the liquid-containing chamber. The method further comprises the step of removing from the substrate a bead of liquid that connects the outlet opening of the applicator slot and the substrate by generating a negative pulse of liquid to temporarily cause a . 24. The method of claim 23, wherein after generation of the negative pulse, the liquid in the appreciator slot is flowed toward the outlet opening of the applicator slot without reconnecting the bead of liquid coating to the substrate. The method further comprises the step of generating a positive pulse of liquid that causes (25) Claims 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, 13, 14, 15, 16, 17, 1
8, 19 or 20, the method further comprising repeating steps (A) to (E) n times, where n is at least 1. (26) The method according to claim 9, characterized in that before step E, the distance x is changed. (27) The method according to claim 9, characterized in that before step E, the distance x is increased. (28) The method according to claim 9, characterized in that before step E, the distance x is reduced. 29. The method of claim 9, further comprising controlling the formation of the liquid bead by generating positive pulses of liquid flowing out of the outlet opening of the applicator slot. 30. The method of claim 1, further comprising controlling the formation of said liquid bead by generating a negative pulse of liquid flowing out of an outlet opening of an applicator slot. 31. The method of claim 5, wherein the portion of the liquid bead is moved by applying an impact to the substrate.