JP2003055779A - Method for etching substrate and etching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To etch a flexible substrate in such a manner that the entire surface thereof receives an etching effect uniformly over the entire surface of the substrate by improving a technique of etching the flexible substrate by spraying an etchant to the flexible substrate 3 from a nozzle 7 while conveying the substrate 3. SOLUTION: The conveyance direction (arrow (d)) of a belt conveyor 9 is inclined with respect to the horizontal and the flexible substrate 3 is placed thereon and is conveyed. As a result, the flatness of the flexible substrate 3 is maintained. Further, the belt conveyor is inclined and therefore the etchant (arrow (e)) sprayed from the nozzle 7 flows in the downhill direction of the inclination and a liquid pool is not produced in about the half in the uphill direction. The uniform etching is performed by spraying the etchant to the area where there is no liquid pool.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching method performed as one of the steps for manufacturing a printed circuit board, and an etching apparatus suitable for carrying out the above method, and more particularly to a flexible substrate surface. It is a technology created to precisely form a fine pattern.

[0002]

2. Description of the Related Art In order to uniformly and efficiently etch the entire surface of a substrate, a technique of spraying an etching solution onto the surface of the substrate while it is being transported is well known and widely used. FIG. 3A is a schematic drawing of the transport mechanism portion of the etching apparatus, in which horizontal straight rollers 11 are arranged along a plane and rotate in the directions of arc arrows r. The substrate S placed thereon is sent at a constant speed in the direction of arrow a. When the etching liquid is sprayed from a nozzle (not shown) onto the surface of the substrate that is being sent at a constant speed, each of the multiple substrates comes into uniform contact with the etching liquid and is uniformly etched. FIG. 3B is a known example of a transport mechanism for etching different from the above, in which a relatively large number of ring rollers 15 are arranged in order to shorten the span for supporting the substrate 1.

[0003]

With the progress of electronic technology, high performance and compactness of electronic equipment have been achieved, the thickness dimension of the substrate has become thin, and the pattern has become fine. A recent board has a copper foil with a thickness of about 9μ formed on a polyimide sheet with a thickness of about 12.5μ (micrometer), and a pattern with a line width and a spacing of about 30μ is etched. The current research and development aims at a sheet thickness of 9μ, foil thickness of 5μ, and line spacing of 20μ. Such an ultra-thin substrate is called a flexible substrate, and its etching process requires a high degree of technical improvement. In order to perform ultrafine pattern etching, as described in detail below, a. Ensure the flatness of the flexible board. And b. It is necessary to strongly spray the etching liquid perpendicularly to the substrate surface, and further, c. It is necessary not to create a "liquid pool" on the flexible substrate surface. As shown in FIG. 3C, even if the intervals between the many ring rollers 15 are shortened, an ultrathin (eg, 9μ) copper foil is formed on an ultrathin (eg, 12.5μ) polyimide sheet. ,
The member 3 covered with an extremely thin dry film (developed photoresist) which is almost equal to this is very flexible, and it is difficult to maintain it on a flat surface. (Note) The member 3 is a semi-finished product or a work-in-process product of a flexible printed circuit board in detail, but hereinafter it may be abbreviated as a flexible circuit board unless it is confusing). Moreover,
When the etching liquid is strongly sprayed from above the flexible substrate 3, the flexible substrate 3 is bent more and more greatly.

Next, spraying of an etching solution for etching a fine pattern will be described below with reference to FIG. FIG. 4A schematically shows a cross section of the flexible substrate before being etched. A copper foil Cu is formed on a polyimide sheet PI and covered with a "resist pattern R formed by exposing and developing a photoresist". The hatched portion of the resist pattern R is the corrosion resistant film. The ideal form of the etching operation is, as shown in FIG. 4B, a portion where the copper foil is covered with the resist pattern R, but is not covered with the resist pattern R (denoted by a symbol E). (Shown) is removed by etching. However, the actual etching state is as shown in FIG. That is, the copper foil Cu is not only corroded and removed in the thickness direction (arrow b), but also in the lateral direction (arrow c). Such a phenomenon is known, and is referred to as "side etching" or "under etching" in the book microfabrication technology published by Nikkan Kogyo Shimbun, for example.
It has been proposed to provide an "etching margin" to correct this side etching. However, with a reluctant means such as providing "etching margin" in this way,
I can't imagine pursuing a line width and spacing of 20μ.
Therefore, the inventor of the present invention maintains the flatness by placing the flexible substrate on the conveyor belt CB, and the etching liquid is perpendicular to the surface of the flexible substrate, as indicated by a large number of arrows with the symbol J. It was discovered and confirmed that the adverse effect of side etching can be suppressed by blowing strongly. In the above strongly sprayed example, the spray pressure is 2.5 kg / cm ² , but the strength of the spray varies depending on many factors such as the nozzle structure, size, position (spray distance), etc. hard. Since the strength of the spray of the etching solution is not a constituent of the present invention, a quantitative definition is omitted. We would like you to understand that it is desirable to spray strongly.

As described above, even if the flatness of the flexible substrate is maintained and the etching liquid is strongly sprayed vertically against it, there is still a problem of "liquid pool" described below. FIG. 5 is a schematic diagram for explaining the problem of liquid pool. As shown in FIG. 5A, the flexible substrate 3 is placed on the belt conveyor 5, the flexible substrate 3 is pressed by the rollers 6 and is conveyed in a stable state, and the nozzle 4 vertically extends from the flexible substrate 3. Spray the etchant strongly in the direction. Thus, the flatness of the flexible substrate 3 is maintained by the belt of the belt conveyor 5, and side etching is reduced by vertical spraying of the etching solution. However, the flexible substrate 3
The etching liquid sprayed on the sheet flows in the width direction (depth direction in the figure) of the belt of the belt conveyor 5, and flows down from the edges on both sides of the belt. in this case,
Since the flexible substrate 3 and the conveyor belt on which the flexible substrate 3 is placed are horizontal, the drainage is not good.
(See FIG. 5 (B)) The etching solution is flexible substrate 3
Even if it tries to flow in the left-right direction in the figure, it is blocked by the roller 6. Since there is no gradient in the depth direction of the figure, it is difficult to flow. Moreover, due to the surface tension of the etching liquid, the etching liquid layer does not have a uniform thickness, and the liquid pool 7 is formed. This amount of liquid pool is large near the center of the belt in the width direction and small near the edges on both sides. In this way, the liquid pool 7 has an uneven distribution on the surface of the flexible substrate 3. Even if the etching liquid is uniformly sprayed from the liquid pool 7 in which the liquid is unevenly distributed, uniform etching cannot be obtained.

While ensuring the flatness of the flexible substrate,
A method shown in FIG. 5C can also be considered in order to strongly spray the etching liquid vertically to the surface. That is,
While the flexible substrate 3 is attached to the lower surface of the lower side of the portion of the belt conveyor 5 where the endless annular belts are stretched in parallel with each other, the flexible substrate 3 is attached by the surface tension of the etching solution and is supported by the roller 6. It is transported, and the etching liquid is sprayed from below through the nozzle 4. According to the configuration of FIG. (C), the sprayed etching liquid can be dropped downward without flowing on the upper surfaces of the belt conveyor 5 and the flexible substrate 3. However, due to the surface tension of the etching solution (specifically, the wettability with respect to the flexible substrate 3 and the roller 6 is also involved),
A liquid pool 7'is formed as shown in FIG. In this case, the "liquid pool" can be restated as a non-uniform liquid film. When the non-uniform etching liquid film (liquid pool 7 ') is formed in this way, the etching action does not proceed even if the etching liquid is evenly sprayed.

The present invention has been made in view of the above-mentioned circumstances, and allows a substrate to be transported in a stable state and to uniformly advance an etching action without causing harmful liquid pools on the surface of the substrate. An etching method to be obtained, and an etching apparatus suitable for carrying out the above etching method are provided,
In particular, it is intended to contribute to the progress of practical technology for forming a fine pattern on a flexible substrate.

[0008]

The basic principle of the present invention created to achieve the above-mentioned object will be briefly described below with reference to FIG. 2 corresponding to the embodiment. That is, in order to improve the technique of etching the flexible substrate by spraying the etching liquid from the nozzle 7 while conveying the flexible substrate 3, the entire surface of the flexible substrate is uniformly subjected to the etching action.
As shown in the figure, the conveyor direction (arrow d) of the belt conveyor 9 is inclined relative to the horizontal direction, and the flexible substrate 3 is placed on the inclined direction and conveyed. Thereby, the flatness of the flexible substrate is maintained. Further, since the belt conveyor 9 is inclined, the etching liquid (arrow e) blown from the nozzle flows in the downward slope direction (lower left in the figure) to form the liquid pool 14, but About half the area of the direction does not cause nonuniformity of the etching solution layer, and uniform etching is performed.

Based on the principle described above, claim 1
The configuration of the method according to the invention, while conveying the substrate, in the etching method of spraying an etching solution to the substrate, the conveying direction of the belt conveyor, while tilting compared to the horizontal direction, by the belt conveyor and the roller. It is characterized in that the substrate is sandwiched and transported, and the etching liquid is sprayed in a direction substantially perpendicular to the surface of the substrate being transported. According to the method of the first aspect of the invention described above, since the substrate is conveyed by the inclined belt conveyor, the flatness of the flexible substrate can be maintained. In addition, since the belt conveyor is inclined, the sprayed etching liquid rapidly flows down the slope, and a harmful liquid pool (an uneven liquid layer of the etching liquid is not generated. Etching action is performed.

According to a second aspect of the invention, in addition to the constituent features of the first aspect of the invention, a straight roller is used as the roller, and the direction of the central axis of rotation of the straight roller is horizontal. It is characterized by normalizing and normalizing with respect to the transfer direction of the substrate. According to the method of the second aspect of the invention described above, since the straight roller is used as the roller and the roller and the substrate hardly slip, there is no possibility of damaging the surface of the substrate. That is, the roller in the method of the first aspect may be a ring roller. However, by limiting to the straight roller as in the second aspect, the possibility of damaging the substrate can be completely eliminated in practical use.

According to a third aspect of the invention, in addition to the constituent features of the second aspect of the invention method, the belt conveyor is installed so as to be inclined in an uphill direction, and is conveyed on the belt conveyor. A plurality of rollers are arranged so as to be in contact with the upper surface of the substrate so as to be separated from each other, and the etching liquid is sprayed toward a half area on the upper side of the slope in a section sandwiched between the rollers. It is characterized by The invention method of claim 3 described above is applied to the invention method of claim 2. Therefore, the "roller" is a straight roller according to the structure of claim 2. The etching solution flowing down the substrate surface in the downhill direction is blocked by the straight roller to form a liquid pool, but the etching solution is directed toward the half area on the upper side of the slope avoiding the half on the downhill side where the liquid pool is formed. Since the etching solution is sprayed, the sprayed etching solution is not affected by the pool of the solution, and the etching action is allowed to proceed uniformly.

According to a fourth aspect of the present invention, in addition to the constituent features of the first or second aspect, the belt conveyor is installed so as to be inclined in the downhill direction, and the lower surface of the belt conveyor is installed. While sticking the substrate to the surface tension of the etching solution, and arrange the roll by contacting the lower surface of the substrate, while sandwiching the substrate between the roller and the belt conveyor, while conveying, It is characterized in that the etching liquid is sprayed from below the substrate toward the substrate. According to the invention method of claim 4 described above,
Even if the substrate is a flexible substrate, its flatness can be held by a belt conveyor, and the etching liquid is sprayed toward the lower surface of the inclined substrate. The drainage is very good. Therefore, a uniform etching action is performed without being adversely affected by the pool of etching liquid.

According to a fifth aspect of the present invention, in addition to the constituent features of the first aspect of the present invention, the number of the belt conveyors is plural, and at least one of the plurality of belt conveyors is provided. With one climbing slope,
At least one of the other belt conveyors is inclined in the downhill direction, the same substrate is used, and both the uphill-inclined belt conveyor and the downhill-inclined belt conveyor are passed to obtain the uphill-inclined inclination. At the time of passing the belt conveyor, while carrying the substrate on the belt conveyor, while spraying the etching solution from above, one side surface of the substrate is etched, and when passing down the sloped belt conveyor, the etching solution While adhering the substrate to the lower surface of the belt conveyor by surface tension and carrying it, while spraying an etching solution from the lower side to etch the other surface of the substrate, carrying the substrate as described above, It is characterized in that both sides are etched. According to the method of the fifth aspect of the present invention described above, it is possible to uniformly etch one surface of the substrate in one of the two continuous steps and uniformly etch the other surface of the substrate in the other of the two steps. it can. Summarizing the above, even if the substrate is a flexible substrate, both surfaces can be uniformly and efficiently etched.

According to a sixth aspect of the present invention, in an etching apparatus having means for transporting a substrate and means for spraying an etching solution on the substrate being transported, the etching direction is higher than the horizontal direction. Assuming a belt conveyor that is inclined, a plurality of rollers provided at a position substantially in contact with the belt conveyor, and a substrate sandwiched between the belt conveyor and the roller, It is characterized by comprising a nozzle installed toward the virtual substrate and a means for feeding an etching solution to the nozzle. Claim 6 described above
According to the invention device of, even if the substrate is flexible,
The substrate can be held in a flat shape by the belt conveyor without being bent, and since the conveyor is inclined, the sprayed etching liquid can be well separated without forming a liquid pool. Therefore, the substrate surface is uniformly etched without being adversely affected by the liquid pool.

According to a seventh aspect of the invention, in addition to the constituent features of the sixth aspect of the invention, the nozzle is installed substantially perpendicular to the surface of the virtual substrate, Alternatively, the structure is such that the inclination angle with respect to the surface of the substrate can be adjusted, and the attitude can be maintained by adjusting the inclination angle perpendicularly to the surface of the substrate.
According to the apparatus of the invention of claim 7 described above, the nozzle is not installed simply downward or upward, but is installed perpendicularly to the inclined surface corresponding to the inclined belt conveyor. (Also known as side etching) does not occur. Therefore, it is possible to form a fine pattern by etching.

According to an eighth aspect of the present invention, in addition to the features of the sixth or seventh aspect of the present invention, the roller is a straight roller, and the rotation axis of the straight roller is It is installed so as to be horizontal, or has a structure that can be adjusted so as to be horizontal, and the direction of the rotation axis of the straight roller intersects the conveyance direction of the belt conveyor at a right angle. It is characterized in that it is installed so as to form an eggplant or that the structure is adjustable so that it becomes a right angle. According to the invention apparatus of claim 8 described above, since the roller is a straight roller, it does not make local contact with the surface of the substrate, and the roller does not slide on the surface of the substrate. There is no risk of damaging the microstructure of.

According to a ninth aspect of the invention, in addition to the constituent features of the sixth aspect of the invention, the belt conveyor has an endless annular belt in which a portion of the belt stretched to the upper side is slanted. It is a structure that moves upward, and in the section between the plurality of rollers, the nozzle is installed toward the vicinity of the upper half area with respect to the inclination of the belt with respect to these rollers. To do. According to the apparatus of the ninth aspect of the present invention described above, the belt conveyor has an uphill shape, so that the substrate placed on the belt conveyor is kept flat and is conveyed while being inclined. Therefore, the etching liquid sprayed on the upper surface of the substrate flows downward in the slope. The flow of the etching liquid is hindered from flowing down by the roller and becomes slightly stagnant, but no liquid pool is formed in the “upper half of the slope between the rollers”. Since the etching liquid is sprayed toward the area having no liquid pool, the substrate is uniformly etched while being transported at a constant speed.

According to a tenth aspect of the invention apparatus, in addition to the constituent features of the sixth aspect of the invention apparatus, the belt conveyor is a belt of a portion stretched to the lower side of an endless annular belt. The structure is such that the roller moves obliquely downward, and the roller is installed below the endless annular belt so as to face the "portion where the endless annular belt moves obliquely downward". According to the invention apparatus of claim 10 described above, the substrate is sandwiched between the lower surface of the belt conveyor and the roller, and the substrate is attached to the lower surface of the belt conveyor by the surface tension of the etching solution. The etching liquid is sprayed onto the lower surface of the substrate while the substrate is being transported in a curved shape. Therefore, the sprayed etching liquid quickly flows away and no liquid pool is formed on the substrate surface. Since the etching liquid is sprayed onto the surface having no liquid pool, it is possible to uniformly perform the etching action without being adversely affected by the side etching (under etching).

According to an eleventh aspect of the invention, in addition to the constituent features of the sixth aspect of the invention, a plurality of the belt conveyors are installed, and each belt conveyor has a plurality of horizontal An endless annular belt is wound around a simple pulley, and at least one belt conveyor is
An uphill-shaped conveyor in which the upper half part of the pulley that is wound around a plurality of pulleys moves diagonally upward,
A plurality of rollers are provided so as to face the upper half belt, and at least one belt conveyor other than those described above has a lower half portion which is wound around a plurality of pulleys and is inclined. It is a downward slope type conveyor that moves downward, and is characterized in that a plurality of rollers are provided so as to face the lower surface of the lower half belt. According to the invention device of claim 11 described above, claim 6
Further, the surfaces on both sides of the substrate can be automatically etched in a continuous process without hindering the effect of the device of the invention. Therefore, even if the substrate is flexible, it is possible to form fine patterns accurately and efficiently on both sides of the substrate, which greatly contributes to the development of the electronic device industry.

[0020]

1 is a schematic view showing an embodiment of the present invention. The left half of the figure is an area U for etching the upper surface of the substrate, and the right half is an area D for etching the lower surface.
A climbing inclined belt conveyor 9 is provided in the upper surface etching area U, and a descending inclined belt conveyor 10 is provided in the lower surface etching area D. The object to be etched is a flexible substrate, which is not shown in FIG. 1, but will be described later in detail with reference to FIG.
In FIG. 1, a flexible substrate (not shown) is carried in from the left side of the figure by a carry-in conveyor 12, sequentially passes through an ascending slope belt conveyor 9 and a descending slope belt conveyor 10, and then is carried out by a carry-out conveyor 13 to the right side of the figure. It is supposed to be carried out.

The climbing inclined belt conveyor 9 of this embodiment has a pair of equal-diameter pulleys 9a and 9b arranged horizontally, and the pulley 9b is located at a higher position than the pulley 9a. The endless annular conveyor belt stretched in between forms two parallel surfaces, and rotates in the clockwise direction as indicated by an additional arrow. When the present invention is carried out, it is not always necessary to wind the two pulleys around each other to form two parallel surfaces. However, in the annular conveyor belt, the portion stretched to the upper side forms an inclined flat surface. Need to be present. A large number of straight rollers 11 are arranged above the climbing slope conveyor 9 at substantially equal intervals. The straight rollers 11 have their central axes of rotation horizontal and are at right angles to the moving direction of the conveyor belt in contact therewith. With such a configuration, the straight roller 11 guides the substrate and stabilizes the transportation without slipping on the substrate (not shown) transported on the climbing slope conveyer 9. A ring roller may be used instead of the straight roller 11. In general, a straight roller is preferable to a ring roller because it does not generate a high local contact pressure, but depending on the type and model of the substrate that is the workpiece (especially, a "pattern that is parallel to the transport direction is It is also possible to use a ring roller (in the case where a “free area” is formed). In such a case, the ring roller can further reduce the formation of the liquid pool.

FIG. 2 is an enlarged detailed view of a part of the climbing inclined belt conveyor 9 shown in FIG. 1 and its vicinity. In FIG. 2, an upper part of the two parallel surfaces of the climbing inclined belt conveyor 9 appears, and the vehicle runs in the direction of arrow d in the direction of uphill. Flexible board 3 on it
Is carried and conveyed in the direction of arrow d. The above-mentioned substrate may have rigidity. However, even if it is flexible, its flatness is maintained. A nozzle 4 for injecting an etching solution is installed above the climbing belt conveyor 9 vertically to the flexible substrate 3. The etching liquid flow (arrow e) jetted from the nozzle 4 is not necessarily blown perpendicularly to the flexible substrate 3 in a strict geometrical sense. The vertical spraying of the etching solution in the present invention is sufficient if the main direction of the jet flow is vertical. When carrying out the present invention, the direction of the nozzle 4 and the direction of the straight roller rotation shaft do not necessarily have to be fixed as described above. Even if the structure is adjustable, it is within the technical scope of the present invention if it can be adjusted to the above state.

If it is assumed that the etching liquid sprayed from the nozzle 4 cannot flow on the flexible substrate 3 in the depth direction and the front direction of the drawing, the imaginary line H
The etching solution accumulates up to the horizontal plane indicated by. However, in the present embodiment, the sprayed etching liquid flows in the depth direction and the front direction of the drawing, and flows down from the edges of the conveyor belt (that is, flows in both sides in the width direction of the conveyor belt), so that it is flexible. The etching liquid surface on the substrate 3 is significantly lower than the virtual horizontal surface H, and the liquid pool 14 shown by spots is formed. The liquid pool 14 is formed in about half of the section between the two straight rollers 11 corresponding to the downhill side. Therefore, a liquid pool (a nonuniform etching liquid layer) is not formed in about half of the above-mentioned section corresponding to the sloped side. Therefore, when the etching solution is sprayed from the nozzle 4 toward the half area on the side of the slope as shown by the arrow e, uniform etching is performed without being affected by the solution pool. As can be understood from the above-described actions and effects, the phrase “half on the side of the slope” is a convenient expression for explaining the structural function, and is referred to as a half area divided and drawn on the drawing. It does not mean the meaning, but rather the area toward the upper side of the slope.

In this embodiment (FIG. 2), the liquid pool 1
The significance of spraying the etching liquid while avoiding No. 4 will be discussed in more detail as follows. The flexible substrate 3 is conveyed at a constant speed in the direction of the arrow d. Therefore, considering only this FIG.
Even if the etching solution is sprayed on the surface of 4, the illusion is easily generated so as not to cause another trouble. However, the etching liquid on the flexible substrate 3 flows downward toward the slope,
The flow toward both sides of the conveyor belt (direction perpendicular to the paper surface) flows in a composite form. FIG. 2 is a sectional view taken along a vertical plane parallel to the conveying direction (arrow d) of the belt conveyor 9. However, even in the vertical cross section parallel to the transport direction, the liquid surface shape of the liquid pool 14 is different between the central portion and the vicinity of the edge in the width direction of the conveyor belt. That is, the thickness dimension of the etching liquid layer on the flexible substrate 3 is not uniform in the width direction of the conveyor belt (the direction perpendicular to the paper surface). Therefore, when the etching liquid is sprayed from above the non-uniform liquid layer, the non-uniform liquid layer is etched.
In consideration of such circumstances, the nozzle 4 is supported vertically to the flexible substrate 3. When the apparatus of this embodiment is at rest, the nozzle 4 is held perpendicular to the belt surface of the ascending inclined belt conveyor 9, although there is no flexible substrate 3.

(See FIG. 2) Now, consider a case where the traveling direction of the climbing inclined belt conveyor 9 is reversed and the belt is run in the direction opposite to the arrow d. Along with this, the rotation direction of the straight roller 11 is also reversed. However, the fact that the liquid pool 14 is biased to the area on the slope lower side of the section between the two rollers and does not cause the liquid pool (uneven thickness of the etching solution layer) to occur in the area on the slope upper side means that the belt does not move. This is the same as when traveling in the d direction. Therefore, even if the etching apparatus shown in FIG. 2 is reversed and the flexible substrate 3 is conveyed in the descending slope direction, and the etching solution is vertically sprayed toward the flexible substrate 3 from the nozzle 4, a uniform etching action is obtained. Can be done.

Next, returning to FIG. 1, the lower surface etching area D shown in the right half of the drawing will be described. The descending inclined belt conveyor 10 is installed in the lower surface etching area D, while the climbing inclined conveyor 9 is installed in the upper surface etching area U described above. The descending inclined belt conveyor 10 includes a pair of equal-diameter pulleys 10a and 10b.
Each of them is installed horizontally and with a vertical difference, and endless annular conveyor belts are wrapped around these pulleys, and two parallel surfaces are stretched downhill (downward in the figure). is there. This bottom etching area D
Since the lower surface of the flexible substrate (not shown) is etched, the nozzle 4 is installed upward below the belt conveyor (more specifically, the nozzle 4 is installed vertically to the two parallel planes stretched over). is there). In this way, a large number of straight rollers 11 are arranged so as to be substantially in contact with the conveyor belt stretched on the lower side of the two parallel faces stretched with a descending inclination. The descending inclined belt conveyor 10 rotates in the counterclockwise direction as indicated by an additional arrow, a flexible substrate (not shown) is sandwiched between the straight roller 11 and the conveyor belt, and the conveyor belt is driven by the surface tension of the etching solution. While being transported in the form of being attached to the substrate, the etching liquid is sprayed from below by the nozzle 4. At this time, the spraying pressure of the etching solution acts so that the flexible substrate (not shown) is brought into close contact with the inclined belt conveyor 10, and the flatness of the flexible substrate is maintained.

The descending inclined belt conveyor 10 provided in the lower surface etching area D includes a pair of equal diameter pulleys 10a, 10a.
The conveyor belt was wrapped around b and stretched over the inclined parallel two faces as shown in FIG. 1, but as understood from the above-mentioned structural function, what is required is the lower inclined face. Only the face. Therefore, even if a pair of horizontal pulleys 10a and 10b having the same diameter are not necessarily provided, it is sufficient to extend the lower half of the endless annular belt so as to be inclined in the conveying direction with respect to the horizontal plane. However, half of the perimeter of the endless annular belt cannot be stretched in a plane. In the present invention, stretching the upper half portion (or the lower half portion) of the endless annular belt is a convenient expression and accurately means that less than half is stretched in a plane.

According to the embodiment shown in FIG. 1, the flexible substrate is continuously conveyed while being held in a flat surface, and one surface and the other surface of the flexible substrate are continuously processed. A fine pattern can be precisely etched by spraying an etching solution on each of the above. Next, an application example of the embodiment of FIG. 1 will be described. The climbing inclined conveyor 9, the descending inclined conveyor 10, the carry-in conveyor 12, and the carry-out conveyor 13 shown in this figure are reversed, and the flexible board (from the right side of the carry-out conveyor 13 toward the lower surface of the descending tilted belt conveyor 10) It is also possible to etch the lower surface by sending an etching liquid to the lower surface while feeding the flexible substrate along the lower surface of the descending inclined belt conveyor 10 obliquely to the upper left. As described above, when the etching liquid is sprayed on the lower surface of the inclined flexible substrate, the sprayed etching liquid is easily separated by its own weight flow, and uniform etching is performed without being adversely affected by the liquid pool. be able to. The flexible substrate (not shown) whose bottom surface is etched passes through the descending inclined belt conveyor 10 and rides on the upper right end of the ascending inclined belt conveyor 9. At this time, since the ascending slope belt conveyor 9 is reversed, the flexible substrate is conveyed diagonally downward and to the left while being sprayed with an etching solution on its upper surface, so that uniform etching can be achieved without being adversely affected by the liquid pool. Then, it is carried out to the left in the figure by the carry-in conveyor 12 which is reversed.

[0029]

According to the method of the invention of claim 1, since the substrate is conveyed by the inclined belt conveyor, the flexible substrate However, the flatness is maintained. In addition, since the belt conveyor is inclined, the sprayed etching liquid quickly flows down the slope, and no harmful liquid pool (uneven liquid layer of etching liquid) is generated. Therefore, a uniform etching action is performed. According to the method of the second aspect of the present invention, since the straight roller is used as the roller and the roller and the substrate hardly slip, there is no possibility of damaging the surface of the substrate. That is, the roller in the method of the first aspect may be a ring roller. However, by limiting to the straight roller as in the second aspect, the possibility of damaging the substrate can be completely eliminated in practical use. The invention method of claim 3 is applied to the invention method of claim 2. Therefore, the "roller" is a straight roller according to the structure of claim 2. The etching solution flowing down the substrate surface in the downhill direction is blocked by the straight roller to form a liquid pool, and the etching solution is directed toward the half area on the downhill side avoiding the half on the downhill side where this liquid pool is formed. Since the etching solution is sprayed, the sprayed etching solution is not affected by the pool of the solution, and the etching action is allowed to proceed uniformly. According to the method of the invention of claim 4, even if the substrate is a flexible substrate, the flatness thereof can be maintained by the belt conveyor, and the etching liquid is attracted toward the lower surface of the inclined substrate. , The cleaning of the sprayed etching solution is very good. Therefore, a uniform etching action is performed without being adversely affected by the pool of etching liquid. According to the method of the fifth aspect of the present invention, one surface of the substrate can be uniformly etched in one of the two consecutive steps, and the other surface of the substrate can be uniformly etched in the other step. Summarizing the above, even if the substrate is a flexible substrate, both surfaces can be uniformly and efficiently etched.

According to the invention device of claim 6, even if the substrate is flexible, it can be held in a flat state by the belt conveyor without being bent, and the conveyor is inclined. The sprayed etching solution does not form a liquid pool and is easily removed. Therefore, the substrate surface is uniformly etched without being adversely affected by the liquid pool. According to the apparatus of the invention of claim 7, the nozzle is not installed downward or upward, but is installed vertically corresponding to the inclined belt conveyor so as to correspond to the inclined belt conveyor. ) Does not occur. Therefore, it is possible to form a fine pattern by etching. According to the invention device of claim 8, since the roller is a straight roller, a local contact pressure is not exerted on the surface of the substrate, and the roller does not slide on the surface of the substrate. There is no danger of damaging the. According to the invention device of claim 9, since the belt conveyor is in the form of an uphill, the substrate placed on the belt conveyor is kept flat and conveyed while being inclined. Therefore, the etching liquid sprayed on the upper surface of the substrate flows downward in the slope. The flow of the etching liquid is hindered from flowing down by the roller and becomes slightly stagnant, but no liquid pool is formed in the “upper half of the slope between the rollers”. Since the etching liquid is sprayed toward the area where there is no liquid pool,
The substrate is uniformly etched while being transported at a constant speed. According to the invention device of claim 10, while sandwiching the substrate between the lower surface of the belt conveyor and the roller,
While the substrate is conveyed in a form in which the substrate is attached to the lower surface of the belt conveyor by the surface tension of the etching liquid, the etching liquid is sprayed on the lower surface of the substrate. For this reason,
The sprayed etching liquid quickly flows away, and no liquid pool is formed on the substrate surface. Since the etching liquid is sprayed onto the surface having no liquid pool, the etching action can be performed uniformly without being adversely affected by the side etching (under etching).
According to the eleventh aspect of the invention, the surfaces of both sides of the substrate can be automatically etched in a continuous process without impeding the effects of the sixth aspect of the invention. Therefore, even if the substrate is flexible, it is possible to form fine patterns accurately and efficiently on both sides of the substrate, which greatly contributes to the development of the electronic device industry.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of an etching apparatus according to the present invention.

FIG. 2 is an enlarged detailed view of part of the climbing inclined belt conveyor and its vicinity in the embodiment of FIG. 1 described above.

FIG. 3 is a schematic diagram for explaining a transport mechanism in a conventional etching apparatus.

FIG. 4 is a schematic diagram for explaining an under-etching phenomenon in an etching action and a method for preventing it.

FIG. 5 is a schematic diagram for explaining a liquid pool phenomenon in an etching operation.

[Explanation of symbols]

1 ... Substrate, 2 ... Conveyor roller, 3 ... Flexible substrate, 4 ... Nozzle, 5 ... Belt conveyor, 6 ... Roller,
7, 7 '... liquid pool, 9 ... climbing inclined belt conveyor, 1
0 ... descending inclined belt conveyor, 11 ... straight roller, 12 ... carry-in conveyor, 13 ... carry-out conveyor, 14 ...
Liquid pool, 15 ... Ring roller.

Claims (11)

[Claims] 1. An etching method for spraying an etching liquid onto a substrate while transporting the substrate, wherein a conveyor direction of the belt conveyor is inclined relative to a horizontal direction, and the substrate is sandwiched by the belt conveyor and rollers. A method for etching a substrate, characterized in that the substrate is attached and conveyed, and an etching solution is sprayed in a direction substantially perpendicular to the surface of the substrate being conveyed. 2. A straight roller is used as the roller, and the direction of the rotation center axis of the straight roller is leveled horizontally and perpendicular to the substrate transport direction. 1. The method for etching a substrate according to 1. 3. The belt conveyor is installed so as to be inclined in an uphill direction, is brought into contact with the upper surface of a substrate being conveyed on the belt conveyor, and a plurality of rollers are arranged so as to be separated from each other. 3. The method for etching a substrate according to claim 2, wherein the etching liquid is sprayed toward a half area on the upper side of the slope in a section sandwiched by the roller and the roller. 4. The belt conveyor is installed so as to be inclined in a descending slope direction, the substrate is attached to the lower surface of the belt conveyor by the surface tension of an etching solution, and the lower surface of the substrate is attached. 2. The roll is arranged so as to be in contact with each other, and the substrate is sandwiched between the roller and the belt conveyor to be conveyed, and the etching liquid is sprayed toward the substrate from below the substrate. Alternatively, the method of etching a substrate according to claim 2. 5. The belt conveyor comprises a plurality of belt conveyors, at least one of the plurality of belt conveyors is provided with a slope in an uphill direction, and at least one of the other belt conveyors is provided. The same board is provided with a slope in the downhill direction, and it passes through both the uphill slope belt conveyor and the downhill slope belt conveyor.When passing the uphill slope belt conveyor, the board is placed on the belt conveyor. While carrying and transporting, the etching liquid is sprayed from above to etch one surface of the substrate, and when passing down the sloped belt conveyor, the substrate is attached to the lower surface of the belt conveyor by the surface tension of the etching liquid. While carrying and transporting the substrate, the etching liquid is sprayed from the lower side to etch the other surface of the substrate, and while transporting the substrate as described above, both surfaces of the substrate are etched. Characterized by quenching, etching method of a substrate according to claim 1. 6. An etching apparatus comprising: a means for transporting a substrate; and a means for spraying an etching liquid onto the substrate being transported, a belt conveyor having a transport direction inclined relative to a horizontal direction, Assuming a plurality of rollers provided at positions almost in contact with the belt conveyor, and a substrate at a position sandwiched between the belt conveyor and the rollers, it is installed toward this virtual substrate. A nozzle, and means for feeding an etching solution to the nozzle,
An etching apparatus comprising: 7. The nozzle is installed substantially perpendicular to the surface of the virtual substrate, or has a structure capable of adjusting an inclination angle with respect to the surface of the substrate, and 7. The etching apparatus according to claim 6, wherein the etching device is vertically adjusted to maintain its posture. 8. The straight roller is a straight roller, and the straight roller has a rotary shaft that is installed so as to be horizontal or has a structure that can be adjusted so as to be horizontal. The direction of the rotation axis of, is installed so as to form a right angle by three-dimensionally intersecting with the conveyance direction of the belt conveyor, or has a structure that can be adjusted to be a right angle. The etching apparatus according to claim 6 or claim 7. 9. The belt conveyor has a structure in which an upper end portion of an endless annular belt moves obliquely upward, and these rollers are provided in a section between the plurality of rollers. 7. The etching apparatus according to claim 6, wherein the nozzle is installed in the vicinity of an upper half area with respect to the inclination of the belt facing the. 10. The belt conveyor has a structure in which a belt of a portion of the endless annular belt stretched downward is moved obliquely downward, and the roller is configured such that “the endless annular belt moves obliquely downward”. 7. The etching apparatus according to claim 6, wherein the etching apparatus is installed below the endless annular belt so as to oppose the "running portion". 11. A plurality of belt conveyors are installed, each belt conveyor comprises a plurality of horizontal pulleys wound with an endless annular belt, and at least one belt conveyor has a plurality of belt conveyors. Is an uphill-shaped conveyor in which the upper half part of the pulley that is wound around the pulley moves diagonally upward, and a plurality of rollers are provided facing the belt of the upper half part, At least one belt conveyor other than the above is a downward slope type conveyor in which the lower half portion that is wound around a plurality of pulleys moves obliquely downward, and the belt of the lower half portion is The etching apparatus according to claim 6, wherein a plurality of rollers are provided so as to face the lower surface.