JP2005200684A - Etching method and etching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an etching device where an etching rate is uniformized to a substrate for wiring, thus the narrowing of pitches in a conductor and its cross-section with a rectangular shape are realized, and, in its turn, a conductor pattern corresponding to high precision and high frequency can be formed. <P>SOLUTION: The etching device 1 is composed of a drum 2, a chamber 10, a nozzle head 4 or the like. The drum 2 has a composition where a flexible delivery board 3 is wound round a drum face 2a so as to be rotated and carried. The chamber 10 is a chamber storing an etching liquid 5 under fixed pressure. The nozzle head 4 is arranged at a position close to the drum face 2a in the upper part of the chamber 10, and is composed in such a manner that the etching liquid 5 pressurized in the chamber 10 is jetted rectilinearily to the drum face 2a from a nozzle hole 40. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an etching method and an etching apparatus for wet-etching a wiring substrate when a conductor pattern is formed on a flexible wiring substrate, and more particularly to a technique for injecting an etching solution onto the wiring substrate.

  In recent years, for example, as shown in FIG. 7A, in a flexible wiring board used for a mounting method such as COF or TAB, the pitch of conductors 3a has been reduced, and line / space = 15/15 μm or less high accuracy. In addition, since the conductor resistance becomes important as the frequency of the signal increases, it is required that the cross-sectional shape of the conductor 3a is not only a narrow pitch but also a rectangle.

  In general, when a subtractive method is employed in forming a flexible wiring board having a conductor pattern using the flexible wiring board 3, an etching resist is applied to the copper foil 3a laminated on an insulating film 3b such as polyimide. After applying 3c, development is performed through a predetermined pattern, and the exposed copper foil 3a is removed by etching. And, in order to realize a narrow pitch and a rectangular cross-sectional shape for the conductor 3a of the substrate 3 for flexible wiring, in all steps such as material, pretreatment (cleaning treatment), etching resist, exposure, etching, Although measures to improve accuracy are necessary, measures in the etching process are particularly important.

By the way, conventionally, as shown in FIG. 6 (only the upper side etching is shown), in the etching process, the flexible wiring board 3 to be horizontally transported is located at an upper and lower position about 50 to 200 mm apart, respectively. The spray nozzle 100 is disposed, and the etching solution 5 is sprayed in a fan shape or a cone shape from the spray nozzle 100 so as to be etched over a wide range (for example, see Patent Document 1).
Further, in order to avoid the phenomenon that the etching solution 5 accumulates on the flexible wiring board 3, the etching solution 5 may be sprayed only from the lower spray nozzle 100 (see, for example, Patent Document 2).

  On the other hand, Patent Document 3 describes an electrolytic etching method in which an edge of a metal strip is not etched by masking. In this electrolytic etching, a main roll and an electrode having a semicircular cross section are immersed in an electrolytic cell filled with an electrolytic solution, and a metal strip having a masking tape in between is immersed in the electrolytic solution. Yes.

JP-A-7-150370 JP 2003-55779 A JP-A-8-209400

However, the conventional etching described above has the following problems.
In the etching as shown in Patent Documents 1 and 2, in the upper etching, the flexible wiring board 3 is bent by the striking force of the spray liquid or the weight of the etching liquid 5 accumulated on the upper surface, and the bending is performed. There is a problem that the spray liquid does not hit the normal portion at a normal angle, and there is a problem that the etching liquid 5 accumulates in the bent portion and the new spray liquid does not hit (see FIG. 6). However, since the spray liquid does not hit the portion bent by the striking force of the spray liquid at a normal angle, there is a problem similar to the above even if there is a difference in degree from the etching on the upper side.

Such a problem of the liquid pool or the spray angle of the spray liquid is caused by the portion of the conductor 3a that is etched early (see FIG. 7C) and the portion of the conductor 3a that is etched late (see FIG. 7). 7 (b)), and consequently, the width and cross-sectional shape of the conductor 3a are varied.
On the other hand, generally, a liquid pool is likely to occur in the central portion of the width of the flexible wiring board 3, and the etching rate of the central portion of the width tends to be slower than that of the edge portion. However, it is difficult to make the etching rate uniform on the surface of the flexible wiring board 3, and even if the flexible wiring is used, the arrangement of the spray nozzle 100 and the spray pressure are adjusted. Even if the substrate 3 does not bend, due to the characteristics of the spray nozzle 100, the spray liquid spreads in a fan shape or a conical shape and there is a difference in the striking force. Therefore, variations in the width and cross-sectional shape of the conductor 3a are fundamental. It has not been resolved.

  As described above, the etching of the flexible wiring substrate 3 has a phenomenon in which the etching rate is partially different due to the difference in the striking force and angle of the spray liquid, the bending of the flexible wiring substrate 3 and the like. As a countermeasure against such a phenomenon, conventionally, the etching rate is determined based on the portion of the conductor 3a that is etched the latest, and as a result, the portion of the conductor 3a that is etched earlier is over-etched. There was a situation where 3a was thinned (see FIG. 7C).

  On the other hand, when the electrolytic etching method shown in Patent Document 3 is applied to the etching of the flexible wiring substrate 3, the conductor 3a is obtained by immersing the flexible wiring substrate 3 wound around the main roll in the etching solution 5. However, it is impossible to obtain a rapid etching effect by the striking force of the spray liquid, and the etching liquid 5 has no etching direction, so that the cross section of the conductor 3a is rectangular. Cannot be realized.

  Accordingly, an object of the present invention is to realize an etching method and an etching capable of forming a conductor pattern with a narrow pitch and a rectangular cross section by making the etching rate uniform with respect to the wiring substrate, and thus forming a highly accurate and high frequency conductor pattern. To provide an apparatus.

  The present invention is a method of etching a traveling wiring board by spraying an etching solution, and while the drum is rotated, the wiring board is transported while being wound around the outer drum surface, and the wiring board is on the drum surface. An etching method characterized in that the etching solution is sprayed linearly from a position close to the drum surface with respect to the wiring substrate, and the wiring substrate that the drum is wound around the outer drum surface is rotated and conveyed. An etching apparatus in which a nozzle head sprays an etchant onto the wiring substrate on the drum surface, the nozzle head being disposed at a position close to the drum surface, The etching apparatus is characterized in that a plurality of nozzle holes are provided so as to spray the etching solution linearly on the drum surface. It is obtained by achieving the above objects by.

  “Etching rate” in the present application means a reaction rate for etching and removing a conductor that is not coated with an etching resist on the surface of the wiring substrate, and the case where the cross-sectional shape of the conductor is rectangular is used as a reference. A case where the conductor width is large and the conductor is thick is referred to as “low etching speed”, and a case where the conductor width is small and the conductor is thin is referred to as “high etching speed”.

  According to the present invention, by winding the wiring substrate around the drum and transporting the wiring substrate, the wiring substrate that has received a striking force from the etching solution is supported on the drum surface, and the bending of the wiring substrate can be eliminated. Further, the straightness of the etching solution and a constant striking force can be ensured by spraying the etching solution linearly from a position close to the drum surface to the wiring substrate on the drum surface. Then, by eliminating the bending of the wiring substrate and ensuring the straightness of the etching solution and ensuring a constant striking force, it is possible to make the etching rate uniform in the wiring substrate and to narrow the conductor pitch and to make the cross section rectangular. it can.

Hereinafter, a most preferred embodiment (first embodiment) of an etching apparatus and an etching method of the present invention will be described in detail.
As shown in FIG. 1 or FIG. 2, the etching apparatus 1 of this embodiment (first embodiment) has a nozzle head 4 adjacent to a flexible wiring substrate (wiring substrate) 3 wound around a drum 2. The etching solution 5 is sprayed in a straight line.
Such an etching apparatus 1 is applied to an etching process among the processes of a subtractive method for forming a conductor pattern on a flexible wiring board 3. It is installed in the processing chamber 6. Details of the etching apparatus 1 will be specifically described.

As shown in FIG. 1 or FIG. 2, the etching apparatus 1 includes a drum 2, a chamber 10, a nozzle head 4, a pump 11, and the like.
The drum 2 is a cylindrical roller having a drum surface 2a formed on its outer peripheral surface, and the flexible wiring substrate 3 between the upstream first roller 12 and the downstream second roller 13 is The drum surface 2a is wound around and rotated and conveyed.

  Here, the etching chamber 6 is connected between the first cleaning chamber 15 having the first tension roller row 14 and the second cleaning chamber 17 having the second tension roller row 16 in the front-rear direction. The first and second tension roller rows 14 and 16 are speed-controlled so as to convey the flexible wiring board 3 at a constant tension and a constant speed.

  The drum 2 is driven and controlled so as to have the same peripheral speed as that of the flexible wiring board 3 between the first and second tension roller rows 14 and 16. Note that the drum 2 may be configured so as to reduce resistance such as rotation and rotate with the flexible wiring board 3.

The chamber 10 is a chamber for storing the etching solution 5 and is disposed below the drum 2. A pump 11 is connected to the side wall of the chamber 10 via a duct 18, a valve 19, and the like. The pump 11 is configured so that the etching solution 5 is pressurized and transported into the chamber 10 and adjusted under a certain pressure.
An upper wall portion 10a is formed in a concave shape at the upper portion of the chamber 10, and the upper wall portion 10a is disposed opposite to the drum surface 2a. In this case, the drum 2 is arranged such that the upper substantially semi-cylindrical portion is exposed from the chamber 10 and the lower substantially semi-cylindrical portion is buried in the chamber 10.

  The upper wall portion 10a has a concavo-convex shape substantially along the outer peripheral direction of the drum 2, and the convex nozzle mounting portion 10b extends in a normal direction of the drum surface 2a (a direction toward the center line of the drum). A plurality of drums 2 are arranged at regular intervals in the outer circumferential direction of the drum 2. This nozzle mounting portion 10b is formed in a cylindrical shape having a rectangular cross section, and its upper side is open. The recess formed between the nozzle mounting portions 10b and 10b adjacent to each other functions as a waste liquid path for the etching solution 5.

  The nozzle head 4 is attached to the opening of the nozzle attachment portion 10b so as to be attachable by screws or the like. The nozzle head 4 linearly etches the etching solution 5 pressurized in the chamber 10 in a state facing the drum surface 2a at a constant region and a constant interval in the circumferential direction of the drum 2. Injecting, it is formed in the shape of a rectangular lid so as to cover the opening of the nozzle mounting portion 10b.

  When the nozzle head 4 is mounted on the nozzle mounting portion 10b, the nozzle head 4 is disposed at a position close to the drum surface 2a, and the interval d between the nozzle surface 4a and the drum surface 2a is set to about 1 to 10 mm. ing. If the distance d is smaller than 1 mm, the etchant 5 that has bounced off the flexible wiring substrate 3 may adversely affect the straightness of the etchant 5 from the nozzle hole 40. If the distance d exceeds 10 mm, There is a possibility that the straightness of the etching solution 5 cannot be maintained.

  A plurality of nozzle holes 40 are formed in the nozzle head 4 so as to penetrate in the substantially normal direction of the drum surface 2a. Here, the penetrating direction of the nozzle hole 40 is equal to the normal direction of the nozzle surface 4a. Strictly speaking, there is a nozzle hole 40 that is not equal to the normal direction of the drum surface 2a, but the error is slight. This does not affect the straightness of the etching solution 5 from the nozzle hole 40 (see FIG. 2).

As shown in FIG. 2, a pressure adjusting plate 21 is attached to the inlet portion of the nozzle attachment portion 10b. The pressure adjusting plate 21 uniformly adjusts the pressure of the etching solution 5 in each nozzle mounting portion 10b when the etching solution 5 in the chamber 10 flows into each nozzle mounting portion 10b. The pressure adjustment plate 21 is formed in a plate-like body that closes the inlet of the nozzle attachment portion 10b, and the amount of the etching solution 5 that flows into the nozzle attachment portion 10b is controlled by the adjustment hole 22 that opens in the plate-like body. doing.
Thereby, the nozzle hole 40 injects the etching liquid 5 with a uniform pressure irrespective of the position of the nozzle attachment part 10b.

Next, details of the shape and the like of the nozzle hole 40 will be described together with a method for controlling the etching rate from the relationship with the nozzle hole 40 and the like.
As shown in FIGS. 3A and 3B, the nozzle head 4 includes a type in which the nozzle holes 40 are slit-shaped and a type in which the nozzle holes 40 are circular.
As shown in FIG. 3A, the slit-like nozzle hole 40 has a plurality of slit holes extending in the generatrix direction A of the drum surface 2a (equal to the width direction A of the flexible wiring board 3 on the nozzle surface 4a). 41. The slit hole 41 preferably has a slit width W of 0.1 to 1 mm, a gap C of 3 to 10 mm, and a number of slits of 3 to 10. The slit width W, the gap C, and the number of slits are set such that the nozzle pressure (for example, 200 kPa) and the flow rate of the etching solution 5 (for example, 20 m / s) when the etching rate is set to the “reference etching rate” in which the cross-sectional shape of the conductor is rectangular. ) And the like are control factors for determining the optimum value.

  The nozzle head 4 having such slit holes 41 is mainly used when the conductors of the flexible wiring substrate 3 are all etched in the width direction A at a uniform etching rate.

As shown in FIG. 3B, the circular nozzle hole 40 is a plurality of circular holes 42 centering on the substantially normal direction of the drum surface 2a (actually, the normal direction of the nozzle surface 4a). . The circular hole 42 preferably has a circular hole diameter φD of 0.1 to 1 mm. The number of round holes varies depending on the width of the flexible wiring board 3, but is about 10 to 50.
As in the case of the slit hole 41, such a circular hole diameter φD and the number of circular holes are controlled so as to set the nozzle pressure, the flow rate of the etching solution, etc. to optimum values when the etching rate is set to the “reference etching rate”. Become a factor.

  The nozzle head 4 having such a circular hole 42 is also used when all the conductors of the flexible wiring board 3 are etched at a uniform etching rate in the width direction. It is effective when there is a difference.

  For example, in the flexible wiring board 3 where the conductor thickness in the width center portion is large and the conductor thickness in the edge portion is small with respect to the reference conductor thickness at the “reference etching rate”, the width center portion and the edge portion It is necessary to perform etching at the same “reference etching rate” as a whole while controlling the etching rate.

Specifically, the central hole in the circumferential direction B of the drum 2 (equal to the conveyance direction B of the flexible wiring board on the nozzle surface 4a) with respect to the reference circular hole diameter φD and the number of reference circular holes at the “reference etching rate”. In the column 42a, the circular hole diameter φD1 is decreased, the number of circular holes is increased, and the nozzle pressure and the total flow rate of the etching solution 5 per unit time are increased. Further, in the edge hole row 42b in the circumferential direction B of the drum 2, the circular hole diameter φD2 is increased and the number of circular holes is decreased, thereby reducing the nozzle pressure and the total flow rate of the etching solution 5 per unit time.
As described above, the etching rate in the width direction A can be controlled by changing the slit width W and the gap C of the nozzle head 4 having the slit holes 41 as described above.

On the other hand, the control of the etching rate in the transport direction B can be realized by changing the number of slits or the like, or changing the number of hole rows in the generatrix direction A of the drum surface 2a, and changing the number of nozzle heads 4 attached. Further, it can be realized by changing the number of installed etching apparatuses 1 themselves.
When the etching rate in the transport direction B is slowed down, control factors such as the number of slits, the number of holes and the number of nozzle heads 4 are reduced, and when the etching rate in the transport direction B is fast, the control factor In addition, the number of the etching apparatuses 1 installed is increased. The opening of the nozzle mounting portion 10b from which the nozzle head 4 is removed is blocked by a shielding plate (not shown).
When the etching rate is controlled in a composite manner in both the width direction A and the transport direction B, the control factors such as the slit width W and the gap C, the number of circular holes, the number of nozzle heads 4 attached, etc. Adjust by combination.

Next, how the etching apparatus 1 of this embodiment is used will be described together with the etching method of this embodiment.
The flexible wiring board 3 is moved with the surface to be etched facing downward, and is conveyed above the upper wall portion 10 a of the chamber 10 while being wound around the drum surface 2 a of the rotating drum 2. On the other hand, the pump 11 is operated to pressurize the etching solution 5 at a constant pressure while flowing into the chamber 10, and the etching solution 5 is sprayed from the nozzle hole 40 of the nozzle head 4 at a uniform pressure. In this case, the etching solution 5 continues to be sprayed linearly along the normal direction of the drum surface 2a.

Then, an etching solution 5 having a constant striking force (pressure) is applied to the conductor surface of the flexible wiring board 3 in the vertical direction from the proximity position. If such etching is continued, in the flexible wiring board 3, the conductor that is not coated with the etching resist always receives the etching solution from the normal direction of the conductor surface and dissolves, so that it is coated with the etching resist. The conductor has a rectangular cross section (see FIG. 7A). Since the etching rate is uniform on the flexible wiring substrate 3 by controlling the etching rates in the width direction A and the conveyance direction B described above, in the flexible wiring substrate 3 that has passed through one or a plurality of chambers 10. The conductor cross section is all rectangular. Further, under the situation where the etching solution 5 is sprayed in a straight line with a constant striking force from the proximity position, the uniform rectangular cross section of the conductor is performed without being affected by the size of the conductor pitch.
On the other hand, during such an etching process, the flexible wiring substrate 3 is supported by the drum surface 2 a by the drum 2, so that it does not bend even when subjected to the striking force of the etching solution 5.

  When etching on both sides of the flexible wiring board 3, after the cleaning process is performed on the flexible wiring board 3 on which the single-sided etching process has been completed, the flexible wiring board 3 is reversed and the lower surface thereof is etched again. Apply.

  As described above, according to the present embodiment, the etching solution 5 is sprayed linearly with a constant striking force from the proximity position to the flexible wiring substrate 3 wound around the drum surface 2a. In addition to eliminating the bending of the flexible wiring board 3, it is possible to ensure the straightness of the etching solution 5 and a constant hitting force. As a result, it is possible to make the etching rate uniform within the plane of the flexible wiring substrate 3, to realize a narrow pitch and a rectangular cross section of the conductor, and to form a highly accurate and high frequency conductor pattern. .

Further, according to the present embodiment, a plurality of nozzle head 4 mounting positions are arranged along the drum surface 2a in the outer circumferential direction of the drum 2, and the nozzle head 4 can be mounted at each mounting position. The etching rate in the transport direction B can be controlled by attaching and detaching or exchanging.
In particular, the nozzle head 4 is divided into a slit hole 41 type and a circular hole 42 type and can be exchanged with each other. Control factors such as the slit width W and the number of slits, the circular hole diameter φD, and the number of circular holes, respectively. By adjusting the control factors such as the above, it is possible to etch at a uniform etching rate even for conductors having a difference in thickness in the plane by controlling not only the conveyance direction B but also the etching rate in the width direction A. .

  Furthermore, according to this embodiment, since the etching solution 5 in the chamber 10 is pressurized at a constant pressure, the etching solution 5 is sprayed at a uniform pressure to give a uniform striking force to the flexible wiring board 3. be able to.

  Furthermore, according to this embodiment, since the flexible wiring board 3 is wound around the drum 2 and transported, the space occupied in such a transport line can be reduced as compared with the case of a straight transport line. Therefore, it is possible to reduce the size of the device itself.

Hereinafter, another preferred embodiment (second embodiment) of the etching apparatus of the present invention will be described in detail.
As shown in FIG. 4, in the etching apparatus 1A of the present embodiment (second embodiment), the upper wall portion of the chamber and the nozzle head are different from those of the first embodiment, and this point is mainly described. The same components are denoted by the same reference numerals and the description thereof is omitted.

In the case of this embodiment, the nozzle head 4 </ b> A forms the upper wall portion 10 a ₁ of the chamber 10, and a concave curved surface equal to the curvature of the drum surface 2 a is formed so as to be continuously integrated in the circumferential direction of the drum 2. Yes. The nozzle head 4A is formed with a plurality of nozzle holes 40 penetrating in the normal direction of the drum surface 2a. Unlike the case of the first embodiment, all the penetrating directions of the nozzle holes 40 are equal to the normal direction of the drum surface 2a.

  A plurality of shielding plates (not shown) are mounted on the inner wall surface of the nozzle head 4a. The shielding plate serves to control the etching rate in the transport direction B by shielding the nozzle holes 40 at a constant region and a constant interval in the circumferential direction of the drum 2. In addition, with respect to the nozzle hole 40, the control of the etching rate in the transport direction B and the width direction A is the same as in the first embodiment.

According to the present embodiment, the nozzle head 4A has a concave curved surface shape equal to the curvature of the drum surface 2a, and the penetrating directions of the nozzle holes 40 are all equal to the normal direction of the drum surface 2a. Since the etching liquid can be sprayed on the conductor on the substrate 3 from the normal direction of the conductor surface, the conductor can be narrowed in pitch and rectangular in cross section with higher accuracy.
Other configurations and operational effects are the same as those of the first embodiment.

Hereinafter, another preferred embodiment (third embodiment) of the etching apparatus of the present invention will be described in detail.
As shown in FIG. 5, in the etching apparatus 1B of the present embodiment (the third embodiment), the upper wall 10a ₂ and the nozzle head 4B of the chamber 10, the first, is different from the second embodiment, This point will be mainly described, and the same components are denoted by the same reference numerals and the description thereof will be omitted.

In this embodiment, the upper wall portion 10a ₂ of the chamber 10, is in that it is generally along the uneven shape in the outer circumferential direction of the drum 2, is similar to the above-described first embodiment, the nozzle mounting portion 10b ₂ The difference is that the upper edge portion has an opening shape in contact with the concave curved surface.
The nozzle head 4B is the same as the first embodiment in that the nozzle head 4B faces the drum surface 2a at a constant region and a constant interval in the circumferential direction of the drum 2, but has a concave curved surface shape equal to the curvature of the drum surface 2a. It is the same as the second embodiment in that it is formed.
Note that the inlet portion of the nozzle mounting portion 10b _2, is attached a pressure adjusting plate 21B, the pressure adjusting plate 21B is the first in that it is formed in a concave curved surface equal to the curvature of the drum surface 2a 1 It is different from the embodiment.

As described above, according to the present embodiment, it is more advantageous than the first embodiment in that the etching liquid 5 can be sprayed from the normal direction of the conductor surface to the conductor on the flexible wiring board 3 at all times. It is more advantageous than the second embodiment in that the etching rate in the transport direction B can be controlled by attaching and detaching or replacing the nozzle head 4B.
Other configurations and operational effects are the same as those of the first and second embodiments.

The present invention is not limited to the above-described embodiment, and various changes can be made.
In the first embodiment, all the penetrating directions of the nozzle holes may be matched with the normal direction of the drum surface.
In the second embodiment, the nozzle head may be configured as an upper wall that can be attached to and detached from the upper portion of the chamber.
In the first to third embodiments, a plurality of nozzle mounting portions may be disposed in the drum bus direction, and the etching rate in the width direction may be controlled by adjusting the number of nozzle heads mounted.
In the first to third embodiments, a shutter mechanism using an electromagnetic valve may be applied to the nozzle holes of the nozzle head and the adjustment holes of the pressure adjustment plate to automatically control the etching rate and the nozzle pressure.

  In the first to third embodiments, the drum may have a double structure including an inner cylindrical portion for injecting the etching liquid and an outer cylindrical portion for rotating and conveying the flexible wiring substrate. In this case, in the inner cylindrical portion, a plurality of nozzle holes similar to those described above are formed on the outer peripheral surface, and the etching solution stored inside is injected from the nozzle holes by the pump pressure. Further, in the outer cylindrical portion, a plurality of passage holes that do not overlap with the nozzle holes of the nozzle head are formed on the outer peripheral surface thereof, and the etching liquid from the inner cylindrical portion is passed through the one surface of the flexible wiring substrate from the passage holes. And the other surface that has received the etching solution from the nozzle head is supported. Such a double-structured drum has the advantage that it can be etched on both sides in a single process.

It is a front view which shows schematic structure of the etching process chamber containing the etching apparatus of 1st Embodiment. It is front sectional drawing which expands and shows the drum and nozzle head of the P section of FIG. (A): It is a top view which shows the nozzle surface of the nozzle head (slit type) of 1st Embodiment. (B): It is a top view which shows the nozzle surface of the nozzle head (porous type) of 1st Embodiment. It is a front view which shows schematic structure of the etching apparatus of 2nd Embodiment. It is front sectional drawing which expands and shows the drum and nozzle head in the etching apparatus of 3rd Embodiment. It is a figure which shows schematic structure of the conventional etching apparatus. (A): It is a figure which shows the state where the cross section of a conductor is a rectangle under the condition of a normal etching rate. (B): It is a figure which shows the state where the conductor cross section was thick under the condition of slow etching rate. (C): It is a figure which shows the state where the conductor cross section was thin under the condition of the high etching rate.

Explanation of symbols

2 Drum 2a Drum surface 3 Flexible wiring board (wiring board)
4, 4A, 4B Nozzle head 40 Nozzle hole 41 Slit hole (nozzle hole)
42 Circular hole (nozzle hole)
5 Etching solution 10 Chamber

Claims (9)

A method of etching a traveling wiring board by spraying an etching solution,
While rotating the drum, the wiring substrate is transported while being wound around the outer drum surface, and the etching solution is sprayed linearly from the position close to the drum surface onto the wiring substrate on the drum surface. Etching method characterized by performing.   2. The etching method according to claim 1, wherein the spraying position of the etching solution is brought close to a position 1 to 10 mm away from the drum surface.   A plurality of the etching liquid injection positions are arranged along the drum surface in the outer circumferential direction of the drum, and the number of the etching liquid injection positions or the size of the etching liquid injection holes is increased or decreased according to the etching rate. The etching method according to claim 1, wherein the etching method is performed. An etching apparatus in which a drum rotates and conveys a wiring substrate wound around an outer drum surface, and a nozzle head sprays an etching solution onto the wiring substrate on the drum surface,
The nozzle head is disposed at a position close to the drum surface, and the nozzle head is provided with a plurality of nozzle holes so that the etching liquid is sprayed linearly onto the drum surface. An etching apparatus characterized by comprising:   The etching apparatus according to claim 4, wherein the nozzle hole is formed in a slit shape extending substantially in the generatrix direction of the drum surface, and the slit width or the number of slits is set according to the etching rate.   5. The etching according to claim 4, wherein the nozzle hole is formed in a circular shape centering on a substantially normal direction of the drum surface, and the nozzle diameter or the number of nozzles is set according to the etching rate. apparatus. A chamber in which the etching solution is stored is disposed outside the drum, and an upper wall portion facing the drum surface is formed in a concave shape in the upper portion of the chamber.
The etching apparatus according to claim 4, wherein the nozzle head is configured to be attachable to a plurality of portions of the upper wall portion.   The etching apparatus according to claim 7, wherein the nozzle head is configured to inject the etching solution by adjusting a pressure in the chamber.   The etching apparatus according to claim 4, wherein the nozzle head is formed in a concave curved surface shape that is substantially equal to a curvature of the drum surface.

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