JPH03255694A - Etching device - Google Patents

Abstract

PURPOSE:To enable an etching solution to be uniformly sprayed against a printed wiring board and the printed wiring board to be uniformly etched and to realize the printed wiring board where a circuits are accurate and uniform in width as prescribed free from excess, shortage, dispersion, error, and defect by a method wherein a spray nozzle which sprays an etching liquid is set at a spraying angle so as to point slightly upward making an angle of a few degrees with a horizontal line to the printed wiring board which is transferred in a vertical position. CONSTITUTION:The spraying angle of a spray nozzle 8 is set and fixed is such a manner that it is set to a spray angle of A1 so as to point slightly upward making an angle of a few degrees with a horizontal direction and also to a spray angle of A2 so as to point slightly forward or rearward to a printed wiring board transfer direction. The spray nozzle 8 is set to the spray angle of A1 so as to point slightly upward making an angle A1 of 5-20 degrees with a horizontal direction when it is observed from the front view point and set to the spray angle of A2 so as to point slightly forward or rearward to the printed wiring board P transfer direction making an angle of A2 of 5-15 degrees with a direction vertical to the printed board P when it is observed from the side view point. The echant 6 is made to flow down on the printed board curving slightly upward and forward or rearward, so that the echant 6 is scarcely localized in flow rate in a vertical direction.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an etching apparatus. That is, the present invention relates to an etching apparatus that performs a circuit forming process by spraying an etchant while transporting a printed wiring board.

"Technical Background" Printed wiring boards have become increasingly dense, complex, and miniaturized in recent years due to advances in the functionality and miniaturization of electronic devices, as well as advances in mounting technology for electronic components mounted on them. As circuits become finer patterns, their surface areas tend to become smaller. For example, the width of circuits formed on printed wiring boards, which used to be about 100μ to 120μ, has become finer and has become smaller than 100μ, reaching about 75μ to 50μ.

By the way, circuits on printed wiring boards are generally formed by spraying a corrosive solution using an etching device, leaving the copper foil portion covered with resist and etching away the other copper foil portions.

"Prior Art" Conventionally, such an etching device is as follows.

FIG. 8 is an explanatory side view of the main parts of a horizontal type etching apparatus that has been widely used in the past. In other words, in this horizontal type etching apparatus, the conveyance rollers 1 of the conveyance mechanism are arranged horizontally, and the printed wiring boards P are conveyed horizontally, that is, laterally, on the conveyance rollers 1, and are arranged one above the other. A corrosive liquid 3 was sprayed onto both surfaces from a large number of spray nozzles 2, and a circuit forming process was performed.

Next, FIG. 9 is an explanatory front view of the main parts of a recently developed conventional vertical etching apparatus. In other words, in this vertical etching apparatus, the printed wiring board 'FiP is sandwiched from both sides by its conveyance mechanism (not shown) and conveyed in a vertical state, that is, in a vertically standing state, while being placed on both the left and right sides. A corrosive liquid 5 is sprayed from a large number of spray nozzles 4.
was sprayed on both sides to form a circuit.

In such conventional horizontal type etching apparatus and contracted type etching apparatus, the spray nozzle 2.
The injection angle of 4 is set perpendicular to the printed wiring board P being transported when fishing by boat, and the spray angle of the corrosive liquid 3.5 is set perpendicular to the printed wiring board P being transported horizontally or vertically. It was being sprayed from all directions. It should be noted that attempts have also been made to make the spray nozzle 2.4 swing back and forth in the transport direction of the printed wiring board P instead of fixing it in a fixed manner.
In this case, the corrosive liquids 3 and 5 were sprayed onto the printed wiring board P sequentially in the front direction, the right angle direction, and the rear direction.

"Problems to be Solved by the Invention" By the way, the following problems have been pointed out in such conventional examples.

First, the general conventional example shown in FIG. 8, that is, the horizontal type enching device, is as follows.

In other words, the corrosive liquid 3 sprayed from the spray nozzle 2 accumulates on the printed wiring board P as a puddle 3', which impedes the uniformity of the spray and the uniformity of etching, thereby reducing the width of the formed circuit. Problems such as excess and deficiency, variations, errors, and defects occurred. Therefore, as mentioned above, a fatal flaw was pointed out that it could not cope with the current state of the printed wiring board P, which is becoming increasingly dense, complex, and miniaturized.

To explain these in detail, when the corrosive liquid 3 is unevenly distributed on the printed wiring board P and a liquid pool 3° is generated, the etching progress rate in that part becomes slower than in other parts. Due to this lack of etching, the necessary corrosion removal of the copper foil is delayed and corrosion removal residue remains, resulting in the phenomenon that the circuit width becomes unreasonably wide and the circuit spacing becomes thin and narrow in the 3" portion of the liquid pool. Therefore, if we wait for such an etching delay and ensure proper circuit spacing in the 3" part of the liquid pool, the circuit width in other parts will become thinner and narrower. In particular, the upper part of the circuit became tapered and was partially missing, making it impossible to secure an appropriate amount of current. This over-etching phenomenon also occurred in other areas other than the liquid pool 3' where etching progressed quickly.

The pool 3' of the corrosive liquid 3 sprayed from the spray nozzle 2 impairs the uniformity of the spray and causes variations in etching, resulting in poor circuit width accuracy and excess/deficiency, variation, and errors.・Defects, etc. had occurred. The occurrence of such a situation has become a fatal problem in terms of reliability in printed wiring boards P whose circuit widths have become smaller than 100 μm due to the progress of fine patterning of circuits. In addition, in such a situation, the spray nozzle 2 should be replaced as described above (
Even if it was not fixed at right angles but allowed to swing back and forth, the fundamental problem was not solved, and the occurrence of liquid pools of 3'' was still noted.

The general conventional example shown in Figure 8, that is, the horizontal type etching device, has already reached its limit in the current situation where finer patterns are becoming more and more sophisticated, and it is difficult to keep up with the progress of higher functionality and miniaturization of electronic devices. I can say that.

Next, the recently developed conventional example shown in FIG. 9, that is, the conventional vertical etching apparatus, is as follows.

That is, in this etching apparatus, the printed wiring board P
was conveyed in a vertical state, and a corrosive liquid 5 was sprayed from spray nozzles 4 arranged at right angles on both sides thereof. Since the corrosive liquid 5 injected there flows down from top to bottom along both sides of the printed wiring board P, the aforementioned liquid pool 3° (see FIG. 8) is no longer generated. In other words, this vertical etching apparatus was developed to solve the problems of the above-mentioned horizontal and horizontal etching apparatus, and eliminates the problem caused by the formation of a liquid pool 3''.

However, with this conventional vertical etching apparatus, the following new problems have been pointed out. That is, since the corrosive liquid 5 flows down both sides of the printed wiring board P in a straight line from top to bottom, the flow rate 5'
The top layer was thinner and the bottom layer was thicker, and from this point on, the uniformity of the spray and the uniformity of the etching were impaired, as described above. That is, on both sides of the printed wiring board P, the flow rate 5'' of the corrosive liquid 5 is unevenly distributed, being thin and small on the top and thick and large on the bottom, and the amount of retention is coarse on the top and dense on the bottom. In the printed wiring board P, etching progresses slowly on the lower side, resulting in a tendency to be insufficiently etched, and conversely, etching progresses quickly on the upper side, resulting in a tendency for over-etching.Thus, the uniformity of the spray is impaired from such surfaces. Variations occurred in the etching, and the circuit width of the printed wiring board P was wide at the bottom and narrow at the top, and the accuracy of the formed circuit width was poor, and excesses and deficiencies, variations, errors, and defects were observed. Incidentally, even if the spray nozzle 4 is oscillated back and forth in the conveyance direction, this situation cannot be fundamentally solved, and it has been pointed out that the uneven distribution of the flow amount 5'' still occurs.

The recently developed conventional example shown in FIG. 9, that is, the conventional vertical etching device, also has problems with reliability as described above.
In the current situation where circuits on printed wiring boards P are increasingly becoming finer patterns, problems have been pointed out.

This point was pointed out in the conventional example.

In view of the above-mentioned circumstances, the present invention was made as a result of the inventor's earnest research efforts in order to solve the problems of the conventional vertical etching apparatus.

According to claims 1 and 2.3, there is provided an etching apparatus in which the spray nozzle has a spray angle set in a predetermined manner, thereby ensuring uniformity in spraying the etching solution onto the printed wiring board and uniformity in etching. The purpose is to make suggestions. Further, in claim 4, the present invention proposes an etching device in which the conveyance mechanism is provided with a predetermined conveyance roller and a lower roller, so that the vertical conveyance of the printed wiring board can be realized more stably. purpose.

"Means for Solving the Problem" The technical means of the present invention to achieve this object are as follows.

This etching apparatus performs a circuit forming process by spraying a corrosive solution while transporting a printed wiring board. The apparatus includes a transport mechanism that vertically transports the printed wiring board, and a large number of spray nozzles that spray corrosive liquid onto the printed wiring board that is transported vertically.

Now, the spray nozzle of the etching apparatus according to claim 1 is configured to spray the printed wiring board conveyed vertically.
The spray angle is slightly upwards from horizontal. The spray nozzle of the etching apparatus according to the second aspect of the present invention is arranged at a spraying angle slightly toward the front or slightly toward the rear of the printed wiring board that is conveyed vertically in the conveying direction. The spray nozzle of the etching apparatus according to claim 3 comprises:
With respect to the printed wiring board that is being transported in a vertical state, the spraying angle is slightly upward from the horizontal and slightly forward or slightly backward in the transport direction.

The transport mechanism of the etching apparatus according to claim 4 includes a number of transport rollers arranged on both sides of the printed wiring board and rotated to nip and transport the printed wiring board, and a plurality of transport rollers that come into contact with the lower end of the printed wiring board to guide it. It is equipped with a large number of lower rollers that are rotationally driven to feed the paper while moving.

"Function" Since the present invention consists of such means, it works as follows.

In this etching apparatus, the printed wiring board is conveyed vertically by a conveyance mechanism, and an etchant is sprayed from spray nozzles on both sides. Then, leaving the copper foil portion covered with the resist, the other copper foil portions are removed due to corrosion, and the circuit formation process proceeds.

At this point, the sprayed corrosive liquid hits both sides of the vertical printed wiring board and flows down from top to bottom along these surfaces, so that no pools of liquid occur.

As a result, spray uniformity and etching uniformity are no longer affected by pools of liquid.

Further, in claim 1, the spray nozzle is oriented slightly upward from horizontal, in claim 2, it is oriented slightly to the front or rear side in the conveying direction, and in claim 3, the spray nozzle is oriented slightly upward from horizontal and slightly to the front or rear side in the conveying direction. Arranged at the injection angle. Therefore, the corrosive liquid draws a unique jet flow on both sides of the printed wiring board, that is, in claim 1, it curves more upwardly, in claim 2, it curves more to the front or rear side, and in claim 3, it curves more diagonally upward and to the front. Or curved backwards, flowing down in jets. Therefore, the flow rate of the corrosive liquid is less unevenly distributed between the top and bottom, and is approximately equalized, and the retention amount is balanced.
There will no longer be large differences in thickness, thickness, or density between the top and bottom. Thus, uniformity of spray and uniformity of etching is achieved.

In the fourth aspect of the present invention, the printed wiring board sandwiched and sent by the conveyance rollers is further guided by a lower roller in contact with the lower end thereof. Printed wiring boards are extremely flexible, but because they are transported vertically, their bottom edges do not get rubbed by frames, etc., and accidents such as bending, deflection, and shaking are prevented, making them extremely stable. transportation is realized.

Embodiment J The present invention will be explained in detail below based on the embodiment shown in the drawings.

FIG. 1 is a front view showing an embodiment of the present invention.

FIGS. 2, 3, and 4 show the spray nozzle, etc., with FIG. 2 being a front view, FIG. 3 being a plan view, and FIG. 4 being a side view. 5 and 6 show the conveyance mechanism, etc., with FIG. 5 being a front view and FIG. 6 being a side view.

First, its configuration will be explained in the order of printed wiring board, etching device and its transport mechanism, spray nozzle, etc.

Regarding printed wiring boards, see below.

On the one hand, the printed wiring board P still has a board thickness of 1.5 mm.
There are plates with a thickness of about
It has reached about 00μ. Furthermore, as mentioned above, the density, complexity, and miniaturization of circuits are increasing, and the formed circuits are becoming finer patterns and their surface areas are also becoming smaller. For example, the circuit width is less than 100μ, ranging from 75μ to about 50μ.

Such a printed wiring board P has a thickness of 3 mm on both sides of an insulating board made of glass epoxy material, polyimide material, etc.
A copper-clad laminate is used, which is laminated with copper foil that is a good electrical conductor and has a thickness of about 5 to 70 μm. First, a developing device exposes the circuit photograph to the photosensitive film attached to the surface of the printed wiring board P, leaving the exposed and hardened photosensitive film part as a resist, and the other film parts are sprayed with a chemical solution. Dissolved and removed. Thereafter, an etching device sprays a copper etchant, leaving the copper foil portions covered with the resist and etching away the other copper foil portions not covered with the resist. Then, the remaining resist is dissolved and removed by spraying a chemical solution using a peeling device, and the resist is dried using a drying device, thereby completing the circuit forming process.

The printed wiring board P has this structure.

Next, the etching device and its transport mechanism will be described.

The etching device conveys the printed wiring board P while
A circuit forming process is performed by injecting the corrosive liquid 6.

As shown in FIG. 1, there is a transport mechanism 7 that transports the printed wiring board P in a vertically vertical state, and a large number of spray nozzles that spray corrosive liquid 6 onto the printed wiring board P that is transported in this vertical state. 8. To explain these in detail, first, the transport mechanism 7 includes a large number of transport rollers 9, which are arranged on both sides of the vertical printed wiring board P, and which are rotated to sandwich and transport the printed wiring board P.
It is equipped with a number of lower rollers 10 which are rotatably driven to abut the lower end of the roller and guide it while feeding it.

That is, as shown in FIG. 1, FIG. 5, and FIG.
The drive of It is designed to be rotationally driven. Reference numeral 15 in FIG. 5 is a frame of such a conveyance mechanism 7, and the frame 15 has vertical shafts 14 rotatably arranged in multiple rows parallel to each other along the conveyance direction at predetermined intervals on the left and right sides. Holds each vertical shaft 1
4, a plurality of conveyance rollers 9 are provided vertically at predetermined intervals. The conveyance roller 9 has a small gap sufficient to sandwich the vertical printed wiring board P, and is entirely covered with opposing films on both left and right sides.

Further, the drive of the conveyor motor 12 described above is also transmitted to a lower roller drive shaft 16 via a shaft, gears, etc. (not shown), and each lower roller 10 is connected to this lower roller drive shaft 16, and is driven in the conveying direction. It is designed to be rotationally driven.

Each of the lower rollers 10 is arranged at a height that contacts the lower end of the printed wiring board P as shown in FIGS. are arranged side by side.

The etching apparatus and its transport mechanism 7 are constructed as described above.

Next, the spray nozzle 8 and the like will be described.

First, as shown in FIG. 1, a liquid tank 17 is provided at the bottom of the chamber 11, in which an aqueous solution of corrosive liquid 6 such as cupric chloride, other ferric chlorides, persulfates, hydrogen peroxide, sulfuric acid, etc. is stored. has been done. The corrosive liquid 6 in the liquid tank 17 is sucked up by a spray pump 18 and guided to each spray nozzle 8 via a branch pipe 19 and a spray pipe 20. As shown in FIG. 1, FIG. 2, FIG. 3, and FIG. 4, the branch pipe 19 is branched to both left and right sides in the middle, and the spray pipe 2 connected to both such branch pipes 19 is
A large number of rollers 0 are vertically disposed outside the vertical shaft 14 and the conveyance roller 9, in parallel with each other at predetermined intervals on the left and right, and along the conveyance direction. A spray nozzle 8 is provided on each of the spray pipes 20 vertically arranged in large numbers in this way, one above the other at the height of each gap between the conveyance rollers 9. The etchant 6 is sprayed onto the printed wiring board P from the spray nozzles 8 arranged in large numbers on both the left and right sides in this way, and the etchant 6 is later collected again into the liquid tank 17 and recycled for circulation.

Now, the spray angle of the corrosive liquid 6 of each spray nozzle 8 is set and fixed as follows.

In other words, in the illustrated example, with respect to the printed wiring board P being conveyed in a vertical state, the spray angle A is slightly upward from the horizontal (see FIGS. 1 and 2), and is slightly forward or slightly forward in the conveying direction. Slightly backward injection angle A! (3rd
(see figure).

First, the spray nozzle 8 has a spray angle A1 of about 5 degrees to about 200 degrees upward from the horizontal when viewed from the front (back).
(see Figures 1 and 2), and from about 5 degrees to 1 degree in the front or rear direction in the conveyance direction from the right angle to the printed wiring board P, which is in a linear state when viewed from the plane (bottom).
The injection angle is set to A2 which is inclined at about 55 degrees (3rd
(see figure).

That is, the spray nozzles 8 in the illustrated example are set at spray angles A1 and A2 that are diagonally upward toward the front side or diagonally upward toward the rear side.

Note that instead of having both of the two conditions as in this illustrated example, it is also conceivable to have only one of the conditions. That is, the spray nozzle 8 is sprayed at a slightly upward spray angle A when viewed from the front (see Figures 1 and 2), and at a spray angle perpendicular to the printed wiring board P when viewed from the plane. You may also set it.

When the spray nozzle 8 is viewed from the front, the spraying angle is horizontal, that is, perpendicular to the printed wiring board P, and when viewed from the plane, the spraying angle is slightly forward or slightly backward in the conveying direction. It may be set to A2 (see FIG. 3).

The spray nozzle 8 and the like are configured as shown above.

The above is the explanation of the configuration, etc.

The operation etc. will be explained below.

In such an etching device, printed wiring board P
The corrosive liquid 6 is sprayed from each spray nozzle 8 on both sides while being conveyed vertically between a large number of conveyance rollers 9 which are rotationally driven by a conveyance mechanism 7. Then, the printed wiring board P leaves the copper foil portion which is the circuit portion covered with the resist, and the other copper foil portions are etched away with the etchant 6, and the circuit forming process proceeds.

Now, in this etching device, the following first
．． Second. Third. The fourth thing (Naru).

First, the injected corrosive liquid 6 hits both sides of the vertically placed printed wiring board P and flows down from top to bottom along these surfaces, resulting in liquid puddles 3 that have been noted in conventional horizontal etching devices. ” (see Figure 8) will no longer occur.

Due to the liquid pool 3', which has been a problem in the past,
The uniformity of the spraying of the etchant 6 and the uniformity of etching are no longer impaired.

Second, the spray nozzle 8 in the illustrated example has a spray angle A1 slightly upward from the horizontal (see FIGS. 1 and 2), and a spray angle A2 that is slightly forward or slightly backward in the conveying direction. (See Figure 3). Therefore, the corrosive liquid 6 flows down both sides of the printed wiring board P in a unique jet stream, that is, in a jet stream that is curved slightly upward and forward or slightly upward and backward compared to the conventional case. Therefore, the flow rate of the corrosive liquid 6 is less unevenly distributed in the upper and lower portions, and is approximately equalized.
The amount of retention is balanced, and there is no longer a large difference in thickness or thickness or density between the top and bottom.

Thus, uniformity of spray and uniformity of etching is achieved.

For example, FIG. 7 is an enlarged front sectional view of the circuit portion Pl of the printed wiring board P. Figure (1) shows a circuit formed by an etching apparatus according to the present invention, and figure (2) shows a circuit formed by a conventional horizontal etching apparatus. ,(3)
The figure shows an ideal state of the circuit formation process. In the example of FIG. 7, (3) the circuit width B of the circuit portion P of the ideal shape in FIG.
(1) As shown in the figure, in the present invention, 39μ
Therefore, a circuit width B2 of about 45 μm can be formed, which is relatively close to the ideal circuit width B1, and the circuit width B2 can be made uniform with high accuracy. On the other hand, as shown in FIG. 2 (2), there is a portion B with a circuit width of about 14μ in the conventional example, which is far from the ideal circuit width B1, and an appropriate amount of current cannot be secured. In the figure, P2 is an insulating plate of the printed wiring board P, and C is the circuit height, which is about 70 μm, for example. In addition, in the example shown in FIG. 7, the temperature is 50 degrees,
Based on the results under conditions such as a spray pressure of 1.8 kg/cJ and a printed wiring board P size of 400 mm x 500 mm.

Thirdly, even if the spray nozzle 8 is employed only at a slightly upward spray angle A, or a slightly forward or slightly rearward spray angle A2, the above-mentioned method can also be used, regardless of the illustrated example. The operation is similar to that described in the second section. That is, in these cases as well, the injected corrosive liquid 6 flows down both sides of the printed wiring board P in a unique jet stream, that is, as a jet stream curved upward, or curved to the front or back side, compared to the conventional case. Accordingly, uniformity of spraying and uniformity of etching can be achieved in accordance with the second point mentioned above.

Fourthly, the printed wiring board P which is sandwiched and sent by the transport rollers 9 of the transport mechanism 7 is further placed at the lower end by a lower roller 10.
is brought into contact with and guided.

Therefore, although the printed wiring board P has become extremely thin and extremely flexible, since it is transported vertically, the bottom edge will not be rubbed by the frame, etc., and its bending, deflection, shaking, etc. Accidents are also prevented and extremely stable vertical transport is achieved.

The above is the explanation of the operation, etc.

[Effects of the Invention] As explained above, the etching apparatus according to claims 1 and 2.3 of the present invention exhibits the following effects by setting the spray angle of the spray nozzle in a predetermined manner.

In other words, the uniformity of the etchant spray on the printed wiring board and the uniformity of the etching are reliably achieved, so the width of the formed circuit can be precisely uniformized to a predetermined width without excess or deficiency, variations, errors, defects, etc. be done. Therefore, the reliability of the printed wiring board is dramatically improved, an appropriate amount of current is ensured after the fact, and short circuits and the like are avoided. Therefore, it is possible to fully cope with the current state of printed wiring boards, where circuits are becoming finer patterns as the density, complexity, and miniaturization progress, and furthermore, it becomes possible to easily cope with the progress of higher functionality and miniaturization of electronic devices.

Further, in the etching apparatus according to claim 4, the conveyance mechanism includes a predetermined conveyance roller and a lower roller, so that
Vertical conveyance of printed wiring boards can be realized more stably. Therefore, the circuit formation process is ensured, and the width of the circuit formed from this side is made uniform with high precision without excess or deficiency, variation, error, or defect, and the reliability of the printed wiring board is improved as described above. It becomes possible to sufficiently and easily correspond to fine patterning, etc.

In this way, the problems that existed in this type of conventional example are completely eliminated, and the effects of the present invention are remarkable and great.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of an etching apparatus according to the present invention. 2, 3, and 4 show the main parts of the spray nozzle, etc., with FIG. 2 being a front view, FIG. 3 being a plan view, and FIG. 4 being a side view. 5 and 6 show main parts such as the conveyance mechanism, and FIG. 5 is a front view and FIG. 6 is a side view. FIG. 7 is an enlarged front sectional view of the printed wiring board. Figure (1) shows a circuit formed by an etching apparatus according to the present invention, and figure (2) shows a circuit formed by a conventional horizontal etching apparatus. , (3) shows an ideal state of the circuit formation process. FIG. 8 shows a conventional horizontal etching device.
It is a side explanatory view of important parts. FIG. 9 is an explanatory front view of the main parts of a conventional vertical etching apparatus. 6... Corrosive liquid 7... Conveyance mechanism 1 8... Spray nozzle 9... Conveyance roller 0... Lower roller A, Spray angle A, Spray angle P... printed wiring board

Claims (4)

[Claims] (1) An etching apparatus that performs a circuit forming process by spraying an etchant while transporting a printed wiring board, which comprises a transport mechanism that transports the printed wiring board vertically, and a printed wiring board that is transported vertically. 1. An etching apparatus comprising a number of spray nozzles which are arranged at a spray angle slightly upward from horizontal and spray a corrosive liquid onto a wiring board. (2) An etching apparatus that performs a circuit forming process by spraying a corrosive solution while transporting a printed wiring board, which comprises: a transport mechanism that transports the printed wiring board in a vertical state; and a transport mechanism that transports the printed wiring board in a vertical state; An etching apparatus comprising: a large number of spray nozzles that spray a corrosive liquid onto a wiring board, the spray nozzles being arranged at spray angles slightly forward or slightly backward in the direction of transport of the wiring board. (3) An etching apparatus that performs a circuit forming process by spraying a corrosive solution while transporting a printed wiring board, which comprises: a transport mechanism that transports the printed wiring board in a vertical state; and a transport mechanism that transports the printed wiring board in a vertical state; It is characterized by having a large number of spray nozzles that are arranged at a spray angle slightly upward from horizontal to the wiring board and slightly forward or slightly backward in the direction of conveyance of the wiring board, and spray a corrosive liquid. Etching equipment. (4) An etching apparatus that performs a circuit forming process by spraying a corrosive solution while transporting a printed wiring board, which comprises: a transport mechanism that transports the printed wiring board in a vertical state; and a transport mechanism that transports the printed wiring board in a vertical state; The transport mechanism includes a large number of spray nozzles that spray corrosive liquid onto the printed wiring board, and the transport mechanism includes a large number of transport rollers that are arranged on both sides of the printed wiring board and are driven to rotate so as to nip and transport the printed wiring board. An etching apparatus comprising: a plurality of lower rollers that are rotatably driven to contact the lower end of the printed wiring board and guide and feed the printed wiring board.