JPH0770819B2 - Cleaning equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a cleaning device. That is, it is used in the manufacturing process of printed wiring boards,
The present invention relates to a cleaning device for cleaning through holes on a printed wiring board.

[0002]

2. Description of the Related Art A printed wiring board is often provided with a large number of through holes, which are through holes having a small diameter, by a drill for electrical connection of circuits on both front and back surfaces or for mounting parts.
In the process of manufacturing a printed wiring board, such through-holes are frequently washed. Conventionally, a high-pressure washing system has been used as such a washing device. That is, this conventional cleaning device is of a type in which a cleaning liquid is sprayed toward a printed wiring board by a nozzle in air at a pressure of 50 kg / cm ² or more, and the cleaning liquid is allowed to pass therethrough to clean through holes.

By the way, the following problems have been pointed out in the conventional high-pressure cleaning type through-hole cleaning device. That is, as for the through hole of the printed wiring board, first, due to the recent miniaturization and densification of the circuit, it is overwhelming that the hole diameter is extremely small from 0.2 mm to 0.5 mm. 2, one printed wiring board, for example 1
An extremely large number of about 000 are formed, and thirdly, they are scattered and distributed in an unspecified and irregular manner. Fourth, on the other hand, the thickness of the printed wiring board is, for example, about 1.6 mm, which is several to ten times as large as the diameter of the through hole (that is, the shape of the through hole is extremely slender), and fifth. Since the cleaning liquid sprayed from the nozzle also hits the printed wiring board surface other than the through hole, the pressure for passing through the through hole is weakened. These first, second, third, fourth
According to the fifth and the like, it has recently become particularly difficult to sufficiently and surely clean long and slender through holes that are extremely small in diameter and scattered in large numbers. Therefore, in this conventional high-pressure cleaning type cleaning device, drill burrs, cutting waste,
Cutting chips, and further, resist deposits, oxidation spots, copper foil stains, other foreign substances adhering to the inner wall, etc., remain without being removed by washing, and therefore after-hole through-hole plating and soldering for component mounting It was a cause of such defects.

In view of such circumstances, the inventor recently newly developed the following through-hole cleaning device. That is, in this recently developed cleaning device, the printed wiring board is conveyed by the roller conveyor group while being immersed in the cleaning liquid in the liquid tank. Then, in the cleaning liquid of the liquid tank, a suction nozzle is provided which is located opposite to the printed wiring board to be conveyed,
The cleaning liquid is sucked through the through holes of the printed wiring board. The slit-shaped openings of the suction nozzles were arranged linearly along the widthwise direction perpendicular to the carrying direction of the printed wiring board. By the way, according to this recently developed cleaning device, even if it is a very small diameter, many irregularly scattered irregularly shaped and slender through-holes, the suction nozzle linearly sucks it and the suction pressure acts strongly,
Make sure that the cleaning solution passes through all through holes.
Therefore, the inside of the through hole is thoroughly and surely cleaned, and the flash, cutting chips, chips, resist deposits, oxidation spots, copper foil stains, and other foreign substances attached to the inner wall are completely removed from the through hole. Will be washed away,
The above-mentioned problems of the conventional high pressure cleaning type cleaning device are solved.

[0005]

However, in spite of such advantages, the recently developed cleaning device has the following disadvantages.
The following problems were pointed out. That is, FIG. 3 shows such a recently developed conventional suction nozzle, etc., FIG. 1 (1) is a plan view of a main part thereof, and FIG. 2 (2) is a front explanatory view of the main part. As shown in the figure, when the printed wiring board P is transported in the liquid tank and reaches the suction nozzle 3, the slit shape of the suction nozzle 3 linearly arranged along the lateral width direction X perpendicular to the transport direction Y. The suction pressure from the opening E causes the front end of the printed wiring board P to be sucked intensively at one time. The suction pressure acts as a strong resistance, and the thin and flexible printed wiring board P is damaged or hindered from being conveyed, is sucked and stopped, and is bent from the front end to be on the roller conveyor 2. There is a problem that various defects are likely to occur, such as overlapping, transporting and cleaning becoming impossible, and the like. 4A and 4B show a top member M used in such a conventional example, FIG. 1A is a front view and FIG. 4B is a side view. It is arranged on the slit-shaped opening E of the suction nozzle 3 so as to be rotatable in the direction Y and is opened and closed as appropriate.

The present invention has been made as a result of earnest research efforts by the inventor in order to solve the problems of the recently developed conventional example in view of the above circumstances, and the method is carried into the cleaning liquid in the liquid tank. By providing a suction nozzle opposed to the printed wiring board to be formed, and arranging the slit-like openings thereof in a predetermined inclination, and further by disposing a top member in a predetermined manner, First, the cleaning liquid can be sucked through the through holes of the printed wiring board, and the inside of the through holes can be sufficiently and surely cleaned. Secondly,
An object of the present invention is to propose a cleaning device in which the suction pressure is dispersed and the printed wiring board is smoothly transported.

[0007]

The technical means of the present invention for achieving this object are as follows. That is, this cleaning device is used in the manufacturing process of a printed wiring board and cleans a large number of small-sized through holes provided between both surfaces of the printed wiring board. A liquid tank of the cleaning liquid in which the printed wiring board is dipped, a group of upper and lower roller conveyors which are arranged in the cleaning liquid of the liquid tank and send by sandwiching the printed wiring board, and the roller conveyor in the cleaning liquid of the liquid tank. It has a suction nozzle arranged between the groups, and a suction mechanism connected to the suction nozzle. The suction nozzle is located opposite to the conveyed printed wiring board and is capable of sucking the cleaning liquid in the liquid tank through the through hole of the printed wiring board based on the suction pressure of the suction mechanism.

In this cleaning apparatus, the suction nozzle is provided with slit-shaped openings arranged obliquely with respect to the lateral direction perpendicular to the conveying direction of the printed wiring board. Covers the width of. The cleaning device according to a second aspect has the following configuration in addition to the configuration according to the first aspect. That is, the suction nozzles are arranged under the printed wiring board, and on the slit-shaped openings of the suction nozzles, an assembly of top members is arranged in close contact with each other along the arrangement direction. Each of the top members is attached to a shaft and is rotatable along the carrying direction. At all times, all of the respective top members descend and close the slit-shaped opening at their respective ends, while the printed wiring board passes over the slit-shaped opening and is conveyed. In the meantime, the top members of the respective top members are pushed up by the passing printed wiring board in this manner and are sequentially rotationally displaced to open the corresponding slit-shaped openings.

[0009]

Since the present invention comprises such means, it operates as follows. In this cleaning device, the printed wiring board is transported by the roller conveyor group while being immersed in the cleaning liquid in the liquid tank. Then, passing through the slit-shaped openings of the suction nozzles that are opposed to each other while inclining over the entire width,
The slit-shaped opening of the suction nozzle sucks the cleaning liquid through the through hole of the printed wiring board based on the suction pressure of the suction mechanism. Therefore, firstly, although the through holes are extremely small in diameter, many are irregularly scattered, and the shape is also elongated, as described above, since the through holes are directly sucked by the slit-shaped openings of the suction nozzle, a strong suction pressure acts. , The cleaning liquid will pass through all through holes. Therefore, even if the hole is extremely thin, the inside of the through hole is sufficiently and reliably washed,
Burr, cutting chips, chips, resist deposits, oxidation spots, copper foil stains, other foreign substances adhering to the inner wall, etc. are completely cleaned and removed from the through holes.

Secondly, since the slit-shaped openings of the suction nozzle are arranged obliquely with respect to the lateral width,
The suction pressure applied to the printed wiring board is dispersed in the carrying direction and the lateral width direction, so that the printed wiring board is smoothly carried without being damaged or bent.
Thirdly, in claim 2, a method is employed in which each top member is arranged on the slit-shaped opening and the corresponding slit-shaped opening is opened and closed. In other words, while the top member is pushed up by the printed wiring board and is rotationally displaced, the corresponding slit-shaped opening is opened and the through hole is sucked, so that the printed wiring board has a predetermined suction pressure. Be washed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the drawings. FIG. 5 is an overall front view of a cleaning device to which the present invention is applied, and FIG. 6 is a side view of the same. FIG. 7 is an enlarged front sectional view of the printed wiring board. First, the whole will be described with reference to these drawings.

This cleaning device is used in the manufacturing process of the printed wiring board P and cleans a large number of small-sized through holes T provided between both surfaces of the printed wiring board P. First, the printed wiring board P will be described. The printed wiring board P has a wide variety of purposes such as a double-sided board for OA, a multi-layer board for a computer, a flexible board for a computer, etc., and thus a variety of manufacturing processes thereof. Through holes T are formed as shown in FIG. The through holes T are for electrical connection / conduction of circuits on both front and back surfaces of the printed wiring board P,
Alternatively, it is used for component mounting, that is, for mounting around the legs of a semiconductor component mounted on the printed wiring board P.
It is formed as a through hole by a drilling machine or the like. With the recent miniaturization and miniaturization of circuits, the through holes T are overwhelmingly small in hole diameter of about 0.2 mm to 0.5 mm, and one printed wiring board P has, for example, An extremely large number of about 1000 pieces are formed.
Randomly scattered and distributed, and printed wiring board P
In view of the fact that the wall thickness is about 1.6 mm, for example, the length, that is, the depth is several to ten times as large as the hole diameter, and the hole is elongated and deep.

A printed wiring board P having such through holes T is manufactured, for example, as follows. That is, the printed wiring board P is
It is manufactured by following processes such as drilling, polishing / electrolytic treatment, through-hole T plating, polishing / electrolytic treatment, resist attachment, exposure, development, etching, resist stripping, and so on. First, a double-sided copper-clad laminate, in which copper foil is laminated on both sides of an insulating material, is cut into a work-size short material, and then subjected to perforation processing for through holes T, followed by double-side polishing for cleaning and surface treatment. Alternatively, through the electrolytic treatment, the through-hole T plating using the plating solution is performed. That is,
The inner wall of the through hole T is plated so as to connect the electric circuit on the front surface with the electric circuit on the back surface. After that, after double-side polishing or electrolytic treatment is performed again as cleaning and surface treatment, a treatment of attaching a photosensitive resist in a film shape is performed,
Then, a circuit photograph, which is a negative film of the circuit, is exposed and exposed. After that, the resist leaves the exposed and cured circuit portion, and the other portion is dissolved and removed by spraying a developing solution. Then, in the etching machine, the copper foil in the circuit portion where the resist is hardened in this way is left, and the copper foil in the portion where the resist is dissolved and removed as described above is dissolved and removed by the jetting of the corrosive liquid. After that, the remaining resist of the above-mentioned cured circuit portion is dissolved and removed by spraying the stripping liquid, and thus the printed wiring board P on which a predetermined electric circuit is formed is manufactured. Then, in the manufacturing process of such a printed wiring board P, cleaning the through holes T and the like with a cleaning device is performed before the above-described through hole T plating, after the resist is dissolved and removed, and the final product finishing stage and the like. , Is repeated in each step.

Now, as shown in FIGS. 5 and 6, this cleaning apparatus used for such cleaning has the following liquid tank 1, roller conveyor 2 group, suction nozzle 3, suction mechanism 4
And so on. To describe these, first, the liquid tank 1
Is a substrate into which the printed wiring board P is dipped, and is composed of a bath of a cleaning liquid H consisting of washing water or a solution of acid, alkali, etc., and is disposed in the processing chamber of the apparatus main body 5. The roller conveyor 2 group is arranged in the cleaning liquid H of the liquid tank 1,
In order to sandwich and feed the printed wiring board P, a large number of them are provided side by side in a pair, and further, outside the liquid tank 1, they are appropriately provided only on the lower side. 6 is a motor for driving such a group of roller conveyors 2, 7 is a transmission section between the motor 6 and the group of roller conveyors 2,
It consists of a pulley and the like.

Two suction nozzles 3 are arranged in the cleaning liquid H of the liquid tank 1 as described above between the two groups of roller conveyors. The suction nozzle 3 is located opposite to one surface of the printed wiring board P to be conveyed, and can suck the cleaning liquid H in the liquid tank 1 through the through hole T of the printed wiring board P based on the suction pressure of the suction mechanism 4. Has become. The suction nozzle 3 is positioned so as to face the one surface of the printed wiring board P to be conveyed with a very small gap of about 0.5 mm, for example, so that it can be appropriately abutted. Regardless of this, the opposing positioning may be performed so as to always abut, or the opposing positioning may be performed in a gap that does not always abut. The suction nozzles 3 in the illustrated example are arranged below the printed wiring board P, that is, between the lower roller conveyors 2 groups, but are arranged above the printed wiring board P, that is, between the upper roller conveyors 2 group. You may. The details of the suction nozzle 3 will be described later.

Next, the suction mechanism 4 is arranged outside the liquid tank 1 and is connected to the suction nozzle 3 in the liquid tank 1. That is, 8 is a motor of the suction mechanism 4, and this motor 8
Are connected to two piston pumps 10 via both crank portions 9. 11 is a tank, and this tank 11
Are connected to the base end sides of the two suction nozzles 3 described above via pipes 12, respectively, and the front end side and the rear end side of the liquid tank 1 are connected to each other via pipes 13. The pipe 13 is provided with a check valve 14, the piston pump 10, the check valve 15, a filter 16 and the like in this order from the tank 11 side. Therefore, in the suction mechanism 4, both piston pumps 10 reciprocate through the crank portion 9 by the drive of the motor 8, and the suction movement causes
Suction pressure acts on the suction nozzle 3 through the tank 11 and the check valve 14, and the vacuum pressure thereof causes the cleaning liquid H in the liquid tank 1 to flow.
Is sucked. Further, the cleaning liquid H thus sucked by the discharge movement of the piston pump 10 is circulated from the piston pump 10 to the liquid tank 1 through the check valve 15 and the filter 16, and at that time, the cleaning liquid H is filtered by the filter 16. Dirt is purified and reduced. Reference numeral 17 in the figure is a mount.

In the illustrated example, two such piston pumps 10 are provided, and when one of the piston pumps 10 performs suction movement, the other is set to discharge movement. Therefore, the interaction causes the flow of the cleaning liquid H. The strength is small, that is, the wave of the suction pulse of the cleaning liquid H is small. Further, in such a suction mechanism 4, for example, the tank 11 or the pipes 12, 1
A pressure reducing valve (not shown) is attached to 3 and the like, and the suction pressure acting on the suction nozzle 3 is adjusted. That is, as described above, a large number of through holes T formed on the printed wiring board P are unspecified / irregularly scattered.
Since they are distributed, the suction pressure for sucking the cleaning liquid H through the through holes T, that is, the vacuum pressure, by the suction nozzles 3 does not greatly change depending on the size, number, presence or absence of the through holes T to be sucked. The pressure reducing valve opens and closes appropriately,
The cleaning liquid H is allowed to escape to another pipe (not shown) and is circulated again. In addition, the pressure reducing valve for controlling the suction pressure, that is, the vacuum pressure to be constant as described above may be directly attached to the suction nozzle 3.

Next, the suction nozzle 3 will be described in detail. FIG. 1 is a plan view of an essential part of an embodiment of the present invention, and FIG.
It is a front view showing the top member N and the like. First, as shown in FIG. 1, the suction nozzle 3 is provided with slit-shaped openings F that are arranged at a slight inclination with respect to the lateral width direction X that is perpendicular to the transport direction Y of the printed wiring board P. The slit-shaped opening F has a length that covers the lateral width of the printed wiring board P. The slit-shaped opening F in the illustrated example is
Although one linear object is arranged in a slanted manner, it is also possible to dispose the slanted things in multiple rows and discontinuously arranged at intervals, irrespective of such an illustrated example.

Next, the top member N of FIG. 2 will be described. As shown in FIG. 2, the inclined slit-shaped opening F
An assembly of top members N is arranged in close contact with each other along the arrangement direction so as to face each other.
It can be rotated along (see also (2) of FIG. 4 relating to the above-mentioned conventional example). At all times, all of the top members N descend to completely seal or close the slit-shaped openings F at their ends, while the printed wiring board P corresponds to the corresponding slit-shaped openings F. While being passed over and being conveyed, each top member N is lifted at the end portion by the passing printed wiring board P and sequentially separated and pivotally displaced, so that the corresponding slit shape is formed. The opening F is opened.

Since the top member N is arranged on the slit-shaped opening F in FIG. 1, the top member N is also arranged to be inclined linearly in a predetermined manner, and the printed wiring board P is conveyed. When it comes, it will be opened in order from the front side, and,
It is closed from the front side. In addition, each of the top members N also functions as an adjusting mechanism for adjusting the overall length of both ends of the slit-shaped opening F, corresponding to the printed wiring board P having various widths. Only the slit-shaped openings F corresponding to the lateral width size of the printed wiring board P passing through are opened, and the slit-shaped openings F outside the lateral width size remain closed.

The present invention is constructed as described above. Then it becomes as follows. In this cleaning device, the printed wiring board P is conveyed while being immersed in the cleaning liquid H in the liquid tank 1 while being sandwiched between the upper and lower roller conveyors 2. Then, the printed wiring board P conveyed in this way is arranged between the groups of the roller conveyors 2 and passes through the slit-shaped opening F of the suction nozzle 3 which is opposed to over the entire width thereof, and the slit-shaped opening of the suction nozzle 3 is formed. Based on the suction pressure of the suction mechanism 4, F sucks the cleaning liquid H in the liquid tank 1 through the through hole T of the printed wiring board P. That is, by driving the motor 8 of the suction mechanism 4, the two piston pumps 10 alternately perform the suction movement and the discharge movement, and the liquid tank 1
The cleaning liquid H in the liquid again passes through the through hole T, the slit-shaped opening F of the suction nozzle 3, the pipe 12, the tank 11, the pipe 13, the check valve 14, the piston pump 10, the check valve 15, the filter 16, etc. Circulate to tank 1.

Now, firstly, the through holes T of the printed wiring board P are extremely small in diameter, and many are irregularly scattered and long and slender in shape, but they are transported in the cleaning liquid H in the liquid tank 1 in this way. At the same time, it is directly sucked by the slit-shaped opening F of the suction nozzle 3 facing the one surface side, so that the suction pressure, that is, the vacuum pressure is strongly applied to all the through holes T. Therefore, due to such suction pressure, the cleaning liquid H passes through all the through holes T and is not repelled by the surface of the printed wiring board P even if the holes are extremely thin, and the slit-shaped opening of the suction nozzle 3 is used. F is sucked. In this way, all of the through holes T are sufficiently and surely cleaned, and from the through holes T, flash, cutting chips, and cutting chips of the drill generated in the previous process, as well as resist deposits, oxidation points, and copper foil stains. , Other foreign substances attached to the inner wall are completely cleaned and removed.

Secondly, the slit-shaped openings F of the suction nozzle 3 are arranged so as to be inclined from the lateral width direction X to the carrying direction Y. Therefore, the suction pressure with respect to the passing printed wiring board P is dispersed in the transport direction Y and the lateral width direction X, so that the leading end of the printed wiring board P is not concentrated and attracted at one time to receive a large resistance. The printed wiring board P is gradually sucked from the tip and gradually receives a resistance that does not hinder its transportation. Therefore, the printed wiring board P is thin and flexible, but is not damaged, bent, or the like, and is smoothly transported. Thirdly, such suction of the printed wiring board P by the suction nozzle 3 is performed as shown in FIG.
Disposing each top member N on the slit-shaped opening F,
This is done by a method of opening and closing this. In other words, while a certain group of top members N is being pushed up by the printed wiring board P that is being conveyed and passed, only the corresponding slit-shaped opening F is opened, so that the through hole T of the printed wiring board P is always at a predetermined value. Suction pressure is used for cleaning.

[0024]

As described above, the cleaning apparatus according to the present invention is provided with the suction nozzle opposed to the printed wiring board conveyed in the cleaning liquid in the liquid tank, and the cleaning liquid can be sucked through the through hole of the printed wiring board. In addition, by arranging the slit-shaped openings in a predetermined manner and further disposing the top member in a predetermined manner, the following effects are exhibited.

That is, first, the inside of the through hole of the printed wiring board is sufficiently and surely cleaned. In other words, from through holes, drill burrs, cutting chips, chips,
Completely cleans and removes resist deposits, oxidization spots, copper foil stains, other foreign substances attached to the inner wall, etc., so that after-hole through-hole plating and soldering for component mounting can be performed without any defects. To be done. Secondly, the suction pressure is dispersed and the printed wiring board is smoothly transported. In other words, the printed wiring board will not be damaged, will not be interrupted by transportation and will not be sucked and stopped, and will not be bent and overlapped from the tip, so that transportation and cleaning will be performed smoothly, and various defects will occur. Avoided.
As a result, a printed wiring board with higher density, smaller size, lighter weight, and higher number of layers, which has a finer and finer circuit, has stable quality and significantly improved reliability. As described above, the effects of the present invention are remarkably large, such as the problems existing in this type of conventional example are eliminated.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of an embodiment of a cleaning device according to the present invention.

FIG. 2 is a front view showing the top member and the like.

FIG. 3 shows a suction nozzle and the like of this type of conventional example, FIG. 1 (1) is a plan view of a main part thereof, and FIG. 3 (2) is a front view of the main part.

4A and 4B show a top member and the like of this type of conventional example, FIG. 1A is a front view, and FIG. 4B is a side view.

FIG. 5 is an overall front view of this type of cleaning device.

FIG. 6 is an explanatory side view of the same.

FIG. 7 is an enlarged front sectional view of a printed wiring board.

[Explanation of symbols]

 1 Liquid Tank 2 Roller Conveyor 3 Suction Nozzle 4 Suction Mechanism 5 Device Main Body 6 Motor 7 Transmission Section 8 Motor 9 Crank Section 10 Piston Pump 11 Tank 12 Pipe 13 Pipe 14 Check Valve 15 Check Valve 16 Filter 17 Frame 18 Shaft E Slit -Shaped opening (conventional example) F slit-shaped opening (present invention) H cleaning liquid M coma member (conventional example) N coma member (present invention) P printed wiring board T through hole Y transport direction X lateral width direction

Claims (2)

[Claims] 1. A cleaning device used in a manufacturing process of a printed wiring board, which cleans a large number of small-sized through holes provided on both sides of the printed wiring board, the cleaning solution being a liquid for immersing the printed wiring board. Tank, upper and lower roller conveyor groups arranged in the cleaning liquid of the liquid tank and sandwiching and sending the printed wiring board, suction nozzles arranged between the roller conveyor groups in the cleaning liquid of the liquid tank, and the suction nozzle And a suction mechanism connected to the suction nozzle, the suction nozzle is positioned to face the printed wiring board to be conveyed, and the cleaning liquid in the liquid tank is supplied to the printed wiring board based on the suction pressure of the suction mechanism. In the cleaning device capable of sucking through the through hole, the suction nozzle is directly connected to the conveying direction of the printed wiring board.
Slit-shaped openings arranged at an angle to the lateral width of the corner
Part is formed to cover the width of the printed wiring board.
A cleaning device characterized by being present. 2. The suction nozzle is located under the printed wiring board.
Is arranged, on the slit-shaped opening of the suction nozzle,
Oppositely along the arrangement direction, the assembly of top members
Closely arranged, each top member is attached to the shaft
It is rotatable along the above-mentioned conveying direction, and all of the respective top members descend at all times and their ends
Part closes the slit-shaped opening, while
Lint wiring board passes over the slit-shaped opening and is transported
While each of the top members is being
The end is pushed up by the printed wiring board that is passing
Rotate and displace sequentially to open the corresponding slit-shaped opening
The cleaning device according to claim 1, wherein