KR20210108083A - Apparatus for cleaning of smear using plasma - Google Patents

Abstract

The present invention relates to a desmear cleaning apparatus using plasma, which comprises: a base plate installed on the inner bottom surface of a chamber of a plasma cleaning facility; an anode electrode plate fixed to the upper surface of the base plate to be spaced apart by a bracket and connected to a power supply means; a cathode electrode plate supported and fixed by a support stand erected in an insulating state at the four corners of the anode electrode plate and connected to the power supply means; a plurality of first and second electrode rods having one end fitted to the anode electrode plate, having the other end fitted to the cathode electrode plate, disposed to allow the two electrode plates to be alternately and electrically connected to each other through an insulating member, having the hollow inner part to allow coolant or thermal medium to flow therethrough, and installed at a certain distance from each other to input and output an object to be treated; and connection pipes connecting the ends of the first and second electrode rods to the same poles, respectively. Accordingly, occurrence of cracks in a portion where the electrode rod and the electrode plate are connected is eliminated, maintenance is facilitated due to ease in replacing parts, and temperature uniformity and uniformity of an applied current are maintained inside the chamber, thereby providing an advantage of significantly increasing processing quality by plasma.

Description

Desmear plasma cleaning apparatus {APPARATUS FOR CLEANING OF SMEAR USING PLASMA}

The present invention relates to a desmear plasma cleaning apparatus, and more particularly, efficiently removes smears, which are organic impurities, moisture and various foreign substances, which are additionally generated during the manufacture of printed circuit board holes according to ultra-fine patterning of printed circuit boards. It relates to a desmear plasma cleaning device of a type that not only improves the anisotropic etching characteristics of the hole, but also has a simple structure and is easy to replace.

Recently, the demand for ultra-high multi-layer PCBs is increasing thanks to the rapid development of printed circuit board (PRINTED CIRCUIT BOARD) (hereinafter referred to as 'PCB') manufacturing technology at home and abroad. ), multi-chip modules, and multi-layer flexible PCBs.

Simultaneously with the development of such PCB (including flexible PCB, rigid PCB, hybrid PCB, etc.) manufacturing technology, the demand for a PCB that requires a micro-via hole, which is a PCB hole, is rapidly increasing. The technology for treating organic impurities, residual moisture, and residues (SMEAR: smear) before hole plating has a great influence on the final quality of the PCB, but is currently very outdated.

There is a wet facility that uses chemicals as a traditional method for cleaning PCB holes, but this has the disadvantage that the equipment is huge and there are economic and environmental problems due to wet use, as well as the fact that accurate control and ultra-fine processing for the process are impossible. have.

Recently, a PCB hole cleaning technology using plasma has been activated, which is environmentally friendly and economical, has excellent smear (residue) removal ability, and is suitable for the situation where PCB holes are becoming lighter and thinner due to miniaturization of PCB holes.

1 (a) and (b) schematically illustrate such a cleaning facility, a main body 10 having a chamber 12 capable of plasma processing is provided, and a plurality of electrodes ( 14) is provided and the processing object, that is, the PCB 20, is placed between the electrodes 14, and then a voltage is applied to the electrode 14 to generate plasma using the reaction gas inside the chamber 12, and the generated plasma is generated. It is designed to clean the PCB hole using plasma.

By the way, the electrode 14 used in this cleaning facility is in the shape of a square bar, and as shown in FIG. 2 , between the cathode electrode plate 30 and the anode electrode plate 40 . At a certain interval, for example, the first column is insulated from the cathode electrode plate 30 and is connected only to the anode electrode plate 40 , and the second column is the cathode electrode in a state insulated from the anode electrode plate 40 . It is connected only to the plate 40, and the third column is arranged in the same manner as in the first column, but any one of the electrodes (not shown) is connected to any one of the electrodes 14 in the first column, and the fourth column is It is arranged in the same manner as in the second column, but one electrode (not shown) is arranged in multiple rows in a form connected to any one electrode in the second column, and in this case, each electrode and the cathode electrode plate 30 or the anode electrode plate The connection between (40) was made by a welding method, in particular, aluminum welding.

Therefore, it is easy to crack the welding part 50 due to the characteristics of the high-temperature processing facility, and in order to replace the defective electrode, the welding part 50 must be dismantled, which is very difficult to replace. It has an inconsequential drawback.

In addition, the plasma processing density is not uniform due to the non-uniformity of the current density through the welding part 50 , which acts as a factor of lowering the processing quality of the processing object accommodated in the jig 60 .

The present invention was created in consideration of the various problems of the prior art as described above and was created to improve the electrode structure of the plasma cleaning facility used to increase the processing quality of the PCB hole, so that installation and assembly and partial replacement are easy, Desmear plasma cleaning that enables the uniform application of current and maintains the plasma processing density uniformly to rapidly improve the processing quality such as cleaning and etching of smear, which are organic impurities, procedures, and various foreign substances remaining inside the PCB hole provide the device.

The present invention, in order to achieve the above technical problem, a base plate installed on the inner bottom surface of the chamber of the plasma cleaning facility; an anode electrode plate fixed to the upper surface of the base plate to be spaced apart by a bracket and connected to a power supply means; a cathode electrode plate supported and fixed by a support stand erected in an insulating state at the four corners of the anode electrode plate and connected to a power supply means; One end is fitted to the anode electrode plate and the other end is fitted to the cathode electrode plate, and the two electrode plates are arranged to be energized with each other through an insulating member. a plurality of first and second electrodes spaced apart from each other and spaced apart from each other; and a desmear plasma cleaning device including a connecting pipe connecting the ends of the first and second electrodes to the same poles.

The desmear plasma cleaning apparatus according to the present invention eliminates cracks caused by plasma etching in the region where the electrode and the electrode plate are connected, and is easy to replace and maintain, as well as temperature uniformity in the chamber, and Since the uniformity is maintained, the quality of treatment by plasma is rapidly improved.

1 is an exemplary view showing a general plasma cleaning apparatus.
2 is an exemplary diagram of a desmear plasma cleaning apparatus according to the prior art.
Figure 3 is a front view showing the installation state of the desmear plasma cleaning apparatus according to the present invention.
4 is a lower perspective view of the desmear plasma cleaning apparatus according to the present invention.
5 is an upper perspective view of the desmear plasma cleaning apparatus according to the present invention.
6 is an exemplary view showing an arrangement example of the desmear plasma cleaning apparatus according to the present invention.

The present invention described below can apply various transformations and can have various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description.

However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Also, terms such as first, second, etc. may be used to distinguish and describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

In addition, when at least two different embodiments are described in the present application, all or part of the components may be used by merging and mixing with each other even if there is no particular description within the scope not departing from the technical spirit of the present invention. .

3 is a front view showing an installation state of the electrode assembly according to the present invention, FIG. 4 is a lower perspective view of the electrode assembly according to the present invention, and FIG. 5 is a main upper perspective view of the electrode assembly according to the present invention.

3 to 5 , in the electrode assembly of the present invention, a plurality of electrodes for generating plasma are formed in a rod shape.

That is, the electrode is divided into a first electrode 110 connected to the anode electrode plate 100 and a second electrode electrode 210 connected to the cathode electrode plate 200 .

At this time, these first and second electrodes 110 and 210 are respectively connected to the anode electrode plate 100 and the cathode electrode plate 200 in the form of FITTING, that is, fitting.

In the fitting structure, as shown in the enlarged view of FIG. 4 , a part of the anode electrode plate 100 is perforated, and a bush 120 having excellent electrical conductivity is inserted into the perforated portion, and the bush ( The first electrode 110 is inserted into the 120 and has a form in which it is assembled.

Of course, this structure is the same in the cathode electrode plate 200 .

In addition, the first and second electrodes 110 and 120 are formed in a hollow shape with an empty interior, and are configured so that cooling water can flow through the hollow portion.

The supplied cooling water may be set differently depending on the characteristics of the object to be treated, but it is preferable to have a temperature distribution of about 20 to 90° C. Energy to be applied by the power supply means is reduced or temperature control is facilitated.

To this end, the upper and lower ends of the first and second electrodes 110 and 210 pass through the anode electrode plate 100 and the cathode electrode plate 200 , and then are connected by a connector 300 .

At this time, it is preferable that the connection pipe 300 is installed to be union-coupled, and the first electrode 110 is connected only between the first electrodes 110 , and the second electrode 210 connects only the second electrodes 210 with each other. to connect it.

Accordingly, in the first column, which is described as being arranged on the front side of the figure, the connecting tube 300 connects the first electrode rods 110 in the horizontal direction (the second, third, fourth, fifth, and n columns are all the same) ), the connecting pipe 300 is vertically connected to each other so that the electrodes connected to the same electrode plate are connected to each other across one row.

In addition, the anode electrode plate 100 and the cathode electrode plate 200 are both plate-shaped electrodes, as in the prior art, with a cathode on the upper part and an anode on the lower part connected to a power supply means and a socket, respectively.

In addition, the first and second electrodes 110 and 210 are arranged in multiple rows, for example, the first electrode 110 is arranged in the frontmost row, the first electrode 110 is arranged in the second row, and the second electrode 210 is arranged in a third row. The column is arranged up to the nth column while the first electrode 110 and the fourth column are arranged as the second electrode 210 .

Accordingly, each row (from the first row to the n-th row) is arranged with the first electrode 110 and the second electrode 210 alternately crossed.

On the other hand, an insulating member 410 is installed between each of the first and second electrode rods 110 and 210. The insulating member 410 has an approximately 'ㅗ' shape and has an anode electrode plate 100 and a cathode electrode plate 200. ) is provided in the form of being attached to the surface of the

The insulating member 410 is particularly preferably made of a Teflon material having excellent insulation, and is a member on which a jig (JIG) 400 in which the PCB is accommodated is seated and supported.

That is, since the jig 400 should not be energized, it should be insulated from the respective electrode rods 110 and 210 . In order to realize this, the insulating member 410 is introduced.

At this time, the jig 400 is provided in a form in which the protruding upper end of the insulating member 410 slides in and out while the concave portions formed on the upper and lower end surfaces thereof are fitted.

In addition, the anode electrode plate 100 and the cathode electrode plate 200 are installed to be connected and supported by the supports 500 provided at the four corners.

To this end, each electrode plate connection portion of the support 500 must also be insulated. Even in this case, the insulating member 510 made of Teflon material is preferably used.

In addition, the anode electrode plate 100 is fixed to the base plate 600 and the fixing structure is 'a' to 'b' connecting the lower surface of the anode electrode plate 100 and the upper surface of the base plate 600 . Alternatively, it is connected and fixed by the 'ㅗ'-shaped bracket 620 .

Even at this time, it is necessary to insulate a part of the base plate 600 from the anode electrode plate 100. To this end, a part of the base plate 600 is made of the same material as the insulating members 410 and 510 through the insulating member 610. It is preferable to insulate in the form of a square band.

Further, FIG. 6 is an exemplary view showing an example of the arrangement of the electrode according to the present invention, in which the front, rear, left, and right sides of any one electrode are cross-arranged, that is, surrounded by electrode rods having different poles. It may be arranged as in (a), or as described above, it may have a form as in (b) of FIG. 6 in which different poles are cross-arranged along columns and rows.

The operational relationship of the present invention having such a configuration is as follows.

First, the jig 400 is pushed into the space between the first and second electrodes 110 and 210 in a state in which the object to be treated is mounted on each jig 400 .

When the object to be treated is received in this way, the operator closes the door to seal the chamber ('12' in FIG. 1).

Thereafter, when power is supplied through the power supply means, the anode and the cathode are respectively applied to the anode electrode plate 100 and the cathode electrode plate 200 connected to the socket.

At this time, a discharge occurs between the first electrode 110 and the second electrode 210, one end of which is connected to each electrode plate, and a reactive gas such as air, argon, nitrogen, CF4, oxygen, etc. charged in the chamber 12 dissociates to generate plasma.

The generated plasma is irradiated to the surface of the target object mounted on each jig 400, and through this process, the smear remaining in the target object, for example, a hole (HOLE) of the PCB, is cleaned and removed, and also As the surface is cleaned, the necessary parts are etched at the same time.

do.

When the plasma treatment is completed, the door is opened in a state in which the power is turned off, and each jig 400 is drawn out from the chamber 12 to achieve the desired purpose.

However, if any one of the electrodes is damaged, it is possible to easily replace the corresponding electrode by simply releasing the fixed state of the fitting of the corresponding electrode being used.

That is, after dismantling the connection tube 300 that is union-coupled to the upper and lower ends of the electrode to be replaced, the anode electrode plate 100 and the cathode electrode plate 200, respectively, are inserted into each of the electrodes to be replaced. It becomes possible to replace the electrode rod.

In addition, since the cooling water or heating medium flows through the hollow portions of the first and second electrodes 110 and 210 during plasma treatment while maintaining the temperature corresponding to the characteristics of the object to be treated, uniform temperature within the chamber 12 is achieved in a short time. This can be achieved, and since the treatment temperature of the plasma is maintained uniformly, the processing quality of the object can be maximized.

Furthermore, since the first and second electrodes 110 and 210 have a fixing structure of a fitting type rather than a welding fixing, the characteristics of the welding current are uniform, and cracks in the fitting portion are eliminated, thereby extending the service life.

As described in detail above, cracks caused by plasma etching are eliminated at the portion where the electrode and the electrode plate are connected, and parts are easily replaced, which facilitates maintenance as well as temperature uniformity and uniformity of applied current inside the chamber. It provides the advantage of rapidly improving the processing quality by plasma.

On the other hand, the embodiments disclosed in the drawings are merely presented as specific examples to aid understanding, and are not intended to limit the scope of the present invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

100: anode electrode plate 110: first electrode
120: bush 200: cathode electrode plate
210: second electrode 300: connector
400: jig 410,510,610: insulating member
500: support 600: base plate

Claims (2)

a base plate installed on the inner bottom surface of the chamber of the plasma cleaning facility;
an anode electrode plate fixed to the upper surface of the base plate to be spaced apart by a bracket and connected to a power supply means;
a cathode electrode plate supported and fixed by a support stand erected in an insulating state at the four corners of the anode electrode plate and connected to a power supply means;
One end is fitted to the anode electrode plate and the other end is fitted to the cathode electrode plate, and the two electrode plates are disposed to be energized through an insulating member. A number of products installed with
1 and 2 electrodes;
and a connecting pipe connecting the ends of the first and second electrodes to the same poles,
The first and second electrodes are cross-arranged along columns and rows, and a desmear plasma cleaning apparatus fitted to the anode electrode plate and the cathode electrode plate with a bush interposed therebetween. According to claim 1,
The base plate is a desmear plasma cleaning device for insulating four sides by inserting a rectangular band-shaped insulating member in a portion thereof.

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