JP2001284773A - Circuit formation method and plasma treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit formation method which does not require a large- scale manufacturing apparatus including a vacuum chamber, whose production costs can be lowered and which is especially suitable for forming a circuit pattern to a three-dimensional structure and to provide a plasma treatment apparatus which is used suitably for the method. SOLUTION: A surface creepage plate 1 which is formed in such a way that a filamentary electrode 4 which is constituted of a plurality of electrode pieces 4a so as to be separated at prescribed intervals is laminated on a sheetlike electrode 2 via a dielectric layer 3 is used. While the filamentary electrode 4 is brought into contact with the circuit formation face of an insulating molded body 10, it is moved along the circuit pattern as a target. A voltage is applied across the filamentary electrode 4 and the sheetlike electrode 2. A region to which the filamentary electrode 4 on the insulating molded body 10 is moved is plasma-treated. A conductive material is stuck to the plasma- treated region by an electroless plating method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a circuit pattern made of a conductive material on the surface of a flat plate or a three-dimensional structure made of an insulating material such as a resin. The present invention relates to a plasma processing apparatus used for pretreatment of electroless plating.

In a method of manufacturing a printed wiring board used for various electric parts, a method of forming a circuit pattern on a resin substrate by an electroless plating method is known. For example, after surface treatment of the resin substrate along the circuit pattern,
In general, a method of immersing the resin substrate in a plating bath to form a metal (for example, copper) plating layer on the surface-treated portion.

[0003]

In the above, as a method of performing a surface treatment on a resin substrate along a circuit pattern, a surface treatment using plasma is widely performed. In this plasma processing, a resin substrate is arranged between discharge electrodes in a vacuum chamber, and a plasma gas is caused to act through an opening of a mask placed on the resin substrate. Therefore, the apparatus becomes large-scale, including a vacuum chamber, a discharge electrode, an exhaust system, and the like, and the distance between the discharge electrodes is large.
The discharge power is also large. In addition, every time a new resin substrate is processed, the inside of the vacuum chamber must be evacuated, which increases the manufacturing cost.

Further, when the resin substrate is a three-dimensional structure and a circuit pattern is formed three-dimensionally along each surface, it is not possible to apply plasma gas uniformly to each surface by one discharge. This is difficult, and the adhesion to the plating layer is different for each surface, so that the quality and yield of products are reduced. In order to avoid this, it is conceivable to perform plasma treatment for each surface, but the same operation will be repeated several times,
Productivity drops significantly. In addition, when a curved surface exists in the three-dimensional structure, the difficulty is further increased.

The present invention has been made in view of such a situation, and does not require a large-scale manufacturing apparatus such as a vacuum chamber, and requires a low manufacturing cost. In particular, the circuit pattern for a three-dimensional structure is required. A circuit forming method suitable for forming,
It is another object of the present invention to provide a plasma processing apparatus suitably used in the above method.

[0006]

In order to achieve the above object, the present invention provides a method for forming a circuit pattern made of a conductive material on an insulative molded body. Through, using a creeping discharge plate formed by laminating linear electrodes formed by separating a plurality of electrode pieces at predetermined intervals, while allowing the linear electrodes to contact the circuit forming surface of the insulating molded body While moving along the intended circuit pattern, a voltage is applied between the linear electrode and the plate-shaped electrode, and the area where the linear electrode of the insulating molded body has moved is subjected to plasma processing, Next, a circuit forming method is provided in which a conductive material is adhered to the region subjected to the plasma treatment by an electroless plating method.

Further, in order to achieve the same object, the present invention is used for pretreatment of electroless plating when forming a circuit pattern made of a conductive material on an insulative molded body by an electroless plating method. In the plasma processing apparatus, on a plate-shaped electrode, via a dielectric layer, a creeping discharge plate formed by laminating linear electrodes formed by separating a plurality of electrode pieces at predetermined intervals, and the plate-shaped electrode A power source for applying a voltage between the linear electrodes, and a creeping discharge plate provided at a tip portion, and a target circuit pattern while contacting the linear electrodes with a circuit forming surface of the insulating molded body. An arm for following and moving in a three-dimensional direction.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. In the present invention, when forming a circuit,
Plasma processing is performed by moving a creeping discharge plate along a target circuit pattern on a circuit forming surface of a molded body (hereinafter, referred to as “workpiece”) made of an insulating material on which a circuit is formed.

In performing the plasma processing, a plasma processing apparatus 100 shown in FIG. 1 is used. This plasma processing apparatus 10
Reference numeral 0 designates an arm 20 for moving the distal end of the arm 20 three-dimensionally in the same manner as a general industrial robot, for example, a welding robot or a coating robot. The creeping discharge plate 1 is attached to the distal end of the arm 20. I have.

As shown in FIG. 2, the surface discharge plate 1 is formed by laminating a linear electrode 4 on one surface of a flat plate-like electrode 2 with a dielectric layer 3 interposed therebetween. Further, the linear electrode 4 is configured by arranging a plurality of linear electrode pieces 4a on the dielectric layer 3 at predetermined intervals. The electrode piece 4a of the plate electrode 1 and the linear electrode 4 is made of a high melting point metal having plasma resistance, such as tungsten, and the dielectric layer 3 is a ceramic thin film of plasma resistant high purity alumina or the like. . Also,
Each electrode piece 4a of the plate electrode 2 and the linear electrode 4 is connected to a power supply 5, and an AC voltage is applied between the two electrodes. By applying this voltage, the electrode pieces 4a, 4a,
Discharge occurs between 4a. Therefore, by introducing a gas serving as an appropriate plasma source between the electrode pieces 4a, 4a of the linear electrode 4, the plasma 6 is generated between the electrode pieces 4a, 4a.
Occurs.

The plasma processing apparatus 100 moves the arm 20 to move the linear electrodes 4 of the surface discharge plate 1 along a target circuit pattern while making contact with the surface of the object 10 to be processed. An AC voltage is applied between the strip electrode 4 and the plate electrode 2. Here, the creeping discharge plate 1 is moved by the arm 20 so that the electrode piece 4a of the linear electrode 4 is orthogonal to the circuit pattern. Thereby, the object to be processed 10
Is activated along the movement path of the linear electrode 4 to form a streak-like plasma processing portion 11. Since the width of the plasma processing section 11 corresponds to the total length (L) of the electrode piece 4a constituting the linear electrode 4 of the creeping discharge plate 1, it is required by changing the total length (L) of the electrode piece 4a. It can easily respond to the line width of the circuit pattern. In addition, by changing the moving speed of the surface discharge plate 1, the degree of activation of the plasma processing unit 11 can be controlled. In some cases, the plasma processing unit 11 can be activated more strongly by reciprocating the surface discharge plate 1. Can also.

According to the above plasma processing apparatus 100,
Since the plasma 6 only needs to be generated between the electrode pieces 4a adjacent to the linear electrode 4, the plasma 6 can be generated with a small discharge voltage, and the manufacturing cost can be reduced. Also,
The plasma source gas may be supplied between the linear electrode 4 of the creeping discharge plate 1 and the circuit forming surface of the workpiece 10.
It is not necessary to perform discharge in a special hermetic container such as a conventional vacuum chamber. For example, by providing a simple exhaust means and a gas introduction portion close to the creeping discharge plate 1, the discharge can be performed under atmospheric pressure. And equipment costs can be greatly reduced. Further, conventionally, it has not been possible to cope with a large workpiece 10 or a long workpiece 10 that cannot be accommodated in the vacuum chamber. However, according to the present invention, plasma processing is possible within the moving range of the arm 20. Alternatively, if the processing target 10 is moved with respect to the arm 20, theoretically, there are no restrictions on the shape and dimensions of the processing target 20.

In the above description, the plasma source gas is appropriately selected depending on the material forming the object to be processed 10, but an inert gas such as argon or nitrogen, hydrogen, oxygen or the like, which is used in general plasma processing, is appropriately selected. Can be used. In some cases, it may be air, in which case it is possible to discharge indoors. The processing time by the plasma is not particularly limited, and is appropriately set in consideration of the material for forming the object to be processed 10, the type of the plasma source gas, the degree of activation, and the like. Is sufficient.

Then, by immersing the plasma-processed object 10 in a plating bath, a plating metal adheres to the plasma processing section 11 to form a circuit pattern composed of the metal film. There are no particular restrictions on the composition of the plating bath or the plating conditions, and conventional techniques can be followed. Also,
If necessary, electrolytic plating using an attached metal film as an electrode may be added.

In the above, the insulating material forming the article to be treated 10 is not particularly limited, but may be polyethylene, polypropylene, acrylic resin, polyester, polyetheretherketone, polyetherimide, polysulfone, polyethersulfone, polyphenylenesulfide or the like. Examples include various resins commonly used for printed wiring boards, or resins obtained by adding fillers such as glass fibers to these resins. Also, to increase the plasma processing efficiency,
These materials may be mixed with a catalyst such as palladium. The plasma processing conditions are appropriately selected in consideration of the types and physical properties of these materials.

[0016]

As described above, by using a surface discharge plate according to the present invention, circuit patterns can be formed on various insulative moldings at low cost without requiring a large-scale apparatus such as a vacuum chamber. Can be formed. Also,
Since the creeping discharge plate is configured to be movable along the circuit forming surface of the object to be processed, it has been difficult in the past, for example, a three-dimensional structure having a complicated curved surface or a large object to be processed that cannot be accommodated in a vacuum chamber. Thus, a circuit pattern having high adhesion can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an example of a plasma processing apparatus used in the present invention.

FIG. 2 is a schematic perspective view showing a surface discharge plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface discharge plate 2 Plate electrode 3 Dielectric layer 4 Linear electrode 4a Electrode piece 5 Power supply 6 Plasma 10 Workpiece 11 Plasma processing part 100 Plasma processing apparatus

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K022 AA13 AA15 AA16 AA17 AA19 AA23 CA12 DA01 5E343 AA01 AA12 AA39 BB14 BB21 BB71 DD33 EE36 FF30 GG11

Claims (3)

[Claims] 1. A method for forming a circuit pattern made of a conductive material on an insulative molded body, comprising a step of forming a plurality of electrode pieces on a plate-like electrode at predetermined intervals via a dielectric layer. Using a creeping discharge plate formed by laminating the linear electrodes, moving the linear electrodes along the intended circuit pattern while abutting the linear electrodes on the circuit forming surface of the insulating molded body, and A voltage is applied between the plate-shaped electrode and the area where the linear electrode of the insulative molded body has been moved is plasma-treated, and then a conductive material is applied to the plasma-treated area by electroless plating. A circuit forming method characterized by attaching. 2. The circuit forming method according to claim 1, wherein the insulating molded body is a resin film, a flat plate, or a three-dimensional structure. 3. A plasma processing apparatus used for pretreatment of electroless plating when forming a circuit pattern made of a conductive material on an insulative molded body by an electroless plating method. Through a layer, a creeping discharge plate formed by laminating linear electrodes formed by separating a plurality of electrode pieces at predetermined intervals, and a power supply for applying a voltage between the plate-shaped electrode and the linear electrodes An arm provided with the creeping discharge plate at a tip end, and an arm for moving the linear electrode in a three-dimensional direction following an intended circuit pattern while making contact with the circuit forming surface of the insulating molded body. A plasma processing apparatus characterized by the above-mentioned.