JPH05343836A - Manufacture of screen-printed circuit - Google Patents

Abstract

PURPOSE:To realize a manufacturing method, of a screen-printed circuit, wherein its printing plate is separated well, it can form an insulating layer which does not cause a problem such as a delamination or the like and which is provided with a good characteristic and its productivity is high. CONSTITUTION:A pattern for a conductor circuit is screen-printed and formed on the surface of a base material 1; the conductor circuit 2 is formed. After that, a circuit-part insulating layer 31 which is formed only in the circumferential part of the conductor circuit 2 and a non-circuit-part insulating layer 32 which has a shape capable of filling the gap of the circuit-part insulating layer 31 are screen-printed separately. Thereby, an insulating layer 3 is printer and formed in two separate operations.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a printed circuit such as a sheet electrode by silk screen printing.

[0002]

2. Description of the Related Art Conventionally, wiring for display elements, electric circuit boards, digitizer electrodes, etc. has been made by thick film printing. In particular, since the degree of freedom in ink selection is high and thick film printing is possible, screen printing is used. It is widely practiced to manufacture printed circuits.

When a printed circuit is manufactured by screen printing, for example, when a product such as a digitizer electrode in which circuits are laminated in two layers is manufactured, a conductive ink is used for the first conductor circuit pattern. After print formation,
An insulating layer is formed on the entire surface of the first conductor circuit pattern using an insulating ink to form a solid pattern, and then a second conductor circuit pattern is formed by printing on the insulating solid layer. The insulating layer was formed entirely and solidly on the second conductor pattern layer.

As a method of forming the above-mentioned insulating layer, conventionally, screen printing has been carried out using a solid plate.

However, since an insulating layer formed by using an insulating ink is generally required to be uniformly applied with a film thickness of about 25 μm, the viscosity of the ink becomes high and the plate and the printing substrate are Since printing is performed with a small gap between the base material and the screen, the gap between the base material and the screen is narrowed, and the contact area between the base material and the printed part of the silk screen is wide. There is a drawback that the plate surface is pulled by the ink due to the resistance due to (shear stress), the separation of the plate from the substrate (plate spreading) becomes poor, and the printing speed becomes slow.

Further, if the plate is forcibly peeled from the substrate in order to increase the printing speed, a part of the ink remains on the plate side, and printing defects easily occur.

Therefore, in order to solve this problem, printing has been carried out using a printing ink in which a filler having a high insulating property is added to make the ink cut well.

It has also been proposed to use a method other than printing as a method for forming the insulating layer. this is,
In this method, a conductive circuit is printed and formed, and then an insulating film is attached by an adhesive to form an insulating layer.

[0009]

By improving the physical properties of the printing ink, the problem of plate burn-off is solved to some extent, but the problem of plate slippage occurs when the amount of filler added increases. Further, there is a problem of performance deterioration such as reduction in strength between layers between the insulating layer and the conductor circuit pattern. On the other hand, in the method of laminating an insulating film that is not based on printing, although the physical properties of the insulating layer are good, the step of applying an adhesive during the printing step, the step of laminating the film, and drying the adhesive There is a problem that productivity is poor because the number of processes such as the process to be performed increases.

The present invention is intended to solve the above-mentioned drawbacks of the prior art, and it is possible to form an insulating layer having good plate burn-off and good characteristics without problems such as delamination.
An object of the present invention is to provide a method for manufacturing a screen printed circuit with high productivity.

[0011]

In order to solve the above problems, the first method of manufacturing a screen printed circuit according to the present invention comprises:
In a method for producing a screen printed circuit by screen-printing a conductor circuit pattern on a base material to form a conductor circuit and then forming an insulating layer on the front surface side of the conductor circuit, the conductor circuit is provided only on the peripheral portion of the conductor circuit. And a non-circuit part insulating layer provided in a shape to fill a gap between the circuit part insulating layer and a non-circuit part insulating layer. It is characterized in that the conductor circuit insulating layers are formed by screen printing separately.

According to a second method of manufacturing a screen printed circuit of the present invention, a pattern of the first conductive circuit is screen-printed on a base material to form a first conductive circuit, and only the periphery of the first conductive circuit is formed. After forming the circuit part insulating layer by screen printing, the pattern of the second conductor circuit is screen-printed on the upper layer of the first conductor circuit through the insulating layer to form the second conductor circuit, and the periphery of the second conductor circuit. The insulating layer is formed only by screen printing.

Further, as a method of manufacturing the screen printed circuit according to the third aspect of the present invention, the pattern of the first conductor circuit is screen-printed on the substrate to form the first conductor circuit by printing, and then the insulating layer is used as the first conductor. A screen printing plate is prepared by dividing into two insulating layer portions, a circuit portion insulating layer provided only in the peripheral portion of the circuit and a non-circuit portion insulating layer provided in a shape filling the gap between the circuit portion insulating layers, The conductive circuit insulating layer and the non-conductive circuit insulating layer are separately formed by screen printing, the surface of the insulating layer is formed to be substantially smooth, and the pattern of the second conductive circuit is screen printed on the surface of the insulating layer. And two non-circuit part insulating layers provided in a shape to fill the gap between the circuit part insulating layer and the circuit part insulating layer which is formed only in the peripheral part of the second conductor circuit. Screen printing plate divided into Prepare the conductor circuit part insulating layer and the non conductor circuit part insulating layer was formed by screen printing respectively separately, and wherein the substantially smooth surface of the surface of the insulating layer.

The printed circuit of the present invention means a circuit in which a conductive pattern is formed on the surface of a base material, and the conductive pattern is covered with an insulating layer, and the whole or a part of the conductive pattern is covered with the insulating layer. For example, such a printed circuit includes the following. Printed circuit boards, component wires such as conductors for thick-film printed integrated circuits, capacitors, coils, etc. Digitizer electrodes: For example, electrodes arranged in a grid in the vertical direction and grids in the horizontal direction so as to be orthogonal to the electrodes in the vertical direction. It is a system in which the electrodes are provided in a vertical shape and stacked on top of the electrodes in the vertical direction with an insulating layer interposed therebetween, and the electrodes in the vertical direction (the vertical direction and the horizontal direction) are not in contact. The position coordinates are detected by generating a fluctuating magnetic field at the pen tip, and at a position intersecting the magnetic field at that time,
There are a method of detecting an induced current flowing in each lateral electrode, a method of detecting a change in electric capacity due to approach of a pen tip or a finger as a change in oscillation frequency or voltage, and the like. Membrane switch contact circuit pattern: Membrane switches are used for telephone dial buttons, calculators, input keyboards for word processors and personal computers, touch panels, etc. A layer is provided to protect the surface with a plastic sheet or the like, and an insulating layer is provided between the patterns of the conductive layer.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. The drawings show one embodiment of the present invention, FIG. 1 is a process diagram which is a plan view showing one example of a method for manufacturing a screen printed circuit of the present invention, and FIG. 2 is a line II-II of the plan view shown in FIG. It is sectional drawing which shows a cross section.

In the present invention, as shown in FIGS. 1A and 2A, first, a conductor circuit pattern is formed on the surface of a base material 1 by silk screen printing to form a conductor circuit 2.

A flexible film is usually used as the substrate 1, and generally 100 to 35 of polyethylene terephthalate is used.
0 μm, preferably 120 to 250 μm is used.
Other materials such as polyimide and polycarbonate can also be used. Further, in the case of a digitizer, a thick film printed integrated circuit or the like, a plate such as an epoxy resin, a phenol resin laminated plate, a glass plate or a ceramic plate such as steatite may be used.

As the ink for forming the conductive circuit 2, a commercially available screen-printing conductive paste for circuit formation is used. This paste is made by dispersing a conductive powder such as silver, nickel or graphite powder in a resin binder.

Next, as shown in FIG. 2B, an insulating layer is formed by printing only on the peripheral portion of the conductor circuit 2 to provide a circuit portion insulating layer 31, and as shown in FIG. The non-circuit insulating layer 32 is provided so as to fill the gap between the circuit portion insulating layers 31. These insulating layers 31 and 32 are formed by separately screen-printing using two screen-printing plates formed in respective shapes. Either the circuit portion insulating layer 31 or the non-circuit portion insulating layer 32 may be formed first.

In the present invention, if the circuit part insulating layer 31 is not entirely solid, the printing spread will be good to some extent.
It is preferable that the surface area of the printed circuit board is 70% or less. Further, in screen printing, the plate bunare has a great influence on the plate misalignment at the center and the periphery of the printed circuit. Therefore, if the area of the circuit part insulating layer 31 near the center is 70% or less, the insulation of the peripheral part becomes The layer forming portion may exceed 70%. This also applies to the case where the non-circuit part insulating layer 32 is printed when the area of the non-circuit part insulating layer is large.

Circuit part insulating layer 31 and non-circuit part insulating layer 32
The insulating layer 3 consisting of is only required to have a sufficient insulating performance with respect to a conductor circuit and other contact objects. For example, like a digitizer electrode, a conductive circuit pattern is laminated in two layers to form an insulating layer between them. In order to obtain sufficient insulation performance between the two conductor circuits, a thickness of about 25 μm is usually required.

As the insulating ink for forming the insulating layer 3, one containing a thermoplastic resin such as acrylic, urethane, silicone, polyester as a main component can be used. The viscosity of the ink for the insulating layer is 500 to 50,000c
It is about ps, and particularly 1000 to 6000 cps is preferable because of good printability.

Further, as shown in FIG. 2C, the surface of the insulating layer 3 is formed by printing so that there is no step between the circuit portion insulating layer 31 and the non-circuit portion insulating layer 32, and the screen printing circuit 4 is formed. It is preferably formed so that the whole is smooth.

In the present invention, both the conductive circuit 2 and the insulating layer 3 are formed by silk screen printing,
For example, using a printing screen in which a screen formed by forming meshes with mutually orthogonal threads is fixed to a holding frame,
A plate cut into a conductor circuit pattern or an insulating layer pattern is placed between the printing screen and the base material, or printing is performed directly using a plate on which a pattern is formed using a photosensitive resin on the screen surface. The squeegee to which the ink is attached is brought into contact with the screen and slid on the screen to print the shape provided on the plate on the substrate.

In order to print a printed circuit having a particularly fine pattern neatly so as not to cause chipping or jagged edges, for example, in Japanese Patent Publication No. 1-23317, the printing direction to be printed (movement of the squeegee). It is advisable to print by inclining the relationship between the printing direction and the plate so that the edge of the circuit pattern is not at right angles to the direction.

When a normal-tensioned gauze screen is used, it is preferable to perform printing by inclining the pattern edges with respect to the direction in which the gauze of the screen is stretched. No. 12549
As described in Japanese Patent Publication No. 3-33344 and Japanese Utility Model Publication No. 1-33344, it is preferable to use a so-called bias burr technique in which a gauze is stretched obliquely with respect to the screen frame (and in the moving direction of the squeegee).

FIG. 3 is an explanatory view for explaining the second invention of the method for manufacturing a screen printed circuit according to the present invention, and is an explanatory view showing an example of forming a digitizer electrode.

When a conductor circuit such as a digitizer electrode is formed by laminating two layers, first, as shown in FIG. 3, the pattern of the first conductor circuit is first screen-printed on the surface of the base material 1 to form a first pattern. The conductor circuit 21 is formed [(a) in the figure], and the circuit part insulating layer 31 is formed by screen-printing only around the first conductor circuit, and the second conductor circuit is formed so as to be orthogonal to the first conductor circuit. The pattern is screen-printed to form the second conductor circuit 22 via the circuit part insulating layer 31 [FIG. Next, as in the case of the first conductor circuit, the circuit part insulating layer 31 is provided only around the second conductor circuit 22.

When the printed circuit is thus formed on the upper and lower two layers via the insulating layer, the insulating layer provided on the first conductive circuit is not limited to the circuit portion insulating layer as shown in FIG. Alternatively, the circuit insulating layer may be formed so as to fill the gap, and the surface may be formed smooth.

Specifically, if the circuit portion insulation 31 is formed only around the conductor circuit 21 after the first conductor circuit 21 is formed as shown in FIG.
As shown in (a), the non-circuit part insulating layer 32 is formed by screen printing so as to fill the voids of the circuit part insulating layer 31.
The circuit part insulating layer 31 and the non-circuit part insulating layer 32 can be formed into a screen printing plate in which the printing part and the non-printing part are formed so that the negative and positive shapes are formed.

Further, the surfaces of the circuit portion insulating layer 31 and the non-circuit portion insulating layer 32 are formed at substantially the same height so that the surfaces are made smooth, and if formed in this way, the second portion formed in the next step. There is an advantage that the conductor circuit can be formed smoothly.

Next, as shown in FIG. 4 (b), the second conductor circuit 22 is formed on the first conductor circuit via the insulating layers 21 and 32, and the first conductor circuit is formed in the same manner. In addition, the circuit part insulating layer 31 only around the second conductor circuit and the non-circuit part insulating layer 32 formed so as to fill the gap of the circuit part insulating layer 31 are prepared twice by respectively preparing a screen printing plate. Then, the printed circuit 4 is obtained by providing the insulating layer 3 by printing and forming the printed circuit 4 [FIG.

The present invention will be further described with reference to specific examples of the present invention.
Will be described in detail.Example 1  First, 100 μm thick clear biaxially oriented polyethylene
On the surface of terephthalate film (Toray's Lumirror)
The first conductor circuit of the A-4 size digitizer is shown in Fig. 2 (a).
As shown in, the circuit width X is 0.5 m / m, and the line spacing is 2.5 m / m.
As printing ink with silver paste (Nippon Acheson: Elec
trodag 427SS) was used for printing. Then insulation
The layer is only on the periphery so as to cover the first conductor circuit.
Insulation ink with a width of 2 m / m in the shape shown (Nihon Acheson: El
ectrodag 411SS). Then the second conductor
Same as the first conductor circuit so that the path is orthogonal to the first conductor circuit
Line width and spacing, only around the second conductor circuit
An insulating layer is formed to cover the same as in the case of the first printed circuit
Then, a digitizer electrode circuit was obtained. The screen
The printing plates used were all 300 mesh.

Example 2 First, the first conductor circuit of an A-4 size digitizer was formed on the surface of a clear biaxially stretched polyethylene terephthalate film (made by Toray: Lumirror) having a thickness of 100 μm, as shown in FIG. 2 (a).
As shown in, the circuit width X is 0.5 m / m, and the line spacing is 2.5 m / m.
As printing ink with silver paste (Nippon Acheson: Elec
trodag 427SS) was used for printing. Then, an insulating ink is applied only to the periphery so as to cover the first conductor circuit so as to have a width of 2 m / m in a shape shown in FIG. 2 (a) (manufactured by Nippon Acheson: El
ectrodag411SS), and an insulating layer was printed by using the same ink as the above-mentioned insulating layer so that the surface of the insulating layer was smoothed so as to fill the gap between the insulating layers. Next, the second conductor circuit is formed to have a line width and a spacing similar to those of the first conductor circuit so as to be orthogonal to the first conductor circuit.
An insulating layer was formed in the same manner as in the first printed circuit so as to cover only the periphery of the conductor circuit, and a digitizer electrode circuit was obtained. The screen printing plates used were all 300 mesh.

[0035]

As described above, in the method for manufacturing a screen printed circuit of the present invention, in the case of the first invention, the insulating layer is divided into two insulating layers, that is, a circuit portion insulating layer and a non-circuit portion insulating layer, and printed. By adopting the method of forming, the contact area between the screen printing plate and the substrate to be printed is small compared to the method of forming by single printing using a conventional solid plate. Therefore, the speed at which the plate separates from the substrate is increased, the plate run-off property is improved, there is no problem of the rate that the plate does not separate from the printing surface, and the printing speed can be improved. In addition, since it is not necessary to add a large amount of a filler such as a filler in order to enhance the plate run-out property, the conventional ink can be used as it is, and there is no risk of plate slippage. Further, in the second aspect of the present invention, since the insulating layer is formed only around the conductor circuit, the printing speed is improved when the conductor circuit is laminated in two or more layers, and the physical properties such as interlayer strength are good. can get. Further, as in the third invention, the first conductor circuit of the insulating layer, the second conductor circuit
In any case of the conductor circuit, if a method of dividing the insulating layer into two parts, that is, the conductor circuit portion and the non-conductor circuit portion, and forming each by printing is adopted, when the conductor circuit is laminated in two or more layers, each conductor layer Since the surface of the insulating layer is formed smoothly and the surface of the insulating layer is formed smoothly, it is possible to form a printed circuit capable of maintaining good insulating performance for a long period of time without fear of deterioration of insulating performance. Have.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing each step of an example of a method for manufacturing a screen printed circuit according to the present invention.

2 is a sectional view taken along line II-II of each step in FIG.

FIG. 3 is an explanatory diagram showing an example of a method of manufacturing a screen printed circuit according to the present invention.

FIG. 4 is an explanatory diagram showing an example of a method of manufacturing a screen printed circuit according to the present invention.

[Explanation of symbols]

 1: Base material 2: Conductor circuit 3: Insulating layer 4: Printed circuit 21: First conductor circuit 22: Second conductor circuit 31: Circuit part insulating layer 32: Non-circuit part insulating layer

Claims (3)

[Claims] 1. A method for producing a screen-printed circuit by screen-printing a pattern of a conductor circuit on a substrate to form the conductor circuit, and then forming an insulating layer on the front surface side of the conductor circuit by printing. A screen printing plate is prepared by dividing into two insulating layer portions, that is, a circuit portion insulating layer provided only in the peripheral portion and a non-circuit portion insulating layer provided in a shape that fills the gap between the circuit portion insulating layers. A method for manufacturing a screen printed circuit, characterized in that the partial insulating layer and the non-conductive circuit insulating layer are separately formed by screen printing. 2. A pattern of a first conductor circuit is screen-printed on a base material to form a first conductor circuit, and a circuit portion insulating layer is formed only on the periphery of the first conductor circuit by screen printing. The second conductor circuit is formed by screen-printing the pattern of the second conductor circuit on the upper layer of the first conductor circuit through the insulating layer to form the second conductor circuit, and the insulating layer is formed by screen printing only around the second conductor circuit. And a method for manufacturing a screen printed circuit. 3. A circuit portion insulating layer provided on only a peripheral portion of the first conductor circuit after a pattern of the first conductor circuit is screen-printed on a substrate to form the first conductor circuit by printing. A screen printing plate is prepared by dividing into two insulating layer portions, a non-circuit portion insulating layer and a non-circuit portion insulating layer provided in a shape to fill the gap of the circuit portion insulating layer, and the conductor circuit insulating layer and the non-conductor circuit insulating layer are respectively formed. Separately screen-printed and formed, the surface of the insulating layer is formed to be substantially smooth, and a second layer is formed on the surface of the insulating layer.
A circuit portion insulating layer in which a pattern of a conductor circuit is formed by screen printing, and an insulating layer is provided only in the peripheral portion of the second conductor circuit, and a non-circuit portion insulating layer provided so as to fill a gap between the circuit portion insulating layers. A screen printing plate is prepared by dividing it into two insulating layer portions, and a conductive circuit insulating layer and a non-conductive circuit insulating layer are separately screen-printed and formed,
A method of manufacturing a screen printed circuit, characterized in that the surface of the insulating layer is formed to be substantially smooth.