JP2603863B2 - Printed wiring board - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a printed wiring board, and more particularly, to a method of manufacturing a printed wiring circuit on a connection land portion of a printed wiring circuit formed on an insulating substrate by using another circuit portion such as a jumper circuit. The present invention relates to a method for manufacturing a printed wiring board manufactured by applying a conductive ink such as a copper paste.

2. Description of the Related Art A conventional printed wiring board is manufactured by forming a required printed wiring circuit by etching a copper foil of a so-called copper-clad laminate in which a copper foil is provided on an insulating substrate in accordance with a required circuit.

In forming a circuit such as a jumper circuit between printed wiring circuits on such a printed wiring board, as shown in FIG. 5, the connection terminal 4a is electrically connected to the connection terminal 1 of the printed wiring circuit 10. A manufacturing method has been developed and implemented in which the connected jumper circuit portion 4 is formed by applying a conductive ink made of copper paste or another conductive paste by means of silk printing or the like, and curing this. Various conductive inks effective for forming such a circuit have been developed.

Problems to be Solved by the Invention However, when a circuit is formed by applying a conductive paste such as a copper paste or by silk printing, the adhesiveness between the circuit terminal portion 1 of the copper foil on the printed wiring board and the conductive paste, that is, the ink. Cause problems. That is, the conductive paste is carbon, silver or copper particles for improving the conductivity in order to mix a large amount of the conductive material into the resin ink, the resin component that determines the adhesive force with the copper foil terminal surface is small, the usual paste Adhesive strength to metal surface is small compared to resin ink, and not only will the electrical connection become unstable, but also mechanical strength is weak, and it will peel off due to thermal shock during soldering of parts etc. There have been serious drawbacks.

Therefore, an object of the present invention is to provide a method for manufacturing a printed wiring board which can improve the electrical and mechanical strength of a conductive paste and a circuit terminal portion.

Means for Solving the Problems A method for manufacturing a printed wiring board according to the present invention is to form a printed wiring circuit on an insulating substrate and to connect another circuit to a circuit terminal portion of the printed wiring circuit with a conductive ink such as copper paste. In the method for manufacturing a printed wiring board, a part of the terminal surface of the circuit terminal portion of the printed wiring circuit is coated with a resin ink, and then the conductive ink is applied thereon to form the printed wiring circuit. A connection circuit for a circuit terminal portion is formed.

According to the method of manufacturing a printed wiring board of the present invention, prior to forming the circuit with the conductive ink, a coating layer of a resin ink is formed on a part of the terminal surface of the circuit terminal portion of the printed wiring circuit of the printed wiring board. After the formation, by forming a circuit of the conductive ink, the coating layer of the resin ink formed on a part of the terminal surface can obtain an adhesion action due to compatibility with the conductive ink, The electrical and mechanical strength of the contact portion between the substrate and the circuit portion made of conductive ink can be improved.

Embodiment An embodiment of a method for manufacturing a printed wiring board according to the present invention will be described with reference to the drawings.

(First Embodiment) FIGS. 1 and 2 show a first embodiment of a method of manufacturing a printed wiring board according to the present invention. FIG. 2a is an enlarged plan view showing a state in which a jumper circuit is connected to a terminal portion, and FIG. 2b is an AA line in FIG. 2a. It is sectional drawing.

As shown in FIGS. 1 and 2, in the method for manufacturing a printed wiring board of the present invention, the terminal portion 1 of the printed wiring circuit 10 formed on the upper side of the insulating substrate 20 is provided with another circuit,
For example, when forming the jumper circuit 4, first the first
As shown in the figure, prior to the formation of the jumper circuit 4,
Using a resin ink on the surface of the terminal portion 1, for example, using a resin ink having the same composition as the resin ink excluding the conductive material in the composition of the conductive paste used to form the jumper circuit 4, by printing or the like. The coating layer 2 in which a plurality of projections 2a are applied in a multipoint manner is formed.

Thereafter, the jumper circuit 4 is printed using a conductive ink and cured, whereby the jumper circuit 4 in which the terminal portion 4a is electrically connected to the terminal portion 1 can be formed.

The jumper circuit 4 is protected by applying an insulating overcoat film 5.

Further, in forming the jumper circuit 4 of the printed wiring board 21, an insulating coating (not shown) is previously applied to a portion which needs to be insulated from other printed wiring circuits 10 due to the relationship with the printed wiring circuit 10. Needless to say, it is formed after being applied.

Therefore, usually, at the same time as the formation of the insulating coating applied to the upper side of the printed wiring circuit 10 which is performed prior to the formation of the circuit such as the jumper circuit 4, that is, the insulating resin ink which is performed at the time of forming the insulating coating. By printing the coating layer 2 for attaching the projections 2a to the terminal surfaces of the terminal portions 1 in multiple points at the same time as the silk printing by the method described above, an increase in the number of steps can be prevented. However, with respect to the resin ink at this time, the projections 2a are naturally formed by the same resin ink as the insulating coating.

The coating layer 2 of the terminal portion 1 has a configuration in which a plurality of protrusions 2a are attached to the terminal surface, the terminal surface is partially covered, and the other surface is exposed.

As is clear from the above embodiments, according to the method for manufacturing a printed wiring board of the present invention, a normal resin ink is applied to a metal surface when forming a necessary circuit such as the jumper circuit 4 after forming the printed wiring circuit 10. A circuit such as a jumper circuit 4 is formed by applying a resin ink to a part of the terminal surface of the terminal portion 1 using a characteristic having excellent adhesion to the conductive ink and then applying the conductive ink. Is formed.

(Second Embodiment) FIGS. 3 and 4 show a second embodiment of the method of manufacturing a printed wiring board according to the present invention. FIG. 3 is an enlarged plan view of a terminal portion, and FIG. 4B is an enlarged plan view showing a state in which a jumper circuit is formed, and FIG. 4B is a sectional view taken along the line BB of FIG. 4A.

The method for manufacturing a printed wiring board according to the second embodiment is different from the multi-point coating layer 2 according to the first embodiment in that the mesh 3a-shaped coating layer 3 is formed on the terminal surface of the terminal portion 1 of the printed wiring circuit 10. It is formed by applying resin ink by means such as silk printing.

Thereafter, the jumper circuit 4 is formed by the same method as in the first embodiment.

The other manufacturing method is exactly the same as that of the first embodiment, and the same parts are denoted by the same reference numerals and description thereof will be omitted.

According to the method for manufacturing a printed wiring board of the present invention, a resin ink is applied to a terminal portion of a printed wiring circuit in a mesh or multipoint shape on a terminal surface, and then a jumper circuit made of conductive ink is formed thereon. By applying a circuit such as that described above, it is possible to prevent separation between the terminal surface and the conductive paste in a circuit connecting portion such as a jumper circuit, and to reliably prevent the occurrence of defects in the printed wiring board. .

[Brief description of the drawings]

1 and 2 show a first embodiment of a method for manufacturing a printed wiring board according to the present invention. FIG. 1 shows a multi-point coating layer made of resin ink on a terminal surface of a terminal portion in a printed wiring circuit. FIG. 2A is an enlarged plan view showing a state where a jumper circuit is connected to a terminal portion, and FIG.
FIG. 2B is a sectional view taken along the line AA of FIG. 2A, FIGS. 3 and 4 show a second embodiment of the method for manufacturing a printed wiring board of the present invention, and FIG. FIG. 4A is an enlarged plan view showing a state in which a jumper circuit is formed in a terminal portion,
FIG. 4B is a sectional view taken along line BB of FIG. 4A, and FIG. 5 is a partially enlarged view showing a conventional connection between a terminal surface and a jumper circuit made of conductive ink. DESCRIPTION OF SYMBOLS 1 ... Terminal part 2,3 ... Coating layer by resin ink 4 ... Jumper circuit formed by conductive paste 10 ... Printed wiring circuit, 20 ... Insulating substrate 21 ... Overcoat coating

Claims (3)

(57) [Claims] 1. A printed wiring circuit formed on an insulating substrate, and a connection circuit such as a jumper circuit formed by applying a conductive ink such as copper paste to a circuit terminal portion of the printed wiring circuit. In a printed wiring board, a coating layer in which a part of a terminal surface of a circuit terminal portion of the printed wiring circuit is coated with a resin ink, and a circuit terminal portion of the printed wiring circuit formed by applying a conductive ink to the coating layer A printed circuit board comprising: 2. The printed wiring board according to claim 1, wherein the coating layer on the terminal surface of the circuit terminal portion is formed by applying a resin ink in a halftone dot shape. 3. The printed wiring board according to claim 1, wherein the coating layer on the terminal surface of the circuit terminal portion is formed by applying resin ink in multiple points.