JPS60211894A - Method of connecting printed coil pattern - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is based on a method in which printed coil patterns formed in multiple layers by a so-called printed circuit method such as a subtractive method or an additive method are laminated in multiple layers, and each coil is sequentially electrically applied. It is related to the method of connection.

(Prior art) Since the printed coil pattern forms a spiral conductor, it is impossible to connect the circuit ends at the center end with other circuits in a two-dimensional manner, so there is no way to connect them three-dimensionally. Various proposals have been made. Conventionally, as described in JP-A No. 57-186940, for example, spiral conductors were formed on both sides of an insulating layer, and their central ends were mechanically pressed together to bring the upper and lower conductors into contact, followed by electric welding. This method has been proposed, but because the method involves mechanically breaking through the insulating layer to bring the conductors into contact with each other, the contact area of the conductors varies, leading to variations in connection resistance and low reliability. There was a problem. On the other hand, as described in JP-A No. 57-207396, spiral conductors are formed on both sides of the insulating layer,
A method has been proposed in which the central end is machined and then copper through-hole plating is performed to connect the upper and lower conductors and to establish a connection between the coils. Although there are no problems such as variations in connection resistance or deterioration of reliability, there are disadvantages in that the copper plating must be thickly applied and the plating time is longer, resulting in higher costs.

(Objective of the Invention) The present invention was developed as a result of research aimed at finding a low-cost and reliable connection method for printed coil patterns for which there was no reliable and low-cost method. It was found that connection can be easily achieved by placing the two bodies facing each other and interposing an insulating sheet with a connecting hole for connecting the central ends, and connecting the central ends with a conductive material through the connecting hole. Furthermore, based on this knowledge, various studies were conducted and the present invention was completed.

(Structure of the Invention) The present invention provides a method for connecting the center ends of the spiral circuits of a printed coil in which a spiral circuit is formed with a conductor on one side of an insulating layer, in which the conductor surfaces of the spiral circuits are faced to each other,
This method of connecting printed coil patterns is characterized in that an insulating sheet having a connection hole for connecting the center ends is interposed, and the center ends are connected to each other with a conductive material through the connection hole.

The conductor used in the present invention is copper, aluminum, silver, etc., and the method for forming the spiral circuit (2) is to paste metal foil such as copper or aluminum foil over the entire surface of the insulating layer (3). There is a subtractive method in which only the necessary parts are left by etching, an additive method in which copper plating is applied to the necessary parts, and a method in which the circuit (2) is formed by screen printing copper paste, silver paste, etc. . The printed coil pattern obtained in this way (1
) is shown in Figure 1. Insulating sheet with connection holes (
4) Polyester film, polyimide film,
Plastic films such as polyamide-imide films (
6) Alternatively, apply an adhesive (5) such as acrylic resin adhesive (5), epoxy resin, phenol/butyral resin, phenol/NBR resin, etc. to both sides of these films (6).
) is used. FIG. 2 shows a cross-sectional view of a plastic film (6) coated with adhesive (5) on both sides, and FIG. 3 shows a cross-sectional view of an insulating sheet (4) with connecting holes (7) formed therein. When connecting printed coil patterns, first, a conductive substance (8) is placed or coated on one or both of the central ends (9) of the printed coil patterns to be connected. Conductive substances include plate-shaped, granular solder,
Refers to solder paste, recording paste, copper paste, etc. Figure 4
At the center end of the printed coil pattern connection point (9)
An example is shown in which a conductive material (8) is placed on one side. The printed coil pattern (1) on which the conductive material (8) of Figure 4 is placed
), align the connection points and place the insulating sheet (4) with holes for the connection points on top of it (Figure 5), then place the center end of the connection point of the other printed coil pattern (1) (9 A method of aligning and overlapping 1 (Fig. 6) so that it faces the center end (9) of the connection point described above, and reflowing the conductive material that has been placed or applied 1 to establish continuity between the upper and lower circuits. Examples include a method of heating and melting on a hot plate, a method of heating and melting through a far infrared rays furnace, and a method of high frequency heating.

(Effects of the Invention) According to the method of the present invention, it is much simpler and can be done at a lower cost than the through-hole plating method, which requires a long process of applying copper plating and requires a large number of man-hours. Also, the connection resistance is low at 0.03~005Ω, -
No deterioration of the connection resistance was observed even after 50 cycles of a temperature shock cycle test of 60°C 10 minutes←100°C 10 minutes.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a printed coil pattern, Figure 2 is a cross-sectional view of an insulating sheet, Figure 3 is a cross-sectional view of an insulating sheet with connection holes, and Figure 4 is a conductor placed at the connection point of the printed coil pattern. FIG. 5 is a diagram in which the insulating sheets with holes drilled in the connection locations shown in FIG. 4 are aligned and superimposed, and FIG. 6 is a diagram in which the locations to be connected are opposed and aligned with the insulating sheet interposed. 1 is a printed coil pattern, 4 is an insulating sheet, 7 is a connection hole, 8 is a conductive material, 9 is a central end O of the coil

Claims (1)

[Claims] In the method of connecting the center ends of the spiral circuit of a printed coil in which a spiral circuit is formed with a conductor on one side of an insulating layer, the conductor surfaces of the spiral circuit are faced to each other and the center ends are connected. 1. A method for connecting printed coil patterns, which comprises interposing an insulating sheet having a connection hole, and connecting the central ends with a conductive material through the connection hole.