JPH01260885A - Method for conducting conductors of double-side printed board - Google Patents

Abstract

PURPOSE:To connect double-side conductors with rivets using a small revet driving force and embedding the ends of the rivet in the surfaces of printed conductors, by heating an insulator between the lands of both surfaces of double- side printed board, compressing the insulator so as to reduce the thickness, and connecting both lands with the revets. CONSTITUTION:In order to conduct lands 3 and 3 of both surfaces, at first, both lands are heated and compressed, and the thickness of an insulator 10 between both lands 3 and 3 is reduced. Since the insulator 10 is softened by heating, the compressing force required for reducing the thickness has relatively low pressure. A V-type heater chip electrode can be used for the heating and compressing. The chip electrode is conducted when the compressing force of the electrode becomes a preset value or more. When the thickness of the insulator 10 between the lands 3 and 3 is reduced, a through hole 4 is formed with a drill. Thereafter, the lands 3 and 3 are connected with a rivet 5. Each end of the rivet is embedded in the surface of a printed conductor.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for conducting conductors on a double-sided printed circuit board.

(Prior Art) The use of rivets may be considered as a method of conducting conductors on both sides of a double-sided printed circuit board.

In this case, in the case of a double-sided printed circuit board that is used in a laminated manner, for example, in the case of a double-sided printed coil that is used when a transformer is assembled by laminating double-sided printed coils, one end and the other end of the rivet are connected to each side of the double-sided printed circuit board. It is necessary for lamination to sink into the surface.

(Problem to be Solved) By the way, there is a plastic film as a printed circuit board support between the conductors to be joined by rivets on a double-sided printed circuit board, and it is necessary to immerse the rivet ends into the surface of the printed circuit board. In order to do this, the thickness of the plush film part at the rivet joint must be reduced when driving the rivet, and this reduction in thickness requires considerable high pressure, thus increasing the rivet driving force. There is a need,
There is a concern that the printed 14 board may break or deform when driving rivets.The object of the present invention is to be able to join double-sided conductors with rivets with a relatively small rivet driving force, and to connect the rivet end to the printed conductor surface. It is an object of the present invention to provide a method for conducting conductors on a double-sided printed circuit board that can be immersed in a double-sided printed circuit board.

<Means for Solving the Problems> The conductor conduction method for a double-sided printed circuit board according to the present invention involves thinning the insulator between the lands on both sides of the double-sided printed circuit board by heating and pressurizing it, and using rivets between both run parts. This method is characterized by comprising a joining process.

<Explanation of Examples> The present invention will be explained below with reference to the drawings.

FIG. 1 shows a double-sided printed circuit board on which conductor conductivity is processed according to the present invention (after the conductor circuit pattern formation has been completed),
FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1.

In FIGS. 1 and 2, 1 is an insulating film, which is usually a thermoplastic resin film (thickness 50 μm-10
00 μm) is used.

2.2 is a conductor with a predetermined pattern formed on both sides, made of gold;
Plating layers of silver, copper, aluminum, nickel, iron or metal foils (thickness 35 μm to 1000 μm) are used. 3.3 is a connecting land.

According to the invention, in order to conduct the lands 3.3 on both sides,
First, both lands are heated and pressurized to reduce the thickness of the insulator 10 between both lands 3.3, as shown in FIG.

Since the insulator 10 is softened by heating, a relatively low pressure is required to reduce the thickness. A ■-shaped heater tip electrode can be used for this heating and pressurization.

This chip electrode is energized and generates heat when the pressure applied to the electrode exceeds a set value (0.1 to 100 kg).

The energization time is 0.1 to 60 seconds. The dimensions of the tip of the tip electrode are 0.5 x 0.5 mm” = 10 x l (lam
”.In this way, the land 3.3 turns of insulator 10
After reducing the thickness, a through hole 4 is drilled as shown in Fig. 4, and then a land 3 is drilled as shown in Fig. 5.
．． 3 are joined with a rivet 5 (outer diameter is 1.5 to 3 times the diameter of the above hole), and each end of the rivet is sunk into the printed conductor surface.

As the material of the rivet, brass, tough pitch copper, oxygen-free copper, aluminum, stainless steel, etc. can be used. It is desirable to use a tubular rivet, and the shape of the head is round, truss, flat, round, etc.

Instead of the above rivet, a solder-attached rivet (6 in Fig. 5 is a solder layer) can be used. In this case, the rivet is fastened with a stem that also serves as an electrode and a curl punch, and then electricity is applied to remove the solder. Melt and solder between the rivet and land. In this case, the setting value of the fastening pressure of the rivet is usually 1.0 to 1000 kg, and the conditions for energizing the electrode are a DC current of 120 to 15 A/dragon 2, and a energization time of 15 to 5 seconds.

In the above embodiment, as shown in FIG.
．． After drilling a hole 4 through the hole 3, a rivet 5 can be inserted into the hole as shown in FIG. 7, and then the rivet 5 can be fastened under heating as shown in FIG. . As the rivet setter in this case, the above-mentioned stem that also serves as an electrode and curl punch can be used. Furthermore, it is also possible to solder between the rivet and the land by using the above-described solder rivet (in FIGS. 7 and 8, 6 is a solder layer). In this case, the setting value of the rivet fastening pressure is usually 1.0 to 1000 kg.
, the current condition of the electric board is DC current 150-300 A/Ryu 2
, the current application time is 20 to 10 seconds.

(Example 1) A double-sided printed circuit board was prepared by laminating rolled copper foil with a thickness of 300 μm on the front and back sides of a polyethylene terephthalate film with a thickness of 125 μm using a polyester resin adhesive.The board was made using photoresist. A pattern was baked using the wafer and etched with cupric chloride to form a conductive circuit pattern.

The size of the connecting land part is 3 x 3■■2.
A NA62Cx welding head (manufactured by Nippon Avionics Co., Ltd.) with a welding head of Electricity was applied for 4 seconds, and the electrode temperature was 480° C. As a result, the polyethylene terephthalate resin between the lands was melted and extruded from the lands.

Furthermore, a drill (diameter 1
, 1 mm).

Next, insert the solder rivet and fasten it with a rivet caulking machine using a stem that also serves as an electrode and a curl punch (diameter 211) with a caulking pressure of 100 kg.
A/Fin 2, electricity was applied for 10 seconds to melt the solder and complete the bonding between the land parts. The solder rivet is a semi-cheaply flat heel made of copper, with a shaft diameter of 1.0 crane, under-neck dimension of 1.0 fin, head diameter of 1.8 dragon, and the same thickness of 0.15 crane size.

After bonding, the contact resistance of the land portion was measured and found to be lOμΩ.
It was below.

<Example 2> A through hole with a diameter of 1.20 was drilled in the center of the connection land (3×3N'') of a double-sided printed board on which a conductive circuit pattern was formed in the same manner as in Example 1.

Next, a solder rivet is inserted into the through hole, and a direct current of 250 A/in'' is applied between both electrodes using the glue vent setter machine.
While applying electricity for 15 seconds and heating, slowly apply pressure until the pressure is 1.
At the same time, the electrical connection was completed by soldering the land part and the rivet.

The solder attachment rivet is a semi-tubular flat rivet made of copper material, with a shaft diameter of 1.2u, under-neck dimension of 1.0fi, and head diameter of 2.0fi.
The size is O1m, the same thickness is 0.10+n.

When the contact resistance of the connection land portion was measured, it was 10 μΩ or less.

(Effects of the Invention) The conductor conduction method of the double-sided printed Or, because it is done when the insulator is heated and softened, cracks in the insulator occur when the insulator is depressurized.

This can effectively prevent the occurrence of damage. Therefore, the edge of the wire can be immersed into the conductor surface of the double-sided printed board without any hindrance.
Conductor continuity of double-sided printed boards used in a laminated manner can be easily achieved.

[Brief explanation of the drawing]

FIGS. 1, 2, 3, 4, and 5 are explanatory diagrams showing the working procedure of one embodiment of the present invention, and FIGS. 6, 7, and 8 are illustrations of another embodiment of the present invention. It is an explanatory diagram showing a work procedure of an example. In the figure, 1 is an insulator, 3.3 is a land, and 5 is a rivet. ? z group γaEB

Claims (1)

[Claims] A method for conducting conductors on a double-sided printed circuit board, comprising the steps of reducing the thickness of an insulator between lands on both sides of the double-sided printed circuit board by applying heat and pressure, and joining the two lands with rivets.