JPS63250192A - Method of providing continuity of conductor in double-sided printed circuit - 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 <Industrial Application Field> The present invention relates to an improvement in a method for conducting conductors in a double-sided printed wiring board.

<Conventional technology> When forming conductor circuits on double-sided printed wiring boards,
The conductor patterns on both sides must be electrically conductive at predetermined locations.

This conduction method includes (A) a method of pressurizing the above-mentioned predetermined location of the double-sided printed wiring board with a chip that heats the conductor to a temperature that allows conductor welding, and welding both conductors with this chip, or (B) a method of welding both conductors with the tip. A method has become known in which both conductors are welded by pressurizing the location with a probe electrode and energizing the location.

<Problem to be solved> However, in method (A), the substrate between the two door bodies at the location to be welded is carbonized, and due to the low fluidity due to this carbonization, the welding between the two door bodies due to the above-mentioned pressurization is Inclusions from (substrate material)
It is difficult to completely eliminate this, and it is difficult to guarantee low resistance conductivity and high welding strength. Furthermore, method (B) μ has the problem that the results are largely dependent on the thickness of the insulating layer used, and is not a practical method.

An object of the present invention is to provide a method for conducting conductors in a double-sided printed wiring board that can ensure low resistance conductivity and strong welding strength.

Technical Means for Solving the Problems> The conductor continuity method in a double-sided printed wiring board according to the present invention involves forming conductor patterns on both sides of an insulating board, and welding the conductor patterns on both sides at predetermined locations. The method involves reducing the thickness of the above-mentioned predetermined area under pressure at a temperature lower than the melting point of the conductor and higher than the melting point of the insulating plate, and then welding the good conductor at that point. This method is characterized by

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

FIG. 1 shows a double-sided printed wiring board immediately before being subjected to conductor conduction processing according to the present invention, and is usually intended for a board on which the formation of a conductor circuit pattern has been completed.

The insulating substrate 1 is usually coated with a thermoplastic resin film 51 such as polyethylene or polyethylene terephthalate film. For the conductor 2, a plating layer of gold, silver, copper, aluminum, nickel 1, iron, or metal foil (thickness 5 μm to 1000 μm) can be used.
can be used.

In Fig. 1, A is the planned conduction point of the good conductor 2.2, and this point is heated at a temperature lower than the melting point of the conductor and higher than the melting point of the insulating substrate. As shown in the figure, the heater chip 3 applies pressure to reduce the thickness.

Due to this pressurization under heating, the insulating substrate 1 is melted, and the insulating substrate 1 is fluidly removed from between both door bodies 2.2. In this way, the inclusions can be removed from between the two conductors and the good conductors can be brought into contact.

After that, as shown in Figure 4, the probe electrode 4.4 is brought into contact with the contact point of the good conductor under a predetermined contact pressure, and the good conductor is welded using the heat generated by current through resistance welding. . In addition to resistance welding, ultrasonic welding, beam welding, etc. can also be used.

A type heater tip electrode can be used to heat and press the predetermined location in the step shown in Figure 2 above. When the pressure of this electrode exceeds the set value, resistance welding is applied to the V type heater tip electrode from the m power source. Power is applied. The setting value of this pressurizing force is usually 0.1 to 100 kg, and the time for energizing the electrode is:
It is 0.001 seconds to 1 minute. The dimensions of the tip of the (2) type heater tip electrode are 0.5 Xo, 5 mm" or more and 10 X 10a++s" or less. As the resistance welding machine, an AC resistance welding machine or a constant temperature resistance welding machine can be used.

The pressing force of the probe electrode 4.4 in resistance welding is usually in the range of 0.1 to 1000 kg, the welding energy is usually in the range of 0.1 to 100 OWs, and the welding time is usually in the range of 0.1 to 1000 OWs.
It is within the range of 0.001 to 0.1 seconds.

In addition, in the ultrasonic welding method, an anvil 6 is placed under the conductor on the back side, a horn 5 is placed over the conductor on the front side, and the front and back conductors are welded by applying pressure and vibration.
(see figure). The pressing force at this time is within the range of 0.1 to 1000 kg, and the frequency is within the range of 10 to 100 KHz.
The horn amplitude is selected within the range of 5 to 500 pm'-', the welding time is selected within the range of 0.1 to 10 seconds, and the shape of the tip of the horn can be freely selected according to the shape of the welded part. You can choose.

Although the state during welding is not necessarily clear, it is possible that the conductors at the interface become integrated as a result of ultrasonic heating and vibration, rather than melting and joining as a result of heating by ultrahigh waves. It is considered.

Example A printed wiring board was formed by bonding a 300 μm thick copper plate to the front and back surfaces of a 125 μm thick polyethylene terephthalate film using Vyron adhesive, and etching this with ferric chloride to form a conductor pattern. was formed.

The size of the welding part is φ4mm + binding. First, we used a thermochondrol welder rcw manufactured by Nippon Avionics Co., Ltd.
115, ■ type heater tip electrode IT'-16-2 (tip shape 1.6 x 2 mm) manufactured by Nippon Avionics Co., Ltd.
) Welding head N made by Nippon Avionics Co., Ltd.
A62C was energized. The signal to start energization is obtained by sending a signal from the head to the power source when the V-shaped heater tip electrode presses the copper plate to be welded with a pressure of 6 kg. The current application time was 4 seconds, and the temperature of the V-shaped heater chip electrode was 400°C. Through this operation, the polyethylene terephthalate film between the upper and lower copper plates is melted, and the melted portion of the polyethylene terephthalate film is welded using a resistance welding machine. The resistance welding machine was NRW-200 (modified product) manufactured by Nippon Avionics Co., Ltd., and the welding was carried out at a pressure of 9 +r, a welding energy of 240 Ws, and a welding time of 0.0028 seconds. The shape of the probe electrode is φ1.
It is 2 open.

The timing to start welding is obtained by sending a signal from the head to the power source when the probe electrode presses the copper plate, which is the object to be welded, with a pressure of 9k+r.

After welding, the contact resistance of the welded part was measured and found to be lOμΩ.
It was below. Next, the strength of the welded portion was measured using Autograph AG-200OA manufactured by Shimabara Seisakusho Co., Ltd. The strength was measured by peeling strength in the 90' direction, and the peeling rate was 50 cm/min.

The peel strength of the welded portion of the printed wiring board was 1.6 kg.

Example 2 In the same manner as in Example 1, the polyethylene terephthalate film between the upper and lower copper plates is melted. Next, the melted portions of the polyethylene terephthalate film are welded using an ultrasonic welder. The ultrasonic welding machine was USR-60022O8 manufactured by Ultrasonic Kogyoku Co., Ltd., and was controlled by a timer with a pressure cuff of 5 kg, a horn amplitude of 38 pm, and a welding time of 9.5 seconds. A grid-shaped object was used.

After welding, the contact resistance of the welded part was measured and found to be 10 μΩ.
It was below. Next, we measured the strength of the welded part.3.
It weighed 8 kg.

Comparative example: The part to be welded was a welding head NA made by Nippon Avionics Co., Ltd.
-6011 and energized using resistance welding 1NRW-200 (modified product) manufactured by Nippon Avionics C Co., Ltd. -1ffl
The signal to start electricity is obtained by sending a signal from the head to the power source when the probe electrode presses the copper plate to be welded with a pressure of 9 kg. 1ffl electric time is 0.0
Welding was performed for 0.28 seconds, the welding energy was 240 Ws, and the tip shape of the probe electrode was φ1.2 mm.

After welding, the contact resistance of the welded area was measured and found to be INΩ.
That was it.

<Effects of the Invention> As described above, in the method for conducting conductors in a double-sided printed wiring board according to the present invention, both conductors are welded after melting and removing the insulating material at the welded area, and there is no possibility of inclusions at the welding interface. (
Since the remaining insulating material can be effectively eliminated, the electrical conductivity of the welded part can be ensured well.

[Brief explanation of drawings]

Claims (1)

[Claims] In a method of forming conductor patterns on both sides of an insulating plate and welding the conductor patterns on both sides at predetermined locations, the above predetermined locations are heated at a temperature lower than the melting point of the conductor and higher than the melting point of the insulating plate. A method for conducting conductors in a double-sided printed wiring board, characterized by reducing the thickness under pressure under heating, and then welding both conductors at that point.