JPS6050881A - Method of connecting wirings of coated electric conductor - 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] fat Technical field of invention The present invention relates to a wiring connection method for coated electrical conductors.

More specifically, the present invention relates to an efficient and improved wiring connection method for connecting predetermined locations such as pads of a printed circuit board by soldering using a laser beam as a heat source using a covered electrical conductor.

(b) Background of the Technology When soldering printed circuit boards for electrical equipment, radiation beams are increasingly used to connect wiring. In this case, the energy of the radiation rays is used as a heat source.)
However, the major advantages are that the laser beam that is the heating source has excellent beam convergence, and that the time and energy intensity can be easily controlled by +lI.

(C1 Prior Art and Problems) Soldering electrical conductors is a method used to connect two points on an electrical circuit as shown in Figure 1.

Cut the coated electrical conductor 1 to a predetermined length, solder it &-1
For this reason, the insulating coating layer 2 on both ends of the wire was peeled off to expose the internal core wire 3.The solder was placed on the part, and the solder was heated together with the material to melt and solidify the solder. It is being done.

Conventionally, the above-mentioned peeling of the insulating coating layer 2 was carried out by mechanical means such as a knife, but when using a laser beam as a heat source for soldering, the convergence of the laser beam is used to peel off the insulating coating layer 2 in a predetermined manner. It has become more efficient to remove the insulating coating layer 2 by heating a narrow area with a laser beam. In particular, when the core wire 3 is a very fine wire of about 0.1 mm, the method of mechanically removing the insulating coating layer may cause the core wire 3 to break 11i, so the laser beam method is effective.

FIG. 2 is an enlarged side view of the soldering portion showing the process of the conventional soldering and connection method of the coated electrical conductor 1 using a Rede beam.

One end of the coated electrical conductor 1 is held down by a welding tip 5 and fixed onto, for example, a connection pad 7 of a printed circuit board 6, and a laser beam 4 is concentratedly irradiated onto a point to be welded through a hollow part inside the welding tip 5.

First, as shown in FIG. 2 (ta+), the insulating coating layer 2 of the covered electrical conductor 1 is sublimated (or carbonized) and removed.

Next, as shown in FIG. 2 fb), the soldering layer on the connection pad 7 is melted, the core wire 3 is wrapped with solder N8, and the connection pad 7 is soldered to the solder pad 7, thereby completing the work. During this time.

Normally, the laser beam 4 is irradiated continuously at a constant intensity until soldering is completed.

On the other hand, the materials for the insulating coating layer include sublimable materials that vaporize when heated, such as polyurethane, and materials that carbonize without vaporizing, such as polyester and Teflon.1 Both materials can be heated by laser beams. It can be removed.

However, in general, sublimable Il! such as polyurethane! l
The amount of energy required to remove a carbonized insulating coating such as polyester is
considerably smaller than After removing the insulation coating layer at the same time,
The energy consumption required to attach the core wire for half a month depends on its dimensions and the heat capacity M of the printed circuit board to be connected.
It changes considerably.

As mentioned above, in the conventional half 111 attachment using a laser beam, the insulation coating layer is removed and the core wire half [1
1 & J work was performed simultaneously by heating at a constant laser beam energy intensity for a predetermined period of time. As a result, various problems occur, leading to a decline in soldering quality and work efficiency. For example, there were problems such as burnout due to excessive heating of the bonding pad used for soldering (]'&J), and conversely, insufficient removal of the insulating coating layer.Thus, by solving these problems, a good semi-ffl bonding is possible. The development of a connection method for laser beam soldering has been long awaited.

(d+ Purpose of the Invention The present invention has been made in view of the above-mentioned points, and it is an object of the present invention to provide a soldering connection method that makes it possible to perform high-quality soldering by fully utilizing the ease of control of a laser beam. be.

(el) Structure of the Invention The object of the above invention is to connect the insulated electrical conductive wire, which is composed of an insulated covering layer and a metal core wire, to a predetermined position by soldering using laser beam energy. Removal of the layer and soldering of the metal core wires can be facilitated by heating the connected parts under different heating conditions configured by a combination of laser beam application time and laser beam intensity, depending on the connection. achieved.

Embodiments of the Invention Examples of the present invention will now be described with reference to the drawings.The welding tip 5 used for soldering connections using laser beams is the same as the conventional one.

The heating conditions for the connection in the half-junction method according to the present invention are different from those in the conventional method. FIG. 3 shows a heating time chart 1 for soldering using a laser beam according to the conventional method and the present invention.

The horizontal axis shows time, and the vertical axis shows intensity E of the laser beam 4. FIG. 3 ta+ shows the conventional heating method, and as mentioned above, the intensity of the laser beam is constant from beginning to end, and heating is performed continuously.

Therefore, as mentioned above, even though there is a difference in the required energy between peeling off the insulating coating layer 2 and soldering the core wire 3, since the irradiation energy is applied to the opening, the required energy for each step is reduced. Control is poor, and in general, soldering tends to result in excessive heating.

Figure 3 (bl) is a laser beam irradiation time chart without showing an example of the soldering connection method according to the present invention.The energy of the irradiated laser beam 4 is kept constant at °C, but After removing the insulation coating!-2 by irradiation and heating in A, the irradiation is stopped for a short time to lower the temperature of the heated part.

Thereafter, heating is performed under heating condition B for a shorter time to melt and solder the solder layer of the connection pad 7 by heating so as not to overheat it.

FIG. 3 (C1 is a method in which there is no heating element stop time,
Under heating condition A, the insulating coating layer 2 is first irradiated with a laser beam 4 with a high energy intensity, and then a laser beam 4 with an energy intensity lower than that of heating condition A is continuously irradiated without a pause. Complete soldering.

This method is suitable when the core wire 3 is relatively thick.

On the other hand, when soldering is performed, when the target connection pad 6 is large and has a heat capacity, as shown in Fig. 3 fdl, first preheat under heating condition A with low energy and for a long time before soldering. There is also a method of raising the temperature of the connection point to a certain extent and then using heating condition B to quickly complete the half-IB connection by heating with high energy and for a short time.

(gl) Effects of the Invention As is clear from the above description, the soldering connection method using laser beam heating based on the present invention can be used to connect coated electrical conductors by soldering.

Soldering with high reliability and excellent work efficiency allows you to obtain connections. In particular, there is an advantage that soldering connections can be made in accordance with the thickness of the core wire of the covered electrical conductor and the heat capacity H# of the connection point.

[Brief explanation of the drawing]

No. 112, [Soldering is a perspective view showing the structure of a coated electrical conductor used for connection, and Fig. 2 shows a soldering process using a laser beam.
1 ('b) A sectional view showing the main parts of the J connection process. 2 is a time chart showing the radiation method. In the figure, 1 is a coated electrical conductor, 2 is an insulating coating)-23
4 is a laser beam, and 5 is a welding tip. Reference numeral 6 indicates a printed circuit board, 7 indicates a connection pad, and 8 indicates a solder layer.

Claims (1)

[Claims] When connecting a coated electrical conductor consisting of an insulating coating layer and a metal core wire to a predetermined position by soldering using laser beam energy, removing the insulating coating layer and soldering the metal core wire are necessary for connection. Correspondingly, there is provided a wiring connection method for electrical conductor wires, characterized in that the connection portions are heated under different heating conditions configured by a combination of laser beam application time and laser beam intensity.