JPH0794035A - Tape wire for relay connection - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a tape electric wire for relay connection, which enables easy, inexpensive, and reliable connection between electronic components. A copper conductor 1 is exposed at an end of a tape electric wire 10 having a predetermined length, and a metal 3 (for example, Sn, Ni, Zn) having a laser reflectance of 75% or less is plated on the exposed surface of the copper conductor 1. Set up. This plating enhances laser absorption,
Electronic parts A and B by laser welding that heats the copper conductor 1 to the extreme part
Since it is possible to reliably join to the lead L, the relay connector is not necessary, and the electronic components are not adversely affected by heat like soldering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape electric wire used for relay connection of electronic parts, and more particularly to a tape electric wire capable of joining relayed conductors by laser welding.

[0002]

2. Description of the Related Art Conventionally, when electronic parts are electrically connected to each other, a connector is used, or a substrate for relay connection or a tape electric wire is used and leads of the electronic parts are attached to conductors of these boards and electric wires. Methods such as soldering were adopted.

[0003]

Connection by a connector requires a large investment in a connector manufacturing facility including a mold for molding a connector housing and a mold for molding a terminal. Moreover, the equipment can manufacture only one part of one kind, which is not preferable in terms of production efficiency and cost reduction.

Further, in the method of soldering the leads of the electronic component to the conductor of the relay component for relaying, the electronic component is exposed to high temperature during soldering and there is concern about the long-term reliability of the solder itself. Is not a preferable connection method.

Therefore, it has been considered to join the conductor of the relay component to the lead of the electronic component by laser welding capable of joining by heating the pole portion. However, conductors such as tape electric wires, which are often used as relay parts, are usually formed of copper, and this copper has poor laser absorption. It will be small and not practical.

The present invention is intended to provide a tape wire for relay connection, which is effective in solving these problems.

[0007]

In the tape wire for relay connection of the present invention which solves the above-mentioned problems, the conductor end portion of the tape wire having a predetermined length is exposed, and the laser reflectance on the surface of this exposed conductor. Is plated with a metal of 75% or less.

Examples of plating metals having a laser reflectance of 75% or less include Ni, Sn and Zn. The film thickness of the plating using these metals is preferably in the range of 0.5 to 50 μm.

If the conductors of the tape electric wire have the same arrangement pitch of the relayed conductors, the arrangement pitches of the one end side and the other end side are the same. Further, when there is a difference in the arrangement pitch of the relayed conductors, the arrangement pitch on the one end side and the other end side are made different according to the pitch difference.

[0010]

The copper conductor of the tape wire is poor in laser absorption as it is and difficult to laser weld. However, in the present invention,
Since the surface of this conductor is plated with a metal having a low laser reflectance, the laser absorptivity is increased and stable laser welding can be performed. Since laser welding concentrates energy and melts only the joint surface, thermal influence on electronic parts can be greatly reduced unlike soldering. Further, if the laser welding is used for direct joining, no connector is required, and all the problems of the prior art are eliminated.

The thickness of the metal plating for laser welding is optimally 0.5 to 50 μm as described above. If the thickness is less than 0.5 μm, the effect of improving the laser weldability does not appear so much.
On the other hand, when the thickness exceeds 50 μm, the effect of improving the laser weldability is leveled off, the productivity is deteriorated, the cost is increased, and the bending property of the electric wire is deteriorated.

[0012]

1 and 2 show specific examples of the tape electric wire of the present invention. The illustrated tape electric wires 10 and 20 are used for relay connection of electronic components A and B, and a copper conductor 1 is covered with an insulating coating 2. This copper conductor 1 is exposed for an appropriate length as shown in the figure, and the laser reflectance is 75 on the conductor surface of this portion.
% Or less of the metal plating 3, the tape electric wire of the present invention is finished.

In the tape electric wire 10 of FIG. 1, the leads L of the electronic components A and B to be relayed and connected have the same pitch, so that the copper conductors 1 are arranged in parallel at the same pitch as the arrangement pitch of the leads. On the other hand, in the tape electric wire 20 of FIG. 2, since the arrangement pitch of the leads L of the electronic components A and B is different, the arrangement pitch of the copper conductors 1 is changed on the way to match the arrangement pitch of each lead.

A more detailed embodiment will be described below.

-Experimental Example 1- The tape electric wire 10 shown in FIG. In this prototype, the copper conductor 1 had a thickness of 70 μm and a width of 0.8 mm, and the exposed surfaces of both ends were plated with metals having different laser absorptivities. There are five types of plating metals used in Table 1,
In both cases, the film thickness was 10 μm. For these samples, electronic component leads (Fe-42 wt% Ni, 0.
2 mm thick) was laser-welded and joined, and the shear strength was measured as the joining strength. The results are also shown in Table 1.

[0016]

[Table 1]

From the results of this experiment, metal plating having a laser reflectance higher than that of the underlying copper has the opposite effect, but metal plating having a laser reflectance of 75% or less often gives good bonding strength. I understand.

-Experimental Example 2- A tape electric wire 10 shown in FIG. Here, as shown in Table 2, Sn plating was used as the plating 3, and 11 kinds of plating having different thicknesses of the copper conductor 1 were prepared.
The width of each copper conductor 1 is 0.8 mm. Then, the copper conductors 1 of the 11 kinds of samples are connected to leads (Fe-
42 wt% Ni, 0.2 mm thick) and joined by laser welding.

Shear strength was measured as the joint strength of the joint portion, and this is also shown in Table 2.

[0020]

[Table 2]

As can be seen from Table 2, the greater the thickness of the copper conductor 1 is, the higher the bonding strength can be obtained, but the effect is not improved even when the thickness is more than 80 μm.

If the Sn plating thickness is less than 0.5 μm, sufficient bonding strength is not obtained, and conversely 50 μm.
Even if it is more than m, the effect does not grow.

[0023]

As described above, in the tape electric wire of the present invention, since the lead of the electronic component can be laser-welded and joined to the copper conductor for relay, the relay by the connector is unnecessary, and It also prevents the electronic components from being adversely affected by heat and contributes to simplification of relay connection, cost reduction, and reliability improvement.

[Brief description of drawings]

FIG. 1 is a plan view showing a tape electric wire of an embodiment including electronic parts to be relayed.

FIG. 2 is a plan view showing a tape electric wire of another embodiment including electronic parts to be relayed.

[Explanation of symbols]

 1 Copper conductor 2 Insulation coating 3 Metal plating with laser reflectance of 75% or less 10, 20 Tape wire

Claims (3)

[Claims] 1. A conductor end portion of a tape electric wire having a predetermined length is exposed, and the surface of the exposed conductor has a laser reflectance of 75.
Tape wire for relay connection, which is formed by plating metal of less than 100%. 2. The thickness of the metal plating is 0.5 μm or more and 5
The tape wire for relay connection according to claim 1, which has a thickness of 0 μm or less. 3. The tape wire for relay connection according to claim 1, wherein the array pitch on one end side of the conductor and the array pitch on the other end side are made different according to the array pitch difference of the relayed conductors.