JPH04331013A - Device for cutting fine wire into constant size - Google Patents

Abstract

PURPOSE:To increase the cutting accuracy of fine wire and reduce the cutting size of the wire smaller. CONSTITUTION:In a device for cutting fine wire into constant size 9 in which a lower blade 1, an upper blade 2, and a stopper 3 are positioned in order, the thickness of the upper blade 2 is made thicker and the stopper 3 is put under the upper blade 2 and a spring 7 is put under the stopper 3 or the stopper 3 is provided integrally under the upper blade 2. Then, as the upper blade 2 is lowered, the stopper 3 is lowered, and as the upper blade 2 is raised, the stopper 3 is raised.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin wire cutting device for obtaining a fixed amount of material from a thin wire, such as a brazing filler metal used for bonding lead pins to an IC package.

0002

2. Description of the Related Art A conventional thin wire cutting device has a lower blade 1, an upper blade 2, and a stopper 3 arranged in this order as shown in FIG. In order to obtain short products, the thin wire 5 is cut into the lower blade 1 as shown in Fig. 3.
The wire is fed forward, the tip touches the stopper 3 and stopped, and then the upper blade 2 is lowered to cut the thin wire 5. Since the lower blade 1 and the stopper 3 are fixed, the length of the short product 6 obtained by cutting the thin wire 5 is between the lower blade 1 and the stopper 3.

By the way, as lead pins have become smaller in recent years, the amount of brazing material used for brazing has also decreased, and the cutting dimensions of thin brazing wires have also become smaller (length: 0.2 mm or less).

[0004] In the above-mentioned sizing cutting device 4, it is possible to reduce the cutting size of the thin wire 5 by reducing the thickness of the upper blade 2 and bringing the lower blade 1 and the stopper 3 closer together. There are problems such as a decrease in the mechanical strength of the thin wire 2 and a lack of precision in the cutting dimensions of the thin wire 5, and there is a limit to the cutting size of the thin wire 5, so that it cannot adequately handle the cutting of the thin wax wire mentioned above. There is.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fixed-size cutting device for thin wires that can cut fine wires with high accuracy even if the cutting size of the thin wires is small.

[0006]

[Means for Solving the Problems] One of the thin wire sizing cutting devices of the present invention for solving the above problems has a lower blade, an upper blade,
In a thin wire sizing cutting device that is arranged in the order of a stopper, the thickness of the upper blade is made thicker, the stopper is placed under the upper blade, and a spring is placed under the stopper, so that the lowering of the upper blade The feature is that the stopper is lowered against a spring, and as the upper blade rises, the stopper is raised to a predetermined position by the spring.

Another aspect of the thin wire sizing cutting device of the present invention is a thin wire sizing cutting device in which a lower blade, an upper blade, and a stopper are arranged in this order, in which the thickness of the upper blade is increased and It is characterized in that a stopper is integrally provided under the upper blade, the stopper is lowered when the upper blade is lowered, and the stopper is raised when the upper blade is raised.

[0008]

[Function] As mentioned above, the thin wire sizing cutting device according to the present invention does not make the thickness of the upper blade thinner, but rather thickens it, so the mechanical strength is improved, and the upper blade does not tighten when cutting fine wire. There is no wobbling and cutting accuracy can be improved. Furthermore, since the stopper moves up and down with the upper blade, the stopper can be moved closer to the lower blade without making the upper blade thinner, and the cutting size of thin wire can be further reduced.

[0009]

[Embodiment] One embodiment of the thin wire sizing cutting device of the present invention will be explained with reference to FIG. The stopper 3 is arranged below the upper blade 2, the spring 7 is arranged below the stopper 3, the stopper 3 and the spring 7 are held in a holder 8, and the lowering of the upper blade 2 The stopper 3 descends against the spring 7,
As the upper blade 2 rises, the stopper is raised to a predetermined position by a spring 7.

Next, another one of the thin wire sizing cutting devices of the present invention
To explain one embodiment with reference to FIG. 2, a lower blade 1, an upper blade 2, and a stopper 3 are arranged in this order, the upper blade 2 is made thicker, and the stopper 3 is integrally provided under the upper blade 2. When the upper blade 2 is lowered, the stopper 3 is lowered.
The stopper 3 is designed to rise together with the rise of the upper blade 2.

The thin wire cutting devices 9 and 10 of each embodiment configured as described above cut Ag-
Thin wire 5 of 15wt% Cu with a length of 0.1 mm (lower blade 1
to stopper 3).
0 million short products (brazing filler metal) 6 were obtained. The cutting dimensional accuracy of this short piece (brazing material) 6 was measured by replacing it with weight, and the results were as shown in the left column and center column of Table 1 below. Moreover, the upper blade 2 which cut 10 million pieces showed no wear, and the cutting condition of the short products (brazing material) 6 was also good.

However, using the conventional thin wire sizing cutting device shown in FIG.
The upper blade 2 broke just before 100,000 short pieces (brazing material) 6 were obtained by sequentially cutting the 5 wt % thin wire 5 into lengths of 0.1 mm (dimension from the lower blade 1 to the stopper 3). The cutting dimensional accuracy of 100,000 short pieces (brazing material) 6 was measured by replacing it with weight, and the results were as shown in the right column of Table 1 below.

[0013]

[Table 1]

As is clear from Table 1 above, the weight of the short products of the conventional example has a large variation and the cutting dimension accuracy is low, whereas the weight of the short products of Examples 1 and 2 has a small variation and the cutting dimension It can be seen that the accuracy is high.

[0015]

As described above, according to the thin wire sizing cutting device of the present invention, the cutting precision of the thin wire can be improved and the cutting size of the thin wire can be further reduced.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of a thin wire sizing cutting device of the present invention.

FIG. 2 is a diagram showing another embodiment of the thin wire sizing cutting device of the present invention.

FIG. 3 is a diagram showing a conventional thin wire sizing cutting device.

[Explanation of symbols]

1 Lower blade 2 Upper blade 3 Stopper 5 Thin line 7 Spring 9 Thin wire sizing cutting device 10 Thin wire sizing cutting device

Claims (2)

[Claims] Claim 1: In a thin wire sizing cutting device in which a lower blade, an upper blade, and a stopper are arranged in this order, the thickness of the upper blade is made thicker, the stopper is arranged under the upper blade, and the stopper is placed under the stopper. A thin wire sizing cutting device characterized in that a spring is disposed so that the stopper is lowered against the spring when the upper blade is lowered, and the stopper is raised to a predetermined position by the spring when the upper blade is raised. Claim 2: In a thin wire sizing cutting device in which a lower blade, an upper blade, and a stopper are arranged in this order, the thickness of the upper blade is increased, and the stopper is integrally provided under the upper blade. A device for cutting thin wire to size, characterized in that a stopper is lowered when the blade is lowered, and the stopper is raised when the upper blade is raised.