JPS6366626B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a semiconductor device, and particularly to a method for cutting a bonding wire.

(Conventional technology) Generally, lead wiring in semiconductor devices uses Au.
The so-called wire bonding work in which wires, A-wires, etc. are crimped or brazed is widely carried out, and in this case, the wires are wound into long wires and are cut each time after each wiring bonding work. .

That is, as shown in FIG.
mount the semiconductor chips (semiconductor elements) 4 and 5, and press the wires 7 with the bonding tool 6.
After wiring from the first chip 4 to the second chip 5 by moving the wire cutting blade 8 to the cutting position of the wire 7,
is lowered (in the direction of arrow A) to cut the wire 7, and then the wire 7 is pinched by the wire clamp device 9 and pulled to the right (in the direction of arrow B) to separate it. The bonding tool 6 is moved to the right at the same time as the wire clamp device 9, so that the wire 7 does not come out of the groove of the bonding tool and the next bonding operation can be easily performed. .

For example, in the case of A wire, if the wire diameter is small, it can be cut using the so-called pull-cut method, which involves simply pulling it with the wire clamp device 9, but if the wire diameter is approximately 200μφ or more, the pull-cut method will cut the wire. In order to avoid problems such as the wire elongating and becoming thinner, or damaging the bonding bond and causing it to peel off, a wire cutting blade as described above is provided and a pull cut method is used in combination with a cutter.

(Problem to be Solved by the Invention) In the above-described cutting method, the wire 7 is completely cut out by the blade 8 as shown in FIG. This may cause damage to the chip 5 (object to be bonded) or the PN junction of a semiconductor chip, and especially when wiring bonding between chips in a hybrid IC using relatively thick wires, the wiring may be damaged due to damage during cutting. It was possible.

The object of the present invention was made in view of the above circumstances, and provides a method that can cut wires of relatively large diameter without damaging the bonded object without changing the mechanism of the existing device. It is something to do.

[Structure of the Invention] (Means for Solving the Problems) In the present invention, a wire cutting blade having a contact portion having a flat surface and a cutting edge protruding from the contact portion to a size smaller than the diameter of the wire is provided. forming a notch in the wire that is smaller than the diameter of the wire by lowering the abutting portion onto the wire until it reaches the upper surface of the wire;
Cut the wire from the notch by pulling on one end of the wire.

(Function) According to the wire cutting method of the present invention as described above, the wire cutting blade that is lowered to cut the wire stops descending when the contact portion reaches the upper surface of the wire. Since the cutting edge of the blade is smaller than the diameter of the wire, only a notch smaller than the diameter for the pull cut is formed in the wire, so there is no damage to objects located under the cutting wire. Wires can be easily cut.

(Embodiment) FIG. 3 illustrates an embodiment of the wire cutting blade 10 and the wire 11 to be cut used in the wire cutting method of the present invention.
The wire cutting blade 10 has a flat contact portion 12 that contacts the wire 11 and a corresponding contact portion 12;
It is formed from a wedge-shaped cutting edge 13 having a length smaller than the diameter of the wire 11 formed on the right side of the corresponding contact portion 12. In wire cutting, the wire cutting blade 10 is swung down, or lowered, onto the wire 11. Then, when descending, the contact part 12 is connected to the wire 11.
It stops when it reaches the upper surface of the wire 11, that is, when the cutting edge 13 bites halfway into the wire 11.
1 has a notch 14 formed therein.
The clamp (not shown) is a normal clamp as shown in FIG.
1 can be cut. Therefore, according to such a wire cutting method, since the cutting edge of the wire cutting blade does not reach the object to be bonded, there is little mechanical damage to the object to be bonded in the wire bonding wiring, and no damage is caused. For example, hybrid IC
Wire bonding between chips in semiconductor devices such as the following becomes possible.

FIG. 4 shows a modified example of the cutting blade in the wire cutting method of the present invention. In FIG. 3, the contact portion 12 is formed on one side of the cutting edge 13, but in It is also possible to form abutting portions 12, 12' on both sides of the cutting edge 13, as shown in FIG.
Also, the length of the cutting edge (C dimension) in Figures 3 and 4.
may be changed depending on the properties of the wire used (material, wire diameter, physical properties such as hardness, cutting conditions such as cutting strength, etc.). Further, in the cutting blades shown in FIGS. 3 and 4, the cutting edge and the contact portion are integrally formed of the same material, but for example, only the cutting edge may be formed of a sharp material.

[Effects of the Invention] As is clear from the above embodiments, the wire cutting method of the present invention can cut relatively thick wires without damaging the bonded object without changing the mechanism of the conventional device. can do.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a wire cutting device showing cutting of a wire bonded wire by a conventional wire cutting method, FIG. 2 is a front view showing a wire cutting blade and a wire cutting section in FIG. 1, and FIG. FIG. 3 is a sectional view showing a wire cutting blade and a wire cutting part in an embodiment of the present invention, and FIG. 4 is a sectional view showing a modification of the wire cutting blade in the wire cutting method of the invention. 1... Substrate, 2, 3... Brazing material, 4, 5... Semiconductor chip, 6... Bonding tool, 7, 11... Wire, 8, 10, 10'... Wire cutting blade,
9... Wire clamp device, 12, 12'... Contact portion of wire cutting blade, 13... Blade edge, 14... Notch, A... Operating direction of wire cutting blade, B
...Operation direction of the wire clamp device, C...Length of the cutting edge.

Claims (1)

[Claims] 1. A wire cutting blade having a contact part with a flat surface and a cutting edge that is smaller than the diameter of the wire and protruding from the contact part is placed on the wire that has been wired and drawn out with electrodes of semiconductor devices, etc. lowering the contact portion until it reaches the upper surface of the wire, forming a notch in the wire that is smaller than the diameter of the wire; and cutting the wire from the notch by pulling one end of the wire. A wire cutting method characterized by: