JPS6225489Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a package for supplying ultra-fine metal wires, and more particularly to a package for supplying ultra-fine metal wires used for wire bonding between semiconductor devices and lead ends. As shown in FIG. 1, a semiconductor element 1 and a lead end 2
For example, the diameter is 20 to 30 mm.
An ultra-fine wire 3 made of micron gold, aluminum, or the like is used. Such ultra-fine metal wires have a weak breaking strength of 5 to 20 g, and as shown in Figure 2, if the metal wire 3 has a bend 4, the joined wire may cause poor contact 5, 5', etc. This poses a serious problem. For this reason, conventionally, when supplying such ultra-fine metal wire, in order to avoid stressing the wire as much as possible, as shown in FIG. For example, the metal wire 7 is sequentially drawn out and consumed by a bonding tool (not shown) through the hollow part 9 of the spool 6. However, in recent years, wire bonding processes have become faster in the semiconductor industry, and conventional packages made of evenly wound metal wires have been inefficient due to the high frequency of package replacement. In order to solve this problem, prior to the invention, a package in which metal wires 10 were wound in multiple layers in an aligned manner as shown in FIG. 4 was devised and put to use. However, in the case of a sufficiently thick material such as an electric wire cord, this aligned winding can be done with a small interval between windings, so there is almost no problem when unwinding, but the metal wire of the present invention In the case of a thin wire with a diameter of 100 microns or less, it is difficult to wind the wire with the same winding pitch as the wire diameter without any gaps, and it is common to wind the wire with a pitch slightly larger than the wire diameter. However, in an aligned winding package like this, which is wound with a pitch slightly larger than the wire diameter, the windings in each layer are arranged almost parallel and the windings in each layer hardly intersect, so when the windings in the upper layer are pressed, the windings in the lower layer are There was a problem in that the pitch of the windings partially expanded, and there were places where the upper layer windings wedged in between the lower layer windings. This point will be explained with reference to FIG. In addition, in FIG. 5, the wire diameter is made thicker and the lower and upper layer windings are exaggerated and angled to make it easier to understand. In this figure, the upper layer winding is generally placed on the lower layer winding, but in the upper layer thin wire 11b, the distance between the lower layer thin wires 11a and 11a' is expanded and the wires are wedged between them. You will understand. If there is such a bite, the wire 10 cannot be unwound smoothly, and when it is forced to unwind, extra force is applied to the part of the wire that is cut into the line, causing the wire to bend. In particular, there was a problem with ultra-fine wires with a diameter of 50 microns or less that could cause wire breakage. The purpose of the present invention is to eliminate these drawbacks of conventional packages, and to provide a multilayer cross-wound package made of ultra-fine metal wires, in which ultra-fine metal wires are successively wound and wound one after another on a winding member to form a multilayer structure. It is something to do. That is, the present invention is a package for supplying ultra-fine metal wire in which a single ultra-fine metal wire is rewindably wound around a winding member, and the winding method is such that the upper layer winding is connected to the lower layer winding. To provide a package for supplying ultra-fine metal wire, which is wound around the entire circumference at an angle so that the upper layer winding crosses the lower layer winding at a plurality of locations. It is. In this way, by adopting cross winding in which the upper layer winding intersects at an angle over the entire circumference of the lower layer winding, even if the thin metal wire is wound in multiple layers, there will be no digging between the layers. , a package for supplying ultrafine metal wires for multilayer wire bonding with less disconnection has been realized. A package 12 in which ultrafine metal wires are cross-wound according to the present invention is schematically shown in FIGS. 6 and 7. The spool 13 has a cylindrical body 14 and flanges 15 at both ends of the cylinder, and the thin wire 16 is substantially moved from one end of the cylinder to the other end and then back to the original end while the spool rotates twice, as shown in FIG. The spool is wound in one reciprocating motion, and it appears that the spool is wound in such a way that it intersects approximately in the middle of the spool cylinder. As is clear from Figure 6, in such cross winding, the windings of the lower and upper layers overlap at an angle over the entire circumference, and the windings of the upper layer overlap the windings of the lower layer. It intersects with the windings at multiple points, so the windings in the upper layer do not cut in between the windings in the lower layer. As a result, by using a multilayer cross-wound package, the number of wire breaks during supply was drastically reduced. In order to explain the crossed state in an easy-to-understand manner, Fig. 7 shows an example in which the metal wire rotates twice during one reciprocation on a spool whose width is longer than its diameter. A short spool may be used, and the metal wire may rotate three or more times during one reciprocation. It will be understood that in this case, the winding becomes more perpendicular to the axis than in the example of FIG. A more detailed explanation will be given below using examples. Example: Cross winding of a gold wire with a diameter of 25 microns on a flanged spool having a cylindrical body with an outer diameter of 50 mm and a height of 30 mm, in which the spool makes approximately one reciprocation in the direction of the rotation axis during two rotations of the spool. I wound up a total length of 500m of gold wire using a handle. On the other hand, for comparison, the diameter is 25
One layer of micron gold wire with a pitch of about 30 microns.
The length was 100 m, and 5 layers were aligned and wound. Ten windings were each used for wire bonding of semiconductor integrated circuits, and the number of disconnections was investigated. The total number of wire breaks for each winding method was divided by the number of samples, 10, to calculate the average wire breakage rate per winding. The results are shown in the table.

[Table] As is clear from the table, the wire breakage rate was significantly reduced by the ultrafine metal wire supply package of the present invention, and the operating rate of the automatic bonder was improved. This significant reduction in the wire breakage rate made it possible to reduce the number of operators monitoring the automatic bonder, further improving productivity. Spools of various shapes as shown in FIG. 8 can be used for such cross winding. In FIG. 8A, the spool body is cylindrical or cylindrical.
Spools of this shape are easy to manufacture and inexpensive, but when cross-winding, there is a risk that the windings will collapse due to vibrations, etc. To prevent this, the spool surface should be polished or turned with a roughness of 2 to 3 μm. Preferably, it is formed on a surface. FIG. 8B is suitable for a winding method in which the wire is wound from one end to the other end and returned to its original position during two rotations of the spool, and has the advantage that the winding wire is less likely to collapse. Also, Figure 8C
This is an application of B, and is a spool with two bulges in the body.As with B, if the wires intersect at the point where the bulges are maximum, the winding wire will not easily collapse. These spool shapes and surface treatments are just examples, and various spools with combinations of these can be used as necessary. Further, it is preferable that the inner surface of the spool brim is sloped as necessary.
Furthermore, it will be clear that if the line is drawn out from the spool on one side, it is not necessary to provide a collar.

[Brief explanation of drawings]

1 and 2 are schematic diagrams showing wire bonded semiconductors. FIG. 3 is a diagram showing a conventional single-layer aligned winding package. FIGS. 4 and 5 are diagrams illustrating a multilayer aligned winding package. FIG. 6 shows a multilayer cross-wound package according to the present invention. FIG. 7 is an explanatory diagram of cross winding. FIG. 8 is a diagram showing an example of a spool used in the present invention. 3,7,10,16...metal wire, 6,13...
Spool, 8, 12...package.

Claims (1)

[Claims for Utility Model Registration] (1) A package for supplying ultra-fine metal wire in which one ultra-fine metal wire is unwound onto a winding member, and the winding method is similar to that of the upper layer winding. It is characterized by being wound around the entire circumference of the lower layer winding at an angle so that it does not enter between the lower layer windings, and the upper layer winding intersects the lower layer winding at multiple locations. A package for supplying ultra-fine metal wire. (2) The ultrafine metal wire supply package according to claim 1, wherein the metal wire has a diameter of 10 to 50 microns. (3) The package for supplying ultrafine metal wire according to claim 1 or 2, wherein the winding member has a circular cross section and a diameter at the middle portion is larger than at the end portions. (4) The package for supplying ultrafine metal wires according to claim 1 or 2, wherein the winding member is formed in the shape of a gourd. (5) The ultrafine metal according to any one of claims 1 to 4 of the utility model registration claim, wherein the surface of the winding member is treated to increase friction with the metal wire. Package cage for wire supply. (6) Utility model registration claim 1, characterized in that the surface of the winding member is formed into a matte finish.
The package for supplying ultrafine metal wires according to any one of items 1 to 4.