JPH0124932Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a fine wire supply package for use in wire bonding of semiconductor devices. 2. Description of the Related Art In the assembly process of semiconductor devices, there is wire bonding work in which electrodes on a semiconductor element and lead ends are connected using fine metal wires (hereinafter referred to as fine wires). This bonding operation is carried out by a wire bonder, and the fine wire is supplied to the bonder in the form of a package wound around a spool having a cylindrical body. In recent years, improvements in wire bonders have significantly improved the bonding speed, but with this, the length of wire held per package has also tended to become longer. This lengthening has been achieved by changing the aligned winding method to a cross winding method (for example, Utility Model Application No. 55-155766, Utility Model Application No. 57-93144, etc.). The advantage of cross winding, compared to aligned winding, is that when multiple layers are used, there is less chance of the wire getting stuck between the wires in the lower layer, and the frequency of wire breakage and wire bending during wire bonding is significantly reduced. However, even in such a cross-wound package, it is not possible to completely eliminate the wire biting during unwinding. Particularly, when a spool having a cylindrical body is used, this biting tends to increase somewhat. The reason for this is that the normally used aluminum spool with an anodized surface has a smooth surface, and although a certain tension is applied when cross-wound on this spool, the spool and wire expand due to shock and temperature changes during handling. This is thought to be due to the lowermost layer being slightly shifted due to differences in the amount of shrinkage. This drawback can be overcome by making the spool body into an entasis shape or by finishing the body surface with a satin finish, but an increase in the cost of the spool cannot be avoided. In view of the above circumstances, the inventors of the present invention investigated various ways to reduce the bite by devising the winding method, and as a result, they discovered that the bite could be reduced by aligning only the first layer, and arrived at the present invention. did. That is, as shown in FIG. 1, the package of the present invention has an aligned winding layer 2 as the first layer in contact with the spool body 1, and an aligned winding portion 2A at the beginning of winding is exposed on the aligned winding layer. It is characterized in that it has a cross-wound layer 3 which is arranged so that it does not protrude beyond the aligned winding layer. The winding pitch of the aligned winding layer 2 is 1.1 of the wire diameter.
~1.5 times is sufficient. Cross winding layer 3
The reason for making the width narrower than the width of the aligned winding layer 2 is to enable the aligned winding section 2A at the beginning of the winding to be connected to a disconnection detection device, and therefore, the exposed width may be small. On top of the aligned winding layer 2, cross winding may then be carried out in a conventional manner. For example, if the diameter of the spool body is about 50 mm, the winding pitch should be 4 to 5 mm. In the case of cross winding, it is necessary to make the folds gentle, but as the amount of winding increases, the ends of the wound layers swell up. To avoid this, for example, it is recommended to wrap the wire so that the winding width becomes narrower at each end by 10 to 100 times the wire diameter every 100 to 700 traverses. According to the package of the present invention, the frequency of wire breakage and bending can be halved compared to a package in which all layers are cross-wound. It is not clear why wire digging is reduced in the package cage of the present invention, but the aligned winding layer 2 directly on the spool body 1 prevents the cross winding layer 3 above from slipping, preventing the cross winding layer 3 from slipping. It is thought that this is to do so. Example: 1000 m of gold wire with a diameter of 20 microns was wound in two ways around an aluminum spool with a surface anodized finish having a cylindrical body with an outer diameter of 50 mm and a length of 49 mm.

[Table] From the results in Table 1, it can be seen that the package cage of the present invention bends and breaks by half the number of times compared to a package with all layers cross-wound.

[Brief explanation of drawings]

FIG. 1 is an explanatory view of the fine wire supply package of the present invention, in which a portion of the cross-wound layer has been removed to show the aligned winding layer. 1... Spool body, 2... Aligned winding layer, 3...
Cross-wound layer.

Claims (1)

[Scope of utility model registration request] It is a package in which a long fine wire is wound in multiple layers around a spool having a cylindrical body, and the first layer in contact with the body is aligned winding, and the winding starting layer is placed on top of the aligned winding layer. A package for supplying fine wire, which is cross-wound so that the aligned winding portion is exposed and does not protrude beyond the aligned winding layer.