JPS59172315A - Conveyance device for magnetic body - Google Patents

Abstract

PURPOSE:To convey a magnetic body in a condition of being adsorbed to a guide face at all times and realize conveyance of said body with stability and precision by providing a magnetic force generation means on a guide face of a device which conveys the magnetic body along the guide face. CONSTITUTION:Lead frame is formed by magnetic material such as copper family metal or the like, and intermittently fed by pitch by sliding on a guide face 4 of a guide rail 2 with a pin, inserted in a hole made in the side part of said frame. The plural number of permanent magnets 6 serving as magnetic force generation means are buried in the guide face 4 at predetermined intervals. Combination of polarities of the permanent magnets 6 is such that there is alteration of N and S polarities in the guide face 4, while the permanent magnets 6 and the reed frame 1 are polarized contrary so as to be adsorbed to each other. Thus, reed frame 1 is fed by pitch in a condition of being adsorbed to the guide face 4 at all times by means of the permanent magnets 6, and the reed frame 1 is prevented from overrunning from a predetermined stopping position due to its inertia.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic material conveying device that can convey magnetic materials with high precision.

2. Description of the Related Art Conventionally, lead frames used in the assembly process of semiconductor products are typically formed by patterning a thin plate of copper (Cu) metal by punching or etching.

Conventionally, such a lead frame has two power rails on both sides of a lead frame 1, as shown in FIG.
While the lead frame 1 is inserted into the guide groove 3 of the lead frame 1, a pin (not shown) is inserted into a hole in the side of the lead frame 1, and the lead frame 1 is conveyed by ε. However, in the case of this conventional method, the dimensions of the force-id groove 3 are slightly larger than the thickness of the lead frame 1, so if there is slight warpage or deformation in the lead frame 1, the lead frame
There is a problem in that the lead frame 1 is clogged in the guide groove 3, and the inertia of the lead frame 1 prevents smooth and accurate conveyance.

In another conventional technique, as shown in FIG. 2, the lead frame 1 is slid on the upper open guy F surface 4 of the guide rail 2, and the lead frame l is supported by a leaf spring 5 or a bearing (not shown). There is one that transports the frame while holding it down. However, in the case of this prior art, the leaf spring 5 wears out due to contact with the lead frame 1, and the spring force is maladjusted, resulting in fluctuations in the holding force against the lead frame 1.
There is a problem in that it is difficult to transport materials stably and accurately.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art described above and to provide a magnetic material conveying device that can stably and accurately transport magnetic materials.

Hereinafter, the present invention will be explained in detail according to embodiments shown in the drawings.

FIG. 3 is a sectional view showing an embodiment of the magnetic material conveying device according to the present invention, and FIG. 2 is a partial plan view of the guide rail.

This embodiment is an example in which the present invention is applied to conveyance of a lead frame in a semiconductor product assembly machine such as a pellet bonder, a wire bonder, or a marking machine in the process of assembling a semiconductor device.

In the conveying device of this embodiment, the lead frame 1 is made of a magnetic material such as copper-based metal, and a pin (not shown) is inserted into a hole in the side of the lead frame 1. The guide surface 4 of the guide rail 2
By sliding it on the top, it is intermittently pinch-fed in the direction of the arrow in FIG.

A plurality of permanent magnets 6 as magnetic force generating means are embedded in the guide surface 4 of the guide rail 2 at predetermined intervals as shown in FIG. The polarities of the permanent magnets 6 are alternately N-pole and S-pole, and the permanent magnets 6 and the lead frame 1 have opposite polarities so that they are attracted to each other.

As a result, in this embodiment, the lead frame 1 is attracted to the guide surface 4 by the magnetic force of the permanent magnet 6, and is in contact with the surface of the permanent magnet 6 exposed on the surface of the guide surface.

Therefore, in this embodiment, when the lead frame 1 is pitch-fed in the direction of the arrow in FIG. Since the lead frame 1 is pinch-fed while being always attracted to the seat 4, the inertia of the lead frame 1 prevents the lead frame 1 from overrunning from the predetermined stop position, and the seat is stably and precisely placed at the predetermined stop position. It can be stopped. Thereby, pellet bonding, wire bonding, marking, etc. on the lead frame 1 can be performed accurately, and the yield can be improved. Of course, since the lead frame l is only restrained by the magnetic force of the permanent magnet 6, even if the lead frame l is warped or deformed,
The pitch feeding operation is not hindered in any way, and smooth conveyance is always possible, and damage to the lead frame 1 during conveyance can be prevented.

According to the present invention, the lead frame 1 is connected to the permanent magnet 6.
Accordingly, it is also possible to convey the material while it is attracted to the guide surface 4 from above (see FIG. 3) without requiring a lower guide rail.

In this case, if the polarities of the permanent magnet 6 and the lead frame 1 are made the same as shown in FIG. 3, the permanent magnet 6 and the lead frame 1 will repel each other, and the lead frame 1
Since it falls from the guide surface, it can be used as a lead frame recovery mechanism.

The present invention is not limited to the embodiments described above, and various other modifications are possible. For example, other magnetic force generating means such as electromagnets can be used instead of permanent magnets, and the arrangement thereof can also be changed to the embodiments described above. It can be made into something else. Also,
The present invention can also be applied to conveying magnetic materials other than lead frames.

As described above, according to the present invention, magnetic materials can always be transported stably and accurately.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a conventional technique, Fig. 2 is a cross-sectional view of another conventional technique, Fig. 3 is a cross-sectional view showing an embodiment of a conveying device according to the present invention, and Fig. 4 is a partial plan view of a guide rail. FIG. 5 is a sectional view showing another embodiment of the present invention. 1... Lead frame, 2... Guide rail, 4...
...Guide surface, 6...Permanent magnet.

Claims (1)

[Claims] 1. In a device for conveying a magnetic material along a guide surface,
A conveyance device for a magnetic material, characterized in that a magnetic force generating means is provided on a guide surface. 2. The magnetic material conveying device according to claim 1, wherein the magnetic force generating means is a magnet embedded within the guide surface. 3. The magnetic material conveying device according to claim 1, wherein the magnetic material is a lead frame made of a magnetic material.