JPS5921172B2 - Lead frame connecting piece cutting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for cutting connecting pieces of a lead frame, which is composed of a plurality of lead conductors arranged side by side and connecting pieces connecting them.

Conventionally, cutting devices used to cut connecting pieces of lead frames for assembling semi-moving body devices (abbreviated as "lead frames" in this specification) have been cut using die-set-type once-cutting molds, that is, in one step of a ram. Most of the molds are those that cut all the connecting pieces of the lead frame, and those that cut the connecting pieces for each semiconductor device or a plurality of semiconductor devices.

In both the former and the latter, when looking at each semiconductor device unit, all of the connecting pieces included in that semiconductor device unit are cut.
e) and punches must be constructed in a number corresponding to the number of connecting pieces of the semiconductor device, making these cutting devices complicated and expensive. Moreover, the above-mentioned cutting device is limited to only one type of lead frame that can be processed due to the structure of the lead frame and the structure of the mold. The present invention was made in order to deal with the drawbacks of the conventional cutting device described above, and it cuts the connecting pieces at corresponding locations of a plurality of semiconductor devices in one lead frame at the same time, and sequentially feeds all the connecting pieces. It is an object of the present invention to provide a cutting device capable of cutting a connecting piece.

In particular, the cutting device according to the present invention is used in semiconductor devices such as integrated circuits, and the cutting device according to the present invention can be used in common with lead frames having different numbers of lead conductors.

That is, even though integrated circuits have different numbers of lead conductors, the width of the lead conductors and the pitch of each lead conductor are generally the same, so the cutting device according to the present invention can be used in common. Furthermore, it is possible to provide an inexpensive cutting device that can follow the shrinkage of the resin and the deformation of the lead frame due to synthetic resin coating molding. An embodiment in which the present invention is applied to a cutting device suitable for lead frames for integrated circuits will be described below with reference to FIGS. 1 to 3.

FIG. 1 shows a state in which semiconductor pellets are assembled and resin-sealed in a lead frame for an integrated circuit, and FIG. 1A is a plan view and FIG. 1B is a front view. FIG. 2 is a perspective view of the assembled integrated circuit. -In general, an integrated circuit has a lead frame 1
Semiconductor pellets (
(not shown) with a resin coating 2 (FIG. 1A and FIG. 1B), and then, by cutting the connecting piece 3 and cutting and bending the lead conductor 4 to a predetermined size. , is formed as shown in FIG.

FIG. 3 is a perspective view showing the basic configuration of a cutting device which is an embodiment of the present invention. In FIG. 3, 5 and 6 are dies, and 7 is a die holder for holding and fixing the dies 5 and 6, and these constitute a lower mold. Further, 8 is a punch, and the punch 8 is held and fixed by a punch holder (not shown). Reference numeral 9 denotes a material retainer that clamps the lead frame, which is the workpiece, during cutting, and these constitute an upper mold.

Further, the upper die is held and fixed to a ram of a press (not shown) so as to fit the lower die. As shown in FIG. 3, the punch 8 and the dies 5, 6 are inserted into the lead frame 1 in a second direction perpendicular to the first direction in which the connecting pieces 3 and the lead conductors 4 are alternately arranged adjacent to each other. The structure is such that only the connecting pieces located in a straight line on the plane of the frame 1 are cut. When cutting the connecting piece 3 of the lead frame 1 with the cutting device configured as described above, the lead frame 1 is cut in the Y direction shown in FIG.
is sent, and the above-mentioned second
The connecting pieces 3 in the same arrangement order on a straight line in the direction are simultaneously cut by lowering the punch holder using a punch holder moving device (not shown) using a ram of a press, etc., and the lead frame 1 is sent one after another. Depending on the situation, it will be severed.

Connecting piece 3 to be cut first in lead frame 1
The lead frame 1 is intermittently fed one pitch at a time between the lead conductors from a to the last connecting piece 3h to be cut. The basic operation is that when the lead frame feeding device stops, the ram of the press descends and cuts the connecting piece 3. Further, when the punch holder rises, the lead frame feeding device operates and feeds the lead frame 1 one pitch. That is, based on the connecting piece cutting device according to the present invention, the feeding mechanism and the press mechanism are electrically connected, and a safety circuit, a detection circuit, etc. are provided to automatically cut the connecting pieces. It goes without saying that you can do this, but here is the first step.
In the front view of the overmolded lead frame shown in FIG. As long as the dimensions (the width dimension here is the dimension in the direction in which the lead conductors and connecting pieces are arranged adjacent to each other alternately) are the same, this device can be used in common even if the lead frames have different numbers of lead conductors. It is.

That is, even if the number of lead conductors that the semiconductor device has is different, the present device can be used as is under the above-mentioned conditions. Therefore, it is possible to cut the connecting pieces of various types of lead frames. In addition, the pitch between the lead conductors becomes slightly smaller due to shrinkage of the resin that occurs during synthetic resin coating molding, but by matching the feeding pitch of the feeding device to the pitch after resin molding, the center between the lead conductors can be adjusted. The above-mentioned connecting piece is cut, and the lead conductor after cutting poses no problem in terms of appearance. Further, the punch and die are configured to cut only the connecting pieces of the lead frame that are perpendicular to the direction in which the connecting pieces of the lead frame and the lead conductors are arranged adjacent to each other and that are in a straight line on the same plane of the lead frame. Therefore, the number of punches and dies is small, and since there is no cumulative error of the punches and dies, there is no need to particularly require precision of the punches and dies, so the mold is inexpensive and economical.

Note that although an example in which the present invention is applied to an integrated circuit has been described above, the present invention can be applied to similar lead frames for other semiconductor devices.

FIG. 4 is a plan view of another example of a lead frame suitable for cutting with a cutting device according to the present invention.

As shown in Figure 4, an elongated hole 1 is formed in the frame portion of the lead frame with the same width as the connecting piece and into which a punch can enter.
0 is the distance between the center of the outermost connecting piece 3 and the center of this elongated hole 10 is the same as the arrangement pitch of the connecting pieces, and the distance between the center of the elongated hole 10 and the outer edge of the frame of the lead frame is 1 of the above pitch. /
If you use a lead frame formed to be 2,
Continuous operation is possible without stopping the punch at the frame,
Improves efficiency. Moreover, the electric circuit etc. become simpler and the cutting device becomes cheaper. As described in detail above, according to the connecting piece cutting device according to the present invention, connecting pieces of various types of lead frames can be cut with one type of cutting device, and resin shrinkage due to synthetic resin coating molding can be performed. This has the effect of being able to follow.

In addition, since the cutting device according to the present invention can be used for other models, the equipment can be used effectively even when the production volume increases or decreases, and the cutting of connecting pieces of lead frames for semiconductor device assembly can be done economically and rationally. It is possible.

Further, by connecting a device for cutting and bending lead conductors to the cutting device according to the present invention, a plurality of semiconductor devices can be continuously produced, resulting in highly efficient equipment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a state in which semiconductor pellets are assembled and resin-sealed in a lead frame for an integrated circuit, and FIG. 1A is a plan view and FIG. B is a front view.

2 is a perspective view of an assembled integrated circuit, FIG. 3 is a perspective view showing the basic configuration of a cutting device according to an embodiment of the present invention, and FIG. 4 is a perspective view of an integrated circuit that is cut by the cutting device according to the present invention. FIG. 6 is a plan view of another example of a suitable lead frame. In the figure, 1 is a lead frame, 2 is a resin coating, 3, 3
a to 3h are connecting pieces, 4 is a lead conductor, 5 and 6 are dies, 7
8 is a die holder, 8 is a punch, and 9 is a material holder.

Claims (1)

[Claims] 1. A group of lead conductors in which a plurality of lead conductors having the same width at their root portions are arranged in parallel to each other in the first direction in the same plane, and are successively connected at the root portion by connecting pieces of a constant width. A plurality of groups of lead conductors are arranged and connected in a second direction perpendicular to the first direction, and the connecting pieces in the same arrangement order of each lead conductor group are on a straight line in the second direction. In the device for cutting connection pieces, a punch holder holds a plurality of punches for simultaneously cutting the connection pieces in the same arrangement order of the lead conductor groups, and the punch holder is used to hold each of the connection pieces in the same arrangement order of each of the lead conductor groups. A plurality of the connecting pieces are moved toward the surface of the lead frame and are being fed to the die positions where the connecting pieces are arranged so as to correspond to each of the connecting pieces. a punch holder moving device that separates the punch holder from the surface of the lead frame after each of the plurality of punches cuts the lead frame; A connecting piece of a lead frame, characterized in that it is equipped with a lead frame feeding device that feeds the connecting pieces in each arrangement order one pitch at a time in the first direction, and sequentially feeds the connecting pieces in each arrangement order to the position of the die. cutting equipment.