JPS6311781B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lead frame used in a semiconductor device, particularly a resin-sealed integrated circuit device.

A conventional lead frame includes a plurality of leads 3, 3' extending from a frame (not shown) to the center, as shown in FIG. They are connected to each other by a connecting band 1 which acts to prevent the resin from flowing during the stopping process. After placing a semiconductor element on a predetermined lead among the leads 3 and 3' or on an element mounting section provided separately at the center position of the lead frame, the electrodes of the semiconductor element and the tips of the leads 3 and 3' (not shown) are placed. ) is wired with thin metal wires and then subjected to a resin sealing process. The lead frame is placed in a mold, and the mold has a cavity of a predetermined shape at the lead end of the lead frame, and a resin inflow channel 6 is connected to this cavity.
is provided. The resin that has passed through the resin inlet passage 6 is introduced into the cavity of the mold mold from the resin inlet 5 to form the resin package 2. Thereafter, the mold is removed, and the frame portion and connecting portion 1 are separated to obtain a resin-sealed semiconductor device.

By the way, the resin inflow channel 6 is located so that one side end 61 meets the corner of the resin package, and the other side end 62 passes through the intersection of the lead 3' located at the end and the connecting band 1. It is suitable to be located at The reason why the resin is introduced from the corner side is to ensure that the resin spreads smoothly throughout the molded resin and does not create cavities or other cavities in the molded resin. The reason why one side end 61 is made to coincide with a corner is to facilitate manufacturing of the entire mold including the inlet channel. The other side end 62 is connected to the lead 3' and the connecting band 1.
The reason for passing through the intersection with is as follows.
If the side ends 62 were wider than this, resin would accumulate outside the connecting band connecting the endmost lead to the next lead. It is necessary to avoid accumulating resin outside the connecting band for preventing resin flow. On the other hand, this side edge 6
If 2 is opened narrower than this, the resin inflow resistance will be large and the introduction of the resin will be hindered. Therefore, if the connecting band 1 is provided on a straight line as in the conventional example, the connecting body will be located near the resin inlet 5 in the resin inlet channel 6, and the resin inlet 5 will be located close to the resin inlet 5.
The cross-sectional area of the resin becomes small, which makes it difficult for the resin to flow in, resulting in insufficient filling of the resin during resin sealing. Insufficient filling of the resin not only causes a defective external shape, but also exposes the semiconductor element or causes parts where the resin is thin, thereby significantly reducing the moisture resistance of the semiconductor device. In particular, lead 3,
As the number of leads 3' increases, the width and pitch of the leads 3, 3' tend to become narrower, and the resin package 2 tends to become extremely thin. Due to these factors, the above-mentioned insufficient resin filling becomes increasingly unavoidable.

An object of the present invention is to provide a lead frame that does not cause insufficient filling during resin filling and is particularly suitable for resin-sealed semiconductor integrated circuit devices having a large number of leads.

The present invention is characterized by a plurality of first leads arranged in parallel to each other, and a plurality of second leads arranged in a planar shape in a direction perpendicular to the first leads and parallel to each other.
and a connection band for preventing resin flow that connects the plurality of first leads and the plurality of second leads to each other, wherein the plurality of first leads are connected to each other. All of the connecting bands that connect the respective leads are located in a straight line, and in the second lead,
A connecting band that connects a second lead located at a corner between the first lead arrangement and the second lead arrangement and a second lead located next is located outside of the other connecting bands. This is found in lead frames for semiconductor devices.

As described above, according to the present invention, the connecting band connecting the leads located near the side ends of the leads arranged in parallel is connected at a position farther from the lead tip than the connecting band connecting the other leads. Even if the pitch is small, the cross-sectional area of the resin inflow path and the cross-sectional area of the resin inlet can be made large, so a sufficient amount of resin can be secured, and the semiconductor device will not have a defective external shape or deteriorate moisture resistance.

Next, the present invention will be explained in more detail with reference to the drawings.

In the embodiment of the present invention shown in FIG. 2, a plurality of leads 23, 23' arranged in parallel are formed on four sides, and the leads 23, 23' are connected to each other by connecting bands 21, 21'. The resin inlet 26 is located at one end 2
6' is positioned so as to touch the corner of the mold, and the other side edge 26 is located between the lead 23' and the connecting band 2.
It is located so as to pass through the intersection with 1'. The resin that has passed through the resin inlet passage 26 is introduced into the cavity of the mold from the resin inlet 25 to form the resin package 22. Thereafter, the mold is removed, the connecting bands 21, 21' are removed, and the leads 23,
23' is removed from the frame (not shown) to obtain a semiconductor device.

According to this lead frame, the connecting band 21'
is formed at a position farther from the lead tip than the connecting band 21, so the cross-sectional area of the resin inflow path 26 and the resin inlet 25 can be increased, and a sufficient amount of resin can be filled into the cavity of the mold. can. Therefore, deterioration in moisture resistance due to poor appearance of the resin package 22 or presence of thin portions does not occur.
This effect is more effective in semiconductor integrated circuit devices where the pitch of the leads 23, 23', that is, the interval between the leads is narrow and the integration density is high.

[Brief explanation of the drawing]

FIG. 1 is a partial plan view showing a conventional lead frame, and FIG. 2 is a partial plan view showing an embodiment of the present invention. 1, 21, 21'... Connection band, 2, 22... Resin package, 3, 3', 23, 23'... Lead, 5,
25... Resin inflow port, 6, 26... Resin inflow path.

Claims (1)

[Claims] 1. A plurality of first leads arranged in parallel to each other, a plurality of second leads arranged in a planar shape in parallel to each other in a direction perpendicular to the first leads, and the plurality of first leads and In the lead frame for a semiconductor device having a connection band for preventing resin flow that connects the plurality of second leads to each other, all of the connection bands that connect each of the plurality of first leads are located in a straight line. and in the second lead, a second lead located at a corner formed by the first lead arrangement and the second lead arrangement and a second lead located next thereto are connected. A lead frame for a semiconductor device, characterized in that a connecting band is located outside of other connecting bands.