JPH02253648A - Lead frame for semiconductor device - Google Patents

Abstract

PURPOSE:To eliminate incorrect positional relation between the ends of leads at the time of bonding and to ensure that the leads are bonded by connecting the ends of inner leads, and wire bonding them. CONSTITUTION:A semiconductor element placing unit 1 is supported between upper and lower frames 6 by hanging leads 2. Many leads 3 disposed radially to surround the unit 1 are held at lead interval by a tie bar 5 bridged between adjacent leads, and eventually supported between the frames 6. 4 sets of inner leads 3a each having three fine and slender leads near the frames 6 of the many inner leads 3a are connected at the ends by connecting members 4. Thus, the ends of the fine and slender leads 3a are gathered to ensure that the wirings are bonded at the time of bonding.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lead frame used for assembling a resin-sealed semiconductor device with leads.

[Conventional technology]

A conventional lead frame for a semiconductor device of type (-) includes a semiconductor element mounting part on which a semiconductor element is mounted, a suspension lead that supports the semiconductor element mounting part on a frame, and a radially arranged structure surrounding the semiconductor element mounting part. In the middle of the length of this lead, a tie bar is extended between the same earthen spaces of the adjacent leads to maintain the lead spacing, and the inner lead of the inner part of one part of this tie bar and the inner lead of the inner part of the tie bar are It is divided into a part of the tie bar and an outer lead of the outside part. After the tip of the inner lead and the electrode of the semiconductor element mounted on the semiconductor element mounting section are connected with a bonding wire, the resin is sealed to obtain a resin-sealed semiconductor device.

[Problem to be solved by the invention]

In the conventional lead frame for semiconductor devices described above, the tie bars connecting adjacent leads must be cut off after resin sealing, so they must be exposed outside the sealing resin body. As the number of pins and the size of IC packages increase, the width of the inner leads inside the tie bars becomes narrower, and the length of the inner leads becomes longer. As a result, there is a drawback that the tip of the lead tends to shift, and the wire may fall during wire bonding.

[Means to solve the problem]

In order to solve the above problem, the lead frame for a semiconductor device of the present invention has at least two inner leads among a large number of inner leads connected to each other at the tip portions by a connecting member,
This prevents the tips of these inner leads from coming close to each other.

However, this connection at the tip is the mount of the semiconductor element,
By disconnecting the wires after the subsequent wire bonding, the inconvenience that the inner leads are in a conductive state due to the connection is eliminated.

〔Example〕

Next, the present invention will be explained by examples.

FIG. 1 is a plan view of one embodiment of the present invention. In FIG. 1, the semiconductor element mounting portion 1 is supported between upper and lower frames 60 by suspension leads 2. As shown in FIG. Semiconductor element mounting section 1
A large number of leads 3 are arranged radially to surround the lead 3, and the lead spacing is maintained by tie bars 5 extending between adjacent leads, and ultimately they are supported between upper and lower frames 6. The portion of each lead 3 inside the tie bar 5 is an inner lead contained in the sealing resin body after resin sealing, and the portion outside thereof including the tie bar is an outer lead. Among the large number of inner leads 3a, four sets of three long thin inner leads close to the upper and lower frames have their tips connected to each other by the connecting member 4. This prevents the tips of the leads from coming together and causing any inconvenience during wire bonding. Of course, if the inner leads are resin-sealed while being connected to each other after wire bonding, they will no longer be able to function as independent leads. The connecting member is naturally separated.

FIG. 2 shows a state in which after a semiconductor element is mounted on the semiconductor element mounting part of the second embodiment of the present invention, the inner lead having interconnection at the tip and the electrode of the semiconductor element are connected by a thin metal wire. FIG. In FIG. 2, a cut groove 7 is provided on the lower surface near the tip of the inner lead 3a, and a portion beyond the cut groove 7 is connected to the same portion of an adjacent inner lead by a connecting member 4a. In this example, after the semiconductor element 8 is mounted on the semiconductor element mounting part 1, connected with the bonding wire 9, and before resin sealing, the cut groove 7 is formed as shown in the partial side view of FIG. The connecting member at the tip can be easily cut off from the section.

FIG. 4 is a partial plan view of a third embodiment of the invention. In FIG. 4, the interconnection of the tips of the inner leads 3a is achieved by embedding a small piece 4b punched out by a press between the leads. Since the small piece 4b is completely separated once,
There is an advantage that separation after pounding becomes easier and press production becomes possible.

〔Effect of the invention〕

As described above, the present invention has the effect that by connecting the tips of the inner leads and performing wire bonding, the positional relationship between the tips of the leads is not disturbed during bonding, and the leads do not drop due to bonding.

[Brief explanation of drawings]

FIG. 1 is a plan view of the first embodiment of the present invention, FIG. 2 is a partial side view of the second embodiment of the present invention, in which a semiconductor element is mounted on the semiconductor element mounting portion and then wire bonded. 2 is a partial side view with the connecting member cut off, and FIG. 4 is a partial plan view showing the tip of the inner lead according to the third embodiment of the present invention. 1...Semiconductor element mounting part, 2...Hanging lead, 3...Lead, 3a...Inner lead, 3b...Outer lead , 4.4
a, 4b... Connection member, 5... Tie bar, 6... Frame, 7... Cut groove,
8... Semiconductor element, 9... Bonding wire. Agent Patent Attorney Susumu Uchihara

Claims (1)

[Claims] In a lead frame for a semiconductor device having a semiconductor element mounting part and a large number of inner leads arranged so as to surround the semiconductor element mounting part, a semiconductor element is mounted on the semiconductor element mounting part, and an electrode of the semiconductor element is provided. A lead frame for a semiconductor device, characterized in that the tips of two or more inner leads are connected by a connecting member that is separated after being connected with a bonding wire.