JPH04134853A - Lead frame for semiconductor device - Google Patents

Abstract

PURPOSE:To reduce a resin amount flowing between wires in a corner part of a semiconductor element, to reduce wire deformation and to improve reliability and yield of a device by enlarging a width of a hanging lead inside an inner lead. CONSTITUTION:A hanging lead which crosses a resin injection direction among hanging leads between an end part of an inner lead 4 and an island 1 is made a hanging lead 2A which is wider than other parts. Thereby, when a semiconductor element 6 is mounted on the island 1 and the element 6 and the lead 4 are connected by a conductive wire 5, the wide hanging lead 2A is positioned to cover a clearance between two wires a, b and that between c, d; a resin amount flowing between the two wires can be thereby reduced in case of resin sealing. Therefore, deformation of a wire can be prevented and reliability and yield can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lead frame for a semiconductor device, and particularly to the structure of a resin-sealed lead frame for a semiconductor device.

[Conventional technology]

As shown in FIGS. 4(a) and 4(b), conventional lead frames of this type include an island 1 held by hanging leads and on which a semiconductor element 6 is mounted, and an island 1 provided around this island 1 and integrated with an external lead 3. It was mainly composed of an internal lead 4 formed in the inner lead 4. After mounting the semiconductor element 6 on the island 1, the bonding pad of the semiconductor element 6 and the internal lead 4 are connected with a conductive wire 5, and then sealed with an insulating resin. is common.

However, in recent years, devices have become highly integrated, and as a result, semiconductor devices have become smaller, so the wires 5 connecting the semiconductor devices and the internal wires 4 have tended to become longer. On the other hand, the number of leads for external connection tends to increase year by year, but since the tip of the internal lead 4 requires a minimum width for connecting the wire 5, the length per side of the semiconductor element 6 is In addition, the width of the total number of tips of the internal leads 4 to which wires are connected to opposite sides tends to be quite wide. As a result, the distance between the island 1 and the tip of the internal lead 4 becomes larger, and as a result, the length of the wire 5 tends to become longer.

In addition, when the semiconductor element 6 and the internal lead 4 are connected by the wire 5, the wire located at a corner of the semiconductor element will sandwich a part of the corner of the semiconductor element, so the wire will be smaller than the wire at other positions. The spacing becomes wider. When a semiconductor element is encapsulated with resin, the upper part of the island is filled with resin quickly, so the resin is applied to wires 5 and internal leads 4.
and flows downward from the gap between islands 1 as shown by the arrow. At this time, the wider the distance between the wires, the greater the amount of resin that flows between the wires, making the wires more likely to deform.

Therefore, the wires 5 located at some corners of the semiconductor element 6 where the wire spacing is wide tend to be easily deformed.

As described above, the wire length has become longer due to the recent trend toward high integration and the increase in the number of external leads, and due to the relationship between wire spacing and wire deformation due to resin flow, some wires at the corners of semiconductor devices are easily deformed, causing electrical problems. There was a tendency for short circuits to occur easily.

[Problems to be Solved by the Invention] As described above, in conventional lead frames for semiconductor devices, due to the high integration of semiconductor elements and the increase in the number of external leads, the connected wires have become longer and the wire spacing has become shorter. Due to the relationship between wire deformation due to the flow of resin and wire deformation due to the flow of resin, wires at the corner portions of semiconductor devices are easily deformed, causing problems such as wire breakage or electrical short-circuiting, resulting in a decrease in yield. Further, if the wire spacing becomes extremely narrow due to wire deformation, the wires may be electrically shorted during use of the semiconductor device, which poses a reliability problem.

[Means to solve the problem]

A lead frame for a semiconductor device of the present invention includes an island on which a semiconductor chip is mounted, a hanging lead that holds the island, and an internal lead provided around the island and integrally formed with an external lead. In the lead frame, the width of the hanging lead between the islands is wider than the width of the other part from the tip of the internal lead.

〔Example〕

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

FIG. 1 is a plan view of a first embodiment of the invention.

In FIG. 1, the lead frame mainly consists of an island 1 on which a semiconductor chip is mounted, a hanging lead 2 that holds the island 1, and an inner part 4 provided around the island 1 and integrally formed with an external lead 3. In particular, among the suspension leads between the tip of the inner board 4 and the island 1, the suspension lead that crosses the resin injection direction is made of two suspension leads that are wider than the other parts.

According to the first embodiment configured in this way, as shown in FIG. In this case, since the wide suspension lead 2A is positioned so as to cover the gap between the two wires ab, c, and d located at a part of the corner of the semiconductor element 6, when the semiconductor element 6 is sealed with resin, these two wires The amount of resin flowing between the two can be reduced. Therefore, deformation of the wire is prevented.

FIG. 3 is a plan view of a second embodiment of the invention.

As shown in FIG. 3, in the second embodiment, the width of the suspension lead 2 in the portion located inside the tip of the internal lead 4 is widened for the suspension leads in four directions. Bookcase 2
According to the embodiment, there is an advantage that deformation of the wires located at some of the four corners of the semiconductor element can be suppressed.

〔Effect of the invention〕

As explained above, the present invention makes it possible to reduce the amount of resin that flows between the wires at a part of the corner of the semiconductor element when the semiconductor element is sealed with resin by making the width of the suspension lead wider than the internal lead. This has the effect of reducing wire deformation due to resin flow compared to the conventional method. Therefore, reliability and yield of the semiconductor device can be improved.

[Brief explanation of the drawing]

1 and 2 are a plan view of the first embodiment of the present invention and a plan view when a semiconductor element is mounted, FIG. 3 is a plan view of the second embodiment of the present invention, and FIG. a) and (b) are a plan view and a cross-sectional view taken along the line A-A when a semiconductor element is mounted on a conventional lead frame for a semiconductor device. 1...Island, 2...Hanging lead, 2A...
Wide suspension lead, 3...external lead, 4...internal lead, 5...wire, 6...semiconductor element.

Claims (1)

[Claims] In a lead frame for a semiconductor device having an island on which a semiconductor chip is mounted, a suspension lead holding the island, and an internal lead provided around the island and integrally formed with an external lead, the tip of the internal lead A lead frame for a semiconductor device, characterized in that the width of the suspension lead between the island and the island is wider than other parts.