JP2000183271A - Lead frame, semiconductor device, and method of manufacturing semiconductor device - Google Patents

Abstract

(57) [Problem] To provide a technique capable of preventing deformation of a lead of a resin-sealed semiconductor device. SOLUTION: For a lead frame used in a semiconductor device sealed with a resin by a sealing body and having a plurality of leads arranged along one side of the sealing body, the plurality of leads are sealed with a resin. A non-conductive member is fixed at the outer edge of the sealing region to be formed, and dummy leads are arranged at column ends of the plurality of leads. Further, in the semiconductor device using the lead frame, the plurality of leads are fixed to a non-conductive member at an outer edge of a sealing region where resin sealing is performed, and dummy leads are arranged at column ends of the plurality of leads. I do. Further, in the method of manufacturing a semiconductor device using the lead frame, the non-conductive member is melted in a mold and filled between the plurality of leads. The resin is sealed while preventing the sealing resin from flowing out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame and a semiconductor device, and more particularly to a technology effective when applied to a multi-lead lead frame and a semiconductor device.

[0002]

2. Description of the Related Art Semiconductor devices such as LSIs are equipped with more complicated circuits and advanced functions as the degree of integration increases. With such advanced functions, more external terminals are required for the semiconductor device, and accordingly, the number of pad electrodes provided on the semiconductor chip and the number of leads as external terminals of the semiconductor device are correspondingly increased. Becomes For example, in a logic semiconductor device, the number of external terminals is several hundred.

As such a multi-lead semiconductor device, a QFP (Quad Flat Package) type semiconductor device is known. This QFP type semiconductor device is suitable for increasing the number of leads because a plurality of leads are provided on each of four sides of a sealing body for sealing a semiconductor chip. Another advantage is that the space around the semiconductor device can be used effectively.

A lead frame used for a QFP type semiconductor device is made of, for example, a Cu-based alloy, and a plurality of inner leads are arranged around a tab on which a semiconductor chip is mounted, and outer leads are integrated with the inner leads. Extends from the sealing body, and ends thereof become external terminals of the semiconductor device and are connected to a substrate or the like.

[0005] Each lead is integrated by a dam bar or a tie bar as a frame of a lead frame, and the inside and outside of the dam bar of each lead become an inner lead and an outer lead, respectively. In addition to the function of integrating the leads, the dam bar has a function of preventing the sealing resin from leaking from between the leads to the outside of the sealing region during resin sealing. The tab is supported by a tab suspension lead provided between the inner leads.

In assembling a semiconductor device using this lead frame, a semiconductor chip is fixed to a tab with a resin or silver paste, and pad electrodes of the semiconductor chip and inner leads are connected by bonding wires. After bonding, the semiconductor chip, the tab, the inner lead, and the bonding wire are sealed with a sealing body made of, for example, an epoxy resin, and the dam bar and the tie bar are cut to separate each lead mechanically and electrically. Thereafter, the outer leads extending from the sealing body are molded to complete the semiconductor device.

In the cutting of the dam bar, it is required to cut fine leads accurately, so that a die used for cutting is expensive. Further, there is a problem that burrs generated by cutting the dam bar affect outer lead molding.

[0008] For this reason, a tape dam type lead frame which does not require cutting by using a non-conductive resin tape instead of the dam bar has been considered. A tape dam type lead frame is disclosed, for example, in Japanese Patent Application Laid-Open No. 9-148512.

[0009]

In order to cope with the above-mentioned increase in the number of leads, it is required for a lead frame to reduce a lead pitch and a lead width, which are intervals between leads. For example, at present, the thickness of the lead frame is about 150 μm, which is almost the limit in terms of deformation of the outer leads, and the lead pitch is 1 μm.
85 μm, lead width 100 μm, gap between leads 85
μm.

Although the mechanical strength of each lead is reduced due to the miniaturization of the leads, the leads are easily deformed by a slight force. The lead at the end of the row was found to have a lot of deformation. Such deformation causes a problem such as occurrence of a short circuit in which adjacent bonding wires or leads come into contact.

An object of the present invention is to provide a technique capable of preventing deformation of a lead of a resin-sealed semiconductor device.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0013]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, typical ones are briefly described as follows.

[0014] For a lead frame used in a semiconductor device sealed with a resin by a sealing body and having a plurality of leads arranged along one side of the sealing body, the plurality of leads are sealed with a resin. A non-conductive member is fixed at the outer edge of the sealing region to be sealed, and dummy leads are arranged at column ends of the plurality of leads.

In the semiconductor device using the lead frame, the plurality of leads are fixed to a non-conductive member at an outer edge of a sealing region where resin sealing is performed, and a dummy is provided at a column end of the plurality of leads. Place the leads.

In the method of manufacturing a semiconductor device using the lead frame, the non-conductive member is filled between the plurality of leads, and the filled non-conductive member is sealed from between the plurality of leads. The resin is sealed while preventing the resin from flowing out.

According to the present invention, when the non-conductive member is filled between the plurality of leads, the force applied by the molten non-conductive member to the side surfaces of the leads at the row ends of the plurality of leads. However, by providing the dummy leads, the leads are equalized and deformation of the leads is prevented.

[0018]

Embodiments of the present invention will be described below.

In all the drawings for describing the embodiments, those having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

FIG. 1 shows a QFP according to an embodiment of the present invention.
FIG. 2 is a plan view showing a semiconductor device shown in FIG. 1, FIG. 2 is a partial plan view showing the semiconductor device shown in FIG. 1 in a partially enlarged manner, and FIG. 3 is a longitudinal sectional view taken along line aa in FIG. . FIG. 2 shows a state before cutting the lead frame, and the sealing body 9 is shown only on the lower side of the lead frame.

The lead frame is made of, for example, an Fe-Ni-based alloy or a Cu-based alloy, and has a plurality of signal leads 3 arranged all around the tab 2 on which the semiconductor chip 1 is mounted. The leads 3 are integrated by a non-conductive dam tape 4 (hatched in the figure).
The leads 3 are also integrated by a tie bar 5 serving as a frame of the lead frame. The inner and outer portions of the dam tape 4 of each lead 3 are inner leads 3a, respectively.
And the outer lead 3b, the tip of the inner lead 3a is connected to the semiconductor chip 1, and the outer lead 3b
Are external terminals of the semiconductor device.

In this embodiment, in addition to the normal leads 3, dummy leads 6 are provided at the ends of the rows of the leads 3. This dummy lead is arranged at the same size and the same lead pitch as the lead 3, but unlike the normal lead 3, one end of the dummy lead 6 is connected to a tab suspension lead 7 supporting the tab 2, The other end of the lead 6 slightly protrudes from the outer edge of the dam tape 4.

In the semiconductor device using this lead frame, the semiconductor chip 1 is fixed to the tab 2 with resin or silver paste, and the semiconductor chip 1 and the inner leads 3a are connected by bonding wires 8 (only one is shown as an example). Have been. After bonding, the semiconductor chip 1, the tab 3, the inner leads 3a, and the bonding wires 8 are sealed by a sealing body 9 made of, for example, an epoxy resin, and the tie bars 5 are cut to electrically separate the respective leads 3. Thereafter, the outer leads 3b extending from the sealing body 9 are formed into a predetermined shape, and the semiconductor device is completed.

The dam tape 4 is made of a thermoplastic resin such as polyimide (Dupont: Kapton) or the like, and is a sheet-shaped tape in a lead frame state as shown in FIG. Is fixed, but as shown in FIG. 5, the dam tape 4 is pressed in a molten state by the upper and lower molds 10 heated before resin sealing, and is filled between the lead 3 and the dummy lead 6. . As the mold 10, a mold for resin sealing is used,
The dam tape 4 may be filled immediately before resin sealing, but a mold prepared separately from a mold for resin sealing may be used.

In the conventional device having no dummy lead 6 shown in FIG. 6, the distance between the adjacent leads 3 and the distance between the tab suspension leads 7 are different between the leads 3 located at the column ends. For this reason, as shown in FIG. 7, when the dam tape 4 in the molten state flows as shown by the arrow and the filling is performed, a force is applied to the side surfaces of the plurality of leads 3 in accordance with this flow, and Since the distance between the adjacent lead 3 and the distance between the tab suspension lead 7 is different, the force applied to the side surface of the lead 3 is not equalized, as illustrated by the arrow, and the lead 3 is horizontal. There was a deformation moving in the direction.

In the present invention, in such a case, the forces applied to the side surfaces of the leads 3 located at the column ends of the plurality of leads 3 are equalized by providing the dummy leads 6 as exemplified by arrows. The deformation of the lead 3 is prevented.

At this time, in the example shown in the figure, the force applied to the side surface of the dummy lead 6 is not equalized. However, since one end of the dummy lead 6 is connected to the tab suspension lead 7 at a short distance, deformation occurs. Less likely. Even if a bias occurs, the other end of the dummy lead 6 moves to the tab suspension lead 7 side, so that a problem such as a short circuit does not occur, and the influence of the movement on the lead 3 at the row end is small.

However, when it is desired to equalize the force applied to the side surface of the dummy lead 6, a plurality of dummy leads 6 are arranged as shown in FIG. 8 to equalize the interval, or as shown in FIG. Can be equalized by changing the width of.

The dummy lead 6 is connected to the tab suspension lead 7
By connecting to the tab, the strength of the tab suspension lead 7 is increased, and the deformation of the tab suspension lead 7 is prevented.

As described above, the invention made by the present inventor is:
Although a specific description has been given based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the invention.

For example, in the above description, the case where the invention made by the present inventor is mainly applied to the QFP type semiconductor device, which is the field of application as the background, has been described. However, the present invention is not limited to this. The invention can be widely applied to other semiconductor devices or electronic components sealed with a resin using a lead frame.

[0032]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) According to the present invention, in manufacturing a semiconductor device using a tape dam type lead frame, there is an effect that deformation of leads can be prevented.

(2) According to the present invention, the effect (1) has an effect that a short circuit due to contact of an adjacent bonding wire or lead can be prevented.

(3) According to the present invention, the effect (2) has an effect that the quality of the semiconductor device is improved.

(4) According to the present invention, the effect (2) has an effect that the yield of the semiconductor device is improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing a QFP semiconductor device according to an embodiment of the present invention.

FIG. 2 is a partially enlarged plan view of the semiconductor device shown in FIG. 1;

FIG. 3 is a longitudinal sectional view taken along the line aa in FIG.

FIG. 4 is a longitudinal sectional view showing a dam tape and leads and dummy leads in a sheet state.

FIG. 5 is a longitudinal sectional view showing a dam tape and leads and dummy leads in a molten state.

FIG. 6 is a partial plan view showing a conventional QFP type semiconductor device in a partially enlarged manner.

FIG. 7 is a longitudinal sectional view showing a dam tape, leads and dummy leads in a molten state of a conventional semiconductor device.

FIG. 8 is a partially enlarged plan view showing a modification of the QFP type semiconductor device according to one embodiment of the present invention;

FIG. 9 is a partially enlarged plan view showing a modification of the QFP type semiconductor device according to one embodiment of the present invention;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor chip, 2 ... Tab, 3 ... Lead, 3a ... Inner lead, 3b ... Outer lead, 4 ... Dam tape,
5 tie bar, 6 dummy lead, 7 tab suspension lead, 8 bonding wire, 9 sealing body, 10 mold.

Claims (10)

[Claims] 1. A lead frame used for a semiconductor device sealed with a resin by a sealing body and having a plurality of leads arranged along one side of the sealing body, wherein the plurality of leads are resin-sealed. A lead frame fixed to a non-conductive member at an outer edge of a sealing region in which a dummy lead is arranged at a column end of the plurality of leads. 2. The lead frame according to claim 1, wherein the dummy leads are arranged at regular intervals with the signal leads. 3. The lead frame according to claim 1, wherein said lead frame is used for a QFP type semiconductor device. 4. The lead frame according to claim 1, wherein one end of said dummy lead is connected to a lead for supporting a semiconductor chip. 5. A semiconductor device having a plurality of leads which are resin-sealed by a sealing body and are arranged along one side of the sealing body, wherein the plurality of leads are sealed with a resin. A semiconductor device fixed to a non-conductive member at an outer edge, and a dummy lead is arranged at a column end of the plurality of leads. 6. The semiconductor device according to claim 5, wherein said dummy leads are arranged at equal intervals with said plurality of leads. 7. The semiconductor device according to claim 5, wherein said semiconductor device is a QFP type semiconductor device. 8. The method for manufacturing a semiconductor device according to claim 5, wherein one end of said dummy lead is connected to a lead for supporting a semiconductor chip. 9. A method of manufacturing a semiconductor device having a plurality of leads which are resin-sealed by a sealing body and are arranged along one side of the sealing body, wherein the plurality of leads are sealed with a resin. Using a lead frame fixed to a non-conductive member at an outer edge of a sealing region and having dummy leads arranged at column ends of the plurality of leads, filling the non-conductive member between the plurality of leads. A method for manufacturing a semiconductor device, comprising: a step of performing sealing with a resin by preventing the sealing resin from flowing out between the plurality of leads by the filled non-conductive member. 10. The method according to claim 9, wherein the dummy leads are arranged at equal intervals with the plurality of leads.