JPH02310955A - Lead frame and semiconductor device using same - Google Patents

Abstract

PURPOSE:To realize high pin counts and multitier mounting by a method wherein a dam stopper member composed of an insulating material is installed between inner lead parts at parts covered with a mold during a resin molding operation or at parts near an outer edge of a resin mold. CONSTITUTION:Dam bars 3 which have been installed at inner lead parts are abolished; dam stopper members 5 are installed, so as to connect individual inner leads 2 to each other, in positions where the dam bars 3 have been installed. The dam stopper members 5 are constituted in such a way that a nonconductive material, e.g. an epoxy resin, an acrylic resin, an epoxy resin containing a reinforcing fiber, such as a glass fiber or the like, or the like is used and that this resin is fixed and bonded between the leads. When the dam stopper members 5 are fixed and bonded between the leads, coupling and bonding members are installed at side-end parts of the leads in such a way that they are not exfoliated and do not fall off during a conveyance operation. That is to say, protrusions 6 are formed or cutout parts are formed at side parts in such a way that the dam stopper members 5 fixed and bonded between the leads are coupled and bonded surely; the dam stopper members 5 are prevented from falling off.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a technology for manufacturing a lead frame and a technology for configuring a semiconductor device using the lead frame, and particularly to a cutting process when a dam bar is provided. The present invention relates to techniques that can be effectively used to solve various problems that occur in semiconductor devices, and techniques for configuring semiconductor devices using new lead frames.

[Conventional technology]

In recent years, fc/LSI devices are becoming more sophisticated and diversified. In particular, one of the logic devices, A S
IC (Application 5 specific
ICs dedicated to specific uses, called ICs, are attracting attention.

In particular, logic IC/LSI devices are becoming more diverse, and as a result of this, their packaging density is increasing, leading to a trend toward increasing the number of pins.

In addition, in mold type IC/LSI, 36oI1
It is manufactured by bonding to a metal lead frame shaped like a single film, connecting each electrode of the semiconductor chip to the lead frame with Au wires, etc., and then fixing it with mold resin.

FIG. 9 shows an example of a lead frame used in such a mold type IC/LSI.

As shown in FIG. 9, the lead frame includes an outer lead 1, an inner lead 2 formed at the end of the outer lead 1, and a dam bar 3 that connects and fixes adjacent parts of the outer lead 1 at a predetermined pitch. , and a tab 4 disposed at the opposing portion of each inner lead 2.

When manufacturing a semiconductor device using the above lead frame, a semiconductor chip is positioned and bonded onto the tab 4. next,
The bonding pad of the chip and a predetermined area of the lead frame are electrically connected using wire bonding technology. Further, the wire-bonded lead frames are arranged in a mold, and epoxy resin (mold resin) is poured into the mold to perform resin molding. At this time, the dam bar 3 functions to prevent the injected resin from leaking out. Thereafter, the leads protruding around the resin are cut to a predetermined length, and the dam bar 3 is also cut. As a result, independent outer leads 1 are formed.

Note that this type of lead frame is described in, for example, Japanese Patent Application Laid-Open No. 152051/1988 and "Characteristics of rAsIc General-purpose Lead Frame", pages 85 to 90, April 1988 issue of Electronic Materials J.

[Problem to be solved by the invention]

However, in a semiconductor device using a lead frame in which a dam bar is formed as described above, when the lead pitch becomes small or a multi-tiered lead frame structure is used for the purpose of increasing the number of pins, it becomes difficult to cut and separate the dam bar. .

Therefore, the presence of the dam bar has been an obstacle to realizing a multi-bin and multi-tiered lead frame structure.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a technique that can eliminate the need for a dam bar and eliminate the need for cutting and separating the dam bar.

Another object of the present invention is to provide a technique that enables multi-bin and multi-throw stacking using a lead frame without a dam bar.

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

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, in a lead frame equipped with a tab portion on which a semiconductor element is mounted, an inner lead portion connected to the semiconductor element via a thin metal wire, and an outer lead portion integrally connected to the inner lead portion, during resin molding. A dam stop member made of an insulating material is provided between the inner lead portions at a portion covered by the mold or a portion near the outer edge of the resin mold.

[Effect]

According to the above-mentioned means, the dam stop member made of an insulating material provided between the inner leads functions as a dam bar integrally formed with the conventional lead, and since it is a non-conductor, it forms an electrical conductor. Never. Therefore, there is no need to intentionally remove the resin after molding, and cutting and removal processing becomes unnecessary. Therefore, it becomes possible to have multiple pins.

[Embodiment] FIG. 1 is a plan view showing an embodiment of a lead frame according to the present invention.

In FIG. 1, the same reference numerals are used for the same parts as in FIG. 9, so redundant explanations will be omitted. The feature of this embodiment is that the dam bar 3 that was conventionally provided on the inner lead part is eliminated, and a dam stopper member 5 is provided at the position where the dam bar 3 was provided so as to connect each inner lead 2 to each other. This is what I did.

The dam stop member 5 is constructed by using a non-conductive material such as epoxy resin, acrylic resin, epoxy resin containing reinforcing fibers such as glass fiber, etc., and fixing this between the leads.

When the dam stopper member 5 is fixed between the leads, an engaging member is provided at the side end of the lead so that the dam stopper member 5 does not come off during transportation.

That is, a protrusion 6 is provided on the side as shown in FIG. 2, or a notch 7 is provided as shown in FIG. 3 to ensure that the dam stopper 5 fixed between the leads is securely engaged. This prevents the dam stopper member 5 from falling off.

The dam stop member 5 can be formed by punching out the lead frame into a predetermined pattern using a press, and then pouring the resin material into the area where the dam bar was conventionally formed and solidifying it. Note that unnecessary parts (protruding parts) are removed as necessary.

Since this dam stop member 5 is made of an insulating material, even if it is bridged between the leads, it does not affect the circuit electrically. Therefore, resin molding after wire bonding can be performed without removing the dam stopper member 5. Since it is not necessary to remove the dam stop member 5, various problems associated with cutting and removal, which were problems in the prior art, do not occur.

The present invention is of course effective when applied to a lead frame in which leads are formed in two directions as shown in FIG. 1, but also in a lead frame in which leads are formed in four directions as shown in FIG. It is particularly suitable for a lead frame 8 having a structure in which the dam bar 3 is not provided integrally with the outer lead l. In this case, since the number of pins becomes large and the lead spacing becomes close, the dam stop member 5 is formed in a band shape so as to connect each inner lead 2 to each other, as shown in FIG.

Next, an example of a semiconductor device using a lead frame having the above structure will be described.

FIG. 6 is a sectional view showing an embodiment of the semiconductor device according to the present invention.

To explain the manufacturing process of the semiconductor device shown in FIG. 6, first, the semiconductor element 10 is placed on the tab 4 of the lead frame shown in FIG. 1 using an automatic pattern recognition device. An epoxy resin containing Ag (Ag paste) is applied on the tab 4 in the previous step, and the semiconductor element 10 is temporarily fixed by simply pressing the semiconductor element 10 thereon. Then, 15
The Ag-containing epoxy resin is cured at 0 to 200° C., and the semiconductor element 10 and the lead frame are electrically connected by the Ag in the resin.

Next, using the Au wire 11, the bonding pad of the semiconductor element IO and a predetermined region of the lead frame are electrically connected, ie, wire bonded, using an automatic bonder. Furthermore, the lead frames that have undergone wire bonding are arranged in a mold, and an epoxy resin (mold resin) is poured into the mold to form a resin mold 12.

Thereafter, the outer lead l protruding around the resin is cut to a predetermined length. As a result, independent outer leads 1 are formed.

At this time, as shown in FIG. 7, the dam stop member 5 may be in a state where the hardened mold resin protrudes outside. In this case, remove it by some method. Alternatively, since it does not affect the performance of the product, it may be left as is.

FIG. 8 is a sectional view of the main parts of another embodiment of the semiconductor device.

In this example, the leads are stacked in multiple layers.
As shown in FIG. 8, the device is characterized in that an outer lead lb is arranged so as to overlap the outer lead 1a. In this case, an insulator 13 is inserted between the leads so that the upper and lower electrodes do not come into contact with each other. For this insulator 13, for example, an epoxy insulating tape is used.

In this way, by making the leads multi-tiered,
For example, by stacking them in two layers, it becomes possible to process twice the number of wires as the number of leads on a plane, and high-density packaging becomes possible. This is possible because it eliminates the need for a dam bar integrated into the lead.

Although the invention made by the present invention has been specifically explained based on Examples above, it goes without saying that the present invention is not limited to the above-mentioned Examples and can be modified in various ways without departing from the gist thereof. .

〔Effect of the invention〕

Among the inventions disclosed in this application, the effects obtained by typical ones are as follows.

(1), that is, a lead frame including a tab portion on which a semiconductor element is mounted, an inner lead portion connected to the semiconductor element via a thin metal wire, and an outer lead portion integrally connected to the inner lead portion. Therefore, a dam stopper member made of an insulating material is provided between the inner lead portions at a portion covered by the resin mold during resin molding or a portion near the outer edge of the resin mold, so that the dam stop member is formed integrally with the lead. The dam bar becomes unnecessary, and the process of cutting and separating the dam bar becomes unnecessary.

(2) With the above (1), it is possible to increase the number of semiconductor devices and also realize a multi-tiered lead frame structure. It is particularly suitable for multi-bin logic semiconductor devices.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of a lead frame according to the present invention, FIGS. 2 and 3 are plan views showing a lead structure of a dam stop member installation part according to the present invention, and FIG. 4 is a plan view showing an embodiment of the lead frame according to the present invention. FIG. 5 is a plan view showing an example of formation of a dam stop member corresponding to the lead frame of FIG. 4, and FIG. 6 is an embodiment of a semiconductor device according to the present invention. 7 is a plan view illustrating removal of the dam stopper member of the semiconductor device shown in FIG. 6, FIG. 8 is a sectional view showing another embodiment of the semiconductor device according to the present invention, and FIG. FIG. 2 is a plan view showing the structure of a conventional lead frame. 1, la, lb...outer lead, 2...inner lead, 4...tab, 5...dam stop member, 6...
...Protrusion, 7... Notch 7.8... Lead frame, 10... Semiconductor element, 11... Au wire, 12
... Resin mold, 13... Insulator. Figure 4 Figure 5 Figure 6 Figure 8 Figure 9

Claims (1)

[Scope of Claims] 1. A lead comprising a tab portion on which a semiconductor element is mounted, an inner lead portion connected to the semiconductor element via a thin metal wire, and an outer lead portion integrally connected to the inner lead portion. The lead frame is characterized in that a dam stopper member made of an insulating material is provided between the inner lead portions at a portion covered by the resin mold during resin molding or a portion near the outer edge of the resin mold. . 2. The lead frame according to claim 1, wherein the lead frame is formed by laminating a plurality of lead frames insulated in the thickness direction, each having a different connection destination. 3. The lead frame according to claim 1 or 2, wherein a protrusion or a notch is provided on the inner lead at a portion where the dam stop member is provided. 4. A semiconductor device, characterized in that a semiconductor chip is mounted on the lead frame according to claim 1, 2 or 3, and a predetermined assembled portion is molded with resin.