JPH0567716A - Lead frame and manufacture thereof - Google Patents

Abstract

PURPOSE:To form a section having different thickness easily to a lead frame. CONSTITUTION:An island 40, on which a semiconductor chip is mounted and which is molded with a resin at the time of resin seal, and inner leads 20 connected to the electrodes of the semiconductor chip mounted on the island 40 and molded with the resin at the time of resin seal are formed in size thinner than outer leads 30 continuously formed to the inner leads 20 and exposed from the resin to the outside. A plurality of sections corresponding to one semiconductor devices are formed so as to be adjoined regarding each of the inner leads 20 and the outer leads 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame for a semiconductor device and a method for manufacturing the same. More specifically, the present invention relates to a lead frame used for an IC package and the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art A semiconductor device such as an IC package is manufactured through processes such as die bonding (chip bonding), wire bonding, resin molding and the like. In these series of processes, a lead formed by punching a thin metal plate is used. It is done for frames.

FIG. 6 is a plan view showing the structure of a main part of a conventional example, and P indicates a range corresponding to one package. As shown in the figure, the lead frame 10 mainly includes an island 40 on which a semiconductor chip is mounted, a plurality of inner leads 20 (slanted lines) connected to the electrodes of the semiconductor chip mounted on the island 40, and inner leads. 20
And the guide rail 50 provided with the guide hole 55 for alignment and the like.

Usually, the lead frame 10 is formed by punching a conductive thin metal plate using a punching die or by using an etching method. To manufacture a semiconductor device using the lead frame 10, first, in a chip bonding step, a semiconductor chip is bonded to the island 40 of the lead frame 10, and then in a wire bonding step, the inner leads 20 extending toward the island 40 are formed. The tip portion of the and the electrode of the semiconductor chip are connected by a gold wire or the like. After that, through a process such as a resin molding process of encapsulating the island 40 and the inner leads 20 with resin so as to wrap them, a lead cutting process of separating the molded semiconductor device from the lead frame, and the like,
The semiconductor device is completed. The lead frame 10 is
It is manufactured for each semiconductor device according to the specifications such as the shape of the semiconductor chip bonded to the island 40 and the number of terminals.

[0005]

Generally, since the lead frame is manufactured by punching a flat metal plate or the like, the inner leads and the outer leads are also formed with the same thickness. The plate thickness is generally DIP (Dual
In-Line Package) is 0.25 mm, SOP (Small Outline Package), QFP (Quad Flat Package) is 0.
It is 15 mm.

On the other hand, the fine pitch (fine processing) of the inner leads 20 is dominated by the thickness of the lead frame, but the outer leads (exterior leads) 30 are required to have mechanical strength. There is a limit to reducing the plate thickness. The thickness of a semiconductor device such as an IC package is determined by the lead frame, the semiconductor chip on the island, the wire for bonding, and the like.

Therefore, when the lead frame is made thin,
There is a problem that the strength of the outer lead becomes insufficient and the heat conduction capacity decreases, and when the lead frame is thickened, there is a limit to the fineness of the inner lead and there is a problem that the semiconductor device cannot be thinned. ..

These problems can be solved by making the inner lead and the island thinner than the outer lead. However, as shown in FIG. 6, when the portion to be thinned is surrounded by the outer leads, one lead frame must be provided with two types of portions having different thicknesses. For that purpose, it is necessary to use a complicated apparatus or method for performing rolling, stamping, etching and the like.

The present invention has been made in view of these problems, and a semiconductor device configured such that the lead frame is partially thin and portions of different thickness are easily formed. It is an object of the present invention to provide a lead frame for a vehicle and a manufacturing method capable of easily manufacturing the same.

[0010]

In order to achieve the above object, a lead frame for a semiconductor device according to the present invention is mounted with a semiconductor chip, an island molded with resin at the time of resin sealing, and the island. A lead frame for a semiconductor device, comprising an inner lead connected to an electrode of a semiconductor chip and molded by a resin at the time of resin sealing, and an outer lead continuously formed on the inner lead and exposed from the resin, The island and the inner lead are formed to be thinner than the outer lead, and the inner lead and the outer lead of a portion corresponding to one semiconductor device and the portion of the inner lead and the outer lead corresponding to another adjacent semiconductor device are adjacent to each other. It is characterized in that a plurality of pieces are continuously provided so as to correspond to each other. To have.

A first method of manufacturing a lead frame for a semiconductor device according to the present invention is characterized in that after forming a recess in a lead frame member by rolling a roller, an inner lead and an island are formed in the recess. .. A second method of manufacturing a lead frame for a semiconductor device of the present invention is
It is characterized in that after forming the inner leads and the islands on the lead frame member, the recesses are formed by rolling the roller in the portions where the inner leads and the islands are formed.

[0012]

According to the above structure, since the portion corresponding to one semiconductor device is adjacent to each of the inner lead and the outer lead, the thinned inner lead and outer lead portions are continuously formed. Therefore, the portion to be thinned can be rolled by a roller having a simple disc shape, for example.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The same parts as those in the conventional example (FIG. 6) are designated by the same reference numerals and detailed description thereof will be omitted. FIG. 2 shows a range corresponding to one package as a semiconductor device in this embodiment. Actually, as shown in FIG. 5, the inner lead 20a of the portion T1 corresponding to one package and the outer lead 30a are adjacent to the inner leads 20b, 20c of the portion T2 and T3 corresponding to another package, and the outer lead 30a. A plurality of units 30b and 30c are continuously provided so as to be adjacent to each other. Moreover, the recess 6
1 is continuously formed along the longitudinal direction of the lead frame 10. Then, a process such as die bonding is performed in a state of being wound on a reel or the like in a predetermined length unit (for example, 10 packages) or in a hoop shape (roll shape). 2A is a plan view and FIG. 2B is its XX 'line.
It is a line sectional view.

The present embodiment has the same structure as the conventional example (FIG. 6) except that the recess 61 is provided. The concave portion 61 is formed smaller than the mold portion 65 (broken line), which is the range sealed by the resin. As in the conventional example, the lead frame 10 is connected to an island 40 on which a semiconductor chip is mounted and molded with resin at the time of resin sealing, and electrodes of the semiconductor chip mounted on the island 40, and at the time of resin sealing. An inner lead 20 molded by a resin and an outer lead 30 continuously formed on the inner lead 20 and exposed from the resin are provided. Therefore, the inner leads 20, the island 40, and the like in the area where the recess 61 is formed are covered with the resin.

The recess 61 is formed only on one surface of the lead frame 10, and the other surface is uniformly flat. Therefore, the inner leads 20 and the like in the range where the recess 61 is formed are thinner than the outer leads 30 and the like in the range outside the recess 20.

Next, a method of manufacturing the lead frame 10 will be described. The manufacturing method of this embodiment is a method of forming a recess in a portion of the lead frame member where the inner lead 20 and the island 40 are formed, and then forming the inner lead 20 and the island 40 in the recess. It should be noted that the lead frame member is conventionally referred to as the lead frame 10
Ni alloy and copper alloy materials used as the material of

First, a recess is formed in the lead frame member. FIG. 1 shows a main part of a metal plate 5 used in this embodiment, (a) is a plan view, and (b) is its AA ′.
It is a line sectional view. The metal plate 5 is obtained by forming the recess 60 in a flat metal plate that has been conventionally used as a lead frame member. In the figure,
S indicates a range corresponding to one package shown in FIG. 2, and the concave portion 60, the outer lead portion 70 and the guide rail portion 80 correspond to the concave portion 61, the outer lead 3 in FIG.
0 and guide rail 50 respectively.

The recess 60 can be formed by, for example, stamping with a press, a mold, etching by contact with an etching solution, or the like. However,
As shown in FIG. 3, since the recess 60 extends linearly along the guide rail portion 80, in this embodiment, the portion of the hoop-shaped flat metal plate to be thinned (the portion that becomes the recess 60) is formed by the roller. It is thinned by plastic deformation by rolling.

FIG. 4 schematically shows how the roller (rolling member) 110 rolls the metal plate 5.
By rolling the roller 110 while pressing it on a flat metal plate, it is possible to form a recess 60 as shown in FIGS. 1 and 4 on the circumferential surface of the roller 110.

Next, a lead pattern such as the inner leads 20 is formed on the metal plate 5. The lead pattern can be formed by punching, etching or the like. As a processing method such as punching, etching, or the like, a method generally used in the past can be adopted.

In this embodiment, the recess 60 is formed only on one side of the metal plate 5, but a member as shown in FIG. 4 is contacted from both sides of the flat metal plate to form the recess on both sides of the metal plate. You may. Therefore, the cross section of the metal plate is not limited to the U-shape. Further, in this embodiment, the metal plate 5 has two kinds of thicknesses as shown in FIG. 1B, but it may have a plurality of thicknesses.

As another manufacturing method, a method may be used in which a lead pattern such as the inner leads 20 and the island 40 is formed on a flat lead frame member, and then a recess is formed in the portion where the lead pattern is formed. .. This method can be performed in the same manner as the above-described manufacturing method, except that the recess forming step is performed after the lead pattern forming step.

FIG. 3 is a perspective view showing the appearance of a package 100 to which the lead frame 10 of this embodiment is applied. Only the outer leads 30 are exposed from the resin mold 90, and the inner leads 20, the island 40, and other portions within the recess 61 are molded by the resin mold 90.

Although the lead frame and the method for manufacturing the same according to the present invention have been described above, the present invention is not limited to this embodiment but can be applied to various frames used for semiconductor products.

[0025]

As described above, according to the present invention, a semiconductor chip is mounted and is connected to the island which is molded by the resin at the time of resin sealing and the electrode of the semiconductor chip mounted on the island, and the resin sealing is performed. In a lead frame for a semiconductor device, which includes an inner lead that is sometimes molded with a resin and an outer lead that is continuously formed on the inner lead and is exposed from the resin, the island and the inner lead are formed to be thinner than the outer lead. Therefore, it is possible to realize a lead frame for a semiconductor device in which the fine pitch of the inner leads and the thickness of the semiconductor device can be reduced without lowering the strength and the heat conduction capacity of the outer lead. Moreover, 1
A plurality of inner leads and outer leads corresponding to one semiconductor device are continuously provided so as to be adjacent to another inner lead and outer lead corresponding to another semiconductor device, respectively. Therefore, portions having different thicknesses are easily formed. As a result, it is possible to further improve the strength of the side rails for feeding the lead frame and the outer leads.

In such a lead frame, after a recess is formed on the lead frame member by rolling a roller,
Manufactured easily by forming inner leads and islands in the recesses, forming inner leads and islands in the lead frame member, and then forming recesses by rolling a roller in the portions where the inner leads and islands are formed. can do.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a metal plate used in an embodiment of the present invention.

FIG. 2 is a diagram showing a range corresponding to one package in one embodiment of the present invention.

FIG. 3 is a perspective view showing an external appearance of a package to which an embodiment of the present invention is applied.

FIG. 4 is a perspective view showing how a recess is formed by a roller used in an embodiment of the present invention.

FIG. 5 is a plan view showing a main part of an embodiment of the present invention.

FIG. 6 is a plan view showing a main part of a conventional example.

[Explanation of symbols]

 5 ... Metal plate 10 ... Lead frame 20 ... Inner lead 30 ... Outer lead 40 ... Island 50 ... Guide rail 55 ... Guide hole 60 ... Recess 61 ... Recess 65 ... Mold part 70 ... Outer lead part 80 ... Guide rail part 90 ... Resin mold 100 … Package 110… Roller (rolling member)

Claims (3)

[Claims] 1. An island on which a semiconductor chip is mounted and molded by resin at the time of resin sealing, and an inner lead which is connected to an electrode of the semiconductor chip mounted on the island and is molded by resin at the time of resin sealing. In a lead frame for a semiconductor device, which is continuously formed on the inner lead and has an outer lead exposed to the outside of the resin, the island and the inner lead are formed to be thinner than the outer lead. It is characterized in that a plurality of corresponding inner leads and outer leads are continuously provided so as to be respectively adjacent to an inner lead and an outer lead of a portion corresponding to another adjacent semiconductor device. Lead frame for semiconductor devices. 2. A method of manufacturing a lead frame for a semiconductor device, which comprises forming a recess in a lead frame member by rolling a roller and then forming an inner lead and an island in the recess. 3. A lead frame for a semiconductor device, which comprises forming inner leads and islands on a lead frame member, and then forming a recess in the portion where the inner leads and islands are formed by rolling a roller. Production method.