JPH09298264A - Lead frame structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead frame structure having than lead frames of many pins and mounted on many faces thereof, even when applied with an external pressure during manufacturing, which can prevent its deformation and thus can be made good in its quality without any deformation. SOLUTION: In the lead frame structure having a plurality of lead frames formed within an outer frame of a metallic plate; a matrix of lead frames 4 are formed within an outer frame 2 while eliminating the need for being linked each other, columns 3 are linked to the outer frame 2 between lead frame rows in a row direction parallel to a feed direction of the lead frame structure 1, and the lead frame 4 are lined and held to at least one of the outer frame 2 or columns by means of linking bridges 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame structure in which lead frames used in a semiconductor integrated circuit device or the like are attached on multiple sides, and more particularly to a lead frame structure in which lead pins having thin plates and multiple pins are attached on multiple sides. Regarding

[0002]

2. Description of the Related Art A lead frame used in a semiconductor integrated circuit device or the like is made of a thin metal plate and is manufactured by a photoetching method or a punching method using a die. Conventionally, when a lead frame is manufactured using a photo-etching method, in order to increase the manufacturing efficiency of the lead frame, it is generally manufactured by attaching a plurality of lead frames to a single plate or a long strip metal plate. It has become a target.

Here, FIG. 3 shows a conventional lead frame structure 1 in which a lead frame is multi-faced on a single metal plate.
Is a schematic representation of the above example. As shown in FIG.
The metal plate used as a material has a square-shaped outer frame 2 and a plurality of lead frames 4 formed by etching. In the example of FIG. 3, the outer frame 2 has three groups of substantially rectangular lead frames 5 in which three substantially square lead frames 4 are connected in series. Although FIG. 3 shows the case of a single metal plate, when the metal plate has a long strip shape, the lead frame structure 1 described above is continuously formed in the longitudinal direction. By appropriately cutting, the final shape of the sheet metal is substantially the same as that of the sheet metal plate.

In obtaining a lead frame, punching using a die is carried out to obtain individual lead frames separated from the lead frame structure.

FIG. 4 is a diagram showing a part of the lead frame group 5 in which the lead frames 4 are connected to each other, which is held in the lead frame structure 1 described above. Conventionally, a lead frame as a final product may be composed of lead portions 10 such as inner leads and outer leads, and a die pad on which an IC chip is mounted if necessary.
As shown in FIG. 4, a frame 6 that surrounds the lead portion 10 and the like is formed on the lead frame 4 that is being manufactured.
10 and the like are connected and held to the frame 6. It should be noted that after mounting the IC chip on the lead frame 4 individually separated from the lead frame structure 1, electrical connection between the IC chip and the lead, and packaging of the main part of the lead frame with a sealing resin, At least the frame 6 is cut off to obtain a semiconductor integrated circuit device.

As shown in FIG. 4, the frames 6 of the lead frame 4 are connected to each other by a bridge 8 to form a lead frame group 5. Further, as shown in FIG. The lead frame structure 1 of the related art is obtained by connecting and holding it to the frame 2.

[0007]

At present, the lead frame has a thin plate thickness and tends to have a large number of pins. For example, in lead frames called layers for ceramics packages, the package size is large, the number of pins is from 200 pins to 300 pins or more, and the plate thickness is very thin, about 100 μm to 150 μm. .

For this reason, the lead frame structure 1 is thin and weak in strength, so that even if a slight pressure is applied to the lead frame structure 1 during manufacturing, deformation such as bending is likely to occur. It is a thing.

For example, the following is an example of the deformation of the lead frame structure 1. That is, the lead frame structure 1 formed by etching is carried on a carrying means such as a carrying roller and subjected to various treatments. During the transportation, the lead frame structure 1 vibrates, pressure is applied to the lead frame structure 1, and the lead frame structure 1 is deformed.

Further, after etching, the etching resistant film made of a photosensitive resin or the like formed on the surface of the lead frame structure 1 is stripped, but it can be said that deformation is likely to occur at that time as well. For example, after contacting the lead frame structure 1 with an alkaline liquid, washing with water is performed, and thereafter, the lead frame structure 1 is passed between a pair of rotating rollers called a squeezing roller. It is common to remove the water remaining on the surface. When the lead frame structure 1 enters the squeezing roller, the rotation of the squeezing roller and the lead frame structure 1
It can be said that the lead frame structure 1 is bent due to a difference in the transport speed of the lead frame structure 1 and the like, and the lead frame structure 1 is also deformed.

Since the lead frame 4 is formed in the lead frame structure 1, the deformation of the lead frame structure 1 means that the finally obtained lead frame becomes defective.

The present invention has been made in view of the above-mentioned problems, and in a lead frame structure having a multi-pin lead frame with a thin plate attached to multiple surfaces, external pressure is applied to the lead frame structure during manufacturing. Even in such a case, it is an object of the present invention to prevent the lead frame structure from being deformed and to obtain a good quality lead frame without deformation defects.

[0013]

In order to achieve the above object in the present invention, first, in claim 1, a lead frame structure for forming a plurality of lead frames in an outer frame formed on a metal plate. In, the lead frames are formed in a matrix in the outer frame without connecting the lead frames, and the columns connected to the outer frame are arranged between the lead frame columns in the row direction parallel to the transport direction of the lead frame structure. A lead frame structure is provided, in which each lead frame is held and connected to at least one of an outer frame and a girder by a connecting bridge.

According to a second aspect of the present invention, in a lead frame structure in which a plurality of lead frames are formed in an outer frame formed of a metal plate, a plurality of lead frames which are not connected to each other are surrounded, and the lead frame is formed. Is formed, and the inner frame is connected and held to the outer frame by a connecting bridge.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings schematically showing the embodiments. In the lead frame structure 1 according to claim 1, as shown in FIG. 1, a square-shaped outer frame 2 formed by etching.
The lead frame 4 is faced in a matrix. The lead frame 4 has a structure including the frame 6 shown in FIG.

As described in the above (Prior Art), when a plurality of lead frames are conventionally formed in the outer frame 2, the lead frames 4 are connected by a bridge 8 to form a lead frame group 5, After that, the lead frame group 5 is connected to the outer frame 2 by a connecting bridge 7.
However, when the lead frames 4 are connected to each other, when external pressure is applied to each lead frame 4, there is no escape area for the external pressure, and the external pressure applied to each lead frame 4 is integrated. Therefore, the accumulated external pressure is concentrated on a specific lead frame located at, for example, the central portion of the lead frame group 5 or the end portion of the lead frame group 5, and the lead frame 4 is deformed. It is a thing.

Therefore, the inventors of the present invention eliminate the connection between the lead frames 4 formed in the outer frame 2 and prevent the external pressure from being integrated even when the external pressure is applied to each lead frame 4. It is a proposal to do.

Then, in order to hold the lead frame 4 to the lead frame structure 1 and structurally strengthen the lead frame structure 1, as shown in FIG. 1, between the lead frame columns in the row direction, A girder 3 connected to the outer frame 2 is provided.

That is, the conventional lead frame structure 1
In the above, as shown in FIGS. 3 and 4 described above, the lead frames 4 are connected to each other to form the lead frame group 5, and then the lead frame group 5 is connected to the outer frame 2. Therefore, even if the number of impositions of the lead frame 4 is large, each lead frame 4 is held by the lead frame structure 1. However, in the present invention, the connection between the lead frames 4 is eliminated. Therefore, for example, when the lead frames 4 are attached to the outer frame 2 in three rows and three columns, the lead frames 4 on the outer peripheral portion are
It can be said that, even if the lead frame 4 can be connected and held to the outer frame 2, the lead frame 4 located at the center has no partner to be connected and falls off from the lead frame structure 1.

For this reason, as shown in FIG. 1, the columns 3 connected to the outer frame 2 are provided between the lead frame columns in the row direction. That is, the lead frame 4 is held in the lead frame structure 1 by connecting each lead frame 4 to at least one of the outer frame 2 and the girder 3 by the connecting bridge 7.

It can be said that the rigidity of the lead frame structure 1 is increased by providing the above-mentioned girder 3 in the outer frame 2.
The strength of the lead frame structure 1 against external pressure is increased.

When the direction in which the girder 3 is provided is at right angles to the carrying direction of the lead frame structure 1, when the lead frame structure 1 is bent, the carrying means of the lead frame structure 1, for example, carrying means. The roller and the beam 3 may collide with each other, and the lead frame structure 1 may be deformed. Therefore, it can be said that it is desirable that the direction in which the girder 3 is provided is parallel to the transport direction of the lead frame structure 1, as shown in FIG. The arrows in FIG. 1 indicate the transport direction of the lead frame structure 1.

Next, FIG. 2 schematically shows an embodiment of the lead frame structure 1 according to claim 2. In the lead frame structure 1 of FIG. 2, the outer frame 2 is formed in a square shape as in the conventional case. Then
Inside the outer frame 2, a square-shaped inner frame 9 is formed separately, and the inner frame 9 is connected and held to the outer frame 2 by a connecting bridge 7.

The lead frame 4 is formed in the inner frame 9. As described above, the lead frames 4 formed in the inner frame 9 are connected to each other to prevent the external pressure from being accumulated. I haven't. Further, the lead frame 4 in the inner frame 9 is connected and held to the inner frame 9 by the bridge 8.

As shown in FIG. 2, by providing the inner frame 9 connected to the outer frame 2, it can be said that the rigidity of the lead frame structure 1 is increased, but the strength of the lead frame structure 1 against external pressure is increased. is there.

Needless to say, the embodiment of the present invention is not limited to the above drawings and description, and various modifications can be made based on the spirit of the present invention. For example,
In FIG. 2, the lead frame 4 formed in the inner frame 9
However, the lead frame 4 may be provided in a plurality of rows. When the lead frames 4 are arranged in a matrix in the inner frame 9, the columns 3 connected to the inner frame 9 are provided between the lead frame columns in the row direction as necessary, so that the individual lead frames 4 are connected to each other. It may be connected and held to at least one of 9 and the girder 3.

Further, a girder 3 which connects the inner frames 9 with each other by a bridge or connects the inner frames 9 with the outer frame 2 is used.
May be provided, and the inner frame 9 may be connected and held to at least one of the outer frame 2 and the girder 3 by a bridge.

[0028]

According to the lead frame structure of the present invention, even when external pressure is applied to each lead frame individually, the integrated external pressure can be prevented from being concentrated on a specific lead frame. Can be prevented from deformation. In addition, the lead frame structure 1 is provided by providing a girder in the outer frame or an inner frame connected to the outer frame.
Since the rigidity is increased and the strength of the lead frame structure 1 is increased, it is possible to prevent the deformation defect of the lead frame structure 1 even when external pressure is applied.

[0029]

[Brief description of drawings]

FIG. 1 is a plan view showing one embodiment of a lead frame structure of the present invention.

FIG. 2 is a plan view showing another embodiment of the lead frame structure of the present invention.

FIG. 3 is a plan view showing an example of a conventional lead frame structure.

FIG. 4 is an explanatory view showing a connection between lead frames in a conventional lead frame structure.

[Explanation of symbols]

 1 lead frame structure 2 outer frame 3 digits 4 lead frame 5 lead frame group 6 frame 7 connecting bridge 8 bridge 9 inner frame 10 lead part

Claims (2)

[Claims] 1. A lead frame structure in which a plurality of lead frames are formed in an outer frame formed on a metal plate, wherein the lead frames are formed in a matrix in the outer frame without connecting the lead frames to each other, and , A girder that is connected to the outer frame is provided between the lead frame columns in a row direction parallel to the transport direction of the lead frame structure, and each lead frame is connected and held by at least one of the outer frame and the girder by a connecting bridge. And lead frame structure. 2. A lead frame structure in which a plurality of lead frames are formed in an outer frame formed of a metal plate, the inner frame enclosing a plurality of lead frames that are not connected to each other and connecting and holding the lead frames. And the inner frame is connected and held to the outer frame by a connecting bridge.