JPH0878590A - Lead frame - Google Patents

Abstract

PURPOSE: To eliminate such an unsatisfactory state as to say that lead fames are entangled with each other or are deformed even in the case where the fellow lead frames, which are stacked when the lead frames are fed to an automatic semiconductor chip mounter, are deviated from each other and to provide the lead frames, which can be separated from each other one sheet by one sheet. CONSTITUTION: The width of a holding part 4 is made wider than the intervals between inner leads 2 adjacent to the part 4 and the holding part 4. Even if the lead frames, which are stacked when these lead frames are fed to an automatic semiconductor chip mounter, are deviated from each other, the holding part 4 of the upper side lead frame does never intrude into the gaps between the holding part 4 of the lower side lead frame and the inner leads 2 because the width of the holding part 4 of each lead frame is wider than the intervals between the leads 2 adjacent to the part 4 and the holding 4 and the entanglement of the lead frames and the deformation of the lead frames are not generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame,
In particular, it relates to a lead frame used for a resin-sealed semiconductor device.

[0002]

2. Description of the Related Art In a conventional resin-sealed semiconductor device, in order to prevent a gold wire connecting an electrode of a semiconductor element and an internal lead of a lead frame from contacting an edge of the semiconductor element,
Alternatively, in order to arrange the semiconductor element in the center of the package body in the thickness direction due to the stress generated by the package, the semiconductor element mounting surface should be lower than the internal lead surface by the semiconductor element thickness. The holding part that holds the part was bent.

For example, in a so-called SIP type lead frame in which external leads are led out from one direction of the package body, as shown in FIG.
When the semiconductor element is mounted on the semiconductor element mounting portion 3, the holding portion 4 is bent so that the surface of the semiconductor element mounting portion 3 is lower than the surface of the inner lead 2 by the thickness of the semiconductor element to form the bent portion 4a. Further, in the case of a package for the purpose of heat dissipation, the holding portion 4 must be bent until the back surface of the semiconductor element mounting portion 3 is exposed to the back surface of the package, and the gold wire becomes too long. Therefore, in JP-A-55-50648. The internal leads are also bent by bending to the back side of the package.

The semiconductor element mounting portion 3 of this lead frame
When semiconductor devices are mounted on, several tens of lead frames are stacked and supplied to an automatic semiconductor device mounting machine in order to improve work efficiency. When vibration is applied to the stacked lead frames during supply, or when the lead frames are displaced due to mishandling or the like, as shown in FIG. 5, the bent portion 4a of the upper lead frame causes the bent lead frame 4a of the lower lead frame to move. When the lead frame enters between the inner lead 2 and the bending part 4a and the lead frames are entangled with each other, the inner lead 2 may be deformed or separated for feeding the lead frame into the automatic semiconductor device mounting machine. The problem of disappearing occurs.

[0005]

As described above,
The conventional lead frame is bent by bending the upper lead frame when vibration is applied to the stacked lead frames when stacking dozens of them and supplying them to the automatic semiconductor device mounting machine, or when the lead frames are misaligned due to mishandling. The processed part enters between the inner lead of the lower lead frame and the bent part, and the lead frames are entangled,
There are problems that the internal leads are deformed and that the lead frames cannot be separated one by one for feeding into the automatic semiconductor device mounting machine.

It is an object of the present invention to provide a lead frame in which the internal leads are not deformed and can be separated one by one and smoothly supplied to an automatic semiconductor device mounting machine.

[0007]

According to the present invention, an external lead, an internal lead connected to the external lead, and a semiconductor element mounting portion connected to the external lead via a holding portion,
A tie bar connecting the external lead and the internal lead, and the connecting part between the external lead and the holding part,
In a lead frame used for a resin-encapsulated semiconductor device in which at least one of the internal lead and the holding portion is bent, the holding portion is connected to the tie bar or is bent. From the bending start point, or by approaching the inner lead at a position facing the bending portion and advancing the width, the width is wider than the distance between the adjacent inner leads.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a perspective view of an essential part of a first embodiment of the present invention. The first embodiment of the present invention, as shown in FIG.
The holding portion 4 that holds the semiconductor element mounting portion 3 is bent to form a bent portion 4a, and the width of the holding portion 4 is determined from the distance between the tie bar 5 and the internal lead 2 that is adjacent to the semiconductor element mounting portion 3. Is also widely formed.

By forming the holding portion 4 in this way, when the lead frames are stacked and supplied to the automatic semiconductor element mounting machine, even if the stacked lead frames are displaced in the front-rear direction, the width of the holding portion 4 is wide. Are formed to be wider than the space between the adjacent inner leads 2, the bending portion 4a of the lead frame located on the upper side and the inner lead 2 adjacent to the bending portion 4a of the lead frame located on the lower side. Since it is wider than the space, the bent portion 4a of the upper lead frame does not enter and become entangled in the gap between the bent portion 4a of the lower lead frame and the adjacent inner lead 2, and the bundle of stacked lead frames is easily formed. It is possible to supply them to the automatic semiconductor element mounting machine without separating the internal leads 2 by separating them one by one.

FIG. 2 is a perspective view of the essential portions of the second embodiment of the present invention. The second embodiment of the present invention, as shown in FIG.
This is an example in which only the bent portion 4a from the bending start point of the holding portion 4 to the semiconductor element mounting portion 3 is formed wider than the space between the adjacent inner leads 2. Bending part 4 of holding part 4
By forming only a in this way, the same effect as in the first embodiment can be obtained, and the portion having a wide width is limited to the inside of the package body. Therefore, the external lead 1 including the vicinity of the tie bar 5 is stepped. It can be formed into a uniform width.

FIG. 3 is a perspective view of the essential portions of a third embodiment of the present invention. The third embodiment of the present invention, as shown in FIG.
This is an example in which a width-shifting portion 2a is formed by bending the position of the holding portion 4 of the inner lead 2 facing the bending portion 4a in a planar manner to shift the width to the holding portion 4 side and bring the width-shifting portion 2a closer. By forming the width-shifting portion 2a on the inner lead 2 as described above, the width of the bent portion 4a can be made wider than the space between the width-shifting portion 2a and the adjacent width-shifting portion 2a. can get. This embodiment is effective when the distance between the external leads 1 is wide.

In the above-mentioned embodiment, the example in which only the holding portion 4 is bent has been described.
Is bent, the same effect can be obtained even if the width of the inner lead 2 is made wider than the space between the adjacent holding portions 4. Further, only the SIP type lead frame has been described, but if the holding portion 4 of the semiconductor element mounting portion 3 or the internal lead 2 is bent and there is a step in the lead frame, the present invention is SOP in which external leads are led out from two opposing surfaces, and QF in which external leads are led out from four sides of the package body
It can also be applied to a lead frame of a semiconductor device such as P. In addition, the width of the holding portion 4 is sufficient to obtain a sufficient effect as long as it is two to three times as large as the distance between the inner leads 2 adjacent to each other.

[0014]

As described above, in the lead frame of the present invention, the width of the holding portion is wider than the distance between the adjacent inner leads, so that the leads stacked when being supplied to the automatic semiconductor device mounting machine. Even if the frame shifts,
There is an effect that it is possible to provide a lead frame in which the holding portion of the lead frame located on the upper side can be separated one by one without the problem that the holding portion of the lead frame located on the lower side enters the gap between the holding portion of the lead frame and the internal lead and is entangled or deformed.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part of a first embodiment of the present invention.

FIG. 2 is a perspective view of a main part of a second embodiment of the present invention.

FIG. 3 is a perspective view of an essential part of a third embodiment of the present invention.

FIG. 4 is a perspective view of an example of a conventional lead frame.

FIG. 5 is a perspective view of a main part when a displacement occurs after stacking the conventional lead frames.

[Explanation of symbols]

 1 External Lead 2 Inner Lead 2a Width Adjusting Section 3 Semiconductor Element Mounting Section 4 Holding Section 4a Bending Section 5 Tie Bar

Claims (4)

[Claims] 1. An external lead, an internal lead connected to the external lead, a semiconductor element mounting part connected to the external lead via a holding part, the external lead, the internal lead, the external lead and the holding part. A lead frame used for a resin-encapsulated semiconductor device in which at least one of the internal lead and the holding part is bent, A lead frame, wherein the holding part has a width wider than a space between the holding part and the adjacent inner lead. 2. The lead frame according to claim 1, wherein the holding portion has a wide width from a connection portion with the tie bar. 3. The lead frame according to claim 1, wherein the holding portion has a wide width from a bending start point of the bending portion. 4. The holding portion has a width wider than a space between the inner leads adjacent to the bending portion by bringing the inner leads close to each other to be closer to each other. Lead frame.