JP2859136B2 - Lead frame - Google Patents

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, the present invention relates to a lead frame used for a resin-sealed semiconductor device.

[0002]

2. Description of the Related Art In a conventional resin-encapsulated semiconductor device, a gold wire connecting an electrode of a semiconductor element and an internal lead of a lead frame is prevented from contacting an edge of the semiconductor element.
Or, for the purpose of arranging the semiconductor element at the center in the thickness direction of the package body due to the stress generated by the package, the semiconductor element mounting part is mounted so that the surface of the semiconductor element mounting part is lower than the internal lead surface by the thickness of the semiconductor element. The holding part holding the part was subjected to bending.

For example, in a so-called SIP type lead frame in which external leads are led out from one direction of a package body, as shown in FIG.
When the semiconductor element is mounted on the semiconductor device, the holding part 4 is bent so that the surface of the semiconductor element mounting part 3 is lower than the surface of the internal lead 2 by the thickness of the semiconductor element, thereby forming a bent part 4a. Further, in the case of a package for heat radiation, 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. The internal leads are also responded by bending to the package back side.

The semiconductor element mounting portion 3 of the lead frame
When mounting a semiconductor device on a semiconductor device, dozens of lead frames are stacked and supplied to an automatic semiconductor device mounting machine in order to improve work efficiency. When vibrations are 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 is It enters between the internal lead 2 and the bent portion 4a, and the lead frames become entangled with each other, causing deformation of the internal lead 2 and separation of the lead frames one by one for feeding the lead frame into the automatic semiconductor device mounting machine. The problem of disappearing occurs.

[0005]

As described above,
When dozens of conventional lead frames are stacked and supplied to an automatic semiconductor device mounting machine, if the stacked lead frames are subjected to vibration or misaligned due to mishandling, the upper lead frame will be bent. The processed part enters between the internal lead of the lower lead frame and the bent part, and the lead frames become entangled,
There have been problems that the internal leads are deformed and that the lead frames cannot be separated one by one for feeding the lead frame into the automatic semiconductor device mounting machine.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lead frame which does not cause deformation of internal leads and can be separated one by one and smoothly supplied to an automatic semiconductor device mounting machine.

[0007]

According to the present invention, there is provided 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 that connects a connection portion between the external lead and the internal lead and the external lead and the holding portion;
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 formed from a connection portion with the tie bar or a bent portion. From the bending start point or close to the internal lead at a position opposite to the bent portion, and has a width wider than the interval between adjacent internal leads.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a main part of a first embodiment of the present invention. The first embodiment of the present invention, as shown in FIG.
The holding portion 4 for holding the semiconductor element mounting portion 3 is bent to form a bent portion 4 a, and the width of the holding portion 4 is larger than the interval between the adjacent internal leads 2 over the entire area from the tie bar 5 to the semiconductor element mounting portion 3. Is also widely formed.

By forming the holding portion 4 in this manner, when the lead frames are superimposed and supplied to the automatic semiconductor device mounting machine, even if the superposed lead frames are shifted from front to back and right and left, the holding portion 4 can have a width over the entire area. Are formed wider than the interval between the adjacent internal leads 2, so that the bent portion 4 a of the lead frame located on the upper side is formed between the bent portion 4 a of the lead frame located on the lower side and the adjacent internal lead 2. Since the gap is wider than the gap, the bent portion 4a of the upper lead frame does not enter the gap between the bent portion 4a of the lower lead frame and the adjacent internal lead 2 and is not entangled. And can be supplied to an automatic semiconductor device mounting machine without deforming the internal leads 2 one by one.

FIG. 2 is a perspective view of a main part of a second embodiment of the present invention. A 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 interval between the adjacent internal leads 2. Bending part 4 of holding part 4
By forming only a in this manner, the same effect as in the first embodiment can be obtained and the portion having a wide width is limited only to the inside of the package body. It can be formed in a uniform width without any irregularities.

FIG. 3 is a perspective view of a main part of a third embodiment of the present invention. A 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 a position of the holding portion 4 of the internal lead 2 facing the bending portion 4a two-dimensionally and by shifting the width toward the holding portion 4 side. In this manner, the width of the bent portion 4a can be made wider than the interval between the adjacent width shift portions 2a by forming the width shift portion 2a on the internal lead 2, so that the same effect as in the first and second embodiments can be obtained. can get. This embodiment is effective when the interval between the external leads 1 is wide.

In the embodiment described above, an example in which only the holding portion 4 is bent is described.
Is bent, the effect is the same even if the width of the internal lead 2 is made wider than the distance between the adjacent holding portions 4. Although only the SIP type lead frame has been described, if the holding part 4 of the semiconductor element mounting part 3 or the internal lead 2 is bent and there is a step in the lead frame, the present invention is applied to the package body. SOP in which external leads are led out from two opposing surfaces, and QF in which external leads are led out from four surfaces of the package body
It can also be applied to lead frames of semiconductor devices such as P. A sufficient effect can be obtained if the width of the holding portion 4 is two to three times as large as the interval between the adjacent internal leads 2.

[0014]

As described above, in the lead frame of the present invention, since the width of the holding portion is wider than the interval between adjacent internal leads, the leads stacked when supplied to an automatic semiconductor device mounting machine are provided. Even if the frame shifts,
There is an effect that it is possible to provide a lead frame which can be separated one by one by eliminating the problem that the holding portion of the lead frame located on the upper side enters the gap between the holding portion of the lead frame located on the lower side and the internal lead and becomes entangled or deformed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main 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 a main 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 shift occurs after stacking conventional lead frames.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 External lead 2 Internal lead 2a Width adjustment part 3 Semiconductor element mounting part 4 Holding part 4a Bending part 5 Tie bar

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 23/48

Claims (1)

(57) [Claims] A first lead facing the first lead;
A second lead, and the first lead and the second lead
A third lead provided in parallel with the second lead;
A terminal for commonly connecting the first, second and third leads.
And a semiconductor connected to one end of the third lead
An element mounting portion, wherein the semiconductor mounting portion and the tie bar are provided.
The third lead connecting the first and second leads is a bent holding portion.
And the holding portion is adjacent to the first and second leads.
A lead frame having a width wider than a distance from the lead frame.