JPH04253363A - Lead frame and semiconductor device using the same - Google Patents

Abstract

PURPOSE:To prevent contact between a thin metal wire and a die pad and that between inner leads by covering from a location near a mount surface of a semiconductor element to be loaded to a tip of the inner lead and then providing an insulation layer which is fixed to the die pad and the inner lead. CONSTITUTION:An insulation layer 7 covers from a location near a mount surface of a semiconductor element 1 to a tip of an inner lead 4 on a surface for loading the semiconductor element 1 on a die pad 2 and at the same time is fixed to the die pad 2 and the inner lead 4. Therefore, even if a thin metal wire 5 is deformed downward, the thin metal wire 5 does not directly contact a location near an end face of the die pad 2 by the insulation layer 7. Also, when a similar stress is applied to the inner lead 4, the inner lead 4 cannot be deformed since a tip portion of the inner lead 4 is fixed by the insulation layer 7 and adjacent inner leads 4 do not contact each other.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a lead frame for a semiconductor device sealed with resin, and a semiconductor device using the lead frame.

0002

2. Description of the Related Art In recent years, resin-sealed semiconductor devices have become mainstream in order to enable mass production at low cost.

A conventional resin-sealed semiconductor device will be described below with reference to FIG. In FIG. 3, semiconductor element 1
is bonded to the upper surface of the die pad 2 with, for example, a conductive resin, and the electrode of the semiconductor element 1 and the inner lead 4 connected to the outer lead 3 are connected by a thin metal wire 5.
The periphery thereof is sealed and molded with a sealing resin 6. When a semiconductor device is operated, the semiconductor element 1 generally generates heat. The generated heat is transferred upwardly to the semiconductor element 1 via the sealing resin 6, downwardly from the die pad 2 via the sealing resin 6, and laterally from the thin metal wire 5 to the inner lead 4. It is dissipated into the air through the sealing resin 6 or only through the sealing resin 6, or is partially dissipated into the board mounted via the outer lead 3.

Generally, the die pad 2, inner leads 4, and outer leads 3 are made of, for example, Fe--Ni alloy or Cu.
Since a metal material such as an alloy is used and has higher thermal conductivity than the sealing resin 6, increasing the proportion of metal parts such as the die pad 2 in the entire semiconductor device is effective in improving heat dissipation. It's advantageous.

[0005]

[Problems to be Solved by the Invention] However, in the above-mentioned conventional structure, especially when the die pad 2 is enlarged, pressure of the injected resin during the resin sealing process and external stress during transportation before the resin sealing process are affected. As a result, the thin metal wire 5 is deformed and comes into contact with the vicinity of the end surface of the die pad 2, which increases the possibility of causing electrical failure.

[0006] Furthermore, the longer the inner lead 4 becomes, the more unstable the tip end of the inner lead 4 becomes with respect to external stress, leading to poor connection in the wire bonding process (connection process using the thin metal wire 5) and resin sealing. It also has drawbacks such as an increased risk of electrical failure due to deformation of the inner leads 4 caused by the resin injection pressure in the stopping process and contact between the inner leads 4.

The present invention solves the above-mentioned conventional problems, and has high heat dissipation properties and a thin metal wire 5 during the manufacturing process.
The purpose of the present invention is to provide a lead frame having a structure that does not cause poor contact between the metal wire 5 and the die pad 2, poor connection between the thin metal wire 5 and the inner leads 4, and poor contact between the inner leads 4, and a semiconductor device using the lead frame. It is something to do.

[0008]

[Means for Solving the Problems] In order to solve the above problems, the lead frame of the present invention and a semiconductor device using the same are provided such that the lead frame of the present invention and the semiconductor device using the same are provided from a position near the side surface of the semiconductor element loaded on the semiconductor element loading surface on the die pad. It is configured as a lead frame that covers up to the tips of the inner leads 4 and has an insulating layer fixed to the die pad and the inner leads, and further uses this lead frame to connect the semiconductor element and the inner leads. The semiconductor device is constructed by using thin metal wires and then encapsulating the entire structure with resin.

[0009]

[Operation] With this structure, the die pad and the thin metal wire are completely insulated by the insulating layer, and the tips of the inner leads are fixed by the insulating layer, so that they are not affected by external forces.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a semiconductor device showing an embodiment of the present invention, and FIG. 2 is a top view showing a lead frame of the same semiconductor device after wire bonding.

In FIGS. 1 and 2, 1 is a semiconductor element, 2 is a die pad, 3 is an outer lead, 4 is an inner lead, 5 is a thin metal wire, and 6 is a sealing resin, which has the same structure as the conventional one. has. Reference numeral 7 denotes an insulating layer, which covers the semiconductor element 1 loading surface on the die pad 2 from a position near the side surface of the loaded semiconductor element 1 to the tip of the inner lead 4, and is fixed to the die pad 2 and the inner lead 4. There is.

The operation of the lead frame constructed in this manner and a semiconductor device using the lead frame will be described below. Even if the thin metal wire 5 is deformed downward due to the pressure of the injected resin during the resin sealing process or external stress before the resin sealing process, such as during transportation, the insulating layer 7 prevents the thin metal wire 5 and the die pad 2 from bonding. There is no direct contact with the vicinity of the end face. Further, even if a similar stress is applied to the inner leads 4, since the tips of the inner leads 4 are fixed by the insulating layer 7, the inner leads 4 will not be deformed, and adjacent inner leads 4 will come into contact with each other. Such a situation will not occur.

[0013]

As described above, according to the present invention, the semiconductor element mounting surface on the die pad is covered from the position near the side surface of the semiconductor element to be loaded to the tip of the inner lead, and is fixed to the die pad and the inner lead. By providing an insulating layer that prevents contact between the thin metal wire and the die pad or contact between the inner leads 4 due to the pressure of the injected resin during the resin encapsulation process or external stress during transportation before the resin encapsulation process, It is possible to prevent such defects, and to realize an excellent lead frame and a semiconductor device using the lead frame.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a semiconductor device in one embodiment of the present invention.

FIG. 2 is a top view showing the state of the lead frame of the semiconductor device after wire bonding.

FIG. 3 is a cross-sectional view of a conventional semiconductor device.

[Explanation of symbols]

1 Semiconductor device 2 Die pad 3 Outer lead 4 Inner lead 5 Thin metal wire 6 Sealing resin 7 Insulating layer

Claims (2)

[Claims] 1. A lead frame used in a resin-sealed semiconductor device, which covers the semiconductor element mounting surface on a die pad from a position near the side of the loaded semiconductor element to the tip of an inner lead, and and a lead frame with an insulating layer fixed to the inner leads. 2. The semiconductor element mounting surface on the die pad of the lead frame is covered with an insulating layer from a position near the side surface of the loaded semiconductor element to the tip of the inner lead, and this insulating layer is fixed to the die pad and the inner lead. A semiconductor device characterized in that a lead frame is used, a semiconductor element and an inner lead are connected by thin metal wires, and the whole is sealed with resin.