JPH11220075A - Resin encapsulated type semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable reduction of effects due to protrusion or resin material at packaging, and miniaturization. SOLUTION: A trench 21 is arranged on the outer peripheral part of the back of an exposed die pad (13). Resin material 16 section which permeates out to the back side of the die pad (13) at the time of packaging is received with the trench 21, so that the permeation of the resin material 16 out to the central part of the back of the die pad is prevented. An overhang part is formed of a part 14a of the outermost lead 14. By preventing the generation of cracks on the overhang due to the impact at cutting and working a semiconductor device into a final shape, the length of the overhang is reduced, and the semiconductor device is miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a structure of a resin-sealed semiconductor device.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show an example of a conventional resin-encapsulated semiconductor device. FIG. 5 is an external perspective view of the device as viewed from the front side, and FIG. FIG. 7 is a schematic sectional view taken along line BB of FIG.

[0005] In FIGS. 5 to 7, a resin-sealed semiconductor device 51 (hereinafter simply referred to as “semiconductor device 51”)
Indicates that the semiconductor chip 52 is bonded and fixed on the die pad 53 via a silver paste,
2 electrode part (not shown) and lead (inner lead) 54
Are connected by a gold wire 55. Further, a part of the lead 54 and the back surface of the die pad 53 are exposed, and the periphery thereof is sealed with a resin material 56, thereby forming a packaged structure.

The semiconductor device 51 is mounted by bringing the exposed back surface of the die pad 53 into contact with the mounting substrate 61 and soldering the leads 54 to the mounting substrate 61. Semiconductor device 5 mounted in this manner
In 1, since the die pad 53 is in contact with the mounting substrate 61, heat can be radiated through the die pad 53 and the mounting substrate 61.

The method of manufacturing the semiconductor device 51 will be briefly described.
The order is made. First, a lead frame (not shown) having a die pad 53 and leads 54 arranged around the die pad 53 is set in a manufacturing apparatus. The semiconductor chip 52 is bonded and fixed to the die pad 53 of the lead frame via a silver paste. Next, the electrode portion of the semiconductor chip 52 and the lead 54 are connected by the gold wire 55. Subsequently, a part of the leads 54 (external leads) and the back surface of the die pad 53 are exposed, and the periphery thereof is sealed with a resin material 56 to form a package. In the following description,
The part packaged with the resin material 56 is referred to as “package 56”. Next, when the lead 54 is separated from the lead frame by press cutting using a dedicated lead molding die, the semiconductor device 51 shown in FIGS. 5 to 7 is completed.

Generally, as shown in FIGS. 5 and 6, the package 56 of the semiconductor device 51 manufactured in this manner is formed in a quadrangular shape having right-angled portions at four corners. In the case of the structure of the semiconductor device 51,
The distance between the outermost lead 54a (see FIG. 5) and the end 57 of the package 56 is called overhang S. The overhang S is designed to have a safe value such that the package 56 is not damaged by an impact when the lead 54 is cut from the lead frame in order to make the semiconductor device 51 the final shape. Usually, this overhang dimension is secured at about 0.3 mm. That is, about 0.6 mm is secured at both ends.

[0007]

When the semiconductor device 51 having the conventional structure described above is packaged by resin sealing, the back surface of the die pad 53 and the back surface of the package 56 are on the same surface. The pressure may cause the resin material to seep out to the back surface of the die pad 53. Reference numeral 58 in FIG. 6 indicates a state in which the resin material has oozed out to the back surface of the die pad 53. Thus, die pad 5
When the semiconductor device 51 is mounted on the mounting substrate 61, the back surface of the die pad 53 rises from the surface of the mounting substrate 61 when the semiconductor device 51 is mounted on the mounting substrate 61, and the soldering property is reduced and the heat radiation is reduced. There has been a problem that inconveniences such as a decrease in performance may occur.

In addition, the semiconductor device 51 having the conventional structure described above
Is designed so that the overhang dimension at both ends of the package is designed to be a safe value so that the package 56 is not damaged by an impact when the lead 54 is cut from the lead frame into a final shape. (See FIG. 6) becomes unnecessarily large, which hinders miniaturization of the semiconductor device 51.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to reduce the influence of the protrusion of a resin material during packaging and reduce the size of the resin-sealed mold. It is to provide a semiconductor device.

[0010]

In order to achieve the above object, according to the present invention, there is provided a resin-sealed mold in which a back surface of a die pad or a heat sink on which a semiconductor element is mounted is exposed and the periphery is sealed with a resin material. The semiconductor device has a structure in which a groove is provided on the back surface of the die pad or the heat sink along the outer peripheral portion of the die pad or the heat sink. With this structure, when the resin material oozes out on the rear surface side of the die pad or the heat sink when being packaged, this extruded portion is received by the groove provided on the outer peripheral portion of the rear surface of the die pad or the heat sink. In addition, it is possible to prevent the die pad or the heat sink from seeping out to the center of the back surface.

In order to achieve the above object, according to the present invention, a back surface of a die pad or a heat sink on which a semiconductor element is mounted is exposed, and the periphery is sealed with a resin material. The resin-encapsulated semiconductor device in which a plurality of leads are led out has a structure in which an overhang portion is formed by a part of an outermost lead among the plurality of leads. In this structure, the lead is made of metal and the sealing resin is made of plastic, and the lead has higher mechanical strength. Accordingly, since the overhang portion is reinforced by a part of the lead, the overhang can be prevented from being chipped by an impact when the semiconductor device is cut into the final outer shape. This makes it possible to reduce the length of the overhang.

[0012]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Although the embodiments described below are preferred specific examples of the present invention, various technically preferable limitations are given thereto. However, the scope of the present invention is particularly limited in the following description. Is not limited to these embodiments unless otherwise described.

FIGS. 1 to 3 show a first embodiment of a resin-encapsulated semiconductor device according to the present invention. FIG. 1 is an external perspective view of the device as viewed from the back side, and FIG. FIG. 3 is an enlarged cross-sectional view taken along the line AA of FIG.

1 to 3, this resin-sealed semiconductor device 11 (hereinafter simply referred to as "semiconductor device 11")
Indicates that the semiconductor chip 12 is bonded and fixed on the die pad 13 via a silver paste,
2 electrode part (not shown) and lead (inner lead) 14
Are connected by a gold wire 15. Further, a part of the lead 14 and the back surface of the die pad 13 are exposed, and the periphery thereof is sealed with a resin material 16 to form a packaged structure. That is, this basic structure is the same as that of the conventional resin-sealed semiconductor device 51 shown in FIGS.

In this semiconductor device 11, similarly to the conventional semiconductor device 51 shown in FIGS. 5 to 7, the exposed back surface of the die pad 13 is brought into contact with a mounting substrate (not shown), 14 is mounted on a mounting board by soldering. In the semiconductor device 11 mounted in this manner, heat is radiated through the die pad 13 and the mounting substrate by the contact of the die pad 13 with the mounting substrate, similarly to the semiconductor device 51 shown in FIGS. Can be.

Next, the semiconductor device 11 according to the embodiment of the present invention will be described.
In this structure, points different from the structure of the conventional semiconductor device 51 shown in FIGS. 5 to 7 will be described. First, in the semiconductor device 11 according to the first embodiment of the present invention, the die pad 1
3 at a position shifted about 0.5 mm inward from the outer peripheral end of the die pad 13 and about 0.1 mm
A groove 21 continuous around the outer periphery of the die pad 13 is formed at a moderate depth. In the groove 21, in the resin sealing step, the resin material 16 that has exuded on the back surface of the die pad 13 due to the sealing pressure is received and accumulated, whereby the resin material 16 exudes to the center of the back surface of the die pad 13. Can be prevented.

Further, in the semiconductor device 11 of the first embodiment of the present invention, the conventional semiconductor device 5 shown in FIGS.
The overhang S formed of the resin material 56 in the structure of FIG. 1 is replaced with a part 14a of the four outermost leads 14 indicated by the symbol E in FIG. As shown in the drawing, each of the portions 14a protrudes to a portion that becomes an overhang, and the portion 14a forms an overhang portion. In this case, the lead 14 is made of metal or resin material 16.
Is made of plastic and has mechanical strength of lead 14
Is stronger, so that the portion 14a of the lead 14 reinforces the overhang. Thereby, it is possible to prevent the overhang from being chipped due to the impact when the semiconductor device 11 is cut into the final outer shape. As a result, the length of the overhang can be reduced, and the size of the semiconductor device 11 can be reduced.

Next, the effects found from the above embodiment will be described below. Since the continuous groove 21 is provided around the exposed back surface of the die pad 13, the resin material 16 that has leaked to the back surface of the die pad 13 by the sealing pressure is received in the groove 21 in the resin sealing step. Can be stored.
As a result, the resin material 16 is moved to the center of the back surface of the die pad 13.
It can prevent oozing. As a result, the die pad 13
While ensuring a certain amount of exposed area on the back of
Since the die pad 13 can be mounted in close contact with the mounting substrate, it is possible to prevent a decrease in heat radiation and a decrease in solderability. Since the overhang portion is formed by the portion 14a of the lead 14 made of metal, the length of the overhang can be reduced, and the semiconductor device 11 can be reduced in size. Note that the overhang dimension is about 0.3 mm in the past, but in the case of the structure of the present invention, it can be reduced to about 0.115 mm, and the width W of the package 16 is smaller than that of the conventional structure. It could be reduced by about 0.37 mm.

FIG. 4 is a schematic vertical sectional side view showing a second embodiment of the resin-sealed semiconductor device according to the present invention. In FIG. 4, components denoted by the same reference numerals as those in FIGS. 1 to 3 indicate the same components as those in FIGS. In the semiconductor device 11 shown in FIG. 4, a semiconductor chip 12 is bonded and fixed on a die pad 13 via a silver paste, and an electrode portion (not shown) of the semiconductor chip 12 and a lead (inner lead) 14 are made of a gold wire. 15 are connected. Further, a metal heat radiating plate 23 having a larger area than the die pad 13 is bonded to the back surface of the die pad 13 via an insulating adhesive. Further, a part of the lead 14 and the back surface of the heat radiating plate 23 are exposed, and the periphery thereof is sealed with a resin material 16 to form a packaged structure.

Further, in the structure of the second embodiment, similar to the structure of the first embodiment, about 0.2 mm is provided on the exposed back surface of the radiator plate 23 from the outer peripheral end of the radiator plate 23 to the inner side.
Groove 21 which is moved 5 mm and is continuous at a depth of about 0.1 mm
Are formed along the outer circumference of the heat sink 23.
That is, similarly to the structure of the first embodiment, in the resin sealing step, the resin material 16 oozing out on the back surface of the heat radiating plate 23 is received and accumulated in the groove 21 in the resin sealing step. Resin material 1 on the center of back surface of heat sink 23
6 has a structure capable of preventing seepage.

In addition, in the second embodiment, although not shown, similar to the structure of the first embodiment, a part of the outermost lead 14 is protruded to a portion where an overhang is formed. Part 1 has a structure in which an overhang portion is formed. Therefore, even in the case of the structure of this embodiment, since the overhang portion is reinforced by a part of the lead 14, the overhang is caused by the impact when the semiconductor device 11 is cut into the final outer shape. Chipping can be prevented from occurring. Thus, the length of the overhang can be reduced, and the size of the semiconductor device 11 can be reduced.

In the structure of each of the above-described embodiments, the case where the groove 21 provided on the back surface of the die pad 13 or the heat radiating plate 23 is formed as a continuous and one round groove is exemplified. Also, the grooves need not be continuous.

[0023]

Since the present invention is configured as described above, it has the following effects. By providing grooves on the back surface of the die pad or heat sink, a certain amount of exposed area on the back surface of the die pad or heat sink can be secured, and the die pad or heat sink can be mounted in close contact with the mounting board. It is possible to prevent a decrease in heat dissipation and solderability. Since the overhang portion is formed by a part of the outermost lead of the lead, the length of the overhang can be reduced, so that the semiconductor device can be downsized.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a device according to a first embodiment of the present invention as viewed from the back side.

FIG. 2 is an enlarged sectional view taken along line AA of FIG.

FIG. 3 is an enlarged view of a main part of the device shown in FIGS. 1 and 2;

FIG. 4 is a schematic longitudinal sectional side view of an apparatus according to a second embodiment of the present invention.

FIG. 5 is an external perspective view of a conventional device as viewed from above.

FIG. 6 is an external perspective view of a conventional device as viewed from the back side.

FIG. 7 is an enlarged sectional view taken along line BB of FIG. 6;

[Explanation of symbols]

11 semiconductor device, 12 semiconductor chip, 13 die pad, 14 lead, 16 resin material, 21 groove, 23
Heat sink

Claims (4)

[Claims] 1. A resin-encapsulated semiconductor device in which a back surface of a die pad on which a semiconductor element is mounted is exposed and a periphery thereof is sealed with a resin material, wherein the back surface of the die pad is formed along the outer peripheral portion of the die pad. A resin-encapsulated semiconductor device comprising a groove. 2. A resin-encapsulated semiconductor device in which a back surface of a radiator plate on which a semiconductor element is mounted is exposed and the periphery is sealed with a resin material. A resin-encapsulated semiconductor device, wherein a groove is provided along the groove. 3. A back surface of a die pad on which a semiconductor element is mounted is exposed, and its periphery is sealed with a resin material.
A resin-encapsulated semiconductor device in which a plurality of leads are led out from a side surface of the package, wherein a resin is formed by forming an overhang portion with a part of an outermost lead among the plurality of leads. Sealed semiconductor device. 4. A resin-sealed semiconductor device having a back surface of a heat sink on which a semiconductor element is mounted, and a periphery thereof sealed with a resin material, and a plurality of leads led out from side surfaces of the package. 2. The resin-sealed semiconductor device according to claim 1, wherein an overhang portion is formed by a part of an outermost lead among the plurality of leads.