JPH11135665A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance moisture resistance of a semiconductor device. SOLUTION: This semiconductor device comprises a sealing body 2 of insulating resin, a plurality of leads 3 extending inward and outward of the encapsulating body 2, a chip support 7 located in the encapsulating body 2 continuously to a part of the leads 3, a semiconductor chip 13 bonded onto the chip support 7 in the encapsulating body 2, and a wire 14 for connecting the electrode of the semiconductor chip 13 electrically with the lead 3 in the encapsulating body 2 wherein the rear side of the chip support 7, i.e., the side opposite to the semiconductor chip bonding side, is exposed from one side of the encapsulating body 2. The surface of the chip support 7 to be bonded with the semiconductor chip is applied with an auxiliary body 12 (adhesive tape) composed of a frame-like insulator, stretching outward substantially over the entire circumference of the chip support 7 in the encapsulating body 2. The auxiliary body 12 also 10e extended on the lead 13. The surface of the chip support 7 to be bonded with the semiconductor chip is flush with the wire connecting face of the lead 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device,
Especially related to the technology for improving the moisture resistance of semiconductor devices, for example,
The present invention relates to a technology effective when applied to a semiconductor device having a structure in which one surface of a chip support for fixing a semiconductor chip is exposed from one surface of a sealing body.

[0002]

2. Description of the Related Art In a resin-sealed semiconductor device (semiconductor integrated circuit device), a semiconductor chip or the like is sealed with a sealing body (package) made of resin, and a plurality of leads (external parts) are formed from the peripheral surface of the package. Terminal).

[0003] The semiconductor chip is fixed on a chip support called a tab, a die pad or the like. However, when the heat generation of the semiconductor chip is large, the back surface of the semiconductor chip fixing surface of the chip support is sealed. It is designed to be exposed on one surface (bottom surface) of the stationary body.

For example, Japanese Unexamined Patent Publication No. 7-4953 (filed on Jan. 19, 1995) discloses a structure in which the back surface of a tab in which a semiconductor pellet is fixed to the bottom or top surface of a sealing body is exposed in order to enhance the heat radiation effect. Is disclosed.

On the other hand, "Hitachi Surface Mount Type Package Mounting Manual" issued by Hitachi, Ltd., Electronic Business Headquarters, Semiconductor Business Division, published in March 1987, has a cross-shaped A semiconductor device having a package structure in which leads are protruded from the semiconductor device is disclosed. This package structure is applied to a high-frequency transistor in a VHF to UHF band.

[0006]

In a resin-encapsulated semiconductor device having a conventional structure in which a chip support (heat spreader) is exposed at the bottom of a sealing body, a chip support exposed at the bottom of the sealing body and a sealing member are provided. Moisture easily penetrates from the interface with the resin forming the stopper. The moisture that has entered the sealing body reaches the semiconductor chip surface via the heat spreader surface, causing electrode corrosion and the like.

The inventor of the present invention has made the present invention in consideration of improving the moisture resistance of a semiconductor device by cutting off moisture and lengthening the passage of moisture (path).

An object of the present invention is to improve the moisture resistance of a semiconductor device.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0010]

The following is a brief description of an outline of typical inventions disclosed in the present application.

(1) A sealing body made of an insulating resin, a plurality of leads extending inside and outside the sealing body, and a chip support located in the sealing body and connected to the some of the leads. Body, a semiconductor chip located in the sealing body and fixed on the chip support, and connection means (eg, wire) for electrically connecting an electrode of the semiconductor chip and the lead located in the sealing body. ), Wherein a back surface opposite to the semiconductor chip fixing surface of the chip support is exposed from one surface of the sealing body, wherein the semiconductor chip fixing surface of the chip support has the sealing An auxiliary body made of a frame-shaped insulator that is located in the stationary body and extends outward over substantially the entire circumference of the chip support is fixed. The auxiliary body also extends on the lead. The semiconductor chip fixing surface of the chip support and the wire connection surface of the lead are the same surface. The chip support and the lead have the same thickness, and the back surface of the lead is also exposed from one surface of the sealing body. The leads extend straight along the chip fixing surface of the chip support. The auxiliary body is formed of an insulating adhesive tape, and an adhesive surface is bonded to the chip fixing surface and the lead.

(2) In the configuration of the means (1), a hole is provided in the auxiliary body portion corresponding to a connection area of a lead to which the connection means (for example, a wire) is connected.

(3) In the configuration of the means (1) and the means (2), the chip support is thicker than the thickness of the lead.

(4) The chip support is made of a support plate having the same thickness as the leads, and a material having good heat conductivity, which is fixed to the back surface of the support plate and whose back surface is exposed from one surface of the sealing body. And a radiator plate.

According to the above-mentioned means (1), (a) a frame-shaped auxiliary body extending outside the chip support is fixed to the semiconductor chip fixing surface of the chip support.
The infiltration path (passage path) from the interface between the chip support and the sealing body to the surface of the semiconductor chip for the moisture that enters the sealing body is lengthened, and the moisture resistance is improved.

(B) In the structure in which the auxiliary body also extends on the lead, the gap between the chip support and the lead is closed, so that moisture can be cut off and the semiconductor can be prevented. The infiltration path to the chip surface can be further lengthened, and the moisture resistance is improved.

(C) The semiconductor chip fixing surface of the chip support is the same as the wire connection surface of the lead, and the auxiliary member is connected to the semiconductor chip fixing surface side and the wire connection surface side. Thus, the semiconductor device can be made thinner than a structure in which an auxiliary body is interposed between the lead and the semiconductor chip.

(D) Since the chip support and the lead have the same thickness, and the back surface of the lead is also exposed from one surface of the encapsulant, the chip support and the bottom of the lead are The heat radiation effect can also be obtained.

(E) Since the leads have a structure extending straight along the chip fixing surface of the chip support, if the semiconductor device is mounted as it is on a mounting substrate, the chip support and the leads are also reduced. The structure comes into direct contact with the mounting substrate, and a high heat radiation effect can be obtained.

(F) Since the auxiliary body is formed of an insulating adhesive tape, it is easy to adhere to the chip fixing surface and the lead.

According to the means (2), in addition to the effect of the structure of the means (1), the auxiliary body portion corresponding to the connection area of the lead to which the connection means (for example, a wire) is connected is provided. Because of the structure in which the holes are provided, the auxiliary body can be stretched widely in the sealing body, and the penetration path from the interface between the chip support body and the sealing body to the semiconductor chip surface can be further increased. It can be made longer and the moisture resistance can be improved.

According to the means (3), in addition to the effects of the structure of the means (1) and the means (2), (a) the chip support is thicker than the lead and is sealed. Since it is exposed from the bottom of the body, a good heat radiation effect can be obtained.

(B) Since the lead surface (bottom surface) on the bottom surface side of the sealing body is covered with the sealing body, the strength of holding the lead by the sealing body is improved.

According to the means (4), (a) the chip support is a support plate having the same thickness as the lead, and is fixed to the back surface of the support plate, and the back surface is formed from one surface of the sealing body. A good heat dissipation effect can be obtained because the heat dissipation plate is made of a material having good thermal conductivity exposed.

(B) Since the lead surface (bottom surface) on the bottom surface side of the sealing body is covered with the sealing body, the strength of holding the lead by the sealing body is improved.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

(Embodiment 1) In Embodiment 1, an example will be described in which the present invention is applied to a surface mount type semiconductor device in which leads protrude in a cross shape from the peripheral surface of a sealing body. This semiconductor device is, for example, a GaAs-
This constitutes a MESFET.

FIG. 1 is a plan view of a semiconductor device according to a first embodiment of the present invention with a part thereof being cut away, and FIG. 2 is a sectional view thereof.

As shown in FIGS. 1 and 2, the semiconductor device 1 has an external appearance in which a lead 3 is projected from a substantially central portion of each side of a sealing body (package) 2 formed of a flat rectangular body. . Although the sealing body 2 is not particularly limited, for example, the height is 0.9 mm, the width is 3.7 mm, the length is 4.2 mm, and the thickness of the lead 3 is 0.4 mm, the width is 0.5 mm, and the protrusion length is 1.0 mm.

Each of the leads 3 is a source (S) lead 4 at the top and bottom in FIG. 1, a gate (G) lead 5 is on the left side, and a drain (D) lead 6 is on the right side.

A rectangular chip support 7 is located at the center of the package 2. The chip support 7 is made of the same plate material as the leads 3 and has a thickness of 0.4 mm. The source leads 4 are integrally connected to both ends of the chip support 7.

The upper surface of the lead 3 and the upper surface of the chip support 7 are located on the same plane. The back surfaces (lower surfaces) of the chip support 7 and the leads 3 are exposed from the package 2.

Therefore, in the first embodiment, the chip support 7 functions as a heat spreader for dissipating heat,
The lead 3 also functions as a heat spreader.

The tip portions of the gate lead 5 and the drain lead 6 located in the sealing body 2 are formed in wide portions 10 and 11 for connecting a plurality of wires in parallel.

The auxiliary body 1 made of a rectangular frame-shaped insulator
2 (dotted portions in FIG. 1) is the chip support 7
And over each lead 3. Auxiliary body 1
Numeral 2 is formed of an insulating adhesive tape, and the adhesive surface is attached to the upper surfaces of the chip support 7 and the leads 3.

The inner portion of the auxiliary body 12 is adhered to the edges of the four sides of the chip support 7 so as to overlap each other by a predetermined width, and the outer portion of the auxiliary body 12 overlaps the edges of the wide portions 10 and 11 by a predetermined width. It is stuck as follows. Therefore, the gap between the gate lead 5 and the drain lead 6 and the chip support 7 is closed by the auxiliary body 12. In addition to serving to block moisture entering from the interface between the chip support 7 exposed at the bottom of the package 2 and the resin forming the package 2, the length of the passage of moisture to the surface of the semiconductor chip, which will be described later, is large. Will be planned.

A semiconductor chip 13 is fixed on the chip support 7 inside the auxiliary body 12.

The electrodes (not shown) of the semiconductor chip 13 and the wide portions 1 of the gate lead 5 and the drain lead 6 are formed.
0 and 11 are electrically connected via a conductive wire 14 as a connection means. The wire 14 is the wide part 1
0, 11 are connected to the area not covered by the auxiliary body 12.

The semiconductor chip 13, auxiliary body 12, chip support 7, wire 14, gate lead 5 and drain lead 6 are sealed with a package 2 made of insulating resin. The back surface of the chip support 7 and the back surface of the lead 3 are exposed from the bottom
Is the same surface as the back surface of the chip support 7, so that it is a surface mount type.

Next, a method of manufacturing the semiconductor device 1 according to the first embodiment will be described.

In manufacturing the semiconductor device 1, a lead frame 20 as shown in FIG. 3 is prepared.

The lead frame 20 is formed by patterning a copper plate or copper alloy plate having a thickness of 0.4 mm by etching or precision press. The lead frame 20 used in the first embodiment is a strip having a plurality of unit lead patterns arranged in one row. FIG. 3 shows a unit lead frame portion.

The lead frame 20 has a pair of outer frames 21 extending in parallel, and an inner frame 22 connecting the outer frames 21, and has a frame structure.

The rectangular chip support 7 is located at the center of the frame. This chip support 7 is attached to the outer frame 2.
1 has a structure supported by leads 3 (source leads 4) projecting from the central portion. The width of the source lead 4 is 0.5 mm.

The leads 3 (gate lead 5 and drain lead 6) extend from the center of the inner frame 22 toward the chip support 7. The gate lead 5
In addition, the distal ends of the drain leads 6 are wide portions 10 and 11 which are wide so as to extend along the sides facing the chip support 7.

Although not shown, the outer frame 21 of the lead frame 20 is provided with guide holes and the like used for transferring and positioning the lead frame 20.

The lead frame 20 is plated at desired locations as required.

When manufacturing the semiconductor device 1 using such a lead frame 20, as shown in FIG. 4, first, the lead frame 20 is hung on the chip support 7 and the wide portions 10, 11 to form a frame. Auxiliary body 12 is attached.

Auxiliary body 12 (dotted portion in FIG. 4)
Is formed of an adhesive tape made of an epoxy resin tape or the like, and has a frame shape. Auxiliary body 1 made of adhesive tape
Reference numeral 2 denotes a thickness of about 0.25 mm, and the inner size of the rectangular frame is smaller than that of the chip support 7, and an inner portion of the rectangular frame is attached to the chip support 7 with a predetermined width.

The external size of the auxiliary body 12 is larger than that of the chip support 7 and is large enough to reach the gate lead 5, the drain lead 6 and the source lead 4. It is attached to the side with a predetermined width.

In the wide portions 10 and 11, the region where the wires are connected is not covered with the auxiliary body 12.

Next, the semiconductor chip 13 is fixed to a central area of the chip support 7 which is not covered by the auxiliary body 12.

Next, the electrodes (not shown) of the semiconductor chip 13 and the wide portions 1 of the gate leads 5 and the drain leads 6 are formed.
0 and 11 are electrically connected by a conductive wire 14.

The connection between the electrode of the semiconductor chip 13 and the lead 3 may be another connection means.

Next, as shown by a two-dot chain line in FIG. 4, the tip support 7, the semiconductor chip 13, the distal ends of the gate leads 5 and the drain leads 6, the wires 14, etc. To form a package 2.

Next, although not shown, the semiconductor device 1 as shown in FIGS. 1 and 2 is manufactured by cutting the leads 3 protruding from the package 2 at predetermined positions.

Such a semiconductor device 1 is mounted on a mounting board 30 by a surface mounting structure, as shown in FIG. 2, for example. That is, it is connected to the land 31 of the mounting board 30 via the conductive bonding material 32 such as solder.

In this example, the mounting substrate 30 is formed to be partially thick in order to radiate heat from the back surface of the chip support 7 and the back surface of the leads 3.

Since the semiconductor device 1 has a structure in which the chip support 7 and the leads 3 have the same surface (the surface for connecting a semiconductor chip and wires) on the same plane, the thickness of the semiconductor device can be further reduced. The mounting height can be reduced.

According to the semiconductor device 1 of the first embodiment, the following effects can be obtained.

(1) On the semiconductor chip fixing surface of the chip support 7, a frame-shaped auxiliary body 1 extending outside the chip support 7.
2 is fixed. Therefore, the penetration path (passing path) from the interface between the chip support 7 and the sealing body 2 to the surface of the semiconductor chip of the moisture penetrating into the sealing body 2 is lengthened, and the moisture resistance is improved.

(2) In the structure in which the auxiliary body 12 also extends on the lead 3, the gap between the chip support 7 and the lead 3 (gate lead 5, drain lead 6) is also closed. In other words, moisture can be blocked. Also,
Since the size of the auxiliary body 12 is large, the path of water penetration to the surface of the semiconductor chip is further increased, and the moisture resistance is further improved.

(3) The semiconductor chip fixing surface of the chip support 7 and the wire connection surface of the lead 3 are the same, and the auxiliary body 12 made of the adhesive tape is provided on the semiconductor chip fixing surface side and the wire connection surface side. Since the structure is connected, the semiconductor device 1 can be made thinner as compared with a structure in which the auxiliary body 12 is interposed between the lead 3 and the semiconductor chip 13.

(4) Since the chip support 7 and the leads 3 have the same thickness and the back surface of the leads 3 is also exposed from one surface of the sealing body 2, the chip supports 7 and Since a heat radiation effect from the bottom surface of the lead 3 is also obtained, the semiconductor device 1 having good heat dissipation properties is obtained.

(5) Since the leads 3 have a structure extending straight along the chip fixing surface of the chip support 7, if the semiconductor device 1 is directly surface-mounted on the mounting substrate 30, the chip support The body 7 and the lead 3 also have a structure in which the body 7 and the lead 3 are in direct contact with the mounting board 30, and a high heat radiation effect is obtained.

(6) Since the auxiliary body 12 is formed of an adhesive tape, the auxiliary body 12 is easily adhered to the chip fixing surface of the chip support 7 and the leads 3, and the semiconductor device 1
The production cost can be reduced in the production of.

(Embodiment 2) FIG. 5 shows Embodiment 2 of the present invention.
6 is a plan view of the semiconductor device in a partially cut-out state, and FIG. 6 is a cross-sectional view.

In the second embodiment, the auxiliary body 12 is
The configuration is as large as possible within. For this reason, holes 35 are provided corresponding to the auxiliary members 12 on the wide portions 10 and 11 so that the wires 14 can be connected to the wide portions 10 and 11 of the gate lead 5 and the drain lead 6. The structure of other components in the second embodiment is the same as that of the first embodiment.

According to the second embodiment, in addition to the effects of the first embodiment, since the auxiliary body 12 is larger, the effect of blocking moisture is enhanced, and the length of the water infiltration path to the surface of the semiconductor chip is increased. And the moisture resistance is further improved.

In the second embodiment, the holes 35 are provided corresponding to the respective wire bonding positions. However, since the wire connecting portions of the gate lead 5 and the drain lead 6 are wide portions 10 and 11, Alternatively, a hole including a plurality of wire bonding positions or a slot including all the wire bonding positions may be used.

(Embodiment 3) FIG. 7 shows Embodiment 3 of the present invention.
FIG. 3 is a cross-sectional view of a semiconductor device which is

The seventh embodiment has a structure in which the thickness of the chip support 7 is formed larger than the thickness of the leads 3.

Therefore, the chip support 7 can be used as a heat spreader, and
Since the lead surface (bottom surface) on the bottom surface side is covered with the sealing body 2, an effect of improving the holding strength of the lead 3 by the sealing body 2 is obtained.

The structure of each of the other components in the third embodiment is the same as that in the first embodiment.

(Embodiment 4) FIG. 8 shows Embodiment 4 of the present invention.
FIG. 9 is a plan view of the semiconductor device with a part cut away.

In the fourth embodiment, the chip support 7 is composed of a support plate 7a having the same thickness as the leads 3 and a heat source fixed to the back surface of the support plate 7a and having a back surface exposed from one surface of the sealing body 2. And a radiator plate 7b made of a material having good conductivity. The lead 3 and the support plate 7a have the same thickness, and the front and back surfaces are located on the same plane.

The fourth embodiment is an example in which the present invention is applied to an IC (integrated circuit device) having a plurality of leads 3 extending in four directions.

In the fourth embodiment, the heat radiation plate 7b can be used as a heat spreader, and the lead surface (bottom surface) on the bottom surface side of the sealing body 2 is covered with the sealing body 2. The effect of improving the holding strength of the lead 3 by the body 2 is obtained.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say. For example, in each of the above embodiments, the lead is formed in a straight shape. However, the same effect as in the above embodiment can be obtained with other lead structures such as gull wing type.

[0080]

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

(1) Since the insulating auxiliary member is provided from the periphery of the semiconductor chip fixing surface of the chip support for fixing the semiconductor chip to the wire connection surface at the tip of the lead, the chip support and the chip support are sealed. Moisture resistance can be improved because it is possible to block the intrusion of moisture that intrudes into the sealing body from the interface with the stationary body, and it is possible to lengthen the infiltration path (passing path) to the semiconductor chip surface.

(2) The semiconductor chip fixing surface of the chip support and the wire connection surface of the lead are the same, and the auxiliary body is connected to the semiconductor chip fixing surface side and the wire connection surface side. The thickness of the semiconductor device can be reduced as compared with a structure in which an auxiliary body is interposed between the lead and the semiconductor chip.

(3) Since the chip support and the lead have the same thickness, and the back surface of the lead is also exposed from one surface of the sealing body, heat is radiated from the chip support and the bottom surface of the lead. The effect is also obtained, and the semiconductor device has a high heat radiation effect.

(4) Since the leads extend straight along the chip fixing surface of the chip support, if the semiconductor device is directly mounted on the mounting substrate, the chip support and the leads are also directly mounted. The structure comes into contact with the substrate, and a high heat radiation effect can be obtained.

(5) Since the auxiliary body is formed of an insulating adhesive tape, the auxiliary body can be easily bonded to the chip fixing surface and the lead, and the manufacturing cost of the semiconductor device can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a semiconductor device according to a first embodiment of the present invention with a part thereof being cut away;

FIG. 2 is a cross-sectional view of the semiconductor device according to the first embodiment.

FIG. 3 is a plan view of a lead frame used for manufacturing the semiconductor device of the first embodiment.

FIG. 4 is a plan view showing a lead frame on which chip bonding and wire bonding have been completed in the manufacture of the semiconductor integrated circuit device according to the first embodiment;

FIG. 5 is a plan view of a semiconductor device according to a second embodiment of the present invention with a part thereof being cut away;

FIG. 6 is a cross-sectional view of the semiconductor device according to the second embodiment.

FIG. 7 is a sectional view of a semiconductor device according to a third embodiment of the present invention;

FIG. 8 is a sectional view of a semiconductor device according to a fourth embodiment of the present invention;

FIG. 9 is a plan view of a semiconductor device according to a fourth embodiment with a part thereof being cut away;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor device, 2 ... Sealing body (package), 3 ... Lead, 4 ... Source lead, 5 ... Gate lead, 6 ... Drain lead, 7 ... Chip support, 7a ... Support plate, 7b ... Heat sink, 10 , 11 wide part, 12 auxiliary body, 13 semiconductor chip, 14 wire, 20 lead frame, 21
... outer frame, 22 ... inner frame, 30 ... mounting board, 31 ... land,
32: conductive bonding material, 35: hole.

Claims (9)

[Claims] 1. A sealing body made of an insulating resin, a plurality of leads extending inside and outside the sealing body, and a chip support located in the sealing body and connected to the part of the leads. And a semiconductor chip located in the sealing body and fixed on the chip support, and connecting means for electrically connecting the electrode and the lead of the semiconductor chip located in the sealing body, A semiconductor device in which a back surface opposite to the semiconductor chip fixing surface of the chip support is exposed from one surface of the sealing body, and the semiconductor chip fixing surface of the chip support is located in the sealing body and A semiconductor device, wherein an auxiliary body made of a frame-shaped insulator extending outward over substantially the entire circumference of the chip support is fixed. 2. The semiconductor device according to claim 1, wherein said auxiliary body also extends on said lead. 3. The semiconductor device according to claim 2, wherein a hole is provided in said auxiliary body portion corresponding to a connection area of a lead to which said connection means is connected. 4. The semiconductor device according to claim 1, wherein the semiconductor chip fixing surface of the chip support and the connecting means connecting surface of the lead are the same surface. . 5. The chip support according to claim 1, wherein the chip support and the lead have the same thickness, and the back surface of the lead is also exposed from one surface of the sealing body. 2. The semiconductor device according to claim 1. 6. The semiconductor device according to claim 1, wherein said chip support is thicker than said leads. 7. The chip support is composed of a support plate having the same thickness as the leads, and a material having good thermal conductivity fixed to the back surface of the support plate and having a back surface exposed from one surface of the sealing body. The semiconductor device according to any one of claims 1 to 4, wherein the semiconductor device comprises a heat sink. 8. The semiconductor device according to claim 1, wherein said leads extend straight along a chip fixing surface of said chip support. 9. The semiconductor device according to claim 1, wherein the auxiliary body is formed of an insulating adhesive tape, and an adhesive surface is bonded to the chip fixing surface and the lead. 3. The semiconductor device according to claim 1.