JPH08181168A - Semiconductor device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the flatness and alignment of leads from being adversely affected during mounting, and to effectively dissipate heat from a semiconductor chip by means of a heat sink. An inner lead portion 3a of a lead 3 formed on a film substrate 2 is bonded to an electrode on a circuit surface 1a of a semiconductor chip 1, and a non-circuit surface 1b of the chip 1 is attached to an upper surface 6 of a heat dissipation plate 6.
Stick to a. The lead connecting portion 7 is provided on the upper surface 6 a of the heat sink 6.
Is provided, and a terminal portion 8 that is electrically connected to the lead connection portion 7 is provided at the outer end of the heat dissipation plate 6. Circuit surface 1a of chip 1
The outer lead portion 3b of the lead 3 extended from the above is joined to the lead connecting portion 7 of the heat dissipation plate 6. The upper surface 6a of the heat sink 6
Then, the whole is sealed with resin 10. At the time of mounting, the lower surface 6b of the heat sink 6 is brought into close contact with the surface of the mounting board 20, and the terminal portion 8 of the heat sink 6 is connected to the wiring pattern 21 of the mounting board 20 by solder 22 or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device in which leads are connected to a semiconductor chip by, for example, a TAB method and a heat sink is fixed to the semiconductor chip and resin-sealed.

[0002]

2. Description of the Related Art Conventionally, this type of semiconductor device is constructed as shown in FIG. 7, for example. That is, the semiconductor chip 1
The inner lead portion 103 a of the lead 103 formed on the film base material 102 is bonded to the electrode on the surface of 01 through the bump 104. A heat dissipation plate 106 is fixed to the back surface of the semiconductor chip 101 with an adhesive 105, and the whole is sealed with a resin 110 so that the outer lead portion 103b and the bottom surface of the heat dissipation plate 106 are exposed.

In such a semiconductor device, after the plurality of outer lead portions 103b are formed into a predetermined shape suitable for the mounting state, the lower surface of the heat radiating plate 106 is brought into close contact with the surface of the mounting substrate 120, and each outer lead portion is formed. The 103b is mounted on the mounting board 120 by being joined to the plurality of wiring patterns 121 on the mounting board 120, respectively.

[0004]

However, in the conventional semiconductor device as described above, the plurality of outer lead portions 103b protruding from the resin 110 are molded. However, internal stress after molding and vibration during handling are generated. As a result, the flatness, alignment, etc. of each of the outer lead portions 103b are likely to deteriorate. Therefore, when the semiconductor device is mounted on the mounting substrate 120, each outer lead portion 103
There is a problem that a defective connection between the wiring pattern b and each wiring pattern 121 of the mounting substrate 120 is likely to occur.

Further, in the conventional semiconductor device as described above, the heat generated from the semiconductor chip 101 during operation is diffused to the mounting substrate 120 via the heat dissipation plate 106,
The mounting substrate 12 is partially mounted via the outer lead portion 103b.
However, there is a problem that its heat radiation effect is not always sufficient.

Therefore, an object of the present invention is to provide a semiconductor device which is not adversely affected by flatness and alignment of leads during mounting and which can effectively radiate heat of a semiconductor chip by a heat radiating plate. To do.

[0007]

In order to achieve the above-mentioned object, the present invention provides a semiconductor device in which leads are connected to a semiconductor chip and a heat sink is fixed to the semiconductor chip and resin-sealed. A lead connection portion corresponding to the lead connected to the semiconductor chip is provided outside the area where the semiconductor chip is mounted on the upper surface of the heat sink, and the non-circuit surface of the semiconductor chip is fixed to the upper surface of the heat sink. In addition, the tip of the lead extending from the circuit surface of the semiconductor chip is joined to the lead connection portion of the heat sink, and a resin portion for sealing is formed on the upper surface of the heat sink. To do.

Further, according to the present invention, in a semiconductor device in which leads are connected to a semiconductor chip and a heat sink is fixed to the semiconductor chip and resin-sealed, the semiconductor chip is mounted on the upper surface of the heat sink. A lead connecting portion corresponding to the lead connected to the semiconductor chip is provided outside the region, and at least the circuit surface of the semiconductor chip is fixed to the upper surface of the heat sink through an insulating material, and The tip of the lead extending from the circuit surface is joined to the lead connection portion of the heat dissipation plate, and the heat dissipation fin is fixed to the non-circuit surface of the semiconductor chip, so that the heat dissipation fin is exposed. A resin portion for sealing is formed on the upper surface of the.

In each of the semiconductor devices, a terminal portion is provided on the outer end of the heat dissipation plate so as to be electrically connected to the lead connection portion, and the terminal portion is abutted when the lower surface of the heat dissipation plate is brought into close contact with a mounting board. It is characterized in that it is connected to the wiring portion of the mounting substrate. In this case, a recess may be provided near the outer end of the lower surface of the heat dissipation plate, and the terminal portion may be exposed in the recess.

Further, in each of the semiconductor devices, the tip of the lead joined to the lead connecting portion is projected from the outer end of the heat dissipation plate, and the lower surface of the heat dissipation plate is brought into close contact with the mounting board, and the semiconductor device is mounted at the time of mounting. The projecting portion of the lead is connected to the wiring portion of the mounting board.

Further, in each of the semiconductor devices, the leads are formed on a film base material, inner lead portions projecting inward from the film base material are connected to the semiconductor chip, and the leads are projected outward from the film base material. The outer lead portion is joined to the lead connecting portion of the heat dissipation plate.

[0012]

In the semiconductor device of the present invention configured as described above, the tips of the leads extending from the semiconductor chip are joined to the lead connecting portions provided on the heat sink, and the outer end of the heat sink is formed. The projecting portion of the lead projecting from the terminal portion or the outer end of the heat dissipation plate which is electrically connected to the lead connecting portion serves as the connecting portion to the wiring portion of the mounting board. by this,
When mounting, it is not necessary to mold the leads protruding from the resin and bond them to the wiring part of the mounting board as in the past, so it is not affected by the flatness or alignment of the leads, The protruding portion of the lead can ensure the connection to the wiring portion of the mounting substrate.

Further, since the semiconductor chip is fixed to the heat sink and the leads of the semiconductor chip are joined to the lead connecting portions of the heat sink, the heat is conducted from the semiconductor chip to the heat sink and the leads are also connected to the heat sink. Since the heat conduction to the is also effectively performed, the heat dissipation effect can be enhanced. Moreover, since the entire lower side of the semiconductor device serves as a heat dissipation plate, and the area occupied by the heat dissipation plate is expanded as compared with the conventional case, the heat conduction efficiency to the mounting substrate can be improved.

[0014]

Embodiments of the semiconductor device according to the present invention will be described below with reference to FIGS. First, FIGS. 1 to 3
1 shows a first embodiment, FIG. 1 is a cross-sectional view of a semiconductor device mounted on a substrate, FIG. 2 is an exploded perspective view of essential parts of a semiconductor chip to which leads are connected and a heat radiating plate provided with lead connecting portions,
FIG. 3 is a perspective view of a main part of the semiconductor device mounted on a substrate.

As shown in FIG. 1, the inner lead portion 3a of the lead 3 made of Cu or the like formed on the film base material 2 made of polyimide or the like is formed on the electrode of the circuit surface 1a which is the surface of the semiconductor chip 1 by Au or the like. The bumps 4 are joined together.
The non-circuit surface 1b, which is the back surface of the semiconductor chip 1, is
Using adhesive 5 such as Ag paste, the upper surface 6a of the heat dissipation plate 6
It is stuck to.

The heat radiating plate 6 is made of a material having good heat conductivity and is formed to have a size substantially corresponding to the tip of the outer lead portion 3b. The central portion of the heat sink 6 is the semiconductor chip 1
The lead connection portion 7 is formed by patterning on the outer side thereof with a conductive material such as Cu so as to correspond to the outer lead portion 3b. Then, the terminal portion 8 is formed on the outer end of the heat dissipation plate 6 with a Pb-Sn alloy or the like,
The tip of the lead connecting portion 7 is connected to the terminal portion 8. The lead connecting portion 7 and the terminal portion 8 may be integrally formed. When the heat sink 6 has conductivity,
The portions forming the lead connection portion 7 and the terminal portion 8 are previously insulated.

As shown in FIGS. 1 and 2, when manufacturing a semiconductor device, first, the semiconductor chip 1 and the inner lead portion 3a are bonded to each other, and the outer lead portion 3b is formed into a predetermined shape. Then, the non-circuit surface 1b of the semiconductor chip 1 is fixed to the upper surface 6a of the heat dissipation plate 6, and the outer lead portion 3b is joined to the lead connection portion 7 of the heat dissipation plate 6 by thermocompression bonding or solder melting. Further, the entire upper surface 6a of the heat dissipation plate 6 is sealed with the resin 10 by using the transfer molding method or the potting method. The resin 10 is an organic type, Si
A system resin may be used.

The semiconductor device completed as described above is
As shown in FIGS. 1 and 3, the lower surface 6 b of the heat sink 6 is brought into close contact with the surface of the mounting board 20, and the terminal portion 8 of the heat sink 6 is connected to the wiring pattern 21 on the mounting board 20. For this connection, for example, ball-shaped solder bumps are arranged on the wiring pattern 21 or cream solder is applied, and the molten solder 22
Can be done by

According to the semiconductor device constructed and mounted as described above, the tips of the outer lead portions 3b are joined to the lead connecting portions 7 of the heat sink 6, and the terminal portions 8 of the heat sink 6 are mounted on the mounting substrate. Since it becomes a connecting portion of the wiring pattern 21 to the wiring pattern 21, the heat radiating plate 6 is not affected by the flatness and the alignment of the outer lead portion 3b at the time of mounting.
The terminal portion 8 of can be connected to the wiring pattern 21 of the mounting substrate 20 extremely reliably. Although the outer lead portion 3b is also molded in this embodiment, this molding is for eliminating the step between the circuit surface 1a of the semiconductor chip 1 and the lead connecting portion 7 of the heat dissipation plate 6, so that it is necessary. Just go.

By the way, conventionally, due to a problem such as the flatness of the outer lead portion, it was necessary to press and join the outer lead portion to the wiring portion of the mounting substrate with a bonding tool at the time of mounting. According to
The terminal portion 8 of the heat sink 6 is connected to the wiring pattern 21 of the mounting board 20.
By using the structure for connecting to, it is possible to perform collective connection by solder reflow, and it is possible to greatly improve productivity.

Further, since the semiconductor chip 1 is fixed to the heat sink 6 and the outer lead portion 3b is joined to the lead connecting portion 7 of the heat sink 6, the semiconductor chip 1 is connected to the heat sink 6 during operation. In addition to heat conduction, heat conduction from the outer lead portion 3b to the heat dissipation plate 6 is also effectively performed, and the heat dissipation effect can be enhanced. Moreover, since the entire lower side of the semiconductor device is the heat dissipation plate 6, and the area occupied by the heat dissipation plate 6 is expanded as compared with the conventional case, the heat conduction efficiency to the mounting substrate 20 can be improved.

Further, the resin 10 is molded on the upper surface 6a of the heat sink 6 to which the semiconductor chip 1 is fixed, and the outer lead portion 3b is already joined to the lead connecting portion 7 of the heat sink 6. Therefore, the vertical movement of the semiconductor chip 1 and the deformation of the leads 3 in the resin 10 are prevented, and the resin molding state can be improved.

By the way, when checking the operation of a semiconductor chip in this type of semiconductor device, conventionally, the outer lead portion protruding from the resin is easily deformed, so that the semiconductor device is housed in a so-called TAB carrier. However, according to the semiconductor device of the present embodiment, the outer lead portion 3b is joined to the lead connecting portion 7 of the rigid heat dissipation plate 6, so that the heat dissipation plate 6 on the heat dissipation plate 6 is not particularly required. Through the outer lead portion 3b, the operation check of the semiconductor chip 1 and the like can be performed extremely easily.

Next, FIG. 4 shows a second embodiment and is a sectional view of a semiconductor device mounted on a substrate. Similar to the first embodiment, after the semiconductor chip 1 and the inner lead portion 3a are joined together, in this example, the semiconductor chip 1 is fixed face down to the heat sink 6.

The circuit surface 1a of the semiconductor chip 1 and the leads 3
Is directed downward, the insulating material 11 is interposed between the heat dissipation plate 6 and the upper surface 6a. An insulating protective sheet such as a polyimide film can be used as the insulating material 11. When the film base material 2 is located below the leads 3, the insulating material 11 may be interposed so as to correspond to the circuit surface 1a of the semiconductor chip 1 and the inner lead portions 3a.

Then, similarly to the first embodiment, the outer lead portion 3b is joined to the lead connecting portion 7 of the heat dissipation plate 6. Further, Ag is not formed on the non-circuit surface 1b of the semiconductor chip 1.
The radiation fins 13 are fixed by using an adhesive 12 such as paste. The entire upper surface 6a of the heat dissipation plate 6 is sealed with the resin 10 so that the heat dissipation fins 13 are exposed.

This semiconductor device is mounted on the mounting substrate 20 as in the first embodiment, but according to the second embodiment,
Since the heat is dissipated not only from the heat dissipation plate 6 but also from the heat dissipation fin 13, the heat dissipation effect can be further improved.

Next, FIG. 5 shows a modification of each of the above-described embodiments, and is an enlarged cross-sectional view of a main portion of a semiconductor device mounted on a substrate. A recess 9 is formed near the outer end of the lower surface 6b of the heat sink 6, and the lower end of the terminal portion 8 is exposed in the recess 9. According to this example, even when the lower end of the terminal portion 8 is located on the wiring pattern 21 of the mounting board 20, the lower surface 6b of the heat dissipation plate 6 can be completely adhered to the surface of the mounting board 20.

Next, FIG. 6 shows another modified example, and is an enlarged cross-sectional view of a main portion of a semiconductor device mounted on a substrate. The tip of the outer lead portion 3b joined to the lead connecting portion 7 of the heat radiating plate 6 is projected further outward than the outer end of the heat radiating plate 6 to form a protruding portion 3b '. Then, at the time of mounting, the protruding portion 3 b ′ has the wiring pattern 21 of the mounting substrate 20.
Are connected to each other by solder 22. According to this example, since it is not necessary to provide the terminal portion 8 at the outer end of the heat dissipation plate 6 as in the first embodiment, it is particularly effective when the heat dissipation plate 6 is formed thin.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various effective modifications and applications can be made based on the technical idea of the present invention. For example, in the present embodiment, the heat dissipation plate has a size substantially corresponding to the tip of the outer lead portion, but the heat dissipation plate may be further enlarged to extend the lead connecting portion outward. Further, in the present embodiment, the TAB method in which the leads on the film base material have the inner lead portion and the outer lead portion has been described, but one end is connected to the semiconductor chip and the other end is joined to the lead connecting portion of the heat sink. Lead having various structures can be used.

[0031]

As described above, according to the present invention,
By providing a lead connection part on the heat dissipation plate to which the semiconductor chip is fixed and joining the tip of the lead connected to the semiconductor chip to the lead connection part of the heat dissipation plate, it may be affected by the flatness or alignment of the leads. Therefore, the mounting on the mounting board can be performed very reliably. In addition, heat conduction from the leads to the heat sink and the occupied area of the heat sink are increased, so that the heat dissipation effect of the semiconductor chip by the heat sink can be significantly improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a semiconductor device according to a first embodiment of the present invention mounted on a substrate.

FIG. 2 is an exploded perspective view of essential parts of a semiconductor chip to which leads are connected and a heat radiating plate provided with lead connecting portions in the semiconductor device of the first embodiment.

FIG. 3 is a perspective view of a main portion of the semiconductor device of the first embodiment mounted on a substrate.

FIG. 4 is a cross-sectional view of a semiconductor device according to a second embodiment of the present invention mounted on a substrate.

FIG. 5 is an enlarged cross-sectional view of a main part of a semiconductor device according to a modification of each of the above-described embodiments mounted on a substrate.

FIG. 6 is an enlarged cross-sectional view of a main part of a semiconductor device according to another modification of each of the above-described embodiments mounted on a substrate.

FIG. 7 is a cross-sectional view of a conventional semiconductor device mounted on a substrate.

[Explanation of symbols]

 1 semiconductor chip 1a circuit surface 1b non-circuit surface 2 film base material 3 lead 3a inner lead portion 3b outer lead portion 3b 'protruding portion 4 bumps 5 and 12 adhesive 6 heat sink 6a upper surface 6b lower surface 7 lead connection portion 8 terminal portion 9 Recess 10 Sealing resin 11 Insulating material 13 Radiating fin 20 Mounting board 21 Wiring pattern 22 Solder

Claims (6)

[Claims] 1. A semiconductor device in which a lead is connected to a semiconductor chip, and a heat sink is fixed to the semiconductor chip and resin-sealed, wherein the upper surface of the heat sink is outside an area where the semiconductor chip is mounted. A lead connecting portion corresponding to the lead connected to the semiconductor chip is provided, the non-circuit surface of the semiconductor chip is fixed to an upper surface of the heat dissipation plate, and the lead extended from the circuit surface of the semiconductor chip. The semiconductor device is characterized in that the tip of the heat radiation plate is joined to the lead connection part of the heat radiation plate, and a resin portion for sealing is formed on the upper surface of the heat radiation plate. 2. A semiconductor device in which a lead is connected to a semiconductor chip and a heat sink is fixed to the semiconductor chip and resin-sealed, wherein the upper surface of the heat sink is outside the region where the semiconductor chip is mounted. A lead connection portion corresponding to the lead connected to the semiconductor chip is provided, and at least the circuit surface of the semiconductor chip is fixed to the upper surface of the heat sink through an insulating material and extends from the circuit surface of the semiconductor chip. The tip of the provided lead is joined to the lead connection portion of the heat dissipation plate, and a heat dissipation fin is fixed to the non-circuit surface of the semiconductor chip, and the heat dissipation fin is sealed on the upper surface of the heat dissipation plate so as to be exposed. A semiconductor device having a resin portion for stopping formed. 3. A terminal portion, which is electrically connected to the lead connecting portion, is provided at an outer end of the heat dissipation plate, and the terminal portion serves as a wiring portion of the mounting board when the lower surface of the heat dissipation plate is closely attached to the mounting board. The semiconductor device according to claim 1, wherein the semiconductor device is connected. 4. The semiconductor device according to claim 3, wherein a recess is provided near the outer end of the lower surface of the heat dissipation plate, and the terminal portion is exposed in the recess. 5. The projecting portion of the lead is mounted at the time of mounting when the tip of the lead joined to the lead connecting portion is projected from the outer end of the heat dissipation plate and the lower surface of the heat dissipation plate is brought into close contact with a mounting board. The semiconductor device according to claim 1, wherein the semiconductor device is connected to a wiring portion of a mounting substrate. 6. The lead is formed on a film substrate,
An inner lead portion projecting inward from the film base material is connected to the semiconductor chip, and an outer lead portion projecting outward from the film base material is joined to the lead connecting portion of the heat dissipation plate. Item 1 or 2
13. The semiconductor device according to claim 1.