JPH04364762A - Semiconductor device - Google Patents

Abstract

PURPOSE:To reduce a stress exerted on a semiconductor element and to improve the thermal diffusion of the title device by a method wherein an insulator plate whose thermal conductivity is high is brought into contact with and arranged on the connection part of the semiconductor element with a metal foil and this assembly is sealed with a sealing resin. CONSTITUTION:After an inner bonding operation and an outer bonding operation which electrically connect a semiconductor element 1 to a lead frame 6 have been finished, a ceramic sheet 9 composed of Al2O3, AlN, SiC or the like as an insulator whose thermal conductivity is good is mounted on a part surrounded by a film carrier tape 4. After that, the semiconductor element 1, leads 3, the film carrier tape 4, the lead frame 6 and the ceramic plate 9 are molded of a sealing resin for protective use. Thereby, a crack which is caused when the sealing resin is expanded and contracted is reduced, a heat- dissipating operation is improved and the reliability of a semiconductor device can be increased.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to semiconductor devices, and particularly to TAB (Tape Automated Bondin).
g) relates to semiconductor devices assembled using technology;

0002

[Background Art] In the packaging process of semiconductor devices, a wire bonding technique is used in which a chip is mounted on a package and the electrodes of the chip and the external terminals of the package are connected using metal wires, or the electrodes of the chip and the external terminals of the package are connected using metal wires. TAB technology is used to connect the film carrier tape through leads formed on the film carrier tape.

FIG. 3 shows an example of a semiconductor device assembled using TAB technology, in which bumps 2 for electrical connection are formed on a semiconductor element 1, and bumps 2 are formed on the inner side of leads 3 made of copper foil, for example. Bonded. The leads 3 are formed by etching a copper foil bonded to the film carrier tape 4, and are plated to ensure good electrical connection. When the bonding of the inner leads is completed, the outer leads are cut, and the outer leads of the leads 3 are bonded to the connection surface of the lead frame 6, which will become the external terminals of the package. When the inner and outer bonding for electrically connecting the semiconductor element 1 and the lead frame 6 is completed, the semiconductor element 1, the leads 3,
The film carrier tape 4 and lead frame 6 are molded with a sealing resin 5 for protection, and the assembly is completed.

FIG. 4 shows an example of a semiconductor device assembled by wire bonding, and parts corresponding to those shown in FIG. 3 are given the same reference numerals. First, the semiconductor element 1 is bonded to the bed 8 of the lead frame. The electrodes of the semiconductor element 1 and the connection surfaces of the lead frame 6, which serve as external terminals of the package, are bonded by metal wires. The semiconductor element 1, wire 7, and lead frame 6 are molded with a sealing resin 5 for protection, and the assembly is completed.

[0005]

[Problems to be Solved by the Invention] When the semiconductor element 1 is assembled by wire bonding as shown in FIG. 4, the upper surface of the semiconductor element 1 is The thickness B of the sealing resin 5 is relatively thin, and the heat generated in the semiconductor element 1 is transferred to the sealing resin 5.
The heat is radiated through the lead frame 8. On the other hand, when the semiconductor element 1 is packaged using TAB as shown in FIG. Dissipation is relatively bad.

[0006] For this reason, the patterned surface of a semiconductor element packaged using the TAB technique is subjected to more stress due to expansion or expansion/contraction of the sealing resin due to heat. In particular, shear stress is applied near the bumps that protrude from the pattern surface, inducing cracks that extend from the surface protective film around the bumps to the underlying semiconductor substrate. Furthermore, the reliability of the semiconductor device is reduced due to the heat generated by the semiconductor element itself.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a semiconductor device in which stress applied to a semiconductor element is reduced and heat dissipation is improved.

[0008]

[Means for Solving the Problems] In order to achieve the above object, a semiconductor device of the present invention includes a metal foil patterned on a film carrier tape, a semiconductor element connected to one end of the metal foil, and a semiconductor device connected to one end of the metal foil. a lead frame with one end connected to the other end of the foil; an insulator plate with high thermal conductivity disposed in contact with the connection portion between the semiconductor element and the metal foil; and a portion other than the other end of the lead frame. It is characterized by comprising a sealed sealing resin.

[0009]

[Function] The insulator plate placed in contact with the connection part between the semiconductor element and the metal foil reduces the thickness of the sealing resin, reduces stress caused by expansion and contraction of the resin, and also reduces the heat generated by the semiconductor element. Dissipates to the outside. Further, generation of shearing force at the connection portion between the semiconductor element and the metal foil is prevented.

As a result, the problem of cracks occurring in the semiconductor element is eliminated, and heat dissipation from the semiconductor element is improved.

[0011]

[Embodiment] An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, parts corresponding to those in FIG. 3 are designated by the same reference numerals. Bumps 2 for electrical connection are formed on the semiconductor element 1, and are bonded to inner leads 3 made of copper foil, for example. The leads 3 are formed by etching a copper foil bonded to the film carrier tape 4, and are plated to ensure good electrical connection. When the bonding of the inner leads is completed, the outer leads are cut, and the outer leads of the leads 3 are bonded to the connection surface of the lead frame 6, which will become the external terminals of the package.

When the inner and outer bonding for electrically connecting the semiconductor element 1 and the lead frame 6 is completed, Al2O3 and A, which are insulators with good thermal conductivity, are bonded.
A so-called ceramic plate 9 made of IN, SiC, etc. is placed in the area surrounded by the film carrier tape 4. Thereafter, the semiconductor element 1, leads 3, film carrier tape 4, lead frame 6, and ceramic plate 9 are molded with a sealing resin 5 for protection, and the assembly is completed.

In this way, the resin thickness A on the semiconductor element 1 is 1.7 to 1.8 mm in the configuration shown in FIG. 3, and 1.3 mm in the configuration shown in FIG. 4, taking a QFP type package as an example. On the other hand, in the configuration of the present invention shown in FIG. 1, the thickness is 0.5 mm or less, which is a significant reduction.

FIG. 2 shows the results of investigating the relationship between the resin thickness A on a semiconductor element and the crack occurrence rate.
When it becomes 0.5 mm or less, the stress caused by the sealing resin suddenly decreases, and no cracks occur around the bump. Therefore,
By using the configuration of the embodiment in which the resin thickness A can be set to 0.5 mm or less, the problem of crack generation is eliminated.

[0015] Furthermore, the thermal conductivity of the sealing resin is 6 to 15×1
0-3 W/cm. K, whereas, for example, the thermal conductivity of an alumina ceramic plate is 2 to 10 x 10-1 W/
cm. K also improves heat dissipation.

[0016]

As explained above, in the semiconductor device of the present invention, an insulator plate with good thermal conductivity is placed on the lead of a film carrier tape that connects the semiconductor element and the lead frame, and the lead frame is sealed with resin. Since the thickness of the sealing resin is reduced, it is possible to reduce the occurrence of cracks due to expansion and contraction of the sealing resin, improve heat dissipation, and increase the reliability of the semiconductor device.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the thickness of the sealing resin and the crack occurrence rate.

FIG. 3 is an explanatory diagram showing a semiconductor device using conventional TAB technology.

FIG. 4 is an explanatory diagram showing a semiconductor device using conventional wire bonding technology.

[Explanation of symbols]

1 Semiconductor element 2 Bump 3 Copper foil lead 4 Film carrier tape 5 Sealing resin 6 Lead frame 7 Bonding wire 8 Lead frame bed 9 Ceramic plate

Claims (1)

[Claims] 1. A metal foil patterned on a film carrier tape, a semiconductor element connected to one end of the metal foil, a lead frame having one end connected to the other end of the metal foil, and the semiconductor element. A semiconductor device comprising: an insulator plate with high thermal conductivity disposed in contact with a connection portion between the lead frame and the metal foil; and a sealing resin that seals an area other than the other end of the lead frame. .