JPH04354342A - Semiconductor device - Google Patents

Abstract

PURPOSE:To stably obtain excellent characteristics of a semiconductor chip by arranging a heat sink on a front and/or rear surface of the chip. CONSTITUTION:A semiconductor device in which a semiconductor chip 2 formed with many contact pads and a wiring sheet in which leads 4 are previously formed on a front surface of an insulation film 3, are so laminated that the leads 4 are superposed on the contact pads of the chip 2 through a bump 5, thermally connected, and sealed with plastic 6, is provided.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention provides a method for connecting a semiconductor chip on which a large number of contact pads are formed and a wiring sheet on which leads are previously formed on the surface of an insulating film so that the leads overlap the contact pads of the semiconductor chip via bumps. The so-called TAB (Tape Automated
TCP (Tap
e Carrier Package).

0002

[Prior Art] TAB is a tape (TAB) in which a Cu foil is applied to an organic insulating film (for example, made of polyimide) and a wiring pattern (lead) is formed by etching the Cu foil.
This is a technique in which a semiconductor chip is mounted by preparing a TAB tape (TAB tape), overlapping the leads of this TAB tape with the contact pads of a semiconductor chip via bumps, and bonding them by heating. This TA
Compared with the conventionally used wire bonding method, (1) the contact pads formed on the semiconductor chip and the pitch thereof can be narrowed, so a large number of contact pads can be provided. ■Since there is no need to route wires, the space required for mounting can be reduced. ■There are no restrictions on the shape of the lead pattern, so it can be changed freely. ■Can be bent. - Since multiple contact pads and leads can be bonded at the same time, bonding time can be shortened. Because it has the following characteristics, it can be said to be a promising technology that advantageously meets the recent demands for higher density, higher pin count, and lower thickness.

[0003] TCP is obtained by electrically connecting a semiconductor chip and leads using the TAB technique, and then sealing the semiconductor chip with plastic.

However, in such TCPs, the amount of heat generated from the semiconductor chip tends to increase as the number of pins increases, that is, the degree of integration of the semiconductor chip increases.
Since the thermal conductivity of TAB tape and molding resin is not good, there are problems with the heat dissipation of semiconductor chips.
This has been a problem for semiconductor chips to stably obtain good characteristics. This problem has been a problem since the lack of a die pad results in poor heat dissipation compared to a semiconductor device manufactured using a commonly used so-called lead frame and wire bonding method.

[0005] In order to solve the above-mentioned TCP heat dissipation problem, it has been considered to provide heat dissipation fins protruding from the package, but providing such protruding heat dissipation fins loses the advantage of thinning, which is a characteristic of TCP. There is also the problem of increasing the cost.

In addition, in semiconductor devices in which a semiconductor chip is die-bonded to a die pad of a lead frame, heat dissipation fins are used to prevent propagation of cracks in the encapsulant and devices that are arranged along the lead frame. There are devices in which the encapsulant on the back side of the die pad is released in advance, but since all of these semiconductor devices use wire bonding, it is not only difficult to make them thinner due to restrictions on wire routing. In the latter case, the number of outer leads decreases by the amount occupied by the radiation fins, making it unsuitable for increasing the number of pins.
This cannot be applied to CP because it does not have a die pad.

[0007]

[Problems to be Solved by the Invention] It is an object of the present invention to propose a semiconductor device that advantageously solves the above-mentioned TCP heat dissipation problem and allows a TCP semiconductor chip to stably obtain good characteristics. .

[0008]

[Means for Solving the Problems] The present invention connects a semiconductor chip on which a large number of contact pads are formed and a wiring sheet on which leads are formed in advance on the surface of an insulating film, and the leads are connected to the contact pads of the semiconductor chip via bumps. The present invention is a semiconductor device formed by stacking the semiconductor chip overlappingly, thermally bonding it, and sealing it with plastic, characterized in that a heat sink is disposed on at least one side of the semiconductor chip.

[0009]

[Function] The semiconductor device of the present invention has a heat dissipation plate on the front and/or back side of the semiconductor chip, which reduces the heat capacity of the semiconductor device packaged with plastic.
Since the heat dissipation efficiency is improved, it becomes possible to stably obtain good characteristics of the TCP semiconductor chip at low cost.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS The semiconductor device of the present invention will be specifically explained below with reference to the drawings. FIG. 1 is a sectional view showing an example of a semiconductor device of the present invention. This semiconductor device 1 is configured such that a semiconductor chip 2 and a Cu lead 4 formed on a TAB tape 3 are thermally bonded via bumps 5 to electrically bond them, and these are bonded together in a plastic package 6.
It is sealed by.

The present invention is characterized in that a heat sink 7 is disposed on the semiconductor chip 2 inside the semiconductor device 1. In this way, in the semiconductor chip 2 inside the semiconductor device 1,
By providing the heat sink 7, the heat capacity of the package can be sufficiently lowered without losing the TCP advantage of making the package thinner and at a relatively low cost. Even in the example of FIG. 1 in which the semiconductor chip 2 is embedded in the semiconductor chip 2, the heat dissipation of the semiconductor chip 2 is sufficiently satisfactory. On the other hand, as shown in FIG. 2, in the conventional semiconductor device in which the heat dissipation fins 8 are provided protruding from the package 6, there is a problem that the advantage of thinning, which is a characteristic of TCP, is lost, and the cost also increases. As mentioned above, it is put away.

FIG. 3 shows another embodiment of the invention in cross section. The figure shows an example in which the thickness of the heat sink 7 is selected so that it is flush with the surface of the plastic package. In this example, since the heat dissipation plate 7 is exposed flush with the surface of the plastic package, the heat dissipation efficiency is further improved while maintaining the thinness of the TCP.

As shown in FIGS. 1 and 3, the heat sink 7 is
It should not protrude from the plastic package 6 so as not to impair the thinness that is an advantage of TCP. Therefore, the thickness of the heat sink 7 is preferably about 0.1 to 0.5 mm, although it depends on the thickness of the plastic package 6.

FIG. 4 shows a cross-sectional view of another embodiment of the present invention. The figure shows an example in which heat sinks 7 and 9 are provided on the front surface of the semiconductor chip (heat sink 7) and also on the back surface (heat sink 9). By disposing the heat sink on both the front and back surfaces of the semiconductor chip in this manner, the heat radiation efficiency of the semiconductor chip is further improved.

[0015] The heat sink is disposed during the semiconductor chip assembly process, especially before and after inner lead bonding.
A heat sink, such as a metal plate such as a copper plate or an aluminum plate, may be attached to the front and/or back surface of the semiconductor chip using a thermally conductive adhesive or the like. As shown in FIGS. 1 and 3, when attaching a heat sink to the surface of a semiconductor chip, it is preferable to use an electrically insulating adhesive from the viewpoint of reliability of the chip. Such adhesives include silicone resins and the like.

It goes without saying that the present invention is not limited to the embodiments described above, and that the heat sink may be provided only on the back surface of the semiconductor chip, for example.

[0017]

Effects of the Invention The semiconductor device of the present invention has a heat dissipation plate on the front surface and/or back surface of the semiconductor chip, so that T
Good characteristics of a CP semiconductor chip can be obtained stably and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a semiconductor device of the present invention.

FIG. 2 is a cross-sectional view showing a conventional semiconductor device.

FIG. 3 is a cross-sectional view showing another example of the semiconductor device of the present invention.

FIG. 4 is a cross-sectional view showing another example of the semiconductor device of the invention.

[Explanation of symbols]

1 Semiconductor device 2 Semiconductor chip 3 TAB tape 4 Cu lead 5 Bump 6 Plastic package 7 Heat sink

Claims (1)

[Claims] 1. A semiconductor chip on which a large number of contact pads are formed and a wiring sheet on which leads are previously formed on the surface of an insulating film are placed one on top of the other and heated so that the leads overlap the contact pads of the semiconductor chip via bumps. 1. A semiconductor device formed by bonding and sealing with plastic, characterized in that a heat sink is disposed on the front surface and/or back surface of the semiconductor chip.