JPS5877250A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a plastic sealed high integrated MOSIC having no soft error by a method wherein an Si chip is adhered on a pellet using polyimide resin as an adhesive. CONSTITUTION:An Si chip 7 is adhered on an insulating film 3 for protection of element using polyimide resin 6. By this constitution, the connecting parts of a pellet 1 and fine metal wires 5 are not covered with resin 6, the Si chip 7 contains no element to generate alpha rays, and because the chip having thickness of 100mum or more can be obtained easily, it has the sufficiently screening effect to alpha rays of high energy, and a high reliable plastic sealed MOSIC can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plastic-encapsulated semiconductor integrated circuit device.

BACKGROUND ART The degree of integration in semiconductor integrated circuit devices, particularly field-effect semiconductor integrated circuit devices (hereinafter referred to as MOS IC), has been increasing rapidly, and the progress in fine patterning technology has also been remarkable. The high integration of MO8IC is
The functions of 8I01 are becoming more and more complex, and the fields of their application are becoming broader year by year. Such high integration and multifunctionality have not only led to an increase in manufacturing problems including element design technology, but also reliability problems such as soft errors caused by alpha rays. However, as micropatterning progresses, it is being looked at closely.

The problem of soft errors caused by α rays is particularly important for dynamic M
It is noticeable in O8 memory (hereinafter referred to as DRAM), and is found in 15Kbit DRAM.
With the commercialization of 64K DRAM, this has become a major problem that cannot be avoided. Soft errors caused by alpha rays in DRAM are explained as follows. In general, MOB DRAM uses polycrystalline silicon and a conductor in the substrate with a thin oxide film in between, and uses the capacitance between them to write and read data using the charge stored there as information. . So-called soft errors caused by alpha rays are caused by the generation of electron-hole pairs in the substrate semiconductor when alpha rays are incident on the part that forms the capacitance, which causes the particles to be stored. This is caused by reversing or erasing the information.

As a means to avoid soft errors caused by alpha rays.

There is a method to increase the capacity of each memory cell that makes up a DRAM, but since this increases the area of each memory cell and increases the element size of the DRAM, there is a limit to increasing the cell capacity. . Therefore, the current method is to prevent alpha rays from reaching the element surface by coating the element with a substance that does not contain elements that can generate alpha rays (usually less than Ippb), thereby reducing soft errors. This is a countermeasure. Is this a shielding material for alpha rays? , the method of coating on the element is extremely effective,
If the film thickness is several micrometers or more, it is possible to block almost all alpha rays existing in nature. Specifically, after mounting the MO8IC element in a case and connecting the case and the pellet with a thin metal wire, a polyimide or silicone resin is dropped from above to form an ia-protective film on the pellet against alpha rays. The most common method is to use pellets, and when mounting on a ceramic case, this method has excellent mass productivity and reliability. That is, polyimide or silicone resin is 1M0
Covers the connection between the external wiring extraction electrode of 8IC and the thin metal wire for case/pellet connection.

The polyimide or silicone resin and MO8I
(Due to the difference in thermal expansion coefficient with the plastic for sealing C pellet), the thin metal wire for connecting the case and pellet may be disconnected, or the thin metal wire for connection may be disconnected from the electrode at the electrode section for external wiring number of MO8IC. It has a failure mode of peeling off.

In order to avoid the above failure mode and realize a plastic-sealed highly integrated MO8IC without any problems with soft errors, after applying polyimide resin, we patterned the polyimide resin and used metal for connecting the case and pellet. Some methods are used in mass production to prevent polyimide resin from getting into the connection between the thin wire and the MO8IC external arrangement 11 throat J) exit electrode, but this method also increases the thickness of the resin film. Then, pattern Jung is difficult, and the pattern is several μm~
Since the limit is about 30 μm, there is no blocking ability against high-energy α rays, and it is not a complete countermeasure against soft errors.

The present invention uses 3i as a polyimide-based wWItl-adhesive.
By gluing the 'piece onto the pellet, a highly integrated M08IC sealed in plastic without soft errors is realized.

Hereinafter, with reference to FIG. 1, the currently adopted countermeasures against soft errors and the problems encountered during plastic sealing will be described, and then examples of the present invention will be explained using FIG. 2.

Currently, the α-ray countermeasures when mounting in a ceramic case are M
In contact with the element wire maintenance insulating film 3 on the O8IC pellet 1,
Mount pellet 1 in the case, connect the electrode of the case to the MO
After connecting the 8 IC external wiring extraction electrode 2 with a thin metal wire 5, polyimide resin 4 is dropped. However, the polyimide resin 4 completely covers the connecting part 8 between the thin metal wire 5 and the electrode 2 of the MO8IC, and when it is sealed with plastic, the metal is completely covered! Since the stress applied to the i-line 5 is different between the sealing plastic and the polyimide resin 4, the metal wire 5 may break or peel off at the connection part 8 with the pellet, which poses a problem in mass production. .

In the present invention, a polyimide resin 6 is used on an insulating film 3 for protecting an element.
Highly integrated plastic encapsulation MO8IC without soft error by installing Si piece 7 as t-glue
It is possible to produce According to the present invention, the poly-ind fruit tree 6 does not have a connecting portion 8t-a between the pellet and the thin metal wire, and the Si piece 7 does not contain any element that can become an α-ray source, and has a thickness of 100 μm or more. Since it is easy to obtain, it has a sufficient shielding effect even against high-energy alpha rays.
Extremely reliable plastic sealed MO8IC tonal. In addition, the circuit that generates a soft error due to alpha rays in the iMo8 IC is not on the entire surface of the MO8IC, but only in a part of it. For example, in the case of a MOS DRAM, it is only the memory cell part, so the size of the Si piece 7 is that α
It is sufficient to make it large enough to cover the part of the circuit that causes a soft error with respect to the line.

By implementing the present invention, an extremely reliable plastic-encapsulated highly integrated MO8 can be produced without changing the device design.
IC can be realized.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional semiconductor device in which a polyimide resin is dropped after the pellet is connected to a case electrode using a mount and thin metal wire, and Figure 2 is a Si piece placed on the pellet using polyimide resin as an adhesive. 1 is a sectional view of a semiconductor device according to an embodiment of the present invention. In addition, in the figure, 1...MO8IC pellet...MO8IC external wiring extraction electrode%3
...Insulation for MO8IC element protection, 4...
...Bori (de-based 11 resin, 5...Case and beret) r'm continuous thin metal wire, 6...Polyimide resin used as adhesive, 7... -Si piece, 8...This is the connection part between the thin metal wire 5 and the MO8IC electrode 2. Figure 1 δ Rod Figure 2

Claims (1)

[Claims] A semiconductor device characterized in that a silicon piece is provided on an insulating film for protecting an element surface with a polyimide resin interposed therebetween.