JPS5814610Y2 - semiconductor equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a semiconductor device, and in particular, a sealed container in which a semiconductor element is enclosed is constituted by a substrate and a cover, and once the substrate and the cover are brought into close contact with each other, the sealed container is constructed. The present invention relates to a device configured such that the cover and the board can be removed even after completion.

Conventionally, integrated circuit devices have been encapsulated in sealed containers to protect them from external atmospheres containing moisture and contaminants by the following means.

That is, after the integrated circuit element is fixed on an insulating substrate such as alumina or synthetic resin, a conductive pattern previously formed on the substrate or a conductive pin provided on the substrate is connected between the integrated circuit element and the integrated circuit element, for example, by wire bonding. Connect electrically.

Then, (1) glue a cover made of the same insulating material or metal cover as the board to the board, or (2) if the board is made of synthetic resin, use a synthetic resin of the same material. The integrated circuit element has been hermetically sealed by means such as molding.

However, not only in case (2) above, but also in case (1) above, it is extremely difficult to separate the substrate and cover once they have been bonded together.

That is, in the case of (1) above, whether the cover is made of an insulating material or a metal, the cover is usually bonded to the substrate with an epoxy resin adhesive.

Since the epoxy resin adhesive is a thermosetting resin, once it has been thermally cured during adhesion, it has been impossible to easily dissolve or soften it and separate the cover from the substrate.

However, recently, semiconductor devices in which a plurality of integrated circuit elements are sealed in a number of sealed containers have been used.

In such multi-chip type semiconductor devices, if one of the integrated circuit elements fails during use, only the failed element can be replaced if the cover and board can be easily separated. Although it was more economical, the entire semiconductor device had to be replaced.

In addition, after using a semiconductor device sealed in a sealed container under certain conditions, it is desired to easily separate the cover and the substrate in order to study the condition of the semiconductor device. There is.

As a means for easily separating the cover and the board, a method has been proposed in which, as shown in Figure 1, when bonding the cover and the board, a method is proposed in which solder is interposed between the epoxy resin layers. has been done.

In the figure, 1 is a substrate, 2 is an integrated circuit element, 3 is an insulating cover, 4.4' is an epoxy resin adhesive, 5 is solder,
6 is a gold wire.

That is, after an integrated circuit element 2 is fixed to an insulating substrate 1 by appropriate means, the integrated circuit element 2 is electrically connected to a conductive pattern (not shown) formed on the substrate 1 and gold wires 6, 6. Connect to.

Then, an insulating cover 3 is fixed to the substrate 1, and the integrated circuit element 2 is enclosed in a sealed container constituted by the substrate 1 and the insulating cover 3.

Of course, a conductive pin (not shown) provided to protrude outside is connected to the conductive pattern.

When bonding the insulating cover 3 and the substrate 1, solder 5 is bonded to the insulating cover 3 in advance using an epoxy resin adhesive 4.

Then, the solder 5 and the substrate 1 are fixed with an epoxy resin adhesive 4' to complete the sealed container.

Thereafter, by heating the solder 5 from the outside by a suitable means, the solder melts and the substrate 1 and the insulating cover 3 can be easily separated.

However, such a sealing means as shown in FIG. 1 must be constructed so that the epoxy resin adhesives 4, 4' are directly bonded to the solder 5.

However, the epoxy resin adhesive and solder are not compatible with each other, and it is difficult to maintain good airtightness, so the sealing means having the above structure has not been practical.

Therefore, an object of the present invention is to provide a semiconductor device equipped with a sealed container that improves such drawbacks, and for this purpose, an insulating substrate, a semiconductor element fixed on the insulating substrate, and the insulating substrate and a cover that is fixed to constitute a container for sealing the semiconductor element, wherein a metal layer is provided on the insulating substrate via a thermosetting resin adhesive layer, and a meltable substance layer is provided on the metal layer. By providing the insulating substrate and the cover, the insulating substrate and the cover can be removed by melting the meltable substance layer by an appropriate means after the insulating substrate and the cover are hermetically fixed. shall be.

An embodiment of the present invention will be described with reference to FIG.

In the figure, the same reference numerals as in FIG. 1 indicate the same parts.

7, 7' are epoxy resin adhesive, 8, 8' are metal plates,
9 is solder.

The metal plates 8 and 8' are selected from metal plates that have good adhesion to both epoxy resin adhesive and solder, such as copper plates.

In the present invention, first, after welding metal plates 8 and 8' with a shape that matches the fixing surface of the cover 3 with solder 9,
These metal plates 8, 8' are bonded with epoxy resin adhesive 7.
A laminate consisting of the above is fixed to the cover.

On the other hand, an integrated circuit element 2 is fixed to the substrate 1, and wiring is provided between the integrated circuit element and the conductive pattern formed on the substrate using gold wires 6, 6.

Then, the cover 3, to which the metal plates 8, 8' have already been fixed as described above, and the substrate 1 are fixed using an epoxy resin adhesive 7'.

In this way, it becomes possible to encapsulate the integrated circuit element 2 in the sealed container constituted by the substrate 1 and the cover 3.

After that, by heating the solder 9 from the outside and melting it, the metal plates 8 and 8' can be separated, so the cover 3 can be removed from the board 1, and for example, the integrated circuit sealed inside can be removed. It becomes possible to inspect or replace the element 2.

If the metal plates 8 and 8' are fixed again with solder 9, the sealed container can be formed again by the substrate 1 and the cover 3.

In the above description, the metal plate 8 fixed by solder 9,
8' was previously fixed to the cover 3 with the epoxy resin adhesive 7, but the metal plates 8, 8'
may be fixed to the substrate 1 in advance using an epoxy resin adhesive 7', and then the cover 3 may be adhered to this using the epoxy resin adhesive 7.

Further, after fixing the metal plates 8 and 8' separately to the cover 3 or the board 1 with epoxy resin adhesives 7 and 7', the metal plates 8 and 8' are fixed with solder 9 to the board 1 and the cover. 3 may complete the sealed container.

Another embodiment of the invention will be described with reference to FIG.

In this embodiment, the cover 10 is made of a metal plate, such as a nickel plate, which has good adhesion to solder.

Therefore, since the cover 10 can be directly soldered, the cover 10 and the metal plate 8' can be fixed with the solder 9 without intervening a metal plate that is fixed with an epoxy resin adhesive.

Of course, in the case of the embodiment shown in FIG. 3, the metal plate 8' is fixed to the cover 10 with solder 9 in advance, and then the substrate 1 and the metal plate 8' are fixed with an epoxy resin adhesive 7'. Alternatively, the sealed container may be completed by fixing the metal plate 8' to the substrate 1 with an epoxy resin adhesive 7' and then fixing the cover 10 and the metal plate 8' with solder 9. may be completed.

Although FIGS. 2 and 3 both illustrate the case where the substrate 1 is planar, another embodiment will be described with reference to FIG. 4.

In the semiconductor device shown in FIG. 4A, the substrate 11 is the upper plate 1.
1' and a lower plate 11''.

These upper plate 11' and lower plate 11'' are made of an insulating material, and the integrated circuit element 2 is fixed in a recess formed in the lower plate 11'', and is formed on the lower plate 11'' with gold wires 6, 6. The inner lead pattern shown above and the integrated circuit element 2 are wired.

The above inner lead pattern has a conductive pin 14.1.
4 are connected.

The cover may be made of an insulating material such as ceramic, or may be made of metal.

A fixing portion 13 fixes the cover and the substrate 11.
13' will be illustrated and explained in an enlarged manner with reference to FIG. 4 and FIG.

Figure 4 shows an example in which a flat plate-shaped insulating cover 12 is used, and Figure 4C shows an example in which a flat plate-shaped metal cover 12' is used, which easily adheres to solder.

The fixing portion 13 fixing the insulator cover 12 and the upper plate 11' is made of an epoxy resin adhesive 14, 14', a metal plate 15, 15', and a solder 16, as in the case shown in FIG.
A sealed container is formed in the same manner as in FIG.

Furthermore, the fixing portion 13' that fixes the metal cover 12' and the upper plate 11' is made of an epoxy resin adhesive 14', a metal plate 15', and solder 16, as in the case of FIG. , a sealed container is formed in the same manner as in FIG.

Of course, in any of the cases shown in Figure 4, the adhesion between the cover 12.12' and the upper plate 11' can be separated by heating and melting the solder 16, and then soldering again. The cover 12.12' and the top plate 11' can be fastened together.

In each of the above embodiments, the case where an epoxy resin adhesive and solder were used was explained, but the present invention is not limited to these, and when other thermosetting resins or meltable substances are used. However, it is possible.

Of course, encapsulated elements are not limited to integrated circuit elements.

As explained above, according to the present invention, since a meltable substance such as solder is interposed in the thermosetting resin adhesive layer via the metal plate, the adhesion between the cover and the insulating substrate can be greatly improved. In addition, the cover and the insulating substrate can be disassembled as many times as necessary.

Therefore, if it can be bonded with a thermosetting resin such as an epoxy resin adhesive, it can be easily sealed, and if multiple integrated circuit elements are sealed in a sealed container, there is no risk of damage to the integrated circuit elements. If a fault occurs, it becomes possible to easily replace the faulty integrated circuit element.

In addition, during test research, it is extremely easy to inspect the inside of a semiconductor chip enclosed in a sealed container to check how it has changed, without damaging the semiconductor chip. And what's more, after the investigation, it can be easily sealed again.

[Brief explanation of the drawing]

Figure 1 illustrates a previously proposed sealed container, Figure 2 illustrates a semiconductor device of the present invention equipped with a sealed container using an insulating cover, and Figure 3 illustrates a semiconductor device using a metal plate cover. Another Embodiment of the Present Invention FIG. 4 illustrates still another embodiment of the present invention. In the figure, 1 is a substrate, 2 is an integrated circuit element, 3 is an insulating cover, 4.4' is an epoxy resin adhesive, 5 is solder,
6 is gold wire, 7, 7' is epoxy resin adhesive, 8, 8'
is a metal plate, 9 is solder, 10 is a cover, 11 is a board, 1
1' is the upper plate, 11'' is the lower plate, 12 is the insulating cover, 1
2' is a metal cover, 13.13' is a fixed part, 14.1
4' is epoxy resin adhesive, 15.15' is metal plate,
16 indicates solder, respectively.

Claims (2)

[Scope of utility model registration request] (1) In a semiconductor device having an insulating substrate, a semiconductor element fixed on the insulating substrate, and a cover fixed to the insulating substrate and forming a container for sealing the semiconductor element, the insulating substrate By providing a metal layer through a thermosetting resin adhesive layer and providing a fusible substance layer on the metal layer, after the insulating substrate and the cover are hermetically bonded, the fusible substance layer is applied in an appropriate manner. A semiconductor device characterized in that the insulating substrate and the cover can be removed by melting the same. (2) Practical use characterized in that the cover is made of an insulating material, and a metal layer is provided on the cover with a thermosetting resin adhesive layer interposed between the cover and the meltable substance layer. A semiconductor device according to claim (1) of patent registration.