JPH01191460A - Semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To make it possible to simplify the manufacturing process and to decrease the number of parts to be used, by fixing an LSI chip to hole parts of a ceramic board, electrically connecting the wiring in a chip that is exposed out of the rear surface of the LSI chip at the rear surface of the board, and forming a circuit. CONSTITUTION:An aluminum wiring 14 is formed in each V groove 16 in an LSI chip. The LSI chip is temporarily attached to a hole part 2 which is provided in a ceramic board 1. The rear surface of each chip 11 is protruding from the rear surface of the board 1. Then, a surface cover layer 5 is formed on the surface of the board 1. The chip 11 is fixed. The rear surface of the board 1 is scraped so that the surface is made to agree with the height of the rear surface of the board 1. An insulating film 3 is formed on the rear surface of the board 1 by using PSG and the like. The exposed part of the aluminum wring 14 is selectively etched, and holes are provided. A film is formed by sputtering aluminum, copper and the like, and a pattern is formed. Thus, a rear wiring 4 is formed. The chips 11 are mutually connected electrically. Thus, a required electric circuit is constituted. Thereafter, a rear surface cover layer 6 is formed. Each LSI chip 11 is sealed, and the manufacturing is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor integrated circuit (hereinafter abbreviated as LSI), and particularly to an LSI in which a plurality of LSI chips constituting a system are collectively mounted.

[Conventional technology]

Conventionally, when constructing an electronic circuit system using a plurality of LSI chips, each LSI chip is mounted in an individual ceramic case or the like and connected with leads to construct an individual package. Then, these LSI packages were mounted on the same printed circuit board, and they were electrically connected to each other to form an electronic circuit, resulting in a two-stage configuration.

[Problem to be solved by the invention]

The LSI using the conventional multiple LSI chips mentioned above is
In the first step, it is necessary to package individual LSI chips, and this process requires precision mechanical work such as wire bonding, and requires an assembly process that is completely different from the wafer processing process. do. Furthermore, the second step requires a step of mounting each of the formed LSI packages onto a printed circuit board. For this reason, there are problems such as the LSI manufacturing process becoming complicated and the number of parts used increasing.

An object of the present invention is to provide an LSI that can simplify the manufacturing process and reduce the number of parts used.

[Means to solve the problem]

The LSI of the present invention includes a ceramic substrate having a plurality of holes, a plurality of LSI chips fixed to each hole of the ceramic substrate, and a plurality of LSI chips provided on the back surface of the ceramic substrate and attached to the back surface of the LSI chips. It consists of backside wiring connected to exposed internal chip wiring.

[Effect]

In the LSI with the above-mentioned configuration, it is possible to configure the required circuit by mounting the LSI chip on a ceramic substrate and making electrical connections, which simplifies the manufacturing process.
It is possible to reduce the number of parts used.

·〔Example〕 Next, the present invention will be explained with reference to the drawings.

Figure 1 shows an embodiment in which the present invention is applied to an LSI in which two LSI chips are mounted to form an electronic circuit. FIG.

In this LSI, a plurality of rectangular openings 2, in this case two square openings 2, are formed in one ceramic substrate 1, and LSI chips 11 are fixed therein. This LSI chip 11 has an element circuit 13 such as a transistor on the surface of a silicon substrate 12.
and aluminum wiring 14 connected thereto are formed and covered with a cover film 15. Here, the aluminum wiring 14 as the intra-chip wiring is formed along the inner surface of the V-shaped groove 16 provided in the silicon substrate 12,
The bottom surface of the V-shaped groove 16 is exposed to the back surface of the chip.

A back insulating film 3 is provided on the back surface of the ceramic substrate 1.
A backside wiring 4 is formed, and the exposed portion of the aluminum wiring 14 of the LSI chip 11 is connected by this backside wiring 4, and the two LSI chips constitute a required electronic circuit.

Furthermore, these LSI chips 11 have a front cover layer 5 and a back cover layer 6 provided on the front and back sides of the ceramic substrate 1.
It is integrally sealed by.

FIGS. 2(a) to 2(C) are cross-sectional views showing the method for manufacturing the LSI shown in FIG. 1 in order of steps.

First, as shown in FIG. 2(a), an LSI chip having aluminum wiring 14 formed in a V-shaped groove 16 is temporarily attached in an opening 2 made in a ceramic substrate 1. At this time,
It is important that the back surface of each LSI chip 11 be made to protrude beyond the back surface of the ceramic substrate 1.

Next, as shown in FIG. 2(b), PSG, oxide film, nitride film, polycrystalline silicon, etc. are deposited on the surface of the ceramic substrate 1, or resin is fused, and a surface cover is formed by a combination of these. A layer 5 is formed and the LSI chip 11 is fixed to the ceramic substrate 1.

Next, as shown in FIG. 2(c), the back surface of the LSI chip 11 is removed by polishing, grinding, etching, etc.
The back surface of the LSI chip 11 is made to match the height of the back surface of the ceramic substrate 1. As a result, a portion of the aluminum wiring 14 is exposed from the bottom of the V-shaped groove 16.

Then, as shown in FIG. 1(b)c, a back insulating film 3 is formed using PSG or the like on the back surface of the ceramic substrate 1, and the exposed portions of the aluminum wiring 14 are selectively etched. Drill the hole.

Further, a metal such as aluminum, copper, tungsten, etc. is deposited in a batter and patterned to form the back wiring 4, and the LSI chips 11 are electrically connected to each other to form a required electronic circuit.

Thereafter, a back cover layer 6 is formed on the back surface of the ceramic substrate 1, and each LSI chip 11 is sealed to complete manufacturing.

According to this structure, when manufacturing an LSI, the required electronic circuit can be constructed by simply mounting the LSI chip 11 directly on the ceramic substrate 1 and providing electrical wiring thereto, so that it is possible to construct the required electronic circuit without using the conventional package forming process. This eliminates the need for a two-step mounting process, making it possible to simplify manufacturing and reduce the number of parts used.

Although this embodiment has been described with the number of LSI chips as two, it is possible to mount three or more LSI chips by changing the size and shape of the ceramic substrate.

Further, in manufacturing the ceramic substrate, a wiring pattern using metal such as copper may be formed in advance on the ceramic substrate. Furthermore, it is also possible to grind the back surface of the LSI chip in the final step of manufacturing the wafer.

FIG. 3 is a cross-sectional view of another embodiment of the present invention, and this figure shows a cross-sectional view in a manufacturing process in which an LSISI chip A is mounted on a ceramic substrate 1.

In this embodiment, the opening 2A provided in the ceramic substrate 1 is
is formed as a non-penetrating recess opened from the back side of the board, into which the top side of the LSISI chip A is inserted and fixed. In this case, the surface cover film 15A of the LSI chip 11A is formed of polycrystalline silicon (thereby, gold-silicon eutectic etc. can be used for fixing to the ceramic substrate 1, and the LSI chip can be easily fixed). It becomes possible.

Moreover, since each LSI chip IIA has polycrystalline silicon formed in a deep groove structure to form the wiring 14A, it becomes easier to grind the back surface of the silicon substrate 12A. in this case,
Since the polycrystalline silicon wiring 14A is arranged over the entire surface of the LSI chip, the degree of freedom in wiring on the back surface of the ceramic substrate 1 can also be increased.

It goes without saying that in this embodiment as well, by using the manufacturing method shown in FIG. 2, a structure substantially similar to that shown in FIG. 1 can be constructed.

〔Effect of the invention〕

As explained above, the present invention configures a circuit by fixing an LSI chip in the opening of a ceramic substrate, and electrically connecting the internal wiring exposed on the back side of the LSI chip to the back side wiring on the back side of the ceramic substrate. This has the effect of making it possible to manufacture an LSI package equivalent to a system in which an LSI package is mounted on a printed circuit board in an extremely simple process.

In addition, the internal layout of the LSI chip is achieved by grinding the back surface of the LSI chip, and since the thickness of the grinding is arbitrary, it is important to match the heights of the back surface of the LSI chip and the surface of the ceramic substrate, and to remove the back surface wiring. This has the effect of making the formation easier and more reliable, and increasing the credibility of the LSI.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the semiconductor integrated circuit of the present invention, FIG. 1(a) is a plan view thereof, FIG. FIG. 3(c) is a sectional view for explaining the manufacturing method, and FIG. 3 is a sectional view in the middle of the manufacturing process of another embodiment of the present invention. ■...Ceramic substrate, 2,2A...Opening part, 3.
... Back insulating film, 4... Back wiring, 5... Front cover layer, 6... Back cover layer, 11... LSI chip, 12゜12A... Silicon substrate, 13... Element Circuit, 14... Aluminum wiring, 14A... Polycrystalline silicon wiring, 15.15A... Cover film, 16
...1-character groove.

Claims (1)

[Claims] 1. A ceramic substrate having a plurality of openings, a plurality of semiconductor integrated circuit chips fixed to each opening of the ceramic substrate, and a ceramic substrate provided on the back surface of the ceramic substrate and attached to the back surface of the semiconductor integrated circuit chips. A semiconductor integrated circuit comprising: backside wiring connected to exposed internal chip wiring;