JPH04291753A - semiconductor equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a semiconductor device in which a plurality of chips are stacked in order to effectively utilize chip mounting space.

0002

2. Description of the Related Art In recent years, as semiconductor devices have become more dense and multi-functional, effective use of chip mounting space has been desired. For this reason, one possible structure is a structure in which semiconductor films with elements formed on the chip surface are multilayered, but since the crystallinity of the semiconductor layer on the insulating film is not sufficient,
At present, it is not sufficient for practical use. Another possible structure is a structure in which a plurality of chips on which elements are formed are stacked, which is more suitable for practical use and has actually been commercialized.

FIGS. 5(a) and 5(b) are diagrams illustrating a conventional semiconductor device in which a plurality of chips are stacked in order to effectively utilize the chip mounting space. FIG. 5(b) is a plan view of the insulating film.

In FIG. 5(a), 1a and 1b are chips whose back surfaces are bonded together by a bonding method using a conductive adhesive or an electrostatic field. Elements such as transistors are formed on the surface of each chip 1a, 1b, and bump electrodes 2a-2t serve as signal entrances and exits for exchanging input/output signals with external leads 7a-7t, 8a-8t. It has 3a to 3t. 4a and 4b are shown in Figure 5.
As shown in (b), a plurality of pads 5a to 5t, respectively.
, 6a to 6t are plate-shaped insulating films formed on one surface, and the pads 5a to 6t of each insulating film 4a, 4b are
5t, 6a-6t are in contact with the corresponding bump electrodes 2a-2t, 3a-3t of each chip 1a, 1b. Pads 5a to 5t, 6a to 6t and bump electrodes 2a to 2t, 3a
~3t is connected using TAB (Tape Automat
ed Bonding) method, each chip 1a
, 1b are performed separately. 7a-7t, 8a-8t are pads 5a-5t, 6a-6 of each insulating film 4a, 4b.
This is an external lead connected to t. In addition, if necessary, the whole chip 1a, 1 is covered with resin.
b is protected.

[0005]

[Problems to be Solved by the Invention] However, in the above structure, since the back surfaces of the chips 1a and 1b are pasted together, it becomes difficult to attach a heat sink.
There is a problem that heat dissipation cannot be performed efficiently.

Further, the assembly for connecting the pads 5a to 5t, 6a to 6t and the bump electrodes 2a to 2t, 3a to 3t is performed using TAB (Tape Automated Board).
Since each chip 1a and 1b are separately assembled using the nding method, when one chip 1a is assembled,
The element forming surface of the other chip 1b faces outward. Therefore,
During assembly, the chips 1a and 1b may come into contact with the holder etc.
There is a risk of damaging the element forming surface.

The present invention has been made in view of these conventional problems, and provides a semiconductor device having a structure in which the element forming surface of the chip is less likely to be damaged during assembly and which facilitates heat dissipation. The purpose is to

[0008]

[Means for Solving the Problems] The above-mentioned problems firstly consist of a plate-shaped insulating substrate on which conductive pads are formed on both plate surfaces, and an element that corresponds to the position of the pads. a chip on which a bump electrode is formed, and the chip is mounted on both surfaces of the insulating substrate so that the pad and the corresponding bump electrode are in contact with each other. Second, the back surface of at least one of the chips mounted on both surfaces of the insulating substrate according to the first invention is in contact with a heat sink. Thirdly, by a semiconductor device characterized in that pads on both surfaces of the insulating substrate according to the first or second invention are connected to external leads. achieved.

[0009]

According to the semiconductor device of the present invention, the chips are mounted with the element forming surfaces of each chip facing the pad forming surfaces of both surfaces of the insulating substrate. Therefore, the assembly for connecting the pad to the bump electrode of each chip is TAB (T
When bonding is performed separately on both sides using the Ape Automated Bonding method, when the chips on one side are assembled, the back side of the chip on the opposite side, which has already been mounted, faces outward. Therefore, even if it comes into contact with a mounting table, a work tool, etc., there is no risk of damaging the element forming surface of the chip.

[0010] Furthermore, since the back surface of each mounted chip faces outward, attachment of a heat sink is facilitated. Therefore, by attaching the heat sink to the back surface of the chip, heat dissipation of the semiconductor device can be efficiently performed.

[0011]

[Embodiment] FIGS. 1(a) and 1(b) are cross-sectional views for explaining a semiconductor device according to a first embodiment of the present invention.
is a plan view of the insulating film before chip mounting, and FIG. 1(b) is a side view of the semiconductor device after chip mounting.

In FIG. 1(a), reference numeral 9 denotes an insulating film (insulating substrate), which is connected to the bump electrodes 14a to 14t and 15a to 15t of the chips 13a and 13b, and covers an area other than the peripheral pad area. Unnecessary film is removed,
A through hole 10 is formed. 11a-11t, 12a
~12t are both surfaces of the insulating film 9,
Bump electrodes 14a to 14t, 1 of chips 13a, 13b
These pads are formed at positions corresponding to 5a to 15t. Although only a part of the pads 12a to 12t on the other side is shown, the pads 11a to 11t, 12a on both sides
~12t may be formed at positions facing each other with the insulating film 9 in between, or may be formed at positions shifted by half a pitch from each other.

Reference numerals 13a and 13b denote chips 14a to 14 which are attached with the insulating film 9 in between so that the element forming surface faces the pad forming surface of the insulating film 9.
t is a bump electrode of one chip 13a, 15a to 15t
is a bump electrode of the other chip 13b.

As described above, according to the semiconductor device of the first embodiment of the present invention, the element forming surfaces of each chip 13a and 13b are opposed to the pad forming surfaces of both plate surfaces of the insulating film 9. Chips 13a and 13b are mounted thereon. Therefore, since the back surfaces of the mounted chips 13a, 13b face outward, the heat sinks 20a, 20b can be easily attached, as shown in FIG. 3(b), and heat can be dissipated efficiently.

Furthermore, since the chips 13a and 13b are mounted so that the element forming surfaces of the chips 13a and 13b always face the pad forming surface of the insulating film 9, when one side of the chip 13a is assembled, The back surface of the chip 13b on the opposite side faces outward. Therefore, even if the chips 13a and 13b come into contact with a mounting table or a work tool,
There is no risk of damaging the element forming surface. Further, after the semiconductor device is completed, it becomes easier to handle it in tests and the like.

In the first embodiment, the insulating film 9 is formed with through holes 10 in areas other than the peripheral pad area, but in the second embodiment of the present invention, the insulating film 9 is As shown in FIGS. 2(a) and 2(b), it is also possible to use a structure in which the insulating film 16 is left as it is without forming through holes in this region. This prevents the chips 13a and 13b on both sides from coming into direct contact due to stress during handling, so that even better insulation can be maintained.

Furthermore, as a third embodiment, FIG. 3(a),
As shown in (b), each pad 11a to 11t, 12a to 1
2t finally has external leads 18a to 18t, 19a to
19t can also be connected. Electrical signals and the like are exchanged between the outside and the chips 13a and 13b through these external leads 18a to 18t and 19a to 19t.

Furthermore, each mounted chip 13a, 13b
Since the back surface of the chips 13a and 13b faces outward, it is easy to attach a heat sink.As a fourth embodiment, as shown in FIG.
0a and 20b can also be attached. This results in
Heat dissipation can be performed efficiently.

Furthermore, as the fifth and sixth embodiments, as shown in FIGS. 4(a) and 4(b), if necessary, the resin 2
It is also possible to cover the chips 13a and 13b with 1st grade. This makes it easier to handle the chips 13a and 13a after assembly.
13b can be further protected.

Next, a method for manufacturing the above semiconductor device will be explained with reference to FIGS. 2(a) and 2(b).

First, the chips 1 are placed on the pads 11a to 11t on one side of the tape 22 where a plurality of insulating films 16 are connected.
The bump electrodes 14a to 14t of 3a are bonded and mounted by thermocompression bonding. Subsequently, while holding the chip 13a side that was mounted immediately before, another chip 13b is mounted on the other side in the same manner by thermocompression bonding.

Next, the tape 22 is rolled up and the next chip mounting area is transported to a predetermined position, and the area where chips 13a and 13b are already mounted on both sides is cut. Subsequently, chips are mounted on both sides of the insulating film in the next chip mounting area in the same manner as above.

[0023] In this way, the assembly is performed one by one.

As described above, according to the method for assembling a semiconductor device according to the first embodiment of the present invention, the chips 13a, 13
Since the chips 13a and 13b are mounted so that the element forming surface of b always faces the pad forming surface of the insulating film 16, the contact between the pads 11a to 11t and 12a to 12t and the bump electrodes 14a to 14t and 15a to 15t is If assembly for connection is done separately on both sides, chip 1 on one side
When assembling chip 3a, the back surface of the chip 13b on the opposite side, which has already been mounted, faces outward. Therefore, there is no risk of damaging the element forming surfaces of the chips 13a, 13b even if they come into contact with a mounting table, a working tool, or the like.

Note that, as shown in FIG. 3(b), when attaching the heat sinks 20a and 20b, first
Chips 13a and 13b are mounted on an insulating film 16 in the same manner as in the embodiment. Next, after heat sinks are attached to the back surfaces of both chips by thermocompression bonding, the tape is rolled up and the next chip mounting area is transported to a predetermined position. After sequentially assembling in this manner, the semiconductor device is completed by cutting each insulating film. Thereby, it is possible to create a semiconductor device with good heat dissipation.

Furthermore, as shown in FIGS. 4(a) and 4(b),
When covering the above semiconductor device with resin 21, chips 13a,
After mounting the chips 13b, the tape 22 is temporarily wound up with the chips 13a and 13b mounted thereon without cutting the tape 22. Subsequently, the insulating films 16 on which the chips 13a and 13b have already been mounted are set in a molding device in bulk and simultaneously covered with the resin 21, and then each insulating film 16 is cut. The semiconductor device of the sixth embodiment is completed. This further facilitates handling during tests and the like after assembly.

[0027]

As described above, according to the semiconductor device of the present invention, chips are mounted with the element forming surfaces of each chip facing the pad forming surfaces of both surfaces of the insulating substrate. Therefore, since the back surface of each chip faces outward, there is no risk of damaging the element forming surface of the chip even if it comes into contact with a mounting table, work tool, etc. during assembly or during testing after assembly. This facilitates handling of the semiconductor device.

Furthermore, since the back surface of each mounted chip faces outward, a heat sink can be attached. Heat dissipation of the semiconductor device can be efficiently performed.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a semiconductor device according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating semiconductor devices according to third and fourth embodiments of the present invention.

FIG. 4 is a cross-sectional view illustrating semiconductor devices according to fifth and sixth embodiments of the present invention.

FIG. 5 is a diagram illustrating a conventional semiconductor device.

[Explanation of symbols]

1a, 1b, 13a, 13b chips, 2a to 2t,
3a-3t, 14a-14t, 15a-15t bump electrode, 4a, 4b, 16 insulating film, 5a-5t, 6
a~6t, 11a~11t, 12a~12t pad, 7a~7t, 8a~8t, 18a~18t, 19a~1
9t external lead, 9 insulating film (insulating substrate), 10 through hole, 20a, 20b heat sink, 21 resin.

Claims (3)

[Claims] 1. A plate-shaped insulating substrate on which conductive pads are formed on both plate surfaces, and a chip on which bump electrodes are formed on the element formation surface to correspond to the positions of the pads. A semiconductor device comprising: a semiconductor device, wherein the chip is mounted on both surfaces of the insulating substrate so that the pad and the corresponding bump electrode are in contact with each other. 2. A semiconductor device, wherein the back surface of at least one of the chips mounted on both surfaces of the insulating substrate according to claim 1 is in contact with a heat sink. 3. A semiconductor device, wherein pads on both surfaces of the insulating substrate according to claim 1 or 2 are connected to external leads.