JPH11297883A - Stackable semiconductor devices and these semiconductor device modules - Google Patents

Abstract

(57) [Problem] To provide an LLCC type package, external terminals cannot be increased because external terminals are formed in a line in the periphery of the package, and a second insulating substrate is necessarily required. Was. The number of external terminals can be increased, and a single insulating substrate can be used. SOLUTION: An insulating substrate having an opening in the center is used,
A plurality of metal conductor layers on its surface have a first
An external terminal is connected to the second external terminal on the back surface through the insulating substrate from the first external terminal. Since the external terminals are arranged in a lattice pattern, the number can be increased even with the same pitch, and if the external terminals are connected to each other via a spherical metal, a sufficient separation distance is secured. Modularization becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stackable semiconductor device and a semiconductor device module in which the devices are stacked, and more particularly, to a BGA (Ball Grid Array) type in which a plurality of semiconductor devices on which semiconductor elements are mounted are stacked. The present invention relates to a semiconductor device module having a laminated structure.

[0002]

2. Description of the Related Art A semiconductor device, particularly a semiconductor memory device such as a DRAM, is used for a CPU module or the like.
Instead of one, it is common to use many. At this time, if these semiconductor storage devices can be stacked and mounted, a higher-density mounting substrate can be realized.

On the other hand, in a semiconductor memory device such as a DRAM, for example, it is known that the performance of an element is improved when an electrode connected to a power supply or the like and supplying power is arranged at the center of the semiconductor element.

[0004] Therefore, due to such objects and demands, the structure of a conventionally used semiconductor device package 40 described in, for example, JP-A-9-139441 has a bottom surface as shown in FIG. First insulating substrate 41 to be constituted
And a second insulating substrate 42 provided on an outer peripheral portion of the surface thereof. The first insulating substrate 41 has a concave portion on the bottom surface, and an opening H is provided at the center thereof. In such a package 40, an electrode (not shown) provided at the center of the surface of the semiconductor element 46 is attached to the inside of the opening by bonding the front side of the semiconductor element 46 to the bottom surface of the first insulating substrate 41 around the opening H. Exposure to The metal conductor layer 43 formed on the surface of the first insulating substrate 41 and the electrode of the semiconductor element 46 are connected by a copper wire 48, and the metal conductor layer 43 is pulled out to the end of the package 40 and passed through the side surface. External terminals 44 and 45 are integrally formed on the bottom surface of the first insulating substrate 41 and the side surface of the second insulating substrate 42 formed on the first insulating substrate, respectively. The packages 40 can be sequentially stacked. This is the so-called LLCC (Leadless Chip C
arrier) type package.

FIG. 5 is an enlarged view of an arrangement of conductors for electrically connecting the semiconductor element 46 to the external terminals 44 and 45 on the side surface of the package via the metal conductor layer 43. As shown in FIG. 5, the electrode 51 of the semiconductor element 46 is connected to the metal conductor layer 43 on the first insulating substrate 41 by a copper wire 48. The peripheral portion of the first insulating substrate 41 is covered with a second insulating substrate 42, and the metal conductor layer 43 is also covered by the second insulating substrate 42 in this peripheral portion.
Covered by The conductors forming the external terminals 44 and 45 on the side surface of the package 40 are formed on the side surface of the second insulating substrate 42 formed by cutting out the end of the second insulating substrate 42 into a semicircle.

[0006]

As can be seen from FIG. 5, in the conventional semiconductor device, the number of external terminals cannot be increased beyond the above-mentioned semicircular formation pitch.

As can be seen from the appearance of FIG. 5, the external terminals 44 and 45 are formed in a row around the package. Further, since this package is of LLCC type, the connection form of the upper and lower packages is a solder connection in order to form a laminated structure. In the case of the solder connection, there is a problem of a solder bridge in which adjacent terminals are short-circuited. Again, there is a certain limitation in narrowing the pitch of the external terminals, and there is a limit in increasing the number of external terminals.

On the other hand, semiconductor devices have been increasingly miniaturized and the number of necessary external terminals has tended to increase in recent years, and the above-mentioned disadvantages of the LLCC type are fatal. Furthermore, the conventional package requires a second insulating substrate. The reason is as follows.

That is, a connecting conductor layer and a protective sealing resin are formed on the surface of the first insulating substrate, and an LLCC type package cannot be directly stacked and connected above the connecting conductor layer and the protective sealing resin. Therefore, the second insulating substrate is formed thereon and the height is increased, thereby realizing the mounting in the vertical direction. In addition, since the package is a surface mount type package called LLCC, an originally useless second insulating substrate is required, and it is inevitably expensive. Further, the reason for processing the first insulating substrate into a shape having a concave portion is also the same. This is also a factor that increases the manufacturing cost.

[0010] On the other hand, since the LLCC type package has no irregularities and is stacked without gaps when stacked, there is also a problem that heat released from the semiconductor element cannot be sufficiently diffused.

As described above, in the conventional LLCC type package, the conductor for conducting the package in the vertical direction passes through the side surface, and the external terminals are formed in a line in the periphery of the package. Therefore, there has been a problem that the recent demand for increasing the number of external terminals cannot be sufficiently satisfied.

Further, since the protective sealing resin and the like are higher than the surface of the first insulating substrate, the LLCC type package necessarily requires the second insulating substrate, and as a result, the structure of the insulating substrate is complicated. And it was also a problem that it became expensive.

An object of the present invention is to provide a semiconductor device and a semiconductor device module which can be easily stacked even when the number of external terminals is large, realize a high-density mounting substrate, and have high heat emission and a low cost. It is to provide.

[0014]

The present inventor basically reviewed the structure of the semiconductor device (package) itself in order to solve the above problems. First, it was considered that arranging external terminals on the side surface of the semiconductor device was an obstacle to increasing the number of external terminals. Arranging on the side surface means that the external terminals are arranged one-dimensionally or linearly. If the external terminals are arranged one-dimensionally and the pitch between the external terminals is reduced, the danger of a solder bridge also appears. Therefore, it has been considered that by arranging the external terminals two-dimensionally, more external terminals can be arranged, and the pitch between the external terminals can be given a margin.

Next, it was examined from a structural point of view to eliminate the concave portion of the first insulating substrate and the second insulating substrate, which would complicate the manufacturing process and increase the cost. The conventional semiconductor device has a completely uneven shape. For this reason, such a structure has to be adopted due to the relationship between the encapsulation of the protective resin and the connection at the side surface. Therefore, even if the semiconductor device has irregularities,
We examined how to connect semiconductor devices.

From the above consideration, it has been considered that the semiconductor devices should be connected to each other with solder balls, and the solder balls should have a role of adjusting the height. Then, the present invention is as follows.

(1) A semiconductor device having an electrode on the front surface, a first external terminal on the front surface having an opening, and a second external terminal on the back surface.
An insulating substrate provided with external terminals, wherein the semiconductor element has a surface adhered to a bottom surface of the insulating substrate so that the electrode is disposed in the opening, and the insulating substrate has a plurality of insulating surfaces on the surface. Wherein the electrode is connected to the metal conductor layer by a conducting wire passing through the opening, the metal conductor layer is connected to the first external terminal, and the first external terminal and the second external terminal are connected to the first external terminal. The semiconductor device according to claim 1, wherein the external terminals are connected via a conductor portion penetrating the insulating substrate.

(2) The semiconductor device according to (1), wherein the first terminal and the second terminal are arranged in a lattice. (3) A semiconductor device module, wherein a plurality of the semiconductor devices according to the above (1) or (2) are stacked, and the external terminals are connected to each of the opposing semiconductor devices via a spherical metal.

As described above, according to the present invention, the connection between the external terminals formed on the upper and lower surfaces of the package and the metal conductor layer is established.
By using conductors that pass through the inside of the insulating substrate without passing through the package side surface, and by arranging external terminals formed on the top and bottom surfaces of the package in a grid pattern, it is possible to increase the number of terminals even if the terminal pitch is widened And the risk of solder bridges can be reduced.

Further, the connection between the external terminals arranged in a lattice is made through a spherical metal, thereby realizing a sufficient space for the separation between the upper and lower packages. The necessity is eliminated and an inexpensive package can be realized.

Further, the necessity of providing a concave portion from the first insulating substrate is eliminated, and a more inexpensive package can be realized.
In addition, with such a semiconductor device structure, the problem of heat release generated from the semiconductor element can be solved.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a semiconductor device according to the present invention, an insulating substrate for bonding a semiconductor element to a bottom surface has an opening at the center. This corresponds to forming an electrode of a semiconductor element at the center of the element in order to improve element characteristics, and to expose the electrode. However, in the case of the present invention, it is not necessary to provide a recess for accommodating a semiconductor element on the bottom surface as in the related art.

A plurality of metal conductive layers are provided on the surface of the insulating substrate.
(Wiring) is formed, and the tip of the wiring is connected to the electrode of the semiconductor element by a conductor. Usually, connection is made using a conductive wire by wire bonding.

Further, the individual wirings of the metal conductor layer are spread radially and extend to a position where the first external terminal disposed on the periphery of the insulating substrate is provided. The arrangement of the external terminals in the present invention is preferably arranged in a lattice.
Here, the lattice arrangement means that the external terminals existing over several rows are alternately arranged. For example, when the external terminals are arranged in two rows as shown in FIG. 2, if metal conductor layers and terminals of the same size are used for convenience, the number of metal conductor layers and terminals can be almost doubled. Such external terminals may be provided in three or more rows. Of course, when the number of external terminals is small, it is not necessary to form a grid, and a single row may be used.

The first external terminal thus formed on the surface of the insulating substrate is connected to the metal conductive layer and connected to the second external terminal formed on the back surface of the insulating substrate by a conductor penetrating the insulating substrate. Is done.

The conductor penetrating the insulating substrate is generally a via hole when the insulating substrate is a ceramic substrate, and a through hole when the insulating substrate is a plastic substrate. In this way, the first and second external terminals are electrically connected in the vertical direction.

It is necessary to protect the opening of the insulating substrate with resin or the like after wire bonding, and the resin is sealed by potting or the like. For this reason, the height of the sealing resin is higher than the surface of the insulating substrate. Further, the semiconductor element is also exposed on the back surface of the insulating substrate, and needs to be sealed with a resin or the like. Therefore, the height of the back surface sealing resin is also lower than the back surface of the insulating substrate.

Therefore, in order to make the semiconductor device of the present invention a laminated structure, a connection method having a certain height is required. Therefore, the present invention employs a so-called BGA structure connected through a spherical metal. As the spherical metal, a high-temperature solder ball, a Cu ball, or the like is desirable. The external terminal and the spherical metal are connected by eutectic solder or conductive resin. These methods are preferable because the mounting temperature is low, the spherical metal is not melted, and the height is maintained.

On the other hand, there is a method of using eutectic solder for the spherical metal. In this case, the solder balls are melted, but the sealing resin formed above and below functions to maintain the connection height. In addition, the first and second metal conductor layers having exposed surfaces are provided.
It is desirable that the external terminals be protected with resin or the like, except for portions required for connection to the outside.

With such a structure, it is possible to provide a semiconductor device module having a laminated structure that is inexpensive and can accommodate multiple terminals. In addition, by arranging the external terminals in a lattice shape, the arrangement density of the external terminals can be almost doubled or the size of the metal conductor layers and the terminals can be reduced simply when the metal conductor layers and the terminals of the same size are used. Then, more external terminals can be arranged.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a sectional view of a semiconductor device according to the present invention. First, a case where the insulating substrate 1 is a printed circuit board will be described as a first embodiment of the present invention.

As shown, an insulating substrate 1 having an opening
Are formed with desired metal conductor layers 3, first external terminals 4, 5, through holes 6, 7 penetrating the insulating substrate 1, and second external terminals 8, 9. The side surfaces of the through holes 6 and 7 are coated with a metal such as Cu and filled with a conductive material. As will be described later, it is preferable that the through holes 6 and 7 are filled with a conductive material as described above in order to mount a metal ball.

Further, the portions of these metal pattern portions which do not need to be exposed are the resin portions 11, 12, 13, 14, 1
Cover with 5, 16 to protect. In this state, the semiconductor element 2, which is an LSI element, is fixed to the bottom surface of the insulating substrate 1 with an adhesive (not shown) so that the electrode terminals (not shown) of the element are exposed in the openings, and the wires 10 are used. Connect to metal conductor layer 3.
At the same time, the resin 17a, 17b seals and protects the wire connection portion and the semiconductor element (LSI element) 2.

As shown in the figure, the first and second external terminals are arranged in a lattice, so that a large number of external terminals can be taken out even in a small package, and the terminal pitch can be widened. , High reliability.

Next, a second embodiment of the present invention in which the insulating substrate 1 is an alumina ceramic substrate will be described with reference to FIG. 1 because the structure is substantially the same. However, the above-mentioned through holes 6 and 7 are the via holes 6 and 7 in this example.

First, a hole is formed in a green sheet of alumina to form openings for wire connection and holes of via holes 6 and 7. Next, the metal conductor layer 3, the first external terminals 4 and 5, the internal metal layers of the via holes 6 and 7, and the second external terminals 8 and 9 are formed using a high-melting metal paste by a method such as screen printing. . Further, for the purpose of protecting these metal patterns, protective films 11, 12, 13, 14, 15, and 16 are formed by a method such as printing an alumina paste, and then firing. Further, Ni / Au plating is applied to the exposed metal pattern portion. The semiconductor element 2 is fixed to the bottom surface of the insulating substrate 1, the wires 10 are formed, and the wire connection portions and the semiconductor element 2 are protected by using the sealing resins 17a and 17b.

In the illustrated example, the metal pattern is formed only on the front and back surfaces of the insulating substrate 1. However, a multi-layer structure may be used for the purpose of improving electric characteristics and arranging a large number of wirings.

Next, a connecting member used for laminating the semiconductor devices of the present invention will be described with reference to FIG.
In this example, the structure itself of the semiconductor device of FIG.
Is the same as that of

As is clear from the cross-sectional view of FIG. 2, the semiconductor device of the present invention has convex portions on the front and back surfaces of the insulating substrate 1, respectively. Therefore, in order to stack them, a connecting member that is higher than the height of the projection is required. In this example, a high-temperature solder ball having a diameter larger than the height of such projections
18 and 19 are used as connecting members. The semiconductor device is connected to such external terminals by a conductive adhesive such as eutectic solder. Therefore, it is desirable to apply a conductive adhesive such as eutectic solder to the surface of the external terminal in advance by printing or the like.

Next, a module using the semiconductor device of the present invention will be described with reference to the schematic sectional view of FIG. FIG. 3 is a schematic cross-sectional view showing a state where the semiconductor device of the present invention is laminated on the mother substrate 29 in three layers. Reference numerals 20, 21, and 22 indicate the semiconductor device of the present invention in a schematic cross section. By connecting these via the high-temperature solder balls 23 to 28, the illustrated laminated structure, that is, the semiconductor device module can be realized. Each semiconductor device and the high-temperature solder ball are connected by eutectic solder or the like.

As shown in the figure, the connecting member between the packages is made of a spherical metal having a height, so that the above-mentioned FIG.
It is not necessary to form a concave portion in the insulating substrate 1 or to form the insulating substrate 2 as in the conventional example shown in FIG.

In addition, by arranging the external terminals in a grid pattern, the arrangement density can be simply increased by a factor of approximately under the same conditions, thereby increasing the integration degree of each semiconductor element. You can cope with the improvement.

[0043]

As described above, according to the semiconductor device of the present invention, a laminated structure can be provided without using an insulating substrate having a complicated structure as in the prior art, so that it is inexpensive.
Also, since the external terminals are arranged two-dimensionally, the number of external terminals can be increased.Especially, by arranging the external terminals in a lattice shape, it can be applied to a small package even when many external terminals are required. It is possible. Further, even in the case of lamination, since the semiconductor devices are connected to each other by the spherical metal having a sufficient height, the lamination structure is simple, a space is formed, and the heat releasing property is good.

[Brief description of the drawings]

FIG. 1 is a sectional view of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a connection member of the semiconductor device according to the embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view schematically showing a semiconductor device module configured using a semiconductor device according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a conventional semiconductor device.

FIG. 5 is an enlarged view of an external terminal passing through a side surface of a conventional semiconductor device.

[Explanation of symbols]

1: Insulating substrate (printed substrate or ceramic substrate such as alumina) 2: Semiconductor element of LSI 3: Plural metal conductive layers 4, 5: First external terminal (surface of insulating substrate) 6, 7: Conductor penetrating insulating substrate (Through hole or via hole) 8, 9: Second external terminal (backside of insulating substrate) 10: Connection member (wire) 11-16: Protective member (resin or alumina) 17a, 17b: Sealing resin 18, 19: For connection Spherical metal (high-temperature solder ball, etc.) 20-22: Semiconductor device of the present invention 23-28: Spherical metal for connection (high-temperature solder ball, etc.) 29: Marza board (printed board)

Claims (3)

[Claims] 1. A semiconductor device having an electrode on a front surface, and an insulating substrate having an opening, a first external terminal on a front surface, and a second external terminal on a back surface, wherein the semiconductor element has the electrode. The surface is adhered to the bottom surface of the insulating substrate so as to be disposed in the opening, and the insulating substrate includes a plurality of metal conductor layers on the surface, and the electrode is formed by a conductive wire passing through the opening. And the metal conductor layer is connected to the first external terminal,
The semiconductor device according to claim 1, wherein the first external terminal and the second external terminal are connected via a conductor penetrating the insulating substrate. 2. The semiconductor device according to claim 1, wherein said first terminal and said second terminal are arranged in a lattice. 3. A semiconductor device module comprising: a plurality of the semiconductor devices according to claim 1 or 2 stacked; and the external terminals connected to each of the opposing semiconductor devices via a spherical metal.