JP3134863B2 - Stack module connection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect solder balls against cracking so as to improve modules in interconnection reliability. SOLUTION: Modules 2 are each equipped with an interposer 3 provided with a large number of electrode pads 5 and a circuit element 45 which is mounted on the interposer 3 and connected to the electrode pads 5, and the modules 2 are stacked up and connected together with solder balls 43 located on the electrode pads 5 for the formation of a stacked module connection device 1, the electrode pads 5 are arranged on the one side of the circuit element 45, a stress-absorbing member 4 is arranged on the other side, and the stress- absorbing member 4 and the solder balls 43 are interposed between the adjacent interposers 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stack module connecting apparatus suitable for use in, for example, electrically connecting and stacking a plurality of package substrates each having a surface mounted semiconductor chip.

[0002]

2. Description of the Related Art In recent years, in an electronic component mounting structure of a high-performance computer, a plurality of modules each having an integrated circuit element such as a semiconductor chip mounted on a package substrate have been laminated for the purpose of high-density mounting. Has been done. In general, as such a module laminate, a stack module connection device in which two adjacent modules are electrically connected by solder balls is known.

Conventionally, a stack module connecting device of this type has been employed as shown in FIG. The stack module connection device will be described with reference to the same drawing. In the same drawing, the stack module connection device indicated by reference numeral 41 includes two modules 42.

Each of these modules 42 is stacked in the module thickness direction and is electrically connected by solder balls 43. Each of these modules 42 has an interposer 44 and a circuit element 45, and is configured as shown in FIG.

[0005] The interposer 44 is formed with a large number of electrode pads 46 located on both sides of the circuit element 45 and arranged in parallel along both side edges. The electrode pads 46 are arranged on both front and back sides of the interposer 44, and the electrode pads 46 on both front and back sides are connected to each other by through holes (not shown). A solder ball 43 is interposed between the electrode pads 46 of two adjacent interposers 44 among the interposers 44.

The circuit element 45 has a large number of electrodes (not shown) arranged in parallel along both side edges, and is entirely formed by a semiconductor chip having a rectangular planar shape. The circuit element 45 is mounted on the interposer 44, and each electrode is connected to a corresponding electrode pad 46.

In the conventional stack module connection device, since the number of signals and the number of terminals are small in a low-speed device, a relatively large amount of solder is applied to each solder ball 43 by setting the pitch between electrode pads to a large size. Can be used. Therefore, even if the interposer 44 is warped due to use in a high temperature and high humidity environment,
The stress due to the warpage can be sufficiently absorbed by the solder ball 43.

[0008]

However, in this type of stack module connecting device, the pitch between electrode pads is increased due to an increase in the number of electrode pads corresponding to the number of electrodes of the circuit element 45 in accordance with the recent increase in component density. Therefore, the amount of solder used for the solder balls 43 on each electrode pad 5 could not be sufficiently secured.
As a result, if the interposer 44 warps and deforms due to use in a high-temperature and high-humidity environment, cracks tend to occur in the solder balls 43 due to the stress due to the warping deformation (this is more remarkable as the number of stacked modules 42 increases). There is a problem that reliability in connection between modules is reduced due to signal disconnection.

The prior arts are disclosed in JP-A-6-243944 and JP-A-6-314890, respectively, as "IC connection device" and "3D package and structure for high-performance computer". However, the above-mentioned problem has not been solved.

The present invention has been made in view of the above circumstances, and it is possible to prevent the occurrence of signal disconnection due to the occurrence of cracks in solder balls, thereby improving the reliability of inter-module connection. The purpose is to provide a connection device.

[0011]

According to a first aspect of the present invention, there is provided a stack module connecting apparatus, comprising: an interposer having a plurality of electrode pads; and an interposer mounted on the interposer and connected to the electrode pads. In a stack module connection device in which a plurality of modules having circuit elements to be connected and stacked by solder balls on the electrode pads, the electrode pads are arranged on one side of the circuit elements, and the stress is applied to the other side. An absorbing member is disposed, and the stress absorbing member and the solder ball are interposed between two adjacent interposers among the interposers. Therefore, when stress due to warpage is generated in the interposer, the stress is dispersed and absorbed by the solder ball and the stress absorbing member.

According to a second aspect of the present invention, in the stack module connecting device according to the first aspect, the electrode pads are arranged in parallel in a plane and in a horizontal direction. Therefore, when warpage deformation occurs in the interposer, a part of the stress due to the warpage deformation is absorbed by the solder balls on the electrode pads arranged in parallel in the vertical and horizontal plane.

According to a third aspect of the present invention, in the stack module device according to the first aspect, the electrode pads are arranged in a staggered pattern. Therefore, the area of application of the solder balls to the interposer is smaller than in the case where the areas are arranged in a plane and in a horizontal direction.

According to a fourth aspect of the present invention, in the stack module connecting device according to the first, second, or third aspect, the stress absorbing member includes a plurality of stress absorbing members. Therefore, a part of the stress due to the warping deformation generated in the interposer is absorbed by the plurality of stress absorbing members.

According to a fifth aspect of the present invention, in the stack module connecting device according to any one of the first to fourth aspects, the stress absorbing member is made of an elastic rubber.
Therefore, when stress due to warpage is generated in the interposer, the stress is dispersed and absorbed by the solder ball and the elastic rubber.

According to a sixth aspect of the present invention, in the stack module connecting device according to any one of the first to fifth aspects, the electrode pads on the front and back sides of the interposer are connected by through holes. Therefore, the connection of the same signal line between two adjacent interposers is performed by the through holes.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. 1A and 1B are a perspective view and a sectional view showing a stack module connection device according to a first embodiment of the present invention, and FIGS. 2A and 2B are drawings according to the first embodiment of the present invention. In the perspective view and the cross-sectional view showing the single module of the stack module connection device, the same members as those in FIGS. 4 and 5 are denoted by the same reference numerals, and detailed description is omitted. 1 and 2, the stack module connection device denoted by reference numeral 1 includes two modules 2.

Each of these modules 2 is stacked in the module thickness direction and is electrically connected by solder balls 43. Each of these modules 2 has an interposer 3, a circuit element 45 and a stress absorbing member 4.

The interposer 3 has a large number of electrode pads 5 located in a zigzag pattern on one side of the circuit element 45. Thereby, the application area of the solder balls 43 to the interposer 3 is reduced as compared with the case where the solder balls 43 are arranged in a plane and in a horizontal direction. Further, when warpage deformation occurs in the interposer 3, a part of the stress due to the warpage deformation is reduced by the circuit element 45.
Is absorbed by each solder ball 43 on one side. In this case, the arrangement of the electrode pads 5 corresponding to the electrodes of the circuit element 45 on one side of the circuit element 45 is as follows.
The stress generated on the solder balls 43 on each of the electrode pads 5 is almost halved as compared with the conventional device in which the electrode pads are arranged on both sides of the circuit element 45.

The electrode pads 5 are arranged on both front and back sides of the interposer 3, and the electrode pads 5 on both front and back sides are connected to each other by through holes 6. The electrode pads 5 of two adjacent interposers 3 among the interposers 3 are connected by solder balls 43, respectively. As a result, the signal lines are connected between both interposers (adjacent interposers).

The stress absorbing member 4 is disposed on the other side of the circuit element 45, and is interposed between the interposers 3 of both modules 2 by an adhesive (not shown) or the like.
The whole is formed by a columnar body having a rectangular cross section made of, for example, elastic rubber. As a result, when a stress due to the warp deformation occurs in the interposer 3, a part of the stress is absorbed by the stress absorbing member 4.

In the stack module connecting device having the above-described structure, if stress is generated in the interposer 3 due to warping such that the circuit element side has a concave or convex portion due to use in a high-temperature and high-humidity environment. The stress is absorbed by the solder ball 43 and the stress absorbing member 4 on each side of the circuit element 45. That is, the stress caused by the warp deformation of the interposer, which has occurred in the solder balls on both sides of the circuit element 45 in the conventional stack module connection device, is partly absorbed by the solder balls 43 and the rest is absorbed by the stress absorbing members 4. You.

Therefore, in the present embodiment, the stress absorbed by each solder ball 43 is almost half as compared with the conventional stack module connection device in which the electrode pads 5 are arranged on both sides of the circuit element 45. Therefore, even if the pitch between the electrode pads is reduced due to the increase in the number of electrode pads corresponding to the number of electrodes of the circuit element 45 with the recent increase in component density, the solder ball 4
3, the solder application amount can be sufficiently secured, and the occurrence of cracks in the solder balls 43 due to the warpage of the interposer 3 can be prevented.

Next, a second embodiment will be described with reference to FIG. FIG. 3 is a perspective view showing a stack module connection device according to a second embodiment of the present invention.
2 and the same members as those in FIG.
Detailed description is omitted. In the figure, the stack module connection device denoted by reference numeral 31 includes two modules 32, as in the first embodiment.

Each of these modules 32 is stacked in the module thickness direction and is electrically connected by solder balls 43. Each of these modules 32 has an interposer 33, a circuit element 45, and a stress absorbing member 4.

The interposer 33 has a large number of electrode pads 5 arranged on one side of the circuit element 45 in a horizontal and vertical plane. Accordingly, when the interposer 33 is warped, a part of the stress due to the warped deformation is absorbed by each solder ball 43. In this case, the arrangement of the electrode pads 5 on one side of the circuit element 45 means that the stress generated in the solder balls 43 on each electrode pad 5 is caused by the conventional device in which the electrode pads are arranged on both sides of the circuit element 45. It is half compared with.

In the stack module connecting device having the above-described structure, if a stress is generated in the interposer 33 due to warping such that the circuit element side has a concave portion or a convex portion due to use in a high-temperature and high-humidity environment. The stress is absorbed by the solder ball 43 and the stress absorbing member 4.

Therefore, in the present embodiment, similarly to the first embodiment, the stress generated in each solder ball 43 is different from that in the conventional stack module connection device in which the electrode pads 5 are arranged on both sides of the circuit element 45. Therefore, even if the pitch between the electrode pads is reduced due to the increase in the number of electrode pads corresponding to the number of electrodes of the circuit element 45 in accordance with the recent increase in the component density, the solder balls 43 for the respective electrode pads 5 are formed. Can be sufficiently secured, and the occurrence of cracks in the solder balls 43 due to the warpage of the interposer 33 can be prevented.

In this embodiment, the case where the electrode pads are arranged in three rows or more in the vertical direction and two rows are arranged in the horizontal direction, but the present invention is not limited to this. The horizontal arrangement in the plane may be three or more.

In each embodiment, the case where the stress absorbing member is formed of a single stress absorbing member has been described. However, the present invention is not limited to this, and may be formed of a plurality of stress absorbing members. In this case, the stress absorbing members may be arranged at positions parallel to each other with a predetermined interval, or may be arranged scattered in a non-mounting region on the interposer.

In addition, in each embodiment, the case where the stress absorbing member is interposed between both interposers with an adhesive or the like has been described, but the present invention is not limited to this.
Even if the stress absorbing member is held by the two interposers, the same effect as in each embodiment can be obtained. The shape of the stress absorbing member, the number of stacked modules, and the like in the present invention are not particularly limited to the above-described embodiments.

[0032]

As described above, according to the present invention, the electrode pad is arranged on one side of the circuit element, and the stress absorbing member is arranged on the other side, and the stress absorbing member and the solder ball are arranged. Since each of the interposers is interposed between two adjacent interposers, when a stress due to warpage is generated in the interposer, the stress is dispersed and absorbed by the solder ball and the stress absorbing member.

Therefore, the stress generated in each solder ball is almost half of that in the conventional device in which the electrode pads are arranged on both sides of the circuit element. Even if the pitch between electrode pads is reduced due to the increase in the number of electrode pads corresponding to
A sufficient amount of solder to be used for the solder balls on each electrode pad can be ensured, and the occurrence of cracks in the solder balls due to warpage of the interposer can be prevented, so that the reliability of connection between modules can be improved.

[Brief description of the drawings]

FIGS. 1A and 1B are a perspective view and a sectional view showing a stack module connection device according to a first embodiment of the present invention.

FIGS. 2A and 2B are a perspective view and a sectional view showing a single module of the stack module connection device according to the first embodiment of the present invention.

FIGS. 3A and 3B are a perspective view and a perspective view showing a stack module connection device according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing a conventional stack module connection device.

FIG. 5 is a perspective view showing a single module of a conventional stack module connection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stack module connection device 2 Module 3 Interposer 4 Stress absorption member 5 Electrode pad 6 Through hole 43 Solder ball 45 Circuit element

Claims (6)

(57) [Claims] 1. An interposer having a large number of electrode pads, and a plurality of modules including a circuit element mounted on the interposer and connected to the electrode pads are connected and laminated by solder balls on the electrode pads. In the stack module connecting device, the electrode pad is disposed on one side of the circuit element, and the stress absorbing member is disposed on the other side, and the stress absorbing member and the solder ball are respectively provided in the interposer. The stack module connection device is interposed between two interposers adjacent to each other. 2. The stack module connection device according to claim 1, wherein said electrode pads are arranged in parallel in a plane and in a horizontal direction. 3. The stack module connection device according to claim 1, wherein said electrode pads are arranged in a staggered grid pattern. 4. The stack module connection device according to claim 1, wherein said stress absorbing member comprises a plurality of stress absorbing members. 5. The stack module connection device according to claim 1, wherein said stress absorbing member is made of elastic rubber. 6. The stack module connection device according to claim 1, wherein the electrode pads on the front and back surfaces of the interposer are connected by through holes.