JP2002334946A - Semiconductor package and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor package, whose durability with reference to a temperature change is superior and reliability is high, and to provide a semiconductor device. SOLUTION: The semiconductor package 12 is provided with a substrate 2, a semiconductor element 1 which is arranged on the substrate 2 and a connecting member 10 which is arranged between the substrate 2 and the semiconductor element 1. The connecting member 10 comprises a flexible substrate 5 and conductors 7 which are embedded in the substrate 5 and which electrically connect the substrate 2 to the semiconductor element 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor package and a semiconductor device, and more particularly, to a semiconductor package in which a semiconductor chip is flip-chip connected to a package substrate and a semiconductor device using the semiconductor package.

[0002]

2. Description of the Related Art Conventionally, there has been known a semiconductor package in which a semiconductor chip is flip-chip connected to a package substrate. FIG. 5 is a schematic sectional view showing a conventional semiconductor package. A conventional semiconductor package will be described with reference to FIG.

[0005] Referring to FIG. 5, a semiconductor package includes a package substrate 102, a semiconductor chip 101 disposed on the package substrate 102, and a semiconductor chip 101.
Bumps 103 for connecting the
And an underfill resin 1 arranged to fill a gap between the semiconductor chip 101 and the package substrate 102
04. The semiconductor package is connected and fixed to a printed board (not shown) or the like by solder balls (not shown) arranged on the lower surface of the package board 102.

In a semiconductor package, a plurality of solder bumps 103 are formed on a lower surface of a semiconductor chip 101. On the other hand, connection pattern terminals (not shown) which are electrodes for connecting the solder bumps 103 are formed on the upper surface of the package substrate 102. The semiconductor chip 101 is connected to the package substrate 102 by melting and connecting the solder bumps 103 of the semiconductor chip 101 to the connection pattern terminals of the package substrate 102. That is, the semiconductor chip 101 is connected to the package substrate 102 by a so-called flip chip method.

[0005] As a material of the package substrate 102, for example, an epoxy resin containing glass fiber can be used. As a material of the underfill resin 104, a thermosetting plastic, for example, an epoxy resin can be used. The underfill resin 104 melts and connects the solder bumps 103 to the connection pattern terminals of the package substrate 102, and then fills the gap between the semiconductor chip 101 and the package substrate 102 with the above-described thermosetting plastic, It can be obtained by curing this plastic by heat treatment.

In a conventional semiconductor package, by disposing such an underfill resin 104, the semiconductor chip 101 when the temperature of the semiconductor package changes is changed.
It is stated that the stress caused by the difference between the linear expansion coefficients of the package and the package substrate 102 can be reduced. That is, when the temperature of the semiconductor package changes, the semiconductor chip 101 and the package substrate 102 expand or contract thermally. At this time, since the material such as silicon forming the semiconductor chip 101 and the epoxy resin forming the package substrate 102 have different linear expansion coefficients, the amount of displacement due to a temperature change also differs. When the underfill resin 104 does not exist, a stress such as a shear stress is applied to the solder bump 103 due to a difference between a displacement amount due to a temperature change of the semiconductor chip 101 and a displacement amount due to a temperature change of the package substrate 102. . This stress causes solder bump 1
03 and the semiconductor chip 101 or the package substrate 102
In some cases, the semiconductor package may be damaged, for example, the junction with the semiconductor package may come off. However, by disposing the underfill resin 104 as described above, the entire stress of the underfill resin 104 and the solder bump 103 can bear the stress. As a result, stress can be prevented from being concentrated only on the solder bumps 103, so that damage to the semiconductor package can be prevented.

[0007]

However, the conventional semiconductor package as described above has the following problems. That is, consider a case where the temperature of the semiconductor package changes, for example, a case where the temperature rises. At this time,
The underfill resin 104 also thermally expands as the temperature rises, but the displacement due to the thermal expansion is horizontal (the package substrate 10).
Not only in the direction substantially parallel to the upper surface of 2)
It also occurs in the vertical direction (direction substantially perpendicular to the upper surface of the package substrate 102). As a result, stress in the direction in which the distance between the semiconductor chip 101 and the package substrate 102 increases (vertical direction) is applied to the lower surface of the semiconductor chip 101 and the upper surface of the package substrate 102. As a result, a vertical tensile stress is applied to the solder bump 103. Such a tensile stress may damage the joint between the solder bump 103 and the semiconductor chip 101 or the package substrate 102. For this reason, the durability (fatigue life) of the semiconductor package with respect to a temperature change (thermal cycle) is reduced, resulting in a reduction in reliability.

Further, when the rigidity of the package substrate 102 is low, it is necessary to use an underfill resin having a small elastic coefficient in order to reduce the warpage of the entire package substrate 102. However, in general, a resin having a small elastic coefficient has a large coefficient of linear expansion, so that a displacement amount accompanying a temperature change is large. For this reason, the tensile stress in the vertical direction applied to the solder bump 103 increases. As a result, the durability of the semiconductor package against a temperature change has been further reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a semiconductor package and a semiconductor device which are excellent in durability against a temperature change and have high reliability. It is to be.

[0010]

According to one aspect of the present invention, a semiconductor package includes a substrate, a semiconductor element disposed on the substrate, and a connection member disposed between the substrate and the semiconductor element. The connection member includes a flexible base, and a conductive line embedded in the base and electrically connecting the substrate and the semiconductor element.

With this configuration, when the temperature of the semiconductor package changes, the connecting member having a flexible base disposed between the substrate and the semiconductor element allows the linear expansion coefficient of the substrate and the semiconductor element to be reduced. The stress in the horizontal direction (the direction parallel to the surface of the substrate facing the semiconductor element) caused by the difference can be absorbed. That is, the flexible base is deformed in accordance with the deformation of the substrate and the semiconductor element, and the conductive wire for electrically connecting the substrate and the semiconductor element is bent and deformed in accordance with the deformation of the base. Horizontal stress due to the difference in linear expansion coefficient between the semiconductor element and the semiconductor element can be prevented from being concentrated on the substrate and the connection between the semiconductor element and the conductive wire. As a result, it is possible to prevent the connection between the substrate and the semiconductor element from being damaged by the shear stress due to the temperature change.

Conventionally, the connection between the substrate and the semiconductor element is made by solder bumps, and the space between the solder bumps is filled with an underfill resin having a low elasticity coefficient, whereby the connection between the substrate and the semiconductor element is formed. The rigidity of the entire part was increased. In this case, as described above, the connection between the substrate and the semiconductor element is prevented from being damaged by the tensile stress caused by the thermal expansion of the underfill resin in a direction perpendicular to the surface of the substrate (vertical direction). Difficult to do. on the other hand,
In the semiconductor package according to the present invention, since the connection member made of the flexible base is disposed between the substrate and the semiconductor element, the rigidity of the connection between the substrate and the semiconductor element is lower than before. For this reason, even if the connecting member thermally expands in the vertical direction when there is a temperature change, the vertical stress applied to the substrate and the semiconductor element is smaller than in the conventional case. Also,
If a part of the conductive wire included in the connecting member is bent, when the base thermally expands to some extent in the vertical direction, the conductive wire can be deformed along the thermal expansion. Therefore, it is possible to suppress the occurrence of a defect such as disconnection between the substrate and the semiconductor element due to the vertical stress. As a result, it is possible to obtain a semiconductor package having excellent durability against temperature changes and high reliability.

In the semiconductor package according to the first aspect, it is preferable that the conductive wire extends from one surface of the connecting member facing the substrate to the other surface facing the semiconductor element and has a bent portion.

In this case, when the base of the connection member thermally expands in the vertical direction due to a change in the temperature of the semiconductor package, the conductive wire can be easily deformed in accordance with the deformation of the base. Therefore, when the base thermally expands in the vertical direction, it is possible to prevent excessive stress from being applied to the connection between the conductive wire and the substrate or the semiconductor element. As a result, it is possible to reliably suppress occurrence of a defect such as disconnection between the substrate and the semiconductor element.

When the base is deformed in the horizontal direction due to a difference in linear expansion coefficient between the substrate and the semiconductor element, the conductive line has a bent portion, so that the conductive line can be easily formed along the deformation of the base. Can be transformed into For this reason, even when the base is deformed in the horizontal direction as described above, it is possible to prevent an excessive stress from being applied to the connection between the conductive wire and the substrate or the semiconductor element.

The semiconductor package according to the first aspect preferably further includes a one-side sealing resin disposed between the semiconductor element and the connection member.

In this case, the surface of the semiconductor element facing the connection member and the surface of the connection member facing the semiconductor element can be reliably connected with one sealing resin. Therefore, displacement due to thermal expansion of the semiconductor element can be transmitted to the base of the connection member by the one sealing resin as the one sealing member. Therefore, the connecting portion between the conductive wire of the connecting member and the semiconductor element (for example, the connecting portion between the end of the conductive wire facing the semiconductor element and the solder bump formed on the surface of the semiconductor element facing the connecting member). In addition, it is possible to prevent stress caused by displacement due to thermal expansion or the like of the semiconductor element from being concentrated. As a result, it is possible to prevent the connection between the conductive wire of the connection member and the semiconductor element from being damaged by the stress.

It is preferable that the semiconductor package according to the first aspect further includes another sealing resin disposed between the substrate and the connection member.

In this case, the surface of the substrate facing the connection member and the surface of the connection member facing the substrate can be reliably connected by the other sealing resin. Therefore, displacement due to thermal expansion of the substrate can be transmitted to the base of the connection member by the one sealing resin as the other sealing member. Therefore, the connection portion between the conductive wire of the connection member and the substrate (for example, the connection portion between the end of the conductive wire facing the substrate and the solder bump formed on the surface of the substrate facing the connection member) is attached to the substrate. Concentration of stress due to displacement due to thermal expansion or the like can be prevented. As a result, it is possible to prevent the connection between the conductive wire of the connection member and the substrate from being damaged by the stress.

In the semiconductor package according to the first aspect, the one sealing resin and the other sealing resin may not be provided. In this case, in the manufacturing process of the semiconductor package, since the sealing process of the one sealing resin and the other sealing resin is not performed, the number of manufacturing processes of the semiconductor package can be reduced.

The semiconductor package according to the first aspect includes a bump for electrically connecting the semiconductor element and the conductive line of the connecting member, and a bump for electrically connecting the substrate and the conductive line of the connecting member. Is preferred.

In this case, the semiconductor element and the substrate can be connected to the connection member by using a so-called flip chip bonding method. As a result, the size of the semiconductor package can be reduced as compared with the case where the semiconductor element and the substrate are connected to the connection member by wire bonding.

A semiconductor device according to another aspect of the present invention includes the semiconductor package according to the first aspect.

In this case, by using the semiconductor package according to the present invention, it is possible to realize a semiconductor device having excellent durability against temperature changes and high reliability.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. Incidentally, the description thereof will not be repeated denoted by the same reference numerals to the same or corresponding parts in the following drawings.

(Embodiment 1) FIG. 1 is a schematic sectional view showing a semiconductor device according to the present invention. FIG. 2 is similar to FIG.
FIG. 4 is a schematic cross-sectional view showing a connection member in the semiconductor device shown in FIG. A semiconductor device according to the present invention will be described with reference to FIGS.

Referring to FIGS. 1 and 2, the semiconductor device 9 includes a printed board 8 and a semiconductor package 12 mounted on the printed board 8. Semiconductor package 1
2 includes a package substrate 2, a semiconductor chip 1, and a connection member 10 located between the semiconductor chip 1 and the package substrate 2.

A plurality of solder balls 6 are arranged on the lower surface of the package substrate 2. This solder ball 6
Are electrically connected to electrodes (not shown) formed on the surface of the printed circuit board 8. A plurality of solder bumps 3b are arranged on the upper surface of the package substrate 2 in a matrix. A connection member 10 including a flexible resin 5 as a base layer (matrix layer) and a wire 7 made of gold is arranged on the solder bump 3b.
The wires 7 are embedded in a matrix in the resin 5 as a base. In the connection member 10, a bent portion 11 is formed substantially at the center of the wire 7. One end (lower end) of each wire 7 is connected to solder bump 3
b. One end of the wire 7 located in a region facing the package substrate 2 is electrically connected to the solder bump 3b.

The semiconductor chip 1 is arranged on the upper surface of the connecting member 10. On the lower surface of the semiconductor chip 1, a plurality of solder bumps 3a are arranged in a matrix. The solder bump 3a is arranged in a region located on the other end of the wire 7 which is the end facing the semiconductor chip 1. The solder bump 3a is electrically connected to a circuit formed on the semiconductor chip 1 and is connected to the other end (upper end) of the wire 7 in the connection member 10.

The semiconductor chip 1 is electrically connected to a circuit (not shown) formed on the printed board 8 via the solder bumps 3a, the wires 7 of the connecting member 10, the solder bumps 3b, the package board 2 and the solder balls 6. It is connected to the.

By doing so, the semiconductor package 12
When the temperature of the semiconductor chip 1 changes, the connection member 10 having the flexible resin 5 disposed between the package substrate 2 as the substrate and the semiconductor chip 1 as the semiconductor element connects the package substrate 2 to the semiconductor chip 1. The stress in the horizontal direction (the direction parallel to the surface of the package substrate 2 facing the semiconductor chip 1) caused by the difference in the linear expansion coefficients can be absorbed.
That is, the flexible resin 5 is deformed in accordance with the deformation of the package substrate 2 and the semiconductor chip 1, and the wires 7 as conductive lines for electrically connecting the package substrate 2 and the semiconductor chip 1 are also formed of the resin 5. By bending and deforming according to the deformation, the horizontal stress due to the difference in linear expansion coefficient between the package substrate 2 and the semiconductor chip 1 is reduced.
It is possible to prevent concentration on the connection portion between the wires a and 3b and the wire 7. As a result, the solder bump 3
It can be prevented that the connection portion between a and 3b and the wire 7 is damaged by receiving the shear stress.

The connecting member 1 made of a flexible resin 5
0 is arranged between the package substrate 2 and the semiconductor chip 1, the connection between the package substrate 2 and the semiconductor chip 1 is smaller than in the conventional case where the package substrate 2 and the semiconductor chip 1 are directly joined by solder bumps. The rigidity of the connection can be reduced. For this reason, even if the connecting member 10 thermally expands in the vertical direction when there is a temperature change, the vertical stress applied to the package substrate 2 and the semiconductor chip 1 can be made smaller than before.

Further, since the wire 7 has the bent portion 11, when the resin 5 of the connecting member 10 thermally expands in the vertical direction with the temperature change of the semiconductor package 12, the deformation is caused by the deformation of the resin 5. The wire 7 can be easily deformed. Therefore, when the resin 5 thermally expands in the vertical direction,
Excessive stress can be prevented from being applied to the connection between the wire 7 and the solder bumps 3a, 3b. As a result, it is possible to reliably suppress the occurrence of defects such as disconnection between the wire 7 and the solder bumps 3a and 3b. In the wire 7 of the connecting member 10 shown in FIGS. 1 and 2, a bent portion 11 is formed as a buffer portion for providing a deformation allowance for the wire 7 to deform following the deformation of the resin 5. However, the shape of the buffer portion is not limited to the bent portion as shown in FIGS. 1 and 2 and may be any shape that allows the wire 7 to have a deformation allowance. For example, a part of the wire 7 may be spirally arranged as a buffer part, or a part of the wire 7 may be formed in an S shape.

The package substrate 2 and the semiconductor chip 1
When the connecting member 10 is deformed in the horizontal direction due to the difference between the linear expansion coefficient and the wire 7, the wire 7 has the bent portion 11,
The wire 7 can be easily deformed so as to follow the deformation of the resin 5. Therefore, as described above, the connecting member 1
0 is deformed in the horizontal direction, the connection between the wire 7 and the solder bumps 3a and 3b and the solder bump 3
Excessive stress can be prevented from being applied to the connection portions between a and 3b and the package substrate 2 or the semiconductor chip 1. As a result, it is possible to realize the semiconductor package 12 and the semiconductor device 9 which are excellent in durability against a temperature change and have high reliability.

Further, since the semiconductor chip 1 and the package substrate 2 are connected to the connecting member 10 by using the solder bumps 3a and 3b (using a so-called flip chip bonding method), the semiconductor chip 1 and the package substrate 2 are connected. The size of the semiconductor package 12 can be reduced as compared with the case where the semiconductor package 12 is connected to the connection member 10 by wire bonding.

As shown in FIG. 1, an underfill resin 4 is arranged between the connection member 10 and the package substrate 2 so as to fill a gap. The underfill resin 4 is made of a thermoplastic resin.

In this way, the surface of the package substrate 2 facing the connection member 10 and the surface of the connection member 10 facing the package substrate 2 are reliably connected by the underfill resin 4 as the other sealing resin. it can. Therefore, displacement due to thermal expansion of the package substrate 2 is
The underfill resin 4 can be transmitted to the resin 5 of the connection member 10. Therefore, the wire 7 of the connecting member 10
Stress caused by displacement due to thermal expansion or the like of the package substrate 2 can be prevented from being concentrated on the connection portion between the package substrate 2 and the connection portion (the connection portion between the solder bump 3b and the wire 7).

Here, as a method of manufacturing the connecting member 10, for example, the following method can be used.

First, a base member having a plurality of linear wires 7 embedded in a matrix in a flexible resin 5 is prepared. Next, the flexible resin 5 of the base member is softened by disposing the base member including the flexible resin 5 and the wire 7 in a high-temperature atmosphere. Next, a stress is applied to the base member in the direction of arrow 13 shown in FIG. As a result, the base member is locally plastically deformed, so that the bent portion 11 can be formed in the wire 7 as shown in FIG. Thereafter, the base member is subjected to machining or the like so as to have a predetermined shape as the connection member 10, whereby the connection member 10 as shown in FIG. 2 can be obtained.

Although gold is used as the material of the wire 7 here, other conductive materials, for example, other metals such as aluminum can be used as the material of the wire 7.

The connection member 10 shown in FIG. 2 is a plate-like member made of a flexible resin in which a plurality of metal wires 7 are embedded in a matrix, or a plurality of metal wires 7 The rod-like body solidified with a conductive resin can also be obtained by slicing the rod at a predetermined thickness in the direction in which the wire extends.

The bent portion 11 of the wire 7 may be formed after the wire 7 is buried in the resin 5 as a base as described above. However, after the bent portion 11 is formed in the wire 7 in advance, the bent portion 11 is formed. The wire 7 on which the portion 11 is formed is
May be buried.

(Embodiment 2) FIG. 3 is a schematic sectional view showing Embodiment 2 of a semiconductor device according to the present invention. FIG.
Embodiment 2 of a semiconductor device according to the present invention will be described with reference to FIG.

Referring to FIG. 3, semiconductor device 9 has basically the same structure as the semiconductor device shown in FIGS. However, in the semiconductor device 9 shown in FIG. 3, the underfill resin 4 (see FIG. 1) is not arranged between the connection member 10 and the package substrate 2. Even in this case, the same effects as those of the semiconductor device shown in FIGS. 1 and 2 can be obtained.

Further, in the semiconductor device shown in FIG. 3, since the underfill resin 4 is not disposed as described above, it is not necessary to perform the step of sealing the underfill resin 4 in the manufacturing process of the semiconductor package 12. For this reason, the number of manufacturing steps of the semiconductor package 12 can be reduced.

(Embodiment 3) FIG. 4 is a schematic sectional view showing Embodiment 3 of a semiconductor device according to the present invention. FIG.
Third Embodiment A semiconductor device according to a third embodiment of the present invention will be described with reference to FIG.

Referring to FIG. 4, semiconductor device 9 has basically the same structure as the semiconductor device shown in FIGS. However, in the semiconductor device shown in FIG. 4, the underfill resin 4b is disposed between the package substrate 2 and the connection member 10, and the underfill resin 4a is also provided between the semiconductor chip 1 and the connection member 10. Is arranged. Even in this case, the same effects as those of the semiconductor device shown in FIGS. 1 and 2 can be obtained.

In addition to the underfill resin 4b disposed between the connection member 10 and the package substrate 2, the underfill resin 4b is disposed between the semiconductor chip 1 and the connection member 10.
Since a is disposed, the surface of the semiconductor chip 1 facing the connecting member 10 and the surface of the connecting member 10 facing the semiconductor chip 1 can be reliably connected by the underfill resin 4a as one sealing resin. . Therefore, displacement due to thermal expansion of the semiconductor chip 1 can be transmitted to the resin 5 of the connection member 10 by the underfill resin 4a. Therefore, it is possible to prevent stress caused by displacement due to thermal expansion or the like of the semiconductor chip 1 from being concentrated on a connection portion between the wire 7 of the connection member 10 and the semiconductor chip 1 (a connection portion between the wire 7 and the solder bump 3a). . As a result, it is possible to prevent the connection portion between the wire 7 of the connection member 10 and the semiconductor chip 1 from being damaged by the stress.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the embodiments described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0050]

As described above, in the semiconductor package, since the connection member including the flexible base is arranged between the semiconductor element and the substrate, the horizontal direction applied to the connection portion between the semiconductor element and the substrate is increased. And the stress in the vertical direction can be reduced by this connecting member. As a result, it is possible to obtain a highly reliable semiconductor package having excellent durability against temperature change and a semiconductor device using this semiconductor package.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a semiconductor device according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a connecting member in the semiconductor device shown in FIG.

FIG. 3 is a schematic sectional view showing a second embodiment of a semiconductor device according to the present invention.

FIG. 4 is a schematic sectional view showing a third embodiment of the semiconductor device according to the present invention.

FIG. 5 is a schematic sectional view showing a conventional semiconductor package.

[Explanation of symbols]

1 semiconductor chip, 2 package substrate, 3a, 3b
Solder bump, 4,4a, 4b underfill resin, 5
Resin, 6 solder balls, 7 wires, 8 printed circuit boards, 9 semiconductor devices, 10 connecting members, 11 bent parts,
12 Semiconductor package, 13, 14 Arrow.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Shuichi Tani, 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Masato Iwaoka 2-6-1, Otemachi, Chiyoda-ku, Tokyo F term (reference) in Mitsubishi Electric Engineering Co., Ltd. 5F044 LL11 LL17 RR18 RR19

Claims (6)

[Claims] 1. A substrate, comprising: a semiconductor element disposed on the substrate; and a connection member disposed between the substrate and the semiconductor element, wherein the connection member includes: a flexible base; A semiconductor package including a conductive line embedded in the base and electrically connecting the substrate and the semiconductor element. 2. The semiconductor package according to claim 1, wherein the conductive line extends from one surface of the connection member facing the substrate to the other surface facing the semiconductor element, and has a bent portion. 3. The semiconductor package according to claim 1, further comprising one sealing resin disposed between said semiconductor element and said connection member. 4. The semiconductor package according to claim 1, further comprising a second sealing resin disposed between said substrate and said connection member. 5. The semiconductor device according to claim 1, further comprising: a first bump for electrically connecting the semiconductor element to the conductive line of the connection member; and a second bump for electrically connecting the substrate to the conductive line of the connection member. The semiconductor package according to any one of claims 1 to 4. 6. A semiconductor device comprising the semiconductor package according to claim 1.