JPH1154564A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deform a sealing member in response to the deformation of an adhesive member and to prevent an interface of the adhesive member and the sealing member from being stripped, by using soft material whose elastic modulus is equal to or smaller than that of the adhesive member for the sealing member for covering the electrode-forming surface, the side of the adhesive member and the side of a sheet-like member of a semiconductor device. SOLUTION: An electrode 2 of a semiconductor device 1 is formed on the outer peripheral part of an electrode-forming surface la of the semiconductor device 1, and an adhesive member 3 is not provided in the region where the electrode 2 is formed. The part where the electrode 2 of the semiconductor device 1 is formed is sealed with a sealing member 7 made of soft material such that the sealing member 7 covers the electrode-forming surface la of the semiconductor device 1, the side 3a of the adhesive member 3 and the side 4a of a sheet-like member. The sealing member 7 is made of material whose Young' s modulus is equal to or smaller than that of the adhesive member 3. Therefore, when the semiconductor device is heated and cooled, the sealing member 7 is deformed in response to the thermal deformation of the adhesive member 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device using a sheet-like member provided with a conductive member for electrically connecting an electrode of a semiconductor element to an external terminal. And a small-sized semiconductor device in which the external dimensions of the package are very close to the external dimensions of the semiconductor element.

[0002]

2. Description of the Related Art In order to cope with high-density mounting of a semiconductor device, a sheet-like member in which conductive leads are formed on a base material made of an insulating tape or film, which is easy to increase the number of pins and reduce the pitch of external terminals. Semiconductor devices using TAB (Tape Automated Bonding) technology for electrically connecting electrodes of a semiconductor element to external terminals for connection to a mounting substrate using the same have been developed. Examples of these are disclosed in JP-A-8-31866, JP-A-8-88243, JP-A-8-88245, and JP-A-8-31869.

[0003] These conventional semiconductor devices include a semiconductor element having electrodes formed thereon, a sheet-like member having conductive leads formed on a film substrate, and at least an electrode-forming surface of the semiconductor element and an electrode exposed from the film substrate. And an external terminal. The electrode of the semiconductor element is arranged on the periphery of the surface of the semiconductor element, and the sheet-shaped member is located outside the electrode of the semiconductor element, and one end of the conductive lead is connected to the electrode. An external terminal made of a spherical solder is provided at the other end of the conductive lead. Since the external terminals are provided outside the electrode forming surface of the semiconductor element, the package size of the semiconductor device is larger than the size of the semiconductor element.

On the other hand, in order to reduce the size of a device on which a semiconductor device is mounted, there is a remarkable tendency to make the package size of the semiconductor device closer to the size of a semiconductor element. These packages are generally called CSP (abbreviation for chip size package or chip scale package). C using TAB technology using a sheet-like member with conductive leads formed on the above-mentioned film substrate
As examples of SP, Japanese Patent Publication No. Hei 6-504408, Japanese Patent Laid-Open No. 7-29
7236 and JP-A-8-8296.

In these conventional semiconductor devices, a sheet-like member in which conductive leads are formed on a film substrate is adhered to the surface of a semiconductor element by an adhesive member, and external terminals are disposed within the electrode forming surface of the semiconductor element. Is provided,
The package size is almost equal to the size of the semiconductor element.

[0006]

In the prior art of the CSP in which the external terminals are arranged in the plane of the semiconductor element, the external terminals are connected to a printed circuit board by using metal bumps such as solder. The problem with the CSP having such a structure is the connection reliability of the solder bumps. The linear expansion coefficient of a semiconductor element (silicon (Si)) is about 3 × 10 ⁻⁶ / ° C., and the linear expansion coefficient of the most commonly used glass epoxy resin-based printed circuit board (such as FR-4) is It is about 17 × 10 ⁻⁶ / ° C. As described above, when the linear expansion coefficients of the two devices are largely different from each other, when a temperature change is applied to the semiconductor device, the solder bumps are distorted, and the solder bumps may be thermally fatigue-ruptured by repeating this.

A conventional semiconductor device which is considered most with respect to thermal fatigue failure of solder bumps and which is considered to have high reliability is the semiconductor device described in Japanese Patent Publication No. Hei 6-504408. In this semiconductor device, a sheet-like member is bonded to an electrode forming surface of a semiconductor element via an adhesive member made of a flexible material (elastomer resin: a polymer substance having rubber-like elasticity at room temperature). The same material is used for the sealing member. For this reason, the difference in linear expansion coefficient between the semiconductor element and the printed circuit board is absorbed by the adhesive member, which is a flexible elastomer resin, and as a result, thermal strain applied to the solder bumps is reduced.

However, in the semiconductor device having the conventional structure, since the conductive resin formed on the sheet-like member is deformed by the elastomer resin, the lead itself or the joint between the lead and the electrode of the semiconductor element is distorted. There is a problem that the repetition of this causes fatigue breakage of the lead or the lead joint. That is, in the above prior art, the fatigue failure of the lead portion is not considered,
Even if the reliability of the solder bumps is sufficient, the lead portion is likely to be fatigue-ruptured, and eventually, the reliability of the semiconductor device is significantly reduced.

In the semiconductor device described in Japanese Patent Application Laid-Open No. 8-8296, almost the entire surface of the semiconductor element except for the electrode portion on the electrode forming surface is sealed with a sealing resin. Usually, a liquid resin (potting resin) mainly composed of an epoxy resin is used for the sealing member, and the resin has a longitudinal elastic modulus of about 7000 MPa to 10,000 MPa. In this semiconductor device, since the periphery of the external terminal is covered with a sealing resin having a large elastic coefficient, the sealing resin cannot absorb a difference in linear expansion coefficient between the semiconductor element and the printed circuit board. There is a problem that thermal strain occurs and thermal fatigue fracture occurs.

[0010] In the semiconductor device described in Japanese Patent Application Laid-Open No. 7-297236, the electrodes of the semiconductor element are provided on the periphery of the surface of the semiconductor element. Although the sealing of the electrode portion is not disclosed in this conventional technique, a material having a large longitudinal elastic modulus is used for the sealing member as described above. Further, in order to improve the thermal fatigue life of the solder bumps, it is conceivable to use an elastomer resin as an adhesive member for adhering the sheet-shaped member to the surface of the semiconductor element as disclosed in Japanese Patent Application Laid-Open No. 6-504408. In general, an elastomer resin has a small coefficient of longitudinal elasticity, but has a large coefficient of linear expansion. When a semiconductor device having such a configuration receives a temperature change, the amount of shrinkage of an adhesive member using an elastomer resin having a large linear expansion coefficient increases in a cooling process, but the semiconductor device is disposed around a semiconductor element. Since the sealing member has a longer modulus of elasticity than that of the elastomer resin, it cannot follow the deformation of the elastomer resin. as a result,
A large strain is generated at the interface between the adhesive member and the sealing member, and peeling occurs at the interface between the two. The occurrence of interface delamination increases the possibility of causing problems such as corrosion of the conductive leads, corrosion of the electrodes due to intrusion of moisture into the semiconductor element surface, or disconnection of the conductive leads protruding from the sheet-like member.

A CSP type semiconductor device to which the TAB technology is applied has a configuration in which a sheet-like member, an adhesive member for bonding the sheet-like member, and a sealing member are provided on the electrode forming surface of the semiconductor device. Since the sheet-shaped member, the adhesive member, and the sealing member have larger linear expansion coefficients than the linear expansion coefficient of the semiconductor element, in the semiconductor device having such a configuration, warpage due to a difference in linear expansion coefficient due to a temperature change is caused. Will occur. When a material having a low elastic coefficient is used for the adhesive member and the sealing member as in the semiconductor device described in Japanese Patent Publication No. 6-504408, the difference in linear expansion coefficient is absorbed by deformation of the adhesive member itself. Therefore, occurrence of warpage can be suppressed. However, if the peripheral portion of the semiconductor element is covered with a sealing member having a large elastic coefficient, the difference in linear expansion coefficient cannot be sufficiently absorbed, and the occurrence of warpage cannot be suppressed. For this reason, a large stress is generated at the end of the electrode forming surface of the semiconductor element, and there is a problem that the semiconductor element is cracked from this part.

As described above, in the CSP type semiconductor device to which the conventional TAB technology is applied, the fatigue failure of the solder bumps or the conductive leads as the external terminals occurs, the interface between the adhesive member and the sealing member is separated, or the semiconductor is removed. One of the problems of cracking of the element occurred, and sufficient reliability could not be obtained as a whole.

An object of the present invention is to overcome the problems of the conventional CSP type semiconductor device and provide a highly reliable CSP type semiconductor device.

[0014]

The present invention employs the following means in order to achieve the above object.

(1) A feature of the invention of the present application is that a semiconductor element having a plurality of surfaces and having an electrode on at least one peripheral portion thereof, an external terminal, and electrically connecting the electrode and the external terminal. A sheet-like member having a conductive member, an adhesive member for adhering the sheet-like member to the surface of the semiconductor element, and an elastic coefficient equal to or less than an elastic coefficient of the adhesive member, and an electrode portion on the surface of the semiconductor element. The semiconductor device is constituted by a sealing member made of a flexible material for sealing the electrode forming surface of the semiconductor element and the end surface of the adhesive member and the end surface of the sheet-shaped member.

In the present invention, a flexible material having an elastic coefficient equal to or smaller than that of the adhesive member is used for a sealing member covering the electrode forming surface of the semiconductor element, the adhesive member end surface, and the sheet-like member end surface. Deformation of the adhesive member can be followed, and peeling at the interface between the adhesive member and the sealing member can be prevented. Further, the heat shrinkage of the adhesive member and the sealing member can be absorbed by the deformation of the sealing member itself.

The longitudinal elastic modulus at room temperature of the adhesive member used in the present invention is desirably 70 MPa or more and 4000 MPa or less. Thereby, the reliability of the solder bumps serving as the external terminals and the conductive leads formed on the sheet-like member can be ensured.

As described above, when a material having a low elastic modulus such as an elastomer resin is used for the adhesive member, the strain generated in the conductive leads formed on the sheet-like member increases, and the possibility of fatigue fracture increases. I do. FIG. 9 shows the result of calculating the life generated from the fatigue strength data of the conductive lead material by calculating the strain generated in the conductive lead when the semiconductor device is subjected to a temperature change by changing the longitudinal elastic modulus of the adhesive member at room temperature. It is. The size of the semiconductor element of the simulated semiconductor device is 6.6 × 9.0 ×
0.28 mm, and the thickness of the adhesive member is 150 μm. Copper (Cu) is used as the conductive lead material. A temperature cycle test (125 ° C. and −55 ° C.) of a package using a material (silicone resin) having the smallest longitudinal elastic modulus as an adhesive member.
(Repetition of ° C.), the conductive lead was disconnected between 500 and 1500 times. In the above temperature cycle test, if a life of at least 1,000 times can be ensured, no reliability problem occurs in the actual machine. However, since it is necessary to consider variations in strength and the like, it is necessary to have a life of 2,000 times on average, and it can be seen from the results of FIG. 9 that this can be achieved by setting the longitudinal elastic modulus of the adhesive member to 70 MPa or more. .

On the other hand, when the elastic coefficient of the adhesive member is increased, the strain generated in the solder bumps serving as the external terminals increases, causing a problem that the reliability of the solder bumps is impaired. FIG. 10 shows the results of calculating the life from the fatigue strength data of the solder material by obtaining the strain generated in the solder bump by simulation while changing the longitudinal elastic modulus of the adhesive member at room temperature. The simulation in FIG. 10 is a result in the case where a spherical solder having a diameter of 0.3 mm is used for the solder bumps serving as the external terminals. As described above, in order to secure a life of 2,000 times in consideration of variations in strength, etc.,
It is understood that the longitudinal elastic modulus of the adhesive member needs to be 4000 MPa or less.

As described above, by setting the longitudinal elastic modulus of the adhesive member used in the present invention to be 70 MPa or more and 4000 MPa or less, the generated strain can be balanced between the solder bumps serving as external terminals and the conductive leads formed on the sheet member. Because of the sharing, destruction can be prevented in an actual use environment, and sufficient reliability can be secured.

It is desirable to use an elastomer resin for the sealing member made of the flexible material of the present invention. Further, by setting the longitudinal elastic modulus of the elastomer resin to 10 MPa or less, sufficient reliability can be secured. Become.

In a structure in which an electrode is provided around the semiconductor element as in the semiconductor device according to the present invention and the sealing member covers only the electrode forming surface of the semiconductor element, if the material used for the sealing member has a large elastic modulus, A large stress is generated at the end of the semiconductor element. FIG. 11 shows the results obtained by changing the longitudinal elastic modulus at room temperature of the sealing member and calculating the stress generated at the upper end of the semiconductor element by simulation. As a result of the evaluation by the inventors' experiments, a result was obtained in which the stress at the upper end portion of the semiconductor element shown in FIG. 11 was 40 MPa or less and the semiconductor element did not crack. Therefore, the longitudinal elastic modulus of the sealing member is 10MP.
By setting a or less, cracking of the semiconductor element can be prevented.

Further, it is desirable that the conductive member formed on the sheet member used in the present invention comprises a wiring pattern provided on the surface of the sheet member and leads connected to the wiring pattern protruding from the sheet member. With such a configuration, the TAB technology conventionally used can be applied as it is.

Furthermore, by forming the adhesive member of the present invention from a tape-like base material made of polyimide resin or the like and having an adhesive formed on the surface thereof, the conventional TAB technology can be used and the manufacturing process suitable for mass production The action which can construct is produced.

(2) Another feature of the invention of the present application is that a semiconductor element having a plurality of surfaces and having an electrode on at least one peripheral portion of the surface, an external terminal, and electrically connecting the electrode and the external terminal are provided. A sheet-shaped member having a conductive member to be connected, an adhesive member for adhering the sheet-shaped member to the surface of the semiconductor element,
An elastic coefficient equal to or less than the elastic coefficient of the adhesive member, and an electrode portion on the surface of the semiconductor element,
The semiconductor device is constituted by a sealing member for sealing the electrode forming surface of the semiconductor element, the side face of the semiconductor element, the end face of the adhesive member and the end face of the sheet-shaped member.

In the present invention, by using a material having an elastic coefficient equal to or less than that of the adhesive member for the sealing member, the sealing member can follow the deformation of the adhesive member. Delamination of the interface between members can be prevented.

Further, the sealing member covers the electrode forming surface of the semiconductor element, the side face of the semiconductor element adjacent thereto, the end face of the adhesive member and the end face of the sheet-like member, thereby reducing the stress generated at the upper end of the semiconductor element. Is obtained.

This is because the sealing member covers not only the electrode forming surface of the semiconductor element but also the side face of the semiconductor element adjacent thereto, so that the stress generated in the semiconductor element is borne over a wide area, and the upper end of the element is exposed to the stress. This is because the generated stress is reduced.

The longitudinal elastic modulus of the adhesive member used in the present invention is 7
It is desirable that the pressure be 0 MPa or more and 4000 MPa or less.
As a result, the generated strain is distributed in a well-balanced manner between the solder bumps serving as the external terminals and the conductive leads formed on the sheet-shaped member, so that destruction can be prevented in an actual use environment and sufficient reliability can be secured.

Further, it is desirable that the conductive member formed on the sheet member used in the present invention comprises a wiring pattern provided on the surface of the sheet member and leads protruding from the sheet member. With such a configuration, the conventionally used TAB technology can be applied as it is.

Further, by constituting the adhesive member of the present invention with a member in which an adhesive is formed on the surface of a tape-shaped base material, an effect that a manufacturing process suitable for mass production can be established.

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment of a semiconductor device according to the present invention, and FIG. 2 is a state in which a part of a sheet-like member and a sealing member of the semiconductor device shown in FIG. 1 have been removed. FIG.

In the figure, a sheet-like member 4 is provided on a surface 1a of the semiconductor element 1 on which an electrode 2 is formed by an adhesive member 3, and the surface of the sheet-like member 4 is made of copper.
(Cu) foil or gold (Au), nickel (N
A patterned lead 5 made of copper foil plated with i) and the like, and a lead 6 connected to the patterned lead 5 and protruding from the sheet-like member 4 are provided. The pattern-like lead 5 is fixed to the sheet-like member 4 by, for example, an adhesive (not shown). The electrode 2 of the semiconductor element 1 is provided on the outer peripheral portion of the electrode forming surface 1a of the semiconductor element, and the adhesive member 3 is not provided in a region where the electrode 2 is formed. The portion of the semiconductor element 1 where the electrode 2 is formed is sealed by a sealing member 7 made of a flexible material so as to cover the semiconductor element electrode forming surface 1a, the adhesive member side surface 3a, and the sheet-like member side surface 4a.

The end 6a of the lead 6 and the electrode 2 are joined by a method such as thermocompression bonding, and the lead 6 and the semiconductor element 1 are electrically connected. The pattern-like lead 5 on the surface of the sheet-like member 4 connected to the lead 6 is disposed up to the portion directly below the external terminal 8 and becomes a land 5a, and the land 5a and the external terminal 8 are joined inside the hole 9 formed in the sheet-like member. doing. For the external terminals 8 formed of metal bumps, solder (for example, Pb-Sn-based eutectic solder) widely used for mounting surface-mount type semiconductor devices is used. The sheet member 4 is formed of a tape or a film member made of a polyimide resin or the like. The sealing member 7 is made of a flexible material having a small elastic coefficient, and a material having a longitudinal elastic coefficient equal to or smaller than the longitudinal elastic coefficient of the adhesive member 3 is used.

According to the semiconductor device of this embodiment, the sealing member deforms following the thermal deformation of the adhesive member during cooling when the semiconductor device receives a temperature change. The stress generated at the interface with the sealing member is reduced, and the occurrence of interface delamination can be prevented. Also,
Since the sealing member is formed of a flexible material, thermal deformation of the adhesive member and the sealing member can be absorbed by deformation of the sealing member itself, and large stress does not occur at the upper end of the semiconductor element.

By using an elastomer resin for the sealing member 7, an effect of reducing the stress generated at the upper end of the semiconductor element of the semiconductor device can be obtained. The elastic modulus of the elastomer resin is
About 0.1 MPa to 50 MPa, silicone rubber,
There are materials such as styrene butadiene rubber and butyl rubber.
In particular, by setting the longitudinal elastic modulus of the elastomer resin used for the sealing member 7 to 10 MPa or less, the reliability of the semiconductor device can be further improved.

As the material of the adhesive member 3, it is desirable to use a material having a longitudinal elastic modulus at room temperature of 70 MPa or more and 4000 MPa or less. As a result, it is possible to optimize the distortion generated in each of the external terminals 8 and the leads 6 made of solder bumps or the like.

The adhesive member 3 is made of a material having a single-layer structure made of a single material, or a material having a three-layer structure or a layer structure having a tape-shaped base material on which an adhesive material is formed.
Epoxy resin, ethoxy +
Polyimide resin, resin composed of epoxy resin and acrylic rubber, acrylic resin, porous polytetrafluoroethylene, silicone resin and the like are used. The adhesive member 3 having a single-layer structure may be formed on the surface of the sheet-like member 3 by a screen printing method, a potting method or a sticking method, or may be formed on the surface of the semiconductor element 1.

The adhesive member 3 having a three-layer structure is composed of a tape-shaped base material made of a polyimide resin, and the above-mentioned material having the single-layer structure formed as an adhesive.
FIG. 3 shows an example of a semiconductor device using the adhesive member 3 having a three-layer structure. In FIG. 3, the adhesive member 3 has a configuration in which an adhesive 31 is formed on a surface of a tape or film-like base material 30 made of a polyimide resin or the like on the semiconductor element 1 side and the sheet-like member 4 side. By using a member in which an adhesive is formed on the surface of a tape-like base material as an adhesive member, a semiconductor device can be manufactured using multiple members in which a plurality of adhesive members are connected, contributing to improvement in mass productivity. Can be.

The semiconductor device according to the present invention shown in FIG.
The printed circuit board is mounted with the surfaces in the direction in which the external terminals 8 are joined facing each other.

In the semiconductor device shown in FIGS. 1 and 2, an example is shown in which a part of the external terminal 8 is inserted into the hole 9 formed in the sheet member 4 and the pattern lead 5 is connected to the external terminal 8. FIG. 4 is a cross-sectional view of a semiconductor device according to the present invention showing another embodiment of the sheet-like member 4.

In the figure, a sheet-like member 4 is provided on a surface 1a of the semiconductor element 1 on which an electrode 2 is formed by an adhesive member 3, and a pattern-like lead 5 is provided on the surface of the sheet-like member 4. A lead 6 connected to the pattern lead 5 and protruding from the sheet-like member 4 is provided. The electrode 2 of the semiconductor element 1 is provided on the outer peripheral portion of the electrode forming surface 1a of the semiconductor element, and the adhesive member 3 is not provided in a region where the electrode 2 is formed. A portion where the electrode 2 of the semiconductor element 1 is formed is sealed by a sealing member 7 made of a flexible material so as to cover the electrode forming surface 1a, the adhesive member side surface 3a, and the sheet-like member side surface 4a of the semiconductor element.

The end 6a of the lead 6 and the electrode 2 are joined by a method such as thermocompression bonding, and the lead 6 and the semiconductor element 1 are electrically connected. The pattern-like lead 5 on the surface of the sheet-like member 4 connected to the lead 6 is disposed up to the portion immediately below the external terminal 8 and forms a land 5a, which is joined to the external terminal 8, and the surface of the sheet-like member excluding the external terminal joint. Is provided with a solder resist 10. The sealing member 7 is formed so as to cover the solder resist side surface 10a.

The sealing member 7 is made of a flexible material having a small elastic coefficient, and is made of a material having a longitudinal elastic coefficient equal to or smaller than that of the adhesive member 3.

Also in the present embodiment, the sealing member follows the thermal deformation of the adhesive member and deforms when the semiconductor device is cooled in response to a temperature change. The stress generated at the interface is reduced, and the occurrence of interface delamination can be prevented. In addition, since the sealing member is formed of a flexible material, thermal deformation of the adhesive member and the sealing member can be absorbed by deformation of the sealing member itself, and large stress does not occur at the upper end of the semiconductor element. Further, in the structure of FIG. 4, since a sheet-like member made of polyimide resin or the like is interposed between the external terminal and the semiconductor element in addition to the adhesive member, a difference in linear expansion coefficient between the semiconductor element and the mounting board results. The effect that the distortion generated in the external terminal is further reduced is obtained.

In the embodiment shown in FIGS. 1 and 2, an example is shown in which the electrode 2 of the semiconductor element 1 is formed on two opposing sides of the outer surface of the semiconductor element surface. The electrode 2 may be formed on one side of the outer peripheral portion, or may be formed on three sides or in FIG.
It may be formed on four sides as shown in FIG.

FIGS. 6 and 7 show a second embodiment of the semiconductor device according to the present invention. FIG. 6 is a sectional view and FIG. 7 is a plan view of the semiconductor device shown in FIG.

In the figure, a sheet-like member 4 is provided by an adhesive member 3 on the surface 1a of the semiconductor element 1 on which the electrode 2 is formed.
(Cu) foil or gold (Au), nickel (N
A patterned lead 5 made of copper foil plated with i) and the like, and a lead 6 connected to the patterned lead 5 and protruding from the sheet-like member 4 are provided. The pattern lead 5 is fixed to the sheet member by, for example, an adhesive (not shown). The electrode 2 of the semiconductor element 1 is provided on the outer peripheral portion of the electrode forming surface 1a of the semiconductor element, and the adhesive member 3 is not provided in a region where the electrode 2 is formed.

The portion where the electrode 2 of the semiconductor element 1 is formed includes the electrode forming surface 1a of the semiconductor element, the side face 1b of the semiconductor element adjacent thereto, the adhesive member side face 3a, and the sheet-shaped member side face 4a
Is sealed by the sealing member 7 so as to cover The sealing member 7 is made of a material having a longitudinal elastic modulus equal to or smaller than that of the adhesive member 3. The end 6a of the lead 6 and the electrode 2 are joined by a method such as thermocompression bonding, and the lead 6 and the semiconductor element 1 are electrically connected.

The pattern-like leads 5 on the surface of the sheet-like member 4 connected to the leads 6 are arranged up to the portion directly below the external terminals 8 to form lands 5a, and the holes 9 formed in the sheet-like member are formed.
The lands 5a and the external terminals 8 are joined inside.
The external terminals 8 composed of metal bumps are connected to solder (for example, Pb
-Sn-based eutectic solder). The sheet member 4 is formed of a tape or a film member made of a polyimide resin or the like.

According to the semiconductor device of the present embodiment, the sealing member deforms following the thermal deformation of the adhesive member during cooling when the semiconductor device receives a temperature change. The stress generated at the interface with the sealing member is reduced, and the occurrence of interface delamination can be prevented. Also,
Since the sealing member covers not only the electrode forming surface of the semiconductor element but also the side surface of the semiconductor element adjacent thereto, the stress generated on the surface of the semiconductor element due to the thermal deformation of the bonding member and the sealing member is borne by a large area. As a result, no large stress is generated at the upper end of the semiconductor element.

It is desirable to use a material having a longitudinal elastic modulus at room temperature of 70 MPa or more and 4000 MPa or less as the material of the adhesive member 3. As a result, it is possible to optimize the distortion generated in each of the external terminals 8 and the leads 6 made of solder bumps or the like.

As the adhesive member 3, a material having a single-layer structure made of one material, or a material having a three-layer structure in which an adhesive material is formed on a tape-shaped base material surface or a material having a layer structure of more than three layers is used. As a material having a single-layer structure, epoxy resin, epoxy + polyimide resin, resin composed of epoxy resin and acrylic rubber, acrylic resin, porous polytetrafluoroethylene, silicone resin and the like are used.
The adhesive member 3 having a single-layer structure may be formed on the surface of the sheet-like member 3 by a screen printing method, a potting method or a sticking method, or may be formed on the surface of the semiconductor element 1. The adhesive member 3 having a three-layer structure is composed of a member in which the above-described material having the single-layer structure is formed as an adhesive on a tape-shaped base material made of a polyimide resin.

By using a member in which an adhesive is formed on the surface of a tape-like base material as an adhesive member, a semiconductor device can be manufactured using multiple members in which a plurality of adhesive members are connected, and mass productivity can be improved. Can contribute.

FIG. 8 is a sectional view showing another embodiment of the second embodiment of the semiconductor device according to the present invention shown in FIG.

In the figure, a sealing member 7 is formed so as to cover the electrode forming surface 1a of the semiconductor device, the side surface 1b of the semiconductor device adjacent thereto, the side surface 3a of the adhesive member, the side surface 4a of the sheet member, and the back surface 1c of the semiconductor device. ing. With such a configuration, the stress generated on the surface of the semiconductor element due to the thermal deformation of the bonding member and the sealing member is borne by a large area, and a large stress is not generated at the upper end of the semiconductor element. Further, by providing the sealing member also on the back surface of the semiconductor element, the amount of deformation of each of the constituent members on the electrode forming surface side and the back surface side of the semiconductor element can be made substantially equal, and the effect of reducing the deformation of the semiconductor device can be reduced. Is obtained.

[0058]

As described above, according to the present invention, the following effects can be obtained, and a highly reliable CSP type semiconductor device can be provided.

(1) Distortion generated due to a difference in linear expansion coefficient between the semiconductor element and the mounting board can be shared by the external terminal formed of metal bumps and the adhesive member in a well-balanced manner, and is generated in both the external terminal and the conductive lead. Distortion can be reduced, and reliability can be improved.

(2) Since the sealing member can follow the deformation of the adhesive member for bonding the sheet-like member on which the conductive leads are formed to the semiconductor element, the peeling of the interface between the adhesive member and the sealing member occurs. Disconnection of the conductive leads or reduction in the moisture resistance of the semiconductor element can be prevented, and the reliability of the semiconductor device can be improved.

(3) By forming the sealing member from a flexible material, the stress generated at the upper end of the semiconductor element can be reduced and the semiconductor element can be prevented from cracking, so that the reliability of the semiconductor device can be improved. it can.

(4) By forming the sealing member so as to cover the electrode forming surface of the semiconductor element and the side face of the semiconductor element adjacent thereto, the stress generated at the upper end of the semiconductor element is reduced, and the semiconductor element is prevented from cracking. Therefore, the reliability of the semiconductor device can be improved.

[Brief description of the drawings]

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

FIG. 2 is a plan view of the first embodiment shown in FIG. 1 with a part of a sheet-like member and a sealing member removed.

FIG. 3 is a sectional view showing another aspect of the first embodiment shown in FIG. 1;

FIG. 4 is a sectional view showing still another mode of the first embodiment shown in FIG. 1;

FIG. 5 is a plan view showing an example in which electrodes are formed on four sides of an outer peripheral portion of a semiconductor element.

FIG. 6 is a sectional view showing a second embodiment of the semiconductor device according to the present invention.

FIG. 7 is a plan view of the second embodiment shown in FIG. 6 with a part of the sealing member removed;

FIG. 8 is a sectional view showing another aspect of the second embodiment shown in FIG.

FIG. 9 is a diagram illustrating an analysis of a relationship between a longitudinal elastic modulus of an adhesive member and a breaking life of a conductive lead.

FIG. 10 is a diagram illustrating an analysis of a relationship between a longitudinal elastic modulus of an adhesive member and a breaking life of a solder bump serving as an external terminal.

FIG. 11 is a diagram in which a relationship between a longitudinal elastic coefficient of a sealing member and a stress at an upper end portion of the semiconductor element is analyzed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor element, 1a ... Electrode formation surface of a semiconductor element, 1b
... Semiconductor device side surface, 1c ... Semiconductor device back surface, 2 ... Electrode,
3 ... Adhesive member, 3a ... Adhesive member side surface, 4 ... Sheet member, 4a ... Sheet member side surface, 5 ... Pattern lead,
6 lead, 7 sealing member, 8 external terminal, 9 sheet member hole, 10 solder resist.

Continued on front page (72) Inventor Ichiro Yasuo 5-2-1, Josuihonmachi, Kodaira-shi, Tokyo Inside Semiconductor Division, Hitachi, Ltd. (72) Asao Nishimura 5--20, Josuihoncho, Kodaira-shi, Tokyo No. 1 In the Semiconductor Division, Hitachi, Ltd.

Claims (1)

[Claims] 1. A sheet-like member comprising: a semiconductor element having a plurality of surfaces and having an electrode on at least one peripheral portion of the surface; an external terminal; and a conductive member for electrically connecting the electrode and the external terminal. And an adhesive member for adhering the sheet-shaped member to the surface of the semiconductor element, an elastic coefficient equal to or less than the elastic coefficient of the adhesive member, and an electrode portion on the surface of the semiconductor element, A semiconductor device including a sealing member made of a flexible material for sealing an electrode forming surface and an end surface of the adhesive member and an end surface of the sheet-shaped member.