JP3321357B2 - Semiconductor device and method of assembling the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a ball grid array (BGA) package type semiconductor device.

[0002]

2. Description of the Related Art FIGS. 11A and 11B show a conventional BGA package. FIG. 11A is a plan view, and FIG.
FIG. 3C is a cross-sectional view taken along a line cc in FIG.

As shown in FIGS. 11 (a) to 11 (c), TA
The stiffener 2 for keeping the flatness of the B tape 1 is TA
It is adhered to the surface of the B tape 1 using an adhesive. In the figure, a layer indicated by reference numeral 3 is an adhesive layer. The stiffener 2 is provided with a rectangular opening 4. The semiconductor integrated circuit chip 5 is disposed in the opening 4. The chip 5 is electrically connected to the lead 6 provided on the TAB tape 1 in the opening 4. The connection status is
It is a so-called face-down type. A square cover plate 7 is adhered to the stiffener 2 using an adhesive. In the figure, a layer indicated by reference numeral 8 is an adhesive layer.
The cover plate 7 is adhered to the entire surface of the stiffener 2. Further, the cover plate 7 is bonded to the chip 5 using an adhesive. The chip 5 is thermally bonded to the cover plate 7 by bonding the chip 5 to the cover plate 7. The cover plate 7 functions as a heat radiating plate for releasing heat generated by the chip 5 to the outside when the chip 5 is operating. On the back surface of the TAB tape 1, a plurality of solder balls 9 are formed.
The solder balls 9 are electrically connected to the leads 6 in the TAB tape 1 and function as external terminals of the chip 5. A member indicated by reference numeral 10 is a potting resin for shielding an electrical connection between the chip 5 and the TAB tape 1 from the outside.

[0004]

In a conventional BGA package, when the package is mounted on a mounting board and subjected to a temperature cycle test, the linear expansion coefficients of the mounting board and the cover plate 7 are different from each other. Stress may be applied, and cracks may be formed in the solder balls 9.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a semiconductor device of a BGA package type having a heat radiating member which can suppress generation of cracks due to heat in solder balls. It is an object of the present invention to provide an apparatus and an assembling method thereof.

[0006]

To achieve the above object, according to the solution to ## in the invention according to claim 1, the chip carrier having a ball-shaped electrodes is electrically connected to the chip carrier, the ball-shaped electrodes A semiconductor integrated circuit chip having an external terminal, connected to the chip carrier, a flattening member for maintaining the flatness of the chip carrier,
A heat radiating member bonded to the flattening member and thermally coupled to the semiconductor integrated circuit chip for releasing heat generated from the semiconductor integrated circuit chip; And an adhesive surface between the heat dissipating member and the flattening member.
The heat-dissipating member and the flatness
Provided on one of the forming members, and
It is characterized by being partially adhered to the supporting member . By partially adhering the heat radiating member to the flattening member in this manner, the force generated when the heat radiating member expands and contracts can be hardly transmitted to the flattening member. Thereby, the deformation of the flattening member that is pulled by the heat radiating member can be suppressed, the stress generated inside the ball-shaped electrode is reduced, and the generation of cracks due to heat in the ball-shaped electrode can be suppressed. In addition, the adhesive projections are
By providing the adhesive on one of the support members, the adhesive can be released.
It is possible to assemble by applying to the entire adhesive side of the heat member.
You. This simplifies assembly and reduces manufacturing costs.
Reduction can be achieved.

Further, in the invention according to claim 4, the flattening member has an opening for accommodating the semiconductor integrated circuit chip, and the heat radiating member is provided around the opening of the flattening member. And the edge of the heat radiation member is opened. Since the heat dissipating member is bonded only around the opening of the flattening member and the edge of the heat dissipating member is opened in this manner, the deformation of the flattening member that is pulled by the heat dissipating member can be further suppressed. This further enhances the effect of suppressing the generation of cracks due to heat in the ball-shaped electrode.

Further, in the invention according to claim 5, the bonding portion between the heat radiating member and the flattening member is provided at a position equidistant from the center of heat generation. By providing the bonding portion at a position equidistant from the center of heat generation, a force when the heat radiating member expands can be evenly applied to the bonding portion. If the force is evenly applied to the bonding portion, the balance of the force applied to the flattening member via the bonding portion is improved.
If the force applied to the flattening member is unbalanced,
Unpredictable forces can act on the planarizing member. When an unpredictable force acts on the flattening member, the ball-shaped electrode may be cracked. Such a possibility is eliminated by providing the bonding portion at a position equidistant from the heat generation center.

According to a sixth aspect of the present invention, the bonding portion between the heat radiating member and the flattening member is dispersed around the opening. In this way, the adhesive part
By dispersing around the opening, the force of the heat dissipating member to expand can be released to some extent around each of the dispersed adhesive portions. Thereby, the deformation of the flattening member as pulled by the heat radiating member is further suppressed,
The effect of suppressing generation of cracks due to heat in the ball-shaped electrode is further enhanced.

[0010] Further, in the invention according to claim 7, the dispersed adhesive portions are provided at positions that satisfy point-symmetric and line-symmetric conditions from the center of heat generation. By providing each of the dispersed adhesive portions at a position that satisfies the symmetrical and symmetrical conditions from the heat generation center, the force when the heat radiation member expands is applied to each of the dispersed adhesive portions. Can be applied evenly, and the balance of the force applied to the flattening member via each of the dispersed adhesive portions is improved. Thereby, the possibility that cracks occur in the ball-shaped electrode due to the imbalance of the force applied to the flattening member is eliminated.

[0011]

Further, in the invention according to claim 8 , the heat dissipating member is deformed in a direction perpendicular to the flattening member in a state where the heat dissipating member is freely deformable in a direction horizontal to the flattening member. A deformation suppressing projection is further provided on one of the heat dissipation member and the flattening member. Thus the deformation-suppressing protrusions, the one of the heat radiating member and the flattening member, that further provided, the heat radiating member, suppress <br/> deformation in the direction perpendicular to the flattening member can do. Moreover, since the deformation in the horizontal direction with respect to the flattening member is free, the force generated when the heat radiating member expands and contracts can be absorbed by sliding. With this, the deformation suppressing protrusions transmit the force when the heat radiation member is prolonged and contracted to the flattening member while suppressing deformation of the ear heat member in a direction perpendicular to the flattening member. There is no. When the heat dissipating member is excessively deformed, the user may visually feel uneasy, but such anxiety is also eliminated.

Further, in the invention according to claim 9 , the deformation suppressing projection has an adhesion surface between the heat radiating member and the flattening member which is smaller than an adhesion surface of the adhesion projection.
The bonding of the deformation suppressing protrusions on the bonding surface is released when the heat radiating member is deformed in a direction horizontal to the flattening member, and after the bonding is released, the flattening of the heat radiating member is performed. It is characterized in that the member can be freely deformed in a horizontal direction. In this way, the bonding of the deformation suppressing protrusions on the bonding surface is released when the heat radiating member is deformed in the horizontal direction with respect to the flattening member, and after releasing the bonding, the heat radiating member is bonded to the flattening member. In this case, the deformation in the horizontal direction can be freely performed, so that the assembly can be performed by applying the adhesive to the entire bonding side of the heat dissipating member even if it has the deformation suppressing protrusion. Further, before the heat dissipating member is deformed in the horizontal direction with respect to the flattening member, the deformation suppressing protrusion is bonded to the flattening member, so that the adhesive strength between the heat dissipating member and the flattening member is high. . When the bonding strength is high, even if the heat radiation member is picked up,
The possibility that a delicate electrical connection point between the chip carrier and the semiconductor integrated circuit chip is broken is small.

According to another aspect of the present invention, there is provided a chip carrier having a ball-shaped electrode group, and the ball carrier is electrically connected to the chip carrier, and the ball electrode group is used as an external terminal. A semiconductor integrated circuit chip, a flattening member connected to the chip carrier, for maintaining the flatness of the chip carrier, and adhered to the flattening member and thermally coupled to the semiconductor integrated circuit chip; A method of assembling a semiconductor device comprising a heat radiating member for radiating heat generated from the semiconductor integrated circuit chip, wherein the bonding protrusion having an adhesive surface between the heat radiating member and the flattening member is provided. An adhesive is provided on one of the heat dissipating member and the flattening member, and an adhesive is applied to the entire adhesive side of the heat dissipating member. The heat radiating member, the flattening member,
It is characterized by being partially adhered. As described above, the adhesive is applied to the entire adhesive side of the heat radiating member, and the heat radiating member is partially bonded to the flattening member by the bonding surface of the bonding protrusion, so that, for example, a masking tape or the like is not used. To
The heat radiating member can be partially bonded to the flattening member. Thus, complication of the assembling process can be prevented, and the manufacturing cost can be reduced.

In order to achieve the above object, according to the third aspect of the present invention, a chip carrier having a ball-shaped electrode group is electrically connected to the chip carrier, and the ball electrode group is used as an external terminal. A semiconductor integrated circuit chip, a flattening member connected to the chip carrier for maintaining flatness of the chip carrier, and heat generated from the semiconductor integrated circuit chip thermally coupled to the semiconductor integrated circuit chip And a heat radiating member for letting out. The heat radiating member is supported by the flattening member in a state where the heat radiating member can be freely deformed in a direction horizontal to the flattening member. As described above, the heat radiating member is supported by the flattening member in a state where the heat radiating member can be freely deformed in the horizontal direction with respect to the flattening member, so that the force generated when the heat radiating member expands and contracts is flattened. It can be hardly transmitted to the members. Thereby, the deformation of the flattening member that is pulled by the heat radiating member can be suppressed, the stress generated inside the ball-shaped electrode is reduced, and the occurrence of cracks due to heat in the ball-shaped electrode can be suppressed. .

Further, in the invention according to claim 10 , the heat radiating member is capable of deforming in a direction perpendicular to the flattening member in a state where the heat radiating member is freely deformable in a direction horizontal to the flattening member. A deformation suppressing protrusion, and the heat radiating member is supported by the flattening member in a state in which the deformation suppressing protrusion can freely deform in a direction horizontal to the flattening member. It is characterized by having. In this way, even if the heat radiating member is supported by the flattening member in a state where it can be freely deformed in the horizontal direction with respect to the flattening member by the deformation suppressing protrusion, the heat radiating member is pulled by the heat radiating member. Can suppress the deformation of the flattening member and reduce the stress generated inside the ball-shaped electrode.
Generation of cracks due to heat can be suppressed.

Further, in the invention according to claim 11 , the deformation suppressing projection has an adhesive surface between the heat radiating member and the flattening member, and the adhesion of the deformation suppressing projection to the bonding surface is the following. Released when the heat radiation member is deformed in the horizontal direction with respect to the flattening member, and after the adhesion is released,
The heat dissipating member may be freely deformed in a direction horizontal to the flattening member. In this way, the bonding of the deformation suppressing protrusions on the bonding surface is released when the heat radiating member is deformed in the horizontal direction with respect to the flattening member, and after releasing the bonding, the heat radiating member is bonded to the flattening member. In this case, the deformation in the horizontal direction can be freely performed, so that the assembly can be performed by applying the adhesive to the entire bonding side of the heat dissipating member even if it has the deformation suppressing protrusion. Further, before the heat dissipating member is deformed in the horizontal direction with respect to the flattening member, the deformation suppressing protrusion is bonded to the flattening member, so that the adhesive strength between the heat dissipating member and the flattening member is high. . When the adhesive strength is high, even if the heat radiating member is picked up, there is little possibility that a delicate electrical connection point between the chip carrier and the semiconductor integrated circuit chip will be broken.

[0018]

FIG. 1 is a view showing a BGA package according to a first embodiment of the present invention. FIG. 1 (a) is a plan view, FIG. 1 (b) is a plan view of FIG. sectional view along line b,
FIG. 3C is a sectional view taken along the line cc in FIG.
The figure is a sectional view along the line dd in the figure (a).

As shown in FIGS. 1A to 1D, the BGA package according to the first embodiment is a TAB tape
A stiffener 2 made of stainless steel for maintaining the flatness of the stiffener. The stiffener 2 is adhered to the surface of the TAB tape 1 with an adhesive. In the figure, a layer indicated by reference numeral 3 is an adhesive layer. Further, the stiffener 2 has a square opening 4. Semiconductor integrated circuit chip 5
Is located in the opening 4 and in the opening 4 TAB
It is electrically connected to the leads 6 provided on the tape 1. The connection state is a so-called face-down type. A rectangular copper cover plate 7 is adhered to the stiffener 2 with an adhesive. In the figure, a layer indicated by reference numeral 8 is an adhesive layer. The size when the cover plate 7 is viewed from a plane is substantially the same as the size when the stiffener 2 is viewed from a plane. Cover plate 7
Are partially bonded, not the entire surface of the stiffener 2. The cover plate 7 has an adhesive projection 12. Since the cover plate 7 has the bonding projections 12, partial bonding between the cover plate 7 and the stiffener 2 is facilitated. At each of the four corners of the cover plate 7, a projection 13 for suppressing deformation is provided. As shown in FIG. 1D, the deformation suppressing projection 13 is bonded to the stiffener 2 with an adhesive. However, the adhesion between the deformation suppressing projection 13 and the stiffener 2 is released when the cover plate 7 expands and contracts due to heat. Details of this will be described later. The protrusions 12 and 13 are formed on the cover plate 7 by, for example, press working. Further, the cover plate 7 is bonded to the chip 5 with an adhesive. The chip 5 is thermally bonded to the cover plate 7 by bonding the chip 5 to the cover plate 7. When the chip 5 generates heat, the cover plate 7 functions as a so-called radiator plate for releasing the heat to the outside. On the back surface of the TAB tape 1, a plurality of solder balls 9 are formed. The solder balls 9 are electrically connected to the leads 6 in the TAB tape 1 and function as external terminals of the chip 5. The BGA package type semiconductor device is obtained by melting and solidifying the solder balls 9.
It is fixed to an electrical contact of a mounting board (not shown) and connected to an electrical contact of the mounting board. One example of a mounting board is a circuit board. A member indicated by reference numeral 10 is a potting resin for shielding an electrical connection between the chip 5 and the TAB tape 1 from the outside.

In the BGA package having the above configuration, since the cover plate 7 is partially bonded to the stiffener 2, the bonding area between the cover plate 7 and the stiffener 2 is reduced. When the bonding area is reduced, transmission of the force to the stiffener 2 when the cover plate 7 is heated and expanded and when the cover plate 7 is cooled and contracted are suppressed. Therefore, the solder balls 9
Is connected to an electrical contact of a mounting board (not shown), cracks generated in the solder balls 9 due to the difference between the linear expansion coefficient of the cover plate 7 and the linear expansion coefficient of the mounting board are suppressed. be able to.

FIG. 2 is a plan view showing a state where the cover plate 7 is removed from the BGA package shown in FIG. As shown in FIG. 2, the BG according to the first embodiment
The stiffener 2 included in the A package has an opening 4 for accommodating a chip 5. Cover plate 7
Is adhered only to the area 20 along the periphery of the opening 4 of the stiffener 2. In the figure, a portion indicated by reference numeral 21 indicates an adhesive surface between the cover plate 7 and the stiffener 2, and a portion indicated by reference numeral 22 indicates an adhesive surface between the cover plate 7 and the chip 5. . By bonding the cover plate 7 only to the area 20 along the periphery of the opening 4 of the stiffener 2 in this manner, the edge of the cover plate 7 is not fixed to the stiffener 2. That is,
The edge of the cover plate 7 becomes elastic. By making the edge of the cover plate 7 expandable and contractible, the cover plate 7
, The force when the cover plate 7 expands and contracts can be released, and the force applied to the adhesive surface 21 can be further reduced. Therefore, the solder balls 9
The effect of suppressing the cracks that occur on the surface is further enhanced.

When bonding is performed only in the area 20 along the periphery of the opening 4 of the stiffener 2, the bonding surface 21 is
2 and as far as possible from the edge of the cover plate 7. For this reason, the bonding surface 21
It becomes difficult to hinder the force trying to escape from the edge of the cover plate 7. Therefore, the force applied to the bonding surface 21 is further reduced. In addition, the bonding surface 21 is
At the edge of the cover plate 7, there is a concern that the force applied to the bonding surface 21 may increase unnecessarily due to the expansion and contraction of the edge of the cover plate 7. Such a concern is solved by separating the adhesive surface 21 from the edge of the cover plate 7 as much as possible.

FIG. 3 is a view showing a bonding surface of a BGA package according to a second embodiment of the present invention. The second embodiment is based on the fact that the cover plate 7 is adhered only to the area 20 along the periphery of the opening 4 of the stiffener 2.

As shown in FIG. 3, the cover plate 7
The stiffener 2 may be adhered over the entire area 20 along the periphery of the opening 4. Reference numeral 23 indicates an adhesion surface when the entire surface of the area 20 is adhered.

As shown in FIG. 2, the BGA package according to the first embodiment has four bonding surfaces 21 between the cover plate 7 and the stiffener 2, and the bonding surface 21 Are distributed. When the bonding surface 21 is dispersed, the total area of the bonding surface 21 is further reduced, so that the bonding area between the cover plate 7 and the stiffener 2 can be further reduced. In addition, when the bonding surface 21 is dispersed, a portion where the cover plate 7 can freely deform is formed around the bonding surface 21, and the force generated when the cover plate 7 expands and contracts is reduced to a certain extent around the bonding surface 21. Is expected to be open to the public. Thus, the bonding surface 21 is
By dispersing in the area 20, the force as the cover plate 7 expands and contracts,
Can be opened to the periphery, and the effect of further reducing the force applied to the bonding surface 21 is expected.

As shown in FIG. 2, in the BGA package according to the first embodiment, the dispersed bonding surfaces 21 are each circular. When the bonding surface 21 is circular, the force generated when the cover plate 7 expands and contracts is reduced by the bonding surface 21.
Can be uniformly opened around the If bonding surface 2
If the force released around 1 is not uniform, an unpredictable force is generated on the bonding surface 21, and the cover plate 7 may be detached from the stiffener 2. Such a possibility is eliminated by making the bonding surface 21 circular. Further, the circular bonding surface 21 has a small possibility that an unpredictable force is generated on the bonding surface 21, so that a maximum bonding strength can be obtained with a minimum bonding area.

FIG. 4 is a plan view showing a state where the cover plate 7 is removed from the BGA package shown in FIG. As shown in FIG. 4, the BG according to the first embodiment
In the A package, the center C ₂₁ of the bonding surface 21 between the cover plate 7 and the stiffener 2 is
From the center C ₂₂ of the bonding surface 22 with, it is set on the circumference of radius r. Thus the center C ₂₁ of the bonding surface 21, the center C ₂₂ of the adhesive surface 22, by setting the equidistant position from the words heating center, the force at which the cover plate 7 is expanded and contracted, the adhesive surface 21 Can be applied evenly. If the force is evenly applied to the bonding surface 21, the balance of the force applied to the stiffener 2 is improved. If the force applied to the stiffener 2 is unbalanced, an unpredictable force may act on the stiffener 2. When an unpredictable force acts on the stiffener 2, the solder ball 9
May crack. Such a possibility,
The center C ₂₁ of the bonding surface 21, disposed equidistant positions from the heating center, by improving the balance of forces, is eliminated.

FIG. 5 is a view showing a bonding surface of a BGA package according to a third embodiment of the present invention. In the third embodiment, the center C ₂₁ of the bonding surface 21 between the cover plate 7 and the stiffener 2 is defined by the cover plate 7 and the chip 5.
From the center C ₂₂ of the bonding surface 22 of the set equidistant positions, in which based on the matters referred.

As shown in FIG. 5, the cover plate 7
The entire surface may be bonded along the circumference of the radius r. Reference numeral 24 indicates the bonding surface when the entire surface is bonded along the circumference of the radius r.

When the opening 4 is square as in the BGA package according to the first embodiment, the center C ₂₂ of the bonding surface 22 is replaced with the center C ₀ of the opening 4. May be.

FIG. 6 is a plan view showing a state where the cover plate 7 is removed from the BGA package shown in FIG. As shown in FIG. 6, the BGA package according to the first embodiment sets the center C22 of the bonding surface ₂₂ to coordinates (x, y) = (0, 0), and Is assumed to be the reference bonding surface, the other three bonding surfaces 21 are set at positions that satisfy the conditions of point symmetry and line symmetry with respect to the reference bonding surface. As described above, when the bonding surface 21 is dispersed on the circumference of the radius r, by setting the bonding surface 21 to a position that satisfies the above condition, the balance of the force applied to the stiffener 2 is further improved. Get better. Therefore, the effect of suppressing cracks generated in the solder balls 9 is further improved.

One example satisfying the above conditions will be described with reference to FIG. As shown in FIG.
One center C ₂₂ is represented as a center C ₂₂ A, a center C ₂₂ B, a center C ₂₂ C, and a center C ₂₂ D, respectively. Then, the bonding surface including the center C ₂₂ A is set as a reference bonding surface. The coordinates of the center C ₂₂ A of the reference bonding surface are (x, y) = (0, r). When the center C ₂₂ A is rotated clockwise by 90 degrees, that is, a point-symmetric position with respect to the coordinates (0, r) is represented by the coordinates (x, y).
= (R, 0). Further, when rotated clockwise by 90 degrees, that is, a position that is line-symmetric with respect to the coordinates (0, r) is the coordinates (x, y) = (0, -r). When rotated further 90 degrees clockwise, that is, the coordinates (0, r)
(X, y) = (− r, 0). Assuming that the coordinates of the center C ₂₂ A of one reference bonding surface are (0, r), the centers C _{22 of the} other three bonding surfaces are equal to each other.
B, the center C ₂₂ C, and the center C ₂₂ D are represented by coordinates (r,
0), coordinates (0, -r), and coordinates (-r, 0).

When the opening 4 is square as in the BGA package according to the first embodiment, the center C ₂₂ of the bonding surface 22 may be replaced with the center of the opening 4. good.

FIG. 7 is a plan view of the cover plate 7 of the BGA package shown in FIG. 1 as viewed from the bonding surface side. As shown in FIG. 7, the cover plate 7 included in the BGA package according to the first embodiment
have. In order to achieve partial adhesion between the cover plate 7 and the stiffener 2, the bonding projection 12 is
Even if the adhesive is not molded on the cover plate 7, the adhesive can be achieved by partially applying the adhesive to the cover plate 7. Of course, this is good. However, if the bonding projection 12 is provided on the cover plate 7,
Only the bonding projection 12 is brought into contact with the stiffener 2.
There is an advantage. Due to this advantage, even if the adhesive is applied to the entire surface of the cover plate 7, an effect is obtained that partial adhesion between the cover plate 7 and the stiffener 2 can be achieved. Applying the adhesive to the entire surface of the cover plate 7 is easier than applying the adhesive to the cover plate 7 partially. When the adhesive is partially applied to the cover plate 7, it is necessary to use, for example, a masking tape or the like in order to form a portion where the adhesive is not applied. However, such a necessity does not exist when the bonding projection 12 is provided. When a masking tape or the like is used, there is a possibility that a mask may be displaced, and the adhesive may not be applied as designed, but there is no such concern. Therefore, the cover plate 7 having the bonding projections 12 can prevent complication of the assembling process, and can reduce the manufacturing cost.

As shown in FIG. 7, a cover plate 7 provided in the BGA package according to the first embodiment is provided.
Has four bonding projections 12, and the bonding projections 12 are provided dispersedly on the cover plate 7. The reason why the bonding protrusions 12 are dispersed is, for example, as shown in FIG.
The purpose is to obtain the effect described with reference to FIG. The dispersed bonding projections 12 are each circular. The reason why each of the dispersed bonding projections 12 is circular is to obtain the effect described with reference to FIG. 2, for example, but the dispersed bonding projections 12 are formed on the cover plate 7. , Easy to mold by pressing,
There is an advantage. That is, when the cover projections 7 are pressed, if the dispersed adhesive projections 12 have corners,
Cracks may occur in the corners and molding is difficult,
By making each of the dispersed bonding projections 12 circular,
There are no corners, making it easier to mold.

Further, as shown in FIG. 7, the dispersed bonding projections 12 each center C ₁₂ of the, from the center C ₇ of the cover plate 7, it is set on a circumference of radius r. The centers C ₁₂ of the bonding projections 12 thus dispersed are respectively
By setting the center C ₇ of the cover plate 7 at equal distances, the bonding projections 12 dispersed, easily molded by pressing in the cover plate 7. At the time of press working, the shear force applied to the cover plate 7 is:
This is because it becomes even.

As shown in FIG. 7, the center C ₁₂ of each of the dispersed bonding projections ₁₂ is defined by the coordinates (x, y) = (0, 0) at the center C ₇ of the cover plate 7. Assuming that one of the bonding projections 12 is a reference projection, the other dispersed bonding projections 12 satisfy the condition of being point-symmetric and line-symmetric with respect to the reference projection. It is set to the position to be. Thereby, at the time of press working,
The uniformity of the shearing force applied to the cover plate 7 is further improved.

As shown in FIG. 7, a cover plate 7 provided in the BGA package according to the first embodiment is provided.
In this embodiment, a deformation suppressing projection 13 is provided in addition to the bonding projection 12. The deformation suppressing projections 13 are provided at corners of the rectangular cover plate 7, respectively. The deformation suppressing projection 13 is formed such that when the cover plate 7 is adhered to the stiffener 2, the tip thereof comes into contact with the stiffener 2. Deformation suppressing projection 1
3 indicates that when a force is applied to the cover plate 7 to press the cover plate 7 toward the stiffener 2,
Suppress corner crush. Further, the deformation suppressing protrusion 13 is not basically bonded to the stiffener 2, but is deformable in a direction horizontal to the stiffener 2. By making the deformation suppressing protrusion 13 deformable in a direction horizontal to the stiffener 2, when the cover plate 7 is to be expanded by heat, the expansion is not hindered. Therefore, stiffener 2
In addition, there is no need to apply a force that pulls the stiffener 2.

Further, the deformation suppressing projection 13 is formed at the same time as the bonding projection 12 by pressing.
Can be molded. Further, when the deformation suppressing protrusions 13 are provided at the corners, there is also an effect that the corners of the cover plate 7 are less likely to be warped than when the deformation suppressing protrusions 13 are not provided at the corners. The effect of suppressing the warpage of the corner can be obtained not only when the cover plate 7 expands and contracts due to heat, but also during press working. By providing the deformation suppressing projections 13 at each corner in this manner, the deformation of the corner of the cover plate 7 in the direction perpendicular to the stiffener 2 can be suppressed.

The deformation of the corner of the cover plate 7 does not affect the reliability of the semiconductor device. However, if the corner is excessively deformed, the user may feel uneasy about the device. Providing the deformation suppressing projections 13 at each corner to suppress excessive deformation of the corners of the cover plate 7 has the effect of also eliminating the user's anxiety.

If the deformation suppressing protrusion 13 is formed in a circular shape as in the case of the bonding protrusion 12, it is easy to mold by press working. Further, as shown particularly in FIG. 1D, in the cover plate 7 provided in the BGA package according to the first embodiment, the deformation suppressing projection 13 is bonded to the stiffener 2. When the deformation suppressing protrusion 13 is bonded to the stiffener 2 as described above, it is preferable that the bonding surface be smaller than the bonding surface between the bonding protrusion 12 and the stiffener 2. The area of the bonding surface between the deformation suppressing protrusion 13 and the stiffener 2 is preferably large enough to release the bonding when the cover plate 7 is deformed in a direction horizontal to the stiffener 2. . As described above, even if the deformation suppressing projection 13 is adhered to the stiffener 2, if the adhesion can be released later, that is, if the deformation suppressing projection 13 is separated from the stiffener 2, FIG. Can be obtained as described with reference to FIG. With such a configuration, the adhesive can be applied to the entire surface of the cover plate 7 even if it has the deformation suppressing projections 13. Therefore, it is possible to prevent the above-described complication of the assembling process and to reduce the manufacturing cost.

Further, while the deformation suppressing projection 13 is adhered to the stiffener 2, the adhesive strength between the cover plate 7 and the stiffener 2 is increased. By the way, at the time of a test performed after completion of a semiconductor device or when mounting the semiconductor device on a mounting board, the semiconductor device is transported to a work point. At this time, the cover plate 7 is often picked up. When the cover plate 7 is picked up, the weight of the semiconductor device is applied to, for example, the bonding surface 21 between the cover plate 7 and the stiffener 2 and the bonding surface 22 between the cover plate 7 and the chip 5 shown in FIG. If the total area of the bonding surface 21 between the cover plate 7 and the stiffener 2 is small and the bonding strength is low, the load on the bonding surface 22 between the cover plate 7 and the chip 5 increases. For this reason, when the cover plate 7 is picked up, the chip 5 is pulled, and the delicate chip 5 and the electrical connection point between the lead 6 may be broken. If the deformation suppressing protrusion 13 is slightly adhered to the stiffener 2, such a possibility can be reduced.
Therefore, it is possible to suppress the occurrence of an accident that the semiconductor device is broken, for example, during transportation.

When the cover plate 7 is deformed in the horizontal direction with respect to the stiffener 2 when the adhesion between the deformation suppressing projection 13 and the stiffener 2 is released, the chip 5 generates heat. Just release the bond automatically. If the bonding can be automatically released in this way, a step for releasing the bonding is not required, and no labor is required. In order to perform such automatic release of the bonding, it is preferable to provide the deformation suppressing protrusion 13 at a position where the force is most concentrated when the cover plate 7 is about to expand due to heat. As shown in FIG. 7, in the cover plate 7 of the BGA package according to the first embodiment, the deformation suppressing projection 13 is set on a diagonal line. When the square cover plate 7 is about to expand, the force tends to concentrate toward the corner. Therefore, by setting the deformation suppressing protrusion 13 on the diagonal line, the adhesion between the deformation suppressing protrusion 13 and the stiffener 2 can be easily released.

FIG. 8 shows a BGA package according to a fourth embodiment of the present invention. FIG.
FIG. 2B is a sectional view taken along line bb in FIG.
The figure is a cross-sectional view taken along the line cc in the figure (a), and the figure (d) is a cross-sectional view taken along the line dd in the figure (a).

As shown in FIGS. 8A to 8D, the BGA package according to the fourth embodiment has
2 is provided on the stiffener 2. Thus, even if the bonding projections 32 are provided on the stiffener 2, cracks in the solder balls 9 can be suppressed as in the BGA package according to the first embodiment. Furthermore, even if the adhesive is applied to the entire surface of the cover plate 7, only the tip of the bonding projection 32 can be brought into contact with the cover plate 7, so that the assembly process is not complicated and the manufacturing cost is reduced. You. Further, since the adhesive projection 32 is provided on the stiffener 2, the adhesive surface of the stiffener 2 does not shift. For this reason, the balance of the force applied to the stiffener 2 is always improved.

The adhesive projection 32 may be formed so as to correspond to any one of the adhesive surfaces described with reference to FIGS. Further, as shown in FIGS. 8A to 8D, in the BGA package according to the fourth embodiment, the deformation suppressing protrusion 33 is provided on the stiffener 2, but the deformation suppressing protrusion 33 is , May be provided on the cover plate 7.

FIG. 9 is a view showing a BGA package according to a fifth embodiment of the present invention. FIG.
FIG. 2B is a sectional view taken along line bb in FIG.
The figure is a cross-sectional view along the line cc in FIG.

As shown in FIGS. 9A to 9C, in the BGA package according to the fifth embodiment, the cover plate 7 is adhered only to the chip 5, and only the stiffener 2 is contacted. It was done. Even with such a configuration, since the cover plate 7 can move freely along the surface of the stiffener 2, the force applied to the stiffener 2 can be reduced. Therefore, generation of cracks in the solder balls 9 can be suppressed. In addition, since the cover plate 7 is in contact with the entire surface of the stiffener 2, the cover plate 7 is not deformed even if a pressing force is applied to the stiffener 2.

FIG. 10 is a view showing a BGA package according to a sixth embodiment of the present invention. FIG.
FIG. 2B is a sectional view taken along line bb in FIG.
The figure is a cross-sectional view taken along the line cc in the figure (a), and the figure (d) is a cross-sectional view taken along the line dd in the figure (a).

As shown in FIGS. 10A to 10D, the sixth
The BGA package according to the embodiment has a configuration in which the cover plate 7 is adhered only to the chip 5 and is only in contact with the stiffener 2, and the deformation suppressing protrusion 13 is further provided on the cover plate 7. is there. Further, as shown in FIG. 10 (d), the deformation suppressing protrusion 13 is bonded to the stiffener 2, but as described with reference to FIG. It is released when it expands and contracts. Thereby, the effect as described with reference to FIG. 7 can be obtained. Furthermore, since only the tip of the deformation suppressing projection 13 can be brought into contact with the stiffener 2, it is possible to assemble the adhesive by applying the adhesive to the entire surface of the cover plate 7.

[0051]

As described above, according to the present invention, in a BGA package type semiconductor device having a heat radiating member, a semiconductor device capable of suppressing generation of cracks in a solder ball due to heat, and an assembling method thereof And can be provided.

[Brief description of the drawings]

FIG. 1 is a BG according to a first embodiment of the present invention;
FIG. 4A is a view showing a package, FIG. 4A is a plan view, FIG. 4B is a cross-sectional view taken along line bb in FIG. 4A, and FIG. 4C is line cc in FIG. (D) is a sectional view along (a).
Sectional drawing which follows the dd line in the figure.

FIG. 2 is a plan view showing a state where a cover plate is removed.

FIG. 3 is a BG according to a second embodiment of the present invention.
The figure which shows the bonding surface of A package.

FIG. 4 is a plan view showing a state where a cover plate is removed.

FIG. 5 is a BG according to a third embodiment of the present invention.
The figure which shows the bonding surface of A package.

FIG. 6 is a plan view showing a state where a cover plate is removed.

FIG. 7 is a plan view of the cover plate as viewed from an adhesive surface side.

FIG. 8 is a BG according to a fourth embodiment of the present invention.
FIG. 4A is a view showing a package, FIG. 4A is a plan view, FIG. 4B is a cross-sectional view taken along line bb in FIG. 4A, and FIG. 4C is line cc in FIG. (D) is a sectional view along (a).
Sectional drawing which follows the dd line in the figure.

FIG. 9 is a BG according to a fifth embodiment of the present invention.
FIG. 4A is a view showing a package, FIG. 4A is a plan view, FIG. 4B is a cross-sectional view taken along line bb in FIG. 4A, and FIG. 4C is line cc in FIG. FIG.

FIG. 10 is a view showing a BGA package according to a sixth embodiment of the present invention, wherein FIG.
FIG. 2B is a sectional view taken along line bb in FIG.
The figure is a sectional view taken along the line cc in the figure (a), and the figure (d) is a sectional view taken along the line dd in the figure (a).

11A and 11B are views showing a conventional BGA package, wherein FIG. 11A is a plan view, FIG. 11B is a view bb in FIG.
FIG. 3C is a cross-sectional view taken along a line cc in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... TAB tape, 2 ... Stiffener, 3, 8 ... Adhesive layer, 4 ... Aperture, 5 ... Semiconductor integrated circuit chip, 6 ... Lead, 7 ... Cover plate, 9 ... Solder ball, 10 ... Potting resin 12, 32: Projecting portion for bonding, 13, 33: Projecting portion for suppressing deformation, 21, 22, 23, 24: Adhesive surface.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Morihiko Ikemizu 1 Kozumu Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Toshiba Tamagawa Plant Co., Ltd. JP-A-9-213837 (JP, A) JP-A-8-31995 (JP, A) JP-A-9-246315 (JP, A) JP-A 9-293808 (JP, A) (58) Fields studied (Int) .Cl. ⁷ , DB name) H01L 23/34 H01L 23/12 H01L 21/60

Claims (11)

(57) [Claims] A chip carrier having a 1. A ball-shaped electrodes, the electrically connected to the chip carrier, a semiconductor integrated circuit chip for the ball-shaped <br/> electrode group and the external terminal, connected to said chip carrier And a flattening member for maintaining the flatness of the chip carrier, and being bonded to the flattening member and thermally coupled to the semiconductor integrated circuit chip to generate heat generated from the semiconductor integrated circuit chip. A heat radiating member for escaping and having an adhesive surface between the heat radiating member and the flattening member;
For the heat radiating member and the flattening member.
Provided on one of them, the heat radiation member, the flattening member,
A semiconductor device characterized by being partially adhered . A chip carrier having a 2. A ball-shaped electrodes, the electrically connected to the chip carrier, a semiconductor integrated circuit chip for the ball-shaped <br/> electrode group and the external terminal, connected to said chip carrier And a flattening member for maintaining the flatness of the chip carrier, and being bonded to the flattening member and thermally coupled to the semiconductor integrated circuit chip to generate heat generated from the semiconductor integrated circuit chip. A method of assembling a semiconductor device including a heat radiating member for releasing, wherein the bonding protrusion having an adhesive surface between the heat radiating member and the flattening member is attached to one of the heat radiating member and the flattening member. An adhesive is applied to the entire surface of the heat-radiating member on the bonding side, and the heat-radiating member is partially bonded to the flattening member by the bonding surface of the bonding protrusion. A method for assembling a semiconductor device, comprising: A chip carrier having a 3. The ball-shaped electrodes, the electrically connected to the chip carrier, a semiconductor integrated circuit chip for the ball-shaped <br/> electrode group and the external terminal, connected to said chip carrier A flattening member for keeping the flatness of the chip carrier, and a heat dissipating member for releasing heat generated from the semiconductor integrated circuit chip, thermally coupled to the semiconductor integrated circuit chip, A semiconductor device, wherein the heat radiating member is supported by the flattening member in a state where the heat radiating member can be freely deformed in a direction horizontal to the flattening member. 4. The flattening member has an opening for accommodating the semiconductor integrated circuit chip, and the heat dissipating member is bonded only around the opening of the flattening member, and the heat dissipation is performed. 2. The semiconductor device according to claim 1, wherein an edge of the member is opened. 5. The semiconductor device according to claim 4, wherein a bonding portion between the heat radiating member and the flattening member is provided at a position equidistant from a heat generation center. 6. The semiconductor device according to claim 4, wherein an adhesive portion between the heat radiating member and the flattening member is dispersed around the opening. 7. A semiconductor device according to claim 6, characterized in that each said distributed adhered portion, from the heating center, provided at a position that satisfies the point-symmetric, and axisymmetric conditions. 8. The heat dissipating member, with respect to the flattening member,
The flattening member can be freely deformed in the horizontal direction.
Deformation suppressing projection that suppresses deformation in the direction perpendicular to
A part of the heat dissipating member and the flattening member.
The semiconductor device according to claim 1, further comprising: 9. The bonding projection according to claim 9, wherein the deformation suppressing projection is formed by the bonding projection.
The heat dissipating member and the flattening are smaller than the bonding surface of the raised portion.
An adhesive surface with the member, and the adhesive on the adhesive surface of the deformation suppressing protrusion is formed by the release
The heat member has deformed in the direction horizontal to the flattening member
Sometimes released, after the bonding is released, the heat dissipation member
Of the flattening member can be freely deformed in the horizontal direction.
The semiconductor device according to claim 8 , wherein the semiconductor device is in a state. 10. The heat dissipating member is provided on the flattening member.
The flattening section in a state where it can be freely deformed in the horizontal direction.
Deformation suppression protrusion that suppresses deformation in the direction perpendicular to the material
Having a raised portion, the heat radiation member, the deformation suppressing protrusion, the
Freely state deformation into horizontal direction to flattener
And characterized by being supported by the flattening member.
The semiconductor device according to claim 3 . 11. The heat-dissipating portion includes a projection for suppressing deformation.
It has adhesive surfaces of the planarization member with product, adhesion at the adhesion surface of the deformation-suppressing protrusions, the release
The heat member has deformed in the direction horizontal to the flattening member
Sometimes released, after the bonding is released, the heat dissipation member
Of the flattening member can be freely deformed in the horizontal direction.
The semiconductor device according to claim 10 , wherein the semiconductor device is in a state.