JP7115861B2 - Bonded structures and structures - Google Patents

Description

The present invention relates to a structure for joining objects.

2. Description of the Related Art A semiconductor device represented by a large scale integrated circuit (hereinafter referred to as "LSI") is usually mounted on a printed circuit board or the like for use.

FIG. 1 is a conceptual diagram showing a cross section of a mounting structure 100, which is a general mounting structure when an LSI chip is mounted on a substrate. 2 is a conceptual diagram assuming a case where the LSI chip 201 shown in FIG. 1 is viewed from the LSI electrode pad 208 side. FIG. 3 is a conceptual diagram assuming that the substrate 402 shown in FIG. 1 is viewed from the substrate electrode pad side. Moreover, FIG. 4 is an enlarged view of the junction structure 320 shown in FIG.

As shown in FIG. 2, the LSI chip 201 has an LSI chip main body 202 and a plurality of circular LSI electrode pads 208 . FIG. 2 shows an example in which the number of LSI electrode pads 208 is twenty-five. The LSI electrode pads 208 are arranged at regular intervals as shown in FIG.

The LSI chip main body 202 is mainly made of silicon. A semiconductor circuit is formed in the LSI chip body portion 202 .

The substrate 402 shown in FIG. 1 includes a substrate body portion 411 and a plurality of circular substrate electrode pads 409 . The number of substrate electrode pads 409 provided on the substrate 402 is equal to the number of LSI electrode pads 208 provided on the LSI chip 201 .

The substrate main body 411 has a structure in which wiring is formed on the surface or inside of a plate made of resin or the like. The wiring and each of the substrate electrode pads 409 are electrically connected.

When the LSI chip 201 and the substrate 402 are overlapped so that the outer circumference of the LSI chip 201 fits in the LSI chip outer circumference position 227 shown in FIG. 3, the corresponding electrode pads overlap each other.

In the mounting structure 100 shown in FIG. 1, the substrate 402 and the corresponding electrodes of the LSI chip overlap each other and are electrically and mechanically connected by the solder bumps 307, as described above.

Each of the bonding structures 320 depicted in FIG. 1 is barrel-shaped, as depicted in FIG.

When the mounting structure 100 shown in FIG. 1 is heated by heat generation or the like, stress is applied to the solder bumps 307 due to the difference in coefficient of linear expansion between the LSI chip main body 202 and the substrate main body 411 . The stress concentrates on the joints between the LSI electrode pads 208 and the solder bumps 307 and the ends of the joints between the substrate electrode pads 409 and the solder bumps 307 . The greatest stress is generated along a straight line toward the center of the LSI chip 201, the point 221 representing the center of the LSI chip shown in FIG.

Therefore, in the connection structures shown in FIGS. 1 and 4, stress concentrates on the joints between the electrode pads of the LSI chip or substrate and the solder bumps during thermal cycle operation due to the difference in coefficient of linear expansion between the LSI chip and substrate. In addition, the same structure has a problem that the resistance to the force applied to the connecting portion is lowered.

In order to alleviate this stress, Patent Document 1 discloses a method of stretching the solder bumps into an hourglass shape by pulling up the LSI chip from the substrate when the solder bumps are melted.

Further, Patent Document 2 discloses a method of increasing stress release during thermal cycle operation by making the shape of the electrode pad elongated in the direction perpendicular to the edge of the device.

Further, Patent Document 3 discloses a semiconductor device having a bonding structure in which solder bumps are formed at an angle when circular pads are used.

In addition, Patent Document 4 discloses a joint having two curved portions, a first curved portion and a second curved portion, wherein the first curved portion includes an electrode pad having a smaller curvature than the second curved portion. Disclose the structure.

JP-A-10-223693 JP-A-11-219968 JP 2005-340674 A Japanese Patent No. 5757323

However, the method disclosed in Patent Document 1 requires precise control of the distance between the LSI chip and the substrate in order to form the desired hourglass-shaped solder bumps. Therefore, this method requires installation of large-sized dummy bumps and a mounting apparatus having a mechanism for precisely holding the height between the LSI chip and the substrate.

Moreover, the method disclosed in Patent Document 2 is ineffective for stress generated along a straight line toward the center of the LSI chip, which is the greatest stress during thermal cycles.

Further, the semiconductor device disclosed in Patent Document 3 is based on the premise that the electrode pads are circular. Therefore, the device cannot relieve the stress concentration on the junction between the solder bump and the electrode pad due to the force applied due to the difference in thermal expansion coefficient between the LSI chip and the substrate during thermal cycles.

In addition, the method disclosed in Patent Document 4 can alleviate the stress concentration on the junction between the solder bump and the electrode pad due to the force applied due to the difference in thermal expansion coefficient between the LSI chip and the substrate during thermal cycles. However, from the viewpoint of further improving the reliability of the joint structure, it is preferable that the stress can be further reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a joint structure that is more excellent in resistance to a force in a predetermined direction applied between a part to be joined and a body to be joined during a thermal cycle.

A joint structure of the present invention includes a first joint having an outer edge formed by a predetermined closed curve, and a joined body to be joined to the first joint, wherein the joined body includes the first joint of the first joint. A force in a first direction parallel to one surface to be joined may be applied, and the force in the first direction and the first From the curvature of the closed curve at the first point, which is the intersection point of the closed curve and the half line drawn in the second direction, which is one of the opposite directions, the second The curvature of the closed curve at the second point, which is the intersection of the half line drawn in the opposite direction to the direction of the closed curve, is smaller, and is formed so as to be inclined in the opposite direction with respect to the joint surface related to the joint.

The joint structure of the present invention is more excellent in resistance to a force in a predetermined direction that is applied between the parts to be joined and the joined body during thermal cycles.

1 is a conceptual diagram showing a cross section of a general mounting structure when an LSI chip is mounted on a substrate; FIG. 1 is a conceptual diagram assuming a case where an LSI chip is viewed from the LSI electrode pad side; FIG. FIG. 2 is a conceptual diagram assuming a case where the substrate is viewed from the substrate electrode pad side; It is an enlarged view of a general joint structure. It is a conceptual diagram showing the structural example of the joining structure of 1st embodiment. FIG. 2 is a conceptual diagram showing the configuration of a joint structure disclosed in Patent Document 4; FIG. 10 is a conceptual diagram showing an example of electrode pad arrangement of an LSI chip used in the connection structure of the second embodiment; 3 is a conceptual diagram showing an enlarged view of an LSI electrode pad; FIG. FIG. 4 is a conceptual diagram showing variations of LSI electrode pads; FIG. 10 is a conceptual diagram showing an example of arrangement of substrate electrode pads on a substrate used in the connection structure of the second embodiment; FIG. 4 is a conceptual diagram showing an enlarged view of a substrate electrode pad; FIG. 4 is a conceptual diagram showing variations of substrate electrode pads; It is an example of an upper surface conceptual diagram of the mounting structure of 2nd embodiment. It is an example of a cross-sectional conceptual diagram of the mounting structure of 2nd embodiment. It is an upper surface conceptual diagram of the joining structure of 2nd embodiment. It is a perspective conceptual diagram example of the joining structure of 2nd embodiment. It is a conceptual diagram showing the formation method of the joining structure of 2nd embodiment. It is a figure showing arrangement|positioning of the joining structure in the mounting structure used for calculation. FIG. 2 is a diagram showing the arrangement (part 1) of LSI chip electrode pads and substrate electrode pads; FIG. 3 is a diagram showing calculation results (part 1) of stress distribution in an LSI electrode pad; FIG. 4 is a diagram showing calculation results (part 1) of stress distribution in a substrate electrode pad; FIG. 10 is a diagram showing the arrangement (part 2) of LSI chip electrode pads and substrate electrode pads; FIG. 10 is a diagram showing calculation results (part 2) of stress distribution in an LSI electrode pad; FIG. 10 is a diagram showing calculation results (part 2) of stress distribution in substrate electrode pads; FIG. 4 is a diagram showing the maximum values of stress at each end of an LS electrode pad and a substrate electrode pad; It is an image figure showing the cross section of a joining structure. It is an image figure showing the minimum composition of the junction structure of an embodiment.

<First embodiment>
The first embodiment relates to a connection structure in which each electrode pad has boundaries with different curvatures and solder bumps are inclined.
[Configuration and operation]
FIG. 5 is a conceptual diagram showing the configuration of a joint structure 310v, which is an example of the joint structure of the first embodiment. FIG. 5A is a top view assuming that the junction structure 310v is viewed from the LSI electrode pad side. FIG. 5(b) is a cross-sectional view assuming that the joint structure 310v is cut along line 931b shown in FIG. 5(a).

The upper surface of the LSI electrode pad 208v as viewed in FIG. 5B is formed on the LSI chip main body (see the LSI chip main body 202 shown in FIG. 1), not shown. Further, the lower surface of the substrate electrode pad 409v as viewed in FIG. 5B is formed on a substrate main body portion (see the substrate main body portion 411 shown in FIG. 1) not shown.

Here, when the temperature rises, a force in the direction of arrow 971c is applied between the LSI electrode pad 208v and the solder bump 307v, and along with this, a force in the direction of the arrow 971d is applied between the substrate electrode pad 409v and the solder bump 307v. ing. This force is caused, for example, by the difference in coefficient of linear expansion between the substrate body and the LSI chip body, as described in the second embodiment.

In the LSI electrode pad 208v, the curvature of the boundary in the direction of arrow 971c is smaller than the boundary in the direction of arrow 971d in the view shown in FIG. 5(a).

5A, the board electrode pad 409v has a smaller curvature at the boundary in the direction of arrow 971d than at the boundary in the direction of arrow 971c.

A solder bump 307v is formed between the LSI electrode pad 208v and the substrate electrode pad 409v.

As shown in FIG. 5B, the solder bumps 307v are formed tilted in the direction of the arrow 971d with the substrate electrode pads 409v as a reference.

A point 907a shown in FIG. 5B represents the center of gravity of the substrate electrode pad 409v. Point 907b represents the center of gravity of solder bump 307v. A point 907c represents the center of gravity of the LSI electrode pad 208v.

A straight line 932a connecting the points 907a and 907b is inclined in the direction of the arrow 971d by an angle θa with respect to the surface 971a. A force is applied in the direction of arrow 971d to the upper surface of substrate electrode pad 409v.

A line 932b, which is a straight line connecting the points 907b and 907c, is inclined in the direction of the arrow 971c by an angle θb with respect to the plane 971b. A force is applied to the lower surface of the LSI electrode pad 208v in the direction of the arrow 971c.

The contact angles of the solder bump 307v to the LSI electrode pad 208v are the contact angles θ1 and θ2 at the ends 941a and 941b, respectively. Also, the contact angles of the solder bump 307v to the substrate electrode pad 409v are the contact angles θ3 and θ4 at the ends 941c and 941d, respectively.

In that case, stress is generated at the interface between the LSI electrode pad 208v and the solder bump 307v due to the force applied between the LSI electrode pad 208v and the solder bump 307v. As described in the description of the simulation results of the second embodiment, the stress is not uniform within the joint surface, but takes a maximum value near each of the ends 941a and 941b.

In that case, stress is generated at the interface between the substrate electrode pad 409v and the solder bump 307v due to the force applied between the substrate electrode pad 409v and the solder bump 307v. As described in the description of the simulation results of the second embodiment, the stress is not uniform within the joint surface, but takes a maximum value near each of the ends 941c and 941d.

FIG. 6 is a conceptual diagram showing the configuration of a joint structure 310w, which is a joint structure disclosed in Patent Document 4. As shown in FIG. FIG. 6A is a top view assuming that the junction structure 310w is viewed from the LSI electrode pad side. FIG. 6(b) is a cross-sectional view assuming that the joint structure 310w is cut along line 931c shown in FIG. 6(a).

Except for the following description, the description of the joint structure 310w is obtained by replacing the letter v included in the reference numerals attached to the components of the joint structure 310v shown in FIG. 5 with w.

In the bonding structure, the solder bumps 307w are formed without tilting in the directions indicated by the arrows 971c and 971d.

The contact angles of the solder bump 307w to the LSI electrode pad 208w are the contact angles θ5 and θ6 at the ends 941e and 941f, respectively. Also, the contact angles of the solder bump 307w to the substrate electrode pad 409w are the contact angles θ7 and θ8 at the ends 941g and 941h, respectively.

Here, the junction structure 310v shown in FIG. 5 and the junction structure 310w shown in FIG. 6 are compared.

First, each of the contact angles θ2 and θ3 represented in FIG. 5 is smaller than the corresponding each of the contact angles θ6 and θ7 represented in FIG. Generally, it is known that stress decreases when the contact angle is small. Accordingly, the stress maxima at each of the ends 941b and 941c depicted in FIG. 5 are less than the stress maxima at the corresponding respective ends 941f and 941g depicted in FIG.

On the other hand, the contact angles at ends 941a and 941d shown in FIG. 5 are greater than the contact angles at each of ends 941e and 941h shown in FIG. Therefore, from this alone, it is likely that the stress maxima at ends 941a and 941d depicted in FIG. 5 are greater than the stress maxima at ends 941e and 941h, respectively, depicted in FIG. However, each of the ends 941a and 941d has a small curvature at the boundary of the electrode pad as described above. Therefore, the stress is dispersed at the ends 941a and 941d, and the maximum value of the stress at the ends 941a and 941d shown in FIG. 5 is suppressed.

It should be noted that the above description of the operation is supported by the results of the simulation in the second embodiment.

In the above, when the temperature rises, a force in the direction of arrow 971c is applied between the LSI electrode pad 208v and the solder bump 307v, and along with this, a force in the direction of the arrow 971d is applied between the substrate electrode pad 409v and the solder bump 307v. explained the case. In this case, the stress applied near the end 941a of the contact surface between the LSI electrode pad 208v and the solder bump 307v is compressive stress. Moreover, the stress applied near the end portion 941b is a tensile stress. Also, in this case, the stress applied near the end 941d of the contact surface between the substrate electrode pad 409v and the solder bump 307v is a compressive stress. Moreover, the stress applied near the end portion 941c is a tensile stress.

In the above description, when the temperature drops, the direction of the force is the case where the arrows 971c and 971d are interchanged, and the stress applied near the end 941a of the contact surface between the LSI electrode pad 208v and the solder bump 307v is tensile stress. Also, the stress applied near the end portion 941b is a compressive stress. The stress applied near the end 941d of the contact surface between the substrate electrode pad 409v and the solder bump 307v is tensile stress. Moreover, the stress applied near the end portion 941c is a compressive stress. It is considered that the compressive stress and the tensile stress at the time of temperature rise and temperature fall have the same stress distribution.

Therefore, even when the arrows 971c and 971d are replaced with each other in the above description, the maximum values of the stresses at the ends 941a and 941d shown in FIG. 5 are suppressed.
[effect]
In the joint structure of the present embodiment, each electrode pad has a curvature in a second direction that is either a first direction in which a force is applied or a direction opposite to the first direction. smaller than the opposite direction of the direction of In the bonding structure, the solder bumps are formed so as to be inclined in the opposite direction. The bonding structure has a small contact angle of the solder bump at the end of the electrode pad opposite to the direction due to the inclination of the solder bump. Therefore, the maximum value of the stress at the edge is lower than when the solder bump is not inclined. On the other hand, the ends of the electrode pads in the direction have a small curvature. Therefore, an increase in the maximum stress value at the end is suppressed.

As described above, the joint structure of the present embodiment further reduces the maximum stress value compared to the joint structure disclosed in Patent Document 4, which can reduce the maximum stress value more than the general joint structure described in the background art section. can.

Failures in bonded structures are generally associated with stress maxima. Therefore, the joint structure of this embodiment can further reduce the probability of breakage as compared with the joint structure disclosed in Patent Document 4. That is, the joint structure of the present embodiment can further improve resistance to a force applied to the joint structure in a predetermined direction, compared with the joint structure disclosed in Patent Document 4.
<Second embodiment>
The second embodiment relates to a mounting structure to which the joining structure of the first embodiment is applied.
[Configuration and Operation]
FIG. 7 is a conceptual diagram showing the electrode pad arrangement of an LSI chip 201a, which is an example of the LSI chip used in the connection structure of the second embodiment. FIG. 7 is a plan view assuming that the LSI chip 201a is seen from the LSI electrode pad side.

The arrangement of the LSI electrode pads 208, which are LSI electrode pads other than the LSI electrode pads 208a to 208d, which are LSI electrode pads at the four corners of the LSI chip 201a, is the same as the arrangement of the LSI electrode pads 208 shown in FIG.

Each of the LSI electrode pads 208a to 208d at the four corners of the LSI chip 201a has a different curvature between the curve representing the boundary in the direction of each of the corresponding arrows 911a to 911d and the curve representing the boundary in the direction opposite to the arrow.

Each of the arrows 911a to 911d indicates a direction away from the point 221 representing the center of the LSI chip 201a along the diagonal line 226a or 226b.

Also, the centers of gravity of the LSI electrode pads 208a to 208d represented by the points 903a to 903d are shifted in the directions of the corresponding arrows 911a to 911d from the arrangement position 231 where the centers of gravity of the outermost LSI electrode pads 208 are arranged. ing. The arrangement position 231 is the position where the outermost LSI electrode pads 208 shown in FIG. 2 are arranged.

FIG. 8 is a conceptual diagram showing an enlarged view of the LSI electrode pad 208a shown in FIG. In FIG. 8, point 903a represents the center of gravity of LSI electrode pad 208a. Also, the arrow 911a is the same as that shown in FIG. Points 901c and 901d are points where half lines drawn from the point 903a in the direction of the arrow 911a and in the opposite direction intersect the outer edge of the LSI electrode pad 208a.

LSI electrode pad 208a has different curvatures between the curve representing the boundary in the direction of arrow 911a and the curve representing the boundary in the direction opposite to arrow 911a. The curvature of the curve starting at point 901a, passing through point 901c, and ending at point 901b, which represents the boundary of the direction of arrow 911a, is approximately equal to the curvature of a circle passing through these points. On the other hand, the average value of the curvature of the curve starting at point 901a, passing through point 901d, and ending at point 901b is smaller than the curvature of the circle. In particular, the curvature of the curve near point 901d is significantly smaller than the curvature of the curve near point 901c.

In the following, the curve representing the boundary of the electrode pad will be considered as being divided into a portion represented by a curve with a higher curvature and a portion represented by a boundary line with a lower curvature. A portion represented by a curve with a higher curvature is called a high curvature side, and a portion represented by a curve with a lower curvature is called a low curvature side. The LSI electrode pad 208a has a high curvature side in the direction of the arrow 911a and a low curvature side in the direction opposite to the arrow 911a.

The description of each of the LSI electrode pads 208b, 208c, and 208d shown in FIG. 7 is obtained by replacing the description of the LSI electrode pad 208a with reference to FIG. 8 as follows. That is, the letter a included in the reference numerals attached to the components shown in FIG. 8 is read as the letter b, c, and d in the order of the LSI electrode pads 208b, 208c, and 208d.

FIG. 9 is a conceptual diagram showing variations of the LSI electrode pads 208a shown in FIG.

In the LSI electrode pad 208aa shown in FIG. 9A, a line starting from point 901a, passing through point 901e, and ending at point 901b is a straight line with zero curvature. In the present invention, a side with zero curvature is included in the aforementioned low curvature side. The high-curvature side of the LSI electrode pad 208aa starting from the point 901a, passing through the point 901c, and ending at the point 901b is the same as shown in FIG.

In FIG. 9A, point 903ab represents the center of gravity of LSI electrode pad 208aa. Also, the arrow 911a is the same as that shown in FIG. Points 901c and 901e are points at which half lines drawn from the point 903ab in the direction of the arrow 911a and in the opposite direction intersect the outer edge of the LSI electrode pad 208a.

The curvature of the curve starting from point 901a, passing through point 901c, and ending at point 901b, which represents the boundary of the LSI electrode pad 208aa in the direction of arrow 911a, is substantially equal to the curvature of a circle passing through these points. On the other hand, the average value of the curvature of the curve starting at point 901a, passing through point 901e, and ending at point 901b is smaller than the curvature of the circle. In particular, the curvature of the curve near point 901e is significantly smaller than the curvature of the curve near point 901c.

The LSI electrode pad 208ab shown in FIG. A curve is formed between the points 901b. Also, the low curvature side is a straight line between the points 901f and 901g. In the LSI electrode pad 208ab, the high curvature side starting from the point 901a, passing through the point 901c, and ending at the point 901b is the same as shown in FIG.

In FIG. 9B, point 903ac represents the center of gravity of LSI electrode pad 208ab. Also, the arrow 911a is the same as that shown in FIG. Points 901c and 901l are points where half lines drawn from the point 903ac in the direction of the arrow 911a and in the opposite direction intersect the outer edge of the LSI electrode pad 208ab.

The curvature of the curve that starts at point 901a, passes through point 901c, and ends at point 901b, which represents the boundary in the direction of arrow 911a of LSI electrode pad 208ab, is substantially equal to the curvature of a circle passing through these points. On the other hand, the average curvature of the curve starting at point 901a, passing through points 901f, 901l and 901g, and ending at point 901b is smaller than the curvature of the circle. In particular, the curvature of the curve near point 901l is significantly smaller than the curvature of the curve near point 901c. The curvature of the curve between the points 901a and 901f and the curve between the points 901b and 901g may be larger than the curvature of the circle.

In the LSI electrode pad 208ac shown in FIG. 9(c), the low curvature side starting from the point 901h, passing through the point 901k, and ending at the point 901i curves in the opposite direction to the low curvature side shown in FIG. there is A side starting from the point 901h, passing through the point 901j, and ending at the point 901i is a high curvature side having a higher curvature than the low curvature side.

In FIG. 9C, point 903ad represents the center of gravity of LSI electrode pad 208ac. Also, the arrow 911a is the same as that shown in FIG. Points 901j and 901k are points where half lines drawn from the point 903ad in the direction of the arrow 911a and in the opposite direction intersect the outer edge of the LSI electrode pad 208ac.

The curvature of the curve starting at point 901h, passing through point 901j, and ending at point 901i, which represents the boundary in the direction of arrow 911a of LSI electrode pad 208ac, is substantially equal to the curvature of a circle passing through these points. On the other hand, the average value of the curvature of the curve starting at point 901h, passing through point 901k, and ending at point 901i is smaller than the curvature of the circle. In particular, the curvature of the curve near point 901k is significantly smaller than the curvature of the curve near point 901j.

The description of each variation of the LSI electrode pads 208b, 208c and 208d shown in FIG. 7 is obtained by replacing the description of the LSI electrode pads 208aa to 208ac with reference to FIG. 9 as follows. That is, the letter a included in the reference numerals attached to the components shown in FIG. 9 is read as the letter b, c, and d in the order of the LSI electrode pads 208b, 208c, and 208d.

FIG. 10 is a conceptual diagram showing the arrangement of electrode pads on a substrate 402a, which is an example of the substrate used in the connection structure of the second embodiment. FIG. 10 is a plan view assuming that the substrate 402a is viewed from the substrate electrode side.

The arrangement of the substrate electrode pads 409 other than the substrate electrode pads 409a to 409d at the four corners of the substrate 402a is the same as the arrangement of the substrate electrode pads 409 shown in FIG.

Each of the substrate electrode pads 409a to 409d at the four corners of the substrate 402a has a different curvature between the curve representing the boundary in the direction of each of the corresponding arrows 912a to 912d and the curve representing the boundary in the direction opposite to the arrow.

Each of the arrows 912a to 912d represents the direction of approaching the point 221 representing the center of the substrate 402a along the diagonal line 226a or 226b.

Further, the center of gravity of the substrate electrode pads 409a to 409d indicated by each of the points 903a to 903d is displaced in the direction of each of the corresponding arrows 912a to 912d from the arrangement position 232 where the center of gravity of the outermost substrate electrode pad 409 is arranged. ing. The arrangement position 231 is the position where the outermost substrate electrode pads 409 shown in FIG. 2 are arranged.

FIG. 11 is a conceptual diagram showing an enlarged view of the substrate electrode pad 409a shown in FIG. The arrow 912a shown in FIG. 11 is the arrow 912a shown in FIG.

In FIG. 11, point 906a represents the center of gravity of substrate electrode pad 409a. Also, the arrow 912a is the same as that shown in FIG. Points 902c and 902d are points at which half lines drawn from the point 906a in the direction of the arrow 912a and in the opposite direction intersect the outer edge of the substrate electrode pad 409a.

The substrate electrode pad 409a has a different curvature between the curve representing the boundary in the direction of the arrow 912a and the curve representing the boundary in the direction opposite to the arrow 912a.

The curvature of the curve starting at point 902a, passing through point 902c, and ending at point 902b, which represents the boundary of substrate electrode pad 409a in the direction of arrow 912a, is substantially equal to the curvature of a circle passing through these points. On the other hand, the average value of the curvature of the curve starting at point 902a, passing through point 902d, and ending at point 902b is smaller than the curvature of the circle. That is, the substrate electrode pad 409a has a high curvature side in the direction of the arrow 912a and a low curvature side in the direction opposite to the arrow 912a.

In particular, the curvature of the curve near point 902d is significantly smaller than the curvature of the curve near point 902c.

The description of each of the substrate electrode pads 409b, 409c, and 409d shown in FIG. 10 is obtained by replacing the description of the substrate electrode pad 409a with reference to FIG. 11 as follows. That is, the letter a included in the reference numerals attached to the components shown in FIG. 11 is read as the letter b, c, and d in the order of the substrate electrode pads 409b, 409c, and 409d.

12A and 12B are conceptual diagrams showing variations of the substrate electrode pads 409a shown in FIG.

In the substrate electrode pad 409aa shown in FIG. 12A, a line starting from point 902a, passing through point 902e, and ending at point 902b is a straight line with zero curvature. In this embodiment, the sides with zero curvature are included in the aforementioned low curvature sides. In the substrate electrode pad 409aa, the high curvature side starting from the point 902a, passing through the point 902c, and ending at the point 902b is the same as shown in FIG.

In FIG. 12A, point 906ab represents the center of gravity of substrate electrode pad 409aa. Also, the arrow 912a is the same as that shown in FIG. Points 902c and 902e are points where half lines drawn from the point 906ab in the direction of the arrow 912a and in the opposite direction intersect the outer edge of the substrate electrode pad 409aa.

The curvature of the curve starting at point 902a, passing through point 902c, and ending at point 902b, which represents the boundary of substrate electrode pad 409aa in the direction of arrow 912a, is substantially equal to the curvature of a circle passing through these points. On the other hand, the average value of the curvature of the curve starting at point 902a, passing through point 902e, and ending at point 902b is smaller than the curvature of the circle. In particular, the curvature of the curve near point 902e is significantly smaller than the curvature of the curve near point 902c.

In the substrate electrode pad 409ab shown in FIG. 12(b), the low curvature side starting from the point 902a, passing through the points 902f, 902l and 902g and ending at the point 902b, between the point 902a and the point 902f and the point Between 902g and point 902b is a curve. Also, the low curvature side is a straight line between the points 902f and 902g. In the substrate electrode pad 409ab, the high curvature side starting from the point 902a, passing through the point 902c, and ending at the point 902b is the same as shown in FIG.

In FIG. 12B, point 906ac represents the center of gravity of substrate electrode pad 409ab. Also, the arrow 912a is the same as that shown in FIG. Points 902c and 902l are points where half lines drawn from the point 906ac in the direction of the arrow 912a and in the opposite direction intersect the outer edge of the substrate electrode pad 409ab.

The curvature of the curve starting at point 902a, passing through point 902c, and ending at point 902b, which represents the boundary of substrate electrode pad 409ab in the direction of arrow 912a, is substantially equal to the curvature of a circle passing through these points. On the other hand, the average curvature of the curve starting at point 902a, passing through points 902f, 902l and 902g, and ending at point 902b is smaller than the curvature of the circle. In particular, the curvature of the curve near point 902l is significantly smaller than the curvature of the curve near point 902c. The curvature of the curve between points 902a and 902f and the curve between points 902b and 902g may be greater than the curvature of the circle.

In the substrate electrode pad 409ac shown in FIG. 12(c), the low curvature side starting from the point 902h, passing through the point 902k, and ending at the point 902i curves in the opposite direction to the low curvature side shown in FIG. there is A side starting from the point 902h, passing through the point 902j, and ending at the point 902i is a high curvature side having a higher curvature than the low curvature side.

In FIG. 12(c), point 906ad represents the center of gravity of substrate electrode pad 409ac. Also, the arrow 912a is the same as that shown in FIG. Points 902j and 902k are points where half lines drawn from the point 906ad in the direction of the arrow 912a and in the opposite direction intersect the outer edge of the substrate electrode pad 409ac.

The curvature of the curve starting at point 902h, passing through point 902i, and ending at point 902j, which represents the boundary of substrate electrode pad 409ac in the direction of arrow 912a, is substantially equal to the curvature of a circle passing through these points. On the other hand, the average value of the curvature of the curve starting at point 902h, passing through point 902k, and ending at point 902j is smaller than the curvature of the circle. In particular, the curvature of the curve near point 902i is significantly smaller than the curvature of the curve near point 902k.

The description of each variation of the substrate electrode pads 409b, 409c and 409d shown in FIG. 10 is obtained by replacing the description of the substrate electrode pads 409aa to 409ac with reference to FIG. 12 as follows. That is, the letter a included in the reference numerals attached to the components shown in FIG. 11 is read as the letter b, c, and d in the order of the substrate electrode pads 409b, 409c, and 409d.

FIG. 13 is a top view of a mounting structure 100a, which is an example of the mounting structure of the second embodiment. 14 is a conceptual diagram showing a cross section assuming that the mounting structure 100a shown in FIG. 13 is cut along the line 931a.

In the mounting structure 100a, each of the substrate electrode pads 409 of the substrate 402a shown in FIGS. 10 and 11 and each of the LSI electrode pads 208 of the LSI chip 201a shown in FIG. 7 face each other. Each of the substrate electrode pads 409 and each of the LSI electrode pads 208 overlap in the view shown in FIG.

On the other hand, each of the substrate electrode pads 409a to 409d is offset from each of the corresponding LSI electrode pads 208a to 208d in the direction of the diagonal line 226a or 226b from the view shown in FIG. The direction of deviation is the direction of the point 221 representing the center of the LSI chip for each of the substrate electrode pads 409a to 409d. Also, each of the LSI electrode pads 208 a to 208 d is in the opposite direction to the direction of the point 221 .

Solder bumps 307 are formed between each of the LSI electrode pads 208 and each of the corresponding substrate electrode pads 409 as shown in FIG. The solder bump 307 has a barrel shape as shown in FIG. The shape is, for example, as shown in FIG.

On the other hand, as shown in FIG. 14, solder bumps 307a are formed between the LSI electrode pads 208a and the substrate electrode pads 409a. A solder bump 307b is formed between the LSI electrode pad 208b and the substrate electrode pad 409b.

In the following description, a joint structure consisting of the LSI electrode pad 208m (m is any one of a to d), the solder bump 307m and the substrate electrode pad 409m will be referred to as a joint structure 310m.

FIG. 15 is a conceptual top view showing the joining structure 310m. Moreover, FIG. 16 is a perspective conceptual diagram showing 310 m of joining structures.

As shown in FIGS. 15 and 16, the center of gravity of the LSI electrode pad 208m represented by the point 903m is in the direction of the arrow 911m representing the direction opposite to the direction of the center of the LSI chip 201a from the center of gravity of the solder bump 307m represented by the point 905m. out of alignment. Also, the center of gravity of the substrate electrode pad 409m represented by the point 904m is shifted in the direction of the arrow 912m representing the direction of the center of the LSI chip 201a from the center of gravity of the solder bump 307m represented by the point 905m.

As shown in FIG. 16, solder bumps 307m are formed between the LSI electrode pads 208m and the substrate electrode pads 409m.

Here, consider a case where the bonding structure 310m shown in FIGS. 15 and 16 is heated together with the LSI chip main body 202 and the substrate main body 411 shown in FIG.

The LSI chip main body 202 shown in FIG. 14 is mainly made of silicon with a relatively small coefficient of linear expansion. Further, the substrate body portion 411 is mainly made of resin having a larger coefficient of thermal expansion than silicon.

Therefore, when the bonding structure 310m is heated together with the LSI chip main body 202 and the substrate main body 411 shown in FIG. 14, the substrate main body 411 expands greatly, while the LSI chip main body 202 expands to a small degree.

Therefore, the LSI electrode pad 208m hardly moves due to the heating. On the other hand, the substrate electrode pad 409m moves in the direction of the arrow 911m opposite to the direction of the point 221 representing the center of the LSI chip shown in FIG. 13 due to the thermal expansion due to the heating.

Therefore, a force in the direction of the arrow 911m is applied to the interface 952 between the board electrode pad 409m and the solder bump 307m. Due to this force, the stress generated at the interface 952 is not uniform within the interface 952, resulting in a stress distribution. A simulation result of the stress distribution will be described later with reference to FIG.

A force in the direction of an arrow 912m is applied to the interface 951 between the LSI electrode pad 208m and the solder bump 307m. Due to this force, the stress generated at the interface 951 is not uniform within the interface 951, and stress distribution occurs. A simulation result of the stress distribution will be described later with reference to FIG.

17A and 17B are conceptual diagrams showing a method of forming the joint structure 310m shown in FIGS. 15 and 16. FIG.

As shown in FIG. 17A, first, solder 308m is supplied to the LSI electrode pad 208m, and the LSI electrode pad 208m and the solder 308m are joined by heating.

Then, solder 309m is supplied to the substrate electrode pad 409m, and the substrate electrode pad 409m and the solder 309m are joined by heating.

Then, as shown in FIG. 17A, the solder 308m and the solder 309m are brought into contact with each other.

The entire configuration shown in FIG. 17(a) is then heated to melt the solders 308m and 309m. As a result, the solder 308m is melted to join and integrate with the similarly melted solder 309m.

The entire structure is then cooled to solidify the combined solders 308m and 309m to form the solder bumps 307m shown in FIG. 17(b).
[Stress simulation]
Next, stress simulation results for the mounting structure of the second embodiment will be described. As the stress derived from the simulation, von Mises stress representing a stress value projected to a uniaxial tensile or compressive stress in a stress field where loads are applied in multiple directions was used.

FIG. 18 is a diagram showing the layout of the joint structure in the mounting structure 112 used in the simulation.

The bonding structures in the mounting structure 112 are arranged in a 6×6 matrix. These joint structures are fixed to a substrate main body (see substrate main body 411 shown in FIG. 1) and an LSI chip main body (see LSI chip main body 202), which are not shown. The 36 joint structures shown in FIG. 18 are obtained by cutting out 1/4 of the 144 joint structures, which is 12×12, in consideration of the symmetry of the joint structures.

The joint structure 310b shown in FIG. 18 is the joint structure of the second embodiment shown in FIGS. 15 and 16, and the other joint structure is the joint structure 320, which is a general joint structure shown in FIG.

An arrow 911b shown in FIG. 18 indicates a direction away from the center position of the LSI chip along a diagonal line of the LSI chip.

The junction structure 310b is the junction structure located farthest from the center position of the LSI chip. Therefore, among all the bonding structures, the bonding structure 310b has the largest stress caused by the difference in temperature expansion coefficient between the LSI chip and the substrate.

The calculation conditions were that the linear expansion coefficient of the LSI chip was 3 ppm/° C., the size was 26 mm×26 mm, and the thickness was 1 mm. The substrate had a coefficient of linear expansion of 32 ppm/° C., a size of 56 mm×56 mm, and a thickness of 1.6 mm. Also, the height of the bump was set to 0.5 mm. Also, the temperature was assumed to rise from 25°C to 150°C.

First, the stress distribution in each of the LSI chip electrode pads and the substrate electrode pads was determined when the arrangement of the LSI chip electrode pads and the substrate electrode pads is shown in FIG. FIG. 19 is a top view assuming that the LSI chip electrode pads and substrate electrode pads are viewed from the LSI chip side.

LSI electrode pads 208v and substrate electrode pads 209v shown in FIG. 19 are LSI chip electrode pads and substrate electrode pads assumed for simulation. The LSI electrode pads 208v are arranged in a direction opposite to the center of the LSI chip, and the substrate electrode pads 209v are arranged in a direction toward the center of the LSI chip.

FIG. 20 is a diagram showing calculation results of stress distribution in the LSI electrode pad 208v shown in FIG. In the diagrams showing the stress distribution, the lines showing the stress values represent iso-stress lines connecting the points where the shown stresses occur.

In the LSI electrode pad 208v, there is a maximum stress at the end 941a facing the center of the LSI chip and the opposite end 941b facing the same direction. The maximum stress at the end 941a is 1877 MPa, and the maximum stress at the end 941b is 731 MPa.

FIG. 21 is a diagram showing calculation results of stress distribution in the substrate electrode pad 409v shown in FIG.

In the substrate electrode pad 409v, there is a maximum stress at an end portion 941c facing the center of the LSI chip and an opposite end portion 941d facing the same direction. The maximum stress at the end 941c is 980 MPa, and the maximum stress at the end 941d is 1487 MPa.

Next, the stress distribution in each of the LSI electrode pads and the substrate electrode pads was calculated for the case where the LSI electrode pads and the substrate electrode pads were arranged as shown in FIG.
FIG. 22 is a top view assuming that the LSL chip electrode pads and substrate electrode pads are viewed from the LSI chip side.

LSI electrode pads 208w and substrate electrode pads 409w shown in FIG. 22 are LSI chip electrode pads and substrate electrode pads assumed for simulation. The LSI electrode pads 208w and the substrate electrode pads 409w are arranged so that the lines representing the maximum width in the direction parallel to the center of the LSI chip overlap each other.

The arrangement of the electrode pads shown in FIG. 22 is disclosed in Patent Document 4.

FIG. 23 is a diagram showing calculation results of stress distribution in the LSI electrode pad 208w shown in FIG.

In the LSI electrode pad 208w, there is a maximum stress at the end 941e facing the center of the LSI chip and the opposite end 941f facing the same direction. The maximum stress at the end 941e is 1793 MPa, and the maximum stress at the end 941f is 1583 MPa.

FIG. 24 is a diagram showing calculation results of stress distribution in the substrate electrode pad 409w shown in FIG.

In the substrate electrode pad 409w, there is a maximum stress at an end portion 941g facing the center of the LSI chip and an opposite end portion 941h facing the same direction. The maximum stress at the end 941g is 1543 MPa, and the maximum stress at the end 941h is 2044 MPa.

FIG. 25 is a diagram showing the maximum values of the stresses at the ends of the LSI electrode pads and substrate electrode pads derived from the above simulation.

In the case of the arrangement shown in FIG. 19, when compared with the case of the arrangement shown in FIG. 22, the maximum value of the stress at the end of the LSI electrode pad facing the center of the LSI chip is approximately the same. Also, the maximum value of the stress at the opposite end of the LSI electrode pad toward the center of the LSI chip greatly decreases from 1583 MPa to 731 MPa in the case of FIG. 19 as compared with the case of FIG. Also, the maximum value of the stress at the end portion of the substrate electrode pad facing the center of the LSI chip is greatly reduced from 1543 MPa to 980 MPa in the case of FIG. 19 as compared with the case of FIG. Also, the maximum value of the stress at the end of the substrate electrode pad opposite to the center of the LSI chip is significantly reduced from 2044 MPa to 1487 MPa in the case of FIG. 19 compared to the case of FIG.

From the above, it can be understood that the maximum stress value at each end tends to decrease by shifting the positions of the electrode pads as shown in FIG.

Next, the reason why the simulation results shown in FIG. 25 are obtained will be considered.

FIG. 26 is an image diagram showing cross sections of joint structures 310v and 310w, which are joint structures including electrode pad pairs shown in FIGS. 19 and 22, respectively.

FIG. 26(a) is a cross-sectional image diagram of a bonding structure 310v including the LSI electrode pad 208v and the substrate electrode pad 409v shown in FIG. FIG. 26(a) assumes a cross section of the joint structure 310v including the ends 941a and 941b shown in FIG. 20 and the ends 941c and 941d shown in FIG. FIG. 26(a) also shows the stress corresponding to each of the ends 941a-941d.

The contact angles of the solder bumps 307v on each of the ends 941a to 941d are contact angles θ1 to θ4, respectively, in the order of the ends 941a to 941d.

FIG. 26(b) is a cross-sectional image view of a bonding structure 310w including the LSI electrode pad 208w and the substrate electrode pad 409w shown in FIG. FIG. 26(b) assumes a cross section of the joint structure 310w including the ends 941e and 941f shown in FIG. 23 and the ends 941g and 941h shown in FIG. FIG. 26(a) also shows the stress corresponding to each of the ends 941a-941d.

The contact angles of the solder bump 307w on each of the ends 941e to 941h are contact angles θ5 to θ8, respectively, in the order of the ends 941e to 941h.

Here, each of the contact angles θ2 and θ3 is smaller than each of the contact angles θ6 and θ7 in the order of the contact angles θ2 and θ3. Here, it is generally known that the smaller the contact angle of solder, the smaller the stress generated at the interface between the electrode and the solder. The stresses at ends 941b and 941c of 731 MPa and 980 MPa are less than the stresses at ends 941f and 941g of 1583 MPa and 1543 MPa. This is probably because each of the contact angles θ2 and θ3 is smaller than each of the contact angles θ6 and θ7.

On the other hand, since the contact angle θ1 is larger than the contact angle θ5, the stress at the end portion 941a should be significantly larger than the stress at the end portion 941e. However, the difference between the stress at the end 941a of 1877 MPa and the stress at the end 941e of 1793 MPa is small. This is thought to mean that, since the end portion 941a is located on the aforementioned low curvature side, the increase in stress is suppressed by the stress distribution due to the effect of the shape due to the presence of the low curvature side. be done.

One of the reasons why the stress 1487 MPa of the end portion 941d is smaller than the stress 2044 MPa of the end portion 941h is that stress distribution due to the effect of the shape due to the presence of the low curvature side suppresses an increase in stress. . Two of the reasons for this are thought to be that stress is relieved by the solder bumps as the length of the solder bumps increases.

The above description of the stress distribution based on the simulation assumes the stress applied to the bonding structure 310b due to the expansion of the substrate due to the mounting structure 112 shown in FIG. 18 being heated.

Here, the stress applied to the bonding structure 310b due to the expansion of the substrate due to the heating of the mounting structure 112 is assumed. The stress distribution of the von Mises stress obtained by the above simulation is the same when the temperature rises and when the temperature drops.

Therefore, even when assuming the force applied to the bonding structure 310b due to the contraction of the substrate due to the cooling of the mounting structure 112 shown in FIG. 18, the stress distribution similar to the above is calculated. The reason for this is that the places where the tensile stress and the compressive stress are generated are reversed in each of the LSI electrode pads and the substrate electrode pads, but the places where they are generated are the same.
[effect]
In the junction structure of the present embodiment, each of the LSI electrode pads and the corresponding substrate electrode pads has a shape surrounded by a high curvature side and a low curvature side. Then, the low-curvature side of the LSI electrode pad is arranged in the direction opposite to the direction of the center of the LSI chip. Also, the substrate electrode pads are arranged toward the center of the LSI chip. Then, the high curvature sides of the electrode pads are shifted away from each other. As a result, as shown by the simulation results of the embodiment, the bonding structure can relax the maximum stress value at least at each end of the LSI chip in the diagonal direction of the LSI electrode pad and the substrate electrode pad as a whole. .

Compared with the joint structure disclosed in Patent Document 4, the joint structure of this embodiment can further reduce the maximum stress generated in the diagonal direction of the LSI chip.

Failures in bonded structures are generally associated with stress maxima. Therefore, the joint structure of this embodiment can further reduce the probability of breakage as compared with the joint structure disclosed in Patent Document 4. That is, the joint structure of the present embodiment can further improve the resistance to the force applied to the joint structure as compared with the joint structure disclosed in Patent Document 4.

FIG. 27 is an image diagram showing the configuration of a joint structure 310x, which is the minimum configuration of the joint structure of the embodiment.

The bonded structure 310x includes a first bonded portion 701x and a bonded body 307x. The first welded portion 701x has a predetermined closed curve as an outer edge.

The bonded body 307x is bonded to the first bonded portion 701x.

A force in a first direction parallel to the first joined portion 701x may be applied to the joined body 307x.

A half line drawn from the first to-be-joined part gravity center, which is the center of gravity of the first to-be-joined part 701x, in a second direction that is either the first direction or the opposite direction of the first direction, and the Let the intersection with the closed curve be the first point 941ax. A second point 941bx is defined as an intersection of a half line drawn from the center of gravity of the first joined portion in the direction opposite to the second direction and the closed curve. In that case, the curvature of the closed curve at the second point 941bx is smaller than the curvature of the closed curve at the first point 941ax.
Further, a straight line connecting the center of gravity of the joined body 307x and the center of gravity of the first joined portion 701x is inclined in the opposite direction with respect to the joining surface 960x involved in joining.

In the junction structure 310x, the junction body 307x is inclined in the opposite direction. Therefore, the contact angle of the bonded body 307x to the bonded surface 960x at the first point 941ax is smaller than when the bonded body is not formed tilted. Therefore, the maximum value of the stress generated near the first point 941ax on the joint surface 960x is smaller than when the joined body is not tilted.

On the other hand, the maximum value of the stress generated near the second point 941bx on the joint surface 960x is that the shape of the joint surface 960x near the second point 941bx when viewed from above has a smaller curvature. occurs and increases to a lesser extent or decreases.

As described above, the bonding structure 310x has a smaller maximum value of stress compared to the case where the bonding body is formed without tilting.

Failures in bonded structures are generally associated with stress maxima. Therefore, the joint structure of this embodiment can further reduce the probability of breakage as compared with the joint structure disclosed in Patent Document 4. That is, the joint structure of the present embodiment can further improve the resistance to the force applied to the joint structure as compared with the joint structure disclosed in Patent Document 4.

Therefore, the junction structure 310x has the effects described in the section [Effects of the Invention] due to the above configuration.

Note that the joint structure 310x shown in FIG. 27 is, for example, the joint structure 310v shown in FIG. 5, one of the joint structures 310a and 310b shown in FIG. 14, or the joint structure 310m shown in FIGS.

5, or the LSI electrode pad 208m and the substrate electrode pad 409m shown in FIGS. 15 and 16. or

Also, the bonded bodies 307x are, for example, the solder bumps 307v shown in FIG. 5 or the solder bumps 307m shown in FIGS.

8, points 901c and 901j in FIG. 9, point 902c in FIG. 11, and points 902c and 902j in FIG. 12, for example. 8, points 901e, 901l and 901k shown in FIG. 9, point 902d shown in FIG. 11, and points 902e, 902l and 902k shown in FIG. be.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and further modifications, replacements, and adjustments can be made without departing from the basic technical idea of the present invention. can be added. For example, the configuration of elements shown in each drawing is an example for helping understanding of the present invention, and the configuration is not limited to the configuration shown in these drawings.

Also, part or all of the above embodiments may be described as the following additional remarks, but are not limited to the following.
(Appendix 1)
A first part to be joined having a predetermined closed curve as an outer edge, and a joined body to be joined to the first part to be joined,
A force in a first direction parallel to the first surface to be joined of the first part to be joined may be applied to the joined body,
A half line drawn from the center of gravity of the first part to be joined, which is the center of gravity of the first part to be joined, in a second direction that is either the first direction or the opposite direction of the first direction, and the half line From the curvature of the closed curve at the first point that is the intersection with the closed curve, at the second point that is the intersection of the closed curve and a half line drawn from the center of gravity of the first joined portion in the opposite direction to the second direction the curvature of the closed curve is smaller,
A straight line connecting the center of gravity of the joint, which is the center of gravity of the joined body, and the center of gravity of the first jointed portion is formed to be inclined in the opposite direction with respect to the joint surface related to the joining,
junction structure.
(Appendix 2)
The first joint portion has a shape surrounded by a first curve having a third curvature with an average value of curvature and a second curve with a fourth curvature having an average value smaller than the third curvature, and 2. The junction structure of Claim 1, wherein the first point is included in the first curve and the second point is included in the second curve.
(Appendix 3)
3. The junction structure of clause 2, wherein the second curve comprises a straight line.
(Appendix 4)
3. The joint structure of clause 2, wherein the second curve is a straight line.
(Appendix 5)
5. The joint structure according to any one of appendices 1 to 4, wherein the joint is solder.
(Appendix 6)
The joining structure according to any one of appendices 1 to 5, wherein the first part to be joined is a first electrode.
(Appendix 7)
7. The joint structure according to any one of appendices 1 to 6, wherein the force is applied to a position of the joint body away from the joint surface.
(Appendix 8)
8. The joining structure according to any one of Appendices 1 to 7, wherein the first part to be joined is formed on the first base.
(Appendix 9)
Among the plurality of formation positions on the formation surface of the first base on which the first to-be-joined portion is formed, at the formation position farthest from the position range center of gravity of the position range of the formation position, the first 9. The joint structure of clause 8, wherein there is a single joint.
(Appendix 10)
The joint structure according to Appendix 9, wherein the position range center of gravity is a forming surface center of gravity that is the center of gravity of the forming surface.
(Appendix 11)
11. The bonding structure of any one of Clauses 8-10, wherein the first substrate is either a large scale integrated circuit chip or a substrate.
(Appendix 12)
12. The joint structure according to any one of appendices 8 to 11, further including the first base.
(Appendix 13)
13. The joining structure according to any one of Appendices 1 to 12, wherein the force is applied by a second joining surface of the joining body between the joining body and the second part to be joined.
(Appendix 14)
14. The joining structure according to Appendix 13, wherein the second joined portion is a second electrode.
(Appendix 15)
15. The joint structure according to appendix 13 or appendix 14, wherein the second joint surface is substantially parallel to the joint surface.
(Appendix 16)
16. The joint structure according to any one of appendices 13 to 15, further including the second jointed portion.
(Appendix 17)
17. The joining structure according to any one of appendices 13 to 16, wherein the second part to be joined is formed on the second base.
(Appendix 18)
18. The bonding structure of Clause 17, wherein said second substrate is either a large scale integrated circuit chip or a substrate.
(Appendix 19)
19. The bonded structure according to Appendix 17 or Appendix 18, further comprising the second substrate.
(Appendix 20)
The first joined portion is included in the first base, and the joined body is second joined to the second joined portion included in the second base,
The joining structure according to Appendix 1, wherein the force is generated by a difference in coefficient of linear expansion between the first base and the second base.
(Appendix 21)
21. The bonding structure of Claim 20, wherein said first substrate is a large scale integrated circuit chip and said second substrate is a substrate.
(Appendix 22)
22. The joining structure of clause 21, wherein the substrate is a printed circuit board.
(Appendix 23)
A structure comprising a plurality of joint structures according to any one of Appendices 1 to 22.

100, 112 mounting structure 201 LSI chip 202 LSI chip main body 208, 208a, 208aa, 208ab, 208ac, 208b, 208c, 208d, 208m, 208v, 208w LSI electrode pads 221, 221, 901a, 901b, 901d, 901e, 901f,901g,901h,901k,901l,902a,902b,902c,902d,902e,902f,902g,902h,902i,902k,902k,902l,903a,903aa,903ab,903ac,903b,903c,903d,903m, 904a, 904b, 904c, 904d, 904m, 905m, 906a, 906aa, 906ab, 906ac Points 226a, 226b Diagonal line 227 LSI chip peripheral position 231, 232 Array position 307, 307a, 307b, 307m, 307v, 307wx Solder bump 307x 308b, 309b Solder 310a, 310b, 310m, 310v, 310w, 310x, 320 Joint structure 402, 402a Substrate 409, 409a, 409aa, 409ab, 409ac, 409b, 409c, 409d, 409m, 409v, 409w Substrate electrode pad 411 Part 701x First joined part 911a, 911b, 911c, 911d, 911m, 912a, 912b, 912c, 912d, 912m, 971c, 971d, 971x Arrow 931b, 931c Line 941a, 941b, 941c, 941d, 941e, 941f, 941g , 941h end portion 941ax first point 941bx second point 951, 952 interface 960x joint surface θ1, θ2, θ3, θ4, θ5, θ6, θ7, θ8 contact angle

Claims (8)

A bonded body arranged between a first base and a second base, a first bonded portion bonded between the first base and the bonded body, and bonded between the second base and the bonded body and a second jointed portion ,
The first jointed portion has a predetermined closed curve as an outer edge,
When the temperature rises, the first to-be-bonded portion of the first to-be-bonded portion is forced between the first base and the bonded body based on the force caused by the difference in coefficient of linear expansion between the first base and the second base. A force is applied in a first direction parallel to the surface,
At a first point that is the intersection of a half line drawn in a second direction opposite to the first direction from the center of gravity of the first part to be joined, which is the center of gravity of the first part to be joined, and the closed curve The curvature of the closed curve at a second point, which is the intersection of the closed curve and a half line drawn from the center of gravity of the first joined portion in the direction opposite to the second direction, rather than the first curvature, which is the curvature of the closed curve. is smaller, and
A straight line connecting the center of gravity of the joined body and the center of gravity of the first to-be-joined portion is inclined in the opposite direction with respect to the normal line of the first to-be-joined surface . A first contact angle, which is a contact angle of the joined body with respect to the first end portion corresponding to the first point of the first portion to be joined, corresponds to the second point of the first portion to be joined. smaller than the second contact angle, which is the contact angle of the joined body with respect to the second end, which is the end;
Since the second curvature is smaller than the first curvature, the stress at the second end is suppressed, and since the first contact angle is smaller than the second contact angle, the first end stress is suppressed in
junction structure. The first joint portion has a shape surrounded by a first curve having a third curvature with an average value of curvature and a second curve with a fourth curvature having an average value smaller than the third curvature, and 2. The joint structure of claim 1, wherein a first point is included in said first curve and said second point is included in said second curve. 3. The joint structure of claim 2, wherein said second curve comprises a straight line. 4. The joining structure according to any one of claims 1 to 3 , wherein said first joined portion is formed on said first substrate. A position range, which is the center of the position range of the formation positions, among the formation positions of the individual parts to be joined on the formation surface of the first base on which a plurality of parts to be joined including the first part to be joined are formed 5. The joining structure according to claim 4 , wherein the first joined portion is located at the forming position farthest from the center . 6. The joining structure according to claim 5 , wherein said position range center is a forming surface center which is the center of said forming surface. A bonding structure according to any one of claims 1 to 6 , wherein said first substrate is a large scale integrated circuit chip and said second substrate is a substrate. A structure comprising a plurality of joint structures according to any one of claims 1 to 7 .

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