JP2010267792A - Semiconductor device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device capable of suppressing crack formation caused by heat stress, and a manufacturing method for the semiconductor device. <P>SOLUTION: According to the semiconductor device 1, a subject to be mounted 2 is mounted on a mounted subject 3 via a plurality of arrayed or randomly arranged connection terminals 41. The semiconductor device 1 includes a means that forms a plurality of electrode pads 43a and 43b on the mounted subject 3, and a means that melts and solidifies the connection terminals 41 on the electrode pads 43a and 43b to join the connection terminals 41 to the mounted subject 3. Some electrode pads 43a each have a body 431 that regulates the solidified shape of the connection terminal 41, and a guide portion 432 that guides part of the connection terminal 41 to the outer periphery of the body 431 when the connection terminal 41 melts. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof, and more particularly to a semiconductor device capable of suppressing the occurrence of cracks due to thermal stress and a manufacturing method thereof.

  In recent semiconductor devices, a BGA (Ball Grid Array) connection structure is adopted as a structure for mounting an electronic component or a circuit board on a wiring board. The BGA connection structure is a structure in which a mounting target is mounted on a mounting target via a plurality of connection terminals arranged in an array or at random. In such a BGA connection structure, since a plurality of connection terminals are arranged in an array or in a random manner, the package can be downsized and electronic components can be mounted at high density. Thereby, size reduction of an electronic device is implement | achieved. In addition, since the BGA connection structure has a leadless structure, the connection distance between the mounting target and the mounting target is shortened. This improves the signal processing speed of the electronic device.

  Here, for example, in a BGA type ceramic circuit module composed of a ceramic substrate obtained by laminating and firing a ceramic material together with a conductive wiring material, the outer peripheral portion of the electrode pad of the BGA connection portion is mounted on the wiring substrate. In some cases, thermal stress concentrates on the ceramic substrate and cracks occur in the ceramic substrate around the electrode pad. Thus, by covering the outer periphery of the electrode pad with a glass protective film, a method for manufacturing a ceramic circuit module is provided that provides a terminal structure in which cracks are unlikely to occur and enables the terminal structure to be obtained with a small number of steps. ing. As such a configuration, for example, a technique described in Patent Document 1 is known.

  In addition, in the BGA connection structure that connects two types of substrates having different linear expansion coefficients, thermal stress is concentrated on a part of the solder that is the connection terminal when a thermal history is applied. Then, there is a problem that the solder is cracked in the vicinity of the joint surface between the solder and the electrode pad of the substrate, and the solder is broken. As a solution to this problem, a configuration is adopted in which thermal stress is prevented from concentrating on a part of the solder of the BGA connection portion. That is, a plastic ball is blended in the solder, and the linear expansion coefficient of the plastic ball is appropriately selected. As a result, a gap is formed between the plastic ball and the underlying solder layer, and distortion due to temperature change of the BGA connection portion is absorbed. Further, since the BGA connection portion has a drum-shaped cross-sectional shape, thermal stress generated in the vicinity of the joint surface between the solder and the electrode pad is dispersed. As such a configuration, for example, a technique described in Patent Document 2 is known.

  In addition, there is a configuration in which an underfill material is filled between the ceramic substrate and the wiring substrate. In such a configuration, the entire electrode pad or a part thereof is reinforced, thereby preventing the occurrence of cracks in the vicinity of the joint between the solder ball and the electrode pad or the generation of cracks in the base material around the electrode pad. As such a configuration, for example, a technique described in Patent Document 3 is known.

JP 2007-250564 A Japanese Patent No. 2856197 Japanese Patent No. 3644340

  However, in the configuration of Patent Document 1, although cracks are unlikely to occur around the electrode pad, the solder ball at the connection portion is crushed and the central portion of the solder ball tends to swell. For this reason, the solder ball has a constricted shape in the vicinity of the joint surface of the electrode pad, and there is a possibility that stress concentrates on the constricted portion and cracks occur. Further, when the endurance temperature range required for the semiconductor device is widened, the thermal stress on the pad bonding portion increases due to the difference in thermal expansion. For this reason, for example, a method of relaxing the stress by increasing the conductor thickness of the electrode pad is considered. However, as the conductor thickness increases, the amount of conductor used increases, resulting in increased costs. In a configuration having a conductor having a general thickness, the conductor film is formed by screen printing of a conductor paste. However, in the structure having a thick conductor, filling of the screen mask and the removal of the mask in the printing process are deteriorated, so that it is difficult to form a conductor film. Furthermore, in such a configuration, there is a problem that only a material (ceramic material or the like) having sufficient adhesion strength to the base material can be selected as a usable conductor material. That is, as described above, in the BGA connection structure having the collapse of the solder ball, the bulge in the center of the connection portion, and the constriction near the bonding surface of the electrode pad, the largest thermal stress is mechanically near the bonding portion of the electrode pad. Works. For this reason, only the reinforcement of the substrate as described above cannot satisfy the requirement of extending the durable temperature range or the substrate size.

  Further, in the configuration of Patent Document 2, in order to solve the collapse of the solder ball, the swelling at the center of the BGA connection portion, and the constriction near the bonding surface of the electrode pad, the heat concentrated on the bonding surface between the solder and the electrode pad is concentrated. A configuration that disperses the stress is employed. That is, a plastic ball or the like is blended in the solder of the BGA connection portion, and the electrode pad diameter of the substrate is set larger than the plastic ball diameter, so that the center of the BGA connection portion has a constricted drum shape. Has been. However, such a configuration requires a process of enclosing plastic balls in the solder, and there is a problem that the manufacturing cost and the number of processes increase.

  Moreover, in the structure of patent document 3, the underfill material is filled in the BGA connection part between a semiconductor device and a wiring board, and the BGA connection part is reinforced. However, such a configuration has a problem that a process for filling the underfill after the BGA connection is required. In addition, when an underfill material exists between the ceramic substrate and the wiring substrate, the dielectric constant increases and the transmission loss of high frequency increases. For this reason, an underfill material is not suitable as a joint reinforcement material between high frequency semiconductor components.

  The present invention has been made in view of the above, and an object of the present invention is to provide a semiconductor device and a method for manufacturing the same that can suppress the occurrence of cracks due to thermal stress.

  In order to solve the above-described problems and achieve the object, a semiconductor device according to the present invention is a semiconductor device in which a mounting target is mounted on a mounting target via a plurality of connection terminals arranged in an array or at random. And a means for forming a plurality of electrode pads on the mounting target side, a means for melting and solidifying the connection terminal on the electrode pad, and coupling to the mounting target. The electrode pad includes a main body part that defines a solidification shape of the connection terminal, and a guide part that guides a part of the connection terminal to the outer periphery of the main body part when the connection terminal is melted. .

  In the semiconductor device according to the present invention, both the electrode pad having the main body portion and the guide portion and the electrode pad having only the main body portion are arranged on a single mounting target.

  In the semiconductor device according to the present invention, the electrode pad having the main body portion and the guide portion is disposed in the signal circuit portion to be mounted.

  In the semiconductor device according to the present invention, the electrode pad having the main body portion and the guide portion is disposed on an outer peripheral diagonal portion of the mounting target.

  Further, in the semiconductor device according to the present invention, the guide portion has an annular structure arranged to surround the outer periphery of the main body portion with a predetermined distance from the main body portion, and is partially connected to the main body portion. Is done.

  In the semiconductor device according to the present invention, the guide portion has an island shape protruding from the main body portion.

  Further, the semiconductor device according to the present invention includes means for forming a plurality of electrode pads on the mounting target side, and low toughness when the mounting target and the mounting target have different toughness. The diameter φDa of the electrode pad on the side having a thickness and the diameter φDb of the electrode pad on the side having a high toughness have a relationship of φDa> φDb.

  The semiconductor device manufacturing method according to the present invention is a method for manufacturing a semiconductor device in which a mounting target is mounted on a mounting target via a plurality of connection terminals arranged in an array or at random. A plurality of electrode pads are formed on the side, and the connection terminals are coupled to the mounting object by melting and solidifying on the electrode pads, and some of the electrode pads are And a main body part that defines a solidification shape of the connection terminal, and a guide part that guides a part of the connection terminal to the outer periphery of the main body part when the connection terminal is melted.

  In the semiconductor device and the semiconductor device manufacturing method according to the present invention, a part of the electrode pads constituting the BGA connection structure includes a main body part that defines a solidification shape of the connection terminal, and a part of the connection terminal when the connection terminal is melted And a guide portion for guiding the guide to the outer periphery of the main body portion. In such a configuration, in the mounting process of the mounting target, a part of the molten connection terminal moves from the main body part to the guide part, and the volume of the connection terminal on the main body part decreases. Then, when the connection terminal solidifies in the solder solidification step, the central part of the connection terminal becomes a constricted drum shape, and the connection part of the connection terminal becomes a fillet shape and is coupled to the first electrode pad to be mounted. To do. Then, when the mounting target is thermally deformed due to the thermal history of the semiconductor device, the thermal stress is likely to act on the center portion of the connection terminal, and the shear thermal stress acting on the joint portion between the connection terminal and the first electrode pad is reduced. Is done. Then, generation | occurrence | production of the crack of the connection terminal by a thermal stress or generation | occurrence | production of the crack in the junction part of a connection terminal and mounting object is suppressed. Thereby, there is an advantage that connection failure of the semiconductor device is suppressed.

FIG. 1 is a configuration diagram showing a semiconductor device according to an embodiment of the present invention. FIG. 2 is an enlarged view showing a BGA connection structure of the semiconductor device shown in FIG. FIG. 3 is an explanatory view showing a manufacturing process of the semiconductor device shown in FIG. FIG. 4 is a plan view showing the first electrode pad of the BGA connection structure. FIG. 5 is a plan view showing a second electrode pad of the BGA connection structure. FIG. 6 is a plan view showing an arrangement example of the first electrode pads and the second electrode pads in the mounting target. FIG. 7 is a plan view showing an arrangement example of the first electrode pads and the second electrode pads on the mounting target. FIG. 8 is an explanatory diagram illustrating a melting state of the connection terminal on the first electrode pad side. FIG. 9 is an explanatory diagram illustrating a melting state of the connection terminals on the second electrode pad side. FIG. 10 is an explanatory view showing a forming process of the electrode pad. FIG. 11 is an explanatory view showing a forming process of the electrode pad. FIG. 12 is a plan view showing a modification of the first electrode pad. FIG. 13 is a plan view showing a modification of the first electrode pad. FIG. 14 is an explanatory diagram showing the relationship between the diameter of the electrode pad to be mounted and the diameter of the electrode pad to be mounted. FIG. 15 is an explanatory diagram showing the relationship between the diameter of the electrode pad to be mounted and the diameter of the electrode pad to be mounted.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Further, the constituent elements of this embodiment include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

[BGA connection structure of semiconductor device]
The semiconductor device 1 is applied to a semiconductor device having a BGA (Ball Grid Array) connection structure. The BGA connection structure refers to a structure in which a mounting target is mounted on a mounting target via a plurality of connection terminals arranged in an array or at random. Hereinafter, the semiconductor device 1 having this BGA connection structure will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram showing a semiconductor device according to an embodiment of the present invention. FIG. 2 is an enlarged view showing a BGA connection structure of the semiconductor device shown in FIG. FIG. 3 is an explanatory view showing a manufacturing process of the semiconductor device shown in FIG. 4 and 5 are plan views showing electrode pads on the mounting target side of the BGA connection structure.

  In this semiconductor device 1, the mounting target 2 is mounted on the mounting target 3 via the BGA connection structure 4 (see FIGS. 1 and 2).

  The mounted object 2 is configured by an electronic component such as a semiconductor element or a passive circuit element (for example, a resistor or a capacitor), or a circuit board on which these electronic components are mounted. For example, in this embodiment, the mounting target 2 is constituted by a circuit board 22 on which a semiconductor element 21 is mounted. A predetermined signal circuit 23 is formed on the circuit board 22 and a cap 24 as a cover member is attached. The mounting target 3 is constituted by, for example, a wiring board having a predetermined printed wiring pattern.

  The BGA connection structure 4 includes a connection terminal 41 and a pair of electrode pads 42 and 43. The connection terminal 41 is a spherical metal material and is made of, for example, a solder ball. The pair of electrode pads 42 and 43 includes an electrode pad 42 formed on the mounting target 2 side and an electrode pad 43 formed on the mounting target 3 side. In this BGA connection structure 4, the mounting target 2 is mounted on the mounting target 3 by connecting the electrode pads 42 on the mounting target 2 side and the electrode pads 43 on the mounting target 3 side by the connection terminals 41. In addition, a plurality of connection terminals 41 (and electrode pads 42 and 43) are arranged in an array or a random manner to connect the mounted object 2 and the mounting object 3. Thereby, downsizing of the package and high-density mounting of electronic components are possible, and downsizing of the electronic device is realized. Moreover, since the BGA connection structure 4 has a leadless structure, the connection distance between the mounted object 2 and the mounted object 3 is shortened. This improves the signal processing speed of the electronic device. The shape and arrangement structure of the electrode pads 43 on the mounting target 3 side will be described later.

  In the manufacturing process of the semiconductor device 1, first, the electrode pad 42 is formed on the lower surface of the mounting target 2, and the connection terminal 41 is bonded onto the electrode pad 42 (see FIG. 3A). Moreover, the electrode pad 43 is formed on the upper surface of the mounting target 3, and the cream solder 44 is printed on the electrode pad 43 (cream solder printing step). The cream solder 44 is powdered solder that is adjusted in viscosity by adding flux. Next, the lower surface of the mounting target 2 and the upper surface of the mounting target 3 are bonded together, and the connection terminals 41 on the mounting target 2 side are pressed against the corresponding cream solder 44 on the mounting target 3 side (substrate mounting step) ( (Refer FIG.3 (b)). As a result, the connection terminal 41 is sandwiched between the electrode pad 42 on the mounting target 2 side and the electrode pad 43 on the mounting target 3 side.

  Next, reflow preheating is performed (reflow preheating step) (see FIG. 3C). Then, the cream solder 44 is softened and covers the electrode pad 43 on the mounting target 3 side. Next, reflow main heating is performed (reflow main heating step) (see FIG. 3D). Then, the connection terminal 41 starts to melt at the melting point and spreads wet on the electrode pad 43 on the mounting target 3 side (solder melting step) (see FIG. 3E). Thereafter, cooling is performed and the connection terminal 41 is solidified, whereby the electrode pad 42 on the mounting target 2 side and the electrode pad 43 on the mounting target 3 side are conducted through the connection terminal 41 (solder solidification step). (Refer FIG.3 (f)). Thereby, the mounting target 2 and the mounting target 3 are connected through the BGA connection structure 4. At this time, the shape of the connection terminal 41 melted and solidified is regulated by the planar shape of the electrode pad 43. Thereby, the shape of the connection terminal 41 is optimized.

[BGA connection structure electrode pads]
Here, in the configuration in which the mounting target and the mounting target have different linear expansion coefficients, thermal stress is generated in the connection terminals of the BGA connection structure due to the difference in the linear expansion coefficients. Then, there is a possibility that a crack is generated in the connection terminal, or a crack is generated in a joint portion between the connection terminal and the mounting target. The occurrence of such a crack causes a connection failure of the semiconductor device.

  Therefore, in the semiconductor device 1, the following configuration is adopted in order to solve such a problem. First, the group of electrode pads 43 on the mounting target 3 side includes two types of electrode pads including a first electrode pad 43a and a second electrode pad 43b (see FIGS. 4 to 7). Then, the first electrode pads 43a and the second electrode pads 43b are arranged in a vertical and horizontal array with a predetermined interval on the bonding surface of the mounting target 3 (the bonding surface with the mounting target 2) ( (See FIG. 6 or FIG. 7). An arrangement example of the first electrode pad 43a and the second electrode pad 43b will be described later.

  The first electrode pad 43a includes a main body portion 431 and a guide portion 432 (see FIG. 4). The second electrode pad 43b is composed only of the main body 431 (see FIG. 5). The main body 431 is a part that defines the solidification shape of the connection terminal 41, and is a part common to both the first electrode pad 43a and the second electrode pad 43b. For example, in this embodiment, the main body 431 is formed in a circular shape (disc shape). The guide portion 432 is a portion that guides a part of the material of the connection terminal 41 to the outer periphery of the main body portion 431 when the connection terminal 41 is melted, and is formed only on the first electrode pad 43a. For example, in this embodiment, the guide portion 432 has an annular structure, and is arranged so as to surround the outer periphery of the main body portion 431 while leaving a predetermined gap between the guide portion 432 and the four connecting portions. It is connected to the main body portion 431 through the portion 433.

  With the above configuration, when the mounting target 2 is mounted on the mounting target 3 by the BGA connection structure 4 in the manufacturing process of the semiconductor device 1, the solidified shape of the connection terminal 41 is formed as follows (FIG. 2). , FIG. 3, FIG. 8 and FIG. 9).

  First, in the first electrode pad 43a, when the cream solder 44 is softened and covers the first electrode pad 43a in the reflow main heating step, the cream solder 44 is transmitted from the main body portion 431 through the connecting portion 433 to the guide portion. It spreads wet to 432 (see FIG. 3D). Then, in the solder melting step, a part of the molten connection terminal 41 moves from the main body portion 431 to the guide portion 432, and the volume of the connection terminal 41 on the main body portion 431 decreases (see “ a part "). Then, when the connection terminal 41 is solidified in the solder solidification step, the central portion 411 of the connection terminal 41 has a drum shape (constricted shape), and the joint portion 412 of the connection terminal 41 has a fillet shape (end portion). It becomes a widened shape) and is coupled to the first electrode pad 43a (refer to “a part” in FIG. 3F). Thereby, the shape of the connection terminal 41 in the 1st electrode pad 43a is optimized (refer FIG. 2).

  On the other hand, in the second electrode pad 43b, when the cream solder 44 is softened and covers the second electrode pad 43b in the reflow main heating step, the cream solder 44 wets and spreads only on the main body 431 (FIG. 3D )reference). Then, in the solder melting step, the molten connection terminal 41 stays on the main body portion 431, and the volume thereof does not decrease (see “b portion” in FIG. 3E). Then, when the connection terminal 41 is solidified in the solder solidification step, the central portion 411 of the connection terminal 41 has a swelled shape (flat ball shape), and the joint portion 412 of the connection terminal 41 has a constricted shape. It joins to the 2nd electrode pad 43b (refer FIG.3 (f) "b part").

  Further, by arranging both the plurality of first electrode pads 43a and the plurality of second electrode pads 43b on a single mounting target 3, the following actions are obtained (FIGS. 3 and 6 to 9). reference). In the first electrode pad 43a, as described above, in the solder melting step, a part of the molten connection terminal 41 moves from the main body portion 431 to the guide portion 432, and the volume of the connection terminal 41 on the main body portion 431 becomes larger. It decreases (refer to “a part” in FIG. 3E). For this reason, the distance Ha between the mounted object 2 and the mounted object 3 is reduced by the volume reduction of the connection terminal 41 (see FIG. 8). Then, the melted connection terminal 41 is crushed, and the connection shape between the connection terminal 41 and the first electrode pad 43a is stabilized. On the other hand, in the second electrode pad 43b, since the second electrode pad 43b does not have a guide part in the solder melting step, the volume of the connection terminal 41 does not decrease (see “b part” in FIG. 3E). . For this reason, the distance Hb between the mounted object 2 and the mounted object 3 is wider than the distance Ha in the first electrode pad 43a (Ha <Hb) and is stably maintained (see FIG. 9). For this reason, when the connection terminal 41 is solidified in the solder solidification step, the interval Ha on the first electrode pad 43a side is widened according to the interval Hb on the second electrode pad 43b side. Then, the suitable shape (FIG. 2 and FIG. 3 (f) “) which has the drum-shaped center part 411 and the fillet-shaped joining part 412 from the shape (refer FIG. 8) which the connection terminal 41 on the 1st electrode pad 43a was crushed. (refer to part a). Thereby, the connection terminal 41 of the first electrode pad 43a is formed into an appropriate shape. Note that the distances Ha and Hb between the mounted object 2 and the mounted object 3 are determined by the surface tension of the molten connection terminal 41 and the weight of the mounted object 2.

  In addition, the electrode pads 42 and 43 can be formed by well-known methods, such as NSMD (non-Solder Mask Defined) method and SMD (Solder Mask Defined), for example (refer FIG. 10 and FIG. 11). Accordingly, the electrode pads 42 and 43 (particularly, the first electrode pad 43a having the guide portion 432) can be easily formed without increasing the number of steps. For example, in the NSMD method, a conductor such as a copper foil is formed on the mounting target 3, and electrode pads 42 and 43 are formed by edging the conductor (see FIG. 10). Further, in the SMD method, the conductor surface (upper surface) of the mounting target 3 is covered with a solder resist leaving only the molded portions of the electrode pads 42 and 43, thereby forming the electrode pads 42 and 43 (see FIG. 11). ).

[effect]
As described above, in this semiconductor device 1, a part of the electrode pads (first electrode pads) 43 a constituting the BGA connection structure 4 includes the main body portion 431 that defines the solidification shape of the connection terminals 41, and the connection terminals 41. And a guide portion 432 that guides a part of the connection terminal 41 to the outer periphery of the main body portion 431 when melting (see FIG. 4). In such a configuration, a part of the molten connection terminal 41 moves from the main body part 431 to the guide part 432 in the mounting process of the mounting target 2, and the volume of the connection terminal 41 on the main body part 431 decreases (see FIG. 3 (e) "Part a"). Then, when the connection terminal 41 is solidified in the solder solidification step, the central portion 411 of the connection terminal 41 has a constricted drum shape, and the joint portion 412 of the connection terminal 41 has a fillet shape, so It couple | bonds with the 1st electrode pad 43a (refer FIG.3 (f) "a part"). Then, when the mounting target 3 is thermally deformed due to the thermal history of the semiconductor device 1, the thermal stress is likely to act on the central portion 411 of the connection terminal 41, and the joint portion 412 between the connection terminal 41 and the first electrode pad 43 a becomes easy. The acting shear thermal stress is reduced. Then, generation | occurrence | production of the crack of the connection terminal by a thermal stress or generation | occurrence | production of the crack in the junction part of a connection terminal and mounting object is suppressed. Thereby, there exists an advantage by which the connection failure of the semiconductor device 1 is suppressed.

  In particular, when the mounting target 2 and the mounting target 3 have different linear expansion coefficients, thermal stress is likely to occur at the connection terminals 41 of the BGA connection structure 4 due to the difference in the linear expansion coefficients. In such a case, the above configuration is advantageous in that the generation of cracks in the connection terminals due to thermal stress or the generation of cracks in the joints between the connection terminals and the mounting target is effectively suppressed.

  Further, in the above configuration, by using the electrode pad (first electrode pad) 43a having the main body portion and the guide portion, in the processing step of the BGA connection structure 4, the above-described drum-shaped central portion 411 and There exists an advantage which can shape | mold the connection terminal 41 which has the fillet-shaped junction part 412 easily and with few processes.

  In the semiconductor device 1, both the electrode pad (first electrode pad) 43 a having the main body portion 431 and the guide portion 432 and the electrode pad (second electrode pad) 43 b having only the main body portion 431 are single. They are arranged on the mounting target 3 (see FIGS. 4 to 6). In such a configuration, the distance Hb between the mounting target 2 and the mounting target 3 is appropriately and stably maintained by the connection terminal 41 of the second electrode pad 43b in the mounting process of the mounting target 2, so that the first electrode When the connection terminal 41 of the pad 43a is melted and solidified, the connection terminal 41 of the first electrode pad 43a is not easily crushed (see FIGS. 3, 8, and 9). Accordingly, there is an advantage that the connection terminal 41 is appropriately formed, and a suitable shape of the connection terminal 41 (a shape having a drum-shaped center portion 411 and a fillet-shaped joint portion 412) is ensured (FIG. 3). (See “a” in (e) and (f)).

[Example of electrode pad arrangement]
In the semiconductor device 1, the first electrode pad 43a and the second electrode pad 43b are preferably arranged as follows with respect to the mounting target 3 (see FIGS. 6 and 7).

  For example, in the configuration illustrated in FIG. 6, the mounting target 3 has a rectangular joint surface (joint surface with the mounted target 2), and the signal circuit unit 31 of the semiconductor device 1 is located at the center of the joint surface. Is formed. A plurality of first electrode pads 43 a are arranged in the area of the signal circuit unit 31. In addition, by arranging the plurality of second electrode pads 43b in other regions (regions around the signal circuit unit 31), the outer periphery of the first electrode pad 43a group is surrounded by the plurality of second electrode pads 43b. Yes.

  In the configuration shown in FIG. 6, as described above, the first electrode pad 43 a includes the main body portion 431 and the guide portion 432, whereby the central portion 411 of the connection terminal 41 is formed in a drum shape, Thermal stress generated in the vicinity of the joint with the one electrode pad 43a is reduced (see FIGS. 2 to 5). Therefore, when the first electrode pad 43a is arranged in the signal circuit unit 31 of the mounting target 3, the connection failure between the mounting target 2 and the mounting target 3 and the joint between the connection terminal 41 and the first electrode pad 43a. Occurrence of cracks in the vicinity is suppressed. Thereby, there exists an advantage which the reliability of a BGA connection structure improves.

  Moreover, in the structure shown in FIG. 6, since the outer periphery of the first electrode pad 43a group is surrounded by the plurality of second electrode pads 43b at the joint surface of the mounting target 3, the connection terminal 41 of the first electrode pad 43a is melted. When solidifying, the distances Ha and Hb between the mounted object 2 and the mounted object 3 are ensured appropriately (see FIGS. 3, 8, and 9). Thereby, there exists an advantage by which shaping | molding of the connection terminal 41 is performed appropriately and the suitable shape (shape which has the center part 411 of a drum shape and the joint part 412 of a fillet shape) of the connection terminal 41 is ensured.

  Further, for example, in the configuration shown in FIG. 7, the plurality of first electrode pads 43 a are arranged on the outer peripheral diagonal portion of the mounting target 3. Specifically, the mounting target 3 has a rectangular bonding surface, and a plurality of first electrode pads 43a are disposed in both end portions and four corner regions in the longitudinal direction. In addition, only the second electrode pad 43b is arranged in the other region (the central region of the mounting target 3).

  In the processing step of the BGA connection structure, the largest thermal stress acts on the outer peripheral portion of the mounting target 3. Therefore, in the configuration shown in FIG. 7, the plurality of first electrode pads 43 a are arranged on the outer peripheral diagonal portion of the mounting target 3, thereby causing thermal stress generated in the vicinity of the joint portion between the connection terminal 41 and the first electrode pad 43 a. Is reduced. As a result, the connection failure between the mounted object 2 and the mounted object 3 and the occurrence of cracks in the vicinity of the joint between the connection terminal 41 and the first electrode pad 43a are suppressed, and the advantage of improving the reliability of the BGA connection structure is obtained. is there.

[Modification of electrode pad]
In the semiconductor device 1, the main body portion 431 of the first electrode pad 43 a has a circular shape (disc shape), and the guide portion 432 is spaced from the main body portion 431 by a predetermined distance. It has the annular structure arrange | positioned surrounding the outer periphery of 431, and is connected with the main-body part 431 through the connection part 433 in the one part (refer FIG. 4). In such a configuration, since the guide portion 432 has an annular structure, when a part of the connection terminal 41 melted in the solder melting step is guided by the guide portion 432, a part of the guided connection terminal 41 is guided. It spreads wet in the circumferential direction of the portion 432 (see FIG. 3E). Therefore, it is difficult for the molten connection terminal 41 to protrude outside the first electrode pad 43a (guide portion 432). Thereby, there exists an advantage by which the insulation state of the adjacent connection terminal 41 is ensured.

  However, the present invention is not limited thereto, and in this semiconductor device 1, the guide portion 432 of the first electrode pad 43a may have an island shape protruding from the main body portion 431 (see FIGS. 12 and 13).

  For example, in the configuration shown in FIG. 12, the guide portion 432 of the first electrode pad 43 a has a substantially arc-shaped (semi-arc-shaped) island shape, and the main body portion 431 is spaced apart from the main body portion 431 by a predetermined distance. It is arranged on the outer periphery. Further, the guide part 432 is connected to the main body part 431 via a connecting part 433. In the configuration shown in FIG. 13, the guide portion 432 of the first electrode pad 43 a has a substantially rectangular island shape, and is arranged on the outer periphery of the main body portion 431 with a predetermined interval from the main body portion 431. . Further, the guide part 432 is connected to the main body part 431 via a connecting part 433.

  In such a configuration, since the guide portion 432 has an island shape, the overall width of the first electrode pad 43a is smaller than the configuration in which the guide portion 432 has an annular structure surrounding the entire circumference of the main body portion 431 (see FIG. 4). small. Thereby, there exists an advantage which can narrow the pitch dimension of the arranged 1st electrode pad 43a group. In addition, since the guide part 432 has a predetermined area, a necessary and sufficient amount of the connection terminals 41 can flow outside the main body part 431.

  Note that the shape of the guide portion 432 of the first electrode pad 43a is not limited to these, provided that the operation of guiding a part of the connection terminal 41 to the outer periphery of the main body portion 431 is ensured when the connection terminal 41 is melted. Can be arbitrarily selected.

[Electrode pad diameter]
Further, in this semiconductor device 1, when the mounted object 2 and the mounted object 3 have different toughnesses, the electrode pad diameter φDa on the side having lower toughness and the electrode pad on the side having higher toughness. The diameter φDb preferably has a relationship of φDa> φDb. The diameter of the first electrode pad 43a is the diameter of the main body 431 of the electrode pad 43a.

  For example, in this embodiment, the to-be-mounted object 2 is made of a ceramic substrate, and the to-be-mounted object 3 is made of a resin material substrate, so that the toughness of the to-be-mounted object 2 is set lower than the toughness of the mounted object 3. (See FIG. 14). Further, the diameter φDa of the electrode pad 42 on the side having low toughness (mounting target 2) is set larger than the diameter φDb of the electrode pad 43 on the side having high toughness (mounting target 3) (φDa> φDb). . For this reason, the bonding area between the electrode pad 42 and the connection terminal 41 on the side having low toughness is larger than the bonding area between the electrode pad 43 and the connection terminal 41 on the side having high toughness. In general, cracks due to thermal stress are likely to occur at the electrode pad 42 on the side having lower toughness.

  In such a configuration, when the mounted object 2 and the mounted object 3 are thermally deformed due to the thermal history, the electrode pad 42 on the side having low toughness has a large diameter φDa (large bonding surface), and thus acts on the electrode pad 42. Thermal stress to be relieved. Thereby, there exists an advantage by which generation | occurrence | production of the crack in the junction part of the connecting terminal 41 and the to-be-mounted object 2 is suppressed.

  In the above configuration, it is preferable that both the first electrode pad 43a and the second electrode pad 43b are arranged between the mounted object 2 and the mounted object 3 (see FIG. 15). In such a configuration, since the distance Hd between the mounting target 2 and the mounting target 3 is properly and stably maintained by the connection terminal 41 of the second electrode pad 43b in the mounting process of the mounting target 2, the first electrode When the connection terminal 41 of the pad 43a is melted and solidified, the connection terminal 41 of the first electrode pad 43a is not easily crushed. Thereby, there exists an advantage by which shaping | molding of the connection terminal 41 is performed appropriately and the suitable shape (shape which has the center part 411 of a drum shape and the joint part 412 of a fillet shape) of the connection terminal 41 is ensured.

  As described above, the semiconductor device and the manufacturing method thereof according to the present invention are useful in that generation of cracks due to thermal stress can be suppressed.

DESCRIPTION OF SYMBOLS 1 Semiconductor device, 2 Mounting object, 21 Semiconductor element, 22 Circuit board, 23 Signal circuit, 24 Cap, 3 Mounting object, 31 Signal circuit part, 4 BGA connection structure, 41 Connection terminal, 42 Electrode pad, 43a 1st electrode Pad, 43b second electrode pad, 44 cream solder, 411 center part, 412 joint part, 431 body part, 432 guide part, 433 connecting part

Claims (8)

A semiconductor device in which a mounting target is mounted on a mounting target via a plurality of connection terminals arranged in an array or randomly,
Means for forming a plurality of electrode pads on the mounting object side, and means for melting and solidifying the connection terminal on the electrode pad to couple to the mounting object; and
Some of the electrode pads include a main body part that defines a solidification shape of the connection terminal, and a guide part that guides a part of the connection terminal to the outer periphery of the main body part when the connection terminal is melted. A featured semiconductor device.   2. The semiconductor device according to claim 1, wherein both the electrode pad having the main body part and the guide part and the electrode pad having only the main body part are arranged on a single mounting target.   The semiconductor device according to claim 1, wherein the electrode pad having the main body portion and the guide portion is arranged in the signal circuit portion to be mounted.   The semiconductor device according to claim 1, wherein the electrode pad having the main body portion and the guide portion is disposed on an outer peripheral diagonal portion to be mounted.   The said guide part has either the cyclic structure arrange | positioned surrounding the outer periphery of the said main-body part at predetermined intervals with respect to the said main-body part, and is connected with the said main-body part in part. The semiconductor device according to one.   The semiconductor device according to claim 1, wherein the guide portion has an island shape protruding from the main body portion. Means for forming a plurality of electrode pads on the mounting target side; and
When the mounting target and the mounting target have different toughnesses, the diameter φDa of the electrode pad on the side having low toughness and the diameter φDb of the electrode pad on the side having high toughness satisfy φDa> φDb The semiconductor device according to claim 1, which has a relationship. A method for manufacturing a semiconductor device, wherein a mounting target is mounted on a mounting target via a plurality of connection terminals arranged in an array or at random,
A step of forming a plurality of electrode pads on the mounting target side, and a step of coupling the mounting terminal to the mounting target by melting and solidifying on the electrode pad, and
Some of the electrode pads include a main body part that defines a solidification shape of the connection terminal, and a guide part that guides a part of the connection terminal to the outer periphery of the main body part when the connection terminal is melted. A method of manufacturing a semiconductor device.

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