Electrical components

Abstract

To provide an electric component which suppresses stress concentration in a solder for connecting a corner terminal part and a corner terminal land.SOLUTION: An electric component 1 includes a semiconductor device 10, a substrate 20, and a solder 40. The semiconductor device 10 has a semiconductor element 12, a heat dissipation part 11, a plurality of terminal parts 13, and a rectangular sealing resin body 14 which seals the semiconductor element and includes four corners. The substrate has a heat dissipation land 22 for dissipating heat of the semiconductor element, a plurality of terminal lands 23 which are electrically connected corresponding to the plurality of terminal parts, and a resist 25 for covering an upper face 21A while exposing a connection part 22C of the heat dissipation land and the plurality of terminal lands. The solder 40 electrically connects the plurality of terminal parts and the plurality of terminal lands. A shortest distance L1 between side terminal lands and the heat dissipation land is shorter than a shortest distance L2 between corner terminal lands and the heat dissipation land.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The disclosure described in this specification relates to electrical components.

Background Art

[0002] Patent Document 1 describes an electronic device in which a package is soldered onto a substrate. The package has a heat sink and terminal electrodes provided on the outer periphery of the heat sink.

[0003] One surface of the substrate is provided with a heat sink connection land, a terminal electrode connection land, and a solder resist. The heat sink and the heat sink connection land, and the terminal electrode and the terminal electrode connection land are connected via solder.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] A solder resist is provided between the heat sink connection land and the terminal electrode connection land. The solder resist may expand due to environmental changes or the like. In that case, the solder resist may come into contact with the electronic device. As a result, stress may concentrate on a part of a plurality of solders connecting a plurality of terminal electrodes and a plurality of terminal electrode connection lands. For example, there was a risk of stress concentration on the solder connecting the terminal electrode provided at the corner of the package and the corresponding terminal electrode connection land.

[0006] An object of the present disclosure is to provide an electrical component in which stress concentration on a part of a plurality of solders is suppressed. To provide an electrical component in which stress concentration on the solder connecting the corner terminal portion and the corner terminal land is suppressed. [Means for solving the problem]

[0007] An electrical component according to one aspect of this disclosure is A semiconductor device (10) having a semiconductor element (12), a heat dissipation portion (11) thermally coupled to the semiconductor element, a plurality of terminal portions (13) positioned around the heat dissipation portion and arranged in at least one row along the heat dissipation portion, and a rectangular sealing resin body (14) including four corners that seals the semiconductor element and exposes the heat dissipation portion and the plurality of terminal portions from its outer surface (14B, 14C), A substrate (20) having a heat dissipation land (22) including a connection part (22C) connected to a heat dissipation part, a plurality of terminal lands (23) connected to a plurality of terminal parts, and a resist (25) that covers the surface (21A) while exposing the connection part and the plurality of terminal lands, The heat dissipation part and the first solder (30) connecting the connection part, It comprises multiple terminal sections and multiple second solders (40) connecting multiple terminal lands, The multiple terminal lands include a corner terminal land (23A) corresponding to the corner terminal (13D) closest to a corner among the multiple terminal sections, and a side terminal land (23B) corresponding to the side terminal (13E) that is further from the corner than the corner terminal. The shortest distance (L1) between the edge terminal land and the heat dissipation land is shorter than the shortest distance (L2) between the corner terminal land and the heat dissipation land. the law of nature, The heat dissipation pad has four corners, The diagonal directions of the semiconductor device and the diagonal directions of the heat dissipation pads do not match. An electrical component according to another aspect of this disclosure is: A semiconductor device (10) having a semiconductor element (12), a heat dissipation portion (11) thermally coupled to the semiconductor element, a plurality of terminal portions (13) positioned around the heat dissipation portion and arranged in at least one row along the heat dissipation portion, and a rectangular sealing resin body (14) including four corners that seals the semiconductor element and exposes the heat dissipation portion and the plurality of terminal portions from its outer surface (14B, 14C), A substrate (20) having a heat dissipation land (22) including a connection part (22C) connected to a heat dissipation part, a plurality of terminal lands (23) connected to a plurality of terminal parts, and a resist (25) that covers the surface (21A) while exposing the connection part and the plurality of terminal lands, The heat dissipation part and the first solder (30) connecting the connection part, It comprises multiple terminal sections and multiple second solders (40) connecting multiple terminal lands, The multiple terminal lands include a corner terminal land (23A) corresponding to the corner terminal (13D) closest to a corner among the multiple terminal sections, and a side terminal land (23B) corresponding to the side terminal (13E) that is further from the corner than the corner terminal. The shortest distance (L1) between the edge terminal land and the heat dissipation land is shorter than the shortest distance (L2) between the corner terminal land and the heat dissipation land. The substrate further includes a heat dissipation member (24) between the connection portion and the terminal land, which is thermally connected to the heat dissipation land and extends in the thickness direction (TD) of the substrate. The heat dissipation pad has four corners, The diagonal directions of the semiconductor device and the diagonal directions of the heat dissipation pads do not match.

[0008] The shortest distance (L2) between the corner terminal land (23A) and the heat dissipation land (22) is suppressed from becoming the shortest among the shortest distances between the terminal land (23) and the heat dissipation land (22). Even if the resist (25) expands due to environmental changes or the like, stress concentration on the second solder (40) that connects the corner terminal portion (13D) and the corner terminal land (23A) is suppressed. Stress concentration on a part of the plurality of second solders (40) is suppressed.

[0009] Note that the reference numbers in the above parentheses only indicate the correspondence with the configurations described in the embodiments below, and do not limit the technical scope in any way.

Brief Description of the Drawings

[0010] [Figure 1] It is a plan view of the electrical component of the first embodiment. [Figure 2] It is a cross-sectional view taken along line II-II of FIG. 1. [Figure 3] It is a cross-sectional view taken along line III-III of FIG. 1. [Figure 4] It is a cross-sectional view for explaining the first stress. [Figure 5] It is a cross-sectional view for explaining the second stress. [Figure 6] It is a plan view of the electrical component of the comparative example. [Figure 7] It is a cross-sectional view taken along line VII-VII of FIG. 6. [Figure 8] It is a cross-sectional view for explaining the second stress in the comparative example. [Figure 9] It is a plan view of the electrical component of the second embodiment. [Figure 10] It is a plan view of the electrical component of the third embodiment. [Figure 11] It is a plan view of the electrical component of the fourth embodiment.

Modes for Carrying Out the Invention

[0011] The following describes several embodiments for implementing this disclosure with reference to the drawings. In each embodiment, parts corresponding to matters described in a preceding embodiment may be denoted by the same reference numerals, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, other embodiments described in a preceding embodiment may be applied to the remaining parts of the configuration.

[0012] Furthermore, not only are combinations of parts explicitly shown as being combinable in each embodiment possible, but it is also possible to partially combine embodiments with each other, embodiments with modified versions, and modified versions with each other, even if not explicitly shown, as long as there are no particular problems with the combination.

[0013] (First Embodiment) The electrical component 1 of the first embodiment shown in Figure 1 will be described. Figure 2 shows a cross-section of the electrical component 1 in the direction of arrow II in Figure 1. Figure 3 shows a cross-section of the electrical component 1 in the direction of arrow III in Figure 1. The electrical component 1 comprises a semiconductor device 10, a substrate 20, a first solder 30, and a second solder 40. When describing each component, the thickness direction of the substrate 20 may be conveniently referred to as the thickness direction TD. The depth direction perpendicular to the thickness direction TD may be referred to as the depth direction DP. The width direction perpendicular to the thickness direction TD and the depth direction DP may be referred to as the width direction WD.

[0014] The semiconductor device 10 includes a heat dissipation section 11, a semiconductor element 12, a plurality of terminal sections 13, and a sealing resin body 14. The heat dissipation section 11 has a heat dissipation upper surface 11A and a heat dissipation lower surface 11B. The heat dissipation section 11 has a plate-like shape with thickness in the thickness direction TD between the heat dissipation upper surface 11A and the heat dissipation lower surface 11B. The heat dissipation section 11 is formed of a conductive metal member such as copper or aluminum. The heat dissipation section 11 is square in projection view from the thickness direction TD. Note that the heat dissipation section 11 does not have to be square; it may simply be rectangular. The semiconductor element 12 is fixed to the heat dissipation upper surface 11A via a connecting member such as Ag paste. The semiconductor element 12 is thermally bonded to the heat dissipation upper surface 11A. This makes it possible to dissipate the heat generated from the semiconductor element 12 to the heat dissipation section 11.

[0015] The semiconductor element 12 is, for example, an IC chip in which circuit elements are formed on a semiconductor chip. The semiconductor element 12 has a semiconductor upper surface 12A and a semiconductor lower surface 12B. The semiconductor element 12 has a plate-like shape with thickness in the thickness direction TD between the semiconductor upper surface 12A and the semiconductor lower surface 12B. Bonding wires, for example, which electrically connect the semiconductor element 12 to a plurality of terminal portions 13 are connected to the semiconductor upper surface 12A. The semiconductor lower surface 12B overlaps with the heat dissipation upper surface 11A of the heat dissipation portion 11 in the thickness direction TD. The semiconductor lower surface 12B and the heat dissipation upper surface 11A are electrically and thermally connected via a connecting member such as Ag paste.

[0016] The multiple terminal sections 13 are external connection terminals formed from metal materials such as copper or aluminum. The terminal sections 13 are electrode pads, not leads. Bonding wires are connected to each terminal section 13. Each terminal section 13 has a rectangular shape that is smaller in size than the heat dissipation section 11 when viewed in projection. The terminal section 13 has a terminal upper surface 13A, a terminal lower surface 13B, and a terminal side surface 13C connecting the terminal upper surface 13A and the terminal lower surface 13B. Between the terminal upper surface 13A and the terminal lower surface 13B, the terminal section 13 has a plate-like shape with thickness in the thickness direction TD.

[0017] The sealing resin body 14 is formed from a molding material that includes, for example, epoxy resin. The heat dissipation portion 11, semiconductor element 12, multiple terminal portions 13, and bonding wires are integrally sealed within the sealing resin body 14. The sealing resin body 14 is square in projected view. The sealing resin body 14 has four corners. The sealing resin body 14 has vertices at its four corners. However, the sealing resin body 14 does not have to be square in projected view. In projected view, the sealing resin body 14 may simply be rectangular. The sealing resin body 14 has a sealing upper surface 14A, a sealing lower surface 14B, and a sealing side surface 14C connecting the sealing upper surface 14A and the sealing lower surface 14B. The sealing side surface 14C extends in an annular shape along the periphery of the sealing upper surface 14A and the sealing lower surface 14B. The sealing resin body 14 has a flattened shape with thickness in the thickness direction TD between the sealing upper surface 14A and the sealing lower surface 14B.

[0018] A portion of the heat dissipation section 11 and a portion of the multiple terminal sections 13 are exposed from the sealing resin body 14. Specifically, the heat dissipation lower surface 11B and the multiple terminal lower surfaces 13B are exposed from the sealing lower surface 14B. The sealing lower surface 14B, the heat dissipation lower surface 11B, and the terminal lower surfaces 13B are flush in a plane along the width direction WD and the depth direction DP. In addition, multiple terminal side surfaces 13C are exposed from the sealing side surface 14C. The sealing side surface 14C and the terminal side surfaces 13C are flush in a plane along the thickness direction TD and the depth direction DP. The sealing lower surface 14B and the sealing side surface 14C correspond to the outer surface.

[0019] The semiconductor device 10 employs a QFN (Quad Flat Non-leaded package) structure. In the QFN structure, instead of leads, multiple terminal portions 13, which are electrode pads, are provided. The multiple terminal portions 13 are provided along the outer periphery of the heat dissipation portion 11. In this embodiment, 12 terminal portions 13 are provided on each side of the outer periphery of the rectangular heat dissipation portion 11. 48 terminal portions 13 are provided along the outer periphery of the heat dissipation portion 11. Note that the structure of the semiconductor device 10 is not limited to QFN. The structure of the semiconductor device 10 may also employ a QFP (Quad Flat Package) structure.

[0020] The substrate 20 comprises an insulating substrate 21, heat dissipation lands 22, a plurality of terminal lands 23, a plurality of heat dissipation vias 24, a resist 25, and wiring. The insulating substrate 21 is formed mainly of an electrically insulating material such as resin. The coefficient of linear expansion of the insulating substrate 21 is greater than that of the sealing resin body 14. The insulating substrate 21 has an insulating upper surface 21A and an insulating lower surface 21B. The insulating upper surface 21A corresponds to the surface. The insulating substrate 21 has a plate-like shape with thickness in the thickness direction TD between the insulating upper surface 21A and the insulating lower surface 21B. The heat dissipation lands 22, a plurality of terminal lands 23, a resist 25, and wiring are provided on the insulating upper surface 21A. A plurality of heat dissipation vias 24 are provided on the insulating substrate 21. A plurality of heat dissipation vias 24 are provided in the heat dissipation land arrangement area 21C of the insulating substrate 21 where the heat dissipation lands 22 are located.

[0021] The heat dissipation land 22 is formed by patterning a conductive metal material such as copper or aluminum. The heat dissipation land 22 is provided in the overlapping portion of the insulating upper surface 21A with the heat dissipation lower surface 11B. The heat dissipation land 22 is square in projected view. However, the heat dissipation land 22 does not have to be square in projected view. In projected view, the heat dissipation land 22 may simply be rectangular. Also, in projected view, the size of the heat dissipation land 22 is approximately equal to the size of the heat dissipation section 11.

[0022] The heat dissipation land 22 has vertices at its four corners. In a projection view from the thickness direction TD, the corners of the heat dissipation land 22 are provided on the insulating upper surface 21A such that they do not overlap with the corners of the semiconductor device 10. The diagonal directions of the heat dissipation land 22 and the diagonal directions of the semiconductor device 10 do not coincide. The corners of the heat dissipation land 22 are provided so as to correspond to the edges of the semiconductor device 10. Specifically, the heat dissipation land 22 is provided on the insulating upper surface 21A such that its corners correspond to the centers of the edges of the semiconductor device 10. The corners of the heat dissipation land 22 are positioned at a 45-degree angle from the corners of the semiconductor device 10 around an axis along the thickness direction TD passing through the center of the semiconductor device.

[0023] Furthermore, the heat dissipation land 22 is connected to the heat dissipation section 11 via the first solder 30. The heat dissipation land 22 has a connection section 22C that is connected to the first solder 30. Heat from the semiconductor element 12 is transferred to the heat dissipation land 22 via the heat dissipation section 11 and the connection section 22C. The heat dissipation land 22 is a land for heat dissipation. The heat dissipation land 22 is not a wiring that forms a circuit, but a conductor pattern that does not provide an electrical connection function on the substrate 20.

[0024] The terminal lands 23 are formed by patterning a conductive metal material such as copper or aluminum. The thickness of the terminal lands 23 and the thickness of the heat dissipation lands 22 are approximately equal. Multiple terminal lands 23 are provided corresponding to each terminal portion 13. In projected view, the multiple terminal lands 23 are arranged to surround the heat dissipation lands 22.

[0025] In other words, multiple terminal lands 23 are provided along the outer edge of the semiconductor device 10. In this embodiment, 12 terminal lands 23 are provided on each side of the outer edge of the rectangular semiconductor device 10. 48 terminal lands 23 are provided along the outer edge of the semiconductor device 10. The terminal lands 23 are connected to the corresponding terminal portions 13 via the second solder 40. The terminal lands 23 are part of the wiring that forms the circuit, and the terminal lands 23 are conductor patterns that provide electrical connection functionality on the substrate 20.

[0026] Furthermore, in projected view, a portion of the terminal land 23 overlaps with the semiconductor device 10. The remaining portion of the terminal land 23 protrudes outward from the semiconductor device 10. The second solder 40 is provided across the lower terminal surface 13B and the terminal side surface 13C of the terminal portion 13. The second solder 40 is provided across the portion of the terminal land 23 that overlaps with the semiconductor device 10 and the portion of the terminal land 23 that protrudes outward from the semiconductor device 10.

[0027] The heat dissipation via 24 is a heat dissipation member for improving the heat dissipation effect of the semiconductor element 12. The heat dissipation via 24 is a hole that penetrates the insulating substrate 21 in the thickness direction TD, and a conductor such as a metal material such as copper or aluminum is arranged on the inner surface of the hole. The heat dissipation via 24 extends with respect to the thickness direction TD. The heat dissipation via 24 is provided in the heat dissipation land arrangement portion 21C. The heat dissipation via 24 is thermally connected to the heat dissipation land 22 on the insulating upper surface 21A side. Heat from the semiconductor element 12 is transferred to the heat dissipation land 22 and the heat dissipation via 24.

[0028] This embodiment also has four heat dissipation vias 24. Each heat dissipation via 24 is provided between the heat dissipation land 22 and the terminal land 23 in the heat dissipation land placement area 21C. Each heat dissipation via 24 is provided corresponding to a corner of the heat dissipation land 22. To avoid contact with the first solder 30 that may unintentionally overflow, it is desirable to provide the heat dissipation vias 24 as close as possible to the corners of the heat dissipation land 22. In addition, the four heat dissipation vias 24 and the heat dissipation section 11 overlap in the thickness direction TD.

[0029] The resist 25 is a protective member that protects patterns such as wiring. The resist 25 is made of, for example, a photosensitive resin or a thermosetting resin. The coefficient of thermal expansion of the resist 25 is greater than that of the first solder 30 and the second solder 40. The resist 25 is patterned on the insulating top surface 21A by a photolithography method or the like. In this embodiment, the resist 25 is widely provided on the insulating top surface 21A. The resist 25 is provided on the insulating top surface 21A so as to cover patterns such as wiring, while exposing a part of the heat dissipation land 22, a heat dissipation via 24, and a part of the terminal land 23. The resist 25 has a first opening 26 that exposes the connection part 22C, four second openings 27 that expose the heat dissipation via 24, and forty-eight third openings 28 that expose the terminal land 23.

[0030] The first aperture 26 is square in projected view. The connecting portion 22C is exposed in a square shape through the first aperture 26. The first aperture 26 may simply be rectangular in projected view. The connecting portion 22C may simply be exposed in a rectangular shape. The connecting portion 22C has four corners. The corners of the connecting portion 22C overlap with the corners of the semiconductor device 10. The four second apertures 27 are each provided between the first aperture 26 and the terminal land 23. One second aperture 27 is provided corresponding to each of the four corners of the heat dissipation land 22. The second apertures 27 are provided corresponding to the sides of the connecting portion 22C. One third aperture 28 is provided corresponding to each of the 48 terminal land 23.

[0031] For the sake of simplicity, the terminal portion 13 closest to the corner of the semiconductor device 10 may be referred to as the corner terminal portion 13D. The terminal portions 13 corresponding to the sides of the semiconductor device 10 other than the corner terminal portion 13D may be referred to as the side terminal portion 13E. The terminal land 23 corresponding to the corner terminal portion 13D may be referred to as the corner terminal land 23A. The terminal land 23 corresponding to the side terminal portion 13E may be referred to as the side terminal land 23B. Each of the four second openings 27 is provided between the side terminal land 23B and the heat dissipation land 22 in the heat dissipation land placement area 21C. Each of the four heat dissipation vias 24 is provided between the side terminal land 23B and the heat dissipation land 22 in the heat dissipation land placement area 21C.

[0032] As described above, in projected view, the heat dissipation land 22 is provided on the insulating upper surface 21A such that the corner of the heat dissipation land 22 corresponds to the center of the edge of the semiconductor device 10. With this configuration, the shortest distance L1 between the edge terminal land 23B closest to the center of the edge of the semiconductor device 10 and the heat dissipation land 22 is the shortest distance among the shortest distances between the heat dissipation land 22 and the terminal land 23. The shortest distance L2 between the corner terminal land 23A and the heat dissipation land 22 is the longest distance among the shortest distances between the heat dissipation land 22 and the terminal land 23. The shortest distance L1 is shorter than the shortest distance L2. The shortest distance L2 is longer than the shortest distance L1.

[0033] In a cross-section including the shortest distance L1, the resist 25 is provided between the connection portion 22C and the heat dissipation via 24, and between the heat dissipation via 24 and the terminal land 23. The resist 25 is provided between the connection portion 22C and the heat dissipation via 24, and between the heat dissipation land 22 and the semiconductor device 10. The resist 25 is provided between the heat dissipation via 24 and the terminal land 23, across the space between the heat dissipation land 22 and the semiconductor device 10, the space between the insulating substrate 21 and the semiconductor device 10 having the shortest distance L1, and the space between the terminal land 23 and the semiconductor device 10.

[0034] In a cross-section including the shortest distance L2, the resist 25 is provided between the connection portion 22C and the terminal land 23. The resist 25 is provided across the space between the heat dissipation land 22 and the semiconductor device 10, the space between the insulating substrate 21 and the semiconductor device 10 having the shortest distance L2, and the space between the terminal land 23 and the semiconductor device 10.

[0035] Figure 4 shows a cross-section of the electrical component 1 in the direction of arrow IV in Figure 1. As described above, the coefficient of linear expansion of the insulating substrate 21 is greater than that of the sealing resin body 14. Therefore, in the insulating substrate 21, which has a larger coefficient of linear expansion than the sealing resin body 14, contraction occurs in the insulating substrate 21. Consequently, in the electrical component 1, convex deformation and expansion occur on the sealing resin body 14 side. A first stress σ1 acts on the second solder 40 connecting the terminal portion 13 and the terminal land 23. The displacement due to the accumulation of warping and expansion becomes larger towards the corners. The first stress σ1 acting on the second corner solder 40A connecting the corner terminal portion 13D and the corner terminal land 23A is the largest of the first stresses σ1 acting on the second solder 40.

[0036] Figure 5 is a schematic diagram illustrating the second stress σ2 acting on the second solder 40, based on the cross-section of electrical component 1 in the direction of arrow III in Figure 1. As described above, the coefficient of linear expansion of the resist 25 is greater than that of the first solder 30 and the second solder 40. The rate of volume change due to environmental changes is greater for the resist 25 than for the solders 30 and 40. Therefore, if the resist 25 expands due to environmental changes, the solders 30 and 40 cannot keep up with the expansion of the resist 25. Consequently, a second stress σ2 is generated in the second solder 40.

[0037] Figure 6 is a plan view showing a comparative example in which the corner of the heat dissipation land 22 overlaps with the corner of the semiconductor device 10, and a heat dissipation via 24 is provided at the corner of the heat dissipation land 22. Figure 7 shows a cross-section of the electrical component 1 in the direction of arrow VII in Figure 6. A resist 25 is provided between the connection portion 22C and the heat dissipation via 24, and between the heat dissipation via 24 and the terminal land 23. The resist 25 is provided between the connection portion 22C and the heat dissipation via 24, in the space between the heat dissipation land 22 and the semiconductor device 10, in the space between the insulating substrate 21 and the semiconductor device 10 with the shortest distance L3, and in the space between the terminal land 23 and the semiconductor device 10.

[0038] Figure 8 is a schematic diagram illustrating the second stress σ2 in the comparative example. In the comparative example, the width occupied by the heat dissipation land 22 in the diagonal direction connecting the diagonal corners of the semiconductor device 10 is wider than in this embodiment. In the comparative example, the shortest distance L3 between the corner terminal land 23A and the heat dissipation land 22 is shorter than in this embodiment. The shortest distance L3 is shorter than the shortest distance L2. The resist 25 expands in response to environmental changes. The width of the thickness direction TD of the space between the insulating substrate 21 and the semiconductor device 10, having the shortest distance L3, is greater than the width of the thickness direction TD of the space between the lands 22, 23 and the semiconductor device 10.

[0039] The space between the insulating substrate 21 and the semiconductor device 10, which has the shortest distance L3, can also be described as a space into which the resist 25 can sag. In the comparative example, the width of the space into which the resist 25 can sag in the diagonal direction is narrow. In the comparative example, even if the resist 25 sags into the space between the insulating substrate 21 and the semiconductor device 10, the area is narrow. Therefore, when the resist 25 expands, it is difficult to reduce the contact area between the resist 25 and the semiconductor device 10. It is difficult to control the contact area between the resist 25 and the semiconductor device 10 to a degree that can absorb the displacement of the resist 25 in the thickness direction TD.

[0040] The semiconductor device 10 is more firmly soldered to the insulating substrate 21 at its center than at its outer edges. The fixing force between the insulating substrate 21 and the heat dissipation part 11 by the first solder 30 is stronger than the fixing force between the terminal land 23 and the terminal part 13. As a result, the starting point of warping and expansion in the electrical component 1 can be conveniently considered to be the center of the semiconductor device 10. In particular, the fixing force to the insulating substrate 21 at the outer edges is weaker in the QFN structure than in the QFP structure. In the QFN structure, the difference in fixing force is more pronounced than in the QFP structure. When the resist 25 expands in the thickness direction TD due to environmental changes, the semiconductor device 10 is displaced away from the insulating substrate 21. The amount of displacement of the semiconductor device 10 is greater at the outer edges than at the center. Since the shortest distance L3 is shorter than the shortest distance L2, a larger second stress σ2 is generated at the second corner solder 40A in the comparative example than in this embodiment. In the comparative example, the maximum first stress σ1 and the maximum second stress σ2 are concentrated at the second corner solder 40A.

[0041] <Effects and Effects> In this embodiment, the shortest distance L2 is longer than the shortest distance L1. The resist 25 is provided on the insulating upper surface 21A such that the connection portion 22C, the heat dissipation via 24, and the terminal land 23 are exposed. The resist 25 is provided in the space between the insulating substrate 21 and the semiconductor device 10, having the shortest distance L1. The resist 25 is provided in the space between the insulating substrate 21 and the semiconductor device 10, having the shortest distance L2. Even if the resist 25 expands due to environmental changes, the contact area between the resist 25 and the semiconductor device 10 can be reduced in a cross-section along the diagonal direction. In a cross-section along the diagonal direction, the contact area can be controlled to be small enough to absorb the displacement of the resist 25 in the thickness direction TD.

[0042] Consequently, the resist 25 is less likely to be displaced with respect to the thickness direction TD between the corner terminal land 23A and the heat dissipation land 22. The resist 25 between the corner terminal land 23A and the heat dissipation land 22 makes it difficult for the semiconductor device 10 to be lifted. As a result, the second stress σ2 acting on the second corner solder 40A is suppressed from becoming maximum. The concentration of the maximum first stress σ1 and the maximum second stress σ2 on the second corner solder 40A is suppressed. The total stress acting on the second corner solder 40A becomes smaller. The occurrence of defects such as cracks on the second corner solder 40A is suppressed.

[0043] Four heat dissipation vias 24 are provided in the heat dissipation land placement area 21C. The heat dissipation vias 24 are holes that penetrate the insulating substrate 21 in the thickness direction TD. A conductor such as a metal material such as copper or aluminum is placed on the inner surface of the hole. The heat dissipation vias 24 extend in the thickness direction TD. The heat dissipation vias 24 are thermally connected to the heat dissipation land 22 on the insulating upper surface 21A side. Heat from the semiconductor element 12 is transferred to the connection part 22C and the heat dissipation vias 24. Because the area available for heat dissipation is increased, the heat from the semiconductor element 12 can be dissipated efficiently.

[0044] The heat dissipation via 24 is provided between the connection portion 22C and the terminal land 23 in the heat dissipation land placement area 21C. More specifically, the heat dissipation via 24 is provided between the side terminal land 23B and the connection portion 22C in the heat dissipation land placement area 21C. Compared to the case where the heat dissipation via 24 is provided between the corner terminal land 23A and the connection portion 22C in the heat dissipation land placement area 21C, the heat dissipation via 24 can be placed closer to the terminal land 23. The reduction in the size of the connection portion 22C is suppressed. Since the heat dissipation via 24 can be placed without reducing the size of the connection portion 22C, the heat of the semiconductor element 12 can be dissipated efficiently.

[0045] Furthermore, a heat dissipation via 24 is exposed from the second opening 27. With respect to the thickness direction TD, the heat dissipation via 24 and the heat dissipation section 11 overlap. As a result, the heat from the semiconductor element 12 is transferred to the heat dissipation via 24 via the air between the semiconductor device 10 and the insulating substrate 21. Because the heat transfer path of the semiconductor element 12 is increased, the heat from the semiconductor element 12 is dissipated efficiently.

[0046] The heat dissipation land 22 and the semiconductor device 10 are both square. The heat dissipation land 22 has vertices at each of its four corners. The semiconductor device 10 also has vertices at each of its four corners. In projected view, the corners of the heat dissipation land 22 are provided on the insulating upper surface 21A such that they do not overlap with the corners of the semiconductor device 10. The heat dissipation land 22 is provided on the insulating upper surface 21A such that its corners correspond to the centers of the edges of the semiconductor device 10. The corners of the heat dissipation land 22 are positioned 45 degrees from the corners of the semiconductor device 10 around an axis that passes through the center of the semiconductor device 10 and is along the thickness direction TD.

[0047] According to this, the configuration with the longest shortest distance L2 between the corner terminal land 23A and the heat dissipation land 22. The configuration with the shortest shortest distance L1 between the edge terminal land 23B, located at the center of the edge, and the heat dissipation land 22. The second stress σ2 generated in the second edge solder 40B connecting the edge terminal portion 13E located at the center of the edge of the semiconductor device 10 and the corresponding edge terminal land 23B is maximized. The second stress σ2 acting on the second corner solder 40A is minimized. The total stress acting on the second corner solder 40A becomes smaller. The occurrence of defects such as cracks in the second corner solder 40A is more effectively suppressed.

[0048] (Second Embodiment) Figure 9 is a plan view of the electrical component 1 of the second embodiment. In the second embodiment, the shape of the heat dissipation land 22 does not have to be rectangular in projection view. It is sufficient that the shortest distance L2 is longer than the shortest distance L1. For example, in projection view, the shape of the heat dissipation land 22 is elliptical. Furthermore, each heat dissipation via 24 does not have to be provided corresponding to an edge of the connection portion 22C. In the second embodiment, the heat dissipation via 24 corresponds only to the edge extending in the depth direction DP of the connection portion 22C. Two heat dissipation vias 24 correspond to the edge extending in the depth direction DP of the connection portion 22C. The heat dissipation vias 24 do not correspond to the edge extending in the width direction WD of the connection portion 22C. Conversely, the heat dissipation vias 24 may correspond only to the edge extending in the width direction WD.

[0049] In addition, heat dissipation vias 24 may be provided corresponding to the corners of the connection portion 22C. One heat dissipation via 24 may be provided corresponding to each of the four corners of the connection portion 22C. Multiple heat dissipation vias 24 may be provided corresponding to each of the four corners of the connection portion 22C. Heat dissipation vias 24 may be provided only to some of the four corners of the connection portion 22C. This also produces the same effects as the first embodiment. The number of heat dissipation vias 24 is not limited.

[0050] (Third embodiment) Figure 10 is a plan view of the electrical component 1 of the third embodiment. In the third embodiment, the shape of the heat dissipation land 22 does not have to be rectangular in projected view. For example, the shape of the heat dissipation land 22 is octagonal in projected view. This also produces the same effects as in the first embodiment. Note that the shape of the heat dissipation land 22 is not limited to an octagon. The shape of the heat dissipation land 22 may be other polygons. The side lengths of the heat dissipation land 22 may be equal or unequal.

[0051] (Fourth Embodiment) Figure 11 is a plan view of the electrical component 1 of the fourth embodiment. In the fourth embodiment, the shape of the heat dissipation land 22 does not have to be rectangular in projected view. For example, the heat dissipation land 22 in the first embodiment has four heat dissipation land pieces 422. The four heat dissipation land pieces 422 come together to form the heat dissipation land 22. The heat dissipation land piece 422 has a connecting piece 422C which is part of the connecting piece 22C. A heat dissipation via 24 is provided in the heat dissipation land piece arrangement area of ​​the insulating substrate 21 where the heat dissipation land piece 422 is arranged. A heat dissipation via 24 is provided between the connecting piece 422C and the terminal land 23. The four heat dissipation land pieces 422 are arranged in a ring shape with a resist 25 between adjacent heat dissipation land pieces 422. This also produces the same effects as in the first embodiment. [Explanation of Symbols]

[0052] 10 Semiconductor device, 11 Heat dissipation section, 12 Semiconductor element, 13 Terminal section, 13D Corner terminal section, 13E Side terminal section, 14 Encapsulating resin body, 14B, 14C Outer surface, 20 Substrate, 21A Surface, 22 Heat dissipation land, 22C Connection part, 23 Terminal land, 23A Corner terminal land, 23B Side terminal land, 24 Heat dissipation material, 25 Resist, 30 solder, 1st solder, 30 solder, 40 solder, 2nd solder, 40 solder 422 heat dissipation land piece, L1, L2 shortest distance, TD thickness direction.

Claims

1. A semiconductor device (10) having a semiconductor element (12), a heat dissipation portion (11) thermally coupled to the semiconductor element, a plurality of terminal portions (13) positioned around the heat dissipation portion and arranged in at least one row along the heat dissipation portion, and a rectangular sealing resin body (14) including four corners that seals the semiconductor element and exposes the heat dissipation portion and the plurality of terminal portions from its outer surface (14B, 14C), A substrate (20) having a heat dissipation land (22) including a connection portion (22C) connected to the heat dissipation portion, a plurality of terminal lands (23) connected to a plurality of terminal portions, and a resist (25) covering the surface (21A) while exposing the connection portion and the plurality of terminal lands, The heat dissipation portion and the first solder (30) connecting the connection portion, It comprises a plurality of terminal portions and a plurality of second solders (40) connecting the plurality of terminal lands, The plurality of terminal lands include a corner terminal land (23A) corresponding to the corner terminal portion (13D) closest to the corner among the plurality of terminal portions, and a side terminal land (23B) corresponding to the side terminal portion (13E) that is further from the corner than the corner terminal portion. The shortest distance (L1) between the side terminal land and the heat dissipation land is shorter than the shortest distance (L2) between the corner terminal land and the heat dissipation land. The heat dissipation land has four corners, An electrical component in which the diagonal direction of the semiconductor device and the diagonal direction of the heat dissipation land do not coincide.

2. A semiconductor device (10) having a semiconductor element (12), a heat dissipation portion (11) thermally coupled to the semiconductor element, a plurality of terminal portions (13) positioned around the heat dissipation portion and arranged in at least one row along the heat dissipation portion, and a rectangular sealing resin body (14) including four corners that seals the semiconductor element and exposes the heat dissipation portion and the plurality of terminal portions from its outer surface (14B, 14C), A substrate (20) having a heat dissipation land (22) including a connection portion (22C) connected to the heat dissipation portion, a plurality of terminal lands (23) connected to a plurality of terminal portions, and a resist (25) covering the surface (21A) while exposing the connection portion and the plurality of terminal lands, The heat dissipation portion and the first solder (30) connecting the connection portion, It comprises a plurality of terminal portions and a plurality of second solders (40) connecting the plurality of terminal lands, The plurality of terminal lands include a corner terminal land (23A) corresponding to the corner terminal portion (13D) closest to the corner among the plurality of terminal portions, and a side terminal land (23B) corresponding to the side terminal portion (13E) that is further from the corner than the corner terminal portion. The shortest distance (L1) between the side terminal land and the heat dissipation land is shorter than the shortest distance (L2) between the corner terminal land and the heat dissipation land. The substrate further includes a heat dissipation member (24) between the connection portion and the terminal land, which is thermally connected to the heat dissipation land and extends in the thickness direction (TD) of the substrate. The heat dissipation land has four corners, An electrical component in which the diagonal direction of the semiconductor device and the diagonal direction of the heat dissipation land do not coincide.

3. The electrical component according to claim 2, wherein the heat dissipation member is provided between the connection portion and the edge terminal land.

4. Furthermore, the heat dissipation member is exposed from the resist, With respect to the thickness direction, the heat dissipation portion overlaps the heat dissipation member, as described in claim 3.

5. The electrical component according to any one of claims 1 to 4, wherein the terminal portion is an electrode pad in which the surface exposed from the outer surface and the outer surface are flush.

6. The electrical component according to any one of claims 1 to 4, wherein the fixing force between the heat dissipation portion and the heat dissipation land is greater than the fixing force between the terminal portion and the terminal land.

7. The electrical component according to any one of claims 1 to 4, wherein the coefficient of thermal expansion of the resist is greater than the coefficient of thermal expansion of the solder (30, 40) including the first solder and the second solder.

8. The system has multiple heat dissipation members, The electrical component according to any one of claims 2 to 4, wherein the heat dissipation member is disposed between the connection portion and the terminal land.

9. The heat dissipation land comprises a plurality of heat dissipation land pieces (422) having a part of the connection portion, The electrical component according to claim 8, wherein the heat dissipation member is provided between the connection portion and the terminal land.

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