JP6458688B2 - Electronic equipment - Google Patents

Description

  The present invention relates to an electronic device that includes a substrate, an electronic component that is surface-mounted on the substrate, a heat dissipation member, and a heat transfer member that is disposed between the electronic component and the heat dissipation member.

  Conventionally, as described in Patent Document 1, an electronic control device (electronic) including a substrate, an electronic component (first electronic component), an IC (second electronic component), a cover (heat dissipation member), and a heat dissipation material (heat transfer member) Device) is known. Electronic components and ICs are surface-mounted on a substrate. The cover is disposed so as to cover the electronic component and the IC. The heat dissipation material is disposed between the IC and the cover. Thus, heat is transferred from the IC to the cover via the heat dissipation material.

JP 2014-75496 A

  However, due to expansion and contraction of the heat dissipation material due to temperature changes, the heat dissipation material may move from between the IC and the cover, and may enter at least one of the space between the substrate and the electronic component and between the substrate and the IC. is there. When a heat dissipation material enters, stress acts on at least one of the electrical connection portion between the substrate and the IC and the electrical connection portion between the substrate and the IC due to expansion and contraction accompanying the temperature change of the heat dissipation material. To do. Therefore, at least one of the electrical connection reliability between the board and the electronic component and the electrical connection reliability between the board and the IC is lowered.

  In view of the above problems, an object of the present invention is to provide an electronic device that can suppress a decrease in electrical connection reliability between a substrate and an electronic component.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in the claims and the parentheses described in this section indicate the correspondence with the specific means described in the following embodiment as one aspect, and limit the technical scope of the invention. Not what you want.

One of the disclosed inventions is a substrate (10) having a land (14b) on one side (10a);
A first body portion (36) and a first electrode (38) electrically connected to the first land (14c) of the lands through a connection member (44), and surface-mounted on the substrate The first electronic component (32),
A second body (40) and a second electrode (42) electrically connected to the second land (14d) of the lands through a connecting member, and are surface-mounted on a substrate. Two electronic components (34);
A heat dissipating member (52) disposed opposite to the first electronic component in a first direction orthogonal to the one surface and dissipating heat of the first electronic component;
A heat transfer member (70) disposed between the first electronic component and the heat dissipating member to transmit heat of the first electronic component to the heat dissipating member;
An electronic device comprising:
The substrate has a protrusion (20) protruding from one surface,
The convex portion is formed using a material having a smaller linear expansion coefficient than the heat transfer member, and overlaps at least one of the first main body portion and the second main body portion in the first direction projection view ,
The projecting portion is a base portion (22a, 24a) that overlaps at least one of the first main body portion and the second main body portion and a peripheral end of at least one of the first main body portion and the second main body portion in the first direction projection view. Wall portions (22b, 24b) formed on the outside,
A gap (26) is formed between the base and the wall,
A gap is formed at both ends of the base in one direction orthogonal to the first direction .

  In the above configuration, the distance between the main body portion and the substrate in the first direction is shortened by the convex portion. According to this, even if it is a case where a heat-transfer member moves, it can suppress that a heat-transfer member enters between a main-body part and a board | substrate.

  Moreover, in the said structure, the linear expansion coefficient of a convex part is made lower than the linear expansion coefficient of a heat-transfer member. That is, even when the temperature of the electronic device changes, the convex portion is difficult to expand and contract. Therefore, it can suppress that a stress acts on the electrical connection part of a board | substrate and an electronic component. Therefore, it can suppress that the electrical connection reliability of a board | substrate and an electronic component falls.

It is sectional drawing which shows schematic structure of the electronic device which concerns on 1st Embodiment. It is a top view which shows the detailed structure of a 1st electronic component and a 1st convex part. It is sectional drawing which follows the III-III line of FIG. It is a top view which shows the detailed structure of a 2nd electronic component and a 2nd convex part. It is sectional drawing which follows the VV line of FIG. It is a figure which shows the calculation result about distortion of an electronic component. FIG. 11 is a plan view showing a detailed structure of a first electronic component and a first convex portion in an electronic device according to a second embodiment. It is sectional drawing which follows the VIII-VIII line of FIG. It is sectional drawing which follows the IX-IX line of FIG. It is a top view which shows the detailed structure of a 2nd electronic component and a 2nd convex part. It is sectional drawing which follows the XI-XI line of FIG. It is sectional drawing which follows the XII-XII line | wire of FIG. FIG. 6 is a plan view showing a detailed structure of a first electronic component and a first convex portion in an electronic device according to a first modification. In the electronic device concerning a 3rd embodiment, it is a sectional view showing the detailed structure of the 2nd electronic parts and the 2nd convex part. In the electronic device which concerns on a 2nd modification, it is a top view which shows the detailed structure of a 1st electronic component and a 1st convex part. It is sectional drawing which follows the XVI-XVI line | wire of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, common or related elements are given the same reference numerals. A direction orthogonal to one surface of the substrate is indicated as a Z direction, a specific direction orthogonal to the Z direction is indicated as an X direction, and a direction perpendicular to the Z direction and the X direction is indicated as a Y direction. A plane defined by the X direction and the Y direction is referred to as an XY plane. A shape along the XY plane is referred to as a planar shape. The Z direction corresponds to the first direction described in the claims.

(First embodiment)
First, a schematic configuration of the electronic device 100 will be described with reference to FIGS. In FIG. 2, the first electronic component 32 is indicated by a broken line. Moreover, in FIG. 4, the 2nd electronic component 34 is shown with the broken line.

  As shown in FIG. 1, the electronic device 100 includes a substrate 10, an electronic component 30, a housing 50, a screw 60, and a heat transfer member 70. As the electronic device 100, for example, an ECU for a vehicle can be employed. The electronic device 100 is disposed at a location where the ambient temperature changes. The ambient temperature of the electronic device 100 is, for example, a minimum temperature of about −30 degrees and a maximum temperature of about 100 degrees.

  As shown in FIGS. 2 to 5, the substrate 10 includes an insulating base material 12, a conductor layer 14, and a solder resist 16. The board | substrate 10 has comprised the substantially flat plate shape in which the thickness direction follows a Z direction, and has the one surface 10a and the back surface 10b opposite to the one surface 10a. In the present embodiment, a printed circuit board is employed as the substrate 10. The one surface 10a and the back surface 10b are both end surfaces in the Z direction of the substrate 10 and are planes orthogonal to the Z direction.

  The insulating base 12 is an electrical insulating layer of the substrate 10. The insulating substrate 12 includes a core layer 12a, and a first flexible layer 12b and a second flexible layer 12c that are more flexible than the core layer 12a. Thus, the substrate 10 is a multilayer substrate. The core layer 12a, the first flexible layer 12b, and the second flexible layer 12c are stacked in the Z direction. In this embodiment, the core layer 12a is arrange | positioned in the center in the insulating base material 12 in a Z direction, and is pinched | interposed into the 1st flexible layer 12b and the 2nd flexible layer 12c.

  In the present embodiment, the core layer 12a, the first flexible layer 12b, and the second flexible layer 12c are formed using a prepreg formed by impregnating a glass cloth with a resin. As the resin impregnated into the glass cloth, different materials are used for the core layer 12a, the first flexible layer 12b, and the second flexible layer 12c.

  The conductor layer 14 is a wiring of the substrate 10 laminated on the insulating base material 12. The conductor layer 14 is formed using a metal material such as copper. The conductor layer 14 has an inner layer 14a and a surface layer. The inner layer 14a is formed between the core layer 12a and the first flexible layer 12b, and between the core layer 12a and the second flexible layer 12c. Specifically, the inner layer 14a is formed only in part between the core layer 12a and the first flexible layer 12b and between the core layer 12a and the second flexible layer 12c. In other words, in the projection view in the Z direction, the insulating base 12 has a portion that overlaps the inner layer 14a and a portion that does not overlap the inner layer 14a.

  The surface layer is formed on the opposite side of the core layer 12a in the first flexible layer 12b and the second flexible layer 12c. Specifically, the surface layer is formed only on a part of the first flexible layer 12b and the second flexible layer 12c opposite to the core layer 12a. In other words, in the projection view in the Z direction, the insulating base 12 has a portion that overlaps the surface layer and a portion that does not overlap the surface layer.

  The solder resist 16 is a member for preventing the surface layers from being short-circuited and for protecting the substrate 10. The solder resist 16 is formed using a resin material. The solder resist 16 is formed on the surface layer on the opposite side of the first flexible layer 12b and the second flexible layer 12c. Moreover, the solder resist 16 is formed also in the part in which the surface layer is not formed in the surface opposite to the core layer 12a in the 1st flexible layer 12b and the 2nd flexible layer 12c. The solder resist 16 forms one surface 10 a and the back surface 10 b of the substrate 10.

  A part of the surface layer is exposed from the formed solder resist 16 on the one surface 10a side. In other words, the solder resist 16 is not formed on a part of the surface layer on the one surface 10a side. Thereby, a part of surface layer has comprised one surface 10a. The surface layer has a land 14 b to which the electronic component 30 is soldered as a portion exposed from the solder resist 16. The land 14 b is an electrode of the substrate 10. The surface layer is connected to the inner layer 14a, for example, via a connection via (not shown). In the present embodiment, the surface layer is not exposed from the solder resist 16 on the back surface 10b. However, a configuration in which the surface layer is exposed from the solder resist 16 on the back surface 10b may be employed.

  A through hole 18 is formed in the substrate 10. The through hole 18 is formed for screwing the substrate 10 to the second case portion 54. The through hole 18 penetrates the substrate 10 in the Z direction. That is, the through hole 18 is formed from the one surface 10a to the back surface 10b.

  The board | substrate 10 has the convex part 20 which protrudes from the one surface 10a. The convex part 20 shortens the distance in the Z direction with the electronic component 30 in the board | substrate 10. FIG. The convex portion 20 protrudes toward at least one of the first main body portion 36 and the second main body portion 40. The detailed structure of the convex portion 20 will be described below.

  The electronic component 30 forms an electronic circuit together with the conductor layer 14. As the electronic component 30, for example, a diode, a coil, a capacitor, a resistor, an IC chip, a microcomputer, and an ASIC can be employed. The electronic component 30 is disposed on the one surface 10 a and is surface-mounted on the substrate 10. The electronic device 100 includes, as the electronic components 30, a first electronic component 32 that generates a large amount of heat and a second electronic component 34 that generates a smaller amount of heat than the first electronic component 32. The first electronic component 32 can also be referred to as a heat generating component. The second electronic component 34 is arranged around the first electronic component 32 on the one surface 10a. Therefore, the second electronic component 34 can also be referred to as a peripheral component.

  In the present embodiment, the electronic device 100 includes a plurality of first electronic components 32 and a plurality of second electronic components 34. As the first electronic component 32, for example, a transistor such as a MOSFET and a resistor can be employed. As the second electronic component 34, for example, a capacitor, a transistor such as a MOSFET, or a resistor can be employed.

  As shown in FIGS. 2 and 3, the first electronic component 32 includes a first main body portion 36 and a first electrode 38 electrically connected to the land 14 b. As shown in FIGS. 4 and 5, the second electronic component 34 includes a second main body portion 40 and a second electrode 42 electrically connected to the land 14 b. In the present embodiment, the electrodes 38 and 42 are soldered to the land 14b. In other words, each electronic component 30 is electrically connected to the substrate 10 via the solder 44. The solder 44 corresponds to the connection member described in the claims. Note that an example in which the electronic component 30 is electrically connected to the substrate 10 via a silver paste may be employed. Detailed structures of the first electronic component 32 and the second electronic component 34 will be described below.

  The housing 50 accommodates the substrate 10, the electronic component 30, the screw 60, and the heat transfer member 70. That is, the housing 50 accommodates other members in the electronic device 100. The housing 50 has a first case portion 52 and a second case portion 54. The first case portion 52 has a box shape in which one surface on one side in the Z direction is open. The second case portion 54 closes the opening of the first case portion 52.

  The first case portion 52 is disposed so as to cover the substrate 10, the electronic component 30, the screw 60, and the heat transfer member 70. Thereby, a part of the first case portion 52 faces the first electronic component 32 in the Z direction. That is, the first case portion 52 is disposed to face the first electronic component 32. The 1st case part 52 is corresponded to the heat radiating member as described in a claim. Further, the second case portion 54 is disposed in contact with the back surface 10b. In other words, the substrate 10 is disposed in the second case portion 54. The first case portion 52 and the second case portion 54 form an internal space 56 that accommodates other members.

  The first case portion 52 and the second case portion 54 are fixed to each other by screw fastening or the like at a location not shown. The first case portion 52 and the second case portion 54 are formed using a metal material such as aluminum. In the present embodiment, both the first case portion 52 and the second case portion 54 function as heat radiating members that radiate heat transferred from the substrate 10 and the electronic component 30 to the outside. The first case portion 52 has heat radiating fins (not shown) in order to improve heat dissipation.

  A screw hole 58 for fastening the screw 60 is formed in the housing 50. The screw hole 58 is formed on the surface of the second case portion 54 on which the substrate 10 is disposed. The screw hole 58 overlaps the through-hole 18 in the Z-direction projection view.

  The screw 60 is a member that fixes the substrate 10 to the second case portion 54. The screw head of the screw 60 is arranged on the one surface 10a. In the screw 60, the side surface of the pillar portion extending in the Z direction from the screw head is threaded. This column portion is inserted through the through hole 18 and fastened to the screw hole 58.

  The heat transfer member 70 is a member for transferring heat from the first electronic component 32 to the first case portion 52. The heat transfer member 70 is disposed between the first electronic component 32 and the housing 50. Note that the heat transfer member 70 is not disposed between the second electronic component 34 and the housing 50. In other words, the first electronic component 32 is the electronic component 30 in which the heat transfer member 70 is disposed between the first case portion 52 and the electronic component 30. On the other hand, among the electronic components 30, the second electronic component 34 is one in which the heat transfer member 70 is not disposed between the first case portion 52 and the electronic component 30.

  The heat transfer member 70 is gel or liquid. In the present embodiment, the heat transfer member 70 is in a gel form. Specifically, the heat transfer member 70 is formed by adding a filler formed using a metal such as alumina to a gel formed using silicone. Therefore, the heat transfer member 70 can also be called a heat radiating gel.

  Next, based on FIGS. 2-6, the detailed structure of the convex part 20, the 1st electronic component 32, and the 2nd electronic component 34 is demonstrated.

  In this embodiment, the convex part 20 is formed in the position which overlaps with both the 1st main-body part 36 and the 2nd main-body part 40 in the projection view of a Z direction. As shown in FIG. 3, the convex portion 20 that overlaps the first main body portion 36 in the projection view in the Z direction protrudes in the Z direction toward the first main body portion 36. Further, as shown in FIG. 5, the convex portion 20 that overlaps the second main body portion 40 in the Z-direction projection view protrudes in the Z direction toward the second main body portion 40. Hereinafter, the convex part 20 projecting toward the first main body part 36 is referred to as a first convex part 22, and the convex part 20 projecting toward the second main body part 40 is referred to as a second convex part 24.

  As shown in FIG. 3, the 1st convex part 22 is formed in the opposite side to the 1st flexible layer 12b in the soldering resist 16 of the one surface 10a side. The 1st convex part 22 has comprised the substantially flat plate shape in which the thickness direction follows a Z direction. As shown in FIG. 2, the planar shape of the first convex portion 22 has a substantially rectangular shape in which each side is along the X direction or the Y direction.

  The substrate 10 has two lands 14 b connected to one first electronic component 32. Hereinafter, the land 14b connected to the first electronic component 32 is referred to as a first land 14c. The first land 14c has a substantially rectangular shape with each side along the X direction or the Y direction. The two first lands 14c are formed on both sides of the first convex portion 22 in the X direction. In other words, the first protrusion 22 is sandwiched between the two first lands 14c in the X direction.

  The width in the Y direction of the first protrusion 22 is substantially equal to the width of the first land 14c in the Y direction. In the Y direction, the first convex portion 22 is formed at substantially the same position as the first land 14c. Therefore, in the projection view in the X direction, the entire first convex portion 22 overlaps with the substantially entire first land 14c.

  In the present embodiment, the entire first protrusion 22 is located closer to the heat transfer member 70 than the first land 14c in the Z direction. In other words, the entire first convex portion 22 is located closer to the first main body portion 36 than the first land 14c in the Z direction.

  The first electronic component 32 has a substantially rectangular parallelepiped shape with each side along the X direction, the Y direction, or the Z direction. The width of the first electronic component 32 in the Y direction is substantially equal to the width of the first convex portion 22 in the Y direction. The first electrode 38 has a substantially flat plate shape whose thickness direction is along the Z direction. The first electrode 38 is formed integrally with the first main body 36 and is formed at a portion of the first electronic component 32 that faces the first land 14 c.

  The 1st main-body part 36 has the opposing surface 36a with the one surface 10a. The planar shape of the facing surface 36a is a substantially rectangular shape in which each side is along the X direction or the Y direction. The planar shape of the facing surface 36 a is substantially equal to the planar shape of the first convex portion 22. Further, in the projection view in the Z direction, the entire facing surface 36 a overlaps with the substantially entire first convex portion 22. The 1st convex part 22 is contacting the whole opposing surface 36a. The facing surface 36a corresponds to a first facing surface described in the claims.

  The first electronic component 32 has two first electrodes 38. Each first electrode 38 is connected to one first land 14c. The two first electrodes 38 are formed on both sides in the X direction with respect to the facing surface 36a. Further, the planar shape of each first electrode 38 has a substantially rectangular shape in which each side is along the X direction or the Y direction. The width in the Y direction of the first main body 36 and the first electrode 38 is substantially equal to the width of the first convex portion 22 in the Y direction. In the Y direction, the first electrode 38 is formed at substantially the same position as the first convex portion 22.

  In this embodiment, as shown in FIG. 5, the 2nd convex part 24 is formed in the opposite side to the 1st flexible layer 12b in the soldering resist 16 of the one surface 10a side. The second convex portion 24 has a substantially flat plate shape whose thickness direction is along the Z direction. As shown in FIG. 4, the planar shape of the second convex portion 24 has a substantially rectangular shape in which each side is along the X direction or the Y direction.

  The substrate 10 has two lands 14 b connected to one second electronic component 34. Hereinafter, the land 14b connected to the second electronic component 34 is referred to as a second land 14d. The second land 14d has a substantially rectangular shape with each side along the X direction or the Y direction. The two second lands 14d are formed on both sides of the second convex portion 24 in the X direction. In other words, the second convex portion 24 is sandwiched between the two second lands 14d in the X direction.

  The width of the second convex portion 24 in the Y direction is substantially equal to the width of the second land 14d in the Y direction. In the Y direction, the second convex portion 24 is formed at substantially the same position as the second land 14d. Therefore, in the projection view in the X direction, the entire second convex portion 24 overlaps with substantially the entire second land 14d.

  In this embodiment, the whole 2nd convex part 24 is located in the Z direction at the heat-transfer member 70 side rather than the 2nd land 14d. In other words, the entire second convex portion 24 is located closer to the second main body portion 40 than the second land 14d in the Z direction.

  The 2nd main-body part 40 has comprised the substantially rectangular parallelepiped shape in which each side follows a X direction, a Y direction, or a Z direction. The second main body 40 has a facing surface 40 a facing the substrate 10. The planar shape of the facing surface 40a is a substantially rectangular shape in which each side is along the X direction or the Y direction. The planar shape of the facing surface 40 a is substantially equal to the planar shape of the second convex portion 24. Further, in the projection view in the Z direction, the entire facing surface 40 a overlaps with the substantially entire second convex portion 24. The 2nd convex part 24 is contacting the whole opposing surface 40a. The facing surface 40a corresponds to a second facing surface described in the claims.

  The second electrode 42 has a substantially rod shape. The second electrode 42 protrudes from the second main body portion 40 in the X direction and is bent toward the second land 14d. The second electronic component 34 has ten second electrodes 42. However, the number of the second electrodes 42 is not limited to ten. In the present embodiment, five second electrodes 42 protrude from the second main body portion 40 in one of the X directions, and the remaining five second electrodes 42 protrude in the other of the X directions. The planar shape of each second electrode 42 has a substantially rectangular shape with long sides along the X direction and short sides along the Y direction. In the projection view in the Z direction, the second convex portion 24 does not overlap the second electrode 42.

  The convex part 20 is formed using the resin material. In other words, the convex portion 20 is a resin layer of the substrate 10. In this embodiment, the convex part 20 is formed using silk printing. Therefore, the convex part 20 can also be called a printing body. In this embodiment, an address or the like is printed on the substrate 10 by silk printing. Therefore, the process of forming the convex part 20 and the process of printing on the substrate 10 are simultaneously performed by silk printing. After forming the convex portion 20, the electronic component 30 is soldered to the substrate 10.

  The convex portion 20 is formed using a material having a smaller linear expansion coefficient than the heat transfer member 70. FIG. 6 shows a calculation result of the distortion of the electronic component 30 in the present embodiment and the reference example when the temperature of the electronic device 100 changes. The distortion of the electronic component 30 is a value obtained by dividing the change amount of the width of the electronic component 30 before and after the temperature change by the width of the electronic component 30 after the temperature change in the Z direction.

  FIG. 6 shows the distortion of the electronic component 30 when the temperature of the electronic device 100 changes by 130 degrees. The linear expansion coefficient is calculated assuming that the convex portion 20 is 50 ppm / K, the heat transfer member 70 is 150 ppm / K, and the main body portions 36 and 40 are 7.5 ppm / K. In addition, the calculation is performed assuming that the thickness of the convex portion 20 is 0.05 mm and the width in the Z direction of the main body portions 36 and 40 is 0.5 nm. As a value of the reference example, the calculation result of the distortion of the electronic component 30 when the heat transfer member 70 enters the entire area between the substrate 10 and the electronic component 30 without the substrate 10 having the convex portion 20 is shown. ing.

  In the present embodiment, the distortion of the electronic component 30 is 1625 μm. On the other hand, in the reference example, the distortion of the electronic component 30 is 2925 μm. According to this, compared with the reference example, in this embodiment, the distortion of the electronic component 30 is halved. That is, in the electronic component 30 of the present embodiment, the stress on the electronic component 30 based on the temperature change is halved.

  Next, effects of the electronic device 100 described above will be described.

  By the way, when the heat transfer member 70 enters between the second electronic component 34 and the substrate 10, that is, when the heat transfer member 70 is infiltrated, the expansion and contraction of the heat transfer member 70 causes the substrate 10 and the second electronic component. A stress acts on an electrical connection portion with the 34. When the heat transfer member 70 enters between the first electronic component 32 and the substrate 10, the first electronic component 32 is sandwiched by the heat transfer member 70 in the Z direction. Even in this case, if the heat transfer member 70 enters only a part between the first electronic component 32 and the substrate 10, the stress acting in the Z direction from the heat transfer member 70 to the first electronic component 32 cancels out. Not. Therefore, stress acts on the electrical connection portion between the substrate 10 and the first electronic component 32.

  On the other hand, in this embodiment, the distance between the main body portions 36 and 40 and the substrate 10 in the Z direction is shortened by the convex portion 20. According to this, even when the heat transfer member 70 moves, the heat transfer member 70 can be prevented from entering between the main body portions 36 and 40 and the substrate 10.

  In the present embodiment, the linear expansion coefficient of the convex portion 20 is set lower than the linear expansion coefficient of the heat transfer member 70. That is, even when the temperature of the electronic device 100 changes, the convex portion 20 is unlikely to expand and contract. Therefore, it can suppress that a stress acts on the electrical connection part of the board | substrate 10 and the electronic component 30. FIG. Therefore, it can suppress that the electrical connection reliability of the board | substrate 10 and the electronic component 30 falls. In the present embodiment in which the electronic component 30 is soldered to the substrate 10, it is possible to suppress cracks in the solder 44.

  In the present embodiment, the projection 20 overlaps substantially the entire facing surfaces 36a and 40a in the Z-direction projection view. According to this, in the projection view in the Z direction, the heat transfer member 70 enters between the main body portions 36 and 40 and the substrate 10 as compared with the configuration in which the convex portion 20 overlaps only a part of the facing surfaces 36a and 40a. Can be effectively suppressed. Therefore, it can suppress effectively that the electrical connection reliability of the board | substrate 10 and the electronic component 30 falls.

(Second Embodiment)
In the present embodiment, the description of the parts common to the electronic device 100 shown in the first embodiment is omitted. In FIG. 7, the first electronic component 32 is indicated by a broken line. In FIG. 10, the second electronic component 34 is indicated by a broken line.

  As shown in FIGS. 7 to 9, the first convex portion 22 includes a base portion 22 a that overlaps the first main body portion 36 and a wall that is formed outside the outer peripheral end of the first main body portion 36 in the Z-direction projection view. Part 22b.

  The planar shape of the base 22a has a substantially rectangular shape in which each side is along the X direction or the Y direction. The planar shape of the base 22a is substantially equal to the planar shape of the facing surface 36a. In the projection view in the Z direction, the entire base portion 22a overlaps with substantially the entire facing surface 36a. The base 22a is in contact with substantially the entire facing surface 36a.

  The first convex portion 22 has two wall portions 22b. The two wall portions 22b are formed on both sides of the base portion 22a in the Y direction. In the present embodiment, the wall 22b is continuous with the base 22a. In other words, the wall 22b is connected to the base 22a. The planar shape of the wall portion 22b has a substantially rectangular shape with long sides along the X direction and short sides along the Y direction. The width of the wall portion 22b in the X direction is longer than the width of the base portion 22a in the X direction. In the X direction, one end of the wall portion 22b is substantially the same position as the end portion of the first land 14c opposite to the base portion 22a. Further, in the X direction, the other end of the wall portion 22b is substantially at the same position as the end portion of the other first land 14c opposite to the base portion 22a.

  In the projection view in the Z direction, the first main body portion 36 is surrounded by the wall portion 22b and the first land 14c. Therefore, in the projection view in the Z direction, the base portion 22a is surrounded by the wall portion 22b and the first land 14c. Thereby, the base 22 a is surrounded by the wall 22 b and the solder 44.

  In the present embodiment, the wall 22b and the first land 14c surrounding the first main body 36 are continuously arranged in the projection view in the Z direction. In other words, no gap is formed between the wall portion 22b surrounding the first main body portion 36 and the first lands 14c in the projection view in the Z direction. However, a gap may be formed between the wall portion 22b surrounding the first main body portion 36 and the first lands 14c in a projected view in the Z direction.

  As shown in FIGS. 10-12, the 2nd convex part 24 is the wall formed in the outer side of the outer peripheral end of the base 24a which overlaps with the 2nd main-body part 40 in the projection view of a Z direction, and the 2nd main-body part 40. Part 24b.

  The planar shape of the base 24a has a substantially rectangular shape in which each side is along the X direction or the Y direction. The planar shape of the base 24a is substantially equal to the planar shape of the facing surface 40a. Further, in the projection view in the Z direction, the entire second convex portion 24 overlaps with substantially the entire opposing surface 40a. The facing surface 40 a is in contact with the entire second convex portion 24.

  The second convex part 24 has two wall parts 24b. The two wall portions 24b are formed on both sides of the base portion 24a in the Y direction. In the present embodiment, the wall 24b is continuous with the base 24a. In other words, the wall 24b is connected to the base 24a. The planar shape of the wall 24b has a substantially rectangular shape in which the long side is along the X direction and the short side is along the Y direction. The width in the X direction of the wall portion 24b is longer than the width in the X direction of the base portion 24a. In the X direction, one end of the wall portion 24b is substantially at the same position as the end portion of the second land 14d opposite to the base portion 24a. Further, in the X direction, the other end of the wall portion 24b is located at substantially the same position as the end portion of the other second land 14d opposite to the base portion 24a.

  In the projection view in the Z direction, the second main body portion 40 is surrounded by the wall portion 24b and the second land 14d. Therefore, in the projection view in the Z direction, the base 24a is surrounded by the wall 24b and the second land 14d. Thereby, the base 24 a is surrounded by the wall 24 b and the solder 44.

  In the present embodiment, the wall portions 22b and 24b and the land 14b surrounding the base portions 22a and 24a are continuously arranged in the projection view in the Z direction. In other words, no gap is formed between the wall portions 22b and 24b and the land 14b in the projection view in the Z direction. However, a gap may be formed between the wall portions 22b and 24b and the lands 14b in the projection view in the Z direction.

  In the present embodiment, the wall portions 22b and 24b can effectively suppress the heat transfer member 70 from entering between the main body portions 36 and 40 and the substrate 10. Therefore, it can suppress effectively that the electrical connection reliability of the board | substrate 10 and the electronic component 30 falls.

  By the way, in the structure which wall part 22b, 24b left | separated from base part 22a, 24a, there exists a possibility that the heat-transfer member 70 may enter between wall part 22b, 24b and base part 22a, 24a. When the heat transfer member 70 enters, stress acts on the base portion 22a due to expansion and contraction accompanying the temperature change of the heat transfer member 70 that has entered.

  On the other hand, in this embodiment, wall part 22b, 24b is continued with base 22a, 24a. According to this, it can suppress that the heat-transfer member 70 enters between wall part 22b, 24b and base part 22a, 24a. Therefore, it is possible to suppress the stress from acting on the base portion 22a from the heat transfer member 70. Therefore, it can suppress that a stress acts on the electronic component 30 via the base 22a from the heat-transfer member 70. FIG. That is, it is possible to effectively suppress a decrease in electrical connection reliability between the substrate 10 and the electronic component 30.

  In the present embodiment, the main body portions 36 and 40 are surrounded by the wall portions 22b and 24b and the land 14b in the projection view in the Z direction. According to this, it is possible to effectively suppress the heat transfer member 70 from entering between the main body portions 36 and 40 and the substrate 10 by the solder 44 and the wall portions 22b and 24b. Therefore, it can suppress effectively that the electrical connection reliability of the board | substrate 10 and the electronic component 30 falls.

  In the present embodiment, the wall portions 22b and 24b are connected to the base portions 22a and 24a. However, the present invention is not limited to this. As shown in the first modified example of FIG. 13, an example in which the base portion 22a and the wall portion 22b are formed apart from each other may be employed. In FIG. 13, the first electronic component 32 is indicated by a broken line.

  In the first modification, a gap 26 is formed between the base portion 22a and the wall portion 22b. In the Y direction, gaps 26 are formed at both ends of the base 22a. In other words, the gap 26 sandwiches the base portion 22a in the Y direction. According to this, when the heat transfer member 70 enters both the gaps 26, the stress in the Y direction acting on the base portion 22a from the heat transfer member 70 can be offset. Therefore, it can suppress effectively that the electrical connection reliability of the board | substrate 10 and the electronic component 30 falls.

(Third embodiment)
In the present embodiment, the description of the parts common to the electronic device 100 shown in the first embodiment is omitted.

  As shown in FIG. 14, the substrate 10 has a recess 28 that is recessed from the one surface 10a. The recess 28 is recessed with a predetermined depth with respect to the one surface 10a. At least one of the first land 14 c and the second land 14 d is formed on the bottom surface of the recess 28. Accordingly, at least one of the first electronic component 32 and the second electronic component 34 is disposed in the recess 28.

  In the present embodiment, a plurality of recesses 28 are formed in the substrate 10. One of the first land 14 c and the second land 14 d is formed on the bottom surface of one recess 28. One first electronic component 32 or one second electronic component 34 is disposed in one recess 28. The structure of the recess 28 in which the first electronic component 32 is disposed is substantially the same as the structure of the recess 28 in which the second electronic component 34 is disposed. Hereinafter, only the structure of the recess 28 in which the second electronic component 34 is disposed will be described.

  The bottom surface of the recess 28 is constituted by the conductor layer 14 and the first flexible layer 12b. The conductor layer 14 formed on the bottom surface of the recess 28 is the second land 14d. The first flexible layer 12 b that forms the bottom surface of the recess 28 is the second protrusion 24. In other words, the second convex portion 24 protrudes from the bottom surface of the concave portion 28. That is, the convex portion 20 protrudes from the bottom surface of the concave portion 28.

  In the Z direction, the surface of the first flexible layer 12b opposite to the core layer 12a is farther from the core layer 12a than the second land 14d. In other words, in the Z direction, the surface of the second convex portion 24 opposite to the core layer 12a is located closer to the second main body portion 40 than the second land 14d. That is, a part of the second convex portion 24 is located closer to the heat transfer member 70 than the second land 14d in the Z direction. In the present embodiment, the thickness of the second land 14d is about 10 μm. On the other hand, the thickness of the 2nd convex part 24, ie, the 1st flexible layer 12b, is about 200 micrometers.

  The recess 28 is formed in the substrate 10 by removing the solder resist 16 and the first flexible layer 12b. For example, the solder resist 16 and the first flexible layer 12b are removed by etching. By removing the solder resist 16 and the first flexible layer 12b on the one surface 10a side, the first flexible layer 12b and the conductor layer 14 forming the inner layer 14a before the removal are exposed to the one surface 10a, and the concave portion is formed. 28 is the bottom surface. The electronic device 100 of the present embodiment can achieve the same effects as the electronic device 100 of the first embodiment.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the above-described embodiment, an example in which the convex portion 20 overlaps with substantially the entire facing surfaces 36a and 40a in the Z-direction projection view is shown, but the present invention is not limited to this. As shown in the second modified example of FIGS. 15 and 16, it is also possible to employ an example in which the convex portion 20 overlaps only a part of the facing surfaces 36a and 40a in the projection view in the Z direction. In FIG. 15, the first electronic component 32 is indicated by a broken line.

  In the second modification, two first convex portions 22 are formed for one first electronic component 32. In the projection view in the Z direction, the first convex portion 22 is formed between the first lands 14c. In the projection view in the Z direction, the entire first protrusion 22 overlaps a part of the facing surface 36a. The two first convex portions 22 are separated from each other in the Y direction. Thereby, a space is formed between the first convex portions 22. The first land 14 c and the first convex portion 22 surround the solder resist 16 in the projection view in the Z direction. In the projection view in the Z direction, the solder resist 16 surrounded by the first land 14c and the first convex portion 22 overlaps the facing surface 36a.

  In the above embodiment, the first electrode 38 has a substantially flat plate shape and is formed integrally with the first main body 36. However, the present invention is not limited to this. Similarly to the second electrode 42, the first electrode 38 may have a substantially rod shape and may protrude from the first main body portion 36.

  Moreover, although the 2nd electrode 42 comprised the substantially rod shape and protruded from the 2nd main-body part 40 in the said embodiment, although it showed, it is not limited to this. Similarly to the first electrode 38, the second electrode 42 has a substantially flat plate shape, and an example in which the second electrode 42 is formed integrally with the second main body 40 can also be adopted.

  Moreover, although the convex part 20 showed the example made into the resin layer of the board | substrate 10 in the said embodiment, it does not limit to this. An example in which the convex portion 20 is formed using a metal material can also be adopted. In the substrate 10, an example in which the solder resist 16 and the conductor layer 14 constituting the surface layer constitute the convex portion 20 can also be adopted. In this example, a part of the convex part 20 is formed using a metal material.

  Moreover, although the convex part 20 showed the example which contacts the main-body parts 36 and 40 in the said embodiment, it is not limited to this. An example in which the convex portion 20 does not contact the main body portions 36 and 40 can also be adopted.

  Moreover, although the example which employ | adopts the 1st case part 52 which is a part of housing | casing 50 as a member which thermally radiates the heat | fever of the 1st electronic component 32 to the exterior was shown in the said embodiment, it does not limit to this. Absent. An example in which the heat dissipation member to which the first electronic component 32 is thermally connected via the heat transfer member 70 does not constitute the housing 50 can also be adopted.

  Moreover, in the said embodiment, although the 1st case part 52 and the 2nd case part 54 showed the example formed using the metal material, it does not limit to this. An example in which at least one of the first case portion 52 and the second case portion 54 is formed using a resin material may be employed.

  In the above-described embodiment, an example in which the substrate 10 is a printed board is shown, but the present invention is not limited to this. An example in which the substrate 10 is a ceramic substrate may be employed. Moreover, although the board | substrate 10 showed the example used as the multilayer board | substrate in the said embodiment, it is not limited to this. An example in which the insulating base 12 is a single layer can also be adopted.

DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 10a ... One side, 10b ... Back surface, 12 ... Insulating base material, 12a ... Core layer, 12b ... 1st flexible layer, 12c ... 2nd flexible layer, 14 ... Conductive layer, 14a ... Inner layer, 14b ... Land, 14c ... 1st land, 14d ... 2nd land, 16 ... Solder resist, 18 ... Through-hole, 20 ... Convex part, 22 ... 1st convex part, 22a ... Base part, 22b ... Wall part, 24 ... 2nd convex part, 24a ... base, 24b ... wall, 26 ... gap, 28 ... concave, 30 ... electronic component, 32 ... first electronic component, 34 ... second electronic component, 36 ... first body, 36a ... opposite surface, 38 ... 1st electrode, 40 ... 2nd main-body part, 40a ... Opposite surface, 42 ... 2nd electrode, 44 ... Solder, 50 ... Housing | casing, 52 ... 1st case part, 54 ... 2nd case part, 56 ... Internal space, 58 ... Screw hole, 60 ... Screw, 70 ... Heat transfer member, 100 ... Electronic device

Claims (5)

A substrate (10) having lands (14b) on one side (10a);
A first body (36) and a first electrode (38) electrically connected to the first land (14c) of the lands through a connecting member (44), A surface mounted first electronic component (32);
A second body (40) and a second electrode (42) electrically connected to the second land (14d) of the lands via the connection member, and is surface-mounted on the substrate The second electronic component (34),
A heat dissipating member (52) disposed opposite to the first electronic component in a first direction orthogonal to the one surface and dissipating heat of the first electronic component;
A heat transfer member (70) disposed between the first electronic component and the heat dissipating member to transmit heat of the first electronic component to the heat dissipating member;
An electronic device comprising:
The substrate has a protrusion (20) protruding from the one surface,
The convex portion is formed using a material having a smaller linear expansion coefficient than the heat transfer member, and overlaps at least one of the first main body portion and the second main body portion in the projection view in the first direction ,
The projecting portion includes a base portion (22a, 24a) that overlaps at least one of the first main body portion and the second main body portion, and the first main body portion and the second main body portion in the projection view in the first direction. A wall portion (22b, 24b) formed on the outer side of at least one of the outer peripheral ends,
A gap (26) is formed between the base and the wall;
The electronic device , wherein the gap is formed at both ends of the base in one direction orthogonal to the first direction . The electronic device according to claim 1 , wherein the wall portion is continuous with the base portion. In the projection view of the first direction, at least one of the first body portion and the second body portion according to claim 1 or claim 2, characterized in that it is surrounded by the wall portion and the land Electronic devices. The substrate has a recess (28) that is recessed from the one surface, and at least one of the first land and the second land is formed on the bottom surface,
The electronic device according to claim 1 , wherein the convex portion protrudes from the bottom surface. The first main body has a first facing surface (36a) facing the one surface in the first direction,
The second main body has a second facing surface (40a) facing the one surface in the first direction,
The convex portion is a projection view of the first direction, in any one of claims 1 to 4, characterized in that overlaps with at least one of the whole of the first opposing face and the second opposing surface The electronic device described.

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