JP2015133419A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device 10 capable of improving its reliability against vibration.SOLUTION: An electronic device 10 comprises a main substrate 30, first and second sub-substrates 40 and 50, and a reinforcement substrate 60. The main substrate 30 is fixed to a housing 20. The first and second sub-substrates 40 and 50 are bonded to the main substrate 30 in a direction perpendicular to the main substrate 30, with their plate surfaces arranged to face each other. The reinforcement substrate 60 are bonded to each of the first and second sub-substrates 40 and 50 in a state bridging over the first and second sub-substrates 40 and 50. With this structure, the rigidity of both the first and second sub-substrates 40 and 50 against vibration may be enhanced, thereby improving the reliability of the electronic device 10 against vibration.

Description

  The present invention relates to an electronic device including a first substrate and a second substrate bonded in a direction intersecting with the first substrate.

  As this type of electronic device, as can be seen in Patent Document 1 below, the protrusion and the protrusion are provided in a state where the protrusion provided on the outer edge of the second substrate is fitted in the through-hole provided in the first substrate. A device in which two substrates are soldered is known. As a result, the second substrate is bonded in a direction intersecting the first substrate.

JP 2001-57465 A

  By the way, as an electronic device, in addition to what is described in Patent Document 1, there is also an electronic device that includes a plurality of second substrates bonded to the first substrate while the first substrate is fixed to the housing. Specifically, each of the plurality of second substrates is bonded so as to intersect with the first substrate, and is provided so that the plate surfaces face each other.

  Here, when the electronic device is used in a vibration environment, each of the second substrates vibrates with a joint portion between each of the plurality of second substrates and the first substrate as a fixed end. In this case, there is a concern that the solder that joins each of the second substrates and the first substrate has a problem such as a crack, and the reliability of the electronic device is lowered.

  SUMMARY An advantage of some aspects of the invention is to provide an electronic device that can improve the reliability of the electronic device against vibration.

  In order to solve the above problems, the present invention is joined to the first substrate (30) fixed to the housing (20) in a direction intersecting the first substrate, and the plate surfaces are opposed to each other. The plurality of second substrates (40, 50) provided in this manner, and the reinforcing substrate (60; 62; 64; 66; 68) joined to each of the second substrates in a state of being stretched over the plurality of second substrates. ).

  In the said invention, the reinforcement board | substrate is joined to each 2nd board | substrate in the state over the several 2nd board | substrate. By joining with the reinforcing substrate, the rigidity of each of the plurality of second substrates with respect to vibration can be increased. For this reason, each vibration of a some 2nd board | substrate can be suppressed suitably. Thereby, the reliability of the electronic device with respect to vibration can be improved.

  Furthermore, in the said invention, it is also possible to electrically connect a reinforcement board | substrate and a 2nd board | substrate. For this reason, it becomes easy to create a mutual electrical connection path for each of the plurality of second substrates that are separated from each other and are erected with respect to the first substrate. The degree of freedom of the electric circuit provided can be improved.

1 is an external view of an electronic device according to a first embodiment. The longitudinal cross-sectional view of the electronic device concerning the embodiment. The assembly drawing of the main board | substrate, sub board | substrate, and reinforcement board | substrate concerning the embodiment. The figure which shows the joining method of the main board | substrate and sub-board | substrate concerning the embodiment. The figure which shows the joining method of the sub-board | substrate and reinforcement board | substrate concerning the embodiment. FIG. 5 is an assembly diagram of a main board, a sub board, and a reinforcing board according to a second embodiment. The assembly drawing of the main board | substrate, sub board | substrate, and reinforcement board | substrate concerning 3rd Embodiment. FIG. 10 is an assembly diagram of a main board, a sub board, and a reinforcing board according to a fourth embodiment. The longitudinal cross-sectional view of the electronic device concerning 5th Embodiment. BB sectional drawing of FIG.

(First embodiment)
A first embodiment in which an electronic device according to the present invention is embodied as an in-vehicle power supply device used in a vibration environment will be described below with reference to FIGS.

  As shown in FIG. 1, the electronic device 10 includes a housing 20, a main board 30 (corresponding to a “first board”), and first and second sub-boards 40 and 50 (“ And a reinforcing substrate 60 joined to each of the sub-substrates 40 and 50. Each of the sub-boards 40 and 50 and the reinforcing board 60 has a substantially rectangular shape in front view of the plate surface. The reinforcing substrate 60 has a rectangular shape when viewed from the front of the plate surface. For example, the electronic device 10 is mounted on the vehicle such that the bottom surface (main board 30) of the housing 20 is substantially horizontal, or is mounted on the vehicle so that the bottom surface of the housing 20 is substantially vertical. .

  The housing 20 accommodates the main board 30, the sub-boards 40 and 50, and the reinforcing board 60. In the present embodiment, the housing 20 is a box-shaped one having an open surface and a peripheral wall portion, and is formed of a metal material. Specifically, a case 20 that is die-cast using aluminum as a material is used as the housing 20. The opening of the housing 20 is closed by the lid body by fixing a lid body (not shown) to the housing 20 with screws or the like. In the present embodiment, a heat radiation hole (not shown) that opens to the outside of the housing 20 may be provided in the side wall portion of the housing 20.

  The housing 20 further includes a cooling fan 70 for cooling elements mounted on the main board 30, the sub-boards 40 and 50, and the reinforcing board 60. The cooling fan 70 is an air flow generator for generating an air flow in the space inside the housing 20. In the present embodiment, the cooling fan 70 is driven so that wind circulates in the space within the housing 20. Hereinafter, of the pair of plate surfaces of the main substrate 30, the side on which the sub-substrates 40 and 50 are mounted will be referred to as the upper surface, and the other will be referred to as the lower surface.

  The main board 30 is fixed to the housing 20. Specifically, as shown in FIG. 2, the bottom surface 20a of the housing 20 is provided with a plurality of boss portions 20b for fixing the main board 30 to the bottom surface 20a. The boss portion 20b has a cylindrical shape, and a screw hole is provided at the center thereof. On the other hand, the main substrate 30 is provided with a through hole 30a. With the lower surface of the main board 30 in contact with the boss portion 20b, a fixing screw 72 as a fixing means is screwed into the screw holes of the through hole 30a and the boss portion 20b. As a result, the main board 30 is fixed to the bottom surface 20 a of the housing 20. By this fixing, in this embodiment, the plate surface of the main substrate 30 and the bottom surface 20a of the housing 20 are made parallel or substantially parallel.

  In each of the sub-boards 40 and 50, the opposing plate surface (inner side surface) is a component mounting surface. Specifically, the first electronic component 80 is mounted on the first sub-board 40, and the second electronic component 82 is mounted on the second sub-board 50. The electronic components 80 and 82 are mounted on the inner side surfaces of the sub-boards 40 and 50 at positions separated from the upper surface of the main board 30. In the present embodiment, as the first and second electronic components 80 and 82, passive elements (for example, resistance elements) that generate heat when energized are used. In addition, this embodiment does not deny that the outer surface which is a back surface of an inner surface among the pair of plate surfaces of the sub-boards 40 and 50 is a component mounting surface.

  On the other hand, the third electronic component 84 is mounted on the reinforcing substrate 60. In the present embodiment, a regulator that generates heat when energized is used as the third electronic component 84.

  Next, a joining method and an electrical connection method between the main substrate 30 and the sub-substrates 40 and 50 will be described with reference to FIGS.

  As shown in the drawing, the outer edges (lower sides 40 a, 50 a) of the sub-substrates 40, 50 are bonded to the upper surface of the main substrate 30. In the present embodiment, the sub substrates 40 and 50 are bonded to the main substrate 30 so that the plate surface of the first sub substrate 40 and the plate surface of the second sub substrate 50 are parallel or substantially parallel. Here, in this embodiment, the joining technique of each sub board | substrate 40 and 50 with respect to the main board | substrate 30 is the same. For this reason, the following description will be given by taking as an example a method of bonding the first sub-substrate 40 to the main substrate 30.

  As shown in FIG. 4, the main board 30 is provided with a plurality of (three examples in the figure) through holes 30 b penetrating the main board 30. These through holes 30b are arranged in a line at a predetermined interval. The main board 30 is provided with a main board side land 30c surrounding each through hole 30b and each main board side pattern 30d electrically connected to each main board side land 30c.

  On the other hand, the lower side 40a of the first sub-board 40 is provided with the same number of protruding connection terminals 40c as the number of through holes 30b. The first sub-board 40 is provided with a first sub-board side pattern 40d extending from each connection terminal 40c to the upper side 50b.

  Each connection terminal 40c is inserted into each through hole 30b. As a result, the first sub-board 40 is bonded to the main board 30 in a direction orthogonal thereto. In addition, the first sub-substrate side pattern 40d of each connection terminal 40c and the main substrate-side land 30c of the main substrate 30 are soldered in a state where each connection terminal 40c is inserted into each through-hole 30b. Thereby, each main board side land 30c of the main board | substrate 30 and each 1st sub board | substrate side pattern 40d of the 1st sub board | substrate 40 are electrically connected. That is, the electric circuit (main board side land 30c, main board side pattern 30d) provided on the main board 30 and the electric circuit (first sub board side pattern 40d, first electronic component) provided on the first sub board 40 80) are electrically connected.

  The second sub board 50 is also bonded in a direction orthogonal to the main board 30. Further, the electric circuit provided on the main board 30 and the electric circuit provided on the second sub board 50 are electrically connected.

  Next, the reason why the characteristic configuration of the electronic device 10 according to the present embodiment is employed and the characteristic configuration will be described.

  Each of the sub-boards 40 and 50 is bonded to the main board 30 only at the lower sides 40a and 50a. In this case, the sub-boards 40 and 50 vibrate with the lower sides 40a and 50a as fixed ends and the upper sides 40b and 50b as free ends due to the vibration of the electronic device 10 as the vehicle travels. As the sub-boards 40 and 50 vibrate, stress acts on the solder that joins the connection terminals of the sub-boards 40 and 50 and the main board 30 to cause cracks. In this case, the reliability of the electronic device 10 decreases. In particular, if the frequency of vibration of each sub-board 40, 50 as the vehicle travels matches the resonance frequency of each sub-board 40, 50, the vibration of each sub-board 40, 50 increases, and the reliability of the electronic device 10 is increased. There is a risk that the deterioration of the property becomes remarkable.

  In order to solve such a problem, in the present embodiment, the reinforcing substrate 60 is joined to the sub-substrates 40 and 50 in a state of being stretched over the sub-substrates 40 and 50. Here, in this embodiment, the joining method of the first sub-substrate 40 and the reinforcing substrate 60 and the joining method of the second sub-substrate 50 and the reinforcing substrate 60 are the same. For this reason, in this embodiment, the joining method of the 1st sub board | substrate 40 and the reinforcement board | substrate 60 is demonstrated to an example.

  A method for joining the first sub-substrate 40 and the reinforcing substrate 60 will be described with reference to FIG. FIG. 5 is an enlarged view of a joining portion between the first sub-board 40 and the reinforcing board 60 before the first sub-board 40 and the reinforcing board 60 are joined.

  As shown in the drawing, the first sub-board 40 is provided with one recess 40e extending from the upper side 40b to the lower side 40a. Further, in the vicinity of the recess 40e of the first sub-substrate 40, a plurality of (three) lands 40f are provided side by side with a predetermined interval in the direction in which the recess 40e extends. Specifically, each land 40f is provided adjacent to the recess 40e. Each land pattern 40g is electrically connected to each land 40f.

  On the other hand, the reinforcing substrate 60 is provided with a recess 60a extending from one of a pair of outer edges facing in the short direction to the other side. In addition, the reinforcing substrate 60 is provided with the same number (three) of lands 60b as the number of the recesses 40e of the first sub-substrate 40. Specifically, the lands 60b are arranged in a line at a predetermined interval in the direction in which the recess 60a of the reinforcing substrate 60 extends (the short direction of the reinforcing substrate 60). A wiring pattern 60c is electrically connected to each land 60b. In the present embodiment, the length of the recess 60 a in the short direction of the reinforcing substrate 60 is set to be less than half the length of the reinforcing substrate 60 in the short direction. This is a setting for securing the strength of the reinforcing substrate 60.

  By engaging the concave portion 40 e of the first sub-substrate 40 with the concave portion 60 a of the reinforcing substrate 60, the first sub-substrate 40 and the reinforcing substrate 60 are joined. In the present embodiment, the land 60b of the reinforcing substrate 60 and the land 40f of the first sub-substrate 40 are adjacent to each other by this bonding. By soldering the lands 40f and 60b in a state where the lands 40f and 60f are adjacent to each other, an electric circuit provided on the first sub-board 40 and an electric circuit (lands 60b and 60b provided on the reinforcing board 60) are provided. The wiring pattern 60c and the third electronic component 84) are electrically connected. Here, when the lands 40f and 60b are adjacent to each other at the time of soldering, the lands 40f and 60b can be easily soldered to each other. Moreover, the amount of solder can be reduced by adjoining each land 40f, 60b.

  The reinforcing substrate 60 is provided with a recess for engaging with the second sub-substrate 50 in addition to the recess 60 a for engaging with the first sub-substrate 40. By engaging the concave portion of the second sub-substrate 50 with this concave portion, the second sub-substrate 50 and the reinforcing substrate 60 are joined. Then, by soldering the land of the second sub-board 50 and the land of the reinforcing board 60, the electric circuit provided on the reinforcing board 60 and the electric circuit (second electronic component) provided on the second sub-board 50 82) are electrically connected to each other.

  Incidentally, in the present embodiment, the reinforcing substrate 60 is disposed at a height position where the flow velocity of air is highest in the height direction of the housing 20. This is because the third electronic component 84 is effectively cooled. Further, the reinforcing substrate 60 is arranged at a height position such that the third electronic component 84 does not contact the lid of the housing.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) The upper sides 40b and 50b of the sub-boards 40 and 50 and the reinforcing board 60 are joined. By joining with the reinforcing substrate 60, the rigidity against vibration of each of the sub-substrates 40 and 50 can be increased. For this reason, each vibration of each sub-board | substrate 40 and 50 can be suppressed suitably, and by extension, the reliability of the electronic apparatus 10 with respect to a vibration can be improved.

  In particular, in the present embodiment, the fact that the sub-boards 40 and 50 and the reinforcing board 60 are joined by engaging the concave parts of the sub-boards 40 and 50 with the concave parts of the reinforcing board 60 means that each sub-board 40 is connected. , 50 to increase the rigidity improvement effect.

  (2) The electric circuit provided on the main board 30 was electrically connected to the electric circuit provided on the reinforcing board 60 via the electric circuit provided on each of the sub-boards 40 and 50. For this reason, at the time of designing the electronic apparatus 10, the degree of freedom of the electric circuits provided on the main board 30 and the sub-boards 40 and 50 can be improved. Specifically, for example, at the time of designing the electronic device 10, an electric circuit to be provided on the main board 30 and the sub-boards 40 and 50 can be transferred to the reinforcing board 60. In this case, it is possible to reduce the mounting area of the main board 30 and the sub-boards 40 and 50, and to reduce the size of the main board 30 and the sub-boards 40 and 50.

  (3) The third electronic component 84 that generates heat when energized is mounted on the reinforcing substrate 60. Then, each of the sub-boards 40 and 50 and the reinforcing board 60 were joined in a state of being separated from the main board 30. According to such a configuration, heat generated by the third electronic component 84 mounted on the reinforcing substrate 60 is not easily transmitted to the main substrate 30. For this reason, the influence of the heat which the 3rd electronic component 84 generate | occur | produces with respect to the main board | substrate 30 can be relieved.

  (4) The electronic components 80 and 82 are mounted on the sub-boards 40 and 50 at positions separated from the main board 30. In this case, there is a concern that the displacement of the mounting positions of the electronic components 80 and 82 increases with the vibration of the sub-boards 40 and 50. Here, according to the present embodiment in which the sub-boards 40 and 50 and the reinforcing board 60 are joined, the displacement of the mounting positions of the electronic components 80 and 82 can be reduced. For this reason, the reliability with respect to the vibration of each electronic component 80 and 82 can be improved.

  (5) The inner surface of each sub-board 40, 50 is a component mounting surface. And the reinforcement board | substrate 60 was provided so that each electronic component 80,82 mounted in the inner surface of each subboard | substrate 40,50 might be connected electrically. For this reason, for example, the electronic components 80 and 82 are mounted on the outer surface of the sub-boards 40 and 50, and the outer surface of the first sub-board 40, the upper surface of the reinforcing substrate 60, and the outer side of the second sub-board 50 are interposed. Compared with the configuration in which the electronic components 80 and 82 are electrically connected, the wiring length of the wiring pattern that electrically connects the electronic components 80 and 82 can be shortened. For this reason, it is possible to reduce the impedance of the wiring pattern and to suppress the mixing of noise through the wiring pattern.

  Further, according to the configuration in which the inner surface of each sub-board 40, 50 is a component mounting surface, the space between each sub-board 40, 50 can be effectively used when mounting tall components such as capacitors. You can also.

  (6) Of the inner side surfaces of the sub-boards 40 and 50, the main board 30 side of the reinforcing board 60 is used as a component mounting surface. According to such a configuration, the electronic components 80 and 82 can be arranged in the airflow passage formed by the main substrate 30, the sub-substrates 40 and 50, and the reinforcing substrate 60. For this reason, each electronic component 80 and 82 can be cooled effectively.

  (7) Recesses are provided in each of the sub-boards 40 and 50 and the reinforcing board 60. For this reason, in the manufacturing process of the electronic device 10, it is possible to position the reinforcing substrate 60 at the time of joining to the sub-substrates 40 and 50. That is, in a state where the sub-substrates 40 and 50 and the reinforcing substrate 60 are joined by engaging the concave portions of the sub-substrates 40 and 50 and the concave portions of the reinforcing substrate 60, the sub-substrates 40 and 50 and the reinforcing substrate 60 are reinforced. The relative positional relationship with the substrate 60 can be fixed. Since the sub-boards 40 and 50 and the reinforcing board 60 are provided with an electric circuit, fixing the relative positional relationship is important in order to electrically connect the boards 40, 50 and 60. Since the relative positional relationship can be fixed, the land 60b adjacent to the land of each of the sub-boards 40, 50 in a state where the recess of each of the sub-boards 40, 50 and the recess of the reinforcing board 60 are engaged with the reinforcing board 60. Can be provided. Thereby, in the manufacturing process of the electronic device 10, the land of the reinforcing substrate 60 and each sub-board can be avoided, for example, the displacement of the reinforcing substrate 60 can be avoided when the land of the reinforcing substrate 60 and the land of each sub-substrate 40, 50 are soldered. The lands of the boards 40 and 50 can be easily soldered.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In this embodiment, each sub board | substrate and a reinforcement board | substrate are joined via an electronic component.

  FIG. 6 shows an assembly diagram of the main board, each sub board, and the reinforcing board according to the present embodiment. In FIG. 6, the same members as those shown in FIG. 3 are given the same reference numerals for the sake of convenience.

  As illustrated, a fourth electronic component 86 is mounted on the inner surface of the first sub-board 40. The fourth electronic component 86 includes a main body portion 86a and an L-shaped connector 86b fixed to the main body portion 86a. Specifically, the main body portion 86 a is mounted on the inner side surface of the first sub board 40.

  The distal end of the connector 86b is fixed to the plate surface of the reinforcing substrate 62. Specifically, the tip of the connector 86b is positioned in a state where the reinforcing substrate 62 is disposed so that the plate surface of each of the sub-boards 40 and 50 and the plate surface of the main substrate 30 and the plate surface of the reinforcing substrate 62 are orthogonal to each other. It is fixed to the reinforcing substrate 62. Thereby, each sub-board | substrate 40 and 50 and the reinforcement board | substrate 62 are joined.

  The second sub-board 50 and the reinforcing board 62 are joined by the same technique as the joining technique of the first sub-board 40 and the reinforcing board 62 by an electronic component having the same shape as the fourth electronic component 86.

  Also according to the present embodiment described above, the same effects as the effects (1) to (3) of the first embodiment can be obtained.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In this embodiment, the joining position of the reinforcing substrate in each sub-substrate is changed.

  FIG. 7 shows an assembly diagram of the main board, each sub-board, and the reinforcing board according to the present embodiment. In FIG. 7, the same members as those shown in FIG. 3 are given the same reference numerals for the sake of convenience.

  As illustrated, in the present embodiment, the reinforcing substrate 64 is bonded to the side edges 41 and 51 of the sub-substrates 40 and 50. Specifically, the recesses provided on the sides 41 and 51 of the sub-boards 40 and 50 are engaged with the recesses provided on the reinforcing board 64, whereby the sub-boards 40 and 50 and the reinforcing board 64 are connected. It is joined.

  Here, in the present embodiment, the sub-boards 40 and 50 and the reinforcing board 64 are joined so that the plate surface of the reinforcing substrate 64 and the plate surface of the main substrate 30 are parallel or substantially parallel. Thereby, it can prevent that the airflow in the space between each subboard | substrate 40 and 50 is prevented. Therefore, according to this embodiment, in addition to the effect obtained in the first embodiment, an effect that the third electronic component 84 mounted on the reinforcing substrate 64 can be effectively cooled can be obtained.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In this embodiment, the joining method of each sub-board and the reinforcing board is changed.

  FIG. 8 is an assembly diagram of the main board, each sub board, and the reinforcing board according to the present embodiment. In FIG. 8, the same members as those shown in FIG. 3 are given the same reference numerals for the sake of convenience.

  As illustrated, the first and second sub-boards 40 and 50 are provided with first and second insertion portions 42 and 52 extending upward from the upper sides 40b and 50b. The reinforcing substrate 66 is provided with first and second through holes 66a and 66b penetrating the plate surface. Each insertion part 42,52 is inserted in each through-hole 66a, 66b, and each sub-board | substrate 40,50 and the reinforcement board | substrate 66 are joined. Specifically, the sub-boards 40 and 50 and the reinforcing board 66 are joined in a state where the plate surface of the reinforcing board 66 and the upper sides 40b and 50b of the sub-boards 40 and 50 are in contact with each other.

  The electrical connection between the sub-boards 40 and 50 and the reinforcing board 66 can be performed by, for example, a method described below. Specifically, a wiring pattern is provided in each of the insertion portions 42 and 52, and lands that surround the through holes 66 a and 66 b are provided on the plate surface of the reinforcing substrate 66. Then, in a state where the sub-boards 40 and 50 and the reinforcing board 66 are joined, the wiring patterns and the lands are soldered to electrically connect the sub-boards 40 and 50 and the reinforcing board 66. To do.

  Thus, in this embodiment, each sub board | substrate 40,50 and the reinforcement board | substrate 66 were joined in the state which the plate | board surface of the reinforcement board | substrate 66 and each upper side 40b, 50b of each sub board | substrate 40,50 contact | abutted. . According to such a configuration, in addition to the effects (1) to (3) of the first embodiment and the effects of the third embodiment, the rigidity of the sub-boards 40 and 50 with respect to vibration is further increased. The effect of being able to be able to be obtained.

(Fifth embodiment)
Hereinafter, a fifth embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

  In this embodiment, the joining method of each sub-board and the reinforcing board is changed.

  9 and 10 are longitudinal sectional views of the electronic device 10 according to the present embodiment. 10 is a cross-sectional view taken along the line BB in FIG. 9 and 10, the same members as those shown in FIG. 2 are given the same reference numerals for the sake of convenience.

  As shown in the figure, the reinforcing substrate 68 is bonded to the sub-substrates 40 and 50 with the plate surface facing the plate surface of the main substrate 30. The reinforcing substrate 68 is joined to the sub-substrates 40 and 50 in a state where the reinforcing substrate 68 is inclined with respect to the plate surface of the main substrate 30 in a direction along the plate surfaces of the sub-substrates 40 and 50. Thereby, between each sub-board | substrate 40 and 50, the flow path of the air flow which makes the side where the separation distance of the reinforcement board | substrate 68 and the main board | substrate 30 is large upstream is upstream, and makes a small side downstream is formed. Specifically, the flow path area of the air flow channel decreases from upstream to downstream.

  According to such a configuration, the flow rate of air flowing out from the downstream of the air flow path is higher than the flow speed of air introduced from the upstream of the air flow path. Thereby, the 5th electronic component 88 which is a heat-emitting component mounted downstream of the air flow path of the main board | substrate 30 can be cooled effectively.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  In the first embodiment, the concave portions are provided in the sub-substrates 40 and 50 and the reinforcing substrate 60, but the present invention is not limited to this. For example, the concave portion may be provided only on the sub-board, or the concave portion may be provided only on the reinforcing substrate. Even in this case, each of the sub-boards 40 and 50 and the reinforcing board 60 can be bonded.

  In the first embodiment, the cooling fan 70 is not essential. Here, when the cooling fan 70 is not provided in the housing 20, the heat radiating hole provided in the side wall portion of the housing 20 serves as an “air flow generation unit” that generates an air flow in the housing 20. Specifically, an air flow can be generated in the housing 20 by the air flowing into the housing 20 from the outside of the housing 20 through the heat radiation holes.

  The number of sub-boards is not limited to two and may be three or more. In this case, for example, each of all the sub-boards and one reinforcing board are joined. Note that the number of reinforcing substrates bonded to each of all the sub-substrates is not limited to one and may be plural.

  The heat generating component mounted on the reinforcing substrate is not limited to the MOSFET but may be another active element. The heat generating component is not limited to an active element, but may be a passive element such as a transformer, a capacitor, or a resistance element. The same applies to the heat-generating component mounted on the sub-board.

  In the first embodiment, the sub-substrates 40 and 50 and the reinforcing substrate 60 are joined to each other in a state where the sub-substrates 40 and 50 and the reinforcing substrate 60 are joined. Not limited to. The lands of the sub-boards 40 and 50 and the lands of the reinforcing board 60 may be close to each other with a gap.

  The joining technique between the main board 30 and the sub-boards 40 and 50 is not limited to the one exemplified in the first embodiment. For example, by providing connectors on the upper surface of the main board 30 and the lower sides 40a, 50a of the sub boards 40, 50, and connecting the connectors of the main board 30 and the connectors of the sub boards 40, 50, the main board 30 30 and the sub-substrates 40 and 50 may be joined. In this case, the main board 30 and the sub-boards 40 and 50 can be electrically connected by connecting the connector of the main board 30 and the connectors of the sub-boards 40 and 50.

  The joining method of the sub-boards 40 and 50 and the reinforcing board 68 is not limited to the one exemplified in the fifth embodiment, and may be described below, for example. Specifically, the sub-boards 40 and 50 are configured such that their upper sides are inclined with respect to the plate surface of the main substrate 30 in a direction along the plate surface of each sub-substrate 40 and 50. In addition, each of the sub-boards 40 and 50 is provided with each insertion portion extending upward from its upper side. Further, the reinforcing substrate 68 is provided with through holes corresponding to the insertion portions of the sub-substrates 40 and 50 through the plate surface. In such a configuration, each insertion portion is inserted into each through hole. As a result, the reinforcing substrate 68 is bonded to the sub-substrates 40 and 50 while being tilted in the direction along the plate surfaces of the sub-substrates 40 and 50 with respect to the plate surface of the main substrate 30. Further, the reinforcing substrate 68 is bonded to the sub-substrates 40 and 50 in a state where the plate surface and the upper sides of the sub-substrates 40 and 50 are in contact with each other.

  DESCRIPTION OF SYMBOLS 20 ... Housing | casing, 30 ... Main board | substrate, 40 ... 1st sub board | substrate, 50 ... 2nd sub board | substrate, 60 ... Reinforcement board | substrate.

Claims (10)

A first substrate (30) fixed to the housing (20);
A plurality of second substrates (40, 50) which are joined in a direction intersecting with the first substrate and provided so that the plate surfaces face each other;
A reinforcing substrate (60; 62; 64; 66; 68) joined to each of the second substrates in a state of being stretched over the plurality of second substrates;
An electronic device comprising: The electrical circuit (30c, 30d; 88) provided on the first substrate and the electrical circuit (40d, 40f, 40f) provided on the second substrate in a state where the first substrate and the second substrate are bonded. 40g, 80, 82; 86) are electrically connected,
In a state where the second substrate and the reinforcing substrate are joined, the electric circuit provided on the second substrate and the electric circuit (60b, 60c, 84) provided on the reinforcing substrate are electrically connected. The electronic device according to claim 1, wherein The reinforcing substrate is provided with an exothermic component (84) that is an electronic component constituting the electric circuit and generates heat when energized.
The electronic device according to claim 2, wherein the reinforcing substrate is bonded to each of the plurality of second substrates in a state of being separated from the first substrate. An air flow generator (70) for generating an air flow in the housing;
The reinforcing substrate (64, 66) is bonded to each of the plurality of second substrates in a state where a plate surface thereof is substantially parallel to a plate surface of the first substrate. Item 4. The electronic device according to any one of Items 1 to 3. An air flow generator (70) for generating an air flow in the housing;
The reinforcing substrate (68) is provided such that its plate surface faces the plate surface of the first substrate and is inclined with respect to the plate surface of the first substrate with respect to the plate surface of the first substrate. And
Between the plurality of second substrates, a flow path of the air flow is formed in which a side having a large separation distance between the reinforcing substrate and the first substrate is an upstream side and a small side is a downstream side. The electronic device according to any one of claims 1 to 3. Each of the reinforcing substrate and the second substrate has a rectangular shape,
In the second substrate and the reinforcing substrate, recesses (40e, 60a) that can be engaged with each other are formed on the outer edges of the plate surfaces,
The electronic device according to claim 1, wherein the second substrate and the reinforcing substrate are joined by the engagement of the concave portions. A land (40f) is provided in the vicinity of the concave portion (40e) of the second substrate,
The reinforcing substrate is provided with a land (60b) adjacent to or adjacent to the land of the second substrate in a state where the respective concave portions are engaged,
By soldering the lands of the second substrates and the lands of the reinforcing substrate in a state where the concave portions are engaged, the electric circuit provided on the second substrates and the reinforcing substrate are provided. The electronic device according to claim 6, wherein the electronic device is electrically connected to the electronic circuit. Each of the reinforcing substrate and the second substrate has a rectangular shape,
Each of the plurality of second substrates is provided with insertion portions (42, 52) protruding outward from the outer edge of the plate surface,
The reinforcing substrate (66) is provided with through holes (66a, 66b) penetrating the plate surface,
6. Each of the plurality of second substrates is inserted into a through hole of the reinforcing substrate, so that each of the second substrates and the reinforcing substrate are joined. The electronic device according to any one of the above.   The said reinforcement board | substrate (66) is joined to each said 2nd board | substrate in the state which the plate | board surface contact | abutted to each outer edge of the said several 2nd board | substrate. 9. The electronic device according to any one of 8 above.   In each of the plurality of second substrates, plate surfaces facing each other are used as component mounting surfaces, and electrical circuits (80, 82) provided on the component mounting surfaces of the respective second substrates are electrically connected. The electronic device according to claim 1, wherein the reinforcing substrate is provided on the electronic device.

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