Three dimensional structure substrate

Abstract

To provide a three dimensional structure substrate with high heat dissipation efficiency.SOLUTION: It has a plurality of substrate sections 1, each having at least one electronic component 6 mounted thereon, and a connection section 2 connecting the plurality of substrate sections 1 in an elastically deformable state and having a circuit pattern 8 that electrically connects respective electronic components 6, and the connection section 2 connects the plurality of substrate sections 1 in a three dimensional configuration with the circuit pattern 8 exposed externally.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a three-dimensional structure substrate on which a plurality of electronic components are mounted three-dimensionally. [Background technology]

[0002] In recent years, automobiles equipped with motors as a driving source (such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), and fuel cell electric vehicles (FCEVs)) have become widespread. Hereinafter, these automobiles will be collectively referred to as electric vehicles. Electric vehicles have many devices that require cooling, such as motors (including internal combustion engines such as engines), batteries, air conditioners, and ECUs. Therefore, in order to reduce the mounting space required for circuit boards, development is underway on three-dimensional structure boards in which multiple electronic components are mounted three-dimensionally. While these three-dimensional structure boards can reduce mounting space, they also require improved heat dissipation efficiency because multiple electronic components face each other.

[0003] The circuit board in Patent Document 1 has a resist film formed on the copper foil that forms the circuit pattern, and solder is applied to the areas other than the resist film. By applying solder to the areas other than the resist film, heat generated by the electronic components is dissipated from the solder surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-6971 Summary of the Invention [Problem to be solved by the invention]

[0005] When heat generated from electronic components is dissipated from the solder surface, as in the circuit board described in Patent Document 1, the thermal conductivity of the solder acts as thermal resistance, resulting in poor heat dissipation efficiency. In particular, when the technology described in Patent Document 1 is applied to a three-dimensional structure board, the heat dissipation performance is insufficient, and there is a need to further improve the heat dissipation efficiency.

[0006] Therefore, a three-dimensional structure substrate with high heat dissipation efficiency is desired. [Means for solving the problem]

[0007] The characteristic configuration of the three-dimensional structure substrate of the present invention is that it comprises a plurality of substrate sections, each having at least one electronic component mounted thereon, and a connection section that connects the plurality of substrate sections in an elastically deformable state and has a circuit pattern that electrically connects each of the electronic components, the connection section having a portion where the circuit pattern is exposed to the outside and connects the plurality of substrate sections in a three-dimensional manner.

[0008] In this configuration, the circuit patterns that electrically connect the electronic components are exposed to the outside, and the circuit patterns have lower thermal resistance than solder, which can improve the efficiency of dissipating heat generated by the electronic components.

[0009] In particular, the circuit pattern provided on the elastically deformable connection part as in this configuration does not require a resist film to prevent solder shorts, and by exposing this circuit pattern to the outside, it can fulfill the role of radiative cooling. In this way, a three-dimensional structure substrate with high heat dissipation efficiency is achieved. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view showing the entire three-dimensional structure substrate. [Figure 2] 2 is a diagram showing a schematic view of electronic components, exposed connection patterns, etc. of a three-dimensional structure substrate; [Figure 3] FIG. 2 is an enlarged cross-sectional view of a three-dimensional structure substrate. [Figure 4]FIG. 2 is a perspective view showing a cylindrical three-dimensional structure substrate and an access substrate. [Figure 5] FIG. 2 is a cross-sectional plan view of a cylindrical three-dimensional structure substrate. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the three-dimensional structure substrate according to the present invention will be described with reference to the drawings. The three-dimensional structure substrate according to the present invention is not limited to the following embodiments, and various modifications are possible without departing from the spirit and scope of the present invention.

[0012] [Basic configuration] As shown in Figure 1, a three-dimensional structure substrate A is constructed by electrically connecting a plate-shaped rigid part 1 (an example of a substrate part) that is difficult to deform and a flexible part 2 (an example of a connection part) that can flexibly deform.

[0013] 4 and 5, the three-dimensional structure substrate A is configured so that it can be housed in a cylindrical case B by bending a plurality of flexible portions 2 (connection portions) and arranging a plurality of rigid portions 1 (substrate portions) in a ring-shaped region when viewed in the vertical direction Y. The three-dimensional structure substrate A is used in the up-down position shown in FIG.

[0014] [Rigid part / Flexible part 2] As shown in Figure 3, the rigid part 1 (substrate part) has multiple substrate patterns 4 made of copper foil formed on multiple insulating layers 3 made of glass epoxy material or the like, and a resist film 5 made of an insulating resin material is formed to cover the substrate patterns 4 on the inner surface S1 and the outer surface S2.

[0015] A plurality of electronic components 6 are mounted on the rigid portion 1, and these electronic components 6 are electrically connected to the board pattern 4.

[0016] 3, the flexible part 2 (connection part) is configured to be flexible and elastically deformable by thinning the area that is continuous with the insulating layer 3 of the rigid part 1. A plurality of connection patterns 8 made of copper foil are formed on this flexible part 2, and the flexible part 2 has a portion that exposes those of the plurality of connection patterns 8 that are formed on the outer surface S2.

[0017] In other words, the connection patterns 8 formed on the outer surface S2 form exposed connection patterns 8Ex by exposing the copper foil without forming a resist film 5, and this exposed connection pattern 8Ex enables heat dissipation by contacting the pattern with the air and by radiation.

[0018] In this embodiment, the flexible part 2 (connection part) is formed by thinning the insulating layer 3 extending outward from the insulating layer 3 of the rigid part 1, but instead, for example, the flexible part 2 (connection part) may be formed by using a flexible material (for example, polyimide or polyester film) different from the insulating layer 3 of the rigid part 1 and forming an exposed connection pattern 8Ex on the outer surface S2 of this material.

[0019] As shown in Figures 1 and 2, the three-dimensional structure substrate A comprises a plurality (four in this embodiment) of rigid parts 1 (substrate parts) and a plurality (three in this embodiment) of flexible parts 2, and is constructed by bending the plurality of flexible parts 2.

[0020] The multiple rigid portions 1 are strip-shaped, with a dimension in the width direction X, which is perpendicular to the length direction Y, being smaller than the dimension in the length direction Y. The flexible portions 2 are disposed between the multiple rigid portions 1, and the dimension in the length direction Y is slightly shorter than the dimension of the rigid portions 1 in the length direction Y.

[0021] The three-dimensional structure substrate A has multiple rigid parts 1 and multiple flexible parts 2 arranged in a cylindrical shape by bending the multiple flexible parts 2, and a pair of access substrates 10 are provided in a fitted state at both ends of the multiple rigid parts 1 in the vertical direction Y to maintain this arrangement (see also Figure 4).

[0022] As shown in Figures 4 and 5, electrode pads 1P for external connection are formed at the ends in the vertical direction Y on the outer surface S2 of the rigid part 1, and by electrically connecting these electrode pads 1P to electrodes (not shown) of the access board 10, power supply and transmission of control signals are realized via the access board 10.

[0023] The three-dimensional structure substrate A is assumed to be housed in a cylindrical case B into which a part of a brushless DC motor (not shown) is fitted in order to control the current supplied to the brushless DC motor.

[0024] [Electronic component placement] 1 and 2, the three-dimensional structure substrate A is used in a position where the longitudinal direction of the rigid portion 1 is aligned with the vertical direction Y. In this position, the relative positional relationship of the electronic components 6 mounted on the rigid portion 1 is set to reduce the effect of heat generated by the electronic components 6 on other electronic components 6.

[0025] 2 is a schematic diagram showing the arrangement of electronic components 6 and connection patterns 8. As shown in the figure, one of the multiple rigid sections 1 (substrate sections) is a first substrate section F that takes into consideration the arrangement of electronic components 6. In the first substrate section F, a first electronic component 6a that generates a relatively large amount of heat, such as a power MOSFET or IGBT, is arranged at the upper end, a second electronic component 6b that has a relatively low heat resistance is arranged at the lower end, and a third electronic component 6c that generates less heat than the first electronic component 6a and has a higher heat resistance than the second electronic component 6b is arranged between them in the vertical direction.

[0026] The first electronic component 6a, the second electronic component 6b, and the third electronic component 6c are included in the concept of electronic component 6, and the electronic components 6 mounted on the rigid parts 1 (substrate parts) other than the first substrate part F have the properties of either the first electronic component 6a, the second electronic component 6b, or the third electronic component 6c.

[0027] By arranging the electronic components 6 in the first substrate portion F, the three-dimensional structure substrate A increases the distance between the first electronic component 6a and the second electronic component 6b in the vertical direction, thereby suppressing the influence of heat due to heat conduction in the first substrate portion F. In addition, because the first electronic component 6a is arranged on the upper end side of the first substrate portion F, the amount of heat acting on the second electronic component 6b due to air convection is reduced.

[0028] By arranging the electronic components 6 in this way, it is possible to increase the durability of the electronic component 6 (third electronic component 6c) which has low heat resistance.

[0029] [Heat dissipation structure] 3, the rigid portion 1 has a multi-layered substrate pattern 4 sandwiched between insulating layers 3. Similarly, the flexible portion 2 has a multi-layered connection pattern 8 sandwiched between insulating layers 3.

[0030] The pattern on the inner surface S1 side of the board pattern 4 is electrically connected (conductive) to the pattern on the inner surface S1 side of the connection pattern 8. In addition, the pattern on the outer surface S2 side of the board pattern 4 and the pattern on the outer surface S2 side of the connection pattern 8 are electrically connected (conductive).

[0031] As described above, in this three-dimensional structure substrate A, the exposed connection pattern 8Ex is exposed on the outer surface S2 of the insulating layer 3 of the flexible portion 2.

[0032] Among the electronic components 6, those that control large power, such as the power MOSFET and IGBT, generate a large amount of heat. Even electronic components 6 that do not control large currents generate heat when in operation (when energized).

[0033] This heat not only causes a rise in temperature in the rigid portion 1, but also in the entire three-dimensional structure substrate A. For this reason, the positional relationship of the patterns is set so that the control signal for controlling the electronic component 6 is sent by the pattern on the inner surface S1 side of the multi-layer substrate pattern 4, and the current controlled by the electronic component 6 flows in the pattern on the outer surface S2 side.

[0034] 2, of the connection patterns 8, the exposed connection patterns 8Ex that are not covered with the resist film 5 and are exposed on the outer surface S2 are formed with a large pattern width W (width in the vertical direction Y). The exposed connection patterns 8Ex are formed in the hatched areas in the figure.

[0035] In this embodiment, the pattern width W of the exposed connection pattern 8Ex connected to the first electronic component 6a, the pattern width W of the exposed connection pattern 8Ex connected to the second electronic component 6b, and the pattern width W of the exposed connection pattern 8Ex connected to the third electronic component 6c are set to have a relationship in which they become smaller in this order. However, the relationship between the pattern widths W is not limited to this.

[0036] For patterns using copper foil of a predetermined thickness, the relationship between the current value and the pattern width is predetermined as a reference width. The board pattern 4 formed on the rigid part 1 shown in Fig. 4 is formed as a pattern with a width according to the reference width. In contrast, the exposed connection pattern 8Ex is formed with a large pattern width W (width in the vertical direction Y) that exceeds the reference width.

[0037] In this way, the exposed connection pattern 8Ex allows for good heat dissipation because the copper foil is exposed (not covered with the resist film 5). As a result, the heat generated by the electronic components 6 of the rigid part 1 is dissipated by the exposed connection pattern 8Ex on the outer surface S2 of the flexible part 2, thereby realizing a reduction in the temperature of the entire three-dimensional structure substrate A.

[0038] [Effects of the embodiment] In this way, the three-dimensional structure substrate A electrically connects multiple substrate sections (rigid sections 1) on which electronic components 6 are mounted with flexible sections 2 (connection sections) on which electronic components 6 are not mounted, thereby enabling the three-dimensional position of the rigid sections 1 to be changed by bending the flexible sections 2. Furthermore, because the three-dimensional structure substrate A has a three-dimensional structure, it can also be housed in the internal space of the cylindrical case B.

[0039] The three-dimensional structure substrate A forms an exposed connection pattern 8Ex by exposing the copper foil of the connection pattern 8 formed on the flexible part 2, and this exposed connection pattern 8Ex does not cause the thermal resistance of the resist film 5 to act, compared to a configuration in which a resist film 5 is formed on the outer surface S2 of the connection pattern 8, and enables heat from the electronic component 6 to be dissipated over a wide area.

[0040] Furthermore, the three-dimensional structure substrate A increases the heat dissipation efficiency from the copper foil by setting the pattern width of the copper foil of the connection pattern 8 to a pattern width W larger than the standard width and expanding the heat dissipation surface, thereby suppressing the temperature rise of the electronic component 6 and improving its durability.

[0041] Among the electronic components 6 mounted on the rigid part 1 (substrate part), the distance between the first electronic component 6a, which generates a large amount of heat, and the second electronic component 6b, which has relatively low heat resistance, is widened, and the first electronic component 6a is positioned on the upper end side of the rigid part 1, thereby increasing the durability of the electronic component 6 with low heat resistance (third electronic component 6c).

[0042] [Another embodiment] The present invention may be configured as follows in addition to the above-described embodiments (common numbers and symbols are used to designate components having the same functions as those in the embodiments).

[0043] (a) As partially described in the embodiment, the three-dimensional structure substrate A may have either a configuration in which the rigid part 1 and the flexible part 2 are integrally formed from the same material, or a configuration in which the rigid part 1 and the flexible part 2 are formed from different materials.

[0044] Furthermore, the three-dimensional structure substrate A may have some of the multiple flexible portions 2 integrally formed with the same material as the rigid portion 1, and other portions formed with a material different from that of the rigid portion 1. Furthermore, the area where the circuit pattern of the flexible portion 2 (connection portion) is exposed may be only part of the area.

[0045] (b) In the embodiment, the access substrate 10 is shown, but it is also possible to configure the three-dimensional structure substrate A without using the access substrate 10.

[0046] (c) The shape and number of the rigid portion 1 and the flexible portion 2 can be set arbitrarily depending on the control target and the size of the space in which the three-dimensional structure substrate A is housed.

[0047] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention.

[0048] In the above-described embodiment, the following configurations are envisioned. (1) The three-dimensional structure substrate comprises a plurality of substrate portions (rigid portions 1) each having at least one electronic component 6 mounted thereon, and a connection portion (flexible portion 2) that connects the plurality of substrate portions (rigid portions 1) in an elastically deformable state and has a circuit pattern (connection pattern 8) that electrically connects each of the electronic components 6, and the connection portion (flexible portion 2) has a portion where the circuit pattern (connection pattern 8) is exposed to the outside, and connects the plurality of substrate portions (rigid portions 1) three-dimensionally.

[0049] In this configuration, the circuit pattern (connection pattern 8) of the connection part (flexible part 2) is exposed to the outside among the circuit patterns that electrically connect the respective electronic components 6. Therefore, the circuit pattern has a lower thermal resistance than solder, which can improve the efficiency of dissipating heat generated from the electronic components 6.

[0050] In particular, the circuit pattern (connection pattern 8) provided on the elastically deformable curved connection portion as in this configuration does not require the resist film 5 used to prevent solder short circuits, and by exposing this circuit pattern (connection pattern 8) to the outside, it can fulfill the role of radiative cooling. In this way, the three-dimensional structure substrate A has high heat dissipation efficiency.

[0051] (2) In the three-dimensional structure substrate A of (1), it is preferable that the circuit pattern (connection pattern 8) of the connection portion (flexible portion 2) has a pattern width W that is larger than the standard width required to electrically connect each electronic component 6.

[0052] As in this configuration, by making the pattern width W of the circuit pattern (connection pattern 8) of the connection part (flexible part 2) larger than the reference width, the unused space of the connection part (flexible part 2) can be effectively utilized to further improve heat dissipation efficiency.

[0053] (3) In the three-dimensional structure substrate A of (1) or (2), it is preferable that the circuit pattern (connection pattern 8) of the connection part (flexible part 2) has a pattern width connected to an electronic component 6 that generates a relatively large amount of heat, which is larger than the pattern width connected to other electronic components 6.

[0054] As in this configuration, by increasing the pattern width W of the circuit pattern (connection pattern 8) connected to the electronic component 6 that generates a relatively large amount of heat, it is possible to effectively improve the heat dissipation efficiency.

[0055] (4) In any one of the three-dimensional structure substrates A of (1) to (3), the substrate portion (rigid portion 1) has a first substrate portion F on which at least three electronic components 6 are mounted, and it is preferable that the first substrate portion F has another electronic component 6 (third electronic component 6c) arranged between an electronic component 6 (first electronic component 6a) that generates a relatively large amount of heat and an electronic component 6 (second electronic component 6b) that has a relatively low heat resistance.

[0056] As in this configuration, by separating the electronic component 6 (first electronic component 6a) that generates a relatively large amount of heat from the electronic component 6 (second electronic component 6b) that has a relatively low heat resistance, it is possible to increase the durability of the electronic components 6. Furthermore, since the heat from the electronic component 6 that generates a relatively large amount of heat is blocked by the other electronic components 6, it is possible to increase the durability of the electronic component 6 that has a low heat resistance (second electronic component 6b). [Industrial Applicability]

[0057] The present invention can be used for a three-dimensional structure substrate. [Explanation of symbols]

[0058] 1: rigid part (substrate part), 2: flexible part (connection part), 6: electronic component, 6a: first electronic component (electronic component 6 with relatively high heat generation), 6b: second electronic component (electronic component 6 with relatively low heat resistance), 6c: third electronic component 6c (other electronic component 6), 8: connection pattern (circuit pattern), A: three-dimensional structure substrate, F: first substrate part, W: pattern width

Claims

1. a plurality of substrate units each having at least one electronic component mounted thereon; a connection portion that connects the plurality of substrate portions in an elastically deformable state and has a circuit pattern that electrically connects the respective electronic components, The connection portion has a portion where the circuit pattern is exposed to the outside, and is a three-dimensional structure substrate that three-dimensionally connects multiple substrate portions.

2. 2. The three-dimensional structure substrate according to claim 1, wherein the circuit pattern of the connection portion has a pattern width greater than a standard width required for electrically connecting the respective electronic components.

3. 3. The three-dimensional structure substrate according to claim 2, wherein the circuit pattern of the connecting portion has a pattern width connected to the electronic component that generates a relatively large amount of heat, the pattern width being larger than the pattern width connected to the other electronic component.

4. the substrate unit includes a first substrate unit on which at least three of the electronic components are mounted, The three-dimensional structure substrate according to any one of claims 1 to 3, wherein the first substrate portion has another electronic component arranged between the electronic component that generates a relatively large amount of heat and the electronic component that has a relatively low heat resistance.

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