Mounted circuit boards, and electrical equipment equipped with mounted circuit boards.

Abstract

To provide a mounting substrate in which distortion occurs in a printing board by the printing board contacting an electronic component when fastening the printing board onto which the electronic component is mounted to a heat sink with a screw, and which can prevent the electronic component from being damaged due to the distortion, and provide an electric device onto which the mounting substrate is mounted.SOLUTION: A mounting substrate comprises: an electronic component; a printing board onto which the electronic component is mounted; and a heat radiation component to which the electronic component is pressed. The place where the electronic component is mounted in the printing board has a predetermined distance expansion structure making a distance between a bottom surface of the electronic component and the printing board expand as compared with the case where the electronic component is mounted onto another place.SELECTED DRAWING: Figure 2

Description

Technical Field

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[0001] The present invention relates to a mounting substrate and an electric device mounted with the mounting substrate.

Background Art

[0002] Conventionally, a semiconductor device capable of significantly enhancing the heat dissipation of an electronic component is known. The semiconductor device includes an electronic component, a substrate on which the electronic component is mounted, a lower housing on which the substrate is mounted, and a heat spreader to which the electronic component is metallically joined via a bonding material on a first surface. The lower housing has an opening for engaging the heat spreader, and the heat spreader is joined to the opening via a bonding material. And, a second surface of the heat spreader facing the first surface is exposed from the lower housing (for example, refer to Patent Document 1).

[0003] Also, a printed circuit board capable of reducing damage due to strain caused by the stress of screwing is known. The printed circuit board has a plurality of screw holes, and slits are formed around the screw holes formed near the outer edge thereof. The slits are formed so as to surround the screw holes, and a screw fixing region formed inside and surrounded by the slits is connected only at one connecting portion at the outer edge of the printed circuit board with a region on the opposite side sandwiching the slits (for example, refer to Patent Document 2). ]>

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] This invention has been made in view of the above-mentioned problems, and provides a mounting board that can prevent damage to electronic components caused by strain on the printed circuit board due to contact between the printed circuit board and the electronic components when the printed circuit board with electronic components mounted on it is screwed to a heat sink (corresponding to the heat spreader described above), and an electrical device equipped with this mounting board. The ultimate goal is to achieve this. [Means for solving the problem]

[0007] The present invention, which solves the above problems, An electronic component including an electronic element and a package formed to surround the electronic element, A printed circuit board on which the aforementioned electronic components are mounted and on which a thin metal film and / or resist is formed on a part of the surface, The system comprises a heat dissipation component that has heat dissipation properties and against which the electronic component is pressed via a bonding material, The printed circuit board is characterized in that the location on which the electronic component is mounted has a predetermined distance-increasing structure that increases the distance between the electronic component and the printed circuit board compared to when the electronic component is mounted in other locations.

[0008] According to the present invention, since there is sufficient distance between the electronic component and the printed circuit board, it is possible to prevent the printed circuit board and the electronic component from coming into contact and causing strain on the printed circuit board, which would ultimately damage the electronic component. Furthermore, since electronic components generate a large amount of heat, it is possible to allow the heat dissipation component to absorb the heat by pressing it against a heat dissipation component with heat dissipation properties via a bonding material, thereby preventing the electronic component from overheating.

[0009] Furthermore, in the present invention, the mounting substrate may be characterized in that the distance between the electronic component and the printed circuit board, which is expanded by the distance expansion structure, is in the range of 0.2 mm to 1.0 mm. Defining a specific numerical range makes it easier to mount the electronic component onto the printed circuit board.

[0010] Furthermore, in the present invention, the electronic component may be a mounting substrate that has a lead as a terminal connected to an external circuit, a first electrode formed on the surface of the printed circuit board to which one end of the lead is electrically connected, and a second electrode formed on the surface of the printed circuit board to which terminals other than the lead are electrically connected, and the distance expansion structure is characterized in that the thickness of the first electrode is thicker than the thickness of the second electrode. With this, it is possible to electrically connect the electronic component and the printed circuit board with a simple configuration and to maintain a sufficient distance between the electronic component and the printed circuit board.

[0011] Furthermore, in the present invention, the mounting substrate may be characterized in that the metal thin film is not formed on the projection surface of the electronic component on the surface of the printed circuit board. With this, since there is no thickness of the metal thin film, it is possible to maintain a sufficient distance between the electronic component and the printed circuit board, and it is possible to suppress distortion of the printed circuit board.

[0012] Furthermore, in the present invention, the distance expansion structure may be a mounting substrate characterized in that the metal thin film is not formed on at least a portion of the projection surface of the electronic component on the surface of the printed circuit board. With this, since there is no thickness of the metal thin film, it is possible to take a sufficient distance between the electronic component and the printed circuit board, and it is possible to suppress distortion of the printed circuit board.

[0013] Furthermore, in the present invention, the distance expansion structure may be a mounting substrate characterized in that the resist is not formed on at least a portion of the projection surface of the electronic component on the surface of the printed circuit board. With this, since there is no thickness of resist, it is possible to take a sufficient distance between the electronic component and the printed circuit board, and it is possible to suppress distortion of the printed circuit board.

[0014] Furthermore, in the present invention, the distance expansion structure is characterized in that a recess is formed on at least a portion of the projection surface of the electronic component on the surface of the printed circuit board. It may also be used as a mounting board. With this, it is possible to ensure a sufficient distance between the electronic components and the printed circuit board due to the depth of the recess, and thus it is possible to suppress distortion of the printed circuit board.

[0015] Furthermore, in the present invention, the printed circuit board may be a mounting board characterized by having a plurality of screw holes for screw fastening, and being connectable to the heat dissipation component by passing screws through the plurality of screw holes. This makes it possible to firmly fix the printed circuit board to the heat dissipation component, and by fixing the printed circuit board to the heat dissipation component, the electronic components are pressed against the bonding material and adhere closely, and the heat generated from the electronic components is absorbed by the heat dissipation component via the bonding material.

[0016] Furthermore, the present invention may also be an electrical device that performs power conversion of power supplied from a power supply device, and which is equipped with the above-described mounting board. This makes it possible to dissipate the heat generated from the heat dissipation component into the air outside the electrical device, or to cool the electrical device with the outside air. In addition, it is possible to mount the circuit pattern of the printed circuit board onto the electrical device.

[0017] Furthermore, in the present invention, A printed circuit board capable of mounting electronic components, The printed circuit board may be characterized in that the location on the surface on which the electronic component is mounted has a predetermined distance-increasing structure that increases the distance between the bottom surface of the electronic component and the printed circuit board compared to when the electronic component is mounted in another location.

[0018] According to the present invention, after mounting an electronic component on a printed circuit board, it is possible to ensure a sufficient distance between the electronic component and the printed circuit board, preventing the printed circuit board from being deformed due to contact with the electronic component and consequently preventing damage to the electronic component caused by this deformation.

[0019] Also, in the present invention, a printed circuit board may be used, characterized in that the distance between the electronic component and the printed circuit board, which is enlarged by the distance enlargement structure, is in the range of 0.2 mm or more and 1.0 mm or less. By defining a specific numerical range, it becomes easier to mount the electronic component on the printed circuit board.

[0020] Further, in the present invention, the electronic component has leads connected to an external circuit as terminals, and the printed circuit board further includes a first electrode formed on the surface of the printed circuit board and electrically connected to one end of the lead, and a second electrode formed on the surface of the printed circuit board and electrically connected to terminals other than the lead. The distance enlargement structure is characterized in that the thickness of the first electrode is made thicker than the thickness of the second electrode. According to this, it is possible to electrically connect the electronic component and the printed circuit board with a simple configuration, and after mounting the electronic component on the printed circuit board, it is possible to ensure a sufficient distance between the electronic component and the printed circuit board.

[0021] Also, in the present invention, a printed circuit board may be used, characterized in that the distance enlargement structure is such that the metal thin film is not formed on at least a part of the area on the surface of the printed circuit board that should be the projection surface of the electronic component. According to this, after mounting the electronic component on the printed circuit board, it is possible to ensure a sufficient distance between the electronic component and the printed circuit board by the thickness of the metal thin film not being present, and it is possible to suppress deformation of the printed circuit board.

[0022] In the present invention, the distance increasing structure is preferably a printed circuit board characterized in that the resist is not formed on at least a part of the region on the surface of the printed circuit board that should be the projection plane of the electronic component. According to this, after mounting the electronic component on the printed circuit board, it is possible to sufficiently provide a distance between the electronic component and the printed circuit board by the thickness of the resist not being present, and it is possible to suppress warping of the printed circuit board.

[0023] In the present invention, the distance increasing structure is preferably a printed circuit board characterized in that a concave portion is formed on at least a part of the projection plane of the electronic component on the surface of the printed circuit board. According to this, after mounting the electronic component on the printed circuit board, it is possible to sufficiently provide a distance between the electronic component and the printed circuit board by the depth of the concave portion, and it is possible to suppress warping of the printed circuit board.

[0024] Note that the means for solving the above problems can be used in combination with each other as much as possible.

Advantages of the Invention

[0025] According to the present invention, when screwing a printed circuit board on which an electronic component is mounted to a heat sink in a mounting substrate, warping of the printed circuit board can be suppressed, and breakage of the electronic component due to this warping can be prevented. Further, the mounting substrate can also be mounted on an electric device.

Brief Description of the Drawings

[0026] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the whole of a mounting substrate according to Embodiment 1 of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an enlarged part of the mounting substrate shown in FIG. 1. [Figure 3] FIGS. 3A and 3B are graphs showing the relationship between the magnitude of the torque of a screw and the magnitude of warping of a printed circuit board when connecting the printed circuit board to a heat sink in Embodiment 1 of the present invention. [Figure 4] Figure 4 is a schematic cross-sectional view showing an example of an electrical device equipped with a mounting substrate according to Embodiment 1 of the present invention. [Figure 5] Figure 5 is a schematic cross-sectional view showing a modified example 1 of the mounting substrate shown in Figure 2. [Figure 6] Figure 6 is a schematic cross-sectional view showing a modified example 2 of the mounting substrate shown in Figure 2. [Modes for carrying out the invention]

[0027] [Examples of application] The following outlines some examples of applications of the present invention, using some drawings. The present invention can be applied to a mounting board 1 as shown in Figure 1. Furthermore, by mounting the mounting board 1 as shown in Figure 1, the present invention can also be applied to a power conditioner 100 (corresponding to the electrical equipment in the present invention) as shown in Figure 4.

[0028] Figure 1 is a schematic cross-sectional view showing an example of an entire mounting substrate 1 to which the present invention can be applied. In this application example, the mounting substrate 1 is composed of electronic components 2, a printed circuit board 3, a heat sink 4, and the like. Figure 2 shows an enlarged view of the area enclosed by the dotted line in Figure 1, and other components of the mounting substrate 1 will be described below in Figure 2.

[0029] The electronic component 2 is, for example, a semiconductor integrated circuit such as an ASIC (Application Specific Integrated Circuit) or a power semiconductor such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), and includes an electronic element (not shown) and a package 21 formed to surround the electronic element. When an electric current is passed through the electronic element, the electronic component 2 generates heat. The mounting board 1 also contains other electronic components (such as capacitors) in addition to electronic component 2, but electronic component 2 generates more heat compared to the other electronic components.

[0030] The printed circuit board 3 may, for example, have a multilayer structure and be a build-up printed wiring board with a thermosetting epoxy resin as the base material. The electronic components 2 are mounted facing the printed circuit board 3 at a certain distance apart. The printed circuit board 3 has a plurality of screw holes 31, and the mounted board 1 can be connected to the heat sink 4 by passing screws 5 through the screw holes 31 and tightening them. The heat sink 4 is mainly composed of a metal with high thermal conductivity and has the property of diffusing absorbed heat into its surroundings. Here, the heat sink 4 corresponds to the heat dissipation component in the present invention.

[0031] When the mounting board 1 is connected to the heat sink 4 by screw fastening, the electronic component 2 is pressed against the heat sink 4 via the heat dissipation sheet 6. The heat dissipation sheet 6 contains fillers such as boron nitride and alumina and has high thermal conductivity, absorbing the heat generated from the electronic component 2 when an electric current is passed through it. The absorbed heat is then dissipated to the heat sink 4, and as described above, the heat sink 4 diffuses the heat into the surroundings. The heat sink 4 is hard and does not easily deform even when pressed, whereas the heat dissipation sheet 6 also has the properties of a cushioning material and is easily deformed when pressed. Therefore, compared to the case where the electronic component 2 is pressed directly against the heat sink 4, pressing the electronic component 2 against the heat dissipation sheet 6 makes it easier for the electronic component 2 to adhere and for heat to be absorbed from the electronic component 2. As a result, the amount of heat that the heat sink 4 diffuses into the surroundings is also increased. In addition, it is possible to prevent the electronic component 2 from being damaged by being pressed against the heat sink 4. Here, the heat dissipation sheet 6 corresponds to the bonding material in this invention.

[0032] As described above, when connecting the printed circuit board 3 to the heat sink 4 by tightening screws, the printed circuit board 3 and the electronic component 2 come into contact, causing strain in the printed circuit board 3, which may damage the electronic component 2. As a means of suppressing this strain in the printed circuit board 3, a certain distance is maintained between the electronic component 2 and the printed circuit board 3 when mounting the electronic component 2 onto the printed circuit board 3. Details will be explained below in Example 1 using Figure 2.

[0033] Figure 2 is a schematic cross-sectional view showing an enlarged view of the portion of the mounting substrate 1 enclosed by the dotted line shown in Figure 1. Note that when mounting electronic components 2 onto the printed circuit board 3, the printed circuit board 3 is generally positioned on the lower side, so Figure 2 shows the mounting substrate 1 upside down compared to Figure 1. In addition to the components shown in Figure 1, the mounting substrate 1 in this application example is composed of a first electrode 8 and a second electrode 81, etc.

[0034] The electronic component 2 has leads 22 that connect as terminals. The leads 22 extend from the inside to the outside of the package 21 of the electronic component 2, and a portion of them is formed in a gull-wing shape. One end of the leads 22 is electrically connected to the first electrode 8 via solder 7. The solder 7 is printed, for example, by a solder printing machine. On a portion of the surface of the printed circuit board 3 (hereinafter, the side on which the electronic component 2 is mounted on the printed circuit board 3 will be referred to as the "surface of the printed circuit board 3"), a conductive metal film, copper foil 32, and an insulating protective film, resist 33 are formed in this order. The copper foil 32 is formed, for example, by immersing the printed circuit board 3 in a plating solution and reducing the copper ions in the plating solution. The resist 33 is formed, for example, by thermocompression bonding to the printed circuit board 3 and then pattern exposure and etching are performed to form a circuit pattern. The thickness of the copper foil 32 is approximately 70 μm, and the thickness of the resist 33 is approximately 50 μm. The first electrode 8 and the second electrode 81 are formed on the surface of the printed circuit board 3 via the copper foil 32 and through the resist 33. The first electrode 8 is electrically connected to one end of the lead 22 via the solder 7 as described above, while the second electrode 81 is electrically connected to an electrical element (e.g., a computing element) not included in the electronic component 2. Here, the copper foil 32 corresponds to the metal thin film in this invention.

[0035] [Example 1] The mounting substrate 1 according to Embodiment 1 of the present invention and the power conditioner 100 as an example of electrical equipment will be described in more detail below with reference to the drawings (including the drawings that were described in the above application example). However, the mounting substrate 1 and power conditioner 100 according to the present invention are not limited to the following configurations.

[0036] <Configuration of a printed circuit board> Now, let's return to the explanation of Figure 2. As described in the application example above, when mounting the electronic component 2 onto the printed circuit board 3, the distance D between the electronic component 2 and the printed circuit board 3 is within a certain range. By having a predetermined distance-expanding structure at the mounting location of the electronic component 2 on the printed circuit board 3, distortion of the printed circuit board 3 can be suppressed. For example, as shown in Figure 2, by not forming copper foil 32 and resist 33 on the projection surface S of the electronic component 2 on the surface of the printed circuit board 3, the distance D can be made sufficiently large, and distortion of the printed circuit board 3 caused by contact between the printed circuit board 3 and the electronic component 2 can be suppressed. Even if copper foil 32 and resist 33 are formed on the projection surface S, they can be removed by processing with a stripping solution or the like. By making the distance D sufficiently large, damage to the electronic elements of the electronic component 2 due to distortion of the printed circuit board 3 can be prevented when connecting the printed circuit board 3 to the heat sink 4. In Figure 2, either copper foil 32 or resist 33 may be formed on the projection surface S.

[0037] <Example of effectiveness verification> Figures 3A and 3B are graphs showing the relationship between the torque of the screw 5 and the amount of strain in the printed circuit board 3 when connecting the printed circuit board 3 to the heat sink 4 in Embodiment 1 of the present invention. In both graphs 3A and 3B, it is clear that the greater the torque of the screw 5, the greater the strain in the printed circuit board 3 tends to be. Figure 3A is a graph showing the conditions in which copper foil 32 is formed (solid line) and not formed (dashed line) on the projection surface S shown in Figure 2. From Figure 3A, it is clear that when comparing at a constant torque, the distance D shown in Figure 2 is larger in the condition where copper foil 32 is not formed, and the strain in the printed circuit board 3 is suppressed. Note that Figure 3A is a graph showing the condition where resist 33 is formed on the projection surface S, regardless of whether copper foil 32 is formed or not, but a similar trend is obtained even in the condition where resist 33 is not formed.

[0038] Figure 3B shows graphs for conditions where the distance D is 0.1 mm (solid line), 0.2 mm (dashed line), and 0.3 mm (dotted line). From Figure 3B, it is clear that, when comparing with a constant torque magnitude, the greater the distance D, the more the strain of the printed circuit board 3 is suppressed. Although the graph in Figure 3B is simplified, verification by changing the distance D in 0.05 mm increments revealed that the strain of the printed circuit board 3 is suppressed when the distance D is in the range of 0.2 mm to 1.0 mm, more preferably 0.2 mm to 0.5 mm. In both the graphs in Figure 3A and Figure 3B, it is desirable that the strain of the printed circuit board 3 be kept below 500 μST.

[0039] <Power conditioner configuration> Figure 4 is a schematic cross-sectional view showing an example of a power conditioner 100 equipped with a mounting board 1 according to Embodiment 1 of the present invention. The mounting board 1 may be mounted on electrical equipment, which may be, for example, a power conversion device such as a power conditioner 100, a motor drive device, a power supply device, etc. The power conditioner 100 is connected to a power supply device (not shown) such as a solar cell, and boosts the voltage of the power supplied from the power supply device, converts it to AC, removes noise and adjusts the waveform, and then supplies AC power to a load (not shown) or a connected power system (not shown).

[0040] A heat-conductive metal base 102 is installed on one side of the housing 101 of the power conditioner 100. The heatsink 4, to which the printed circuit board 3 is connected, is screwed to the metal base 102 by a second screw 51. In this way, the heatsink 4, having absorbed the heat generated from the electronic components 2, becomes more efficient at transferring heat to the outside air. The heat transferred to the metal base 102 is further transferred to the housing 101 and cooled by the outside air.

[0041] The printed circuit board 3 is screwed to the heat sink 4 via spacer 103. A terminal block 107 is fixedly mounted to a base 106, one end of which is screwed to the printed circuit board 3 via spacer 104, and the other end of which is screwed to the metal base 102 via spacer 105. Furthermore, a control circuit board (not shown) may be mounted on the side of the printed circuit board 3 opposite to the front surface via a connector (not shown). In this way, the circuit pattern on the printed circuit board 3 is connected to the metal base 102.

[0042] [Variation 1] Next, a modified example 1 of the present invention, specifically the mounting substrate 1a, will be described using Figure 5. The mounting substrate 1a has a distance expansion structure that differs from that of the mounting substrate 1 of Example 1 in the area where the electronic components 2 are mounted. Since the mounting substrate 1a shares many components with the mounting substrate 1 of Example 1, such components are denoted by the same reference numerals, and further explanation is omitted. It is also possible to apply the configuration shown in Figure 5 to the mounting substrate 1 of Example 1.

[0043] <Configuration of a printed circuit board> Figure 5 is a schematic cross-sectional view showing a modified example 1 of the mounting substrate 1 shown in Figure 2. In the mounting substrate 1a according to modified example 1 of the present invention, by forming a recessed structure on the projection surface S of the electronic component 2 on the surface of the printed circuit board 3a, the distance D between the electronic component 2 and the printed circuit board 3a can be made sufficiently large, and distortion of the printed circuit board 3a can be suppressed. Means for forming a recessed structure on the surface of the printed circuit board 3a include, for example, a method of cutting by router processing, or a method of bonding substrate material with a resin layer cut out, such as a cavity substrate. If the distance D is in the range of 0.2 mm to 1.0 mm, more preferably 0.2 mm to 0.5 mm, copper foil 32 or resist 33 may be formed on the bottom surface of the recessed structure.

[0044] [Variation 2] Next, the mounting substrate 1b according to Modification 2 of the present invention will be described with reference to Figure 6. The area on the mounting substrate 1b where the electronic components 2 are mounted has a distance expansion structure that differs from the mounting substrates 1 and 1a of Example 1 and Modification 1. Since the mounting substrate 1b shares many components with the mounting substrate 1 of Example 1, such components are given the same reference numerals and their further explanation is omitted. Furthermore, the configuration shown in Figure 6 can also be applied to the mounting substrates 1 and 1a of Example 1 and Modification 1.

[0045] <Configuration of a printed circuit board> Figure 6 is a schematic cross-sectional view showing a modified example 2 of the mounting substrate 1 shown in Figure 2. In the mounting substrate 1b according to modified example 2 of the present invention, by forming the first electrode 8a thicker than the second electrode 81, the distance D between the electronic component 2 and the printed circuit board 3 can be made sufficiently large, and distortion of the printed circuit board 3 can be suppressed. Means for increasing the thickness of the first electrode 8a include, for example, the additive method. If the distance D is in the range of 0.2 mm to 1.0 mm, more preferably 0.2 mm to 0.5 mm, copper foil 32 or resist 33 may be formed on the projection surface S of the electronic component 2 on the surface of the printed circuit board 3.

[0046] <Note 1> An electronic component (2) including an electronic element and a package (21) formed to surround the electronic element, A printed circuit board (3, 3a) on which the aforementioned electronic components are mounted and on which a thin metal film (32) and / or resist (33) is formed on a part of the surface, The device comprises a heat dissipation component (4) that has heat dissipation properties and against which the electronic component is pressed via a bonding material (6), A mounting board (1, 1a, 1b) characterized in that the location on the printed circuit board where the electronic component is mounted has a predetermined distance-increasing structure that increases the distance between the electronic component and the printed circuit board compared to when the electronic component is mounted at another location.

[0047] <Note 2> A printed circuit board (3, 3a) on which electronic components (2) can be mounted, A printed circuit board (3, 3a) characterized in that the location on the surface on which the electronic component is mounted has a predetermined distance-increasing structure that increases the distance between the bottom surface of the electronic component and the printed circuit board compared to when the electronic component is mounted at another location. [Explanation of symbols]

[0048] 1, 1a, 1b: Mounting board 2: Electronic components 21: Package 22: Lead 3, 3a: Printed circuit board 31: Screw hole 32: Copper foil 33: Resist 4: Heatsink 5: Screws 51: The second screw 6: Heat dissipation sheet 7: Solder 8, 8a: First electrode 81: Second electrode 100: Power Conditioner 101: Cabinet 102: Metal base 103-105: Spacer 106: Bass 107:Terminal block

Claims

1. An electronic component including an electronic element, a package formed to surround the electronic element, and leads connected to an external circuit as terminals, A printed circuit board on which the aforementioned electronic components are mounted and on which a thin metal film and / or resist is formed on a part of the surface, A first electrode is formed on the surface of the printed circuit board, and one end of the lead is electrically connected to it, A second electrode formed on the surface of the printed circuit board, to which terminals other than the leads are electrically connected, A heat dissipation component having heat dissipation properties, against which the electronic component is pressed via a bonding material, is provided. The location on the printed circuit board where the electronic component is mounted has a predetermined distance-increasing structure that increases the distance between the electronic component and the printed circuit board compared to when the electronic component is mounted in other locations. The mounting substrate is characterized in that the distance expansion structure includes a structure in which the thickness of the first electrode is made thicker compared to the thickness of the second electrode.

2. The mounting substrate according to claim 1, characterized in that the distance between the electronic component and the printed circuit board, as a result of the distance-enhancing structure, is in the range of 0.2 mm or more and 1.0 mm or less.

3. The mounting substrate according to claim 1 or 2, further characterized in that the distance expansion structure includes a structure in which the metal thin film is not formed on at least a portion of the surface of the printed circuit board that is the projection surface of the electronic component.

4. The mounting substrate according to any one of claims 1 to 3, further characterized in that the distance expansion structure includes a structure in which the resist is not formed on at least a portion of the surface of the printed circuit board that is the projection surface of the electronic component.

5. The mounting substrate according to any one of claims 1 to 4, further characterized in that the distance expansion structure includes a structure in which a recess is formed on at least a portion of the surface of the printed circuit board that is the projection surface of the electronic component.

6. The printed circuit board is characterized in that it has a plurality of screw holes for screw fastening, and can be connected to the heat dissipation component by passing screws through the plurality of screw holes, as described in any one of claims 1 to 5.

7. An electrical device that performs power conversion of power supplied from a power supply device, An electrical device equipped with a mounting board according to any one of claims 1 to 6.

8. A printed circuit board capable of mounting electronic components having leads that connect to an external circuit as terminals, A first electrode is formed on the surface on which the aforementioned electronic component is mounted, and one end of the lead is electrically connected to it, A second electrode formed on the surface, to which terminals other than the lead are electrically connected, The surface has a predetermined distance-increasing structure that increases the distance between the bottom surface of the electronic component and the printed circuit board at the location where the electronic component is mounted, compared to when the electronic component is mounted at another location. The distance-extending structure is characterized in that the thickness of the first electrode is made thicker compared to the thickness of the second electrode, in a printed circuit board.

9. The printed circuit board according to claim 8, characterized in that the distance between the electronic component and the printed circuit board, as a result of the distance-enhancing structure, is in the range of 0.2 mm or more and 1.0 mm or less.

10. The printed circuit board according to claim 8 or 9, characterized in that the distance expansion structure is such that a thin metal film is not formed on at least a portion of the surface of the printed circuit board in the area that is to become the projection surface of the electronic component.

11. The printed circuit board according to any one of claims 8 to 10, characterized in that the distance expansion structure is such that a resist is not formed on at least a portion of the surface of the printed circuit board in the area that is to become the projection surface of the electronic component.

12. The printed circuit board according to any one of claims 8 to 11, characterized in that the distance expansion structure has a structure in which a recess is formed on at least a part of the projection surface of the electronic component on the surface of the printed circuit board.

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