JP7564697B2 - Substrate packages and power tools - Google Patents

Description

The present disclosure relates generally to substrate packages and power tools, and more particularly to substrate packages including substrates and power tools including substrate packages.

Patent document 1 describes an inverter circuit board for a power tool that uses a brushless motor.

JP 2010-214518 A

In circuit boards (substrates) used in such power tools, it is desirable to make it easier to dissipate the heat generated on the board when switching elements and other components are activated.

This disclosure has been made in consideration of the above-mentioned reasons, and aims to provide a circuit board package and a power tool that facilitates dissipation of heat generated on the circuit board.

In order to solve the above problems, a substrate package according to one aspect of the present disclosure is mounted with a switching element for driving a motor used in an electric tool. The substrate package includes a substrate, a pattern portion, a resin, a heat dissipation portion, an insulating resin, and a heat dissipation sheet . The substrate has electrical insulation. The pattern portion is formed on the surface of the substrate and has electrical conductivity. The resin covers a part of the pattern portion. The heat dissipation portion is disposed on a portion of the pattern portion that is not covered by the resin, and has a higher thermal conductivity than the resin. The insulating resin has electrical insulation and a higher thermal conductivity than air. The heat dissipation sheet is disposed so as to be in contact with the surface of the heat dissipation portion. The heat dissipation sheet has flexibility and electrical insulation, and has a higher thermal conductivity than the air. The insulating resin covers the heat dissipation portion and the heat dissipation sheet.

The power tool includes the substrate package and the motor.

The present disclosure provides a circuit board package and a power tool that facilitates dissipation of heat generated on the circuit board.

FIG. 1 is a schematic diagram showing a schematic configuration of a power tool according to an embodiment. FIG. 2 is an exploded perspective view of a main part of the power tool. FIG. 3 is a perspective view of a board package and a motor in the power tool. FIG. 4 is an exploded perspective view of the substrate package. FIG. 5 is a plan view of a drive substrate in the substrate package. FIG. 6 is a cross-sectional view taken along line AA of FIG. FIG. 7 is an exploded perspective view of a main part of a power tool according to a modified example.

A preferred embodiment of the present disclosure will be described in detail below with reference to the drawings. The following embodiment is merely one of the various embodiments of the present disclosure. Various modifications of the embodiment are possible depending on the design, etc., as long as the object of the present disclosure can be achieved. Each figure described in this disclosure is a schematic diagram, and the ratio of the size and thickness of each component in each figure does not necessarily reflect the actual dimensional ratio. Note that the arrows indicating each direction in the drawings are merely examples, and are not intended to specify the directions in which the power tool 1 is used. Also, the arrows indicating each direction in the drawings are merely indicated for explanatory purposes, and do not have any substance.

(1) Overview First, an overview of the power tool 1 according to this embodiment will be described with reference to Figures 1, 4, and 6. In the following description, the direction along the axial direction of the rotating shaft 111 is defined as the front-rear direction, the side of the tool tip such as the driver bit 18 as viewed from the rotating shaft 111 is defined as the front, and the side of the board package 2 as viewed from the rotating shaft 111 is defined as the rear. In the following description, the direction in which the body 101 and the mounting portion 103 are lined up is defined as the up-down direction, and the body 101 side as viewed from the mounting portion 103 is defined as the top, and the mounting portion 103 side as viewed from the body 101 is defined as the bottom.

As shown in FIG. 1, the power tool 1 is operated by power (electricity, etc.) from a power source such as a battery pack 17. Specifically, the rotating shaft 111 of the motor 11 (driving source) supplied with power from the battery pack 17 rotates, and the rotational driving force is transmitted to the output shaft 13 via the transmission mechanism 12. An attachment portion 14 (chuck) to which a tip tool such as a driver bit 18 can be detached is fixed to the output shaft 13. In other words, when the output shaft 13 rotates, the attachment portion 14 also rotates. When a tip tool is attached to this attachment portion 14, the power tool 1 can attach a fastening part (e.g., a screw, etc.) to a workpiece (object to be processed) to be operated.

In this embodiment, the housing 10 of the power tool 1 contains a circuit board package 2, a motor 11, a transmission mechanism 12, and the like. As shown in FIG. 4, the circuit board package 2 has a drive board 3 for driving the motor 11.

The drive board 3 has multiple (six in the example of FIG. 4) switching elements E1 to E6 for driving the motor 11. The six switching elements E1 to E6 generate heat due to Joule heat when driving the motor 11.

As shown in FIG. 6, the substrate package 2 of this embodiment includes a heat dissipation section 34 that is disposed on a portion of the pattern section 32 formed on the surface of the substrate 31 that is not covered with resin 33 (resist). Since the heat dissipation section 34 has a higher thermal conductivity than the resin 33, disposing the heat dissipation section 34 on the pattern section 32 instead of the resin 33 reduces the thermal resistance value of the heat dissipation path from the pattern section 32. Therefore, the substrate package 2 of this embodiment is configured to easily dissipate heat generated on the substrate 31 of the drive substrate 3.

(2) Details Hereinafter, a detailed configuration of the power tool 1 according to this embodiment will be described with reference to FIGS.

(2.1) Configuration of the Power Tool First, the configuration of a power tool 1 according to this embodiment will be described with reference to FIGS. 1 to 3. FIG.

As shown in FIG. 1, the power tool 1 is a portable power tool that can be held by a user in one hand. The power tool 1 includes a housing 10, a motor 11, a transmission mechanism 12, an output shaft 13, an attachment portion 14, a trigger 15, and a control portion 16.

The housing 10 has a body section 101, a grip section 102, and an attachment section 103. The body section 101 is shaped like a cylinder with a bottom at the rear end. The body section 101 houses the board package 2, the motor 11, and the transmission mechanism 12. The grip section 102 protrudes downward from the body section 101. The attachment section 103 is configured so that the battery pack 17 can be removably attached. In this embodiment, the attachment section 103 is provided at the tip (lower end) of the grip section 102. In other words, the body section 101 and the attachment section 103 are connected by the grip section 102.

A rechargeable battery pack 17 is removably attached to the power tool 1. The power tool 1 of this embodiment operates using the battery pack 17 as a power source. That is, the battery pack 17 is a power source that supplies a current to drive the motor 11. The battery pack 17 is not a component of the power tool 1. However, the power tool 1 may be equipped with the battery pack 17. The battery pack 17 includes a battery pack formed by connecting multiple secondary batteries (e.g., lithium ion batteries) in series, and a case that houses the battery pack.

The trigger 15 protrudes from the grip portion 102. The trigger 15 is an operation portion that receives operations for controlling the rotation of the motor 11. The motor 11 can be switched on and off by pulling the trigger 15. In addition, the rotation speed of the motor 11 can be adjusted by the pulling amount of the trigger 15. The greater the pulling amount, the faster the rotation speed of the motor 11.

The control unit 16 controls the rotation speed of the motor 11 in response to the operation of the trigger 15. Specifically, the control unit 16 outputs a control signal to the drive board 3 of the board package 2 to control the rotation speed of the motor 11 in response to the amount of pulling of the trigger 15.

The board package 2 has a drive board 3 for driving the motor 11, and drives the motor 11 based on a control signal output from the control unit 16. As shown in FIG. 2, the board package 2 is accommodated in the body portion 101 of the housing 10 behind the motor 11. The board package 2 also has a plurality of screws 21 (four in the example of FIG. 2). The four screws 21 fit into a plurality of screw holes 114 (see FIG. 3) in the motor 11, thereby fixing the board package 2 to the motor 11. Details of the board package 2 will be explained in the section "(2.2) Configuration of the board package".

The motor 11 has a rotating shaft 111 and converts the power supplied from the battery pack 17 into a rotational driving force of the rotating shaft 111. The motor 11 in this embodiment is an inner rotor type brushless motor. As shown in FIG. 2, the motor 11 is housed in the body section 101 on the front side of the board package 2.

As shown in FIG. 3, the motor 11 has multiple coils 112 (nine in the example of FIG. 3), multiple connection terminals 113 (three in the example of FIG. 3), and multiple screw holes 114 (four in the example of FIG. 3). The three connection terminals 113 are terminals that electrically connect the nine coils 112 to the drive board 3 of the board package 2. In other words, the nine coils 112 and the drive board 3 are electrically connected via the three connection terminals 113. The four screw holes 114 are screw holes into which the four screws 21 of the board package 2 fit.

As shown in FIG. 1, the transmission mechanism 12 is located forward of the motor 11 in the internal space of the body 101. The transmission mechanism 12 transmits the rotational driving force transmitted from the rotating shaft 111 of the motor 11 to the output shaft 13. Note that the transmission mechanism 12 of this embodiment includes an impact mechanism that generates a large tightening torque by applying a rotational impact to the anvil. In other words, the power tool 1 of this embodiment is an impact rotary tool.

The output shaft 13 has a mounting portion 14 at its tip (front end). A tip tool such as a driver bit 18 or a drill bit can be attached and detached to the mounting portion 14. As the output shaft 13 rotates, the tip tool attached to the mounting portion 14 rotates. When the driver bit 9 is attached to the mounting portion 14 as shown in FIG. 1, the driver bit 9 rotates while in contact with a fastening member (screw, etc.), thereby enabling operations such as tightening or loosening the fastening member.

(2.2) Configuration of the Board Package Next, the configuration of the board package 2 according to this embodiment will be described with reference to FIGS.

As shown in FIG. 3, the substrate package 2 of this embodiment includes a drive substrate 3, a heat dissipation sheet 4 (insulating resin), a fixing plate 5, and a potting portion 6 (insulating resin).

As shown in FIG. 4, the drive board 3 has a substrate 31 and a plurality of switching elements E1 to E6 (six in the example of FIG. 4). A plurality of first recesses 311 (four in the example of FIG. 4) and a plurality of second recesses 312 (three in the example of FIG. 4) (see FIG. 5) are formed on the substrate 31. The four first recesses 311 and the three second recesses 312 are recessed toward the inside in the radial direction of the rotating shaft 111 (see FIG. 2). In particular, the three second recesses 312 are recessed in an arc shape. The drive board 3 is positioned relative to the fixed plate 5 by fitting a plurality of protrusions 52 (four in the example of FIG. 2) of the fixed plate 5 into the four first recesses 311. With the three screws 23 fitted into the three second recesses 312, the three screws 23 are fitted into the three screw holes 51 of the fixed plate 5. As a result, the drive board 3 is fixed to the fixed plate 5. Additionally, multiple holes 313 (three in the example of FIG. 4) are formed in the substrate 31. Three connection terminals 113 (see FIG. 3) are passed through the three holes 313. Details of the drive substrate 3 will be explained in the section "(2.3) Configuration of the drive substrate."

The heat dissipation sheet 4 is made of, for example, silicone resin and has flexibility and electrical insulation. In other words, the heat dissipation sheet 4 is an insulating resin. Furthermore, the thermal conductivity of the heat dissipation sheet 4 at room temperature is approximately 0.5 to 10.0 W/m·K, which is much higher than the thermal conductivity of air (approximately 25 mW/m·K). By arranging such a heat dissipation sheet 4 so that it is in contact with the drive board 3, the heat dissipation performance of the drive board 3 can be improved.

The base 40 of the heat dissipation sheet 4 has a plurality of recesses 41 (four in the example of FIG. 4) and a plurality of holes 42 (three in the example of FIG. 4). The four recesses 41 are recessed inward in the radial direction of the rotation shaft 111 (see FIG. 2). The four protrusions 52 of the fixing plate 5 fit into the four recesses 41, thereby positioning the heat dissipation sheet 4 relative to the fixing plate 5. The three holes 42 are provided so that the three connection terminals 113 do not come into contact with the base 40. With the four recesses 41 and the four protrusions 52 of the fixing plate 5 fitted together, the heat dissipation sheet 4 is positioned between the drive board 3 and the fixing plate 5 in the front-rear direction. The heat dissipation sheet 4 is also positioned so that it comes into contact with the rear side of the drive board 3.

The fixed plate 5 is made of a metal such as aluminum or iron. In this embodiment, the fixed plate 5 is made of aluminum. Since aluminum is conductive, the fixed plate 5 is placed on the rear side of the drive board 3 via the heat dissipation sheet 4, which has electrical insulation.

The base 50 of the fixing plate 5 has three screw holes 51, four protrusions 52, and a plurality of holes 53 (three in the example of FIG. 4). Three screws 23 fit into the three screw holes 51. The four protrusions 52 protrude forward from the base 50. The four protrusions 52 are shaped to fit into the four first recesses 311 of the drive board 3 and the four recesses 41 of the heat dissipation sheet 4. The three holes 53 are provided so that the three connection terminals 113 do not come into contact with the base 50. With the four protrusions 52 fitted into the four first recesses 311 and the four recesses 41, the three screws 23 are fitted into the three screw holes 51. As a result, with the heat dissipation sheet 4 sandwiched between the fixing plate 5 and the drive board 3, the fixing plate 5, the drive board 3, and the heat dissipation sheet 4 are fixed together.

Furthermore, the four protrusions 52 have a plurality of holes 521 (four in the example of FIG. 4). With the fixing plate 5, the drive board 3, and the heat dissipation sheet 4 fixed together, four screws 21 are passed through the four holes 521. With the four screws 21 passed through the four holes 521, the four screws 21 fit into the four screw holes 114 (see FIG. 3) of the motor 11 (see FIG. 3), thereby fixing the fixing plate 5, the drive board 3, and the heat dissipation sheet 4 to the motor 11.

The potting portion 6 is formed of, for example, urethane resin and has electrical insulation properties. In other words, the potting portion 6 is an insulating resin. The potting portion 6 is used for the purpose of improving the electrical insulation, waterproofing, dustproofing, and vibration resistance of the drive substrate 3. In addition, the thermal conductivity of the potting portion 6 at room temperature is about 0.2 to 1.0 W/m·K, which is much higher than the thermal conductivity of air (about 25 mW/m·K).

As shown in FIG. 3, the potting portion 6 is formed so as to cover the drive substrate 3, heat dissipation sheet 4, and mounting plate 5, which are fixed together. If there is a gap between the drive substrate 3 and heat dissipation sheet 4, between the heat dissipation sheet 4 and mounting plate 5, or between the drive substrate 3 and mounting plate 5, the gap is filled with the resin constituting the potting portion 6. In addition, in this disclosure, "covering" includes not only directly covering a certain member, but also indirectly covering the certain member via another member. For example, when the switching element E1 (see FIG. 4) of the drive substrate 3 is covered by the heat dissipation sheet 4 and the potting portion 6 further covers the heat dissipation sheet 4, it is said that "the potting portion 6 covers the switching element E1."

The potting section 6 is formed to cover the drive board 3, heat dissipation sheet 4, and fixed plate 5 when the drive board 3, heat dissipation sheet 4, and fixed plate 5 are fixed together, and the fixed plate 5 and motor 11 are fixed together.

(2.3) Configuration of the Drive Substrate Next, the configuration of the drive substrate 3 according to this embodiment will be described with reference to FIG. 5 and FIG.

As shown in FIG. 6, the drive board 3 of this embodiment has a substrate 31, a pattern portion 32, a resin 33 (solder resist), and a heat dissipation portion 34.

The substrate 31 is an electrically insulating substrate such as a paper-phenol substrate made of a paper substrate and phenolic resin, or a glass-epoxy substrate made of a glass cloth substrate and epoxy resin. In this disclosure, the term "substrate" includes prepreg if the substrate is made of four or more layers.

The pattern portion 32 is formed on the surface of the substrate 31. In this disclosure, the "surface of the substrate 31" refers to the front or rear surface of the substrate 31. The pattern portion 32 is formed of a metal such as copper, and is conductive.

As shown in FIG. 5, the drive substrate 3 of this embodiment has a plurality of pattern portions 32 (six in the example of FIG. 5). The plurality of pattern portions 32 include a first pattern portion 321, a second pattern portion 322, a plurality of third pattern portions 323 (three in the example of FIG. 5), and a fourth pattern portion 324.

The first pattern portion 321 is formed in the region A1 of the drive substrate 3. The first pattern portion 321 is connected to at least one of the six switching elements E1 to E6. As shown in FIG. 6, the connection terminal T2 of the switching element E2 is connected to the first pattern portion 321. In this embodiment, the first pattern portion 321 is connected to three switching elements E1 to E3 (see FIG. 5). The connection terminals of the three switching elements E1 to E3 may be connected to the first pattern portion 321 via solder. Since the first pattern portion 321 is connected to the switching element E2, heat generated in the switching element E2 is transferred from the connection terminal T2 to the first pattern portion 321. Therefore, the first pattern portion 321 is a portion to which heat generated in the switching element E2 is easily transferred.

As shown in FIG. 5, the second pattern portion 322 is formed in region A2 of the drive substrate 3. The second pattern portion 322 is a dummy pattern portion that is not electrically connected to electronic components (elements) such as the six switching elements E1 to E6. In other words, the second pattern portion 322 is not connected to any of the six switching elements E1 to E6. Heat generated by the six switching elements E1 to E6 is transferred to the second pattern portion 322 via the substrate 31.

The three third pattern parts 323 are formed in three regions A3 to A5. The three third pattern parts 323 are formed around the three holes 313. The three connection terminals 113 are connected to the three third pattern parts 323. That is, the three third pattern parts 323 are connected to the nine coils 112 (see FIG. 3) of the motor 11 (see FIG. 3) through the three connection terminals 113. The three third pattern parts 323 are also connected to one of the three switching elements E1 to E3 and one of the three switching elements E4 to E6. The third pattern part 323 formed in the region A3 is connected to the switching element E1 and the switching element E4. The third pattern part 323 formed in the region A4 is connected to the switching element E2 and the switching element E5. The third pattern part 323 formed in the region A5 is connected to the switching element E3 and the switching element E6. Because the three third pattern parts 323 are connected to two of the six switching elements E1 to E6, heat generated in two of the six switching elements E1 to E6 is transferred from the connection terminals to the three third pattern parts 323. Therefore, the three third pattern parts 323 are parts to which heat generated in two of the six switching elements E1 to E6 is easily transferred.

The fourth pattern portion 324 is connected to two diodes D1 to D2, which are elements other than the six switching elements E1 to E6. The six switching elements E1 to E6 are not connected to the fourth pattern portion 324. In other words, the fourth pattern portion 324 is connected to elements other than the six switching elements E1 to E6, and is not connected to the six switching elements E1 to E6.

As shown in FIG. 6, resin 33 is a thin film resin that covers a portion of pattern portion 32. In this embodiment, resin 33 covers a portion of first pattern portion 321, a portion of second pattern portion 322, and a portion of each of three third pattern portions 323. The thermal conductivity of resin 33 at room temperature is approximately several hundreds of mW/m·K.

The heat dissipation section 34 is disposed on the pattern section 32 in a portion that is not covered by the resin 33. In the example of FIG. 6, the heat dissipation section 34 is disposed on the first pattern section 321 in a portion that is not covered by the resin 33. In this embodiment, the heat dissipation section 34 is formed of solder. The thermal conductivity of solder at room temperature is about 45 W/m·K, which is much higher than the thermal conductivity of the resin 33.

In addition, the heat dissipation section 34 of this embodiment is thicker than the resin 33 in the direction (front-to-back direction) perpendicular to the surface on which the pattern section 32 is provided. In other words, the thickness dimension of the heat dissipation section 34 in the front-to-back direction is greater than the thickness dimension of the resin 33 in the front-to-back direction. The heat dissipation section 34 is covered by the heat dissipation sheet 4 and the potting section 6. The surface of the heat dissipation section 34 is in contact with the heat dissipation sheet 4. In addition, if there is a gap between the heat dissipation section 34 and the heat dissipation sheet 4, the gap is filled with the resin that constitutes the potting section 6, and the heat dissipation section 34 comes into contact with the potting section 6.

As shown in FIG. 5, the drive substrate 3 of this embodiment has multiple (six in the example of FIG. 5) heat dissipation sections 34. The five heat dissipation sections 34 formed in region A1 are first heat dissipation sections 341 formed on the first pattern section 321 in a portion not covered by resin 33. The heat dissipation sections 34 formed in region A2 are second heat dissipation sections 342 formed on the second pattern section 322 in a portion not covered by resin 33.

(3) Effects As described above, the power tool 1 of this embodiment includes the board package 2 and the motor 11. The board package 2 of this embodiment also includes the heat dissipation section 34 that is disposed on the pattern section 32 in a portion that is not covered with the resin 33 (solder resist). The heat dissipation section 34 of this embodiment has a higher thermal conductivity than the resin 33, and therefore can facilitate dissipation of heat from the pattern section 32. This allows heat generated on the board 31 to be easily dissipated.

In addition, the pattern portion 32 in this embodiment is made of copper. Copper has a relatively high thermal conductivity, which makes it easier for heat generated on the substrate 31 to escape.

The substrate package 2 of this embodiment further includes a heat dissipation sheet 4 or a potting portion 6 arranged to be in contact with the surface of the heat dissipation portion 34. The heat dissipation sheet 4 and the potting portion 6 have a higher thermal conductivity than air, so they can more easily dissipate heat from the pattern portion 32.

In addition, the heat dissipation sheet 4 or potting portion 6 in this embodiment covers at least the heat dissipation portion 34. Because the heat dissipation sheet 4 or potting portion 6 covers the heat dissipation portion 34, heat generated on the substrate 31 can be easily dissipated from the heat dissipation portion 34 to the heat dissipation sheet 4 or potting portion 6.

In addition, three switching elements E1 to E3 are connected to the first pattern portion 321 in which the first heat dissipation portion 341 of this embodiment is arranged. This makes it easier to dissipate heat generated by the three switching elements E1 to E3.

In addition, the second pattern portion 322 in which the second heat dissipation portion 342 of this embodiment is arranged is a dummy pattern portion that is not electrically connected. Furthermore, none of the six switching elements E1 to E6 are connected to the second pattern portion 322. By forming the second pattern portion 322 in the free space of the drive substrate 3 and arranging the second heat dissipation portion 342 on the second pattern portion 322 instead of the resin 33, it is possible to make it easier for heat to escape from the second pattern portion 322.

In this embodiment, the first heat dissipation portion 341 is disposed on the first pattern portion 321 in a portion not covered by the resin 33, and the second heat dissipation portion 342 is disposed on the second pattern portion 322 in a portion not covered by the resin 33. This makes it easier to dissipate heat from the first pattern portion 321 and also makes it easier to dissipate heat from the second pattern portion 322.

In this embodiment, the heat dissipation section 34 is made of solder. The thermal conductivity of solder is much higher than that of the resin 33, so it is easier to dissipate heat from the heat dissipation section 34.

In this embodiment, the heat dissipation section 34 is thicker than the resin 33 in the front-to-rear direction, which makes it easier for the heat dissipation section 34 to come into contact with the heat dissipation sheet 4 or the potting section 6, making it easier for heat to escape from the heat dissipation section 34 to the heat dissipation sheet 4 or the potting section 6.

(4) Modifications Modifications of the above embodiment are listed below. The modifications described below can be applied in appropriate combination with the above embodiment.

One or more third heat dissipation parts may be formed on at least one of the three third pattern parts 323. The third heat dissipation parts are disposed on the third pattern part 323 in a portion that is not covered by the resin 33. By forming the third heat dissipation parts, it is possible to facilitate dissipation of heat from the third pattern part 323.

A fourth heat dissipation portion may be formed on the fourth pattern portion 324, in a portion that is not covered by the resin 33. By forming the fourth heat dissipation portion, it is possible to make it easier to dissipate heat from the fourth pattern portion 324.

The heat dissipation section 34 may be formed of a conductive polymer or the like. Furthermore, the first heat dissipation section 341, the second heat dissipation section 342, the third heat dissipation section, and the fourth heat dissipation section described above do not all need to be formed of the same material. For example, the first heat dissipation section 341 may be formed of solder, and the second heat dissipation section 342 may be formed of a conductive polymer.

The resin 33 does not have to cover a portion of the second pattern portion 322.

Also, as shown in FIG. 7, the board package 2a may be arranged in front of the motor 11a and housed in the housing 10a. The board package 2a has a hole 22 through which the rotating shaft 115 of the motor 11a passes. The rotating shaft 115 of the motor 11a is supported by a bearing 19.

The power tool 1 may be a drill driver, rather than an impact driver that tightens fastening parts by applying an impact to the tip tool.

In addition, in the power tool 1 of the above embodiment, the tip tool can be replaced depending on the application, but it is not essential that the tip tool be replaceable. For example, the power tool 1 may be a power tool in which only a specific tip tool can be used.

(summary)
As described above, the board package (2; 2a) according to the first aspect is equipped with a switching element (E1; E2; E3) for driving a motor (11; 11a) used in a power tool (1). The board package (2; 2a) includes a board (31), a pattern portion (32), a resin (33), and a heat dissipation portion (34). The board (31) has electrical insulation. The pattern portion (32) is formed on the surface of the board (31) and has electrical conductivity. The resin (33) covers a part of the pattern portion (32). The heat dissipation portion (34) is disposed on a portion of the pattern portion (32) that is not covered by the resin (33), and has a higher thermal conductivity than the resin (33).

According to this embodiment, by arranging the heat dissipation portion (34) instead of the resin (33) on the pattern portion (32), it is possible to reduce the thermal resistance in the heat dissipation path from the pattern portion (32). This makes it easier to dissipate heat generated on the substrate (31) by driving the switching elements (E1; E2; E3) and the like.

The substrate package (2; 2a) according to the second aspect is the same as the first aspect, but further includes an insulating resin (heat dissipation sheet 4; potting portion 6). The insulating resin (heat dissipation sheet 4; potting portion 6) is arranged so as to be in contact with the surface of the heat dissipation portion (34). The insulating resin (heat dissipation sheet 4; potting portion 6) has electrical insulation properties and a higher thermal conductivity than air.

According to this embodiment, the insulating resin (heat dissipation sheet 4; potting portion 6) that has a higher thermal conductivity than air is in contact with the surface of the heat dissipation portion (34), so the thermal resistance in the heat dissipation path from the pattern portion (32) can be further reduced.

In the substrate package (2; 2a) of the third aspect, in the second aspect, the insulating resin (heat dissipation sheet 4; potting portion 6) covers at least the heat dissipation portion (34).

According to this embodiment, the insulating resin (heat dissipation sheet 4; potting portion 6) covers the heat dissipation portion (34), so that heat generated on the substrate (31) can easily escape from the heat dissipation portion (34) to the insulating resin (heat dissipation sheet 4; potting portion 6).

In the substrate package (2; 2a) according to the fourth aspect, in any of the first to third aspects, the switching elements (E1; E2; E3) are connected to the pattern portion (32) in which the heat dissipation portion (34) is arranged.

According to this embodiment, it is possible to reduce the thermal resistance in the heat dissipation path from the pattern portion (32) to which the switching elements (E1; E2; E3) that generate a large amount of heat are connected.

In the substrate package (2; 2a) according to the fifth aspect, in any of the first to third aspects, the pattern portion (32) in which the heat dissipation portion (34) is arranged is a dummy pattern portion that is not electrically connected. The switching elements (E1; E2; E3) are not connected to the dummy pattern portion.

According to this embodiment, a dummy pattern portion can be formed in an empty space of the substrate (31), thereby reducing the thermal resistance in the heat dissipation path from the dummy pattern portion.

The board package (2; 2a) according to the sixth aspect is provided with a plurality of pattern portions (32) in the first to third aspects. The plurality of pattern portions (32) include a first pattern portion (321) and a second pattern portion (322). The first pattern portion (321) is connected to the switching elements (E1; E2; E3). The second pattern portion (322) is a dummy pattern portion that is not electrically connected, and the switching elements (E1; E2; E3) are not connected. The heat dissipation portion (34) has a first heat dissipation portion (341) and a second heat dissipation portion (342) as the heat dissipation portion (34). The first heat dissipation portion (341) is disposed on a portion of the first pattern portion (321) that is not covered with the resin (33). The second heat dissipation portion (342) is disposed on a portion of the second pattern portion (322) that is not covered with the resin (33).

According to this aspect, the first heat dissipation section (341) is arranged on the first pattern section (321) to which the switching elements (E1; E2; E3) are connected, and the second heat dissipation section (342) is arranged on the second pattern section (322), which is a dummy pattern section, thereby making it easier to dissipate heat generated on the substrate (31).

In the seventh aspect of the substrate package (2; 2a), in any of the first to sixth aspects, the heat dissipation portion (34) is formed of solder.

According to this embodiment, the heat dissipation portion (34) can be easily formed by forming the heat dissipation portion (34) with solder that is used when mounting the switching elements (E1; E2; E3) to the pattern portion (32).

In the substrate package (2; 2a) according to the eighth aspect, in any one of the first to seventh aspects, the heat dissipation portion (34) is thicker than the resin (33) in a direction perpendicular to the surface on which the pattern portion (32) of the substrate (31) is provided.

According to this embodiment, the heat dissipation portion (34) is thicker than the resin (33), which makes it easier for the heat dissipation portion (34) and the insulating resin (heat dissipation sheet 4; potting portion 6) to come into contact with each other, thereby reducing the thermal resistance in the heat dissipation path from the pattern portion (32).

The configurations other than the first aspect are not essential to the substrate package (2; 2a) and may be omitted as appropriate.

The electric power tool (1) of the ninth aspect includes a board package (2; 2a) of any one of the first to eighth aspects and a motor (11, 11a).

According to this aspect, in the substrate package (2; 2a), by arranging the heat dissipation portion (34) instead of the resin (33) on the pattern portion (32), it is possible to reduce the thermal resistance in the heat dissipation path from the pattern portion (32). This makes it easier to dissipate heat generated on the substrate (31) by driving the switching elements (E1; E2; E3) and the like.

REFERENCE SIGNS LIST 1 Power tool 2, 2a Board package 31 Board 32 Pattern portion 321 First pattern portion 322 Second pattern portion 33 Resin 34 Heat dissipation portion 341 First heat dissipation portion 342 Second heat dissipation portion 4 Heat dissipation sheet (insulating resin)
6 Potting part (insulating resin)
11, 11a Motors E1 to E6 Switching elements

Claims (7)

A substrate package having a switching element mounted thereon for driving a motor used in an electric power tool,
An electrically insulating substrate;
A pattern portion formed on a surface of the substrate and having electrical conductivity;
a resin covering a part of the pattern portion;
a heat dissipation portion that is disposed on the pattern portion in a portion not covered with the resin and has a higher thermal conductivity than the resin;
an insulating resin having electrical insulation properties and a higher thermal conductivity than air;
a heat dissipation sheet that is arranged in contact with a surface of the heat dissipation portion, has flexibility and electrical insulation properties, and has a higher thermal conductivity than air;
Equipped with
The insulating resin covers the heat dissipation portion and the heat dissipation sheet.
Substrate package. The switching element is connected to the pattern portion on which the heat dissipation portion is arranged.
The substrate package according to claim 1 . the pattern portion in which the heat dissipation portion is disposed is a dummy pattern portion that is not electrically connected,
The switching element is not connected to the dummy pattern portion.
The substrate package according to claim 1 . The pattern portion includes a plurality of the pattern portions,
The plurality of pattern portions include a first pattern portion and a second pattern portion,
the first pattern portion is connected to the switching element,
The second pattern portion is a dummy pattern portion that is not electrically connected, and the switching element is not connected to the second pattern portion.
The heat dissipation portion includes a first heat dissipation portion and a second heat dissipation portion,
the first heat dissipation portion is disposed on the first pattern portion in a portion not covered with the resin,
The second heat dissipation portion is disposed on a portion of the second pattern portion that is not covered with the resin.
The substrate package according to claim 1 . The heat dissipation portion is formed of solder.
The substrate package according to claim 1 . the heat dissipation portion is thicker than the resin in a direction perpendicular to a surface of the substrate where the pattern portion is provided;
The substrate package according to claim 1 . A substrate package according to any one of claims 1 to 6,
The motor;
Equipped with
Power tools.

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