Circuit board and electromagnetic cooker

Abstract

To suppress breakage of an electronic component when vibration is applied, while reducing the thickness of a circuit board.SOLUTION: The circuit board 20 includes a board body 21 to which a plurality of electronic components 23 are attached. The substrate body 21 is provided with a punched part 23E punched in the thickness direction at a part for attaching the first electronic part 21c, and at least a part of the first electronic part 21c is arranged so as to enter the punched part 23E. In the substrate body 21, a support part 26 for supporting the first electronic part 23E is provided separately from or integrally with the substrate body 21.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a circuit board and an induction cooker. [Background technology]

[0002] Patent Document 1 discloses a circuit board that can be made thinner. In this circuit board, a notch is provided in a portion where an electronic component (capacitor) that is larger than the other components attached to the board body is to be attached, and the electronic component is arranged in this notch so that it protrudes from both sides in the thickness direction of the board body. The lead wires protruding from the electronic component are bent into an L shape and soldered to the circuit on the board body. This makes it possible to reduce the thickness of the circuit board by the thickness of the board body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JIPP No. 61-39984 Summary of the Invention [Problem to be solved by the invention]

[0004] The lead wires of electronic components are more susceptible to forces perpendicular to the protruding direction than to forces acting in the protruding direction. Furthermore, circuit boards tend to vibrate more easily in a direction perpendicular to the board body than in the direction in which the board body extends. Therefore, in the circuit board of Patent Document 1, when vibrations are applied to the circuit board, electronic components including the lead wires may be damaged. In other words, the circuit board of Patent Document 1 still has room for improvement in terms of preventing damage to electronic components when vibrations are applied.

[0005] An object of the present invention is to reduce the thickness of a circuit board and also to suppress damage to electronic components when vibration is applied. [Means for solving the problem]

[0006] One aspect of the present invention provides a circuit board comprising a substrate body having a plurality of electronic components attached thereto, the substrate body having a punched-out portion punched out in the thickness direction at a portion where a first electronic component of the plurality of electronic components is to be attached, the first electronic component being positioned so that at least a portion of the first electronic component fits within the punched-out portion, and the substrate body having a support portion for supporting the first electronic component, either separate from or integral with the substrate body.

[0007] In this embodiment, the first electronic component is positioned so that at least a portion of it fits into a punched-out portion punched in the thickness direction of the board body. This allows the thickness of the circuit board to be reduced by the size of the portion of the electronic component that fits into the punched-out portion. The board body also includes a support portion that supports the first electronic component, either separately or integrally with the board body. This allows the support portion to suppress oscillation of the first electronic component within the punched-out portion when vibration is applied. This prevents damage to the first electronic component, including the lead wires.

[0008] The first electronic component is disposed so as to protrude from the punched portion on both sides in the thickness direction, thereby reducing the thickness of the circuit board by the thickness of the board body.

[0009] The substrate body includes an adhesive portion that supports the first electronic component in addition to the portion where the support portion is provided, which effectively prevents the first electronic component from swinging within the punched portion, thereby preventing damage to the first electronic component, including the lead wires.

[0010] The support portion is plate-shaped and stands upright to face the lead wire protruding from the first electronic component, and the lead wire passes through the support portion and is connected to a circuit on the board body. This allows the support portion to support the lead wire, thereby preventing damage to the lead wire when a force is applied to the lead wire in a direction perpendicular to the protruding direction.

[0011] The circuit board further includes a heat sink attached to the board body for cooling a second electronic component among the plurality of electronic components, the first electronic component having a minimum dimension greater than a protrusion dimension of the heat sink from the board body.By adopting a structure in which the first electronic component is disposed in the punched-out portion for such a circuit board, the overall thickness can be effectively reduced.

[0012] The substrate body is formed by punching out a base substrate, and the support portion is formed by punching out a region of the base substrate other than the region where the substrate body is formed. The region of the base substrate other than the region where the substrate body is formed is a discarded substrate that would normally be discarded, and the support portion is formed using this discarded substrate, so that a structure for supporting the first electronic component can be easily and reliably formed without increasing manufacturing costs.

[0013] Another aspect of the present invention provides an induction cooker comprising a casing, a heating coil disposed within the casing for induction heating an object to be heated disposed on the casing, and a circuit board including a substrate body on which are attached a plurality of electronic components for controlling the heating coil, wherein the substrate body has a punched-out portion punched out in the thickness direction at a portion where a first electronic component of the plurality of electronic components is to be attached, and the first electronic component is positioned so that at least a portion of the first electronic component fits within the punched portion, and the substrate body has a support portion for supporting the first electronic component provided separately or integrally with the substrate body.

[0014] In this embodiment, at least a portion of the first electronic component is disposed within a punched portion punched in the thickness direction of the substrate body, thereby reducing the thickness of the circuit board by the size of the portion of the electronic component that fits within the punched portion. This allows the induction cooker itself to be made thinner. Furthermore, when vibrations are applied to the substrate body, the support portion, which is provided separately or integrally with the substrate body, can suppress the oscillation of the first electronic component, thereby suppressing damage to the first electronic component, thereby improving the reliability of the induction cooker. [Effects of the Invention]

[0015] In the present invention, the thickness of the circuit board can be reduced and damage to electronic components when vibration is applied can be suppressed. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view of an induction cooker using a circuit board according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a portion cut along line II-II in FIG. [Figure 3] FIG. 2 is a perspective view of an induction cooker with the top plate and upper case removed. [Figure 4] FIG. 2 is a perspective view showing a lower case, a coil set, and a circuit board. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] Cross-sectional view taken along line VII-VII in Figure 5. [Figure 8] Cross-sectional view taken along line VIII-VIII in Figure 5. [Figure 9] FIG. 9 is an exploded perspective view of FIG. 8. [Figure 10] 9 is an exploded perspective view of FIG. 8, seen from a different direction than FIG. [Figure 11] FIG. 10 is a plan view of the base substrate from which the substrate body is punched. [Figure 12] 9 is a cross-sectional view similar to FIG. 8 of a circuit board according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] (First embodiment) 1 and 2, an induction cooker 1 using a circuit board 20 according to a first embodiment of the present invention is a so-called tabletop type, and has a rectangular shape when viewed from above.

[0019] In the induction cooker 1, the extension direction of one pair of opposite sides of the rectangle is the width direction W, with the direction indicated by the arrow being the left side and the direction opposite to the arrow being the right side. In the induction cooker 1, the extension direction of the other pair of opposite sides of the rectangle is the depth direction D, with the direction indicated by the arrow being the front side and the direction opposite to the arrow being the back side. The direction perpendicular to both the width direction W and the depth direction D is the height direction (thickness direction) H, with the direction indicated by the arrow being the top side and the direction opposite to the arrow being the bottom side. When the induction cooker 1 is placed horizontally on a table, the width direction W and the depth direction D are oriented horizontally, and the height direction H is oriented vertically. This concept of directions is merely an example and can be changed as appropriate depending on the posture of the induction cooker 1, etc.

[0020] 3 and 4, the circuit board 20 includes a board body 21 and a plurality of electronic components 23. In this embodiment, the mounting structure of the electronic components 23, which are larger than the other components mounted on the board body 21, is improved, reducing the thickness of the circuit board 20 and suppressing damage to the electronic components 23 when vibrations are applied.

[0021] First, the configuration of the induction cooker 1 in which the circuit board 20 is used will be described.

[0022] 1 to 3, an induction cooker 1 includes a casing 3, a coil set 10, and a circuit board 20.

[0023] The casing 3 is composed of a lower case 4, an upper case 5, and a top plate 6. The lower case 4, the upper case 5, and the top plate 6 define an internal space 7 in which the coil set 10 and the circuit board 20 are disposed.

[0024] 3 and 4, the lower case 4 is tray-shaped with an open top and includes a bottom wall 4a and a peripheral wall 4b. The bottom wall 4a is rectangular when viewed from above, and the peripheral edge of the bottom wall 4a defines the rectangular outline. The peripheral wall 4b is rectangular in shape and protrudes upward from the peripheral edge of the bottom wall 4a.

[0025] The bottom wall 4a is provided with three types of bosses 4c to 4e. Of these, the first boss 4c is configured to be screwed to assemble the upper case 5. The second boss 4d is configured to be screwed to assemble the coil set 10. The third boss 4e is configured to be screwed to assemble the circuit board 20. A plurality of ribs 4f that support the underside of the circuit board 20 are formed on the outer periphery of the boss 4e.

[0026] 2 and 3, the upper case 5 is formed as a rectangular ring-shaped body and is fitted from above into the upper end opening of the lower case 4 (the upper end of the peripheral wall 4b). A rectangular upper opening 5a is formed in the center of the upper case 5. The upper case 5 covers only the outer periphery of the lower case 4 and forms a flange. The upper case 5 is assembled to the lower case 4 by fastening screws that pass through the bosses 4c.

[0027] Top plate 6 is made of a material (such as ceramic) that is permeable to magnetic flux, and is attached in close contact with upper case 5 so as to close upper opening 5a.

[0028] 2 and 4, the coil set 10 is housed in the internal space 7 of the casing 3. The coil set 10 includes a heating coil 11, a coil bobbin 12, and a ferrite core 13.

[0029] Heating coil 11 is configured with multiple windings wound in a double annular shape, and when a high-frequency current is passed through it, eddy currents are generated in an object to be heated (for example, a cooking vessel not shown) placed on top plate 6, thereby inductively heating the object to be heated. Heating coil 11 is supported by coil bobbin 12 and is placed close to the underside of top plate 6.

[0030] The coil bobbin 12 is attached to the casing 3 and supports the ferrite core 13 and the heating coil 11 in that order from bottom to top. The coil bobbin 12 includes a cylindrical boss portion 12a disposed in the center, a ring-shaped rim portion 12b concentric with the boss portion 12a, and a plurality of spoke portions 12c connecting the boss portion 12a and the rim portion 12b.

[0031] A plurality of (three in this embodiment) screw fastening portions 12d are provided at intervals in the circumferential direction on the outer periphery of the rim portion 12b. The coil bobbin 12 is assembled to the lower case 4 by fastening screws that pass through the screw fastening portions 12d to bosses 4d of the lower case 4. A groove for accommodating one ferrite core 13 is provided in each of the plurality of spoke portions 12c.

[0032] The ferrite core 13 is a component for converging the magnetic flux generated from the heating coil 11. The ferrite core 13 is made of a rectangular plate and is housed in a groove formed in the spoke portion 12c of the coil bobbin 12.

[0033] Two temperature sensors are attached to the coil set 10 to detect the temperature of the object to be heated placed on the top plate 6. One of the two temperature sensors is a center sensor 15 attached to the boss portion 12a of the coil bobbin 12. The other is a side sensor 16 attached between adjacent predetermined spoke portions 12c. The center sensor 15 and the side sensor 16 can both be thermistors.

[0034] The center sensor 15 is attached to the upper surface side of a center holder 17 that is fitted into the boss portion 12a of the coil bobbin 12. The center sensor 15 is exposed upward from the center holder 17 and is disposed close to or in contact with the lower surface of the top plate 6.

[0035] The side sensor 16 is attached to the upper surface of a side holder 18 that is fitted between a pair of spokes 12c of the coil bobbin 12. The side sensor 16 is exposed upward from the side holder 18 and is disposed close to or in contact with the lower surface of the top plate 6.

[0036] Next, the configuration of the circuit board 20 will be described in detail.

[0037] 2 to 4, the circuit board 20 is disposed in the internal space 7 of the casing 3 so as to be adjacent to the outer side of the heating coil 11 when viewed from above. The circuit board 20 includes a board main body 21 and a plurality of electronic components 23 attached to the board main body 21. A heating circuit for passing electricity through the heating coil 11 to heat the object to be heated is configured by a wiring pattern 22 (see FIG. 11), which is a circuit printed on the board main body 21, and the plurality of electronic components 23.

[0038] The board main body 21 is U-shaped when viewed from above and is placed in the lower case 4 with the right side open in FIGS. 3 and 4 . The outer periphery of the board main body 21 is provided with multiple punched portions 21a corresponding to the multiple bosses 4c, 4e of the lower case 4. Some of the punched portions 21a are formed as holes penetrating the board main body 21 in the height direction (thickness direction). The remaining punched portions 21a are formed as U-shaped notches cut out from the outer periphery of the board main body 21. The size of the punched portions 21a is larger than the outline of the bosses 4e and smaller than the imaginary outline connecting the outer ends of the multiple ribs 4f. When the board main body 21 is placed inside the lower case 4, the upper portion of the boss 4e protrudes from the punched portion 21a. The circuit board 20 is assembled to the lower case 4 by placing a spacer 24 over this protruding portion and screwing the spacer 24 from above.

[0039] The coil set 10 is disposed in the center of the U-shaped space of the substrate body 21. When viewed from above, the substrate body 21 barely overlaps the heating coil 11. However, part of the inner peripheral edge 21b of the substrate body 21 may overlap part of the outer peripheral edge of the heating coil 11 in the height direction. Part of the inner peripheral edge 21b of the substrate body 21 overlaps part of the rim portion 12b of the coil bobbin 12 in the height direction. After being attached to the lower case 4, the inner peripheral portion of the substrate body 21 is sandwiched and supported between the coil bobbin 12 and the lower case 4 by further attaching the coil set 10 to the lower case 4. In other words, the outer peripheral portion of the substrate body 21 is fixed by screws via spacers 24, and the inner peripheral portion of the substrate body 21 is supported by the coil bobbin 12, which is also screwed.

[0040] 4 to 6, the electronic components 23 include a diode bridge 23A that converts AC from a commercial power source into DC, a transistor 23B that adjusts the amount and frequency of the current passed through the heating coil 11, an IC chip 23C that functions as a controller that controls the operation of the transistor 23B, a plurality of capacitors 23D for smoothing or resonance, and a switching coil 23E that switches the diode bridge 23A. The transistor 23B is, for example, an IGBT (insulated gate bipolar transistor). At least a portion of the capacitor 23D is an electrolytic capacitor.

[0041] The circuit board 20 configured in this manner supplies power to the heating coil 11 in response to operation on the operation unit 35 (see FIG. 1), thereby inductively heating an object to be heated on the top plate 6. When the induction cooker 1 is in operation, the heating coil 11 and several electronic components 23 generate heat. Examples of electronic components 23 that generate a lot of heat include the diode bridge 23A, the transistor 23B, and the IC chip 23C. Examples of electronic components 23 whose operation may become unstable due to heat include the IC chip 23C. Examples of electronic components 23 whose deterioration is accelerated by heat include the capacitor 23D (particularly, an electrolytic capacitor).

[0042] A heat sink 25 is disposed on the board main body 21 to dissipate heat from the electronic components 23, and a pair of fans 30, 31 are disposed in the internal space 7 of the casing 3. A ferrite core 32 is attached between the circuit board 20 and the first fan 30 to eliminate noise from the circuit board 20. The ferrite core 32 is disposed close to or in contact with the lower surface of the upper case 5.

[0043] The heat sink 25 cools (exchanges heat with) the diode bridge 23A and transistor 23B, which are examples of the second electronic components of the present invention, by mounting them thereon. The first fan 30 and the second fan 31 are low-profile blower fans with a rotating shaft extending in the height direction, and blow air above and below the circuit board 20. This makes it possible to suppress unstable operation of the heating circuit due to heat and deterioration of the electronic components 23. Note that although only the housings of the fans 30 and 31 are shown in the figure, a rotatably supported impeller (not shown) is disposed within the housing.

[0044] 4 to 6, the switching coil 23E among the plurality of electronic components 23 is an example of a first electronic component of the present invention. However, the first electronic component of the present invention is not limited to the switching coil 23E and can be changed as necessary.

[0045] 7 to 10, switching coil 23E is cylindrical and includes a pair of lead wires 23a protruding from one axial end. The axial dimension of switching coil 23E, which is the direction in which lead wires 23a protrude, is greater than the radial dimension. In the following description, the axial dimension of switching coil 23E may be referred to as maximum dimension Smax, and the radial dimension of switching coil 23E may be referred to as minimum dimension Smin.

[0046] The substrate main body 21 has a punched-out portion 21c punched out in the height direction (thickness direction) at a portion where the switching coil 23E is attached. The punched-out portion 21c is a rectangular hole when viewed from above, with a pair of long sides greater than the maximum dimension Smax of the switching coil 23E and a pair of short sides greater than the minimum dimension Smin of the switching coil 23E. However, the punched-out portion 21c may be formed by a U-shaped notch cut out from the outer periphery of the substrate main body 21, or may have a shape other than a rectangle.

[0047] The switching coil 23E is disposed in the punched portion 21c in a horizontal orientation with its axial direction (maximum dimension Smax) aligned with the substrate body 21. As a result, the switching coil 23E is oriented such that its minimum dimension Smin corresponds to the thickness direction of the substrate body 21. By disposing the switching coil 23E in the punched portion 21c, the switching coil 23E protrudes from both the upper and lower surfaces of the substrate body 21. In other words, the switching coil 23E protrudes on both sides in the thickness direction of the substrate body 21. As a result, the switching coil 23E protrudes upward from the substrate body 21 by a dimension S1 and downward from the substrate body 21 by a dimension S2. The dimension obtained by subtracting the dimensions S1 and S2 from the minimum dimension Smin corresponds to the thickness dimension of the substrate body 21.

[0048] As shown most clearly in FIG. 7 , the maximum dimension Smax (see FIG. 8 ) of the switching coil 23E is larger than the protrusion dimensions of the other electronic components 23, including the heat sink 25, from the substrate main body 21. In the circuit board 20 of this embodiment, the IC chip 23C protrudes the most from the top surface of the substrate main body 21. The protrusion dimension Sa of the IC chip 23C is larger than the protrusion dimension Sb of the heat sink 25. The minimum dimension Smin of the switching coil 23E is larger than both the protrusion dimensions Sa and Sb. However, because the switching coil 23E is disposed within the punched portion 21c, the dimension S1 of the portion of the switching coil 23E protruding from the top surface of the substrate main body 21 can be smaller than both the protrusion dimensions Sa and Sb. Of course, the dimension S2 of the portion of the switching coil 23E protruding from the bottom surface of the substrate main body 21 is smaller than the protrusion dimensions of the other electronic components 23 protruding from the bottom surface of the substrate main body 21.

[0049] As described above, in order to prevent damage to the switching coil 23E attached to the punched portion 21c of the substrate body 21, the circuit board 20 of this embodiment is provided with a support portion 26 that supports the switching coil 23E.

[0050] The support portion 26 is plate-shaped and stands along one edge (one of the pair of short sides) of the substrate main body 21 that defines the punched portion 21c and that faces the end of the switching coil 23E from which the lead wire 23a protrudes. The height dimension of the support portion 26 is smaller than the protrusion dimension S1 of the switching coil 23E. However, the height dimension of the support portion 26 may be larger than the protrusion dimension S1 of the switching coil 23E as long as it is equal to or smaller than the protrusion dimension Sa of the IC chip 23C that protrudes most from the substrate main body 21. The width dimension of the support portion 26 is larger than both the short side dimension of the punched portion 21c and the minimum dimension Smin of the switching coil 23E. However, the width dimension of the support portion 26 may be smaller than the minimum dimension Smin of the switching coil 23E as long as it is larger than the maximum dimension between the pair of lead wires 23.

[0051] A pair of through holes 26a are provided in the support portion 26. The through holes 26a are provided in positions facing the lead wires 23a when the switching coil 23E is disposed in the punched portion 21c and the support portion 26 is placed on the substrate main body 21. The pair of lead wires 23a that pass through the through holes 26a are bent into an L shape and soldered to the wiring pattern 22 (see FIG. 11) of the substrate main body 21.

[0052] The support portion 26 is adhered to the substrate main body 21 by an adhesive portion 27. The adhesive portion 27 is made of a hardened silicone adhesive. However, since the support portion 26 can be positioned by soldering the lead wires 23a to the substrate main body 21, the support portion 26 may not be adhered to the substrate main body 21 by the adhesive portion 27.

[0053] 8, gap G between support portion 26 and the end of switching coil 23E is equal to or less than half the minimum dimension Smin of switching coil 23E. It is preferable that gap G be as small as possible, and support portion 26 and the end of switching coil 23E may abut against each other. This shortens the length of lead wire 23a between support portion 26 and the end of switching coil 23E, which corresponds to an arm of a cantilever structure, and therefore makes it possible to suppress oscillation of switching coil 23E when vibrations are applied to circuit board 20 in the height direction.

[0054] An end of switching coil 23E opposite to the end from which lead wire 23a protrudes is adhered to an edge of substrate main body 21 facing punched portion 21c (the other of the pair of short sides) by adhesive portion 28. Adhesive portion 28 is made of a cured silicone adhesive. However, adhesive portion 28 may be provided on one or both of the edges that define punched portion 21c in substrate main body 21, the edges corresponding to the pair of long sides. In other words, adhesive portion 28 may be provided between switching coil 23E and the edge that defines punched portion 21c other than the portion where support portion 26 is provided.

[0055] The switching coil 23E attached in this manner has its end on the lead wire 23a side supported by the support portion 26 via the lead wire 23a. Moreover, the lead wire 23a is also supported by the support portion 26 by passing through the through-hole 26a. This improves the rigidity in the height direction, which is perpendicular to the direction in which the lead wire 23a protrudes. This makes it possible to suppress the swinging of the switching coil 23E within the punched portion 21c even if vibration occurs in the circuit board 20 in the height direction. This makes it possible to suppress damage when vibration is applied to the circuit board 20.

[0056] 3 and 4, an operation board 37 is disposed adjacent to the circuit board 20 in the width direction. The operation board 37, together with a liquid crystal display unit 36 ​​attached to the circuit board 20, constitutes the operation unit 35 (see FIG. 1). The operation board 37 includes a board main body 38, a wiring pattern 39 (see FIG. 11) printed on the board main body 38, and a plurality of touch switches 40 (four in this embodiment) attached to the board main body 38, and a microcomputer 41. Like the circuit board 20, the operation board 37 is assembled to the lower case 4 by screwing it to the boss 4e via the spacer 24.

[0057] The circuit board 20 and operation board 37 are placed inside the lower case 4, and screws passing through the bosses 4c are fastened to the screw fastening portions 5b of the upper case 5. This sandwiches the circuit board 20 and operation board 37 between the bosses 4c and the screw fastening portions 5b, allowing the LCD display unit 36 ​​and touch switches 40 to be positioned in fixed positions. As a result, the LCD display unit 36 ​​and touch switches 40 are placed in predetermined positions near the top plate 6 that constitutes the operation unit 35 (see FIG. 1). Therefore, visibility of the LCD display unit 36 ​​and operability of the touch switches 40 can be ensured without adding any dedicated parts.

[0058] The operation board 37 is connected to the circuit board 20 via a flat cable (not shown). The microcomputer 41 outputs a Hi signal for each touch switch 40 when it is operated and a Lo signal when it is not operated. The microcomputer (not shown) on the circuit board 20 receives the signal and performs the specified control. However, the microcomputer 41 may be configured to output a signal when the touch switch 40 is operated and not output a signal when it is not operated. By configuring the operation board 37 to transmit a bipolar signal and the circuit board 20 to receive it, the same circuit board 20 can be used when tactile switches are used instead of the touch switches 40 and the microcomputer 41. This improves convenience when changing the model of the induction cooker 1.

[0059] 11, the substrate body 21 and support portion 26 of the circuit board 20, and the substrate body 38 of the operation board 37 are formed by punching out from a single base substrate 45. Cutting lines 46a, 46b, and 46c corresponding to the shapes of the substrate body 21, support portion 26, and substrate body 38 of the operation board 37 are printed on the base substrate 45. In the region of the base substrate 45 surrounded by cutting line 46a where the substrate body 21 is formed, the wiring pattern 22 is printed, and in the region of the base substrate 45 surrounded by cutting line 46c where the substrate body 38 is formed, the wiring pattern 39 is printed.

[0060] Here, the area of ​​base substrate 45 other than the area where substrate main body 21 is formed is a discarded substrate that is normally discarded. Support portion 26 and operation substrate 37 are formed in this discarded area. This makes it possible to manufacture the structure that supports switching coil 23E and operation substrate 37 without increasing the manufacturing cost of induction cooker 1.

[0061] (Second embodiment) Referring to FIG. 12, the circuit board 20 of the second embodiment differs from the first embodiment in that only a portion of the switching coil 23E is inserted into the punched portion 21c, the plate-shaped support portion 26 is spaced from the edge of the punched portion 21c, and the adhesive position of the adhesive portion 28 is changed.

[0062] 12, the switching coil 23E is arranged from above the punched portion 21c of the substrate body 21. The lower end of the switching coil 23E is located within the punched portion 21c and does not protrude from the lower surface of the substrate body 21. In other words, the switching coil 23E is arranged in the punched portion 21c so as to protrude from only one surface (the upper surface) of the substrate body 21.

[0063] The support portion 26 is disposed at a distance from the edge that defines the punched portion 21c with respect to the substrate body 21. It is preferable that the distance (gap G) between the end of the switching coil 23E on the lead wire 23a side and the punched portion 21c be set in the same manner as in the first embodiment.

[0064] The adhesive portion 28 bonds the end of the switching coil 23E opposite to the end from which the lead wire 23a protrudes, to the upper surface of the substrate body 21. In this way, the bonding position of the adhesive portion 28 is not limited to the edge that defines the punched portion 21c, and can be changed as necessary.

[0065] The present invention is not limited to the configuration of the above embodiment, and various modifications are possible.

[0066] Support portion 26 may have any configuration as long as it can support switching coil 23E, and may be configured, for example, to extend from the outer periphery of punched portion 21c of substrate main body 21 below punched portion 21c at a distance, and support the lower end of switching coil 23E. Support portion 26 may also be provided integrally with substrate main body 21.

[0067] The adhesive portion 28 for bonding the substrate main body 21 and the switching coil 23E may not be provided.

[0068] The lead wire 23a of the switching coil 23E may be bent into an L shape without passing through the support portion 26 and connected to the wiring pattern 22 of the substrate main body 21.

[0069] The board body 21 of the circuit board 20, the support portion 26, and the board body 38 of the operation board 37 may each be manufactured by punching out a dedicated base board 45.

[0070] The circuit board 20 having the mounting structure for the electronic component 23 (switching coil 23E) of the present invention may be used in appliances other than the induction cooker 1. The orientation in which the circuit board 20 is arranged may be vertical.

[0071] The circuit board 20 configured as above has the following features.

[0072] At least a portion of switching coil 23E is disposed in punched-out portion 21c punched in the thickness direction of substrate main body 21. Therefore, the thickness of circuit board 20 can be reduced by the dimension of the recessed portion of switching coil 23E. Furthermore, substrate main body 21 is provided with support portion 21c that supports switching coil 23E, either separately from or integral with substrate main body 21. As a result, when vibration is applied to substrate main body 21, support portion 21c can suppress oscillation of switching coil 23E, and damage to switching coil 23E, including lead wire 23a, can be suppressed.

[0073] In the first embodiment, the switching coil 23E is disposed so as to protrude on both sides in the thickness direction, so that the thickness of the circuit board 20 can be reduced by the thickness of the board body 21.

[0074] The substrate body 21 has an adhesive portion 28 that supports the switching coil 23E in addition to the portion where the support portion 26 is provided. This effectively prevents the switching coil 23E from swinging within the punched portion 21c, thereby preventing damage to the switching coil 23E, including the lead wire 23a.

[0075] The lead wire 23a protruding from the switching coil 23E passes through the support portion 26 and is connected to the wiring pattern 22 of the substrate main body 21. This allows the support portion 26 to also support the lead wire 23a, thereby preventing damage to the lead wire 23a when a force is applied to the lead wire 23a in a height direction perpendicular to the protruding direction.

[0076] The minimum dimension Smin of the switching coil 23E is larger than the protrusion dimension of the heat sink 25 from the substrate body 21. For such a circuit substrate 20, by adopting a structure in which the switching coil 23E is disposed in the punched portion 21c, the thickness can be effectively reduced.

[0077] The substrate main body 21 is formed by punching out a base substrate 45, and the support portion 26 is formed by punching out a region of the base substrate 45 other than the region where the substrate main body 21 is formed. The region of the base substrate 45 other than the region where the substrate main body 21 is formed is a discarded substrate that is normally discarded, and the support portion 26 is formed using this discarded substrate, so that a structure for supporting the switching coil 23E can be easily and reliably formed without increasing manufacturing costs.

[0078] In an induction cooker 1 using the circuit board 20, the thickness of the circuit board 20 can be reduced by the dimension of a portion of the switching coil 23E that fits into the punched portion 21c, thereby making it possible to make the induction cooker 1 itself thinner. Furthermore, when vibrations are applied to the circuit board 20, the support portion 26, which is provided separately from or integral with the board main body 21, can suppress the oscillation of the switching coil 23E and suppress damage to the switching coil 23E, thereby improving the reliability of the induction cooker 1. [Explanation of symbols]

[0079] 1 Induction cooker 3 Casing 4 Lower case 4a Bottom wall 4b Surrounding wall 4c Boss 4D Boss 4e boss 4F Rib 5 Upper case 5a Upper opening 5b Screw fastening part 6 Top Plate 7. Interior Space 10 coil set 11 Heating coil 12 Coil bobbin 12a Boss section 12b rim section 12c spokes 12d Screw fastening part 13 Ferrite core 15 Center sensor 16 Side sensor 17 Center holder 18 Side holder 20 Circuit Board 21 Board body 21a Punching section 21b inner edge 21c Punching section 22 Wiring pattern (circuit) 23 Electronic Components 23A Diode Bridge (Second Electronic Component) 23B Transistor (secondary electronic component) 23C IC chip 23D capacitor 23E Switching coil (first electronic component) 23a lead wire 24 spacer 25 Heatsink 26 Support part 26a Through hole 27,28 Adhesive part 30 First Fan 31 Second Fan 32 Ferrite core 35 Control section 36 LCD display section 37 Operation board 38 Board body 39 Wiring Pattern 40 Touch Switch 41 Microcomputer 45 base board 46a~46c cutting line Smin Minimum size of switching coil Smax Maximum size of switching coil Sa IC chip protrusion size Sb Heat sink protrusion dimensions G Gap W width direction D Depth direction H Height direction (thickness direction)

Claims

1. A substrate body having a plurality of electronic components attached thereto; a punched portion punched in a thickness direction of the substrate body is provided at a portion where a first electronic component of the plurality of electronic components is to be attached, and the first electronic component is disposed so that at least a portion of the first electronic component fits into the punched portion; The circuit board has a support portion for supporting the first electronic component, the support portion being provided on the board body separately from or integral with the board body.

2. The circuit board according to claim 1 , wherein the first electronic component is disposed so as to protrude from the punched portion on both sides in the thickness direction.

3. The circuit board according to claim 1 , wherein the substrate body includes an adhesive portion for supporting the first electronic component in addition to the portion where the support portion is provided.

4. the support portion is plate-shaped and stands upright so as to face the lead wire protruding from the first electronic component, The circuit board according to claim 1 or 2, wherein the lead wires pass through the support portion and are connected to a circuit of the board body.

5. a heat sink attached to the substrate body for cooling a second electronic component among the plurality of electronic components; The circuit board according to claim 1 , wherein a minimum dimension of the first electronic component is greater than a protrusion dimension of the heat sink from the board body.

6. The substrate body is formed by punching out a base substrate, The circuit board according to claim 1 , wherein the support portion is formed by punching out an area of ​​the base substrate other than an area where the substrate main body is formed.

7. A casing; a heating coil disposed within the casing for induction heating an object to be heated disposed on the casing; a circuit board including a board body on which a plurality of electronic components for controlling the heating coil are mounted; Equipped with a punched portion punched in a thickness direction of the substrate body is provided at a portion where a first electronic component of the plurality of electronic components is to be attached, and the first electronic component is disposed so that at least a portion of the first electronic component fits into the punched portion; The substrate body has a support portion for supporting the first electronic component, the support portion being provided separately from or integral with the substrate body.

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