Induction heating cooker

Abstract

To suppress uneven heating in an induction heating cooker formed by winding a conductor around a substrate.SOLUTION: An induction heating cooker includes an insulating multi-layer substrate, an inner coil formed by winding a conductor across two layers of the substrate, an outer coil formed by winding a conductor across two layers of the substrate and formed outside the outermost circumference of the inner coil, and a power supply substrate to which the inner coil and outer coil are independently connected.SELECTED DRAWING: Figure 15

Description

[Technical field]

[0001] The present technology relates to an induction heating cooker for cooking. [Background technology]

[0002] Conventionally, induction heating cookers have been known in which a coil is formed by winding a thin metal film on the surface of an insulating substrate (see, for example, Patent Document 1). The induction heating cooker of Patent Document 1 aims to efficiently heat an object to be heated by providing coils at both the center and the periphery of the heating part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-043697 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the induction heating cooker of Patent Document 1, the coils provided at the center and the periphery are connected, and therefore cannot be controlled independently. Therefore, in the induction heating cooker of Patent Document 1, uneven heating may occur depending on the size and arrangement of the heated object.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to prevent uneven heating in an induction heating cooker having a coil formed by winding a conductor around a substrate. [Means for solving the problem]

[0006] The induction heating cooker according to the present disclosure comprises an insulating multi-layer substrate, an inner coil formed by winding a conductor across two layers of the substrate, an outer coil formed by winding a conductor across two layers of the substrate and formed outside the outermost circumference of the inner coil, and a power supply substrate to which the inner coil and outer coil are independently connected. Effect of the Invention

[0007] According to the induction heating cooker of the present disclosure, the inner coil and the outer coil are independently connected to the power supply board. Therefore, the induction heating cooker can drive the inner coil and the outer coil independently, thereby suppressing uneven heating. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view of an induction heating cooker according to a first embodiment. [Diagram 2] FIG. 2 is a diagram for illustrating a configuration inside a main body case of the induction heating cooker according to the first embodiment. [Diagram 3] FIG. 2 is a schematic diagram showing an internal configuration of the induction heating cooker according to the first embodiment. [Figure 4] FIG. 3 is a diagram for explaining the positional relationship between the induction heating unit and a top plate according to the first embodiment. [Diagram 5] FIG. 2 is a diagram for explaining the configuration of the induction heating unit according to the first embodiment. [Figure 6] FIG. 2 is a diagram showing a substrate according to the first embodiment as viewed from above. [Figure 7] FIG. 2 is a bottom view of the substrate according to the first embodiment. [Figure 8] 3A and 3B are diagrams showing an inner connection terminal according to the first embodiment. [Figure 9] 5A to 5C are diagrams for explaining a method of connecting an inner connection terminal and a lead wire according to the first embodiment. [Figure 10] FIG. 2 is a view of the substrate according to the first embodiment as viewed from the right. [Figure 11]FIG. 2 is a diagram for explaining the structure of the substrate according to the first embodiment. [Figure 12] FIG. 2 is a diagram showing an upper layer of a substrate according to the first embodiment. [Figure 13] FIG. 4 is a diagram showing a middle layer of the substrate according to the first embodiment. [Figure 14] FIG. 3 is a diagram showing a lower layer of a substrate according to the first embodiment. [Figure 15] 2 is a diagram for explaining a power supply system by a power supply board 20. FIG. [Figure 16] FIG. 11 is a top view of a substrate according to a second embodiment. [Figure 17] FIG. 11 is a bottom view of the substrate according to the second embodiment. [Figure 18] FIG. 11 is a view of the substrate according to the second embodiment as viewed from the right. [Figure 19] FIG. 11 is a diagram showing an upper layer of a substrate according to a second embodiment. [Figure 20] FIG. 11 is a diagram showing a middle layer of a substrate according to a second embodiment. [Figure 21] FIG. 11 is a diagram showing a lower layer of a substrate according to a second embodiment. [Figure 22] FIG. 11 is a top view of a substrate according to a third embodiment. [Diagram 23] FIG. 11 is a bottom view of the substrate according to the third embodiment. [Figure 24] FIG. 11 is a view of the substrate according to the third embodiment as viewed from the right. [Diagram 25] FIG. 11 is a diagram showing an upper layer of a substrate according to a third embodiment. [Figure 26] FIG. 11 is a diagram showing a middle layer of a substrate according to a third embodiment. [Figure 27] FIG. 11 is a diagram showing a lower layer of a substrate according to a third embodiment. [Figure 28] 2 is a diagram for explaining a power supply system by a power supply board 20. FIG. [Figure 29] FIG. 11 is a top view of a substrate according to a fourth embodiment. [Diagram 30] FIG. 11 is a bottom view of the substrate according to the fourth embodiment. [Diagram 31]FIG. 11 is a cross-sectional view showing a substrate and ferrite according to a fourth embodiment. [Diagram 32] FIG. 11 is a cross-sectional view showing a substrate and ferrite according to a fourth embodiment. [Diagram 33] 13 is a diagram showing a substrate and a jig according to a fourth embodiment. FIG. [Diagram 34] FIG. 13 is a diagram showing a substrate set in a jig according to a fourth embodiment. [Diagram 35] FIG. 13 is a diagram showing a substrate set in a jig according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Embodiment 1 FIG. 1 is a perspective view of an induction heating cooker 1 according to the first embodiment. As shown in FIG. 1, the induction heating cooker 1 according to the first embodiment is a cooking cooker that uses electromagnetic induction to heat a cooking container and an object to be heated (food to be cooked), which are heating targets. A main body case 2 of the induction heating cooker 1 houses an appliance that performs cooking. In addition, in each of the following figures, arrows indicating appropriate directions are shown. The X direction is the right direction when the induction heating cooker 1 is installed. The Y direction is the upward direction when the induction heating cooker 1 is installed. The Z direction is the forward direction when the induction heating cooker 1 is installed.

[0010] The top plate 3, which serves as a baking tray, is placed on top of the main body case 2, and a metal cooking container containing an object to be heated is placed on it. The top plate 3 is made of, for example, crystallized glass that transmits infrared rays. The top plate 3 in the first embodiment corresponds to the induction heating unit 10 described below, and has two heating areas 4 that are regions where the cooking container and the object to be heated (hereinafter, these are referred to as the object to be heated) placed on the surface of the top plate 3 can be induction heated. The boundaries of the heating areas 4 that can be heated are indicated to the user by a circular pattern printed on the back surface of the top plate 3.

[0011] Moreover, the induction heating cooker 1 in the first embodiment has an operation display panel 7 on the upper front. The operation display panel 7 accepts operations for setting various cooking conditions and displays information indicating the setting values ​​of the cooking conditions and abnormalities. Furthermore, the induction heating cooker 1 in the first embodiment has a grill cooker 5 on the lower left side when viewed from the front. The grill cooker 5 is installed on the left side of the front part of the induction heating cooker 1, and has a grill door 6 for opening and closing a grill chamber 5a (see FIG. 3).

[0012] Fig. 2 is a diagram for explaining the configuration inside the main body case 2 of the induction heating cooker 1 of the embodiment 1. Fig. 2 shows the main body case 2 with the top plate 3 removed. The main body case 2 of the induction heating cooker 1 has an air intake port 8 at the rear for taking in air from the outside to be sent to the grill chamber 5a of the grill cooker 5. The main body case 2 also has an exhaust port 9 for discharging smoke generated from the heated object in the grill chamber 5a together with the air.

[0013] Moreover, the induction heating cooker 1 in the first embodiment has two induction heating units 10. The induction heating units 10 have a coil, which will be described later, and inductively heat an object to be heated placed on the heating area 4 of the top plate 3. Here, the number of induction heating units 10 included in the induction heating cooker 1 is not limited to two.

[0014] Fig. 3 is a schematic diagram showing the internal configuration of the induction heating cooker 1 according to the embodiment 1. Fig. 3 shows the internal configuration when the induction heating cooker 1 is viewed from the front. A power supply board 20 is installed inside the main body case 2. The power supply board 20 has a circuit formed by fixing components such as semiconductor integrated circuits, resistors, capacitors, and transistors and wiring between the components with copper foil.

[0015] The power supply board 20 supplies power from a commercial power source (not shown) to the induction heating unit 10. Specifically, the power supply board 20 first converts AC power supplied from the commercial power source (not shown) into DC power and rectifies it. The converted DC power is then converted into AC power of a frequency based on the set values ​​of the cooking conditions set via the operation display panel 7, and supplied to the induction heating unit 10 via the lead wires 12. The lead wires 12 are wires made of twisted wires with an insulating coating.

[0016] FIG. 4 is a diagram for explaining the positional relationship between the induction heating unit 10 and the top plate 3 according to the first embodiment. In FIG. 4, the flow of air is indicated by arrows. The induction heating unit 10 is supported from the back side by a spring (not shown) which is an elastic body, and is pressed against the back side of the top plate 3 by the elastic force of the spring and fixed. At this time, as shown in FIG. 4, the induction heating unit 10 is fixed at a position with a certain distance from the top plate 3 by a spacer 11. The spacer 11 is an elastic member such as rubber. Here, although not particularly limited, for example, the distance between the substrate 102 and the top plate 3 is about 3 mm to about 4 mm. By providing a gap between the substrate 102 and the top plate 3, it is possible to suppress the influence of the heat from the heated object on the coil on the substrate 102, which will be described later. Furthermore, the air flowing in from the intake port 8 passes over the coil provided on the substrate 102, thereby cooling the coil. In addition, it is possible to suppress damage to the printing applied to the back side of the top plate 3 by a protrusion such as a screw protruding from the substrate 102. Furthermore, the spacer 11 can stabilize the distance between the top plate 3 and a sensor (not shown) for measuring the temperature of the object to be heated, thereby improving the accuracy of temperature detection.

[0017] Fig. 5 is a diagram for explaining the configuration of induction heating unit 10 according to embodiment 1. Fig. 5 is an exploded view of induction heating unit 10. Induction heating unit 10 in embodiment 1 has magnetic shielding member 101, substrate 102, ferrite 103, holding member 104, and fixing screw 105.

[0018] The magnetic shielding member 101 is a plate-shaped member made of non-magnetic metal that prevents the magnetism generated in the inner coil 30 and the outer coil 40 (see FIG. 6) from leaking outside the heating area 4. The magnetic shielding member 101 forms the outer shell of the induction heating unit 10, and has a shape that exposes the inner coil 30 and the outer coil 40. The magnetic shielding member 101 also sandwiches the holding member 104 and the substrate 102, suppressing warping of the substrate 102. Note that the magnetic shielding member 101 is not a member that necessarily needs to be attached.

[0019] The substrate 102 is a printed circuit board on which the inner coil 30 and the outer coil 40 (see FIG. 6) formed by printing are provided. The substrate 102 is made of an insulating material. The substrate 102 is heat resistant since it receives radiant heat from the object to be heated. The inner coil 30 and the outer coil 40 may be protected by applying a solder resist to the substrate 102. In the following description, the surface of the substrate 102, which is a plate-shaped member, facing upward is referred to as the front surface, and the surface opposite the front surface is referred to as the back surface, based on the state in which the induction heating cooker 1 is installed.

[0020] The appearance of the substrate 102, the inner coil 30, and the outer coil 40 will be briefly described with reference to Figs. 6 to 10. Fig. 6 is a view of the substrate 102 according to the first embodiment as viewed from above. Fig. 7 is a view of the substrate 102 according to the first embodiment as viewed from below. As shown in Fig. 6, the substrate 102 is provided with the inner coil 30 and the outer coil 40. The inner coil 30 and the outer coil 40 are thin-film conductors such as copper foil, and are wound in a spiral shape around the substrate 102. Since the inner coil 30 and the outer coil 40 are formed by printing, no jig for winding copper wire is required during manufacturing, and the coil shape that can be manufactured has a high degree of freedom. The inner coil 30 and the outer coil 40 generate a magnetic field by receiving power from the power supply substrate 20 via the lead wire 12, and form an eddy current by electromagnetic induction. The inner coil 30 is disposed in the center of the surface of the substrate 102. The outer coil 40 is formed concentrically with the inner coil 30. The innermost periphery of the outer coil 40 is disposed outside the outermost periphery of the inner coil 30 on the surface of the substrate 102 .

[0021] As shown in Fig. 7, connection parts 50 to 52 are provided on the back surface of the substrate 102. The connection part 50 is made of a thin film conductor such as copper foil. The connection part 50 is electrically connected to the inner coil 30, as will be described in detail later. An inner connection terminal 300 to which the lead wire 12 is connected is attached to the connection part 50 by soldering or the like. The inner connection terminal 300 is made of metal, and is an input terminal that connects between the lead wire 12 and the connection part 50 and passes electricity from the power supply substrate 20 to the inner coil 30.

[0022] Here, a method of connecting the inner connection terminal 300 and the lead wire 12 will be described with reference to Figs. 8 and 9. Fig. 8 is a diagram showing the inner connection terminal 300 according to the first embodiment. Fig. 9 is a diagram for explaining a method of connecting the inner connection terminal 300 and the lead wire 12 according to the first embodiment. As shown in Fig. 8, the inner connection terminal 300 has a screw hole 300a formed in the center. As shown in Fig. 9, the tab terminal is fixed to the inner connection terminal 300 by tightening a terminal screw 12b into the inner connection terminal 300 and a screw hole (not shown) of a terminal portion 12a connected to the end of the lead wire 12. As a result, the lead wire 12 and the inner connection terminal 300 are electrically connected. Accordingly, the power supply board 20 and the inner coil 30 are electrically connected to each other.

[0023] Returning to FIG. 7, the connection portion 51 is made of a thin film conductor such as copper foil. The connection portion 51 is electrically connected to the outer coil 40, as will be described later in detail. An outer connection terminal 400 to which the lead wire 12 is connected is attached to the connection portion 51 by soldering or the like. The outer connection terminal 400 is made of metal and is an input terminal for connecting between the lead wire 12 and the connection portion 51 and passing electricity from the power supply board 20 to the outer coil 40. The configuration of the outer connection terminal 400 and the method of connecting the outer connection terminal 400 and the lead wire 12 are similar to those of the inner connection terminal 300, and therefore will not be described here. In this way, the inner coil 30 and the outer coil 40 are independently connected to the power supply board 20.

[0024] The connection portion 52 is made of a thin film conductor such as copper foil. The connection portion 52 is electrically connected to the inner coil 30 and the outer coil 40, as will be described later in detail. A common connection terminal 500 to which the lead wire 12 is connected is attached to the connection portion 52 by solder or the like. The common connection terminal 500 is made of metal and connects between the lead wire 12 and the connection portion 52 to pass electricity from the inner coil 30 and the outer coil 40 to the power supply board 20, and is a terminal shared by the inner coil 30 and the outer coil 40. The configuration of the common connection terminal 500 and the method of connecting the common connection terminal 500 to the lead wire 12 are similar to those of the inner connection terminal 300 and the outer connection terminal 400, and therefore will not be described here.

[0025] FIG. 10 is a view of the substrate 102 according to the first embodiment as viewed from the right. As shown in FIG. 7 and FIG. 10, the inner connection terminal 300, the outer connection terminal 400, and the common connection terminal 500 are arranged side by side along the same side of the substrate 102. By arranging the inner connection terminal 300, the outer connection terminal 400, and the common connection terminal 500 side by side, the connection work of the lead wire 12 can be efficiently performed. In addition, when the outer coil 40 provided on the front surface is projected onto the back surface, the inner connection terminal 300, the outer connection terminal 400, and the common connection terminal 500 are all located outside the outermost circumference of the outer coil 40. This makes it possible to connect the power supply substrate 20 to the inner connection terminal 300, the outer connection terminal 400, and the common connection terminal 500 without drawing the lead wire 12 below the inner coil 30 and the outer coil 40. Therefore, the cooling air can be efficiently applied to the inner coil 30 and the outer coil 40.

[0026] Returning to FIG. 5, the ferrite 103 is a magnetic material that guides magnetic flux due to magnetism generated in the inner coil 30 and the outer coil 40 to an object to be heated located above the induction heating unit 10 via the top plate 3. The ferrite 103 also suppresses magnetic flux leakage downward from the inner coil 30 and the outer coil 40. The ferrite 103 suppresses magnetic flux leakage, thereby preventing various boards and control devices (not shown) from malfunctioning due to magnetism. In the first embodiment, eight ferrites 103 are provided such that their longitudinal directions are aligned with the radial direction of the board 102.

[0027] The holding member 104 is a member that holds the substrate 102 and the ferrite 103 sandwiched between the substrate 102. The holding member 104 is fixed to the substrate 102 by a fixing screw 105, and suppresses warping of the substrate 102 due to heat.

[0028] In addition, the inner connection terminal 300, the outer connection terminal 400, and the common connection terminal 500 are exposed to the lower part of the induction heating unit 10 through through holes (not shown) formed in the holding member 104, making it possible to connect the lead wire 12.

[0029] Fixing screws 105 fix substrate 102, holding member 104, and magnetic shielding member 101. Fixing substrate 102, holding member 104, and magnetic shielding member 101 together by fastening with fixing screws 105 eliminates the need for adhesive to fix substrate 102 when manufacturing induction heating unit 10, facilitating disassembly, etc. Here, fixing screws 105 are made of a non-magnetic material.

[0030] Here, the inner coil 30 and the outer coil 40, as well as the conductor patterns of the connection parts for connecting them to the respective connection terminals, will be described in detail with reference to Figs. 11 to 14. Fig. 11 is a diagram for explaining the structure of the substrate 102 according to the first embodiment. Fig. 11 shows a cross section of the substrate 102 in the vertical direction. As shown in Fig. 11, the substrate 102 has a first substrate 102a and a second substrate 102b provided below the first substrate 102a. The first substrate 102a and the second substrate 102b are non-conductive insulating layers of the substrate 102, which is a multi-layer substrate. In addition, the conductor layer formed on the surface of the first substrate 102a is referred to as the upper layer 111, the conductor layer formed on the back surface of the second substrate 102b is referred to as the lower layer 113, and the conductor layer formed between the first substrate 102a and the second substrate 102b is referred to as the middle layer 112. The conductor layer refers to the entire conductor pattern formed on one side of the insulating layer. As shown in FIG. 11, the inner coil 30 is formed across the upper layer 111 and the middle layer 112. In addition, the connection parts 50 and 52 for connecting the inner coil 30 to each connection terminal are formed in the lower layer 113. Although not shown, the outer coil 40 is similar to the inner coil 30. That is, the outer coil 40 is also formed across the upper layer 111 and the middle layer 112. In addition, the connection parts 51 and 52 for connecting the outer coil 40 to each connection terminal are formed in the lower layer 113. In the first embodiment, the upper layer 111 corresponds to the "first layer" of the present disclosure, and the middle layer 112 corresponds to the "second layer" of the present disclosure.

[0031] The inner coil 30 and the outer coil 40 of each layer are connected to the connection portion by vias. A via is an opening that penetrates the substrate 102, and the portion surrounding the opening is plated with metal. Vias V1 to V3 shown in FIG. 11 indicate types of vias. Via V1 that penetrates the first substrate 102a and the second substrate 102b electrically connects the conductor of the upper layer 111 to the conductor of the lower layer 113. Via V2 that penetrates only the first substrate 102a electrically connects the conductor of the upper layer 111 to the conductor of the middle layer 112. Via V3 that penetrates only the second substrate 102b electrically connects the conductor of the middle layer 112 to the conductor of the lower layer 113.

[0032] Fig. 12 is a diagram showing an upper layer 111 of substrate 102 according to embodiment 1. Fig. 13 is a diagram showing a middle layer 112 of substrate 102 according to embodiment 1. Fig. 14 is a diagram showing a lower layer 113 of substrate 102 according to embodiment 1. Figs. 12 to 14 all show diagrams of substrate 102 as viewed from above. The configuration formed in each layer and the electrical connections therebetween will be described below.

[0033] First, the configuration formed in each layer in order from the upper layer 111 will be described. As shown in FIG. 12, the first coil 31, which is a part of the inner coil 30, is formed in the upper layer 111 by winding a thin film conductor. The first coil 31 is wound from the via 311 to the via 312. The via 311 is one of the vias V1 that connect the upper layer 111 and the lower layer 113. The via 312 is one of the vias V2 that connect the upper layer 111 and the middle layer 112. In addition, the third coil 41, which is a part of the outer coil 40, is formed in the upper layer 111 by winding a thin film conductor. The third coil 41 is wound from the via 411 to the via 412. The via 411 is one of the vias V1 that connect the upper layer 111 and the lower layer 113. The via 412 is one of the vias V2 that connect the upper layer 111 and the middle layer 112.

[0034] As shown in FIG. 13, the second coil 32, which is a part of the inner coil 30, is formed on the middle layer 112 by winding a thin-film conductor. The second coil 32 is wound from the via 312 to the via 313. The via 313 is one of the vias V3 that connect the middle layer 112 and the lower layer 113. In addition, the fourth coil 42, which is a part of the outer coil 40, is formed on the middle layer 112 by winding a thin-film conductor. The fourth coil 42 is wound from the via 412 to the via 413. The via 413 is one of the vias V3 that connect the middle layer 112 and the lower layer 113.

[0035] 14, connection portions 50 to 52 are formed on the lower layer 113. The connection portion 50 is elongated in the front-rear direction and connects the inner connection terminal 300 and the via 311 described above. The connection portion 51 is substantially rectangular and connects the inner connection terminal 300 and the via 411 described above. The connection portion 52 is elongated in the front-rear direction and connects the common connection terminal 500 and the vias 313 and 413 described above.

[0036] Next, the electrical connection of the components formed in each layer will be described along the flow of electricity. Note that in parentheses, it is indicated which conductor layer each conductor constitutes. Regarding the inner coil 30, the power supplied from the power supply board 20 flows in the order of the inner connection terminal 300, the connection portion 50 (lower layer 113), the via 311, the first coil 31 (upper layer 111), the via 312, the second coil 32 (middle layer 112), the via 313, the connection portion 52 (lower layer 113), and the common connection terminal 500. Regarding the outer coil 40, the power supplied from the power supply board 20 flows in the order of the outer connection terminal 400, the connection portion 51 (lower layer 113), the via 411, the third coil 41 (upper layer 111), the via 412, the fourth coil 42 (middle layer 112), the via 413, the connection portion 52 (lower layer 113), and the common connection terminal 500.

[0037] FIG. 15 is a diagram for explaining the system of power supply by the power supply board 20. As shown in FIG. 15, the inner coil 30 and the outer coil 40 are individually connected to the power supply board 20 by the lead wire 12, and power is individually supplied to them. Therefore, the induction heating cooker 1 can drive one of the inner coil 30 and the outer coil 40 and stop the other. For example, when the object to be heated is small, it may be heated only by the inner coil 30, and when the object to be heated is large, it may be heated only by the inner coil 30 and the outer coil 40, so that the object to be heated is heated uniformly. Alternatively, the induction heating cooker 1 can drive one of them at high frequency and drive the other at low frequency. In this way, the induction heating cooker 1 can drive the inner coil 30 and the outer coil 40 independently.

[0038] As described above, according to the induction heating cooker 1 of the first embodiment, the inner coil 30 and the outer coil 40 are independently connected to the power supply board 20. Therefore, the induction heating cooker 1 can independently drive the inner coil 30 and the outer coil 40. Therefore, the induction heating cooker 1 can suppress uneven heating.

[0039] Embodiment 2 The induction heating cooker 1 of the embodiment 2 differs from the embodiment 1 in the conductor patterns of the inner coil 30A and the outer coil 40A. In the following, the differences from the embodiment 1 will be described, and a description of the commonalities will be omitted.

[0040] First, the appearance of the substrate 102, the inner coil 30A, and the outer coil 40A according to the second embodiment will be briefly described with reference to Figs. 16 to 18. Fig. 16 is a top view of the substrate 102 according to the second embodiment. Fig. 17 is a bottom view of the substrate 102 according to the second embodiment. As shown in Fig. 16, the inner coil 30A and the outer coil 40A are provided on the substrate 102.

[0041] 17, the inner coil 30A, the outer coil 40A, and connection parts 53 to 55 are provided on the back surface of the substrate 102. The connection part 53 is made of a thin film conductor such as copper foil. The connection part 53 is electrically connected to the inner coil 30A, as will be described in detail later. Furthermore, an inner connection terminal 300 to which the lead wire 12 is connected is attached to the connection part 53 by soldering or the like.

[0042] The connection portion 54 is made of a thin film conductor such as copper foil. The connection portion 54 is electrically connected to the outer coil 40A, as will be described in detail later. In addition, an outer connection terminal 400 to which the lead wire 12 is connected is attached to the connection portion 54 by soldering or the like.

[0043] The connection portion 55 is made of a thin film conductor such as copper foil. The connection portion 55 is electrically connected to the outer coil 40A and the inner coil 30A, as will be described in detail later. A common connection terminal 500 to which the lead wire 12 is connected is attached to the connection portion 55 by solder or the like.

[0044] Fig. 18 is a right view of the substrate 102 according to embodiment 2. As shown in Fig. 17 and Fig. 18, the inner connection terminal 300, the outer connection terminal 400, and the common connection terminal 500 are arranged side by side along the same side of the substrate 102. Moreover, the inner connection terminal 300, the outer connection terminal 400, and the common connection terminal 500 are all located outside the outermost periphery of the outer coil 40A.

[0045] Here, the inner coil 30A, the outer coil 40A, and the conductor patterns of the connection parts for connecting them to the respective connection terminals will be described in detail with reference to Figs. 19 to 21. Fig. 19 is a diagram showing an upper layer 111 of the substrate 102 according to the second embodiment. Fig. 20 is a diagram showing a middle layer 112 of the substrate 102 according to the second embodiment. Fig. 21 is a diagram showing a lower layer 113 of the substrate 102 according to the second embodiment. Figs. 19 to 21 all show diagrams of the substrate 102 as viewed from above. The configuration formed in each layer and their electrical connections will be described below.

[0046] First, the configuration formed in each layer in order from the upper layer 111 will be described. As shown in FIG. 19, the first coil 31A, which is a part of the inner coil 30A, is formed in the upper layer 111 by winding a thin film conductor. The first coil 31A is wound from the via 322 to the via 323. The via 322 is one of the vias V2 that connect the upper layer 111 and the middle layer 112. The via 323 is one of the vias V1 that connect the upper layer 111 and the lower layer 113. In addition, the third coil 41A, which is a part of the outer coil 40A, is formed in the upper layer 111 by winding a thin film conductor. The third coil 41A is wound from the via 421 to the via 422. The via 421 is one of the vias V1 that connect the upper layer 111 and the lower layer 113. The via 422 is one of the vias V1 that connect the upper layer 111 and the lower layer 113.

[0047] As shown in FIG. 20, the middle layer 112 has connection parts 53a and 53b. The connection part 53a is long in the front-rear direction and connects the via 321 and the via 322. The via 321 is one of the vias V3 that connect the middle layer 112 and the lower layer 113. The connection part 53b is long in the front-rear direction and connects the via 324 and the via 325. The via 324 is one of the vias V3 that connect the middle layer 112 and the lower layer 113. The via 325 is one of the vias V3 that connect the middle layer 112 and the lower layer 113.

[0048] As shown in FIG. 21, the second coil 32A, which is a part of the inner coil 30A, is formed on the lower layer 113 by winding a thin-film conductor. The second coil 32A is wound from the via 323 to the via 324. The fourth coil 42A, which is a part of the outer coil 40A, is formed on the middle layer 112 by winding a thin-film conductor. The fourth coil 42A is wound from the via 412 to the connection portion 55. The lower layer 113 is further formed with the connection portions 53 to 55. The connection portion 53 is substantially rectangular in shape and connects the inner connection terminal 300 and the via 321. The connection portion 54 is substantially rectangular in shape and connects the outer connection terminal 400 and the via 421. The connection portion 55 is elongated in the left-right direction and connects the common connection terminal 500, the outer coil 40A, and the via 325.

[0049] Next, the electrical connections of the components formed on each layer will be described along the flow of electricity. Note that the parentheses indicate which conductor layer each conductor constitutes. Regarding the inner coil 30A, the power supplied from the power supply board 20 flows in the order of the inner connection terminal 300, the connection portion 53 (lower layer 113), the via 321, the connection portion 53a (middle layer 112), the via 322, the first coil 31A (upper layer 111), the via 323, the second coil 32A (lower layer 113), the via 324, the connection portion 53b (middle layer 112), the via 325, the connection portion 55 (lower layer 113), and the common connection terminal 500. With regard to the outer coil 40A, the power supplied from the power supply board 20 flows in the following order: outer connection terminal 400, connection portion 54 (lower layer 113), via 421, third coil 41A (upper layer 111), via 422, fourth coil 42A (lower layer 113), connection portion 55 (lower layer 113), and common connection terminal 500.

[0050] In the second embodiment, the inner coil 30A and the outer coil 40A are also individually connected to the power supply board 20 by the lead wires 12, and are individually supplied with power. Therefore, the induction heating cooker 1 can drive one of the inner coil 30A and the outer coil 40A and stop the other. Alternatively, the induction heating cooker 1 can drive one at high frequency and the other at low frequency. In this way, the induction heating cooker 1 can drive the inner coil 30A and the outer coil 40A independently.

[0051] As described above, according to the induction heating cooker 1 of the second embodiment, similarly to the first embodiment, the inner coil 30A and the outer coil 40A are independently connected to the power supply board 20. Therefore, the induction heating cooker 1 can independently drive the inner coil 30A and the outer coil 40A, thereby suppressing uneven heating.

[0052] According to the second embodiment, the inner coil 30A and the outer coil 40A are provided on the upper layer 111 and the lower layer 113, i.e., on the front surface of the first substrate 102a and the back surface of the second substrate 102b. Therefore, the inner coil 30A and the outer coil 40A, which generate a large amount of heat, can be cooled more efficiently than when the inner coil 30A and the outer coil 40A are provided on the middle layer 112.

[0053] In addition, the inner coil 30A and the outer coil 40A in the second embodiment are formed across the upper layer 111 and the lower layer 113. Therefore, in the second embodiment, the upper layer 111 corresponds to the "first layer" in the present disclosure, and the lower layer 113 corresponds to the "second layer" in the present disclosure.

[0054] Embodiment 3 The induction heating cooker 1 of the third embodiment differs from the first embodiment in that it has an inner coil 30, a rear coil 60, a front coil 70, a left coil 80, and a right coil 90. In the following, the differences from the first embodiment will be described, and the description of the commonalities will be omitted.

[0055] First, the appearance of the substrate 102 according to the third embodiment, and the inner coil 30, the rear coil 60, the front coil 70, the left coil 80, and the right coil 90 will be briefly described with reference to Figs. 22 to 24. Fig. 22 is a view of the substrate 102 according to the third embodiment seen from above. Fig. 23 is a view of the substrate 102 according to the third embodiment seen from below. As shown in Fig. 22, the substrate 102 is provided with the inner coil 30, the rear coil 60, the front coil 70, the left coil 80, and the right coil 90. The inner coil 30 is provided at the same position as in the first embodiment, and has the same conductor pattern. The rear coil 60 is provided behind the inner coil 30. The front coil 70 is provided in front of the inner coil 30. The left coil 80 is provided to the left of the inner coil 30. The right coil 90 is provided to the right of the inner coil 30. The rear coil 60, the front coil 70, the left coil 80, and the right coil 90 are all provided outside the substrate 102 relative to the outermost periphery of the inner coil 30. Therefore, the rear coil 60, the front coil 70, the left coil 80, and the right coil 90 are all forms of the "outer coil 40" of the present disclosure. In other words, in the third embodiment, four outer coils 40 are provided.

[0056] As shown in FIG. 23, the rear surface of the substrate 102 is provided with a connection portion 50 and connection portions 56 to 58. The connection portion 50 has the same configuration as that of the first embodiment. The connection portion 56 is made of a thin film conductor such as copper foil. The connection portion 56 is electrically connected to the rear coil 60 and the front coil 70, as will be described later in detail. In addition, the front-rear connection terminal 600 to which the lead wire 12 is connected is attached to the connection portion 56 by soldering or the like. The front-rear connection terminal 600 is made of metal and is an input terminal for connecting between the lead wire 12 and the connection portion 56 and passing electricity from the power supply substrate 20 to the rear coil 60 and the front coil 70. The configuration of the front-rear connection terminal 600 and the method of connecting the front-rear connection terminal 600 and the lead wire 12 are the same as those of the inner connection terminal 300 of the first embodiment, and therefore will not be described.

[0057] The connection portion 57, which will be described in detail later, is electrically connected to the left coil 80 and the right coil 90. Furthermore, a left / right connection terminal 800 to which the lead wire 12 is connected is attached to the connection portion 57 by soldering or the like. The left / right connection terminal 800 is made of metal and is an input terminal that connects between the lead wire 12 and the connection portion 57 and passes electricity from the power supply board 20 to the left coil 80 and the right coil 90. The configuration of the left / right connection terminal 800 and the method of connecting the left / right connection terminal 800 and the lead wire 12 are similar to those of the inner connection terminal 300 in the first embodiment, and therefore will not be described here.

[0058] The connection portion 58 is made of a thin film conductor such as copper foil. The connection portion 58 is electrically connected to the inner coil 30, the rear coil 60, the front coil 70, the left coil 80, and the right coil 90, as will be described later in detail. A common connection terminal 500 to which the lead wire 12 is connected is attached to the connection portion 58 by solder or the like. The common connection terminal 500 is made of metal and connects between the lead wire 12 and the connection portion 58 to pass electricity from the inner coil 30, the rear coil 60, the front coil 70, the left coil 80, and the right coil 90 to the power supply board 20. The common connection terminal 500 is a terminal shared by the inner coil 30, the rear coil 60, the front coil 70, the left coil 80, and the right coil 90. The configuration of the common connection terminal 500 and the method of connecting the common connection terminal 500 to the lead wire 12 are the same as those of the inner connection terminal 300 in the first embodiment, and therefore will not be described.

[0059] Fig. 24 is a view of the substrate 102 according to the third embodiment as viewed from the right. As shown in Figs. 23 and 24, the inner connection terminal 300, the front and rear connection terminal 600, the left and right connection terminal 800, and the common connection terminal 500 are arranged side by side along the same side of the substrate 102. When the rear coil 60, the front coil 70, the left coil 80, and the right coil 90 provided on the front surface are projected onto the back surface, the inner connection terminal 300, the front and rear connection terminal 600, the left and right connection terminal 800, and the common connection terminal 500 are all located outside the outermost circumference of the rear coil 60, the front coil 70, the left coil 80, and the right coil 90.

[0060] Here, the inner coil 30, the rear coil 60, the front coil 70, the left coil 80, and the right coil 90, as well as the conductor patterns of the connection parts for connecting them to the respective connection terminals, will be described in detail with reference to Figs. 25 to 27. Fig. 25 is a diagram showing the upper layer 111 of the substrate 102 according to the third embodiment. Fig. 26 is a diagram showing the middle layer 112 of the substrate 102 according to the third embodiment. Fig. 27 is a diagram showing the lower layer 113 of the substrate 102 according to the third embodiment. Figs. 25 to 27 all show diagrams of the substrate 102 as viewed from above. The following describes the configuration formed in each layer and their electrical connections. The inner coil 30 is the same as in the first embodiment, and therefore will not be described.

[0061] First, the configuration formed in each layer in order from the upper layer 111 will be described. As shown in FIG. 25, the fifth coil 61, which is a part of the rear coil 60, is formed in the upper layer 111 by winding a thin film conductor. The fifth coil 61 is wound from the via 611 to the via 612. The via 611 is one of the vias V1 that connect the upper layer 111 and the lower layer 113. The via 612 is one of the vias V2 that connect the upper layer 111 and the middle layer 112. In addition, the seventh coil 71, which is a part of the front coil 70, is formed in the upper layer 111 by winding a thin film conductor. The seventh coil 71 is wound from the via 711 to the via 712. The via 711 is one of the vias V1 that connect the upper layer 111 and the lower layer 113. The via 712 is one of the vias V2 that connect the upper layer 111 and the middle layer 112. In addition, in the upper layer 111, a ninth coil 81, which is a part of the left coil 80, is formed by winding a thin film conductor. The ninth coil 81 is wound from a via 811 to a via 812. The via 811 is one of the vias V1 that connect the upper layer 111 and the lower layer 113. The via 812 is one of the vias V2 that connect the upper layer 111 and the middle layer 112. In the upper layer 111, an eleventh coil 91, which is a part of the right coil 90, is formed by winding a thin film conductor. The eleventh coil 91 is wound from a via 911 to a via 912. The via 911 is one of the vias V1 that connect the upper layer 111 and the lower layer 113. The via 912 is one of the vias V2 that connect the upper layer 111 and the middle layer 112.

[0062] As shown in FIG. 26, the sixth coil 62, which is a part of the rear coil 60, is formed in the middle layer 112 by winding a thin-film conductor. The sixth coil 62 is wound from the via 612 toward the via 613. The via 613 is one of the vias V3 that connect the middle layer 112 and the lower layer 113. The eighth coil 72, which is a part of the front coil 70, is formed in the middle layer 112 by winding a thin-film conductor. The eighth coil 72 is wound from the via 712 toward the via 713. The via 713 is one of the vias V3 that connect the middle layer 112 and the lower layer 113. The tenth coil 82, which is a part of the left coil 80, is formed in the middle layer 112 by winding a thin-film conductor. The tenth coil 82 is wound from the via 812 toward the via 813. The via 813 is one of the vias V3 that connect the middle layer 112 and the lower layer 113. A twelfth coil 92, which is a part of the right coil 90, is formed by winding a thin film conductor on the middle layer 112. The twelfth coil 92 is wound from a via 912 to a via 913. The via 913 is one of the vias V3 that connect the middle layer 112 and the lower layer 113.

[0063] As shown in Fig. 27, the lower layer 113 has connection parts 56 to 58 formed thereon. The connection part 56 is elongated in the front-rear direction and connects the inner connection terminal 300, the via 611, and the via 711. The connection part 57 extends from the rear of the substrate 102 to the left via the right and front and connects the left and right connection terminals 800, the via 811, and the via 911. The connection part 58 extends from the center of the substrate 102 to the right via the rear, left, and front and connects the common connection terminal 500, the via 313, the via 613, the via 713, the via 813, and the via 813.

[0064] Next, the electrical connections of the components formed in each layer will be described along the flow of electricity. Note that parentheses indicate which conductor layer each conductor constitutes. The inner coil 30 is the same as in the first embodiment, so a description thereof will be omitted. As for the rear coil 60, the power supplied from the power supply board 20 flows in the order of the front and rear connection terminal 600, the connection portion 56 (lower layer 113), the via 611, the fifth coil 61 (upper layer 111), the via 612, the sixth coil 62 (middle layer 112), the via 613, the connection portion 58 (lower layer 113), and the common connection terminal 500. With regard to the front coil 70, the power supplied from the power supply board 20 flows in the following order: front and rear connection terminal 600, connection portion 56 (lower layer 113), via 711, seventh coil 71 (upper layer 111), via 712, eighth coil 72 (middle layer 112), via 713, connection portion 58 (lower layer 113), and common connection terminal 500.

[0065] With respect to the left coil 80, the power supplied from the power supply board 20 flows in the following order: left / right connection terminal 800, connection portion 57 (lower layer 113), via 811, ninth coil 81 (upper layer 111), via 812, tenth coil 82 (middle layer 112), via 813, connection portion 58 (lower layer 113), and common connection terminal 500. With respect to the right coil 90, the power supplied from the power supply board 20 flows in the following order: left / right connection terminal 800, connection portion 57 (lower layer 113), via 911, tenth coil 82 (upper layer 111), via 912, eleventh coil 91 (middle layer 112), via 913, connection portion 58 (lower layer 113), and common connection terminal 500.

[0066] FIG. 28 is a diagram for explaining the system of power supply by the power supply board 20. As shown in FIG. 28, the inner coil 30, the rear coil 60 and the front coil 70, and the left coil 80 and the right coil 90 are individually connected to the power supply board 20 by the lead wires 12, and power is individually supplied to them. Therefore, the induction heating cooker 1 can drive either the inner coil 30, the rear coil 60 and the front coil 70, or the left coil 80 and the right coil 90, and stop the rest. Alternatively, the induction heating cooker 1 can drive either the inner coil 30, the rear coil 60 and the front coil 70, or the left coil 80 and the right coil 90 at high frequency, and drive the rest at low frequency. In this way, the induction heating cooker 1 can independently drive the inner coil 30, the rear coil 60 and the front coil 70, and the left coil 80 and the right coil 90.

[0067] As described above, according to the induction heating cooker 1 of the third embodiment, similarly to the first embodiment, the inner coil 30, the rear coil 60, the front coil 70, the left coil 80, and the right coil 90 are independently connected to the power supply board 20. Therefore, the induction heating cooker 1 can independently drive the inner coil 30, the rear coil 60, the front coil 70, the left coil 80, and the right coil 90, thereby suppressing uneven heating.

[0068] In addition, according to the induction heating cooker 1 of the third embodiment, since it has the rear coil 60, the front coil 70, the left coil 80, and the right coil 90, it is possible to finely adjust the position where the object to be heated is heated. Therefore, it is possible to further suppress the occurrence of uneven heating.

[0069] Embodiment 4 The induction heating cooker 1 of the fourth embodiment differs from the first embodiment in that a slit 120 and a positioning hole 130 are formed in the substrate 102. In the following, the differences from the first embodiment will be described, and a description of the commonalities will be omitted.

[0070] FIG. 29 is a view of the substrate 102 according to the fourth embodiment as viewed from above. FIG. 30 is a view of the substrate 102 according to the fourth embodiment as viewed from below. As shown in FIG. 29 and FIG. 30, the substrate 102 has a plurality of slits 120 and a plurality of positioning holes 130 formed therein. The slits 120 are formed between the inner coil 30 and the outer coil 40, and penetrate the substrate 102 in the vertical direction. The inner coil 30 is surrounded by the plurality of slits 120. The slits 120 surround almost the entire circumference of the inner coil 30, but are not formed in the portion where the inner coil 30 and the outer coil 40 are located, and in the portion where the ferrite 103 is disposed. The positioning holes 130 are formed outside the outermost circumference of the outer coil 40, and penetrate the substrate 102 in the vertical direction. The positioning holes 130 are shaped so that the protrusions 150 of the jig 106 described later are generally fitted into the positioning holes 130.

[0071] 31 and 32 are cross-sectional views showing the substrate 102 and the ferrite 103 according to the fourth embodiment. FIG. 31 shows a cross section of the substrate 102 and the ferrite 103 of FIG. 30 cut along the AA cross section. That is, FIG. 31 is a cross section including the slit 120. FIG. 32 shows a cross section of the substrate 102 and the ferrite 103 of FIG. 30 cut along the BB cross section. That is, FIG. 32 is a cross section including the positioning hole 130. As shown in FIG. 31 and FIG. 32, the ferrite 103 is bonded to the substrate 102 by the silicone 140. Although the details will be described later, the bonding position of the ferrite 103 relative to the substrate 102 is determined by inserting the jig 106 into the end of the slit 120 located on the side of the ferrite 103 and all the positioning holes 130. For this reason, as shown in FIG. 31, the end of the slit 120 is located on both sides of each ferrite 103. As shown in FIG. 32, each ferrite piece 103 has positioning holes 130 formed on both sides thereof.

[0072] Here, a procedure for bonding the ferrite 103 to the substrate 102 will be described with reference to Figs. 33 to 35. Fig. 33 is a diagram showing the substrate 102 and the jig 106 according to the fourth embodiment. As shown in Fig. 33, the dimensions of the bottom surface of the jig 106 are almost the same as the dimensions of the surface of the substrate 102, and the edges are raised from the bottom surface in all four directions. The jig 106 is provided with a plurality of protrusions 150. The protrusions 150 are provided corresponding to the positions at which the ferrite 103 is bonded. Specifically, after the substrate 102 is fitted into the jig 106, the bonding positions of the ferrite 103 are determined such that both sides of the ferrite 103 are sandwiched at two different positions in the radial direction of the substrate 102. For this reason, eight pairs of two protrusions 150 corresponding to the eight ferrites 103 are provided in a ring shape on the jig 106. In Fig. 33, one of the pairs is indicated by a dashed line P1. Further, eight further sets of protrusions 150 are provided on the jig 106 on the outer sides of these eight sets of protrusions 150. In Fig. 33, the set provided on the outer side of P1 is indicated by a dashed line P2.

[0073] 34 and 35 are diagrams showing the substrate 102 set in the jig 106 according to the fourth embodiment. FIG. 34 shows a cross section similar to FIG. 31 in a state where the jig 106 is inserted into the substrate 102. FIG. 35 shows a cross section similar to FIG. 32 in a state where the jig 106 is inserted into the substrate 102. As a first bonding procedure, the substrate 102 is set in the jig 106 so that the surface of the substrate 102 contacts the bottom surface of the jig 106. At this time, as shown in FIG. 34, a plurality of protrusions 150 are inserted into the opposing slits 120. The protrusions 150 inserted into the slits 120 are located at the ends of the slits 120. Also, as shown in FIG. 35, a plurality of protrusions 150 are inserted into the opposing positioning holes 130. As a second bonding procedure, silicone 140 is applied to the position of the substrate 102 where the ferrite 103 is to be bonded. Then, as a third bonding procedure, the ferrite 103 is placed on the silicone 140. As a result, the ferrite 103 is adhered to the rear surface of the substrate 102. Since the slits 120 and the positioning holes 130 are formed at different positions in the radial direction of the substrate 102, the multiple protrusions 150 inserted into the slits 120 and the positioning holes 130 prevent the adhesion position of the ferrite 103 from shifting.

[0074] As described above, according to the induction heating cooker 1 of the fourth embodiment, similarly to the first embodiment, the inner coil 30 and the outer coil 40 are independently connected to the power supply board 20. Therefore, the induction heating cooker 1 can independently drive the inner coil 30 and the outer coil 40, thereby suppressing uneven heating.

[0075] Furthermore, according to the fourth embodiment, slits 120 are formed in substrate 102. This allows air blown from a fan from the back surface to the front surface of substrate 102 to escape easily, improving the cooling efficiency of the front surface of substrate 102.

[0076] Furthermore, according to the fourth embodiment, the substrate 102 is formed with the slit 120 and the positioning hole 130. By inserting the jig 106 into the slit 120 and the positioning hole 130, the attachment position of the ferrite 103 can be determined.

[0077] Various aspects of the present disclosure are summarized below as appendices.

[0078] (Appendix 1) an insulating multi-layer substrate; an inner coil formed by winding a conductor across two layers of the substrate; an outer coil formed by winding a conductor across two layers of the substrate and located outside the outermost circumference of the inner coil; and a power supply board to which the inner coil and the outer coil are independently connected. Induction heating cooker. (Appendix 2) The inner coil is a first coil formed by winding a conductor on a first layer of the substrate; a second coil electrically connected to the first coil and formed by winding a conductor on a second layer of the substrate, The outer coil is a third coil formed by winding a conductor around the first layer and disposed outside an outer periphery of the first coil; a fourth coil formed by winding a conductor around the second layer, the fourth coil being electrically connected to the third coil and formed outside an outer periphery of the third coil. 2. An induction heating cooker as described in appendix 1. (Appendix 3) The substrate is A first substrate; A second substrate provided below the first substrate, the first layer is a layer formed on an upper surface of the first substrate, The second layer is a layer sandwiched between the first substrate and the second substrate. 5. An induction heating cooker as described in appendix 2. (Appendix 4) The substrate is A first substrate; A second substrate provided below the first substrate, the first layer is a layer formed on an upper surface of the first substrate, The second layer is a layer formed on the lower surface of the second substrate. 5. An induction heating cooker as described in appendix 2. (Appendix 5) An inner connection terminal that connects the inner coil to the power supply board is disposed outside the outer periphery of the outer coil. 5. An induction heating cooker according to any one of claims 1 to 4. (Appendix 6) An outer connection terminal that connects the outer coil to the power supply board is disposed outside the outer periphery of the outer coil. 6. An induction heating cooker according to any one of claims 1 to 5. (Appendix 7) The outer coil has four of the outer coils. The outer coils are arranged on all four sides of the inner coil. 7. An induction heating cooker according to any one of claims 1 to 6. (Appendix 8) The substrate is A slit is formed between the inner coil and the outer coil. An induction heating cooker according to any one of appendixes 1 to 7. (Appendix 9) Further comprising ferrite provided on the substrate and guiding magnetic flux toward an object to be heated; The substrate is A positioning hole is formed outside the outer periphery of the outer coil, The ferrite is attached to the substrate at a position determined by a jig inserted into the slit and the positioning hole. 9. The induction heating cooker according to claim 8. [Explanation of symbols]

[0079] 1 induction heating cooker, 2 main body case, 3 top plate, 4 heating area, 5 grill cooker, 5a grill chamber, 6 grill door, 7 operation display panel, 8 air intake, 9 exhaust, 10 induction heating unit, 11 spacer, 12 lead wire, 12a terminal section, 12b terminal screw, 20 power supply board, 30, 30A inner coil, 31, 31A, first coil, 32, 32A second coil, 40, 40A outer coil, 41, 41A third coil, 42, 42A fourth coil, 50 to 52, 53, 53a, 53b, 54, 55, 56, 57, 58 connection section, 60 rear coil, 61 fifth coil, 62 sixth coil, 70 front coil, 71 seventh coil, 72 eighth coil, 80 left coil, 81 ninth coil, 82 10th coil, 90 right coil, 91 11th coil, 92 12th coil, 101 magnetic shielding member, 102 substrate, 102a first substrate, 102b second substrate, 103 ferrite, 104 holding member, 105 fixing screw, 106 jig, 111 upper layer, 112 middle layer, 113 lower layer, 120 slit, 130 positioning hole, 140 silicone, 150 protrusion, 300 inner connection terminal, 300a screw hole, 311-313, 321-325 vias, 400 outer connection terminal, 411-413, 421, 422 vias, 500 common connection terminal, 600 front and rear connection terminals, 611-613 vias, 711-713 vias, 800 left and right connection terminals, 811-813 Via, 911~913 Via, V1~V3 Via.

Claims

1. an insulating multi-layer substrate; an inner coil formed by winding a conductor across two layers of the substrate; an outer coil formed by winding a conductor across two layers of the substrate and located outside the outermost circumference of the inner coil; and a power supply board to which the inner coil and the outer coil are independently connected. Induction heating cooker.

2. The inner coil is a first coil formed by winding a conductor on a first layer of the substrate; a second coil electrically connected to the first coil and formed by winding a conductor on a second layer of the substrate, The outer coil is a third coil formed by winding a conductor around the first layer and disposed outside an outer periphery of the first coil; a fourth coil formed by winding a conductor around the second layer, the fourth coil being electrically connected to the third coil and formed outside an outer periphery of the third coil.

2. The induction heating cooker according to claim 1.

3. The substrate is A first substrate; A second substrate provided below the first substrate, the first layer is a layer formed on an upper surface of the first substrate, The second layer is a layer formed between the first substrate and the second substrate.

3. The induction heating cooker according to claim 2.

4. The substrate is A first substrate; A second substrate provided below the first substrate, the first layer is a layer formed on an upper surface of the first substrate, The second layer is a layer formed on the lower surface of the second substrate.

3. The induction heating cooker according to claim 2.

5. An inner connection terminal that connects the inner coil to the power supply board is disposed outside the outer periphery of the outer coil. The induction heating cooker according to any one of claims 1 to 4.

6. An outer connection terminal that connects the outer coil to the power supply board is disposed outside the outer periphery of the outer coil. The induction heating cooker according to any one of claims 1 to 4.

7. The outer coil includes four of the outer coils. The outer coils are arranged on all four sides of the inner coil. The induction heating cooker according to any one of claims 1 to 4.

8. The substrate is A slit is formed between the inner coil and the outer coil. The induction heating cooker according to any one of claims 1 to 4.

9. The substrate further includes a ferrite that guides magnetic flux toward an object to be heated. The substrate is A positioning hole is formed outside the outer periphery of the outer coil, The ferrite is attached to the substrate at a position determined by a jig inserted into the slit and the positioning hole.

9. The induction heating cooker according to claim 8.

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