Coil case and switching power supply

Abstract

To provide a coil case capable of suppressing solder cracks, and a switching power supply unit.SOLUTION: A coil case concerning the disclosure is a coil case for holding a coil. The coil case has a hole into which a terminal of the coil is inserted, which is soldered to the board and includes a terminal hole portion having a slit formed around the hole. The slit is a gap in the coil case.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present disclosure relates to a coil case and a switching power supply device.

Background Art

[0002] Conventionally, in a power supply device, a coil is housed in a coil case. The coil case has a terminal hole into which a terminal of the coil is inserted. Then, the terminal of the coil is soldered to a substrate through the terminal hole.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the coil case is deformed due to thermal expansion or thermal contraction, pressure is applied to the portion where the terminal of the coil is soldered to the substrate. Therefore, solder cracks may occur, which break the soldering between the terminal of the coil and the substrate.

[0005] An object of the present disclosure is to provide a coil case and a switching power supply device that can suppress solder cracks.

Means for Solving the Problems

[0006] The coil case according to the present disclosure is a coil case that holds a coil, and includes a terminal hole portion that has a hole into which a terminal of the coil is inserted and is soldered to a substrate, and a slit is formed around the hole. The slit is a gap in the coil case.

Effects of the Invention

[0007] According to this disclosure, it is possible to provide a coil case and a switching power supply that can suppress solder cracks. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing an example of the appearance of a coil case according to the first embodiment, viewed from above. [Figure 2] Figure 2 is a perspective view showing an example of the appearance of a coil case according to the first embodiment, viewed from below. [Figure 3] Figure 3 is a perspective view showing an example of the appearance of the planar terminal hole portion according to the first embodiment. [Figure 4] Figure 4 is a perspective view showing an example of the appearance of the edge terminal hole portion according to the first embodiment. [Figure 5] Figure 5 is a cross-sectional view showing an example of a state in which the terminals are soldered to the circuit board. [Figure 6] Figure 6 is a cross-sectional view showing an example of a planar terminal hole according to Modification 1. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described in detail below, with reference to the drawings as appropriate. However, unnecessarily detailed explanations may be omitted. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0010] (First Embodiment) Figure 1 is a perspective view showing an example of the external appearance of the coil case 1 according to the first embodiment, viewed from above. Figure 2 is a perspective view showing an example of the external appearance of the coil case 1 according to the first embodiment, viewed from below. In this embodiment, a Cartesian coordinate system consisting of the X axis, Y axis, and Z axis is defined. The X axis direction is parallel to the longitudinal direction of the coil case 1. The Y axis direction is parallel to the short direction of the coil case 1. The Z axis direction is perpendicular to the X axis direction and the Y axis direction, and is perpendicular to the upper surface 12 of the coil case 1.

[0011] The coil case 1 holds the coil. For example, the coil case 1 is housed in a switching power supply device such as a charger. The switching power supply device includes, for example, a filter circuit, a rectifier circuit, a DC / DC converter, and a smoothing circuit. The filter circuit is a circuit that suppresses noise in the AC power input from an external AC power source. The rectifier circuit is a circuit that rectifies AC power into DC power. The DC / DC converter is a conversion circuit that converts voltage. The smoothing circuit is a circuit that smooths fluctuations in the output voltage. The DC / DC converter also has a coil. For example, the coil of the DC / DC converter is held in the coil case 1.

[0012] The coil case 1 houses multiple coils. More specifically, the coil case 1 comprises a first coil storage section 11a, a second coil storage section 11b, a third coil storage section 11c, a fourth coil storage section 11d, a fifth coil storage section 11e, and a sixth coil storage section 11f. Each of the first coil storage section 11a, the second coil storage section 11b, the third coil storage section 11c, the fourth coil storage section 11d, the fifth coil storage section 11e, and the sixth coil storage section 11f houses one coil. Hereinafter, when the first coil storage section 11a, the second coil storage section 11b, the third coil storage section 11c, the fourth coil storage section 11d, the fifth coil storage section 11e, and the sixth coil storage section 11f are not distinguished, they will be referred to as coil storage section 11.

[0013] Furthermore, the coil case 1 has a first spacing section 20a, a second spacing section 20b, a third spacing section 20c, a fourth spacing section 20d, a fifth spacing section 20e, and a sixth spacing section 20f on its upper surface 12. Hereinafter, when the first spacing section 20a, the second spacing section 20b, the third spacing section 20c, the fourth spacing section 20d, the fifth spacing section 20e, and the sixth spacing section 20f are not distinguished, they will be referred to as the coil housing section 11. More specifically, the coil case 1 has one spacing section 20 in each coil housing section 11 on its upper surface 12. Here, the substrate 2 (see Figure 5) is placed on the upper surface 12 of the coil case 1. The spacing section 20 is a cylindrical protrusion that provides a gap between the upper surface 12 of the coil case 1 and the substrate 2.

[0014] Furthermore, the coil case 1 is provided with a first projection 30a, a second projection 30b, a third projection 30c, and a fourth projection 30d on its upper surface 12. Hereinafter, when the first projection 30a, the second projection 30b, the third projection 30c, and the fourth projection 30d are not distinguished, they will be referred to as the coil housing section 11. The projections 30 are projections located on the upper surface 12. Components are placed on top of the projections 30. This allows additional components to be placed on top of the substrate 2.

[0015] Furthermore, the projection 30 transfers heat from the placed component to the coil. Since the coil generates heat, a heat dissipation component is placed nearby. The coil case 1 can also dissipate heat from the coil. Therefore, the projection 30 can efficiently cool the placed component by transferring heat from the component to the coil.

[0016] Further, the coil case 1 includes first to eighth planar terminal hole portions 40a to 40h in a flat portion of the upper surface 12. Hereinafter, when not distinguishing between the first to eighth planar terminal hole portions 40a to 40h, they are collectively referred to as the planar terminal hole portion 40.

[0017] Furthermore, the coil case 1 includes first to fourth edge terminal hole portions 50a to 50d at an edge portion of the coil case 1. Hereinafter, when not distinguishing between the first to fourth edge terminal hole portions 50a to 50d, they are collectively referred to as the edge terminal hole portion 50.

[0018] The planar terminal hole portion 40 has a through hole 41 into which a terminal 3 formed at an end of a lead wire of a coil stored in the coil storage portion 11 is inserted. Similarly, the edge terminal hole portion 50 has a through hole 51 into which a terminal 3 formed at an end of a lead wire of a coil stored in the coil storage portion 11 is inserted. Here, the lead wire of the coil has two ends. Therefore, two planar terminal hole portions 40 or edge terminal hole portions 50 are arranged in each coil storage portion 11.

[0019] FIG. 3 is a perspective view showing an example of the appearance of the planar terminal hole portion 40 according to the first embodiment. The planar terminal hole portion 40 has a through hole 41 into which a terminal 3 of a coil to be soldered to the substrate 2 is inserted, and a slit 42 is formed around the through hole 41.

[0020] More specifically, the planar terminal hole portion 40 has an insertion portion 43 having a through hole 41 into which a terminal 3 of a coil is inserted, and a support portion 44 that supports the insertion portion 43 in a direction perpendicular to the insertion direction of the terminal 3. And a substantially U-shaped slit 42 is formed around the insertion portion 43 and the support portion 44 of the planar terminal hole portion 40.

[0021] The slit 42 is a gap where a part of the coil case 1 is removed. The slit 42 is formed in a substantially U-shape surrounding the insertion portion 43 and the support portion 44. And the slit 42 is not formed at the end of the support portion 44 on the side that does not support the insertion portion 43.

[0022] The insertion portion 43 has a through hole 41 into which the terminal 3 of the coil is inserted. The insertion portion 43 is formed in a substantially circular shape and has the through hole 41 at substantially the center. The through hole 41 is formed in a funnel shape whose outer diameter narrows as it goes from the upper surface 12 toward the inside of the coil case 1.

[0023] One end of the support portion 44 supports the insertion portion 43, and the other end is fixed to the coil case 1. More specifically, the support portion 44 supports the insertion portion 43 from a direction perpendicular to the longitudinal direction of the coil case 1. In other words, the slit 42 is formed so as to surround the insertion portion 43 and sandwich the support portion 44. Here, the degree of volume change due to thermal expansion or thermal contraction is larger in the longitudinal direction than in the short-side direction of the coil case 1. Therefore, by forming the slit 42 in the longitudinal direction of the coil case 1, the pressure applied to the insertion portion 43 can be suppressed.

[0024] Also, the width of the support portion 44 in the direction perpendicular to the longitudinal direction of the coil case 1 is narrower than that of the insertion portion 43. In other words, the length of the support portion 44 in the X-axis direction is narrower than the diameter of the insertion portion 43 formed in a substantially circular shape. Thus, since the support portion 44 is narrower than the insertion portion 43, it is easily deformed when pressure is applied in the X-axis direction or in the direction in which the X-axis direction and the Z-axis direction are combined. Therefore, the support portion 44 can reduce the pressure applied to the portion where the substrate 2 and the terminal 3 are soldered. Thus, the support portion 44 can suppress solder cracks that break the soldering between the substrate 2 and the terminal 3.

[0025] Furthermore, the length of the support portion 44 in the direction perpendicular to the longitudinal direction of the coil case 1 is longer than the diameter of the insertion portion 43. In other words, the length of the support portion 44 in the Y-axis direction is longer than the diameter of the substantially circular insertion portion 43. Thus, because the support portion 44 is longer than the diameter of the insertion portion 43, it is more likely to flex when pressure is applied in the Z-axis direction. Therefore, the support portion 44 can reduce the pressure applied to the part where the substrate 2 and the terminal 3 are soldered together. Thus, the support portion 44 can suppress solder cracks.

[0026] Figure 4 is a perspective view showing an example of the appearance of the edge terminal hole portion 50 according to the first embodiment. Similar to the planar terminal hole portion 40, the edge terminal hole portion 50 has a through hole 51 into which the terminals 3 of the coil, which are soldered to the substrate 2, are inserted, and a slit 52 is formed around the through hole 51. The planar terminal hole portion 40 and the edge terminal hole portion 50 are examples of terminal holes.

[0027] More specifically, the edge terminal hole portion 50 has an insertion portion 53 having a through hole 51 into which the terminals 3 of the coil are inserted, and a support portion 54 that supports the insertion portion 53 from a direction perpendicular to the insertion direction of the terminals 3. Furthermore, a slit 52 is formed around the insertion portion 53 and the support portion 54 of the edge terminal hole portion 50.

[0028] Here, the edge terminal hole portion 50 is located on the edge of the coil case 1. Therefore, the support portion 54 of the edge terminal hole portion 50 is bent at approximately a right angle along the coil case 1. That is, the support portion 54 extends from the side of the coil case 1 in the Z-axis direction and is bent in the Y-axis direction on the upper surface 12 of the coil case 1.

[0029] Furthermore, the insertion portion 53 has the same shape as the insertion portion 43 of the planar terminal hole portion 40. Also, the slit 52 is formed around the insertion portion 53 and the support portion 54. Therefore, the slit 52 is formed on the side surface of the coil case 1 and on the top surface 12 of the coil case 1.

[0030] Here, the coil case 1 deforms due to thermal expansion and contraction. Furthermore, the degree of deformation of the coil case 1 is greater on the outside of the top surface 12 than on the inside. The coil case 1 has a planar terminal hole portion 40 located on the inside of the top surface 12 of the coil case 1, and an edge terminal hole portion 50 located outside of the planar terminal hole portion 40. The slit 52 of the edge terminal hole portion 50 is larger than the slit 42 of the planar terminal hole portion 40. The planar terminal hole portion 40 is an example of a first terminal hole portion. The edge terminal hole portion 50 is an example of a second terminal hole portion. In addition, the slit 42 of the fourth planar terminal hole portion 40d, located outside of the third planar terminal hole portion 40c located on the inside of the top surface 12 of the coil case 1, may be larger.

[0031] Next, we will explain the case where the coil terminal 3 is soldered to the substrate 2. Figure 5 is a cross-sectional view showing an example of the state in which the terminal 3 is soldered to the substrate 2. Figure 5 also shows the state in which the terminal 3 inserted into the planar terminal hole 40 is soldered.

[0032] The circuit board 2 is placed on the spacing portion 20 formed on the upper surface 12 of the coil case 1. The terminals 3 of the coil lead wires are inserted from below to above through holes 41 provided in the insertion portion 43 of the planar terminal hole portion 40. The terminals 3 that have passed through the through holes 41 are soldered to the circuit board 2. In other words, the terminals 3 are connected to the wiring of the circuit board 2 by solder 4.

[0033] As shown in Figure 5, a slit 42 is formed around the insertion portion 43. Even if pressure is applied in the X-axis direction, Y-axis direction, Z-axis direction, or a combination of these directions due to thermal expansion or contraction of the coil case 1, the slit 42 absorbs the pressure, thereby suppressing solder cracks.

[0034] As shown in Figure 5, the coil terminals 3 are inserted from below through the through-hole 41 upwards and soldered to the substrate 2. The insertion portion 43 having the through-hole 41 is held by the support portion 44. One end of the support portion 44 is a fixed end fixed to the coil case 1, but the side on which the insertion portion 43 is provided is a free end that is not fixed. Furthermore, the width of the support portion 44 in the X-axis direction is narrower than the diameter of the insertion portion 43, and the length in the Y-axis direction is longer than the diameter of the insertion portion 43. Therefore, the support portion 44 is easily flexible. In other words, the insertion portion 43 moves easily within the slit 42. Thus, since the insertion portion 43 moves within the slit 42 in response to pressure, the pressure on the soldered portion can be reduced. As a result, the support portion 44 can suppress solder cracks.

[0035] Furthermore, as shown in Figure 5, the coil case 1 is provided with a gap portion 20 that forms a gap between the substrate 2 and the upper surface 12. When the coil case 1 deforms due to thermal expansion or contraction, the pressure due to the deformation is absorbed by the gap formed by the gap portion 20. As a result, the insertion portion 43 can reduce the pressure applied to the soldered portion. Therefore, the gap portion 20 can suppress solder cracks.

[0036] As described above, the coil case 1 according to the first embodiment holds the coil. The coil case 1 has through holes 41 and 51 into which the terminals 3 of the coil, which are soldered to the substrate 2, are inserted, and is equipped with planar terminal holes 40 and edge terminal holes 50 with slits 42 and 52 formed around the through holes 41 and 51. The planar terminal holes 40 and edge terminal holes 50 can reduce the pressure on the soldered portion even when pressure is generated due to thermal expansion or contraction. Therefore, the coil case 1 can suppress solder cracks.

[0037] (Variation 1) In the first embodiment described above, the support portion 44 of the planar terminal hole portion 40 was described as being flat. However, the support portion 44 of the planar terminal hole portion 40 is not limited to being flat, and may be curved.

[0038] Figure 6 is a cross-sectional view showing an example of a planar terminal hole 40 according to Modification 1. The planar terminal hole 40 includes an insertion portion 63 having a through hole 61, a support portion 64, and a slit 62, similar to the planar terminal hole 40 according to the first embodiment. The insertion portion 63 and the slit 62 have the same shape as the insertion portion 43 and slit 42 of the planar terminal hole 40 according to the first embodiment. As shown in Figure 6, the support portion 64 is curved. Because the support portion 64 is curved in this way, it is easily flexible. Therefore, the support portion 64 can suppress solder cracks. In addition, although the support portion 64 shown in Figure 6 is curved upward, it is not limited to being curved upward, but may be curved to the left or right, or downward.

[0039] While several embodiments of this disclosure have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of symbols]

[0040] 1 Coil Case 2 circuit boards 3 terminals 4 Handa 11. Coil storage section 12 Top side 20 Intervals 30 Protrusion 40 Flat terminal hole 41, 51, 61 through holes 42, 52, 62 slits 43, 53, 63 Insertion part 44, 54, 64 Support part 50 Edge terminal hole

Claims

1. A coil case for holding a coil, A terminal hole portion having a hole into which the terminals of the coil are inserted and which is soldered to the substrate, with a slit formed around the hole, Equipped with, The slit is a gap in the coil case. Coil case.

2. The terminal hole portion has an insertion portion having a hole into which the terminal of the coil is inserted, and a support portion that supports the insertion portion from a direction perpendicular to the insertion direction of the terminal. The coil case according to claim 1.

3. The terminal hole portion comprises an insertion portion having a hole into which the terminal of the coil is inserted, and a support portion that supports the insertion portion from a direction perpendicular to the direction in which the terminal is inserted, with the slit formed around the support portion. The coil case according to claim 1.

4. The support portion supports the insertion portion from a direction perpendicular to the longitudinal direction of the coil case. The coil case according to claim 2 or 3.

5. The support portion has a length in the same direction as the longitudinal direction of the coil case, and is thinner than the insertion portion. The coil case according to claim 4.

6. The support portion has a length in the direction perpendicular to the longitudinal direction of the coil case that is longer than the diameter of the insertion portion. The coil case according to claim 4.

7. The aforementioned support part is curved, A coil case according to any one of claims 2 to 6.

8. The coil case has a first terminal hole located on the inside of the upper surface of the coil case, and a second terminal hole located on the outside of the first terminal hole. The slit in the second terminal hole is larger than the slit in the first terminal hole. A coil case according to any one of claims 1 to 7.

9. The hole has a first outer diameter and a second outer diameter. The first outer diameter is the outer diameter of the hole on the upper surface of the coil case, The second outer diameter is narrower than the first outer diameter. The coil case according to claim 1.

10. The coil case has a projection positioned on the upper surface, The projection is positioned on the outside of the terminal hole. The coil case according to claim 1.

11. A coil case for holding a coil, having a terminal hole portion which has a hole into which the terminals of the coil are inserted and which is soldered to a substrate, and which has a slit formed around the hole, The coil held in the coil case, Equipped with, The slit is a gap in the coil case. Switching power supply.

12. The terminal hole portion comprises an insertion portion having the hole and a support portion that supports the insertion portion from a direction perpendicular to the insertion direction of the terminal. The switching power supply device according to claim 11.

13. The terminal hole portion has an insertion portion having the hole and a support portion that supports the insertion portion from a direction perpendicular to the insertion direction of the terminal, with the slit formed around the support portion. The switching power supply device according to claim 11.

14. The support portion supports the insertion portion from a direction perpendicular to the longitudinal direction of the coil case. A switching power supply device according to claim 12 or 13.

15. The support portion has a length in the same direction as the longitudinal direction of the coil case, and is thinner than the insertion portion. The switching power supply device according to claim 14.

16. The support portion has a length in the direction perpendicular to the longitudinal direction of the coil case that is longer than the diameter of the insertion portion. The switching power supply device according to claim 14.

17. The aforementioned support part is curved, A switching power supply device according to any one of claims 12 to 16.

18. The coil case has a first terminal hole located on the inside of the upper surface of the coil case, and a second terminal hole located on the outside of the first terminal hole. The slit in the second terminal hole is larger than the slit in the first terminal hole. A switching power supply device according to any one of claims 11 to 17.

19. The hole has a first outer diameter and a second outer diameter. The first outer diameter is the outer diameter of the hole on the upper surface of the coil case, The second outer diameter is narrower than the first outer diameter. The switching power supply device according to claim 11.

20. The coil case has a projection positioned on the upper surface, The projection is positioned on the outside of the terminal hole. The switching power supply device according to claim 11.

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