A capacitor and a circuit board on which it is mounted.

Abstract

The present invention relates to a capacitor of the type molded with molding resin on a circuit board, and a capacitor-mounted circuit board on which such a capacitor is mounted, and aims to prevent the sealing body from being pushed into the case by the flowing molding resin during the molding process. [Solution] A pressure receiving plate 12 is placed on the side of the sealing body 5 facing the opening 2 of the case 3. A projection 16 is provided on the pressure receiving plate 12 that protrudes toward the base plate 6. The pressure receiving plate 12 and the base plate 6 are connected and fixed with adhesive via this projection 16. Therefore, even if the flowing mold resin tries to push the pressure receiving plate 12 during molding, the pressure receiving plate 12 is connected and fixed to the base plate 6, and the base plate 6 is in contact with the opening 2 of the case 3. As a result, the pressure receiving plate 12 cannot be pushed toward the sealing body 5, and damage to the capacitor element 4 can be prevented.

Description

Technical Field

[0001] The present invention relates to a capacitor and a capacitor-mounted circuit board on which the capacitor is mounted.

Background Art

[0002] In a capacitor-mounted circuit board in which a capacitor is mounted together with other components on the surface side of a circuit board, a structure has been proposed in which the surface side of the circuit board is covered with a molding resin to protect the capacitor and other components from heat, shock, etc. (for example, Patent Document 1 below).

[0003] In this prior document, as a problem in the case of covering a capacitor and other components with a molding resin, it is pointed out that the case constituting the capacitor receives pressure from the molding resin and is deformed.

[0004] That is, the capacitor has a cylindrical case with one end side being an opening, a capacitor element housed in this case, a sealing body mounted on the opening side of the capacitor element in the case, and a seat plate disposed opposite to the sealing body outside the opening side of the case. In order to prevent the side surface of the case from deforming inward due to the pressure of the flowing molding resin during mold molding, a pressure absorbing member made of silicon is provided on the outer peripheral surface of the case.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The aforementioned prior literature focuses on the inward deformation of the case sides due to the molding resin, but in reality, the bigger problem is that the sealing body installed on the opening side inside the case is pushed into the case by the pressure of the flowing molding resin during molding, rather than the deformation of the case itself.

[0007] In other words, the sealing element is a constricted part of the case that deforms inward to create an airtight seal inside the case, so it is essential that it be made of an elastic material.

[0008] Therefore, if the pressure of the flowing mold resin during the above-mentioned molding process is applied to the sealing body exposed to the outside of the case at the case opening, this sealing body may elastically deform, be pushed into the case, and potentially damage the capacitor element.

[0009] Therefore, the present invention aims to prevent the sealing body from being pushed into the case by the flowing mold resin during mold molding. [Means for solving the problem]

[0010] To achieve this objective, the capacitor of the present invention has a pressure receiving plate placed on the opening side of the case of the sealing body, and the connection terminals of the capacitor element are configured to extend through this pressure receiving plate and out of the opening of the case.

[0011] Furthermore, on the side of the case facing the opening, the outer periphery of the pressure receiving plate, beyond the portion through which the connecting terminals pass, is covered by the bent portion of the case when viewed from the opening side of the case.

[0012] Furthermore, at least one of the pressure receiving plate and the seat plate is provided with a projection that extends toward the other side, and the pressure receiving plate and the seat plate are connected via this projection.

[0013] Furthermore, in the capacitor of the present invention, at least one of the pressure receiving plate and the base plate is provided with a projection that protrudes toward the other side, and the base plate portion or pressure receiving plate corresponding to this projection is provided with a fitting portion into which the projection fits, and the projection is fixed in this fitting portion.

[0014] Furthermore, the pressure receiving plate in the capacitor of the present invention is provided with a projection that protrudes toward the base plate, and the portion of the base plate corresponding to this projection is provided with a through hole through which the projection passes, serving as the fitting portion, and an enlarged diameter portion is provided at the end of this through hole opposite to the pressure receiving plate.

[0015] Furthermore, the capacitor of the present invention has an adhesive placed in the enlarged portion of the through hole, and the projection of the pressure receiving plate is fixed to the base plate with this adhesive.

[0016] Furthermore, the capacitor of the present invention is constructed in which the pressure receiving plate and the seat plate are made of synthetic resin, and the tip of the projection on the seat plate side is thermally deformed at the enlarged diameter portion of the through hole in the seat plate, thereby fixing the projection to the seat plate.

[0017] Furthermore, the capacitor mounting circuit board of the present invention has a configuration in which a capacitor is mounted on the surface of the circuit board, and on the surface of the circuit board, at least the part of the capacitor closer to the circuit board than the constricted portion, and the base plate are covered with molded resin. [Effects of the Invention]

[0018] As described above, in the capacitor of the present invention, a pressure receiving plate is disposed on the surface of the sealing body on the opening side of the case, and the connection terminal of the capacitor element penetrates through this pressure receiving plate and extends outside the opening of the case. The outer peripheral portion of the pressure receiving plate on the surface on the opening side of the case, at the portion where the connection terminal penetrates, is configured to be covered by the bent portion of the case when viewed from the opening side of the case. At least one of the pressure receiving plate and the seat plate is provided with a protrusion protruding toward the other side, and the pressure receiving plate and the seat plate are connected via this protrusion. Therefore, when performing mold molding, it is possible to suppress the sealing body from being pushed into the case by the flowing mold resin.

[0019] That is, in the present invention, a pressure receiving plate is disposed on the surface of the sealing body on the opening side of the case, and at least one of this pressure receiving plate and the seat plate is provided with a protrusion protruding toward the other side, and the pressure receiving plate and the seat plate are connected with an adhesive via this protrusion.

[0020] Therefore, during mold molding, even if the flowing mold resin tries to push the pressure receiving plate, the pressure receiving plate is connected and fixed to the seat plate, and the seat plate abuts against the opening of the case, so the pressure receiving plate cannot be pushed toward the sealing body side. As a result, damage to the capacitor element can be prevented.

Brief Description of the Drawings

[0021] [Figure 1] Perspective view of a capacitor according to an embodiment of the present invention [Figure 2] Same, exploded perspective view of the capacitor [Figure 3] Same, perspective view showing the state where the sealing body and the pressure receiving plate of the capacitor are combined [Figure 4] Same, exploded perspective view of the surface side of the sealing body and the pressure receiving plate of the capacitor [Figure 5] Same, exploded perspective view of the back side of the sealing body and the pressure receiving plate of the capacitor [Figure 6] Same, front view showing the state where the capacitor element, the sealing body, and the pressure receiving plate of the capacitor are combined [Figure 7] Same, partial cross-sectional view of the capacitor [Figure 8] Perspective view showing the manufacturing method of the capacitor [Figure 9] Cross-sectional view showing the manufacturing method of the capacitor [Figure 10] Cross-sectional view showing the manufacturing method of the capacitor

Mode for Carrying Out the Invention

[0022] (Embodiment 1) Hereinafter, an embodiment of the present invention will be described.

[0023] As shown in FIGS. 1 and 2, the capacitor 1 of this embodiment is made of aluminum, and includes a cylindrical case 3 with an opening 2 at one end, a capacitor element 4 housed in the case 3, and a disk-shaped sealing body 5 made of an elastic material and mounted on the side of the opening 2 of the case 3 closer to the capacitor element 4. And a seat plate 6 disposed opposite to the sealing body 5 outside the opening 2 side of the case 3.

[0024] As is well known, the capacitor element 4 is formed into a cylindrical shape by overlapping a strip-shaped anode foil (not shown) and a strip-shaped cathode foil (not shown) with a strip-shaped separator interposed therebetween and winding them.

[0025] Further, the capacitor element 4 passes through the through-hole 7 of the sealing body 5 and extends to the seat plate 6 outside the opening 2 of the case 3. Next, as shown in FIG. 8, it passes through the through-hole 8 of the seat plate 6. Next, as shown in FIG. 1, on the lower surface side of the seat plate 6, it has a connection terminal 9 bent outward.

[0026] Further, on the outer peripheral portion of the case 3 corresponding to the outer peripheral portion of the sealing body 5, a constriction portion 10 constricted toward the outer peripheral portion of the sealing body 5 is provided as shown in FIGS. 1 and 7. Further, at the end portion on the opening 2 side of the case 3, as shown in FIG. 7, a bent portion 11 bent in the inner circumferential direction of the case 3 is provided.

[0027] The above configuration is the same as that of the conventional example. Hereinafter, the features of this embodiment will be described.

[0028] In this embodiment, as shown in Figures 2 to 7, a disc-shaped pressure receiving plate 12 made of synthetic resin is placed on the side of the sealing body 5 facing the opening 2 of the case 3.

[0029] The connection terminal 9 of the capacitor element 4 extends through the through-hole 13 of the pressure receiving plate 12 and out of the opening 2 of the case 3.

[0030] In other words, the connection terminal 9 of this capacitor element 4 first passes through the through hole 7 of the sealing body 5, then through the through hole 13 of the pressure receiving plate 12, then through the through hole 8 of the base plate 6, and then, as shown in Figure 1, is bent outward on the lower surface side of the base plate 6.

[0031] Furthermore, as shown in Figure 7, on the side of the pressure receiving plate 12 facing the opening 2 of the case 3, the outer circumference of the through-hole 13 through which the connection terminal 9 passes is covered by the bent portion 11 of the case 3 when viewed from the opening 2 side of the case 3.

[0032] Let's continue the explanation regarding the pressure receiving plate 12 and the sealing body 5.

[0033] Both the pressure receiving plate 12 and the sealing body 5 are disc-shaped, but the outer diameter of the pressure receiving plate 12 is smaller than that of the sealing body 5. However, as described above, on the side of the case 3 facing the opening 2, the outer circumference of the pressure receiving plate 12 beyond the through-hole 13 through which the connection terminal 9 passes is covered by the bent portion 11 of the case 3 when viewed from the opening 2 side of the case 3. In other words, the pressure receiving plate 12 and the sealing body 5 are structured in such a way that movement outside the opening 2 is prevented by the bent portion 11.

[0034] Furthermore, the outer circumference of the pressure receiving plate 12 is larger than the inner circumference of the constricted portion 10 of the case 3, which prevents the pressure receiving plate 12 from moving towards the capacitor element 4 while pressing against the sealing body 5.

[0035] It is not necessary to firmly fix the pressure receiving plate 12 and the sealing body 5, but it is necessary to align them.

[0036] This is because, as described above, the connection terminal 9 of the capacitor element 4 must first pass through the through hole 7 of the sealing body 5, and then through the through hole 13 of the pressure receiving plate 12.

[0037] To this end, in this embodiment, as shown in Figures 3 to 5, a projection 14 is provided on the upper surface of the pressure receiving plate 12 (the surface facing the sealing body 5), and a groove 15 is provided on the lower surface of the sealing body 5 (the surface facing the pressure receiving plate 12). By fitting these projections 14 and grooves 15 together, the pressure receiving plate 12 and the sealing body 5 are positioned as shown in Figure 3.

[0038] Furthermore, as shown in Figure 5, the groove 15 of the sealing body 5 is rectangular in shape, extending between the left and right through holes 7 in a direction perpendicular to the line connecting these two through holes 7.

[0039] Furthermore, to match the shape of this groove 15, the projection 14 of the pressure receiving plate 12 was also made rectangular, as shown in Figure 5.

[0040] However, both the long-side and short-side dimensions of the projection 14 of the pressure receiving plate 12 are shorter than the long-side and short-side dimensions of the corresponding groove 15 of the sealing body 5.

[0041] Furthermore, the height dimension of the projection 14 of the pressure receiving plate 12 is smaller than the depth dimension of the groove 15 of the sealing body 5.

[0042] In the configuration described above, the dimensions of the base portion of the projection 14 of the pressure receiving plate 12 in the short-side direction are approximately the same as the dimensions of the opening of the groove 15 of the sealing body 5 in the short-side direction (the projection 14 of the pressure receiving plate 12 is slightly larger in the short-side direction).

[0043] As a result, when the projection 14 of the pressure receiving plate 12 is fitted into the groove 15 of the sealing body 5, the two can maintain the integrated state shown in Figure 3, thereby improving convenience during production.

[0044] Furthermore, even when the two are fitted together with these dimensional relationships, since the sealing body 5 is made of an elastic material, the opening edge of the groove 15 of the sealing body 5 widens, thereby allowing the projection 14 of the pressure receiving plate 12 to fit properly into the groove 15 of the sealing body 5, and holding the two together in the integrated state shown in Figure 3.

[0045] Next, I will explain the pressure receiving plate 12 and the seat plate 6.

[0046] As shown in Figure 5, a projection 16 is provided at the center of the pressure receiving plate 12 on the seat plate 6 side, projecting toward the seat plate 6. As shown in Figure 2, a fitting portion 17 into which the projection 16 fits is provided in the portion of the seat plate 6 corresponding to this projection 16. The projection 16 is connected to and fixed to this fitting portion 17.

[0047] To explain in more detail, the pressure receiving plate 12 is provided with a cylindrical projection 16 that protrudes toward the seat plate 6, and the portion of the seat plate 6 corresponding to this projection 16 is provided with a cylindrical through-hole as the fitting portion 17 through which the projection 16 passes, and a circular enlarged diameter portion 18 is provided at the end of this through-hole opposite to the pressure receiving plate 12, as shown in Figure 8.

[0048] The assembly procedure for capacitor 1 will be explained below.

[0049] First, as shown in Figure 3, the sealing body 5 and the pressure receiving plate 12 are integrated. Next, as shown in Figure 6, the connection terminals 9 of the capacitor element 4 are made to pass through the sealing body 5 and the pressure receiving plate 12. After that, the capacitor element 4 is inserted through the opening 2 of the case 3, leaving the connection terminals 9 of the capacitor element 4 protruding outside the case 3.

[0050] Subsequently, as shown in Figure 7, a constricted portion 10 is provided on the outer circumference of the case 3, corresponding to the outer circumference of the sealing body 5, and is narrowed toward the outer circumference of the sealing body 5 as shown in Figures 1 and 7. Next, a bent portion 11 is provided at the end of the case 3 on the opening 2 side, as shown in Figure 7, and is bent toward the inner circumference of the case 3.

[0051] In this state, as shown in Figure 8, the base plate 6 is attached to the opening 2 side of the case 3, and then, as shown in Figure 1, the tip of the connection terminal 9 is bent to the left and right. In this state, the base plate 6 is in contact with the opening 2 of the case 3, just as in the conventional method. In other words, as its name suggests, the base plate 6 is designed so that the bottom surface of the case 3 rests on its upper surface, allowing the capacitor 1 with the case 3 to be surface-mounted onto a circuit board (not shown).

[0052] Finally, invert the assembly upwards from the state shown in Figure 1, with the seat plate 6 positioned upwards. Then, apply adhesive (not shown) to the circular enlarged portion 18 located at the end of the through-hole provided as the fitting portion 17 in the seat plate 6, on the side opposite to the pressure receiving plate 12.

[0053] The application of this adhesive connects and fixes the projection 16 of the pressure receiving plate 12 to the seat plate 6.

[0054] In this embodiment, the capacitor 1, configured as described above, has a pressure receiving plate 12 positioned on the side of the opening 2 of the case 3 of the sealing body 5. The pressure receiving plate 12 is provided with a projection 16 that protrudes toward the base plate 6, and the pressure receiving plate 12 and the base plate 6 are connected and fixed with adhesive via this projection 16. This greatly helps to prevent damage to the capacitor element 4 by the flowing molding resin during molding.

[0055] In other words, as described above, the capacitor 1 in this embodiment is mounted on the circuit board by the base plate 6. However, when the capacitor 1 is molded together with the circuit board using molding resin, the capacitor 1 and the circuit board are housed in a molding fitting, and the molding resin is injected into the molding die under pressure.

[0056] At this time, the flowing mold resin flows into the opening 2 of the case 3, and a force is applied that pushes the sealing body 5, which is made of an elastic material, toward the capacitor element 4.

[0057] However, in this embodiment, a pressure receiving plate 12 is placed on the side of the sealing body 5 facing the opening 2 of the case 3, and a projection 16 is provided on the pressure receiving plate 12 that protrudes toward the base plate 6. The pressure receiving plate 12 and the base plate 6 are connected and fixed with adhesive via this projection 16. Therefore, even if the flowing mold resin tries to push the pressure receiving plate 12 during molding, the pressure receiving plate 12 is connected and fixed to the base plate 6, and the base plate 6 is in contact with the opening 2 of the case 3, so the pressure receiving plate 12 cannot be pushed toward the sealing body 5, and as a result, damage to the capacitor element 4 can be prevented.

[0058] In the above embodiment, the pressure receiving plate 12 is provided with a projection 16 that protrudes toward the seat plate 6, connecting and fixing the pressure receiving plate 12 and the seat plate 6. However, a projection (similar to projection 16, though not shown) may be provided from the seat plate 6 toward the pressure receiving plate 12, and the pressure receiving plate 12 may be provided with a recess into which the projection penetrates, and these projections and recesses may be fitted together to connect and fix the pressure receiving plate 12 and the seat plate 6. In this case, adhesive is applied to the tip of the projection on the seat plate 6, and then it is inserted into the recess on the pressure receiving plate 12.

[0059] Furthermore, in the above embodiment, the projection 16 of the pressure receiving plate 12 and the seat plate 6 were connected and fixed with adhesive, but the projection 16 of the pressure receiving plate 12 and the seat plate 6 may also be heat-welded.

[0060] Figures 9 and 10 show model examples of ultrasonic welding.

[0061] As shown in Figures 9 and 10, by bringing the ultrasonic horn 19 into contact with the tip of the projection 16 of the pressure receiving plate 12 that has passed through the through hole provided as the fitting portion 17 of the seat plate 6, and vibrating the ultrasonic horn 19, the projection 16 will melt, and the projection 16 of the pressure receiving plate 12 and the seat plate 6 can be heat-welded together.

[0062] Alternatively, the projection 16 of the pressure receiving plate 12 and the seat plate 6 may be heat-welded together by irradiating the projection 16 of the pressure receiving plate 12 with laser light as shown in Figure 9.

[0063] The pressure receiving plate 12 and the seat plate 6 can be formed from PPS (polyphenylene sulfide) resin, PPA (polyphthalamide) resin, LCP (liquid crystal polymer) resin, or the like.

[0064] When heat-welding the projection 16 of the pressure receiving plate 12 and the seat plate 6 by irradiating them with laser light, it is preferable to make the pressure receiving plate 12 and the seat plate 6 out of LCP (liquid crystal polymer) resin from the viewpoint of heat resistance. [Explanation of Symbols]

[0065] 1 Capacitor 2 openings 3 cases 4 Capacitor elements 5 Sealing body 6 Seat board 7 Through hole 8 Through hole 9 Connection terminals 10 Aperture section 11 Bend section 12 Pressure receiving plate 13 Through hole 14 protrusions 15 groove 16 protrusions 17 Inset part 18 Expanded diameter part 19. Ultrasonic horn

Claims

1. The device comprises a cylindrical case with an opening at one end, a capacitor element housed within the case, a sealing body made of an elastic material mounted on the side of the case closer to the opening than the capacitor element, and a base plate positioned opposite the sealing body on the outside of the case on the opening side. The capacitor element has a connection terminal that penetrates the sealing body and extends to the base plate outside the opening. The outer periphery of the case, corresponding to the outer periphery of the sealing body, is provided with a constricted portion that narrows toward the outer periphery of the sealing body. In a capacitor in which a bent portion is provided at the end of the case on the opening side, the case is bent in the circumferential direction, A pressure receiving plate is placed on the opening side of the case of the sealing body. The aforementioned connection terminal is configured to extend beyond the opening of the case, passing through the pressure receiving plate. On the surface of the pressure receiving plate facing the opening, the outer circumference beyond the portion through which the connecting terminal passes is covered by the bent portion when viewed from the opening side. A capacitor in which at least one of the pressure receiving plate and the seat plate is provided with a projection that protrudes toward the other side, and the pressure receiving plate and the seat plate are connected via this projection.

2. The capacitor according to claim 1, wherein the portion of the seat plate corresponding to the projection, or the pressure receiving plate, is provided with a fitting portion into which the projection is fitted, and the projection is fixed in this fitting portion.

3. The projection is provided on the pressure receiving plate so as to protrude toward the seat plate, The capacitor according to claim 2, wherein the portion of the base plate corresponding to the projection is provided with a through hole through which the projection passes, and an enlarged diameter portion is provided at the end of the through hole opposite to the pressure receiving plate.

4. The capacitor according to claim 3, wherein an adhesive is placed in the enlarged diameter portion, and the projection is fixed to the base plate with this adhesive.

5. The capacitor according to claim 3, wherein the pressure receiving plate and the seat plate are made of synthetic resin, and the tip of the projection on the seat plate side in the enlarged diameter portion is thermally deformed to fix the projection to the seat plate.

6. A capacitor mounting circuit board having a capacitor according to any one of claims 1 to 5 mounted on the surface of a circuit board, wherein at least the part of the capacitor closer to the circuit board than the constricted portion, and the base plate, on the surface of the circuit board are covered with molded resin.

Images