A high-reliability sealed surface mount thin film capacitor

Abstract

The application discloses a high-reliability sealed direct-insert type film capacitor, which comprises a capacitor shell, a capacitor core group, lead-out wires and a cover plate. The lower ends of the opposite two side plates of the capacitor shell are respectively provided with two upward recessed shell grooves. The lead-out wires comprise transverse lead-out straight sections and vertical lead-out straight sections. The transverse lead-out straight sections of the four lead-out wires respectively pass through the four shell grooves. The cover plate is arranged at the lower end in the capacitor shell, and the cover plate is provided with vertical cover plate through holes. The application can realize direct-insert type installation and form the transverse lead-out straight sections for positioning and fixing. Under the long-term action of mechanical vibration stress and working temperature stress, the lead-out wires are not cracked with the sealing glue because the lead-out wires are positioned and fixed and not led out from the surface of the sealing glue, the performance of the capacitor is not affected, the environmental adaptability of the capacitor is enhanced, positioning tools are not needed before the sealing glue is poured and sealed, cost is saved and the positioning precision of the lead-out wires is high.

Description

TECHNICAL FIELD

[0001] The present application relates to a thin film capacitor, in particular to a high-reliability sealed direct insertion thin film capacitor, and belongs to the technical field of thin film capacitor production. BACKGROUND

[0002] The thin film capacitor is also called organic dielectric thin film capacitor, and is usually in a direct insertion structure, that is, is mainly installed on a circuit board by plug-in welding, and is simply called direct insertion thin film capacitor.

[0003] As shown in Figure 1 and Figure 2 , the conventional direct insertion thin film capacitor comprises a packaging shell 1, a capacitor core 2 and straight lead-out wires 3, two straight lead-out wires 3 form a group, two groups of straight lead-out wires 3 are respectively connected to two ends of the capacitor core 2, the capacitor core 2 is placed in the packaging shell 1 and is fixed and sealed by pouring epoxy resin 4, and the straight lead-out wires 3 directly pass out from the epoxy resin 4 as external lead electrodes; the straight lead-out wires 3 are usually tinned copper wires, and are connected to the gold-plated end face of the capacitor core 2 by welding to form electrical connection inside the capacitor.

[0004] The defects of the conventional direct insertion thin film capacitor are as follows:

[0005] Since the straight lead-out wires 3 directly pass out from the end face of the epoxy resin 4, and the material of the straight lead-out wires 3 is usually tinned copper wire, the combination between the straight lead-out wires 3 and the organic polymer material epoxy resin 4 is poor, and under the long-term action of mechanical vibration stress and working temperature stress, the straight lead-out wires 3 and the epoxy resin 4 are prone to cracking, which reduces the sealing reliability, forms a fine channel for external substances to enter the inside, reduces the performance of the capacitor, and affects the environmental adaptability of the capacitor; meanwhile, before pouring, another positioning tool is needed to position the straight lead-out wires 3 to complete the pouring sealing of the product, and the positioning accuracy of the straight lead-out wires 3 is also difficult to reach the ideal state.

[0006] In addition, as shown in Figure 3 , in actual application, in order to improve the space utilization rate in the whole machine case, the direct insertion thin film capacitor 5 is usually installed on both sides of the printed board 6, and during the double-sided installation, since the spacing between the two groups of straight lead-out wires 3 and the spacing between the two straight lead-out wires 3 of each group are the same, the welding positions are the same during the double-sided installation, which leads to that the two direct insertion thin film capacitors 5 can only be installed in staggered positions, and cannot be installed in aligned positions, as shown in Figure 3 , which greatly reduces the space utilization rate in the machine case. SUMMARY

[0007] The present application aims at providing a high-reliability sealed surface-mounting thin-film capacitor which can avoid cracking between lead-out wires and sealing glue (usually epoxy resin) to solve the above problems.

[0008] The present application realizes the above-mentioned purpose by the following technical solutions:

[0009] The present application realizes the above-mentioned purpose by the following technical solutions: A high-reliability sealed surface-mounting thin-film capacitor comprises a capacitor shell, a capacitor core group and lead-out wires, two of which form a group, two groups of the lead-out wires are connected to two ends of the capacitor core group respectively, the capacitor core group is placed in the capacitor shell and fixed by sealing glue, the lead-out wires extend out of the sealing glue, the high-reliability sealed surface-mounting thin-film capacitor further comprises a cover plate, the open end of the capacitor shell is downward, the lower end of two side walls of the capacitor shell is respectively provided with two concave shell grooves, the lead-out wires are first bent 90° outward to form horizontal lead-out straight segments, then bent 90° downward to form vertical lead-out straight segments from the position close to the shell grooves, the horizontal lead-out straight segments of four lead-out wires respectively pass through four shell grooves, the horizontal shape of the cover plate is the same as that of the lower end of the capacitor shell, the horizontal size of the cover plate is slightly smaller than that of the lower end of the capacitor shell, the cover plate is placed at the lower end of the capacitor shell and tightly contacts with the inner wall of the lower end of the capacitor shell, the horizontal lead-out straight segments of four lead-out wires respectively contact with the upper surface of the cover plate, the vertical lead-out straight segments of four lead-out wires are respectively placed outside the capacitor shell and the cover plate, and the cover plate is provided with vertical cover plate through holes.

[0010] As a preferred, in order to realize the connection reliability between the cover plate and the capacitor shell and realize more stable and reliable positioning and support of the lead-out wires, the opposite two side walls of the cover plate are respectively provided with two outward convex bosses, four bosses are respectively placed in four shell grooves and tightly contact, and the outer wall of the boss is flush with the corresponding outer wall of the capacitor shell.

[0011] As a preferred, in order to realize more stable and reliable positioning and fixing of the lead-out wires, the upper end of the shell groove is reduced to the width slightly larger than the outer diameter of the lead-out wire to form a shell threading groove, the upper surface of the boss is provided with a downward boss groove, the shell threading groove and the corresponding boss groove jointly form a circular threading hole, and the horizontal lead-out straight segments of four lead-out wires respectively pass through four threading holes.

[0012] As preferred, in order to facilitate the setting of the boss and improve the stability of the connection between the cover plate and the capacitor shell, two sides of the boss provided on the cover plate are provided with upwardly protruding flanges, the boss is provided on the outer wall of the corresponding flange, the upper surface of the flange is provided with a flange groove corresponding to the boss groove, the groove bottom of the boss groove is level with the groove bottom of the corresponding flange groove, and the transversely leading straight segments of the lead-out wires are respectively arranged in the corresponding boss groove and flange groove.

[0013] As preferred, in order to facilitate the realization of double-sided alignment installation on the same circuit board to save installation space, the two side walls of the capacitor shell provided with the shell grooves are respectively a first shell side wall and a second shell side wall, and the distance between the two shell grooves provided on the first shell side wall is greater than the distance between the two shell grooves provided on the second shell side wall.

[0014] The present application has the following beneficial effects:

[0015] The present application has the following beneficial effects: BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a traditional straight-in type thin film capacitor before assembly;

[0017] Figure 2 is a traditional straight-in type thin film capacitor after assembly;

[0018] Figure 3 is a traditional straight-in type thin film capacitor during double-sided installation;

[0019] Figure 4 is a high-reliability sealed straight-in type thin film capacitor before assembly;

[0020] Figure 5is the enlarged view of "A" in the perspective exploded view of the high-reliability sealed surface-mounting film capacitor before assembly according to the present application;

[0021] Figure 6 is the perspective view of the high-reliability sealed surface-mounting film capacitor after assembly according to the present application;

[0022] Figure 7 is the perspective view of the high-reliability sealed surface-mounting film capacitor when mounted on both sides according to the present application. DETAILED DESCRIPTION

[0023] The present application will be further described below in conjunction with the accompanying drawings:

[0024] As shown in Figures 4-6 the high-reliability sealed surface-mounting film capacitor according to the present application comprises a capacitor housing 7, a capacitor core set 12, lead wires 13 and a cover plate 19, two lead wires 13 form a group, two groups of lead wires 13 are connected to two ends of the capacitor core set 12 respectively, the capacitor core set 12 is placed in the capacitor housing 7 and is fixed and sealed by a sealing glue 20, the lead wires 13 extend out of the sealing glue 20, the opening end of the capacitor housing 7 is arranged downward, the lower ends of the two opposite side walls (i.e. the first housing side wall 9 and the second housing side wall 8) of the capacitor housing 7 are respectively provided with two upward recessed housing recesses 11, the lead wires 13 are first bent 90° laterally to form lateral lead straight segments 14 from the positions close to the housing recesses 11, and then bent 90° downward to form vertical lead straight segments 15, the lateral lead straight segments 14 of the four lead wires 13 respectively pass through the four housing recesses 11, the lateral cover plate 19 has the same lateral shape as the lower end of the capacitor housing 7, the lateral size of the cover plate 19 is slightly smaller than the lateral size of the lower end of the capacitor housing 7, the cover plate 19 is placed at the lower end of the capacitor housing 7 and tightly contacts the inner wall of the lower end of the capacitor housing 7, the lateral lead straight segments 14 of the four lead wires 13 respectively contact the upper surface of the cover plate 19, the vertical lead straight segments 14 of the four lead wires 13 are respectively placed outside the capacitor housing 7 and the cover plate 19, and the cover plate 19 is provided with vertical cover plate through holes 18.

[0025] As shown in Figures 4-6As shown, preferably, in order to ensure reliable connection between the cover plate 19 and the capacitor housing 7 and to achieve more stable and reliable positioning and support for the lead wire 13, the outer walls of opposite sides of the cover plate 19 are each provided with two protruding bosses 17. The four bosses 17 are respectively placed in the four housing grooves 11 and are in close contact. The outer walls of the bosses 17 are flush with the corresponding outer walls of the capacitor housing 7. In order to achieve more stable and reliable positioning and fixation for the lead wire 13, the upper width of the housing groove 11 is reduced to be slightly larger than that of the lead wire 13. The outer diameter forms the outer casing through-hole 10. The upper surface of the boss 17 is provided with a recessed boss groove 16. The outer casing through-hole 10 and the corresponding boss groove 16 together form a circular through-hole, and the horizontal straight segments 14 of the four leads 13 pass through the four through-holes respectively. In order to facilitate the setting of the boss 17 and improve the stability of the connection between the cover plate 19 and the capacitor casing 7, the cover plate 19 is provided with the boss 17 and the two sides are provided with upward protruding edges 23. The boss 17 is provided on the outer wall of the corresponding protruding edge 23. The upper surface of the protruding edge 23 is provided with a protruding edge groove 24 corresponding to the boss groove 16. The bottom of the boss groove 16 is at the same height as the bottom of the corresponding protruding edge groove 24. The horizontal straight segments 14 of the leads 13 are respectively placed in the corresponding boss groove 16 and the protruding edge groove 24. In order to facilitate the installation of the boss 17 on the same circuit board (see Figure 6 To save installation space, double-sided mounting is achieved on the circuit board 22). The capacitor housing 7 has two side walls with housing grooves 11, namely the first housing side wall 9 and the second housing side wall 8. The distance between the two housing grooves 11 on the first housing side wall 9 is greater than the distance between the two housing grooves 11 on the second housing side wall 8.

[0026] like Figures 4-7 As shown, in use, two high-reliability sealed through-hole film capacitors 21 are inserted into the mounting holes from opposite sides of the circuit board 22, so that the first outer shell sidewall 9 of the first high-reliability sealed through-hole film capacitor 21 and the second outer shell sidewall 8 of the second high-reliability sealed through-hole film capacitor 21 are on the same side. Then, the vertical lead segments 15 of the two closer leads 13 on the second high-reliability sealed through-hole film capacitor 21 are placed between the two farther leads 13 on the first high-reliability sealed through-hole film capacitor 21, and the vertical lead segments 15 of the two closer leads 13 on the first high-reliability sealed through-hole film capacitor 21 are placed between the two farther leads 13 on the second high-reliability sealed through-hole film capacitor 21. The soldering of the two high-reliability sealed through-hole film capacitors 21 does not affect each other, thus achieving double-sided alignment of the two high-reliability sealed through-hole film capacitors 21 on the circuit board 22.

[0027] The above embodiments are only the preferred embodiments of the present application, and are not intended to limit the technical solutions of the present application, and any technical solutions that can be realized on the basis of the above embodiments without creative labor shall be considered to fall within the protection scope of the present application patent.

Claims

1. A high-reliability sealed-in surface mount thin film capacitor comprising a capacitor housing, a capacitor core assembly and lead wires, two of said lead wires being a set, two sets of said lead wires being connected to two ends of said capacitor core assembly, respectively, said capacitor core assembly being disposed in said capacitor housing and being sealed and fixed by a sealing glue, said lead wires extending out of said sealing glue, characterized in that: The high-reliability sealed surface-mounting film capacitor further comprises a cover plate, the open end of the capacitor shell is arranged downward, the lower end of the two side walls of the capacitor shell is respectively provided with two upward recessed shell grooves, the lead-out wire is first bent 90° outward to form a horizontal lead-out straight line segment, then bent 90° downward to form a vertical lead-out straight line segment, the horizontal lead-out straight line segments of the four lead-out wires respectively pass through the four shell grooves, the horizontal shape of the cover plate is the same as the horizontal shape of the lower end of the capacitor shell, the horizontal size of the cover plate is slightly smaller than the horizontal size of the lower end of the capacitor shell, the cover plate is arranged at the lower end of the capacitor shell and is in close contact with the inner wall of the lower end of the capacitor shell, the horizontal lead-out straight line segments of the four lead-out wires are respectively in contact with the upper surface of the cover plate, the vertical lead-out straight line segments of the four lead-out wires are respectively arranged outside the capacitor shell and the cover plate, the cover plate is provided with a vertical cover plate through hole, the two side walls of the capacitor shell provided with the shell grooves are respectively a first shell side wall and a second shell side wall, the distance between the two shell grooves arranged on the first shell side wall is greater than the distance between the two shell grooves arranged on the second shell side wall. ​ 2. The high-reliability sealed surface mount film capacitor of claim 1, wherein: The opposite two side outer walls of the cover plate are respectively provided with two outward convex bosses, the four bosses are respectively arranged in the four shell grooves and are in close contact, the outer wall of the boss is flush with the corresponding outer wall of the capacitor shell.

3. The high-reliability sealed surface mount film capacitor of claim 2, wherein: The upper end width of the shell groove is reduced to be slightly greater than the outer diameter of the lead-out wire to form a shell threading groove, the upper surface of the boss is provided with a downward recessed boss groove, the shell threading groove and the corresponding boss groove jointly form a circular threading hole, and the horizontal lead-out straight line segments of the four lead-out wires respectively pass through the four threading holes.

4. The high-reliability sealed surface mount film capacitor of claim 3, wherein: The two sides of the cover plate provided with the bosses are provided with upward convex edges, the bosses are arranged on the outer walls of the corresponding convex edges, the upper surface of the convex edge is provided with a convex edge groove corresponding to the boss groove, the groove bottom of the boss groove is flush with the groove bottom of the corresponding convex edge groove, and the horizontal lead-out straight line segments of the lead-out wires are respectively arranged in the corresponding boss groove and the convex edge groove.

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