CN213816482U

CN213816482U - Lead terminal for power module

Info

Publication number: CN213816482U
Application number: CN202023310579.1U
Authority: CN
Inventors: 王志超
Original assignee: Huaxinwei Semiconductor Technology Beijing Co ltd
Current assignee: Huaxinwei Semiconductor Technology Beijing Co ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2021-07-27
Anticipated expiration: 2030-12-30

Abstract

The utility model discloses a lead terminal for a power module, which comprises a plug part, a transition part, a buffer part, a supporting part and a welding part; the lower extreme of transition portion is connected with the separation buffering portion with the supporting part, buffering portion is connected with the welding part is equipped with the pad foot in the top of welding part, is equipped with vertical clearance between buffering portion and the supporting part, be equipped with horizontal clearance between supporting part and the pad foot. The utility model discloses a longitudinal gap and horizontal clearance have been set up respectively between supporting part and buffer part and the weld part to guarantee that when the PCB circuit board is impressed the terminal, the lead terminal has the buffering effect, can not sink downwards simultaneously and damage; the setting of foot pad has avoided being in the same place supporting part and weld part welding, has guaranteed good buffering of lead terminal, support effect, has promoted power module's reliability. The utility model discloses a lead terminal has improved its elastic deformation resilience, strengthens the yield strength of its bottom, and then improves the life of lead terminal.

Description

Lead terminal for power module

Technical Field

The utility model belongs to the technical field of power semiconductor device technique and specifically relates to a lead terminal for power module is related to.

Background

The IGBT or MOSFET chip is packaged inside the power module to form the power module, which has the advantages of high power density, low thermal resistance, convenient use and the like, and is widely applied to various motor control frequency converters, and the power modules can also be used for switching power supplies, UPS, medical systems, new energy power generation systems (solar energy, wind energy, fuel cells and the like), are core components of power conversion, and are also called as 'CPU' of the power system.

The power module is connected with the external interface through the lead terminal, and in the using process, due to factors such as vibration environment and installation, the lead terminal is broken and falls off, so that the reliability of the power module is affected. Fig. 1 and 2 show a lead terminal recently introduced, which includes a plug portion 1, a transition portion 2, a buffer portion 3, a support portion 4, and a soldering portion 5, wherein a transverse gap 6 is formed between the support portion 4 and the soldering portion 5, and a longitudinal gap 7 is formed between the support portion 4 and the buffer portion 5, when the lead terminal is used, a PCB is directly inserted from a plug hole, and a fish-eye hole 8 is extruded to elastically deform a product, thereby achieving good contact with the PCB and avoiding a soldering process. When the lead terminal is stressed downwards, the buffer part 3 has a buffer effect, the transmission of mechanical stress to welding spots is avoided, and meanwhile, the support part 4 can avoid the lead terminal product from being greatly deformed, so that the reliability of the lead terminal is ensured. However, when the conventional lead terminal is mounted on the ceramic insulating substrate or the circuit board 10 in the power module, since the amount of solder and the wettability of the terminal cannot be accurately controlled, the solder 9 climbs over the soldering portion 5 after the soldering is completed, and fills up the lateral gap between the support portion 4 and the soldering portion 5 as shown in fig. 3, thereby losing the effect of the buffer portion and affecting the use and reliability of the lead terminal. Theoretically, the welding part can be set to be large in area, the phenomenon that the supporting part and the welding part are welded due to climbing of welding flux can be effectively prevented, the size of the power module is continuously reduced along with the continuous increase of power density, no space is reserved for the large welding part, and the application of the lead terminal in the aspect of the power module is influenced.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a lead terminal for power module to solve the problem that exists among the prior art.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides a lead terminal for a power module, which comprises a plug part, a transition part, a buffer part, a supporting part and a welding part; one end of the plug portion extends downwards to form the transition portion, the lower end of the transition portion is connected with the separated buffering portion and the supporting portion, the buffering portion is connected with the welding portion, a pad foot is arranged above the welding portion, a longitudinal gap is arranged between the buffering portion and the supporting portion, and a transverse gap is arranged between the supporting portion and the pad foot.

As a further technical scheme, the foot pad extends outwards at a part of the welding part and is bent above the welding part.

As a further technical solution, the thickness of the foot pad is smaller than the thickness of the welding part.

As a further technical scheme, the number of the foot pads is multiple.

As a further technical solution, a gap is provided between the foot pad and the welding part.

As a further technical scheme, the cross section of the buffer part is S-shaped or Z-shaped.

As a further technical scheme, the gap size of the longitudinal gap is 0.2-0.8 mm.

As a further technical scheme, the gap size of the transverse gap is 0.05mm-0.5 mm.

Adopt above-mentioned technical scheme, the utility model discloses following beneficial effect has:

1. longitudinal gaps and transverse gaps are respectively arranged among the supporting parts, the buffering parts and the welding parts, so that when the PCB is pressed into the terminals, the lead terminals have a buffering effect and cannot collapse downwards to be damaged; the setting of foot pad has avoided being in the same place supporting part and weld part welding, has guaranteed good buffering of lead terminal, support effect, has promoted power module's reliability.

2. The utility model discloses a lead terminal has improved its elastic deformation resilience, strengthens the yield strength of its bottom, and then improves the life of lead terminal.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of a prior art I;

FIG. 2 is a schematic diagram of a second prior art;

FIG. 3 is a schematic diagram of a prior art structure in use;

fig. 4 is a schematic structural diagram of a first embodiment of the present invention;

fig. 5 is a schematic structural diagram of a second embodiment of the present invention;

fig. 6 is a schematic structural diagram of a third embodiment of the present invention;

fig. 7 is a schematic structural diagram of a fourth embodiment of the present invention;

fig. 8 is a schematic structural diagram of a first embodiment of the present invention in a use state.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

The following detailed description of the embodiments of the present invention will be made with reference to the accompanying drawings. It is to be understood that the description of the embodiments herein is for purposes of illustration and explanation only and is not intended to limit the invention.

As shown in fig. 4, for the first embodiment of the lead terminal of the present invention, the lead terminal includes a plug portion, a transition portion, a buffer portion 3, a support portion 4, and a welding portion 5, the plug portion may be in a fish eye structure, the lower end of the plug portion is connected to the transition portion, the lower end of the transition portion is connected to the support portion 4 and the buffer portion 3, wherein the buffer portion 3 is disposed on two sides of the support portion 4, and a longitudinal gap 7 exists between the buffer portion and the support portion 4, and the longitudinal gap 7 is 0.2-0.8 mm. The cushioning portion 3 has an S-bend shape, a Z-shape, or the like having a stress cushioning effect, and the support portion 4 is directed vertically downward. The lower extreme of buffer portion 3 is connected planar structure welding portion, and between buffer portion two part structure, the planar welding portion extends local rectangular structure to the direction of buffer portion, through forming pad foot 11 to the local rectangular structure of 180 degrees bendings of welding portion direction, can direct contact between pad foot 11 and the welding portion 5, also can set up tiny clearance 12. The thickness of the foot pad 11 may be the same as or different from that of the welded portion. A transverse gap 6 exists between the bent foot pad 11 and the support part 4, and the transverse gap 6 is 0.05mm-0.5 mm. As shown in fig. 8, when the lead terminals 13 are soldered to the ceramic insulating substrate or the circuit board 10, the solder ascends to possibly fill up the fine gaps, but the lateral gaps are ensured to be free from the solder, thereby ensuring the cushioning effect of the lead terminals.

As shown in fig. 5, in the second embodiment of the present invention, the difference from the first embodiment is that the supporting portions 4 are distributed on both sides of the cushioning portion 3, and the pad 11 extends from both sides of the welding portion 5 to the cushioning portion, and is bent to form the pad 11. A longitudinal gap 7 is also arranged between the supporting part 4 and the buffer part 3, and a transverse gap 6 is respectively arranged between the supporting parts at both sides and the foot pads at both sides.

As shown in fig. 6, for the third embodiment of the present invention, it is different from the second embodiment in that the pad 11 extends in the direction away from the buffering portion 3 at the welding portion 5, and is bent by 180 ° to the direction of the supporting portion to form an integral pad, a transverse gap 6 is provided between the pad 11 and the supporting portion 4, and a longitudinal gap 7 is provided between the supporting portion 4 and the buffering portion 3. The foot pad 11 does not contact the cushioning portion 3.

As shown in fig. 7, for the embodiment of the present invention, the buffer portion 3 and the support portion 4 respectively extend downwards from the two sides of the transition portion, the lower end of the buffer portion 3 is connected to the welding portion 5, the other side of the welding portion 5 extends and bends upwards for 180 ° to form the pad foot 11, the pad foot 11 is only located below the support portion 4, the transverse gap 6 is arranged between the pad foot 11 and the support portion 4, the longitudinal gap 7 is arranged between the support portion 4 and the buffer portion 3, and the longitudinal gap 7 extends to the position between the pad foot 22 and the buffer portion 3.

As shown in fig. 8, for the application of the embodiment of the present invention in a power module, the lead terminals 13 are soldered on the corresponding positions on the surface of the ceramic insulating substrate or the circuit board 10 according to the requirements of the circuit topology and the application, so as to achieve the electrical connection with the outside.

The utility model provides a pad foot is in the form of the top through machining of weld part, like punching press, turning, mill etc.. In addition, the foot pad can also press another material above the welding part, and the foot pad is a material different from the lead terminal.

The utility model provides a ceramic insulation substrate covers copper in ceramic substrate's both sides, forms three layer construction, and wherein the corrosion of upper surface copper layer has the pattern to specific circuit function has been realized. The ceramic material may be Al₂O₃、AlN、Si₃N₄And the like.

The utility model discloses well lead terminal material is preferred to be copper alloy C18400 or C19400, has higher yield strength, and electric conductive property is unanimous basically with pure copper simultaneously.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. A lead terminal for a power module includes a plug portion, a transition portion, a buffer portion, a support portion, and a welding portion; the plug is characterized in that one end of the plug portion extends downwards to form the transition portion, the lower end of the transition portion is connected with the separated buffering portion and the supporting portion, the buffering portion is connected with the welding portion, the pad foot is arranged above the welding portion, a longitudinal gap is arranged between the buffering portion and the supporting portion, and a transverse gap is arranged between the supporting portion and the pad foot.

2. The power module lead terminal according to claim 1, wherein the foot pad is extended outward at a part of the welded portion and is bent above the welded portion.

3. The power module lead terminal according to claim 1, wherein a thickness of the footpad is smaller than a thickness of the soldering portion.

4. A lead terminal for a power module according to any one of claims 1 to 3, wherein the number of the foot pads is plural.

5. The power module lead terminal according to claim 1, wherein a gap is provided between the foot pad and the soldering portion.

6. The power module lead terminal according to claim 1, wherein the buffer portion has an S-bend or Z-bend shape in cross section.

7. The lead terminal for a power module as recited in claim 1, wherein a gap size of the longitudinal gap is 0.2-0.8 mm.

8. The power module lead terminal according to claim 1, wherein a gap size of the lateral gap is 0.05mm to 0.5 mm.