Power module
By adopting a combined structure of carrier plate, power element, die seal layer and conductive needle in the power module, and using nut locking conductive needles, the problems of low space utilization and interface tolerance in the prior art are solved, and the yield and production efficiency of the power module are improved.
Patent Information
- Application Number
- CN202422217491.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-10
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2034-09-10
AI Technical Summary
The prior art potting and mold sealing processes have problems such as overflow and rupture caused by low space utilization, insufficient oven space, and interface height tolerance, which affects the yield and production efficiency of the power module.
The combined structure of the carrier plate, power element, die seal layer and conductive needle is adopted. The conductive needle is locked on the carrier plate by a nut to prevent the conductive needle from being broken or bent under the extrusion pressure, and the perforation of the carrier plate is selectively exposed through the die seal layer, thus eliminating the use of the releasable film.
It improves the stability of the conductive needle, simplifies the production process, improves the yield and production efficiency of the power module, reduces assembly tolerances, and achieves easier mass production.
Smart Images
Figure CN223181142U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a power module. Background Art
[0002] Figures 1 to 3 The prior art shows that the conductive pin 1 is encapsulated into the product through a dispensing / potting process. Figure 1 It shows that the conductive pin 1 is picked and placed onto the carrier 2, a container 3 is formed on the carrier 2, and then the conductive pin 1 and the carrier 2 made of metal material are welded. Figure 2 and Figure 3 It shows that the encapsulation layer 4 is potted into the container 3. The material of the encapsulation layer 4 is, for example, epoxy resin, and then baking is carried out, with a duration of, for example, 10 hours. The potting process has inherent disadvantages. After potting, the colloid is still in a liquid state and needs to be cured through oven baking, but the space of the oven is limited and the products cannot use batch magazines, so the space utilization rate of the oven is not good.
[0003] See Figures 4 to 7 , the prior art shows that a molding process is used to form a power module. Figure 4 It shows that the holder 5 is picked and placed onto the carrier 2. The carrier 2 is, for example, a copper clip (Cu Clip) or a lead frame. A reflow process is performed to bond the holder 5 and the carrier 2, and a release film 6 is used to stick to the holder 5. Figure 5 It shows that the encapsulation layer 4 is molded Figure 4 The structure shown. The material of the encapsulation layer 4 is, for example, epoxy molding compound (EMC). After molding, a postmold curing (PMC) process is performed, with a duration of, for example, 4 hours, and then the release film 6 is removed (trimmed) to expose the holder 5. Figure 6 It shows that the conductive pin 1 is bonded to the holder 5.
[0004] Figure 7 It shows that the socket 7 of the upper mold and the release film 6 are used together to prevent the colloid of the encapsulation layer 4 from overflowing into the holder 5. However, as Figure 8 shown, there is a tolerance in the height of the holder 5. As Figure 8 the leftmost holder 5 in, its height is too low, and the release film 6 may not stick to the holder 5, resulting in the colloid overflowing into the holder 5 and affecting the subsequent electrical connection with the conductive pin 1. As Figure 8The rightmost interface 5 has too high a height and may hit the socket 7 of the mold, resulting in cracking or deformation 90.
[0005] Figure 9 The alignment pins (moving pins) 9 of the upper mold, as well as the insertion piece 92, spacer 93, and spring 94 of the lower mold are shown. Since, as Figure 8 shown, there are tolerances in the interface 5, the elastic release film 6 of the upper mold and the spring 8 are used to increase the allowable value of the assembly tolerance. However, as Figure 10 shown, the alignment pins 9 will cause elastic fatigue of the release film 6 and result in puncturing the release film 6, thereby causing the colloid to overflow into the interface 5. Summary of the Utility Model
[0006] Aiming at the problems existing in the related art, the purpose of the present utility model is to provide a power module to at least improve the yield rate of the power module.
[0007] To achieve the above purpose, the present utility model provides a power module, including: a carrier board having through holes; power elements disposed on the carrier board; a molding compound layer covering the power elements and exposing the through holes; conductive pins, at least part of which are disposed in the through holes; and nuts for locking and fixing the conductive pins to the carrier board.
[0008] In some embodiments, the external connection ends of the conductive pins are disposed at the first end of the carrier board, and the nuts are disposed at the second end of the carrier board opposite to the first end.
[0009] In some embodiments, a part of the conductive pins is located at the second end of the carrier board, and part has a shape meshing with the nuts.
[0010] In some embodiments, the power elements are located at the first end of the carrier board.
[0011] In some embodiments, the through holes are located outside the power elements.
[0012] In some embodiments, the through holes are arranged in an array.
[0013] In some embodiments, the conductive pins correspond to the through holes one by one.
[0014] ]>In some embodiments, the external connection ends of the conductive pins have stop portions abutting against the carrier board.
[0015] In some embodiments, the stop portions and the nuts sandwich the carrier board therebetween.
[0016] In some embodiments, the conductive pins are electrically connected to the power elements through the carrier board.
[0017] In some embodiments, the nuts are disposed in the space defined by the molding compound layer.
[0018] In some embodiments, the back of the nut with respect to the first end face of the carrier plate extends beyond the back of the encapsulation layer with respect to the second end face of the carrier plate.
[0019] In some embodiments, the conductive pins extend from the first end face of the nut.
[0020] In some embodiments, the carrier plate is a lead frame.
[0021] In some embodiments, the diameter of the conductive pins is smaller than the diameter of the perforations.
[0022] Embodiments of the present application further provide a power module, including: a carrier plate having perforations; a power element disposed on the carrier plate; an encapsulation layer covering the power element, the side wall of the encapsulation layer having a notch extending towards the power element, the notch exposing the perforations; conductive pins, at least partially disposed in the perforations; and a nut for locking and fixing the conductive pins to the carrier plate.
[0023] In some embodiments, the notches and the perforations correspond one by one.
[0024] In some embodiments, the nut is located in the notch.
[0025] In some embodiments, the external connection end of the conductive pin has a stop portion, and the diameter of the stop portion is larger than the diameter of the perforation to abut against the carrier plate.
[0026] In some embodiments, the stop portion is located in the notch.
[0027] The beneficial technical effects of the present utility model are as follows:
[0028] The conductive pins in the embodiments of the present application are locked to the carrier plate by nuts, which can prevent the conductive pins from breaking or bending due to extrusion force, and can improve the stability of the conductive pins. The encapsulation layer in the embodiments of the present application selectively encapsulates the carrier plate, exposes the perforations reserved on the carrier plate, the conductive pins are inserted into the perforations and locked to the carrier plate by locking nuts, replacing the two manufacturing processes of the prior art, without the need to use the interface design of the prior art, so there is no need to consider the assembly tolerance brought by the interface, improving the yield of the power module, and the manufacturing of the power module is simpler. There is no need to use the releasable film of the prior art, providing more choices in product design. The assembly method of the locking nut is easier to achieve mass production, improving the manufacturing efficiency of the product. Description of the Drawings
[0029] Figure 1 Illustrates picking up and placing a conductive pin of the prior art on a carrier and forming a container on the carrier.
[0030] Figure 2 And Figure 3 Illustrates pouring an encapsulation layer into the container.
[0031] Figure 4Shows the taking and placing of the interface on the carrier.
[0032] Figure 5 Shows the use of an encapsulation layer for encapsulation Figure 4 The structure shown.
[0033] Figure 6 Shows the bonding of the conductive pins to the interface.
[0034] Figure 7 Shows the use of the socket of the upper mold and the releasable film together to prevent the colloid of the encapsulation layer from overflowing into the interface.
[0035] Figure 8 Shows that there is a tolerance in the height of the interface.
[0036] Figure 9 Shows the cooperation between the power module of the prior art and the alignment pins.
[0037] Figure 10 Shows the alignment pins piercing the releasable film.
[0038] Figure 11 Shows the carrier board according to the embodiment of the present application.
[0039] Figure 12 Shows the formation of an encapsulation layer covering the power element and a part of the carrier board.
[0040] Figure 13 Shows half of the encapsulation layer to show the specific structure it wraps.
[0041] Figure 14 Shows the carrier board after singulation.
[0042] Figure 15 Shows the power module according to the embodiment of the present application.
[0043] Figure 16 Shows the cooperation between the power module of the embodiment of the present application and the positioning pins of the mold. Detailed implementation
[0044] To better understand the spirit of the embodiments of the present application, the following further explains it in conjunction with some preferred embodiments of the present application.
[0045] The embodiments of the present application will be described in detail below. Throughout the specification of the present application, components that are the same or similar and components having the same or similar functions are denoted by like reference numerals. The embodiments of the drawings described herein are illustrative, diagrammatic and are used to provide a basic understanding of the present application. The embodiments of the present application should not be construed as a limitation of the present application.
[0046] As used herein, the terms "substantially", "essentially", "substantive" and "about" are used to describe and account for minor variations. When used in conjunction with an event or circumstance, these terms can refer to instances where the event or circumstance occurs precisely as well as instances where the event or circumstance occurs very nearly as such.
[0047] In this specification, unless specifically designated or limited otherwise, relative terms such as "central", "longitudinal", "lateral", "front", "rear", "right", "left", "inner", "outer", "lower", "higher", "horizontal", "vertical", "above", "below", "over", "under", "top", "bottom" and derivative terms thereof (such as "horizontally", "downwardly", "upwardly", etc.) should be construed to refer to the directions described in the discussion or illustrated in the drawings. These relative terms are for descriptive convenience only and do not require the present application to be constructed or operated in a particular direction.
[0048] For convenience of description, "first", "second", "third", etc. may be used herein to distinguish different components of a figure or a series of figures. "First", "second", "third", etc. are not intended to describe corresponding components.
[0049] Figures 11 to 14 A method for forming a power module 100 according to an embodiment of the present application is shown. Figure 11 A carrier board 10 according to an embodiment of the present application is shown, and power elements 20 are formed on a first end (the lower end shown in the figure) 14 of the carrier board 10. In some embodiments, the carrier board 10 is a copper clip (Cu Clip) or a lead frame.
[0050] Figure 12 A molding compound layer 30 that forms to cover the power elements 20 and a part of the carrier board 10 is shown, and the molding compound layer 30 exposes a perforation 12 of the carrier board 10.
[0051] Figure 13 Half of the molding compound layer 30 is shown to illustrate its specific wrapped structure, wherein the carrier board 10 includes a bottom plate 19 and pins 18. Figure 13 Also shown are conductive pins 40 and nuts 50. The power elements 20 are disposed on the bottom plate 19 and are electrically connected to the conductive pins 40 through the pins 18. The power elements 20, the pins 18 and the conductive pins 40 correspond one by one, and the conductive pins 40 are electrically connected to the power elements 20 through the carrier board 10.
[0052] Figure 14 The carrier board 10 after singulation is shown. Figure 11 and Figure 12 The carrier board 10 in one unit is schematically shown. In Figure 12After the encapsulation step shown, the frame around the encapsulation layer 30 is trimmed to form Figure 14 the singulated carrier board 10 shown.
[0053] Figure 15 It is shown that the conductive pin 40 passes through the perforation 12 and the nut 50 is rotated onto the conductive pin 40 to lock the conductive pin 40 to the carrier board 10 by the nut 50. Thus, the manufacturing of the power module 100 is completed. The portion 46 of the conductive pin passes through the perforation 12 and is disposed within the perforation 12. The conductive pin 40 in the embodiment of the present application is not connected to the carrier board 10 in a pressing manner, but is locked to the carrier board 10 by the nut 50, which can prevent the conductive pin 40 from breaking or bending due to extrusion force and can also improve the stability of the conductive pin 40.
[0054] Figure 16 It is shown the cooperation between the power module 100 in the embodiment of the present application and the positioning pin 9 of the mold. The embodiment of the present application does not need to use a release film, so there is no risk of the positioning pin 9 piercing the release film and causing the colloid to overflow.
[0055] Refer to Figure 15 , the external connection end 42 of the conductive pin 40 in the embodiment of the present application is disposed at the first end 14 of the carrier board 10, and the nut 50 is disposed at the second end 16 of the carrier board 10 opposite to the first end 14. Refer to Figure 13 , a part 46 of the conductive pin 40 is located at the second end 16 of the carrier board 10, and the above-mentioned part 46 has a shape meshing with the nut 50. The power element 20 is located at the first end 14 of the carrier board 10. The perforations 12 are arranged in an array. The nut 50 is disposed in the space defined by the encapsulation layer 30. The back of the nut 50 with respect to the first end face (the upper surface in the figure) 51 of the carrier board 10 exceeds the back of the encapsulation layer 30 with respect to the second end face (the upper surface in the figure) 302 of the carrier board 10, and the conductive pin 40 extends from the first end face 51 of the nut 50.
[0056] Continue to refer to Figure 15 , the external connection end 42 of the conductive pin 40 has a stop portion 44 abutting against the carrier board 10, and the stop portion 44 and the nut 50 clamp the carrier board 10 therebetween.
[0057] The diameter of the conductive pin 40 in the embodiment of the present application is smaller than the diameter of the perforation 12, and there is no interference fit between the two to avoid damage or bending deformation of the conductive pin 40.
[0058] Refer to Figure 15, an embodiment of the present application provides a power module 100, including: a carrier board 10 having through holes 12; power components 20 disposed on the carrier board 10; a molding compound layer 30 covering the power components 20, and a notch 32 extending toward the power components 20 is provided on the side wall of the molding compound layer 30, and the notch 32 exposes the through holes 12; conductive pins 40, at least part of which are disposed in the through holes 12; a nut 50 for locking and fixing the conductive pins 40 to the carrier board 10, the notches 32 and the through holes 12 correspond one by one, the nut 50 is located in the notch 32, and the external connection end 42 of the conductive pin 40 has a stop portion 44, the diameter of the stop portion 44 is larger than the diameter of the through hole 12 to abut against the carrier board 10, and the stop portion 44 is located in the notch 32. In the embodiment of the present application, the conductive pins 40 are locked to the carrier board 10 by the nuts 50, which can prevent the conductive pins 40 from being broken or bent due to extrusion force, and can improve the stability of the conductive pins 40. In the embodiment of the present application, the molding compound layer 30 selectively encapsulates the carrier board 10, exposes the reserved through holes 12 of the carrier board 10, the conductive pins 40 are inserted into the through holes 12 and locked to the carrier board 10 by locking the nuts 50, replacing the two manufacturing processes of the prior art, without the need to use the interface design of the prior art, so there is no need to consider the assembly tolerance brought by the interface, improving the yield of the power module 100, and the manufacturing of the power module 100 is simpler, without the need to use the releasable film of the prior art, providing more choices in product design, and the assembly method of the locking nuts 50 is easier to achieve mass production, improving the manufacturing efficiency of the product.
[0059] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A power module, characterized in that, Comprising: A carrier board having perforations; A power component disposed on the carrier board; A molding layer covering the power component and exposing the perforations; A conductive pin, at least partially disposed within the perforations; A nut for locking and fixing the conductive pin to the carrier board.
2. The power module according to claim 1, wherein The external connection end of the conductive pin is disposed at a first end of the carrier board, and the nut is disposed at a second end of the carrier board opposite to the first end.
3. The power module according to claim 2, wherein A portion of the conductive pin is located at the second end of the carrier board, and the portion has a shape meshing with the nut.
4. The power module according to claim 2, characterized in that, The power component is located at the first end of the carrier board.
5. The power module according to claim 4, characterized in that, The perforations are located outside the power component.
6. The power module according to claim 1 or 5, characterized in that, The perforations are arranged in an array.
7. The power module according to claim 2, wherein The external connection end of the conductive pin has a stop portion abutting against the carrier board.
8. The power module according to claim 7, wherein The stop portion and the nut sandwich the carrier board therebetween.
9. The power module according to claim 1, wherein The conductive pin electrically connects the power component through the carrier board.
10. The power module according to claim 1, characterized in that The nut is disposed in the space defined by the molding layer.